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   47869篇
  免费   3840篇
  国内免费   112篇
耳鼻咽喉   381篇
儿科学   1998篇
妇产科学   1304篇
基础医学   6836篇
口腔科学   982篇
临床医学   6584篇
内科学   9321篇
皮肤病学   899篇
神经病学   4839篇
特种医学   1085篇
外科学   4294篇
综合类   410篇
一般理论   62篇
预防医学   5810篇
眼科学   677篇
药学   2671篇
  2篇
中国医学   54篇
肿瘤学   3612篇
  2024年   60篇
  2023年   424篇
  2022年   587篇
  2021年   1277篇
  2020年   948篇
  2019年   1400篇
  2018年   1535篇
  2017年   1212篇
  2016年   1346篇
  2015年   1411篇
  2014年   1797篇
  2013年   2653篇
  2012年   3684篇
  2011年   3809篇
  2010年   2095篇
  2009年   1854篇
  2008年   3084篇
  2007年   3170篇
  2006年   3138篇
  2005年   2941篇
  2004年   2856篇
  2003年   2602篇
  2002年   2344篇
  2001年   392篇
  2000年   293篇
  1999年   335篇
  1998年   536篇
  1997年   398篇
  1996年   360篇
  1995年   349篇
  1994年   276篇
  1993年   278篇
  1992年   202篇
  1991年   172篇
  1990年   163篇
  1989年   123篇
  1988年   142篇
  1987年   109篇
  1986年   112篇
  1985年   114篇
  1984年   108篇
  1983年   113篇
  1982年   132篇
  1981年   129篇
  1980年   105篇
  1979年   62篇
  1978年   71篇
  1977年   59篇
  1976年   48篇
  1972年   37篇
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
981.
982.
983.
984.

Purpose

To quantify the longitudinal division of the internal anal sphincter (IAS) and external anal sphincter (EAS) after fistulotomy using three-dimensional endoanal ultrasound (3D-EAUS) and correlate the results with postoperative faecal incontinence.

Methods

A prospective, consecutive study was performed from December 2008 to October 2010. All patients underwent 3D-EAUS before and 8?weeks after surgery. Thirty-six patients with simple perianal fistula were included. Patients with an intersphincteric or low transphincteric fistula (<66% sphincter involved) without risk factors for incontinence underwent fistulotomy. The outcome measures were the longitudinal extent of division of the IAS and EAS in relation to total sphincter length and continence (Jorge and Wexner scores).

Results

One-year follow-up revealed a 0% recurrence rate. There was a strong correlation between preoperative 3D-EAUS measurement of fistula height with intraoperative and postoperative 3D-EAUS measurement of IAS and EAS division (p?p?>?0.05).

Conclusions

In patients without risk factors, division of the EAS during fistulotomy limited to the lower two thirds of the EAS is associated with excellent continence and cure rates.  相似文献   
985.
Alagille syndrome is a rare congenital multisystem disorder that may involve heart disease and pulmonary or peripheral artery stenosis. We report the clinical and radiological presentation of five adult patients with Alagille syndrome, hypertension and renal artery stenosis. All had systolic hypertension and a narrowing of the abdominal aorta, corresponding to a secondary midaortic syndrome. Renovascular disease progressed during follow-up, with increases in blood pressure, decreases in glomerular filtration rate and/or kidney atrophy. A literature review identified several anecdotal reports of Alagille syndrome associated with hypertension, renal artery stenosis and/or midaortic syndrome. We discuss this condition, focusing on diagnosis, differential diagnosis, associated conditions and management. Cardiologists, nephrologists and radiologists should be aware of this rare cause of renovascular hypertension and of the need for clinical, biological and echographic follow-up.  相似文献   
986.
987.
Gut-activated T cells migrating into the liver can cause extraintestinal manifestations of inflammatory bowel disease. T cells acquire a gut-homing phenotype dependent on retinoic acid (RA) provided by intestinal dendritic cells (DC). We investigated whether liver antigen-presenting cells can induce gut tropism supporting an enterohepatic lymphocyte circulation. Priming of CD4(+) T cells by liver sinusoidal endothelial cells (LSEC) supported migration into gut and gut-associated lymphoid tissue. As observed for T cells primed by intestinal DCs, this gut tropism depended on α(4) β(7) integrin and CC chemokine receptor 9 (CCR9) expression by LSEC-primed CD4(+) T cells. The induction of gut-homing molecules was mediated by RA, a derivate of vitamin A that is stored in large amounts within the liver. LSECs expressed functional retinal dehydrogenases and could convert vitamin A to RA. Conversely, the lack of signaling via the RA receptor prevented the expression of α(4) β(7) integrin and CCR9 on LSEC-primed CD4(+) T cells, consequently reducing their in vivo migration to the intestine. Other liver antigen-presenting cells failed to support high expression of α(4) β(7) integrin on CD4(+) T cells, thus, the potential to induce gut homing is restricted to LSECs. CONCLUSION: The capacity to promote gut tropism via vitamin A use is not unique for intestinal DCs but is also a feature of LSECs. Our data support the assumption that CD4(+) T cells can migrate from the liver to the gut as one branch of a postulated enterohepatic lymphocyte circulation.  相似文献   
988.
989.
990.
Antibiotics have a role in the management of acute exacerbations of bronchiectasis and may also benefit selected subsets of patients with bronchiectasis as a part of a long-term maintenance strategy. At present, there are no Food and Drug Administration-approved antibiotics for acute or chronic management of bronchiectasis. Clinical trials are underway to determine the efficacy and safety of various inhaled antibiotics for chronic therapy for bronchiectasis. Until those results are available, clinicians need to tailor their therapies to individual patients based on their best clinical judgment and information from data and guidelines currently available in the published literature.  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