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   2534926篇
  免费   208911篇
  国内免费   4943篇
耳鼻咽喉   36006篇
儿科学   77113篇
妇产科学   66236篇
基础医学   355196篇
口腔科学   70975篇
临床医学   232647篇
内科学   501718篇
皮肤病学   50446篇
神经病学   217759篇
特种医学   102882篇
外国民族医学   899篇
外科学   385544篇
综合类   58003篇
现状与发展   2篇
一般理论   1119篇
预防医学   202724篇
眼科学   59622篇
药学   188202篇
  5篇
中国医学   4601篇
肿瘤学   137081篇
  2019年   20716篇
  2018年   28431篇
  2017年   21946篇
  2016年   24047篇
  2015年   27227篇
  2014年   39277篇
  2013年   58848篇
  2012年   80607篇
  2011年   84692篇
  2010年   49637篇
  2009年   47547篇
  2008年   79912篇
  2007年   84760篇
  2006年   85349篇
  2005年   83232篇
  2004年   80026篇
  2003年   76778篇
  2002年   75538篇
  2001年   113856篇
  2000年   117598篇
  1999年   99795篇
  1998年   29798篇
  1997年   27056篇
  1996年   26786篇
  1995年   25872篇
  1994年   24257篇
  1993年   22579篇
  1992年   80086篇
  1991年   77035篇
  1990年   74119篇
  1989年   71354篇
  1988年   66342篇
  1987年   65238篇
  1986年   61793篇
  1985年   58878篇
  1984年   44861篇
  1983年   38222篇
  1982年   23649篇
  1981年   21029篇
  1979年   41639篇
  1978年   29354篇
  1977年   24679篇
  1976年   23169篇
  1975年   24210篇
  1974年   29868篇
  1973年   28254篇
  1972年   26362篇
  1971年   24279篇
  1970年   22834篇
  1969年   21150篇
排序方式: 共有10000条查询结果,搜索用时 281 毫秒
101.

Purpose

Chest wall pain is an uncommon but bothersome late complication following lung stereotactic body radiation therapy. Despite numerous studies investigating predictors of chest wall pain, no clear consensus has been established for a chest wall constraint. The aim of our study was to investigate factors related to chest wall pain in a homogeneous group of patients treated at our institution.

Patients and methods

All 122 patients were treated with the same stereotactic body radiation therapy regimen of 48 Gy in three fractions, seen for at least 6 months of follow-up, and planned with heterogeneity correction. Chest wall pain was scored according to the Common Terminology Criteria for Adverse Events classification v3.0. Patient (age, sex, diabetes, osteoporosis), tumour (planning target volume, volume of the overlapping region between planning target volume and chest wall) and chest wall dosimetric parameters (volumes receiving at least 30, 40, and 50 Gy, the minimal doses received by the highest irradiated 1, 2, and 5 cm3, and maximum dose) were collected. The correlation between chest wall pain (grade 2 or higher) and the different parameters was evaluated using univariate and multivariate logistic regression.

Results

Median follow-up was 18 months (range: 6–56 months). Twelve patients out of 122 developed chest wall pain of any grade (seven with grade 1, three with grade 2 and two with grade 3 pain). In univariate analysis, only the volume receiving 30 Gy or more (P = 0.034) and the volume of the overlapping region between the planning target volume and chest wall (P = 0.038) significantly predicted chest wall pain, but these variables were later proved non-significant in multivariate regression.

Conclusion

Our analysis could not find any correlation between the studied parameters and chest wall pain. Considering our present study and the wide range of differing results from the literature, a reasonable conclusion is that a constraint for chest wall pain is yet to be defined.  相似文献   
102.
To evaluate the changes in alveolar contour after guided bone regeneration (GBR) with two different combinations of biomaterials in dehiscence defects arou  相似文献   
103.
104.
105.
106.
107.
108.
109.
Porocarcinoma is an unusual, locally aggressive and potentially fatal neoplasm. Several cutaneous malignancies have been described in association with porocarcinoma, including squamous cell carcinoma, basal cell carcinoma and tricholemmal carcinoma. Previous reports have indicated that the occurrence of malignant tumours in combination with porocarcinoma is extremely rare, in particular with regard to Bowen disease (BD). We report an uncommon case of porocarcinoma occurring synchronously in a single BD lesion in a 63‐year‐old woman with multiple BD lesions. The clinical and histological findings confirmed this diagnosis.  相似文献   
110.
Advancement in microelectromechanical system has facilitated the microfabrication of polymeric substrates and the development of the novel class of controlled drug delivery devices. These vehicles have specifically tailored three dimensional physical and chemical features which together, provide the capacity to target cell, stimulate unidirectional controlled release of therapeutics and augment permeation across the barriers. Apart from drug delivery devices microfabrication technology’s offer exciting prospects to generate biomimetic gastrointestinal tract models. BioMEMS are capable of analysing biochemical liquid sample like solution of metabolites, macromolecules, proteins, nucleic acid, cells and viruses. This review summarized multidisciplinary application of biomedical microelectromechanical systems in drug delivery and its potential in analytical procedures.  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