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   3952篇
  免费   195篇
  国内免费   9篇
耳鼻咽喉   83篇
儿科学   237篇
妇产科学   48篇
基础医学   391篇
口腔科学   86篇
临床医学   280篇
内科学   695篇
皮肤病学   32篇
神经病学   298篇
特种医学   185篇
外科学   774篇
综合类   118篇
一般理论   1篇
预防医学   186篇
眼科学   242篇
药学   264篇
中国医学   18篇
肿瘤学   218篇
  2023年   28篇
  2022年   69篇
  2021年   139篇
  2020年   53篇
  2019年   89篇
  2018年   126篇
  2017年   91篇
  2016年   113篇
  2015年   121篇
  2014年   147篇
  2013年   213篇
  2012年   300篇
  2011年   319篇
  2010年   185篇
  2009年   174篇
  2008年   242篇
  2007年   235篇
  2006年   211篇
  2005年   206篇
  2004年   165篇
  2003年   145篇
  2002年   157篇
  2001年   78篇
  2000年   48篇
  1999年   55篇
  1998年   28篇
  1997年   20篇
  1996年   20篇
  1995年   10篇
  1993年   15篇
  1992年   22篇
  1991年   32篇
  1990年   28篇
  1989年   35篇
  1988年   19篇
  1987年   27篇
  1986年   17篇
  1985年   12篇
  1984年   10篇
  1983年   12篇
  1982年   7篇
  1981年   19篇
  1979年   9篇
  1977年   8篇
  1976年   9篇
  1975年   8篇
  1974年   7篇
  1973年   11篇
  1971年   9篇
  1969年   8篇
排序方式: 共有4156条查询结果,搜索用时 0 毫秒
21.
22.
Drug-induced secondary angle closure is quite common and in the majority of cases simply stopping the medication leads to rapid reversal of the condition and resolution of glaucoma. We describe here a patient who presented with secondary angle closure glaucoma and myopia following mefenamic acid ingestion which was managed successfully by stopping the medication, symptomatic treatment and reassurance.  相似文献   
23.
24.
It was our purpose to determine the characteristics of practitioners in the United States who were among the first to inquire about and use the BRCA1 and BRCA2 (BRCA1/2) genetic tests outside of a research protocol. Questionnaires were mailed to all practitioners who requested information on or ordered a BRCA1/2 test from the University of Pennsylvania (UPenn) Genetic Diagnostics Laboratory (GDL) between October 1, 1995 and January 1, 1997 (the first 15 months the test was available for clinical use). The response rate was 67% of practitioners; 54% (121/225) were genetic counselors, 39% (87/225) were physicians or lab directors. Most physicians were oncologists, pathologists, or obstetrician/gynecologists, but 20% practiced surgery or internal or general medicine. Fifty-six percent (125/225) had ordered a BRCA1/2 test for a patient; most of the rest had offered or were willing to offer testing. Of those who had offered testing, 70% had a patient decline BRCA1/2 testing when offered. Practitioners perceived that patients' fear of loss of confidentiality was a major reason for declining. Nearly 60% of practitioners reported that their patients had access to a genetic counselor, but 28% of physicians who ordered a BRCA1/2 test reported having no such access, despite the GDL's counseling requirement. The proportion of physicians reporting no access to genetic counselors for their patients increased from 22.4% in the first half of the study to 50% in the last half. Many practitioners have an interest in BRCA1/2 testing, despite policy statements that discourage its use outside of research protocols. Practitioner responses suggest that patient interest in testing seems to be tempered by knowledge of potential risks. An apparent increase in patient concern about confidentiality and inability to pay for testing could indicate growing barriers to testing. Although most practitioners reported having access to counseling facilities, perceived lack of such access among an increasing proportion of practitioners indicates that lab requirements for counseling are difficult to enforce and suggests that an increasing proportion of patients may not be getting access to counseling.  相似文献   
25.
Systemic lupus erythematosus (SLE) is an autoimmune disease characterized by immune complex-mediated tissue injury. Many different adhesion molecules are thought to participate in the development of SLE; however, few studies have directly examined the contributions of these proteins. Here we demonstrate that LFA-1 plays an essential role in the development of lupus in MRL/MpJ-Fas(lpr) mice. Mice deficient in LFA-1, but not Mac-1, showed significantly increased survival, decreased anti-DNA autoantibody formation, and reduced glomerulonephritis. The phenotype of the LFA-1-deficient mice was similar to that observed in beta(2) integrin-deficient (CD18-null) MRL/MpJ-Fas(lpr) mice, suggesting a lack of redundancy among the beta(2) integrin family members and other adhesion molecules. These studies identify LFA-1 as a key contributor in the pathogenesis of autoimmune disease in this model, and further suggest that therapeutic strategies targeting this adhesion molecule may be beneficial for the treatment of SLE.  相似文献   
26.
Reperfusion after ischemia results in endothelial cell injury and Kupffer cell activation. Inflammatory cytokines thus released can induce major histocompatibility complex antigens and increase the immunogenecity of the graft. An orthotopic rat liver allotransplant model was used to test the hypothesis that prevention of reperfusion injury by infusion of polyethylene glycol superoxide dismutase (PEG-SOD) would result in long-term allograft survival in the presence of subthreshold immunosuppressive dosages. ACI rats were used as donors, and Lewis strain rats as recipients. Orthotopic liver transplantation was initially performed to identify a subthreshold dose of the immunosuppressant FK-506, which would be unable to extend survival longer than control untreated rats with this strain combination. After testing three intramuscular FK-506 doses of 0.04, 0.08, and 0.16 mg/kg, it was observed that an FK-506 dose of 0.04 mg/kg/day for 14 days was unable to extend survival longer than in untreated recipients. This dose of FK-506 was used in combination with PEG-SOD at doses of 1000, 3000, 10,000, or 30,000 units. Recipient animals were treated intravenously with PEG-SOD as a loading dose to facilitate tissue penetration on day 1, and beginning on the day of transplantation, every 2 days for the duration of the study. Results of histologic studies and mean survival time were compared in untreated recipients and in rats treated with PEG-SOD plus 0.04 mg/kg/day FK-506. Mean survival time was increased significantly in these animals (p < 0.007) to 40.6 ± 25.6 days as compared with either untreated rats (10.0 ± 2.7 days) or rats treated with 0.04 mg/kg FK-506 alone (13.7 ± 4.2 days). Histologic examination demonstrated a significant reduction in the cellular infiltrate in rats treated with PEG-SOD plus FK-506, as compared with recipients treated with either agent alone or left untreated. Our results therefore suggest a potential approach to reducing immunosuppression in transplantation. (J ALLERGY CLIN IMMUNOL 1995;95:1276-81.)  相似文献   
27.
Parallel to the inactivation of the X chromosome in somatic cells of female, the male X in mammals is rendered inactive during spermatogenesis. Pseudoautosomal genes, those present on the X-Y meiotically pairable region of male, escape inactivation in female soma. It is suggested, but not demonstrated, that they may also be refractory to the inactivation signal in male germ cells. We have assayed activity of the enzyme steroid sulfatase, product of a pseudoautosomal gene, in testicular cells of the mouse and shown its presence in premeiotic, meiotic (pachytene), and postmeiotic (spermatid) cell types. It appears that, as in females, pseudoautosomal genes may escape inactivation in male germ cells also.  相似文献   
28.
Signaling to NF-kappaB   总被引:30,自引:0,他引:30  
Hayden MS  Ghosh S 《Genes & development》2004,18(18):2195-2224
  相似文献   
29.
30.
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