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   3544篇
  免费   181篇
  国内免费   8篇
耳鼻咽喉   75篇
儿科学   301篇
妇产科学   52篇
基础医学   334篇
口腔科学   146篇
临床医学   297篇
内科学   745篇
皮肤病学   73篇
神经病学   151篇
特种医学   81篇
外科学   444篇
综合类   120篇
预防医学   180篇
眼科学   101篇
药学   382篇
中国医学   33篇
肿瘤学   218篇
  2023年   53篇
  2022年   129篇
  2021年   173篇
  2020年   92篇
  2019年   102篇
  2018年   179篇
  2017年   113篇
  2016年   149篇
  2015年   145篇
  2014年   188篇
  2013年   233篇
  2012年   288篇
  2011年   307篇
  2010年   162篇
  2009年   121篇
  2008年   151篇
  2007年   145篇
  2006年   131篇
  2005年   102篇
  2004年   80篇
  2003年   91篇
  2002年   62篇
  2001年   55篇
  2000年   47篇
  1999年   33篇
  1998年   21篇
  1997年   19篇
  1996年   8篇
  1995年   9篇
  1994年   8篇
  1993年   8篇
  1992年   19篇
  1991年   30篇
  1990年   26篇
  1989年   27篇
  1988年   36篇
  1987年   23篇
  1986年   20篇
  1985年   26篇
  1984年   8篇
  1983年   10篇
  1979年   21篇
  1978年   21篇
  1977年   6篇
  1976年   6篇
  1973年   5篇
  1972年   4篇
  1970年   4篇
  1969年   10篇
  1968年   5篇
排序方式: 共有3733条查询结果,搜索用时 0 毫秒
11.
12.
13.
Primary nasal septal adenocarcinoma is a rare lesion. A sporadic case of septal adenocarcinoma in a 22 years old male is being described along with review of literature.  相似文献   
14.
Members of the Mycobacterium chelonae complex (MCC), including M. immunogenum, M. chelonae, and M. abscessus, have been associated with nosocomial infections and occupational hypersensitivity pneumonitis due to metalworking fluid (MWF) exposures. In order to minimize these health hazards, an effective and rapid assay for detection of MCC species and differentiation of MCC species from other species of rapidly growing mycobacteria (RGM) and from one another is warranted. Here we report such a method, based on the variable 16S-23S rRNA gene internal transcribed spacer (ITS) region. Mycobacterium genus-specific primers derived from highly conserved sequences in the ITS region and the flanking 16S rRNA gene were used. Specificity of the primers was verified using the MCC member species, 11 non-MCC RGM species, 3 slow-growing mycobacterial (SGM) species (two strains each), and 19 field isolates, including 18 MCC isolates (from in-use MWF) and one non-MCC isolate (from reverse osmosis water). The ITS amplicon size of M. immunogenum varied from those of M. chelonae and M. abscessus. Sequencing of the approximately 250-bp-long ITS amplicons of the three MCC member species showed differences in 24 to 34 bases, thereby yielding variable deduced restriction maps. ITS PCR-restriction analysis using the in silico-selected restriction enzyme MaeII or HphI differentiated the three MCC members from one another and from other RGM and SGM species without sequencing. The enzyme MaeII discriminated all three member species; however, HphI could only differentiate M. immunogenum from M. chelonae and M. abscessus. Use of an optimized rapid DNA template preparation step based on direct cell lysis in the PCR tube added to the simplicity and adaptability of the developed assay.  相似文献   
15.
16.
Soft tissue aneurysmal bone cysts (STABCs) are extremely rare extraosseous counterpart of aneurysmal bone cyst (ABC), with close resemblance to histo-morphologic characteristics of ABC. Here we would like to report a 13-year-old female patient, who presented with a large mass, occupying the entire left hemithorax. Patient underwent resection of the thoracic mass. On histopathological examination, it was found to be a soft tissue ABC. It is a very rare tumor and until date 28 cases have been reported in English literature, to the best of our knowledge. On review of the literature, we found this to be the first case of STABC reported in thoracic cavity. The objective of this case presentation is to provide information regarding clinical presentation, radiological and pathological features, and course of management for this rare disease. Soft tissue ABCs are a new class of tumors, so more extensive research is required to establish standard guidelines for their diagnosis and management, to yield better prognosis.  相似文献   
17.
Immune checkpoint inhibitors (ICPIs) are monoclonal antibodies against inhibitory receptors on T cells resulting in anticancer activity. In kidney transplant (KT) recipients, ICPI use has been associated with acute allograft rejection. In failed allografts, however, the effects of ICPIs are unknown. We present a case of a 66-year-old man with a history of diabetes, renal cell cancer, left native nephrectomy, and end-stage kidney disease. He received a deceased donor KT which failed after 6 years due to biopsy-proven recurrent diabetic nephrosclerosis. He was started on hemodialysis and his immunosuppression was gradually weaned off. A year later, he was diagnosed with renal cell cancer in his right native kidney requiring nephrectomy. He later developed metastasis and was started on combination ICPIs. He developed hematuria, allograft pain, and malaise consistent with graft intolerance syndrome 28 days after starting ICPIs. Urine culture and cystoscopy were normal. A computed tomography scan of his abdomen revealed an enlarged allograft with patchy enhancement. After a multidisciplinary discussion, he underwent transplant nephrectomy. Histopathology showed chronic active T cell–mediated rejection. As ICPI use becomes prevalent, practitioners need to be aware of its potential complications among KT recipients both with functioning and failed allografts.  相似文献   
18.
Previous research on sex ratio at birth (SRB) in India has largely relied on macro‐analysis of census data that do not contain the breadth of factors needed to explain patterns in SRB. Additionally, no previous research has examined the differentiation of factors associated with SRB across birth orders, a key determinant in societies affected by son preference. This study aims to fill these gaps using micro‐data related to 553,461 births occurring between 2005 and 2016 collected as part of the 2015–2016 National Family Health Survey. Analyses used multivariable logistic regressions stratified by birth order to examine associations with SRB at the national level. The SRB at birth order 1 was outside the biological normal limit, and generally increased with birth order. First births in households with wealth in the middle and richest quintiles, with mothers who desired a higher ideal number of sons than daughters, and in lower fertility communities had a higher probability of being male. Most SRB correlates were visible at birth orders 3 or higher. Programs and policies designed to address India's male‐skewed SRB must consider the diverse factors that influence SRB, particularly for higher order births.  相似文献   
19.
20.
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