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   53273篇
  免费   3935篇
  国内免费   218篇
耳鼻咽喉   604篇
儿科学   1213篇
妇产科学   1122篇
基础医学   7562篇
口腔科学   1063篇
临床医学   5077篇
内科学   11031篇
皮肤病学   1253篇
神经病学   5148篇
特种医学   2136篇
外国民族医学   7篇
外科学   9404篇
综合类   517篇
一般理论   76篇
预防医学   2942篇
眼科学   1113篇
药学   3209篇
中国医学   76篇
肿瘤学   3873篇
  2023年   499篇
  2022年   984篇
  2021年   1795篇
  2020年   1073篇
  2019年   1420篇
  2018年   1613篇
  2017年   1095篇
  2016年   1302篇
  2015年   1498篇
  2014年   2026篇
  2013年   2366篇
  2012年   3807篇
  2011年   3788篇
  2010年   2094篇
  2009年   1887篇
  2008年   3008篇
  2007年   3016篇
  2006年   2844篇
  2005年   2681篇
  2004年   2464篇
  2003年   2283篇
  2002年   2072篇
  2001年   751篇
  2000年   724篇
  1999年   716篇
  1998年   508篇
  1997年   407篇
  1996年   307篇
  1995年   278篇
  1994年   254篇
  1993年   247篇
  1992年   467篇
  1991年   426篇
  1990年   392篇
  1989年   346篇
  1988年   346篇
  1987年   324篇
  1986年   305篇
  1985年   317篇
  1984年   261篇
  1983年   243篇
  1982年   200篇
  1981年   187篇
  1980年   195篇
  1979年   234篇
  1978年   180篇
  1977年   164篇
  1974年   183篇
  1973年   157篇
  1966年   154篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
71.
72.
Flavocoxid (Limbrel), a proprietary mixture of flavonoid molecules (baicalin and catechin), was tested against a traditional nonsteroidal anti-inflammatory drug, naproxen, for the management of the signs and symptoms of moderate osteoarthritis (OA) in humans. Discomfort and global disease activity were used as the primary end points, and safety assessments were also taken for both treatments as a secondary endpoint. In this double-blind study, 103 subjects were randomly assigned to receive either flavocoxid [500 mg twice daily (BID)] or naproxen (500 mg BID) in a 1-month onset of action trial. Outcome measures included the short Western Ontario and McMaster University Osteoarthritis Index, subject Visual Analogue Scale for discomfort and global response, and investigator Visual Analogue Scale for global response and fecal occult blood. Both flavocoxid and naproxen showed significant reduction in the signs and symptoms of knee OA (P ≤ .001). There were no statistically detectable differences between the flavocoxid and naproxen groups with respect to any of the outcome variables. Similarly, there were no statistically detectable differences between the groups with respect to any adverse event, although there was a trend toward a higher incidence of edema and nonspecific musculoskeletal discomfort in the naproxen group. In this short-term pilot study, flavocoxid was as effective as naproxen in controlling the signs and symptoms of OA of the knee and would present a safe and effective option for those individuals on traditional nonsteroidal anti-inflammatory drugs or cyclooxygenase-2 inhibitors. A low incidence of adverse events was reported for both groups.  相似文献   
73.
74.
Intravenous ganciclovir is the standard treatment for cytomegalovirus disease in solid organ transplant recipients. Oral valganciclovir is a more convenient alternative. In a randomized, international trial, recipients with cytomegalovirus disease were treated with either 900 mg oral valganciclovir or 5 mg/kg i.v. ganciclovir twice daily for 21 days, followed by 900 mg daily valganciclovir for 28 days. A total of 321 patients were evaluated (valganciclovir [n = 164]; i.v. ganciclovir [n = 157]). The success rate of viremia eradication at Day 21 was 45.1% for valganciclovir and 48.4% for ganciclovir (95% CI -14.0% to +8.0%), and at Day 49; 67.1% and 70.1%, respectively (p = NS). Treatment success, as assessed by investigators, was 77.4% versus 80.3% at Day 21 and 85.4% versus 84.1% at Day 49 (p = NS). Baseline viral loads were not different between groups and decreased exponentially with similar half-lives and median time to eradication (21 vs. 19 days, p = 0.076). Side-effects and discontinuations of assigned treatment (18 of 321 patients) were comparable. Oral valganciclovir shows comparable safety and is not inferior to i.v. ganciclovir for treatment of cytomegalovirus disease in organ transplant recipients and provides a simpler treatment strategy, but care should be taken in extrapolating to organ transplant recipients not properly represented in the present study.  相似文献   
75.
76.
The first part of this serial paper dealt with the medical criteria used in evaluation of the clinical picture caused by physical stress and the evaluation of other candidate causes and was published in issue no. 3/2005 (pp. 711–752) of Trauma and Berufskrankheit. This follow-up paper (II) presents criteria to be used in the evaluation of whether it is necessary to give up the occupations putting the spine at risk and in estimation of the degree of disability.  相似文献   
77.
78.
Massive immune hemolysis due to passenger lymphocyte-derived anti-D has not been reported in renal transplantation. A 50-year-old (B-positive) male received a dual deceased-donor kidney transplant (B-negative) for diabetic renal failure. Two weeks post-transplant, the patient developed severe hemolytic anemia. The donor anti-D titer was 1:8. The recipient anti-D titer (zero pre-transplant) increased from 1:4 to 1:16 over 4 days. Rapid hemolysis caused severe anemia, minimum Hb = 4.2 g/dL, while selectively lysing the patient's autologous red cells during this time. The hemolytic anemia did not impair the allografts and subsided without monoclonal B-cell pharmacotherapy or apheresis. The anti-D titer decreased to barely detectable levels at four months and had cleared when checked 2 years post-transplant. Transfusion support subsided after two months. If complications of anemia can be avoided, the deleterious effects of hemolysis may be well tolerated by renal allografts using antigen negative transfusion alone.  相似文献   
79.
Experimental gene therapy is a promising strategy to prevent ischemia-reperfusion (I/R) injury and allograft rejection after lung transplantation, and methods will eventually be needed to characterize pulmonary transgene expression in vivo in humans. Therefore, we studied positron emission tomography (PET) as a means of performing in vivo molecular imaging in rodent models of lung transplantation. Rats were transfected endotracheally with adenovirus encoding a fusion gene of a mutant Herpes simplex virus-1 thymidine kinase and the green fluorescent protein gene (the former serving as an imaging reporter gene). Twenty-four hours after transfection, lungs were transplanted in groups representing normal transplantation, I/R injury and acute allograft rejection. Imaging was obtained either 24 h after transplantation to study reperfusion injury or 4 days after transplantation to study graft rejection. After imaging, lungs were excised and analyzed for thymidine kinase activity. Imaging detected transgene expression in transplanted lungs even in the presence of acute rejection or I/R injury. The PET imaging signal correlated with in vitro lung tissue assays of thymidine kinase activity (r(2) = 0.534). Thus, noninvasive molecular imaging with PET is a feasible, sensitive and quantitative method for characterizing pulmonary transgene expression in experimental lung transplantation.  相似文献   
80.
We present a case of Bernard Soulier syndrome in a 9-year-old boy caused by a novel genetic mutation. This child was shown to be homozygous for a single nucleotide deletion (c.1077delG) in the GP1BA gene not previously reported. Clinically, the boy has become refractory to platelet transfusions with both allo-antibodies and iso-antibodies and a massive transfusion requirement for ongoing haemorrhage. We describe the critical role that the blood product transfusion continues to play in the management of Bernard Soulier syndrome and discuss therapeutic options in these patients.  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