14 research outputs found

    Field Emission Behaviour of the Single Wall Carbon Nanotubes Grown by Plasma Enhanced Chemical Vapour Deposition (PECVD) System

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    Single wall carbon nanotubes have been grown on Fe using Plasma Enhanced Chemical Vapour Deposition (PECVD) system. The thickness of the Fe film prepared by RF sputtering system was about 10 nm. The field emission characteristic was measured which showed good enhancement factor. The grown CNTs were characterized by various techniques such as SEM, Raman study etc. When you are citing the document, use the following link http://essuir.sumdu.edu.ua/handle/123456789/3100

    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

    Minimally Invasive Left Ventricular Assist Device Implantation: A Comparative Study

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    Left ventricular assist device (LVAD) is now a routine therapy for advanced heart failure. Minimally invasive approach via thoracotomy for LVAD implantation is getting popular due to its potential advantage over the conventional sternotomy approach in terms of reduced risk at re-operation due to sternal sparing. We compared the approaches (thoracotomy and sternotomy) to determine the superiority. Minimally invasive approach involved fitting of the LVAD inflow cannula into left ventricle apex via left anterior thoracotomy and anastomosis of outflow graft to ascending aorta via right anterior thoracotomy. In the sternotomy approach, both the procedures were performed via sternotomy. Outcomes in patients after LVAD implantation were compared depending on these approaches for the surgery. Two hundred and five continuous flow LVAD implantations performed between July 2006 and June 2015 at a single center were divided based on surgical approach, that is, sternotomy (n = 180) and thoracotomy (n = 25) groups. There was no significant difference between the groups in relation to patient demographics, preoperative hemodynamic parameters, laboratory markers, or risk factors. There was no significant difference between the groups in terms of postoperative hemodynamic parameters, laboratory markers, bleeding and requirement of blood products, intensive care unit, and hospital stay or complications of LVAD surgery. There were no significant differences in terms of long-term survival (Log-Rank P = 0.953), however, thoracotomy, compared to sternotomy approach, incurred significantly less requirement of temporary right ventricular assist (4 vs. 19.4%, P = 0.041). Minimally invasive bilateral thoracotomy approach for LVAD implantation in addition to benefits of sternal sparing avoids dilatation of right ventricle and reduces chances of right ventricular failure requiring temporary right ventricular assist

    Minimally Invasive Spine Surgery: A Historical Perspective

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    Efficacy and safety of lampalizumab for geographic atrophy due to age-related macular degeneration: Chroma and Spectri phase 3 randomized clinical trials

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    IMPORTANCE: Geographic atrophy (GA) secondary to age-related macular degeneration is a leading cause of visual disability in older individuals. A phase 2 trial suggested that lampalizumab, a selective complement factor D inhibitor, reduced the rate of GA enlargement, warranting phase 3 trials.OBJECTIVE: To assess the safety and efficacy of lampalizumab vs sham procedure on enlargement of GA.DESIGN, SETTING, AND PARTICIPANTS: Two identically designed phase 3 double-masked, randomized, sham-controlled clinical trials, Chroma and Spectri, enrolled participants from August 28, 2014, to October 6, 2016, at 275 sites in 23 countries. Participants were aged 50 years or older, with bilateral GA and no prior or active choroidal neovascularization in either eye and GA lesions in the study eye measuring 2.54 to 17.78 mm(2) with diffuse or banded fundus autofluorescence patterns.INTERVENTIONS: Participants were randomized 2:1:2:1 to receive 10 mg of intravitreous lampalizumab every 4 weeks, sham procedure every 4 weeks, 10 mg of lampalizumab every 6 weeks, or sham procedure every 6 weeks, through 96 weeks.MAIN OUTCOMES AND MEASURES: Safety and efficacy assessed as mean change from baseline in GA lesion area at week 48 from centrally read fundus autofluorescence images of the lampalizumab arms vs pooled sham arms, in the intent-to-treat population and by complement factor I-profile genetic biomarker.RESULTS: A total of 906 participants (553 women and 353 men; mean [SD] age, 78.1 [8.1] years) were enrolled in Chroma and 975 participants (578 women and 397 men; mean [SD] age, 77.9 [8.1] years) were enrolled in Spectri; 1733 of the 1881 participants (92.1%) completed the studies through 48 weeks. The adjusted mean increases in GA lesion area from baseline at week 48 were 1.93 to 2.09 mm(2) across all groups in both studies. Differences in adjusted mean change in GA lesion area (lampalizumab minus sham) were -0.02 mm(2) (95% CI, -0.21 to 0.16 mm(2); P = .80) for lampalizumab every 4 weeks in Chroma, 0.16 mm(2) (95% CI, 0.00-0.31 mm(2); P = .048) for lampalizumab every 4 weeks in Spectri, 0.05 mm2 (95% CI, -0.13 to 0.24 mm(2); P = .59) for lampalizumab every 6 weeks in Chroma, and 0.09 mm(2) (95% CI, -0.07 to 0.24 mm(2); P = .27) for lampalizumab every 6 weeks in Spectri. No benefit of lampalizumab was observed across prespecified subgroups, including by complement factor I-profile biomarker. Endophthalmitis occurred after 5 of 12 447 injections (0.04%) or in 5 of 1252 treated participants (0.4%) through week 48.CONCLUSIONS AND RELEVANCE: In Chroma and Spectri, the largest studies of GA conducted to date, lampalizumab did not reduce GA enlargement vs sham during 48 weeks of treatment. Results highlight the substantial and consistent enlargement of GA, at a mean of approximately 2 mm(2) per year
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