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   718篇
  免费   26篇
  国内免费   82篇
耳鼻咽喉   6篇
儿科学   81篇
妇产科学   9篇
基础医学   60篇
口腔科学   10篇
临床医学   115篇
内科学   139篇
皮肤病学   20篇
神经病学   51篇
特种医学   108篇
外科学   59篇
综合类   32篇
预防医学   25篇
眼科学   14篇
药学   68篇
  1篇
中国医学   1篇
肿瘤学   27篇
  2023年   3篇
  2022年   3篇
  2021年   16篇
  2020年   4篇
  2019年   9篇
  2018年   7篇
  2017年   15篇
  2016年   10篇
  2015年   13篇
  2014年   18篇
  2013年   23篇
  2012年   20篇
  2011年   29篇
  2010年   21篇
  2009年   22篇
  2008年   23篇
  2007年   73篇
  2006年   21篇
  2005年   46篇
  2004年   28篇
  2003年   28篇
  2002年   21篇
  2001年   15篇
  2000年   12篇
  1999年   16篇
  1998年   27篇
  1997年   32篇
  1996年   27篇
  1995年   25篇
  1994年   19篇
  1993年   15篇
  1992年   6篇
  1991年   8篇
  1990年   8篇
  1989年   10篇
  1988年   18篇
  1987年   6篇
  1986年   14篇
  1985年   14篇
  1984年   5篇
  1983年   6篇
  1982年   13篇
  1981年   13篇
  1980年   10篇
  1979年   4篇
  1978年   6篇
  1977年   9篇
  1976年   11篇
  1975年   12篇
  1971年   3篇
排序方式: 共有826条查询结果,搜索用时 15 毫秒
41.
42.
43.
The impact of computed tomography on neuroradiologic practice   总被引:1,自引:0,他引:1  
Baker  HL  Jr 《Radiology》1975,116(3):637
  相似文献   
44.
45.
Traumatic diaphragmatic herniation   总被引:3,自引:0,他引:3  
Traumatic diaphragmatic hernia is rare in children. Left-sided Herniations are seen in 90%. The diagnosis is often delayed for months to years because of its rarity and overshadowing injuries. Chest/abdominal radiographs and, in particular cases, computed tomography and ultrasound improve the accuracy of diagnosis. We report two cases of traumatic diaphragmatic rupture in children. The history of trauma along with plain X-rays/barium study was diagnostic in both the cases.  相似文献   
46.
The mechanism by which lithium exerts either its anti-manic or antidepressant effects remains to be fully elucidated. Although lithium inhibits the enzyme glycogen synthase kinase-3 (GSK-3) at concentrations that are relevant for treatment of bipolar disorder, it is unclear whether GSK-3-related mechanisms are responsible for its therapeutic effects in the treatment of this disease. We report that AR-A014418 (a selective GSK-3 inhibitor) induces behavioural changes that are consistent with the effects of antidepressant medications. Subacute intraperitoneal injections of AR-A014418 reduced immobility time in rats exposed to the forced swim test, a well-established model for antidepressant efficacy. In addition, the specificity of this effect is supported by our finding that AR-A014418 decreased spontaneous as well as amphetamine-induced activity. Taken together, these data support the hypothesis that lithium may exert its antidepressant effects through inhibition of GSK-3, and that novel small-molecule GSK-3 inhibitors may be useful for the treatment of bipolar disorder and depression.  相似文献   
47.
Neuronal death, attributable to perturbed redox homeostasis, is the underlying factor in many acute and chronic neurological disorders. The mechanisms employed by oxidatively stressed neurons to commit to cell death pathways are beginning to be characterized, but this is hampered by a lack of good models that extrapolate readily to redox-dependent neuronal death paradigms. In this Mini-Review, we discuss mechanisms by which oxidative stress can result in neurodegeneration. We examine evidence on which terminally differentiated neurons might commit to death under conditions of oxidative stress. In some cases, death may be linked to an aberrant and uncoordinated reentry into the cell cycle and mitotic catastrophe. Other evidence suggests that cell cycle reentry is not mandatory for death execution. Rather, the reexpression of cell cycle proteins may induce apoptotic pathways in a cell cycle-independent manner. In contrast to these models, there is also evidence that oxidative neuronal death is independent of cell cycle proteins. We conclude that oxidative stress-induced neuronal death may be promoted via several pathways, which may be cycle protein dependent or independent. The determining factor for which or how many pathways are induced appears to be context dependent and determined by the level and duration of oxidative stress.  相似文献   
48.
Dey RK  Ray AR 《Biomaterials》2003,24(18):2985-2993
This work reports the development of new non-thrombogenic polymers based on the linear polymers of polyamidoamines (PAAs), having heparin binding ability, obtained by polyaddition of secondary amines to N,N'-methylene bis-acrylamide. PAAs could not be used directly in the making of blood-contacting materials due to their poor mechanical strength. In order to overcome this lacuna, copolymers of amidoamine with methylmethacrylate (MMA) were prepared. Characterization studies indicated that the PAAs have been suitably incorporated into the MMA matrix. The relative hydrophilic nature of the synthesized copolymers was established from the measurement of water contact angle. The heparinized copolymers showed significant improvement in non-thrombogenic characteristics.  相似文献   
49.
Fournier's gangrene in neonates-differences from that in adults   总被引:1,自引:0,他引:1  
  相似文献   
50.
OBJECTIVE: We assessed and compared the benefit of using images acquired 1 year or 2 years previously during mammography interpretations. MATERIALS AND METHODS: Eleven radiologists and one resident reviewed 128 cases three times: once without prior mammograms for comparison, once with mammograms from the most recent (1 year) examination, and once with mammograms acquired 2 years previously. They were asked to determine whether the patient should be recalled for additional procedures. Performances under the three conditions were compared. RESULTS: Radiologists were significantly more accurate (p < 0.001) when comparison mammograms (obtained 1 or 2 years previously) were available. Although sensitivity was not significantly affected between the availability of mammograms from 1 or 2 years earlier (p > 0.10), the specificity was. Specificity using mammograms from the latest examination (obtained 1 year previously) as a reference was significantly better (p = 0.03) than specificity using mammograms obtained 2 years previously. CONCLUSION: Comparison mammograms are important for accurate diagnosis-in particular, for increasing specificity. The latest prior examination seems to be the optimal one for this purpose.  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