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   379126篇
  免费   24169篇
  国内免费   2809篇
耳鼻咽喉   5199篇
儿科学   8204篇
妇产科学   10086篇
基础医学   53122篇
口腔科学   11783篇
临床医学   30095篇
内科学   78284篇
皮肤病学   8545篇
神经病学   27197篇
特种医学   13931篇
外国民族医学   82篇
外科学   60589篇
综合类   9956篇
现状与发展   1篇
一般理论   64篇
预防医学   17419篇
眼科学   9440篇
药学   30987篇
  1篇
中国医学   2195篇
肿瘤学   28924篇
  2021年   2608篇
  2019年   2730篇
  2018年   4521篇
  2017年   3429篇
  2016年   3521篇
  2015年   4017篇
  2014年   5693篇
  2013年   7374篇
  2012年   10016篇
  2011年   10206篇
  2010年   6206篇
  2009年   5843篇
  2008年   9451篇
  2007年   10282篇
  2006年   10212篇
  2005年   9270篇
  2004年   8778篇
  2003年   8512篇
  2002年   8192篇
  2001年   28238篇
  2000年   28774篇
  1999年   23652篇
  1998年   5161篇
  1997年   4248篇
  1996年   3831篇
  1995年   3480篇
  1994年   3103篇
  1993年   2844篇
  1992年   16048篇
  1991年   14816篇
  1990年   14154篇
  1989年   13962篇
  1988年   12585篇
  1987年   12060篇
  1986年   11104篇
  1985年   10323篇
  1984年   6915篇
  1983年   5603篇
  1982年   2720篇
  1979年   5481篇
  1978年   3348篇
  1977年   2973篇
  1975年   2642篇
  1974年   3064篇
  1973年   2866篇
  1972年   2829篇
  1971年   2777篇
  1970年   2511篇
  1969年   2545篇
  1968年   2252篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
111.
112.
113.
AIMS: A rare case of the insulin autoimmune syndrome (IAS) accompanied by insulin receptor anomaly is reported. METHODS: Antibodies to insulin and insulin receptor were determined in the patient with severe hypoglycaemia before and after the treatment with prednisolone. RESULTS: Titers of antibody to insulin and insulin receptors were 73.0% and 41.5%, respectively. Drug-induced lymphocyte stimulation tests were all negative for the suspicious drugs. Her HLA-DR was DRB1*0403/04051. Following steroid therapy, the formation of antibodies was suppressed and alleviated her symptoms. Scatchard analysis yielded findings specific to polyclonal antibodies. CONCLUSIONS: The changes in autoantibodies resulted in alleviation of the hypoglycemic symptoms as a result of steroid therapy.  相似文献   
114.
X Dong  M He  X Song  B Lu  Y Yang  S Zhang  N Zhao  L Zhou  Y Li  X Zhu  R Hu 《Diabetic medicine》2007,24(12):1482-1486
AIMS: Our aim was to assess performances of the Cockcroft-Gault and simplified Modification of Diet in Renal Disease (MDRD) formulae in estimating glomerular filtration rate (GFR) in Chinese diabetic populations and their association with vascular risks. METHODS: A total of 1009 patients with Type 2 diabetes were categorized into low estimated GFR groups (GFR < 60 ml/min/1.73 m(2)) and control groups by the two equations. The performances of these formulae were assessed at different stages of kidney function. Carotid artery intima-media thickness (IMT) and the prevalence of diabetic retinopathy or albuminuria were compared among the groups. The ability of these formulae to identify established vascular risk markers using sensitivity, specificity, positive and negative predictive values were also compared. RESULTS: The prevalence of low estimated GFR was 32.7% with the Cockcroft-Gault formula and 5.2% with the MDRD formula, respectively. In low estimated GFR subjects by the MDRD formula, IMT was significantly thicker than those by the Cockcroft-Gault formula (1.2 mm vs. 1.0 mm; P < 0.05), with a higher prevalence of albuminuria (78.4 vs. 52.8%, P < 0.05) and diabetic retinopathy (46.5 vs. 30.5%; P < 0.05). The Cockcroft-Gault formula gave a specificity of 71.7% and a sensitivity of 37.0%, and the MDRD formula gave a specificity of 96.6% and a sensitivity of 7.9% in estimating low GFR relevant for established vascular risks. CONCLUSIONS: These formulae performed differently in Chinese diabetic populations. The simplified MDRD formula is minimally superior to the Cockcroft-Gault formula for its high specificity and positive predictive values in estimating low GFR relevant for vascular risks.  相似文献   
115.
The incidence of late infection after cranioplasty was studied in 130 patients with 133 cranioplasties. The materials used were prefabricated resin in 62 cases, autogenic bone in 38, intraoperatively fashioned resin in 25, and vitallium in eight. Six infections were documented, for an infection rate of 4.5%. In addition to these six cases, we studied eight patients with infections who had undergone cranioplasty elsewhere but had the infected plates removed in our hospitals. Among the 14 cases of infection, the intervals between cranioplasty and plate removal were 3 to 43 months (average, 10.5 months). The eight patients referred from other hospitals had a significantly shorter average interval between external decompression and cranioplasty than did patients who did not develop infection (2.6 versus 6.7 months; p less than 0.005). Systemic signs were mild despite obvious local signs of infection. Of the 11 first infections, nine (82%) were associated with discharge of pus from a fistula; in these cases a galeal suture had become infected apparently through scratching by the patients. In contrast, in the three patients who had had a previous infection, the second infection manifested as subgaleal and epidural empyema or meningitis without a fistula or pus discharge. Nine infections (69%) were due to Staphylococcus. All but two patients required removal of the infected plates. One recovered with conservative therapy and one died of meningitis, giving a mortality rate of 0.8%. No matter how mild the systemic signs, late infection warrants surgical debridement and plate removal. The risk factors for late infection of cranioplasty are discussed.  相似文献   
116.
The optimal size of tricuspid valve annular area (TVAA) by annuloplasty for tricuspid regurgitation remains controversial. Recently, we developed a new measuring system which permits to do real-time measurement of tricuspid valve annular area in anesthetized dogs. Using this system, we studied the optimal size of TVAA by annuloplasty. After the right atrial incision, a metal thread which functions as a sense loop of the electromagnetic fields was stitched along the tricuspid valve annulus (visible juncture of the valve leaflets and the cardiac wall). The drive coil assembly was placed perpendicular to the extension of the long axis of the heart and was directed toward the tricuspid valve region. During control conditions, the maximum TVAA appeared at the onset of ventricular systole. The minimum TVAA appeared during the early ventricular diastolic phase which included the ventricular isovolumic relaxation phase. The maximum TVAA varied in five dogs between 2.2 cm2 and 3.1 cm2, the minimum TVAA also varied between 1.8 cm2 and 2.5 cm2: During regular sinus rhythm, a decrease of TVAA during one cardiac cycle ranged between 11.9% and 22.4% of the maximum size. When TVAA was not decreased by annuloplasty to the minimum area which was observed during cardiac cycle in the control state, the cardiac output and the right atrial pressure remained unchanged, because the ventricular filling was not obstructed. On the other hand, when TVAA was decreased smaller than this minimum area, the cardiac output decreased and the right atrial pressure rose.(ABSTRACT TRUNCATED AT 250 WORDS)  相似文献   
117.
118.
119.
120.
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