9 research outputs found

    Theoretical Study of Solvent Effects on 1,3- Dipolar Cycloaddition Reaction

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    في هذه الدراسة تم اجراء التحليل الانحداري لثابت التفاعل 15 مع معاملات المذيبات لمجموعتين من تفاعلات الاضافة الحلقي ال1و3-ثنائي القطب. الاولى هي تفاعل الازوميثاين(1)  مع السايكلواوكتاين (2),و اليينامين(3), و ثنائي مثيل اسيتيلين كاربوكسيليت(4). والمجموعة الثانية هي تفاعل النيترونات 5و6 مع الدايبولاروفيل 7 . كما تم اجراء الحسابات الشبه تجريبية للمتفاعلات حيث رسمت القيم الكمية الناتجة ضد معاملات التفاعل وضد معاملات المذيبات. وتم الحصول على نتائج متباينة الجودة لهذه التفاعلات. واجري تحليل رج الانحداري لغرض تصحيح الشذوذ الخطي للنماذج ذات المعاملات المتعددة. الغرض من هذه الدراسة هو الحصول على نموذج او نماذج والتي بواسطتها يمكن التنبؤ بالظروف المثالية للتفاعل قبل العمل المختبري.In the present study the regression analysis of the rate constant k 15with solvent parameters, for two sets of 1,3-dipolarcycloaddition reactions were done. The first was the reaction azomethine 1 with cyclooctyne 2, ynamine 3 and dimethyl acetylenecarboxylate (4) in different nonprotic solvents. The second were the reactions of the nitrones 5 and 6 with dipolarophile 7. Semiempirical calculations (PM3) were done for the reactants. The resulting quantum descriptors HOMO-LUMO and the transition state quantum descriptors (LUMOdipolarophile - HOMOdipole (HdL) and LUMOdipole – HOMOdipolarophile (LdH)) were plotted against solvent parameters, in order to obtain predictive computational models. Good to excellent correlations were obtained for these reactions. The multiparameteric models obtained were corrected for collinearity   by using Ridge regression

    Measuring routine childhood vaccination coverage in 204 countries and territories, 1980-2019 : a systematic analysis for the Global Burden of Disease Study 2020, Release 1

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    Background Measuring routine childhood vaccination is crucial to inform global vaccine policies and programme implementation, and to track progress towards targets set by the Global Vaccine Action Plan (GVAP) and Immunization Agenda 2030. Robust estimates of routine vaccine coverage are needed to identify past successes and persistent vulnerabilities. Drawing from the Global Burden of Diseases, Injuries, and Risk Factors Study (GBD) 2020, Release 1, we did a systematic analysis of global, regional, and national vaccine coverage trends using a statistical framework, by vaccine and over time. Methods For this analysis we collated 55 326 country-specific, cohort-specific, year-specific, vaccine-specific, and dosespecific observations of routine childhood vaccination coverage between 1980 and 2019. Using spatiotemporal Gaussian process regression, we produced location-specific and year-specific estimates of 11 routine childhood vaccine coverage indicators for 204 countries and territories from 1980 to 2019, adjusting for biases in countryreported data and reflecting reported stockouts and supply disruptions. We analysed global and regional trends in coverage and numbers of zero-dose children (defined as those who never received a diphtheria-tetanus-pertussis [DTP] vaccine dose), progress towards GVAP targets, and the relationship between vaccine coverage and sociodemographic development. Findings By 2019, global coverage of third-dose DTP (DTP3; 81.6% [95% uncertainty interval 80.4-82 .7]) more than doubled from levels estimated in 1980 (39.9% [37.5-42.1]), as did global coverage of the first-dose measles-containing vaccine (MCV1; from 38.5% [35.4-41.3] in 1980 to 83.6% [82.3-84.8] in 2019). Third- dose polio vaccine (Pol3) coverage also increased, from 42.6% (41.4-44.1) in 1980 to 79.8% (78.4-81.1) in 2019, and global coverage of newer vaccines increased rapidly between 2000 and 2019. The global number of zero-dose children fell by nearly 75% between 1980 and 2019, from 56.8 million (52.6-60. 9) to 14.5 million (13.4-15.9). However, over the past decade, global vaccine coverage broadly plateaued; 94 countries and territories recorded decreasing DTP3 coverage since 2010. Only 11 countries and territories were estimated to have reached the national GVAP target of at least 90% coverage for all assessed vaccines in 2019. Interpretation After achieving large gains in childhood vaccine coverage worldwide, in much of the world this progress was stalled or reversed from 2010 to 2019. These findings underscore the importance of revisiting routine immunisation strategies and programmatic approaches, recentring service delivery around equity and underserved populations. Strengthening vaccine data and monitoring systems is crucial to these pursuits, now and through to 2030, to ensure that all children have access to, and can benefit from, lifesaving vaccines. Copyright (C) 2021 The Author(s). Published by Elsevier Ltd.Peer reviewe

    Regional variations in antimicrobial susceptibility of community-acquired uropathogenic Escherichia coli in India: findings of a multicentric study highlighting the importance of local antibiograms

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    Background: Evidence-based prescribing is essential to optimise patient outcomes in cystitis. This requires knowledge of local antibiotic resistance rates. DASH to Protect Antibiotics (https://dashuti.com/) is a multicentric mentorship programme guiding centres in preparing, analysing and disseminating local antibiograms to promote antimicrobial stewardship in community UTI. Here we map the susceptibility profile of Escherichia coli from 22 Indian centres. Methods: These centres spanned 10 Indian States and three Union Territories. Antibiograms for urinary E. coli from the outpatient departments were collated. Standardisation was achieved by regional online training; anomalies were resolved via consultation with study experts. Data were collated and analysed. Findings: Nationally, fosfomycin, with 94% susceptibility (inter-centre range 83-97%), and nitrofurantoin with 85% susceptibility (61-97%) retained widest activity. Susceptibility rates were lower for co-trimoxazole (49%), fluoroquinolones (31%) and oral cephalosporins (26%). Rates for third- and fourth- generation cephalosporins were 46% and 52%, respectively, with 54% (33-58%) ESBL prevalence. Piperacillin-tazobactam (81%) amikacin (88%), meropenem (88%) retained better activity, but one centre in Delhi recorded only 42% meropenem susceptibility. Susceptibility rates were mostly higher in South, West and Northeast India; centres in the heavily-populated Gangetic plains, across North and Northwest India, had greater resistance. These findings highlight the importance of local antibiograms in guiding appropriate antimicrobial choices. Interpretation: Fosfomycin and nitrofurantoin are the preferred oral empirical choices for uncomplicated E. coli cystitis in India, though elevated resistance in some areas is concerning. Empiric use of fluoroquinolones and third generation cephalosporins is discouraged whereas piperacillin/tazobactam and aminoglycosides remain carbapenem-sparing parenteral agents

    Age–sex differences in the global burden of lower respiratory infections and risk factors, 1990–2019: results from the Global Burden of Disease Study 2019

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    Background: The global burden of lower respiratory infections (LRI) and corresponding risk factors in children older than five years and adults has not been studied as comprehensively as in children under five years old. We assessed the burden and trends of LRI and risk factors across all age groups by sex for 204 countries and territories. Methods: We used clinician-diagnosed pneumonia or bronchiolitis as our case definition for lower respiratory infections. We included ICD9 codes 073.0-073.6, 079.82, 466-469, 480-489, 513.0, and 770.0 and ICD10 codes A48.1, J09-J22, J85.1, P23-P23.9, and U04. We used the Cause of Death Ensemble modelling strategy to analyse 23,109 site-years of vital registration data, 825 site-years of sample vital registration data, 1766 site-years of verbal autopsy data, and 681 site-years of mortality surveillance data. We used DisMod-MR 2.1, a Bayesian meta-regression tool, to analyse age-sex-specific incidence and prevalence data identified via systematic review, population-based surveys, and claims and inpatient data. Additionally, we estimated age-sex-specific LRI mortality that is attributable to the independent effects of 14 risk factors.Results: Globally, we estimated LRI episodes of 257 million (95% UI 240–275) for males and 232 million (217–248) for females in 2019. In the same year, LRI accounted for 1.3 million (1.2–1.4) deaths among males and 1.2 million (1.1–1.3) deaths among females. Age-standardised incidence and mortality rates were 1.2 times and 1.3 times greater in males than in females in 2019. Between 1990 and 2019, LRI incidence and mortality rates declined at different rates across age groups while an increase in LRI episodes and deaths was estimated among all adult age groups, with males aged 70 years and older experiencing the highest increase in LRI episodes (126.0% [121.4–131.1]) and deaths (100.0% [83.4–115.9]). During the same period, LRI episodes and deaths in children younger than 15 years were estimated to have decreased, and the greatest decline was observed for mortality among males under the age of five (70.7% [61.8–77.3]). The leading risk factors for LRI mortality varied across age groups and sex. More than half of global LRI deaths among males and females younger than five years were attributable to child wasting, and more than a quarter of LRI deaths among those aged 5–14 years were attributable to household air pollution in 2019. For males aged 15–49, 50–69, and 70 years and older, 20.4 (15.4-25.2), 30.5% (24.1–36.9), and 21.9% (16.8–27.3), respectively, of estimated LRI deaths were attributable to smoking in the same year. For females aged 15–49 and 50–69 years, 21.1% (14.5–27.9) and 7.9% (5.5–10.5) of estimated LRI deaths were attributable to household air pollution in 2019. For females aged 70 years and older, the leading risk factor, ambient particulate matter, was responsible for 11.7% (8.2–15.8) of LRI deaths in the same year.Interpretation: The patterns and progress in reducing the burden of LRI and key risk factors varied across age groups and sexes.. The progress seen in under five children was clearly a result of targeted interventions, such as vaccination and reduction of exposure to risk factors. Similar interventions for other age groups could contribute to achieving multiple Sustainable Development Goals targets, including promoting well-being at all ages and reducing inequalities. Interventions, including addressing risk factors such as child wasting, smoking, ambient particulate matter pollution, and household air pollution, would mean preventable deaths and millions of lives saved, as well as reduced health disparities

    Measuring routine childhood vaccination coverage in 204 countries and territories, 1980–2019: a systematic analysis for the Global Burden of Disease Study 2020, Release 1

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    10.1016/s0140-6736(21)00984-3The Lancet39810299503-52

    Burden of disease scenarios for 204 countries and territories, 2022–2050: a forecasting analysis for the Global Burden of Disease Study 2021

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    BackgroundFuture trends in disease burden and drivers of health are of great interest to policy makers and the public at large. This information can be used for policy and long-term health investment, planning, and prioritisation. We have expanded and improved upon previous forecasts produced as part of the Global Burden of Diseases, Injuries, and Risk Factors Study (GBD) and provide a reference forecast (the most likely future), and alternative scenarios assessing disease burden trajectories if selected sets of risk factors were eliminated from current levels by 2050.MethodsUsing forecasts of major drivers of health such as the Socio-demographic Index (SDI; a composite measure of lag-distributed income per capita, mean years of education, and total fertility under 25 years of age) and the full set of risk factor exposures captured by GBD, we provide cause-specific forecasts of mortality, years of life lost (YLLs), years lived with disability (YLDs), and disability-adjusted life-years (DALYs) by age and sex from 2022 to 2050 for 204 countries and territories, 21 GBD regions, seven super-regions, and the world. All analyses were done at the cause-specific level so that only risk factors deemed causal by the GBD comparative risk assessment influenced future trajectories of mortality for each disease. Cause-specific mortality was modelled using mixed-effects models with SDI and time as the main covariates, and the combined impact of causal risk factors as an offset in the model. At the all-cause mortality level, we captured unexplained variation by modelling residuals with an autoregressive integrated moving average model with drift attenuation. These all-cause forecasts constrained the cause-specific forecasts at successively deeper levels of the GBD cause hierarchy using cascading mortality models, thus ensuring a robust estimate of cause-specific mortality. For non-fatal measures (eg, low back pain), incidence and prevalence were forecasted from mixed-effects models with SDI as the main covariate, and YLDs were computed from the resulting prevalence forecasts and average disability weights from GBD. Alternative future scenarios were constructed by replacing appropriate reference trajectories for risk factors with hypothetical trajectories of gradual elimination of risk factor exposure from current levels to 2050. The scenarios were constructed from various sets of risk factors: environmental risks (Safer Environment scenario), risks associated with communicable, maternal, neonatal, and nutritional diseases (CMNNs; Improved Childhood Nutrition and Vaccination scenario), risks associated with major non-communicable diseases (NCDs; Improved Behavioural and Metabolic Risks scenario), and the combined effects of these three scenarios. Using the Shared Socioeconomic Pathways climate scenarios SSP2-4.5 as reference and SSP1-1.9 as an optimistic alternative in the Safer Environment scenario, we accounted for climate change impact on health by using the most recent Intergovernmental Panel on Climate Change temperature forecasts and published trajectories of ambient air pollution for the same two scenarios. Life expectancy and healthy life expectancy were computed using standard methods. The forecasting framework includes computing the age-sex-specific future population for each location and separately for each scenario. 95% uncertainty intervals (UIs) for each individual future estimate were derived from the 2·5th and 97·5th percentiles of distributions generated from propagating 500 draws through the multistage computational pipeline.FindingsIn the reference scenario forecast, global and super-regional life expectancy increased from 2022 to 2050, but improvement was at a slower pace than in the three decades preceding the COVID-19 pandemic (beginning in 2020). Gains in future life expectancy were forecasted to be greatest in super-regions with comparatively low life expectancies (such as sub-Saharan Africa) compared with super-regions with higher life expectancies (such as the high-income super-region), leading to a trend towards convergence in life expectancy across locations between now and 2050. At the super-region level, forecasted healthy life expectancy patterns were similar to those of life expectancies. Forecasts for the reference scenario found that health will improve in the coming decades, with all-cause age-standardised DALY rates decreasing in every GBD super-region. The total DALY burden measured in counts, however, will increase in every super-region, largely a function of population ageing and growth. We also forecasted that both DALY counts and age-standardised DALY rates will continue to shift from CMNNs to NCDs, with the most pronounced shifts occurring in sub-Saharan Africa (60·1% [95% UI 56·8–63·1] of DALYs were from CMNNs in 2022 compared with 35·8% [31·0–45·0] in 2050) and south Asia (31·7% [29·2–34·1] to 15·5% [13·7–17·5]). This shift is reflected in the leading global causes of DALYs, with the top four causes in 2050 being ischaemic heart disease, stroke, diabetes, and chronic obstructive pulmonary disease, compared with 2022, with ischaemic heart disease, neonatal disorders, stroke, and lower respiratory infections at the top. The global proportion of DALYs due to YLDs likewise increased from 33·8% (27·4–40·3) to 41·1% (33·9–48·1) from 2022 to 2050, demonstrating an important shift in overall disease burden towards morbidity and away from premature death. The largest shift of this kind was forecasted for sub-Saharan Africa, from 20·1% (15·6–25·3) of DALYs due to YLDs in 2022 to 35·6% (26·5–43·0) in 2050. In the assessment of alternative future scenarios, the combined effects of the scenarios (Safer Environment, Improved Childhood Nutrition and Vaccination, and Improved Behavioural and Metabolic Risks scenarios) demonstrated an important decrease in the global burden of DALYs in 2050 of 15·4% (13·5–17·5) compared with the reference scenario, with decreases across super-regions ranging from 10·4% (9·7–11·3) in the high-income super-region to 23·9% (20·7–27·3) in north Africa and the Middle East. The Safer Environment scenario had its largest decrease in sub-Saharan Africa (5·2% [3·5–6·8]), the Improved Behavioural and Metabolic Risks scenario in north Africa and the Middle East (23·2% [20·2–26·5]), and the Improved Nutrition and Vaccination scenario in sub-Saharan Africa (2·0% [–0·6 to 3·6]).InterpretationGlobally, life expectancy and age-standardised disease burden were forecasted to improve between 2022 and 2050, with the majority of the burden continuing to shift from CMNNs to NCDs. That said, continued progress on reducing the CMNN disease burden will be dependent on maintaining investment in and policy emphasis on CMNN disease prevention and treatment. Mostly due to growth and ageing of populations, the number of deaths and DALYs due to all causes combined will generally increase. By constructing alternative future scenarios wherein certain risk exposures are eliminated by 2050, we have shown that opportunities exist to substantially improve health outcomes in the future through concerted efforts to prevent exposure to well established risk factors and to expand access to key health interventions.FundingBill & Melinda Gates Foundation.</p
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