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   578篇
  免费   42篇
  国内免费   9篇
耳鼻咽喉   5篇
儿科学   30篇
妇产科学   5篇
基础医学   83篇
口腔科学   8篇
临床医学   111篇
内科学   120篇
皮肤病学   10篇
神经病学   24篇
特种医学   56篇
外科学   81篇
综合类   17篇
一般理论   1篇
预防医学   26篇
眼科学   2篇
药学   27篇
肿瘤学   23篇
  2023年   5篇
  2022年   3篇
  2021年   14篇
  2020年   8篇
  2019年   9篇
  2018年   6篇
  2017年   13篇
  2016年   4篇
  2015年   9篇
  2014年   15篇
  2013年   21篇
  2012年   19篇
  2011年   18篇
  2010年   32篇
  2009年   23篇
  2008年   31篇
  2007年   40篇
  2006年   23篇
  2005年   21篇
  2004年   28篇
  2003年   26篇
  2002年   21篇
  2001年   21篇
  2000年   25篇
  1999年   26篇
  1998年   13篇
  1997年   28篇
  1996年   17篇
  1995年   12篇
  1994年   12篇
  1993年   13篇
  1992年   13篇
  1991年   8篇
  1990年   8篇
  1989年   7篇
  1988年   11篇
  1987年   6篇
  1986年   2篇
  1985年   5篇
  1984年   2篇
  1983年   1篇
  1981年   1篇
  1977年   2篇
  1975年   2篇
  1974年   1篇
  1973年   1篇
  1967年   2篇
  1955年   1篇
排序方式: 共有629条查询结果,搜索用时 15 毫秒
1.
2.
The third reported case of pelvic gliomatosis found within foci of endometriosis is documented 16 years after the removal of a benign cystic teratoma. Grossly at laparoscopy the lesions appear as typical deep fibrotic endometriotic implants.  相似文献   
3.
Defecography in multiple sclerosis patients with severe constipation   总被引:3,自引:0,他引:3  
Gill  KP; Chia  YW; Henry  MM; Shorvon  PJ 《Radiology》1994,191(2):553
  相似文献   
4.
5.
Percutaneous transluminal balloon angioplasty (PTA) was performed in 17 tibial arteries with an average cross-sectional area stenosis of 92% (range 75–99%) in 13 patients (14 limbs) for limb salvage. In 4 of 14 lower extremities, PTA of femoropopliteal arteries was also performed. Technical success with 50% or less residual stenosis was achieved in all 17 tibial vessels. At approximately 2 months after PTA, clinical improvement had occurred in 10 of 14 limbs; no patient was made worse. Most recent follow-up (mean 19 months, range 8–34 months) revealed continued satisfactory clinical success with no further vascular intervention in 9 of these 10 limbs (one patient died). Short segmental stenoses, residual stenoses less than 40% following PTA, and absence of diabetes or gangrene appear to be predictors of favorable clinical outcomes. Our results suggest that PTA of focal tibial stenosis is an effective and safe treatment modality in properly selected patients and that wider use of PTA may be justified.  相似文献   
6.
7.
8.
Summary: The involvement of the IgA immune system and complement components in IgA glomerulonephritis (IgAGN) has prompted the use of immunosuppressive drugs in therapy, but none has so far been shown to alter the natural course of the disease. Because most patients with IgAGN present during the chronic phase of their illness, at the time when the initiating immune events may no longer be active, nonimmune therapy which targets the common pathway of progressive renal injury is likely to be more useful. There is increasing evidence that angiotensin-converting enzyme inhibitors (ACEI) reduce proteinuria and renal injury in patients with IgAGN, and this effect may be observed in both normotensive and hypertensive patients. Yet to be determined is whether this effect is specific for ACEI and whatever other effective antihypertensive drugs may achieve a similar result. Fish oil has recently been shown to retard the progression of renal failure in patients with aggressive IgAGN, but a narrow therapeutic window appears to exist for this form of treatment. Antiplatelet agents on their own appear to be ineffective but in combination with anticoagulation (low dose warfarin) have been shown to have an antiproteinuric effect and may preserve renal function in patients with progressive disease. Future directions of non-immune therapy of IgAGN include evaluation of the renoprotective effect of angiotensin II receptor antagonists, free-radical scavengers and antilipid drugs. More work should also be done to identify factors which put the patients at risk of developing progressive disease and which predict therapeutic response, as has been done recently with the identification of the deletion polymorphism of the angiotensin-converting enzyme gene as a marker of progressive disease and therapeutic response to ACEI in patients with IgAGN.  相似文献   
9.
Sosinowski T  Killeen N  Weiss A 《Immunity》2001,15(3):457-466
In this report, we show that the Src-like adaptor protein (SLAP) plays an important role in thymocyte development. SLAP expression is developmentally regulated; it is low in CD4-CD8- thymocytes, it peaks in the CD4+CD8+ subset, and it decreases to low levels in more mature cells. Disruption of the SLAP gene leads to a marked upregulation of TCR and CD5 expression at the CD4+CD8+ stage. The absence of SLAP was also developmentally significant because it enhanced positive selection in mice expressing the DO11.10 transgenic T cell receptor. Moreover, SLAP deletion at least partially rescued the development of ZAP-70-deficient thymocytes. These results demonstrate that SLAP participates in a novel mechanism of TCR downregulation at the CD4+CD8+ stage and regulates positive selection.  相似文献   
10.
Usher syndrome is recognized as the most frequent cause of hereditary deaf-blindness. Usher syndrome type I (USH1), the most severe form of the disease, is characterized by profound congenital sensorineural deafness, constant vestibular dysfunction, and retinitis pigmentosa of prepubertal onset. This form is genetically heterogeneous and five loci (USH1A-E) have been mapped thusfar. However, only the gene responsible for USH1 B (which accounts for approximately 75% of USH1 cases) has been characterized. It encodes a long-tailed unconventional myosin, myosin VIIA, with a predicted 2215 amino acid sequence. Primers covering the complete myosin VIIA coding sequence as well as the 3' non coding sequence were designed, allowing direct sequence analysis of each of the 48 coding exons and flanking splice sites in seven patients affected by USH1. Four novel mutations were thereby identified. The possibility should now be considered of a sequence-based prenatal diagnosis in some of the families affected by this very severe form of Usher syndrome.   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