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   1231篇
  免费   76篇
  国内免费   5篇
耳鼻咽喉   21篇
儿科学   52篇
妇产科学   34篇
基础医学   116篇
口腔科学   30篇
临床医学   80篇
内科学   320篇
皮肤病学   9篇
神经病学   162篇
特种医学   41篇
外科学   191篇
综合类   21篇
一般理论   2篇
预防医学   42篇
眼科学   48篇
药学   87篇
肿瘤学   56篇
  2024年   1篇
  2023年   32篇
  2022年   34篇
  2021年   76篇
  2020年   51篇
  2019年   56篇
  2018年   65篇
  2017年   28篇
  2016年   30篇
  2015年   44篇
  2014年   49篇
  2013年   79篇
  2012年   116篇
  2011年   75篇
  2010年   68篇
  2009年   67篇
  2008年   82篇
  2007年   70篇
  2006年   51篇
  2005年   32篇
  2004年   38篇
  2003年   44篇
  2002年   47篇
  2001年   9篇
  2000年   8篇
  1999年   3篇
  1998年   5篇
  1997年   2篇
  1995年   2篇
  1994年   4篇
  1992年   5篇
  1991年   5篇
  1990年   1篇
  1989年   3篇
  1988年   5篇
  1987年   2篇
  1986年   5篇
  1985年   3篇
  1983年   6篇
  1982年   1篇
  1981年   1篇
  1979年   1篇
  1978年   1篇
  1975年   1篇
  1974年   1篇
  1973年   1篇
  1972年   1篇
  1949年   1篇
排序方式: 共有1312条查询结果,搜索用时 15 毫秒
41.

Introduction  

A significant proportion of patients with Crohn’s disease (CD) lose response to antibodies directed against tumor necrosis factor α (TNF). Prior TNF-antagonist failure is associated with lower rates of response to subsequent TNF-antagonist therapy. In patients failing two anti-TNF agents, a choice exists between using a third-anti-TNF therapy or natalizumab (NAT), an α-4 integrin inhibitor. A cost-effectiveness analysis comparing these competing strategies has not been performed.  相似文献   
42.

Aim

We describe the first living donor intestinal transplant (LDIT) in India and discuss the indications and problems of this complex procedure.

Methods

A 43-year-old male patient required massive bowel resection for gangrene due to thrombosis of the superior mesenteric artery. He was maintained on parenteral nutrition but developed cholestasis and well as repeated catheter related infections with progressive loss of venous access due to thrombosis of central veins. A LDIT was performed using 200?cm of small intestine from the patient's son. The graft was based on the continuation of the superior mesenteric vessels beyond the ileocolic branch. The artery was anastomosed directly to the aorta and the vein to the venacava.

Results

The graft functioned well and he was weaned off parenteral nutrition. However, he later developed complications (wound dehiscence and enterocutaneous fistula) and developed sepsis. He succumbed to sepsis with a functioning graft 6?weeks after the transplant. The donor recovered uneventfully and was discharged on the 4th postoperative day.

Conclusions

LDIT can be life saving in patients with intestinal failure and failure of parenteral nutrition. There is a need to introduce this modality in India. In a setting of scarcity of deceased donor organs the living donor option has advantages.  相似文献   
43.
Hu antigen R (HuR) is a central RNA-binding protein regulating cell dedifferentiation, proliferation, and survival, which are well-established hallmarks of cancer. HuR is frequently overexpressed in tumors correlating with tumor malignancy, which is in line with a role for HuR in tumorigenesis. However, the precise mechanism leading to changes in HuR expression remains unclear. In the liver, HuR plays a crucial role in hepatocyte proliferation, differentiation, and transformation. Here, we unraveled a novel mean of regulation of HuR expression in hepatocellular carcinoma (HCC) and colon cancer. HuR levels correlate with the abundance of the oncogene, murine double minute 2 (Mdm2), in human HCC and colon cancer metastases. HuR is stabilized by Mdm2-mediated NEDDylation in at least three lysine residues, ensuring its nuclear localization and protection from degradation. Conclusion: This novel Mdm2/NEDD8/HuR regulatory framework is essential for the malignant transformation of tumor cells, which, in turn, unveils a novel signaling paradigm that is pharmacologically amenable for cancer therapy.  相似文献   
44.

Background

Primary gastrointestinal stromal tumours (GISTs) of the duodenum are rare. The aim of this study was to review the surgical management of GISTs in this anatomically complex region.

Methods

Retrospective review from January 1999 to August 2011 of patients with primary GISTs of the duodenum.

Results

Forty-one patients underwent resection of duodenal GISTs. All operations were performed with intent to cure with negative margins of resection. The most common location of origin was the second portion of the duodenum. Local excision (n = 19), segmental resection with primary anastomosis (n = 11) and a pancreatoduodenectomy (n = 11) were performed. Two patients underwent an ampullectomy with local excision. Peri-operative mortality and overall morbidity were 0 and 12, respectively. Patients with high-risk GISTs (P = 0.008) and those who underwent a pancreatoduodenectomy (P = 0.021) were at a greater risk for morbidity. The median follow-up was 18 months. Eight patients developed recurrence. High-risk GISTs and neoplasms with ulceration had the greatest risk for recurrence (P = 0.017, P = 0.029 respectively). The actuarial 3- and 5-year survivals were 85% and 74%, respectively.

Conclusion

The choice and type of resection depends on the proximity to the ampulla of Vater, involvement of adjacent organs and the ability to obtain negative margins. The morbidity depends on the type of procedure for GIST.  相似文献   
45.
46.
47.
In this study we investigated 36 single nucleotide polymorphisms within 10 genes previously associated with major depression and bipolar disorder, as well as with the response to their treatment (ABCB1, ABCB4, TAP2, CLOCK, CPLX1, CPLX2, SYN2, NRG1, 5HTR1A and GPRIN2). No association with mood disorders and clinical outcomes was observed.  相似文献   
48.
Deep brain stimulation (DBS) electrodes have been used effectively to perform radiofrequency lesions in the brain. This study aimed to characterize lesion geometry and peak tissue temperature achieved when lesioning through DBS electrodes. Fresh bovine liver was chosen for a medium as the tissue reliably changes color between 45 and 50°C. Medtronic 3387 DBS electrodes (Medtronic Sofamor Danek, Inc., Memphis, TN, USA) and the Cosman G4 Radiofrequency Generator (Cosman Medical, Inc., Burlington, MA, USA) were used for lesioning. Bipolar lesions were created at currents between 25 mA and 100 mA for 60–120 seconds. Peak tissue temperature was monitored with Cosman disposable cordotomy electrode (LCED; Cosman Medical Inc.) and recorded. Photographic analysis of the lesions was performed. Tissue impedance ranged between 800–900 Ohms, and tissue temperature was maintained at 20°C. With lesions at 25 mA for up to 120 seconds, maximal tissue temperature achieved was 36°C. This correlated with no visible lesions. At 50 mA, maximal tissue temperature exceeded 100°C, which was associated with tissue charring. Lesions created at 35 mA and 40 mA led to an increase in tissue temperature of 63°C and 75°C, respectively. Lesion size was highly reproducible, increasing from 4.5 mm × 7 mm at 35 mA, to 6 mm × 7.5 mm at 50 mA. Preliminary analysis suggests that caution should be exerted in using lesion amplitudes exceeding 40 mA (at 800 Ohms), as peak tissue temperatures in vivo could exceed 100°C. Further in vivo experiments with imaging correlates are needed to further test the safety of this technique.  相似文献   
49.
50.
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