31 research outputs found

    Catalytic Activation of PVP-Stabilized Gold/Silver Cluster on p- Nitrophenol Reduction: A DFT

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    Systematic DFT calculations on poly(N-vinyl-2-pyrrolidone) (PVP) stabilization of Ag13 cluster have shown that the former acts not only as a stabilizer but also plays an important role in activating the Ag catalyst by supplying extra electrons to it through its oxygen atoms. Natural Bonding Orbital (NBO) calculations show that weak back donation of electrons from M(dπ) orbital of Ag to antibonding σ* of one of the N-O bond, facilitates the formation of the nitroso intermediate. Vibrational frequency calculation of PNP association with Ag13-2PVP cluster carried out to understand the extent and the nature of this interaction better. Red shift in the frequencies is result of strong interaction with that of silver cluster present in Ag13-2PVP-PNP model

    Predicting Risk of Atrial Fibrillation in Hematopoietic Stem Cell Transplant

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    Background Atrial fibrillation (AF) in hematopoietic stem cell transplant (HSCT) recipients is associated with significant morbidity. We have previously reported that obstructive sleep apnea (OSA), older age and presence of dilated left atrium (LA) are significant predictors of AF early post HSCT. In the current study, we sought to evaluate if TSH pre HSCT and serum electrolytes and eGFR at engraftment in patients undergoing HSCT are associated with increased risk of AF. Methods This is a single center retrospective study, involving 748 consecutive patients undergoing autologous and allogenic HSCT from 2012 to 2022. Patients’ charts were reviewed to acquire clinical information (age, gender, HTN, body mass index [BMI], Obstructive sleep apnea [OSA], TSH, and LA volume index that was obtained from pre-HSCT echocardiogram, in addition to potassium [K], magnesium [Mg], and eGFR at time of engraftment [ENG]). Results For the 748 patients, the median age at HSCT was 61. Majority of patients were male (57%). Most common diagnoses were Myeloma (42.5%), acute leukemia (19.5%), lymphoma (19.5%), myelodysplastic syndromes and myeloproliferative neoplasms (11%). A total of 116 (15.5%) patients developed AF early post-HSCT. AF patients’ mean LA measurement was 37.3ml/m2, whereas non-AF patients’ mean measure was 30.6ml/m2 (P-value: 0.002). For age at HSCT, AF patients’ mean was 62.4 years old and non-AF patients’ mean was 57.4 years old (P-value: \u3c0.001). OSA diagnosis, 39 (29.5%) of AF patients had OSA and 67 (11.3%) of non-AF patients had OSA (P-value: \u3c0.001). At time of ENG, AF patients had higher mean K of 4.1 (P-value: 0.001) and lower mean eGFR of 81.1 (P-value\u3c0.001) versus non-AF patients with mean K of 3.7 and eGFR of 94.3. In the multivariable regression analysis, larger LA size (P-value: 0.016), older age at HSCT (P-value: 0.001), diagnosis of OSA (P-value: \u3c0.001), and higher K (P-value: 0.010) and lower GFR (P-value: 0.007) at ENG were significant predictors of AF. Male gender, HTN, BMI, use of ATG or Melphalan based chemotherapies, pre-HSCT TSH, and Mg at ENG were not predictive of AF post-HSCT (table 1). Conclusion In our single center retrospective study, we found that compared to patients who did not develop AF early post-HSCT, the AF patients, in addition to having dilated LA, being older and more OSA, surprisingly they had higher K and lower eGFR at day of ENG. A limitation of our study is the diagnosis of OSA, which sometimes was not supported with a sleep study or diagnosis came from an external practitioner. Another limitation of our study would be the fluctuations in electrolytes around time of engraftment and overhydration due to IV fluids during the inpatient stay. Further research is needed to develop a risk calculator to identify high risk patients and study the effects of prophylactic therapies on the incidence of post-HSCT AF

    Scrub typhus: as it stands today

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    Scrub typhus is one of the three most common causes of prolonged fever in Southeast Asia and Pacific affecting almost 1 million people annually worldwide out of 1 billion exposed. Scrub typhus is a rickettsial infection caused by Orientia Tsutsugamushi transmitted through bite of Chiggers (larval stage of trombiculid mite). It is an acute febrile illness which generally causes non-specific symptoms and signs. The clinical manifestations of this disease range from sub-clinical disease to organ failure and death. Deaths are attributable to late presentation, delayed diagnosis, and drug resistance. Scrub typhus, though endemic in India; yet is under reported. It should be considered as an important differential diagnosis in a febrile patient with thrombocytopenia, deranged liver or renal functions, and B/L chest opacities. Relapse is not uncommon. Presumptive treatment with Doxycycline can be a suitable option in febrile patients from Typhus pockets. Alert physician should keep an eye on deviation from usual presentation to changing spectrum of the disease. Early diagnosis and appropriate treatment is rewarding and prevents morbidity and mortality

    Global age-sex-specific mortality, life expectancy, and population estimates in 204 countries and territories and 811 subnational locations, 1950–2021, and the impact of the COVID-19 pandemic: a comprehensive demographic analysis for the Global Burden of Disease Study 2021

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    Background: Estimates of demographic metrics are crucial to assess levels and trends of population health outcomes. The profound impact of the COVID-19 pandemic on populations worldwide has underscored the need for timely estimates to understand this unprecedented event within the context of long-term population health trends. The Global Burden of Diseases, Injuries, and Risk Factors Study (GBD) 2021 provides new demographic estimates for 204 countries and territories and 811 additional subnational locations from 1950 to 2021, with a particular emphasis on changes in mortality and life expectancy that occurred during the 2020–21 COVID-19 pandemic period. Methods: 22 223 data sources from vital registration, sample registration, surveys, censuses, and other sources were used to estimate mortality, with a subset of these sources used exclusively to estimate excess mortality due to the COVID-19 pandemic. 2026 data sources were used for population estimation. Additional sources were used to estimate migration; the effects of the HIV epidemic; and demographic discontinuities due to conflicts, famines, natural disasters, and pandemics, which are used as inputs for estimating mortality and population. Spatiotemporal Gaussian process regression (ST-GPR) was used to generate under-5 mortality rates, which synthesised 30 763 location-years of vital registration and sample registration data, 1365 surveys and censuses, and 80 other sources. ST-GPR was also used to estimate adult mortality (between ages 15 and 59 years) based on information from 31 642 location-years of vital registration and sample registration data, 355 surveys and censuses, and 24 other sources. Estimates of child and adult mortality rates were then used to generate life tables with a relational model life table system. For countries with large HIV epidemics, life tables were adjusted using independent estimates of HIV-specific mortality generated via an epidemiological analysis of HIV prevalence surveys, antenatal clinic serosurveillance, and other data sources. Excess mortality due to the COVID-19 pandemic in 2020 and 2021 was determined by subtracting observed all-cause mortality (adjusted for late registration and mortality anomalies) from the mortality expected in the absence of the pandemic. Expected mortality was calculated based on historical trends using an ensemble of models. In location-years where all-cause mortality data were unavailable, we estimated excess mortality rates using a regression model with covariates pertaining to the pandemic. Population size was computed using a Bayesian hierarchical cohort component model. Life expectancy was calculated using age-specific mortality rates and standard demographic methods. Uncertainty intervals (UIs) were calculated for every metric using the 25th and 975th ordered values from a 1000-draw posterior distribution. Findings: Global all-cause mortality followed two distinct patterns over the study period: age-standardised mortality rates declined between 1950 and 2019 (a 62·8% [95% UI 60·5–65·1] decline), and increased during the COVID-19 pandemic period (2020–21; 5·1% [0·9–9·6] increase). In contrast with the overall reverse in mortality trends during the pandemic period, child mortality continued to decline, with 4·66 million (3·98–5·50) global deaths in children younger than 5 years in 2021 compared with 5·21 million (4·50–6·01) in 2019. An estimated 131 million (126–137) people died globally from all causes in 2020 and 2021 combined, of which 15·9 million (14·7–17·2) were due to the COVID-19 pandemic (measured by excess mortality, which includes deaths directly due to SARS-CoV-2 infection and those indirectly due to other social, economic, or behavioural changes associated with the pandemic). Excess mortality rates exceeded 150 deaths per 100 000 population during at least one year of the pandemic in 80 countries and territories, whereas 20 nations had a negative excess mortality rate in 2020 or 2021, indicating that all-cause mortality in these countries was lower during the pandemic than expected based on historical trends. Between 1950 and 2021, global life expectancy at birth increased by 22·7 years (20·8–24·8), from 49·0 years (46·7–51·3) to 71·7 years (70·9–72·5). Global life expectancy at birth declined by 1·6 years (1·0–2·2) between 2019 and 2021, reversing historical trends. An increase in life expectancy was only observed in 32 (15·7%) of 204 countries and territories between 2019 and 2021. The global population reached 7·89 billion (7·67–8·13) people in 2021, by which time 56 of 204 countries and territories had peaked and subsequently populations have declined. The largest proportion of population growth between 2020 and 2021 was in sub-Saharan Africa (39·5% [28·4–52·7]) and south Asia (26·3% [9·0–44·7]). From 2000 to 2021, the ratio of the population aged 65 years and older to the population aged younger than 15 years increased in 188 (92·2%) of 204 nations. Interpretation: Global adult mortality rates markedly increased during the COVID-19 pandemic in 2020 and 2021, reversing past decreasing trends, while child mortality rates continued to decline, albeit more slowly than in earlier years. Although COVID-19 had a substantial impact on many demographic indicators during the first 2 years of the pandemic, overall global health progress over the 72 years evaluated has been profound, with considerable improvements in mortality and life expectancy. Additionally, we observed a deceleration of global population growth since 2017, despite steady or increasing growth in lower-income countries, combined with a continued global shift of population age structures towards older ages. These demographic changes will likely present future challenges to health systems, economies, and societies. The comprehensive demographic estimates reported here will enable researchers, policy makers, health practitioners, and other key stakeholders to better understand and address the profound changes that have occurred in the global health landscape following the first 2 years of the COVID-19 pandemic, and longer-term trends beyond the pandemic

    Global age-sex-specific mortality, life expectancy, and population estimates in 204 countries and territories and 811 subnational locations, 1950–2021, and the impact of the COVID-19 pandemic: a comprehensive demographic analysis for the Global Burden of Disease Study 2021

    Get PDF
    BACKGROUND: Estimates of demographic metrics are crucial to assess levels and trends of population health outcomes. The profound impact of the COVID-19 pandemic on populations worldwide has underscored the need for timely estimates to understand this unprecedented event within the context of long-term population health trends. The Global Burden of Diseases, Injuries, and Risk Factors Study (GBD) 2021 provides new demographic estimates for 204 countries and territories and 811 additional subnational locations from 1950 to 2021, with a particular emphasis on changes in mortality and life expectancy that occurred during the 2020–21 COVID-19 pandemic period. METHODS: 22 223 data sources from vital registration, sample registration, surveys, censuses, and other sources were used to estimate mortality, with a subset of these sources used exclusively to estimate excess mortality due to the COVID-19 pandemic. 2026 data sources were used for population estimation. Additional sources were used to estimate migration; the effects of the HIV epidemic; and demographic discontinuities due to conflicts, famines, natural disasters, and pandemics, which are used as inputs for estimating mortality and population. Spatiotemporal Gaussian process regression (ST-GPR) was used to generate under-5 mortality rates, which synthesised 30 763 location-years of vital registration and sample registration data, 1365 surveys and censuses, and 80 other sources. ST-GPR was also used to estimate adult mortality (between ages 15 and 59 years) based on information from 31 642 location-years of vital registration and sample registration data, 355 surveys and censuses, and 24 other sources. Estimates of child and adult mortality rates were then used to generate life tables with a relational model life table system. For countries with large HIV epidemics, life tables were adjusted using independent estimates of HIV-specific mortality generated via an epidemiological analysis of HIV prevalence surveys, antenatal clinic serosurveillance, and other data sources. Excess mortality due to the COVID-19 pandemic in 2020 and 2021 was determined by subtracting observed all-cause mortality (adjusted for late registration and mortality anomalies) from the mortality expected in the absence of the pandemic. Expected mortality was calculated based on historical trends using an ensemble of models. In location-years where all-cause mortality data were unavailable, we estimated excess mortality rates using a regression model with covariates pertaining to the pandemic. Population size was computed using a Bayesian hierarchical cohort component model. Life expectancy was calculated using age-specific mortality rates and standard demographic methods. Uncertainty intervals (UIs) were calculated for every metric using the 25th and 975th ordered values from a 1000-draw posterior distribution. FINDINGS: Global all-cause mortality followed two distinct patterns over the study period: age-standardised mortality rates declined between 1950 and 2019 (a 62·8% [95% UI 60·5–65·1] decline), and increased during the COVID-19 pandemic period (2020–21; 5·1% [0·9–9·6] increase). In contrast with the overall reverse in mortality trends during the pandemic period, child mortality continued to decline, with 4·66 million (3·98–5·50) global deaths in children younger than 5 years in 2021 compared with 5·21 million (4·50–6·01) in 2019. An estimated 131 million (126–137) people died globally from all causes in 2020 and 2021 combined, of which 15·9 million (14·7–17·2) were due to the COVID-19 pandemic (measured by excess mortality, which includes deaths directly due to SARS-CoV-2 infection and those indirectly due to other social, economic, or behavioural changes associated with the pandemic). Excess mortality rates exceeded 150 deaths per 100 000 population during at least one year of the pandemic in 80 countries and territories, whereas 20 nations had a negative excess mortality rate in 2020 or 2021, indicating that all-cause mortality in these countries was lower during the pandemic than expected based on historical trends. Between 1950 and 2021, global life expectancy at birth increased by 22·7 years (20·8–24·8), from 49·0 years (46·7–51·3) to 71·7 years (70·9–72·5). Global life expectancy at birth declined by 1·6 years (1·0–2·2) between 2019 and 2021, reversing historical trends. An increase in life expectancy was only observed in 32 (15·7%) of 204 countries and territories between 2019 and 2021. The global population reached 7·89 billion (7·67–8·13) people in 2021, by which time 56 of 204 countries and territories had peaked and subsequently populations have declined. The largest proportion of population growth between 2020 and 2021 was in sub-Saharan Africa (39·5% [28·4–52·7]) and south Asia (26·3% [9·0–44·7]). From 2000 to 2021, the ratio of the population aged 65 years and older to the population aged younger than 15 years increased in 188 (92·2%) of 204 nations. INTERPRETATION: Global adult mortality rates markedly increased during the COVID-19 pandemic in 2020 and 2021, reversing past decreasing trends, while child mortality rates continued to decline, albeit more slowly than in earlier years. Although COVID-19 had a substantial impact on many demographic indicators during the first 2 years of the pandemic, overall global health progress over the 72 years evaluated has been profound, with considerable improvements in mortality and life expectancy. Additionally, we observed a deceleration of global population growth since 2017, despite steady or increasing growth in lower-income countries, combined with a continued global shift of population age structures towards older ages. These demographic changes will likely present future challenges to health systems, economies, and societies. The comprehensive demographic estimates reported here will enable researchers, policy makers, health practitioners, and other key stakeholders to better understand and address the profound changes that have occurred in the global health landscape following the first 2 years of the COVID-19 pandemic, and longer-term trends beyond the pandemic. FUNDING: Bill & Melinda Gates Foundation
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