ARTICLE | doi:10.20944/preprints201910.0273.v1
Subject: Earth Sciences, Atmospheric Science Keywords: all-sky imager; sodium lidar; gravity waves; mesosphere nightglow; growth rate; wave dissipation
Online: 24 October 2019 (05:46:07 CEST)
Amplitude growth rates of monochromatic gravity waves were estimated and compared from multiple instrument measurements carried out in Brazil. Wave dynamic parameters were obtained from sodium density profiles from lidar observations carried out in Sao Jose dos Campos (23°S, 46°W), while all-sky images of multiple airglow layers provided amplitudes and parameters of waves over Cachoeira Paulista (23°S, 45°W). Growth rates of gravity wave amplitudes from lidar and airglow imager data were consistent with dissipative wave behavior. Only a small amount of the observed wave events presented freely propagating behavior. Part of the observed waves presented saturated amplitude. The general saturated/damped behavior is consistent with diffusive filtering processes imposing limits to amplitude growth rates of the observed gravity waves.
ARTICLE | doi:10.20944/preprints201810.0556.v1
Online: 24 October 2018 (08:01:35 CEST)
Background: Sodium intake has been related to several adverse health outcomes; such as, hypertension, and cardiovascular diseases. Processed foods are major contributors to the population’s dietary sodium intake. The aim of the present study was to determine sodium levels in Mexican packaged foods; also to evaluate the proportion of foods that comply with sodium benchmark targets set by the UK Food Standards Agency (UK FSA) and those set by the Mexican Commission for the Protection of Health Risks (COFEPRIS). We also evaluated the proportion of foods that exceeded the Pan American Health Organization (PAHO) targets. Methods: This was a cross-sectional study that comprised data collected from the package of 2,248 processed foods from selected supermarkets of Mexico. Results: Many processed food categories contained excessive amount of sodium, being the processed meats (ham, bacon and sausages) those that have the highest concentrations. The proportion of foods classified as compliant in our sample was lower for international targets (FSA UK and PAHO) compared to the Mexican COFEPRIS criteria. Conclusions: These data provide a critical baseline assessment for monitoring sodium levels in Mexican processed foods.
ARTICLE | doi:10.20944/preprints201812.0023.v1
Online: 3 December 2018 (13:36:41 CET)
Excess salt and inadequate potassium intakes are associated with high cardiovascular disease (CVD). In Montenegro, CVD is the leading cause of death and disability. There is no survey that has directly measured salt and potassium consumption in Montenegro. The aim is to estimate population salt and potassium intakes and explore knowledge, attitudes and behaviour (KAB), amongst the adult population of Podgorica. Random samples of adults were obtained from primary care centres. Participants attended a screening including demographic, anthropometric and physical measurements. Dietary salt and potassium intakes were assessed by 24h urinary sodium (UNa) and potassium (UK) excretions. Creatinine was measured. KAB was collected by questionnaire. Six hundred and thirty-nine (285 men, 25-65 years) were included in the analysis (response rate 63%). Mean UNa was 186.5 (SD 90.3) mmol/day, equivalent to 11.6g of salt/day, and potassium excretion 62.5 (26.2) mmol/day, equivalent to 3.2g/day. Only 7% of them had a salt intake below the WHO recommended target of 5g/day, and 13% ate enough potassium (>90 mmol/day). The majority (86%) knew that high salt causes ill-health. However, only 44% thought it would be useful to reduce consumption. Salt consumption is high, and potassium consumption is low, in men and women living in Podgorica.
ARTICLE | doi:10.20944/preprints202012.0027.v1
Subject: Medicine & Pharmacology, Allergology Keywords: Decellularized scaffold; Acellular scaffold; Kidney; Rat; Sodium dodecyl sulfate; Sodium lauryl ether sulfate
Online: 1 December 2020 (13:30:34 CET)
Chronic kidney diseases (CKD) and end stage renal disease (ESRD) are growing threats worldwide. Tissue engineering is a new hope to surpass the current limitations such as the shortage of donor. To do so, the first step would be fabrication of an intact decellularized kidney scaffold. In the current study, an automatic decellularization device was developed to perfuse and decellularize male rats' kidneys using both sodium lauryl ether sulfate (SLES) and sodium dodecyl sulfate (SDS) and to compare their efficacy in kidney decellularization and post-transplantation angiogenesis. After anesthesia, kidneys were perfused with either 1% SDS solution for 4 h or 1% SLES solution for 6 h. The decellularized scaffolds were stained with hematoxylin and eosin (H&E), periodic acid Schiff (PAS), Masson’s trichrome, and alcian blue to determine cell removal and glycogen, collagen and glycosaminoglycans (GAGs) contents, respectively. Moreover, scanning electron microscopy (SEM) was performed to evaluate the cell removal and preservation of microarchitecture of both SDS and SLES scaffolds. Additionally, DNA quantification assay was applied for all groups in order to measure residual DNA in the scaffolds and normal kidney. In order to demonstrate biocompatibility and bioactivity of the decellularized scaffolds, allotransplantation was performed in back muscle and angiogenesis was evaluated. Complete cell removal in both SLES and SDS groups was observed in SEM and DNA quantification assays. Moreover, the extracellular matrix (ECM) architecture of rat kidney in the SLES group was significantly preservation better than the SDS group was shown. The formation of blood capillaries and vessels were observed in the kidney allotransplantations in both SLES and SDS decellularized kidneys. In conclusion, we demonstrated that both SLES and SDS could be promising tools in kidney tissue engineering. The better preservation of ECM than SDS, introduces SLES as the solvent of choice for kidney decellularization. ¬¬
ARTICLE | doi:10.20944/preprints202107.0391.v1
Online: 16 July 2021 (17:07:29 CEST)
Population studies have demonstrated an association between sodium (Na) and po-tassium (K) intake and levels of blood pressure (BP) and cholesterol. The aim of this study was to describe the dietary intake and distribution of Na and K in Mexicans, and their as-sociation with metabolic risk outcomes. We analyzed a national survey that included 4,219 participants. Dietary information was obtained through a 24-hour recall. Foods and beverages were classified based on the degree of processing. BP and biomarkers in blood and urine were measured. The mean intake (mg/d) of Na was 1512 in pre-schoolchildren, 2844 in schoolchildren, 3743 in adolescents, and 3132 in adults. The mean intake of K was 1616 in pre-schoolchildren, 2256 in schoolchildren, 2967 in adolescents, and 3401 in adults. Processed and ultra-processed foods (UPF) contribute to sodium intake: 49% in preschool and schoolchildren, 47% in adolescents, and 39% in adults. Adults in the fourth quartile of sodium intake had lower serum concentrations of cholesterol (181.4 mg/dL) and HDL-c (35.5 mg/dL). The Mexican population has high Na and low K intakes. There is a relationship between Na sodium consumption and cholesterol, and LDL levels. UPF contributes to almost 40% of the sodium consumed by Mexicans.
ARTICLE | doi:10.20944/preprints202209.0225.v1
Subject: Physical Sciences, Applied Physics Keywords: lithium; sodium; silicon; nanowire; quantum mechanics
Online: 15 September 2022 (08:47:32 CEST)
This computational research study will compare the specific charge capacity (SCC) between lithium ions inserted into crystallize silicon (c-Si) nanowires versus sodium ions inserted into amorphous silicon (a-Si) nanowires. It will be demonstrated that the potential energy V(r) within the lithium-silicon nanowire supports a coherent energy state model with discrete electron particles while the sodium-silicon nanowire potential energy will be discovered to be essentially zero and thus the electron current that travels through the sodiated silicon nanowire will be modeled as free electron with wave-like characteristics. This is due to the vast differences in the electric fields of the lithiated and sodiated silicon nanowires where the electric fields are of the order of 1e10 V/m and 1e-15 V/m respectively. The main reason for the great disparity in electric fields are due to the present of optical amplification within lithium ions and the absence of this process within sodium ions. It will be shown that optical amplification develops coherent optical interactions which is the primary reason for the surge of specific charge capacity in the lithiated silicon nanowire. Conversely, the lack of optical amplification is the reason for the incoherent optical interactions within sodium ions which is the reason for the low presence of SCC in sodiated silicon nanowires.
ARTICLE | doi:10.20944/preprints201907.0322.v1
Subject: Medicine & Pharmacology, Veterinary Medicine Keywords: ceftiofur sodium; pharmacokinetics; NLME; beagle dogs
Online: 28 July 2019 (17:09:01 CEST)
Ceftiofur (CEF) sodium is a third-generation broad-spectrum cephalosporin commonly used in an extra-label manner in dogs for the treatment of respiratory and urinary system infections. To contribute to the literature supporting CEF use in companion animals, we have developed a compartmental, nonlinear mixed-effects (NLME) model of CEF pharmacokinetics in dogs (PK). We then used the mathematical model to predict (via Monte Carlo simulation) the duration of time for which plasma concentrations of CEF and its pharmacologically active metabolites remained above minimum inhibitory concentrations (respiratory tractEscherichia coli spp). Twelve healthy beagle dogs were administered either 2.2 mg/kg ceftiofur-sodium (CEF-Na) intravenously (I.V) or 2.2 mg/kg CEF-Na subcutaneously (S.C). Plasma samples were collected over a period of 72 hours post-administration. To produce a measurement of total CEF, both CEF and CEF metabolites were derivatized into desfuroylceftiofur acetamide (DCA) before analysis by UPLC-MS/MS. No adverse effects were reported after I.V or S.C dosing. The NLME PK models were parameterized using the stochastic approximation expectation maximization algorithm as implemented in Monolix 2018R2. A two-compartment mamillary model with first-order elimination and first-order S.C absorption best described the available kinetic data. Final parameter estimates indicate that CEF has a low systemic clearance (0.25 L/h/kg) associated with a low global extraction ratio E = 0.02) and a moderate volume of distribution (2.97 L/kg) in dogs. The absolute bioavailability after S.C administration was high (93.7%). Gender was determined to be a significant covariate in explaining the variability of S.C absorption. Our simulations predicted that a dose of 2.2 mg/kg CEF-Na S.C would produce median plasma concentrations of CEF of at least 0.5 µg/mL (MIC50) for approximately 30 hours.
ARTICLE | doi:10.20944/preprints201902.0081.v1
Online: 8 February 2019 (09:41:15 CET)
(1) Background: After the discovery and application of Chlamydomonas reinhardtii channelrhodopsins, the optogenetic toolbox has been greatly expanded with engineered and newly discovered natural channelrhodopsins. However, channelrhodopsins of higher Ca2+ conductance or more specific ion permeability are still in demand. (2) Methods: In this study, we mutated the conserved aspartate of the transmembrane helix 4 (TM4) within Chronos (Stigeoclonium helveticum channelrhodopsin = ShChR) and PsChR (Platymonas subcordiformis channelrhodopsin) and compared them with published ChR2 (C. reinhardtii channelrhodopsin-2) aspartate mutants. (3) Results: We found that the ChR2 D156H mutant (XXM) showed enhanced Na+ and Ca2+ conductance, which was not noticed before, while the D156C mutation (XXL) influenced the Na+ and Ca2+ conductance only slightly. Furthermore, the D173H mutant of PsChR showed a much improved photocurrent, compared to wildtype, and even higher Na+ selectivity to H+ than XXM. PsChR D173H also showed a strongly enhanced Ca2+ conductance, more than 2-fold that of the calcium translocating L132C of ChR2 (CatCh). (4) Conclusions: We found that mutating the aspartate of the TM4 to histidine influences the ion selectivity of channelrhodopsins. With the large photocurrent and enhanced Na+ selectivity and Ca2+ conductance, XXM and PsChR D139H are promising powerful optogenetic tools, especially for Ca2+ manipulation.
ARTICLE | doi:10.20944/preprints201703.0079.v2
Online: 21 April 2017 (07:36:43 CEST)
A reduction in population sodium (as salt) consumption is one of the most cost-effective strategies to reduce the burden of cardiovascular disease and it is a global health priority. High potassium intake is also recommended to reduce cardiovascular disease. To establish effective policies for setting targets and monitoring effectiveness within each country, the current level of consumption should be known. Greece lacks data on actual sodium and potassium intakes. The aim of the present study was therefore to assess dietary salt (using sodium as biomarker) and potassium intakes in a sample of healthy adults in northern Greece and to determine whether adherence to a Mediterranean diet is related to different sodium intakes or sodium-to-potassium ratio. A cross-sectional survey was carried out in Thessaloniki greater metropolitan area (northern Greece) (n=252, aged 18-75 years, 45.2% males). Participants’ dietary sodium and potassium intakes were determined by 24h urinary sodium and potassium excretions. In addition, we estimated their adherence to Mediterranean diet by the use of an 11-item MedDietScore (range 0-55). The mean sodium excretion was 175 (SD 72) mmol/day, equivalent to 4,220 (1,745) mg of sodium or 10.7 (4.4) g of salt per day and potassium excretion was 65 (25) mmol/day, equivalent to 3,303 (1,247) mg/day. Men had higher sodium and potassium excretions compared to women. Only 5.6% of the sample had salt intake <5g/d, which is the target intake recommended by the WHO. Mean sodium-to-potassium excretion ratio was 2.82 (1.07). There was no significant difference in salt or potassium intake or their ratio across MedDietScore quartiles. No significant relationships were found between salt intake and adherence to Mediterranean diet, suggesting that the perception of the health benefits of the Mediterranean diet does not hold when referring to salt consumption. These results suggest the need for a larger nation-wide survey on salt intake in Greece and underline the importance of continuation of salt reduction initiatives in Greece.
ARTICLE | doi:10.20944/preprints202201.0046.v1
Subject: Life Sciences, Biophysics Keywords: voltage-gated sodium channels; cardiac sodium channels; SCN5A; veratridine; toxins; molecular docking; Rosetta; electrophysiology; site-directed mutagenesis
Online: 5 January 2022 (18:02:52 CET)
The cardiac sodium ion channel (NaV1.5) is a protein with four domains (DI-DIV), each with six transmembrane segments. Its opening and subsequent inactivation results in the brief rapid influx of Na+ ions resulting in the depolarization of cardiomyocytes. The neurotoxin veratridine (VTD) inhibits NaV1.5 inactivation resulting in longer channel opening times, and potentially fatal action potential prolongation. VTD is predicted to bind at the channel pore, but alternative binding sites have not been ruled out. To determine the binding site of VTD on NaV1.5, we performed docking calculations and high-throughput electrophysiology experiments. The docking calculations identified two distinct binding regions. The first site was in the pore, close to the binding site of NaV1.4 and NaV1.5 blocking drugs in experimental structures. The second site was at the “mouth” of the pore at the cytosolic side, partly solvent-exposed. Mutations at this site (L409, E417, and I1466) had large effects on VTD binding, while residues deeper in the pore had no effect, consistent with VTD binding at the mouth site. Overall, our results suggest a VTD binding site close to the cytoplasmic mouth of the channel pore. Binding at this alternative site might indicate an allosteric inactivation mechanism for VTD at NaV1.5.
ARTICLE | doi:10.20944/preprints202205.0385.v1
Subject: Medicine & Pharmacology, Nutrition Keywords: genetics of alcohol; urinary sodium; cardiovascular traits
Online: 30 May 2022 (03:34:20 CEST)
Abstract Background: Alcohol consumption is linked to urinary sodium excretion and both of these traits are linked to hypertension and cardiovascular diseases (CVDs). The interplay between alcohol consumption and sodium on hypertension, and cardiovascular diseases (CVDs) is not well-described. Here, we used genetically predicted alcohol consumption and explored relationships between alcohol consumption, urinary sodium, hypertension, and CVDs. Methods: We performed a comparative analysis among 295,189 participants from the prospective cohort of the UK Biobank (baseline data collected between 2006 and 2010). We created a genetic risk score (GRS) using 105 published genetic variants in Europeans that were associated with alcohol consumption. We explored relationships between GRS, alcohol consumption, urinary sodium, blood pressure traits, and incident CVD. We used linear, logistic regression and Cox proportional hazards (PH) models in our analysis. Results: Our analyses supported an interaction effect between alcohol GRS and urinary sodium on hypertension (P interaction =0.03) and CVD (P interaction =0.03). In presence of high urinary sodium excretion, alcohol GRS increases blood pressure in a more enhanced fashion. Conclusions: Our results show that decrease in urinary sodium excretion offsets the risk posed by genetic risk of alcohol consumption.
ARTICLE | doi:10.20944/preprints201810.0234.v1
Subject: Medicine & Pharmacology, Nutrition Keywords: sodium levels; processed meat; food reformulation; Australia
Online: 11 October 2018 (08:12:31 CEST)
High sodium intake increases blood pressure and consequently increases the risk of cardiovascular diseases. In Australia, the best estimate of sodium intake is 3840 mg sodium/day, almost double the World Health Organization guideline (2000 mg/day), and processed meats contribute approximately 10% of daily sodium intake to the diet. This study assessed the median sodium levels of 2510 processed meat products, including bacon and sausages, available in major Australian supermarkets in 2010, 2013, 2015 and 2017, and assessed changes over time. The median sodium content of processed meats in 2017 was 775 mg/100 g (IQR 483–1080). There was an 11% reduction in the median sodium level of processed meats for which targets were set under the government’s Food and Health Dialogue (p < 0.001). This includes bacon, ham/cured meat products, sliced luncheon meat and meat with pastry categories. There was no change in processed meats without a target (median difference 6%, p = 0.093). The new targets proposed by the current government’s Healthy Food Partnership, capture a larger proportion of products than the Food and Health Dialogue (66% compared to 36%) and a lower proportion of products are at or below the target (35% compared to 54%). These results demonstrate that voluntary government targets can drive nutrient reformulation. Future efforts will require strong government leadership and robust monitoring and evaluation systems.
ARTICLE | doi:10.20944/preprints202203.0082.v1
Subject: Biology, Plant Sciences Keywords: Hydro-priming; lettuce; Sodium chloride; synchronization; electrolyte leakage
Online: 4 March 2022 (13:44:53 CET)
Seed germination is the most sensitive stage to abiotic stress, including salt stress (SS). SS affects plant growth and performance through ion toxicity, decreases seed germination percentage, and increases the germination time. Several priming treatments were used to enhance germination under SS. The objectives of this study are to 1) identify priming treatments to shorten the emergence period; 2) evaluate priming treatments against the SS; 3) induce synchronized seed germination. Salt-sensitive “Burpee bibb’ lettuce seeds were treated with 0.05% Potassium nitrate, 3 mM Gibberellic acid, and distilled water (HP). All the primed and non-primed seeds were subjected to 100 mM NaCl or 0 mM NaCl. The 7-day experiment arranged in a complete randomized block design with four replications was conducted in a growth chamber maintained with 16/8 h photoperiod (light/dark), 60% relative humidity, and day/night temperature of 22/18 °C. The result indicated that HP seeds were better synchronized under SS. Similarly, FM and DM of cotyledon, hypocotyl, and radicle were highest in HP lettuce regardless of SS. Electrolyte leakage was the lowest in the HP lettuce, while other priming methods under SS increased membrane permeability leading to osmotic stress and tissue damage. Overall, the HP can be a suitable priming method to synchronize germination and increase FM and DM by creating the least osmotic stress and ion toxicity in lettuce under SS.
ARTICLE | doi:10.20944/preprints202107.0664.v1
Subject: Materials Science, Biomaterials Keywords: sodium alginate; microsphere; ultrasonic atomization; Dox; pH-adjusted
Online: 29 July 2021 (14:07:33 CEST)
The objective of this study aimed to develop biodegradable calcium alginate microspheres carrying doxorubicin (Dox) at the micrometer-scale for sustained-release and the capacity of pH regulatory for transarterial chemoembolization. Ultrasonic atomization and CaCl2 cross-linking technologies were used to prepare the microspheres. A 4 by 5 experiment was first designed to identify imperative parameters. The concentration of CaCl2 and the flow rate of the pump were found to be critical to generate microspheres with a constant volume median diameter (~ 39 m) across 5 groups with different alginate:NaHCO3 ratios using each corresponding flow rate. In each group, the encapsulation efficiency was positively correlated to the Dox-loaded efficiency. Fourier-transform infrared spectroscopy showed that NaHCO3 and Dox were step-by-step incorporated into the calcium alginate microspheres successfully. Microspheres containing alginate:NaHCO3 = 1 exhibited rough and porous surfaces, high Young’s modulus and hardness. In each group with the same alginate:NaHCO3 ratio, the swelling rates of microspheres were higher in PBS containing 10% FBS compared to those in PBS alone. Microspheres with relative high NaHCO3 concentrations in PBS containing 10% FBS maintained better physiological pH and higher accumulated Dox release ratios. In two distinct hepatocellular carcinoma-derived cell lines, treatments with microspheres carrying Dox demonstrated that the cell viabilities decreased in groups with relative high NaHCO3 ratios in time- and dose-dependent manners. Our results suggested that biodegradable alginate microspheres containing relative high NaHCO3 concentrations improved the cytotoxicity effects in vitro.
ARTICLE | doi:10.20944/preprints202009.0057.v1
Subject: Chemistry, Applied Chemistry Keywords: Chromium; precipitation; tanning; leather industries; wastewater; sodium hydroxide
Online: 3 September 2020 (04:54:26 CEST)
Abstract The global concern about the leather industries is increasing as the leather industries grow bigger each year. These industries face a very challenging task with an increase in stringent pollution control regulation enforced by various bodies due to environmental concern and human risks. The chromium salts are the most widely used chemical for the tanning process in leather industries, about 35% of chromium used for the tanning process remain as metal and discharge to wastewater stream. The removal and recovery of this quantity of wasted chromium are necessary for environmental pollution control and economic reason. This paper sheds light on the chromium recovery and reuse system of Chromium salts in tanning wastewater by using NaOH as an effective chemical precipitation method to regenerate chromium solution, adapted chrome recovery plant, and evaluated the system technically and economically.
ARTICLE | doi:10.20944/preprints201910.0328.v1
Subject: Medicine & Pharmacology, Nutrition Keywords: Republic of Moldova; salt; sodium; potassium; iodine; population
Online: 29 October 2019 (10:15:58 CET)
In the Republic of Moldova, nearly 90% of all deaths are due to noncommunicable diseases (NCDs), tha majority of which (58%) are caused by cardiovascular disease (CVD). Excess salt (sodium) and inadequate potassium intakes are associated with high CVD. Moreover, salt iodisation is the preferred policy to prevent iodine deficiency and associated disorders. However, there is no survey that has directly measured sodium, potassium and iodine consumption in adults in the Republic of Moldova. The aim is to estimate population sodium, potassium and iodine intakes and explore knowledge, attitudes and behaviour (KAB) towards the use of salt, amongst the adult population in the Republic of Moldova. Proportional random samples of adults were obtained from 28 of the 37 Districts and Municipalities and one Administrative Territorial Unit of Moldova. Participants attended a screening including demographic, anthropometric and physical measurements. Dietary sodium, potassium and iodine intakes were assessed by 24h urinary sodium (UNa), potassium (UK) and iodine (UI) excretions. Creatinine was measured. KAB was collected by questionnaire. Eight hundred and fifty-eight participants (326 men and 532 women, 18–69 years) were included in the analysis (response rate 66%). Mean age was 48.5 yrs (SD 13.8). Mean UNa was 172.7 (79.3) mmoL/day, equivalent to 10.8 g of salt/day and potassium excretion 72.7 (31.5) mmoL/day, equivalent to 3.26 g/day. Men ate more sodium and potassium than women. Only 11.3% of the sample had a salt intake below the World Health Organization (WHO) recommended target of 5 g/day and approximately 39% met WHO targets for potassium excretion (>90 mmoL/day). Whilst 81.7% declared limiting their consumption of processed food and over 70% declared not adding salt at the table, only 8.8% looked at sodium content of food, 31% still added salt when cooking and less than 1% took other measures to control salt consumption. Measures of awareness were significantly more common in urban compared to rural areas. Mean urinary iodine was 225 (SD: 152; median 196) mcg/24h, with no difference between sexes. According to WHO criteria, 41.0% had adequate iodine intake, 28.6% had intake below requirements and 17.8% and 12.6% had above requirement or excessive levels, respectively. Iodine content of salt table was 21.0 (SD: 18.6) mg/kg, with no difference between men and women. However, the content was lower in rural than urban areas (16.7 [SD: 18.6] vs 28.1 [SD: 16.5] mg/kg, p<0.001). There were weak or no correlations between urinary sodium and iodine excretions, and between urinary iodine excretion and iodine concentration in the table salt used in the participants’ households, indicating that in most cases participants were not using iodised salt as their main source of salt, more so in rural areas. In the Republic of Moldova, salt consumption is unequivocally high, potassium consumption is lower than recommended, both in men and in women, whilst iodine intake is still inadequate in 1 in 3 people, although severe iodine deficiency is rare. Salt consumed is often not iodised, with less iodised salt being used in rural areas.
ARTICLE | doi:10.20944/preprints201807.0125.v1
Subject: Medicine & Pharmacology, Dentistry Keywords: Endodontic treatment, Irrigant activation, bacteria, biofilm, Sodium Hypochlorite
Online: 6 July 2018 (17:07:21 CEST)
INTRODUCTION The goal of root canal treatment is to shape and clean the endodontic space, reducing the bacterial load and removing the pulp tissue. Obviously, the action of the endodontic instruments is limited to the main canals, regardless of the complexity of the endodontic space. Consequently, finding the best possible cleaning technique, which can be obtained chemically using irrigation solutions, is a fundamental aid in the endodontic therapy. One of the most commonly used root canal irrigant is sodium hypochlorite (NaOCl), available in various commercial formulations. The effectiveness of NaOCl is undeniable. However, the action of dissolution of the pulp tissue is merely dependent on the concentration and the characteristics of the irrigant itself. AIM The aim of this study is to evaluate the effective concentration of different commercial formulas of sodium hypochlorite, by evaluating the percentage of total chlorine in each product. The dissolution capacity of the pulp tissue of each of the tested products was then analyzed by measuring the required time. MATERIALS AND METHODS Three commercial types of sodium hypochlorite were selected for this study: 5% NaOCl (ACE, Procter & Gamble), 5% NaOCl (N5, Simit Dental) and 6% NaOCl (CanalPro, Coltene). For each product, 10 packages were used, from which samples of the product were taken and 30 x 5 ml tubes were filled. All samples were divided into 3 groups and were analyzed using the DIN EN ISO 7393-2 method and the percentage of total chlorine (expressed as a percentage) was calculated. 40 samples of vital pulp were obtained from teeth freshly extracted for periodontal reasons and stored in physiological solution. In order to unify the size and weight of the samples (0.0001 mg), a microtome and a precision balance (Pro Explorer Ohaus) were used. Each sample, carefully examined by stereomicroscope (40x), was placed in artificial plastic containers and submerged in 0.1 ml of irrigating solution at room temperature (26 ° C). A fourth control group used saline solution as irrigant. Simultaneously with the insertion of the irrigating solution, a digital stopwatch was activated and the time necessary for the complete dissolution of the pulp sample was measured. The data obtained were subjected to statistical analysis. RESULTS The average percentages of chlorine detected for each group were: 4.26% (ACE), 5.16% (N5) and 5.97% (CanalPro). The Kruskal-Wallis test showed statistically significant differences between the different commercial formulations of hypochlorite (P <0.05). CanalPro showed the lowest values, while ACE showed the highest values of dissolution time of the pulp. DISCUSSION The analysis of the total chlorine percentage found that the actual concentration of the sodium hypochlorite in the samples is close to the values declared by the manufacturers both in the case of N5 and CanalPro. On the contrary, the concentration detected in the samples of common bench bleach (ACE) is significantly lower, which has average values less than 5%. This explains the longer time taken for the complete dissolution of the pulp tissue. The average dissolution time of the pulp samples was in fact inversely proportional to the concentration detected in the tested irrigants, so that a lower time corresponds to a higher concentration.
ARTICLE | doi:10.20944/preprints201806.0178.v1
Subject: Biology, Animal Sciences & Zoology Keywords: NSAIDs; salicylic acid; sodium salicylate; HPLC; sheep; pharmacokinetics
Online: 12 June 2018 (09:35:41 CEST)
The pharmacokinetics of salicylic acid (SA) in sheep was evaluated following intravenous (IV) and oral administration of sodium salicylate (sodium salt of salicylic acid) at different doses. Six healthy sheep were administered sodium salicylate (SS) IV at doses of 10, 50, 100 and 200 mg/kg body weight and another six sheep were drenched with 100 and 200 mg/kg of SS orally. Both studies were randomised crossover trials. A one-week washout period between each treatment was allowed in both studies. Blood samples were collected at 0, 15, 30 minutes and 1, 2, 4 and 6 hours after IV and oral SS administrations. Plasma SA concentrations were determined using high performance liquid chromatography with diode array detection method. Pharmacokinetic variables were calculated in a non-compartmental model. The elimination half-life (T1/2 el) of SA after IV administration of 200 mg/kg SS was 1.16 ± 0.32 hours. Mean bioavailability of SA was 64%, and mean T1/2 el was 1.90 ± 0.35 hours, after 200 mg/kg of oral SS. The minimum plasma SA concentration (16.8 µg/mL) required to produce analgesia in humans was achieved after IV administration of 100 and 200 mg/kg SS in sheep for about 0.17 hour in this study. Experiments on pharmacokinetic-pharmacodynamics modelling are required to determine the actual effective plasma concentration range of SA in sheep.
ARTICLE | doi:10.20944/preprints202112.0166.v1
Subject: Biology, Animal Sciences & Zoology Keywords: methyl sulfonyl methane; sodium sulfate; laying hen; antioxidant capacity
Online: 10 December 2021 (08:32:41 CET)
The present study was conducted to investigate the comparative effects of organic and inorganic forms of sulfur, methyl sulfonyl methane (MSM) and sodium sulfate (SS), on laying performance, egg quality, ileal morphology, ileal volatile fatty acids, and antioxidant and stress markers in various biological samples in aged laying hens. A total of 144, 73-week-old Lohman Brown-Lite laying hens were randomly assigned to one of three experimental diets: basal diet (CONT), CONT + 0.2% MSM (MSM), and CONT + 0.3% SS (SS). The trial lasted for 12 weeks. MSM and SS groups contained 0.07% of sulfur, either organic or inorganic. Dietary MSM did not affect egg production and feed conversion ratio at 12 weeks compared with the CONT group. Dietary sulfur did not affect egg quality except for Haugh unit at 4 weeks which was lowered (P < 0.05) in the SS group. Compared with the CONT group, higher (P < 0.05) villus height and crypt depth ratio was observed in the SS group. None of dietary sulfur affected the percentages of short-chain fatty acids in the ileum. Total antioxidant capacity of liver increased (P < 0.05) in laying hens fed MSM- and SS-added diets compared with the CONT group. The MSM and SS groups lowered (P < 0.05) malondialdehyde (MDA) concentration in serum samples compared with the CONT. Finally, dietary MSM had the lowest (P < 0.05) MDA concentrations in yolk samples. Taken together, our study showed that dietary organic and inorganic sulfur have positive effects on ileal morphology and antioxidant capacity in laying hens. However, SS-mediated inhibition in laying performance needs to be clarified.
ARTICLE | doi:10.20944/preprints202105.0368.v1
Subject: Earth Sciences, Atmospheric Science Keywords: sodium selenate; zinc sulfate; cereal; rainfed conditions; forage yield
Online: 17 May 2021 (07:54:59 CEST)
Millions of people worldwide have an inadequate intake of selenium (Se) and zinc (Zn), and agronomic biofortification may minimise these problems. To evaluate the efficacy of combined foliar Se and Zn fertilisation in bread making wheat (Triticum aestivum L.), foliar Se (as NaSeO4) and soil and foliar Zn applications (as ZnSO4·7H2O) were tested individually and in all combinations. A 2-year field experiment was established in southern Spain under semiarid Mediterranean conditions, by following a split-split-plot design. The study year (2017/2018, 2018/2019) was considered as the main-plot factor, soil Zn application (50 kg Zn ha-1, nil Zn) as a subplot factor, and foliar application (nil, 10 g Se ha-1, 8 kg Zn ha-1, 10 g Se ha-1 + 8 kg Zn ha-1) as a sub-subplot factor. The best treatment to increase both Zn and Se concentration in both straw, 12.3- and 2.7-fold respectively, and grain, 1.2- and 4.1-fold respectively was the combined foliar application of Zn and Se. This combined Zn and Se application also increased on average the yield of grain, main product of this crop, by almost 26%. Therefore, bread-making wheat seems to be a very suitable crop to be used in biofortification programs with Zn and Se to alleviate their deficiency in both, people when using its grain and livestock when using its straw.
ARTICLE | doi:10.20944/preprints202104.0047.v2
Subject: Materials Science, Biomaterials Keywords: Hydrogels; Sodium alginate; Betamethasone; Drug delivery; Cartilage tissue engineering
Online: 6 April 2021 (10:03:04 CEST)
Hydrogels obtained from the combination of different polymers are an interesting strategy for the development of controlled release system platforms and tissue engineering scaffolds. In this study, the applicability of sodium alginate-g-(QCL-co-HEMA) hydrogels for these biomedical applications was evaluated. Hydrogels were synthesized by free-radical polymerization using different concentration of the components. The hydrogels were characterized by Fourier transform infrared spectroscopy, scanning electron microscopy, and swelling degree; betamethasone release as well as the in vitro cytocompatibility with chondrocytes and fibroblast cells were also evaluated. Scanning electron microscopy confirmed the porous surface morphology of the hydrogels in all cases. The swelling percent was determined at different pH and was observed to be pH-sensitive. The controlled release behavior of betamethasone from the matrices was investigated in PBS media (pH = 7.4) and the drug was released in a controlled manner up to 8 h. Human chondrocytes and fibroblasts were cultured on the hydrogels. The MTS assay shown that almost all hydrogels are cytocompatibles and an increase the proliferation in both cell types after one week of incubation was observed by Live/Dead® assay. These results demonstrate that these hydrogels are attractive materials for pharmaceutical and biomedical applications due to their characteristics, their release kinetics and biocompatibility.
ARTICLE | doi:10.20944/preprints202012.0251.v1
Subject: Materials Science, Biomaterials Keywords: poplar; glucose resin; sodium silicate; impregnation modification; wood properties
Online: 10 December 2020 (11:34:11 CET)
In order to improve the performance of soft plantation wood, an environmentally friendly inorganic-organic hybrid wood modifier was developed. First, using urea and melamine as crosslinking agents, the waterborne glucose silicone resin (MUG) was prepared with glucose under the catalysis of inorganic acid and metal ions. Then MUG resin was diluted to 10% and 20% mass fraction, and compounded with sodium silicate (S) of 20% and 10% mass fraction, so the inorganic-organic hybrid G10S20 and G20S10 wood modifier were obtained respectively. Then plantation poplar wood (Populus tomentosa) were impregnated and modified with them. Their physical and mechanical properties were tested and compared with those of the wood treated with S of 20% mass fraction (S20). Infrared analysis showed that amino resin characteristic structure (CO-NH-) existed in MUG resin. The resin has good permeability. Compared with S20 modified wood, the degree of shrinkage of G10S20 or G20S10 modified wood is reduced, their moisture absorption is reduced, and their dimensional stability is improved. Waterborne glucose silicone modifier can effectively improve the wood density, modulus of elasticity, modulus of rapture and compression strength. SEM analysis showed that the cell wall of G20S10 modified wood was significantly thicker than the untreated wood, and there were columnar and granular solid substances attached in some cell cavities, ducts and corners, etc. EDX showed that the number of Si elements on the cell wall was significantly increased compared with the control, indicating that the modifier effectively entered the wood cell wall. The waterborne glucose silicone resin can greatly improve the physical and mechanical properties of wood through organic-inorganic hybridization. It is a green, non-formaldehyde, eco-friendly, low cost, compound wood modifier with broad application prospects.
ARTICLE | doi:10.20944/preprints202001.0234.v1
Subject: Materials Science, Nanotechnology Keywords: Full Factorial Design; Optimization; metronidazole; nanocomposites; sodium alginate; Chitosan
Online: 21 January 2020 (09:58:09 CET)
The purpose of this study was to investigate the effect of chitosan (CS) and Alginate (Alg) polymers concentrations and CaCl2 concentration on metronidazole (MET) drug loading (LE), size particles and zeta potential. Nanocomposites were prepared by ionotropic pregelation method. A (21 *31 *21) *3= 36 full factorial design (FFD) was used to predict statistical equation and responses. The MET-CS-AlgNPs nanocomposites were characterized by X-ray diffraction, Fourier-transform infrared spectroscopy, thermal gravimetric analysis, scanning electron microscope and in vitro drug release studies. All data indicated the presence of drug into MET-CS-AlgNPs nanocomposites. The release profile of MET-CS-AlgNPs nanocomposites was found to be sustained
ARTICLE | doi:10.20944/preprints201811.0459.v1
Subject: Materials Science, General Materials Science Keywords: Lithium-Ion Battery; Cathode Material; Spinel LiMn2O4; Sodium Substitution
Online: 19 November 2018 (11:30:42 CET)
Sodium substitution Li1-xNaxMn2O4 cathodes were synthesized by a solid-state reaction method. The morphologies and crystal structures of Li1-xNaxMn2O4 were characterized by scanning electron microscopy (SEM) and X-ray diffraction (XRD), respectively. All Li1-xNaxMn2O4 samples exhibited a single phase LiMn2O4 spinel structure with good crystallinity. The effect of Na+ ions on the electrochemical performance of Li1-xNaxMn2O4 was investigated by galvanostatic charge-discharge test. The results showed that lithium substituted by sodium deteriorated its capacity retention but enhance its discharge capacity when it worked at large current densities. The initial discharge capacity was 114.2 mAh/g for Li0.94Na0.06Mn2O4, and 93.1 mAh/g remained after 300 cycles at a current density of 2220 mA/g in the voltage range 3.0–4.3 V at room temperature.
ARTICLE | doi:10.20944/preprints201808.0061.v1
Subject: Medicine & Pharmacology, Nutrition Keywords: Asian Americans; child; diet; eating; feeding behavior; sodium, dietary
Online: 3 August 2018 (05:05:05 CEST)
Obesity has been identified as an emerging health concern for Chinese American children; however, very little is known about diets in Asian American children. The objective of our paper was to describe the dietary intakes of urban Chinese American schoolchildren using a state-of-the-art approach for dietary assessment. Data for this analysis come from the Food Journal Project 2017, a pilot and feasibility study conducted by a multi-sector collaboration. Children aged 8-12 (n=83) completed two dietary assessments using a food diary from January-June 2017. Children were then interviewed using the food diary as a guide and dietary data were entered into the online ASA24 system by study staff. Chinese American children were identified using surname, and were compared to non-Chinese peers with respect to nutrient intake and the Healthy Eating Index 2010 (HEI-2010). Chinese American children consumed more sodium dense diets, more protein, and less sugar compared to non-Chinese children. With regards to the HEI-2010, Chinese American children had less favorable whole grains and sodium scores; and more favorable seafood protein and empty calories scores compared to non-Chinese children. Sodium reduction and increasing whole grain intakes may be warranted in this group, but should be verified with additional studies.
ARTICLE | doi:10.20944/preprints201807.0384.v1
Subject: Medicine & Pharmacology, General Medical Research Keywords: Flavonoids, nitric oxide, heart, kidney, sodium balance, phenylephrine, acetylcholine
Online: 20 July 2018 (12:57:00 CEST)
We have evaluated the antihypertensive effect of several flavonoid extracts in the spontaneous hypertensive rat model (SHR). Treatments were carried out for 6 and 12 weeks in two groups of SHR rats which received Apigenin, Lemon Extract, Grapefruit + Bitter Orange (GBO) extracts and Cocoa extract. Captopril was used as a positive control in the SHR group treated for 6 weeks (SHR6) and Diosmin was used as the industry reference in the SHR group treated for 12 weeks (SHR12). Captopril and GBO extracts significantly reduced the elevated blood pressure of the SHR6 animals, but none of the extracts was effective in the SHR12 group. Apigenin, LE, GBO and captopril also ameliorated nitric oxide-dependent and independent aortic vascular relaxation and elevated plasma and urinary excretion of nitrites, only in the SHR6 group. Kidney and urinary TBARS were also significantly reduced by GBO in the SHR6 rats. Apigenin also improved vascular relaxation in the SHR12 group and all the flavonoids studied reduced urinary TBARS excretion and proteinuria. Vascular abnormalities such as lumen/wall ratio in coronary arteries and thoracic aorta were moderately improved by these treatments in the SHR6 group. In conclusion, the flavonoids included in this study, especially apigenin, LE and GBO improved vascular vasodilatory function of young adult SHRs but only the GBO-treated rats benefited from a reduction in BP. These extracts may be used as functional food ingredients with a moderate therapeutic benefit, especially in the early phases of arterial hypertension.
ARTICLE | doi:10.20944/preprints201806.0024.v1
Subject: Materials Science, Nanotechnology Keywords: magnetic nanoparticles; sodium polyacrylate; nanocomposites; draw solutes; forward osmosis
Online: 4 June 2018 (08:43:01 CEST)
Aqueous dispersions of magnetic nanocomposites have been proposed as draw electrolytes in forward osmosis. One possible approach for the production nanocomposites based on magnetite nanoparticles and sodium polyacrylate, is the synthesis of the magnetic iron oxide by coprecipitation or oxidative precipitation in presence of an excess of the polymer. In this work we explored the effect of the polymer proportion on the nanomaterials produced by these procedures. The materials obtained were compared s with the obtained by the coating of magnetite nanocrystals produced beforehand with the same polymer. The samples were characterized by chemical analysis, photon correlation spectroscopy, thermogravimetry, X-ray diffraction, infrared spectroscopy, transmission electron microscopy and magnetometry. The general trend observed is that part of the polymer is incorporated to the magnetic material during the synthesis heavily modifying its texture, with a drastic reduction of the particle size and magnetic response. The aqueous dispersions of the nanocomposites were highly stable with hydrodynamic size roughly independent on the polymer proportion. Their osmotic pressure proportional to the concentration of the polyelectrolyte, was similar than the generated by the equivalent amount of free polymer in the case of samples generated by oxidative precipitation and smaller in the case of samples generated by coprecipitation. Finally the possibilities of using these materials as draw electrolytes in forward osmosis will be briefly discussed.
ARTICLE | doi:10.20944/preprints201803.0060.v1
Subject: Medicine & Pharmacology, Pharmacology & Toxicology Keywords: flavonoids; nitric oxide; heart; kidney; sodium balance; phenylephrine; acetylcholine
Online: 8 March 2018 (03:31:29 CET)
1) Background: we have evaluated the antihypertensive effect of several flavonoid extracts in a rat model of arterial hypertension caused by chronic administration (6 weeks) of the nitric oxide synthesis inhibitor, L-NAME. 2) Methods: Sprague Dawley rats received L-NAME alone or L-NAME plus flavonoid-rich vegetal extracts (Lemon, Grapefruit + Bitter Orange, and Cocoa) or purified flavonoids (Apigenin and Diosmin) for 6 weeks. 3) Results: L-NAME treatment resulted in a marked elevation of blood pressure, and treatment with Apigenin, Lemon Extract, and Grapefruit + Bitter Orange extracts significantly reduced the elevated blood pressure of these animals. Apigenin and some of these flavonoids also ameliorated nitric oxide-dependent and independent aortic vasodilation and elevated nitrite urinary excretion. End-organ abnormalities such as cardiac infarcts, hyaline arteriopathy and fibrinoid necrosis in coronary arteries and aorta were improved by these treatments, reducing the end-organ vascular damage. 4) Conclusions: the flavonoids included in this study, specially apigenin, may be used as functional food ingredients with potential therapeutic benefit in arterial hypertension.
REVIEW | doi:10.20944/preprints201709.0026.v1
Subject: Biology, Physiology Keywords: conotoxin; µ-conotoxin; ion current; sodium channel; pain transmission
Online: 8 September 2017 (08:22:26 CEST)
The Conus genus includes around 500 species of marine mollusks with a peculiar production of venomous peptides known as conotoxins (CTX). Each species is able to produce up to 200 different biological active peptides. Common structure of CTX is the low number of aminoacids stabilized by disulfide bridges and post-translational modifications that give rise to different isoforms. µ and µ-O CTX are two isoforms that specifically target voltage-gated sodium channels. These, by inducing the entrance of sodium ions in the cell, modulate the neuronal excitability by depolarizing plasma membrane and propagating the action potential. Hyperxcitability and mutations of sodium channels are responsible for perception and transmission of inflammatory and neuropathic pain states. In this review, we describe the current knowledge of µ-CTX interacting with the different sodium channels subtypes, the mechanism of action and their potential therapeutic use as analgesic compounds in the clinical management of pain conditions.
ARTICLE | doi:10.20944/preprints201707.0093.v1
Subject: Keywords: triiodide; antibacterial activity; antifungal activity; sodium; crown ether complex
Online: 31 July 2017 (15:25:01 CEST)
New antibacterial agents are needed to overcome the increasing number of infectious diseases caused by pathogenic microorganisms due to the emergence of multi-drug resistant strains. In this context, halogens, especially Iodine is known since ages for its antimicrobial activity. Therefore, especially triiodides encapsulated in organometallic complexes can be helpful as new agents against microorganisms. The aims of this work was to study the biological activity of [Na(12-Crown-4)2]I3 against gram positive Streptococcus pyogenes, Streptococcus faecalis, the spore forming bacteria Bacillus subtilis and gram negative bacteria Escherichia coli, Proteus mirabilis, Pseudomonas aeruginosa and Klebsiella pneumoniae, as well as the yeast Candida albicans. The antimicrobial and antifungal activities of the triiodide were determined by zone of inhibition plate studies. [Na(12-Crown-4)2]I3 exhibited potent antimicrobial activity on gram positive Streptochocci and the yeast C. albicans. Furthermore, the gram negative bacteria P. aeruginosa and K. pneumoniae were less effectively inhibited, while E. coli and P. mirabilis proved to be even resistant.
ARTICLE | doi:10.20944/preprints201906.0197.v1
Subject: Materials Science, Nanotechnology Keywords: L-ascorbic acid; Sodium alginate; Gum arabic; Spray-drying; Encapsulation
Online: 20 June 2019 (10:24:11 CEST)
The potential of sodium alginate (ALG) and gum arabic (GA) as wall polymers for L-ascorbic acid (AA) encapsulation as a tool for their preservation against the thermo-oxidative degradation was investigated. The influence of such polymers used as wall material on the AA-content, size, encapsulation efficiency, encapsulation yield and thermo-oxidative stability were evaluated. The AA-microparticles were obtained using the spray-drying technique. An experimental Taguchi design was employed to assess the influence of the variables in the encapsulation process. The microparticles morphology and size distribution were characterized by scanning electron microscopy and laser diffraction. The thermal stability of AA microparticles was studied by differential scanning calorimetry and thermogravimetry analysis. This work points out the viability to encapsulate AA using GA and ALG through a spray-drying process. In general, a product yield ranging from 35.1% to 83.2% and an encapsulation efficiency above 90% was reached. Spherical microparticles with a smooth surface were obtained with a mean diameter around 6 μm and 9 μm for the those prepared with GA and ALG, respectively. The thermo-oxidative analysis showed that both polymers allow maintaining AA stable up to 188 °C, which is higher than the traditional processing temperature used in the fish feed industry.
ARTICLE | doi:10.20944/preprints201810.0395.v1
Subject: Chemistry, Electrochemistry Keywords: sodium rechargeable battery; polymer electrolyte; Nafion; cycle stability; electrochemical stability
Online: 18 October 2018 (04:16:01 CEST)
The possibilities of manufacturing batteries with Nafion 117 membranes in the Na+-form intercalated by mixtures of non-aqueous organic solvents used both as electrolyte, separator and binder were investigated. Electrochemical stability of various organic solvent mixtures based on N,N-dimethylacetamide, ethylene carbonate, propylene carbonate, tetrahydrofuran was characterized. It was shown that sodium battery based on Nafion-Na membrane intercalated by mixture of ethylene carbonate ‑ propylene carbonate with Na3V1.9Fe0.1(PO4)3/C positive electrode is characterized by a discharge capacity of ca. 110 mAh g-1 (C/10) at room temperature and shows the ability to cycle for a long time. Batteries with Nafion membrane electrolytes, containing N,N-dimethylacetamide were characterized by capacity fading during cycling, which is due to the interaction of N,N-dimethylacetamide and a negative sodium electrode.
ARTICLE | doi:10.20944/preprints201808.0532.v1
Subject: Chemistry, General & Theoretical Chemistry Keywords: MDR transporters; MATE family; NorM; MD simulation; loops; sodium ions
Online: 30 August 2018 (14:43:53 CEST)
The multidrug resistance transporter NorM is an important drug resistance pump and plays a critical role in multidrug resistance in bacteria and mammals. In this study we carried out molecular dynamics simulation to study the mechanism of Na+ binding and dynamical structures of two long loops in the substrate-releasing process in substrate binding NorM. Our simulation study identified several key residues (D41, E261 D377) along the Na+ binding pathway and a multi-state ion-binding mechanism is proposed based on the simulation study. In this proposed model, the transport of Na+ is a multi-stage process with D41 being the first station for binding to Na+, followed by Na+ binding to the second station E262 and finally to the cation-binding site of E262 and D377. During the transport of Na+, the transmembrane components TM1, TM7 and TM2 are rearranged to facilitate the ion transport as well conformational changes of NorM to a closed state. Further, substrate-bound simulation revealed that Loop3-4 and Loop9-10 control the substrate-releasing process.
ARTICLE | doi:10.20944/preprints202108.0132.v1
Subject: Chemistry, Analytical Chemistry Keywords: Sodium ferrate (VI); Oxidation and Coagulation; Neutralization of AMD; Metal removal
Online: 5 August 2021 (09:44:18 CEST)
The screening and treatment of acid mine drainage (AMD) using Na2FeO4 has been explored. Elemental composition was performed using an ICP-OES for the raw and treated AMD. The AMD samples were collected from three different sampling sites (RTW1, RTW2 and RTW3) in Pretoria, South Africa with acidic pH ranging between 2.50 and 3.13. Total dissolved solids and Electrical Conductivity of AMD samples ranged between 960 and > 1000 mg. L-1, 226 and 263 µS. cm-1, respectively. The final pH of treated water samples increased up to ≥ 9.5 after treatment with Na2FeO4. Sodium ferrate showed dual functions by removing metals and raising the pH of the treated water. Concentrations of most trace elements were not complying with WHO and DWAF guideline standards in raw AMD while after treatment with Na2FeO4 the concentrations were below guidelines for domestic and irrigation purposes.
COMMUNICATION | doi:10.20944/preprints202012.0589.v1
Subject: Materials Science, Biomaterials Keywords: mineral suspension; thinner; free radical polymerization; molecular weight regulator; sodium polyacrylate
Online: 23 December 2020 (13:50:07 CET)
The synthesis of additives for thinning mineral suspensions based on sodium polyacrylate was carried out. The effect of molecular weight regulators on the molecular weight characteristics of the polymer and the effect of such polymers on the rheological properties of suspensions was studied. Sodium acrylate polymers are synthesized by free radical polymerization in aqueous solution using molecular weight regulators. The molecular weight characteristics of the polymeric samples were estimated by viscometry using Mark-Houwink-Kuhn-Sakurada (MHKS) equation. Synthesized polymers were used as thinners ceramic slurries, prepared according to the recipe of the enterprises producing ceramic products. The thinning ability of polymer samples with different molecular weights was estimated using an Engler viscometer from the time of the ceramic slurry flow. The influence of the type and amount molecular weight regulator on polyacryates was revealed. It was found that molecular weight synthesized samples was in the range of 21000 - 91000. It was determined that samples with a molecular weight of 28000 - 35000 synthesized using mercaptoethanol (at a dosage of 0.5-1.5% by weight of the monomer) provide optimal fluidity to the ceramic slurry.
ARTICLE | doi:10.20944/preprints202009.0519.v1
Subject: Materials Science, General Materials Science Keywords: fly ash; Geopolymer; silicon dioxid; sodium silicate; sand dune; egg Shell
Online: 22 September 2020 (10:25:07 CEST)
In recent years, the dominant cementitious materials have been industrial by products such as fly ash. This present paper describes some of the cementitious products that are attracting attention in the global research community and the properties and characteristics of these materials that affect their performance such durability, mechanically properties and reduction of carbon dioxid (CO2). The present investigation deals with the chemical synthesis of cementitious material using fly ash of eggs shell rich in calcium(Ca) and sand dune(southern of Algeria) rich in silica(SiO2).The composition is the most compressive resistant with a maximum stress of 49.71 MPa, the most flexible (E = 2.63 GPa) and the most ductile (εr = 65.42 %).The characteristic properties of the chemically synthesized cementitious materials were analyzed by the chemical composition analysis XRF, XRD and SEM analyses.
Subject: Life Sciences, Other Keywords: pharmacology; drug development; sodium channel; potassium channel; TRP channel; HCN channels
Online: 8 August 2019 (12:31:26 CEST)
Ion channels contribute fundamental properties to all cell membranes. The ion channels are highly diverse in conductivity, structure, location and function. However, many of them can be regulated by common mechanisms, such as voltage or (de-)phosphorylation. Considering primarily pain-related ion channels, this review covers more novel and less known features of ion channel function, also with the aim to transfer knowledge between fields, which get inevitably more separate due to their size.
ARTICLE | doi:10.20944/preprints201907.0213.v1
Subject: Materials Science, Nanotechnology Keywords: magnetic nanoparticles, poly-sodium-acrylate, osmotic pressure, forward osmosis, draw solution.
Online: 18 July 2019 (10:02:20 CEST)
The synthesis of magnetic nanoparticles (MNPs) coated with hydrophilic poly-sodium-acrylate ligands (PSA) was studied to assess PSA-MNP complexes as draw solution (DS) solutes in forward osmosis (FO). For MNP-based DS, the surface modification and the size of the MNPs are two crucial factors to achieve a high osmolality. Superparamagnetic nanoparticles (NP) with functional groups attached may represent the ideal DS where chemical modifications of the NPs can be used in optimizing the DS osmolality and the magnetic properties allows for efficient recovery (DS re-concentration) using an external magnetic field. In this study MNPs with diameters of 4 nm have been prepared by controlled chemical co-precipitation of magnetite phase from aqueous solutions containing suitable salts of Fe2+ and Fe3+ under inert atmosphere and a pure magnetite phase could be verified by X-ray diffraction. Magnetic colloid suspensions containing PSA coated MNPs with three different molar ratios of PSA : MNP = 1:1, 1:2 and 1:3 were prepared and assessed in terms of osmotic pressure, aggregation propensity and magnetization. FTIR confirmed the presence of PSA on coated MNPs and pristine PSA-MNPs with a molar ratio PSA : MNP = 1:1 exhibited an osmotic pressure of 30 bar. Molar ratios of PSA : MNP = 1:2 and 1:3 lead to formation of less stabile magnetic colloid solutions which led to formation of aggregates with larger average hydrodynamic sizes and modest osmotic pressures (5.5 bar and 0.2 bar respectively). After purification with ultrafiltration, the 1:1 nanoparticles exhibited an osmotic pressure of 9 bar with no aggregation and a sufficient magnetization of 25 emu/g to allow for DS regeneration using an external magnetic field. However, it was observed that the amount of PSA molecules attached to the MNPs decreased during DS recycling steps leaving only strong chelate bonded core-shell PSA as coating on the MNPs. This demonstrates the crucial role of MNP coating robustness in designing an efficient MNP-based DS for FO.
ARTICLE | doi:10.3390/sci1010032
Subject: Keywords: germination; heteromorphism; imbibition; seed color; seedling growth; sodium chloride; <i>Trifolium pratense</i>
Online: 21 June 2019 (00:00:00 CEST)
The seeds of red clover are heteromorphic and two color morphs can be visually recognized, light purple and yellow, resulting from heterozygosity and recessive homozygosity at two loci. Here, we report the responses of seed imbibition, seed germination, and early seedling growth of the two morphs to distilled water, sodium chloride, and complete nutrient solution. The sensitivity of red clover seeds to treatments increased with the stage of development in what seems to be a cumulative process. No differences were found in seed imbibition between morphs or between treatments. In seedling growth, on the contrary, treatments were always effective, but differences between morphs were only observed in seeds that were treated with nutrient solution, whereas in the intermediate stage of seed germination, the effects by treatments were observed together with the appearance of differences between morphs in distilled water and in the treatment by sodium chloride solution. Simultaneously, the superior performance of the yellow morph that was found in germination, which appears to be a trait stable across cultivars of red clover seeds, turned into a superior performance of the light purple morph in seedling growth.
ARTICLE | doi:10.20944/preprints201809.0575.v1
Subject: Chemistry, Chemical Engineering Keywords: melanin like nanoparticles; sodium periodate; enzymatic activity; layer-by-layer films
Online: 29 September 2018 (04:16:12 CEST)
Polydopamine (PDA) deposition, obtained from the oxidation of dopamine and other catecholamines is an universal way to coat all known materials with a conformal coating which can subsequently be functionalyzed at will. The structural analogies between polydopamine and eumelanin, the black-brown pigment of the skin, incited to produce stable polydopamine nanoparticles in solution instead of amorphous precipitates obtained from the oxidation of dopamine. Herein, we demonstrate that size controlled and colloidally stable PDA based nanoparticles can be obtained in acidic conditions, where spontaneous auto-oxidation of dopamine is suppressed, using sodium periodate as the oxidant and a protein like alkaline phosphatase as a templating agent. The size of the PDA@Alp nanoparticles depends on the dopamine/enzyme ratio and the obtained particles display the enzymatic activity of alkaline phosphatase with an activity extending up to two weeks after particle synthesis. The PDA@ alkaline phosphatase (Alp) nanoparticles can be engineered in polyelectrolyte multilayered films to potentially design model biosensors.
ARTICLE | doi:10.20944/preprints201705.0086.v1
Subject: Materials Science, General Materials Science Keywords: binary liquid alloy; chemical ordering; sodium; theoretical study; Warren-Cowley parameter
Online: 9 May 2017 (11:28:07 CEST)
A simple model has been used to investigate the nature of chemical order in Na-Pb and Na-Hg liquid binary alloy at 700K and 673K respectively. The energy parameter obtained from the model was used to calculate the concentration dependent mixing properties such as Gibb’s free energy of mixing, Concentration fluctuations in the long wavelength limit and the Warren-Cowley chemical short range order parameter. Results obtained showed that both alloys are hetero-coordinated throughout the entire concentration and there is tendency for segregation and demixing to take place in the liquid alloys. We observed that Na-Hg liquid alloy is more strongly interacting binary alloy and chemically ordered than Na-Pb liquid alloy.
ARTICLE | doi:10.20944/preprints202201.0236.v1
Subject: Life Sciences, Other Keywords: apple vinegar; sodium diacetate; high moisture maize grain; aerobic stability; infrared thermography
Online: 17 January 2022 (15:21:36 CET)
This study was carried out to determine the effects of apple vinegar and sodium diacetate addition on the aerobic stability of fermented high moisture maize grain (HMM) silage after opening. In the study, the effect of three different levels (0, 0.5, 1.0%) of apple vinegar (AV) and sodium diacetate (SDA) supplementation to fermented HMM at two different storage conditions (27-29°C, 48% Humidity; 35-37°C, 26% Humidity) were investigated. The material of the study was fermented rolled maize grain with 62% moisture content stored for about 120 days. Silage samples were subjected to aerobic stability test with 3 replicates for each treatment group. Wendee and microbiological analyses were made at 0, 2, 4, 7, and 12 days. Meanwhile, samples were displayed in the T200 IR brand thermal camera. According to the thermogram results, 1% SDA addition positively affected HMM silages at the second and fourth days of aerobic stability at both storage conditions (p<0.05). Aerobic stability and infrared thermography analysis indicated that 1% AV, 0.5%, and 1% SDA additions to HMM silages had promising effects. Due to our results, we concluded that thermal camera images might be used as an alternative quality indicator for silages in laboratory conditions.
ARTICLE | doi:10.20944/preprints202106.0201.v1
Subject: Mathematics & Computer Science, Algebra & Number Theory Keywords: Serum Creatinine; Serum Sodium; Ejection Fraction; Creatinine Phosphokinase; Multicollinearity; Matthew Correlation coefficient.
Online: 8 June 2021 (09:19:02 CEST)
Around the world, every year, about 17 million people death cause happen due to CardioVascular Diseases (CVD). As per clinical records, primarily sufferers exhibit myocardial infarctions and Heart Failures (HF). Creatinine is a Musculo - skeletal waste product. The kidneys filter creatinine from the blood and excrete it through the urine in a healthy body. High creatinine levels can suggest renal problems. Elevated Serum Creatinine (SC) has been well established in the HF. Patients’ electronic medical records can be used to quantify symptoms and other related clinical laboratory test values, which would then be utilized to direct biostatistics exploration to uncover patterns and associations that doctors would otherwise miss. The latest American Heart Association guidelines for 1500 mg/d sodium tend to be sufficiently relevant for patients with stage A and B with HF. In this article, we used a dataset of the year 2015 of heart patients records of 299 patients. The present paper used the data analytic and statistical tools to verify the significant differences between alive and dead patients’ SC and Serum Sodium (SS). It also demonstrates the impact of significant features on abnormal SC and SS on the Survival-Status levels. The Age-Group feature, which is derived from age attribute and, Ejection Fraction (EF), anemia, platelets, Creatinine Phosphokinase (CPK), Blood-Pressure (BP), gender, diabetes, and smoking-status were utilized to determine the potential contributing features to mortality with Cox regression model. The Kaplan Meier plot was used to investigate the overall pattern of survival concerning age-group. During pre-processing of the dataset, Age and SS were removed due to multicollinear features during performing machine learning algorithms experiments. This paper also predicted patients’ survival, age group, and gender using supervised machine learning classifiers. Detection of significant features would help in making informed decisions to balance the lifestyle of heart patients. The author revealed that the patient’s follow-up months, as well as SC, EF, CPK, and platelets, are sufficient key features to predict heart patient survival using Random Forest (RF) stratified 10-fold CV method with accuracy (96%) with 5% Standard Deviation (SD) from medical records dataset. We identified the age-group and gender of the patient, and the RF model outperformed others with the best accuracy 96% and 94% in both cases having 11% SD. Also, prominent features such as CPK, SC, follow-up month, platelets, and ejection were found to be significant factors in predicting the patient’s age-group. Smoking habits, CPK, platelets, follow-up month, and SC of each patient were discovered to be significant predictors of patient gender. The hypothetical study proved that SC and SS making substantial differences in the survival of patients (p < 0.05) and failed to reject that anemia, diabetes, and BP making a significant impact on the creatinine and sodium of each patient (p > 0.05). With χ2(1) = 8.565, the Kaplan Meier plot revealed that mortality was high in the extremely elder age-group. The finding has possible effects on clinical practice and becomes a new medical support system when predicting whether a patient can survive a heart attack or not. The doctor should primarily concentrate on follow-up month, SC and EF, CPK, and platelet count since the aim is to understand whether a patient survives after HF.
ARTICLE | doi:10.20944/preprints201908.0252.v1
Subject: Materials Science, Biomaterials Keywords: Chinese fir wood; sodium silicate; phenol formaldehyde oligomer; respiratory impregnation; comparative study
Online: 25 August 2019 (15:32:30 CEST)
To compare The effects of organic and inorganic impregnation on the properties of unmodified, phenol formaldehyde oligomer-modified (PFOMCF), and sodium silicate-modified Chinese fir wood (SSMCF) were compared using samples prepared using the respiratory impregnation method. Impregnation and reinforcement effects and water resistance of PFOMCF and SSMCF were compared and the results was showed that the weight percentage gain, density increase rate, bending strength, and compressive strength of SSMCF were clearly higher than those of PFOMCF and had a lower water absorption rate within 60 h. The impregnation and reinforcement effects and dimensional stability of SSMCF were better than those of PFOMCF. FT-IR, XRD, CONE, and TGA examinations were used to test and analyze the chemical structure, crystalline structure, flame retardancy, and heat resistance of these modified woods. The results indicated that SSMCF possessed more hydrogen bonds than PFOMCF and that Si–O–Si chemical bonding with high bond energy was formed. Meanwhile, the weakened degree of the diffraction peak of SSMCF was much less than that of PFOMCF. These results explained that the mechanical properties and water resistance of SSMCF were better than PFOMCF. Compared with PFOMCF, SSMCF had a lower heat release rate (HRR), peak-HRR, mean-HRR, total heat release, smoke production rate, and total smoke production as well as higher thermal decomposition temperature and residual rate. Inorganic sodium silicate was shown to be a better flame retardant, while SSMCF had good smoke suppression effects, thermal stability, and safety performance in the case of fire.
ARTICLE | doi:10.20944/preprints201801.0025.v1
Subject: Earth Sciences, Environmental Sciences Keywords: freezing/melting desalination process; aqueous solutions of sodium chloride; theoretical diffusive models
Online: 4 January 2018 (07:08:51 CET)
Considering the important demand of fresh water and its scarce availability, water desalination is an interesting technology, producing about 44 Mm3/year worldwide, but, in general the most common desalination techniques are highly energy demanding. Freezing-Melting (F/M) desalination uses just up to 70% less thermal energy, but is the least used process mainly, due to the difficulty of the salt separation. This study proposes a model able to analyses the thermodynamic potential that allows the salt diffusion during the F/M process, using an aqueous solution of sodium chloride. This should allow to obtain a sensitive analysis of the process to promote the separation between the high concentration brine and the ice with liquid separation by physical process. The unidimensional model is based on the evolution of both processes: thermal and mass diffusions, depending on temperature and saline gradients, predicting whether the salt will remain inside the ice or not. Thus, the thermal potential is adjusted to frozen only when the salt has been "pushed" towards the brine. Mostly models have base their results on the assumption of a “certain value of saline concentration of the liquid fraction”, value in which there is great disagreement. In this paper the calculations are based on the concentration in the solid-liquid interface, which has been extensively studied and there is a coincidence in those results, being the main advantage of the proposed model.
ARTICLE | doi:10.20944/preprints202107.0585.v1
Subject: Medicine & Pharmacology, Other Keywords: Functional receptor; Hepatitis B virus; Polymorphism; Sodium taurocholate co-transporting polypeptide; hepatic fibrosis; Egypt
Online: 26 July 2021 (14:42:42 CEST)
Background: Single nucleotide polymorphisms (SNPs) in the SLC10A1 gene, coding for a functional receptor of hepatitis B virus (HBV), sodium taurocholate co-transporting polypeptide (NTCP), may influence the susceptibility, the outcome, and disease course of HBV infection in some populations. Aim: to determine the prevalence of SNPs of NTCP gene, rs2296651 and rs943277, and their relationship with chronic HBV infection in a group of Egyptian patients. Methods: 137 patients with HBV and 65 healthy controls were enrolled, and the patients were divided into two groups; group I chronic HBV infection (68 patients with normal ALT and minimal or no liver necroinflammation or fibrosis) and group II chronic hepatitis B (69 patients with elevated ALT and moderate or severe liver necroinflammation). They were subjected to full history taking, clinical examination, laboratory investigations, abdominal ultrasound, and liver stiffness measurement using both Echosens® Fibroscan and acoustic radiation force impulse (ARFI). Real time PCR TaqMan 5’ allelic discrimination assay was applied to detect the SNPs in NTCP gene, rs2296651 and rs943277. Results: On studying the rs2296651 variant, all controls and patients had genotype GG without any significant association with HBV infection or disease progression. However, the rs943277 variant in all controls and 98% of patients had genotype GA, except for two chronic HBV infection patients who had genotype AA, but no significant difference between patients and controls was found. The non-invasive methods for liver fibrosis assessment ARFI, AST/platelet's ratio (APRI), and fibrosis-4 score (FIB-4) could predict the stages of fibrosis in agreement with Fibroscan with AUCOR 0.8, 0.79, and 0.76, respectively. Conclusion: These findings may suggest that there is no relation between these SNPs of the NTCP gene and susceptibility or chronicity of HBV infection in the Egyptian population. We also suggest that the use of the non-invasive methods for liver fibrosis assessment, ARFI, FIB-4, and APRI may decrease the need for liver biopsies in prediction of significant hepatic fibrosis in chronic HBV patients.
ARTICLE | doi:10.20944/preprints202010.0187.v1
Subject: Keywords: sodium adsorption ratio; SAR; CROSS, electrical conductivity; specific conductivity; salinity; irrigation; groundwater; water quality
Online: 9 October 2020 (08:45:56 CEST)
Soil water loss by evaporation influences the sodium adsorption ratio (SAR) of irrigation drainage water. Evaporation concentrates sodium and magnesium but calcite precipitation has a more complicated effect on soluble calcium and alkalinity. Here we propose a revised sodicity hazard assessment that quantifies the impact of evaporative water loss and calcite precipitation on drainage water SAR. This paper shows sodicity hazard is determined by the initial composition of irrigation water as originally suggested by previous researchers, and provide a simple, accurate way to identify the potential sodicity hazard of any irrigation water. In particular, the initial equivalent concentration of alkalinity and calcium determine the salinization pathway followed during evaporation. If the irrigation water alkalinity exceeds soluble calcium expressed as equivalent concentrations, drainage water SAR approaches an upper limit determined by the initial relative concentration of sodium and magnesium. If irrigation water alkalinity is less than soluble calcium, drainage water SAR approaches a lower limit determined by the initial calcium, magnesium and sodium. In both cases the SAR is scaled by the square root of the concentration factor √Fc quantifying soil water loss. To assess the impact of evaporation and calcite precipitation on the SAR and test the accuracy of the new sodicity hazard assessment, we evaluated data from previously published lysimeter studies. We plotted water composition boundaries for each source water, comparing these boundaries to the drainage water composition recorded in the lysimeter studies. As salinity increased by evaporation, each drainage water followed a distinct salinization path.
REVIEW | doi:10.20944/preprints201901.0066.v1
Subject: Earth Sciences, Environmental Sciences Keywords: salinity; drinking water sodium (DWS), high blood pressure; maternal health; pond sand filter (PSF)
Online: 8 January 2019 (11:26:40 CET)
Increasing salt intake has substantial negative impacts on health and well-being. This review article focusses on the effect of salinity intrusion (SI) on the water quality and community health of coastal Bangladesh and to find out the effectiveness of interventions for reducing the negative effects of salinity. Saline water is a noteworthy reason for hypertension or high blood pressure in the coastal areas. Health status of women especially the pregnant women are vulnerable because of drinking water sodium (DWS) prompting to pre-eclampsia, high blood pressure and hypertension as well as infant mortality. Several interventions such as rainwater harvesting and Pond sand filter (PSF) system as well as managed aquifer recharge (MAR) usage and the integration of mixed sources were reviewed on the content of drinking water sodium (DWS). Although rainwater has the positive impact of low or no sodium intake on human health, it still possesses negative impacts from not having vital minerals. Despite what might be expected, in MAR a steady increment in sodium concentration through the span of the dry season was observed. It is, subsequently, important to increase awareness about drinking water sodium (DWS) intake by providing and adopting correct technological interventions.
ARTICLE | doi:10.20944/preprints202111.0180.v1
Subject: Earth Sciences, Environmental Sciences Keywords: Electrical Conductivity, Sodium Adsorption Ratio, Salinity, Sodicity, Groundwater Chemistry, Surface Water Chemistry, Irrigation Water Quality
Online: 9 November 2021 (14:08:29 CET)
Seyfe Lake is an important part of the natural ecosystem of Central Anatolia and lies within a 1487 km2 closed basin. Groundwater withdrawal for irrigation and recent climatic change have caused lake area to decrease for decades and to completely disappear briefly in August 2008. Groundwater quality is crucial for sustainable irrigation in the Seyfe Basin. A key finding of this study is the difference in the Hardie-Eugster alkalinity-to-calcium ratio of the lake water and that of most groundwater wells in the basin. This difference in the chemical signature of Seyfe Lake and basin groundwater means the evaporative salinization pathway of most groundwater discharged into the lake cannot account for the composition of Seyfe Lake. The ratio of actual evapotranspiration to precipitation will increase under current climate change projections. A second finding, with implications for soil salinization, is that most groundwater in Seyfe Basin has a Hardie-Eugster alkalinity-tocalcium ratio greater than unity, meaning soil alkalization will accompany soil salinization.
Subject: Life Sciences, Biochemistry Keywords: low intensity exercise; intestine; sodium-dependent glucose transporter; glucose transporter 2; glucagon like peptide 2
Online: 20 April 2021 (11:48:02 CEST)
Exercise affects various organs. However, its effects on nutrient digestion and absorption in the intestinal tract are not well understood. A few studies have reported that exercise training in-creases the expression of carbohydrate digestion and absorption molecules. Exercise was also shown to increase the concentration of blood glucagon like peptide-2(GLP-2), which regulates carbohydrate digestion and absorption in small intestinal epithelium. Therefore, we investigated the effects of exercise on intestinal digestion and absorption molecules and the levels of GLP-2. 6-wk-old of male mice were divided into 2 groups; sedentary (SED) and low-intensity exercise (LEx). LEx mice were required to run on a treadmill (12.5 m/min, 60 min), whereas SED mice rested. All mice were euthanized 1 h after exercise or rest and plasma, jejunum, ileum, and colon were sampled. Samples were analyzed using EIA and immunoblotting. The levels of plasma GLP-2 and the expression of the GLP-2 receptor, sucrase-isomaltase (SI), and glucose transporter (GLUT2) in the jejunum were increased in LEx group. We showed that acute low-intensity exer-cise affects the intestinal carbohydrate digestion and absorption molecules via GLP-2. Our results suggest that exercise might provide new benefits to the small intestine for people with intestinal frailty.
ARTICLE | doi:10.20944/preprints201911.0243.v1
Subject: Life Sciences, Genetics Keywords: adrenergic signaling; ankyrin-B; calcium channel; calcium signaling; glycolysis; oxidative phosphorylation; potassium channel; sodium channel
Online: 20 November 2019 (15:58:20 CET)
Myocardium transcriptomes of mouse left and right atria and ventricles were profiled separately to identify the differences that might be responsible for the distinct functional roles of the four heart chambers. In total, 16,886 distinct unigenes have been quantified in all 16 samples collected from four adult male mice from the same litter. 15.76% of the quantified genes on the left and 16.5% on the right exhibited differential expression between the corresponding atrium and ventricle of the same side, while 5.8% in atria and 1.2% in ventricles were differently expressed between the left and the right. Beyond the differentially expressed genes, the study revealed distinct expression control and coordination of ion channels and genes within the cardiac muscle contraction, oxidative phosphorylation, glycolysis/glucogenesis, calcium and adrenergic signaling pathways. Interestingly, while expression of Ank2 (encoding ankyrin-B) oscillates in phase with all its binding partners in the left ventricle, the percentage of synergistically expressed partners of Ank2 is 15% and 37% in the left and right atria and 74% in the right ventricle. The analysis revealed also the high interventricular synchrony of the expression of ion channels.
ARTICLE | doi:10.20944/preprints202206.0197.v1
Subject: Life Sciences, Other Keywords: sodium chloride; photosystem II; Green Forest; carbon assimilation; salt-sensitive; C3 plant; climate change; abiotic stress
Online: 14 June 2022 (08:04:31 CEST)
Lettuce is a salt-sensitive crop and has a threshold electrical conductivity of 1.3–2.0 mS cm-1 and above that is considered detrimental. As there has been very little information on the physio-logical response of different critical stages of lettuce under different salt stress (SS), the current study is focused on investigating the effects of SS on the critical physiological traits influencing the carbon assimilation in different growth stages of lettuce. The experiment was conducted in deep-water culture hydroponic system in a greenhouse condition. Four levels of sodium chloride salt treatments (EC: 20, 16, 8, and 1.8 mS cm-1) were applied. During both growth stages (day 11 (GS1) and day 19 (GS2) after salt treatment), the leaf transpiration rate, stomatal conductance, and intercellular CO2 were severely decreased. However, the carbon assimilation rate remained unchanged under SS. Similarly, the water use efficiency increased under the SS. It is concluded that the increasing SS increased stomatal and non-stomatal limiting factors during GS1 suggesting the enhanced limitation in photosynthetic activity while no such trend was observed during GS2. The decreased gm with increased SS at GS1 and GS2 suggested that SS induced the irreversible decrease of gm, which in turn can be responsible for the transient reduction in the Vcmax and Jmax during GS2. Taken together, the evidence from this research recommends that varying the SS levels can significantly affect the physiological performance of lettuce at both growth stages.
COMMUNICATION | doi:10.20944/preprints202112.0193.v1
Subject: Medicine & Pharmacology, Nutrition Keywords: hyperlipidic diet; overweight rats; non-alcoholic liver steatosis; arterial hypertension; increased renal sodium reabsorption; hepatocardiorenal syndrome
Online: 10 December 2021 (15:08:53 CET)
Overweight/obesity is a growing pandemic nowadays that affects many organs and tissues. We have investigated whether a high-lipid diet provokes an imbalance between type 1 and type 2 angiotensin II (Ang II) receptors signaling, leading to liver alterations associated with previously described cardiovascular and kidney disturbances. Chronic administration of a high-lipid diet can provoke an hepatocardiorenal syndrome as the result of activation of the Ang II→type 1 receptor axis, which is completely counteracted by Ang-(3–4) the allosteric enhancer of the Ang II→type 2 receptor pathway.
ARTICLE | doi:10.20944/preprints202003.0049.v1
Subject: Materials Science, Polymers & Plastics Keywords: compostable; edible films; Duplex; Triplex Laminates; whey protein; gelatin; sodium alginate; film structure; mechanical; barrier properties
Online: 4 March 2020 (05:05:32 CET)
The objective of this study was to assess the ability of producing laminated edible films manufactured using the following proteins; gelatin (G), whey protein isolate (WPI), and polysaccharide; sodium alginate (SA), and to evaluate their physical properties. Additionally, films’ preparation employing these ingredients was optimized through the addition of corn oil (O), Overall, 8-types of laminated films (G-SA, G-WPI, SA-WPI, SA-G-WPI, GO-SAO, GO-WPIO, SAO-WPIO, SAO-GO-WPIO were developed in this study. The properties of the prepared films were characterized through the measurement of; tensile strength (TS), elongation at break point (EB), puncture resistance (PR), tear strength (TT), water vapour permeability (WVP) and oxygen permeability (OP). The microstructure of cross-sections of laminated films was investigated by scanning electron microscopy (SEM). Mechanical properties of films were dramatically enhanced through the addition of film layers. GO-SAO laminate showed the best barrier properties to water vapour (22.6 ± 4.04 g mm/kPa d m2) and oxygen (18.2 ± 8.70 cm3 mm/kPa d m2). SAO-GO-WPIO laminate film was the strongest of all laminated films tested, having the highest TS of 55.77 MPa, PR of 41.36 N and TT of 27.32 N. SA-G-WPI film possessed the highest elasticity with an EB value of 17.4%.
ARTICLE | doi:10.20944/preprints201809.0544.v1
Subject: Medicine & Pharmacology, Nutrition Keywords: Bodybuilding; Drug Free; Competing; Peaking; Carbohydrate Loading; Water Loading; Sodium Loading; Fat Loading: Vitamin C; Fibre Restriction
Online: 27 September 2018 (12:58:34 CEST)
Bodybuilders utilize peaking strategies in a bid to fine-tune their aesthetics for competition day. The most prevalent peaking strategies utilized by natural bodybuilders are unreported in the current literature. Eighty-one (M - 59, F - 22) natural bodybuilders were recruited from competitions during the 2016 and 2017 British Natural Bodybuilder Federation seasons. Competitors completed a 34-item questionnaire designed to investigate peaking and contest day strategies. The questionnaire listed commonly utilized peaking strategies and provided additional space for qualitative information. Analysis of the data indicated that carbohydrate (CHO), water and sodium manipulation were the most commonly utilized peak week strategies. The consumption of high glycemic index CHO was the most common competition day strategy. Only 6.2 % of competitors reported following their regular diet the week prior to competition. The CHO manipulation strategies were similar to classical CHO loading, whereby bodybuilders attempt to maximize muscle glycogen concentrations. Furthermore, bodybuilders attempted to remove superfluous water by exploiting the diuretic/polyuria effect associated with water loading/restriction. The potentially deleterious effects of peaking on bodybuilders' health is considered and the efficacy of these strategies to enhance appearance is discussed. The findings of the present investigation are likely to be of interest to bodybuilders and their coaches.
REVIEW | doi:10.20944/preprints201710.0002.v1
Subject: Materials Science, Nanotechnology Keywords: titanium dioxide; crystal structure; surface/interface structure; photocatalysis; lithium/sodium ion batteries; Li-S batteries; phase stability
Online: 1 October 2017 (06:11:58 CEST)
Titanium dioxide (TiO2) micro and nano architectures have been intensively studied in the past years because of many varied applications in environmental, energy conversion, and storage fields, such as heterogeneous catalysis, dye-sensitized solar cells, lithium/sodium ion batteries, lithium-sulfur (Li-S) batteries, and bio-nanotechnology, etc. Especially the surface and interface structures in the TiO2 structures play important roles in those applications. This mini review article focuses on TiO2 micro and nano architectures with the prevalent crystal structures (anatase, rutile, brookite, and TiO2(B)), and summarizes major advances in the surface and interface engineering and applications in environmental and electrochemical applications. We present the principles and growth mechanisms of TiO2 nanostructures via different strategies, with an emphasis on rational control of the surface and interface structures. We further discuss the applications of TiO2 micro and nano architectures in photocatalysis, lithium/sodium ion batteries, and Li-S batteries. Throughout the discussion, the relationship between the device performance and the surface structures of TiO2 micro/nano structures will be highlighted. Then we discuss the phase transitions of TiO2 nanostructures and possible strategies of improving the phase stability. The review concludes with a perspective on the current challenges and future research directions.
BRIEF REPORT | doi:10.20944/preprints202207.0220.v1
Subject: Life Sciences, Virology Keywords: Hepatitis B virus; HepG2-NTCP cells; Immunofluorescence; Sodium taurocholate cotransporting polypeptide (NTCP) Receptor; Subcloning; Limiting dilution; Myrcludex B
Online: 14 July 2022 (12:06:08 CEST)
HepG2 cells reconstituted with Hepatitis B virus (HBV) entry receptor sodium taurocholate co-transporting polypeptide (NTCP) are widely used as a convenient in vitro cell culture infection model for HBV replication studies. As such, it is pertinent that HBV infectivity is maintained at steady-state levels for accurate interpretation of in vitro data. However, variations in HBV infection efficiency due to imbalanced NTCP expression levels in the HepG2 cell line may affect experimental results. In this study, we performed single cell cloning of HepG2-NTCP-A3 parental cells via limiting dilution and obtained multiple subclones with increased permissiveness to HBV. Specifically, one subclone (HepG2-NTCP-A3/C2) yielded more than 4-fold higher HBV infection compared to the HepG2-NTCP-A3 parental clone. In addition, though HBV infectivity was universally reduced in the absence of polyethylene glycol (PEG), subclone C2 maintained relatively greater permissiveness under PEG-free conditions, suggesting the functional heterogeneity within parental HepG2-NTCP-A3 may be exploitable in developing a PEG-free HBV infection model. The increased viral production correlated with increased intracellular viral antigen expression as evidenced through HBcAg immunofluorescence staining. Further, these subclones were found to express different levels of NTCP, albeit with no remarkable morphology or cell growth differences. In conclusion, we isolated subclones of HepG2-NTCP-A3 which support efficient HBV production and thus provide an improved in vitro HBV infection model.
ARTICLE | doi:10.20944/preprints202104.0332.v1
Subject: Engineering, Automotive Engineering Keywords: smart water grid; advanced metering infrastructure; short-term water demand forecasting; end-use level; on-site sodium hypochlorite generator
Online: 13 April 2021 (09:20:08 CEST)
It is crucial to forecast the water demand accurately for supplying water efficiently and stably in a water supply system. In particular, accurately forecasting short-term water demand helps in saving energy and reducing operating costs. With the introduction of the Smart Water Grid (SWG) in a water supply system, the amount of water consumption is obtained in real time through an advanced metering infrastructure (AMI) sensor, which can be used for forecasting the short-term water demand. The models widely used for water demand forecasting include the autoregressive integrated moving average, radial basis function-artificial neural network, quantitative multi-model predictor plus, and long short-term memory. However, there is a lack of research on assessing the performance of models and forecasting the short-term water demand by applying the data on the amount of water consumption by purpose and the pipe diameter of an end-use level of the SWG demonstration plant in each demand forecasting model. Therefore, in this study, the short-term water demand was forecasted for each model using the data collected from the AMI, and the performance of each model was assessed. The Smart Water Grid Research Group installed ultrasonic-wave-type AMI sensors in the block 112 located in YeongJong Island, Incheon, and the actual data used for operating the SWG demonstration plant were adopted. The performance of the model was assessed by using the residual, root mean square error (RMSE), normalized root mean square error (NRMSE), Nash–Sutcliffe efficiency (NSE), and Pearson correlation coefficient (PCC) as indices. The water demand forecast was slightly underestimated in models that employed the assessment results based on the RMSE and NRMSE. Furthermore, the forecasting accuracy was low for the NSE due to a large number of negative values; the correlation between the observed and forecasted values of the PCC was not high, and it was difficult to forecast the peak amount of water consumption. Therefore, as the short-term water demand forecasting models using only time and the amount of water consumption have limitations in reflecting the characteristics of consumers, a water supply system can be managed more precisely if other factors (weather, customer behavior, etc.) influencing the water demand are applied.
ARTICLE | doi:10.20944/preprints202102.0065.v1
Subject: Materials Science, Biomaterials Keywords: red mud; bauxite residue; reduction roasting; sodium sulfate; magnetic separation; alumina; high pressure acid leaching; hydrochloric acid; recycling; utilization
Online: 1 February 2021 (17:32:51 CET)
Red mud is a hazardous waste of alumina industry that contains high amounts of iron, aluminum, titanium and REEs. One of the promising methods for the extraction of iron from red mud is car-bothermic reduction with the addition of sodium salts. This research focuses on the process of hy-drochloric high-pressure acid leaching using 10–20% HCl of two samples of non-magnetic tailings obtained by 60-minute carbothermic roasting of red mud at 1300 °C and the mixture of 84.6 wt. % of red mud and 15.4 wt. % Na2SO4 at 1150 °C, respectively, with subsequent magnetic separation of metallic iron. An influence of temperature, leaching duration, solid-to-liquid-ratio and acid con-centration on dissolution behavior of Al, Ti, Mg, Ca, Si, Fe, Na, La, Ce, Pr, Nd, Sc, Zr were studied. Based on the investigation of the obtained residues, mechanism of passing of valuable elements into the solution was proposed. It has shown that 90% Al, 91% Sc and above 80% of other REEs can be dissolved under optimal conditions; Ti can be extracted into the solution or the residue depending on the leaching temperature and acid concentration. Based on the research results, novel flowsheets for red mud treatment were developed.
ARTICLE | doi:10.20944/preprints201910.0185.v1
Subject: Medicine & Pharmacology, Nutrition Keywords: sodium; potassium; nutrition; diet; urine spot; food frequency questionnaire; cardiovascular disease; childhood cancer survivors; Swiss childhood cancer registry; Europe
Online: 16 October 2019 (10:25:07 CEST)
Risk of cardiovascular disease (CVD), common in childhood cancer survivors (CCSs), may be affected by diet. We assessed sodium (Na) and potassium (K) intake, estimated from food frequency questionnaires (FFQs) and morning urine spots, and its associations with cardiovascular risk in CCSs. We stratified CCS into three risk profiles based on A) personal history (CVD, CVD risk factors, or CVD risk free), B) body mass index (obese, overweight, or normal/underweight), and C) cardiotoxic treatment (anthracyclines and/or chest irradiation, or neither). We obtained a FFQ from 802, and sent a spot urine sample collection kit to 212, of which 111 (52%) returned. We estimated Na intake 2.9 g/day based on spot urine and 2.8 g/day based on FFQ; estimated K intake was 1.6 g/day (spot urine) and 2.7 g/day (FFQ). CCSs with CVD risk factors had a slightly higher Na intake (3.3 g/day), than CCSs risk free (2.9 g/day) or with CVD (2.7 g/day, p = 0.017), and obese participants had higher Na intake (4.2 g/day) than normal/underweight CCSs (2.7 g/day, p<0.001). Daily Na intake was above, and daily K intake below national recommended levels. Adult survivors of childhood cancer need dietary assistance to reduce Na and increase K intake.
REVIEW | doi:10.20944/preprints202103.0523.v1
Subject: Keywords: basic copper(II) formate; ‘Black Spots’; chalconatronite; copper(II) hydroxide; copper sulfide; curly malachite; namuwite; sodium copper(II) formate; verdigris
Online: 22 March 2021 (11:50:06 CET)
Information taken from David A. Scott’s book “Copper and Bronze in Art” was crucial for research on copper corrosion products in Stuttgart. Examples discussed are the nature and variability of ‘Black Spots’ (aka ‘Brown Fuzzies’); cupric hydroxide by cleaning, patination, and pigment synthesis; the wondrous phenomenon of curly malachite; chalconatronite formed by contact to soda glass; the formation of copper formates by glass-induced metal corrosion; and synthesis and X-ray diffraction of basic copper acetates (‘verdigris’).
ARTICLE | doi:10.20944/preprints202104.0512.v1
Subject: Materials Science, Biomaterials Keywords: hepatitis B virus (HBV); Myr47 lipopeptide; cellular uptake; liposomes; sodium taurocholate cotransporting polypeptide (NTCP); HBV surface antigen (HBsAg); apolipoprotein E (ApoE)
Online: 19 April 2021 (17:08:53 CEST)
Myr47 lipopeptide consisting of hepatitis B virus (HBV) pre-S1 domain (myristoylated 2-48 peptide) is a commercialized effective anti-HBV drug, preventing the interaction of HBV with sodium taurocholate cotransporting polypeptide (NTCP) on human hepatocytes, of which the activity requires both N-myristoylation residue and specific amino acid sequence. Meanwhile, we recently reported that Myr47 reduces the cellular uptake of HBV surface antigen (HBsAg, subviral particle of HBV) in the absence of NTCP expression (Somiya; et al. Virology 2016, 497, 23–32). In this study, we analyzed how Myr47 reduces the cellular uptake of lipid nanoparticles (including liposomes (LPs) and HBsAg) without NTCP expression. By using Myr47 mutants lacking the HBV infection inhibitory activity, they could reduce the cellular uptake of LPs in an N-myristoylation-dependent manner whereas in an amino acid sequence-independent manner. Moreover, Myr47 and its mutants could reduce the interaction of LPs with apolipoprotein E3 (ApoE3) in an N-myristoylation-dependent manner regardless of their amino acid sequences. From these results, N-myristoyl residue of lipopeptides generally could interfere the LPs/HBsAg-ApoE3 complex formation, thereby reducing the cellular uptake of LPs/HBsAg. When lipid nanoparticles are used as a DDS (drug delivery system) nanocarrier, the surface modification with lipopeptides may be a new method to inhibit unwanted cellular uptake of DDS nanocarriers by non-target cells.
REVIEW | doi:10.20944/preprints202001.0171.v1
Subject: Medicine & Pharmacology, Nutrition Keywords: Dipeptidyl peptidase-4; Fibroblast growth factor; Gastrointestinal peptide; Glucagon-like peptide 1; Glucagon receptor; Peroxisome proliferator-activated receptor; Sodium glucose cotransporter
Online: 16 January 2020 (11:44:49 CET)
Liver related diseases are the 3rd leading causes (9.3%) of mortality in type 2 diabetes mellitus (T2DM) in Japan. T2DM is closely associated with nonalcoholic fatty liver disease (NAFLD) which is the most prevalent chronic liver disease worldwide. Nonalcoholic steatohepatitis (NASH), a severe form of NAFLD, can lead to hepatocellular carcinoma (HCC) and hepatic failure. There are no established pharmacotherapies for NASH patients with T2DM. Though vitamin E is established as a 1st line agent in NASH without T2DM, its efficacy was recently denied in NASH with T2DM. The effects of pioglitazone on NASH histology with T2DM have extensively been established, but several concerns exist such as body weight gain, fluid retention, cancer incidence, and bone fracture. Glucagon-like peptide 1 (GLP-1) receptor agonists and sodium/glucose cotransporter 2 (SGLT2) inhibitors are expected to ameliorate NASH (LEAN study, LEAD trial, and E-LIFT study). Among a variety of SGLT2 inhibitors, dapagliflozin have already entered phase 3 trials (DEAN study). A key clinical question is what kinds of anti-diabetic drugs are the most appropriate for the treatment of NASH to prevent progression of hepatic fibrosis resulting in HCC/liver-related mortality without increasing risk at cardiovascular or renal events. The combination therapies such as glucagon receptor agonist/GLP-1 or gastrointestinal peptide /GLP-1 will be under development. This review focuses on antidiabetic agents and future perspectives on the view of the treatment of NAFLD with T2DM.
REVIEW | doi:10.20944/preprints201911.0264.v1
Subject: Medicine & Pharmacology, Other Keywords: cardiovascular risk; dipeptidyl peptidase-4 inhibitors; glucagon like peptide-1 receptor agonists; sodium glucose cotransporter-2 inhibitors; type 2 diabetes mellitus
Online: 24 November 2019 (04:26:47 CET)
Type 2 Diabetes Mellitus (T2DM) is associated with a high risk of atherosclerotic cardiovascular (CV) disease. Contributing pathophysiologic factors include endothelial dysfunction caused by excessive production of reactive oxygen species (ROS), increased activity of nuclear factor kB (NFkB), altered macrophage polarization, and reduced synthesis of endothelial progenitor cells (EPC). Consequently, there can be a potentially rapid progression of the atherosclerotic disease with a higher propensity to unstable plaque, leading to increased cardiovascular mortality. Management is aimed at prevention, early diagnosis, and treatment of hyperglycemia and vascular complications. Innovative therapeutic approaches for T2DM seek to customize the antidiabetic treatment to each patient in order to optimize glucose-lowering effects, minimize hypoglycemia and adverse effects, and prevent cardiovascular events. The newer drugs (Glucagon Like Peptide-1 Receptor Agonists, GLP-1 RAs; Sodium GLucose coTransporter-2 inhibitors, SGLT2is; DiPeptidyl Peptidase-4 inhibitors, DPP4is) impact body weight, lipid parameters, and blood pressure, as well as endothelial function, inflammatory markers, markers of oxidative stress, and subclinical atherosclerosis. The present review summarizes the results of trials that evaluated the cardiovascular safety of these drugs and found them to be safe from the CV standpoint.
ARTICLE | doi:10.20944/preprints201608.0162.v1
Subject: Life Sciences, Microbiology Keywords: bacterial ghosts (BGs); Vibrio parahaemolyticus; chemically induced lysis; minimum inhibition concentration (MIC); sodium hydroxide (NaOH); lipopolysaccharides (LPS); endotoxic activity; macrophages; cytotoxicity; cytokine
Online: 17 August 2016 (10:26:00 CEST)
Acellular bacterial ghosts (BGs) are empty non-living bacterial cell envelopes, commonly generated by controlled expression of the cloned lysis gene E of bacteriophage PhiX174. In this study, Vibrio parahaemolyticus ghosts (VPGs) were generated by chemically induced lysis and the method is based on minimum inhibitory concentration (MIC) of sodium hydroxide (NaOH), acetic acid, boric acid, citric acid, maleic acid, hydrochloric acid and sulfuric acid. The MIC values of the respective chemicals were 3.125, 6.25, < 50.0, 25.0, 6.25, 1.56 and 0.781 mg/ml. Except boric acid, the lysis efficiency was reached more than 99.99% at 5 min after treatment of all chemicals. Among those chemicals, NaOH-induced VPGs showed completely DNA-free that was confirmed by quantitative real-time PCR. Besides, lipopolysaccharides (LPS) extracted from the NaOH-induced VPGs showed no distinctive band on SDS-PAGE gel after silver staining. On the other hand, LPS extracted from wild-type bacterial cells as well as the organic acids-induced VPGs showed triple major bands and LPS extracted from the inorganic acids-induced VPGs showed double bands. It suggests that some surface structures in LPS of the NaOH-induced VPGs may be lost, weakened or modified by the MIC of NaOH. Nevertheless, Limulus amoebocyte lysate assay revealed that there is no significant difference in endotoxic activity between the NaOH-induced VPGs and wild-type bacterial cells. Macrophages exposed to the NaOH-induced VPGs at 0.5 × 106 CFU/mL showed cell viability of 97.9%, however the MIC of NaOH did not reduce the cytotoxic effect of wild-type bacterial cells. Like Escherichia coli LPS, the NaOH-induced VPGs are an excellent activator of pro-inflammatory cytokines (IL-1β and iNOS), anti-inflammatory cytokine (IL-10) and dual activities (IL-6) in the stimulated macrophage cells. On the other hand, the induction of TNF-α mRNA was remarkable in the macrophages exposed with wild-type cells. Scanning electron microscopy showed the formation of trans-membrane lysis tunnel structures in the NaOH-induced VPGs. SDS-PAGE and agarose gel electrophoresis also confirmed that cytoplasmic proteins and genomic DNA released from the VPGs to culture medium through the lysis tunnel structures. Taken together, all these results indicated that the NaOH-induced VPGs show the potency of safe, economical and effective inactivated bacterial vaccine candidate.
ARTICLE | doi:10.20944/preprints202207.0058.v1
Subject: Life Sciences, Biophysics Keywords: human interferon gamma; human interferon gamma receptor; receptor binding; heparan sulfate; co-receptor; molecular dynamics simulations; sodium chlorate; kynurenine antiproliferative assays; hIFNγ signalling
Online: 5 July 2022 (04:43:05 CEST)
The extremely controversial conclusions about the function of human interferon-gamma (hIFNγ) C-terminus as well as the lack of a consistent model explaining its role in the receptor binding prompted us to scrutinize the interaction of hIFNγ with its extracellular receptor hIFNGR1 in different scenarios by means of molecular dynamics simulations. We find that the two molecules alone fail to form a stable complex but the presence of heparan-sulfate-like oligosaccharides largely facilitates the process by both demobilizing the highly flexible C-termini of the cytokine and assisting in the proper positioning of its globule between the receptor subunits. An antiproliferative-activity essay on cells depleted from surface sulfation confirms qualitatively the simulation-based multistage complex-formation model. Our results reveal the key role of HS and its proteoglycans in all processes involving hIFNγ signalling.
ARTICLE | doi:10.20944/preprints201812.0126.v1
Subject: Chemistry, Analytical Chemistry Keywords: advanced glycation end products (AGEs); enzymatic hydrolysis; glycation; methylglyoxal-derived hydroimidazolone 1 (MG-H1); seeds; seed ageing; seed quality; sodium dodecyl sulfate (SDS)
Online: 11 December 2018 (10:40:15 CET)
Seeds represent the major source of food protein, impacting on both human nutrition and animal feeding. Therefore, seed quality needs to be appropriately addressed in the context of viability and food safety. Indeed, long-term and inappropriate storage of seeds might result in enhancement of protein glycation, which might affect their quality and longevity. Glycation of seed proteins can be probed by exhaustive acid hydrolysis and quantification of the glycation adduct Nɛ-(carboxymethyl)lysine (CML) by liquid chromatography-mass spectrometry (LC-MS). This approach, however, does not allow analysis of thermally and chemically labile glycation adducts, like glyoxal-, methylglyoxal- and 3-deoxyglucosone-derived hydroimidazolones. Although enzymatic hydrolysis might be a good solution in this context, it requires aqueous conditions, which cannot ensure reconstitution of seed protein isolates. Because of this, the complete profiles of seed AGEs are not characterized so far. Therefore, here we propose the approach, giving access to quantitative solubilization of seed proteins in presence of sodium dodecyl sulfate (SDS) and their quantitative enzymatic hydrolysis prior to removal of SDS by reversed phase solid phase extraction (RP-SPE). Using MG-H1 as a case example, we demonstrate the applicability of this method for reliable and sensitive LC-MS-based quantification of chemically labile AGEs and its compatibility with bioassays.
ARTICLE | doi:10.20944/preprints202104.0271.v1
Subject: Materials Science, Biomaterials Keywords: magnesite; dolomite; semi-soluble salt-type minerals; tailings; sodium hexametaphosphate SHMP; 1-hydroxyethylene-1,1-diphosphonic acid HEDP; Dynamic Froth Analyzer; froth properties; remining; pneumatic Imhoflot; reactor-separator; FineFuture
Online: 9 April 2021 (15:58:10 CEST)
Depletion of ore deposits, increasing demand for raw materials, the need to process low-grade, complex and finely disseminated ores and the reprocessing of tailings are challenges, especially for froth flotation separation technologies. Even though capable of handling relatively fine grain sizes the flotation separation of very fine and ultrafine particles faces many problems still. Further, the flotation of low-contrast semi-soluble salt-type minerals with very similar surface properties, many complex interactions between minerals, reagents and dissolved species often result in poor selectivity. This study investigates the flotation beneficiation of ultrafine magnesite rich in dolomite from de-sliming, currently reported to the tailings. The paper especially focuses on the impact of the depressant sodium hexametaphosphate (SHMP) on: (i) the froth properties using dynamic froth analysis (DFA), (ii) the separation between magnesite and dolomite/calcite and (iii) its effect on the entrainment. Furthermore, the application of 1-hydroxyethylene-1,1-diphosphonic acid (HEDP) is a more environmentally friendly and low-cost alternative to SHMP is presented and discussed. The paper contributes to understanding on the complexity of depressant responses in froth flotation.
ARTICLE | doi:10.20944/preprints202203.0332.v1
Subject: Life Sciences, Biochemistry Keywords: protein determination; soft protein corona; hard protein corona; covalent immobilization; supernatant method; gold nanoparticles; latex polymer particles; gold sodium chloride method; amino acid analysis; aromatic amino acid analysis; AAAA; acid hydrolysis
Online: 24 March 2022 (14:32:48 CET)
Protein immobilization for the functionalization of particles is used in various applications, including biosensors, lateral-flow immunoassays (LFIA), bead-based assays, and others. Common methods for the quantification of bound protein are measuring protein in the supernatant before and after coating and calculating the difference. This popular approach has the potential for a significant overestimation of the amount of immobilized protein since layers not directly bound to the surface (soft protein corona) are usually lost during washing and handling. Only the layer directly bound to the surface (hard corona) can be used in subsequent assays. A simplified amino acid analysis method based on acidic hydrolysis and RP-HPLC-FLD of tyrosine and phenylalanine (aromatic amino acid analysis, AAAA) is proposed to directly quantify protein bound to the surface of gold nano- and latex microparticles. The results are compared with indirect methods such as colorimetric protein assays, such as Bradford, bicinchoninic acid (BCA), as well as AAAA of the supernatant. For both particle types, these indirect quantification techniques show a protein overestimation of up to 1700% compared to the direct AAAA measurements. In addition, protein coating on latex particles was performed both passively through adsorption and covalently through EDC/sulfo-NHS chemistry. Our results showed no difference between the immobilization methodologies. This finding suggests that usual protein determination methods are no unambiguous proof of a covalent conjugation on particles or beads.