Study the Physical Properties of Some Alloy Materials and Effect of Gamma Radiation

The present paper reports the effect of replacement of selenium by tellurium on the optical gap and some other physical parameters of new quaternary chalcogenide TexGe20Se(60-x)As20 (x = 0, 10, 15 and 20 at. %) thin films. Thin films with thickness 100 nm of TexGe20Se(60-x)As20 were prepared by thermal evaporation of the bulk samples. Increasing tellurium content is found to affect the average heat of atomization, cohesive energy and energy gap of the TexGe20Se(60-x)As20 alloys. Optical absorption measurements showed that the fundamental absorption edge is a function of composition. The optical absorption is due to allowed direct transition and the energy gap decreases with the increase of tellurium content. The chemical bond approach has been applied successfully to interpret the decrease of the optical gap with increasing tellurium content. it has also been observed that the increase of Te was followed by decrease in glass transition temperature. The prepared films were irradiated by gamma rays at doses up to 200kGy. It was found that the compositions were almost stable against gamma radiation. Keywords: amorphous, chalcogenide, optical properties

New insights into the genetic etiology of Alzheimer's disease and related dementias

Characterization of the genetic landscape of Alzheimer's disease (AD) and related dementias (ADD) provides a unique opportunity for a better understanding of the associated pathophysiological processes. We performed a two-stage genome-wide association study totaling 111,326 clinically diagnosed/'proxy' AD cases and 677,663 controls. We found 75 risk loci, of which 42 were new at the time of analysis. Pathway enrichment analyses confirmed the involvement of amyloid/tau pathways and highlighted microglia implication. Gene prioritization in the new loci identified 31 genes that were suggestive of new genetically associated processes, including the tumor necrosis factor alpha pathway through the linear ubiquitin chain assembly complex. We also built a new genetic risk score associated with the risk of future AD/dementia or progression from mild cognitive impairment to AD/dementia. The improvement in prediction led to a 1.6- to 1.9-fold increase in AD risk from the lowest to the highest decile, in addition to effects of age and the APOE ε4 allele

The evolving SARS-CoV-2 epidemic in Africa: Insights from rapidly expanding genomic surveillance

INTRODUCTION Investment in Africa over the past year with regard to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) sequencing has led to a massive increase in the number of sequences, which, to date, exceeds 100,000 sequences generated to track the pandemic on the continent. These sequences have profoundly affected how public health officials in Africa have navigated the COVID-19 pandemic. RATIONALE We demonstrate how the first 100,000 SARS-CoV-2 sequences from Africa have helped monitor the epidemic on the continent, how genomic surveillance expanded over the course of the pandemic, and how we adapted our sequencing methods to deal with an evolving virus. Finally, we also examine how viral lineages have spread across the continent in a phylogeographic framework to gain insights into the underlying temporal and spatial transmission dynamics for several variants of concern (VOCs). RESULTS Our results indicate that the number of countries in Africa that can sequence the virus within their own borders is growing and that this is coupled with a shorter turnaround time from the time of sampling to sequence submission. Ongoing evolution necessitated the continual updating of primer sets, and, as a result, eight primer sets were designed in tandem with viral evolution and used to ensure effective sequencing of the virus. The pandemic unfolded through multiple waves of infection that were each driven by distinct genetic lineages, with B.1-like ancestral strains associated with the first pandemic wave of infections in 2020. Successive waves on the continent were fueled by different VOCs, with Alpha and Beta cocirculating in distinct spatial patterns during the second wave and Delta and Omicron affecting the whole continent during the third and fourth waves, respectively. Phylogeographic reconstruction points toward distinct differences in viral importation and exportation patterns associated with the Alpha, Beta, Delta, and Omicron variants and subvariants, when considering both Africa versus the rest of the world and viral dissemination within the continent. Our epidemiological and phylogenetic inferences therefore underscore the heterogeneous nature of the pandemic on the continent and highlight key insights and challenges, for instance, recognizing the limitations of low testing proportions. We also highlight the early warning capacity that genomic surveillance in Africa has had for the rest of the world with the detection of new lineages and variants, the most recent being the characterization of various Omicron subvariants. CONCLUSION Sustained investment for diagnostics and genomic surveillance in Africa is needed as the virus continues to evolve. This is important not only to help combat SARS-CoV-2 on the continent but also because it can be used as a platform to help address the many emerging and reemerging infectious disease threats in Africa. In particular, capacity building for local sequencing within countries or within the continent should be prioritized because this is generally associated with shorter turnaround times, providing the most benefit to local public health authorities tasked with pandemic response and mitigation and allowing for the fastest reaction to localized outbreaks. These investments are crucial for pandemic preparedness and response and will serve the health of the continent well into the 21st century

Electronic & IR Spectra of Some 4-Arylhydrazano-3-(3’-pyridyl)-2-pyrazolin-5-ones

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Electronic & IR Spectra of Some 4-Arylhydrazano-3-(3’-pyridyl)-2-pyrazolin-5-ones

789-79

New arylhydrazonothiazolidin-5-one disperse dyes for dyeing polyester fibers

A series of new thiazolidin-5-one disperse dyes was synthesized from the reactions of 2-substituted 3-phenylthiazolidinones with various aryldiazonium chlorides. The synthesized dyes were characterized by UV-visible absorption, IR, NMR and MS spectroscopy. The dyes gave orange to reddish-violet shades with very good depth on polyester fibers. The dyed fabrics show moderate to good fastness to light and very good to excellent fastness to washing and perspiration. Also, the assessment of color coordinates was discussed

Caffeine addiction and determinants of caffeine consumption among health care providers: a descriptive national study

OBJECTIVE: Caffeine is the most commonly used psychostimulant compound with a long history of worldwide consumption. Consuming low to moderate doses of caffeine is generally safe and quite beneficial; however, several clinical studies show that high doses could be toxic.  Additionally, caffeine users can become dependent on the drug and find themselves unable to reduce consumption despite impending and recurrent health problems associated with continued use. This study was conducted to explore the prevalence, determinants, and positive and negative effects of caffeine consumption among governmental health care providers (HCPs) who were caffeine users. It aims to determine the frequency of caffeine dependence and addiction in the Kingdom of Saudi Arabia (KSA) in January 2020. SUBJECTS AND METHODS: This cross-sectional study recruited 600 randomly selected HCPs from all regions of KSA, who fulfilled the selection criteria through a self-administrated, online-validated questionnaire composed of three main parts using the DSM-IV to diagnose dependence and probable addiction. RESULTS: The majority of the studied HCPs were females (67.8%), nonsmokers (82.0%), and Saudis (80.5%), with a mean age of 35 years. According to the DSM-IV, the prevalence of caffeine consumption was 94.3%. Caffeine dependence was reported in 270 (47.7%), while 345 (60.9%) were diagnosed as addicts. The most commonly consumed caffeine-containing substances were coffee and its variants/types (70%), tea (59%), and chocolate (52%), with each person spending about 220 SR per week on them. The main reported adverse effects, in descending order, were sleep disturbances, stomach problems, and cardiac symptoms. The most positive effects reported of caffeine consumption were feeling active, alert, confident, and happy. These findings were significantly affected by sex, occupation, and general health. CONCLUSIONS: Caffeine use, dependence, and addiction are common among government HCPs in KSA. Caffeine has both positive and negative effects on this population and further research is necessary to better understand the long-term consequences of caffeine consumption