首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   37篇
  免费   0篇
综合类   31篇
污染及防治   1篇
评价与监测   2篇
社会与环境   3篇
  2018年   1篇
  2012年   2篇
  2010年   1篇
  2008年   1篇
  1998年   1篇
  1994年   1篇
  1985年   1篇
  1984年   1篇
  1981年   1篇
  1980年   2篇
  1969年   2篇
  1964年   2篇
  1961年   2篇
  1959年   2篇
  1958年   6篇
  1957年   3篇
  1955年   2篇
  1954年   1篇
  1953年   1篇
  1951年   1篇
  1941年   2篇
  1939年   1篇
排序方式: 共有37条查询结果,搜索用时 437 毫秒
11.
12.
13.
In this article, we investigate the changing role of the Danube river in relation to urban resource use, transport and land use for the case of nineteenth and early twentieth century Vienna. Vienna makes a good case study due to its geographical position as a continental city and its dynamic development of population numbers and transport infrastructure in the nineteenth century. We trace the amount of energy used in the city and identify a shift from a biomass-based energy supply to the large-scale use of coal. Along with this shift went a change in the Danube??s role as transport route: while until the 1870s, the Danube was the most important freight transport route, river transport lost importance after the great Danube regulation in 1875, and the railway took over. The river was the most important route for providing fuel wood well into the nineteenth century: Vienna drew wood from remote areas situated upstream along the Danube to the West of the city. Only after the railway connection to Northern coal deposits in the 1850s could Vienna??s energy base shift to coal. Finally, we investigate how land use in the city was affected by resource consumption and the river regulation. Wood use around the city was subject to legislative protection and was only little affected by Vienna??s resource demand. On the other hand, the Danube river regulation heavily impacted urban land use by supplying new areas suitable for settlement expansion.  相似文献   
14.
Contamination of amniotic fluid cell cultures by maternal cells can be expected to lead to misdiagnosis of fetal genotype in 0·1 to 0·5/100 cultures, when assays are carried out directly on cultured cells. Chemical analysis of the cell-free amniotic fluid supernatant may overcome this source of error and has the added advantages of speed and independence from amniotic cell culture failure. We describe a pregnancy at risk for Hurler's disease where amniotic cells cultured at amniocentesis had a female karyotype and an α-iduronidase activity towards both phenyl and 4-methylumbelliferyl substrates at the lower end of the normal range, suggesting a heterozygous fetus. An affected fetus was predicted, however, because of a high concentration of dermatan sulphate in the amniotic fluid. The discrepancy between these findings was shown to be due to maternal cell contamination of amniotic fluid cell cultures by the birth of a male infant with Hurler's disease.  相似文献   
15.
A case of low atresia of the ileum, diagnosed prenatally by real-time ultrasound scanning, is presented. The ultrasound examination showed progressive distension of intestinal loops, with strong peristaltic movements. The stomach was also distended, presenting as a large cystic area in the upper left abdomen. Real-time ultrasound technique is most advantageous in the diagnosis of fetal ileus. Prenatal diagnosis of fetal intestinal obstruction is of great importance, making early and safe treatment of the newborn possible.  相似文献   
16.
The perinatal outcome of 26 patients with confined placental mosaicism (CPM) detected in chorionic villus sampling (CVS) who wished to continue their pregnancies was compared with that of two controls per patient matched for age and parity (n=52). There were no significant differences in birth weight or gestational age at delivery between patients with CPM and controls. There were no cases of intrauterine growth retardation (IUGR) in the CPM patients as compared with two (2/52, 3·8 per cent) in the control group (P>0·05). There was no significant increase in fetal loss between the study group (1/26, 3·6 per cent) and the controls (1/52, 1·9 per cent) (P>0·05).  相似文献   
17.
18.
19.
20.
The use of antineoplastic drugs in health care steadily increases. Health care workers can be occupationally exposed to antineoplastic drugs classified as carcinogenic or teratogenic. Monitoring of surface contamination is a common way to assess occupational exposure to antineoplastic drugs, since wipe sampling is used as a surrogate measure of dermal exposure. Since no occupational limits for antineoplastic drugs in work environments exist, 'hygienic guidance values' (HGVs) should be used instead. HGVs are practicable, achievable levels, not health based, and can be calculated from exposure data from representative workplaces with good occupational hygiene practices. So far, guidance values for surface monitoring of antineoplastic drugs only exist for pharmacies where antineoplastic drugs are prepared. The objective was to propose HGVs for surface monitoring of cyclophosphamide (CP) and ifosfamide (IF) in Swedish hospitals where antineoplastic drugs are administered to patients. In total, 17 workplaces located at six hospitals in Sweden were surveyed by wipe sampling. Wipe samples were collected, worked up and then analyzed with liquid chromatography tandem mass spectrometry. Surface contamination of CP and IF was found on 80% and 73% of the sampled surfaces, thus indicating that there is potential for health care workers to be exposed to CP and IF via the skin. The median surface load of CP was 3.3 pg cm(-2) (range <0.05-10,800 pg cm(-2)). The corresponding value for IF was 4.2 pg cm(-2) (range <0.13-95,000 pg cm(-2)). The highest surface loads were found on the floors. The proposed HGVs were set at 90th percentile values, and can be applicable to hospital workplaces where patients are treated with CP or IF. Surface monitoring combined with HGVs is a useful tool for health care workers to regularly benchmark their own surface loads which could control and reduce the occupational exposure to CP and IF in hospital workplaces. Thus, the occupational safety of the health care workers will be increased.  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号