Facies and geochemistry of non-marine gypsum, EMISAL, Egypt

Diverse gypsum facies in terms of crystal size and morphology are deposited in a shallow, non-marine, sulfateenriched, semi-closed, perennial evaporite basin. These gypsum facies were deposited in intimate association with cyanobacterial mats. Facies analyses and geochemistry revealed two distinct primary facies, based on gypsum fabric; massive selenite, and laminated gypsum varieties. The massive selenite facies is composed of clusters of single and twinned crystals along (100), with upward pointing re-entrant angle. The laminated gypsum varies from rhythmically laminated grass-like selenite to gypsum microbialite (stromatolite). The change from massive selenite to laminated gypsum facies implies fluctuation in lateral and vertical salinity profiles, seasonal brine concentrations and wind action. Post-depositional changes in the form of dissolution, slight to moderate crystal deformation and recrystallization to anhydrite are evaluated. We develop a qualitative model for the depositional basin and facies distribution in order to simulate ancient analogues

Facies and geochemistry of non-marine gypsum, EMISAL, Egypt

Diverse gypsum facies in terms of crystal size and morphology are deposited in a shallow, non-marine, sulfate-enriched, semi-closed, perennial evaporite basin. These gypsum facies were deposited in intimate association with cyanobacterial mats. Facies analyses and geochemistry revealed two distinct primary facies, based on gypsum fabric; massive selenite, and laminated gypsum varieties. The massive selenite facies is composed of clusters of single and twinned crystals along (100), with upward pointing re-entrant angle. The laminated gypsum varies from rhythmically laminated grass-like selenite to gypsum microbialite (stromatolite). The change from massive selenite to laminated gypsum facies implies fluctuation in lateral and vertical salinity profiles, seasonal brine concentrations and wind action. Post-depositional changes in the form of dissolution, slight to moderate crystal deformation and recrystallization to anhydrite are evaluated. We develop a qualitative model for the depositional basin and facies distribution in order to simulate ancient analogues

SECONDARY METABOLITES FROM RICE CULTURE OF ASPERGILLUS SP. ISOLATED FROM MELALEUCA SUBULATA (CHEEL) CRAVEN LEAVES AND THEIR ANTICANCER ACTIVITY

Objective: Aspergillus fungus is a rich source of natural products with broad biological activities. This study was conducted to identify secondary metabolites from the rice culture of Aspergillus species isolated from Melaleuca subulata leaves and evaluated their anticancer activity. Methods: Ethyl acetate extract was fractionated on silica gel and Sephadex columns. Structures of the compounds were established using physical and chemical methods. Cytotoxic activities of the extract and pure compounds against two human cancer cell lines (Mcf-7and Hep G2) were evaluated using microculture tetrazolium assay as well as the mode of the cytotoxicity was evaluated. Molecular docking studies have been performed using the Hsp 90 enzyme as an anticancer target. Results: Methyl linoleate (1), arugosin C (2), ergosterol (3), sterigmatocystin (4), diorcinol (5), alternariol-5-O-methyl ether (6), averufin (7), averufanin (8), and alternariol (9) were identified from ethyl acetate extract. All tested compounds exhibit week activity against MCF-7 and Hep G2 cell lines but a mixture of compounds 7 and 8 is considered to be more active towards both MCF-7 and Hep G 2 in comparison to other compounds. Compound 4 exhibits moderate activity against Hep G2 only as well as the ethyl acetate extract exerts moderate activity against MCF-7 cell line Moreover, compound 4 and a mixture of 7 and 8 caused a decrease in the number of Hep G2 cancer cells due to apoptotic and necrotic processes. Most active anticancer candidates 7 and 8 showed binding to the active site similar to geldanamycin reference ligand. Conclusion: Secondary metabolites identified from Aspergillus sp. and their anticancer activity were evaluated. Molecular docking suggested active candidates as Hsp 90 inhibitors

Aven and Survivin Expression in Egyptian Acute Leukemia and Their Relation to Apoptosis

Background: Several anti apoptotic signals have been recently identified. Aven and Survivin are broadly expressed and are conserved in mammalian species. Patients and Methods: 39 AML and 25 ALL were tested. Aven and Survivin expression were detected by RT-PCR. DNA fragmentation was carried out daily after treatment..Results: Survivin was expressed (P=0.06) more in AML (74%) than in ALL (52%). While, Aven was equally expressed in both leukemias. Patients were categorized into 3 groups based on DNA fragmentation. Absence of Aven significantly (p‹0.001) contributed to DNA fragmentation,but Survivin did not contribute as much. None of the concordant both positive Survivin and Aven were in group III (the good 5 day fragmentation, (P< 0.001). Survivin was statistically related to CD7 expression (P<0.001) in AML only. There was a significant dissociation between Aven and Survivin in AML (p=0.03) and near significant dissociation in ALL (p=0.07). Conclusion: Aven seems to be more important as an inhibitor of apoptosis than survivin in acute leukemia. The presence of both confers a survival disadvantage and a significantly worse DNA fragmentation pattern suggesting a synergistic inhibition of apoptosis. The highly significant relation between CD7 and survivin expression might suggest their involvement in a common signal transduction pathway

Quinazolinone-based rhodanine-3-acetic acids as potent aldose reductase inhibitors: Synthesis, functional evaluation and molecular modeling study

A series of quinazolinone-based rhodanine-3-acetic acids was synthesized and tested for in vitro aldose reductase inhibitory activity. All the target compounds displayed nanomolar activity against the target enzyme. Compounds 3a, 3b, and 3e exhibited almost 3-fold higher activity as compared to the only marketed reference drug epalrestat. Structure-activity relationship studies indicated that bulky substituents at the 3-phenyl ring of the quinazolinone moiety are generally not tolerated in the active site of the enzyme. Insertion of a methoxy group on the central benzylidene ring was found to have a variable effect on ALR-2 activity depending on the nature of peripheral quinazolinone ring substituents. Removal of the acetic acid moiety led to inactive or weakly active target compounds. Docking and molecular dynamic simulations of the most active rhodanine-3-acetic acid derivatives were also carried out, to provide the basis for further structure-guided design of novel inhibitors

Targeting methionyl tRNA synthetase: design, synthesis and antibacterial activity against Clostridium difficileof novel 3-biaryl-N-benzylpropan-1-amine derivatives

The synthesis of a series of benzimidazole-N-benzylpropan-1-amines and adenine-N-benzylpropan-1-amines is described. Subsequent evaluation against two strains of the anaerobic bacterium Clostridium difficile was performed with three amine derivatives displaying MIC values of 16 μg/mL. Molecular docking studies of the described amines determined that the amines interact within two active site pockets of C. difficile methionyl tRNA synthetase with methoxy substituents in the benzyl ring and an adenine biaryl moiety resulting in optimal binding interaction

Perspective Chapter: The Toxic Silver (Hg)

In the late 1950s, residents of a Japanese fishing village known as “Minamata” began falling ill and dying at an alarming rate. The Japanese authorities stated that methyl-mercury-rich seafood and shellfish caused the sickness. Burning fossil fuels represent ≈52.7% of Hg emissions. The majorities of mercury’s compounds are volatile and thus travel hundreds of miles with wind before being deposited on the earth’s surface. High acidity and dissolved organic carbon increase Hg-mobility in soil to enter the food chain. Additionally, Hg is taken up by areal plant parts via gas exchange. Mercury has no identified role in plants while exhibiting high affinity to form complexes with soft ligands such as sulfur and this consequently inactivates amino acids and sulfur-containing antioxidants. Long-term human exposure to Hg leads to neurotoxicity in children and adults, immunological, cardiac, and motor reproductive and genetic disorders. Accordingly, remediating contaminated soils has become an obligation. Mercury, like other potentially toxic elements, is not biodegradable, and therefore, its remediation should encompass either removal of Hg from soils or even its immobilization. This chapter discusses Hg’s chemical behavior, sources, health dangers, and soil remediation methods to lower Hg levels

New model to estimate daily global solar radiation over Nigeria

This study focussed on developing an appropriate model for estimating daily global solar radiation for any location in Nigeria. Data for the study were obtained from the Nigeria Meteorological Agency, covering 12 sites, spread across the six geopolitical zones, for a period between 1987 and 2010. Various statistical methods were employed to determine the performance and accuracy of the model. A multivariate model that expresses global solar irradiance in terms of location latitude, daily relative sunshine, maximum daily temperature, daily average relative humidity, and cosine of day number was developed. The inclusion of the maximum daily temperature and daily mean relative humidity makes the model much more sensitive to climatic and weather changes. Also, the seasonal fluctuations of the humid tropical region are also well captured in the model. The analysis showed a good agreement between the measured data and computed results. Thus the model can be used to predict the global solar irradiance over Nigeria with minimum error. Further to this, the global solar radiation intensity values produced by this approach can be used in the design and estimation of the performance of solar applications

Global prevalence and genotype distribution of hepatitis C virus infection in 2015 : A modelling study

Publisher Copyright: © 2017 Elsevier LtdBackground The 69th World Health Assembly approved the Global Health Sector Strategy to eliminate hepatitis C virus (HCV) infection by 2030, which can become a reality with the recent launch of direct acting antiviral therapies. Reliable disease burden estimates are required for national strategies. This analysis estimates the global prevalence of viraemic HCV at the end of 2015, an update of—and expansion on—the 2014 analysis, which reported 80 million (95% CI 64–103) viraemic infections in 2013. Methods We developed country-level disease burden models following a systematic review of HCV prevalence (number of studies, n=6754) and genotype (n=11 342) studies published after 2013. A Delphi process was used to gain country expert consensus and validate inputs. Published estimates alone were used for countries where expert panel meetings could not be scheduled. Global prevalence was estimated using regional averages for countries without data. Findings Models were built for 100 countries, 59 of which were approved by country experts, with the remaining 41 estimated using published data alone. The remaining countries had insufficient data to create a model. The global prevalence of viraemic HCV is estimated to be 1·0% (95% uncertainty interval 0·8–1·1) in 2015, corresponding to 71·1 million (62·5–79·4) viraemic infections. Genotypes 1 and 3 were the most common cause of infections (44% and 25%, respectively). Interpretation The global estimate of viraemic infections is lower than previous estimates, largely due to more recent (lower) prevalence estimates in Africa. Additionally, increased mortality due to liver-related causes and an ageing population may have contributed to a reduction in infections. Funding John C Martin Foundation.publishersversionPeer reviewe

Burnout among surgeons before and during the SARS-CoV-2 pandemic: an international survey

Background: SARS-CoV-2 pandemic has had many significant impacts within the surgical realm, and surgeons have been obligated to reconsider almost every aspect of daily clinical practice. Methods: This is a cross-sectional study reported in compliance with the CHERRIES guidelines and conducted through an online platform from June 14th to July 15th, 2020. The primary outcome was the burden of burnout during the pandemic indicated by the validated Shirom-Melamed Burnout Measure. Results: Nine hundred fifty-four surgeons completed the survey. The median length of practice was 10 years; 78.2% included were male with a median age of 37 years old, 39.5% were consultants, 68.9% were general surgeons, and 55.7% were affiliated with an academic institution. Overall, there was a significant increase in the mean burnout score during the pandemic; longer years of practice and older age were significantly associated with less burnout. There were significant reductions in the median number of outpatient visits, operated cases, on-call hours, emergency visits, and research work, so, 48.2% of respondents felt that the training resources were insufficient. The majority (81.3%) of respondents reported that their hospitals were included in the management of COVID-19, 66.5% felt their roles had been minimized; 41% were asked to assist in non-surgical medical practices, and 37.6% of respondents were included in COVID-19 management. Conclusions: There was a significant burnout among trainees. Almost all aspects of clinical and research activities were affected with a significant reduction in the volume of research, outpatient clinic visits, surgical procedures, on-call hours, and emergency cases hindering the training. Trial registration: The study was registered on clicaltrials.gov "NCT04433286" on 16/06/2020