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   6293篇
  免费   452篇
  国内免费   12篇
耳鼻咽喉   86篇
儿科学   144篇
妇产科学   211篇
基础医学   765篇
口腔科学   179篇
临床医学   767篇
内科学   1285篇
皮肤病学   127篇
神经病学   610篇
特种医学   362篇
外科学   792篇
综合类   138篇
一般理论   5篇
预防医学   471篇
眼科学   142篇
药学   436篇
中国医学   11篇
肿瘤学   226篇
  2021年   74篇
  2020年   67篇
  2019年   111篇
  2018年   120篇
  2017年   102篇
  2016年   104篇
  2015年   92篇
  2014年   156篇
  2013年   213篇
  2012年   270篇
  2011年   335篇
  2010年   178篇
  2009年   142篇
  2008年   282篇
  2007年   270篇
  2006年   303篇
  2005年   309篇
  2004年   273篇
  2003年   237篇
  2002年   246篇
  2001年   218篇
  2000年   228篇
  1999年   172篇
  1998年   61篇
  1997年   62篇
  1996年   81篇
  1995年   57篇
  1994年   50篇
  1992年   115篇
  1991年   140篇
  1990年   138篇
  1989年   128篇
  1988年   107篇
  1987年   117篇
  1986年   124篇
  1985年   109篇
  1984年   86篇
  1983年   77篇
  1982年   48篇
  1981年   37篇
  1980年   39篇
  1979年   59篇
  1978年   44篇
  1977年   45篇
  1974年   43篇
  1973年   39篇
  1972年   37篇
  1971年   34篇
  1967年   38篇
  1966年   35篇
排序方式: 共有6757条查询结果,搜索用时 46 毫秒
1.
2.
3.
Biopsies from the diseased bones of patients with familial expansile osteolysis (FEO) were examined by light and electron microscopy. Focal concentrations of multinuclear osteoclasts were present, and these contained viral-like microcylindrical inclusions which appeared exclusive to their nuclei. No consistent relationship was found between osteoclast size and the number of osteoclast nuclei containing microcylindrical inclusions. Quantitative histomorphometry showed evidence of increased bone remodelling with high bone cell densities and a decrease of the reversal period in bone remodelling. The lesions contained prominent woven bone and fibrovascular tissue, together with mononuclear cells and adipocytes. Little bone was found in the most radiolucent lesions, which were almost totally occupied by adipocytes and fibrovascular tissue. Serology did not reveal any significant differences between the viral antibody titres of patients and their age- and sex-matched controls. The present study suggests that intranuclear viral-like microcylindrical inclusions of osteoclasts are not a specific feature of Paget's disease, and are found in other disorders of osteoclast function, including pycnodysostosis, osteopetrosis, giant cell tumours, and familial expansile osteolysis.  相似文献   
4.
Aims: On the Edge is a mental health education programme designed to support early intervention by increasing knowledge and understanding of early psychosis, reducing the stigma associated with mental health issues and improving awareness of avenues of help. The target audience was young people aged 14–22 years in schools and colleges. Methods: An interactive drama programme was developed through collaborative working across psychiatry, applied drama and those with direct experience of psychosis. A national tour engaged 2500 students in 71 performances that took place in 51 schools and colleges. The programme was evaluated against its aims with data collected both during and after the tour. Results: Quantitative and qualitative evaluation found significant gains with respect to all three aims. Thirty‐one schools developed supportive links with local mental health services. Conclusions: This programme shows the value and effectiveness of delivering health education on early psychosis through the medium of applied drama, and offers a model for a programme that can be incorporated into early intervention services. Lessons learned through delivering this programme are a valuable contribution towards future developments of mental health education programmes for schools.  相似文献   
5.
All nine exons of the ADH2(3) allele, which encodes the human alcohol dehydrogenase beta 3 subunit, have been cloned and sequenced. Comparison of this sequence to the ADH2(1) nucleotide sequence revealed only a single difference that results in an amino acid change, thus proving that the significant kinetic differences between these two isozymes is due to the Cys for Arg substitution at position 369. There are also two silent polymorphisms, and two changes in noncoding regions.  相似文献   
6.
Progressive peripheral cone dysfunction   总被引:1,自引:0,他引:1  
A 22-year-old man had a three-year history of progressive day blindness, most notably peripherally, and denied difficulty with central vision or color vision. Visual function studies demonstrated a diffuse dysfunction of the photopic system and normal scotopic function. The central cone function, however, was essentially normal. Visual acuity was 20/20 in each eye, results on AO-HRR and Ishihara color plate testing were normal, color naming visual fields demonstrated color discrimination in the central 10 degrees, and foveal adaptation was normal.  相似文献   
7.
8.
9.
Temporal modulation transfer functions (MTF's) were recorded from the macula of nine normal subjects using focal electroretinography (FERG). An array of light emitting diodes (LED's) was used to experimentally manipulate stimulus temporal frequency, modulation depth, and mean luminance values. Two techniques were used to derive FERG modulation thresholds at several temporal frequencies: conventional averaging with extrapolation to a criterion amplitude, and a swept stimulus lock-in retrieval method. These two methods produced comparable results. The electrophysiologically derived MTF's were similar in shape to those obtained psychophysically. Six patients with retinal disease were also examined; all patients showed sensitivity losses which were most marked at the higher frequencies. Such losses tended to be greater in patients with poorer visual acuity.  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