224 research outputs found

    Red-sea dolomite as a sustainable catalyst in the synthesis of bis-indolyl methanes with molecular docking validation as HIV-1 replication inhibitor

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    ABSTRACT. Dolomite minerals were collected from the Red Sea Mountains around the Sokhna region. The rock was collected, rinsed, and crushed using a ball mailing machine and used without further purification. The dolomite sample was characterized using FTIR, XRD, SEM/EDAX, and mapping to ensure their composition and homogeneity. The obtained data reveal that the presence of a homogenous crystalline structure of CaMg(CO3)2. The characterized rock was used as a catalyst in the eco-friendly synthesis of bis-indolyl methane derivatives by reacting two moles of unsubstituted indole and various aromatic aldehydes in the presence of Red-Sea Dolomite mineral as an economical, recyclable, easily obtained, and nontoxic catalyst under solvent-free conditions. The molecular docking study explained that the bis-indolyl methane can be considered as a small molecule stimulator of HIV-1 frameshifting and inhibitor of viral replication.                     KEY WORDS: Indole, Dolomite, HIV-1, Catalyst, Frameshifting, Viral replication   Bull. Chem. Soc. Ethiop. 2021, 35(3), 647-657. DOI: https://dx.doi.org/10.4314/bcse.v35i3.1

    Social and demographic factors associated with morbidities in young children in Egypt: A Bayesian geo-additive semi-parametric multinomial model.

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    Globally, the burden of mortality in children, especially in poor developing countries, is alarming and has precipitated concern and calls for concerted efforts in combating such health problems. Examples of diseases that contribute to this burden of mortality include diarrhoea, cough, fever, and the overlap between these illnesses, causing childhood morbidity and mortality. Methods: To gain insight into these health issues, we employed the 2008 Demographic and Health Survey Data of Egypt, which recorded details from 10,872 children under five. This data focused on the demographic and socio-economic characteristics of household members. We applied a Bayesian multinomial model to assess the area-specific spatial effects and risk factors of co-morbidity of fever, diarrhoea and cough for children under the age of five. Results: The results showed that children under 20 months of age were more likely to have the three diseases (OR: 6.8; 95% CI: 4.6-10.2) than children between 20 and 40 months (OR: 2.14; 95% CI: 1.38-3.3). In multivariate Bayesian geo-additive models, the children of mothers who were over 20 years of age were more likely to have only cough (OR: 1.2; 95% 2 CI: 0.9-1.5) and only fever (OR: 1.2; 95% CI: 0.91-1.51) compared with their counterparts. Spatial results showed that the North-eastern region of Egypt has a higher incidence than most of other regions. Conclusions: This study showed geographic patterns of Egyptian governorates in the combined prevalence of morbidity among Egyptian children. It is obvious that the Nile Delta, Upper Egypt, and south-eastern Egypt have high rates of diseases and are more affected. Therefore, more attention is needed in these areas. Funding: The authors have no support or funding to report. Competing Interests: The authors have declared that no competing interests exist

    Copper-based glass-ceramic as an efficient catalyst in the synthesis of pyrazolo[1,5-a] pyrimidineunder solvent-free condition with docking validation as Covid-19 main protease (Mpro) inhibitor

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    Copper-based oxide glass-ceramic was successfully synthesized through the single-step melt annealing technique. Synthesized glass-ceramics was characterized using X-ray diffraction (XRD) and scanning electron microscopy (SEM) supported with energy dispersive X-ray (EDX) and mapping. Pyrazolo[1,5-a]pyrimidines 5a-f were synthesized via the reaction of 5-amino-1H-pyrazole-4-carboxamide (1) with enaminones 2a-f in the presence of synthesized oxide glass-ceramic catalyst powder under solvent-free condition. The molecular docking study demonstrated that the COVID-19 main protease (MPro) inhibitor.                     KEY WORDS: Pyrazolopyrimidine, Enaminones, Copper-based catalysis, Solvent-free, COVID-19   Bull. Chem. Soc. Ethiop. 2021, 35(1), 185-196. DOI: https://dx.doi.org/10.4314/bcse.v35i1.1

    Outsourcing selective maintenance problem in failure prone multi-component systems

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    In many industrial settings, there are systems designed to perform consecutive missions interspersed with finite breaks during which only a set of component repairs can be carried out due to limited time, budget, or resources. The decision maker then has to decide which components to repair in order to guarantee a given performance level. This is known as the selective maintenance problem (SMP). This paper introduces a new variant of the SMP by specifically taking into account the maintenance outsourcing alternative. A novel integrated non-linear programming formulation where both the in-house and outsourcing maintenance alternatives are accounted for is developed and optimally solved. The effect of the outsourcing alternative on maintenance decisions is investigated through numerical experiments. The overall results obtained demonstrate the validity of the proposed approach. (C) 2018, IFAC (International Federation of Automatic Control) Hosting by Elsevier Ltd. All rights reserved

    Risk factors associated with asbestos-related diseases: results of the asbestos surveillance programme Aachen

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    The aim of this study was to examine the association between workplace exposure to asbestos and risk factors for developing related chronic respiratory diseases, using the analysis of a cohort of 8,582 formerly asbestos-exposed workers, as well as to assess the grade value of three risk categories used for a focused surveillance procedure. The results showed that the participants who were aged over 65 (OR and 95% CI: 11.47 [5.48-23.99]) and active smokers (OR and 95% CI: 9.48 [4.07-22.09]), were at a significantly high risk for developing lung cancer. The risk of developing benign lesions of the lung or pleura (BLLP) was almost 6-times higher (OR and 95% CI: 5.76 [4.7-7]) for the age group over 65. The risk of developing mesothelioma was influenced by exposure duration (OR and 95% CI: 4.36 [1-19.01]); and for the age group over 65 (OR and 95% CI: 4.58 [1.86-11.27]). The study has demonstrated that the use of risk categories based on a combination of risk factors (age, smoking status, and duration of exposure) could be advantageous for planning the target health surveillance programmes

    Drivers of U.S. toxicological footprints trajectory 1998–2013

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    By exploiting data from the Toxic Release Inventory of the United States, we have established that the toxicological footprint (TF) increased by 3.3% (88.4 Mt) between 1998 and 1999 and decreased by 39% (1088.5 Mt) between 1999 and 2013. From 1999 to 2006, the decreasing TF was driven by improvements in emissions intensity (i.e. gains in production efficiency) through toxic chemical management options: cleaner production; end of pipe treatment; transfer for further waste management; and production scale. In particular, the mining sector reduced its TF through outsourcing processes. Between 2006 and 2009, decreasing TF was due to decrease in consumption volume triggered by economic recession. Since 2009, the economic recovery increased TF, overwhelming the influence of improved emissions intensity through population growth, consumption and production structures. Accordingly, attaining a less-toxic economy and environment will be influenced by a combination of gains in production efficiency through improvement in emissions mitigation technologies and changes in consumption patterns. Overall, the current analysis highlights the structural dynamics of toxic chemical release and would inform future formulation of effective mitigation standards and management protocols towards the detoxification of the environmen

    V2O5/SiO2 as an efficient catalyst in the synthesis of 5-amino- pyrazole derivatives under solvent free condition

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    An efficient and facile approach for the synthesis of 5-aminopyrazoles from ketene S,N-acetal and hydrazine hydrate via catalytic reaction under solvent free condition has been described. V2O5/SiO2 as a heterogeneous catalyst was prepared and characterized using X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR) and scanning electron microscope (SEM).               KEY WORDS: One-pot synthesis, 5-Amino-1H-pyrazole, Hydrazine hydrate, Vanadium oxide, Silica Bull. Chem. Soc. Ethiop. 2019, 33(1), 135-142DOI: https://dx.doi.org/10.4314/bcse.v33i1.13

    Individual and contextual factors associated with malaria among children 6–59 months in Nigeria: a multilevel mixed effect logistic model approach

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    Background/Purpose: Over the last two decades, malaria has remained a major public health concern worldwide, especially in developing countries leading to high morbidity and mortality among children. Nigeria is the world most burdened malaria endemic nation, contributing more than a quarter of global malaria cases. This study determined the prevalence of malaria among children at 6–59 months in Nigeria, and the effects of individual and contextual factors. Methods: This study utilized data from 2018 Nigeria Demographic and Health Survey (NDHS) involving a weighted sample size of 10,185 children who were tested for malaria using rapid diagnostic test (RDT). Given the hierarchical structure of the data set, such that children at Level-1 were nested in communities at Level-2, and nested in states and Federal Capital Territory (FCT) at Level-3, multilevel mixed effect logistic regression models were used for the analysis. Results: The proportion of children 6–59 months of age in Nigeria that had malaria fever positive as assessed by RDTs was 35.5% (3418/10,185), (CI: 33.9–37.1). Kebbi State had 77.7%, (CI: 70.2–83.5), which was the highest proportion of 6–59 months who were malaria positive, next in line was Katsina State with 55.5%, (CI: 47.7–63.1). The Federal Capital Territory (FCT), Abuja had the proportion of 29.6%, (CI: 21.6–39.0), malaria positive children of 6–59 months of age. Children between the age of 48 and 59 months were 2.68 times more likely to have malaria fever than children of ages 6–11 months (AOR = 2.68, 95% CI: 2.03–3.54). In addition, children from the rural area (AOR = 2.12, 95% CI: 1.75–2.57), were more likely to suffer from malaria infection compared to children from urban area. Conclusion: The study identified some individual and contextual predictors of malaria among children in Nigeria. These factors identified in this study are potential areas that need to be considered for policy designs and implementations toward control and total elimination of malaria-related morbidity and mortality among children in Nigeria

    Risk factors associated with multimorbidity among children aged under-five years in Sub-Saharan African countries: a scoping review

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    Background/purpose: Globally, the prevalence of multimorbidity (defined as the cooccurrence of two or more diseases in an individual without reference to an index disease) is greater than 33%. Consequently, childhood multimorbidity, a growing public health concern in Low- and Middle-Income-Countries (LMICs), frequently has an impact on children’s health. Therefore, the aim of this scoping review was to locate and describe studies that investigate the association between socioeconomic, demographic, and environmental factors and the prevalence of multimorbidity among children aged under five years in Sub-Saharan Africa (SSA). Methods/Design: We searched MEDLINE, Cumulative Index to Nursing and Allied Health Literature (CINAHL), PubMed, Scopus, and Web of Science for papers written in English, and published between January 1990 and March 2022. The search included papers that focused on children aged under five years with multimorbidity from Sub-Saharan Africa and used classical regression methods in their analysis. Results: A total of 261 articles were identified. Out of the 66 articles selected for full-text reading, 60 were removed for various reasons. Therefore, data from a sample of six articles were finally extracted and reported in this study. The sample size for the 6 studies included ranged from 2343 to 193,065 children under five years of age. There were six distinct disease conditions (Pneumonia, diarrhoea, malaria, being overweight, stunting, and anaemia) analysed in the included studies. One of the studies had three concurrent diseases, while the other five studies had two current diseases as their multimorbidity outcome of interest. The prevalence of multimorbidity in these six studies ranged from 1.2% to 24.8%. Conclusions: The relatively few studies found in this research area is an indication of an evidence deficit/knowledge gap yearning to be filled to help policymakers in coming up with integrated multimorbidity care for children in SSA

    Strain and localization effects in InGaAs(N) quantum wells: Tuning the magnetic response

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    We investigated effects of localization and strain on the optical and magneto-optical properties of diluted nitrogen III-V quantum wells theoretically and experimentally. High-resolution x-ray diffraction, photoluminescence (PL), and magneto-PL measurements under high magnetic fields up to 15 T were performed at low temperatures. Bir-Pikus Hamiltonian formalism was used to study the influence of strain, confinement, and localization effects. The circularly polarized magneto-PL was interpreted considering localization aspects in the valence band ground state. An anomalous behavior of the electron-hole pair magnetic shift was observed at low magnetic fields, ascribed to the increase in the exciton reduced mass due to the negative effective mass of the valence band ground state
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