37 research outputs found

    SARS-CoV-2 vaccination modelling for safe surgery to save lives: data from an international prospective cohort study

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    Background Preoperative SARS-CoV-2 vaccination could support safer elective surgery. Vaccine numbers are limited so this study aimed to inform their prioritization by modelling. Methods The primary outcome was the number needed to vaccinate (NNV) to prevent one COVID-19-related death in 1 year. NNVs were based on postoperative SARS-CoV-2 rates and mortality in an international cohort study (surgical patients), and community SARS-CoV-2 incidence and case fatality data (general population). NNV estimates were stratified by age (18–49, 50–69, 70 or more years) and type of surgery. Best- and worst-case scenarios were used to describe uncertainty. Results NNVs were more favourable in surgical patients than the general population. The most favourable NNVs were in patients aged 70 years or more needing cancer surgery (351; best case 196, worst case 816) or non-cancer surgery (733; best case 407, worst case 1664). Both exceeded the NNV in the general population (1840; best case 1196, worst case 3066). NNVs for surgical patients remained favourable at a range of SARS-CoV-2 incidence rates in sensitivity analysis modelling. Globally, prioritizing preoperative vaccination of patients needing elective surgery ahead of the general population could prevent an additional 58 687 (best case 115 007, worst case 20 177) COVID-19-related deaths in 1 year. Conclusion As global roll out of SARS-CoV-2 vaccination proceeds, patients needing elective surgery should be prioritized ahead of the general population

    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

    Forgotten ureteral stents: Risk factors, complications and management

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    Objectives: To assess complications of neglected stents, risk factors for the occurrence of complications, and management options and outcomes. Subjects and methods: A prospective study including patients presenting to our center with neglected polyurethane ureteral stents (indwelling for more than 6 months in the period from February 2012 to September 2015). We noted the complications of neglected stents (urinary tract infections (UTI), urinary obstruction, elevated creatinine, encrustations and stent fragmentation), management challenges (need for complex endo-urologic or open procedures). We evaluated potential risk factors for these complications (duration of stenting, lack of urinary acidification, cause of stent placement). Results: The study included 68 patients with mean age 49.3 ± 12.6 years 80.9% were males. Mean stenting duration 17.3 ± 12.7 months. A total of 29% of patients received urine acidifier while the stent was indwelling, 92% were stone formers, 60% presented with UTI and 25% presented with elevated creatinine. Preoperative non-contrast spiral CT abdomen and pelvis showed encrustations on the stent in 23.5% of patients and fragmented stent in 13%. The stent was removed by cystoscopy only as an outpatient procedure in 26 (38.3%) cases (7 of them with encrustation) while 42 (61.7%) cases needed more than simple cystoscopy. Management challenges included need for complex endourological interventions (URS, PCNL, cystolithotripsy or even open surgery). Lack of urinary acidification was a significant risk factor for UTI and stent fragmentation (P-value = 0.038 and 0.006, respectively). Stone former patients needed complex interventions (P = 0.046). UTIs were more likely with longer duration of stenting (P = 0.027). Conclusion: Forgotten ureteral stents are associated with significant complications. Urinary acidification is protective against complications. Patients with stones are more liable to forgotten stents complications. Keywords: Ureteral stents, Infection, Encrustations, Urinary acidificatio

    A renewable lignin-derived bio-oil for boosting the oxidation stability of biodiesel

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    The valorisation of lignin is being increasingly recognised to improve the economics of pulp and paper making mills. In the present study, an integrated lignin–glycerol valorisation strategy is introduced with an overarching aim for enhancing the process value chains. LignoBoost kraft lignin was subjected to base-catalysed depolymerisation using glycerol as a co-solvent. The generated bio-oil was used as a renewable additive to biodiesel for enhancing its oxygen stability. The influence of three independent parameters including temperature, time and glycerol amount on lignin depolymerisation was investigated. Response surface methodology was applied to design the experiments and to optimise the process for maximising the yield and antioxidant impact of bio-oil. The results showed that glycerol has a positive qualitative and quantitative impact on the produced bio-oil, where an enhancement in the yield (up to 23.8%) and antioxidant activity (up to 99 min induction period) were achieved using the PetroOxy method (EN16091). The addition of 1 wt% bio-oil to biodiesel has led to an improvement in the oxidation stability over a neat sample of up to ∌340%, making it compliant with European standard (EN14214). The proposed process presents a biorefinery paradigm for the integrated utilisation of waste cooking oil, lignin and glycerol

    Response of foster grapefruit (Citrus paradisi Macf.) to organic and inorganic fertilization in central Sudan

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    The response of Foster grapefruit (Citrus paradisi Macf.) to organic and inorganic fertilization in Sennar area (13°37â€ČN–33°37â€ČE) representing central Sudan, was studied for two successive seasons (2003/2004 and 2004/2005). Urea, sheep manure and terra-sorb (as foliar) at the rates of 2.17 kg/tree/year, 20 kg/tree/year and 200 ml/100 L water, respectively, and their combinations were applied to 18 years old trees to determine their effects on fruit yield and quality. The layout was a randomized complete block design replicated three times. Results indicated that all treatments significantly increased average yield over control with inconsistent effects on fruit quality parameters. Trees received urea at the rate of 2.17 kg/tree/year, yielded thick peel fruits of reduced vitamin C. Sheep manure at the rate of 20 kg/tree/year resulted in dark green fruits of thick peel. The foliar treated trees at the rate of 200 ml/100 L water gave little thick peel fruits of lower total soluble solids, low % titrable acidity and low vitamin C. The best fruits reflected by color, thinner peel, high % TSS and high vitamin C were obtained from urea + sheep manure treatment. Application of urea with foliar gave green large fruits. Small fruits of intensive green color on surface and low titrable acidity were recorded by combination of sheep manure and foliar. Application of the three fertilizers together gave fruits of dark green color on surface and thick peel. Therefore, application of 2.17 kg urea + 20 kg sheep manure/tree/year is recommended to Foster grapefruit trees in Sennar area and areas of similar environmental conditions
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