ObjectiveTo examine the associations of blood pressure with all cause mortality and cause specific mortality at three years among oldest old people in China.DesignCommunity based, longitudinal prospective study.Setting2011 and 2014 waves of the Chinese Longitudinal Healthy Longevity Survey, conducted in 22 Chinese provinces.Participants4658 oldest old individuals (mean age 92.1 years).Main outcome measuresAll cause mortality and cause specific mortality assessed at three year follow-up.Results1997 deaths were recorded at three year follow-up. U shaped associations of mortality with systolic blood pressure, mean arterial pressure, and pulse pressure were identified; values of 143.5 mm Hg, 101 mm Hg, and 66 mm Hg conferred the minimum mortality risk, respectively. After adjustment for covariates, the U shaped association remained only for systolic blood pressure (minimum mortality risk at 129 mm Hg). Compared with a systolic blood pressure value of 129 mm Hg, risk of all cause mortality decreased for values lower than 107 mm Hg (from 1.47 (95% confidence interval 1.01 to 2.17) to 1.08 (1.01 to 1.17)), and increased for values greater than 154 mm Hg (from 1.08 (1.01 to 1.17) to 1.27 (1.02 to 1.58)). In the cause specific analysis, compared with a middle range of systolic blood pressure (107-154 mm Hg), higher values (>154 mm Hg) were associated with a higher risk of cardiovascular mortality (adjusted hazard ratio 1.51 (95% confidence interval 1.12 to 2.02)); lower values (<107 mm Hg) were associated with a higher risk of non-cardiovascular mortality (1.58 (1.26 to 1.98)). The U shaped associations remained in sensitivity and subgroup analyses.ConclusionsThis study indicates a U shaped association between systolic blood pressure and all cause mortality at three years among oldest old people in China. This association could be explained by the finding that higher systolic blood pressure predicted a higher risk of death from cardiovascular disease, and that lower systolic blood pressure predicted a higher risk of death from non-cardiovascular causes. These results emphasise the importance of revisiting blood pressure management or establishing specific guidelines for management among oldest old individuals.

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Powder mixed near dry electrical discharge machining (PMND-EDM), which uses gas-liquid-powder mixture as three phase dielectric medium to remove materials, is proposed. Compared with dry EDM, much higher material removal rate (MRR) is achieved in PMND-EDM. The mechanism of PMND-EDM is analyzed and reasons for its MRR improvement are illustrated. Comparative experiment is done in compressed air and three phase dielectric medium, respectively. MRR is calculated. And discharge voltage waveforms are obtained by oscilloscope. It is shown that three phase dielectric medium can improve MRR effectively.

This paper introduced the machinability and the state-of-art of Ti6Al4V machining. Turning test with thee different tungsten carbide tool have be done at cutting speed 40, 80, 120, 160 m/min, the relationship between cutting force and cutting speed, cutting distance was analyzed, the influence of working cutting edge angle on the tool wear and cutting force was investigated as well. Finally, the tool wear and wear mechanics was analyzed.

A novel metal-organic frameworks (MOFs), {[Ho (ox)1.5(H2O)3] ·CH3OH·(C2N2H6)0.5}n, has been hydrothermally synthesized and characterized by single-crystal X-ray diffraction, IR analyses, elemental analysis. The complex crystallizes in the monoclinic system with theP21/c space group. The metal ion is nine-coordinate and connected by oxalate to form 2D honeycomb-like structure.