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   73728篇
  免费   6388篇
  国内免费   3427篇
耳鼻咽喉   768篇
儿科学   808篇
妇产科学   1356篇
基础医学   10835篇
口腔科学   1643篇
临床医学   7392篇
内科学   13081篇
皮肤病学   1169篇
神经病学   5010篇
特种医学   2533篇
外国民族医学   19篇
外科学   9328篇
综合类   7612篇
现状与发展   6篇
一般理论   6篇
预防医学   4418篇
眼科学   2026篇
药学   7202篇
  31篇
中国医学   2256篇
肿瘤学   6044篇
  2024年   82篇
  2023年   587篇
  2022年   1286篇
  2021年   1749篇
  2020年   1306篇
  2019年   1356篇
  2018年   1874篇
  2017年   1617篇
  2016年   1557篇
  2015年   2020篇
  2014年   2594篇
  2013年   2692篇
  2012年   3703篇
  2011年   3960篇
  2010年   2403篇
  2009年   2206篇
  2008年   2975篇
  2007年   3063篇
  2006年   2935篇
  2005年   2625篇
  2004年   2068篇
  2003年   2013篇
  2002年   1814篇
  2001年   5072篇
  2000年   5001篇
  1999年   4397篇
  1998年   1671篇
  1997年   1313篇
  1996年   851篇
  1995年   742篇
  1994年   649篇
  1993年   529篇
  1992年   2057篇
  1991年   1755篇
  1990年   1615篇
  1989年   1555篇
  1988年   1352篇
  1987年   1250篇
  1986年   1109篇
  1985年   920篇
  1984年   594篇
  1983年   474篇
  1982年   253篇
  1981年   185篇
  1980年   142篇
  1979年   285篇
  1978年   77篇
  1974年   75篇
  1973年   95篇
  1972年   71篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
51.
52.
Experimental study on the immunosuppressive effects of gui zhi tang   总被引:1,自引:0,他引:1  
X F Lu 《中西医结合杂志》1989,9(5):283-5, 262
In this paper the immunosuppressive effects of Gui Zhi Tang (a famous Chinese medicine) on the murine immune functions are reported. Varying dosages of Gui Zhi Tang administrated orally, i.p. and i.m. were able to inhibit the amounts of PFC, SRFC and the DTH response induced by BSA and the proliferation response of murine spleen cells to Con A and LPS. Further studies showed that Gui Zhi Tang had the inhibitory effect on Interleukin-2 production of murine spleen cells, which might be one of the mechanisms leading to the immunosuppressive effects of Gui Zhi Tang.  相似文献   
53.
54.
55.
56.
A 40-year-old man presented a painful haemorrhagic plaque on his chest in the same location where a nodular lesion had been presented for many years. After 2 months, the plaque was replaced by a depressed lesion. The lesion diagnosed as an anetoderma was excised and the biopsy showed an atrophic dermatofibroma accompanied by aneurysmatic characteristics.  相似文献   
57.
PURPOSES: Inhibition of cerulenin on the endogenous fatty acid synthetic activities of oral squamous cell carcinoma (OSCC) and normal oral mucosa was assayed. METHODS: Squamous cell carcinoma and normal oral mucosa were collected fresh from surgical specimens. The collected tissues were minced in RPMI 1640 and divided into 3 groups: cerulenin treated, dimethylsulfoxide treated, and control. The tissues were incubated in [1(2)-(14)C]acetic acid, sodium salt for the last 2.5 hours of the treatment at 37 degrees C in 5% CO(2). After labeling, total lipids were extracted and counted for (14)C by scintillation counting. RESULTS: Endogenous fatty acid synthetic activities of oral squamous cell caranoma in the cerulenin-treated group decreased by 19% at 1 hour, 64% at 2 hours, and 87% at 4 hours; remained nearly unchanged in the dimethylsulfoxide-treated group; and increased slightly in the control group. The oral mucosa tissues were only mildly affected by cerulenin in fatty acid synthesis. CONCLUSIONS: Cerulenin significantly inhibits fatty acid synthetic activity in squamous cell carcinoma and only mildly affected the oral mucosa, indicating that the fatty acid synthetic pathway may be exploited as a target for developing anticancer drugs.  相似文献   
58.
59.
60.
Bone marrow stromal cells (MSCs) increase vascular endothelial growth factor (VEGF) expression and promote angiogenesis after stroke. Angiopoietin-1 (Ang1) and its receptor Tie2 mediate vascular integrity and angiogenesis as does VEGF and its receptors. In this study, we tested whether MSC treatment of stroke increases Ang1/Tie2 expression, and whether Ang1/Tie2 with VEGF/ vascular endothelial growth factor receptor 2 (VEGFR2) (Flk1), in combination, induced by MSCs enhances angiogenesis and vascular integrity. Male Wistar rats were subjected to middle cerebral artery occlusion (MCAo) and treated with or without MSCs. Marrow stromal cell treatment significantly decreased blood-brain barrier (BBB) leakage and increased Ang1, Tie2, and occludin (a tight junction protein) expression in the ischemic border compared with MCAo control. To further test the mechanisms of MSC-induced angiogenesis and vascular stabilization, cocultures of MSCs with mouse brain endothelial cells (MBECs) or astrocytes were performed. Supernatant derived from MSCs cocultured with MBECs significantly increased MBEC expression of Ang1/Tie2 and Flk1 compared with MBEC alone. Marrow stromal cells cocultured with astrocytes also significantly increased astrocyte VEGF and Ang1/Tie2 expression compared with astrocyte culture alone. Conditioned media from MSCs alone, and media from cocultures of MSCs with astrocytes or MBECs, all significantly increased capillary tube-like formation of MBEC compared with control Dulbecco's modified Eagle's medium media. Inhibition of Flk1 and/or Ang1 significantly decreased MSC-induced MBEC tube formation. Knockdown of Tie2 expression in MBECs significantly inhibited MSC-induced tube formation. Our data indicate MSC treatment of stroke promotes angiogenesis and vascular stabilization, which is at least partially mediated by VEGF/Flk1 and Ang1/Tie2.  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