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   92篇
  免费   4篇
  国内免费   4篇
  2022年   1篇
  2021年   4篇
  2020年   4篇
  2019年   2篇
  2018年   2篇
  2017年   2篇
  2016年   4篇
  2015年   3篇
  2014年   2篇
  2013年   5篇
  2012年   5篇
  2011年   3篇
  2010年   4篇
  2009年   4篇
  2008年   2篇
  2007年   5篇
  2006年   4篇
  2004年   6篇
  2003年   2篇
  2001年   2篇
  1998年   3篇
  1997年   2篇
  1996年   2篇
  1995年   1篇
  1993年   2篇
  1990年   1篇
  1982年   1篇
  1979年   1篇
  1978年   1篇
  1976年   1篇
  1973年   1篇
  1972年   1篇
  1971年   1篇
  1970年   1篇
  1968年   1篇
  1966年   1篇
  1964年   2篇
  1962年   1篇
  1955年   1篇
  1954年   4篇
  1950年   1篇
  1934年   1篇
  1916年   1篇
  1906年   1篇
  1905年   1篇
排序方式: 共有100条查询结果,搜索用时 15 毫秒
1.
Twenty-two patients with Parkinson''s disease were treated for the periods of up to six months with L-dopa. In nine of the male patients metabolic observations were made after oral administration of 14C-L-dopa.Peak serum levels of total radioactivity represented small fractions of the dose given and occurred at one to two hours after ingestion. Two-thirds of the dose was excreted as metabolites in urine in eight hours. Insignificant fractions of the dose were excreted in stool and expired air. These results indicate rapid and complete absorption from the gastrointestinal tract, as well as rapid distribution and excretion. Clinical observations confirmed that L-dopa is an effective treatment for Parkinson''s disease. Improvements in disability averaged 47% at 30 days, 55% at 50 days, and 60% at three months. Degree of improvement tended to be inversely related to age of patient, duration of illness, and severity of disease. Side-effects were seen in most patients, but were always reversible with dose reduction. Nausea was the chief dose-limiting side-effects in early therapy and choreoathetosis after two months of treatment. The average tolerated daily dose was 3 g. On the basis of this experience it seems that the drug can be used safely and effectively on an outpatient basis provided that dosage increments are introduced gradually, maximum dosage is limited to 4 g. a day, and supervision is both close and continuous.  相似文献   
2.
This is the first record of seed transmission of turnip yellow mosaic virus (TYMV) in oilseed and turnip rapes. The seed transmission of TYMV in a naturally infected winter turnip rape (Brassica napus var. silvestris) cultivar Perko PVH was investigated. By ELISA 1.6%, 3.2% and 8.3% seed transmission of the virus was found in seed of plants from three localities. The proportion of infected seeds produced by artificially infected plants of winter oilseed rape (Brassica napus ssp. oleifera) and winter turnip rape cultivars was determined. The virus transmission rate, expressed as the proportion of virus-infected plants which germinated from the seed was for the oilseed rape cvs Jet Neuf 0.1%, Solida 0.4%, Silesia 0.8%, Darmor 1.2%, SL-507 0.2%, SL-509 0.0% and for the winter turnip rape cv. Perko 1.5%. ELISA cannot be used in direct tests on bulk seed lots to estimate proportion of infected seed, but must be used on germinated seedlings.  相似文献   
3.
Supraorbital bones in Saurolophus angustirostris are described, and their presence in all hadrosaurs is suggested. Frontal-nasal and premaxillar-nasal fontanellae are distinguished in hadrosaurs; their presence is explained as connected with growth and considered to he responsible for the variability of crest structures. New data indicating the presence of a cartilaginous diverticulum nasi within the circumnarial depression in Saurobphus ongustirostris are presented. A physiological (respiratory and/or thermoregulatory) function of the nasal diverticulum is proposed.  相似文献   
4.
5.
The paper presents multiplex panels of polymorphic microsatellites for two closely related cryptic species Pipistrellus pipistrellus and Pipistrellus pygmaeus. We tested the cross‐species amplification of 34 microsatellite loci, originally developed for five vespertilionid bat species. Ten and nine polymorphic loci in P. pipistrellus (mean number of alleles per locus = 10.5) and P. pygmaeus (8.1), respectively, in three multiplex polymerase chain reactions per species were amplified. All loci can be analysed in a single fragment analysis and can be used as markers to the study of evolution and the ecology of structured populations of socially living bats.  相似文献   
6.
7.
8.
9.

Background  

Cystic Fibrosis is a pleiotropic disease in humans with primary morbidity and mortality associated with a lung disease phenotype. However, knockout in the mouse of cftr, the gene whose mutant alleles are responsible for cystic fibrosis, has previously failed to produce a readily, quantifiable lung phenotype.  相似文献   
10.
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