The preparation and testing of thiol-functionalised silica-coated magnetite nanoparticles (TF-SCMNPs) is described. The characteristics of these particles are assessed at different stages in the production process using X-ray diffraction (XRD), transmission electron microscopy (TEM), Fourier Transform Infrared Spectroscopy (FTIR), and a magnetometer. The particles were found to be almost spherical with a uniform mesoporous structure with a pore size of ~2.1 nm. The particles were strongly responsive to an external magnetic field making separation from solution possible in less than 1 min. The adsorption characteristics of the particles were quantified in a series of isotherm experiments using Hg(II) solution concentrations between 40 and 1000 μg l -1 at adsorbent concentrations of 4 and 8 mg l -1 . The adsorption capacity was higher than for other commonly used adsorbents with 90% of Hg(II) removed during the first 5 min and equilibrium in less than 15 min. Both the Langmuir and Freundlich isotherm models were applied to the isotherm data and the maximum adsorption capacity was achieved when the ratio of adsorbent to adsorbate was low. temperature and pH had an effect on adsorption but when the TF-SCMNPs were used for removal of Hg(II) from tap water and bottled water, which contained other ions, there appeared to be no interference. Hg(II) could be successfully desorbed using thiourea in a 3M HCl solution; this did not result in the destruction of the nanoparticles and they could subsequently be reused without loss of their activity in repetitive adsorption tests.

BackgroundDepression, anxiety, and stress levels are considered important indicators for mental health. Khat chewing habit is prevalent among all segments of Jazan population in Saudi Arabia. Few studies have been conducted to evaluate depression, anxiety, and stress among Jazan University students, and information about the correlation between khat use and these disorders is scarce. Thus, this study aims to evaluate the prevalence of depression, anxiety, and stress and their correlation with khat chewing and other risk factors among Jazan University students.MethodsA cross-sectional study was conducted on 642 students from Jazan University. Multistage sampling was used, with probability proportional to size-sampling technique. The Depression, Anxiety, and Stress Scale 21 questionnaire was used to collect the data, which were analyzed using SPSS Version 20.0 software.ResultsModerate depression was prevalent among 53.6% of the sample, anxiety was found among 65.7%, while 34.3% of the students suffered from stress. Female gender was strongly associated with higher mean scores for symptoms of depression, anxiety, and stress, with P-values <0.05 for all. Moreover, anxiety symptoms scores were statistically associated with grade point average and caffeine consumption. Khat use was statistically associated with higher mean scores of anxiety among males and a higher mean score of depression and anxiety among females.ConclusionThe results indicate a high rate of symptoms of depression, anxiety, and stress among Jazan University students. Khat use was associated with anxiety, and a higher rate of symptoms of depression, anxiety, and stress was indicated among female students. Therefore, strategy for the prevention and management of depression, anxiety, and stress is highly recommended to minimize the impact of these serious disorders.

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BackgroundThe prevalence of irritable bowel syndrome (IBS) worldwide remains heterogeneous. In Saudi Arabia, there are insufficient studies on the prevalence of IBS among the general population, yet the prevalence of IBS in certain professional groups has been reported. This study was conducted to determine the prevalence of IBS and its associated risk factors in the Jazan Region of Saudi Arabia. MethodsAn online cross-sectional study was conducted from January to March 2020 in the Jazan Region of Saudi Arabia, using a multi-stage stratified sampling technique. The data were collected using a web-based validated Rome IV questionnaire. The Rome IV criteria are used to diagnose functional gut disorders, including IBS. Logistic regression analysis was used to determine the odds ratio (OR) with 95% confidence intervals (95% CI) for the selected risk factors. ResultsThe survey included 1554 participants with an overall IBS prevalence of 16%. Women had a higher incidence of IBS than men (55.3% and 44.7%, respectively). IBS-mixed (32.66%) and constipation-predominant (32.25%) were the most common subtypes. In multiple regression analysis, female gender (OR = 1.503, pvalue = 0.037), stress (OR = 2.386, p-value = 0.000), anxiety (OR = 1.943, p-value = 0.000), and tobacco smoking (OR = 2.093, p-value = 0.001) showed a statistically significant association with IBS. ConclusionsThe prevalence of IBS in the southwest region of Saudi Arabia is high. Female sex, tobacco smoking, stress, and anxiety are the major risk factors associated with IBS.

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