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   5969篇
  免费   314篇
  国内免费   14篇
耳鼻咽喉   64篇
儿科学   261篇
妇产科学   111篇
基础医学   763篇
口腔科学   137篇
临床医学   436篇
内科学   1223篇
皮肤病学   86篇
神经病学   612篇
特种医学   183篇
外科学   784篇
综合类   106篇
预防医学   408篇
眼科学   248篇
药学   442篇
中国医学   14篇
肿瘤学   419篇
  2023年   38篇
  2022年   75篇
  2021年   151篇
  2020年   77篇
  2019年   124篇
  2018年   159篇
  2017年   118篇
  2016年   135篇
  2015年   152篇
  2014年   222篇
  2013年   290篇
  2012年   446篇
  2011年   493篇
  2010年   251篇
  2009年   236篇
  2008年   349篇
  2007年   364篇
  2006年   354篇
  2005年   318篇
  2004年   309篇
  2003年   272篇
  2002年   247篇
  2001年   122篇
  2000年   113篇
  1999年   94篇
  1998年   51篇
  1997年   45篇
  1996年   38篇
  1995年   17篇
  1994年   27篇
  1993年   39篇
  1992年   66篇
  1991年   66篇
  1990年   43篇
  1989年   35篇
  1988年   33篇
  1987年   41篇
  1986年   31篇
  1985年   32篇
  1984年   24篇
  1983年   22篇
  1982年   13篇
  1981年   15篇
  1980年   15篇
  1979年   15篇
  1978年   15篇
  1976年   9篇
  1975年   11篇
  1974年   11篇
  1967年   7篇
排序方式: 共有6297条查询结果,搜索用时 46 毫秒
51.
52.
Granulosa Cell Tumors (GCT) constitutes 1.5% to 3.5% of all primary ovarian neoplasms. They may be solid, cystic or both. Unilocular cystic GCT are very rare. We report here a case of 32 years female with unicystic GCT in which the distinction from follicular cyst was difficult and was made by carefully examining the lining of the cyst,which showed occasional multiple layers of granulosa cells with a few Call-Exner bodies.  相似文献   
53.
Hypothalamic hamartomas are rare tumours of particular interest because of their unusual symptoms. Three cases of hypothalamic hamartomas are reported in children, who presented with precocious puberty and gelastic seizures.  相似文献   
54.
55.
CTL play a pivotal role in the immune response during viral infections. In this study, the HLA class II restricted T(H) requirement for optimal in vivo induction of HLA class I restricted CTL responses has been investigated. Towards this goal, transgenic mice expressing both HLA class I (A*0201 or A2.1) and class II (DRB1*0101 or DR1) molecules have been derived. Immunization of these mice with an HLA A*0201-restricted and CMV-specific CTL epitope (pp65(495-503)), and either of three different tetanus toxin-derived MHC class II-binding T(H) epitopes, resulted in a vigorous CTL response. CTL specific for the pp65(495-503) epitope were dramatically enhanced in mice expressing both the HLA-DR1 and HLA-A*0201 transgenes. Notably, preinjection of three TT peptides (TT(639-652), TT(830-843), and TT(947-967)) increased the capability of HLA A*0201/DR1 Tg mice to respond to subsequent immunization with the T(H) + CTL peptide mixture. These results indicate that the use of HLA A*0201/DR1 Tg mice constitute a versatile model system (in lieu of immunizing humans) for the study of both HLA class I and class II restricted T-cell responses. These studies provide a rational model for the design and assessment of new minimal-epitope vaccines based on their in vivo induction of a pathogen-specific CTL response.  相似文献   
56.
A simple method is described for labelling cells with fluorescein and using them in artificial mixtures to assess cell separation procedures. The method facilitates the examination of the variables in a separation procedure. It is thus possible to tailor a separation procedure (for example panning with monoclonal antibody) to suit the specific requirements of the experiment.  相似文献   
57.
Subcortical structural changes have been reported to occur in some elderly subjects with late age onset depression. Given the association between diseases affecting subcortical structures and affective disorders, this suggests that these structural changes may be involved in the etiology of late age onset depression in some patients. With the advent of Brain Magnetic Resonance Imaging (MRI), "in vivo" analysis of these subcortical structures is now possible. The authors report a higher occurrence of caudate (60% vs. 11%) and large deep white matter hyperintensities (60% vs. 11%) in late age onset elderly depressed subjects compared with early onset elderly depressed subjects. These results suggest that late age onset depression may be mediated by caudate and white matter structural changes in some patients.  相似文献   
58.
A 60-year-old female developed a right parotid swelling six months after surgery for intra-oral squamous cell carcinoma. Fine needle aspiration (FNA) cytological smears showed dissociated large and small pleomorphic tumour cells with abundant mitoses and oncocytic features. A cytological diagnosis of parotid acinic cell carcinoma (ACC) was made. Histological study of the subtotal parotidectomy specimen showed a papillary cystic variety of acinic cell carcinoma (ACC-PCV). FNA cytological features in this case of ACC-PCV differs from the two previously reported cases in that it showed prominent oncocytic and high grade features and absence of papillary pattern in the cytological smears. ACC-PCV is an uncommon tumour and knowledge of its varied FNA cytological features is important for the diagnosis of this neoplasm.  相似文献   
59.
60.
Neurovegetative symptoms in chronic pain and depression   总被引:1,自引:0,他引:1  
The pattern and frequency of neurovegetative symptoms was studied in 57 patients with chronic pain. Seventy-nine percent of these patients had a diagnosable depressive illness, but endogenous depression was rare (5%). Patients with chronic pain were divided into major depressives, minor/intermittent depressives and patients with no depression. A control group of nonendogenous major depressives without pain was also utilized. Major depressives differed from the other two chronic pain groups in that there was more frequent or severe early waking, weight loss, anorexia, diminished libido and initial insomnia. Diurnal variation of mood was not a characteristic of major depression with chronic pain, and did not differ in frequency from the other two chronic pain groups. Major depressives exhibited a profile of neurovegetative symptoms very similar to that found in the control group of major depressives. Over one-third of minor/intermittent depressed patients with chronic pain exhibited atypical (reversed) vegetative symptoms of hyperphagia and weight gain. This finding, together with our review of the literature, suggests an important and previously unrecognized link between atypical depression and chronic pain.  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