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   2174篇
  免费   153篇
  国内免费   76篇
耳鼻咽喉   1篇
儿科学   177篇
妇产科学   30篇
基础医学   276篇
口腔科学   62篇
临床医学   262篇
内科学   519篇
皮肤病学   98篇
神经病学   74篇
特种医学   408篇
外科学   105篇
综合类   47篇
预防医学   112篇
眼科学   20篇
药学   101篇
  2篇
肿瘤学   109篇
  2023年   6篇
  2022年   9篇
  2021年   13篇
  2020年   14篇
  2019年   18篇
  2018年   34篇
  2017年   26篇
  2016年   27篇
  2015年   45篇
  2014年   48篇
  2013年   62篇
  2012年   41篇
  2011年   40篇
  2010年   89篇
  2009年   92篇
  2008年   57篇
  2007年   99篇
  2006年   52篇
  2005年   60篇
  2004年   33篇
  2003年   26篇
  2002年   30篇
  2001年   48篇
  2000年   36篇
  1999年   36篇
  1998年   132篇
  1997年   157篇
  1996年   133篇
  1995年   110篇
  1994年   120篇
  1993年   98篇
  1992年   35篇
  1991年   49篇
  1990年   41篇
  1989年   64篇
  1988年   53篇
  1987年   42篇
  1986年   55篇
  1985年   48篇
  1984年   30篇
  1983年   17篇
  1982年   24篇
  1981年   31篇
  1980年   26篇
  1979年   9篇
  1978年   9篇
  1977年   22篇
  1976年   28篇
  1975年   14篇
  1968年   4篇
排序方式: 共有2403条查询结果,搜索用时 15 毫秒
1.
Cutaneous plasmacytosis is a rare disorder characterized by a benign proliferation of mature plasma cells that appears as multiple dark-brown to purplish skin lesions, often associated with polyclonal hypergammaglobulinaemia. We present the case of a 55-year-old Caucasian man who suffered from a cutaneous plasmacytosis associated with two different carcinomas. Cutaneous plasmacytosis seems to be a reactive process because most cases reported are not associated with any apparent underlying disease. Nevertheless, because few reported cases were associated with malignancies, screening of additional neoplasms would be justified.  相似文献   
2.
The aim of this study was to evaluate the cerebral synthesis of eicosanoids in the asphyctic newborn and to investigate the relation between the prostanoid profiles in cerebrospinal fluid (CSF) and the appearance and severity of hypoxic-ischaemic encephalopathy (HIE). Levels of 6-keto-PGF 1-α, TXB2, PGE2 and PGF2-α in CSF were measured in 40 full term newborns during the first day of life. Thirty of these newborns had birth asphyxia and were divided into three groups: 10 without HIE, 12 with mild HIE and 8 with moderate-severe HIE. They were compared to a control group of 10 non-hypoxic newborns. Determinations of the metabolites in CSF were performed by RIA and expressed as pg/ml (mean ± SD). The CSF TXB2 (thromboxane A2 metabolite) in asphyxiated newborns was always higher than in the control group (28.12 ± 10.6), and related to the severity of HIE ( p = 0:005): without HIE (50.84 ± 16.4; p = 0:02), mild HIE (80.65 ± 12.64; p ± 0:01) and moderate-severe HIE (178.14 ± 20.5; p < 0:01). The CSF 6-keto-PGF 1-α (prostacyclin metabolite) in asphyxiated newborns was always higher than in the control group (80.55 ± 12.56), but indirectly related to the severity of HIE: without HIE (240.95 ± 28.12; p < 0:01), mild HIE (183.65 ± 30.1; p < 0:01) and moderate-severe HIE (140.55 ± 25.12; p < 0:01). In the moderate-severe HIE group, the increase in TXB2 was higher than the rise in 6-keto-PGF 1-α.  相似文献   
3.
4.
5.
6.
7.
8.
9.
FM sonography - a signal-processing technique that uses frequency and phase information as well as amplitude data - shows promise in evaluation of patients with diffuse liver disease. In a prospective blinded review of 37 patients with biopsy-proved liver disease and 42 healthy volunteers, FM sonography was clearly superior to traditional amplitude-based (AM) sonography in distinguishing healthy from diseased subjects. Statistically significant differences were seen in accuracy (FM, 98.7%; AM, 84.8%), sensitivity (FM, 97.3%; AM, 70.3%), and negative predictive value (FM, 97.7%; AM, 78.8%). Our data also suggest that current FM sonographic techniques cannot differentiate among histologic findings associated with different hepatic parenchymal abnormalities. It is unclear, therefore, whether FM imaging can reduce the numbers of patients who require biopsy for diagnosis or the frequency of biopsy procedures in patients with known disease.  相似文献   
10.
Thirty-five patients hospitalized for recent angiographically documented arterial occlusion in the legs (27 femoropopliteal arteries and eight grafts) benefited from local fibrinolytic therapy delivered at the site of the occlusion with a 4- or 5-F catheter. This therapy combined a continuous urokinase (UK) infusion of 1,000 U/kg/hour and a lysyl plasminogen (LYS-PLG) infusion of 15 microkatals every 30 minutes. Angiographically confirmed lysis was obtained in 85% of the cases. Only 3% of the patients had major and 6% had minor groin hematomas. Only two patients had concentrations of fibrinogen as low as 100 mg/dl. Intravascular infusion of UK-LYS-PLG is as effective as streptokinase. Its excellent tolerance makes it a good alternative in the treatment of acute ischemia in the lower limbs.  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