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   3525篇
  免费   217篇
  国内免费   25篇
耳鼻咽喉   29篇
儿科学   190篇
妇产科学   32篇
基础医学   392篇
口腔科学   37篇
临床医学   356篇
内科学   980篇
皮肤病学   28篇
神经病学   243篇
特种医学   282篇
外国民族医学   2篇
外科学   475篇
综合类   24篇
预防医学   138篇
眼科学   203篇
药学   202篇
中国医学   6篇
肿瘤学   148篇
  2022年   22篇
  2021年   53篇
  2020年   29篇
  2019年   50篇
  2018年   87篇
  2017年   49篇
  2016年   46篇
  2015年   45篇
  2014年   76篇
  2013年   116篇
  2012年   128篇
  2011年   134篇
  2010年   109篇
  2009年   121篇
  2008年   137篇
  2007年   164篇
  2006年   163篇
  2005年   139篇
  2004年   115篇
  2003年   114篇
  2002年   127篇
  2001年   108篇
  2000年   123篇
  1999年   103篇
  1998年   79篇
  1997年   69篇
  1996年   87篇
  1995年   63篇
  1994年   57篇
  1993年   56篇
  1992年   73篇
  1991年   49篇
  1990年   65篇
  1989年   89篇
  1988年   59篇
  1987年   81篇
  1986年   79篇
  1985年   58篇
  1984年   41篇
  1983年   31篇
  1982年   29篇
  1981年   24篇
  1979年   20篇
  1977年   19篇
  1976年   23篇
  1975年   34篇
  1974年   21篇
  1970年   21篇
  1966年   18篇
  1965年   21篇
排序方式: 共有3767条查询结果,搜索用时 15 毫秒
11.
Eight patients with a delayed-onset heparin-induced thrombocytopenia, with thrombotic complications requiring immediate anticoagulation in 7 of them, were given low molecular weight heparin (LMWH) fractions as alternative therapy. This treatment led to normalization of platelet count within 3-5 days in 6 patients with clinical recovery in 5. In 2 patients, thrombocytopenia persisted despite LMWH therapy. In vitro platelet aggregation tests performed in all patients gave evidence of a relationship between the presence (or absence) of a LMWH-dependent platelet-aggregating factor in the patients' plasma and the persistence (or correction) of the thrombocytopenia with LMWH therapy. Although positive in vitro tests may not necessarily be associated with thrombocytopenia, in vitro testing may prove to be a useful guide before giving LMWH fractions as an alternative therapy in patients with heparin-induced thrombocytopenia requiring immediate anticoagulation.  相似文献   
12.
13.
14.
15.
16.
17.
The involvement of arachidonic acid (AA) and its metabolites in the control of PTH secretion by porcine parathyroid cells was investigated. Increasing the extracellular calcium concentration from 0.5 to 2 mM increased free [3H]AA release and decreased PTH secretion from labeled parathyroid cells as a function of time (1-30 min). Free [3H]AA in the medium was significantly increased (+153 +/- 6%) after 5 min, while PTH secretion was significantly decreased (-75 +/- 7%) only after 15 min, suggesting a link between the two. [3H]AA release was associated with a decrease in [3H]AA incorporated into phosphatidylinositol, phosphatidic acid, and phosphatidylcholine, suggesting that these phospholipids are the major source of AA. Exogenous phospholipase-A2 (PL-A2; 1-500 mU/ml) and AA (5-40 microM) inhibited PTH secretion in a dose-dependent manner. PTH secretion inhibited by 2 mM Ca2+ was restored by two PL-A2 inhibitors, indomethacin (30 microM) and mepacrine (50 microM). The cyclooxygenase pathway inhibitor ibuprofen (20 microM) did not restore PTH secretion of affect high Ca(2+)-, AA-, or PL-A2-inhibited PTH secretion. Two inhibitors of the lipoxygenase pathway (LO), phenidone (1 microM) and baicalein (0.1 microM), a relatively selective 12-LO inhibitor, blunted high Ca(2+)-induced inhibition of PTH secretion (+101 +/- 10% and +105 +/- 6%, respectively), but nordihydroguaiaretic acid, which inhibits the 5-LO pathway, did not restore PTH secretion inhibited by high Ca2+, AA, or PL-A2. These results suggested that AA and agents that cause its liberation inhibit PTH secretion. AA may act via the 12-LO, but not via the 5-LO or cyclooxygenase, pathway. Thus, 12-LO products may be second messengers in parathyroid cells.  相似文献   
18.
Extracorporeal shockwave lithotripsy (ESWL) has been initially designed for stones located in the kidney and the upper ureter. Our lithotripter is no exception. Its components (the table and the orientation of the semi-ellipsoid reflector) are adapted for the treatment of kidney or lumbar ureter stones. However, the elements forming the unit of treatment (the table, the C-arm and the Tripter) can be modified in such a way that focalization of stones of the lower ureter becomes possible through a perineal exposure. The aim is to avoid the pelvic bone shield while a good focalization of the stone is realized. From June 1989 to March 1991, 35 patients were treated for distal ureteric stones by ESWL in this original positioning.  相似文献   
19.
BACKGROUND: We have noted an unexpectedly high incidence of prostate cancer in our heart transplant recipients (HTR). METHODS: We conducted a retrospective review of patients after heart transplantation to investigate the prevalence, treatment, and outcome of prostate cancer diagnosed after systematic screening (study group). We compared them with case-matched HTR (control). RESULTS: Among 702 recipients, 15 patients had elevated prostate-specific antigen (PSA) levels. Fourteen cases of prostate cancer were diagnosed and treated. The median time between transplantation and prostate cancer diagnosis was 73 months. No patient was diagnosed in a locally advanced (>T2) or metastatic stage. Eleven patients (78.6%) received curative treatment. During follow-up (median, 44 months), 1 patient died from prostate cancer. The survival rate between the study and control groups did not differ. CONCLUSION: Routine PSA testing is recommended as a screening test for prostate cancer in patients after heart transplantation. We believe this could also result in detection of early stages of prostate cancer, thus allowing curative treatment, and achieving similar survival to other case-matched HTR with no prostate cancer.  相似文献   
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