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   2766篇
  免费   164篇
  国内免费   3篇
耳鼻咽喉   6篇
儿科学   125篇
妇产科学   48篇
基础医学   314篇
口腔科学   53篇
临床医学   220篇
内科学   651篇
皮肤病学   37篇
神经病学   282篇
特种医学   282篇
外科学   322篇
综合类   37篇
预防医学   297篇
眼科学   11篇
药学   130篇
中国医学   1篇
肿瘤学   117篇
  2022年   13篇
  2021年   25篇
  2019年   13篇
  2018年   37篇
  2017年   40篇
  2016年   28篇
  2015年   39篇
  2014年   48篇
  2013年   73篇
  2012年   79篇
  2011年   90篇
  2010年   74篇
  2009年   83篇
  2008年   93篇
  2007年   89篇
  2006年   91篇
  2005年   106篇
  2004年   91篇
  2003年   86篇
  2002年   78篇
  2001年   87篇
  2000年   58篇
  1999年   75篇
  1998年   69篇
  1997年   84篇
  1996年   70篇
  1995年   59篇
  1994年   62篇
  1993年   59篇
  1992年   55篇
  1991年   62篇
  1990年   52篇
  1989年   66篇
  1988年   78篇
  1987年   58篇
  1986年   60篇
  1985年   71篇
  1984年   52篇
  1983年   61篇
  1982年   41篇
  1981年   39篇
  1980年   38篇
  1979年   36篇
  1978年   31篇
  1977年   27篇
  1976年   28篇
  1975年   32篇
  1974年   28篇
  1971年   12篇
  1969年   17篇
排序方式: 共有2933条查询结果,搜索用时 13 毫秒
121.
Allogeneic bone marrow transplantation (BMT) for advanced acute leukemia is associated with a high risk of relapse. It is postulated that interleukin-2 (IL-2) administered after BMT might induce or amplify a graft-versus-leukemia effect and thereby reduce the relapse rate. To identify an IL-2 regimen for testing this hypothesis, a phase I trial of IL-2 (Roche) was performed in children in complete remission (CR) without active graft-versus-host disease (GVHD) off immunosuppressive agents after unmodified allogeneic matched-sibling BMT for acute leukemia beyond first remission. Beginning a median of 68 days after BMT, 17 patients received escalating doses of induction IL-2 (0.9, 3.0, or 6.0 x 10(6) IU/m2/d representing levels I, II, and III) for 5 days by continuous intravenous infusion (CIV). After 6 days of rest, they received maintenance IL-2 (0.9 x 10(6) IU/m2/d) for 10 days by CIV infusion. Levels I and II were well-tolerated, but, of 6 patients at level III, 1 developed pulmonary infiltrates, 1 developed hypotension (both resolved), and 1 died of bacterial sepsis and acute respiratory distress syndrome. Grade II acute GVHD developed in 1 patient at level I and 1 at level III. The maximum tolerated dose of induction IL-2 was level II. IL-2 induced lymphocytosis, with an increase in CD56+ and CD8+ cells. Ten patients remain in CR at 5+ to 67+ months. Thus, a regimen of IL-2 has been identified that did not induce a high incidence of acute GVHD when administered to children after unmodified allogeneic BMT. Its clinical activity will be assessed in a phase II trial.  相似文献   
122.

Background  

This randomized double blind placebo controlled dual site clinical trial compared a probiotic dietary supplement to placebo regarding effects on gastrointestinal symptoms in adults with post-prandial intestinal gas-related symptoms (abdominal pain, distention, flatulence) but no gastrointestinal (GI) diagnoses to explain the symptoms.  相似文献   
123.
124.
125.
Huntington disease (HD) is caused by an expanded CAG repeat sequence in the HD gene. Although the age at onset is correlated to the CAG repeat length, this correlation only explains approximately half of the variation in onset age. Less variation between siblings indicates that the variation is, in part, explained by genetic modifiers. We analyzed polymorphic loci within or close to the HD gene on the HD chromosome in Danish HD patients. We found one specific haplotype segregating with later age at onset, compared with patients with similar CAG repeat length and another haplotype. The nine Danish families in the study carrying this haplotype most likely have a common founder. Several of the polymorphic loci displayed alleles that may be specific to the late-onset haplotype, implicating that from this study we cannot determine which of the loci tested (or other polymorphic loci in this chromosomal area) do in fact contain genetic modifiers of age at onset.  相似文献   
126.
Neo-intima development and atherosclerosis limit long-term vein graft use for revascularization of ischaemic tissues. Using a rat model, which is technically less challenging than smaller rodents, we provide evidence that the temporal morphological, cellular, and key molecular events during vein arterialization resemble the human vein graft adaptation. Right jugular vein was surgically connected to carotid artery and observed up to 90 days. Morphometry demonstrated gradual thickening of the medial layer and important formation of neo-intima with deposition of smooth muscle cells (SMC) in the subendothelial layer from day 7 onwards. Transmission electron microscopy showed that SMCs switch from the contractile to synthetic phenotype on day 3 and new elastic lamellae formation occurs from day 7 onwards. Apoptosis markedly increased on day 1, while α-actin immunostaining for SMC almost disappeared by day 3. On day 7, cell proliferation reached the highest level and cellular density gradually increased until day 90. The relative magnitude of cellular changes was higher in the intima vs . the media layer (100 vs . 2 times respectively). Cyclin-dependent kinase inhibitors (CDKIs) p27Kip1 and p16INKA remained unchanged, whereas p21Cip1 was gradually downregulated, reaching the lowest levels by day 7 until day 90. Taken together, these data indicate for the first time that p21Cip1 is the main CDKI protein modulated during the arterialization process the rat model of vein arterialization that may be useful to identify and validate new targets and interventions to improve the long-term patency of vein grafts.  相似文献   
127.
128.
129.
130.
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