59 research outputs found

    A peptide topological template for the dispersion of [60]fullerene in water

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    Solubilization of [60]fullerene in water is a major challenge for biological and medical applications. To this purpose in this communication we describe for the first time a new dispersing system based on a peptide topological template. The presence of two carbobenzyloxy groups on the peptide side chains allows \u3c0-\u3c0 interactions with [60]fullerene leading to the formation of stable supramolecular nanocomposites by means of mechanochemical methods. In particular, by high speed vibration milling colloidal dispersions (mean particle diameter 63 nm) containing up to 1.3 mg mL(-1) of [60]fullerene were obtained. Its presence in water was verified through UV-Vis and MALDI-TOF measurements, while its concentration was determined by thermogravimetric analysi

    Assessment of Lipid Profile of Enteric Fever Patients in Enugu Metropolis, South-East Nigeria: Useful or Useless?

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    Abstract: Enteric fever has been implicated in complications such as severe sepsis and in alteration of some biochemical and hematological parameters. Enteric fever affects the intestine, which is also the site for lipid absorption, but its possible effect on lipid metabolism is unclear. The present study was aimed at estimating the lipid profile of enteric fever patients in Enugu metropolis. Lipid profile of 200 enteric fever patients and 100 apparently healthy subjects in Enugu metropolis were determined using standard techniques. Enteric fever was investigated using rapid slide titration method and the confirmatory test done with Enterocheck-WB ® kit. Serum Total Cholesterol (TC), Triacylglycerol (TG), High-Density Lipoprotein Cholesterol (HDL-C), Low-Density Lipoprotein Cholesterol (LDL-C) and Very Low Density Lipoprotein Cholesterol (VLDL-C) were assayed using standard operative procedures. Statistical analysis was done with graph pad prism computer soft ware using student's t-test to test for statistical significance. P-values of <0.05 were considered to be statistically significant. The lipid profile of all the patients showed non-significant difference (p>0.05) when compared with the control. However, when the male and female subjects where separately analyzed, TC and LDL-C significantly increased (p<0.05) in the male subjects compared to the male controls, whereas the female subjects showed significant decrease (p<0.05) compared to the female control. The study suggests that lipid profile is not significantly altered in enteric fever infection and thus may be useless in enteric fever management

    Independent and combined effects of improved water, sanitation, and hygiene, and improved complementary feeding, on child stunting and anaemia in rural Zimbabwe: a cluster-randomised trial.

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    BACKGROUND: Child stunting reduces survival and impairs neurodevelopment. We tested the independent and combined effects of improved water, sanitation, and hygiene (WASH), and improved infant and young child feeding (IYCF) on stunting and anaemia in in Zimbabwe. METHODS: We did a cluster-randomised, community-based, 2 × 2 factorial trial in two rural districts in Zimbabwe. Clusters were defined as the catchment area of between one and four village health workers employed by the Zimbabwe Ministry of Health and Child Care. Women were eligible for inclusion if they permanently lived in clusters and were confirmed pregnant. Clusters were randomly assigned (1:1:1:1) to standard of care (52 clusters), IYCF (20 g of a small-quantity lipid-based nutrient supplement per day from age 6 to 18 months plus complementary feeding counselling; 53 clusters), WASH (construction of a ventilated improved pit latrine, provision of two handwashing stations, liquid soap, chlorine, and play space plus hygiene counselling; 53 clusters), or IYCF plus WASH (53 clusters). A constrained randomisation technique was used to achieve balance across the groups for 14 variables related to geography, demography, water access, and community-level sanitation coverage. Masking of participants and fieldworkers was not possible. The primary outcomes were infant length-for-age Z score and haemoglobin concentrations at 18 months of age among children born to mothers who were HIV negative during pregnancy. These outcomes were analysed in the intention-to-treat population. We estimated the effects of the interventions by comparing the two IYCF groups with the two non-IYCF groups and the two WASH groups with the two non-WASH groups, except for outcomes that had an important statistical interaction between the interventions. This trial is registered with ClinicalTrials.gov, number NCT01824940. FINDINGS: Between Nov 22, 2012, and March 27, 2015, 5280 pregnant women were enrolled from 211 clusters. 3686 children born to HIV-negative mothers were assessed at age 18 months (884 in the standard of care group from 52 clusters, 893 in the IYCF group from 53 clusters, 918 in the WASH group from 53 clusters, and 991 in the IYCF plus WASH group from 51 clusters). In the IYCF intervention groups, the mean length-for-age Z score was 0·16 (95% CI 0·08-0·23) higher and the mean haemoglobin concentration was 2·03 g/L (1·28-2·79) higher than those in the non-IYCF intervention groups. The IYCF intervention reduced the number of stunted children from 620 (35%) of 1792 to 514 (27%) of 1879, and the number of children with anaemia from 245 (13·9%) of 1759 to 193 (10·5%) of 1845. The WASH intervention had no effect on either primary outcome. Neither intervention reduced the prevalence of diarrhoea at 12 or 18 months. No trial-related serious adverse events, and only three trial-related adverse events, were reported. INTERPRETATION: Household-level elementary WASH interventions implemented in rural areas in low-income countries are unlikely to reduce stunting or anaemia and might not reduce diarrhoea. Implementation of these WASH interventions in combination with IYCF interventions is unlikely to reduce stunting or anaemia more than implementation of IYCF alone. FUNDING: Bill & Melinda Gates Foundation, UK Department for International Development, Wellcome Trust, Swiss Development Cooperation, UNICEF, and US National Institutes of Health.The SHINE trial is funded by the Bill & Melinda Gates Foundation (OPP1021542 and OPP113707); UK Department for International Development; Wellcome Trust, UK (093768/Z/10/Z, 108065/Z/15/Z and 203905/Z/16/Z); Swiss Agency for Development and Cooperation; US National Institutes of Health (2R01HD060338-06); and UNICEF (PCA-2017-0002)

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

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    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

    A Peptide-Based Hydrogel for Adsorption of Dyes and Pharmaceuticals in Water Remediation

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    The removal of dyes and pharmaceuticals from water has become a major issue in recent years due to the shortage of freshwater resources. The adsorption of these pollutants through nontoxic, easy-to-make, and environmentally friendly adsorbents has become a popular topic. In this work, a tetrapeptide-pyrene conjugate was rationally designed to form hydrogels under controlled acidic conditions. The hydrogels were thoroughly characterized, and their performance in the adsorption of various dyes and pharmaceuticals from water was investigated. The supramolecular hydrogel efficiently adsorbed methylene blue (MB) and diclofenac (DCF) from water. The effect of concentration in the adsorption efficiency was studied, and results indicated that while the adsorption of MB is governed by the availability of adsorption sites, in the case of DCF, concentration is the driving force of the process. In the case of MB, the nature of the dye-hydrogel interactions and the mechanism of the adsorption process were investigated through UV-Vis absorption spectroscopy. The studies proved how this dye is first adsorbed as a monomer, probably through electrostatic interactions; successively, at increasing concentrations as the electrostatic adsorption sites are depleted, dimerization on the hydrogel surface occurs

    Regio- and stereoselective addition of Grignard and organolithium reagents to 4-hydroxy-2-cyclopentenones

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    a highly regio- and stereoselective method for the 1,2- or 1,4-addition reactions to 4-hydroxy- 2-cyclopentenones has been devised, which makes use of readily available organolithium and Grignard reagents. This procedure allows for stereochemistry complementary to that observed in the 1,4-addition of organocuprates and makes possible the attachment of aromatic groups to carbons C-2 and C-3 of cyclopentenones 5 or 6 and carbons C-4 and C-5 of cyclopentanones 7, which are of interest for further elaboration into biologically active target

    Enantioselective synthesis of gamma,delta-disubstituted beta-hydroxy delta-lactones from furans: Synthesis of (+)-prelactone B and its C-4 epimer

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    A new method for the enantioselective synthesis of gamma,delta-disubstituted beta-hydroxy delta-lactones (5,6-dialkyl-5,6-dihydropyran-2-ones) is reported and exemplified for (+)-prelactone B and its C-4 epimer. Our approach is based on the ring-enlargement of suitably functionalized optically pure 4-hydroxycyclopentanones, which are readily obtained from chiral 4-hydroxycyclopent-2-enones derived from furans. The procedure is amenable to the large-scale synthesis of the title compounds

    Asymmetric synthesis of cyclopentenones with benzylic alpha-quaternary carbon stereogenic centres from furans

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    A new procedure for the synthesis of cyclopentenones containing benzylic alpha-quaternary carbon stereogenic centres is reported. This method makes use of a one-pot alkylation-elimination sequence from readily available starting materials and simple procedures, which makes it useful for the large-scale preparation of densely functionalised cyclopentanoids. (C) 2004 Elsevier Ltd. All rights reserved

    Coordination Chemistry and Applications of Nitrilotris(N-Methylenephenoxy)-Metal ComplexesPATAI'S Chemistry of Functional Groups

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    Nitrilotris(N-methylenephenols), commonly called triphenolamines (TPA), are highly modular, tetradentate molecules that effectively coordinate to transition metals and main group elements with podand topology. They form chiral complexes with intrinsically well-defined geometries (pentacoordinate trigonal bipyramidal, hexacoordinate octahedral, and, more rarely, trigonal monopyramidal geometries) controlled by the ligand. Nitrilotris(N-methylenephenoxy)\u2013metal complexes have been found to be effective and robust catalysts in a series of important processes like polymerizations (titanium(IV), zirconium(VI), hafnium(VI), germanium(VI), and vanadium(V) complexes), oxygen transfer reactions (titanium(VI), vanadium(V), molybdenum(VI), and nickel(II) complexes), carbon\u2013carbon bond formation (aluminium(III), and titanium(VI) complexes), carbon dioxide fixation (iron(III) complexes), and metathesis (Mo(VI) complexes)

    Organic Functionalized Carbon Nanostructures for Functional Polymer-Based Nanocomposites

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    Carbon nanostructures (CNSs), which are made up of extended sp2-hybridized carbon networks, are largely employed as nanofillers for polymer phases to obtain polymerbased nanocomposites (PNCs). Following their inclusion, the polymer matrices are often improved in many ways, such as enhanced electrical and thermal conductivity, increased stability, and mechanical robustness. The chemical functionalization of the external CNS surfaces with organic substituents is often a key tool for their effective and homogeneous incorporation within a polymer phase, avoiding the formation of aggregates, which can lower the performance of the the final material. This microreview furnishes an overview of PNCs that contain substituted CNSs with organic functionalities. These CNS-based PNCs can be used as organic functional materials in different applications that range from clean energy harvesting and storage to sensing and biomedicine
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