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   26260篇
  免费   1348篇
  国内免费   174篇
耳鼻咽喉   199篇
儿科学   539篇
妇产科学   448篇
基础医学   2877篇
口腔科学   643篇
临床医学   2101篇
内科学   6868篇
皮肤病学   489篇
神经病学   2979篇
特种医学   794篇
外科学   4062篇
综合类   45篇
一般理论   5篇
预防医学   1104篇
眼科学   452篇
药学   1479篇
中国医学   30篇
肿瘤学   2668篇
  2024年   27篇
  2023年   172篇
  2022年   390篇
  2021年   756篇
  2020年   450篇
  2019年   622篇
  2018年   705篇
  2017年   560篇
  2016年   633篇
  2015年   695篇
  2014年   1020篇
  2013年   1277篇
  2012年   2014篇
  2011年   2006篇
  2010年   1172篇
  2009年   1077篇
  2008年   1768篇
  2007年   1825篇
  2006年   1686篇
  2005年   1670篇
  2004年   1658篇
  2003年   1367篇
  2002年   1345篇
  2001年   207篇
  2000年   138篇
  1999年   165篇
  1998年   254篇
  1997年   221篇
  1996年   213篇
  1995年   176篇
  1994年   135篇
  1993年   138篇
  1992年   127篇
  1991年   103篇
  1990年   108篇
  1989年   78篇
  1988年   77篇
  1987年   74篇
  1986年   73篇
  1985年   67篇
  1984年   83篇
  1983年   51篇
  1982年   48篇
  1981年   47篇
  1980年   35篇
  1979年   26篇
  1978年   22篇
  1977年   32篇
  1976年   23篇
  1974年   19篇
排序方式: 共有10000条查询结果,搜索用时 328 毫秒
21.
22.
Forty consecutive adult patients under the age of 50 with acute non-lymphoblastic leukemia (ANLL) in first complete remission, underwent autologous bone marrow transplantation (ABMT) between March 1984 and April 1990. The conditioning regimen employed included cyclophosphamide and total body irradiation, followed by the administration of unpurged ABMT. The median time from diagnosis to transplant was 7 months (3-15 months), and the median time from complete remission to ABMT was 4 months (range 3-9 months). Twenty-two (51%) patients remain in complete remission 6-81 months (median 24 months) after ABMT.

The causes of death were, recurrent leukemia (11 patients), parenchymal toxicities such as acute respiratory distress syndrome and veno-occlusive disease (3 patients), hemorrhage (2 patients) and infection (2 patients). Eleven patients relapsed after 3-12 months (median 5 months). This study has produced survival data comparable to those of other institutions employing TBI for either allo or autotransplants.  相似文献   
23.
24.
Femoral attachment of the anterior cruciate ligament   总被引:3,自引:1,他引:2  
Endoscopic anterior cruciate ligament (ACL) reconstruction is one of the most popular orthopaedic procedures. Correct tunnel positioning is a prerequisite to success. Current surgical techniques are unable to duplicate the complex anatomy and function of the native ACL. Surgery mainly aims at restoring anteroposterior laxity. The ACL is not isometric and only a few fibers are nearly isometric over the full range of motion. However, a nearly isometric behaviour of the ACL graft is desirable. Isometry is mainly influenced by femoral attachment; thus the femoral tunnel position has a greater effect than the tibial on graft length changes. The purpose of this article is to describe the anatomy of the femoral ACL insertion and to discuss the surgical techniques used to replicate it.  相似文献   
25.
26.
Hormone replacement therapy is the optimal therapeutic choice for postmenopausal syndrome. While low doses of estrogens (0.3 mg/day of conjugated estrogens) can counteract neurovegetative menopausal symptoms, higher doses (0.625 mg/day of conjugated estrogens) are required to prevent bone loss in postmenopausal women. Experimental and clinical studies have shown that ipriflavone, a non-hormonal isoflavone derivative, is effective in the prevention and treatment of postmenopausal osteoporosis. The aim of the present investigation was to evaluate the efficacy and toler-ability of ipriflavone and very low doses of equine conjugated estrogens on bone loss in early postmenopausal women. Eighty-three healthy postmenopausal women (50.3±0.7 years) were enrolled for this 1-year multicenter study. All subjects were randomly allocated to receive: double placebo (n=24; group A), placebo plus conjugated equine estrogens 0.30 mg/day (n=31; group B) or conjugated equine estrogens 0.30 mg/day plus oral ipriflavone 200 mg tris in die at meals (n=28; group C), according to a double-masked design. Among women who completed the treatment period (valid completers), those of group A showed a progressive decrease in forearm bone density (FBD; measured by dual photon absorptiometry) that reached 1.7% after 12 months. The women in group B maintained their FBD in the first 6 months of treatment but, at the end of the study, showed a bone loss of 1.4% compared with basal values. By contrast, women in group C showed a significant increase in FBD after 1 year of treatment (+5.6%;p<0.01). Bothvalid completers andintention to treat analyses revealed a significant difference (p<0.05) between group A and group C over the study period. None of the treatments produced significant changes of biochemical markers of bone turnover, while hot flushes and other climacteric symptoms were significantly reduced after the sixth month of treatment in women receiving estrogens. Adverse events were generally mild, and did not differ among the groups. The results of this study suggest that low doses of estrogens combined with ipriflavone could represent a new therapeutic approach to the treatment of the postmenopausal syndrome.  相似文献   
27.
The relation between sexual function and serum free testosterone (fT) levels, which represent the active fraction of circulating testosterone, was evaluated. Two groups of impotent male subjects with mild hypogonadism were treated with oral testosterone undecanoate (TU); these men presented with tT/luteinizing hormone (LH) ratio and tT levels at the lower limits of normal. The first group had serum fT below 6.6 ng/ml, considered the lower normal value, according to our laboratory method, whereas the second group had normal fT limits. Administration of TU improved sexual function only in impotent men with low fT levels, but not in subjects with normal fT levels, even though the tT levels and the tT/LH ratio of the two groups were not significantly different. The results of our study suggest the presence of a minimun serum fT threshold, lying near the lower normal range, which determines the male sexual function. Moreover, serum fT levels were a more sensitive index than tT for identifying impotent men who can be successfully treated with androgens.  相似文献   
28.
29.
30.
Neutrophil oxidative metabolism, C3d and beta 2 microglobulin levels, were assessed in nine consecutive patients undergoing cardiopulmonary bypass surgery with polypropylene hollow fiber oxygenators for open cardiac operations. Generation of oxygen free radicals by neutrophils was measured as luminol-enhanced chemiluminescence after stimulation with opsonized Zymosan and phorbol myristate acetate. A significant increase in light emission was detected by using both of the chemiluminescence stimulators. Moreover, a remarkable and significant increase in C3d levels was found already at 10 min. Conversely minimal changes in levels of beta 2 microglobulin were detected during cardiopulmonary bypass surgery. These data suggest that the impact of the patient blood with the foreign surface of cardiopulmonary bypass results in activation of phagocyte cells with increased potential in oxygen consumption. These effects could be partially complement-mediated.  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