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   29273篇
  免费   1416篇
  国内免费   195篇
耳鼻咽喉   318篇
儿科学   544篇
妇产科学   705篇
基础医学   3386篇
口腔科学   1522篇
临床医学   2231篇
内科学   7864篇
皮肤病学   444篇
神经病学   2726篇
特种医学   1183篇
外科学   4227篇
综合类   113篇
一般理论   7篇
预防医学   1531篇
眼科学   432篇
药学   1609篇
中国医学   118篇
肿瘤学   1924篇
  2023年   162篇
  2022年   273篇
  2021年   802篇
  2020年   456篇
  2019年   632篇
  2018年   819篇
  2017年   574篇
  2016年   698篇
  2015年   804篇
  2014年   1106篇
  2013年   1491篇
  2012年   2280篇
  2011年   2447篇
  2010年   1408篇
  2009年   1255篇
  2008年   2128篇
  2007年   2188篇
  2006年   2013篇
  2005年   2021篇
  2004年   1796篇
  2003年   1554篇
  2002年   1448篇
  2001年   187篇
  2000年   128篇
  1999年   176篇
  1998年   241篇
  1997年   192篇
  1996年   185篇
  1995年   147篇
  1994年   133篇
  1993年   91篇
  1992年   92篇
  1991年   86篇
  1990年   71篇
  1989年   70篇
  1988年   70篇
  1987年   54篇
  1986年   50篇
  1985年   42篇
  1984年   84篇
  1983年   54篇
  1982年   72篇
  1981年   45篇
  1980年   27篇
  1979年   24篇
  1978年   26篇
  1977年   30篇
  1976年   21篇
  1974年   16篇
  1973年   22篇
排序方式: 共有10000条查询结果,搜索用时 390 毫秒
971.
972.
Basal cell carcinoma (BCC) is a common skin cancer worldwide. However, BCC of the nipple and areola complex is rare. Men are more affected than women. Most of the cases were treated with simple excision. We report a case of BCC of the right nipple–areola complex in a 75‐year‐old man, treated with Mohs surgery and simple mastectomy.  相似文献   
973.
974.
975.
976.

Introduction

Although impaired pulmonary function and respiratory sleep disorders are described as responsible for increased mortality in acromegalic patients, little is known about the tracheal abnormalities in this group of patients. Thus, the objectives of this study were to describe the tracheal structural abnormalities and correlate these changes with the respiratory function and clinical data of acromegalic patients.

Material and methods

This is a cross-sectional study that was carried out at two university hospitals. Twenty acromegalic patients underwent spirometry, forced oscillation technique, and computed tomography (CT) assessments. Dyspnea and daytime sleepiness were assessed using the Modified Medical Research Council (MMRC) scale and the Epworth Sleepiness Scale (ESS), respectively. Forty matched subjects served as controls.

Results

The acromegalic patients exhibited larger median ratios between forced expiratory flow and forced inspiratory flow at 50% of the forced vital capacity (FEF50%/FIF50%) (2.05 vs. 1.06, p = 0.0001) compared with healthy volunteers. In the CT analysis, acromegalic patients exhibited larger median differences between their cervical and thoracic tracheal diameters (Δ tracheal diameters) (3 vs. 1 mm; p = 0.003). An association was found between FEF50%/FIF50% and the following variables: mean resistance (Rm), cervical tracheal diameter, and Δ tracheal diameters. Rm also exhibited a negative correlation with cervical tracheal diameter. Neither the MMRC scale nor the ESS exhibited any significant correlation with large airway obstruction (LAO) indices or with the measured tracheal diameters.

Conclusions

Acromegalic patients have tracheal structural abnormalities which are associated with functional indicators of LAO but not with clinical data.  相似文献   
977.
978.
979.
OBJECTIVE: Over a 70-month period, 100 consecutive Mexican mestizo individuals with a clinical marker associated with a primary hypercoagulable state were studied. METHODS: We prospectively assessed: the sticky platelet syndrome (SPS), the activated protein C resistance (aPCR) phenotype, coagulation protein C activity and antigen, coagulation protein S, antithrombin III, plasminogen, IgG and IgM isotypes of antiphospholipid antibodies, homocysteine levels, the factor V gene Leiden, Cambridge, Hong Kong, and Liverpool mutations, the 677 C-->T mutation in the 5,10-methylenetetrahydrofolatereductase (MTHFR), and the G20210A polymorphism in the 3'-untranslated region of the prothrombin gene. RESULTS: Of the 100 consecutive patients prospectively accrued in the study, only 29% were males. In only 6 individuals could we not record any abnormality, whereas in most individuals (81%), two to five co-existing abnormalities were identified. In a multivariate analysis of the association of all these assesments, the only significant association was found between the factor V Leiden mutation and the aPCR phenotype (r = .495; p < 0.001). CONCLUSIONS: These results confirm previous observations on thrombophilia in Mexico underlining that it is a multifactorial disease. They also suggest that the abnormalities detected are not associated to each other.  相似文献   
980.
In two experiments we assessed whether seeing objects automatically activates information regarding how to manipulate them. In Experiment 1 participants categorized photographs of objects that could be manipulated either with a power or a precision grip into artefacts or natural kinds. Target-objects were preceded by primes consisting of photographs of hands in grasping postures (precision or power grip). Experiment 2 involved a preliminary motor training phase in which each visual prime was associated with the actual motor action. In both experiments, natural kinds graspable with a power grip produced the fastest responses. In Experiment 2 we also found a congruency effect between the prime and the kind of grip required by the object (precision, power). Results suggest that visual stimuli automatically activate motor information. Specific motor programs are, however, activated only if motor training is performed before the categorization task. Implications of the results for the understanding of the organization of conceptual and motor information in the brain are discussed.  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