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11.
In 19 pregnancies at risk for 21-hydroxylase deficiency (21OHD) in 18 families with at lea one affected child, prenatal diagnosis was performed by RFLP analysis using the enzymi Taq I and EcoRI and the DNA probes specific for the 21 OH genes, the closely linke complement C4 genes and the highly polymorphic HLA class II genes DRB, DQB, and DPI For fetal DNA analysis either chorionic villi or cultivated amniotic cells were used. In all 1 cases, a clear prenatal diagnosis was possible either with the 21OH probe alone or in mo cases, by combining the results of the different closely linked loci.  相似文献   
12.
对汽车组装流水线作业工人的作业体位、人机测量、劳动状况和生产环境的调查结果表明,过分低头、向前弯腰、手抬高过肩、手抬高过头、长时间站立、工作时间率较高、工作场所照度不足以及噪声值超标可能是存在的主要工效学问题,是导致慢性肌肉骨骼损伤的重要因素,应根据有关标准和法规,采取相应的劳动保护和工效学改进措施  相似文献   
13.
Introduction. Most work-related musculoskeletal disorders (MSDs) are associated with improper postures and poorly designed workstations. This study is an attempt to examine the prevalence and severity of MSDs as well as anthropometric dimensions among city bus drivers. Methodology. This cross-sectional study was carried out on 60 male bus drivers. A body discomfort chart was used to evaluate MSDs. Spearman correlation was employed to examine the relationship between body size and the severity of discomfort. Results. Data analysis showed that discomfort reported in the lower back (33.3%), upper back (18.3%) and knee (15%) was severe and there was a direct and significant correlation between the body mass index and the severity of discomfort in the shoulder, arm and hip (p?p?Conclusion. The results of the study can be used to address ergonomic risk factors and reduce their associated disorders. The findings of the study can be used in training programs to educate drivers how to decrease the risk associated with work-related MSDs by adopting appropriate behavior strategies.  相似文献   
14.
This study investigates differences between male and female public office workers’ satisfaction levels, sick building syndrome (SBS) symptoms and musculoskeletal disorder (MSD) complaints in workplace and office environments. Questionnaire surveys were performed in 30 offices from 15 public institutions. Male and female workers of the same age were coupled and selected from each office, gathering a total of 120 male and 120 female subjects. The results show that differences exist between genders in noise and lighting satisfaction levels, SBS-related symptoms (eye, nose, skin) and MSD complaints of hand/wrist/finger, while there is no difference in overall satisfaction level of office environments. The study also suggests that office design for public office workers should take into account gender differences in preventing MSDs and also SBS. The findings of this study are expected to serve as basic data for designing effective public office environments.  相似文献   
15.
为了考察氮磷同时缺乏对活性污泥系统的影响,采用2个序批式间歇反应器(SBR),按照缺氧/好氧的方式平行运行,通过调节不同的进水COD/N/P比,考察了氮磷同时缺乏状态下活性污泥系统的污泥沉降性、絮体形态、出水水质以及比耗氧速率等方面的表现。结果表明,在氮磷同时缺乏时,当进水COD/N/P比为100/2/0.4时,活性污泥系统会发生丝状菌膨胀,而当进水COD/N/P为100/0.5/0.1时,污泥沉降性保持良好;各反应器的活性污泥浓度均在逐渐地下降,MLSS由约2200mg/L下降至1800mg/L以下;各反应器的比耗氧速率均呈现逐渐上升的趋势,COD的去除率呈现逐渐下降的趋势。  相似文献   
16.
低溶解氧和磷缺乏引发的非丝状菌污泥膨胀及控制   总被引:9,自引:2,他引:7  
针对污泥培养过程中出现的非丝状菌污泥膨胀,分析了发生膨胀后污泥的特征、性状及其降解污染物性能.反应器中低溶解氧浓度(0~0.7mg/L)和低P/BOD5值(0.78/100) 2种因素共同作用导致污泥膨胀.污泥胞外多聚糖含量越高,污泥憎水性越小,SVI也越高.通过提高溶解氧浓度和P/BOD5值,可使污泥沉降性能得到恢复.此外,向膨胀污泥中投加多孔填料,在不降低处理效能的情况下,很快使系统免受污泥沉降性能恶化的困扰,而向膨胀污泥中投加强氧化剂NaClO并不能有效控制污泥膨胀.  相似文献   
17.
大气气溶胶中碘形态研究进展   总被引:3,自引:0,他引:3  
徐思琦  谢周清  李冰 《环境科学》2010,31(5):1121-1129
大气中的碘直接影响对流层中多种光化学反应并间接影响全球气候变化,因而碘的大气化学机制研究受到越来越多关注.气溶胶中的碘是其大气化学反应的最终产物,通过其赋存形态可以推测和了解碘的大气化学过程.大气碘化学理论一直认为IO3-是大气碘沉降中最主要的碘形态,但近年来的各地实测数据发现大气气溶胶中的碘形态大多以可溶性有机碘或I-为主.这种分歧说明目前的大气碘化学理论尚有待完善.本文详细介绍了近年来碘的大气化学以及气溶胶颗粒物中碘形态的研究进展.  相似文献   
18.
废弃印刷线路板碘化法浸金研究   总被引:1,自引:0,他引:1  
针对碘化法从废弃印刷线路板中提取金的工艺设计,分别考察了碘的质量分数、n(I2)/n(I-)比值、固液比、双氧水的质量分数、pH值、浸出时间和浸出温度对金浸出率的影响。结合正交设计优化实验方法,提出了从废弃印刷线路板中碘化法浸取金的最佳工艺条件:碘的质量分数为1.1%,n(I2)∶n(I-)=1∶10,双氧水的质量分数为1.5%,浸出时间4 h,固液比为1∶10,浸出温度为常温(25℃),溶液pH值为中性,此时金浸出率可达97.5%。  相似文献   
19.
本文概述了植物的铁素营养、果材缺铁黄化病的诊断治疗方法,论述了高涌液注射法矫治果树缺铁黄化病的理论、假说、树木微型注射器、克黄灵高渗液、树干穴位注射法、树干穴位插管法及其应用前景。  相似文献   
20.
Due to rapid industrialization and urbanization during last two decades, contamination of soils by heavy metals is on an increase globally. Lands under peri-urban agriculture are the worst affected. In NCT, Delhi about 14.4% of land area is chemically degraded. In order to take care of this problem, recently the Supreme Court of India ordered to shift various non-confirming (about 39,000 units) industries to regions outside NCT, Delhi. However in spite of this, there have been several reports and parliamentary debates on the phyto-toxicity and extensive accumulation of heavy metals in the region. Literature review revealed that the basis of these debates is a few studies on some point locations in/around Delhi. It was further observed that information on the distribution and extent of heavy metal pollution problem in the region was completely missing. The present study was thus basically aimed at assessing the spatial distribution/extent and type of heavy metal pollution in the study area, for enabling future designing of appropriate site-specific management measures by the decision makers.For this, detailed spatial information on bio-available heavy metal concentrations in the soils and surface/sub-surface waters of NCT (Delhi) was generated through actual soil/water surveys, standard laboratory methods and GIS techniques. The study showed that concentration of all micronutrients (viz. Zn: 0.05–0.18 ppm; Cu: in traces; Fe: 0–0.5 ppm; and Mn: 0–1.2 ppm) and most heavy metals (viz. Ni: 0–0.7 ppm; Pb: 0–0.15 ppm and Cd: in traces) in the surface/sub-surface irrigation waters were well within permissible limits. However Cr concentrations in irrigation waters of Alipur and Shahdara blocks were far above their maximum permissible limit of 1 ppm. It was further observed that Ni and Cr concentrations in the drinking waters of almost entire test area were far above maximum permissible levels of 0.02 and 0.01 ppm, respectively. Bio-available concentrations of several heavy metals (viz. Pb: 0.1–2 ppm; Cd: traces; Ni: 0.05–2 ppm and Cr: 0–0.4 ppm) in the study area soils were also observed to be well within the maximum permissible limits. However there were point Cu contaminations (5–10 ppm) in the sewage-sludge amended soils of vegetable growing areas near south Shahdara block. This was attributed to increased Cu availability due to oxidized acidic conditions generated by over-irrigation of agricultural lands. Available Mn concentrations in Kanjhawala, western Najafgarh and Alipur soils were also observed to be above maximum permissible limit of 10 ppm. This was observed to be mainly due to the geology (i.e. presence of Mn rich sedimentary rocks) and prevalence of reduced acidic conditions, due to paddy cultivation, in these areas. It was further observed that there is acute zinc (Zn) deficiency (< 0.6 ppm) in paddy growing soils of north Kanjhawala, Alipur and some parts of Najafgarh and Shahdara blocks due to extensive leaching of available Zn fractions to lower soil horizons. Similar available Zn deficiencies in high pH (8.5) soils of areas around Bamnoli village in E-Najafgarh block were also observed.  相似文献   
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