Prenatal diagnosis of congenital human cytomegalovirus infection

Fifteen fetuses at risk of congenital human cytomegalovirus (HCMV) infection underwent prenatal diagnosis at 16–30 weeks' gestation by a combination of amniocentesis and fetal blood sampling. HCMV was isolated from the amniotic fluid in six patients, but HCMV-specific IgM was detected in only three of them. Two of the nine neonates, who were delivered following a negative prenatal diagnosis, had congenital HCMV infection diagnosed by virus isolation in the urine. The interval from infection to prenatal testing was 3 and 4 weeks in the two false-negative cases and ⩾ 7 weeks in the true-positive cases. Although timely testing for HCMV infection allows the option of termination of pregnancy, it may be flawed by false-negative results.     

气田开发对环境的影响及减少措施

在天然气的开发过程中,钻井会造成地层结构、地貌和植被（或农作物）的破坏,采气会使地层压力下降,地层压力平衡状态被打破。西南油气分公司通过生产实践,详细探讨了钻井对环境的影响;天然气开采对地层的影响;气田水对环境的影响;SO2对环境的影响;井下作业废液对环境的影响;降低气田开发对环境影响的措施。     

杆状病毒在昆虫宿主内的感染途径及其复制

昆虫病毒的发现始于１６世纪,但直到本世纪５０年代,伴随着电子显微镜的发明,昆虫病毒学的研究才得到飞速发展．近年来,昆虫病毒学的研究已引起人们的高度重视,主要是因为：１．杆状病毒可做为载体,以表达外源基因;２．做为杀虫剂,可有效地控制农业病虫害的发生,...     

阿尔金山国家级自然保护区人为活动的影响简析

通过对阿尔金山国家级自然保护区生态环境现状的调查,分析了保护区内偷猎、采金以及过度放牧等人为活动对保护区生态环境退化的影响,并提出了解决问题的建议。     

Effect of alginic acid decomposing bacterium on the growth of Laminaria japonica (Phaeophyceae)

We collected the diseased blades of Larninaria japonica from Yantai Sea Farm from October to December 2002, and the alginic acid decomposing bacterium on the diseased blade was isolated and purified, and was identified as A lteromonas espejiana. This bacterium was applied as the causative pathogen to infect the blades of L. japonica under laboratory conditions. The aim of the present study was to identify the effects of the bacterium on the growth of L. japonica, and to find the possibly effective mechanism. Results showed that： （1）The blades of L.japonica exhibited symptoms of lesion,bleaching and deteriortion when infected by the bacterium. and their growth and photosynthesis were dramatically suppressed. At the same time, the reactive oxygen species （ROS） generation enhanced obviously, and the relative membrane permeability increased significantly. The contents of malonaldehyde （MDA） and free fatty acid in the microsomol membrane greatly elevated, but the phospholipid content decreased. Result suggested an obvious peroxidation and deesterrification in the blades of L. japonica when infected by the bacterium. （2） The simultaneous assay on the antioxidant enzyme activities demonstrated that superoxide dismutase （SOD） and catalase （CAT） increased greatly when infected by the bacterium, but glutathione peroxidase （Gpx） and ascorbate peroxidase （APX） did not exhibit active responses to the bacterium throughout the experiment. （3） The histomorphological observations gave a distinctive evidence of the severity of the lesions as well as the relative abundance in the bacterial population on the blades after infection. The bacterium firstly invaded into the endodermis of L. japonica and gathered around there, and then resulted in the membrane damage, cells corruption and ultimately, the death of L. japonica.     

纳氏试剂降低氨氮空白值影响因素探讨

纳氏试剂是光度法测定水中氨氮空白值影响的主要因素,纳氏试剂的质量由KI和HgCl2的比例决定。通过减少HgCl2用量试验,找到降低氨氮空白值的最佳方法,减少了分析误差,提高了测试准确性。分析指标符合水质技术要求,且节约了化学试剂,经济可行。     

呼吸道感染患儿血清微量元素的测定及其与抗体水平的关系

应用流动注射氢化物发生原子吸收光谱法（HGAAS）测定了呼吸道感染（RTI）患儿血清中Se和Pb,火焰原子吸收光谱法（AAS）测定Fe、Cu、Zn、Ca、Mg及Mn,光度法测定了P,以标准牛血清作质控,在最佳实验条件下,9种元素的精密度,检出限以及回收率均令人满意,根据患儿IgG,IgA,IgM补体C3及C4的测定结果,对测定方法及呼吸道感染与血清微量元素和抗体水平的关系进行了探讨,发现RTI患儿血清Se、Fe、Zn、Mn、Ca明显低于同龄正常儿童,且Ig、C3均与CK存在显著性差异。认为对RIT患儿有必要监测其血清微量元素水平。     

Under-Reporting of Accidents Involving Biological Material by Nursing Professionals at a Brazilian Emergency Hospital

Background. Pathogens can be transmitted to health professionals after contact with biological material. The exact number of infections deriving from these events is still unknown, due to the lack of systematic surveillance data and under-reporting. Methods. A cross-sectional study was carried out, involving 451 nursing professionals from a Brazilian tertiary emergency hospital between April and July 2009. Through an active search, cases of under-reporting of occupational accidents with biological material by the nursing team were identified by means of individual interviews. The Institutional Review Board approved the research project. Results. Over half of the professionals (237) had been victims of one or more accidents (425 in total) involving biological material, and 23.76% of the accidents had not been officially reported using an occupational accident report. Among the under-reported accidents, 53.47% were percutaneous and 67.33% were bloodborne. The main reason for nonreporting was that the accident had been considered low risk. Conclusions. The under-reporting rate (23.76%) was low in comparison with other studies, but most cases of exposure were high risk.     

Comparative assessment of primary and secondary infection risks in a norovirus outbreak using a household model simulation

Diarrheal diseases can be transmitted via both primary infection due to exposures to contaminated materials from the environment and secondary infection due to personto-person contacts. Usually, the importance of secondary infection is empirically assessed by fitting mathematical models to the epidemic curves. However, these empirical models may not be applicable to other epidemic cases because they are developed only for the target epidemics and they don't consider the detail routes of infection. In our previous study, we developed a theoretical model taking into account the various routes of infection that commonly occur in households(e.g., shaking hands, food handling, and changing diapers).This model was made flexible and applicable to any epidemics by means of adjusting model parameters. In this study, we proposed a new index "Vulnerability indicator to secondary infection(VISI)", which expressed a ratio of secondary infection to primary infection risks and calculated this index in a simulated norovirus(No V) epidemic that involved 10,000 households.The results demonstrated that households composed of more than three members including infant(s) had much higher levels of VISI(5–45) than two-member-households with VISI(0.1–4).These results concluded that the infants were likely to be a hub of secondary infections in highly dense families and therefore careful handling of diapers was deemed indispensible in such families to effectively control the secondary infections.