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   208136篇
  免费   28582篇
  国内免费   7157篇
耳鼻咽喉   1920篇
儿科学   1591篇
妇产科学   5158篇
基础医学   15114篇
口腔科学   2182篇
临床医学   16752篇
内科学   19588篇
皮肤病学   1364篇
神经病学   729篇
特种医学   6001篇
外国民族医学   266篇
外科学   29055篇
综合类   26835篇
现状与发展   42篇
一般理论   3篇
预防医学   10219篇
眼科学   131篇
药学   14436篇
  142篇
中国医学   5014篇
肿瘤学   87333篇
  2024年   702篇
  2023年   4494篇
  2022年   8767篇
  2021年   11421篇
  2020年   10662篇
  2019年   9587篇
  2018年   9179篇
  2017年   9609篇
  2016年   10350篇
  2015年   12042篇
  2014年   17199篇
  2013年   16875篇
  2012年   13669篇
  2011年   13850篇
  2010年   10062篇
  2009年   10286篇
  2008年   10487篇
  2007年   9806篇
  2006年   8642篇
  2005年   7050篇
  2004年   5872篇
  2003年   4870篇
  2002年   4134篇
  2001年   3768篇
  2000年   3124篇
  1999年   2667篇
  1998年   2206篇
  1997年   1956篇
  1996年   1575篇
  1995年   1468篇
  1994年   1203篇
  1993年   930篇
  1992年   810篇
  1991年   731篇
  1990年   538篇
  1989年   498篇
  1988年   417篇
  1987年   361篇
  1986年   277篇
  1985年   362篇
  1984年   298篇
  1983年   194篇
  1982年   197篇
  1981年   182篇
  1980年   158篇
  1979年   108篇
  1978年   69篇
  1977年   58篇
  1976年   51篇
  1975年   31篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
11.
[目的]观察比较异环磷酰胺(IFO)、顺铂(DDP)、5-氟尿嘧啶(5-Fu)联合方案(IPF方案)与DDP,5-Fu(PF方案)治疗晚期复发鼻咽癌(Ⅲ-Ⅳ期)的近期疗效及毒副反应。[方法]136例均经病理证实为晚期复发鼻咽癌患者,随机分为IPF组69例,PF组67例(对照组)[结果]IPF组和PF组有效率分别为69.56%(48/69)和43.3%(29/67),两组间差异有显著性(X2=8.519,P<0.01)。中位生存期:IPF组16个月(8-34个月),PF组为6.5个月(4-21个月),两组间差异有显著性(X2=22.36,P<0.05)。毒副作用主要为骨髓抑制,Ⅲ-Ⅳ度白细胞下降率IPF组为49.4%,PF组为5.97%,两组差异有显著性(X2=29.54,P<0.01)。Ⅲ-Ⅳ度血小板下降率IPF组为29.18%,PF组为0%(X2=30.29,P<0.01);Ⅲ-Ⅳ度消化道反应两组的发生率分别为15.94%和11.94%(x2=0.234,P>0.01).且以Ⅲ度为主。[结论]以IFO为主的方案联合治疗晚期复发鼻咽癌疗效好,毒副反应能耐受,可作为一线方案。  相似文献   
12.
13.
OBJECTIVES: The aim was to assess the natural course of oral lichen lesions (OLL) among unselected, non-consulting individuals. SUBJECTS AND METHODS: A cohort of 327 subjects with OLL, confirmed in 1973-1974 during a population-based survey in two Swedish municipalities, was followed through January 2002 via record linkages with nationwide and essentially complete registers. A sample of 80 drawn from the 194 surviving subjects who still resided in the area in 1993-1995 was invited for interview and oral re-examination. RESULTS: At the end of follow-up, one case of oral cancer was detected, while 0.4 were expected. The overall mortality among subjects with OLL was not significantly different from that in the 15,817 OLL-free subjects who participated in the initial population based survey in 1973-1974. The lesion had disappeared in 14 (39%) of 36 re-examined subjects with white OLLs in 1973-1974, and four (11%) had transformed into red types. In the corresponding group of 19 with red forms initially, five (26%) had become lesion free and four (21%) had switched to white types. Although the cohort size does not permit firm conclusions regarding oral cancer risk, the natural course over up to 30 years appears to be benign in the great majority.  相似文献   
14.
15.
16.
17.
18.
BACKGROUND: Although it is clear that dissemination via the blood system involves angiogenesis, it is uncertain whether tumors also induce lymphangiogenesis or simply invade existing peritumoral vessels. The purpose of this study was to elucidate changes in tumor blood and lymph vessels in cases involving the invasion of squamous cell carcinoma in the oral cavity, and its significance. Blood and lymph vessels densities in tongue carcinomas induced in hamsters were investigated. METHODS: Tongue cancer was induced by abrading the right margin of the tongue of each hamster with an endodontic barbed broach and subsequently applying 1.0% 9,10-dimenthl-1,2-benzanthracene (DMBA) dissolved in acetone, three times a week, at the same site. Fresh frozen sections were prepared and blood vessels stained blue by perfusion with Coomassie Brilliant Blue and lymph vessels stained brown for 5'-nucleotidase. The effects on the blood vessels and lymph vessels were observed. RESULTS: The results showed that blood and lymph vessel densities were greater in the advanced carcinoma tissues than in normal tissue. These were compared in terms of the mode of cancer invasion. As tumor invasion progressed, the blood vessel density decreased but lymph vessel density tended to be higher in high-degree tumor invasion than in low-degree tumor invasion. The expression of vascular endothelial growth factor-C was seen more frequently as tumor invasion progressed. CONCLUSIONS: The present findings indicated that angiogenesis and lymphangiogenesis are affected by cancerous invasion.  相似文献   
19.
We report a case of recurrent inguinal lymphocele formation after inguinal lymphadenectomy treated by lymphographic mapping and selective ligation of the lymphatic vessels. Lymphographic mapping was performed by puncturing a lymphatic vessel at the dorsum of the foot. After isolating the vessels that drained into the lymphocele, they were clipped and divided through a small skin incision. The described technique showed an instant and complete suspension of the lymph secretion with subsequent complete healing. Lymphatic mapping and selective ligation of afferent lymphatic vessels proved to be an effective treatment of a recurrent inguinal lymphocele.  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