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   5428篇
  免费   532篇
  国内免费   8篇
耳鼻咽喉   53篇
儿科学   190篇
妇产科学   100篇
基础医学   923篇
口腔科学   174篇
临床医学   748篇
内科学   790篇
皮肤病学   99篇
神经病学   377篇
特种医学   270篇
外科学   781篇
综合类   110篇
一般理论   6篇
预防医学   582篇
眼科学   77篇
药学   382篇
中国医学   2篇
肿瘤学   304篇
  2021年   61篇
  2019年   61篇
  2018年   88篇
  2017年   63篇
  2016年   67篇
  2015年   83篇
  2014年   122篇
  2013年   182篇
  2012年   194篇
  2011年   244篇
  2010年   149篇
  2009年   126篇
  2008年   199篇
  2007年   255篇
  2006年   197篇
  2005年   193篇
  2004年   197篇
  2003年   177篇
  2002年   179篇
  2001年   201篇
  2000年   197篇
  1999年   153篇
  1998年   85篇
  1997年   79篇
  1996年   85篇
  1995年   75篇
  1994年   65篇
  1993年   71篇
  1992年   100篇
  1991年   122篇
  1990年   119篇
  1989年   118篇
  1988年   109篇
  1987年   119篇
  1986年   97篇
  1985年   93篇
  1984年   86篇
  1983年   70篇
  1982年   50篇
  1981年   51篇
  1980年   51篇
  1979年   63篇
  1978年   60篇
  1977年   66篇
  1976年   56篇
  1975年   57篇
  1974年   49篇
  1973年   64篇
  1971年   49篇
  1970年   42篇
排序方式: 共有5968条查询结果,搜索用时 8 毫秒
1.
2.
Cidofovir is an acyclic nucleoside phosphonate with broad-spectrum activity against DNA viruses, including human papilloma virus (HPV). However, data on the efficacy of cidofovir in an immunosuppressive setting remain contradictory. We report for the first time on the promotion of the healing of recalcitrant warts in a patient with myelodysplastic syndrome with intravenous cidofovir treatment.  相似文献   
3.
The spatial spread within fly photoreceptors of 2 forms of desensitization by bright light have been investigated: the natural process of light adaptation in normal Musca photoreceptors and a receptor-potential inactivation in the no-steady-state (nss) mutant of the sheep blowfly Lucilia. The suction-electrode method used for recording from vertebrate rods was applied to fly ommatidia. A single ommatidium in vitro was partially sucked into a recording pipette. Illumination of the portion of the ommatidium within the pipette resulted in a flow of current having a wave form similar to that of the receptor potential and polarity consistent with current flow into the illuminated region of the photoreceptors. Two 5-microns slits of light, positioned at right angles to the ommatidial axis, were employed to determine the spread of light adaptation or inactivation along the ommatidium. The intensity of a flash of light delivered to one (adapting) slit was adjusted until it produced a criterion fractional reduction in the response to the other (test) slit. The reciprocal of this intensity of the adapting slit was taken as a measure of the effectiveness of the slit in causing light adaptation or inactivation. The effectiveness of the slit in causing light adaptation in normal Musca ommatidia fell as the adapting and test slits were moved farther apart along the ommatidial axis, declining to half its maximal value at a distance of 13 +/- 2 microns. Similar measurements of the effectiveness of a slit in causing light-induced inactivation in the nss mutant of Lucilia also demonstrated localization, declining to half its maximal value at a distance between the slits of 9 +/- 1 microns. Neither light adaptation nor inactivation by the nss mutation, therefore, appear to be mediated by voltage or by a highly diffusible agent. The results are consistent with the idea that inactivation by the nss mutation replaces adaptation in the mutant photoreceptors.  相似文献   
4.
5.
6.
Multiple primary lung cancers. Results of surgical treatment   总被引:4,自引:0,他引:4  
During a 13-year period, multiple primary lung cancers were diagnosed in 80 consecutive patients. Forty-four patients had metachronous cancers. The initial pulmonary resection was lobectomy in 36 patients, bilobectomy in 3, pneumonectomy in 1, and wedge excision or segmentectomy in 4. The second pulmonary resection was lobectomy in 16 patients, bilobectomy in 2, completion pneumonectomy in 7, and wedge excision or segmentectomy in 19. There were two 30-day operative deaths (mortality rate, 4.5%). Actuarial 5- and 10-year survival rates after the first pulmonary resection for stage I disease were 55.2% and 27.0%, respectively. Five-year and 10-year survival rates for stage I disease after the second pulmonary resection were 41.0% and 31.5%, respectively. The remaining 36 patients had synchronous cancers. The pulmonary resection was lobectomy in 18 patients, bilobectomy in 3, pneumonectomy in 10, and wedge excision or segmentectomy in 8. There were two 30-day operative deaths (mortality rate, 5.6%). Actuarial overall 5- and 10-year survival rates after pulmonary resection were 15.7% and 13.8%, respectively. We conclude that an aggressive surgical approach is safe and warranted in most patients with multiple primary lung cancers and that the presence of synchronous primary cancers is ominous.  相似文献   
7.
8.
Gingival crevicular fluid (GCF) IL-8 and IL-1,1β levels were determined by sandwich enzyme-linked immunosorbent assays. Associations between IL-8 and IL-1β GCF levels, and between these cytokines and patient estrogen status were evaluated. IL-8 and IL-1β were detected more frequently and in higher amounts/30 s GCF sample in estrogen-deficient patients than in estrogensufficient patients. IL-8 and IL-1β GCF levels were significantly correlated. These lindings suggest that GCF IL-8 levels are associated with patient estrogen status and local IL-1β concentrations.  相似文献   
9.
A catheter audit was performed at the Central Manchester Trust, which found that there was excessive ordering, inappropriate catheter selection by size, materials, balloon size and poor guidelines on catheter storage. From these findings and from the available literature, we have proposed guidelines on catheter selection with the aim of offering the best patient care and to provide cost efficiency which may be of benefit to other hospitals.  相似文献   
10.
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