Mortality registration and surveillance in China: History, current situation and challenges

Background: Mortality statistics are key inputs for evidence based health policy at national level. Little is known of the empirical basis for mortality statistics in China, which accounts for roughly one-fifth of the world's population. An adequate description of the evolution of mortality registration in China and its current situation is important to evaluate the usability of the statistics derived from it for international epidemiology and health policy. Current situation: The Chinese vital registration system currently covers 41 urban and 85 rural centres, accounting for roughly 8 % of the national population. Quality of registration is better in urban than in rural areas, and eastern than in western regions, resulting in significant biases in the overall statistics. The Ministry of Health introduced the Disease Surveillance Point System in 1980, to generate cause specific mortality statistics from a nationally representative sample of sites. Currently, the sample consists of 145 urban and rural sites, covering populations from 30,000 - 70,000, and a total of about 1 % of the national population. Causes of death are derived through a mix of medical certification and 'verbal autopsy' procedures, applied according to standard guidelines in all sites. Periodic evaluations for completeness of registration are conducted, with subsequent corrections for under reporting of deaths. Conclusion: Results from the DSP have been used to inform health policy at national, regional and global levels. There remains a need to critically validate the information on causes of death, and a detailed validation exercise on these aspects is currently underway. In general, such sample based mortality registration systems hold much promise as models for rapidly improving knowledge about levels and causes of mortality in other low-income populations

Silver-Based Radical Reactions: Development and Insights

Silver-mediated reactions have recently emerged as a frontier area in organic chemistry. Indeed, the remarkable property of silver as a single- electron oxidant has led to its exploitment into the field of radical chemistry. The excellent reactivity and high selectivity exhibited by silver salts in the ac- tivation of different organic substrates place them among the most prominent reagents in free radical reactions. The present review aims to provide the readers with a critical overview of silver-based radi- cal reactions, especially emphasizing the reactivity, selectivity and a detailed description of the reaction mechanism with particular attention to the role of Ag(I)-based catalysts/reactants. The selected exam- ples have been classified according to the type of radicals generated, namely carbon-centered radicals and heteroatom (such as nitrogen, oxygen, phospho- rus, sulfur)-centered radicals. The generation of such radicals as well as their application in synthetic pro- cesses including oxidation, addition, coupling, and radical cascades have been described in detail