15 research outputs found

    Workplace Psychosocial Factors and Mental Health among a Sample of Expatriates and the Country’s Nationals Who Working at King Khalid University, Saudi Arabia

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    Worplace stress is the harmful physical and emotional response that occurs when there is a poor match between job demands and the capabilities, resources, or needs of the worker. Mental health is an important issue in the workplace, particularly in developing countries. This study was aimed to explore the workplace psychosocial factors and mental health among expatriates and the country’s nationals; examine the relationship between workplace psychosocial factors and mental health. . The sample was composed of 518 country's nationals and 554 expatriates teaching staff on job at King Khalid University. Two tools were used for data collection: Socio-demographic data sheet, and Copenhagen Psychosocial Questionnaire (COPSOQ). The study results indicated that Poor mental health had a strongly statistically significant positive correlation with “quantitative  demands”,” Work-family conflict”, and “Emotional demands “ in total country’s nationals and expatriates   (p<0.01). While it was a strongly statistically significant negative  correlation with “Work pace”, “Influence at work”, “Social support from colleague”, “Social support from supervisors”, “Meaning of work”, “Commitment to the workplace” “Predictability”, and  “Recognition” (p<0.01). It was concluded that country's nationals experience worse mental health than expatriates and  this  to some extent caused by exposure to psychosocial factors at work. It has indicated the importance of taking action to reduce psychosocial factors, as this would benefit both country’s nationals and expatriate workers. Key words: Expatriates , country's nationals , workplace psychosocial factors, mental health

    Antifungal efficacy of chitosan nanoparticles against phytopathogenic fungi and inhibition of zearalenone production by Fusarium graminearum

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    Chitosan (COS) is a natural safe biopolymer that received great attention in agriculture, food, biomedical, pharmaceutical and environmental industries because their biocompatible, biodegradable, non-toxic and non-allergenic natures. The aims of the current study were to synthesize and characterize chitosan nanoparticles (COS-NPs), to evaluate their antifungal activity against phytopathogenic fungi and inhibition of zearalenone (ZEN) production by Fusarium graminearum. The results revealed that the deacetylation degree of COS was 86.9 0.44 %, the average of molar mass was 171.41 ± 0.29 g/mol, molecular weight was 244 ± 7 kDa and the concentration of free amino groups was 0.05 ± 0.019 mol L-1. COS-NPs showed the nanorod form with rough nature and particle size was around 180 nm. COS-NPs showed an excellent antifungal activity against Alternaria tenuis, Aspergillus niger, A. flavus, Baeuvaria bassiana, Fusarium graminearum, Fusarium oxysporum, Penicillium sp. and Sclerotium rolfsii in dose dependent manner. At a concentration of 800 ppm, it inhibits ZEN production by Fusarium graminearum. It could be concluded that COS-NPs are promise candidate as safe antifungal capable for the prevention of ZEN production.Chitosan (COS) is a natural safe biopolymer that received great attention in agriculture, food, biomedical, pharmaceutical and environmental industries because their biocompatible, biodegradable, non-toxic and non-allergenic natures. The aims of the current study were to synthesize and characterize chitosan nanoparticles (COS-NPs), to evaluate their antifungal activity against phytopathogenic fungi and inhibition of zearalenone (ZEN) production by Fusarium graminearum. The results revealed that the deacetylation degree of COS was 86.9 0.44 %, the average of molar mass was 171.41 ± 0.29 g/mol, molecular weight was 244 ± 7 kDa and the concentration of free amino groups was 0.05 ± 0.019 mol L-1. COS-NPs showed the nanorod form with rough nature and particle size was around 180 nm. COS-NPs showed an excellent antifungal activity against Alternaria tenuis, Aspergillus niger, A. flavus, Baeuvaria bassiana, Fusarium graminearum, Fusarium oxysporum, Penicillium sp. and Sclerotium rolfsii in dose dependent manner. At a concentration of 800 ppm, it inhibits ZEN production by Fusarium graminearum. It could be concluded that COS-NPs are promise candidate as safe antifungal capable for the prevention of ZEN production

    Extraction and partial purification of Aspergillus flavus cell wall associated saponin hydrolase

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    In spite of the importance of saponin hydrolase (SH) enzyme, in the production of biologically active compounds from natural saponins, it is surprising that many aspects of its nature are unknown. The results of the present work revealed that Aspergillus flavus was capable of expressing three SH forms; extracellular, intracellular and cell wall-bound forms. SH cell bound enzyme constituted to more than 75% of the total enzymatic activity in the production medium. The sequential extraction process of SH cell bound enzyme revealed that 47.5% of SH was cytosolic and the rest (52.5%) was associated with the cell wall. The highest SH extraction yield was achieved when 0.25 M Tris-HCl lysis buffer supplemented with 1% Triton X-100 for 24 h at 4-25 °C and pH 8 were applied. Under these optimized conditions, A. flavus SH yield increased from 23.6 to 85.83%. The partial purification was achieved by applying successively acetone precipitation, lyophilization, dialysis, and anion exchange chromatography on Fractogel EMD DEAE-650S to the extract. The specific activity of the enzyme extract was 0.27 U/mg after 75% acetone fractionation, while that after anion exchange chromatography was 0.65 U/mg protein. The final enzyme preparation was 7.3-fold purer than the crude extract

    Antifungal efficacy of chitosan nanoparticles against phytopathogenic fungi and inhibition of zearalenone production by Fusarium graminearum

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    Chitosan (COS) is a natural safe biopolymer that received great attention in agriculture, food, biomedical, pharmaceutical and environmental industries because their biocompatible, biodegradable, non-toxic and non-allergenic natures. The aims of the current study were to synthesize and characterize chitosan nanoparticles (COS-NPs), to evaluate their antifungal activity against phytopathogenic fungi and inhibition of zearalenone (ZEN) production by Fusarium graminearum. The results revealed that the deacetylation degree of COS was 86.9 0.44 %, the average of molar mass was 171.41 ± 0.29 g/mol, molecular weight was 244 ± 7 kDa and the concentration of free amino groups was 0.05 ± 0.019 mol L-1. COS-NPs showed the nanorod form with rough nature and particle size was around 180 nm. COS-NPs showed an excellent antifungal activity against Alternaria tenuis, Aspergillus niger, A. flavus, Baeuvaria bassiana, Fusarium graminearum, Fusarium oxysporum, Penicillium sp. and Sclerotium rolfsii in dose dependent manner. At a concentration of 800 ppm, it inhibits ZEN production by Fusarium graminearum. It could be concluded that COS-NPs are promise candidate as safe antifungal capable for the prevention of ZEN production

    Essential oil composition and biological activities of Hyssopus officinalis and Perilla frutescens

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    This article reports on the main constituents of Hyssopus officinalis and Perilla frutescens essential oils (EOs) and their activity as antioxidant, antimicrobial, anti inflammatory and anticancer. The major component of H. officinalis essential oil was isopinocamphone followed by pinocamphone, β-pinene, β-phellandrene, α-thujene and bicyclo-germacrene. The main constituent of the essential oil of P. frutescens was identified as L-perillaldehyde followed by trans-caryophyllene and D-limonene. Both essential oils (hyssop and perilla) showed antioxidant activities with the used three methods and the increase of activity was concentration dependent up to 32ÎĽg/ml comparing to ascorbic acid.  The values of IC50 for DPPH radical scavenging were in the order of P. frutescens< ascorbic acid< H. officinalis. The values of IC50 for FIC method were in the order of ascorbic acid< P. frutescens< H. officinalis. The IC50 for ABTS method was 8ÎĽg for P. frutescence and the values were in the order as ascorbic acid< H. officinalis< P. frutescence. The essential oil of both plant species showed variable activities against all the tested bacterial. The results displayed also that the essential oil of P. frutescens showed significant fungal inhibitions against the four tested Candida strains.&nbsp

    Antiproliferative and Antiangiogenic Properties of New VEGFR-2-targeting 2-thioxobenzo[g]quinazoline Derivatives (In Vitro)

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    A series of 3-ethyl(methyl)-2-thioxo-2,3-dihydrobenzo[g]quinazolines (1–17) were synthesized, characterized, and evaluated in vitro for their antiangiogenesis VEGFR-2-targeting, antiproliferative, and antiapoptotic activities against breast MCF-7 and liver HepG2 cells. Flow cytometry was used to determine cancer-cell cycle distributions, and apoptosis was detected using annexin-V-FITC (V) and propidium iodide (PI) dyes. Fluorescence microscopy, in combination with Hoechst staining was used to detect DNA fragmentation. Most of the tested benzo[g]quinazolines demonstrated promising activity (IC50 = 8.8 ± 0.5–10.9 ± 0.9 μM) and (IC50 = 26.0 ± 2.5–40.4 ± 4.1 μM) against MCF-7 and HepG2, respectively. Doxorubicin was used as a reference drug. Compounds 13–15 showed the highest activity against both cancer cell lines. Differential effects were detected by cell-cycle analysis, indicating similarities in the actions of 13 and 14 against both MCF7 and HepG2, involving the targeting of G1 and S phases, respectively. Compound 15 showed similar indices against both cells, indicating that its cytotoxicity toward the examined cancer cells could be unselective. Interestingly, 14 and 15 showed the highest apoptosis (30.76% and 25.30%, respectively) against MCF-7. The DNA fragmentation results agreed well with the apoptosis detected by flow cytometry. In terms of antiangiogenesis activity, as derived from VEGFR-2 inhibition, 13 and 15 were comparable to sorafenib and effected 1.5- and 1.4-fold inhibition relative to the standard sorafenib. A docking study was conducted to investigate the interaction between the synthesized benzo[g]quinazolines and the ATP-binding site within the catalytic domain of VEGFR-2

    Synthesis, Biocidal and Antibiofilm Activities of New Isatin–Quinoline Conjugates against Multidrug-Resistant Bacterial Pathogens along with Their In Silico Screening

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    Isatin–quinoline conjugates 10a–f and 11a–f were assembled by the reaction of N-(bromobutyl) isatin derivatives 3a, b with aminoquinolines 6a–c and their corresponding hydrazinyl 9a–c in good yields. The structures of the resulting conjugates were established by spectroscopic tools and showed data consistent with the proposed structures. In vitro antibacterial activity against different bacterial strains was evaluated. All tested conjugates showed significant biocidal activity with lower MIC than the first line drugs chloramphenicol and ampicillin. Conjugates 10a, 10b and 10f displayed the most potent activity against all clinical isolates. The antibiofilm activity for all tested conjugates was screened against the reference drug vancomycin using the MRSA strain. The results revealed that all conjugates had an inhibitory activity against biofilm formation and conjugate. Conjugate 11a showed 83.60% inhibition at 10 mg/mL. In addition, TEM studies were used to prove the mechanism of antibacterial action of conjugates 10a and 11a against (MRSA). Modeling procedures were performed on 10a–f and 11a–f and interestingly the results were nearly consistent with the biological activities. In addition, in silico pharmacokinetic evaluation was performed and revealed that the synthesized compounds 10a–f and 11a–f were considered drug-like molecules with promising bioavailability and high GI absorption. The results confirmed that the title compounds caused the disruption of bacterial cell membranes and could be used as potential leads for the further development and optimization of antibacterial agents

    The Prevalence and Molecular Biology of Staphylococcus aureus Isolated from Healthy and Diseased Equine Eyes in Egypt

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    This work aimed to characterize S. aureus isolates from the eyes of healthy and clinically affected equines in the Kafrelsheikh Governorate, Egypt. A total of 110 animals were examined for the presence of S. aureus, which was isolated from 33 animals with ophthalmic lesions and 77 healthy animals. We also investigated the antimicrobial resistance profile, oxacillin resistance mechanism, and the major virulence factors implicated in many studies of the ocular pathology of pathogenic S. aureus. The association between S. aureus eye infections and potential risk factors was also investigated. The frequency of S. aureus isolates from clinically affected equine eyes was significantly higher than in clinically healthy equids. A significant association was found between the frequency of S. aureus isolation from clinically affected equine eyes and risk factors including age and season but not with sex or breed factors. Antimicrobial resistance to common antibiotics used to treat equine eyes was also tested. Overall, the isolates showed the highest sensitivity to sulfamethoxazole (100%) and the highest resistance to cephalosporin (90.67%) and oxacillin (90.48%). PCR was used to demonstrate that mecA was present in 100% of oxacillin- and β-lactam-resistant S. aureus strains. The virulence factor genes Spa (x region), nuc, and hlg were identified in 62.5%, 100%, and 56%, of isolates, respectively, from clinically affected equines eyes. The severity of the eye lesions increased in the presence of γ-toxin-positive S. aureus. The phylogenetic tree of the Spa (x region) gene indicated a relationship with human reference strains isolated from Egypt as well as isolates from equines in Iran and Japan. This study provides insight into the prevalence, potential risk factors, clinical pictures, zoonotic potential, antimicrobial resistance, and β-lactam resistance mechanism of S. aureus strains that cause eye infection in equines from Egypt
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