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   3130408篇
  免费   231933篇
  国内免费   4569篇
耳鼻咽喉   44749篇
儿科学   104613篇
妇产科学   85729篇
基础医学   454936篇
口腔科学   86597篇
临床医学   280348篇
内科学   602737篇
皮肤病学   69545篇
神经病学   247334篇
特种医学   119744篇
外国民族医学   1096篇
外科学   475712篇
综合类   67041篇
一般理论   1119篇
预防医学   244192篇
眼科学   73643篇
药学   234415篇
  10篇
中国医学   5913篇
肿瘤学   167437篇
  2019年   24474篇
  2018年   34215篇
  2017年   25921篇
  2016年   28894篇
  2015年   32651篇
  2014年   46348篇
  2013年   70121篇
  2012年   96694篇
  2011年   102922篇
  2010年   61311篇
  2009年   58009篇
  2008年   97006篇
  2007年   103656篇
  2006年   104588篇
  2005年   101322篇
  2004年   97625篇
  2003年   94051篇
  2002年   91550篇
  2001年   144497篇
  2000年   148604篇
  1999年   125215篇
  1998年   34382篇
  1997年   29980篇
  1996年   30374篇
  1995年   30690篇
  1994年   28560篇
  1993年   26680篇
  1992年   98399篇
  1991年   96541篇
  1990年   93952篇
  1989年   90173篇
  1988年   82973篇
  1987年   81778篇
  1986年   76420篇
  1985年   73559篇
  1984年   54937篇
  1983年   46595篇
  1982年   27613篇
  1981年   24843篇
  1979年   50256篇
  1978年   35632篇
  1977年   29859篇
  1976年   28329篇
  1975年   30643篇
  1974年   36369篇
  1973年   34828篇
  1972年   32516篇
  1971年   30415篇
  1970年   28368篇
  1969年   26688篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
1.
2.
Spindler  L.  Alam  A.  Fathallah  N.  Rentien  A.-L.  Draullette  M.  Pommaret  E.  Thierry  M.-L.  Mituialy  A. El  Abbes  L.  Aubert  M.  Benfredj  P.  Far  E. Safa  Beaussier  H.  de Parades  V. 《Techniques in coloproctology》2022,26(2):143-146
Techniques in Coloproctology - The aim of our study was to assess the efficacy of sinus laser therapy (SiLaT) for the treatment of pilonidal disease. All adult patients treated with SiLaT in our...  相似文献   
3.
The International Journal of Cardiovascular Imaging - Global longitudinal strain (GLS) has proven to be a powerful prognostic marker in various patient populations, but the prognostic value of...  相似文献   
4.
BackgroundReverse total shoulder arthroplasty (RSA) primarily varies between 2 implant design options: a 135 humeral stem inclination that closely resembles anatomic orientation, versus the Grammont-style 155 humeral stem inclination that further medializes and distalizes the center of rotation (COR). The purpose of this study was to compare deltoid force, glenoid strain, and simulated glenohumeral range of motion (ROM) between RSA 135 and RSA 155 designs, with a series of standardized permutations of glenosphere offset and rotator cuff pathology.MethodsTwelve fresh-frozen cadaveric shoulder specimens were studied using a shoulder simulator. Native shoulder motion profiles for reproducible abduction range of motion were established using a customized testing device. Optical 3-dimensional tracking and pressure sensors were used to accurately record glenohumeral range of motion (ROM), deltoid force, and glenoid strain for RSA 135 and RSA 155 designs. For each cohort, all combinations of glenosphere offsets and rotator cuff tendon involvement were evaluated.ResultsThere was no significant difference in the overall abduction ROM between the 155 and the 135 humeral stem implants (P = .75). Resting abduction angle and maximum abduction angle were significantly greater with a 155 + STD (standard offset) construct than with a 135 + STD construct (P < .001 and P = .01, respectively). Both stem inclinations decreased combined deltoid force requirements as compared the native shoulder with a massive cuff tear. Effective glenoid strain did not vary significantly between 135 + STD and 155 + STD constructs (P = .66).ConclusionOverall, range of motion between the 135 and the 155 humeral stem inclinations was not significantly different. The cumulative deltoid force was lower in RSA shoulders when compared to native shoulders with massive rotator cuff tears, highlighting the utility of both implant designs. The Grammont-style 155 stem coupled with a 2.5 mm inferior offset glenosphere required less deltoid force to reach maximum abduction than did the more anatomic, lateralized 135 stem coupled with a 4 mm lateral offset glenosphere.Level of EvidenceBasic Science, Biomechanics Controlled Laboratory Study  相似文献   
5.
In the last decade, the development of new radiopharmaceuticals for the imaging and therapy of prostate cancer has been a highly active and important area of research, especially focusing on the prostate-specific membrane antigen (PSMA), an antigen which is upregulated in prostate, as well as in other tumor cells. A large variety of PSMA ligands have been radiolabeled, to date. Among the various derivatives, PSMA-617 resulted to be one of the most interesting in terms of interaction with the antigen and clinical properties, and its lutetium-177 labeled version has recently been approved by regulatory agencies for therapeutic purposes. For this reasons, the radiolabeling with fluorine-18 of a PSMA-617 derivative might be of interest. Beside other methodologies to radiolabel macromolecules with fluorine-18, the “click-chemistry” approach resulted to be very useful, and the copper-catalyzed azide-alkyne cycloaddition (CuAAC) is considered one of most efficient and reliable. This paper proposes the synthesis of a suitable precursor for the radiolabeling with fluorine-18 of a new PSMA-617 derivative. The whole radiosynthetic procedure has been fully automated, and the final product, which proved to be stable in plasma, has been obtained with radiochemical yield and purity suitable for subsequent preclinical studies.  相似文献   
6.
Sport Sciences for Health - The purposes of this study were to describe the fitness and hormonal levels according to playing time (PT) (i.e., PT during season less (PT1) or more (PT2) than 50% of...  相似文献   
7.
8.
BackgroundResearch into oral health care for older people has shown that dental care in general decreases with increasing age and frailty and, therefore, oral health care provision may be complex. The aim of this study is to identify the oral health care dentists provide to community-dwelling older people and which barriers they experience in doing this.MethodsIn this cross-sectional study, a representative sample of dentists in the Netherlands was asked to prospectively select one older patient and describe this patient using a specially developed registration form; the patient was requested to fill out a questionnaire. The relationship between experienced barriers in providing oral health care to older patients and characteristics of the dentists and the patients was studied by means univariate and multivariate logistic regression analysis.ResultsIn total, 923 dentists were asked to participate in the study. Data were available for 39.4% dentist–patient pairs. In most cases (87.4%), oral health care was focussed on conservation of the dentition. In all, 14.0% of the dentists experienced barriers in providing oral health care for older people. Some patient factors increase the risk of experiencing barriers, eg, the more difficult behaviour of older patients and the greater disease burden.ConclusionsOral health care was mostly focussed on conservation of the dentition, and dentists especially experience barriers in oral health provision to older patients if they are already frail.  相似文献   
9.
10.
Clinical Oral Investigations - To analyze differences in variation of orthodontic diagnostic measurements on lateral cephalograms reconstructed from ultra low dose-low dose (ULD-LD) cone beam...  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