23 research outputs found

    Synthesis and Structures of Dimeric Zinc Complexes Supported by Unsymmetrical Rigid Bidentate Imino- acenapthenone Ligand

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    We report two zinc complexes of molecular formulae [ZnCl 2 (Mes - BIAO)] 2 ( 3 ) and [ZnCl 2 (Dipp - BIAO)] 2 ( 4 ) ( Mes = Mesityl, Dipp = 2,6 - diisopropylphenyl) of rigid unsymmetrical bidentate iminoacenapthenone ligands (Mes - BIAO) ( 1 ) and Dipp - BIAO) ( 2 ). The zinc complexes 3 and 4 can be achieved by the reaction of ZnCl 2 and neutral [ N - (mesityl) - iminoacenapthenone] ( 1 ) and [ N - (2,6 - diisopropylphenyl) - iminoacenapthenone] ligand ( 2 ) respectively in dichloromethane at ambient temperature. The solid state structures of the complexes 3 and 4 were established by single crystal X – ray diffraction analysis. In the solid state structures, bo th the complexes are dimeric in nature. In complexes 3 and 4 , each of the zinc coordination polyhedron is formed by the ligation of imine nitrogen, carbonyl oxygen atoms of the ligand 1 and 2 respectively along with three chlorine atoms. Out these three ch lorine atoms, two are 2 bridged with adjacent zinc atom to form the dimer. Thus overall zinc atom is penta - coordinated and the geometry can be best described as a distorted trigonal bipyramidal or a distorted square pyramidal

    The functional, social and economic impact of acute encephalitis syndrome in Nepal--a longitudinal follow-up study.

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    notes: PMCID: PMC3772013Open Access JournalOver 133,000 children present to hospitals with Acute Encephalitis Syndrome (AES) annually in Asia. Japanese encephalitis (JE) accounts for approximately one-quarter of cases; in most cases no pathogen is identified and management is supportive. Although JE is known to result in neurological impairment, few studies have examined the wider impact of JE and AES on patients and their families.Wellcome TrustUniversity of Liverpool Clinical Fellowshi

    Exploring the solid state and solution structural chemistry of the utility amide potassium hexamethyldisilazide (KHMDS)

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    The structural chemistry of eleven donor complexes of the important Brønsted base potassium 1,1,1,3,3,3-hexamethyldisilazide (KHMDS) has been studied. Depending on the donor, each complex adopted one of four general structural motifs. Specifically, in this study the donors employed were toluene (to give polymeric 1 and dimeric 2), THF (dimeric 3), N,N,N',N'-tetramethylethylenediamine (TMEDA) (dimeric 4), (R,R)-N,N,N',N'-tetramethyl-1,2-diaminocyclohexane [(R,R)-TMCDA] (dimeric 5), 12-crown-4 (dimeric 6), N,N,N',N'-tetramethyldiaminoethyl ether (TMDAE) (tetranuclear dimeric 8 and monomeric 10), N,N,N',N',N''-pentamethyldiethylentriamine (PMDETA) (tetranuclear dimeric 7), tris[2-dimethyl(amino)ethyl]amine (Me6TREN) (tetranuclear dimeric 9) and tris{2-(2-methoxyethoxy)ethyl}amine (TMEEA) (monomeric 11). The complexes were also studied in solution by 1H and 13C NMR spectroscopy as well as DOSY NMR spectroscopy

    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

    Fosphenytoin for seizure prevention in childhood coma in Africa: a randomized clinical trial.

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    PURPOSE: We conducted a double-blind trial to determine whether a single intramuscular injection of fosphenytoin prevents seizures and neurologic sequelae in children with acute coma. METHODS: We conducted this study at Kilifi District Hospital in coastal Kenya and Kondele Children's Hospital in western Kenya. We recruited children (age, 9 months to 13 years) with acute nontraumatic coma. We administered fosphenytoin (20 phenytoin equivalents/kg) or placebo and examined the prevalence and frequency of clinical seizures and occurrence of neurocognitive sequelae. RESULTS: We recruited 173 children (median age, 2.6 [interquartile range, 1.7-3.7] years) into the study; 110 had cerebral malaria, 8 had bacterial meningitis, and 55 had encephalopathies of unknown etiology. Eighty-five children received fosphenytoin and 88 received placebo. Thirty-three (38%) children who received fosphenytoin had at least 1 seizure compared with 32 (36%) who received placebo (P = .733). Eighteen (21%) and 15 (17%) children died in the fosphenytoin and placebo arms, respectively (P = .489). At 3 months after discharge, 6 (10%) children in the fosphenytoin arm had neurologic sequelae compared with 6 (10%) in the placebo arm (P = .952). CONCLUSION: A single intramuscular injection of fosphenytoin (20 phenytoin equivalents/kg) does not prevent seizures or neurologic deficits in childhood acute nontraumatic coma

    Incremental detection of pulmonary tuberculosis among presumptive patients by GeneXpert MTB/RIF® over fluorescent microscopy in Mwanza, Tanzania: an operational study

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    Laboratory confirmation among presumptive tuberculosis (PTB) patients is pivotal in ensuring prompt management. Limited information exists in Tanzania regarding the performance of GeneXpert MTB/RIF® in comparison with conventional methods. An operational study was conducted involving 806 PTB patients at Sekou Toure Hospital in Mwanza, Tanzania from June to November 2013. Patients’ information was obtained and their respective sputum samples analyzed by lightemitting diode fluorescent microscopy (LED FM) and GeneXpert MTB/RIF®. The mean age of study participants was 39.6±16.0 years, with males accounting for 50.5%. The majority of patients (97.5%) were new cases. The proportions of PTB patients confirmed by LED FM and GeneXpert MTB/RIF® were 14.1% (114/806) and 23.7% (191/806) respectively, resulting into a 9.6% incremental detection rate by GeneXpert MTB/RIF® over LED FM. The detection rate among HIV positive individuals was also higher [23.6% (63/267) vs 14.2% (38/267), respectively], with an incremental detection of 9.4%. The incremental detection of PTB by GeneXpert MTB/RIF® over LED FM calls for expansion of its use to increase detection of smear negative PTB among people living with HIV
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