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   1765篇
  免费   80篇
  国内免费   2篇
耳鼻咽喉   61篇
儿科学   69篇
妇产科学   22篇
基础医学   167篇
口腔科学   164篇
临床医学   105篇
内科学   289篇
皮肤病学   120篇
神经病学   61篇
特种医学   37篇
外科学   314篇
综合类   1篇
预防医学   62篇
眼科学   24篇
药学   118篇
中国医学   4篇
肿瘤学   229篇
  2023年   16篇
  2022年   18篇
  2021年   60篇
  2020年   34篇
  2019年   27篇
  2018年   45篇
  2017年   26篇
  2016年   29篇
  2015年   38篇
  2014年   50篇
  2013年   43篇
  2012年   65篇
  2011年   81篇
  2010年   44篇
  2009年   54篇
  2008年   72篇
  2007年   57篇
  2006年   68篇
  2005年   89篇
  2004年   113篇
  2003年   88篇
  2002年   96篇
  2001年   74篇
  2000年   68篇
  1999年   51篇
  1998年   26篇
  1997年   19篇
  1996年   19篇
  1995年   9篇
  1994年   9篇
  1993年   7篇
  1992年   37篇
  1991年   38篇
  1990年   54篇
  1989年   30篇
  1988年   25篇
  1987年   24篇
  1986年   31篇
  1985年   29篇
  1984年   11篇
  1983年   10篇
  1982年   10篇
  1981年   9篇
  1980年   6篇
  1979年   8篇
  1978年   6篇
  1977年   3篇
  1973年   3篇
  1972年   3篇
  1965年   3篇
排序方式: 共有1847条查询结果,搜索用时 15 毫秒
1.
2.
Long bone injuries in clinical cases are studied by comparison of roentgenograms with a rational mechanical analysis of the injuries. Fractures produced by torsional loads have a spiral shape with a smooth and even surface. Fractures induced by bending loads have uneven and rugged fracture surfaces perpendicular to the bone axis. Long bones are weak in torsion but strong in tensile stress produced by bending. This result corresponds to the clinical fact that a large direct external force is needed to produce a transverse fracture while a spiral fracture is produced by a relatively small torque.  相似文献   
3.
4.
OBJECTIVE: To investigate the eruption pattern of the cleft-side canine regarding its pre-eruption position relative to the cleft in bone-grafted (BG) and nongrafted (NonBG) patients with cleft lip and palate. METHODS: Fifty-three patients with cleft lip and palate (21 BG, 32 NonBG) were examined by panoramic radiography and posteroanterior cephalography taken before and after canine eruption. Subjects were categorized into BG, NonBG, and control groups. Canines at the pre-eruption stage were categorized as close to (group 1) or distant from (group 2) the cleft area. The canine angle and its change between the two stages were evaluated. RESULTS: No significant differences were noted between the initial canine angle of the BG and NonBG groups. Although canines in the BG group erupted without a significant change in angle, the canine angle increased significantly (p < .0001) in the NonBG and control groups. In group 1, a greater change in canine angle was noted in the NonBG (p < .05) and control (p < .01) groups than in the BG group. In group 2, no significant difference was noted among the three groups. CONCLUSIONS: In BG patients, a canine located near the cleft appears to erupt at the same angle as it had before grafting. However, in NonBG patients, it erupts more vertically, guided by cortical bone. For canines distant from the cleft area, there is no significant difference in the change in angulation between NonBG and BG patients.  相似文献   
5.
6.
One mol perchloric acid-soluble fraction (PASF) obtained from ascitic fluid of a patient (blood group B) with metastatic omentum tumor from ovarian cancer was a glycoprotein fraction containing 35.4% carbohydrate and exhibited A, B and Thomsen-Friedenreich (T) activities. This fraction was separated into three fractions, Frs. 1-3, by a gel filtration with Bio-Gel A-1.5 m column. Among these fractions, Fr. 1 which was obtained in a 5.5% yield to PASF, was a glycoprotein fraction with a high molecular weight, 23.3% carbohydrate and A, B and T activities. Other minor fraction, Fr. 2, and the major fraction, Fr. 3, contained 43.2% and 43.9% carbohydrate, but did not show A, B and T activities, respectively.  相似文献   
7.
8.
9.
The authors report on 48 patients with calculous pyelonephritis. Urinary obstruction was caused by renal calculi in 21 patients and ureteral calculi in 27. Urine cultures were positive in 87.5% and bacteremia was seen in 70%. The common organisms in urine and blood culture wereE. coli, Proteus and Klebsiella. Septic shock occurred in 10 (20.8%) out of 48 patients. Calculous pyelonephritis with urinary obstruction is a very serious condition.  相似文献   
10.
The adherence of circulating leukocytes to the vascular endothelium is a critical step in the emigration of leukocytes through blood vessel walls to inflammatory lesions. The influence of nasal secretions on the adherence of neutrophils to the vascular endothelium was investigated using monolayers of human mucosal microvascular endothelial cells derived from the inferior turbinate. Preincubation of vascular endothelial cells with retention fluids from the maxillary sinus of the patients with chronic sinusitis showed increased neutrophil adherence. Recombinant IL-1 beta was also tested and found to induce adherence of neutrophils to human mucosal microvascular endothelial cells. However, no adhesive effect was observed with the nasal secretions of nasal allergy. An enzyme-linked immunosorbent assay detected considerable amounts of IL-1 beta in the chronic sinusitis retention fluids, while the amounts of IL-1 alpha and TNF-alpha were very low. The increased adhesion of the neutrophils by the retention fluids of chronic sinusitis was also neutralized by the incubation with anti-IL-1 beta antibody in a dose dependent manner. These findings suggest that IL-1 beta in the paranasal secretion of chronic sinusitis induces the adherence of neutrophils to vascular endothelium and subsequent infiltration of neutrophils in the paranasal sinuses, thus contributing to the persistence of chronic sinusitis.  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