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   1178篇
  免费   36篇
  国内免费   5篇
耳鼻咽喉   13篇
儿科学   45篇
妇产科学   35篇
基础医学   123篇
口腔科学   49篇
临床医学   110篇
内科学   243篇
皮肤病学   112篇
神经病学   68篇
特种医学   116篇
外科学   97篇
综合类   1篇
预防医学   24篇
眼科学   4篇
药学   118篇
中国医学   2篇
肿瘤学   59篇
  2023年   9篇
  2022年   9篇
  2021年   27篇
  2020年   13篇
  2019年   20篇
  2018年   25篇
  2017年   17篇
  2016年   13篇
  2015年   18篇
  2014年   39篇
  2013年   56篇
  2012年   79篇
  2011年   77篇
  2010年   46篇
  2009年   41篇
  2008年   97篇
  2007年   74篇
  2006年   85篇
  2005年   77篇
  2004年   83篇
  2003年   78篇
  2002年   86篇
  2001年   11篇
  2000年   3篇
  1999年   11篇
  1998年   10篇
  1997年   11篇
  1996年   15篇
  1995年   14篇
  1994年   7篇
  1993年   6篇
  1992年   6篇
  1991年   6篇
  1990年   3篇
  1989年   2篇
  1988年   8篇
  1987年   1篇
  1986年   7篇
  1985年   3篇
  1984年   5篇
  1983年   2篇
  1982年   5篇
  1981年   3篇
  1980年   3篇
  1979年   3篇
  1977年   1篇
  1976年   1篇
  1974年   1篇
  1973年   2篇
排序方式: 共有1219条查询结果,搜索用时 15 毫秒
41.
We report idiopathic central precocious puberty in a boy with Klinefelter syndrome and describe the pattern of linear growth and body proportion from the onset of precocious puberty to final height. The patient was not treated for precocious puberty. He reached adequate adult height, for both general population and normative values of Klinefelter syndrome and normal body proportions. We conclude that precocious puberty in Klinefelter syndrome may result in normal body proportion by inducing a major growth spurt of the trunk rather than in the limbs, and that adult height prognosis is not altered by precocious puberty. Given the possible occurrence of precocious puberty in Klinefelter syndrome, we advise a karyotype analysis in boys with sexual precocity, mainly in those who show small rather than enlarged testes. © 1996 Wiley-Liss, Inc.  相似文献   
42.
Fifty-seven patients took part in a controlled double-blind trial between tiopronin and D-penicillamine as basic treatment for rheumatoid arthritis. Thirty-nine (19 receiving tiopronin, 20 receiving D-penicillamine) completed the trial after 1 year. Both drugs resulted in a decrease of the erythrocyte sedimentation rate, Ritchie index, and Lee index and in a sparing effect on symptomatic antiinflammatory therapy. Improvement in these variables was statistically highly significant at any interval with tiopronin, but was sometimes less or not at all significant with D-penicillamine. Nevertheless, the difference in effects between the 2 drugs never reached statistical significance. Six patients receiving tiopronin and 6 receiving D-penicillamine were taken out of the experiment because of side effects.  相似文献   
43.

Purpose

The aim of this study is to evaluate the long-term outcome of patients with locally advanced breast cancer treated with neoadjuvant systemic chemotherapy (NST) in routine clinical practice.

Methods

Four hundred and nine patients were identified between January 1999 and December 2011. All patients received NST followed by surgery, adjuvant treatments and radiotherapy, as appropriate.

Results

At Kaplan–Meier analysis, patients with surgical stage III disease were more likely to develop distant metastasis and die from breast cancer (p < 0.001). Luminal A and luminal B/HER2-negative patients had better prognosis; moreover, patients with hormone receptor (HR)-positive tumors had a significantly longer DRFS (p < 0.0049) and OS (p < 0.0001) compared with patients with HR-negative tumors as well as patients who underwent breast-conserving surgery (DRFS and OS: p < 0.001). In multivariate analysis, HR negativity (p < 0.001 for both DRFS and OS), mastectomy (DRFS: p = 0.009; OS: p = 0.05) and stage III disease (DRFS: p < 0.001; OS: p = 0.003) were associated with shorter DRFS and OS.

Conclusions

HR negativity, mastectomy and pathological stage III disease are the variables independently associated with a worse outcome in our cohort of patients. These data are of high interest since they derive from a very heterogeneous group of patients, treated with different neoadjuvant/adjuvant regimens outside of clinical trials and with a long follow-up period.  相似文献   
44.
45.
46.
47.

Background

Actinic keratosis (AK) is a common keratinocyte intraepidermal neoplasia.

Objective

To assess AK prevalence and potential risk factors in patients attending Italian general dermatology clinics.

Materials & methods

This retrospective study was conducted on clinical data from consecutive white outpatients aged ≥30 years, attending 24 general dermatology clinics between December 2014 and February 2015. AK prevalence (entire population) and multivariate risk factor analysis (patients with current/previous AK and complete data) are presented.

Results

AK prevalence in 7,284 patients was 27.4% (95% CI: 26.4-28.4%); 34.3% in men and 20.0% in women (p<0.001). Independent AK risk factors in 4,604 patients were: age (OR: 4.8 [95% CI: 3.5-6.5] for 46-60 years, increasing with older age to OR: 41.5 [95% CI: 29.5-58.2] for >70 years), history of other non-melanoma skin cancers (OR: 2.7 [2.2-3.3]), residence in southern Italy/Sardinia (OR: 2.6 [2.1-3.0]), working outdoors >6 hours/day (OR: 1.9 [1.4-2.4]), male gender (OR: 1.7 [1.4-2.0]), facial solar lentigos (OR: 1.6 [1.4-1.9]), light hair colour (OR: 1.5 [1.2-1.8]), prolonged outdoor recreational activities (OR: 1.4 [1.2-1.7]), light eye colour (OR: 1.3 [1.1-1.6]), skin type I/II (OR: 1.3 [1.1-1.6]), and alcohol consumption (OR: 1.2 [1.0-3.3]). BMI ≥25.0 (OR: 0.6 [0.5-0.7]), regular sunscreen use (OR: 0.7 [0.6-0.8]), and a lower level of education (OR: 0.8 [0.7-1.0]) were independent protective factors.

Conclusions

AK prevalence was high in Italian dermatology outpatients. We confirm several well-known AK risk factors and reveal possible novel risk and protective factors. Our results may inform on the design and implementation of AK screening and educational programmes.
  相似文献   
48.

Background

Glue fixation of mesh has been explored for some time as a strategy for reducing postoperative chronic groin pain. Previous studies have come to different conclusions about the superiority of one method over another. We conducted a meta-analysis of randomized control trials comparing the performance of glue versus suture fixation of mesh in open inguinal hernioplasty.

Methods

Studies published up to November 2012 were searched using PubMed, EMBASE, MEDLINE, Cochrane Library, and the international standard randomised controlled trials number (ISRCTN) register. Mean differences (MDs) were derived from secondary continuous outcomes and pooled risk ratios (RRs) for categoric outcomes. Meta-analysis was conducted utilizing the random-effects and fixed-effects models as appropriate.

Results

Ten randomized controlled studies were selected, with a total of 1,623 patients. Glue fixation for open inguinal hernioplasty reduced chronic groin pain (RR 0.46, 95 % confidence interval (CI) 0.22–0.97), hematoma (RR 0.56, 95 % CI 0.34–0.90), acute postoperative pain (MD ?7.92, 95 % CI, ?13.17 to ?2.66), and time taken to return to normal activities (MD ?1.39, 95 % CI, ?2.58 to ?0.21). There was no evidence of an increase in adverse outcomes including recurrence with glue fixation (RR 0.83, 95 % CI 0.30–2.35).

Conclusions

Glue fixation of mesh for open inguinal hernioplasty is superior in many outcomes including the reduction of chronic groin pain. Glue fixation was not associated with an increased risk of hernia recurrence.  相似文献   
49.
Increased oxidative stress has been implicated in the pathogenesis of a number of cardiovascular diseases. Recent findings suggest that myeloperoxidase (MPO) may play a key role in the initiation and maintenance of chronic heart failure (CHF) by contributing to the depletion of the intracellular reservoir of nitric oxide (NO). NO consumption through MPO activity may lead to protein chlorination or nitration, leading to tissue damage. Primary cultures of human endocardial endothelial cells (EEC) obtained at heart transplantation of patients with CHF and human umbilical vein endothelial cells (HUVEC) were subjected to oxidative stress by incubation with hydrogen peroxide at non lethal (60 μM) dose for different exposure times (3 and 6 h). Treated and control cells were tested by immunohistochemistry and RT-PCR for MPO and 3-chlorotyrosine expression. Both endothelial cell types expressed myeloperoxidase following oxidative stress, with higher levels in EEC. Moreover, 3-chlorotyrosine accumulation in treated cells alone indicated the presence of MPO-derived hypochlorous acid. Immunohistochemistry on sections from post-infarcted heart confirmed in vivo the endothelial positivity to MPO, 3-chlorotyrosine and, to a minor extent, nitrotyrosine. Immunohistochemical observations were confirmed by detection of MPO mRNA in both stimulated EEC and HUVEC cells. This study demonstrates for the first time that EEC can express MPO after oxidative stress, both in vitro and in vivo, followed by accumulation of 3-chlorotyrosine, an end product of oxidative stress. Deregulation of endothelial functions may contribute to the development of a number of cardiovascular diseases, including CHF. The results also highlight the notion that endothelium is not only a target but also a key player in oxidative-driven cardiovascular stress. Electronic supplementary material  The online version of this article (doi: ) contains supplementary material, which is available to authorized users. G. La Rocca and A. Di Stefano contributed equally to the current work. Returned for 1. Revision: 7 January 2008 1. Revision received: 18 June 2008 Returned for 2. Revision: 17 July 2008 2. Revision received: 17 October 2008  相似文献   
50.
Objectives: This randomized‐controlled trial aimed to evaluate marginal bone level alterations at implants restored according to the platform‐switching concept, using different implant/abutment mismatching. Material and methods: Eighty implants were divided according to the platform diameter in four groups: 3.8 mm (control), 4.3 mm (test group1), 4.8 mm (test group2) and 5.5 mm (test group3), and randomly placed in the posterior maxilla of 31 patients. After 3 months, implants were connected to a 3.8‐mm‐diameter abutment and final restorations were performed. Radiographic bone height was measured by two independent examiners at the time of implant placement (baseline), and after 9, 15, 21 and 33 months. Results: After 21 months, all 80 implants were clinically osseointegrated in the 31 patients treated. A total of 69 implants were available for analysis, as 11 implants had to be excluded from the study due to early unintentional cover screw exposure. Radiographic evaluation showed a mean bone loss of 0.99 mm (SD=0.42 mm) for test group1, 0.82 mm (SD=0.36 mm) for test group2 and 0.56 mm (SD=0.31 mm) for test group3. These values were statistically significantly lower (P<0.005) compared with control (1.49 mm, SD=0.54 mm). After 33 months, five patients were lost to follow‐up. Evaluation of the remaining 60 implants showed no difference compared with 21 months data except for test group2 (0.87 mm) and test group3 (0.64 mm). There was an inverse correlation between the extent of mismatching and the amount of bone loss. Conclusions: This study suggested that marginal bone level alterations could be related to the extent of implant/abutment mismatching. Marginal bone levels were better maintained at implants restored according to the platform‐switching concept. To cite this article:
Canullo L, Fedele GR, Iannello G, Jepsen S. Platform switching and marginal bone‐level alterations: the results of a randomized‐controlled trial.
Clin. Oral Impl. Res. 21 , 2010; 115–121.  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