ARTICLE | doi:10.20944/preprints201810.0006.v1
Subject: Materials Science, Nanotechnology Keywords: iron oxide nanoparticles, shape anisotropy, nanoplates, nanocubes, synthesis mechanisms
Online: 1 October 2018 (11:44:11 CEST)
Iron oxide nanoparticles are widely used as contrast agent for MRI and may be used as therapeutic agent by magnetic hyperthermia if they display a high magnetic anisotropy. Considering the effect of the nanoparticles shape on anisotropy, the reproducible shape control of nanoparticles is currently a challenge of synthesis methods. By investigating reaction parameters which are the iron precursor structure, the water content and the amount of the surfactant, sodium oleate, reported to trigger the cubic shape, iron oxide nanoparticles with different shape and composition were observed to form. In particular, iron oxide nanoplates have been thus synthesized. The effect of the surfactant coming from precursor was taking into account by using in house iron stearates bearing either two or three stearate chains and the negative effect of water on shape was confirmed by considering these precursors after their dehydration. Nanocubes with straight faces and a FeO@Fe3-xO4 composition were obtained only with dehydrated precursors and 50% of sodium oleate in the oleic acid and sodium oleate surfactant mixtures. When iron stearates with three chains led mainly to nanocubes in presence of soduim oleate, Iron stearates with two chains led to the formation of nanoplates with 80% of sodium oleate. The original flat shape of the plates was confirmed with 3D TEM tomography. The investigation of the synthesis mechanisms confirmed the major role of deprotonated carboxylic acid and of the heating rate to drive the cubic shape of nanoparticles and showed that the nanoplate formation would depend mainly on the nucleation step and possibly on the presence of a given ratio of oleic acid and deprotonated carboxylic acid.
ARTICLE | doi:10.20944/preprints202212.0436.v1
Subject: Materials Science, Nanotechnology Keywords: Green synthesis, antibacterial PPT, iron oxide nanoparticles, orange peel extract, cytotoxicity, superparamagnetic behavior.
Online: 23 December 2022 (02:15:06 CET)
Magnetic nanoparticles based on iron oxides (MNPs-Fe) with magnetite or maghemite phases have been widely employed in bio-applications. Thus, they have been used as contrast agents in magnetic resonance imaging (MRI) and oncological treatments through different therapies. Besides, due to the vast health problem of multidrug-resistant bacterial infections, several studies have proposed MNPs-Fe as photothermal agents (PTAs) within antibacterial photothermal therapy (PTT). This work presents a quick and easy green synthesis (GS) to obtain MNPs-Fe using orange peel extract from orange waste from local commerce, which presents an environmentally friendly approach compared to traditional methods such as coprecipitation. The GS can be irradiated with microwaves to reduce the synthesis time drastically. We evaluated the weight yield of the GS and the physical-chemical and magnetic features of the synthesized MNPs-Fe. Besides their cytotoxicity in animal cell line ATCC RAW 264.7, their antibacterial activity against Staphylococcus Aureus (S. Aureus) and Escherichia Coli (E. Coli) was assessed. We found that the MNPs-Fe synthesized using the GS, with 50% v/v of NH4OH and 50% v/v of orange peel extract (50GS-MNPs-Fe) had an excellent weight yield, negligible cytotoxicity for concentrations of MNPs-Fe below 250 µg·mL-1 in 24 hours, and 8 days. In the MNPs-Fe surface, we identified a coating of organic molecules (~ 25 nm) such as terpenes, aldehydes, etc. MNPs-Fe inhibited S. Aureus and 2.54 log10 (CFU) of E. Coli under red LED light irradiation (630 nm, 65.5 mW·cm-2, 30 min). Likewise, they exhibited a superparamagnetic (SPM) behavior for temperatures above 60 K, with a size of 49.3±9.6 nm and saturation magnetization (Ms) of 72.83 and 44.16 emu·g-1 at 60 and 300 K, respectively. Therefore, 50GS-MNPs-Fe are excellent candidates as broad-spectrum PTAs in antibacterial PTT, magnetic hyperthermia (MH), or MRI.
ARTICLE | doi:10.20944/preprints201811.0135.v1
Subject: Life Sciences, Biotechnology Keywords: iron oxide nanoparticles; multimodal nanoparticles; biodistribution; magnetic resonance imaging; aging; coating degradation
Online: 6 November 2018 (10:37:57 CET)
Medical imaging is an active field of research that fosters the necessity for novel multimodal imaging probes. In this line, nanoparticle-based contrast agents are of special interest, since those can host functional entities either within their interior, reducing potential toxic effects of the imaging tracers, and on their surface, providing high payloads of probes, due to their large surface-to-volume ratio. The long-term stability of the particles in solution is an aspect usually under-tackled during probe design in research laboratories, since their performance is generally tested briefly after synthesis. This may jeopardize a later translation into practical medical devices, due to stability reasons. To dig into the effects of nanoparticle aging in solution, respect to their behavior in vivo, iron oxide stealth nanoparticles were used at two stages (3 weeks vs. 9 months in solution), analyzing their biodistribution in mice. Both sets of nanoprobes showed similar sizes, zeta potentials and morphology, as observed by DLS and TEM but, fresh nanoparticles accumulated in the kidneys after systemic administration, while aged ones accumulated in liver and spleen, confirming an enormous effect of particle aging on their in vivo behavior, despite barely noticeable changes perceived on a simple inspection of their structural integrity.
ARTICLE | doi:10.20944/preprints202105.0709.v1
Subject: Life Sciences, Biotechnology Keywords: Gene delivery; Non-viral carrier; Dextran-stearic acid-spermine; Iron oxide nanoparticles; Static magnetic field.
Online: 31 May 2021 (08:25:25 CEST)
Non-viral gene carriers because of their limited side effects, biocompatibility, simplicity and taking the advantages of electrostatic interactions have shown noticeable potential in gene delivery. The low transfection rate of non-viral vectors under physiological conditions is a significant issue. Here, the aim of this study was to investigate the efficacy of hydrophilic and hydrophobic groups on gene carriers such as two synthesized amphiphilic polymer of dextran-stearic acid-spermine (DSASP) with verified lipid and amine conjugations that associated with Fe3O4 superparamagnetic nanoparticles to promote the target delivery and decrease the transfection time using static magnetic field. Our findings illustrate that magnetic nanoparticles are spherical with positive surface charges and superparamagnetic behaviors. The DSASP–pDNA/MNPs offered a strong pDNA condensation, protection against DNase degradation, significant cell viability in HEK 293T cells and. Although conjugations of spermine play a critical role in transfection efficiency, amphiphilic polymer with more derivatives of stearic acid showed better transfection yields. Therefore, DSASP amphiphilic magnetic carriers offer new insights for gene delivery due to the amine contents and ameliorate the uptake of complexes via cell membrane based on its hydrophilic surface.
ARTICLE | doi:10.20944/preprints201711.0043.v1
Subject: Medicine & Pharmacology, Urology Keywords: superparamagnetic iron oxide nanoparticles (SPION); prostate cancer; sentinel node; magnetometer; lymphadenectomy
Online: 7 November 2017 (02:50:25 CET)
Sentinel lymph node dissection (sLND) using a magnetometer and superparamagnetic iron oxide nanoparticles (SPIONs) as a tracer was successfully applied in prostate cancer (PCa). Radioisotope-guided sLND combined with extended pelvic LND (ePLND) achieved better node removal, increasing the number of affected nodes or the detection of sentinel lymph nodes outside the established ePLND template. We determined the diagnostic value of additional magnetometer-guided sLND after intraprostatic SPION-injection in high-risk PCa. This retrospective study included 104 high-risk PCa patients (PSA >20 ng/ml and/or Gleason score ≥8 and/or cT2c) from a prospective cohort who underwent radical prostatectomy with magnetometer-guided sLND and ePLND. The diagnostic accuracy of sLND was assessed using ePLND as a reference standard. Lymph node metastases were found in 61 of 104 patients (58.7%). sLND had a 100% diagnostic rate, 96.6% sensitivity, 95.6% specificity, 96.6% positive predictive value, 95.6% negative predictive value, 3.4% false negative rate, and 4.4% false positive rate (detecting lymph node metastases outside the ePLND template). These findings demonstrate the high sensitivity and additional diagnostic value of magnetometer-guided sLND, exceeding that of ePLND through the individualized extension of PLND or the detection of sentinel lymph nodes / lymph node metastases outside the established node template in high-risk PCa.
ARTICLE | doi:10.20944/preprints201911.0017.v1
Subject: Medicine & Pharmacology, Urology Keywords: lymphadenectomy; magnetometer; prostate cancer; sentinel lymph node dissection; spion; superparamagnetic iron oxide nanoparticles
Online: 3 November 2019 (15:38:28 CET)
Targeted radioisotope-guided sentinel lymph node dissection (sLND) has shown high diagnostic accuracy in prostate cancer (PCa). To overcome the downsides of the radioactive tracers, magnetometer-guided sLND using superparamagnetic iron oxide nanoparticles (SPIONs) was successfully applied in PCa. This prospective study (SentiMag Pro II, DRKS00007671) determined the diagnostic accuracy of magnetometer-guided sLND in intermediate- and high-risk PCa. Fifty intermediate- or high-risk PCa patients (PSA≥10 ng/ml and/or Gleason score ≥7; median PSA 10.8 ng/ml, IQR 7.4–19.2 ng/ml) were enrolled. After intraprostatic SPIONs injection a day earlier, patients underwent magnetometer-guided sLND and eLND, followed by radical prostatectomy. SLNs were detected in vivo and in ex vivo samples. Diagnostic accuracy of sLND was assessed using eLND as the reference. SLNs were detected in all patients (detection rate 100%), with 447 SLNs (median 9, IQR 6–12) being identified and 966 LNs (median 18, IQR 15-23) being removed. Thirty-six percent (18/50) of patients had LN metastases (median 2, IQR 1–3). Magnetometer-guided sLND had 100% sensitivity, 97.0% specificity, 94.4% positive predictive value, 100% negative predictive value, 0.0% false negative rate, and 3.0% additional diagnostic value (LN metastases only in SLNs outside the eLND template). In vivo, one positive SLN/LN-positive patient was missed, resulting in a sensitivity of 94.4%. In conclusion, this new magnetic sentinel procedure has high accuracy for nodal staging in intermediate- and high-risk PCa. The reliability of intraoperative SLN detection using this magnetometer system requires verification in further multicentric studies.
ARTICLE | doi:10.20944/preprints201912.0036.v1
Subject: Materials Science, Nanotechnology Keywords: iron oxide nanoparticles; hydrothermal synthesis; high pressure; magnetic properties; thermal stability
Online: 4 December 2019 (04:10:31 CET)
Magnetic iron oxide particles are used for in vitro diagnostics for nearly 40 years. Due to their unique physical, chemical, thermal and mechanical properties, as well as biocompatibility and low toxicity in the human body, iron oxide nanoparticles have been used in many biomedical applications, such as contrast agents for magnetic resonance imaging, carriers for controlled drug delivery and immunoassays, but also in magnetic hyperthermia. Our aim is to investigate the effect of pressure and temperature on the structural, thermal and magnetic properties of iron oxide nanomaterials prepared by hydrothermal synthesis. Iron oxide nanoparticles were synthesized at temperatures of 100-200°C and pressures of 20-1000 bar. It has been found that pressure influences the type of iron oxide crystalline phase. Thus, for lower pressure values (< 100 bar), iron oxide is predominantly formed as hematite, while at pressures > 100 bar, the major crystalline phase is goethite. The complex thermal analysis revealed the polymorphic changes of iron oxides at different temperatures. The existence of specific magnetite and hematite phases in all thermally treated samples are evidenced through the specific Verwey and Morin transitions highlighted by ZFC-FC (Zero Field Cooled-Field Cooled) measurements, whereas their relative content is precisely provided by Mössbauer spectroscopy.
ARTICLE | doi:10.20944/preprints202001.0337.v1
Subject: Engineering, Industrial & Manufacturing Engineering Keywords: slag; basicity; hydrogen plasma; smelting reduction; iron oxide; plasma arc; hydrogen utilisation; degree of reduction; hematite
Online: 28 January 2020 (10:33:33 CET)
Replacing carbon by hydrogen is a huge step towards reducing CO2 emissions in the iron- and steel-making industry. The reduction of iron oxides using hydrogen plasma smelting reduction as an alternative to conventional steel-making routes has been studied at Montanuniversitaet Leoben, Austria. The aim of this work was to study the slag formation during the reduction process and the reduction behaviour of iron oxides. Furthermore, the reduction behaviour of iron ore during continuous feeding was assessed. Mixtures of iron ore and calcined lime with a basicity of 0, 0.8, 1.6, 2.3, and 2.9 were melted and reduced by hydrogen. The off-gas composition was measured during the operations to calculate the process parameters. The reduction parameters, namely the degree of reduction, degree of hydrogen utilisation, produced iron, and slag, are presented. The results of the batch-charged experiments showed that at the beginning of the reduction process, the degree of hydrogen utilisation was high, and then, it decreased over the operation time. In contrast, during the continuous-feeding experiment, the degree of hydrogen utilisation could be kept approximately constant. The highest degrees of reduction and hydrogen utilisation were obtained upon the application of a slag with a basicity of 2.3. The experiment showed that upon the continuous feeding of iron ore, the best conditions for the reduction process using hydrogen could be applied.
ARTICLE | doi:10.20944/preprints202112.0221.v1
Subject: Earth Sciences, Environmental Sciences Keywords: metal adsorption; soil organic matter; iron oxide; Semi-quantitative analysis method; antagonistic effect; DCB extraction
Online: 14 December 2021 (10:23:18 CET)
The combination of organic matter, iron oxide, and clay minerals is of great significance for the adsorption of copper ions (Cu). The purpose of this study is to explore the characteristics of Cu adsorption and laws governing Cu complexation to organic–inorganic, organic–clay mineral, and iron-oxide–clay mineral complexes in the sediments in the estuary of plateau fault and sinking lake——Dianchi Lake. In this study, Cu adsorption tests were performed on the three complexes, in order to study the kinetic behavior of adsorption, Langmuir and Freundlich isotherm models were used. The samples before and after adsorption were characterized via scanning electron microscope (SEM), Fourier infrared spectroscopy (FTIR), and X-ray diffraction (XRD). Our results show that, the Freundlich isotherm models model was able to describe adsorbent behavior in comparison to the Langmuir models. During the Cu adsorption process, the iron-oxide–clay mineral complex is able to adsorb Cu, via coordination exchange, through the –OH contained therein. Organic-matter–clay mineral complexes bonded to the surfaces of clay minerals by replacing the hydroxyl groups with functional groups (carboxyl groups or phenolic hydroxyl groups) contained in the organic matter. Organic–inorganic composites then adsorbed Cu through the coordination exchange of –OH in the polar functional groups of alcohols, phenols, and carboxylic acids. The adsorption capacity of Cu in these three sediment complexes was observed to have the following order: organic–inorganic complex > organic-matter–clay mineral complex > iron-oxide–clay mineral complex. The semi-quantitative analysis results of Fourier Infrared Spectroscopy show that the organic matter (changes in the peak area of functional groups such as carboxyl groups) in the organic-inorganic composite material has an important effect on the amount of copper ions adsorbed by clay minerals.
ARTICLE | doi:10.20944/preprints202007.0223.v1
Subject: Materials Science, Nanotechnology Keywords: Iron oxides; nanoparticles; organic dye degradation; photocatalytic effect; antibacterial behavior
Online: 11 July 2020 (03:38:48 CEST)
Currently, the use of sustainable chemistry as an ecological alternative for the generation of products or processes, free of polluting substance has assumed a preponderant role. The aim of this work is propose a bioinspired, facile, at low cost, non-toxic and environmentally friendly alternative to obtaining magnetic nanoparticles whit a majority phase of magnetite (Fe3O4). Is important to empathize that the synthesis was based on the chemical reduction through the Cnicus Benedictus extract, whose use as reducing agent has not been reported in the synthesis of iron oxides nanoparticles. In addition, the Cnicus Benedictus is abundant endemic plant in Mexico, with several medicinal properties and a large number of natural antioxidants. The obtained nanoparticles exhibited significant magnetic and antibacterial properties and an enhanced photocatalytic activity. The crystallite size of the Fe3O4 nanoparticles (Fe3O4 NP’s) was calculated by Williamson-Hall method. The photocatalytic properties of the Fe3O4 NP´s were studied by kinetics absorptions models in the Congo red (CR) degradation. Finally the antibacterial effect of the Fe3O4 NP´s were evaluated mediated the Kirby-Bauer method against E. coli and S. aureus bacteria. This route offers a green alternative to obtain Fe3O4 NP´s with remarkable magnetic, photocatalytic and antibacterial properties.
ARTICLE | doi:10.20944/preprints202212.0353.v1
Subject: Materials Science, Metallurgy Keywords: synthetic cast iron; charge materials; steel scrap; nitrogen in cast iron iron; mechanical properties
Online: 20 December 2022 (04:05:55 CET)
In the field of metallurgy, there are many factors that influence the final quality of cast iron. These are mainly charge materials, chemical composition, metallurgical preparation up to the final casting process. Even small deviations from metallurgical processing lead to fluctuations in melt quality and the occurrence of casting defects. Charge materials has a significant impact on the quality of cast iron, especially steel scrap, which is increasingly used from an economic and ecological point of view, especially when melting cast iron in electric furnaces. Cast iron produced from a higher proportion of steel scrap in the charge has higher hardness and tensile strength. On the other side, these cast irons has a higher tendency to chillout, brittleness, shrinkage, pearlitic microstructure, stresses and higher purity due to the difference in hardness at different wall thicknesses of the castings. It is the high hardness that is the problem in the final machining of castings. These negative properties are recorded mainly in heavy thick-walled castings with higher tensile strength and hardness. This negative effect is mainly due to the nitrogen content in the steel scrap. Based on these knowledges, operating melts were realized in the foundry's operating conditions. The influence of steel scrap in the charge and the possibility of eliminating its negative effects on the properties of cast iron were investigated.
ARTICLE | doi:10.20944/preprints202106.0553.v1
Subject: Engineering, Biomedical & Chemical Engineering Keywords: Iron-oxide nanoparticles, primary-secondary method, diagnostics of cancer, A549 cell line, transferrin protein receptors, adenocarcinoma, biotin-streptavidin, biotinylated antibodies
Online: 23 June 2021 (09:17:59 CEST)
The streptavidin and biotin interaction is one of the strongest non-covalent interactions in nature. As a result, this non-covalent interaction has been of great interest when it comes to biochemical assays, diagnosis of diseases, and cell-targeted drug delivery. Past research has proven that biotin-streptavidin is useful in biosensor development to improve the detection of a system when conjugated to nanoparticles. This study aims to prove that streptavidin-coated nanoparticles can be conjugated with biotinylated antibodies using the primary-secondary method to non-invasively detect adenocarcinoma in-vitro. While the use of nanoparticles is not uncommon to the diagnostics area of scientific research, the technique this research aims to investigate is a non-invasive one, utilizing the primary-secondary method. Specifically, the increased stability of fluorophores when bound to antibodies as opposed to nanoparticles directly can be indicative of the particles conjugated through the primary-secondary method’s ability to specifically bind to overexpressed transferrin receptors in the A549 cell line. In this paper, streptavidin-coated nanoparticles were conjugated with biotinylated anti-transferrin receptor antibodies and AlexaFluor-488 secondary antibodies were used to enable fluorescence-based detection. The efficiency of these particles were observed quantitatively through a plate reader and qualitatively through a fluorescence microscope. I demonstrated that these nanoparticles are able to specifically bind to the target proteins in this study. These findings contribute to the field of nanoparticle diagnostics and can be extended to different diseases caused by overexpression of proteins in the future. While this was conducted in-vitro, conjugates can be prepared to detect cancer in-vivo and can be tested with magnetic relaxometry in the future.
REVIEW | doi:10.20944/preprints201810.0189.v1
Subject: Life Sciences, Other Keywords: hepcidin, iron deficiency anemia, iron dextran, neonatal period, pig, supplementation
Online: 9 October 2018 (15:34:13 CEST)
In pigs, iron deficiency anemia (IDA) is the most prevalent deficiency disorder during the early postnatal period frequently developing into a critical illness. Meanwhile, in humans, only low-birth-weight infants, including premature infants are especially susceptible to developing IDA. In both human and pig neonates, the initial cause of IDA is low birth iron stores. In piglets this shortage of stored iron results mainly from genetic selection over the past few decades for large litter size and high birth weight. In consequence, pregnant sows cannot provide sufficient amount of iron to the increasing number of developing fetuses. Supplementation with iron is a common practice for the treatment of IDA in piglets. For decades, the preferred procedure for delivering iron supplements during early life stages has been through the intramuscular injection of large amount of iron dextran. However, this relatively simple therapy, which in general, efficiently corrects IDA, may generate toxic effects, and by inducing hepcidin expression, may decrease bioavailability of supplemental iron. New iron supplements are considered now with the aim to combine improvement of hematological status, blunting hepcidin expression, and minimizing toxicity of the administered iron. We propose that iron-deficient piglets constitute a convenient animal model for performing pre-clinical studies with iron supplements.
ARTICLE | doi:10.20944/preprints201904.0054.v1
Online: 4 April 2019 (12:35:43 CEST)
Beta-thalassemia major (β-TM) is a severe form of thalassemia caused by mutations in the β-globin gene, resulting in partial or complete deficiency of β-globin chains. This deficiency results in oxidative stress, dyserythropoiesis, and chronic anemia. Cytokine dependent hematopoietic cell linker (CLNK) belongs to the adaptor protein family and has the capacity to interact with multiple signaling proteins thereby modulating signal transduction. The aim of the present study was to examine CLNK in sera of β-TM patients and examine its association with iron overload biomarkers. Sixty β-TM patients, aged 3–12 years old and undergoing blood transfusions, and 30 healthy control children were recruited and CLNK, ferritin and iron status parameters were measured. The results showed a significant increase (p < 0.001) in serum CLNK levels in β-TM patients as compared with normal controls. The increased levels of CLNK were significantly associated with increased ferritin levels. Increased CLNK levels in β-TM may be explained by reciprocal effects between immune signaling and immature erythrocytes, which, release soluble receptors and signaling molecules, including CLNK, in the blood.
ARTICLE | doi:10.20944/preprints201807.0422.v1
Subject: Medicine & Pharmacology, General Medical Research Keywords: iron deficiency anemia; obestatin; ghrelin
Online: 23 July 2018 (12:34:21 CEST)
Ghrelin and obestatin, two antagonist peptide hormones, are purportedly involved in stimulating appetite and controlling energy balance in humans. Serum ghrelin level is also associated with iron deficiency anemia (IDA), but no study has yet been made of the obestatin level in patients with IDA, even though both hormones are a single gene product. Therefore, the purpose of this investigation is to see whether there is a link between IDA and these two hormones among other hematological parameters in patients with IDA. To measure ghrelin and obestatin, human saliva and serum were collected from 30 women with IDA, aged 31.7 ± 10.7 years, and 30 control women, aged 30.2 ± 8.0 years, with repeated collection of samples over a period of 1 week and 1 month. Saliva and serum ghrelin levels were measured by ELISA. Serum hemoglobin, ferritin, hematocrit and total iron-binding capacity (TIBC) values were determined with an Olympus AU2700. Saliva and serum ghrelin and obestatin levels were significantly lower in the IDA group compared with controls; these levels increased slightly above baseline with iron treatment, but remained below the control values. Furthermore, and as expected, serum hemoglobin, ferritin, and hematocrit levels were significantly increased with iron treatment, while total iron-binding capacity decreased compared to baseline concentrations. The findings suggest that IDA might be linked to imbalance of circulating (serum) and non-circulating (saliva) ghrelin and obestatin levels. Decreased ghrelin and obestatin might destroy iron homeostasis through its effect on intestinal absorption. Measuring these hormone levels might be useful for monitoring the response to iron treatment. Also, serum and saliva levels for both hormones were well correlated. Thus, using saliva in place of serum for monitoring the two hormones should minimize inconvenience and patient discomfort.
ARTICLE | doi:10.20944/preprints201910.0107.v1
Subject: Engineering, Energy & Fuel Technology Keywords: hydrogen; methane pyrolysis; direct reduced iron; industrial decarbonization; iron and steel; electric arc furnace
Online: 9 October 2019 (11:33:17 CEST)
Reducing emissions from the iron and steel industry is essential to achieve the Paris climate goals. A new system to reduce the carbon footprint of steel production is proposed in this article by coupling hydrogen direct reduction of iron ore (H-DRI) and natural gas pyrolysis on liquid metal surface inside a bubble column reactor. If grid electricity from EU is used, the emissions would be 435 kg CO2/tls without considering methane leakage from the extraction, storage and transport of natural gas. Solid carbon, produced as a by-product of natural gas decomposition, finds applications in many industrial sectors, including as a replacement for coal in coke ovens. Specific energy consumption (SEC) of the proposed system is approximately 6.3 MWh per ton of liquid steel(tls). It is higher than other competing technologies, 3.48 MWh/tls for water electrolysis based DRI, and, 4.3-4.5 MWh/tls for natural gas based DRI and blast furnace-basic oxygen furnace (BF-BOF) respectively. Utilization of large quantities of natural gas, where the carbon remains unused, is the major reason for high SEC. Preliminary analysis of the system revealed that it has the potential to compete with existing technologies to produce CO2 free steel, if renewable electricity is used. Further studies on the kinetics of the bubble column reactor, H-DRI shaft furnace, design and sizing of components, along with building of industrial prototypes are required to improve the understanding of the system performance.
ARTICLE | doi:10.20944/preprints202105.0283.v1
Online: 13 May 2021 (11:20:29 CEST)
Wheat (Triticum aestivum L.) being a staple food crop is an important nutritional source providing protein and minerals. It is important to fortify staple cereals like wheat with essential minerals to overcome the problems associated with malnutrition. The experiment was designed to evaluate the status of 11 micronutrients including grain iron (GFe) and zinc (GZn) in 62 wheat cultivars released between 1911 and 2016 in Pakistan. Field trials were conducted over two years and GFe and GZn were quantified by both inductively coupled plasma optical emission spectroscopy (ICP-OES) and energy dispersive X-ray fluorescence spectrophotometer (EDXRF). The GZn ranged from 18.4 to 40.8 mg/kg by ED-XRF and 23.7 to 38.8 mg/kg by ICP-OES. Similarly, GFe ranged from 24.8 to 44.1 mg/kg by ICP-OES and 26.8 to 36.6 mg/kg by EDEXR. The coefficient of correlation was higher for GZn (r=0.90), compared to GFe (r=0.68). Modern cultivars like Zincol-16 and AAS-2011 showed higher GFe and GZn along with improved yield components. Old wheat cultivars WL-711, C-518 and Pothowar-70 released before 1970 also exhibited higher value of GFe and GZn, however their agronomic performance was poor. Multivariate analysis using ten micronutrients (Al, Ca, Cu, K, Mg, Mn, Na and P) along with agronomic traits, and genome-wide SNP markers identified the potential cultivar with improved yield, biofortification trait and wider genetic diversity. Genetic gain analysis identified significant increase in grain yield (0.4% year-1), while there was negative gain for GFe (-0.11% year-1) and GZn (-0.15% year-1) over the span of 100 years. The Green Revolution Rht-B1 and Rht-D1 genes had strong association with plant height, and grain yield (GY), while semi-dwarfing alleles had negative effect on GFe and GZn contents. This study provided a valuable insight into biofortification status of wheat cultivars deployed historically in Pakistan and is a valuable source to initiate a breeding strategy for simultaneous improvement in wheat phenology and biofortification.
REVIEW | doi:10.20944/preprints202010.0447.v1
Subject: Medicine & Pharmacology, Oncology & Oncogenics Keywords: Iron homeostasis; Cancer; Prognostic; Diagnostic; Therapy
Online: 22 October 2020 (08:56:33 CEST)
Iron (Fe) is a trace element that plays essential roles in various biological processes such as DNA synthesis and repair, as well as cellular energy production, or oxygen transport, and it is currently widely recognized that iron homeostasis is dysregulated in many cancers. Indeed, several iron homeostasis proteins may be responsible for malignant tumor initiation, proliferation, and for metastatic spread of tumors. A large number of studies demonstrated the potential clinical value of turning these deregulated proteins as prognostic and/or predictive biomarkers of malignancy and /or response to anticancer treatments. Additionally, the iron addiction of cancer cells and the importance of iron in ferroptosis cell death signaling pathways prompted the development of therapeutic strategies against advanced stage or resistant cancers. In this review, we selected relevant and promising studies in the field of iron metabolism in cancer research and clinical oncology. Besides, we discuss some co-existing discrepant findings. We will also present and discuss the latest lines of research related to targeting iron, or its regulatory pathways, as potential promising anti-cancer strategies for human therapy. Iron chelators, such as deferoxamine or iron-oxide based nanoparticles, which are already tested in clinical trials, alone or in combination with chemotherapy will also be reported.
ARTICLE | doi:10.20944/preprints201909.0147.v1
Subject: Medicine & Pharmacology, General Medical Research Keywords: iron; TIBC; ferritin; osmotic fragility; hypertension
Online: 15 September 2019 (03:10:09 CEST)
Background: Essential hypertension is a major public health associated with increase pressure on the vascular walls and red blood cells (RBCs). In the present work, osmotic fragility (OF) of RBCs was reexamined in the means of its correlation with two risk factor; iron status and lipid profile. Experimental: OF, iron status parameters, and lipid profile components were measured in 60 patients and compared with the results of 30 controls. Results: The results showed a significant increase in all iron indices of hypertensive patients in comparing with healthy control group except TIBC, UIBC, and transferrin concentrations, which decrease in these patients in comparing with control group. Serum TGs, total cholesterol, VLDLc, and LDLc were increased while there is no significant in serum HDLc in patients to comparing with control group. There is no significant change in OF between patients and controls where p=0.173. The iron status parameters and lipid profile components were dependent on sex and smoking state. Hemoglobin and PCV were correlated significantly with total cholesterol and LDLc. Transferrin saturation showed a positive correlation with cholesterol, LDLc, and TGs, but negatively correlated with HDLc. No significant correlation between all the measured parameters and OF in HT patients. There is a significant correlation between serum ferritin and systolic BP and between Hb and systolic BP. Conclusion: No significant effect on the OF in HT patients. HT patients have elevated level of iron parameters in comparing with controls. OD has no correlation with iron status parameters or with lipid profile components.
REVIEW | doi:10.20944/preprints202012.0583.v1
Subject: Life Sciences, Biochemistry Keywords: sideroflexin; mitochondria; mitochondrial transporters; iron homeostasis; iron-sulfur cluster; heme biosynthesis; one-carbon metabolism; ferroptosis; ferritinophagy.
Online: 23 December 2020 (10:40:15 CET)
Sideroflexins (SLC56 family) are highly conserved multi-spanning transmembrane proteins inserted in the inner mitochondrial membrane in eukaryotes. Few data are available on their molecular function but, since their first description, they were thought to be metabolite transporters probably required for iron utilization inside the mitochondrion. Such as numerous mitochondrial transporters, sideroflexins remain poorly characterized. The prototypic member SFXN1 has been recently identified as the previously unknown mitochondrial transporter of serine. Nevertheless, pending questions on the molecular function of sideroflexins remain unsolved, especially their link with iron metabolism. Here, we review the current knowledge on sideroflexins, their presumed mitochondrial functions and the sparse - but growing - evidence linking sideroflexins to iron homeostasis and iron-sulfur cluster biogenesis. Since an imbalance in iron homeostasis can be detrimental at the cellular and organismal levels, we also investigate the relationship between sideroflexins, iron and physiological disorders. Investigating Sideroflexins’ functions constitutes an emerging research field of great interest and will certainly lead to main discoveries on mitochondrial physiopathology.
ARTICLE | doi:10.20944/preprints202007.0564.v1
Subject: Materials Science, Metallurgy Keywords: history of metallurgy; co-fusion steelmaking; ancient China; microstructure evolution; simulation experiments; cast iron; wrought iron
Online: 23 July 2020 (12:49:21 CEST)
The study of co-fusion was one of the essential topics in the history of metallurgy in China. Simulation experiments had been an essential concept in the study of the co-fusion steelmaking process. This paper mainly studied the simulation experiments of co-fusion from two aspects: the replication of co-fusion swords by three different methods, and the micro-analysis of the co-fusion samples. The experimental results indicated that several co-fusion swords could be made by different processes, but the carbon content and surface hardness were quite different. During repeated forging welded, the microstructure of the samples transformed from laminated to homogenized, finally the steel with a uniform carbon content was obtained. It was challenging to find the characteristics of co-fusion from the homogenized samples. The results prompted people to rethink the microstructure characteristics of ancient co-fusion artifacts.
ARTICLE | doi:10.20944/preprints202102.0603.v1
Subject: Chemistry, Analytical Chemistry Keywords: ORR; PGM-free; iron; chitosan; biomass, acid electrolyte; iron-nitrogen-doped carbon; graphitization, site density, Fe-Nx
Online: 26 February 2021 (09:43:44 CET)
The development of platinum group metal-free (PGM-free) electrocatalysts derived from cheap and environmentally friendly biomasses for oxygen reduction reaction (ORR) is a topic of relevant interest, particularly from the point of view of sustainability. Fe-nitrogen-doped carbon materials (Fe-N-C) have attracted particular interest as alternative to Pt-based materials, due to the high activity and selectivity of Fe-Nx active sites, the high availability and good tolerance to poisoning. Recently, many studies focused on developing synthetic strategies, which could transform N-containing biomasses into N-doped carbons. In this paper chitosan was employed as a suitable N-containing biomass for preparing Fe-N-C catalyst in virtue of its high N content (7.1%) and unique chemical structure. Moreover, the major application of chitosan is based on its ability to strongly coordinate metal ions, a precondition for the formation of Fe-Nx active sites. The synthesis of Fe-N-C consists in a double step thermochemical conversion of a dried chitosan hydrogel. In acidic aqueous solution, the preparation of physical cross-linked hydrogel allows to obtain sophisticated organization, which assure an optimal mesoporosity before and after the pyrolysis. After the second thermal treatment at 900 °C, a highly graphitized material was obtained, which has been fully characterized in term of textural, morphological and chemical properties. RRDE technique was used for understanding the activity and the selectivity of the material versus the ORR in 0.5 M H2SO4 electrolyte. Special attention was put in the determination of the active site density according to nitrite electrochemical reduction measurements. It was clearly established that the catalytic activity expressed as half wave potential linearly scales with the number of Fe-Nx sites. It was also established that the addition of the iron precursor after the first pyrolysis step leads to an increased activity because of both an increased number of active sites and of a hierarchical structure, which improves the access to active sites. At the same time, the increased graphitization degree, and a reduced density of pyrrolic nitrogen groups are helpful to increase the selectivity toward the 4e- ORR pathway.
REVIEW | doi:10.20944/preprints202201.0026.v1
Subject: Engineering, Energy & Fuel Technology Keywords: Anaerobic digestion; iron additives; biogas; catalyst; bioenergy
Online: 5 January 2022 (10:23:53 CET)
The world is facing a serious energy crisis and environmental pollution problems due to a sharp increase in the world population. Bioenergy is an eminent solution to these problems. Anaerobic digestion is a green energy technology used worldwide for the conversion of organic waste to biogas. It is reported that organic wastes are hard to digest and need some technical improvement in the anaerobic digestion process to improve biogas yield. Iron-based additives, due to their electron acceptance and donation capabilities, have been emphasized as being exceptional in improving anaerobic digestion process efficiency amongst all other enhancement options. This study reviews the major available types of iron-based additives, their characteristics, and their preparation methods. The preferred iron-based additive that has a significant effect on the enhancement of biogas yield is also discussed. The use of iron-based additives in the anaerobic digestion process with varying dosages and their impact on the biogas generation rate is also being studied. Substrates, operating parameters, and types of anaerobic digesters used in recent studies while researching the effects of iron-based additives are also part of this review. Lastly, this study also confirms that iron-based additives have a significant effect on the reduction rate of the volatile suspended solids, methane content, biogas yield, and volatile fatty acids.
ARTICLE | doi:10.20944/preprints202107.0166.v1
Subject: Medicine & Pharmacology, Allergology Keywords: Pica; iron deficiency anemia; Relationship; pregnant women
Online: 7 July 2021 (07:54:39 CEST)
INTRODUCTION. The most common cause of eating non-food items (pica) is specific deficiencies of minerals, such as iron. This study aimed to assess the relationship between Pica and Iron deficiency anemia among pregnant women. METHODS. The study was conducted in the out-patient department, antenatal Clinic at East Jeddah Hospital from July to September 2020. Design: A quantitative descriptive correlation design. Sample size: A total of 400 pregnant women, included anemic pregnant women, ≥ 18 years old, with singleton fetus and iron deficiency anemia. RESULTS. The mean age was 32.2 ± 6.6, half of the participants reported food cravings. Ice was the main item in pica followed by clay and chalk. Two-thirds had pica, more than half during the 1st trimester. There is a statistically significant relationship between pica and the history of a family member, parity, and gravidity at (P< 0,001, P <0,001, P <0,005) respectively. Hb and hematocrit in relation to pica reflected a statistically significant relationship (P< 0,001) and (P< 0,001), respectively. The symptoms attributed to iron deficiency were significantly associated with pica (P< 0,006). CONCLUSION. The pica and iron deficiency anemia had a significant association with pregnant women in EJH. RECOMMENDATION. The follow-up visits should integrate the food behavior inquiry to check if the pica existing with anemic or non-anemic pregnant women. Also, increase the awareness among midwives-nurses about the prevalence of pica and iron deficiency anemia among pregnant women.
ARTICLE | doi:10.20944/preprints202001.0177.v1
Online: 17 January 2020 (04:32:53 CET)
Copper smelting slag is a solution of molten oxides created during the copper smelting and refining process, and about 1.5 million tons of copper slag is generated annually in Korea. Oxides in copper smelting slag include ferrous (FeO), ferric oxide (Fe2O3), silica (SiO2 from flux), alumina (AI2O3), calcia (CaO) and magnesia (MgO). Main oxides in copper slag, which iron oxide and silica, exist in the form of fayalite (2FeO·SiO2). Since the copper smelting slag contains high content of iron, and copper and zinc. Common applications of copper smelting slag are the value added products such as abrasive tools, roofing granules, road-base construction, railroad ballast, fine aggregate in concrete, etc., as well as the some studies have attempted to recover metal values from copper slag. This research was intended to recovery Fe-Cu alloy, raw material of zinc and produce reformed slag like a blast furnace slag for blast furnace slag cement from copper slag. As a results, it was confirmed that reduction smelting by carbon at temperatures above 1400°С is possible to recover pig iron containing copper from copper smelting slag, and CaO additives in the reduction smelting assist to reduce iron oxide in the fayalite and change the chemical and mineralogical composition of the slag. Copper oxide in the slag can be easily reduced and dissolved in the molten pig iron, and zinc oxide is also reduced to a volatile zinc, which is removed from the furnace as the fumes, by carbon during reduction process. When CaO addition is above 5wt.%, acid slag has been completely transformed to calcium silicate slag and observed like blast furnace slag.
ARTICLE | doi:10.20944/preprints201912.0356.v1
Subject: Medicine & Pharmacology, Pediatrics Keywords: Beta-thalassemia, Erythroferrone, Ferritin, Hepcidin, Iron overload
Online: 26 December 2019 (12:37:36 CET)
Beta thalassemia major (β-TM) disorder characterized by the lack, or severe reduction in the production of hemoglobin β-globin chains. The standard protocol for the management of β-TM is blood transfusion and iron chelation therapy to reduce the iron overload state. The present study aimed to investigate the relationships between two iron regulatory hormones, hepcidin (HEPC) and erythroferrone (ERFE) levels and iron status parameters (ISPs) in Iraqi patients with β-TM. ISPs and hormones were measured in sixty patients and compared with thirty healthy controls. The results indicated significant changes in different iron status parameters, while ferritin (FRT) with the ~11 fold increase showed the most change. Significant reduction in HEPC and increase in ERFE levels were detected in patients as compared to the control group, while no direct correlation was identified with the other measured ISPs. Receiver operating characteristic (ROC) analysis showed that the z-score of the composite of ERFE+FRT has a full diagnostic ability for β-TM. In conclusion, our finding indicated the correlation between different ISPs, FRT as the leading predictor of iron overload and tow main iron regulatory hormones.
ARTICLE | doi:10.20944/preprints201903.0092.v1
Subject: Biology, Agricultural Sciences & Agronomy Keywords: Biofortification, Pearl millet, Malnutrition, Iron, Zinc, Market.
Online: 7 March 2019 (12:08:24 CET)
Pearl millet is an important food crop in the arid and semi-arid tropical regions of Africa and Asia. These regions are home to millions of poor smallholder’s households living in harsh agro ecology and reported higher prevalence of malnutrition. Such poor households have few options in terms of food crops, besides the limited markets. Indeed, pearl millet is one of the food crops they continue to grow for their food and nutritional security. Pearl millet is important sources of dietary carbohydrates, energy, protein, and important minerals such as calcium, iron and zinc. Considering inherent high nutritional values and climate resilient nature (drought and heat), demand for pearl millet as food, beside valued for its Stover as a source of livestock fodder, is projected to grow strongly in Asia (India) and Africa (West and Central Africa). Iron (cause anemia) and zinc (cause stunting) deficiencies are widespread and serious public health problems worldwide, including India and Africa. Biofortification is a cost-effective and sustainable agricultural strategy to address this problem. Research on pearl millet has shown that large genetic variability (30-140 mg/kg Fe and 20-90 mg/kg Zn) available in this crop can be effectively utilized to develop high-yielding cultivars with high iron and zinc densities. Both Open –pollinated varieties (Dhanshakti and Chakti) and hybrids (ICMH 1202, ICMH 1203 and ICMH 1301) of pearl millet with high grain yield (>3.5 tons/ha in hybrids) and high levels of iron (70-75 mg/kg) and zinc (35-40 mg/kg) densities have been developed and released. Currently, India growing >70,000 ha of biofortified pearl millet, besides more pipeline hybrids and varieties are under various stage of testing at the national (India) and international (west Africa) trials for possible release. Genomic tools will be an integral part of breeding program particularly for nutritional traits to use diagnostic markers and genomic selection. Clinical studies showed that 200g grains from biofortified cultivar would provide bioavailable Fe to meet full recommended daily allowance (RDA) in children, adult men and 80% of the RDA in women. Till today, no markets to promote biofortified cultivars/grains/products as no incentive price and such products aims to address food and nutritional security challenges simultaneously. The demand is likely to increase only after investment and integration into modern public distribution system, nutritional intervention schemes, private seed and food companies with strong mainstreaming nutritional policies. In the non-traditional regions, this will contribute to livestock and poultry feed industry as spill-over benefits to improve nutrition.
REVIEW | doi:10.20944/preprints201809.0148.v1
Subject: Life Sciences, Biochemistry Keywords: NCOA4, ferritinophagy, iron homeostasis, erythropoiesis, ferroptosis, cancer
Online: 9 September 2018 (16:13:18 CEST)
Nuclear receptor coactivator 4 (NCOA4) is a selective cargo receptor that mediates the autophagic degradation of ferritin (“ferritinophagy”), the cytosolic iron storage complex. NCOA4-mediated ferritinophagy maintains intracellular iron homeostasis by facilitating ferritin iron storage or release according to demand. Ferritinophagy is involved in iron-dependent physiological processes such as erythropoiesis, where NCOA4 mediates ferritin iron release for mitochondrial heme synthesis. Recently, ferritinophagy has been shown to regulate ferroptosis, a newly described form of iron-dependent cell death mediated by excess lipid peroxidation. Dysregulation of iron metabolism and ferroptosis have been described in neurodegeneration, cancer, and infection, but little is known about the role of ferritinophagy in the pathogenesis of these diseases. Here, we will review the biochemical regulation of NCOA4, its contribution to physiological processes and its role in disease. Finally, we will discuss the potential of activating or inhibiting ferritinophagy and ferroptosis for therapeutic purposes.
ARTICLE | doi:10.20944/preprints201608.0179.v1
Subject: Materials Science, Biomaterials Keywords: bioleaching; molecuar analysis; bacteria; sequencing; iron ore
Online: 19 August 2016 (09:23:04 CEST)
One consequence of the global technological advancement in conventional metallurgy is the fast depletion rate of valuable minerals, which are also becoming increasingly difficult to find in pure and economically viable forms. This has spurred more interest in technologies that investigate ability of different microorganisms to mobilize valuable metals from their ores via diverse metabolic processes. This study was carried out therefore to isolate, identify and characterize iron solubilizing bacteria from Iron stones of Agbaja iron ore mining site of Kogi State, Nigeria. Crushed samples in the range of 0.25µm and 0.75µm particle sizes were cultured in a modified 9k media to facilitate bacterial growth and pure cultures were then isolated and sub-cultured for further bioleaching studies. Morphological and biochemical analysis suggests that some of the bacteria identified are members of Acidithiobacillus spp, Pseudomonas spp, and Leptospirillum spp. Studies conducted on pure cultures and mixed consortium of the identified organisms shows that a mixture of the three organisms leached iron ore to about 96.16%. Also results of growth pattern due to bacteria countafter 24-72hours of incubation ranged between 0.1×103 cfu/ml and 12.3 ×103 cfu/ml for Acidithiobacillus spp. The need to explore the molecular characteristics of these organisms with a view to generating more information on the quality/quantity of their DNA for future cloning activities was also investigated in this work. DNA was extracted using zymo fungal/bacterial extraction mini prep kit TM (cat #6001) and subsequently subjected to 1% agarose gel electrophoresis. Visible bands were obtained with Alpha Innotech Gel Documentation Machine. DNA amplification was carried out using a pettier based thermo cycler PCR machine and electrophoresed on 1.5% agarose gel. Results of the PCR shows a visible band corresponding to 1.5kbp using this primer 27F (51-GAGTTTGATCCTGGCTCAG-31) and 1492R (51-GGTTACCTTGTTACGACT-31). DNA purity check shows two of the bacteria possess very good qualities for sequencing for further molecular analysis.
ARTICLE | doi:10.20944/preprints202301.0097.v1
Subject: Biology, Plant Sciences Keywords: mitochondria; iron transporters; MIT; developmental defects; RNA-seq
Online: 5 January 2023 (03:42:32 CET)
Iron is the most abundant micronutrient in plant mitochondria and it has a crucial role in biochemical reactions involving electron transfer. It has been described in Oryza sativa that Mitochondrial Iron Transporter (MIT) is an essential gene and that knockdown mutant rice plants have a decreased amount of iron in mitochondria, strongly suggesting that OsMIT is involved in mitochondrial iron uptake. In Arabidopsis thaliana, two genes encode MIT homologues. In this study, we analyzed different AtMIT1 and AtMIT2 mutant alleles, confirming that individually AtMIT1 nor AtMIT2 genes are essential. When we generated crosses between Atmit1 and Atmit2 alleles we were able to isolate homozygous double mutant plants. Interestingly, homozygous double mutant plants were obtained only when mutant alleles of Atmit2 with the T-DNA insertion in the intron region were used for crossings, and in these cases a correctly spliced AtMIT2 mRNA was generated, although at a low level. Atmit1 Atmit2 double homozygous mutant plants, which were knockout for AtMIT1 and knockdown for AtMIT2, were grown and chacterised in iron sufficient conditions. Pleiotropic developmental defects were observed including abnormal seeds, increased number of cotyledons, slow growth rate, pinoid stems, defects in flower structures and reduced seed set. We observed a possible phenomenon of T-DNA suppression in the next generation of Atmit1 Atmit2 double homozygous mutant plants, correlating with an increased splicing of the AtMIT2 intron containing the T-DNA. Molecular analysis of gene expression markers for mitochondrial and oxidative stress showed that Atmit1 Atmit2 double homozygous mutant plants express a degree of mitochondrial perturbation. A RNA-Seq study was performed and we could identify more than 760 genes differentially expressed in Atmit1 Atmit2, including genes involved in iron transport, coumarin metabolism, and hormones metabolism, transport and signaling. Our data suggest that some of the phenotypes observed in Atmit1 Atmit2 double homozygous mutant plants are mediated by defects in auxin homeostasis.
ARTICLE | doi:10.20944/preprints202205.0309.v1
Subject: Earth Sciences, Environmental Sciences Keywords: steel shot; iron; soil; environmental risk; shooting activity
Online: 23 May 2022 (12:28:40 CEST)
This study is follow-up of the steel shot transformation under the influence of environmental factors research (Lisin et al., 2022) and is the initial stage of investigating the iron behavior in soils during steel shot corrosion under a number of factors: the metallic lead in soils, atmospheric precipitation, excess organic matter. The results obtained show that corrosion of steel ammunition is a continuous process, including the formation of a poorly soluble rust crust on the surface of the steel and the mineralization of the metal until it is destroyed. As a result, the metal transformed into rust form, is a constant source of iron ions and dispersed rust particles migrating in soil waters and accumulating in soils. In addition, the aggregation of corrosion products of steel ammunition is the cause of a change in physical and mechanical properties of soils, which leads to a violation of the air and water migration regime of soils and an increase in surface runoff from the territories of shooting activity. The highest environmental risks are observed when steel ammunition is used on shooting areas where metallic lead intensifies steel shot corrosion rate, while the deposited steel shot activates the deterioration of previously encapsulated metal and — if steel and lead ammunition are used at the same time — slows down the encapsulation of newly deposited metallic lead, which catalyses the accumulation and migration of lead in environmental components.
ARTICLE | doi:10.20944/preprints202204.0132.v1
Subject: Medicine & Pharmacology, Oncology & Oncogenics Keywords: SLNB; SPIO; ALND; LS; superparamagnetic iron oxide nanoparticles
Online: 14 April 2022 (10:51:37 CEST)
(1) Background: Sentinel lymph node biopsy assumes importance in the search for metastases, especially in patients with malignant breast disease. Our study approaches the new techniques to prevent complications such as possible postoperative seroma formation, pain or hypoesthesia of the axillary cord and medial arm surface, as well as motor deficits in a preventive manner to avoid disabling outcomes and presents initial data from its experience with the sentinel lymph node biopsy technique. (2) Methods: There are mainly two radioactive tracer detection techniques and a new technique using a radiotracer called Sentimag-magtrace. The positive lymph node is located and removed to perform histologic analysis. In our study, we evaluate 100 patients who underwent breast cancer surgery (3) Results: our experience allowed us to calculate the identification rate with the different methods of sentinel lymph nodes by radioactive tracer 88.9 % vs magnetic tracer technology (Sendimag) 89.5%. (4) Conclusions Thus, this technique avoids radiation exposure for both patients and health care providers, as well as reducing costs and time.
ARTICLE | doi:10.20944/preprints202105.0413.v1
Subject: Medicine & Pharmacology, Allergology Keywords: Zinc; vitamin D; iron; Gripes; COVID-19; Anemia
Online: 18 May 2021 (10:34:15 CEST)
Abstract: COVID-19 in 2020 brought challenges to the Brazilian public health system with an emerging virus with respiratory contagion called SARS-CoV-2. There are few studies in Brazil and in some countries, on the increased incidence of certain viral respiratory infections, includ-ing H1N1 and coronavirus and their association with low levels of vitamin D, zinc and iron. The aim of this study was to demonstrate that the deficit of vitamin D, zinc and iron has an impact on the infectious process of patients with COVID-19 and to establish new forms of prevention for the worsening of COVID-19 in the human body. Data were collected from medical records and test results from patients being followed up during the treatment period for COVID-19. Patients with low blood levels of vitamin D, zinc and iron during the treatment period of COVID-19 had a higher percentage of worsening and complications requiring hospitalization in intensive care beds. The ingestion of vitamin D, zinc and iron in the treatment period of patients with COVID-19 in addition to being an immunological protector against SARS-CoV-2 and alleviating the process of worsening the disease can also act as a biomarker in cases of this disease.
ARTICLE | doi:10.20944/preprints202012.0180.v1
Subject: Medicine & Pharmacology, Allergology Keywords: Chronic diseases; iron deficiency; haemoglobin; anaemia; aminoacids; rehabilitation
Online: 8 December 2020 (06:58:25 CET)
Chronic diseases are characterised by cell’s autophagy and proteins disarrangement resulting in sarcopenia, hypoalbuminemia and hypo-haemoglobinaemia. Hypo-haemoglobinaemia couses worse prognosis independentely of the principal disease. Currently, the cornerstone of therapy of anaemia is iron supplementation, with or without erythropoietin for the stimulation of hematopoiesis. However, treatment strategies should incorporate the addition of heme, the principal biochemical constituent of haemoglobin. Heme synthesis follows a complex biochemical pathway. The limiting step of heme synthesis is D-ALA availability which, for its synthesis, requires Glycine and Succinil-CoA. Consequently, treatment of anaemia should not be based only on iron availability, but also on the availability of the molecules fundamental for heme synthesis. Therefore, an adequate clinical therapeutic strategy should integrate the standard iron infusion and the supply of essential amino acids and vitamins involved in the heme synthesis. We report preliminary data in selected elderly anaemic patients with congestive heart failure (CHF) and catabolic disarrangement, who, in addition to standard iron therapy, received personalized therapy with essential-AAs and vitamins involved in the maintenance of heme. Notably, such individualized therapy resulted in a significant increase in the serum concentration of haemoglobin after 30 days of treatment compared to standard iron therapy.
ARTICLE | doi:10.20944/preprints202008.0708.v1
Subject: Life Sciences, Microbiology Keywords: streptococcus suis; transcriptome; ferrous iron; cobalt; RNA sequencing
Online: 31 August 2020 (09:51:43 CEST)
Streptococcus suis is a zoonotic pathogen causing serious infections in both swine and humans. Although metals are essential for life, excess amounts of metals they are toxic to bacteria. when accumulated in excess amounts. Except for zinc, Transcriptome-level data of the mechanisms for resistance to metal-induced toxicity in S. suis are available for no metals other than zinc. have not been investigated from the transcriptome level in S. suis. Herein, we explored the transcriptome-level changes of in S. suis in response to ferrous iron and cobalt toxicity by RNA sequencing. Many A lot of genes were differentially expressed in the presence of excess ferrous iron and cobalt. Most of the genes in response to cobalt toxicity showed the same expression trends as those were expressed in the same trend in response to ferrous iron toxicity. qRT-PCR analysis of the selected genes confirmed the accuracy of RNA sequencing results. Bioinformatics analysis of the differentially expressed genes indicated that ferrous iron and cobalt have similar impacts effects on the cellular processes of S. suis. Treatment with ferrous Ferrous iron treatment resulted in down-regulation of several oxidative stress tolerance-related genes involved in oxidative stress tolerance and up-regulation of the genes in an amino acid ABC transporter operon. Expression of the several genes in the arginine deiminase system was down-regulated in the presence of after ferrous iron and cobalt treatment. Collectively, our results suggested that S. suis alters the expression of a lot of multiple genes to respond to ferrous iron and cobalt toxicity.
ARTICLE | doi:10.20944/preprints202005.0185.v1
Subject: Materials Science, General Materials Science Keywords: severe plastic deformation; iron hardness; micro/nano-structure
Online: 11 May 2020 (03:33:40 CEST)
The evolution of metals micro/nano-structure upon severe plastic deformation (SPD) is still far to be theoretically explained, while experimental datasets are persistently growing for several decades. Major problem associated with understanding of SPD is related to a fact that the latter is a synergetic product of several competing physical effects which alter the material micro/nano-structure. In attempt to find deformational boundaries, where predominantly one mechanism determines the micro/nano-structure, in this paper we propose a continuous piecewise model for the analysis of experiments on material hardness vs strain of SPD processed materials. The novelty of this approach lies in its ability to find, as free-fitting parameters, the strain breakpoints which separate different micro/nano-structure modes generated upon SPD process. The model is applied to analyse experimental data for polycrystalline samples of pure iron and two distinctive strain breakpoints are revealed with good accuracies. This finding is in a good agreement with our earlier results on TEM microscopy studies on pure iron polycrystals after SPD treatment.
ARTICLE | doi:10.20944/preprints202001.0178.v1
Online: 17 January 2020 (04:44:20 CET)
The current study investigated the impacts of light quality and different levels of fertility on mineral nutrient concentrations in shoot and root tissues of Chinese kale (Brassica oleracea var. alboglabra). ‘Green Lance’ Chinese kale were grown under: 1) fluorescent/incandescent light; 2) 10% blue (447 ± 5 nm) / 90% red (627 ± 5 nm) LED light; 3) 20% blue / 80% red LED light; and 4) 40% blue / 60% red LED light as sole-source lighting at two different levels of fertility. All plants were harvested 30 d after seeding, and shoot and root tissues were analyzed for mineral nutrients. Lighting and fertility interacted to influence kale shoot and root mineral nutrient concentrations. Results indicate sole-source LED lighting used in production can impact mineral nutritional values of baby leafy greens now popular for the packaged market.
ARTICLE | doi:10.20944/preprints201704.0053.v1
Subject: Medicine & Pharmacology, General Medical Research Keywords: iron deficiency anemia; osteoporosis; ferrum infusion; blood transfusion
Online: 10 April 2017 (06:32:56 CEST)
The cause-effect relationship between iron deficiency anemia (IDA) and osteoporosis has not been established in the general population. Thus, the current longitudinal study determined the role of IDA as a risk factor for osteoporosis by analyzing a large nationwide population-based sample. In a sample of 1,000,000 randomly sampled individuals from the 1998-2012 Taiwan National Health Insurance Research Database, patients with IDA (case group [n=35,751]) and individuals without IDA (control group [n=178,755]) were compared. Patients who were <20 years of age and who had pre-existing osteoporosis prior to the diagnosis of IDA were excluded. Each patient with IDA was age- and gender-matched to 5 individuals without IDA. The diagnoses of IDA and osteoporosis (coded using ICD-9CM) were further confirmed with blood test results and X-ray bone densitometry to ensure the accuracy of the diagnoses. Osteoporosis occurred more often among patients with IDA compared to individuals without IDA (2.27% vs. 1.32%, p<0.001). Cox proportional hazard analysis revealed that the risk for osteoporosis was significantly higher in the case than the control group (hazard ratio [HR]=1.74; 95% CI=1.61-1.88) and remained similar after adjustment for covariates (adjusted HR=1.81; 95% CI=1.67-1.97). Compared with individuals without IDA, the risk for osteoporosis was even higher for patients with IDA who received intravenous ferrum therapy (adjusted HR=2.21; 95% CI=1.85-2.63). In contrast, the risk for osteoporosis was reduced for patients with IDA who received a blood transfusion (adjusted HR=1.47; 95% CI=1.20-1.80). As a predictor, prior IDA is a significant and independent risk factor for development of osteoporosis. In contrast to blood transfusion treatment, the use of intravenous ferrum may further increase the risk for future osteoporosis.
ARTICLE | doi:10.20944/preprints202207.0019.v1
Subject: Chemistry, Chemical Engineering Keywords: catalysts; iron oxides; cobalt; oxygen; oxidation; phenol; magnetic composites
Online: 1 July 2022 (16:42:17 CEST)
The development and improvement of methods for the synthesis of environmentally friendly catalysts based on base metals is currently an urgent and promising task of modern catalysis. Catalysts based on nanoscale magnetite and maghemite have fast adsorption-desorption kinetics and high chemical activity. The purpose of this work was to obtain magnetic composites, determine their physicochemical characteristics and verify their activity in the process of liquid-phase oxidation of phenol with oxygen. Magnetic nanocomposites were obtained by chemical co-deposition of salts of ferrous and trivalent iron. The synthesized magnetic composites were studied by X-ray diffractometry, energy dispersive X-ray fluorescence and Mössbauer spectroscopy, IR-Fourier spectroscopy, elemental analysis. To increase the catalytic activity in oxidative processes, the magnetite surfaces were modified using cobalt nitrate salt. Further, CoFe2O4 was stabilized by adding polyethylenimine (PEI) as a surfactant. Preliminary studies of the oxidation of phenol with oxygen, as the most typical environmental pollutant were carried out on the obtained Fe3O4, CuFe2O4, CoFe2O4/PEI catalysts. The spectrum of the reaction product shows the presence of CH in the aromatic ring and double C=C bonds, stretching vibrations of the C=O groups of carbonyl compounds; the band at 3059 cm–1 corresponds to the presence of double C=C bonds, the band at 3424 cm–1 hydroquinone compounds. The band at 1678 cm–1 and the intense band at 1646 cm–1 refer to vibrations of the С=О bonds of the carbonyl group of benzoquinone. Peaks at 1366 cm–1 and 1310 cm–1 can be related to the vibrations of C–H and C–C bonds of the quinone ring. Thus it was demonstrated that produced magnetic composites based on iron oxide are quite effective in the oxidation of phenol with oxygen.
ARTICLE | doi:10.20944/preprints202110.0313.v1
Subject: Chemistry, Applied Chemistry Keywords: membrane transport; Cyanex 923; iron(III); manganese (II); separation.
Online: 21 October 2021 (14:10:48 CEST)
The transport of iron(III) from Fe(III)-Mn(II)-HCl mixed solutions through a flat-sheet supported liquid membrane is investigated, being the carrier phase of Cyanex 923 (commercially available phosphine oxide extractant) dissolved in Solvesso 100 (commercially available diluent), as a function of hydrodynamic conditions, concentration of manganese and HCl in the feed phase, and carrier concentration in the membrane phase. A transport model is derived that describes the transport mechanism, consisting of diffusion through a feed aqueous diffusion layer, a fast interfacial chemical reaction, and diffusion of the Fe(III)-Cyanex 923 complex across the membrane phase. The membrane diffusional resistance (Δm) and feed diffusional resistance (Δf) are calculated from the model, and their values are 145 s/cm and 361 s/cm, respectively. It is apparent that the transport of iron(III) is mainly controlled by diffusion through the aqueous feed boundary layer, being the thickness of this layer calculated as 2.9x10-3 cm. Since Mn(II) is not transported through the membrane phase, the present system allows to the purification of this manganese-bearing solutions.
ARTICLE | doi:10.20944/preprints202103.0161.v1
Subject: Life Sciences, Biochemistry Keywords: chicken eggs; quail eggs; fatty acids; iron; zinc; cholesterol
Online: 4 March 2021 (14:02:38 CET)
All over the world birds’ eggs are an important and valuable component of the human diet. The study aimed to compare the content of lipid components and their nutritional value as well as iron and zinc levels in chicken and quail eggs commonly available on the market. In egg lipids, unsaturated acids were dominated, especially oleic acid, the content of which was about 40% of total fatty acids (TFA). Linoleic acid was the major polyunsaturated fatty acid. Compared to other products of animal origin, eggs were characterized by favourable values of lipid quality indices, especially index of atherogenicity, thrombogenicity and hypocholesterolemic to hypercholesterolemic ratio. In the present study, no differences in the content of tested nutrients between eggs from different production methods (organic, free-range, barn, cages), as well as inter-breed differences were noticed. Cluster analysis showed that eggs enriched in n3 PUFA (according to producers’ declaration) differ from other groups of chicken eggs. However, only in eggs from one producer, the amount of EPA and DHA exceed 80 mg per 100 g, entitling to use the nutrition claim on the package. Quail eggs differed from chicken eggs in FA profile; they also had much higher iron and cholesterol levels.
COMMUNICATION | doi:10.20944/preprints202012.0365.v1
Subject: Chemistry, Analytical Chemistry Keywords: corrosion; amino acids; inhibitors; steel; iron; Monte Carlo simulation
Online: 15 December 2020 (10:09:29 CET)
This research evaluates the inhibitory effect of L-amino acids (AAs) with different side chain lengths on Fe surface implementing Monte Carlo (MC) simulation. A quantitative and qualitative description of the adsorption behavior of AAs on the iron surface has been carried out. Calculations have shown that the absolute values of the adsorption energy of L-amino acids increase with side chain prolongation; they are also determined by the presence of heteroatoms. AAs from nonpolar and basic groups have the best adsorption ability to the iron surface, which indicates their highest inhibitory efficiency according to the results of MC simulation.
REVIEW | doi:10.20944/preprints201907.0277.v1
Subject: Biology, Animal Sciences & Zoology Keywords: thalassemia; iron overload; chelation therapy; gene therapy; blood transfusion
Online: 25 July 2019 (01:20:41 CEST)
Thalassemia is genetic blood disease cause by absence or decrease of one or more of the globin chain synthesis. Beta thalassemia is characterized by one or more mutations in beta globin gene. Absence or reduced amount the of beta globin chains cause ineffective erythropoiesis which leads to anemia. Beta thalassemia has been further divided into three main forms: Thalassemia minor/silent carrier, major and intermedia. More severe form is thalassemia major in which patients depend upon blood transfusion for survival and high level of iron occur as a consequence of consistent blood transfusion. Over loaded iron invokes the synthesis of reactive oxygen species that are toxic in redundancy and triggering the impairment to vascular, endocrine and hepatic system. Thalassemia can be diagnosed and detected through various laboratory tests such as blood smear, prenatal testing (genetic testing of amniotic fluid), DNA analysis (genetic testing) and complete blood count. Treatment of thalassemia intermedia is symptomatic but it can also be managed by splenectomy and folic supplementation. While thalassemia major can be treated by transplantation of bone marrow, regular transfusion of blood and iron chelation treatment, stimulation of fetal hemoglobin production, hematopoietic stem cell transplantation and gene therapy.
ARTICLE | doi:10.20944/preprints201906.0084.v1
Subject: Engineering, Industrial & Manufacturing Engineering Keywords: manufacturing; energy efficiency; life cycle assessment; aluminium; cast-iron
Online: 11 June 2019 (06:39:26 CEST)
Considering the manufacturing of automotive components, there exists a dilemma around the substitution of traditional Cast Iron (CI) with lighter metals. Nowadays, aluminium alloys, being lighter compared to traditional materials, are considered as a more environmentally friendly solution. However, the energy required for the extraction of the primary materials and manufacturing of components is usually not taken into account in this debate. In this study, an extensive literature review has been performed to estimate the overall energy required for the manufacturing of an engine cylinder block using (a) cast iron and (b) aluminium alloys. Moreover, data from over 100 automotive companies, ranging from mining companies to consultancy firms, have been collected in order to support the soundness of this investigation. The environmental impact of the manufacturing of engine blocks made of these materials is presented with respect to the energy burden; the “cradle-to-grave approach” has been implemented to take into account the energy input of each stage of the component lifecycle starting from the resource extraction and reaching to the end-of-life processing stage. Our results indicate that although aluminium components contribute towards reduced fuel consumption during their use phase, the vehicle distance needed to be covered in order to compensate for the up-front energy consumption related to the primary material production and manufacturing phases is very high. Thus, the substitution of traditional materials with lightweight ones in the automotive industry should be very thoughtfully evaluated.
ARTICLE | doi:10.20944/preprints201905.0305.v1
Subject: Materials Science, General Materials Science Keywords: Gray cast iron, Wear resistance, Intermetallic phase, SEM, Hardness
Online: 27 May 2019 (09:49:38 CEST)
Gray cast iron is one of the most important engineering materials that has many applications in various industries including automotive and machinery manufacturing due to its mechanical properties, wear resistance, machining potentials and low price. In this research effect of adding aluminum and silicon to composition of gray cast iron on microstructure and wear resistance was studied. Moreover, it was investigated the role of formation of Fe-Al-Si intermetallic compound in final properties of the alloy. For studying wear resistance of samples pin-on-disc method was carried out. The results showed that addition of aluminum to gray cast iron causes formation of ferrite matrix, which leads to a decrease in hardness value. Increasing silicon content up to 2 wt. % in cast iron with 4 wt. % aluminum intensifies the formation of ferrite matrix, while further increase to 3 wt. % causes emerging a Fe-Al-Si intermetallic phase. Improvement in hardness value was achieved by increasing silicon content from 3 wt. % to 4 wt. % due to the increased percentage of intermetallic phase. Effect of intermetallic phase on decreasing wear rate was showed by studying microstructure and hardness values, however the lowest wear resistance was observed in aluminum bearing cast iron containing 2 wt. % silicon.
ARTICLE | doi:10.20944/preprints201904.0213.v1
Subject: Engineering, Mechanical Engineering Keywords: gray cast iron; wear resistance; intermetallic phase; SEM; hardness
Online: 19 April 2019 (09:43:07 CEST)
Gray cast iron is one of the most important engineering materials that has many applications in various industries including automotive and machinery manufacturing due to its mechanical properties, wear resistance, machining potentials and low price. In this research effect of adding aluminum and silicon to composition of gray cast iron on microstructure and wear resistance was studied. Moreover, it was investigated the role of formation of Fe-Al-Si intermetallic compound in final properties of the alloy. For studying wear resistance of samples pin-on-disc method was carried out. The results showed that addition of aluminum to gray cast iron causes formation of ferrite matrix, which leads to a decrease in hardness value. Increasing silicon content up to 2 wt. % in cast iron with 4 wt. % aluminum intensifies the formation of ferrite matrix, while further increase to 3 wt. % causes emerging a Fe-Al-Si intermetallic phase. Improvement in hardness value was achieved by increasing silicon content from 3 wt. % to 4 wt. % due to the increased percentage of intermetallic phase. Effect of intermetallic phase on decreasing wear rate was showed by studying microstructure and hardness values, however the lowest wear resistance was observed in aluminum bearing cast iron containing 2 wt. % silicon.
ARTICLE | doi:10.20944/preprints201703.0039.v1
Subject: Chemistry, Inorganic & Nuclear Chemistry Keywords: alkanes; amides; hydrogen peroxide; dinuclear complexes; iron complexes; metallasiloxanes
Online: 7 March 2017 (09:23:03 CET)
Two types of heterometallic (Fe(III),Na) silsesquioxanes [Ph5Si5O10]2[Ph10Si10O21]Fe6(O2‒)2Na7(H3O+)(MeOH)2(MeCN)220.127.116.11(MeCN), I, and [Ph5Si5O10]2[Ph4Si4O8]2Fe6Na6(O2‒)3(MeCN)8.5(H2O)8.44, II, were obtained and characterized. X-Ray studies established distinctive structures of both products, with pair of Fe(III)-O-based triangles surrounded by siloxanolate ligands, giving fascinating cage architectures. Complex II proved to be catalytically active in the formation of amides from alcohols and amines, thus becoming a rare example of metallasilsesquioxanes performing homogeneous catalysis. Benzene, cyclohexane and other alkanes, as well as alcohols, can be oxidized in acetonitrile solution to phenol, the corresponding alkyl hydroperoxides and ketones, respectively, by hydrogen peroxide in air in the presence of catalytic amounts of complex II and trifluoroacetic acid. Thus, the cyclohexane oxidation at 20 °C gave oxygenates in very high for alkanes yield (48% based on alkane). The kinetic behaviour of the system indicates that the mechanism includes the formation of hydroxyl radicals generated from hydrogen peroxide in its interaction with diiron species. The latter are formed via monomerization of starting hexairon complex with further dimerization of the monomers.
ARTICLE | doi:10.20944/preprints201810.0137.v1
Subject: Chemistry, Physical Chemistry Keywords: anoxic iron oxidation; abiogenic ferric iron; high-subcritical water; alkaline; ferric oxides; ferric silicates; amorphous silica; origin of life; fluid inclusions; geobiotropy
Online: 8 October 2018 (10:42:53 CEST)
The expression "Follow the water" is used in order to recognize inside the universe, life as it exists on Earth. It is shown here that the expression "Follow the water in its high-subcritical state" can be used in order to recognize the components of life which form prior to the emergence of life. This specific state of water leaves signatures inside the minerals which are produced during high-subcritical water/rock interaction.
ARTICLE | doi:10.20944/preprints202209.0345.v1
Subject: Biology, Ecology Keywords: Abiotic Stress; Amazon; Canga; Iron mining; Mineland Rehabilitation; Proteomics; Symbiosis
Online: 22 September 2022 (13:34:43 CEST)
Mimosa acutistipula is endemic to Brazil and grows in ferruginous outcrops (canga) in Serra dos Carajás, eastern Amazon, where one of the largest iron ore deposits in the world is located. Plants that develop in these ecosystems are subject to severe environmental conditions and must have adaptive mechanisms to grow and thrive in cangas. Mimosa acutistipula is a native species used to restore biodiversity in post-mining areas in canga. Understanding the molecular mechanisms involved in the adaptation of M. acutistipula in canga is essential to deduce the ability of native species to adapt to possible stressors in rehabilitating minelands over time. In this study, the root proteomic profiles of M. acutistipula grown in a native canga ecosystem and rehabilitating minelands were compared to identify essential proteins involved in the adaptation of this species in its native environment and that should enable its establishment in rehabilitating minelands. The results showed differentially abundant proteins, where 436 proteins with significant values (p < 0.05) and fold change ≥ 2 were more abundant in canga and 145 in roots from the rehabilitating minelands. Among them, a representative amount and diversity of proteins were related to responses to water deficit, heat, and responses to metal ions. Other identified proteins are involved in biocontrol activity against phytopathogens and symbiosis. This research provides insights into proteins involved in M. acutistipula responses to environmental stimuli, suggesting critical mechanisms to support the establishment of native canga plants in rehabilitating minelands over time.
ARTICLE | doi:10.20944/preprints202104.0467.v1
Subject: Materials Science, Biomaterials Keywords: Tripodal Ligands; pseudohalide coligands; Iron Complex; Spin crossover; Magnetic properties
Online: 19 April 2021 (12:03:37 CEST)
Reactions of Fe(II) with the tris-(pyridin-2-yl)ethoxymethane (py3C-OEt) tripodal ligand in presence of the pseudohalide ancillary NCE- (E = S, Se, BH3) ligands led to a series of three mononuclear complexes formulated as [Fe(py3C-OEt)2][Fe(py3C-OEt)(NCE)3]2·2CH3CN, with E = S (1), BH3 (2) and Se (3). Single crystal characterizations (complexes 1-2) and X-ray powder diffraction (complexes 1-3) reveal monomeric isomorph structures formed by the spin crossover (SCO) anionic [Fe(py3C-OEt)(NCE)3] complex, associated with the low spin (LS) cationic [Fe(py3C-OEt)2]2+ complex and two solvent acetonitrile molecules. In the [Fe(py3C-OEt)2]2+ cation, the Fe(II) is coordinated by two py3C-OEt tridentate ligands, while the [Fe(py3C-OEt)(NCE)3] anion displays a hexacoordinated environment involving three N-donor atoms of one py3C-OEt ligand and three nitrogen atoms arising from of the three (NCE) coligands. The magnetic studies show the presence of gradual SCO behavior for the three complexes: a one-step transition around 205 K for 1 and two step-transitions for compounds 2 and 3, centred at 245 K and 380 K for 2, and at 170 K and 298 K for 3. The magnetic behaviors of complexes 1 and 2 remain unchanged when heating up to 500 K, while complex 3 shows significant changes which are caused by the crystallisation solvent loss above room temperature.
ARTICLE | doi:10.20944/preprints202103.0552.v1
Subject: Biology, Anatomy & Morphology Keywords: Huma Serum Albumin; Acinetobacter baumannii; quorum sensing; iron; human fluids.
Online: 22 March 2021 (15:49:16 CET)
Acinetobacter baumannii is a nosocomial pathogen capable of causing serious infections associated with high rates of morbidity and mortality. Due to its antimicrobial drug resistance profile, A. baumannii is categorized as an urgent priority pathogen by the Centers for Disease Control and Prevention in the United States and priority group 1 critical microorganism by the World Health Organization. Understanding how A. baumannii adapts to different host environments may provide critical insights into strategically targeting this pathogen with novel antimicrobial and biological therapeutics. Exposure to human fluids was previously shown to alter the gene expression profile of a highly drug susceptible A. baumannii strain A118 leading to persistence and survival of this pathogen. Herein, we explore the impact of human pleural fluid (HPF) and human serum albumin (HSA) on the gene expression profile of a highly multi-drug resistant strain of A. baumannii AB5075. Differential expression was observed for ~30 genes, whose products are involved in quorum sensing, quorum quenching, iron acquisition, fatty acid metabolism, biofilm formation, secretion systems and type IV pilus formation. Phenotypic and further transcriptomic analysis using quantitative RT-PCR confirmed RNA-seq data and pointed out a distinctive role of HSA as the molecule involved in A. baumannii response.
ARTICLE | doi:10.20944/preprints202102.0200.v1
Subject: Earth Sciences, Atmospheric Science Keywords: Iron ore; Maghemite; Nonstoichiometric magnetite; X-Ray diffraction; Ore characterization
Online: 8 February 2021 (12:13:32 CET)
Maghemite (γ-Fe2O3) is a mineral formed from magnetite oxidation at low temperatures, an intermediate metastable term of the magnetite to hematite oxidation and could be mixed with both. It has magnetic susceptibility similar to magnetite, crystal structure close to magnetite with which it forms a solid solution, while compositionally it equals hematite. Maghemite is thus easily misidentified as magnetite by X-ray diffraction and/or as hematite by spot chemical analysis in iron ore characterization routines. Nonstoichiometric magnetite could be quantified in samples of Brazilian soils and iron ores by the Rietveld method using a constrained refinement of the X-ray patterns. The results were confirmed by reflected light microscopy and Raman spectroscopy, thus qualitatively validating the method. X-ray diffraction with the refinement of the isomorphic substitution of Fe2+ by Fe3+ along the magnetite-maghemite solid solution could help to suitably characterize maghemite in iron ores, allowing for the evaluation of its ultimate influence on mineral processing, by affecting its surface and breakage properties.
ARTICLE | doi:10.20944/preprints202011.0146.v4
Subject: Chemistry, Other Keywords: Ferric Uptake Regulation; Fur, Iron(II), Molecular dynamics; DNA; protein
Online: 10 November 2020 (12:23:58 CET)
Ferric uptake regulation protein is a repressor protein which binds an AT rich region of DNA (the iron box). Fur binds as a dimer in a helix turn helix mode and it is activated by iron(II) and other divalent transition metal ions at elevated concentrations in a process to regulate the ion uptake. Each transition metal ion induces certain conformational changes to aid the Fur binding, both the N-terminal and C-terminal domains take part in binding to DNA in addition to His 88 and His 86 residues. The process is discussed in view of experimental reports. Fe(II), Mn(II) and Co(II) activate Fur to bind DNA experimentally but Zinc plays a structural role and does not activate Fur to bind DNA.
ARTICLE | doi:10.20944/preprints201704.0003.v1
Subject: Materials Science, Metallurgy Keywords: Iron Aluminum Alloys; Cold/ Hot PM; Compressibility Factor; Wear Resistance.
Online: 3 April 2017 (16:23:00 CEST)
Iron powders having average particle sizes of ~40µm are mechanically mixed thoroughly with aluminum powders ranging from 1 to 10 in wt.% with an average particle size of ~10µm. Two different powder metallurgical techniques cold and hot pressing are used to study the effect of the additive element powder on the mechanical properties, wear properties and the microstructure of the iron based alloys. The hot pressing technique was performed at a temperature up to 500°C at 445.6 MPa. The cold pressing technique was performed at 909 MPa in room temperature. By increasing the Al content to 10 wt. % in the base Fe-based matrix, the hardness was decreased from 780 to 690 MPa and the radial strength was decreased from 380 to 202 MPa with reductions of 11.5% and 40%, respectively. Improvement of the wear resistance with the increase addition of the Al powder to the Fe matrix up to 5 times was achieved compared to the alloy without Al addition for different wear parameters namely; wear time and sliding speed.
ARTICLE | doi:10.20944/preprints201609.0112.v1
Subject: Materials Science, Surfaces, Coatings & Films Keywords: carbonyl iron; composites film; external magnetic field; microwave absorption properties
Online: 28 September 2016 (10:32:52 CEST)
The carbonyl iron particles were dispersed in a polychloroprene rubber (CR) matrix under an external magnetic field for practical application as microwave absorption composites film. The film prepared under external magnetic field with a thickness of only 0.54 mm showed least reflection loss of -15.98 dB and the reflection loss value less than -10.0 dB over the frequency range of 11.4~14.8 GHz. In comparison with the microwave absorption properties of calculation by transmission line theory based on the tested relative complex permittivity and permeability and film prepared by general route without external magnetic field, the film made with external magnetic field exhibited more excellent microwave absorption properties, strongly depending on the increment of anisotropy and rearrangement of magnetic particles. The results indicated the composite film made under external magnetic field have excellent microwave absorption properties, which suggest that the composites thin film could be used as a thinner and lighter microwave absorber.
Subject: Chemistry, Analytical Chemistry Keywords: Second-Order Derivative (SOD) method; Graphic method; Potential Energy Scan (PES); Charge-Transfer complex; Iron(III) bromide; Iron(V) complex; Transition metal-halogen tandem catalysis
Online: 21 June 2021 (14:08:50 CEST)
To date, theoretical analyses have provided several useful methods/algorithms for studying transition states and non-covalent interactions. Potential Energy Scan (PES) is one such method that has found wide application in the physicochemical community. Analyzing the PES profiles of the catalytic system of FeBr3 in Electrophilic Aromatic Substitution (EAS) with molecular halogens, one can notice an obvious difference from the modern textbook mechanisms proposed in this area of study. Moreover, the newly presented Graphic Methodology (GM) allows a simple and reliable transition state determination even for very weakly bound charge transfer complexes using second-order derivatives as an efficient tool in the graphical analysis. Relative errors that can be reduced to a few parts per thousand in transition state estimation make this method a potentially very useful tool in further graphical studies of non-covalent interactions. Studies performed using high-precision semiempirical methods suggest that the process of halonium ion quenching proceeds along a completely different pathway, suggesting a possible novel transition metal-nonmetal catalytic system involved in the EAS electrophilic quenching step. The results presented here strongly suggest a future GM application that is widely used and the introduction of pseudo and pre-transition states as new terms in the description of non-covalent interactions.
REVIEW | doi:10.20944/preprints202206.0253.v1
Subject: Life Sciences, Biophysics Keywords: Bioinorganic chemistry; metal-binding; structural biology; zinc; iron; copper; transition metals
Online: 17 June 2022 (09:30:07 CEST)
All living organisms require some metal ions for their energy production as well as metabolic and biosynthetic processes. Within cells, metal ions are involved in the formation of adducts interact with metabolites and macromolecules (proteins and nucleic acids). The proteins that require binding to one or more metal ions to be able to carry out their physiological function are called metalloproteins. About one third of all protein structures in the Protein Data Bank involve metalloproteins. Over the past few years there has been a tremendous progress in the number of computational tools and techniques making use of 3D structural information to support the investigation of metalloproteins. This trend has been boosted also by the successful applications of neural networks and deep learning approaches in molecular and structural biology at large. In this review, we discuss recent advances in the development and availability of resources dealing with metalloproteins from a structure-based perspective. We start by addressing tools for the prediction of metal-binding sites (MBSs) using structural information on apo-proteins. Then, we provide an overview of methods for and lessons learned from the structural comparison of MBSs in a fold-independent manner. We then move to describing databases of metalloprotein/MBS structures. Finally, we summarize recent DL applications enhancing the functional interpretation of metalloprotein structures.
ARTICLE | doi:10.20944/preprints202203.0321.v1
Subject: Engineering, Electrical & Electronic Engineering Keywords: electric vehicle; electromagnetic model; optimization; silicon-iron; thermal model; Vanadium Cobalt
Online: 24 March 2022 (02:59:21 CET)
The use of cobalt-iron (VaCoFe) core is investigated as an alternative to silicon-iron (FeSi) on the design of interior permanent magnet synchronous motors (IPMSM). A spoke-type IPMSM geometry is optimized considering FeSi and VaCoFe cores for a torque range up to 40 N.m, providing a general comparative analysis between materials, considering the application of a 4-motor competition vehicle’s powertrain. A genetic optimization algorithm is applied over a hybrid analytical/finite-element model of the motor to provide sufficiently accurate electromagnetic and thermal results within a feasible time. VaCoFe can result in an estimated increase of up to 5 % in efficiency for the same torque, or up to 64 % torque increase for the same efficiency level. After optimization, and using a detailed time-dependent model, a potential 3.2 % increase in efficiency, a core weight reduction of 4.1 %, and a decrease of 9.6 % in the motor’s core volume was found for the VaCoFe at 20 Nm. In addition, for the same motor volume, the VaCoFe allows an increase of 51.9 % of torque with an increase of 1.1 % of efficiency, when compared with FeSi.
ARTICLE | doi:10.20944/preprints202111.0470.v1
Subject: Chemistry, Inorganic & Nuclear Chemistry Keywords: ionic liquids; liquid-liquid extraction; iron extraction; 8-hydroxyquinoline; acetylacetone; thenoyltrifluoroacetone
Online: 25 November 2021 (11:58:50 CET)
(200 words) Imidazolium ionic liquids containing acetylacetone, thenoyltrifluoroacetone, or 8-hydroxyquinoline, respectively, were used as the extracting agents for the separation of traces of iron (III) from its aqueous solutions with or without citric and oxalic acids. The results show that 8-hydroxyquinoline in imidazolium ionic liquids extract iron quantitatively from all the tested solutions including complexing ones, regardless indications of unexpected iron behavior/speciation.
ARTICLE | doi:10.20944/preprints202110.0221.v1
Subject: Earth Sciences, Environmental Sciences Keywords: river; forest; bog; permafrost; carbon; major ions; iron; colloids; trace element
Online: 15 October 2021 (08:59:43 CEST)
Assuming that climate warming in the WSL will lead to a northward shift of the forest and permafrost boundaries, a “substituting space for time” approach predicts an increase in concentration of DIC and labile major and trace elements and a decrease of the transport of DOC and low soluble trace metals in the form of colloids in the main stem of the Ob River. However, an unknown factor is the change in hydrochemistry of the largest southern tributary, the Irtysh River, which is impacted by permafrost-free steppe and forest-steppe zone. Overall, seasonally-resolved transect studies of large riverine systems of western Siberia are needed to assess the hydrochemical response of this environmentally-important territory to on-going climate change.
ARTICLE | doi:10.20944/preprints202010.0589.v1
Subject: Earth Sciences, Atmospheric Science Keywords: Natural Hydrogen System; circular depressions; Archean iron-rich Craton; Western Australia
Online: 28 October 2020 (11:57:31 CET)
There is a marked momentum towards the use of clean hydrogen energy as an alternative for fossil fuels. Renewable energies such as solar and wind are being used to generate hydrogen from the water hydrolysis process. Indeed, this approach stores renewable energies in the form of combustible hydrogen for other energy uses. The other alternative that could be economically more cost-effective at the current technology stage is to explore the natural “Hydrogen System” where the natural hydrogen is generated and accumulated within the earth system, the same that stands for a “Petroleum System”. The Discovery of a large accumulation of relatively pure natural hydrogen (H2) in Mali has triggered the opportunity of searching for natural hydrogen accumulations in other countries. The generation of hydrogen from a circular depression in Mali and some other countries is linked to the presence of geologically very old iron-rich basement rocks. Solid-liquid redox reactions between iron-rich minerals and groundwater that split water are a possible source of H2 in deep basement rocks. It is believed that the hydrogen degassing may be detected by surface topographic circular to sub-circular shallow depressions. Chemical processes such as dissolution by hydrogen are considered to play the main role in the formation of the circular depressions through preferential vertical hydrogen migration channel. Archean iron-rich Yilgarn Craton that covers a vast area of Western Australia (WA) contains abundant iron-rich mafic-ultramafic rocks. The craton reveals many surficial circular depressions visible through satellite images. The area has abundant fault systems and is blanketed with Eocene sedimentary rocks containing high-quality reservoir rocks. All these characteristics seem to provide most of the required elements, such as hydrogen source, migration pathway, and reservoir rock for a “Hydrogen System” in this area.
ARTICLE | doi:10.20944/preprints202003.0462.v1
Subject: Medicine & Pharmacology, Nutrition Keywords: iron; blood donation; restless legs syndrome; quality of life; sleep; fatigue
Online: 31 March 2020 (22:32:59 CEST)
Background: Besides anemia, iron deficiency may cause more subtle symptoms including those of the restless legs syndrome (RLS), the chronic fatigue syndrome (CFS) or sleeping disorders. Objective: The aim of this pre-planned secondary analysis was to compare the frequency and severity of symptoms associated with iron deficiency before and after (intravenous or oral) iron supplementation in iron deficient blood donors. Methods/Design: Prospective, randomized, controlled, single centre trial. (ClinicalTrials.gov: NCT01787526). Setting: Tertiary care center in Graz, Austria Participants: 138 female and 38 male whole blood and platelet apheresis donors aged ≥18 and ≤65 years with iron deficiency (ferritin ≤30ng/ml at the time of blood donation). Interventions: Intravenous iron (1 g ferric carboxymaltose, n=86) or oral iron supplementation (10 g iron fumarate, 100 capsules, n=90). Measurements: Clinical symptoms were evaluated by a survey before iron therapy (visit 0, V0) and after 8-12 weeks (visit 1, V1) including questions about symptoms of RLS, CFS, sleeping disorders, quality of life and symptoms like headaches, dyspnoea, dizziness, palpitations, pica and trophic changes of fingernails or hair. Results: We found a significant improvement in the severity of symptoms for RLS, fatigue and sleep quality (p<0.001). Furthermore, a significant decrease of headaches, dyspnoea, dizziness and palpitations was reported (p<0.05). There was no difference between the type of iron supplementation (intravenous versus oral) and clinical outcome data. Conclusion: Iron supplementation in iron deficient blood donors may be an effective strategy to improve symptoms related to iron deficiency and the wellbeing of blood donors.
ARTICLE | doi:10.20944/preprints201910.0134.v1
Subject: Biology, Plant Sciences Keywords: stingless bees; honey; pollen; Serra dos Carajás; Amazônia; Melipona; Iron mining
Online: 11 October 2019 (11:49:06 CEST)
The pollen content of honey samples collected in the years 2017 and 2019 from experimental apiaries of Melipona seminigra pernigra Moure & Kerr 1950 installed in campo rupestre on canga (CRC) vegetation of the Serra dos Carajás, southeastern Amazonia, was analyzed to understand the local variability of floral resources occurring on natural and disturbed areas. Around one hundred pollen types were identified mainly belonging to Fabaceae, Myrtaceae and Euphorbiaceae (31, 6 and 5 types, respectively). The N5 mine presented the highest pollen richness with 95 pollen types identified, almost twice of those identified in the other areas, including the better preserved ones. Eighty percent of the pollen types are rare with concentrations ≤ 2,000 pollen grains/10 g; the remaining types are the most abundant and frequent, and are considered the primary bee sources (PBS). PBS correspond mostly to native plants such as Tapirira guianensis Aubl., Protium spp., Aparisthmium cordatum (A.Juss.) Baill., Mimosa acutistipula var. ferrea Barneby, Periandra mediterrânea (Vell.) Taub., Miconia spp., Pleroma carajasense K.Rocha, Myrcia splendens (Sw.) DC., Serjania spp. and Solanum crinitum Lam. All pollen types were identified during both seasons, but higher pollen concentration are related to the dry period (June-September). The statistical analysis indicated that there was no significant difference in honey pollen data between the natural and disturbed areas since the plant species considered as PBS in this work are intensively used in revegetation of degraded area (RDA) processes by mining activities.
ARTICLE | doi:10.20944/preprints201809.0583.v1
Subject: Materials Science, Nanotechnology Keywords: iron-doped TiO2; photocatalytic activity; low UV-irradiation; hydroxyl radical; estriol
Online: 29 September 2018 (05:48:51 CEST)
Iron Doped TiO2 nanoparticles (Fe-TiO2) were synthesized and photocatalitically investigated under high and low fluence values of UV-radiation. The Fe-TiO2 physical characterization was performed using X-ray Powder Diffraction (XRD), Brunauer-Emmett-Teller (BET) surface area analysis, Transmission Electron Microscope (TEM), Scanning Electron Microscope (SEM), Diffuse Reflectance Spectroscopy (DRS), and X-Ray Photoelectron Spectroscopy (XPS) technique. The XPS evidenced that ferric ion (Fe3+) was in the lattice of TiO2 and co-dopants no intentionally added were also present due to the precursors of the synthetic method. The Fe3+ concentration played a key role in the photocatalytic generation of hydroxyl radical (•OH) and estriol (E3) degradation. Fe-TiO2 materials accomplished E3 degradation, and it was found that the catalyst with 0.3 at. % content of Fe (0.3 Fe-TiO2) enhanced the photocatalytic activity under low UV-irradiation compared with no intentionally Fe-added TiO2 (zero-iron TiO2) and Aeroxide® TiO2 P25. Furthermore, the enhanced photocatalytic activity of 0.3 Fe-TiO2 under low UV-irradiation may have applications when radiation intensity must be controlled, as in medical applications, or when strong UV absorbing species are present in water.
ARTICLE | doi:10.20944/preprints201809.0465.v1
Subject: Life Sciences, Other Keywords: Phaseolus vulgaris L., yellow beans, Manteca, cooking time, iron, bioavailability, polyphenols
Online: 24 September 2018 (15:24:38 CEST)
The common dry bean (Phaseolus vulgaris L.) is a nutrient dense food produced globally as a major pulse crop for direct human consumption, and is an important source of protein and micronutrients for hundreds of millions of people across Latin America, the Caribbean and Sub-Saharan Africa. Beans require large amounts of heat energy and time to cook, deterring consumers worldwide from purchasing beans. In regions where consumers rely on expensive fuelwood for food preparation, the yellow bean is often marketed as fast cooking. A Yellow Bean Panel (YBP) was assembled to explore the cooking time and health benefits of the five major seed types within the yellow bean market class (Amarillo, Canary, Manteca, Mayocoba, Njano) over two field seasons. This study shows how the Manteca yellow bean possess a fast cooking phenotype, which could serve a genetic resource for introducing fast cooking properties into a new generation of dry beans with cooking times < 20 minutes when pre-soaked and < 80 minutes unsoaked. Nutritional evaluation revealed fast cooking yellow beans have high iron retention (>80%) after boiling. An in vitro digestion/Caco-2 cell culture bioassay revealed a strong negative association between cooking time and iron bioavailability in the YBP (r values > -0.73). When either pre-soaked or left unsoaked the highest iron bioavailability scores were measured in the fast cooking Manteca genotypes providing evidence that this yellow market class is worthy of germplasm enhancement through the added benefit of improved iron quality after cooking.
ARTICLE | doi:10.20944/preprints201710.0090.v1
Subject: Materials Science, General Materials Science Keywords: austempered ductile iron; austempering parameters; microstructure; mechanical properties; salt bath agitation
Online: 13 October 2017 (15:44:58 CEST)
In this paper the influence of austempering temperature and salt bath agitation on the final microstructure and mechanical properties of the ferritic ductile iron were studied. 17 samples had been subjected to different heat treatment parameters. Different microstructures were recorded upon the completion of the tests. From the obtained micro images, it is obvious that both the austempering temperature and salt bath agitation affect the final microstructure of the austempered ductile iron. Lower austempering temperatures and salt bath agitation produce more ausferrite in the microstructure, hence the harder and tougher phases are present. This was confirmed with hardness and toughness test of the 17 heat-treated samples. Lower austempering temperatures give more ausferrite phase and therefore higher hardness, but hardness decreases with increasing austempering temperatures. Toughness rises with rising austempering temperatures, but drops significantly with temperatures above 395°C because of the final microstructure.
ARTICLE | doi:10.20944/preprints201701.0131.v1
Subject: Engineering, Automotive Engineering Keywords: Electromagnetic devices; Iron losses; LS model; Magnetic equivalent circuit; Models coupling
Online: 30 January 2017 (08:20:38 CET)
In this paper, an original approach allowing the determination of the iron losses in the electromagnetic devices is presented. This new approach exploits the Loss Surface (LS) hysteresis model and the magnetic flux density waveforms resulting from a generalized nonlinear adaptive magnetic equivalent circuit (MEC) using a mesh-based formulation in two-dimensional (2-D) or quasi three-dimensional (3-D). The model coupling has been applied to a 18-slots/16-poles radial-flux interior permanent-magnet (PM) synchronous machine (PMSM) dedicated to automotive applications, mainly for electric/hybrid/fuel cell vehicles (EVs/HEVs/FCVs). The obtained results have been compared with those made retrospectively in the 2-D transient finite-element (FE) Flux. The influence of the MEC discretization on the iron loss calculation and the electromagnetic performances has been analyzed. The computation time is divided by 3/2 with an error less than 7 %.
ARTICLE | doi:10.20944/preprints202211.0105.v1
Subject: Chemistry, Chemical Engineering Keywords: alkali leaching; red mud; high-iron waste; disposal; Al-goethite; conversion; magnetite
Online: 7 November 2022 (04:30:13 CET)
Bauxite residue (BR), also known as red mud, is a by-product of the production of alumina via the Bayer process. Because of the high sodium oxide and other impurities content, this material is not used to obtain iron or other iron-containing products. In this paper, the hydro-chemical conversion of goethite (FeOOH) to magnetite (Fe3O4) in high-iron BR from the Friguia alumina refinery (Guinea) by Fe2+ ions in highly concentrated alkaline media was studied. The simultaneous extraction of Al and Na made it possible to obtain a product containing more than 96% Fe3O4. The results show that the magnetization of Al-goethite and Al-hemetite accelerates the dissolution of the Al from the iron mineral solid matrix and from the desilication product (DSP). After ferrous sulfate (FeSO4·7H2O) was added directly at the FeO:Fe2O3 molar ratio of 1:1 at 120 °C for 150 min in the solution with the 360 g L-1 Na2O concentration, the alumina extraction ratio reached 96.27% for the coarse bauxite residue size fraction (Sands) and 87.06% for fine BR obtained from red mud. The grade of iron (total iron in the form of iron element) in the residue can be increased to 69.55% for Sands and 58.31% for BR. The solid residues obtained after leaching were studied by XRD, XRF, TG-DTA, VSM, Mössbauer spectroscopy and SEM to evaluate the conversion and leaching mechanisms and the recovery ratio of Al from different minerals. The iron-rich residues can be used in the steel industry or as a pigment.
ARTICLE | doi:10.20944/preprints202201.0218.v3
Subject: Arts & Humanities, Archaeology Keywords: Archaeological survey; Inner Tian Shan Mountain region; Iron Age; Medieval period; agropastoralism
Online: 3 March 2022 (07:44:09 CET)
This paper discusses the preliminary results of archaeological surveys conducted in the Juuku Region of north-central Kyrgyzstan on the south side of Lake Issyk kul. Our goal was to document ancient and contemporary agropastoral systems over a four millenia time period. During the surveys about 350 loci were identified as settlements, burial mounds, graves, single artifact finds, and artifact scatters (ceramic). The areas of Juuku Valley survey included two discrete polygons: Polygon 1, Lower Juuku at 1750 to 1950 m asl in elevation and Polygon 2, Chak Juuku or Upper Eastern Branch Juuku Valley at 2060 to 2100 m asl in elevation. Three radiometric dates and preliminary archaeobotanical studies were conducted at three exposed profile cuts. The methods included here are: (1) pedestrian surveys; (2) use of digital maps (Google Earth, Encarta); (3) placing archaeological loci within known chronological time periods; (4) AMS dating of charcoal samples collected from profile deposits; and (5) preliminary identification of plant remains found from archaeobotanical samples. The results of our research represent the first step toward inventorying and interpreting archaeological data in the Juuku Valley derived from field studies.
REVIEW | doi:10.20944/preprints202108.0088.v1
Subject: Life Sciences, Other Keywords: Minerals, Trace elements, Fish, Copper, Iron, Selenium, Manganese, Zinc, Calcium, Phosphous, Magnesium
Online: 3 August 2021 (14:57:19 CEST)
Aquatic animals have unique physiological mechanisms to absorb and retain minerals from their diets and water. Research and development in the area of mineral nutrition of farmed fish and crustaceans have been relatively slow and major gaps exist in the knowledge of trace element requirements, physiological functions and bioavailability from feed ingredients. Quantitative dietary requirements have been reported for three macroelements (calcium, phosphorus and magnesium) and six trace minerals (zinc, iron, copper, manganese, iodine and selenium) for selected fish species. Mineral deficiency signs in fish include reduced bone mineralization, anorexia, lens cataracts (zinc), skeletal deformities (phosphorus, magnesium, zinc), fin erosion (copper, zinc), nephrocalcinosis (magnesium deficiency, selenium toxicity), thyroid hyperplasia (iodine), muscular dystrophy (selenium) and hypochromic microcytic anaemia (iron). An excessive intake of minerals from either diet or gill uptake causes toxicity and therefore a fine balance between mineral deficiency and toxicity is vital for aquatic organisms to maintain their homeostasis either through increased absorption or excretion. Release of minerals from uneaten or undigested feed and from urinary excretion can cause eutrophication of natural waters, which requires additional consideration in feed formulation. The current knowledge in mineral nutrition of fish is briefly reviewed.
Subject: Medicine & Pharmacology, Cardiology Keywords: cardiovascular disease; heavy metals; cooper; zinc; manganese; cobalt; iron; health risk assessment
Online: 9 June 2020 (03:25:06 CEST)
Cardiovascular diseases (CVDs) constitute the first cause of death among the population of developing and developed countries. Atherosclerosis, which is a disorder with multifactorial etiopathogenesis, underlies most CVDs. The available literature includes ample research studies on the influence of classic cardiovascular (CV) risk factors. However, environmental exposure to heavy metals, among other substances, is still an unappreciated risk factor of CVDs. This study aimed to assess the concentration of some heavy metals (copper (Cu), zinc (Zn), manganese (Mn), cobalt (Co), and iron (Fe)) in the blood serum of postmyocardial infarction (post-MI) patients and patients free from myocardial infarction (MI) as well as estimate the relationship between the occurrence of MI and increased concentration of heavy metals. The concentration of heavy metals (Cu, Zn, Mn, Co, and Fe) was assessed using the inductively coupled plasma mass spectrometry technique in a group of 146 respondents divided into two groups: post-MI group (study group (SG), n = 74) and group without cardiovascular event (CVE) having a low CV risk (control group (CG), n = 72). The concentration of the analyzed heavy metals was higher in SG. All the heavy metals showed a significant diagnostic value (p < 0.001). The highest value of area under the curve (AUC) was observed for manganese (Mn) (0.955; 95% confidence interval (CI) = 0.922–0.988), while the lowest value was found for zinc (Zn) (0.691; 95% CI = 0.599–0.782). In one-dimensional models, high concentrations of each of the analyzed heavy metals significantly increased the chances of having MI from 7-fold (Cu) to 128-fold (Mn). All the models containing a particular metal showed a significant and high discrimination value for MI occurrence (AUC 0.72–0.92). Higher concentrations of Cu, Zn, Mn, Co, and Fe were found to considerably increase the chances of having MI. Considering the increasingly higher environmental exposure to heavy metals in recent times, their concentrations can be distinguished as a potential risk factor of CVDs.
ARTICLE | doi:10.20944/preprints202003.0071.v1
Subject: Keywords: Anemia classification; dynamic harmony search; iron deficiency anemia; thalassemia trait; machine learning
Online: 4 March 2020 (15:34:04 CET)
In recent decades, attention has been directed at anemia classification for various medical purposes, such as thalassemia screening and predicting iron deficiency anemia (IDA). In this study, a new method has been successfully tested for discrimination between IDA and β-thalassemia trait (β-TT). The method is based on a Dynamic Harmony Search (DHS). Complete blood count (CBC), a fast and inexpensive laboratory test, is used as the input of the system. Other models, such as a genetic programming method called structured representation on genetic algorithm in non-linear function fitting (STROGANOFF), an artificial neural network (ANN), an adaptive neuro-fuzzy inference system (ANFIS), a support vector machine (SVM), k-nearest neighbor (KNN), and certain traditional methods, are compared with the proposed method.
Subject: Engineering, Energy & Fuel Technology Keywords: soot oxidation; catalytic; heterogeneous catalysis; oxygen vacancies; iron doped ceria catalyst; ceria
Online: 1 September 2019 (09:02:29 CEST)
This study investigates the role of oxygen vacancy on Fe-doped CeO2 catalyst activity for soot oxidation. The oxygen vacancy was assessed through Ce3+ content. The Fe content was varied between 0 and 30% for two catalyst preparation methods, co-precipitation (CP) and solution combustion synthesis (SCS). X-ray photoelectron spectroscopy indicates that ceria exists as both Ce4+ and Ce3+, while iron is present only as Fe3+. The catalyst’s activity was evaluated by ignition (T10) and combustion (T50) temperatures using thermogravimetric analysis. Optimum Fe contents yielding the highest activity were found to be 10% and 5% for CP and SCS catalysts, respectively. The surface area and morphology have shown moderate effect on catalyst activity, because catalytic soot oxidation involves solid-solid contact. More importantly, regardless of the fabrication method, it was found that Ce3+ content, which is closely related to oxygen vacancies, plays the most important role in affecting the catalyst activity.
ARTICLE | doi:10.20944/preprints201907.0254.v1
Subject: Medicine & Pharmacology, Nutrition Keywords: economic evaluation, micronutrient fortification, iron deficiency anemia, Cote d’Ivoire, model, impact, DALYs
Online: 23 July 2019 (10:25:26 CEST)
Iron deficiency anemia (IDA) is highly prevalent in the Cote d’Ivoire, and has severe health and economic consequences. In this paper, we apply a health economic model to quantify the burden of IDA, and the contribution of nation-wide mandatory iron fortification of wheat flour and voluntary iron fortification of condiments to the reduction of this burden. The analysis for the population from six months to 64 years builds on published reviews and publicly available datasets, and is stratified by age-groups and socio-economic strata. Without the impact of these fortification strategies, the annual burden of IDA is estimated at 242,100 disability adjusted life years (DALYs) and 978.1 million USD. Wheat flour and condiment fortification contributed to a reduction of the IDA burden by approximately 5% each. In places with high prevalence of malaria and environmental factors, such as the Côte D’Ivoire, policy makers should combine nutritional intervention with infectious disease prevention and environmental factors. The findings of this study provide additional input for policy makers about the magnitude of the impact and can support the conception of future fortification strategies.
Subject: Medicine & Pharmacology, Nutrition Keywords: Iron, Zinc, Interactions, DMT1, ZIP4, Pancreas, Metabolism, Homeostasis, Intestine, Caco-2 cells
Online: 9 July 2019 (14:32:11 CEST)
Iron and zinc are essential micronutrients required for growth and health. Deficiencies of these nutrients are highly prevalent among populations, but can be alleviated by supplementation. Cross-sectional studies in humans showed positive association of serum zinc levels with hemoglobin and markers of iron status. Dietary restriction of zinc or intestinal specific conditional knock out of ZIP4 (SLC39A4), an intestinal zinc transporter, in experimental animals demonstrated iron deficiency anemia and tissue iron accumulation. Similarly increased iron accumulation has been observed in cultured cells exposed to zinc deficient media. These results together suggest a potential role of zinc in modulating whole body iron metabolism. Studies in intestinal cell culture models demonstrate that zinc induces iron uptake and transcellular transport via induction of divalent metal iron transporter-1 (DMT1) and ferroportin (FPN) expression, respectively. It is interesting to note that intestinal cells are exposed to very high levels of zinc through pancreatic secretions, which is a major route of zinc excretion from the body. Therefore, zinc appears to be modulating the iron metabolism possibly via regulating the DMT1 and FPN1 levels. Herein we critically reviewed the available evidence to hypothesize novel mechanism of Zinc-DMT1/FPN axis in regulating intestinal iron absorption and tissue iron accumulation to facilitate future research aimed at understanding the yet elusive mechanisms of iron and zinc interactions.
ARTICLE | doi:10.20944/preprints201811.0007.v1
Subject: Biology, Ecology Keywords: Iron bacteria; sulfate reduction; sulfur oxidizing bacteria; tufa; marl; manganese oxidizing bacteria
Online: 2 November 2018 (02:53:10 CET)
Microbial populations involved in forming the distinctive precipitates of the S, Fe, Mn, and Ca cycles in the San Diego River watershed reflect an interplay between mineralogy of the rocks in the watershed, sparse rainfall, ground- and surface-water anoxia, and runoff of high sulfate, treated imported water. In the less developed headwaters, Temescal Creek tributary emerges from pyrite-bearing metamorphic rocks, and thus exhibits both an oxidized Fe and reduced S cycle. In the middle reaches, the river moves through developed land where treated, imported high sulfate Colorado River water enters from urban runoff. Mast Park surrounded by caliche-bearing sedimentary rocks is a site where marl is precipitating. Cobbles in riffles in the river are coated black with Mn oxide. When the river encounters deep-seated volcanic bedrock, it wells up to precipitate both Fe and Mn oxides at Old Mission Dam. Then, directly flowing through caliche-laced sedimentary rocks, Birchcreek tributary precipitates tufa. Further downstream, at a site that periodically receives full sunlight, a sulfuretum sets up during the summer when the river is deoxygenated. Such a rich geochemistry results in activity of iron and manganese oxidizing bacteria, sulfur oxidizers and reducers, and cyanobacteria precipitating calcareous marl and tufa.
ARTICLE | doi:10.20944/preprints201807.0459.v1
Subject: Materials Science, Biomaterials Keywords: Superparamagnetic iron oxide; Magnetic resonance imaging; Solid lipid nanoparticles; Galactose; Liver-targeted
Online: 24 July 2018 (14:01:51 CEST)
The aim of this study was to develop a novel nanostructured lipid carriers (NLCs) with hepatocytes targeting as carriers for the magnetic resonance imaging (MRI) contrast agent (i.e., magnetic nanostructured lipid carriers, MNLCs), and to evaluate the targeting ability of the MNLCs with T2-weighted MRI both in vitro and in vivo. Here, the galactose-octadecylamine (Gal-ODA) conjugates were synthesized by chemical coupling reaction between lactose acid (LA) and octadecylamine (ODA). Then the superparamagnetic iron oxide (SPIO) loaded nanostructured lipid carrier (conjugated by Gal-ODA, Gal-NLC-SPIO) was prepared by emulsification-ultrasonic method using monoglyceride as lipid materials. The Gal-NLC-SPIO with a diameter of about 50 nm could specifically internalize into LO2 (human hepatic cell line) cells. In vitro MRI results also proved the specific targeting ability of Gal-NLC-SPIO to LO2 cells. The in vivo MR imaging experiments using an orthotopic intrahepatic xenograft tumor model further validated the hepatocytes targeted effect of Gal-NLC-SPIO. The results of this study suggested that Gal-NLC-SPIO can be used as a contrast agent to aid in the diagnosis of hepatic diseases.
ARTICLE | doi:10.20944/preprints201805.0005.v1
Subject: Materials Science, Surfaces, Coatings & Films Keywords: Cemented carbides, cermets, iron binders, oxide coating, radiation shielding, nanoindentation, passivation, silicides.
Online: 1 May 2018 (11:04:54 CEST)
An oxidation resistant coating on cemented tungsten carbides is characterised in this work. Cemented tungsten carbides (cWCs) are routinely used in mining and manufacturing but are also candidate materials for compact radiation shielding in fusion power generation. In both environments, cWCs will suffer significant degradation due to oxidation at relatively low temperatures. In a recent study, a Si-deposition coating method was demonstrated to improve the oxidation resistance of cWCs by up to a factor of 1,000. This work focusses on the growth kinetics, phase composition, and mechanical properties of these coatings. By combining quantitative X-ray diffraction, electron microscopy and nanoindentation, we show that the coating layer has a 20 % higher hardness than the substrate, which was explained on the basis of a previously-unknown presence of a fine distribution of very hard SiC laths. To interpret the coating stability, a coating growth map is developed. The map shows the structure is stable under a broad range of processing temperatures and composite compositions, demonstrating the potential application of these coatings in a variety of nuclear shielding cWCs.
ARTICLE | doi:10.20944/preprints201804.0236.v1
Subject: Materials Science, Nanotechnology Keywords: prefabricated metal crowns (PMCs); nickel (Ni); chromium (Cr); iron (Fe); ion release
Online: 18 April 2018 (08:38:25 CEST)
Dental caries is a public health problem worldwide according to WHO data. Among treatments in pediatric dentistry, prefabricated metal crowns (PMCs) have been one of the most successful options since they were introduced in cases of considerable tooth destruction. Our objective was to detect the presence and concentration of iron (Fe), chromium (Cr), and nickel (Ni) in saliva of patients who require rehabilitation with PMCs, before and after their placement. A quasi-experimental study was performed in 32 patients who attended dental care in a pediatric dentistry clinic at a public university and who required rehabilitation with PMCs. Parametric tests (ANOVA and Pearson correlation) were performed, and a p ≤ 0.05 was considered statistically significant. Statistically significant differences were found when comparing the Ni release before, 1 week, and 1 month after placing the crowns. Similarly, we observed a positive correlation between the number of crowns and Ni release. No tests were performed for Fe and Cr because the amounts of these metals were less than 0.1 ppb, which was not detectable by inductively coupled plasma optical emission spectrometry (ICP-OES). The levels of Fe, Cr, and Ni released were below toxic health levels. Studies are required to evaluate whether this release has negative effects at cellular levels.
ARTICLE | doi:10.20944/preprints202211.0157.v1
Subject: Materials Science, Metallurgy Keywords: Vanadium-titanium-iron concentrate; Pellet; Sulfuric acid; Cyclic leaching; Vanadium; Eh-pH diagrams
Online: 8 November 2022 (16:04:55 CET)
Here, a process for leaching vanadium from calcified roasting pellets (CPVC) of vanadium-titanium iron concentrate by a two-stage sulfuric acid cycle was proposed. When the silicon removal acid concentration of the pellet in the first stage was 1.5 mol/L, the solid-liquid ratio was 6: 1, the silicon removal acid concentration of the leaching solution was 3.0 mol/L, and the standing time was 48 h, the silica gel formation time was 23 h, the filtration time was 70 s, and the loss rates of vanadium and iron were 1.52% and 0.17%, respectively. When the acid concentration was 2 mol/L, at room temperature, using a leaching time of 28 days, and a solid-liquid ratio of 5: 1 in the second stage, the total leaching rates of vanadium and iron were 75.52% and 0.71%, respectively. The concentration of vanadium in the leaching solution reached 6.80 g/L, and vanadium was directly precipitated without extraction. After secondary roasting, the crushing strength of the pellets reached 2250 N, which met the requirement for blast furnace iron making. The Eh-pH diagrams of the V-Fe-H2O system at different temperatures were plotted. Thermodynamically, it was difficult to selectively leach vanadium and iron by changing the conventional acid leaching conditions. In addition, the pellets before and after leaching were analyzed. The grade of iron in the pellets increased slightly after leaching, and the main phases in the pellets remained as Fe2O3 and Fe9TiO15. The S in the sulfuric acid solution entered the leached pellets during the acid leaching reaction and was removed by the secondary roasting of the leached pellets.
ARTICLE | doi:10.20944/preprints202107.0629.v1
Subject: Engineering, Automotive Engineering Keywords: phase-field; multiphase-field; grey cast iron; brittle fracture; ductile fracture; anisotropic fracture
Online: 28 July 2021 (12:16:13 CEST)
In this work, a small-strain phase-field model is presented, which is able to predict crack propagation in systems with anisotropic brittle and ductile constituents. To model the anisotropic brittle crack propagation, an anisotropic critical energy release rate is used. The brittle constituents behave linear-elastically, in a transversely isotropic manner. Ductile crack growth is realised by a special crack degradation function, depending on the accumulated plastic strain, which is calculated by following the J2-plasticity theory. The mechanical jump conditions are applied in solid-solid phase transition regions. The influence of the relevant model parameters on a crack, propagating through a planar brittle-ductile interface, and furthermore a crack developing in a domain with a single anisotropic brittle ellipsoid, embedded in a ductile matrix, is investigated. We demonstrate that important properties, concerning the mechanical behaviour of grey cast iron, such as the favoured growth of cracks along the graphite lamellae and the tension-compression load asymmetry of the stress-strain response, are covered by the model. The behaviour is analysed on basis of a simulation domain consisting of three differently oriented elliptical inclusions, embedded in a ductile matrix, which is subjected to tensile and compressive load. The used material parameters correspond to graphite lamellae and pearlite.
REVIEW | doi:10.20944/preprints201906.0077.v1
Subject: Chemistry, Electrochemistry Keywords: aqueous electrolyte; corrosion; iron-air; metal-air batteries; silicon-air; stationary energy storage
Online: 10 June 2019 (11:24:23 CEST)
Abstract: Metal-air batteries provide a most promising battery technology given their outstanding potential energy densities, which are desirable for both stationary and mobile applications in a ‘beyond lithium-ion’ battery market. Silicon- and iron-air batteries underwent less research and development compared to lithium- and zinc-air batteries. Nevertheless, in the recent past, the two also-ran battery systems made considerable progress and attracted rising research interest due to the excellent resource-efficiency of silicon and iron. Silicon and iron are among the top five of the most abundant elements in the earth’s crust, which ensures almost infinite material supply of the anode materials, even for large scale applications. Furthermore, primary silicon-air batteries are set to provide one of the highest energy densities among all batteries, while iron-air batteries are frequently considered as a highly rechargeable system with decent performance characteristics. Considering fundamental aspects for the anode materials, i.e., the metal electrodes, in this review, we will first outline the challenges, which explicitly apply to silicon- and iron-air batteries and prevented them from a broad implementation so far. Afterwards, we provide an extensive literature survey regarding state-of-the-art experimental approaches, which are set to resolve the aforementioned challenges and might enable the introduction of silicon- and iron-air batteries into the battery market in the future.
ARTICLE | doi:10.20944/preprints201805.0168.v1
Subject: Engineering, Other Keywords: electrical resistance sintering; MF-ERS; FAST; ECAS; Iron; hot pressing; sintering; powder metallurgy
Online: 10 May 2018 (15:34:08 CEST)
Commercially pure (c.p.) iron powders with a deliberate high degree of oxidation were consolidated by medium-frequency electrical resistance sintering (MF-ERS). This is a consolidation technique where pressure, and heat coming from a low-voltage and high-intensity electrical current, are simultaneously applied to a powder mass. In this work, the achieved densification rate is interpreted according to a qualitative microscopic model, based on the compacts global porosity and electrical resistance evolution. The effect of current intensity and sintering time on compacts was studied on the basis of micrographs revealing the porosity distribution inside the sintered compact. The microstructural characteristics of compacts consolidated by the traditional cold-press and furnace-sinter powder metallurgy route are compared with results of MF-ERS consolidation. The goodness of MF-ERS versus the problems of conventional sintering when working with oxidized powders is analyzed. The electrical consolidation allows to obtain higher densifications than the traditional route under non-reducing atmospheres.
ARTICLE | doi:10.20944/preprints201803.0069.v1
Subject: Materials Science, General Materials Science Keywords: Fe–6.5 wt.% Si; ribbon; melt spinning; ac iron loss prediction; magnetic properties
Online: 9 March 2018 (05:07:06 CET)
Ultra-thin Fe–6.5wt.%Si ribbons with 35 μm in thickness were prepared by melt-spinning. The magnetic properties were investigated before and after annealing 1000 ºC. DC properties and low-frequency (400 Hz ~ 10 kHz) iron losses have significantly improved after heat treatment. A simplified formula based on Steinmetz law which can be used to predict the AC iron loss is presented. According to the results of some iron losses data, a simplified formula has been determined, and the extent of AC iron losses can be predicted. The results obtained from the formula predict AC iron loss to a good degree. The method developed in this work could be extended to other magnetic materials for predicting AC iron loss with greater ease.
ARTICLE | doi:10.20944/preprints201802.0067.v1
Subject: Life Sciences, Microbiology Keywords: external resistances; soil microbial fuel cells; paddy soil; Geobacter; arsenic; iron; organic matter
Online: 8 February 2018 (03:29:46 CET)
Soil microbial fuel cells (sMFC) are a novel technique that use organic matters in soils as an alternative energy source. External resistance (ER) is a key factor influencing sMFC performance and, furthermore, alters the soil’s biological and chemical reactions. However, little information is available on how the microbial community and soil component changes in sMFC with different ER. Therefore, the effects of anodes of sMFC at different ER (2000 Ω, 1000 Ω, 200 Ω, 80 Ω and 50 Ω) were examined by measuring organic matter (OM) removal efficiency, trace elements in porewater and bacterial community structure in contaminated paddy soil. The results indicated that ER has significant effects on sMFC power production, OM removal efficiency and bacterial beta diversity. Moreover ER influences iron, arsenic and nickel concentration as well in soil porewater. In particular, greater current densities were observed at lower ER (2.4mA, 50Ω) compared to a higher ER (0.3mA, 2000Ω). The removal efficiency of OM increased with decreasing ER whereas it decreased with soil distance away from the anode. Furthermore, principal coordinate analysis (PCoA) revealed that ER may shape the bacterial communities that develop in the anode vicinity but have minimal effect on that of the bulk soil. The current study illustrates that lower ER can be used to selectively enhance the relative abundance of electrogenic bacteria and lead to high OM removal.
ARTICLE | doi:10.20944/preprints201708.0052.v1
Subject: Mathematics & Computer Science, Applied Mathematics Keywords: air- or iron-cored coil; polar coordinates; fourier analysis; two-dimensional; subdomain technique
Online: 14 August 2017 (06:07:40 CEST)
This paper presents a new scientific contribution on the two-dimensional (2-D) subdomain technique in polar coordinates taking into account the finite relative permeability of the ferromagnetic material. The constant relative permeability corresponds to linear part of the nonlinear B(H) curve. As in conventional technique, the method of separation of variables and the Fourier’s series are used for the resolution of magnetostatic Maxwell’s equations in each region. Although, the general solutions of magnetic field in the subdomains and boundary conditions (BCs) between regions are different in the conventional and proposed method. In this later, the magnetic field solution in each subdomain is a superposition of two magnetic quantities in the two directions (i.e., r- and Q-axis) and the BCs between two regions are also in both directions. For example, the scientific contribution has been applied to an air- or iron-cored coil supplied by a constant current. The distribution of local quantities (i.e., the magnetic vector potential and flux density) has been validated by a corresponding 2-D finite-element analysis (FEA). The obtained semi-analytical results are in very good agreement with those of numerical method.
ARTICLE | doi:10.20944/preprints202301.0143.v1
Subject: Physical Sciences, Nuclear & High Energy Physics Keywords: Cold nuclear fusion; Iron-56 as a fuel; Eco friendly Thermal energy; Power plant;
Online: 9 January 2023 (06:46:39 CET)
In this contribution, we make an attempt to write a theoretical proposal for designing an eco friendly thermal power plant which runs with cold nuclear fusion technology at a temperature of (1500 to 2000) deg.C. In our recently published papers, we have proposed a clear cut mechanism for understanding and implementing cold nuclear fusion technique pertaining to fusion of hydrogen with metals of mass numbers starting from 50. In this context, we would like to stress the point that, fusion of hydrogen under controllable temperature and pressure can be understood as a phenomenon of fusing neutron to the nucleus of the base atom. Part of isotopic nuclear binding energy difference of final and base atomic nuclides can be seen in the form of safe thermal energy of the order of (1 to 3) MeV per atom against 200 MeV released in nuclear fission of one Uranium atom. Due to increased heaviness and weak interaction, sometimes fused neutron splits into proton and electron. Proton seems to be retained by the base atom’s nuclear core and electron seems to join with the electronic orbits of the base atom. In this way, increased mass of base atomic nuclide helps in eco friendly production of thermal energy in large quantity. For this purpose we consider Iron-56 as a fuel. In a simplified view, under strong nuclear attractive forces, Iron-56 absorbs hydrogen atom as a neutron and by emitting 1MeV equivalent thermal energy transforms to Iron-57. Thus, one gram of Iron-56 can generate 1000MJ of heat with 50% efficiency. In a shortcut approach, by bombarding powder and semi-liquid forms of Iron-56 with direct neutrons coming from neutron source, our proposal can be tried, understood and verified experimentally.
Subject: Engineering, General Engineering Keywords: mine rock drainage; sulfide oxidation; neutralization by silicates; secondary iron minerals; toxic element scavenging
Online: 15 October 2021 (12:22:41 CEST)
Mine waste rock and drainage pose lasting environmental, social, and economic threats to the mining industry, regulatory agencies, and society as a whole. Mine drainage can be alkaline, neutral, moderately or extremely acidic and contains significant levels of sulfate, dissolved iron, and frequently a variety of heavy metals and metalloids, such as cadmium, lead, arsenic, and selenium. In acid neutralization by carbonate and silicate minerals, a range of secondary minerals can form and possibly scavenge these potentially harmful elements. Apart from the extensively-studied microbial-facilitated sulfide oxidation, the diverse microbial communities present in mine rock and drainage may also participate in the formation, dissolution, and transformation of secondary minerals influencing the mobilization of these metals and metalloids. This article reviews major microbial-mediated geochemical processes occurring in mine rock piles that affect drainage chemistry, with a focus on the role of microorganisms in the formation, dissolution and transformation of secondary minerals. Understanding this is crucial for developing biologically-based measures to deal with contaminant release at the source, i.e., source control.
COMMUNICATION | doi:10.20944/preprints202108.0045.v1
Subject: Engineering, Automotive Engineering Keywords: Magnetic Instruments; Digital compass; Soft and Hard iron compensation; Helmholtz coil; Towed hydrophone array
Online: 2 August 2021 (13:32:53 CEST)
Usually, towed hydrophone arrays are instrumented with a set of compasses. Data from these sensors are utilized while beamforming the acoustic signal for target bearing estimation. However, elements of the hydrophone array mounted in the neighborhood of a compass can affect the Earth’s magnetic field detection. The effects depend upon the kind of elements present in the platform hosting the compass. If the disturbances are constant in time, they can be compensated for by means of a magnetic calibration. This process is commonly known as soft and hard iron compensation. In this paper, a solution is presented to carry out the magnetic calibration of a COTS (Commercial Off The Shelf) digital compass without unattainable sensor motion. This approach is particularly suited in applications where a physical rotation of the platform that hosts the sensor is unfeasible. In our case, the platform consists in an assembled and operational towed hydrophone array. A standard calibration process relies on physical rotation of the platform and thus on the use of the geomagnetic field as a reference during the compensation. As a variation on this approach, we provide to the sensor an artificial reference magnetic field to simulate the unfeasible physical rotation. We obtain this by using a tri-axial Helmholtz coil, which enables programmability of the reference magnetic field and assures the required field uniformity. In our work, the simulated geomagnetic field is characterized in terms of its uncertainty. The analysis indicates that our method and experimental set-up represent a suitably accurate approach for the soft and hard iron compensation of the compasses equipped in the hydrophone array under test.
REVIEW | doi:10.20944/preprints202004.0490.v1
Subject: Keywords: nanomaterials; iron oxide nanoparticles; magnetic nanodiscs; synthetic antiferromagnetic nanostructures; nanowires; contrast agents; MRI; theragnosis
Online: 28 April 2020 (08:53:32 CEST)
Magnetic Resonance Imaging (MRI) is a powerful, non-invasive and nondestructive tool, capable of providing three-dimensional (3D) images of living organisms. The use of magnetic contrast agents has allowed clinical researchers and analysts to enormously increase the sensitivity and specificity of MRI since these substances change the intrinsic properties of the tissues within a living body, increasing the information present in the images. The advances in nanotechnology and materials science as well as the research of new magnetic effects have been the driving forces that propel the use of magnetic nanostructures as promising alternatives to the commercial contrast agents used in MRI. This review discusses the principles associated with the use of contrast agents in MRI as well as the most recent reports focused on nanostructured contrast agents. The potential applications of gadolinium (Gd) and manganese Mn-based nanomaterials and iron oxide nanoparticles in this imaging technique are discussed as well, from their magnetic behavior to the mainly used materials and nanoarchitectures. Then, it is also addressed the recent efforts made to develop new types of contrast agents based on synthetic antiferromagnetic and high-aspect ratio nanostructures. Furthermore, the application of these materials in theragnosis, either as contrast agents and controlled drug release, contrast agents and thermal therapy or contrast agents and radiosensitizers, is also presented.
Subject: Medicine & Pharmacology, Clinical Neurology Keywords: blood-brain barrier; copper/iron homeostasis; neurodegenerative (Alzheimers, Parkinsons, Prion) disease; North Ronaldsay sheep
Online: 27 May 2019 (12:27:10 CEST)
The neurodegenerative diseases (Alzheimers, Parkinsons, amyotrophic lateral sclerosis, Huntingdons) and the prion disorders, have in common a dysregulation of metalloprotein chemistry involving redox metals (Cu,Fe,Mn). The consequent oxidative stress gives rise to protein plaques and neuronal cell death. An equilibrium exists between the functional requirement of the brain for Cu and Fe and their destructive potential with the production of reactive oxygen species. The importance of the brain barrier is highlighted in regulating the import of these metals. Upregulation of key transporters occurs in foetal and neonatal life when brain metal requirement is high and is down-regulated in adult life when need is minimal. By contrast a neonatal mode of CTR1 upregulation persists in feral N.Ronaldsay sheep. This has led to the premise that metal regulation may return to the default setting in ageing with implications for neurodegenerative disease.
ARTICLE | doi:10.20944/preprints201807.0014.v1
Subject: Life Sciences, Biotechnology Keywords: beans; iron, zinc and copper bioaccessibility; myo-inositol phosphates; anti-nutrients; polyphenols; household processing
Online: 2 July 2018 (13:19:42 CEST)
Micronutrient deficiencies are a major public health problem. Beans are an important plant-based source of iron, zinc and copper, but their absorption is reduced in the presence of anti-nutrients such as phytates, polyphenols and tannins. Soaking and discarding the soaking water before cooking is unanimously recommended, but this can result in mineral loss. Data on the consequences for mineral bioaccessibility is still limited. This study aimed to evaluate iron, zinc and copper bioaccessibility in black beans cooked (regular pan, pressure cooker) with and without the soaking water. Minerals were quantified by ICP-MS, myo-inositol phosphates (InsP5, InsP6) by HPLC ion-pair chromatography, total polyphenols using Folin-Denis reagent and condensed tannins using Vanillin assay. Mineral bioaccessibility was determined by in vitro digestion and dialysis. All treatments resulted in a statistically significant reduction of total polyphenols (30%) and condensed tannins (20%). Only when discarding the soaking water a loss of iron (6%) and copper (30%) was observed, and InsP6 was slightly decreased (7%) in one treatment. Bioaccessibility of iron and zinc were low (about 0.2% iron and 35% zinc), but copper presented high bioaccessibility (about 70%). Cooking beans under pressure without discarding the soaking water resulted in the highest bioaccessibility levels among all household procedures. Discarding the soaking water before cooking did not improve the nutritional quality of the beans.
ARTICLE | doi:10.20944/preprints202208.0225.v1
Subject: Life Sciences, Other Keywords: hemoglobin; iron nutrition status; metabolic syndrome; metabolic disorders; observational study; Taiwanese Han Chinese; European White
Online: 12 August 2022 (04:03:24 CEST)
Iron overnutrition has been implicated with higher risk of developing metabolic and cardiovascular diseases, including metabolic syndrome (MetS), while iron deficiency anemia exacerbates many underlying chronic conditions. Hemoglobin (Hb) concentration in the blood, which reflects a major functional iron (i.e., heme iron) in the body, may serve as a surrogate of iron nutrition status. We conducted sex-specific observational association studies where we carefully titrated the association between Hb deciles and MetS and its components among the Taiwanese Han Chinese (HC) from the Taiwan Biobank and Europeans of White ancestry from the UK Biobank, representing two large ethnicities. Our data show that at higher-than-normal levels of Hb, increasing deciles of Hb concentration were significantly associated with MetS across all sex subgroups in both ethnicities, with the highest deciles resulting in up to three times greater risks than the reference group [Taiwanese HC: OR=3.17 (95% CI, 2.75-3.67) for Hb >16.5 g/dL in men, OR=3.11 (2.78-3.47) for Hb >14.5 g/dL in women; European Whites: OR=1.89 (1.80-1.98) for Hb >16.24 g/dL in men, OR=2.35 (2.24-2.47) for Hb >14.68 g/dL in women]. The association between stronger risks and increasing Hb deciles was similarly observed with all metabolic components except diabetes. Here we found that both the highest Hb decile groups and contrarily the lowest ones, with respect to the reference, were associated with higher odds of diabetes in both ethnic groups [e.g., Taiwanese HC men: OR=1.64 (1.33-2.02) for Hb >16.5 g/dL, OR=1.71 (1.39-2.10) for Hb <13.5 g/dL; European Whites women: OR=1.39 (1.26-1.45) for Hb >14.68 g/dL, OR=1.81 (1.63-2.01) for Hb <12.39 g/dL]. These findings confirm that elevated Hb concentrations, a potential indicator of iron overnutrition, may play a role in the pathophysiology of MetS and metabolic components.
ARTICLE | doi:10.20944/preprints201910.0252.v1
Subject: Life Sciences, Molecular Biology Keywords: ferric ammonium citrate; deferoxamine; 2,2′-bipyridine; iron homeostasis; ISC; mitochondrial clearance; longevity; starvation; Parkinson’s disease
Online: 22 October 2019 (05:01:43 CEST)
Lifespan extension was recently achieved in Caenorhabditis elegans nematodes by mitochondrial stress and mitophagy, triggered via iron depletion. Conversely in man, deficient mitophagy due to Pink1/Parkin mutations triggers iron accumulation in patient brain and limits survival. We now aimed to identify murine fibroblast factors, which adapt their mRNA expression to acute iron manipulation, relate to mitochondrial dysfunction and may influence survival. After iron depletion, expression of the plasma membrane receptor Tfrc with its activator Ireb2, the mitochondrial membrane transporter Abcb10, the heme-release factor Pgrmc1, the heme-degradation enzyme Hmox1, the heme-binding cholesterol metabolizer Cyp46a1, as well as the mitophagy regulators Pink1 and Parkin showed a negative correlation to iron levels. After iron overload, these factors did not change expression. Conversely, a positive correlation of mRNA levels with both conditions of iron availability was observed for the endosomal factors Slc11a2 and Steap2, as well as for the iron-sulfur-cluster (ISC)-containing factors Ppat, Bdh2 and Nthl1. Positive correlation only after iron depletion was observed for the iron export factor Slc40a1, mitochondrial iron transporters Slc25a28, Abcb7 and Abcb8, mitochondrial ISC-containing factors Glrx5, Nfu1, Bola1 and Abce1, cytosolic Aco1 and Tyw5, as well as nuclear Dna2, Elp3, Pold1 and Prim2. The latter are regulators of nucleotide synthesis and DNA quality control, which have known importance for growth and lifespan. The only Pink1-/- triggered transcript modulation was the reduced expression of the ISC-containing ribosomal factor Abce1. These mammalian findings support previous fly data that Pink1 influences co-translational quality control via Abce1, as well as mitophagy. Our findings provide the first systematic survey how iron dosage triggers homeostatic transcriptional regulations and elucidate how iron deprivation results in mitophagy.
ARTICLE | doi:10.20944/preprints201609.0106.v2
Subject: Mathematics & Computer Science, Applied Mathematics Keywords: air- or iron-cored coil; Cartesian coordinates; Fourier analysis; two-dimensional; saturation effect; subdomain technique
Online: 16 January 2017 (04:38:11 CET)
The most significant assumptions in the subdomain technique (i.e., based on the formal resolution of Maxwell's equations applied in subdomain) is defined by: “The iron parts (i.e., the teeth and the back-iron) are considered to be infinitely permeable so that the saturation effect is neglected”. In this paper, the author presents a new scientific contribution on improving of this method in two-dimensional (2-D) and in Cartesian coordinates by focusing on the consideration of iron. The subdomains connection is carried out in the two directions (i.e., x- and y-edges). For example, the improvement was performed by solving magnetostatic Maxwell's equations for an air- or iron-cored coil supplied by a direct current. To evaluate the efficacy of the proposed technique, the magnetic flux density distributions have been compared with those obtained by the 2-D finite-element analysis (FEA). The semi-analytical results are in quite satisfying agreement with those obtained by the 2-D FEA, considering both amplitude and waveform.
REVIEW | doi:10.20944/preprints202208.0190.v1
Subject: Medicine & Pharmacology, Clinical Neurology Keywords: iron-deficient anemia; IDA; stroke; cerebral venous thrombosis; brain MRI; aortic thrombosis; pulmonary embolism; embolic pattern
Online: 10 August 2022 (04:31:26 CEST)
Background: Anemia is one of the most frequent diseases worldwide, affecting a third of the general population. Anemia in general and in particular, iron-deficient anemia (IDA), has been associated to a higher risk of thrombotic manifestations, including ischemic stroke and cerebral venous thrombosis (CVT), as well as systemic extra cerebral arterial and venous thrombosis. Despite these data, anemia is seldom considered as an etiological factor of stroke. Methods: An individual case encompassing all known neurovascular and systemic arterial and venous thrombotic manifestations related to IDA is presented with the focus on clinical reasoning issues in the diagnostic pathways, starting from the neuroradiological signs. The main questions have been identified and addressed in a narrative review of the most relevant data in the literature from a pragmatic and clinical viewpoint. Results and Discussion: The presented case concerns a 46 years old man admitted to the Stroke Unit because of acute is-chemic stroke with multiple thrombi in large intracranial and extracranial vessels, multifocal ischemic lesions in several arterial territories and the concurrent finding of asymptomatic CVT, pulmonary embolism with lung infarction and aortic thrombosis. An extended diagnostic work-up excluded the main etiologies (arterial dissection, cardiac embolism, genetic and acquired prothrombotic disorders, as cancer and antiphospholipid syndrome), except for a severe IDA, such as to require blood transfusions followed by anticoagulant therapy for the several thrombotic manifestations. Neuroimaging and systemic vascular findings have been analyzed and the main issues proposed by the case in the diagnostic pathway have been identified and discussed in a pragmatic clinical road map reviewing the data provided by the literature. Conclusions: IDA is a common but treatable condition that, independently or synergically, may increase the risk of thrombotic events. The diagnostic and therapeutic approach has not yet defined and each case should be individually addressed in a pragmatic clinical road map.
ARTICLE | doi:10.20944/preprints202205.0219.v1
Subject: Arts & Humanities, Archaeology Keywords: archaeological landscapes; Iron Age; Medieval period; agriculture; pastoralism; vertical zonation, Issyk-Kul Lake; archaeobotany; GIS mapping
Online: 17 May 2022 (03:29:22 CEST)
The main goal of this paper is to present results of preliminary archaeological research on the south side of Lake Issyk-Kul in Kyrgyzstan. We test the hypothesis that agropastoral land use changed over four millennia from the Bronze Age through the ethnographic Kirghiz period due to economic, socio-political, and religious changes in the prehistoric and historic societies of this region. Our research objectives are to: (1) describe and analyze survey results from Lower Kizil Suu Valley; (2) discuss the results of radiometric and archaeobotanical samples taken from three stratigraphic profiles from three settlements from the Juuku Valley, including these chronological periods: the Wusun period (200 to 400 CE), the Qarakhanid period (1100 to 1200 CE), and the ethnographic Kirghiz period (1700 to 1900 CE); and (3) conduct preliminary GIS spatial analyses on the Iron Age mortuary remains (Saka and Wusun period). This research emerges out of the first archaeological surveys conducted in 2019 - 2021 and includes the Lower Kizil Suu alluvial fan; it is an initial step toward developing a model for agropastoral land use for upland valleys of the Inner Tian Shan Mountains.
REVIEW | doi:10.20944/preprints201810.0429.v1
Subject: Medicine & Pharmacology, Gastroenterology Keywords: Copper; fructose; Kupffer cell (KC); iron; non-alcoholic fatty liver disease (NAFLD); metabolic syndrome; gut microbiota
Online: 18 October 2018 (16:57:06 CEST)
Compelling epidemiologic data support the critical role of dietary fructose in the epidemic of obesity, metabolic syndrome and nonalcoholic fatty liver disease (NAFLD). The metabolic effects of fructose on the development of metabolic syndrome and NAFLD are not completely understood. High fructose intake impairs copper status, and copper-fructose interactions have been well documented in rats. Altered copper-fructose metabolism leads to exacerbated experimental metabolic syndrome and NAFLD. A growing body of evidence has demonstrated that copper levels are low in NAFLD patients. Moreover, hepatic and serum copper levels are inversely correlated with the severity of NAFLD. Thus, high fructose consumption and low copper availability are considered two important risk factors in NAFLD. However, the causal effect of copper-fructose interactions as well as the effects of fructose intake on copper status remain to be evaluated in humans. The aim of this review is to summarize the role of copper-fructose interactions in the pathogenesis of the metabolic syndrome and discuss the potential underlying mechanisms. This review will shed light on the role of copper homeostasis and high fructose intake and point to copper-fructose interactions as novel mechanisms in the fructose induced NAFLD.
ARTICLE | doi:10.20944/preprints201809.0115.v2
Subject: Materials Science, Metallurgy Keywords: ironmaking; direct reduction; iron ore; DRI; shaft furnace; mathematical model; heterogeneous kinetics; heat and mass transfer
Online: 9 October 2018 (11:46:23 CEST)
This paper addresses the modeling of the iron ore direct reduction process, a process likely to reduce CO2 emissions from the steel industry. The shaft furnace is divided into three sections (reduction, transition, and cooling), and the model is two-dimensional (cylindrical geometry for the upper sections and conical geometry for the lower one), to correctly describe the lateral gas feed and cooling gas outlet. This model relies on a detailed description of the main physical–chemical and thermal phenomena, using a multi-scale approach. The moving bed is assumed to be comprised of pellets of grains and crystallites. We also take into account eight heterogeneous and two homogeneous chemical reactions. The local mass, energy, and momentum balances are numerically solved, using the finite volume method. This model was successfully validated by simulating the shaft furnaces of two direct reduction plants of different capacities. The calculated results reveal the detailed interior behavior of the shaft furnace operation. Eight different zones can be distinguished, according to their predominant thermal and reaction characteristics. An important finding is the presence of a central zone of lesser temperature and conversion.
ARTICLE | doi:10.20944/preprints201808.0096.v1
Subject: Keywords: Hadean; carbonic ocean; mantle plumes; Banded Iron Formation; green rust; submarine alkaline vents; emergence of life
Online: 6 August 2018 (05:19:46 CEST)
Korenaga and coworkers present evidence to suggest that 4.3 billion years ago the Earth’s mantle was dry and water filled the ocean to twice its present volume. CO2 was constantly exhaled during the mafic to ultramafic volcanic activity associated with magmatic plumes that produced the thick, dense and relatively stable oceanic crust. In that setting two distinct major types of sub-marine hydrothermal vents were active: ~400 °C acidic springs whose effluents bore vast quantities of iron into the ocean, and ~120 °C, highly alkaline and reduced vents exhaling from the cooler, serpentinizing crust at some distance from the heads of the plumes. When encountering the alkaline effluents, the iron from the plume head vents precipitated out forming mounds likely surrounded by voluminous exhalative deposits similar to the banded iron formations known from the Archean. These mounds and the surrounding sediments likely comprising nanocrysts of the variable valence FeII/FeIII oxyhydroxide, green rust. The precipitation of green rust, along with subsidiary iron sulfides and minor concentrations of Ni, Co and Mo in the environment at the alkaline springs may have established both the key bio-syntonic disequilibria, and the means to properly make use of them – those needed to drive the essential inanimate-to-animate transitions that launched life. In the submarine alkaline vent model for the emergence of life specifically it is first suggested that the redox-flexible green rust microcrysts spontaneously formed precipitated barriers to the complete mixing of carbonic ocean and alkaline hydrothermal fluids, barriers that created and maintained steep ionic disequilibria; and second, that the hydrous interlayers of green rust acted as 'engines' that were powered by those ionic disequilibria and drove essential endergonic reactions. There, aided by sulfides and trace elements acting as catalytic promoters and electron transfer agents, nitrate could be reduced to ammonia and carbon dioxide to formate, while methane may have been oxidized to methyl and formyl groups. Acetate and higher carboxylic acids could then have been produced from these C1 molecules and aminated to amino acids, and thence oligomerized to offer peptide nests to phosphate and iron sulfides and secreted to form primitive amyloid-bounded structures, leading conceivably to protocells.