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   591篇
  免费   60篇
  国内免费   3篇
耳鼻咽喉   4篇
儿科学   3篇
妇产科学   19篇
基础医学   113篇
口腔科学   2篇
临床医学   70篇
内科学   141篇
皮肤病学   5篇
神经病学   31篇
特种医学   22篇
外科学   105篇
综合类   5篇
预防医学   44篇
眼科学   20篇
药学   36篇
中国医学   6篇
肿瘤学   28篇
  2023年   10篇
  2022年   2篇
  2021年   29篇
  2020年   13篇
  2019年   21篇
  2018年   19篇
  2017年   12篇
  2016年   15篇
  2015年   23篇
  2014年   31篇
  2013年   26篇
  2012年   49篇
  2011年   56篇
  2010年   26篇
  2009年   23篇
  2008年   26篇
  2007年   46篇
  2006年   30篇
  2005年   27篇
  2004年   26篇
  2003年   26篇
  2002年   24篇
  2001年   12篇
  2000年   8篇
  1999年   5篇
  1998年   5篇
  1997年   5篇
  1996年   1篇
  1995年   5篇
  1994年   1篇
  1993年   2篇
  1992年   8篇
  1991年   8篇
  1990年   2篇
  1989年   5篇
  1988年   4篇
  1987年   4篇
  1986年   8篇
  1985年   3篇
  1984年   1篇
  1983年   2篇
  1982年   1篇
  1980年   1篇
  1979年   1篇
  1977年   1篇
  1974年   1篇
排序方式: 共有654条查询结果,搜索用时 187 毫秒
1.
A 70‐year‐old man with a history of coronary artery bypass grafting 15 years back and arteriovenous (AV) fistula creation in the left arm 1 month back presented with acute coronary syndrome (ACS). He had not received dialysis before his referral. We felt the most likely etiology for these complaints was increased cardiac oxygen demand from an increased cardiac output related to the newly formed left AV fistula. Coronary angiography was done to detect any significant stenosis in the native or grafted vessels. This revealed that the left subclavian artery was totally occluded in the ostioproximal segment and the coronary arteries did not have occlusions to explain the ACS setting. CT angiography confirmed the angiographic findings of the totally occluded left subclavian artery followed by a well‐developed and patent left internal mammary artery to left anterior descending artery. This led to the consideration of a steal syndrome from the coronary artery by the subclavian artery distal to the occlusion. A successful percutaneous endovascular intervention on the left subclavian artery occlusion was performed. Subsequently, the patient became asymptomatic and experienced a dramatic increase in left ventricular ejection fraction.  相似文献   
2.
International Urology and Nephrology - Many attempts are being made to find an association between varicocele characteristics and sperm parameters. In this study, we investigated the association...  相似文献   
3.
4.
Combining work and care can be very challenging. If not adequately supported, carers’ employment, well-being and relationships may be at risk. Technologies can be potential solutions. We carried out a scoping review to find out what is already known about technologies used by working carers. The search included academic and grey literature published between January 2000 and June 2020. Sixteen relevant publications were analysed and discussed in the context of the broader discourse on work-care reconciliation. Technologies discussed can be classified as: (a) web-based technologies; (b) technologies for direct communication; (c) monitoring technologies; and (d) task-sharing tools. Technologies can help to make work-care reconciliation more manageable and alleviate psychosocial and emotional stress. General barriers to using technology include limited digital skills, depending on others to use technologies, privacy and data protection, cost, limited technological capabilities, and limited awareness regarding available technologies. Barriers specific to some technologies include work disruptions, limited perceived usefulness, and lacking time and energy to use technologies. More research into technologies that can address the needs of working carers and how they are able to use them at work is needed.  相似文献   
5.
6.
7.
The main aim of this study was to assay the testicular H2S levels in the varicocele rat model and then to investigate the protective effects of NaHS on morphometric changes, sperm parameters, oxidative stress and apoptosis markers in rat's testis. D,L-propargylglycine (PAG) was administrated to show the effects of cystathionine γ-lyase enzyme (CSE) inhibition in the varicocele. Rats were assigned to four groups: (a) Sham, (b) varicocele, (c) varicocele + PAG and (d) varicocele + NaHS. Animals in varicocele + NaHS group received 30 µmol/L NaHS in drinking water for 56 days. In the varicocele + PAG group, animals received PAG 19 mg/kg twice a week. Morphometric assessment, oxidative stress markers, testicular H2S levels, sperm parameters, TUNEL assay and expression of Bax/Bcl2 were evaluated at the end of experiment. Testicular H2S levels were significantly decreased in varicocele group. NaHS significantly improved sperm parameters, morphometric characteristics and oxidative stress compared to varicocele group. Oxidative stress status deteriorated in the PAG group compared to the varicocele group. This study showed that a low testicular H2S level might play a critical role in male infertility. Thus, NaHS administration may be a promising treatment strategy for male infertility in varicocele. In addition, CSE may not be the only important enzyme in testicular H2S production.  相似文献   
8.

Objective

The use of preparations based on minerals extracts of Calicotome villosa and butter is born from the misuse of drugs without specific microbiological analyzes. Seventeen different preparations were performed. The antibacterial and antifungal activities were determined on five bacteria and two fungi strains respectively.

Material and methods

C.villosa ashes are obtained by incineration of roots plant at 498 °C for 4 hours. They are analyzed to determine the shape of the particles and the mineral constituents by scanning electronic microscopy (SEM) and energy dispersive X-ray spectrometry (EDX) techniques respectively. The effectiveness of preparations or tablets is measured in solid medium. It allows to calculating the diameter of the inhibition zone for the antibacterial activity as well as the diameter of mycelia growth and the critical values (MIC, MFC, IC50 and IC90) for the antifungal activity. Finally, the results are compared to the activity of a commercial positive control aiming to give value of the observed activity.

Results

SEM observations reveal the presence of nanoparticles agglomerated with size of about 50 nm. The EDX analyzes indicate the presence of Fe, Na, Al, Mg, Si, K, Ca, O2 and C. Among all the results, the preparation (Bs + A) or (Bsd + A) can completely inhibit the growth of two fungal pathogens. The activity of the preparation is faced with the activity of the synthetic fungicide nystatin.

Conclusion

The efficacy of the preparation (Bs + A) or (Bsd + A) is larger than that of nystatin against Aspergillus sp. and Fusarium sp. The preparation could serve as natural antifungal for the pharmaceutical industry.  相似文献   
9.
10.
Ten patients with advanced cancer were treated with weekly intravenous escalating doses of human beta-interferon (HuIFN beta) 4 days each week. The starting dose of HuIFN beta was 3.0 X 10(6) units/m2 and the dose was doubled each week until dose-limiting toxicity was observed. Subjective toxicity included mild fevers and chills, malaise and flu-like symptoms. The lowest dose which caused suppression of the platelet and/or white cell count was 64 X 10(6) units daily, and the maximum dose given was 320 X 10(6) units daily. Both subjective and objective toxicity were not dose-related, easily managed and reversible. Serum interferon levels and the duration of measurable interferon activity on natural killer cells was in general dose-dependent. Two patients had an objective partial response, and two others showed stable disease while receiving HuIFN beta.  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