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   270篇
  免费   12篇
  国内免费   52篇
耳鼻咽喉   3篇
儿科学   10篇
基础医学   18篇
口腔科学   6篇
临床医学   60篇
内科学   57篇
皮肤病学   4篇
神经病学   2篇
特种医学   89篇
外科学   28篇
综合类   9篇
预防医学   9篇
药学   27篇
肿瘤学   12篇
  2024年   1篇
  2023年   1篇
  2019年   1篇
  2018年   3篇
  2017年   1篇
  2016年   3篇
  2015年   3篇
  2014年   5篇
  2013年   8篇
  2012年   2篇
  2011年   5篇
  2010年   12篇
  2009年   11篇
  2008年   6篇
  2007年   44篇
  2006年   8篇
  2005年   13篇
  2004年   3篇
  2003年   1篇
  2002年   7篇
  2001年   8篇
  2000年   6篇
  1999年   2篇
  1998年   23篇
  1997年   17篇
  1996年   21篇
  1995年   16篇
  1994年   19篇
  1993年   11篇
  1991年   2篇
  1990年   4篇
  1989年   9篇
  1988年   5篇
  1987年   5篇
  1986年   8篇
  1985年   6篇
  1984年   3篇
  1982年   1篇
  1981年   4篇
  1980年   3篇
  1979年   1篇
  1978年   3篇
  1977年   6篇
  1976年   5篇
  1975年   4篇
  1973年   1篇
  1971年   1篇
  1962年   1篇
  1959年   1篇
排序方式: 共有334条查询结果,搜索用时 0 毫秒
81.
目的为了进一步保证巨乳缩小术后乳头乳晕的血供和感觉,减少手术并发症。方法设计应用乳房下真皮单蒂瓣,并保留部分乳腺组织的垂直乳腺蒂,及切除的乳腺组织位于乳房下方两侧的巨乳缩小术,自1994年1月至1995年11月,为67例(132侧)巨乳患者在法国斯德拉斯堡欧洲美容整形诊所进行治疗。结果术后全部患者无乳头乳晕并发症,感觉正常。结论结合乳腺垂直蒂和乳房下真皮单蒂瓣的改良巨乳缩小术,不但可以确保乳头乳晕的血供,且可减少感觉损伤,降低手术并发症,及提供良好形态。  相似文献   
82.
In diagnostic radiology, the routine measurement of exposure levels for a reference patient is an important part of an effective quality assurance program. In the United States, chest radiography is the most frequent examination and has the lowest exposure level of all radiologic examinations. We estimated the amount of exposure an average patient received from both manual and automatic exposure-controlled radiographic techniques by using a "patient-equivalent" chest phantom during measurements. A densitometric procedure was used to assess processor performance. The mean exposure from 194 chest systems was 20 mR (5.16 X 10(-5) C/kg); the mean film density, 1.38; and the mean processing speed, 108. It is interesting to note that a wide range of radiographic techniques, processing conditions, and screen-film speeds are currently being used. With the information given in our study, investigators can begin to identify the problems that lead to unusual exposure levels and, perhaps, poor image quality.  相似文献   
83.
84.

Background  

The major clinical feature in chronic pancreatitis is pain, but the genetic basis of pancreatic pain in chronic pancreatitis is poorly understood. The transient receptor potential vanilloid receptor 1 (TRPV1) gene has been associated with pain perception, and genetic variations in TRPV1 may modify the presence and phenotype of chronic pancreatitis. The aim of our study was to investigate the genetic variation of TRPV1 in Dutch patients with chronic pancreatitis and healthy controls.  相似文献   
85.
86.
19-失碳-16-亚甲基-17α-乙酰氧基黄体酮(3)最早由我国合成,后来西德E.Merk AG药厂使其开发成高效低毒的非口服避孕药,称ST-1435,其皮下埋植缓释系统国外已临床使用,有效避孕期约一年,临床研究还发现它对脂代谢、糖代谢、内分泌与肝功能等均无不良影响,并因其口服无效,近年来国外认为它更适合于哺乳期妇女使用。  相似文献   
87.
Placement of a guiding catheter through a tortuous, narrowed, or intrinsically small vessel may result in severe reduction or occlusion of blood flow. However, nonbraided guiding catheters can be simply modified with a catheter hole punch to create a temporary stent. The stent reestablishes blood flow, which is routed through the distal segment of the guiding catheter while maintaining the guide platform for the introduction of microcatheters and devices necessary to perform intervention.  相似文献   
88.
Magnetic resonance (MR) imaging studies of the head and neck (excluding the brain) were obtained in 49 children believed to have lesions of the head and neck. Seven children had normal images; in the remaining 42, lesions were divided into four categories: midline lesions, lesions of symmetric paired structures, facial lesions, and nasopharyngeal and oropharyngeal lesions. All entities were well delineated by MR imaging. The imaging planes and sequences chosen depended on the suspected abnormality. Midline lesions were best imaged in the sagittal plane, lesions of paired structures and the face in the axial or coronal planes, and nasopharyngeal and oropharyngeal lesions in the axial or sagittal planes. Intracranial extension of head and neck neoplasms was best evaluated in the coronal plane. Surface coils provided better resolution and were thus more useful in evaluating small superficial lesions; head or body coils were more useful in defining the extent of large lesions. T2-weighted images provided better differentiation between normal and tumor tissue in patients with head and neck neoplasms.  相似文献   
89.
苦红菇化学成分的研究   总被引:1,自引:0,他引:1  
从野生真菌苦红菇(Russula rosacea(Bull)Grrayem,Fr.)子实体酸性部分得到两个新的四环三萜酸化合物,经光谱(IR,1HNMR,13CNMR,MS)、尤其是二维核磁共振(13C-1HCOSY,COLOC,NOEDIFF)谱解析,确定其结构分别如Ⅰ和Ⅱ所示,Ⅰ命名为苦红菇酸A(rosaceaacidA),Ⅱ为苦红菇酸B(rosaceaacidB)。  相似文献   
90.
Selective renal angiograms were retrospectively evaluated for the identification of renal cell cancers in patients with von Hippel-Lindau disease (VHL). Seven patients underwent angiography and surgery because of solid or complex renal masses identified at cross-sectional imaging. Nine kidneys underwent detailed examination by the surgeon and by a pathologist. There were 31 renal cancers. Angiography had enabled identification of only five cancers (16%), and six others (19%) had been suspected. Cancers detected angiographically were larger than those not detected (P less than .05). Solid tumors tended to appear less hypervascular than expected and occasionally had the angiographic appearance of atypical cysts. There were no false-positive angiograms. Angiography revealed only one cancer not previously suspected and changed the surgeon's approach for only one kidney (11%). The sensitivity and specificity of angiography were 35% and 100%, respectively. In these patients, selective renal angiography is not helpful for the detection or exclusion of cancer in a kidney. It does not have a limited role for vascular mapping prior to partial nephrectomy or tumor enucleation.  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