目的:探讨大气污染物和绿地暴露对初治结核病患者治疗期间病亡率的影响,从环境监测层面上为结核病患者的健康管理提供科学依据。方法:收集安徽省合肥市、淮南市、黄山市2015年1月1日至2020年12月31日的29519例初治结核病患者的数据。通...目的:探讨大气污染物和绿地暴露对初治结核病患者治疗期间病亡率的影响,从环境监测层面上为结核病患者的健康管理提供科学依据。方法:收集安徽省合肥市、淮南市、黄山市2015年1月1日至2020年12月31日的29519例初治结核病患者的数据。通过环境监测站收集大气污染物细颗粒物[空气动力学直径≤2.5μm的颗粒(particulate matter with an aerodynamic diameter≤2.5μm,PM_(2.5))]、可吸入颗粒物[空气动力学直径≤10μm的颗粒(particulate matter with an aerodynamic diameter≤10μm,PM_(10))]、一氧化碳(CO)、二氧化氮(NO_(2))数据。应用Cox比例风险模型计算大气污染物暴露与初治结核病患者病亡率的风险比(HR)及其95%置信区间(95%CI),同时结合绿地暴露进行亚组分析。结果:29519例结核病患者中,有369例(1.25%)在治疗期间死亡。多因素Cox回归分析结果显示,PM_(2.5)每增加10μg/m^(3),患者的死亡风险上升15.6%(HR=1.156,95%CI:1.146~1.165),PM_(10)每增加10μg/m^(3),患者的死亡风险上升18.3%(HR=1.183,95%CI:1.176~1.190),CO每增加0.10 mg/m^(3),患者的死亡风险上升6.7%(HR=1.067,95%CI:1.060~1.074),NO_(2)每增加10μg/m^(3),患者的死亡风险上升2.8%(HR=1.028,95%CI:1.019~1.037)。将绿地暴露按照四分位数(Q_(1)~Q_(4))由低到高进行分组后,大气污染物对病亡率的影响随绿地暴露的提升逐渐降低[以PM_(2.5)为例,其在250 m和500 m缓冲区归一化植被指数对病亡率的HR值,Q_(1)分别为1.218(95%CI:1.197~1.240)和1.231(95%CI:1.210~1.253),Q_(4)分别下降至1.125(95%CI:1.106~1.146)和1.138(95%CI:1.118~1.159)]。结论:大气污染物暴露是初治结核病患者治疗期间的危险因素,更高的绿化程度能够降低因暴露于大气污染物所导致的死亡风险。展开更多
In order to further improve the strength and the thermal shock resistance of Al_(2)O_(3)-C materials for steel ladle slide gates,the effects of four kinds of alumina micropowders(unimodal activated alumina micropowder...In order to further improve the strength and the thermal shock resistance of Al_(2)O_(3)-C materials for steel ladle slide gates,the effects of four kinds of alumina micropowders(unimodal activated alumina micropowder 07RAL,unimodal activated alumina micropowder 15RA,bimodal activated alumina micropowder 22RABL,and calcined alumina micropowder 40CA)on the density,the strength and the thermal shock resistance of Al_(2)O_(3)-C materials were studied.The results show that the density,the strength and the thermal shock resistance of Al_(2)O_(3)-C materials can be improved with the introduction of activated alumina micropowders.Among them,the specimen with bimodal activated alumina micropowder shows the best comprehensive performance,especially the hot modulus of rupture.Its actual application results in steel mills show that the average service life of the Al_(2)O_(3)-C slide plates prolongs,and the problems of cast hole reaming,plate oxidation,roughening and cracking during the use of slide plates are obviously improved.展开更多
文摘目的:探讨大气污染物和绿地暴露对初治结核病患者治疗期间病亡率的影响,从环境监测层面上为结核病患者的健康管理提供科学依据。方法:收集安徽省合肥市、淮南市、黄山市2015年1月1日至2020年12月31日的29519例初治结核病患者的数据。通过环境监测站收集大气污染物细颗粒物[空气动力学直径≤2.5μm的颗粒(particulate matter with an aerodynamic diameter≤2.5μm,PM_(2.5))]、可吸入颗粒物[空气动力学直径≤10μm的颗粒(particulate matter with an aerodynamic diameter≤10μm,PM_(10))]、一氧化碳(CO)、二氧化氮(NO_(2))数据。应用Cox比例风险模型计算大气污染物暴露与初治结核病患者病亡率的风险比(HR)及其95%置信区间(95%CI),同时结合绿地暴露进行亚组分析。结果:29519例结核病患者中,有369例(1.25%)在治疗期间死亡。多因素Cox回归分析结果显示,PM_(2.5)每增加10μg/m^(3),患者的死亡风险上升15.6%(HR=1.156,95%CI:1.146~1.165),PM_(10)每增加10μg/m^(3),患者的死亡风险上升18.3%(HR=1.183,95%CI:1.176~1.190),CO每增加0.10 mg/m^(3),患者的死亡风险上升6.7%(HR=1.067,95%CI:1.060~1.074),NO_(2)每增加10μg/m^(3),患者的死亡风险上升2.8%(HR=1.028,95%CI:1.019~1.037)。将绿地暴露按照四分位数(Q_(1)~Q_(4))由低到高进行分组后,大气污染物对病亡率的影响随绿地暴露的提升逐渐降低[以PM_(2.5)为例,其在250 m和500 m缓冲区归一化植被指数对病亡率的HR值,Q_(1)分别为1.218(95%CI:1.197~1.240)和1.231(95%CI:1.210~1.253),Q_(4)分别下降至1.125(95%CI:1.106~1.146)和1.138(95%CI:1.118~1.159)]。结论:大气污染物暴露是初治结核病患者治疗期间的危险因素,更高的绿化程度能够降低因暴露于大气污染物所导致的死亡风险。
文摘In order to further improve the strength and the thermal shock resistance of Al_(2)O_(3)-C materials for steel ladle slide gates,the effects of four kinds of alumina micropowders(unimodal activated alumina micropowder 07RAL,unimodal activated alumina micropowder 15RA,bimodal activated alumina micropowder 22RABL,and calcined alumina micropowder 40CA)on the density,the strength and the thermal shock resistance of Al_(2)O_(3)-C materials were studied.The results show that the density,the strength and the thermal shock resistance of Al_(2)O_(3)-C materials can be improved with the introduction of activated alumina micropowders.Among them,the specimen with bimodal activated alumina micropowder shows the best comprehensive performance,especially the hot modulus of rupture.Its actual application results in steel mills show that the average service life of the Al_(2)O_(3)-C slide plates prolongs,and the problems of cast hole reaming,plate oxidation,roughening and cracking during the use of slide plates are obviously improved.
