PM2.5/O3暴露损伤细胞及线粒体的分子调控机制差异

流行性病学研究表明,PM_2.5和O₃均与一些不良健康结局相关,如心肺、神经系统等相关疾病。在健康结局层面,PM_2.5和O₃的暴露效果具有一定的相似性。然而,PM_2.5/O₃的理化性质具有显著差异：PM_2.5是分散在大气中呈固态或液态的颗粒物;而O₃是具有强氧化性质的气体。生物体对不同性质的干扰有不同的防御及反应机制,故推测二者导致疾病发生的过程及分子调控机制可能存在差异。体外实验综述表明,氧化应激是PM_2.5及O₃造成损伤的重要机制。在细胞层面,PM_2.5主要通过诱导细胞内自噬相关的炎症反应发挥作用;而O₃通过攻击细胞膜上不饱和结构导致膜损伤。线粒体产能过程伴随着活性氧（ROS）的产生。当外界环境变化,细胞内的ROS平衡被打破,进而导致线粒体损伤。线粒体在细胞发育、代谢、信号传导及细胞命运调控等方面起着关键作用。近年来在线粒体层面的研究表明,PM_2.5暴露可引起细胞内离子变化,诱导与线粒体相关的生理变化;而O₃作为氧化分子直接损伤线粒体。本文综述了PM_2.5/O₃暴露导致的线粒体结构、功能、线粒体DNA（mtDNA）及相关信号通路的损伤机制,进一步探讨了二者在健康结局和疾病发生中的异同。通过阐明PM_2.5/O₃对线粒体及细胞损伤的机制,本文为大气污染相关疾病的预防和诊断提供了新的思路和研究方向。     

农作物病虫害气象环境成因研究进展

简要概述了近年来农作物病虫害气象环境成因研究方面的最新进展,包括农作物病虫害发生流行的气候背景指示及其影响机制、与气象条件的关系和气候变化对病虫害发生流行的可能影响等.结果表明:海温、厄尔尼诺事件、大气环流等大尺度因子对病虫害的发生流行具有明显的前兆性指示;温度、湿度、降雨、风、光照等气象要素,对促进或抑制某种病虫害的发生、发展、流行及其危害程度都可能产生显著的影响;气候变化可能造成病虫害危害的地理范围扩大,程度加剧.     

园林工人割灌作业职业性肌肉骨骼疾患的工效学研究

职业性肌肉骨骼疾患是园林工人的常见职业病,严重影响园林工人的工作效率和身体健康。对18名从事园林割灌作业的工人通过NMQ北欧肌肉骨骼系统问卷调查表进行调查,统计得出园林割灌作业的下背痛患病率约在60%左右,从事割灌整枝作业工人下背痛患病率为25%,从事割草作业下背痛患病率达444%,割草作业的下背痛患病率明显高于割灌整枝操作者。应用SPSS190软件进行下背痛的危害因子分析,得出下背痛的发生主要与重复动作、工龄、日提举负荷等有关。     

改进有毒作业分级方法在工业企业中的应用

介绍了有毒作业分级(GB12331-90)存在的问题,并提出了相应的改进措施。针对工业企业中存在的有毒作业危害,以某汽车工业企业为例,采用改良后的有毒作业分级方法对企业中各岗位进行分析,确定各岗位职业病危害因素及危险程度大小。通过理论分析和实例应用,证明该方法工作量小,计算结果可靠,使职业危害的预防和控制更具针对性,有很强的实用性。     

煤矿工人常见的呼吸系统疾病及防护

文章介绍了煤矿工人常见的呼吸系统疾病,并从加强职业安全卫生监督、改革工艺、宣传教育、定期体检等多个方面提出了干预措施,为今后保障煤炭工人的健康提出科学依据。     

土层锚杆的常见病害及防治对策研究

为了深入研究土层锚杆可能出现的各种病害及原因,有针对性地提出防治措施,进行了室内模型试验.根据试验结果分析了在水的作用下土层锚杆破坏时的应力传递过程,提出土层锚杆发生破坏时所遵循的逐次破坏的突破观点.首先失效的是坡顶锚杆,其次是坡脚的锚杆,最后才是坡体中部的锚杆.并对破坏时土层锚杆发生的6种病害形式进行了详细论述及原因分析: 灌浆体和土体界面的破坏、土体的破坏、锥体-黏结复合破坏、锥体破坏、灌浆体的拉裂和压碎、灌浆体与杆体之间的黏结破坏.在综合分析的基础上,提出了土层锚杆常见病害防治的几个关键性对策.     

First-trimester prenatal diagnosis in twin pregnancies

Two twin pregnancies at risk for a sex-linked disorder are described. Both pregnancies were dichorionic. Transabdominal sampling was chosen for prenatal diagnosis. Molecular genetic techniques raised suspicion with regard to the accuracy of the samples in one case. Second-trimester amniocentesis confirmed the error. Selective feticide of the affected fetus was performed. When first-trimester prenatal diagnosis is offered in dichorionic twin pregnancies, confirmation through molecular genetic testing can confirm that villi have been obtained from different fetuses. All parties must be aware that additional invasive diagnostic procedures in the second trimester may be required in cases of doubt.     

Fetal two-dimensional doppler echocardiography (colour flow mapping) and its place in prenatal diagnosis

One hundred and fifty fetuses between 16 and 38 weeks of gestation were studied by fetal echocardiography using colour-coded two-dimensional Doppler echocardiography. Two-dimensional, M-mode, and Doppler spectral analyses were also performed. In 14 fetuses, structural and/or functional abnormalities were detected. Abnormalities were correctly ruled out in all the other fetuses. The advantages of two-dimensional Doppler echocardiography are (1) rapid screening for flow abnormalities in the fetal heart, and thus shortening of the Doppler examination time; (2) rapid diagnosis of valvular regurgitation, valvular stenosis, and abnormal shunting of blood across the interatrial and interventricular septa; and (3) facilitation of the diagnosis of complex congenital heart defects which in certain cases is possible only by using two-dimensional Doppler echocardiography.     

最高气温对呼吸系统疾病急诊人次的影响研究

采用基于时间序列的半参数的广义相加模型,在控制星期几效应、长期趋势、气象要素等混杂因素后,分析2009~2012年北京市日最高气温与四类呼吸系统疾病急诊人次的暴露-反应关系,探讨日最高气温对人群健康的影响,并考虑了不同年龄和性别人群分层以及0~6d的滞后效应.结果表明：日最高气温对呼吸系统疾病急诊存在0~1d滞后效应,男性急诊人次均要高于女性;日最高气温每上升1℃,男性上呼吸道感染和支气管炎急诊人次分别增加2.10%和2.14%,女性肺炎、哮喘和支气管炎急诊人次分别增加2.00%、4.21%和2.95%.对性别而言,日最高气温每上升1℃,小于15岁人群支气管炎急诊人次增加3.60%;15~59岁人群支气管炎急诊人次增加2.16%;对60~74岁年龄段急诊人次无显著统计学意义;≥75岁人群肺炎和哮喘急诊人次分别增加2.69%和8.05%.     

Deceased co-twin as a cause of false positive amniotic fluid AFP and AChE

A pregnancy was terminated because of persistently elevated amniotic fluid AFP (+10 S.D.) and an AChE band of low intensity on gel electrophoresis. No fetal anomalies were detected by ultrasonographic examination. Autopsy revealed an apparently normal fetus of about 20 weeks gestation. Attached to the placenta was a small sac containing a fetus papyraceus co-twin of about 8–9 weeks gestation. The small deceased co-twin and its gestational sac were not detected prenatally despite multiple ultrasonographic examinations. The difficulty in the interpretation of apparently conflicting results is emphasized.