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   1768篇
  免费   219篇
  国内免费   4篇
耳鼻咽喉   31篇
儿科学   48篇
妇产科学   35篇
基础医学   358篇
口腔科学   68篇
临床医学   194篇
内科学   447篇
皮肤病学   20篇
神经病学   80篇
特种医学   100篇
外科学   256篇
综合类   24篇
预防医学   116篇
眼科学   8篇
药学   142篇
中国医学   3篇
肿瘤学   61篇
  2021年   28篇
  2020年   29篇
  2019年   25篇
  2018年   31篇
  2017年   18篇
  2016年   32篇
  2015年   27篇
  2014年   34篇
  2013年   53篇
  2012年   88篇
  2011年   77篇
  2010年   55篇
  2009年   48篇
  2008年   74篇
  2007年   94篇
  2006年   67篇
  2005年   67篇
  2004年   63篇
  2003年   54篇
  2002年   60篇
  2001年   46篇
  2000年   59篇
  1999年   44篇
  1998年   27篇
  1997年   20篇
  1996年   35篇
  1995年   34篇
  1994年   27篇
  1993年   26篇
  1992年   26篇
  1991年   23篇
  1990年   20篇
  1989年   20篇
  1988年   26篇
  1986年   21篇
  1985年   26篇
  1984年   24篇
  1983年   20篇
  1977年   32篇
  1976年   22篇
  1975年   21篇
  1974年   58篇
  1973年   43篇
  1972年   43篇
  1971年   29篇
  1970年   25篇
  1969年   16篇
  1968年   19篇
  1967年   18篇
  1966年   15篇
排序方式: 共有1991条查询结果,搜索用时 31 毫秒
41.
42.
These three case reports describe the long-term duration of function of ovarian cortical tissue grafts among patients in a university fertility preservation programme in Europe and in a private practice programme in the USA. One woman underwent sterilizing cancer treatment and had frozen ovarian tissue transplanted, and two women underwent fresh ovarian tissue transplants. The function of ovarian cortical strips has continued for more than 7 years in these three women, with the birth of eight healthy babies following a single graft per patient. In addition to these three cases, transplantation (repeatedly in some cases) of cryopreserved ovarian tissue has restored reproductive function to all other women in the study centres’ programmes for some years. The sustained longevity of function of the transplanted tissue suggests that it may also be possible to postpone the normal time of menopause or to alleviate its symptoms.These three case reports describe the long-term duration of function of ovarian cortical tissue grafts among patients in a university fertility preservation programme in Europe and in a private practice programme in the USA. One woman underwent sterilizing cancer treatment and had frozen ovarian tissue transplanted, and two women underwent fresh ovarian tissue transplants. Function of ovarian cortical strips has continued for more than 7 years in these three women, with the birth of eight healthy babies following a single graft per patient. In addition to these three cases, transplantation (repeatedly in some cases) of cryopreserved ovarian tissue has restored reproductive function to all other women in our programmes for some years. The sustained longevity of function of the transplanted tissue suggests that it may also be possible to postpone the normal time of menopause or to alleviate its symptoms.  相似文献   
43.
44.
45.
OBJECTIVE: Double blind studies were conducted with the anti-CD4 monoclonal antibody (Mab) keliximab in patients with active, stable rheumatoid arthritis (RA), to confirm preliminary evidence of efficacy and safety from open. uncontrolled studies. METHODS: We enrolled 136 and 186 patients into 2 consecutive, randomized, double blind trials, with similar populations [apart from inclusion of disease modifying antirheumatic drug (DMARD)-na?ve patients in Study 2]. Patients received 4 weeks intravenous placebo or keliximab [40, 80, 120, or 140 mg twice weekly (bw), or 240 mg once weekly (ow)].The primary endpoint was the American College of Rheumatology (ACR) 20 response criteria, one week after the end of treatment. RESULTS: ACR 20 response rates in Study I were 19%, 42%, 51%*, and 69%* (*p < 0.05 compared to placebo), with placebo, 40, 80, or 140 mg keliximab bw, respectively. The response rates in Study 2 were 30%, 39%, 46% and 47% with placebo, 80 or 120 mg bw, or 240 mg keliximab ow, respectively. In the 2 studies, there was a dose dependent increase in peripheral blood CD4+ T cell coating with keliximab, but a different pattern of CD4 depletion was seen. While only 12% of keliximab treated patients in Study I had CD4 counts below 250 cells/mm3 at the end of the treatment period, 47% fell below this level in Study 2. Clinical response was not correlated with CD4 depletion, but was correlated with CD4+ T cell coating with keliximab. CONCLUSION: Coating of peripheral blood CD4+ T cells with keliximab, but not CD4 depletion, is a determinant of clinical response.  相似文献   
46.
Anti-tumor necrosis factor-a (anti-TNF-a) therapy strategies result in significant clinical benefits in patients with rheumatoid arthritis, but with an increased rate of serious infectious diseases. We describe a patient receiving infliximab who developed a primary cutaneous Nocardia otitidiscaviarum infection after a skin injury.  相似文献   
47.

Background

Optimal management of urinary tract infections (UTIs) in the emergency department (ED) is challenging due to high patient turnover, decreased continuity of care, and treatment decisions made in the absence of microbiologic data. We sought to identify risk factors for return visits in ED patients treated for UTI.

Methods

A random sample of 350 adult ED patients with UTI by ICD 9/10 codes was selected for review. Relevant data was extracted from medical charts and compared between patients with and without ED return visits within 30 days (ERVs).

Results

We identified 51 patients (15%) with 59 ERVs, of whom 6% returned within 72 h. Nearly half of ERVs (47%) were UTI-related and 33% of ERV patients required hospitalization. ERVs were significantly more likely (P < 0.05) in patients with the following: age  65 years; pregnancy; skilled nursing facility residence; dementia; psychiatric disorder; obstructive uropathy; healthcare exposure; temperature  38 °C heart rate > 100; and bacteremia. Escherichia coli was the most common uropathogen (70%) and susceptibility rates to most oral antibiotics were below 80% in both groups except nitrofurantoin (99% susceptible).Cephalexin was the most frequently prescribed antibiotic (51% vs. 44%; P = 0.32). Cephalexin bug-drug mismatches were more common in ERV patients (41% vs. 15%; P = 0.02). Culture follow-up occurred less frequently in ERV patients (75% vs. 100%; P < 0.05).

Conclusions

ERV in UTI patients may be minimized by using ED-source specific antibiogram data to guide empiric treatment decisions and by targeting at-risk patients for post-discharge follow-up.  相似文献   
48.
49.
50.
Aye  MT; Dunne  JV 《Blood》1981,58(5):1043-1046
The finding of elevated intracellular levels of adenosine deaminase (ADA) in some patients with acute lymphoblastic leukemia has led to attempts to control this disease with the adenosine deaminase inhibitor 2'-deoxycoformycin (dCF). Because of clinical reports indicating its relative freedom from myelotoxicity, we have tested the effects of this drug on erythroid, granulocytic, and T-lymphocyte colony formation by normal marrow and peripheral blood cells. While clinically the drug has been found to be active at serum concentrations of approximately 10 microM, we have tested it at concentrations up to and including 1 mM. It was found that both erythroid and granulocytic colony growth was completely unaffected by 1 mM dCF, a concentration at least 2 magnitudes higher than that necessary to totally ablate intracellular ADA levels. T-lymphocyte colony growth was unaffected by 100 microM dCF, but at 1 mM some inhibition was observed. These findings therefore indicate that dCF, while able to cause leukemic cell lysis in vivo, has no inhibitory effect on the proliferative capacity of normal hematopoietic cells.  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