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   624篇
  免费   47篇
  国内免费   11篇
耳鼻咽喉   5篇
儿科学   9篇
妇产科学   5篇
基础医学   65篇
口腔科学   4篇
临床医学   79篇
内科学   136篇
皮肤病学   8篇
神经病学   66篇
特种医学   76篇
外科学   51篇
综合类   9篇
预防医学   51篇
眼科学   2篇
药学   52篇
肿瘤学   64篇
  2023年   5篇
  2021年   9篇
  2020年   8篇
  2018年   12篇
  2017年   7篇
  2016年   5篇
  2015年   6篇
  2014年   17篇
  2013年   20篇
  2012年   18篇
  2011年   26篇
  2010年   23篇
  2009年   20篇
  2008年   22篇
  2007年   28篇
  2006年   15篇
  2005年   14篇
  2004年   17篇
  2003年   14篇
  2002年   7篇
  2001年   18篇
  2000年   14篇
  1999年   5篇
  1998年   20篇
  1997年   14篇
  1996年   10篇
  1995年   10篇
  1994年   13篇
  1993年   14篇
  1992年   18篇
  1991年   19篇
  1990年   14篇
  1989年   11篇
  1988年   14篇
  1987年   16篇
  1986年   19篇
  1985年   8篇
  1984年   7篇
  1983年   6篇
  1982年   10篇
  1981年   15篇
  1980年   6篇
  1979年   17篇
  1978年   14篇
  1977年   11篇
  1976年   7篇
  1974年   11篇
  1973年   5篇
  1971年   10篇
  1969年   4篇
排序方式: 共有682条查询结果,搜索用时 15 毫秒
641.
Acute appendicitis: high-resolution real-time US findings   总被引:3,自引:1,他引:2  
Jeffrey  RB  Jr; Laing  FC; Lewis  FR 《Radiology》1987,163(1):11-14
High-resolution, real-time ultrasonography (US) with graded compression was used to evaluate 90 patients with clinically suspected acute appendicitis. US visualization of a noncompressible appendix was the primary criterion for a diagnosis of acute appendicitis. The overall sensitivity was 89%, the specificity was 95%, and the accuracy was 93%. When the results in women were analyzed separately (n = 49), the overall accuracy was 96%. Several important limitations of US scanning were encountered. There were three false-positive examinations in patients with a sonographically visible appendix whose symptoms spontaneously resolved. Another patient had a normal compressible appendix with a thin (2-mm), symmetric wall surrounded by ascites. There were three nondiagnostic studies (3%) due to inability to compress the cecum and right lower quadrant adequately because of exquisite tenderness (two patients) or massive ascites (one patient). When interpreted in light of the clinical examination, sonography should significantly reduce the rate of false-negative appendectomies, particularly in women.  相似文献   
642.
Renal artery stenosis in kidney transplants   总被引:1,自引:0,他引:1  
Transplant renal artery stenosis (TRAS) is an increasingly recognized complication of renal transplantation, with a reported incidence of between 1% and 23%. The clinical features include refractory hypertension, new-onset hypertension, allograft dysfunction, and the presence of a bruit over the graft. In this report, we describe the investigation and treatment of one such patient and review the current diagnostic approaches and therapy in this setting.  相似文献   
643.
Distal ureteral calculi: detection with vaginal US   总被引:2,自引:0,他引:2  
  相似文献   
644.
645.
Heterotopic gray matter, which previously had been associated with severe congenital malformations of the brain and developmental delay, was found without these associated conditions. The authors found ten cases of heterotopic gray matter on magnetic resonance (MR) images. The lesions had a signal intensity that was isointense compared with that of gray matter on T1, spin-density, and T2-weighted images. Nine of the ten cases were associated with a seizure disorder. The tenth case, discovered during a workup for metastatic lung disease, was confirmed with pathologic studies. Heterotopic gray matter is the presence of cortical neurons in an abnormal location, which may be periventricular (nodular) or within the white matter (laminar). A knowledge of heterotopic gray matter and its association with seizures may prevent the misinterpretation of findings on MR images.  相似文献   
646.
647.
648.
Erythrocytes, granulocytes and platelets from patients with paroxysmal nocturnal haemoglobinuria (PNH) are abnormally sensitive to lysis by complement. We studied T-lymphocytes from PNH patients for abnormal complement lysis sensitivity. T-lymphocytes free of other contaminating blood cells were prepared by sedimentation, nylon wool filtration, and density gradient centrifugation. The lymphocytes were then labelled with 51Cr and lysis induced by antithymocyte globulin and rabbit complement. PNH lymphocytes were no more susceptible to complement-mediated lysis than lymphocytes from normal individuals. The unusual sensitivity of PNH erythrocytes could still be demonstrated when rabbit serum was a source of complement so the lack of any difference in the sensitivity of normal and PNH lymphocytes was probably not attributable to the inability of rabbit serum to elicit the membrane defect. PNH erythrocytes and granulocytes also acquire more membrane-bound C3 when human complement is activated. Therefore we also searched for increased membrane C3 binding on PNH lymphocytes using anti-I antibody and human serum as a complement source. C3 binding was measured using 125I labelled monoclonal mouse anti-human C3. While we verified increased membrane C3 binding on PNH granulocytes during complement activation we were unable to show similar differences between PNH and normal T-lymphocytes. Thus PNH T-lymphocytes do not share the membrane abnormalities of PNH erythrocytes and granulocytes.  相似文献   
649.
Thirteen patients who sustained spinal cord trauma causing persisting disability, developed new symptoms, the chief one of which was severe pain unrelieved by analgesics. The clinical diagnosis of post traumatic syringomyelia was confirmed in each case by means of myelography, as well as endomyelography in seven patients. In every case exploration of the spinal cord syrinx was performed. Ten patients were troubled by severe pain while three patients were mainly subject to altered sensation in the upper limbs. Of the six patients who had initially sustained complete cord transections, three were treated by cord transection and three were treated by syringostomy. The seven patients who sustained incomplete cord lesions were all treated by syringostomy. The patients who initially sustained incomplete sensory motor spinal cord damage had a better symptomatic response to surgery than hose who had sustained a complete spinal cord lesion. The ten patients whose main symptom was severe pain were completely relieved of their symptoms by surgery.  相似文献   
650.
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