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   3132篇
  免费   164篇
  国内免费   9篇
耳鼻咽喉   45篇
儿科学   388篇
妇产科学   108篇
基础医学   457篇
口腔科学   74篇
临床医学   164篇
内科学   624篇
皮肤病学   86篇
神经病学   71篇
特种医学   108篇
外科学   390篇
综合类   130篇
一般理论   1篇
预防医学   152篇
眼科学   117篇
药学   230篇
中国医学   14篇
肿瘤学   146篇
  2021年   65篇
  2020年   45篇
  2019年   38篇
  2018年   55篇
  2017年   39篇
  2016年   43篇
  2015年   52篇
  2014年   84篇
  2013年   76篇
  2012年   119篇
  2011年   145篇
  2010年   87篇
  2009年   93篇
  2008年   129篇
  2007年   117篇
  2006年   98篇
  2005年   106篇
  2004年   92篇
  2003年   96篇
  2002年   98篇
  2001年   103篇
  2000年   89篇
  1999年   81篇
  1998年   62篇
  1997年   44篇
  1996年   54篇
  1995年   35篇
  1994年   24篇
  1993年   25篇
  1992年   54篇
  1991年   60篇
  1990年   72篇
  1989年   61篇
  1988年   66篇
  1987年   59篇
  1986年   73篇
  1985年   49篇
  1984年   46篇
  1983年   32篇
  1979年   40篇
  1977年   27篇
  1976年   29篇
  1975年   29篇
  1973年   33篇
  1972年   38篇
  1971年   29篇
  1970年   31篇
  1969年   32篇
  1968年   27篇
  1967年   34篇
排序方式: 共有3305条查询结果,搜索用时 31 毫秒
31.
32.
We report a case of postsurgical wound infection of polymicrobial etiology caused by Serratia marcescens and Pseudomonas aeruginosa following the use of a radial forearm free flap for oncological tongue reconstruction. S. marcescens was a producer of SHV-12 extended-spectrum beta-lactamase (ESBL). This is the first report from India of this ESBL. S. marcescens and P. aeruginosa were resistant to the empirical perioperative antibiotics administered. Delay in the recognition of the type of infection and in the institution of appropriate therapy resulted in total loss of the free flap.  相似文献   
33.
34.
35.
Cyclic ADP-ribose (cADPR) mobilizes calcium from intracellular stores and contributes to agonist-induced intracellular calcium elevation in airway smooth muscle (ASM). In this study we determined the functional role of CD38/cADPR signaling in the regulation of airway tone using CD38 deficient (cd38(-/-)) mice. The responsiveness to different doses of methacholine, as determined by changes in lung resistance and dynamic compliance, was significantly (P < or = 0.05) lower in cd38(-/-) mice compared with wild-type controls. To determine the mechanism responsible for the reduced responsiveness, we measured the intracellular calcium responses to contractile agonists in ASM cells. In ASM cells isolated from cd38(-/-) mice, the intracellular calcium responses to acetylcholine and endothelin-1 were significantly lower than in controls. Pretreatment of ASM cells with a cADPR antagonist resulted in attenuated intracellular calcium responses to endothelin-1 in cells isolated from wild-type mice, but not in those isolated from the cd38(-/-) mice. Very low cADPR levels and no detectable ADP-ribosyl cyclase activity were observed in lung tissue from cd38(-/-) mice, suggesting that CD38 is a critical source for cADPR synthesis. The results of the present study demonstrate that CD38/cADPR contributes to airway smooth muscle tone and responsiveness through its effects on agonist-induced elevation of intracellular calcium in ASM cells.  相似文献   
36.
Primary malignant lymphomas of the breast (PBL) are uncommon constituting only 0.04 to 0.53% of malignant breast neoplasms. We wish to report the clinical, cytological and histologic findings of PBL diagnosed in a 52 years old female.  相似文献   
37.
The need for fast, accurate and high resolution dosimetric quality assurance in radiation therapy has been outpacing the development of new and improved 2D and 3D dosimetry techniques. This paper summarizes the efforts to create a novel and potentially very fast, 3D dosimetry method based on the observation of scintillation light from an irradiated liquid scintillator volume serving simultaneously as a phantom material and as a dose detector medium. The method, named three-dimensional scintillation dosimetry (3DSD), uses visible light images of the liquid scintillator volume at multiple angles and applies a tomographic algorithm to a series of these images to reconstruct the scintillation light emission density in each voxel of the volume. It is based on the hypothesis that with careful design and data processing, one can achieve acceptable proportionality between the local light emission density and the locally absorbed dose. The method is applied to a Ru-106 eye plaque immersed in a 16.4 cm3 liquid scintillator volume and the reconstructed 3D dose map is compared along selected profiles and planes with radiochromic film and diode measurements. The comparison indicates that the 3DSD method agrees, within 25% for most points or within approximately 2 mm distance to agreement, with the relative radiochromic film and diode dose distributions in a small (approximately 4.5 mm high and approximately 12 mm diameter) volume in the unobstructed, high gradient dose region outside the edge of the plaque. For a comparison, the reproducibility of the radiochromic film results for our measurements ranges from 10 to 15% within this volume. At present, the 3DSD method is not accurate close to the edge of the plaque, and further than approximately 10 mm (<10% central axis depth dose) from the plaque surface. Improvement strategies, considered important to provide a more accurate quick check of the dose profiles in 3D for brachytherapy applicators, are discussed.  相似文献   
38.
39.
40.
Extraskeletal chondroma is a rare entity. A fairly benign condition, it is usually seen in adults. It presents as an enlarging mass, most commonly in the hand. Local excision is the treatment of choice. We present a case of extraskeletal chondroma of hand in a 12 year male child. Its variable histological appearance not infrequently leads to a mistaken diagnosis of chondrosarcoma.  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