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   479篇
  免费   55篇
  国内免费   31篇
耳鼻咽喉   2篇
儿科学   36篇
妇产科学   5篇
基础医学   39篇
口腔科学   14篇
临床医学   65篇
内科学   98篇
皮肤病学   2篇
神经病学   25篇
特种医学   55篇
外科学   19篇
综合类   32篇
预防医学   34篇
眼科学   50篇
药学   72篇
中国医学   1篇
肿瘤学   16篇
  2022年   3篇
  2021年   4篇
  2020年   6篇
  2019年   9篇
  2018年   11篇
  2017年   6篇
  2016年   9篇
  2015年   9篇
  2014年   23篇
  2013年   23篇
  2012年   20篇
  2011年   20篇
  2010年   14篇
  2009年   20篇
  2008年   18篇
  2007年   28篇
  2006年   16篇
  2005年   10篇
  2004年   8篇
  2003年   3篇
  2002年   5篇
  2001年   13篇
  2000年   10篇
  1999年   18篇
  1998年   19篇
  1997年   22篇
  1996年   19篇
  1995年   17篇
  1994年   20篇
  1993年   19篇
  1992年   14篇
  1991年   11篇
  1990年   6篇
  1989年   14篇
  1988年   10篇
  1987年   13篇
  1986年   11篇
  1985年   9篇
  1984年   7篇
  1983年   3篇
  1982年   3篇
  1981年   11篇
  1980年   5篇
  1979年   4篇
  1977年   4篇
  1976年   3篇
  1975年   5篇
  1973年   2篇
  1971年   2篇
  1970年   2篇
排序方式: 共有565条查询结果,搜索用时 15 毫秒
1.
Neuroimaging in Pineal Tumors   总被引:4,自引:0,他引:4  
F Reis  MD  AV Faria  MD  PhD  VA Zanardi  MD  PhD  JR Menezes  MD  F Cendes  MD  PhD  LS Queiroz  MD  PhD 《Journal of neuroimaging》2006,16(1):52-58
BACKGROUND AND PURPOSE: The authors report radiological findings in 11 tumors in the pineal region, which were histologically diagnosed as germinomas, pineocytomas pineoblastomas, ependymomas, teratomas, and astrocytomas. METHODS: Computed tomography (CT) was performed in seven patients and magnetic resonance imaging (MRI) was performed in all patients. RESULTS: CT showed a solid or solid/cystic mass with variable contrast enhancement. MRI showed a heterogeneous mass, with hypointense signal on T1 and iso/hyperintense signal on T2-weighted images (WI) and gadolinium enhancement. Extension to adjacent structures occurred in five patients and spread through the cerebral spinal fluid (CSF) in two. CONCLUSIONS: Pineal region tumors have no pathognomonic imaging pattern. MRI and CT are complementary in diagnosis and are important to determine localization, extension, and meningeal spread.  相似文献   
2.
中药材龟板和鳖甲中DNA的提取与扩增   总被引:22,自引:0,他引:22  
中药材龟板和鳖甲中DNA的提取与扩增王亚明,周开亚,吴平,徐珞珊(南京师范大学生物系,南京210097;中国药科大学生药学研究室,南京210009)龟鳖类药材在我国使用历史悠久,具补阴益气的功效。《中国药典》(1990年版)规定龟甲(龟板)的原动物为...  相似文献   
3.
4.
5.
6.
To express the core protein of HIV-1 of Chinese prevalent strain (HIV-1 (CN)) in Pichia pastoris, the fulllength gag gene was inserted into the secretory expression vector pHILS1. Linearized recombinant plasmid pHILGAG by Sail was electrotransformed into the yeast strain GS115, and the yeast transformants were identified by PCR. To induce the interest protein to be expressed, the PCR positive transformants were inoculated in the medium of BMGY and BMMY, mRNA of the strain was detected by RT-PCR, and the expressed protein was analyzed by SDS-PAGE, Western blotting and thin layer scanning. mRNA (1.3 kb) was amplified by RT-PCR. SDS-PAGE and Western blotting analysis showed that the molecular mass of the expressed protein was 55 kD, which was similar to the expected value, and the expressed protein could react with McAb to HIV-1 p24. Thin layer scanning analysis demonstrated that the whole amount of the expressed protein was approximately 13 % of the soluble protein in the supernatant. The recombinant yeast had good genetic stability. The optimal expression conditions of the engineering yeast were as follows: BMMY medium, 80-90% of dissolved oxygen, 1% methanol, and 3-day-cultivation course. Gag proteins were expressed under the optimal expression condition and purified via gel filtration chromatography. The purity of the interest protein was up to 85 %. After the purified proteins were inoculated into BALB/c mice, the anti-HIV-1 antibodies in the immunized mice could be detected by Western blotting.  相似文献   
7.

Background  

Depression consistently predicts nonadherence to human immunodeficiency virus antiretroviral therapy, but which aspects of depression are most influential are unknown. Such knowledge could inform assessments of adherence readiness and the type of depression treatment to utilize.  相似文献   
8.
9.
10.
Modern population based oral health management requires a complete understanding of the impact of disease in order to provide efficient and effective oral health care and guidance. Periodontitis is an important cause of tooth loss and has been shown to be associated with a number of systemic conditions. The impact of oral conditions and disorders on quality of life has been extensively studied. However, the impact of periodontitis on quality of life has received less attention. This review summarizes the literature on the impact of periodontitis on oral health‐related quality of life (OHRQoL). Relevant publications were identified after searching the MEDLINE and EMBASE electronic databases. Screening of titles and abstracts and data extraction was conducted. Only observational studies were included in this review. Most of the reviewed studies reported a negative impact of periodontitis on OHRQoL. However, the reporting standards varied across studies. Moreover, most of the studies were conducted in developed countries.  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