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   170205篇
  免费   15027篇
  国内免费   8992篇
耳鼻咽喉   1669篇
儿科学   2300篇
妇产科学   3191篇
基础医学   17519篇
口腔科学   3319篇
临床医学   20954篇
内科学   25167篇
皮肤病学   2067篇
神经病学   8228篇
特种医学   5873篇
外国民族医学   50篇
外科学   18187篇
综合类   27567篇
现状与发展   34篇
一般理论   19篇
预防医学   12537篇
眼科学   4339篇
药学   17756篇
  188篇
中国医学   9598篇
肿瘤学   13662篇
  2024年   2223篇
  2023年   3268篇
  2022年   6176篇
  2021年   7929篇
  2020年   6386篇
  2019年   5461篇
  2018年   5370篇
  2017年   5153篇
  2016年   4601篇
  2015年   7109篇
  2014年   8945篇
  2013年   9271篇
  2012年   13203篇
  2011年   14172篇
  2010年   9872篇
  2009年   8105篇
  2008年   9924篇
  2007年   9839篇
  2006年   9176篇
  2005年   8399篇
  2004年   5954篇
  2003年   5326篇
  2002年   4443篇
  2001年   3699篇
  2000年   3400篇
  1999年   3157篇
  1998年   1560篇
  1997年   1476篇
  1996年   1198篇
  1995年   1127篇
  1994年   1041篇
  1993年   576篇
  1992年   976篇
  1991年   883篇
  1990年   743篇
  1989年   623篇
  1988年   576篇
  1987年   485篇
  1986年   385篇
  1985年   295篇
  1984年   201篇
  1983年   169篇
  1982年   106篇
  1981年   103篇
  1979年   147篇
  1978年   122篇
  1977年   88篇
  1974年   98篇
  1973年   76篇
  1972年   94篇
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
1.
2.
3.
4.
Signaling of RANK (receptor activator of nuclear factor kappa B) through its ligand RANKL appears critical in osteolysis associated with aseptic loosening (AL). The purpose of this study was to investigate the role of RANK in a murine osteolysis model developed in RANK knockout (RANK(-/-)) mice. Ultra high molecular weight polyethylene (UHMWPE) debris was introduced into established air pouches on RANK(-/-) mice, followed by implantation of calvaria bone from syngeneic littermates. Wild type C57BL/6 (RANK(+/+)) mice injected with either UHMWPE or saline alone were included in this study. Pouch tissues were collected 14 days after UHMWPE inoculation for molecular and histology analysis. Results showed that UHMWPE stimulation induced strong pouch tissue inflammation in RANK(-/-) mice, as manifested by inflammatory cellular infiltration, pouch tissue proliferation, and increased gene expression of IL-1beta, TNFalpha, and RANKL. However, the UHMWPE-induced inflammation in RANK(-/-) mice was not associated with the osteoclastic bone resorption observed in RANK(+/+) mice. In RANK(+/+) mice subjected to UHMWPE stimulation, a large number of TRAP(+) cells were found on the implanted bone surface, where active osteoclastic bone resorption was observed. No TRAP(+) cells were found in UHMWPE-containing pouch tissues of RANK(-/-) mice. Consistent with the lack of osteoclastic activity shown by TRAP staining, no significant UHMWPE particle-induced bone resorption was found in RANK(-/-) mice. A well preserved bone collagen content (Van Gieson staining) and normal plateau surface contour [microcomputed tomography (microCT)] of implanted bone was observed in RANK(-/-) mice subjected to UHMWPE stimulation. In conclusion, this study provides the evidence that UHMWPE particles induce strong inflammatory responses, but not associated with osteoclastic bone resorption in RANK(-/-) mice. This indicates that RANK signaling is essential for UHMWPE particle-induced osteoclastic bone resorption, but does not participate in UHMWPE particle-induced inflammatory response.  相似文献   
5.
6.
7.
8.
上世纪末曾有人提出我国的中药产业将成为本世纪的“朝阳产业”,口号甚是鼓舞人心。但结合我国中药产业的现状分析,却不容乐观。想在本世纪的头几年达到蓬勃兴盛的状态可能还有很大差距。问题在哪里,笔者以为,除了中药生产企业本身存在诸多问题外,关键还在于针对中药学本身的现代研究没有取得明显的突破性进展。以致我国有关中药研发的政策、法  相似文献   
9.
From 1955 to 1984, radical neck dissection (RND) had been done in 300 salivary carcinoma patients, 114 of which had regional lymph node metastasis, with a 38% metastatic rate. Respective 3, 5, 10, 15, 20 year survival rates were 76, 64, 47, 35, 35% in a 3 to 20 years follow-up study in 283 patients (94.33%). The following four points are concluded: 1. The metastatic rate is determined not only on tumor staging, but more to its typing (pathologic behaviour). 2. Elective RND gave a better prognosis than therapeutic and negative metastasis has a better survival chance than positive where the low level metastasis is the worst. 3. According to pathologic typing, Elective RND is indicated for undifferentiated adenocarcinoma, high malignant mucoepidermoid carcinoma, squamous cell carcinoma, adenocarcinoma and papillary cystic adenocarcinoma, therapeutic RND for malignant pleomorphic adenoma, acinic cell carcinoma and mucoepidermoid carcinoma. 4. Unilateral RND is indicated for all but sublingual and buccal tumors.  相似文献   
10.
While balloon valvuloplasty has been widely used for the treatment of congenital valvular pulmonary stenosis (PS) in children and adults, its use in elderly patients is less common. An 80-year-old woman with congenital valvular PS received valvuloplasty with double-balloon technique. Right ventricle systolic pressure and pulmonary valve systolic pressure gradient decreased from 95 to 44 mm Hg and from 75 to 35 mm Hg, respectively. Follow-up Doppler echocardiography 2 months later showed further decrease in the transvalvular systolic pressure gradient to 29 mm Hg. The patient had symptomatic relief, and no major complication was noted. Balloon pulmonary valvuloplasty can be an effective treatment for elderly patients with congenital valvular PS.  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