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   23355篇
  免费   1525篇
  国内免费   77篇
耳鼻咽喉   309篇
儿科学   457篇
妇产科学   536篇
基础医学   3092篇
口腔科学   1682篇
临床医学   1730篇
内科学   5317篇
皮肤病学   519篇
神经病学   1825篇
特种医学   507篇
外国民族医学   1篇
外科学   2906篇
综合类   140篇
一般理论   8篇
预防医学   2110篇
眼科学   514篇
药学   1869篇
中国医学   158篇
肿瘤学   1277篇
  2023年   183篇
  2022年   496篇
  2021年   890篇
  2020年   533篇
  2019年   714篇
  2018年   848篇
  2017年   604篇
  2016年   654篇
  2015年   770篇
  2014年   976篇
  2013年   1241篇
  2012年   1722篇
  2011年   1863篇
  2010年   986篇
  2009年   844篇
  2008年   1317篇
  2007年   1301篇
  2006年   1168篇
  2005年   1053篇
  2004年   882篇
  2003年   826篇
  2002年   702篇
  2001年   472篇
  2000年   445篇
  1999年   358篇
  1998年   137篇
  1997年   127篇
  1996年   112篇
  1995年   93篇
  1994年   83篇
  1993年   80篇
  1992年   232篇
  1991年   216篇
  1990年   208篇
  1989年   167篇
  1988年   161篇
  1987年   117篇
  1986年   134篇
  1985年   127篇
  1984年   94篇
  1983年   75篇
  1982年   64篇
  1981年   52篇
  1979年   103篇
  1978年   50篇
  1977年   53篇
  1976年   54篇
  1975年   62篇
  1974年   59篇
  1973年   50篇
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
11.
12.
13.
The outbreaks of rabies in humans transmitted by Desmodus rotundus in 2004 and 2005, in the northeast of the Brazilian State of Para, eastern Amazon basin, made this a priority area for studies on this zoonosis. Given this, the present study provides data on this phenomenon in an urban context, in order to assess the possible circulation of the classic rabies virus (RABV) among bat species in Capanema, a town in the Amazon basin. Bats were collected, in 2011, with mist nets during the wet and dry seasons. Samples of brain tissue and blood were collected for virological and serological survey, respectively. None of the 153 brain tissue samples analyzed tested positive for RABV infection, but 50.34% (95% CI: 45.67-55.01%) of the serum samples analyzed were seropositive. Artibeus planirostris was the most common species, with a high percentage of seropositive individuals (52.46%, 95% CI: 52.31 52.60%). Statistically, equal proportions of seropositive results were obtained in the rainy and dry seasons (c2 = 0.057, d.f. = 1, p = 0.88). Significantly higher proportions of males (55.96%, 95% CI: 48.96-62.96%) and adults (52.37%, 95% CI: 47.35-57.39%) were seropositive. While none of the brain tissue samples tested positive for infection, the high proportion of seropositive specimens indicates that RABV may be widespread in this urban area.  相似文献   
14.
We report on 3 patients with pseudoathetosis, which are involuntary, slow, writhing movements due to loss of proprioception.  相似文献   
15.
Spinocerebellar ataxia (SCA) types 2 and 3 are autosomal-dominant neurodegenerative disorders caused by mutations in two different genes. We identified mutations for SCA2 and SCA3 segregating simultaneously in a single Brazilian family. The index patient had SCA2, whereas her two second-degree cousins had SCA3. Disease was more rapidly progressive in the SCA2 patient, who presented severe brainstem and pancerebellar atrophy, as opposed to the two SCA3 patients, who had only mild cerebellar vermian atrophy. In such situations, molecular confirmation of all patients may avoid misdiagnosis of SCA subtypes and eventual errors in predictive testing of unaffected family members.  相似文献   
16.
17.
Juvenile Parkinsonism: clinical and metabolic characteristics.   总被引:1,自引:1,他引:0       下载免费PDF全文
Twenty one patients with idiopathic Parkinsonism beginning before the age of 40 years were investigated. The mean duration of the disease was 19 years. There was a good and sustained response to levodopa. Only four patients reached stages IV and V (Hoehn and Yahr). Intolerance to levodopa was observed in the more advanced stages of the disease. In the series the familial incidence of Parkinsonism (2 cases) and essential tremor (3 cases) was very low. Thyroid disorder, diabetes mellitus or macrocytic anaemia was not found in any of the cases.  相似文献   
18.
The postnatal evolution of depolarizing after-potentials (DAPs) and after-hyperpolarizations (AHPs) was studied in rat CA1 hippocampal neurones (5-68 days of age) using in vitro slices. Results were pooled into 4 age groups: P5-9, P10-16, P17-24 and P26-68. In P5-9 cells, DAPs were seen as passive signals, with a time constant similar to the time constant of the membrane. The evolution of the DAP was characterized by a decrease in amplitude, an increase in duration and a change in contour. In P10-16 and P17-24 cells, the DAPs often had a plateau or a hump-like shape which increased the probability of firing and the occurrence of spike doublets. The firing pattern and bursting behaviour of P10-16 CA1 neurones differed from the pattern typical of the adult. P5-9 and P10-16 cells had post-burst AHPs with a smaller amplitude and a more prolonged early phase than at late stages of development.  相似文献   
19.
20.
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