Impact of synthesis route on structural, magnetic, magnetocaloric and critical behavior of Nd0.6Sr0.4MnO3 manganite

Nd0.6Sr0.4MnO3 polycrystalline manganite was synthesized by two different methods: the auto-combustion reaction (NSMO-AC) and the sol-gel method (NSMO-SG). The structural, magnetic, magnetocaloric and critical behavior of the samples were examined. Rietveld refinements of the XRD patterns revealed that both compounds are pure single phase indexed to the orthorhombic system adopting the Pnma space group. The nanometric size estimated using the Williamson-Hall method was confirmed by TEM micrographs. Magnetic measurements as a function of temperature indicated that both samples underwent a second order ferromagnetic (FM)-paramagnetic (PM) phase transition at Curie temperature (T C). The relative cooling power was observed to be around 95.271 J kg-1 for NSMO-AC and 202.054 J kg-1 for NSMO-SG at μ 0 H = 5 T, indicating that these materials are potential candidates for magnetic refrigeration application close to room temperature. The critical behavior was estimated using diverse techniques based on the isothermal magnetization data recorded around the critical temperature T C. The calculated values are fully satisfactory to the requirements of the scaling theory, implying their reliability. The estimated critical exponents matched well with the values anticipated for the mean-field model and the 3D Ising model for NSMO-AC and NSMO-SG, respectively, showing that the magnetic interactions depended on the process of elaboration.

Chitosan-Stabilized Selenium Nanoparticles and Metformin Synergistically Rescue Testicular Oxidative Damage and Steroidogenesis-Related Genes Dysregulation in High-Fat Diet/Streptozotocin-Induced Diabetic Rats

BACKGROUND

this study examined the metformin (MF) and/or chitosan stabilized selenium nanoparticles (CH-SeNPs) efficacy to alleviate the male reproductive function impairment in a high-fat diet feed with low-dose streptozotocin (HFD/STZ) induced type 2 diabetes mellitus (T2DM) diabetic rat model.

METHODS

control non-diabetic, HFD/STZ diabetic, HFD/STZ+MF, HFD/STZ+CH-SeNPs, and HFD/STZ+MF+CH-SeNPs rat groups were used. After 60 days, semen evaluation, hormonal assay, enzymatic antioxidant, lipid peroxidation, testis histopathology, and the steroidogenesis-related genes mRNA expressions were assessed.

RESULTS

in the HFD/STZ diabetic rats, sperm count and motility, male sexual hormones, and testicular antioxidant enzymes were significantly reduced. However, sperm abnormalities and testicular malondialdehyde were significantly incremented. The steroidogenesis-related genes, including steroidogenic acute regulatory protein (StAr), cytochrome11A1 (CYP11A1), cytochrome17A1 (CYP17A1), and hydroxysteroid 17-beta dehydrogenase 3 (HSD17B3), and the mitochondrial biogenesis related genes, including peroxisome proliferator-activated receptor gamma coactivator 1-alpha (PGCα) and sirtuin (SIRT), were significantly downregulated in the HFD/STZ diabetic rats. However, CYP19A1mRNA expression was significantly upregulated. In contrast, MF and/or CH-SeNPs oral dosing significantly rescued the T2DM-induced sperm abnormalities, reduced sperm motility, diminished sexual hormones level, testicular oxidative damage, and steroidogenesis-related genes dysregulation. In the MF and CH-SeNP co-treated group, many of the estimated parameters differ considerably from single MF or CH-SeNPs treated groups.

CONCLUSIONS

the MF and CH-SeNPs combined treatment could efficiently limit the diabetic complications largely than monotherapeutic approach and they could be considered a hopeful treatment option in the T2DM.

Mechanistic Insight of Allantoin in Protecting Tomato Plants Against Ultraviolet C Stress

Allantoin ((AT) a purine metabolite)-mediated ultraviolet C (UVC) stress mitigation has not been studied to date. Here, we reported the physicochemical mechanisms of UVC-induced stress in tomato (Solanum lycopersicum L.) plants, including an AT-directed mitigation strategy. UVC stress reduced plant growth and photosynthetic pigments. Heatmap and principal component analysis (PCA) revealed that these toxic impacts were triggered by the greater oxidative damage and disruption of osmolyte homeostasis. However, pre-treatment of AT noticeably ameliorated the stress-induced toxicity as evident by enhanced chlorophyll, soluble protein, and soluble carbohydrate contents in AT-pretreated UVC-stressed plants relative to only stressed plants leading to the improvement of the plant growth and biomass. Moreover, AT pre-treatment enhanced endogenous AT and allantoate content, phenylalanine ammonia-lyase, non-enzymatic antioxidants, and the enzymatic antioxidants leading to reduced oxidative stress markers compared with only stressed plants, indicating the protective effect of AT against oxidative damage. Moreover, PCA displayed that the protective roles of AT strongly associate with the improved antioxidants. On the other hand, post-treatment of AT showed less efficacy in UVC stress mitigation relative to pre-treatment of AT. Overall, this finding illustrated that AT pre-treatment could be an effective way to counteract the UVC stress in tomato, and perhaps in other crop plants.

Analysis and Evaluation of COVID-19 Web Applications for Health Professionals: Challenges and Opportunities

The multidisciplinary nature of the work required for research in the COVID-19 pandemic has created new challenges for health professionals in the battle against the virus. They need to be equipped with novel tools, applications, and resources-that have emerged during the pandemic-to gain access to breakthrough findings; know the latest developments; and to address their specific needs for rapid data acquisition, analysis, evaluation, and reporting. Because of the complex nature of the virus, healthcare systems worldwide are severely impacted as the treatment and the vaccine for COVID-19 disease are not yet discovered. This leads to frequent changes in regulations and policies by governments and international organizations. Our analysis suggests that given the abundance of information sources, finding the most suitable application for analysis, evaluation, or reporting, is one of such challenges. However, health professionals and policy-makers need access to the most relevant, reliable, trusted, and latest information and applications that can be used in their day-to-day tasks of COVID-19 research and analysis. In this article, we present our analysis of various novel and important web-based applications that have been specifically developed during the COVID-19 pandemic and that can be used by the health professionals community to help in advancing their analysis and research. These applications comprise search portals and their associated information repositories for literature and clinical trials, data sources, tracking dashboards, and forecasting models. We present a list of the minimally essential online, web-based applications to serve a multitude of purposes, from hundreds of those developed since the beginning of the pandemic. A critical analysis is provided for the selected applications based on 17 features that can be useful for researchers and analysts for their evaluations. These features make up our evaluation framework and have not been used previously for analysis and evaluation. Therefore, knowledge of these applications will not only increase productivity but will also allow us to explore new dimensions for using existing applications with more control, better management, and greater outcome of their research. In addition, the features used in our framework can be applied for future evaluations of similar applications and health professionals can adapt them for evaluation of other applications not covered in this analysis.

Dependence of new environmental nano organic semiconductor nickel-(II)-tetraphenyl-21H,23H-porphyrin films on substrate type for energy storage applications

Characterization of organic nickel-(II)-tetraphenyl-21H,23H-porphyrin films as a function of substrate type was performed for energy storage applications and consequently environmental enhancement. Nickel-(II)-tetraphenyl-21H,23H-porphyrin films show an amorphous phase. They have a crystallite size of 8-11 nm. Strain caused a shift of different humps' positions. The measured transmittance has high values within the range of 85-91%, and the absorption coefficient values were included within the high-absorption region. Both optical gap and fundamental gap, refractive index, carrier-concentration-to-effective-mass ratio and lattice dielectric constant were calculated, and they were found to be increased, except refractive index and lattice dielectric constant. The obtained data indicated that nickel-(II)-tetraphenyl-21H,23H-porphyrin films are a candidate for energy storage applications.

Impact of salicylic acid on the growth and physiological activities of parsley plants under lead toxicity

Impact of spraying 50 µM salicylic acid (SA), lead nitrate soil treatments [1 and 2 mM Pb (NO₃)₂] and their combinations on parsley leaves (Petroselinum crispum L.) for 3 weeks was studied to evaluate leaf symptoms, photosynthetic pigments, anthocyanin, ultrastructure, malondialdehyde (MDA), soluble proteins, phenolic compounds, and guaiacol peroxidase activity (GPOX). Under Pb effect, parsley leaves showed chlorosis and decline in the content of photosynthetic pigments chlorophyll a (Chl a), chlorophyll b (Chl b) and carotenoid (Car) with increasing Pb treatments compared to the control. SA spraying helped to reduce chlorosis and increase photosynthetic pigments of Pb-treated plants compared to that of Pb treatment alone. Leaf anthocyanin content of SA-sprayed plants significantly increased compared to the control. On contrast, the anthocyanin content of Pb-treated plants with or without SA treatment decreased compared to the control. Parsley leaf chloroplasts were characterized by many and large starch grains. Deformations of chloroplast shape, increasing formation of plastoglobules and degeneration of chloroplast grana thylakoids were observed in Pb-treated plants. MDA and total phenolic compound contents increased in Pb-treated plants compared to the control. In contrast, soluble protein content decreased in Pb-treated plants. The decrease in leaf photosynthetic pigments and increase MDA contents was Pb-concentration dependent. The results as indicated by increasing lipid peroxidation confirmed Pb treatments generated reactive oxygen species (ROS) which caused oxidative stress. In contrast, SA application declined the extent of detrimental and harmful influence of Pb toxicity as indicated by the decrease MDA content, and increase in photosynthetic pigments, anthocyanin and phenolic compound contents of parsley leaves.

Ginger Water Reduces Body Weight Gain and Improves Energy Expenditure in Rats

Obesity is a serious global problem that causes predisposition to numerous serious diseases. The current study aims to investigate the effect of ginger water on body weight and energy expenditure through modulation of mRNA expression of carbohydrate and lipid metabolism. A white colored liquid obtained during freeze-drying of fresh rhizomes of Zingiber officinal was collected and named ginger water. It was used to treat rats, then blood and tissue samples were collected from the liver and white adipose at the end of the experiment. The serum was prepared and used for biochemical assays, while tissue samples were used for RNA isolation and gene expression analysis via Reverse transcription polymerase chain reaction (RT-PCR). Results of High Performance Liquid Chromatography (HPLC) analysis of ginger water revealed the presence of chrysin and galangin at concentrations of 0.24 µg/mL and 0.53 µg/mL, respectively. Average body weight gain decreased significantly in groups that received ginger water. In addition, both total cholesterol and serum triacylglycerol were reduced in the groups that received ginger water. Furthermore, mRNA expression of Sterol regulatory element-binding protein 1 (SREBP-1c) in the liver and leptin in adipose tissues were downregulated, while those of adiponectin, hepatic carnitine palmitoyltransferase1 (CPT-1), acyl-coA oxidase (ACO), Glucose transporter 2 (GLUT-2), and pyruvate kinase (PK) were upregulated in ginger water-treated groups. These results clearly revealed the lowering body weight gain effect of ginger water, which most likely occurs at the transcriptional level of energy metabolizing proteins.

Investigation of 5'-Norcarbocyclic Nucleoside Analogues as Antiprotozoal and Antibacterial Agents

Carbocyclic nucleosides have long played a role in antiviral, antiparasitic, and antibacterial therapies. Recent results from our laboratories from two structurally related scaffolds have shown promising activity against both Mycobacterium tuberculosis and several parasitic strains. As a result, a small structure activity relationship study was designed to further probe their activity and potential. Their synthesis and the results of the subsequent biological activity are reported herein.

Eustress with H2O2 Facilitates Plant Growth by Improving Tolerance to Salt Stress in Two Wheat Cultivars

In this study, the positive role of hydrogen peroxide (H2O2) pretreatment in mitigating the adverse impacts of seawater stress has been evaluated in two wheat (Triticum aestivum L.) cultivars, namely Gemmiza 11 as a salt-sensitive and Misr 1 as a salt-tolerant cultivar, with contrasting phenotypes in response to the salinity stress. Under normal conditions, wheat seeds eustress with H2O2 have shown significant effects on the improvement of plant growth parameters, such as dry weight and root and shoot lengths. Under salt stress conditions, seeds eustress with H2O2 have shown a reduction in damage to plant growth and physiological parameters as compared to the seeds kept as un-primed in both wheat cultivars. In addition, eustress of seeds with H2O2 has induced an increment in the pigments content, proline level and mineral uptake (K+, Ca2+ and Mg2+). Moreover, seeds eustress with H2O2 have shown significant decrement in Na+ content uptake in plants and that subsequently reduced lipid peroxidation. Seawater stress has increased the activity of the antioxidant system based on catalase (CAT), peroxidase (POD) and ascorbate peroxidase (APX) in both cultivars, except POD in Gemmiza 11. Similarly, the application of H2O2 has further enhanced the activity of the antioxidant system in stressed plants and this enhancement of the antioxidant system further reduced Na+ content in plants and subsequently increased the growth parameters. Results of inter-simple sequence repeat (ISSR) markers have shown clear differentiation among the treatments and have provided strong evidence in support of the hypothesis proposed in this study that H2O2 eustress improves seed tolerance and enhances plant growth parameters under seawater stress.

Malaria Prevalence in a Low Transmission Area, Jazan District of Southwestern Saudi Arabia

Detailed description of malaria in low transmission areas is crucial for elimination. The current study aimed to provide a comprehensive description for malaria transmission in Jazan, a low transmission district, southwestern Saudi Arabia. Patients at a tertiary care hospital were recruited in our study between August 2016 and September 2018. Malaria diagnosis was performed through a species-specific nested polymerase chain reaction (nested PCR), microscopy and Paramax-3TM rapid detection test (RDT). Malaria was detected in 30 patients by the PCR, with point prevalence of 10.9%. Of these malaria infections, 80% was imported, 26.6% was asymptomatic and 23.3% was sub-microscopic. Malaria was reported throughout the year, with February/March and September/October peaks. Infection was significantly more in males than in females (P=0.01). Likewise, infections were detected more in febrile than in non-febrile patients (P=0.01). Adult aged 15-24 years, fever and travel were identified as high-risk factors. Malaria was primarily attributed to Plasmodium falciparum mono-infections, followed by P. vivax mono-infections and lastly to falciparum/vivax mixed infections accounting 76.6%, 16.6%, and 6.6% of PCR-confirmed malaria cases, respectively. The nested PCR was superior to the smear microscopy (sensitivity 76.6%; specificity 100%) and the RDT (sensitivity 83.3%, specificity 94.2%). The overall percent agreement between microscopy and the RDT was 92.7% (kappa=0.63). High proportion of imported malaria including sub-microscopic and sub-patent cases were described. We suggest that incorporation of molecular tool into the conventional malaria diagnosis is beneficial in Jazan district.

Identifying potential prescribing safety indicators related to mental health disorders and medications: A systematic review

BACKGROUND

Prescribing errors and medication related harm may be common in patients with mental illness. However, there has been limited research focusing on the development and application of prescribing safety indicators (PSIs) for this population.

OBJECTIVE

Identify potential PSIs related to mental health (MH) medications and conditions.

METHODS

Seven electronic databases were searched (from 1990 to February 2019), including the bibliographies of included studies and of relevant review articles. Studies that developed, validated or updated a set of explicit medication-specific indicators or criteria that measured prescribing safety or quality were included, irrespective of whether they contained MH indicators or not. Studies were screened to extract all MH related indicators before two MH clinical pharmacists screened them to select potential PSIs based on established criteria. All indicators were categorised into prescribing problems and medication categories.

RESULTS

79 unique studies were included, 70 of which contained at least one MH related indicator. No studies were identified that focused on development of PSIs for patients with mental illness. A total of 1386 MH indicators were identified (average 20 (SD = 25.1) per study); 245 of these were considered potential PSIs. Among PSIs the most common prescribing problem was 'Potentially inappropriate prescribing considering diagnoses or conditions' (n = 91, 37.1%) and the lowest was 'omission' (n = 5, 2.0%). 'Antidepressant' was the most common PSI medication category (n = 85, 34.7%).

CONCLUSION

This is the first systematic review to identify a comprehensive list of MH related potential PSIs. This list should undergo further validation and could be used as a foundation for the development of new suites of PSIs applicable to patients with mental illness.

The Influence of Microstructure on the Passive Layer Chemistry and Corrosion Resistance for Some Titanium-Based Alloys

The effect of microstructure and chemistry on the kinetics of passive layer growth and passivity breakdown of some Ti-based alloys, namely Ti-6Al-4V, Ti-6Al-7Nb and TC21 alloys, was studied. The rate of pitting corrosion was evaluated using cyclic polarization measurements. Chronoamperometry was applied to assess the passive layer growth kinetics and breakdown. Microstructure influence on the uniform corrosion rate of these alloys was also investigated employing dynamic electrochemical impedance spectroscopy (DEIS). Corrosion studies were performed in 0.9% NaCl solution at 37 °C, and the obtained results were compared with ultrapure Ti (99.99%). The different phases of the microstructure were characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM). Chemical composition and chemistry of the corroded surfaces were studied using X-ray photoelectron spectroscopy (XPS) analysis. For all studied alloys, the microstructure consisted of α matrix, which was strengthened by β phase. The highest and the lowest values of the β phase's volume fraction were recorded for TC21 and Ti-Al-Nb alloys, respectively. The susceptibility of the investigated alloys toward pitting corrosion was enhanced following the sequence: Ti-6Al-7Nb < Ti-6Al-4V << TC21. Ti-6Al-7Nb alloy recorded the lowest pitting corrosion resistance (Rpit) among studied alloys, approaching that of pure Ti. The obvious changes in the microstructure of these alloys, together with XPS findings, were adopted to interpret the pronounced variation in the corrosion behavior of these materials.

Detection of human bocavirus in Saudi healthy blood donors

Human bocavirus is associated with respiratory disease worldwide, mainly in children. There are conflicting results, however, regarding the existence of the HBoV in blood donors. Three hundred whole blood samples from non-immunodeficient healthy blood donors were screened for the presence of HBoV by polymerase chain reaction. The HBoV genotype of positive samples was determined using direct gene sequencing. Twenty-one out of the three hundred blood samples were found to be positive for HBoV. Sequence analysis of the positive samples revealed that all the strains were related to the HBoV-1 type with a low rate of variation among the detected sequences. It was concluded that there is a considerable risk of contracting HBoV from a blood transfusion from normal healthy individuals.