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   986篇
  免费   80篇
  国内免费   4篇
耳鼻咽喉   8篇
儿科学   19篇
妇产科学   8篇
基础医学   135篇
口腔科学   7篇
临床医学   167篇
内科学   227篇
皮肤病学   24篇
神经病学   50篇
特种医学   46篇
外科学   147篇
综合类   1篇
现状与发展   1篇
一般理论   1篇
预防医学   51篇
眼科学   23篇
药学   50篇
肿瘤学   105篇
  2023年   14篇
  2022年   22篇
  2021年   56篇
  2020年   28篇
  2019年   52篇
  2018年   61篇
  2017年   34篇
  2016年   35篇
  2015年   37篇
  2014年   55篇
  2013年   48篇
  2012年   83篇
  2011年   71篇
  2010年   43篇
  2009年   40篇
  2008年   53篇
  2007年   41篇
  2006年   47篇
  2005年   38篇
  2004年   46篇
  2003年   29篇
  2002年   23篇
  2001年   6篇
  2000年   12篇
  1999年   3篇
  1998年   6篇
  1997年   2篇
  1996年   3篇
  1995年   4篇
  1994年   2篇
  1992年   3篇
  1991年   3篇
  1990年   6篇
  1989年   10篇
  1988年   11篇
  1987年   4篇
  1986年   5篇
  1985年   4篇
  1984年   4篇
  1983年   2篇
  1981年   2篇
  1977年   6篇
  1973年   2篇
  1972年   2篇
  1970年   1篇
  1969年   1篇
  1968年   1篇
  1964年   2篇
  1962年   2篇
  1960年   1篇
排序方式: 共有1070条查询结果,搜索用时 15 毫秒
61.
62.
We present a case of chronic disruption of the patellar tendon in a patient with Osteogenesis Imperfecta. This patient was treated with a customized extensor mechanism allograft. Results were excellent at 5 years follow up. To our knowledge this treatment has not previously been published in this situation. We present this as a reliable treatment option.  相似文献   
63.
Stimulation mapping of motor cortex is an important tool for assessing motor cortex physiology. Existing techniques include intracortical microstimulation (ICMS) which has high spatial resolution but damages cortical integrity by needle penetrations, and transcranial stimulation which is non-invasive but lacks focality and spatial resolution. A minimally invasive epidural microstimulation (EMS) technique using chronically implanted polyimide-based thin-film microelectrode arrays (72 contacts) was tested in rat motor cortex and compared to ICMS within individual animals. Results demonstrate reliable mapping with high reproducibility and validity with respect to ICMS. No histological evidence of cortical damage and the absence of motor deficits as determined by performance of a motor skill reaching task, demonstrate the safety of the method. EMS is specifically suitable for experiments integrating electrophysiology with behavioral and molecular biology techniques.  相似文献   
64.
The JIKEI trial     
Boutitie F  Gueyffier F  Achard JM  Temmar M  Fournier A 《Lancet》2007,370(9602):1825-1826
  相似文献   
65.
BACKGROUND: Stroke prevention by antihypertensive therapy is believed to be related to the fall in blood pressure (BP). Experimental data have documented that activation of non-AT1 receptors of angiotensin II may exert anti-ischaemic mechanisms in the brain. The present meta-analysis of various randomized clinical trials attempts to relate stroke risk to angiotensin II formation during antihypertensive therapy. METHODS: Primary and secondary stroke prevention was examined in 26 prospective, randomized clinical trials including 206,632 patients without heart failure, in whom a total of 7,108 strokes occurred. The trials were selected because a difference in angiotensin II generation was expected between the two treatment arms on the basis of the drugs' pharmacodynamic effects, and allowed 36 evaluations of the relative risk of stroke. FINDINGS: In placebo-controlled trials, stroke risk was significantly higher with angiotensin II-decreasing than increasing drugs, but systolic BP decreased less in the former. Compared with an active therapy having a neutral effect on angiotensin II formation, stroke risk was also higher with angiotensin-decreasing drugs than with angiotensin-increasing drugs, whereas BP decrease was comparable with both drug classes. When angiotensin II-decreasing drugs were directly compared with angiotensin II-increasing drugs in the same trials, stroke risk was significantly increased. On-treatment systolic BP was minimally and significantly higher with angiotensin II-decreasing drugs, but not large enough to explain the excess in stroke risk. CONCLUSION: Within the limitations of the methodology, our meta-analysis supports the hypothesis that angiotensin II-decreasing drugs are less stroke protective than angiotensin II-increasing drugs, although this difference is not entirely explained by their smaller BP-lowering effect.  相似文献   
66.

Background

DNA methylation in the SHOX2 locus was previously used to reliably detect lung cancer in a group of critical controls, including 'cytologically negative' samples with no visible tumor cell content, at a high specificity based on the analysis of bronchial lavage samples. This study aimed to investigate, if the methylation correlates with SHOX2 gene expression and/or copy number alterations. An amplification of the SHOX2 gene locus together with the observed tumor-specific hypermethylation might explain the good performance of this marker in bronchial lavage samples.

Methods

SHOX2 expression, gene copy number and DNA methylation were determined in lung tumor tissues and matched morphologically normal adjacent tissues (NAT) from 55 lung cancer patients. Quantitative HeavyMethyl (HM) real-time PCR was used to detect SHOX2 DNA methylation levels. SHOX2 expression was assayed with quantitative real-time PCR, and copy numbers alterations were measured with conventional real-time PCR and array CGH.

Results

A hypermethylation of the SHOX2 locus in tumor tissue as compared to the matched NAT from the same patient was detected in 96% of tumors from a group of 55 lung cancer patients. This correlated highly significantly with the frequent occurrence of copy number amplification (p < 0.0001), while the expression of the SHOX2 gene showed no difference.

Conclusions

Frequent gene amplification correlated with hypermethylation of the SHOX2 gene locus. This concerted effect qualifies SHOX2 DNA methylation as a biomarker for lung cancer diagnosis, especially when sensitive detection is needed, i.e. in bronchial lavage or blood samples.  相似文献   
67.
68.
69.
This prospective, randomised clinical trial compared pain, comfort, exudate management, wound healing and safety with Hydrofiber dressing with ionic silver (Hydrofiber Ag dressing) and with povidone-iodine gauze for the treatment of open surgical and traumatic wounds. Patients were treated with Hydrofiber Ag dressing or povidone-iodine gauze for up to 2 weeks. Pain severity was measured with a 10-cm visual analogue scale (VAS). Other parameters were assessed clinically with various scales. Pain VAS scores decreased during dressing removal in both groups, and decreased while the dressing was in place in the Hydrofiber Ag dressing group (n = 35) but not in the povidone-iodine gauze group (n = 32). Pain VAS scores were similar between treatment groups. At final evaluation, Hydrofiber Ag dressing was significantly better than povidone-iodine gauze for overall ability to manage pain (P < 0.001), overall comfort (P < or = 0.001), wound trauma on dressing removal (P = 0.001), exudate handling (P < 0.001) and ease of use (P < or = 0.001). Rates of complete healing at study completion were 23% for Hydrofiber Ag dressing and 9% for povidone-iodine gauze (P = ns). No adverse events were reported with Hydrofiber Ag dressing; one subject discontinued povidone-iodine gauze due to adverse skin reaction. Hydrofiber Ag dressing supported wound healing and reduced overall pain compared with povidone-iodine gauze in the treatment of open surgical wounds requiring an antimicrobial dressing.  相似文献   
70.
The benefit of corticosteroids in acute urticaria is controversial. Our objective was to determine the factors associated with relapses in patients presenting with acute urticaria. A retrospective observational study, including all patients with acute urticaria who visited the angioedema reference center of Academic Public Hospitals – Saint‐Antoine in Paris between January 2015 and June 2017, was conducted. The study inclusion criterion was a diagnosis of acute urticaria in an adult patient. The urticaria was spontaneous or inducible urticaria. The primary outcome was relapse at day 7 and the secondary outcome was relapse at week 6. A total of 184 patients with a first episode of acute urticaria were included. Most of the patients were female (66%) with a mean age of 42 ± 16 years. Corticosteroid administration for treatment of acute urticaria was used in 102 (55%) patients. Overall, 85 (46%) patients had relapses after less than 7 days whereas 168 (91%) patients had relapses after more than 6 weeks. In univariate analysis, the rate of corticosteroid administration was significantly higher in cases of relapse after less than 7 days. No difference in relapse rates after more than 6 weeks appeared. In the multivariate analysis, the independent factor associated with relapses after less than 7 days was the administration of corticosteroids as treatment of acute urticaria (odds ratio, 1.93; 95% confidence interval, 1.06–3.57; P = 0.03). The prevalence of corticosteroid administration for patients with acute urticaria was high. Corticosteroid administration was an independent risk factor associated with relapses after less than 7 days.  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