Global burden of 288 causes of death and life expectancy decomposition in 204 countries and territories and 811 subnational locations, 1990–2021: a systematic analysis for the Global Burden of Disease Study 2021

Background: Regular, detailed reporting on population health by underlying cause of death is fundamental for public health decision making. Cause-specific estimates of mortality and the subsequent effects on life expectancy worldwide are valuable metrics to gauge progress in reducing mortality rates. These estimates are particularly important following large-scale mortality spikes, such as the COVID-19 pandemic. When systematically analysed, mortality rates and life expectancy allow comparisons of the consequences of causes of death globally and over time, providing a nuanced understanding of the effect of these causes on global populations. Methods: The Global Burden of Diseases, Injuries, and Risk Factors Study (GBD) 2021 cause-of-death analysis estimated mortality and years of life lost (YLLs) from 288 causes of death by age-sex-location-year in 204 countries and territories and 811 subnational locations for each year from 1990 until 2021. The analysis used 56 604 data sources, including data from vital registration and verbal autopsy as well as surveys, censuses, surveillance systems, and cancer registries, among others. As with previous GBD rounds, cause-specific death rates for most causes were estimated using the Cause of Death Ensemble model—a modelling tool developed for GBD to assess the out-of-sample predictive validity of different statistical models and covariate permutations and combine those results to produce cause-specific mortality estimates—with alternative strategies adapted to model causes with insufficient data, substantial changes in reporting over the study period, or unusual epidemiology. YLLs were computed as the product of the number of deaths for each cause-age-sex-location-year and the standard life expectancy at each age. As part of the modelling process, uncertainty intervals (UIs) were generated using the 2·5th and 97·5th percentiles from a 1000-draw distribution for each metric. We decomposed life expectancy by cause of death, location, and year to show cause-specific effects on life expectancy from 1990 to 2021. We also used the coefficient of variation and the fraction of population affected by 90% of deaths to highlight concentrations of mortality. Findings are reported in counts and age-standardised rates. Methodological improvements for cause-of-death estimates in GBD 2021 include the expansion of under-5-years age group to include four new age groups, enhanced methods to account for stochastic variation of sparse data, and the inclusion of COVID-19 and other pandemic-related mortality—which includes excess mortality associated with the pandemic, excluding COVID-19, lower respiratory infections, measles, malaria, and pertussis. For this analysis, 199 new country-years of vital registration cause-of-death data, 5 country-years of surveillance data, 21 country-years of verbal autopsy data, and 94 country-years of other data types were added to those used in previous GBD rounds. Findings: The leading causes of age-standardised deaths globally were the same in 2019 as they were in 1990; in descending order, these were, ischaemic heart disease, stroke, chronic obstructive pulmonary disease, and lower respiratory infections. In 2021, however, COVID-19 replaced stroke as the second-leading age-standardised cause of death, with 94·0 deaths (95% UI 89·2–100·0) per 100 000 population. The COVID-19 pandemic shifted the rankings of the leading five causes, lowering stroke to the third-leading and chronic obstructive pulmonary disease to the fourth-leading position. In 2021, the highest age-standardised death rates from COVID-19 occurred in sub-Saharan Africa (271·0 deaths [250·1–290·7] per 100 000 population) and Latin America and the Caribbean (195·4 deaths [182·1–211·4] per 100 000 population). The lowest age-standardised death rates from COVID-19 were in the high-income super-region (48·1 deaths [47·4–48·8] per 100 000 population) and southeast Asia, east Asia, and Oceania (23·2 deaths [16·3–37·2] per 100 000 population). Globally, life expectancy steadily improved between 1990 and 2019 for 18 of the 22 investigated causes. Decomposition of global and regional life expectancy showed the positive effect that reductions in deaths from enteric infections, lower respiratory infections, stroke, and neonatal deaths, among others have contributed to improved survival over the study period. However, a net reduction of 1·6 years occurred in global life expectancy between 2019 and 2021, primarily due to increased death rates from COVID-19 and other pandemic-related mortality. Life expectancy was highly variable between super-regions over the study period, with southeast Asia, east Asia, and Oceania gaining 8·3 years (6·7–9·9) overall, while having the smallest reduction in life expectancy due to COVID-19 (0·4 years). The largest reduction in life expectancy due to COVID-19 occurred in Latin America and the Caribbean (3·6 years). Additionally, 53 of the 288 causes of death were highly concentrated in locations with less than 50% of the global population as of 2021, and these causes of death became progressively more concentrated since 1990, when only 44 causes showed this pattern. The concentration phenomenon is discussed heuristically with respect to enteric and lower respiratory infections, malaria, HIV/AIDS, neonatal disorders, tuberculosis, and measles. Interpretation: Long-standing gains in life expectancy and reductions in many of the leading causes of death have been disrupted by the COVID-19 pandemic, the adverse effects of which were spread unevenly among populations. Despite the pandemic, there has been continued progress in combatting several notable causes of death, leading to improved global life expectancy over the study period. Each of the seven GBD super-regions showed an overall improvement from 1990 and 2021, obscuring the negative effect in the years of the pandemic. Additionally, our findings regarding regional variation in causes of death driving increases in life expectancy hold clear policy utility. Analyses of shifting mortality trends reveal that several causes, once widespread globally, are now increasingly concentrated geographically. These changes in mortality concentration, alongside further investigation of changing risks, interventions, and relevant policy, present an important opportunity to deepen our understanding of mortality-reduction strategies. Examining patterns in mortality concentration might reveal areas where successful public health interventions have been implemented. Translating these successes to locations where certain causes of death remain entrenched can inform policies that work to improve life expectancy for people everywhere. Funding: Bill & Melinda Gates Foundation

Void formation in wide gap brazing using prepacks of nickel base braze mixes

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A Study of Thomas Kuhn's Paradigm Shift in Terms of the Finding of Helicobacter Pylori

本文以二○○五??貝爾醫學獎得主馬歇爾(Barry J. Marshall)和華?(Robin Warren)的醫學革命??，?明醫學典範轉移的??問題。?人在一九八二?發現幽門?旋桿菌(Helicobacter Pylori)確定造成人?消化性潰瘍的病因，徹底改變?舊消化醫學界的認知（壓?或生活?正常等因素造成人?消化性潰瘍主因）。如此顛覆醫學傳統認知的研究，確實印證孔恩對科學研究典範轉移(paradigm shift)特徵的重要?證。本文先?孔恩典範?基本概?，再導入?文霍克發現細菌的?史過程，敘述巴斯德提出微生物是肉汁腐敗之因，推翻亞?士多德的「自然發生?」，強調微生物觀點的醫學革命，?明過去細菌學建?醫學史典範的?證，?細菌醫學奠下重要基石。人?消化性潰瘍疾病的困擾下，求證這個細菌與疾病的密?關係，?位醫學家??驗證科學真?，遵循柯霍準則完成科學事實和??的吻合，並詳述馬歇爾「以身試菌」過程，進而確?細菌感染的事實，創?醫學新典範等觀點，印證科學典範移轉的特徵與過程。孔恩的典範轉移?述??動和??的一致，完成?自然科學和社會科學解釋科學史之哲學。本文另分析典範認知之爭議，針對孔恩典範定義引起語言學的批判，分析?同的看法。但回歸社會科學對科學史認知主題，醫學科學革命的史實，詳盡描述細菌史研究及幽門?旋桿菌發現的過程，?明科學家嚐盡科學社群的阻?，排除萬難焠?典範，?經?二十三?得以被肯定，印證是醫學科學革命成功的新典範。This paper deals with the example of the Nobel Prize winners for medicine in 2005, Barry J. Marshal and Robin Warren and its implications of paradigm shift in science asserted by Thomas Kuhn. The two scientists found the Helicobacter pylori in 1982 that caused the peptic ulcer. Having changed the cognition and assertion of conventional gastroenterological circles who assumed the factor of the disease being pressure on emotion and abnormal life style, they discussed and discovered the real cause of the disease. Such research subverts the traditional and conventional medical knowledge to the extent that it confirms the importance of Kuhn's theory of paradigm and its shift. This essay treats Anton van Leeuwenhoek's finding of bacterium, through the discovery of the microorganism causing the corruption of gravy by Louis Pasteur, to the conventional scientific community which accepted the concept of bacterium and its effect on the peptic ulcer. In the history of human peptic ulcer, bacterium in fact was close to the occurrence of the disease. However, the two Australian physicians, in order to solve the problem, began to take another research approach and finally found helicobacter pylori as the real cause of peptic ulcer. Thus confirmed the existence and application of Kuhn's postulate, namely the paradigm shift in science. This paper discusses the historical fact of medical scientific revolution, including the doubts raised by the members of medical scientific community and the final success of the "dissidents", their efforts to get rid of the obstructions established by the scientific circles. Thus, it is worthy to study the theory and practice of the paradigm and its shift propounded by Thomas Kuhn

Wide gap brazing with prepacks of nickel base braze mixes

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Microstructural evolution and control in BNi-4 brazed joints of nickel 270

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Repair of trailing edge of C1023 NGVs by a gouge-and-braze technique

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Solidification phenomena in nickel base brazes containing boron and silicon

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Evolution of nickel borides in Ni-Si-B brazed joints of nickel during post-braze heat treatment

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