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   35359篇
  免费   1899篇
  国内免费   217篇
耳鼻咽喉   325篇
儿科学   785篇
妇产科学   845篇
基础医学   5070篇
口腔科学   637篇
临床医学   2490篇
内科学   8371篇
皮肤病学   651篇
神经病学   4046篇
特种医学   1231篇
外科学   4482篇
综合类   112篇
一般理论   6篇
预防医学   1549篇
眼科学   563篇
药学   2321篇
中国医学   53篇
肿瘤学   3938篇
  2023年   274篇
  2022年   615篇
  2021年   1029篇
  2020年   565篇
  2019年   721篇
  2018年   932篇
  2017年   710篇
  2016年   804篇
  2015年   899篇
  2014年   1113篇
  2013年   1470篇
  2012年   2206篇
  2011年   2217篇
  2010年   1228篇
  2009年   1116篇
  2008年   1868篇
  2007年   1883篇
  2006年   1752篇
  2005年   1605篇
  2004年   1516篇
  2003年   1430篇
  2002年   1339篇
  2001年   710篇
  2000年   762篇
  1999年   720篇
  1998年   353篇
  1997年   258篇
  1996年   239篇
  1995年   224篇
  1994年   231篇
  1993年   193篇
  1992年   645篇
  1991年   562篇
  1990年   556篇
  1989年   567篇
  1988年   501篇
  1987年   489篇
  1986年   441篇
  1985年   444篇
  1984年   249篇
  1983年   210篇
  1982年   95篇
  1979年   233篇
  1978年   127篇
  1977年   100篇
  1975年   99篇
  1974年   98篇
  1973年   97篇
  1970年   100篇
  1969年   114篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
1.
2.
3.
4.
OBJECTIVES: To reveal the frequency and the clinical characteristics of dystrophic calcification that occurs in children with juvenile dermatomyositis, multi-center analysis was constructed. METHOD: Fifty children with JDM were enrolled, and 14 of them (28.0%) were complicated with calcinosis. Clinical symptoms and laboratory tests at onset, initial therapy and disease course were compared in children with and without calcinosis. RESULTS: The mean age of the onset of calcinosis was 4.78 +/- 3.33 years, and it was younger than those of children without calcinosis (8.66 +/- 3.85 years) (P = 0.0017). No differences of clinical manifestation except Gower's sign were observed. The frequency of positive anti-nuclear antibody was 7.1% in children with calcinosis and 52.9% without calcinosis (P = 0.0112). The initial therapy of methylprednisolon pulses gave no effects on prognosis of calcium deposition. The calcinosis appeared in 1.56 +/- 1.91 year after the onset of the disease. The various types of calcium deposition including large tumorous clumps, subcutaneous plaques or nodules, sheet-type calcification were deserved. They appeared over knee joints (64.3%), elbow joint (64.3%), and hip processes (50.0%). Calcinosis affecting the subcutaneous tissues frequently resulted in painful superficial ulceration of the overlying skin (42.9%), local infection (50.0%), and limitation of joint movement (14.3%). Although aluminum phosphate was effective in 2 children among 7, no other effective treatment was recommended. In 5 cases, surgical removal of tumorous clumps was operated. Thus, juvenile dermatomyositis is frequently complicated with calcinosis. This type of calcinosis was found to be unlikely to resolve completely, and resulted in severe disability in children.  相似文献   
5.
6.
7.
8.
9.
Ketogenic capacity of mitochondria from the remnant liver of 70% hepatectomized rats was studied in relation to mitochondrial phosphorylative activity. Ketogenic capacity increased to a maximum of 6.04 +/- 0.39 from 3.84 +/- 0.13 of control, with an enhancement of mitochondrial phosphorylative activity 6 hr after hepatectomy, and then decreased to normal levels within 24 hr. Adenylate energy charge, (ATP + 1/2ADP)/(ATP + ADP + AMP), of the remnant liver decreased to 0.825 +/- 0.006 as compared to 0.849 +/- 0.002 of control 6 hr after operation. At 12 hr, total ketone body concentrations of the arterial blood increased concomitant with a fall in ketone body ratio (acetoacetate/3-hydroxybutyrate) which reflects the decreased liver mitochondrial redox (NAD+/NADH) state. These findings suggest that an enhancement of mitochondrial fatty acid oxidation and ketogenesis occurs concomitant with an enhancement of mitochondrial phosphorylative activity in the remnant liver in response to a decreased energy charge after 70% hepatectomy.  相似文献   
10.
Using high resolution ultrasonography (US), diagnostic accuracy of thrombi in each venous segment of lower limbs and qualitative evaluation of thrombi in deep vein thrombosis (DVT) were investigated. The subjects were 106 lower limbs in 81 patients. The thrombi in common femoral vein (CFV), were diagnosed by compression technique and, were qualitatively analysed by echogenicity and consistency. Venography was performed in 18 limbs and histologic tests of thrombi were made in 6 limbs. The total accuracy of US was 100% for diagnosis of DVT, but was 83% for diagnosis of its extent. The total accuracy of US in each segment was greater than 90%, but the sensitivity of iliac veins was less than 90%. The thrombi in CFV were divided into 3 types and 8 sub-types. Type A was homogenous, type B was heterogenous, and type C was contracted echo. The types of us were consistent with results of histologic tests. We concluded that high resolution US is available for screening test for diagnosis of DVT and that qualitative evaluation of thrombi by US is a useful clinical test for selection of more adequate treatments.  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