REVIEW | doi:10.20944/preprints201610.0009.v1
Subject: Chemistry And Materials Science, Organic Chemistry Keywords: Essential(s) oils; monoterpenes; insecticidal activity; antimicrobial activity; acaricide activity; herbicidal activity
Online: 4 October 2016 (16:08:09 CEST)
Several plant species produce mixtures of odorous and volatile compounds known as essential oils (EOs). These mixtures play important roles in nature and have been utilized by man for pharmaceutical and agrochemical purposes. There are more than 3000 EOs reported in the literature with approximately 300 having commercial use, including the oils from Eucalyptus species. Such oils are rich in monoterpenes and have found applications as pharmaceuticals, agrochemicals, food flavorants and in the perfume industry. Such applications are related to their diverse biological and organoleptic properties. In view of their importance, we review in this article up to date information concerning chemical composition and biological activities of essential oils from different species of Eucalyptus. Among the 900 species and subspecies of the Eucalyptus genus¸ we examined 68 species. The studies associated with these species were conducted in 27 countries. We have focused on the antimicrobial, acaricide, insecticide and herbicide activities, hoping that such information will contribute in the advances of the research in this field. It is also intended that the information herein described can be useful in the rationalization of the use of Eucalyptus EOs as components for new pharmaceutical and agrochemical applications as well as food preservatives and flavorants.
ARTICLE | doi:10.20944/preprints202310.1805.v1
Subject: Biology And Life Sciences, Food Science And Technology Keywords: quinoa polysaccharides; chemical composition; antioxidant activity; anti-proliferation activity; anti-microbial activity
Online: 27 October 2023 (12:15:48 CEST)
Quinoa, known as the "golden grain" for its high nutritional value, is a significant source of essential nutrients, including proteins, minerals, vitamins, polyphenols, phytosterols, and flavonoids. However, the biological functions of quinoa polysaccharides remain understudied. In this research, two crude quinoa polysaccharides extracts (Q-40 and Q-60) were obtained extracting by 40% and 60% alcohol. The purity of Q-40 and Q-60 was 58.29% and 62.15%, with protein contents of 8.27% and 9.60%, respectively. Monosaccharide analysis revealed that Q-40 contained glucose (Glc), galacturonic acid (GalA), and arabinose (Ara) in a molar ratio of 0.967:0.027:0.006. Q-60 was composed of xylose (xyl), arabinose (Ara), galactose, and galacturonic acid (GalA) with a molar ratio of 0.889:0.036:0.034:0.020. The average molecular weight of Q-40 ranged from 47484 to 626488 Da, while Q-60 showed a range of 10025 to 47990 Da. Rheological experiments showed that Q-40 exhibited higher viscosity, while Q-60 demonstrated more elastic properties. Remarkably, Q-60 showed potent antioxidant abilities, with scavenging rates of 98.49% for DPPH and 57.5% for ABTS. Antibacterial experiments using the microdilution method revealed that Q-40 inhibited the growth of Methicillin-resistant Staphylococcus aureus (MRSA) and E. coli, while Q-60 specifically inhibited MRSA. At lower concentrations, both polysaccharides inhibited MDA cell proliferation, but at higher concentrations, they promoted proliferation. Similar proliferation-promoting effects were observed in HepG2 cells. The research provides important information in application of quinoa in food and functional food industries.
REVIEW | doi:10.20944/preprints202310.0123.v1
Subject: Biology And Life Sciences, Biology And Biotechnology Keywords: antimicrobial resistance; green synthesis; IONPs; antibacterial activity; antifungal activity; antiparasitic; antiviral activity
Online: 3 October 2023 (10:43:18 CEST)
Pathogenic microorganisms can cause a range of infectious diseases and are often treated with antimicrobial agents. The rise of antimicrobial resistance caused by inappropriate use of these agents in various settings has become a global health threat. There is, therefore, a need to find new and effective agents to combat infections caused by resistant pathogens. Nanotechnology has seen significant growth and development in recent years and has a wide range of applications in various fields, including health, agriculture, and industry. This novel area offers the potential for the synthesis of nanoparticles (NPs) with antimicrobial activity, such as iron oxide nanoparticles (IONPs). The use of IONPs is a promising way to overcome antimicrobial resistance or pathogenicity because of their ability to interact with several biological molecules and to inhibit microbial growth. This review focuses on the most common green synthesis methods for producing IONPs using bacteria, fungi, plants, and organic waste, as well as the most common methods for the characterization of these IONPs. Finally, it summarizes their application as promising antibacterial, antifungal, antiparasitic, and antiviral agents.
ARTICLE | doi:10.20944/preprints202204.0119.v1
Subject: Medicine And Pharmacology, Pharmacology And Toxicology Keywords: Micromeria fruticosa; GC-MS; metabolites; anticancer activity; MTT; antioxidant activity; antimicrobial activity
Online: 13 April 2022 (08:29:56 CEST)
This study assesses the secondary metabolites, minerals, antimicrobial, antioxidant, and anticancer properties of Micromeria fruticosa plant different botanical parts (leaf, stem, root, flower) extracted with various solvents. The plant samples were sequentially obtained using different solvents (n-hexane, ethanol and water) through steeping. Then, each of the extracts was further analyzed by using gas chromatography–mass spectrometry (GC-MS). Moreover, the extracts were bio-assayed to test their antioxidant, antibacterial, and anti-cancer activities. Quali-quantitative analysis of M. fruticosa crude extracts revealed the occurrence of 27 secondary metabolites were identified including mainly monoterpenes, sesquterpenes, and fatty acids, with varying quantities. Some of the major bioactive compounds included, Menthone (5.42-30.05%), Oleamide (3.40-32.20%), Pulegone (10.66-64.1%), and Menthol (3.61-100.0%), which were detected mostly in all plant parts with significant quantities. Several antioxidant minerals, mainly, Fe, Zn, and Mn, were detected with the highest amounts in the Micromeria water extracts. Results from antimicrobial assays showed that the water extract of leaves exhibited the highest DPPH scavenging activity (89.73%) followed by the water extract of flowers (80.07%) at a concentration of 100 μg/mL. The water extract of stems showed greater antimicrobial activity against all the tested gram negative and positive bacteria (Methicillin-resistant Staphylococcus aureus, Staphylococcus aureus, Escherichia coli, and Shigella sonnie). The leaves ethanolic and stem aqueous extracts had a strong antimicrobial activity against E. coli. and C. albicans. Flower aqueous extract demonstrated the highest cytostatic effect on the colon cell line by reducing viability up to 30.4%, followed by the leaf ethanol extract with 38.6% cell viability reduction at 1000 µg/mL. In conclusion, extraction solvents influenced the recovery of phytocompounds and the highest pharmacological activities of the different extracts could be correlated to the presence of additional bioactive compounds. Our results suggest that M. fruticosa plant is a promising source of natural products with antioxidant, anti-microbial and anti-cancer properties for potential nutraceutical, therapeutic, and functional food applications. , , , , , ,
ARTICLE | doi:10.20944/preprints201904.0262.v1
Subject: Chemistry And Materials Science, Medicinal Chemistry Keywords: total synthesis; antitumor activity; structure-activity relationship
Online: 24 April 2019 (05:29:48 CEST)
(-)-Zeylenone is a promising cytotoxic agent，which is a natural product isolated from Uvaria grandiflora Roxb. Though substantial antitumor mechanism has been researched , little has focused on its enantiomer (+)-Zeylenone.This article will try to find a gram scale synthesis method of (+)-Zeylenone and explain the structure-activity relationship of this kind of compound. Total synthesis of (+)-zeylenone was completed in 13 steps with quinic acid as starting material in 8.8% overall yield. The highlight of the route was the control of the three carbon’s chirality by clever use of single step dihydroxylation under the direction of the key C-3 chirality. In addition, zeylenone derivatives were designed and synthesized and their antitumor activity were evaluated against three human cancer cell lines using the CCK8 assay. Structure-activity relationship suggested compounds with both two absolute configurations exhibited good activity. Besides, hydroxyls at C-1/2 position were crucial for the activity and esterification of C-1 hydroxyl with large groups made the activity disappeared. Hydroxyl at C-3 position was also important as proper ester substituent could increase the potency.
ARTICLE | doi:10.20944/preprints201609.0018.v1
Subject: Medicine And Pharmacology, Pharmacology And Toxicology Keywords: polyphenols, flavonoids, seaweeds, antioxidant activity, anticancer activity
Online: 5 September 2016 (14:23:52 CEST)
Seaweeds are considered as one of the largest biomass producers in marine environment that is rich in bioactive metabolites and a source of natural ingredients for functional foods. The potential antioxidant activity and the potential inhibition of Caco2 cell proliferation, of crude extracts of: Chlorophyta (Ulva lactuca, and Codium tomentosum), Phaeophyta (Cystoseira crinita, Cystoseira stricta, and Sargassum vulgare), and Rhodophyta (Gelidium latifolium, Hypnea musciformis, and Jania rubens) collected from western Libyan coast were evaluated in vitro. The antioxidant activity was determined by reducing power and DPPH assays while cell proliferation, morphological changes and the cell cycle arrest were assessed by MTT, inverted light microscope and flow cytometry methods respectively. The polyphenols and flavonoids rich extracts showed remarkable reducing power and antiradical properties. After exposure of Caco2 cells to; various concentrations of extracts (50, 100,150 and 200 µg/mL) especially from brown algae for 72 h, significantly reduced cell proliferation. The antiproliferative effect of algae extracts was correlated with their polyphenol and flavonoid contents. Cell cycle analysis further showed that cells were arrested in G phases along with an increment in sub-diploidal cell population (sub-G) after extract application. These results imply that seaweeds which are rich in bioactive compounds may be in anticancer drug research programs. However, further investigations are essential to reveal the molecular mechanisms of the anticancer activities of these algae.
ARTICLE | doi:10.20944/preprints201703.0122.v1
Subject: Engineering, Electrical And Electronic Engineering Keywords: activity classification; activity monitoring; wearable sensors; sensor positions
Online: 16 March 2017 (17:19:01 CET)
This paper focuses on optimal sensor positioning for monitoring activities of daily living and investigates different combinations of features and models on different sensor positions, i.e., the side of the waist, front of the waist, chest, thigh, head, upper arm, wrist, and ankle. Sixteen features are extracted and the feature importance is measured by using the Relief-F feature selection algorithm. Eight classification algorithms are evaluated on a dataset collected from young subjects and that collected from elderly subjects, with two different experimental settings. To deal with different sampling rates, signals with a high data rate are down-sampled and a transformation matrix is used for aligning signals to the same coordinate system. The thigh, chest, side of the waist, and front of the waist are the best four sensor positions for the first dataset (young subjects), with average accuracy values being greater than 95%. The best model obtained from the first dataset for the side of the waist is validated on the second dataset (elderly subjects). The most appropriate number of features for each sensor position is reported. The results provide a reference for building activity recognition models for different sensor positions, as well as for data acquired from different hardware platforms and subject groups.
ARTICLE | doi:10.20944/preprints201612.0121.v1
Subject: Medicine And Pharmacology, Dermatology Keywords: antibacterial activity, cinnamon, honey, checkerboards method, synergistic activity
Online: 23 December 2016 (18:37:59 CET)
Propionibacterium acnes and Staphylococcus epidermidis are the major skin bacteria that cause the formation of acne. The present study was conducted to investigate antibacterial activity of ethanolic extract of cinnamon bark, honey and their combination against acne bacteria. The antibacterial activity of extract of cinnamon bark and honey were investigated against P. acnes and S. epidermidis using disc diffusion method. Minimum Inhibitory Concentration (MIC) and minimal bactericidal concentration (MBC) were performed using Clinical and Laboratory Standard Institute (CLSI) methods. The interaction combination between extract of cinnamon bark and honey was determined by using a checkerboards method. The results showed that he MIC of extract of cinnamon bark and honey against P. acne were 256 µg/mL and 50% v/v, respectively, while against S. epidermidis were 1024 µg/mL and 50% v/v, respectively. The MBC of extract of cinnamon against P. acnes and S. epidermidis were more than 2048 µg/mL, whereas the MBC for honey against P. acnes and S. epidermidis were 100%. The combination of cinnamon bark extract and honey against against P. acnes and S. epidermidis, showed additive activity with the FICI value 0.625. Therefore, the combination of extract of cinnamon bark and honey has potential activity against acne causing bacteria.
ARTICLE | doi:10.20944/preprints201701.0084.v1
Subject: Chemistry And Materials Science, Food Chemistry Keywords: onions; A. × cornutum; A. cepa; phenolic compounds; antioxidant activity; genotoxicity; antimutagenic activity; antiproliferative activity
Online: 19 January 2017 (02:09:32 CET)
Here we report a comparative study of the pyhtochemical profile and a biological activity of the two onion extracts, namely A. cepa L. and A. × cornutum (Clementi ex Visiani 1842). Identification of flavonoids and anthocyanins and their individual quantities were determined by high performance liquid chromatography (HPLC). The potency of both extracts to scavenge free radicals was determined by DPPH (2,2'-diphenyl-1-picrylhydrazyl) radical-scavenging activity and oxygen radical absorbance capacity (ORAC) methods. DNA protective role was further tested by single-cell gel electrophoresis (COMET) assay and by Fenton’s reagent causing double strand brakes on pUC19 plasmid. In the presence of both extracts, a significant decrease in the DNA damage was observed, which indicates a protective role of A. cepa and A. × cornutum on the DNA strand brakes. Additionally, cytotoxicity was tested on glioblastoma and breast cancer cell lines. The results showed that both extracts had antiproliferative effect, but the most prominent decrease in cellular growth was observed with glioblastoma cells
ARTICLE | doi:10.20944/preprints202309.1553.v1
Subject: Chemistry And Materials Science, Medicinal Chemistry Keywords: aminophosphonium salt; liposome; solid lipid nanoparticle; anticancer activity; apoptosis; antimicrobial activity; hemolytic activity; acute toxicity.
Online: 22 September 2023 (09:40:48 CEST)
The creation of mitochondria-targeted vector systems is a new tool for the treatment of socially significant diseases. Phosphonium groups provide targeted delivery of drugs through biological barriers to organelles. For this purpose, a new class of alkyl(diethylamino)(phenyl) phosphonium iodides (bromides) 1 containing one, two, or three diethylamino groups were obtained by the reaction of alkyl iodides (bromides) with (diethylamino)(phenyl)phosphines under mild conditions and high yields. The structure of compounds 1 was established by NMR and XRD. In vitro a high cytotoxicity against the lines M-Hela, HuTu 80, PC3, DU-145, PANC-1 and MCF-7 was found. Selectivity index are in the range of 0.06-4.0 M (SI 17-277) for the most active compounds. ROS production, mitochondrial localization and the process of cellular apoptosis were investigated. Decorated by 1 of lipid systems (liposomes and solid lipid nanoparticles) improve the cytotoxicity and a decrease in toxicity against normal cell lines. Compounds 1 induce apoptosis proceeding along the mitochondrial pathway. Aminophosphonium salts 1 also exhibit a high selective activity against the Gram-positive bacteria strains S. aureus 209P, B. segeus 8035, including methicillin-resistant strains of S. aureus (MRSA-1, MRSA-2), comparable to the activity of the fluoroquinolone antibiotic norfloxacin. A moderate in vivo toxicity in CD-1 mice was established for the lead compounds.
ARTICLE | doi:10.20944/preprints202311.1285.v1
Subject: Medicine And Pharmacology, Medicine And Pharmacology Keywords: antimicrobial activity; molecular dynamics; membrane; peptide; structure-activity relationship
Online: 21 November 2023 (07:27:05 CET)
In our previous work, we demonstrated the potential of the amphiphilic cyclic peptide [W4R4] as a promising antimicrobial agent. The extensive data accumulated on the antimicrobial activity of this peptide and its homologs presented an opportunity to unravel the molecular mechanisms governing their action and establish crucial structure-activity relationships (SAR). To achieve this, we employed a comprehensive approach involving peptide synthesis, in vitro biological testing, and molecular modeling to systematically analyze the SAR of a series of cyclic peptides derived from the [W4R4] scaffold. Minimal modifications were introduced to the original peptide by incorporating either one aromatic hydrophobic residue (W) or one polar positively charged residue (R) while maintaining the sequential W/R arrangement. Additionally, we introduced an "intermediate" substitution by incorporating 2,5-diketopiperazine (DKP), possessing both aromatic and polar properties, into the macrocycle [W4R4] between the W and R residues. Notably, this study marked the first synthesis and evaluation of the [W4R4(DKP)] peptide. Structural, dynamic, hydrophobic, and membrane-binding properties of four cyclic peptides ([W4R4], [W5R4], [W4R5], [W4R4(DKP)]) were explored using molecular dynamics simulations within a DOPC/DOPG lipid bilayer that mimics the bacterial membrane. The results obtained revealed distinct SAR profiles for all peptides, enabling the establishment of correlations between their antimicrobial activity and structural/dynamic parameters. These parameters included the degree of conformational plasticity, the depth of immersion into the bi-layer, and the population of the membrane binding mode characterized by the embedding of the hydrophobic peptide pattern into the acyl chain region of lipids. In particular, the peptide [W4R5] exhibited an optimal "activity/binding to the bacterial membrane" pattern. This work highlights the significance of our multidisciplinary approach in efficiently deciphering finely regulated SAR profiles for a series of homologous peptides with diverse activities. Furthermore, this research provides a solid foundation for the rational design of novel antimicrobial peptides.
ARTICLE | doi:10.20944/preprints202308.0996.v1
Subject: Biology And Life Sciences, Biochemistry And Molecular Biology Keywords: N’-phenylhydrazide; antifungal activity; structure-activity relationship; antifungal mechanism
Online: 14 August 2023 (07:13:28 CEST)
Fifty-two kinds of N’-phenylhydrazides were successfully designed and synthesized. Their anti-fungal activity in vitro against five strains of C. alb. was evaluated. All prepared compounds owned varying degrees of activity and their MIC80, TAI, and TSI values were calculated. The in-hibitory activities of 27/52 compounds against fluconazole-resistant fungi C. alb. 4395 and C. alb. 5272 were much higher than those of fluconazole. The MIC80 values of 14/52 compounds against fluconazole-resistant fungus C. alb. 5122 were less than 4 μg/mL, so it was the most sensitive fungus (TSIB = 12.0). A11 showed the highest inhibitory activity against C. alb. SC5314, 4395, and 5272. The antifungal activities of B14 and D5 against four strains of fluconazole-resistant fungi were higher than those of fluconazole. The TAI values of A11 (2.71), B14 (2.13), and D5 (2.25) are the highest. Further exploring the antifungal mechanism revealed that the fungus treated with compound A11 produced free radicals and reactive oxygen species, and their mycelium mor-phology was damaged. In conclusion, the hydrazide scaffold showed potential in the develop-ment of antifungal lead compounds. Among them, A11, B14, and D5 demonstrated particularly promising antifungal activity and hold potential as novel antifungal agents.
ARTICLE | doi:10.20944/preprints202306.0419.v1
Subject: Biology And Life Sciences, Food Science And Technology Keywords: chalky rice; xylanase activity; cellulase activity; hard water; hardness
Online: 6 June 2023 (08:40:23 CEST)
Global warming has led to the increase in chalky grains of rice, which has also caused the deteriorations of physicochemical and cooking qualities of rice grains. These chalky rice grains are characterized by high α-amylase activity, high protease activity, and low apparent amylose contents, low degree of hardness and stickiness of boiled rice than those of the whole rice grains. In the present paper, we evaluated 14 Japonica unpolished rice grains harvested in Japan in 2021, and these samples (original grains) were divided to two groups (whole grain group and chalky grain one). We found that the chalky rice grains showed higher values of xylanase activity than those of the whole rice grains, while cellulase activity were lower than that of whole rice grains. Using rice grains blended with 30 % of chalky grains as material, we compared sugar and mineral contents and textural properties of the boiled rice grains soaked and boiled in the ordinary water or in the hard water, such as Evian or Contrex. It was shown that the hard water is useful for the prevention of the texture deterioration of the boiled rice grains due to the inhibition of the reduction of endogenous hydrolytic enzymes, such as amylase, proteinase, and xylanase. Furthermore, we found that hard water is useful for the increase of calcium and magnesium intake through the meal with the boiled rice grains soaked and cooked using hard water.
ARTICLE | doi:10.20944/preprints202305.1329.v1
Subject: Medicine And Pharmacology, Veterinary Medicine Keywords: Caprine herpesvirus; virucidal activity; Ozone; in vitro; antiviral activity
Online: 18 May 2023 (10:27:21 CEST)
Alphaherpesviruses cause genital lesions and reproductive failure in both humans and animals. Their control is mainly based on prevention by hygienic prophylactic measures, due to the ab-sence of vaccines and limitations of antiviral drug therapy. Ozone is an oxidating gas showing a strong microbicidal activity on bacteria, fungi, viruses, and protozoa. The present study assessed the in vitro virucidal and antiviral activity of ozone against Caprine herpesvirus type 1. Virucidal activity of a gaseous mixture containing O3 at 20 and 50 μg /mL was assessed against the virus for different contact times (30 s, 60s, 90s, 120s, 180s and 300s). Antiviral activity of a gaseous mix-ture containing O3 at 20 and 50 μg /mL was evaluated against the virus to for 30s and 60s. Ozone displayed significant virucidal activity when used at all the tested concentrations whilst signifi-cant antiviral activity was observed using ozone at 50 μg/ml. The gaseous mixture, tested in the present study, showed virucidal and antiviral activity against CpHV-1 with a dose- and a time-contact -dependent fashion. Ozone therapy could be evaluated in vivo for the treatment of CpHV-1-induced genital lesions in goats, through topical applications.
ARTICLE | doi:10.20944/preprints202301.0546.v1
Subject: Biology And Life Sciences, Anatomy And Physiology Keywords: motor activity; orienting exploratory activity; epigenetic inheritance; conception; rats
Online: 30 January 2023 (07:53:43 CET)
The aim of this work was to study the, so far, unexplored possibility that non-genetic inheritance of animal behavioral characteristics could depend on the state of the parents at the time of conception, by studying inheritance of high and low motor and exploratory activity in the first generation of rats. In this study, we measured the levels of motor and exploratory activity in rats at the ages of 2 and 5 months. Male and female rats were mated at the age of 5 months. The following groups were used: male and female rats with high motor activity at ages of 2 and 5 months (ACT+); male and female rats with high activity at the age of 2 months, but low activity at the age of 5 months (ACT–); male and female rats with low activity at the ages of 2 and 5 months (PAS–); male and female rats with low activity at the age of 2 months, but high activity at the age of 5 months (PAS+). Significant differences in the severity of exploratory activity were found between the offspring of ACT+ and ACT– rats. Moreover, these differences were observed only in males, and not in females. Differences between the offspring of PAS+ and PAS– rats were observed in both the male and female rats. The motor activity of animals in the period from 20 minutes after the start of registration did not differ between groups. Thus, it can be considered that individual characteristics of general motor activity are due to genetically inherited factors, while differences in the level of exploratory activity, apparently, are formed due to non-genetic influences from parents during mating.
ARTICLE | doi:10.20944/preprints202108.0296.v1
Subject: Medicine And Pharmacology, Pharmacology And Toxicology Keywords: Ephedra alata; antioxidant activity; anti-inflammatory activity; phytochemical screening
Online: 13 August 2021 (09:23:00 CEST)
Ephedra alata Decne. (Ephedraceae) is a medicinal species commonly used to treat cancers, respiratory diseases, fever, and hypertension. The present study aimed to establish a phytochemical profile, evaluate the antioxidant potential and estimate the anti-inflammatory activities of .. Aqueous and methanolic extracts of E. alata aerial parts were phytochemically investigated using standard methods. DPPH, phosphomolybdenum total antioxidant capacity and reducing power assays were used to evaluate the antioxidant activity. Antioxidant activity was determined using total antioxidant capacity, the scavenging activity of the stable DPPH free radical and ferric reducing antioxidant power assays. The anti-inflammatory activity was determined using egg albumin membrane denaturation and human red blood cells membrane stabilizing assays. The anti-inflammatory potential of E. alata extracts was evaluated using human red blood cells membrane stabilization, egg albumin and BSA albumin denaturation assays. Quinones, anthraquinones, steroids, phytosteroids, phenols, terpenoids, flavonoids, saponins, glycosides, Cardiac glycosides, reducing sugars and anthocyanins were present in the E. alata’s aqueous extract, in addition to coumarins and proteins in the methanolic extract. The highest total phenolic and flavonoid content was recorded in the aqueous extract with 8.66 ±0.09 mg GA/g and 248.04 ±1.47 mg Q/g, respectively. On the other hand, E. alata methanolic extract had the highest tannin content of 62.12 ±0.10 mg C/g. The best radical scavenging activity (IC50 = 4.63±0.00 mg/ml) and total antioxidant capacity were exhibited by the E. alata aqueous (7.35±0.12 mg/ml AAE), whereas the methanolic extract possessed the highest reducing power activity (1.81±0.00 mg AAE/ml). Regarding the anti-inflammatory activities, E. alata methanolic extract exerted the highest HRBC stabilization of 34.72 ±0.08% whereas the aqueous extract exhibited the highest bovine serum and Egg albumin denaturation inhibition of 99.22 ±0.02% and 73.31 ±0.90, respectively. Taken together, our results suggest that E. alata aerial parts aqueous and methanolic extracts can be utilized as future antioxidants and anti-inflammatory ethnomedicines owing to their rich bioactive molecules content.
ARTICLE | doi:10.20944/preprints202105.0371.v1
Subject: Chemistry And Materials Science, Biomaterials Keywords: carboxymethy chitosan; corn peptide; antioxidant activity; antibacterial activity; film
Online: 17 May 2021 (07:59:06 CEST)
Active films based on carboxymethyl chitosan incorporated corn peptide were developed. Physicochemical properties of the films, including thickness, opacity, moisture content, color, mechanical properties, water vapor permeability, and oil resistance, were measured. Biological activities of the films, including the antioxidant and antibacterial activities, were characterized in terms of 2, 2-diphenyl-1-picrylhydrazyl free radical scavenging activity, reducing power, the total antioxidant activity, and the filter disc inhibition zone method. The results indicated that the incorporation of corn peptide caused interactions between carboxymethyl chitosan and corn peptide in Maillard reaction and gave rise to the films light yellow appearance. Compared with the Control, the degree of glycosylation, browning intensity, thickness, opacity, tensile strength, antioxidant activity, and antibacterial activity of films were increased, but the elongation, vapor permeability, and oil resistance of films were decreased. The films based on corn peptide and carboxymethyl chitosan can potentially be applied to food packaging.
ARTICLE | doi:10.20944/preprints201707.0093.v1
Subject: Chemistry And Materials Science, Inorganic And Nuclear Chemistry 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/preprints201608.0119.v1
Subject: Chemistry And Materials Science, Medicinal Chemistry Keywords: thiazoles; thiadiazoles; hydrazonoyl chlorides; anticancer activity; structure activity relationship
Online: 11 August 2016 (11:05:21 CEST)
A novel series of thiazole based-1,3,4-thiadiazoles were designed and prepared via the reaction of the 2-(4-methyl-2-phenylthiazole-5-carbonyl)-N-phenylhydrazinecarbothioamide with the appropriate hydrazonoyl chlorides. The structures of the newly synthesized compounds were established based on spectroscopic evidences and their alternative syntheses. Thirteen new 1,3,4-thiadiazoles have been evaluated for their anticancer activity against liver carcinoma cell line (HepG2). Also, their structure activity relationship (SAR) was studied. The 1,3,4-thiadiazoles 12d, 12c, 6g,18b, 6c, and 6f(IC50 = 0.82, 0.91, 1.06, 1.25, 1.29 and 1.88 µM, respectively) have promising antitumor activity against liver carcinoma cell line (HepG2).
ARTICLE | doi:10.20944/preprints202210.0368.v1
Subject: Chemistry And Materials Science, Organic Chemistry Keywords: anabasine; amides; quaternary pyridinium salts; isoxazole; isothiazole; pyridine; adamantane; antiviral activity; antimicrobial activity; analgesic activity; cytisine
Online: 24 October 2022 (13:58:21 CEST)
A series of N-acyl derivatives of anabasine and cytisine were prepared to discover novel natural product-based medicinal agents. All synthesized compounds were tested for antimicrobial, antifungal, antiviral and analgesic activity. The most pronounced antibacterial activity was shown by the compounds with isoxazole fragments, while adamantane derivatives showed the greatest antiviral effect. It was found that the majority of anabasine derivatives showed significant analgesic activity reducing the pain response of animals to the irritating effect of acetic acid. The presence of a high level of antimicrobial and antiviral activity in newly synthesized compounds makes it possible to consider them promising for further study of their pharmacological properties.
ARTICLE | doi:10.20944/preprints202309.1234.v1
Subject: Medicine And Pharmacology, Cardiac And Cardiovascular Systems Keywords: acute emotional stress; sympathetic activity; vagal activity; endothelin; bradyarrhythmias; tachyarrhythmias
Online: 19 September 2023 (11:25:02 CEST)
The ubiquitous peptide endothelin is currently under investigation as a modulatory factor of autonomic responses to acute emotional stress. Baseline plasma levels of endothelin alter blood pressor responses, but it remains unclear whether autonomic activity and arrhythmogenesis are affected. We recorded sympathetic and vagal indices (derived from heart rate variability analysis), rhythm disturbances, voluntary motion, and blood pressure after acute emotional stress in conscious rats with implanted telemetry devices. Two strains were compared, namely wild-type and ETB-deficient rats, the latter displaying elevated plasma endothelin. No differences in heart rate or blood pressure were evident, but sympathetic responses were blunted in ETB-deficient rats, contrasting prompt activation in wild-type rats. Vagal withdrawal was observed in both strains at the onset of stress, but vagal activity was subsequently restored in ETB-deficient rats, accompanied by low voluntary motion during recovery. Reflecting such distinct autonomic patterns, frequent premature ventricular contractions were recorded in wild-type rats, as opposed to sinus pauses in ETB-deficient rats. Thus, chronically elevated plasma endothelin levels blunt autonomic responses to acute emotional stress, resulting in vagal dominance and bradyarrhythmias. Our findings provide further insights into the pathophysiology of stress-induced tachyarrhythmias and syncope.
ARTICLE | doi:10.20944/preprints202307.1759.v1
Subject: Biology And Life Sciences, Biology And Biotechnology Keywords: Antioxidant; Biological activity; GC-MS; Mycochemicals; Pharmacological Activity; Wild Mushrooms
Online: 26 July 2023 (10:17:06 CEST)
Mushrooms are unexploited treasures of secondary metabolites. Analysis of the chemical constituents of these mushrooms would be necessary for the assessment of their pharmacological and biological activities. This study aimed at profiling of mycochemical constituents of five wild mushroom extracts thereby understanding their biological and pharmacological properties. Mushrooms were collected from Arabuko-Sokoke and Kakamega National Reserved Forests, Kenya. Specimens were identified by both morphological and molecular methods. Bioactive compounds were extracted using chloroform, 70% ethanol, and hot water solvents. Chloroform, 70% ethanol, and hot water extracts of Auricularia auricula-judae, Microporus xanthopus, Termitomyces umkowaani, Trametes elegans, and Trametes versicolor were determined using gas chromatography and mass spectrometry (GC-MS). From all extracts, a total of fifty-one (51) compounds were identified and grouped into carboxylic acids, esters, phenols, fatty acids, alcohol, epoxides, aldehyde, fatty aldehyde, isoprenoid lipids, and steroid. Of the total compounds, Oleic acid (72.90%) from Trametes elegans was detected abundantly. Most of the compounds obtained from the chloroform extract of Trametes elegans and 70% ethanol extract of T. umkowaani are fatty acids. The identified compounds have revealed many biological and pharmacological activities such as antimicrobial, antioxidant, antimalarial, anti-inflammatory, insecticidal, anti-helminthic, larvicidal, vasodilator, antihypertensive, hepatoprotective, anticancer, antidiabetic, antifertility anti-diuretic, antiasthma, antifouling, anti-dermatophytic, antispasmodic, anti-hypocholesterolemic, nematicide, pesticide, immunostimulant, antiarthritic, and antihistaminic. These fatty acids are particularly playing important roles in the anti-inflammatory, hypocholesterolemic anticancer, and anti-biofilm formation activities. The presence of these bioactive components suggests that the extracts of five wild mushrooms could be good sources of secondary metabolites for drug discovery.
ARTICLE | doi:10.20944/preprints202307.0286.v1
Subject: Medicine And Pharmacology, Pharmacology And Toxicology Keywords: human hemoglobin; bovine hemoglobin; bioactive peptides; antibacterial activity; antioxidant activity
Online: 6 July 2023 (02:12:27 CEST)
This study focuses on the enzymatic hydrolysis of hemoglobin, the main component of cruor that gives blood its red color in mammals. The antibacterial and antioxidant potential of human hemoglobin hydrolysates were evaluated in comparison to bovine hemoglobin. The results showed strong antimicrobial activity of the peptide hydrolysates against six bacterial strains, independent of the initial substrate concentration level. The hydrolysates also showed strong antioxidant activity measured by four different tests. In addition, the antimicrobial and antioxidant activity of the human and bovine hemoglobin hydrolysates showed little or no significant difference, with only the concentration level being the determining factor in their activity. The results of the mass spectrometry study showed the presence of a number of bioactive peptides, the majority of which have characteristics similar to those mentioned in the literature. New bioactive peptides were also identified in human hemoglobin, such as antibacterial peptides PTTKTYFPHF (α37-46), FPTTKTYFPH (α36-45), TSKYR (α137-141) and STVLTSKYR (α133-141), as well as an antioxidant TSKYR (α137-141). According to these findings, human hemoglobin represents a promising source of bioactive peptides beneficial to the food or pharmaceutical industries.
ARTICLE | doi:10.20944/preprints202008.0524.v1
Subject: Chemistry And Materials Science, Organic Chemistry Keywords: Isoxazolines; nitrile oxide; 1,3-dipolar cycloaddition; antibacterial activity; antioxidant activity
Online: 24 August 2020 (10:03:22 CEST)
A series of derivatives of trans-3-(2,4,6-trimethoxy phenyl)-4,5-dihydro isoxazolo-4,5-bis(aroylcarbohydrazide) and of trans-3-(2,4,6-trimethoxyphenyl)4,5-dihydroisoxazolo-4,5-bis[carbonyl-(4’phenyl)thiosemi- carbazide (9) were synthesized from trans-3-(2,4,6-trimethoxyphenyl)-4,5-dihydro-4,5-bis(hydrazenocarbonyl) Isoxazole (8). The structures of the Compounds were elucidated by elemental and spectral (IR, NMR, and MS) analysis. The compound 9 show activity against some bacterial species. Whereas, no activity was observed for compounds 10a, 10b and 10c against all bacterial species. The antioxidant activity of new compounds has been screened. Compound 9 showed higher antioxidant activity using the DPPH and ATBS method.
Subject: Chemistry And Materials Science, Food Chemistry Keywords: antimicrobial activity; antiradical activity; chitosan; hydroxypropylmethylcellulose; lignin; pathogenic microorganisms; organosolv
Online: 25 March 2019 (11:40:11 CET)
The antiradical and antimicrobial activity of lignin and lignin-based films are both of great interest for applications such as food packaging additives. The polyphenol structure of lignin in addition to the presence of O-containing functional groups is potentially responsible for these activities. This study used DPPH assays to discuss the antiradical activity of HPMC/lignin and HPMC/lignin/chitosan films. The scavenging activity (SA) of both binary (HPMC/lignin) and ternary (HPMC/lignin/chitosan) systems was affected by the percentage of the added lignin: the 5% addition showed the highest activity and the 30% addition had the lowest. Both, scavenging activity and antimicrobial activity are depending on the biomass source showing the following trend: organosolv of softwood > Kraft of softwood > organosolv of grass. Testing the antimicrobial activities of lignins and lignin-containing films showed high antimicrobial activities against gram-positive and gram-negative bacteria at 35 °C and at low temperatures (0-7 °C). Purification of kraft lignin has a negative effect on the antimicrobial activity while storage has positive effect. The lignin release in the produced films affected the activity positively and the chitosan addition enhances the activity even more for both gram-positive and gram-negative bacteria. Testing the films against spoilage bacteria that grow at low temperatures revealed the activity of the 30% addition on HPMC/L1 film against both B. thermosphacta and P. fluorescens while L5 was active only against B. thermosphacta. In HPMC/lignin/chitosan films the 5% addition exhibited activity against both B. thermosphacta and P. fluorescens.
REVIEW | doi:10.20944/preprints202308.0422.v1
Subject: Environmental And Earth Sciences, Sustainable Science And Technology Keywords: biopesticides; plant extracts; essential oils; extraction methods; chemical composition; antimicrobial activity; insecticidal activity; herbicidal activity; alternative agriculture
Online: 4 August 2023 (11:38:20 CEST)
Development and implementation of safe natural alternatives to synthetic pesticides are urgent needs that will provide ecological solutions for control of plant diseases, bacteria, viruses, nematodes, pests, and weeds, to ensure economic stability of the farmers and food security as well as protection of the environment and human health. Unambiguously, production of botanical pesticides will allow sustainable and efficient use of natural resources and finally decrease the use of chemical inputs and burden. This is underlined by the strict regulations on pesticide residues in agricultural products and harmonized with the Farm to Fork strategy aimed to reduce pesticide use by 55%, by 2030. Recognizing the urgent need for natural pesticides development, this work is an overview of the current research on the valorization of Mediterranean plants as potential source of biopesticides. More specifically, the extraction methods, the chemical composition, the biopesticidal activity, the commonly used assays for evaluating the antimicrobial, the pesticidal, the repellant and the herbicidal activity of plant extracts as well as toxicological and safety aspects of biopesticides formulation are discussed in detail. Finally, the aspects that have not yet been investigated or are under- investigated and future perspectives are highlighted.
ARTICLE | doi:10.20944/preprints201903.0244.v1
Subject: Biology And Life Sciences, Neuroscience And Neurology Keywords: vertebrate retina, mouse, zebrafish, two-photon microscopy, biosensor, activity probes, visual stimulus-evoked activity, laser-evoked retinal activity
Online: 26 March 2019 (14:01:49 CET)
Two-photon imaging of light stimulus-evoked neuronal activity has been used to study all neuron classes in the vertebrate retina, from the photoreceptors to the retinal ganglion cells. Clearly, the ability to study retinal circuits down to the level of single synapses or zoomed out at the level of complete populations of neurons, has been a major asset in our understanding of this beautiful circuit. In this chapter, we discuss the possibilities and pitfalls of using an all-optical approach in this highly light-sensitive part of the brain.
ARTICLE | doi:10.20944/preprints202310.1992.v1
Subject: Chemistry And Materials Science, Food Chemistry Keywords: Feta cheese; Metsovone cheese; antioxidant activity; peptide content; anti-inflammatory activity
Online: 31 October 2023 (10:32:13 CET)
The purpose of the present study was to evaluate the antioxidant activity and peptide levels of Feta cheese and other brined cheeses, and Metsovone cheese, and other smoked cheeses. The antioxidant activity was determined by Folin and FRAP assays, while the peptide content was determined by Bradford and Lowry assays. The assays were applied in the water soluble extract of cheeses. The results showed that Feta cheese and brined cow cheese differ in antioxidant activity. Feta cheese and brined goat cheese also differ in both antioxidant activity and peptide levels. Results also showed that Metsovone cheese and other smoked cheeses exhibit antioxidant activity and significant peptide levels. Moreover, the water soluble extracts of all cheeses show some anti-inflammatory activity, suggesting that may peptides exhibit anti-inflammatory activity.
ARTICLE | doi:10.20944/preprints202309.0098.v1
Subject: Chemistry And Materials Science, Medicinal Chemistry Keywords: indole chalcone; antiproliferative activity; antioxidant activity; 2-fluoro substitution; hydroxy substitution
Online: 4 September 2023 (03:11:22 CEST)
The synthesis, anticancer and antioxidant activity of a series of indole-derived hybrid chalcones are reported here. First, using well known Claisen-Schmidt condensation method a set of 29 chalcones has been designed, synthesized, and consequently characterized. Subsequently, screening for the antiproliferative activity of the synthesized hybrid chalcones was performed on the on five cancer (HCT116, HeLa, Jurkat, MDA-MB-231 and MCF7) and two non-cancer (MCF-10A and Bj-5ta) cell lines. Chalcone 18c bearing 1-methoxyindole and catechol structural features, exhibited selective activity against cancer cell lines with IC50 values of 8.0 ± 1.4 µM (Jurkat) and 18.2 ± 2.9 µM (HCT116) and showed no toxicity to non-cancer cells. Furthermore, antioxidant activity was evaluated using tree different methods. The in vitro studies of radical scavenging activity utilizing DPPH radicals, as well as FRAP method, demonstrated the strong activity of catechol derivatives 18a-c. According to the ABTS radical scavenging assay, the 3-methoxy-4-hydroxy substituted chalcones 19a–c were slightly more favorable. In general, a series of 3,4-dihydroxychalcone derivatives showed properties as a lead compound for both antioxidant and anticancer activity.
ARTICLE | doi:10.20944/preprints202305.1839.v2
Subject: Medicine And Pharmacology, Medicine And Pharmacology Keywords: Anti-tubercular agents; DprE1 inhibitor; Structure activity relationship; in vivo activity
Online: 1 June 2023 (07:42:34 CEST)
Tuberculosis (TB) is a leading infectious disease with serious antibiotic resistance. The benzothiazinone (BTZ) scaffold PBTZ169, an inhibitor of the decaprenylphosphoryl-β-D-ribose 2'-oxidase (DprE1) in Mycobacterium tuberculosis (Mtb), showed anti-TB potential in animal model and piloted clinical tests. Although highly potent, the BTZ type DprE1 inhibitors in general shows extremely low aqueous solubility, which adversely affect the drug like property. To improve the compounds physiochemical properties, we generated a series of BTZ analogues. Several optimized compounds had MIC values against Mtb in single digit nanomolar. The representative compound 37 displayed improved solubility and bioavailability compared to the lead compound. Additionally, compound 37 shows Mtb-killing ability in an acute infection mouse model.
ARTICLE | doi:10.20944/preprints202211.0146.v1
Subject: Biology And Life Sciences, Immunology And Microbiology Keywords: Antioxidant activity; Antibacterial activity; Melissopalynological and Physiochemical analysis; Moringa alfileria honey
Online: 8 November 2022 (04:49:57 CET)
Objective: The aim of the study was to characterize varieties of Moringa alfileria honey (unfloral and polyfloral) from Saudi Arabia based on antibacterial, antioxidant activities, physicochemical, melissopalynological analysis, total phenolic and flavonoid contents. Material and Methods: The fresh 376 honey samples (3 kg of each) were kindly provided by Alnahal aljwal Company, 2021 flowering season. The honey samples collected in sterile universal glass containers and kept at 2– 8°C until tested. Antibacterial, antioxidant activities and physiochemical analysis were done. Determination of sediment content, total grains, moisture content, water-soluble solids, acidity, electrical conductivity, total sugars content, inverted sugars, glucose (g/100 g), fructose (g/100 g), total glucose + fructose, fructose/ glucose ratio, sucrose (g/100 g), diastase enzyme activity and HMF were calculated. As well as total phenolic and flavonoid contents Results: Antibacterial activity and physiochemical analysis of honey samples w varied. All parameters studied were significantly different (P < 0.05) among all honey varieties. The results of the physiochemical analysis were compared with Saudi National Standard, Codex standard, as well as published data in the literature. Conclusion: It was obvious that the honey quality was varied based on the botanical origins
ARTICLE | doi:10.20944/preprints201810.0236.v1
Subject: Biology And Life Sciences, Immunology And Microbiology Keywords: essential oils; drug resistant microorganisms; antimicrobial activity; antifungal activity; medicinal plants
Online: 11 October 2018 (11:51:16 CEST)
Antimicrobial resistance (AMR) is a recurring global problem, which constantly demands new antimicrobial compounds to challenge the resistance. It is well known that essential oils (EOs) have been known for biological activities including antimicrobial properties. In this study, EOs from seven aromatic plants of Asir region of southwestern Saudi Arabia were tested for their antimicrobial efficacy against four drug resistant pathogenic bacterial isolates (Staphylococcus aureus, Streptococcus pyogenes, Escherichia coli and Streptococcus typhimurium) and one fungal isolate (Candida albicans). Chemical compositions of EOs were determined by Gas chromatography-Mass Spectrometry (GC-MS). The results revealed that EOs from Mentha cervina, Ocimum basilicum and Origanum vulgare proved most active against all isolates with inhibitory zone range between17 to 45 mm. The lowest minimum inhibitory concentration (MIC) of 0.025mg/ml was observed for Staph. aureus and Streptococcus pyogenes with EO of Origanum vulgare. All the three EOs showed significant anti candida activity. Together form the results the EOs from Mentha cervina, Ocimum basilicum and Origanum vulgare demonstrated a significant antimicrobial efficacy against drug resistant microorganisms.
ARTICLE | doi:10.20944/preprints201811.0574.v1
Subject: Chemistry And Materials Science, Medicinal Chemistry Keywords: activity cliff; activity landscape plotter; epigenetics; docking; drug discovery; D-tools; molecular dynamics; Epi-polypharmacology; SmART; structure-activity relationships
Online: 26 November 2018 (07:14:05 CET)
In this work we discuss the insights from activity landscape, docking and molecular dynamics towards the understanding of the structure-activity relationships of dual inhibitors of major epigenetic targets: lysine metiltransferase (G9a) and DNA metiltranferase 1 (DNMT1). The study was based on a novel data set of 50 published compounds with reported experimental activity for both targets. The activity landscape analysis revealed the presence of activity cliffs, e.g., pairs of compounds with high structure similarity but large activity difference. Activity cliffs were further rationalized at the molecular level by means of molecular docking and dynamics simulations that led to the identification of interactions with key residues involved in the dual activity or selectivity with the epigenetic targets.
ARTICLE | doi:10.20944/preprints202107.0138.v2
Subject: Computer Science And Mathematics, Artificial Intelligence And Machine Learning Keywords: Contrastive learning; activity recognition; healthcare
Online: 9 July 2021 (15:46:05 CEST)
Human Activity Recognition (HAR) is a process to automatically detect human activities based on stream data generated from various sensors, including inertial sensors, physiological sensors, location sensors, cameras, time, and many others. Unsupervised contrastive learning has been excellent, while the contrastive loss mechanism is less studied. In this paper, we provide a temperature (τ) variance study affecting the loss of SimCLR model and ultimately full HAR evaluation results. We focus on understanding the implications of unsupervised contrastive loss in context of HAR data. In this work, also regulation of the temperature(τ) coefficient is incorporated for improving the HAR feature qualities and overall performance for downstream tasks in healthcare setting. Performance boost of 1.3% is observed in experimentation.
REVIEW | doi:10.20944/preprints202307.0358.v1
Subject: Biology And Life Sciences, Agricultural Science And Agronomy Keywords: botanical extracts; sustainable management of pests; insecticide activity; insectistatic activity; insect pests
Online: 6 July 2023 (03:03:43 CEST)
The use of botanical extracts of the plant Jatropha curcas (Euphorbiaceae) represents a valuable alternative to control insect pests and avoid the detrimental effects on the environment and health that arise due to synthetic chemical insecticides. Thus, we conducted a systematic review to summarize the published evidence on the bioactivity of J. curcas against insect pests. Electronic databases were searched to identify studies that assessed J. curcas extracts against insect pests in various types of crops. We included 39 articles that reported the insecticidal and insectistatic activity of several botanical extracts from J. curcas against insects of eight different taxonomic orders. The evidence demonstrates that aqueous and methanolic extracts from seeds and leaves, seed oil, and petroleum ether seed extracts were effective against insect pests of stored grains, aphids of cabbage, sorghum, fruit flies, and desert locusts. The extracts caused high mortality, controlled the populations, reduced oviposition, diminished hatchability, and increased the antifeedant effect. However, the type of solvent used to obtain the botanical extract and the method of application (contact or food) are fundamental to increase its bioactivity. Therefore, botanical extracts from seeds and leaves of J. curcas should be considered as an alternative against insect pests and may be incorporated into integrative and sustainable management for insect control.
ARTICLE | doi:10.20944/preprints202304.0454.v1
Subject: Biology And Life Sciences, Animal Science, Veterinary Science And Zoology Keywords: Bovine Interferon-λ3; Pichia pastoris; Codon optimization; Glycosylation; Antiviral activity; Antiproliferative activity
Online: 17 April 2023 (10:53:42 CEST)
Type III interferon (IFN-λs) exhibit potent antiviral activity and immunomodulatory effects in specific cells. Nucleotide fragements of bovine ifn-λ (boifn-λ) gene was synthetized after codon optimization. The boifn-λ gene was then amplified by splicing by overlap extension PCR (SOE PCR), resulting in serendipitous acquisition of the mutated boIFN-λ3V18M. Recombinant plasmids pPICZαA-boIFN-λ3/λ3V18M were constructed and the corresponding proteins were expressed in Pichia pastoris with high-level extracellular soluble form. Dominant expression strains of boIFN-λ3/λ3V18M were selected by Western blot and ELISA, cultured on a large scale, and the recombinant proteins purified by ammonium sulphate precipitation and ion exchange chromatography, yielding 1.5g/L and 0.3 g/L, with 85% and 92% purity, respectively. The antiviral activities of boIFN-λ3/λ3V18M exceeded 106 U/mg, were neutralized with IFN-λ3 polyclonal antibodies, were susceptible to trypsin, and retained stability within defined pH and temperature ranges. Furthermore, boIFN-λ3/λ3V18M exerted antiproliferative effects on MDBK cells without cytotoxicity at 104 U/mL. Overall, boIFN-λ3 and boIFN-λ3V18M did not differ substantially in biological activity, except for reduced glycosylation of the latter. Development of boIFN-λ3 and comparative evaluation with the mutant provide theoretical insights into antiviral mechanisms of boIFN-λs and provide material for therapeutic development.
ARTICLE | doi:10.20944/preprints202211.0463.v1
Subject: Social Sciences, Behavior Sciences Keywords: Neuroscience; Education; Learning; Brain activity; Heart activity; Skin Conductance; Neuroimaging; Wearable devices
Online: 25 November 2022 (02:40:05 CET)
Nowadays, fostered by technological progress and contextual circumstances such as economic crisis and pandemic restrictions, remote education is living a growing deployment. However, this growth generated widespread doubts about the actual effectiveness of remote/online compared to face-to-face education. The present study aimed at comparing face-to-face and remote education through a multimodal neurophysiological approach. It involved forty students at a driving school, during a real classroom, experiencing both the modalities. Wearable devices to measure brain, ocular, heart and sweating activities were employed in order to analyse the students’ neurophysiological signals to obtain insights about their cognitive dimension. In particular, four parameters were considered, the Eye Blink Rate, the Heart Rate and its Variability and the Skin Conductance Level. Also, the students filled a questionnaire at the end to obtain an explicit measure of their learning performance. Data analysis showed a higher cognitive activity, in terms of attention and mental engagement, in presence with respect to remote modality. On the other hand, students by remote felt more stressed, in particular during the first part of the lesson. Analysis of questionnaires demonstrated worst performance by remote, thus suggesting a common “disengaging” behaviour when attending remote courses, thus undermining their effectiveness. In conclusion, neuroscientific tools could help to obtain insights about mental concerns, often «blind», such as attentional decreasing and stress increasing, as well as their dynamics during the lesson itself, so allowing to define proper countermeasures to emerging issues when introducing new practices into daily life.
HYPOTHESIS | doi:10.20944/preprints202106.0313.v1
Subject: Computer Science And Mathematics, Algebra And Number Theory Keywords: group activity recognition; graph convolution network; video understanding; video analytics; activity recognition
Online: 11 June 2021 (10:37:38 CEST)
In this paper, we propose a robust video understanding model for activity recognition by learning the actor’s pair-wise correlations and relational reasoning, exploiting spatial and temporal information. In order to measure the similarity between the pair appearances and construct an actor relations map, the Zero Mean Normalized Cross-Correlation (ZNCC) and the Zero Mean Sum of Absolute Differences(ZSAD) is proposed to allow the Graph Convolution Network (GCN) to learn how to distinguish group actions. We recommend that MNASNet be used as the backbone to retrieve features. Experiments show a 38.50% and 23.7% reduction in training time in the 2-stage training process along with a 1.52% improvement in accuracy against traditional methods.
ARTICLE | doi:10.20944/preprints201805.0356.v1
Subject: Biology And Life Sciences, Immunology And Microbiology Keywords: Scoprion Venoms; Hos Defence Peptides; antimicrobial activity; antibiofilm activity; synergism; bacterial resistance
Online: 25 May 2018 (09:26:11 CEST)
Current research in the field of antimicrobials is focused on the development of novel antibiotics and antimicrobial agents to counteract the huge dilemma that the human population is mainly facing in regards to the rise of bacterial resistance and biofilm infections. Host Defense peptides (HDPs) are a promising group of molecules for antimicrobial development as they share unique characteristics suitable for antimicrobial activity including their broad spectrum of activity and potency against bacteria. AamAP1 is a novel HDP that was identified through molecular cloning from the venom of the North African scorpion Androctonus amoeruxi. In vitro antimicrobial assays revealed that the peptide displays moderate activity against different strains of Gram-positive and Gram-negative bacteria. Additionally, the peptide proved to be highly hemolytic and displaying significantly high toxicity against mammalian cells. In our study, a novel synthetic peptide analogue named A3 was designed from the naturally occurring scorpion venom host defense peptide. The design strategy depended on modifying the amino acid sequence of the parent peptide in order to increase its net positive charge, percentage helicity and optimize other physico-chemical parameters involved theoretically in HDPs activity. Accordingly, A3 was evaluated for its in vitro antimicrobial and anti-biofilm activity individually and in combination with four different types of conventional antibiotics against clinical isolates of multi-drug resistant (MDR) Gram-positive bacteria. A3 was also evaluated for its cytotoxicity against mammalian cells. A3 displayed potent and selective in vitro antimicrobial activities against a wide range of MDR Gram-positive bacteria. Our results also showed that combining A3 with conventional antibiotics displayed a synergistic mode of action which resulted in decreasing the MIC value for A3 peptide as low as 0.125 µM. These effective concentrations were associated with negligible toxicities on mammalian cells. In conclusion, A3 exhibits enhanced activity and selectivity when compared with the parent natural scorpion venom peptide. The combination of A3 with conventional antibiotics may be pursued as a potential novel treatment strategy against MDR and biofilm forming bacteria.
ARTICLE | doi:10.20944/preprints201804.0100.v1
Subject: Medicine And Pharmacology, Orthopedics And Sports Medicine Keywords: Cd36; mass spectrometry; NAFLD; anti-lypase activity; anti-amylase activity; insulin resistance
Online: 9 April 2018 (08:28:02 CEST)
Rhizophora mangle L. is a well-known medicinal plant found in mangroves worldwide used to treatment diabetes. This study evaluated the chemical composition of the acetonic extract from Rhizophora mangle barks (AERM), by HPLC-PDA and FIA-ESI-IT-MS/MS and the effects on high-fat diet induced obesity in mice and its mechanism of action by gene expression of inflammatory markers (Pparg, Ppara, Srebf1, Cd36, Tnf, Ccl2, Lep, Il10, Il6, Fasn, 18s). High-fat diet fed mice during 12 weeks was used as model of obesity and associated alterations. The results were very satisfactory, the extract, rich in polyphenolic compounds, flavonoids and phenolic acids, displayed intense antioxidant activity in vitro (608 µmol Trolox/g), and showed excellent activity against non-alcoholic fatty liver disease (NAFLD) and reverse insulin resistance in a model of diet-induced obesity. We can registered a modulatory effect of AERM in liver PPAR-γ mRNA expression associated to an important inhibition of CD36 mRNA expression suggesting that AERM induces the down regulation of CD36 mRNA via PPAR-gamma inhibition. These results support the traditional knowledge about the use of R. mangle for the treatment of type 2 diabetes and reveal the potential of AERM for the treatment of NAFLD and management of obesity and comorbidities.
ARTICLE | doi:10.20944/preprints202311.1063.v1
Subject: Chemistry And Materials Science, Nanotechnology Keywords: carvacrol; microemulsion; nanoemulsion; active coatings; nanostructure; pork meat preservation; antioxidant activity; antibacterial activity
Online: 16 November 2023 (10:30:11 CET)
Carvacrol is well-documented for its antibacterial and antioxidant effects. However, its high volatility has directed researchers towards nanoencapsulation technology according to bioeconomy and sustainability trends. This study examined and compared carvacrol microemulsion (MC), carvacrol microemulsion busted with chitosan (MMC) and carvacrol nanoemulsions as active coatings on extending minced pork meat shelf-life at 4±1 oC for 9 days, focusing on microbiological, physiochemical, and sensory characteristics. The research involved pre-characterizing droplet sizes, evaluating antioxidant, and determining antibacterial efficacy. The results demonstrated that NC with a 21 nm droplet size exhibited the highest antioxidant and antibacterial activity. All coatings succeed to extend the preservation of fresh minced pork meat in comparison to free carvacrol sample (FC). NC coating showed the highest extension of minced pork meat preservation and maintained meat freshness for 9 days, with a lower TBARs of 0.736 mg MDA/Kg, and effectively reduced mesophilic, lactic acid, and psychrotrophic bacterial counts more significantly 1.2, 2, and 1.3 log respectively as compared to FC. Sensory assessments confirmed the acceptability of NC and MCC coatings. Overall, the carvacrol based nanoemulsion can be considered as novel antioxidant and antimicrobial active coating due to its demonstrated higher efficacy in all the examined tests performed.
ARTICLE | doi:10.20944/preprints202308.0877.v1
Subject: Medicine And Pharmacology, Pharmacology And Toxicology Keywords: Quinolizidine derivatives; Lupinine, Cytisine; Sparteine; Antiarrhythmic activity; Inotropic and chronotropic activities; Vasorelaxant activity
Online: 11 August 2023 (03:03:24 CEST)
Fourteen quinolizidine derivatives, structurally related to the alkaloids lupinine and cytisine and previously studied for other pharmacological aims, were presently tested for antiarrhythmic, inotropic, and chronotropic effects on isolated guinea pig heart tissues, and to assess calcium antagonism in comparison to amiodarone, lidocaine, procainamide, and quinidine. All compounds, but two, compared favorably with the reference drugs. Potent antiarrhythmic activity was observed for compounds (in increasing order) 4, 1, 6 and 5. The last compound N-(3,4,5-trimethoxybenzoyl)aminohomolupinane) was outstanding, exhibiting a nanomolar potency (EC50 = 0.017 µM) for the increase of threshold of ac-arrhythmia, and being devoid of antihypertensive activity against spontaneously hypertensive rats.
ARTICLE | doi:10.20944/preprints202104.0026.v1
Subject: Biology And Life Sciences, Biochemistry And Molecular Biology Keywords: chloramphenicol; alkyl(triphenyl)phosphonium; bacterial ribosome; molecular dynamics simulations; antibiotic activity; antiproliferative activity
Online: 1 April 2021 (14:38:19 CEST)
In the current work, in continuation of our recent research  we synthesized and studied new chimeric compounds comprising the ribosome-targeting antibiotic chloramphenicol (CHL) and the membrane-penetrating cation triphenylphosphonium (TPP) connected by alkyl linkers of different lengths. Using various biochemical assays, we showed that these CAM-Cn-TPP compounds bind to the bacterial ribosome, inhibit protein synthesis in vitro and in vivo in a way similar to that of the parent CHL, and significantly decrease membrane potential. Similar to CAM-C4-TPP, the mode of action of CAM-C10-TPP and CAM-C14-TPP on bacterial ribosomes differ from that of CHL. By simulating the dynamics of complexes of CAM-Cn-TPP with bacterial ribosomes, we have proposed a possible explanation for the specificity of the action of these analogs on the translation process. CAM-C10-TPP and CAM-C14-TPP stronger inhibit the growth of the Gram-positive bacteria in comparison to the CHL and suppress some strains of CHL-resistant bacteria. Thus, we have shown that TPP derivatives of CHL are dual-acting compounds that target the ribosomes and the cellular membranes of bacteria. The TPP fragment of CAM-Cn-TPP compounds contributes to the inhibitory effect on bacteria. Moreover, since the mitochondria of eukaryotic cells have qualities similar to those of their prokaryotic ancestors, we demonstrate the possibility of targeting chemoresistant cancer cells with these compounds.
ARTICLE | doi:10.3390/sci2030060
Subject: Computer Science And Mathematics, Artificial Intelligence And Machine Learning Keywords: locomotion; machine learning; support vector machines; activity classification; activity of daily life (ADL)
Online: 18 July 2020 (00:00:00 CEST)
Although Support Vector Machines (SVM) are widely used for classifying human motion patterns, their application in the automatic recognition of dynamic and static activities of daily life in the healthy older adults is limited. Using a body mounted wireless inertial measurement unit (IMU), this paper explores the use of SVM approach for classifying dynamic (walking) and static (sitting, standing and lying) activities of the older adults. Specifically, data formatting and feature extraction methods associated with IMU signals are discussed. To evaluate the performance of the SVM algorithm, the effects of two parameters involved in SVM algorithm—the soft margin constant C and the kernel function parameter
—are investigated. The changes associated with adding white-noise and pink-noise on these two parameters along with adding different sources of movement variations (i.e., localized muscle fatigue and mixed activities) are further discussed. The results indicate that the SVM algorithm is capable of keeping high overall accuracy by adjusting the two parameters for dynamic as well as static activities, and may be applied as a tool for automatically identifying dynamic and static activities of daily life in the older adults.
ARTICLE | doi:10.20944/preprints202306.0378.v1
Subject: Biology And Life Sciences, Neuroscience And Neurology Keywords: Electrodermal activity; Photoplethysmography; Consumer wearables
Online: 6 June 2023 (04:27:30 CEST)
The capability of measuring specific neurophysiological and autonomic parameters plays a crucial role in the objective evaluation of the human’s mental and emotional states. These human aspects are commonly known in scientific literature to be involved in a wide range of processes, such as the stress and arousal. These aspects represent a relevant factor especially in real and operational environment. Neurophysiological autonomic parameters, such as the Electrodermal Activity (EDA) and Photoplethysmographic data (PPG), have been usually investigated through research-graded devices, therefore resulting in a high degree of invasiveness, which could negatively interfere with the monitored user’s activity. For such a reason, in the last decade the recent consumer-grade wearable devices, usually designed for fitness tracking purposes, are receiving an increasing attention from the scientific community, being characterized by higher comfort, easiness of use and, therefore, by higher compatibility with dailylife environments. The present preliminary study aimed at assessing the reliability of a consumer wearable device, i.e., the Fitbit Sense, with respect to a research-graded wearable, i.e., the Empatica E4 wristband, and a laboratory device, i.e., the Shimmer GSR3+. The EDA and PPG were collected among 12 participants while performing multiple resting conditions. The results demonstrated that the EDA and PPG-derived features computed through the wearable and research devices were positively and significantly correlated, while the reliability of the consumer device resulted to be significantly lower.
ARTICLE | doi:10.20944/preprints202305.1975.v1
Subject: Biology And Life Sciences, Biology And Biotechnology Keywords: Cosmetic activity; resveratrol; glucosylation; amylosucrase
Online: 29 May 2023 (05:23:38 CEST)
A biocatalytic system that could produce bioactive resveratrol poly-glucosides using sucrose as a low-cost source of UDP-glucose donors and amylosucrase DgAS from Deinococcus geothermalis was developed in this study. This system boasts several advantages, including fast and direct conversion of substrates to products, thermostable, and regio-stereospecific, and effectiveness in vitro and in vivo at 40°C. With a success rate of around 97.0% in a short period in vitro and 95.0% in vivo, resveratrol-O-glucosides showed exciting outcomes in cosmetic activities, such as antioxidant, anti-inflammatory, anti-aging, and whitening effects when tested with Raw 264.7, B16, and HS68 cell lines. DgAS is recognized as an important biocatalyst due to its higher thermostability, effectiveness, and specificity among all known amylosucrases (ASases) in the production of poly-glucosides in a chain of polyphenols, like resveratrol, making it an ideal candidate for industrial use to cost-effective production of cosmetic items.
REVIEW | doi:10.20944/preprints202203.0009.v1
Subject: Biology And Life Sciences, Biology And Biotechnology Keywords: bee propolis; biological activity; antibacterial
Online: 1 March 2022 (08:30:12 CET)
Antibiotic resistance was described soon discovery of penicillin by Fleming. In recent years, there has been increasing research interest in the development of alternatives to address this problem. Natural products, mainly, have long been considered as sources of drugs, and a great part of pharmaceuticals available in modern medicine are directly or indirectly derived from natural sources. propolis been used to treat human diseases since ancient times, propolis, is a natural resinous mixture produced by honeybees (Apis mellifera) from collected parts of plants, he is increasingly recognized by their wide range of biological and pharmacological properties, As anti- infective agent, combination synergy with standard antibiotics could be very promising alternative strategy
COMMUNICATION | doi:10.20944/preprints202102.0306.v1
Subject: Public Health And Healthcare, Public, Environmental And Occupational Health Keywords: Quarantine; COVID-19; Physical activity
Online: 12 February 2021 (14:39:16 CET)
The COVID-19 pandemic which have affected every part of the world have been deemed a public health concern and classified as a pandemic. The government imposing travel bans and quarantine measures have been found to be effective in preventing and reducing the spread of COVID-19. A reduction in physical activity and increase in the consumption of unhealthy foods have been observed to be some of the major implications of quarantine. Adequate physical activity and increased access to healthy foods would help in improving the psychological wellbeing of individuals thereby preventing the development of cardiovascular diseases.
ARTICLE | doi:10.20944/preprints201901.0307.v1
Subject: Chemistry And Materials Science, Medicinal Chemistry Keywords: molecular docking; fluoroquinolones; antimicrobial activity
Online: 30 January 2019 (09:31:52 CET)
An important parameter in the development of a new drug is the drug's affinity to the identified target (protein/enzyme). Predicting the ligand binding to the target (protein/enzyme) by molecular simulation would allow the synthesis to be restricted to the most promising compounds.A restricted hybrid HF-DFT calculation was performed in order to obtain the most stable conformer of each ligand and a series of DFT calculations using the B3LYP levels with 6-31G* basis set has been conducted. The docking studies of the quinolone compounds will be performed with the CLC Drug Discovery Workbench to identify and visualize the ligand-receptor interaction mode.
ARTICLE | doi:10.20944/preprints201811.0417.v1
Subject: Biology And Life Sciences, Biochemistry And Molecular Biology Keywords: nanoparticles; biological; stability; antimicrobial activity
Online: 19 November 2018 (05:10:11 CET)
Previously the nanoparticles were synthesized by chemical methods which were costly and toxic to bio-systems. Plant extracts provides simpler, eco-friendly and cost efficient method for synthesizing nanoparticles. Lemon peel extract (LPE) was used to synthesize silver nanoparticles (AgNPs) which were evaluated for their antimicrobial effects after optimizing the pH of extract and concentration of both extract and synthesized AgNPs. The characterization of synthesized AgNPs was carried out using Ultraviolet-Visible (UV-Vis) Spectrophotometer, Fourier transform infrared spectroscopy (FTIR), and X-ray diffraction (XRD). Well diffusion method was used to determine the antimicrobial activities of synthesized AgNPs. The presence of phenols and proteins was assumed to reduce the Ag+ ion into silver nanoparticles. The characteristic surface plasmon resonance frequency was observed at 405–425 nm for all varying condition of silver nanoparticles synthesis. Furthermore, results revealed that the synthesized AgNPs remains stable upto 75 days. The average particle size was 2–5 nm, calculated with the help of scherrer’s equation by using XRD data. LPE mediated AgNPs (200 µg/mL) showed significant antimicrobial activity, compared to commercially available nanoparticles while LPE (50 mg/ml) showed no effect. LPE mediated AgNPs might get attention of pharmacists in order to design medicines against different diseases including the infections of bacteria.
ARTICLE | doi:10.20944/preprints201611.0043.v1
Subject: Chemistry And Materials Science, Medicinal Chemistry Keywords: chalcone; cytotoxic activity; pharmacophore model
Online: 7 November 2016 (08:30:12 CET)
A series of novel isobutylchalcones (A1-A20) were prepared, evaluated for their cytotoxic activity and characterized by FTIR, 1H NMR, 13C NMR, and elemental analysis data. The logic behind the design is to synthesize and compare chalcones containing electron releasing lipophilic isobutyl substituent on aromatic ring A and the B ring with aromatic ring containing a range of electron releasing and electron withdrawing groups as well as heteroaromatic rings for their cytotoxic activity. The compounds were tested against HT-29 (colon cancer), MCF-7 (breast cancer) and DU-145 (prostate cancer) cell lines using methotrexate (IC50 12 ± 1 (HT-29), 9 ±1 (MCF-7) 5 ± 1 (DU-145)) as reference standard. Compound A6 having 2,4-difluorphenyl moiety was most potent of the series against all the three cell lines and notably A6 was mainly effective against DU-145 cell lines with an IC50 value of 18 µg/mL. The critical structural features required for the activity against all the cell lines were identified through pharmacophore model using PHASETM which has recognised a 5 point AHHRR model and is consistent with the cytotoxic activity of the tested compounds.
ARTICLE | doi:10.20944/preprints202306.1502.v1
Subject: Biology And Life Sciences, Plant Sciences Keywords: Opilia amentacea; phytochemical screening; antioxidant activity; antimicrobial activity; Minimal inhibitory concentration; Minimal bactericidal concentration
Online: 21 June 2023 (08:24:19 CEST)
Dermatoses are essentially due to infectious or free radical aggression, immunoallergic disor-ders, or can be secondary to general diseases. To investigate new antimicrobial sources against dermatoses, Opilia amentacea crude ethanol extracts and fractions were subjected to phytochemical screening and tested for antioxidant and antimicrobial activities on Gram-positive cocci, Gram negative bacilli and fungi. Phytochemical screening revealed secondary metabolites such as sterols, triterpenes, flavonoids and tannins. Leaves and stem bark of Opilia amentacea exhibited the highest total phenolic contain (65,92 ± 0,93 and 65,71 ± 0,57 mg GAE/g DW respectivily) and flavonoids (38,8 ± 1,05 and 26,81 ± 0,19mg QE/g DW respectively). Dichloromethane fractions of leaves (FDFe) and stem bark (FDET) exhibited the best antioxidant activity with FRAP values of 741,15 and 662,84 mMol AAE/g and IC50 values of ABTS of 88,40 and 36,85 µg/mL respectively. These fractions were also the most active on Gram positive bacilli while Hexane leaves (FHFe) and hexane root bark (FHER) fractions exhibited the best antifungal activity against Candida tropicalis at MIC values of 0.23 mg/mL and 0.43 mg/mL respectively. Gram-negative bacteria were particularly resistant. This study constitutes a solid scientific basis that could justify the traditional uses of Opilia amen-tacea as an antidermatosis plant.
ARTICLE | doi:10.20944/preprints202104.0137.v1
Subject: Environmental And Earth Sciences, Atmospheric Science And Meteorology Keywords: urban surface deposited sediments (USDS); gross alpha activity (GA); gross beta activity (GB); dust
Online: 5 April 2021 (13:00:40 CEST)
Study of gross alpha (GA) and gross beta (GB) activity in road and surface deposited sediments were performed in various geographical areas in three Russian cities. To perform radiation measurements, new methods were applied which allow dealing with low mass and low volume dust size (2-100μm) samples obtained after the size fractionation procedure. The 2-10 μm fraction size has the highest gross beta activity concentration (GB)– 1.32Bq/g in Nizhny Novgorod (NN) and Rostov-On-Don (RND) while the 50-100 μm fraction size in Ekaterinburg. This is maybe associated with the subsistence of radionuclides that conveyed through natural processes and anthropogenic applications. The highest gross alpha activity concentration (GA) in fraction sizes was found in Rostov-on-Don city within the 50-100 μm– 0.22Bq/g. The fraction size 50-100 μmhas a higher gross alpha activity concentration than 2-10 and 10-50 μmfraction sizes due to natural partitioning of the main minerals constituting the urban surface deposited sediment (USDS). The geochemical processes that occur during the formation and transportation of USDS are reflected in the observed dependencies.Developed experimental methods of radiation measurements allowed to the extent the methodological base of urban geochemical studies.
Subject: Social Sciences, Behavior Sciences Keywords: emotion recognition; EEG signal decoding; brain anticipatory activity; machine learning; emotion related brain activity
Online: 31 December 2019 (10:05:27 CET)
Machine Learning (ML) approaches have been fruitfully applied to several classification problems of neurophysiological activity. Considering the relevance of emotion in human cognition and behaviour, ML found an important application field in emotion identification based on neurophysiological activity. Nonetheless, the literature results present a high variability depending on the neuronal activity measurement, the signal features and the classifier type. The present work aims to provide new methodological insight on ML applied to emotion identification based on electrophysiological brain activity. For this reason, we recorded EEG activity while emotional stimuli, high and low arousal (auditory and visual) were provided to a group of healthy participants. Our target signal to classify was the pre-stimulus onset brain activity. Classification performance of three different classifiers (LDA, SVM and kNN) was compared using both spectral and temporal features. Furthermore, we also contrasted the classifiers performance with static and dynamic (time evolving) features. The results show a clear increased in classification accuracy with temporal dynamic features. In particular, the SVM classifiers with temporal features showed the best accuracy (63.8 %) in classifying high vs. low arousal auditory stimuli.
ARTICLE | doi:10.20944/preprints201711.0082.v1
Subject: Medicine And Pharmacology, Oncology And Oncogenics Keywords: fatty hydroxamic acids; synthesis; spectroscopy; antioxidant activity; cytotoxic activity; biological targets; ADMET; safety profile
Online: 14 November 2017 (04:42:18 CET)
A fatty hydroxamic acid (FHA) mixture synthesized from olive oil triacylglycerides by hydroxylaminolysis and composed predominantly of oleyl and linoleyl hydroxamic acid (OHA and LHA, respectively) was characterized by means of IR, Raman, MS and 1D and 2D 1H- and 13C-NMR spectroscopy. The ratio of OHA and LHA (4:1) was confirmed by MALDI TOF/TOF mass spectrometry. The radical scavenging and the Fe2+-chelating activity, as well as antioxidant activity in β-carotene-linoleic acid and the Fe3+-reducing power assays of the FHAs yielded positive results. The results of FHA cell toxicity on normal fibroblast (BJ) and a tumour cell line (HeLa) revealed that the normal cell line was sensitive to FHAs within the entire range of applied concentrations (5 × 10−4 mg/mL to 5 × 10−1 mg/mL), while the HeLa tumour cell line was sensitive only at the highest FHA concentration (5 × 10−1 mg/mL). In silico target prediction indicated cannabinoid receptors 1 and 2, the fatty-acid amide hydrolase 1 and hystone deacetylases as the most probable targets of OHA and LHA. According to ADMET predictor analysis, the safety profiles of OHA and LHA are comparable to that of SAHA (vorinostat) the histone deacetylase inhibitor in use as an antineoplastic and immunomodulating agent.
ARTICLE | doi:10.20944/preprints201703.0017.v1
Subject: Chemistry And Materials Science, Nanotechnology Keywords: green synthesis; silver nanoparticles; trimethylchitosan nitrate; catalytic activity; antibacterial activity; multidrug-resistant Acinetobacter baumannii
Online: 2 March 2017 (08:49:35 CET)
We report a facile route for the green synthesis of trimethylchitosan nitrate-capped silver nanoparticles (TMCN-AgNPs) with positive surface charge. In this synthesis, silver nitrate, glucose, and trimethyl chitosan nitrate (TMCN) were used as silver precursor, reducing agent, and stabilizer, respectively. The reaction was carried out in a stirred basic aqueous medium at room temperature without the use of energy-consuming or expensive equipment. We investigated the effects of the concentrations of NaOH, glucose, and TMCN on the particle size, zeta potential, and formation yield. The AgNPs were characterized by UV-visible spectroscopy, photon correlation spectroscopy, laser Doppler anemometry, transmission electron microscopy, X-ray diffraction, and X-ray photoelectron spectroscopy. The catalytic activity of the TMCN-AgNPs was studied by the reduction of 4-nitrophenol using NaBH4 as a reducing agent. We evaluated the antibacterial effects of the TMCN-AgNPs on Acinetobacter baumannii, Escherichia coli, Pseudomonas aeruginosa, and Staphylococcus aureus using the broth microdilution method. The results showed that both gram-positive and gram-negative bacteria were killed by the TMCN-AgNPs at very low concentration (< 6.13 μg/mL). Moreover, the TMCN-AgNPs also showed high antibacterial activity against clinically isolated multidrug-resistant A. baumannii strains, and the minimum inhibitory concentration (MIC) was ≤ 12.25 μg/mL.
ARTICLE | doi:10.20944/preprints202309.1275.v1
Subject: Chemistry And Materials Science, Analytical Chemistry Keywords: OSMAC method; marine-derived actinobacteria; molecular network; natural product; specialized metabolites; cytotoxic activity; antiplasmodial activity
Online: 19 September 2023 (08:50:39 CEST)
Actinobacteria are known for their production of bioactive specialized metabolites, but still under-exploited due to silent biosynthetic gene clusters (BGCs) not expressed in conventional laboratory cultures conditions. In this study, three marine-derived actinobacteria were cultured using the one strain many compounds method (OSMAC) to explore the real potential of these microorganisms. Salinispora arenicola (SH-78) and two Micromonospora sp. (SH-82 and SH-57) were grown under varying parameters such as time, medium composition, and culture support. The microbial extracts produced were chemically screened by high-resolution analysis (HRMS/MS). The data were used to build ion identity molecular networks (IIMN) and annotate the specialized metabolites detected. A selection of extracts was biologically screened for their cytotoxic and antiplasmodial activities. The IIMNs and the annotations produced were used to assess the impact of culture parameters on the metabolomic diversity of the selected actinobacteria and highlight the presence of unique molecules to specific culture conditions. Micromonospora sp. SH-57 produced a greater quantity of metabolites in liquid culture, with higher associated biological activity. The method employed allowed to explore deeper the specialized metabolites production and to identify the best culture conditions to produce bioactive natural products.
ARTICLE | doi:10.20944/preprints202304.1009.v1
Subject: Chemistry And Materials Science, Nanotechnology Keywords: Ag nanoparticles; Ag-TiO2 nanoparticles; cotton fabrics; photocatalytic activity; biocide activity; E. coli; S. aureus
Online: 27 April 2023 (03:05:20 CEST)
Composites of Ag and TiO2 nanoparticles on cotton fabrics were synthetized in-situ by sono-chemical and hydrothermal methods achieving the successive formation of Ag-NPs and Ti-NPs directly on the fabric. The impregnated fabrics were characterized by ATR-FTIR spectroscopy, high resolution microscopy (HREM), scanning electron microscopy coupled with Ener-gy-dispersive X-ray spectroscopy (SEM-EDS), Raman, photoluminescence, UV-vis and DRS spectroscopies and by tension tests. Results showed the successful formation and impregnation of NPs on the cotton fabric, with a negligible leaching of NPs after several washing cycles. The photocatalytic activity of supported NPs was assessed by the degradation of methyl blue dye (MB) under solar and UV irradiation revealing improved photocatalytic activity of the Ag-TiO2/cotton composites due to a synergy of both Ag and TiO2 nanoparticles. This behavior is attributed to a diminished electron-hole recombination effect in the Ag-TiO2 cotton samples. The biocide activity of these composites on the growth inhibition of Staphylococcus aureus (Gram+) and Escherichia coli (Gram-) was confirmed, revealing interesting possibilities for the utilization of the functionalized cotton fabric as protective cloth for medical applications.
ARTICLE | doi:10.20944/preprints202209.0068.v1
Subject: Computer Science And Mathematics, Analysis Keywords: wearable device; physical activity; behavior; COVID-19; pandemic; exercise habits; analysis; objectively-measured physical activity
Online: 5 September 2022 (13:49:56 CEST)
The COVID-19 pandemic resulted in government restrictions that altered the lifestyle of people worldwide. Studying the impact of these restrictions on exercise behaviors will improve our understanding of environmental factors that influence individuals’ PA. We conducted a retrospective analysis using an index of government pandemic stringency developed by Oxford and a wearable device for runners to compare strictness of lockdowns and exercise habits, using digitally-logged PA data from more than 7,000 runners on a global scale. Additionally, time-of-day of PA globally and levels of PA in 14 countries are compared between the pre-pandemic year of 2019 and the first pandemic year of 2020. We found that during the pandemic the time-of-day that people exercised experienced a major shift, with significantly more activities logged during standard working hours on workdays (p<0.001) and fewer during the same time frame on weekends (p<0.001). Of the countries examined, Italy and Spain had among the most strict lockdowns and suffered the largest decreases in activity counts, whereas France experienced a minimal decrease in activity counts despite enacting a similarly strict lockdown. This study suggests that there are several factors affecting PA, including government policy, workplace policy, and cultural norms.
ARTICLE | doi:10.20944/preprints202010.0367.v1
Subject: Computer Science And Mathematics, Computer Science Keywords: Human Activity Recognition; Smart Activity Sensors; Optimal Feature Selection; Colliding Bodies Optimization; Recurrent Neural Network
Online: 19 October 2020 (10:44:36 CEST)
— In a smart healthcare system," Human Activity Recognition (HAR)" is considered as an efficient approach in pervasive computing from activity sensor readings. The "Ambient Assisted Living (AAL)" in the home or community helps the people to provide independent care and enhanced living quality. However, many AAL models are restricted to multiple factors that include both the computational cost and system complexity. Moreover, the HAR concept has more relevance because of its applications, such as content-based video search, sports play analysis, crowd behavior prediction systems, patient monitoring systems, and surveillance systems. This paper attempts to implement the HAR system using a popular deep learning algorithm, namely "Recurrent Neural Network (RNN)" with the activity data collected from smart activity sensors over time, and it is publicly available in the "UC Irvine Machine Learning Repository (UCI)". The proposed model involves three processes: (1) data collection, (b) optimal feature learning, and (c) activity recognition. The data gathered from the benchmark repository was initially subjected to optimal feature selection that helped to select the most significant features. The proposed optimal feature selection method is based on a new meta-heuristic algorithm called "Colliding Bodies Optimization (CBO)". An objective function derived from the recognition accuracy has been used for accomplishing the optimal feature selection. The proposed model on the concerned benchmark dataset outperformed the conventional models with enhanced performance.
ARTICLE | doi:10.20944/preprints202312.0047.v1
Subject: Chemistry And Materials Science, Surfaces, Coatings And Films Keywords: antimicrobial activity; nanoparticles synthesis; copper selenide
Online: 1 December 2023 (05:42:27 CET)
The accumulation of microorganisms, plants, algae, or small animals on wet surfaces that have a mechanical function causes biofouling, which can result in structural or other functional deficiencies. The maritime shipping industry must constantly manage biofouling to optimize operational performance, which is a common and long-lasting problem. It can occur in any metal structure in contact or submerged in ocean water, which represents additional costs in terms of repairs and maintenance. This study is focused on the production of antifouling coatings, made with nanoparticles of copper selenide (CuSe) modified with gum arabic, within a water-base acrylic polymeric matrix. During the curing of the acrylic resin, the CuSe NPs remain embedded in the resin but this does not prevent the release of ions. The coatings presented to release copper and selenium ions for up to 80 days, selenium was the element that was released the most. The adhesion of film coatings to metallic substrates showed good adhesion, scale 5B (ASTM D3359 standard). Antimicrobial activity tests show that the coatings have an inhibitory effect on Escherichia coli and Candida albicans. The effect being more noticeable when the coating is detached from the substrate and placed on a growing medium, than compared to the coating on a substrate. Scanning electron microscopy (SEM) observations show that nanostructured CuSe coatings are made up of rod-shaped and spherical particles whose range ranges from 12 to 25 nm. The Energy Dispersive X-ray spectroscopy (EDS) studies showed that the ratio of selenium nanoparticles is greater than that of copper and that their distribution is homogeneous
ARTICLE | doi:10.20944/preprints202310.2096.v1
Subject: Public Health And Healthcare, Public Health And Health Services Keywords: body composition; physical activity; intellectual disability
Online: 1 November 2023 (03:09:45 CET)
This study aims to assess several morphofunctional parameters in female teenagers with and without intellectual disability to characterise normality and its disturbances. More precisely, the purpose was to examine the factors contributing to the differences in body composition elements between groups, such as the physical activity level. To evaluate these parameters, we used bioelectrical impedance analysis technology (BIA), most commonly used in studies concerning body composition because it is non-invasive, quick, with high data fidelity; it can be easily moved to various locations and applied straightforwardly among populations with diverse types of intellectual disability. Our research sample comprised 212 subjects (boys and girls) aged 17.1±0.6, divided into six groups by gender and type of intellectual disability. The study found influences of physical activity level on body composition components. In addition, we report a highly significant relationship for p<0.05, body mass index and the independent variable (No. of min./week) in some groups.
ARTICLE | doi:10.20944/preprints202310.1258.v1
Subject: Public Health And Healthcare, Physical Therapy, Sports Therapy And Rehabilitation Keywords: physical activity; older adults; periodized training
Online: 19 October 2023 (12:46:18 CEST)
Abstract: Background: The periodization of physical exercise to optimize the objectives is common in competitive sports, however physical exercise programs for the older adults do not usu-ally present periodization in their programming, they are limited to carrying out similar sessions throughout the program. Methods:137 people over 60 years old performed a physical exercise program, 71 people participated in a multicomponent non-periodized program as the Control Group (CG) and 66 people participated in a program periodized in blocks as the Experimental Group (EG). The block periodization program was oriented to the development of strength, and was carried out in 86 sessions three times per week during a period of 8 months. Anthropometric assessments were made using: weight, height, BMI and electrical bioimpedance; and functional evaluations through standardized tests: SPPB, TUG, handgrip and two-minute stair test. Results: After the intervention, the EG presents significant improvements in the TUG, in the weight and in the BMI. On the other hand, the CG presents significant improvements in fat weight, in BMI and in the 2-minute stair test. The SPPB did not present changes after the intervention. Conclusion: The periodization of physical exercise for older adults does not have a significant impact on the functional capacity in this population group.
ARTICLE | doi:10.20944/preprints202309.0635.v1
Subject: Computer Science And Mathematics, Artificial Intelligence And Machine Learning Keywords: human activity recognition; MLP-Mixer; efficiency
Online: 11 September 2023 (05:30:21 CEST)
Convolution, recurrent and attention-based deep learning techniques have produced the most recent state-of-the-art results in multiple sensor-based human activity recognition (HAR) datasets. However, these techniques have high computing costs, restricting their use in low-powered devices. Different methods have been employed to increase the efficiency of these techniques; however, this often results in worse performance. Recently, pure MLP architectures have demonstrated competitive performance in vision-based tasks with lower computation costs than other deep-learning techniques. The MLP-Mixer is a pioneering pure MLP architecture that produces competitive results with state-of-the-art models in computer vision tasks. This paper shows the viability of the MLP-Mixer in sensor-based HAR. Furthermore, experiments are performed to gain insight into the Mixer modules essential for HAR, and a visual analysis of the Mixer’s weights is provided, validating the Mixer’s learning capabilities. As a result, the Mixer achieves an F1 score of 97%, 84.2%, 91.2% and 90% on the PAMAP2, Daphnet Gait, Opportunity Gestures and Opportunity Locomotion datasets, respectively, outperforming state-of-the-art models in all datasets except Opportunity Gestures.
ARTICLE | doi:10.20944/preprints202309.0473.v1
Subject: Public Health And Healthcare, Public Health And Health Services Keywords: exercise; physical activity; postpartum; exercise prescription
Online: 7 September 2023 (11:42:43 CEST)
The postpartum period is marked by profound changes in women at a physical, psychological, and physiological level. Many of these changes persist after four to six weeks postpartum, and most women do not resume their levels of physical activity, which increases the risk of remaining inactive for many years. It is crucial to implement effective programs that promote exercise during the postpartum period. The objective of this study was to test the feasibility and analyze the effects of a structured and supervised postpartum exercise program on the maternal health and fitness parameters. To analyze the potential effects of the intervention, the level of physical activity, quality of life, pelvic girdle and low back pain, fatigue, depression, and the level of functional and physical fitness were assessed at baseline, after 8 weeks, and after 16 weeks of intervention. Feedback on the exercise program was collected after the final assessment. The results showed that a structured and supervised postpartum exercise program was feasible and safe, and produced positive effects on selected maternal health and fitness parameters. These results will encourage a study protocol with a larger sample in order to prove its effectiveness, improve the guidelines for postpartum exercise, and incorporate this program into a routine health care setting.
ARTICLE | doi:10.20944/preprints202309.0360.v1
Subject: Biology And Life Sciences, Biology And Biotechnology Keywords: ytotoxic activity; 2,3-dihydrobenzofuran; cervical cancer
Online: 6 September 2023 (03:51:03 CEST)
: The cytotoxic effect of four extracts obtained from the wild plant and two from a culture of Ag-eratina pichinchensis calluses on cell lines: prostate carcinoma, cervical cancer, hepatocellular car-cinoma, human hepatoma, lung cancer and cellular keratinocytes was evaluated; the extracts were obtained with ethyl acetate and methanol, leaves and stems were used from the wild plant. The results of the cytotoxic evaluation showed that only the ethyl acetate extract obtained from the callus culture showed an effect on the cervical cancer cell line (HeLa) with an IC50 of 94.79 ± 2.0 µg/mL. The purification of this extract allowed obtaining a benzofuran type compound as the main product, which was identified as 2,3-dihydrobenzofuran. The cytotoxic evaluation of this compound showed an important effect against the HeLa cell line with an IC50 of 23.86 ± 2. .5µg/mL. These results contribute to the development of alternatives for the production of com-pounds for the treatment of cancer.
ARTICLE | doi:10.20944/preprints202307.1858.v2
Subject: Environmental And Earth Sciences, Atmospheric Science And Meteorology Keywords: thermospheric density; GAMDM; QBO; solar activity
Online: 31 July 2023 (11:23:50 CEST)
In this study, we discuss the thermospheric density response to the solar activity and QBO. By using the wavelet power spectrum method, the thermospheric density from 1967 to 2013 shows ~11-year period, semiannual and annual variations, while the seasonal variation is usually more significant under high solar activity conditions. Importantly, we investigate the possible link between the density and the QBO, with the aid of GAMDM model and different density residual method. As a result, the difference between the measured density and empirical model seemingly has QBO signal, but the ratio of them revels that the QBO signal does not exist in the thermospheric density. Comprehensively, we thought the stratospheric QBO cannot impact on the thermosphere, and more data and numerical modeling are needed for further validation.
REVIEW | doi:10.20944/preprints202305.0671.v1
Subject: Public Health And Healthcare, Primary Health Care Keywords: physical activity; counseling; primary health care
Online: 9 May 2023 (14:53:26 CEST)
Background: To identify and appraise the impacts and effectiveness of counseling interventions based on the 5A model on indicators of physical activity in adults. Methods: In May, 2022, a systematic review was carried out. Searches were performed in Embase, Lilacs, Pubmed, Scielo, Scopus, Sportdiscus and Web of Science. To avoid potential losses searches also were made in Google Scholar and in reference lists. Assessment of studies, data extraction and synthesis took place independently by two researchers. Results: Four studies composed the synthesis, which involved people with an average age between 40 and 55 years, being women in the majority of the samples. It was observed that counseling was carried out in conjunction with other strategies, such as drawing up an action plan, sending text messages and offering educational material. Only one study showed a statistically significant difference between the intervention and control groups in the “daily number of steps” indicator. Conclusions: counseling based on the 5A model did not reflect significant findings in relation to physical activity. Considering that behavior change for many people is neither a simple nor a quick process and that the 5A model is promising for other behavioral indicators, we indicate the need to carry out new intervention studies, with an expanded focus in relation to themes related to physical activity (e.g., types, dos-es, risks, benefits, identification of barriers and assessment) and, in parallel, the offer of practices in the Primary Health Care setting.
ARTICLE | doi:10.20944/preprints202212.0544.v1
Subject: Chemistry And Materials Science, Inorganic And Nuclear Chemistry Keywords: bisthiosemicarbazone ligands; zinc; helicates; biological activity.
Online: 28 December 2022 (12:45:04 CET)
The design of artificial helicoidal molecules derived from metal ions with biological properties is one of the objectives within Metallosupramolecular Chemistry. Herein, we report three zinc helicates derived from a family of bisthiosemicarbazone ligands with different terminal groups, Zn2(LMe)2∙2H2O 1, Zn2(LPh)2∙2H2O 2 and Zn2(LPhNO2)2 3, obtained by an electrochemical methodology. These helicates have been fully characterized by different techniques, including X-Ray diffraction. Biological studies of the zinc(II) helicates such as toxicity assays with erythrocytes and interaction studies with proteins and oligonucleotides were performed, demonstrating in all cases low toxicity and an absence of covalent interaction with the proteins and oligonucleotides. The in vitro cytotoxicity of the helicates was tested against MCF-7 (human breast carcinoma), A2780 (human ovarian carcinoma cells), NCI-H460 (human lung carcinoma cells) and MRC-5 (normal lung human fibroblast), comparing the IC50 values with cisplatin. We will try to demonstrate if the terminal substituent of the ligand precursor exerts any effect in toxicity or in the antitumor activity of the zinc helicates.
ARTICLE | doi:10.20944/preprints202211.0465.v1
Subject: Chemistry And Materials Science, Organic Chemistry Keywords: Lasiodiplodan; Anticoagulant; Immunomodulatory Activity; Antiviral activities
Online: 25 November 2022 (02:52:37 CET)
Lasiodiplodan, an exocellular Lasiodiplodia theobromae β-glucan exopolysaccharide (LaEPS), has at-tracted interest because of its antioxidant, antimicrobial, anti-inflammatory, and antiproliferative properties. LaEPS carboxymethylation enhances LaEPS water solubility and biological activities. However, carboxymethylated fractions of LaEPS (LaEPS-C): LLaEPS-C (Linear) and BLaEPS-C (Branched) were not widely studied yet. So, LaEPS-C, LLaEPS-C, and BLaEPS-C were assessed for their antioxidant, antimicrobial, antiproliferative, anticoagulant, immunomodulatory, and anti-viral activities. Elementary Chemical Composition Analysis confirmed their structural charac-teristics by Energy Dispersive X-Ray Detector (EDS), Fourier Transform Infrared (FTIR), Nuclear Magnetic Resonance (NMR), and Scanning Electron Microscopy (SEM) techniques. The best DPPH scavenging potential was achieved for LLaEPS-C for concentrations lower than 200mg/mL. LaEPS-C showed moderate antiproliferative activity for the NCI-ADR/RES cell (GI50 65.3 µg/mL), and BLaEPS-C showed weak activity for the K562 cell (GI50 235 µg/mL). LLaEPS-C had a reduced Prothrombin Time (PT) and a procoagulant effect. LLaEPS-C and BLaEPS-C are inducers of pro-inflammatory activity due to their ability to induce TNF-α in human macrophages. LLaEPS-C also showed anti-hRSV, which confirmed the antiviral activity of this molecule.
ARTICLE | doi:10.20944/preprints202211.0327.v1
Subject: Biology And Life Sciences, Virology Keywords: Activity; Driving force; Metabolism; Catabolism; Environment
Online: 17 November 2022 (08:24:45 CET)
The model of T4 phage, Lambda phage and Escherichia coli is often used in research on virus-host interactions. This paper reports for the first time the thermodynamic driving force of biosynthesis, catabolism and metabolism for the three organisms, on the M9 medium. Moreover, the influence of activities of nutrients and metabolic products is analyzed. All three organisms were found to have very similar Gibbs energies of metabolism. Moreover, since they share the same catabolism, their Gibbs energies of catabolism are identical. However, Gibbs energies of biosynthesis differ. The calculated thermodynamic properties have been used to explain the coexistence of both bacteria and phages in a dynamic equilibrium in natural ecosystems.
ARTICLE | doi:10.20944/preprints202203.0353.v1
Subject: Environmental And Earth Sciences, Soil Science Keywords: chlorothalonil; dissipation; enzyme activity; microbial community
Online: 28 March 2022 (03:46:35 CEST)
To get a better knowledge of the effects of residual chlorothalonil on soil characteristics and soil microbial communities, we evaluated the dissipation of chlorothalonil and the effects of different chlorothalonil concentrations on soil respiration, enzyme activities, and microbial community structure in yellow-brown loam soils. Bacterial and fungal soil communities were examined using traditional plate counting and polymerase chain reaction-denaturing gradient gel electrophoresis (PCR–DGGE) methods. Soil properties and the results of DGGE band analysis were both used to estimate the status of the soil microbial ecosystem. The results show that residual chlorothalonil has considerable effects on soil respiration, enzymatic activities, and microbial community structure. In particular, soil respiration and phosphatase activities were increased, while saccharase activity, microbial biomass, and microbial community diversity were decreased by increasing levels of chlorothalonil treatment. Correlation analyses revealed that the application of chlorothalonil was significantly correlated with the change of the soil respiration, urease activity, sucrase activity, soil culturable bacteria and culturable fungi biomass. We conclude that residual chlorothalonil is directly related to soil respiration, enzyme activities, and microbial community structure.
ARTICLE | doi:10.20944/preprints202111.0174.v1
Subject: Medicine And Pharmacology, Orthopedics And Sports Medicine Keywords: coordination abilities; training; handball; physical activity
Online: 9 November 2021 (13:42:11 CET)
According to the reviewed literature, the selection system in the handball game is quite complex and requires new approaches from specialists, based on the current requirements of this game. It was found that a main selection criterion in the game of handball is the coordination abilities because the handball game is mainly based on coordination. In this paper is related the importance of coordinative abilities development in the handball game for young children (10-12 years old) selection process meet in Romania. The results are obtained from a sociological questionnaire, where 109 specialists in the handball game are interrogated, 38 of them being handball coaches, and 71 being teachers of physical education and sports with abilities in handball game. The answers delivered depend on each specialist experience, the knowledge possessed and the difficulties encountered over the years. As a general overview, in the opinion of the surveyed specialists, the selection process in the handball game for Romania does not live up to their expectations, and the development level of coordination abilities meet in 10-12 years children is medium to weak. A total of 51.9% from the respondents stressed the importance of developing coordination abilities to optimize the selection process of children for handball game, opening a new approach in the modern training methods for performance achievement.
ARTICLE | doi:10.20944/preprints202105.0478.v1
Subject: Engineering, Automotive Engineering Keywords: biopolymers; paper packaging; antimicrobial activity; nanoparticles
Online: 20 May 2021 (10:30:46 CEST)
Here, we designed the composition of the coating of the paper sheets composed of chitosan, bacterial cellulose (nanofibres), and ZnO with boosted antibacterial and mechanical activity. We investigated the compositions with ZnO exhibiting two different sizes/shapes: (1) rods and (2) irregular sphere-like particles. The proposed processing of bacterial cellulose resulted in the formation of nanofibers. Antimicrobial behavior was tested using E. coli ATCC® 25922™ following ASTM E2149-13a standard. Mechanical properties of the paper sheets were measured by comparison of tearing resistance, tensile strength, and bursting strength according to ISO 5270 standard. The increased antibacterial response is assigned to the combination of chitosan and ZnO (independently of its shape and size), while the boosted mechanical behavior is due to bacterial cellulose nanofibers. Therefore, the proposed composition is an interesting multifunctional mixture for coatings in food packaging applications.
COMMUNICATION | doi:10.20944/preprints202104.0011.v1
Subject: Biology And Life Sciences, Anatomy And Physiology Keywords: laterality; brain; hemisphere; asymmetry; activity; biofeedback
Online: 1 April 2021 (10:52:07 CEST)
In the current pilot study, we attempt to find out how double neurofeedback influences functional hemispheric asymmetry and activity. We examined 30 healthy participants (8 males; 22 females, mean age = 29; SD= 8). To measure functional hemispheric asymmetry and activity, we used computer laterometry in the ‘two-source’ lead-lag dichotic paradigm. Double biofeedback included 8 minutes of EEG oscillation recording with five minutes of basic mode. During the basic mode, the current amplitude of the EEG oscillator gets transformed into feedback sounds while the current amplitude of alpha EEG oscillator is used to modulate the intensity of light signals. Double neurofeedback did not directly influence the asymmetry itself but accelerated individual sound perception characteristics during dichotic listening in the preceding effect paradigm. Further research is needed to investigate the effect of double neurofeedback training on functional brain activity and asymmetry taking into account participants’ age, gender, and motivation.
COMMUNICATION | doi:10.20944/preprints202009.0134.v1
Subject: Chemistry And Materials Science, Biomaterials Keywords: Bacterial cellulose; Nisin; Antimicrobial activity; Stability
Online: 5 September 2020 (08:52:11 CEST)
Nisin is a 3.4 kDa antimicrobial peptide, produced by Lactococcus lactis (ATCC 11454). This bacteriocin can inhibit spores gemination and gram-positive bacteria development and has gained visibility in therapeutic use. The bacterial cellulose (CB) has been considered an ideal material and with high quality applied in food and medical-pharmaceutical inputs. Because of all this benefits, it is important to know the system proceeding of CB with nisin. Therefore, it was realize nisin release profile analysis of CBs was performed; analysis of the minimum inhibitory concentration (MIC) of nisin against Escherichia coli ATCC 25922, Pseudomonas aeuroginosa ATCC 9721 and Staphylococus aureus ATCC 10390; antimicrobial stability test, for 100 days at different temperatures of 4º, 25º and 37 ° C against microorganisms: S. aureus e L. sakei. The results show that nisin is released by the CB in 4 hours of contact with medium and the MIC of nisin is 78 µg/mL for S. aureus, doesn’t have gram-negative inhibition. It had stability until 100 days against L. sakei and 60 days for S. aureus. The system proved to be efficient and CB potentiated the antimicrobial action of nisin, acting as a selective barrier for other compounds present in the standard solution, serving as protection of the peptide at different temperatures. The CB loading system can be an ideal antimicrobial stability system for nisin.
ARTICLE | doi:10.20944/preprints202008.0541.v1
Subject: Biology And Life Sciences, Biology And Biotechnology Keywords: antioxidant activity; dietary supplements; microalgal cultivation
Online: 25 August 2020 (08:41:14 CEST)
Microalgae production is expensive and demands high volumes of water and energy to meet all market demands and yet the production of secondary metabolites using alternative media needs deeper studies. Among alternative media, the use of sugar cane vinasse has gained attention for microalgae cultivation. In this work, we’ve compared the biomass yield and secondary metabolites of Chlorella sorokiniana grown in a commercial medium (Sueoka) and in alternative medium prepared with cane vinasse (0.1%) supplemented with N, P2O5 and K2O (commercial formula 20-5-20 g.L-1). The production of microalgae biomass grown in an alternative medium was 2.2% lower, but reached its maximum growth point 14 days faster than the commercial medium. The average level of Phenolic compounds on the commercial medium were 6.02 ± 0.13 mg GAE .g-1 and increased to 15.28 ± 0.32 mg GAE.g-1when C. sorokinianawere grown in the vinasse medium. Same how, Flavonoids contents varied from 13.12 ± 1.33 to 72.30 ± 5.28 mg QE. g-1 to commercial and vinasse medium, respectively. The maximum AOA of C. sorokiniana grown in vinasse medium was 88.05% at a concentration of 1500 µg.mL-1 of extract, with IC50 at 357.7 ± 27.35 µg.mL-1. Different factors seem to induce variances on secondary metabolites synthesis, mostly stress due to QOD and ions added to the medium by vinasse. The authors recognize there are more investigations to be done, but increasing a natural and low cost pathway for flavonoids yield open up an interesting field for the bioprospection of microalgae.
ARTICLE | doi:10.20944/preprints202002.0362.v1
Subject: Medicine And Pharmacology, Urology And Nephrology Keywords: physical activity; hemodialysis; sclerostin; interleukin 6
Online: 25 February 2020 (06:18:45 CET)
Background: Chronic kidney disease and renal replacement therapy are associated with reduced physical activity, which may result in the presence of mineral-bone disorders and an increase in inflammation markers. The aim of the study was to assess the relationship between the performance of daily physical activity, expressed in the number of steps performed by patients undergoing hemodialysis and the concentration of selected biochemical parameters (SCL, IL-6). Materials and Methods: The study involved 33 patients aged 59.8 ± 9.8 years from the dialysis station at the Department of Nephrology, Transplantology and Internal Medicine PUM. Group C consisted of 30 people aged 54.9 (9.37), with GFR over 60 mL/min/1.73m. The study group was divided into S-N and N-S. Participants of the S-N group were assigned the task of performing the appropriate daily number of steps, and the N-S group was to perform spontaneous physical activity. The tasks were replaced after the third month of the research project. Physical activity was measured with pedometers. Anthropometric and biochemical parameters were assessed at baseline, after the third and sixth month of the study. Descriptive statistics, intergroup comparisons using Mann-Whitney U or Kruskal-Wallis tests and Spearman correlation analysis were performed. The level of significance was set at p≤0.005. Results: Patients from the S-N and N-S groups compared to group C performed significantly fewer steps in the 0-3 month and 4-6 month periods. In the S-N group, with an increase in steps performed in the period of 4-6 months, sclerostin levels dropped in the 6th month. In group C, the concentration of SCL and IL-6 decreased with the increase in the number of steps taken. Only in group C the waist circumference decreased with the increase of the number of steps performed. Conclusions: Patients receiving renal replacement therapy by hemodialysis showed significantly lower physical activity compared to people without kidney disease. Performing bigger number of steps can lower sclerostin levels in hemodialysis patients.
HYPOTHESIS | doi:10.20944/preprints201904.0210.v2
Subject: Biology And Life Sciences, Biochemistry And Molecular Biology Keywords: regulation; membrane; glycerophospholipid; composition; chemical activity
Online: 31 October 2019 (04:39:47 CET)
Mammalian cells maintain the complex glycerophospholipid (GPL) class compositions of their various membranes within close limits because this is essential to their well-being or viability. Surprisingly, however it is still not understood how those compositions are maintained except that GPL synthesis and degradation closely coordinated. Here, we hypothesize that abrupt changes in the chemical activity of the individual GPL classes coordinate the synthesis and degradation, as well other homeostatic processes. A previously proposed model proposed that in cellular membranes only a limited number of “allowed” or optimal GPL glass compositions exist because they are energetically more favorable than the other compositions, i.e. they represent local free energy minima (Somerharju et al. 2009). This model, however, could not satisfactorily explain how the optimal compositions are sensed by the key homeostatic enzymes i.e., the rate-limiting synthetizing enzymes and the degrading enzymes (i.e., homeostatic phospholipases). We now propose that when the mole fraction of a GPL class exceeds an optimal one, its chemical activity abruptly increases, which (i) increases its propensity to efflux from the membrane thus making it susceptible for hydrolysis by homeostatic phospholipases, (ii) increases its potency to inhibit its own biosynthesis via a feedback mechanism, (iii) enhances its conversion to another GPL class via a novel process termed “head group remodeling” or (iv) enhances its translocation to other subcellular membranes. Accordingly, abrupt changes in the chemical activity of the individual GPL classes is proposed to regulate and coordinate those four processes maintaining GPL class homeostasis in mammalian cells.
ARTICLE | doi:10.20944/preprints201906.0058.v1
Subject: Social Sciences, Education Keywords: enjoyment; outdoor activities: education; physical activity
Online: 7 June 2019 (12:45:47 CEST)
The aim of this study was to assess the psychometric properties of the Physical Activity Enjoyment Scale in the context of outdoor physical activities. In order to do this, we carried out a research in some Primary and Secondary school l located in western Andalucía (Spain), with kids aged 9-12 years old [M= 11.22; SD= 1.07), therefore a sample of 455 students (228 boys= 50.1% 227 girls = 49.9% = 50.1) was used]. Descriptive, exploratory and confirmatory analyses were conducted. We also analyzed several factors such as internal consistency, composite reliability, average variance extracted and convergent validity. Afterwards, differences by gender and school year were also studied. Data showed the need to eliminate many of the items from the original scale, giving as a result a model of 5 items with satisfactory fit in the confirmatory analysis. The ANOVA statistical test carried out in terms of sex and school year didn’t show any tangible difference between the target groups.
ARTICLE | doi:10.20944/preprints201811.0519.v1
Subject: Social Sciences, Psychology Keywords: personality; emotional aspects; communication; work activity
Online: 21 November 2018 (07:06:12 CET)
One of the trends in current research in psychology explores how personal variables can determine a person’s communication style. Our objective was to find out the moderating effect of Mood in the relationship between the five big personality traits and an aggressive verbal communication style risk factor from work activity in a sample of nursing professionals. This study is a quantitative descriptive design. The final sample was 596 nurses with a range of 22 to 56 years. An ad hoc questionnaire was used to collect sociodemographic data, the 10-item Big Five Inventory, the Communication Styles Inventory, and the Brief Emotional Intelligence Inventory for Senior Citizens. This study showed that for nursing professionals, the “Agreeableness”, “Conscientiousness” and “Neuroticism” traits have a close relationship with aggressive verbal communication. Even though Mood moderates this relationship, it is only significant for those individuals with high scores in “Neuroticism”. Because personality dimensions are considered relatively stable over time and consistent from one situation to another, organizations should hold workshops and other types of practical activities to train workers in communication skills and Emotional Intelligence in order to promote employee health and that of their patients and avoid risk factor from work activity in nursing.
ARTICLE | doi:10.20944/preprints201811.0116.v1
Subject: Biology And Life Sciences, Agricultural Science And Agronomy Keywords: Fusarium graminearum; deoxynivalenol; RGB; water activity
Online: 5 November 2018 (12:09:07 CET)
Deoxynivalenol (DON) is a well-known mycotoxin, responsible for outbreaks of gastrointestinal disorders in Japan. Fusarium graminearum, a parasite of cereal crops, produces this toxin and this is one of the reasons why it is important to understand its metabolism. It is possible to predict the mold’s color change and the quantity of DON synthesized throughout its lifecycle. Furthermore, aw has been found to affect the amount of DON. This study aimed to analyze the potential of F. graminearum surface color as a predictor of DON concentration at aw = 0.94, 0.97 and 0.99. Thus, 36 specimens were incubated at 25 °C, 12 at each aw. After 4, 8, 12 and 16 days, 3 specimens from each aw were collected for color analysis and DON quantification. For color analysis, photos were taken and red, green and blue (RGB) channels were measured on ImageJ software. DON was quantified through liquid chromatography (HPLC). Color changes were only observed at aw = 0.99 because at lower aw the molds presented high growth of white mycelium. Yet, DON increased in all cases. It was only possible to relate the colors with DON concentration at aw = 0.99, where they presented inverse proportionality.
ARTICLE | doi:10.20944/preprints201807.0039.v1
Subject: Chemistry And Materials Science, Medicinal Chemistry Keywords: xanthohumol; biotinylated chalcones; anticancer activity; antioxidants
Online: 3 July 2018 (11:42:41 CEST)
Two biotinylated derivatives of the main hop chalcone xanthohumol (1) were prepared by a one-step synthesis via esterification using biotin and 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide hydrochloride (EDC HCl) and 4-dimethylaminopyridine (DMAP) as coupling reagents. The products were characterized spectroscopically and their antiproliferative activity toward MCF-7, MCF-10A, HepG2, MDA-MB-231, 4T1 and Balb/3T3 cell lines was investigated using the SRB assay. For all three tested compounds the best activity was noted in the case of human (MCF-7) and mice (4T1) breast cancer cell lines (IC50 values < 9 μM). Both biotinylated derivatives showed higher anticancer activity than xanthohumol (1) towards all types of tested breast cancer cells. Double biotinylated xanthohumol (3) proved to be the most active in inhibiting cell growth, with IC50 values equal to 5.35 ± 1.5 μM for 4T1 and 8.03 ± 0.53 µM for MCF-7 cell lines. Compound 3 was also more active than 1 and 2 against liver cancer cells HepG2 (IC50 = 17.37 ± 5.1 μM), while the IC50 values for 1 and 2 were equal to 21.5 ± 2.7 and 22.1 ± 3.9 µM, respectively. 4‑O‑biotinylxanthohumol (2) was the second most active growth inhibitor, particularly with respect to MCF-7 (IC50 = 6.19 ± 1.7 μM) and 4T1 (IC50 = 6.64 ± 0.4 μM) cell lines. The antioxidant activity was evaluated using the 1.1-diphenyl-2-picrylhydrazyl radical (DPPH) method. All tested compounds (1-3) have antioxidant activity between 2.73 and 3.38 mM. It was reported for the first time that new prenylated chalcones containing the biotin moiety effectively inhibited proliferation of cancer cells in vitro.
ARTICLE | doi:10.20944/preprints201804.0330.v1
Subject: Biology And Life Sciences, Ecology, Evolution, Behavior And Systematics Keywords: nonylphenol; montmorillonite; zebrafish; enrichment; enzyme activity
Online: 26 April 2018 (05:48:32 CEST)
To investigate the effect of montmorillonite on nonylphenol enrichment in a zebrafish model. The AB strain zebrafish were used as the animal subjects and three concentration gradients were set for both nonylphenol and montmorillonite, according to their actual concentrations in aquaculture water in Huzhou city. A group treated with nonylphenol alone was also set, adding up to 12 experimental groups. Concentrations of nonylphenol enriched in the liver, muscle, and gill of zebrafish were detected by solid phase microextraction–high performance liquid chromatography at Day 7, 15, and 30, respectively. Besides, the relative enzymatic activity of Superoxide dismutase (SOD) and the Glutathione S-transferase (GST) were also been detected, and the data were statistically analyzed. The results showed that the concentrations of nonylphenol in zebrafish peaked at Day 7 and gradually decreased afterwards for all the experimental groups. And the montmorillonite reduces short-term accumulation of nonylphenol in gills, and the high concentration of nonylphenol facilitates its enrichment in liver and muscle while the low concentration of nonylphenol doesn’t. Meanwhile, the low concentration of nonylphenol in liver exerts an influence on the inductive effect of SOD and GST while the high concentration of nonylphenol shows the inhibiting effect of SOD and GST.
ARTICLE | doi:10.20944/preprints201612.0073.v1
Subject: Chemistry And Materials Science, Nanotechnology Keywords: W18O49; microstructure; phase transformation; photocatalytic activity
Online: 14 December 2016 (08:33:41 CET)
Hierarchical tungsten oxide assemblies such as spindle-like, flowers with sharp petals, nanowires and regular hexagonal structures are successfully synthesized via a solvothermal reduction method by simply adjusting the reaction conditions. On the basis of the experimental results, it is determined that the reaction time significantly influences the phase transition, microstructure and photocatalytic activity of the prepared samples. The possible mechanisms for the phase transition and morphology evolution process have been systematically proposed. Moreover, the as-prepared products exhibit significant morphology-depended photocatalytic activity. The flower-like W18O49 prepared at 6 h possesses large specific surface area (150.1 m2g-1), improved separation efficiency of electron-hole pairs and decreased electron-transfer resistance by the photoelectrochemical measurements. As a result, the flower-like W18O49 prepared at 6 h exhibits the highest photocatalytic activity for the degradation of Methyl orange aqueous solution. The radical trap experiments showed that the degradation of MO was driven mainly by the participation of h+ and •O2− radicals.
REVIEW | doi:10.20944/preprints201610.0049.v1
Subject: Biology And Life Sciences, Agricultural Science And Agronomy Keywords: plant extracts; antifungal activity; fungal pathogens
Online: 13 October 2016 (11:50:21 CEST)
Abstract Plant fungal pathogens are frequently found as one of limiting factors for crop production. More than 10,000 species of fungi can cause disease in plants. To control the diseases, many farmers are still rely on the use of chemical fungicides, however most synthetic fungicides can cause acute toxicity, and some cause chronic toxicity as well. Thus, an appropriate technological improvement towards a more effective use of natural resources is required in agriculture to develop environmentally friendly sustainable farming system. This paper highlights the potential of extracts of tropical plants as antifungal agent to control plant fungal diseases. Information and data presented in this paper are mainly derived from selected and related references that previously published in the scientific journals. Many higher plants of tropical origin with fungicidal activities and their potential for fungal disease control of agricultural crops have been studied, however most of the studies have been done under in vitro condition. Some plant extracts showed strong antifungal activities on in vitro as well as in vivo tests, but some plant extracts showed significant antifungal activities on in vitro test, but did not obvious on in vivo tests. A great variation in antifungal activities were shown by plants extracts of different species and plant parts, in one hand, and on the other hand, variation was also observed on the responses of different fungal species to the same plant extract. Since the purpose of the use of plant extract is to control plant fungal diseases, the field trial is needed to ensure the stability of efficacy of certain plant extract. In addition, isolation and identification of active substances in the extracts is needed to assess possible mode of action and side effect of their use.
ARTICLE | doi:10.20944/preprints201609.0121.v1
Subject: Computer Science And Mathematics, Computer Science Keywords: activity recognition; physical attributes; classification capability
Online: 29 September 2016 (12:57:00 CEST)
Motion related human activity recognition using wearable sensors can potentially enable various useful daily applications. So far, most studies view it as a stand-alone mathematical classification problem without considering the physical nature of human motions. Consequently, they suffer from data dependencies and encounter the dimension disaster problem and the over-fitting issue, and their models are never human-readable. In this study, we start from a deep analysis on natural physical properties of human motions, and then propose a useful feature selection method to quantify each feature's classification contribution capability. On one hand, the "dimension disaster" problem can be avoid to some extent, due to the affined dimension of key features; On the other hand, over-fitting issue can be depressed since the knowledge implied in human motions are nearly invariant, which compensates the possible data inadequacy. The experiment results indicate that the proposed method performs superior to those adopted in related works, such as decision tree, k-NN, SVM, neural networks.
ARTICLE | doi:10.20944/preprints202309.1056.v1
Subject: Biology And Life Sciences, Horticulture Keywords: Onopordum nervosum ssp. platylepis; spontaneous plant; cultivated plant; drying; chemical composition; clotting milk activity; antioxidant activity
Online: 15 September 2023 (11:22:31 CEST)
This study aims to evaluate the effect of different drying methodologies (room, microwave, convective, oven and freeze-drying) on the chemical composition, the microbiological quality of extracts and the biological activities namely clotting milk and antioxidant activities for both spontaneous and cultivated Onopordum nervosum ssp. platylepis. The results showed that the drying methodology has significantly affected the phenolic composition. Freeze dried flowers showed the best amounts of total phenols, flavonoids and condensed tannins followed by the microwave dried flowers. However, the latest presented the lowest protein content. Finally, the biological activities were significantly dependent on the used drying process. The effective concentration EC50 values let to classify the samples according to their decreasing power to inhibit DPPH free radicals: dryer<oven<room <microwave<freeze-drying. The drying process significantly affected the clotting milk activity, freeze dried flowers showed the highest activity. All the obtained results do not reveal a significant difference between cultivated and spontaneous plants.
REVIEW | doi:10.20944/preprints202308.1824.v1
Subject: Biology And Life Sciences, Life Sciences Keywords: antifungal peptides; enzyme-like activity; growth inhibition; antifungal activity; fungal metabolites; quorum response molecules; combined antifungals
Online: 28 August 2023 (09:44:34 CEST)
Biomimetics, which are similar to natural compounds that play an important role in the metabolism, manifestation of functional activity and reproduction of various fungi, have a pronounced attrac-tion in the current search for new effective antifungals. Actual trends in the development of this area of research indicate that unnatural amino acids can be used as such biomimetics, including those containing halogen atoms; compounds similar to nitrogenous bases embedded in the nucleic acids synthesized by fungi; peptides imitating fungal analogues; molecules similar to natural sub-strates of numerous fungal enzymes and Quorum Sensing signaling molecules of fungi and yeast; etc. Most part of the review is devoted to the analysis of semi-synthetic and synthetic antifungal peptides and their targets of action. This review is aimed at combining and systematizing the cur-rent scientific information accumulating in this area of research, developing various antifungals with an assessment of the effectiveness of the created biomimetics and the possibility of combining them with other antimicrobial substances to reduce cell resistance and improve antifungal effects.
ARTICLE | doi:10.20944/preprints202106.0050.v1
Subject: Biology And Life Sciences, Immunology And Microbiology Keywords: Montivipera bornmuelleri snake venom; F1F0-ATPase; Staphylococcus epidermidis; Escherichia coli; antibacterial activity; HCT116 cells; anticancer activity
Online: 2 June 2021 (07:21:59 CEST)
In this work, we pursued the biological characterization of the venom of Montivipera born-muelleri, a viper from the Lebanese mountains. In relativity to its antibacterial potential, the in-hibitory effect of this venom on the F1F0-ATPase enzymes of Gram-positive Staphylocoocus epider-midis and Gram-negative Escherichia coli bacteria was examined. In order to determine the de-gree of cytotoxicity of the venom on the HCT116 human colon cancer cell lines, the biological MTT proliferation and cell viability test were implemented. After validation of the enzymatic F1F0-ATPase model by the spectrophotometric method, using quercetin as the reference ligand, re-sults revealed that M. bornmuelleri venom is able to inhibit the activity of the enzyme of these two bacteria with a concentration of the order of 100-150 µg/mL. In addition, a venom concentration of 10 µg/mL was sufficient to kill the totality of HCT116 cell lines cultivated in vitro. These data show that M. bornmuelleri venom is a mixture of diverse molecules presenting activities of interest and is a potential source to explore in order to discover new drug candidates.
ARTICLE | doi:10.20944/preprints202012.0451.v1
Subject: Social Sciences, Psychology Keywords: academic lessons; moderate-to-vigorous physical activity; MVPA; whole-school; physical activity; physically active learning; PAL
Online: 18 December 2020 (11:11:07 CET)
Background: A large majority of primary school pupils fail to achieve 30-minutes in-school moderate-to-vigorous physical activity (MVPA). The aim of this study was to investigate MVPA accumulation and subject frequency during academic lesson segments and the broader segmented school day. Methods: 122 children (42.6% boys; 9.9±0.3yrs) from six primary schools in North East England, wore uniaxial accelerometers for eight consecutive days. Subject frequency was assessed by teacher diaries. Multilevel models (children nested within schools) examined significant predictors of MVPA across each school-day segment (lesson one, break, lesson two, lunch, lesson three). Results: Pupils averaged 18.33±8.34 minutes of in-school MVPA and 90.2% failed to achieve the in-school 30-minute MVPA threshold. Across all school-day segments, MVPA accumulation was typically influenced at the individual level. Lesson one and two - dominated by Math and English - were less active than lesson three. Break and lunch were the most active segments. Conclusion: This study breaks new ground, revealing MVPA accumulation and subject frequency varies greatly during different academic lessons. Morning lessons were dominated by the inactive delivery of Math and English, whereas afternoon lessons involved a greater array of subject delivery that resulted in marginally higher levels of MVPA.
ARTICLE | doi:10.20944/preprints202008.0077.v1
Subject: Chemistry And Materials Science, Medicinal Chemistry Keywords: anti-oxidant activity; anti-oxidant enzymes, anti-proliferative activity; maslinic acid; melanoma; Olea europaea; ROS levels
Online: 4 August 2020 (04:57:13 CEST)
Maslinic acid (MA) is a natural triterpene from Olea europaea whose pharmacological functions have been showed. The objective of this study was to examine MA effect on cell viability (by MTT assay), reactive oxygen species (ROS levels, by flow cytometry) and key anti-oxidant enzyme activities (by spectrophotometry) in murine skin melanoma (B16F10) cells compared to healthy cells (A10). MA induced cytotoxic effects in cancer cells (IC50 42 µM) whereas no effect was found in A10 cells treated with MA (up to 210 µM). In order to produce a stress situation in cells, 0.15 mM of H2O2 were added. Under stressful conditions, MA protected both cell lines against oxidative damage, decreasing intracellular ROS, being higher in B16F10 than in A10 cells. The treatment with H2O2 and without MA produced different responses in anti-oxidant enzymes activities depending on cell line. In A10 cells, all enzymes were up-regulated, but in B16F10 cells only superoxide dismutase, glutathione S-transferase and glutathione peroxidase increased their activities. MA restored the enzyme activities to similar levels than control group in both cell lines, highlighting that in A10 cells the highest MA doses induced values lower than control. Overall, these findings demonstrate the great anti-oxidant capacity of MA.
ARTICLE | doi:10.20944/preprints201709.0164.v1
Subject: Chemistry And Materials Science, Organic Chemistry Keywords: Salvia ballotiflora; icetexane diterpenoids; abietane diterpenoids; antiproliferative activity; anti-inflammatory activity; radical scavenger capacity; DCV analyses
Online: 30 September 2017 (05:04:11 CEST)
From the aerial parts of Salvia ballotiflora, eleven diterpenoids were isolated, among them, four icetexanes, and one abietane (1–5), which are first reported. Their structures were established by spectroscopic means, mainly 1H and 13C NMR, including 1D and 2D homo- and hetero-nuclear experiments. Most of the isolated diterpenoids were tested for their antiproliferative, anti-inflammatory, and radical scavenging activities using the sulforhodamine B assay on six cancer cell lines, the TPA induced ear edema test in mice, and the reduction of the DPPH assay, respectively. Some diterpenoids showed anti-proliferative activity, these being icetexanes 6 and 3, which were the most active with IC50 (µM) = 0.27 ± 0.08 and 1.40 ± 0.03, respectively, for U251 (human glioblastoma) and IC50 (µM) = 0.0.46 ± 0.05, and 0.82 ± 0.06 for SKLU-1 (human lung adenocarcinoma), when compared with adriamycin (IC50 (µM) = 0.08 ± 0.003, and 0.05 ± 0.003, as the positive control, respectively. Compounds 3 and 10 showed significant reduction of the induced ear edema of 37.4 ± 2.8 and 25.4 ± 3.0% (at 1.0 µmol/ear), respectively. Compound 4 was the sole active diterpenoid in the antioxidant assay (IC50 = 98. 4 ± 3.3), using α-tocopherol as positive control, IC50 (µM) = 31.7 ± 1.04. The diterpenoid profile found is of chemotaxonomic relevance and reinforces the evolutionary link of S. ballotiflora with other members of the section Tomentellae.
REVIEW | doi:10.20944/preprints202307.1230.v1
Subject: Medicine And Pharmacology, Pharmacology And Toxicology Keywords: biosurfactants; antibacterial/antifungal/antiviral activity; antiadhesive/antibiofilm agents; anticancer agents; anticancer agents; immunomodulatory activity; wound-healing promoters
Online: 19 July 2023 (07:47:08 CEST)
Biosurfactants (BSs) are microbial compounds that have emerged as potential alternatives to chemical surfactants due to their multifunctional properties, sustainability, and biodegradability. Owing to their amphipathic nature and distinctive structural arrangement, biosurfactants exhibit a range of physicochemical properties, including excellent surface activity, efficient critical micelle concentration, humectant properties, foaming and cleaning abilities and the capacity to form microemulsions. Furthermore, numerous biosurfactants display additional biological characteristics, such as antibacterial, antifungal, and antiviral effects, antioxidant, anticancer, and immunomodulatory activities. Over the past two decades, numerous studies have explored their potential applications, including pharmaceuticals, cosmetics, antimicrobial and antibiofilm agents, wound healing, anticancer treatments, immune system modulators and drug/gene carriers. These applications are particularly important in addressing challenges such as antimicrobial resistance and biofilm formation in clinical, hygiene, and therapeutic settings. They can also serve as coating agents for surfaces, enabling antiadhesive, suppression, or eradication strategies. Not least importantly, biosurfactants have shown compatibility with various drug formulations, including nanoparticles, liposomes, micro and nanoemulsions, and hydrogels, improving drug solubility, stability, and bioavailability and enabling targeted and controlled drug release. These qualities make biosurfactants promising candidates for the development of next-generation antimicrobial, antibiofilm, anticancer, wound healing, immunomodulating, drug or gene delivery agents, as well as adjuvants to other antibiotics. Analyzing recent literature, this review aims to provide insights into the present understanding, highlight emerging trends, identify promising directions and advancements in the utilization of biosurfactants within the pharmaceutical and biomedical fields.
ARTICLE | doi:10.20944/preprints202104.0195.v1
Subject: Medicine And Pharmacology, Immunology And Allergy Keywords: doubly labeled water; total energy expenditure; physical activity level; lactate threshold, physical fitness; International Physical Activity Questionnaire
Online: 7 April 2021 (11:32:02 CEST)
Adequate energy intake is critical for the healthy longevity of older adults, and the estimated energy requirement is determined by total energy expenditure (TEE). We aimed to identify the relationship between measured aerobic capacity and TEE, activity energy expenditure (AEE) or physical activity level (PAL) with the doubly labeled water (DLW) methods in the advanced older adults. A total of 12 physically independent older adults (10 males and 2 females) aged between 81 to 94 years participated in this study. Aerobic capacity was evaluated according to the lactate threshold (LT). TEE under free-living conditions was assessed using the DLW method, and self-reported physical activity was obtained through the Japanese version of the International Physical Activity Questionnaire (IPAQ). LT was significantly positively correlated with TEE, AEE, and PAL after adjustment for age and sex (ρ= 0.77 (P<0.01), 0.86 (p<0.01), and 0.86 (p<0.01), respectively). We found the LT as an aerobic capacity is positively and independently correlated with TEE, AEE or PAL. The present results suggest that maintaining aerobic capacity is an important factor for preventing frailty, although further research is needed to multisite studies and many samples.
ARTICLE | doi:10.20944/preprints201907.0055.v1
Subject: Chemistry And Materials Science, Analytical Chemistry Keywords: Barhi date palm kernels (BDPK); non-extractable polyphenols (NEPP); anticancer activity; antioxidant activity; response surface methodology; optimisation.
Online: 3 July 2019 (09:23:01 CEST)
Dietary polyphenols exist in two forms; extractable polyphenols (EPP) or compounds solubilised by aqueous/organic solvents, and non-extractable polyphenols (NEPP) or compounds remain in the corresponding residues after the extraction. At present, most researchers focus on EEP fractions, while NEPP is neglected. Thus, this study aimed to release NEPP from the remaining powder residue of Barhi date palm kernels (BDPK) with acid hydrolysis. The related extraction conditions were determined and optimised using response surface methodology (RSM) for maximisation of NEPP with highest cytotoxic and antioxidant activities. The face-centred central composite design (FCCCD) was used to establish treatments based on three independent variables, namely; extraction temperature, time, and solvent/sample ratio. Under the optimal conditions, the experimental values for DPPH radical-scavenging capacity of NEPP (IC50=57.52µg/mL), and cytotoxicity of NEPP against A549 and HT29 cells were IC50=17.4 µg/mL and 31.4µg/mL, respectively. The experimental values were in agreement with those predicted by RSM models, confirming the suitability of the model employed and the success of RSM for optimisation of the extraction conditions for NEPP from BDPK. These results indicate that NEPP from industrial date fruit waste could be a promising candidate as natural antioxidants with significant antiproliferation effect against A549 and HT29 cancer cells in-vitro.
Subject: Environmental And Earth Sciences, Environmental Science Keywords: physical activity; exercise; green cover; open space; Metabolic Equivalent of Task; International Physical Activity Questionnaire; health promotion
Online: 20 March 2019 (10:46:23 CET)
1) Background: A population-based cross-sectional study was conducted to understand how green cover and accessibility of common public open spaces in compact urban areas affect physical activeness of resident. 2) Methods: A total of 554 residents completed a structured questionnaire on quality-of-life, physical activity level, and healthy eating practice. 3) Results: The sampled population lived with green cover averaged 10.11 ± 7.95% (ranged 1.56–9.88), whereas majority (90%) of the residents performed physical activities at medium and high levels. Metabolic Equivalent of Task (MET)-minutes/week was associated with the green cover percentage (Pearson r = 0.092; p < 0.05). Irrespective of age and physical activity level, active residents commonly used public open spaces within district for performing exercise, especially parks and promenade were mostly used by older residents while sports facilities by the younger groups. 4) Conclusions: Current findings suggested promotion of exercise could be achieved by the design or redesign of built environment to include more parks accessible to the residents with the increase of vegetation.
ARTICLE | doi:10.20944/preprints202311.1368.v1
Subject: Biology And Life Sciences, Plant Sciences Keywords: Empetrum rubrum; Antioxidant; Antifungal activity; HPLC-MS
Online: 22 November 2023 (03:43:26 CET)
In searching for compounds with antioxidant and antifungal activity, our study focused on the subshrub species Empetrum rubrum Vahl ex Willd. (Ericaceae), commonly known as Brecillo or Murtilla de Magallanes. We measured the antioxidant activity of its methanolic extract (MEE) obtained from the aerial parts (leaves and stems). The antioxidant activity of MEE was evaluated in vitro by 2,2-Diphenyl-1-picrylhydrazyl (DPPH) free radical and 2,2′-Azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt (ABTS) cationic radical. Results were expressed in gallic acid and Trolox equivalents for DPPH and ABTS assays, respectively. The antioxidant activities, for the DPPH and ABTS assays, were also calculated as an inhibitory concentration of extract needed to inhibit 50% of the absorbance (IC50 value). The results of IC50 values measured by the DPPH and ABTS methods were 0.4145 mg mL-1 and 0.1081 mg mL-1, respectively. In relation to the antioxidant activity, the total phenolic content (TPC) in MEE was determined by the Folin-Ciocalteu method, and the presence of secondary metabolites groups, including phenolic compounds, was determined by using different standardized test procedures. Phenolic compounds contained in leaves, stems, and fruits of E. rubrum were determined qualitatively by means of high-performance liquid chromatography coupled with mass spectrometry (HPLC-MS) analysis. The antifungal activity of MEE obtained from aerial parts of E. rubrum was tested against Rhizoctonia solani. In vitro, mycelial growth of this fungus was reduced from 90% to 100% in the presence of MEE.
ARTICLE | doi:10.20944/preprints202311.0397.v1
Subject: Chemistry And Materials Science, Biomaterials Keywords: Antimicrobial activity; vesicles; endolysin; encapsulation; gelatine films
Online: 7 November 2023 (06:45:46 CET)
Antimicrobial resistance (AMR) has become a worldwide health problem. Consequently, there is a global interest in the study of the antimicrobial activity of natural compounds as an alternative to antibiotics. One of the possibilities studied during the last years is the use of bacteriophages and their derived proteins. More specifically, phage lytic proteins or endolysins are specific enzymes that cause cell lysis and can be easily produced and purified after overexpression in bacteria. However, one of the major disadvantages of these proteins is their sensitivity to some environmental conditions that can reduce their efficiency. The use of vesicles for endolysin encapsulation could help overcome this disadvantage, offering an additional protection to the protein and allowing its controlled release and long-term stability.
ARTICLE | doi:10.20944/preprints202311.0305.v1
Subject: Biology And Life Sciences, Insect Science Keywords: Insect; cockroach; locomotor activity; insecticide; neonicotinoid; acetamiprid
Online: 6 November 2023 (07:54:11 CET)
Toxicological studies have shown that the cockroach Periplaneta americana is a classical model for studying the mode of action of commonly used insecticides. In a previous study, we demonstrated that thiamethoxam and clothianidin decreased locomotor activity and decreased the locomotor activity in an open-field-like apparatus. Here, we tested the effect of the neonicotinoid acetamiprid when applied orally, topically, or injected into the haemolymph. We found that acetamiprid decreased locomotor activity in the open-field-like apparatus. When treated with acetamiprid, a strong alteration in locomotor activity was observed 1 h, 24 h and 48 h after haemolymph and topical applications. Oral application of acetamiprid demonstrated that it impaired locomotor activity at 24 h and 48 h. A comparison of the present data with our previously published results showed that neonicotinoids were more active when injected into the haemolymph compared to oral and topical applications. These findings increased our understanding of the effect of neonicotinoid insecticides on insect locomotor activity, and demonstrated that the cyano-substituted neonicotinoid, acetamiprid, was able to alter cockroach locomotor activity.