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Methyl vinyl silicone rubber (VMQ) composites were prepared by blending chopped carbon fiber (CF), silica and VMQ with carbon fiber cloth (CFC). The effects of the layer number of CFC on the tensile properties, Shore A hardness, wear resistance and dynamic mechanical properties of the composites were investigated. The results showed that the elongation at break of the composites was basically unchanged and the tensile strength increased with the increasing layer number of CFC. Compared with the composites with only 10 phr (mass,the same below)of CF, the tensile strength of the composites with 10 phr of CF and 4 layers of CFC increased by 409%. The friction coefficients of the composites had little difference. And compared with the samples without CF and CFC, the wear of the composites with 10 phr of CF and 3 layers of CFC increased by 168%. The loss factor of VMQ compo-sites increased with increasing frequency. Compared with the samples without CF and CFC, the loss factor of VMQ composites with 10 phr CF only increased from 0.120 to 0.151.

Context The relationship between the components of particulate matter with an aerodynamic diameter of 2.5 or less (PM2.5) and bone strength remains unclear. Objective Based on a large-scale epidemiologic survey, we investigated the individual and combined associations of PM2.5 and its components with bone strength. Methods A total of 65 906 individuals aged 30 to 79 years were derived from the China Multi-Ethnic Cohort Annual average concentrations of PM2.5 and its components were estimated using satellite remote sensing and chemical transport models. Bone strength was expressed by the calcaneus quantitative ultrasound index (QUI) measured by quantitative ultrasound. The logistic regression model and weighted quantile sum method were used to estimate the associations of single and joint exposure to PM2.5 and its components with QUI, respectively. Results Our analysis shows that per-SD increase (μg/m3) in 3-year average concentrations of PM2.5 (mean difference [MD] −7.38; 95% CI, −8.35 to −6.41), black carbon (−7.91; −8.90 to −6.92), ammonium (−8.35; −9.37 to −7.34), nitrate (−8.73; −9.80 to −7.66), organic matter (−4.70; −5.77 to −3.64), and soil particles (−5.12; −6.10 to −4.15) were negatively associated with QUI. In addition, these associations were more pronounced in men, and people older than 65 years with a history of smoking and chronic alcohol consumption. Conclusion We found that long-term exposure to PM2.5 and its components may lead to reduced bone strength, suggesting that PM2.5 and its components may potentially increase the risk of osteoporosis and even fracture. Nitrate may be responsible for increasing its risk to a greater extent. [ABSTRACT FROM AUTHOR]

Objective: Association between particulate matter with aerodynamic diameters ≤2.5 μm (PM2.5) components and diabetes remains unclear. We therefore aimed to investigate the associations of long-term exposure to PM2.5 components with diabetes.Research Design and Methods: This study included 69,210 adults with no history of diabetes from a large-scale epidemiologic survey in Southwest China from 2018 to 2019. The annual average concentrations of PM2.5 and its components were estimated using satellite remote sensing and chemical transport modeling. Diabetes was identified as fasting plasma glucose ≥7.0 mmol/L (126 mg/dL) or hemoglobin A1c ≥48 mmol/mol (6.5%). The logistic regression model and weighted quantile sum method were used to estimate the associations of single and joint exposure to PM2.5 and its components with diabetes, respectively.Results: Per-SD increases in the 3-year average concentrations of PM2.5 (odds ratio [OR] 1.08, 95% CI 1.01-1.15), black carbon (BC; 1.07, 1.01-1.15), ammonium (1.07, 1.00-1.14), nitrate (1.08, 1.01-1.16), organic matter (OM; 1.09, 1.02-1.16), and soil particles (SOIL; 1.09, 1.02-1.17) were positively associated with diabetes. The associations were stronger in those ≥65 years. Joint exposure to PM2.5 and its components was positively associated with diabetes (OR 1.04, 95% CI 1.01-1.07). The estimated weight of OM was the largest among PM2.5 and its components.Conclusions: Long-term exposure to BC, nitrate, ammonium, OM, and SOIL is positively associated with diabetes. Moreover, OM might be the most responsible for the relationship between PM2.5 and diabetes. This study adds to the evidence of a PM2.5-diabetes association and suggests controlling sources of OM to curb the burden of PM2.5-related diabetes. [ABSTRACT FROM AUTHOR]

The aim of the present study was to perform genetic diversity and population structure estimation on 382 individuals from seven Chinese Tibetan ecotype yak population using twenty-one microsatellites. The results revealed that the HO ranged from 0.4854±0.0194 in NNV to 0.6086±0.0267 in YRY, and the NA ranged from 3.86±1.98 in XMY to 6.05±3.37 in NNV. The least number of markers which deviated from Hardy-Weinberg equilibrium within the population was W, and largest number of deviations was in the NNV population. Consistent of phylogenetic relationships between the seven populations was identified by Phylogenetic N-J network (Reynold’s genetic distance), FST and Principal components factor (PCA) analysis. These analyses inferred that the population cluster data was not only consistent with the populations’ geographic habits but could also be influenced by artificial selection and feeding style. Lastly, two credible genetic backgrounds were identified from the yak populations in this study using STRUCTURE software, which corresponded to previous knowledge about different molecular genetic markers. Therefore, unexpectedly, our study indicated that the diversity of some of the populations was decreased, leaving us to improve and refine our conversional strategy. In addition, this resulted in a greater understanding of human yak phylogenetic differentiation as well as providing data support for understanding the evolution and migration of yak population in future studies. [ABSTRACT FROM AUTHOR]

Brucellosis is considered as an endemic disease in yaks (Bos grunniens) in China, but few economic analyses describing the cost of the disease and potential benefits of control have been reported. The aim of the study was to estimate the economic cost of brucellosis in yaks and the economic value of three control strategies: (a) vaccination; (b) test‐and‐slaughter; and (c) a combination of vaccination and test‐and‐slaughter programs in Damxung and Maizhokunggar counties and Pali township of Yadong county in Tibet. Using data from a cross‐sectional seroprevalence survey conducted in 2015, combined with financial data, the predicted costs and benefits of the different control strategies were simulated over a 6‐year period. The annual estimated cost of brucellosis in yaks within the study area was US$ 521,043 (95% CI: US$ 334,441; US$ 759,862), with an annual average cost per yak estimated at US$ 1.42 (95% CI: US$ 0.91, US$ 2.07). The benefit‐cost analysis predicted that vaccination was the most effective control method with a benefit‐cost ratio (BCR) of 3.19 (95% CI: 2.17, 4.66) and a net present value (NPV) of US$ 313,355 (95% CI: US$ 157,679, US$ 541,062) over a 6‐year period. A sensitivity analysis found the NPV was most sensitive to the loss from a female yak aborting in the vaccination control program. In contrast, the price of yaks that were slaughtered had the largest influence on the NPV for both the test‐and‐slaughter control program and the combination control program. These estimates provide valuable information and establish a foundation for formulating and implementing cost‐effective measures for controlling the disease in yaks on the Tibetan plateau, and more broadly in China. [ABSTRACT FROM AUTHOR]