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   2643篇
  免费   380篇
  国内免费   10篇
耳鼻咽喉   6篇
儿科学   82篇
妇产科学   292篇
基础医学   218篇
口腔科学   29篇
临床医学   921篇
内科学   337篇
皮肤病学   79篇
神经病学   211篇
特种医学   297篇
外科学   143篇
综合类   57篇
预防医学   115篇
眼科学   15篇
药学   113篇
肿瘤学   118篇
  2023年   52篇
  2022年   17篇
  2021年   32篇
  2020年   46篇
  2019年   42篇
  2018年   84篇
  2017年   111篇
  2016年   96篇
  2015年   119篇
  2014年   128篇
  2013年   138篇
  2012年   86篇
  2011年   105篇
  2010年   126篇
  2009年   125篇
  2008年   78篇
  2007年   77篇
  2006年   76篇
  2005年   46篇
  2004年   40篇
  2003年   66篇
  2002年   46篇
  2001年   54篇
  2000年   41篇
  1999年   60篇
  1998年   107篇
  1997年   120篇
  1996年   114篇
  1995年   102篇
  1994年   67篇
  1993年   54篇
  1992年   46篇
  1991年   41篇
  1990年   28篇
  1989年   51篇
  1988年   46篇
  1987年   30篇
  1986年   33篇
  1985年   35篇
  1984年   20篇
  1983年   29篇
  1982年   19篇
  1981年   17篇
  1980年   18篇
  1979年   10篇
  1978年   20篇
  1977年   19篇
  1976年   13篇
  1975年   19篇
  1971年   12篇
排序方式: 共有3033条查询结果,搜索用时 15 毫秒
1.
2.
BACKGROUND: Computer-assisted image analysis has been proposed for human hair growth studies. METHODS: The performances of Trichoscan, a commercially available automated system combining epiluminiscence microscopy with digital image analysis, developed for office-based hair growth measurements, have been evaluated comparatively on the same skin sites using standardized photographic equipment and calibrated processing for contrast-enhanced phototrichogram (CE-PTG) analysis. This reference method has been validated with scalp biopsies and histological examination of serial sectioning. RESULTS: Besides edge effects, hair fibres escaped the Trichoscan analysis for various reasons including, but not limited to, thickness, pigmentation, closeness and crossing. CONCLUSION: Most of these problems have been identified in the late 1980s and remain largely unsolved by the processing software that was evaluated in 2004. Therefore claims promoting the Trichoscan method for accurate hair measurements in clinical trials on scalp and body hair are not supported by the present investigation. The speed at which the analysis is performed is outweighed by the errors in signal detection. Therefore we suggest that improvements must be clearly documented before Trichoscan is established for quantified diagnostic purposes and detailed hair cycle monitoring during hair trials.  相似文献   
3.
双波长紫外分光光度法测定贝母中腺苷和胸苷的含量   总被引:4,自引:0,他引:4  
将4种贝母的甲醇提取物经薄层色谱法粗分离后,直接用双波长紫外分光光度法测定其含量。结果表明,该方法线性关系好,腺苷和胸苷标准曲线的相关系数均为0.9999,同时也发现平贝、炉贝和伊贝中腺苷都占核苷总量60%以上,而浙贝中仅占约40%,提示贝母生药的抗凝血活性可能与贝母中核苷类化合物的种类和含量的差别有关。  相似文献   
4.
We have reviewed the incidence of cisplatin-induced anaemia in patients affected with solid tumours treated with at least three courses of first-line cisplatincontaining regimens. In our experience, a low percentage (5%) of patients required transfusions of red blood cells. We think it is of the utmost importance to adopt uniform criteria in monitoring and treatment of patients at risk of developing cisplatin anaemia and to identify subsets of patients to eventually treat with erythropoietin.  相似文献   
5.
BACKGROUND: Based on good results in the treatment of superficial skin tumours, since the early 1990s topical photodynamic therapy with aminolaevulinic acid (ALA PDT) has been used for disseminated, inflammatory dermatoses including psoriasis. However, there is still a lack of well-documented trials. OBJECTIVE: A prospective randomized, double-blind phase I/II intrapatient comparison study was conducted in 12 patients to investigate whether topical ALA PDT is an effective treatment for chronic plaque-type psoriasis. METHODS: In each patient three psoriatic plaques were randomly treated with a light dose of 20 J/cm(2) and 0.1%, 1% and 5% ALA, respectively. Treatment was conducted twice a week until complete clearance or for a maximum of 12 irradiations. Therapeutic efficacy was assessed by weekly determination of the psoriasis severity index (PSI). RESULTS: The mean percentage improvement was 37.5%, 45.6% and 51.2% in the 0.1%, 1% and 5% ALA-treated groups, respectively. Irradiation had to be interrupted several times because of severe burning and pain sensation. CONCLUSION: Topical ALA PDT did not prove to be an appropriate treatment option for plaque-type psoriasis due to disappointing clinical efficacy, the time-consuming treatment procedure and its unfavourable adverse event profile.  相似文献   
6.
7.
8.
9.
AIM: The aim of this study was to investigate the nature and organization of maternal needs and priorities in a neonatal unit. BACKGROUND: The relationship between maternal needs and priorities appears to be an under studied area in neonatal nursing. METHODS: A quantitative survey was carried out based on 209 mothers with premature infants. Two self-assessment schedules were used: critical care maternal needs inventory (J. Leske, Heart and Lung 15, 27-42) and a ranking scale. The data were analysed with multivariate analysis. FINDINGS: Data analysis revealed clear priorities in maternal needs. In particular the need for accurate infant related information was a priority for 93% of the mothers. Good communication practices with professionals were also valued. The mothers displayed altruistic behaviour, and self-related needs took second place. It is proposed that maternal needs demonstrate a hierarchical organization. CONCLUSION: It is important for nurses to consider the individual needs of the mothers, simply because the satisfaction of these needs is essential for maternal well-being.  相似文献   
10.
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