孕期PM10和PM2.5暴露对新生儿出生体质量的影响

目的 探讨母亲孕期PM₁₀和PM_2.5暴露与新生儿出生体质量的关系,并进一步确定孕期PM₁₀和PM_2.5暴露对新生儿出生体质量影响的关键窗口期。 方法 以济南市婴幼儿哮喘出生队列基线研究为基础,研究区域内的新生儿为研究对象,获取新生儿出生体质量。结合济南市区17个监测站的颗粒物监测数据、孕期母亲的居住地址经纬度及监测站地址经纬度,使用反距离权重法得到每位母亲孕期的逐日个体暴露浓度,获得每位母亲整个孕期和孕早期、孕中期、孕晚期的暴露浓度。结合广义相加模型与阴性对照暴露分析的方法探索孕期PM₁₀和PM_2.5暴露与新生儿出生体质量之间的关系,并将孕早期、孕中期和孕晚期的暴露情况同时纳入模型寻找关键窗口期。 结果 (1) 纳入4 602名研究对象,平均出生体质量为(3 420.98±465.27)g,母亲孕期PM₁₀和PM_2.5平均暴露浓度分别为114.15 μg/m³和54.71 μg/m³;(2) 整个孕期PM₁₀和PM_2.5暴露浓度每升高10 μg/m³,新生儿出生体质量分别减少30.46 g(P=0.013)和51.81 g(P=0.028);其阴性暴露对照期PM₁₀和PM_2.5暴露浓度与新生儿出生体质量变化之间关系均无统计学意义(PM₁₀: P=0.166; PM_2.5: P=0.650)。(3) 进一步分析结果显示,孕早期PM₁₀和PM_2.5暴露浓度每升高10 μg/m³,出生体质量分别降低11.56 g(P=0.004)和43.85 g(P<0.001)。孕晚期PM₁₀和PM_2.5暴露浓度每升高10 μg/m³,出生体质量分别降低13.09 g(P=0.001)和44.04 g(P<0.001)。 结论 母亲孕期大气PM₁₀和PM_2.5暴露会降低新生儿出生体质量,孕早期与孕晚期是其关键暴露窗口期。     

Dietary intake of total polyphenol and polyphenol classes and the risk of colorectal cancer in the European Prospective Investigation into Cancer and Nutrition (EPIC) cohort

Polyphenols may play a chemopreventive role in colorectal cancer (CRC); however, epidemiological evidence supporting a role for intake of individual polyphenol classes, other than flavonoids is insufficient. We evaluated the association between dietary intakes of total and individual classes and subclasses of polyphenols and CRC risk and its main subsites, colon and rectum, within the European Prospective Investigation into Cancer and Nutrition (EPIC) study. The cohort included 476,160 men and women from 10 European countries. During a mean follow-up of 14 years, there were 5991 incident CRC cases, of which 3897 were in the colon and 2094 were in the rectum. Polyphenol intake was estimated using validated centre/country specific dietary questionnaires and the Phenol-Explorer database. In multivariable-adjusted Cox regression models, a doubling in total dietary polyphenol intake was not associated with CRC risk in women (HR_log2?=?1.06, 95% CI 0.99–1.14) or in men (HR_log2?=?0.97, 95% CI 0.90–1.05), respectively. Phenolic acid intake, highly correlated with coffee consumption, was inversely associated with colon cancer in men (HR_log2?=?0.91, 95% CI 0.85–0.97) and positively associated with rectal cancer in women (HR_log2?=?1.10, 95% CI 1.02–1.19); although associations did not exceed the Bonferroni threshold for significance. Intake of other polyphenol classes was not related to colorectal, colon or rectal cancer risks. Our study suggests a possible inverse association between phenolic acid intake and colon cancer risk in men and positive with rectal cancer risk in women.     

男性心输出量参考值与地理环境的因子分析

目的为揭示中国成年男性心输出量正常参考值的地理分布规律,制定中国成年男性心输出量正常参考值的统一标准提供科学依据。方法收集了中国48个市（县）级医院和有关研究单位及高等院校测定的11794例正常人心输出量参考值,年龄在18至60岁之间成年男性的数据,应用SPSS17．0统计软件对数据处理,运用相关分析、因子分析及GIS软件,研究其与海拔、年日照时数、年平均气温等8项地理因素指标之间的关系。结果发现成年男子心输出量参考值与地理因素之间有显著的相关关系。利用因子分析及回归分析推导出一个回归方程：9—6．203—0．000007175X1—0．0001034X2＋0．009402X3＋0．004965X4＋0．00008485X5—0．009010X6—0．02415X7—0．004593X8±0．068（F=13．344,P=0．000）。在以上回归方程中,P是心输出量参考值（L）,X1是海拔高度（m）、X2是年日照时数（h）、X3是年平均气温（℃）、Xa是年平均相对湿度（％）、X5是年降水量（mL）、X6是气温年较差（℃）、X7是年平均风速（m／s）、X8是年日照百分率（％）,0．068是剩余标准差。借助GIS软件中的地统分析模块,通过克里格（kriging）插值法精确地内插出中国成年男性心输出量参考值的空间趋势分布图。站论如果要知道中国某地成年男性心输出量参考值,可以根据当地的海拔高度、年日照时数、年平均气温、年平均相对湿度、年降水量、气温年较差、年平均风速、年日照百分率,通过回归方程计算,即可获得该地的成年男性心输出量参考值。同时也可以通过中国成年男性心输出量参考值的空间趋势分布图得出中国任何地区的成年男性心输出量参考值。     

Efficient nebulisation of powdered antibiotics

Antibiotic aerosols have a role to play in the treatment of certain respiratory tract infections, but relatively viscous antibiotic solutions may be difficult to nebulise efficiently. Solutions of ceftazidime and colistin, made up by adding 3 ml diluent to powder, have been nebulised in vitro by 4 combinations of jet nebuliser and compressor in order to determine the most efficient apparatus for use with each substance. Nebulisation time, droplet size and drug output were determined. Droplet mass median diameters varied according to the type of nebuliser and compressor, but were confined to the range 3.2–5.0 μm throughout the studies. For colistin, DeVilbiss and Turret were both efficient nebulisers, and the use of the more powerful Maxi compressor reduced nebulisation time. For ceftazidime, Turret nebuliser with Maxi compressor was the most efficient system, while the “dead” solution volume retained within the DeVilbiss nebuliser was unacceptably high. These results emphasize the need for careful choice of nebuliser and compressor for use with antibiotic aerosols.