Growing studies have linked metal exposure to diabetes risk.However,these studies had inconsistent results.We used a multiple linear regression model to investigate the sexspecific and dose-response associations betwe...Growing studies have linked metal exposure to diabetes risk.However,these studies had inconsistent results.We used a multiple linear regression model to investigate the sexspecific and dose-response associations between urinary metals(cobalt(Co)and molybdenum(Mo))and diabetes-related indicators(fasting plasma glucose(FPG),hemoglobin A1c(HbA1c),homeostasis model assessment for insulin resistance(HOMA-IR),and insulin)in a cross-sectional study based on the United States National Health and Nutrition Examination Survey.The urinary metal concentrations of 1423 eligible individuals were stratified on the basis of the quartile distribution.Our results showed that the urinary Co level in males at the fourth quartile(Q4)was strongly correlated with increased FPG(β=0.61,95%CI:0.17–1.04),HbA1c(β=0.31,95%CI:0.09–0.54),insulin(β=8.18,95%CI:2.84–13.52),and HOMA–IR(β=3.42,95%CI:1.40–5.44)when compared with first quartile(Q1).High urinary Mo levels(Q4 vs.Q1)were associated with elevated FPG(β=0.46,95%CI:0.17–0.75)and HbA1c(β=0.27,95%CI:0.11–0.42)in the overall population.Positive linear dose-response associations were observed between urinary Co and insulin(Pnonlinear=0.513)and HOMA–IR(Pnonlinear=0.736)in males,as well as a positive linear dose-response relationship between urinary Mo and FPG(Pnonlinear=0.826)and HbA1c(Pnonlinear=0.376)in the overall population.Significant sex-specific and dose-response relationships were observed between urinary metals(Co and Mo)and diabetes-related indicators,and the potential mechanisms should be further investigated.展开更多
The cobalt-based alloy coating with different Co contents was deposited on 45 steel by electro-spark deposition with the self-made electrode. The coating has a compact and uniform microstructure with low porosity and ...The cobalt-based alloy coating with different Co contents was deposited on 45 steel by electro-spark deposition with the self-made electrode. The coating has a compact and uniform microstructure with low porosity and no visible microcracks. When Co content increases grad- ually, oxygen content of coating samples 1-5 decreases first and then increases in the range of 2.52 wt%-3.05 wt%; sample 3 has the lowest oxygen content of 2.52 %. Mi- crohardness of the coating is improved remarkably com- pared with the substrate （HV 230.18）. With Co content increasing, microhardness of the coating samples 1-5 first rises slightly and then declines rapidly in the range of HV 580.61-1052.33. Sample 3 gets the maximum of HV 1052.33, which is about 4.6 times that of the substrate. The coating presents excellent wear resistance, which first increases and then decreases when Co content increases. Sample 3 shows the best wear resistance of about 6.4 times that of the substrate. Main wear mechanism of the coating is abrasive wear and fatigue wear, along with oxidation wear under high speed or heavy load conditions.展开更多
文摘采用离子注入法对生物医用 Ti Ni形状记忆合金及二种 Co合金进行表面改性 ,利用电化学测试技术、动态凝血时间及溶血率的测量 ,研究了改性前后合金的耐蚀性及血液相容性 .结果表明 ,离子注入后合金的电化学稳定性显著提高 ,阳极极化性能变优 .对 Ti Ni、Co Cr Ni W和 Co Cr Ni Mo合金分别进行 Mo +C和 Ti+C双离子注入后 ,表面改性合金的腐蚀电位升高 2 0 0 m V以上 ,维钝电流密度减小 ,钝化区拓宽 ;合金的凝血时间延长 ,溶血率下降 ,说明离子注入提高了合金的耐蚀性及血液相容性 ,其中双离子注入较单离子注入效果更为显著 .对双离子注入合金进行 X射线衍射分析发现 ,在 Ti Ni合金表面主要形成了 Ti C相及少量 Ti O、Mo2 C、Mo9Ti4 及 Mo,在 Co合金表面主要为 Co Cx和 Co3Ti及少量 Ti C、Ti O相 .这些相弥散分布在合金表面 ,形成无序膜层 ,阻止了合金元素溶解 ,改善了合金的耐蚀性及血液相容性 .
基金supported by the National Institutes of Health (U.S.)-(NIH Grant Number: 1R01ES029082)
文摘Growing studies have linked metal exposure to diabetes risk.However,these studies had inconsistent results.We used a multiple linear regression model to investigate the sexspecific and dose-response associations between urinary metals(cobalt(Co)and molybdenum(Mo))and diabetes-related indicators(fasting plasma glucose(FPG),hemoglobin A1c(HbA1c),homeostasis model assessment for insulin resistance(HOMA-IR),and insulin)in a cross-sectional study based on the United States National Health and Nutrition Examination Survey.The urinary metal concentrations of 1423 eligible individuals were stratified on the basis of the quartile distribution.Our results showed that the urinary Co level in males at the fourth quartile(Q4)was strongly correlated with increased FPG(β=0.61,95%CI:0.17–1.04),HbA1c(β=0.31,95%CI:0.09–0.54),insulin(β=8.18,95%CI:2.84–13.52),and HOMA–IR(β=3.42,95%CI:1.40–5.44)when compared with first quartile(Q1).High urinary Mo levels(Q4 vs.Q1)were associated with elevated FPG(β=0.46,95%CI:0.17–0.75)and HbA1c(β=0.27,95%CI:0.11–0.42)in the overall population.Positive linear dose-response associations were observed between urinary Co and insulin(Pnonlinear=0.513)and HOMA–IR(Pnonlinear=0.736)in males,as well as a positive linear dose-response relationship between urinary Mo and FPG(Pnonlinear=0.826)and HbA1c(Pnonlinear=0.376)in the overall population.Significant sex-specific and dose-response relationships were observed between urinary metals(Co and Mo)and diabetes-related indicators,and the potential mechanisms should be further investigated.
基金financially supported by the National Natural Science Foundation of China (No. 50875261)
文摘The cobalt-based alloy coating with different Co contents was deposited on 45 steel by electro-spark deposition with the self-made electrode. The coating has a compact and uniform microstructure with low porosity and no visible microcracks. When Co content increases grad- ually, oxygen content of coating samples 1-5 decreases first and then increases in the range of 2.52 wt%-3.05 wt%; sample 3 has the lowest oxygen content of 2.52 %. Mi- crohardness of the coating is improved remarkably com- pared with the substrate （HV 230.18）. With Co content increasing, microhardness of the coating samples 1-5 first rises slightly and then declines rapidly in the range of HV 580.61-1052.33. Sample 3 gets the maximum of HV 1052.33, which is about 4.6 times that of the substrate. The coating presents excellent wear resistance, which first increases and then decreases when Co content increases. Sample 3 shows the best wear resistance of about 6.4 times that of the substrate. Main wear mechanism of the coating is abrasive wear and fatigue wear, along with oxidation wear under high speed or heavy load conditions.
