A total of 481,414 Korean participants aged 40-79 years at enrollment were examined. The hazard ratios for all-cause, all-cancer, and head and neck cancer mortality were analyzed using Cox proportional hazards models, which were adjusted for potential confounding factors. In the overall study population, the highest AST/ALT ratio level was significantly associated with risk of all-cause, all-cancer, and head and neck cancer mortality (p < 0.01). After excluding participants who died of all-cause, all-cancer, and head and neck cancer within five years of enrollment, the main results remained similar to those of the analysis of all deaths in the study population. These findings indicate that serum AST/ALT ratio is positively associated with an increased mortality risk in all-cause, all-cancer, and head and neck cancer.
Wide-area surface decontamination is essential in the emergency situation of release of radioisotopes to public such as nuclear accident or terrorist attack. Here, a self-generated hydrogel based on the reversible complex between poly (vinyl alcohol) (PVA) and phenylboronic acid-grafted poly (methyl vinyl ether-alt-mono-sodium maleate) (PBA-g-PVM-SM) was developed to remove the radioactive cesium from surface. Two aqueous polymeric solutions of PVA and PBA-g-PVM-SM containing sulfur-zeolite were simultaneously applied to surfaces, which subsequently self-generated a hydrogel based on the PBA-diol ester bond. The sulfur-zeolite suspended in hydrogel selectively remove the 137Cs from contaminated surface and easily separated from the dissociable used hydrogel by simple water rinsing. In radioactive tests, the resulting hydrogel containing sulfur-chabazite displayed high 137Cs removal efficiencies of 96.996% for painted cement and 63.404% for cement, which was 2.33 times higher than that of commercial strippable coating (Decongel). Considering the intrinsic various ion-exchange ability of zeolite, our hydrogel system has the excellent potential for the effective removal of various hazardous contamination including radionuclides from the surface.
In the manufacturing process the most widely used x chart has been applied to control the process mean. Also, Accelerated Life Test(ALT) is commonly used for efficient assurance of product life in development phases, which can be applied in production reliability acceptance test. When life data has lognormal distribution, through censored ALT design so that censored ALT data has asymptotic normal distribution, ALTx control chart integrating x chart and ALT procedure could be applied to control the mean of process in the manufacturing process. In the situation that process variation is controlled, Zp control chart is an effective method for the very small fraction nonconforming of quality characteristic. A simultaneous control scheme with ALTx control chart and Zp control chart is designed for the very small fraction nonconforming of product lifetime.
The paper presents the analysis of Accelerated Reliability Growth (ARG) process data during design and development on non repairable systems. A projection model has been developed which will compress testing time and also accelerate failure mechanisms in which all corrective actions are delayed until at the end of the test. In addition, time to failure in stress test do not have to be converted to time to failure in normal condition. By applying this model, it targets to save cost through speedier testing time and reducing number of prototypes needed. As a result, the total life cycle cost of product will be reduced.
This paper presents the log likelihood function for integrated models for ALT such as exponential-general Eyring, Weibull-temperature and specific heat, lognormal-temperature and specific heat. Additionally this paper estimates the system reliability and mean time to failure(MTTF) for series, parallel, k of n, and standby system using ALT linkage parameter. Lastly this study designs three variable reliability acceptance sampling(RAS) plans such as type I, II censored test, sequential test by the use of integrated models for ALT.