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   2341483篇
  免费   184580篇
  国内免费   7507篇
耳鼻咽喉   32029篇
儿科学   78559篇
妇产科学   64370篇
基础医学   326647篇
口腔科学   63945篇
临床医学   209430篇
内科学   472459篇
皮肤病学   53393篇
神经病学   188817篇
特种医学   94788篇
外国民族医学   883篇
外科学   362832篇
综合类   53189篇
现状与发展   3篇
一般理论   748篇
预防医学   183793篇
眼科学   51088篇
药学   169014篇
  7篇
中国医学   4194篇
肿瘤学   123382篇
  2018年   23755篇
  2017年   18305篇
  2016年   21254篇
  2015年   23878篇
  2014年   33289篇
  2013年   50471篇
  2012年   65109篇
  2011年   69651篇
  2010年   42678篇
  2009年   41158篇
  2008年   65768篇
  2007年   70428篇
  2006年   71481篇
  2005年   69292篇
  2004年   66863篇
  2003年   65105篇
  2002年   62834篇
  2001年   112507篇
  2000年   116431篇
  1999年   98014篇
  1998年   28482篇
  1997年   25611篇
  1996年   26546篇
  1995年   26139篇
  1994年   24549篇
  1993年   22910篇
  1992年   79896篇
  1991年   78090篇
  1990年   75508篇
  1989年   72151篇
  1988年   66617篇
  1987年   65381篇
  1986年   61399篇
  1985年   59068篇
  1984年   44880篇
  1983年   37814篇
  1982年   22938篇
  1981年   20713篇
  1980年   19117篇
  1979年   40442篇
  1978年   28856篇
  1977年   24486篇
  1976年   22568篇
  1975年   23955篇
  1974年   28157篇
  1973年   27026篇
  1972年   24907篇
  1971年   22909篇
  1970年   21245篇
  1969年   19583篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
41.
Imaging     
  相似文献   
42.
43.
44.
Infections due to Penicillium species other than P.marneffei are rare. We identified a boy with X-linked chronic granulomatous disease (X-CGD) with a pulmonary nodule and adjacent rib osteomyelitis caused by Penicillium piceum. The only sign of infection was an elevated sedimentation rate. P. piceum was isolated by fine needle aspirate and from excised infected tissues. Surgical removal and one year of voriconazole treatment were very well tolerated and led to complete recovery. Microbiological, microscopic and molecular studies support the fungal diagnosis. P. piceum should be considered as a relevant pathogen in immunocompromised patients.  相似文献   
45.
Abstract: Background: Fetal pulse oximetry improves the assessment of fetal well‐being during labor. The objective of this study was to evaluate women's satisfaction with their experience with this additional technology. Methods: We surveyed women participating in the FOREMOST trial, a randomized controlled trial comparing the addition of fetal pulse oximetry (FPO) to conventional cardiotocograph (CTG) monitoring (intervention group), versus CTG‐only (control group), in the presence of nonreassuring fetal status during labor. Our survey evaluated 3 aspects of women's experience: labor, fetal monitoring, and participation in the research. The survey was administered within a few days of giving birth and repeated 3 months later. Results: No differences were found between the intervention and control groups for women's evaluations of their labor, fetal monitoring, research, or overall experiences when surveyed on both occasions. Within each study group, a small but statistically significant decline occurred in women's scores for their experience of labor and overall experience from the initial survey close to the time of giving birth, to 3 months later. The magnitude of differences in responses over time was similar for the both groups. Women were more satisfied after a spontaneous or assisted vaginal birth than after cesarean section. Length of time the research midwife was present had a significant positive effect on women's ratings of their experience several days after giving birth (p = 0.006), but no effect at 3 months. Conclusions: The addition of fetal pulse oximetry for the assessment of fetal well‐being during labor did not affect childbearing women's perceptions of fetal monitoring or their labor. Women evaluated their experience in the research process positively overall. Small changes occurred in women's perception of their satisfaction over time. (BIRTH 33:2 June 2006)  相似文献   
46.
47.
48.
49.
50.
BACKGROUND: Three dimensional skin equivalents are widely used in dermatopharmacological and toxicological studies and as autologous transplants in wound healing. In pharmacology, there is tremendous need for monitoring the response of engineered skin equivalents to external treatment. Transplantation of skin equivalents for wound healing requires careful verification of their quality prior to transplantation. Optical coherence tomography (OCT) is a non-contact, non-destructive imaging technique for living tissues offering the potential to fulfill these needs. This work presents an analysis of OCT for high-resolution monitoring of skin equivalents at different stages during the culture process. METHODS: We developed a high-resolution OCT imaging setup based on a commercially available OCT system. A broadband femtosecond laser light source replaces the original superluminescence diode. Tomograms of living skin equivalents were recorded with an axial resolution of 3 mum and correlated with histology and immunofluorescence images. Comparison with standard low-resolution OCT is presented to emphasize the advantages of high-resolution OCT for this application. RESULTS: OCT is particularly able to distinguish between different layers of skin equivalents including stratum corneum, epidermal and dermal layer as well as the basement membrane zone. The high-resolution OCT scans correlate closely with two key benchmarks, histology and immunofluorescence imaging. CONCLUSIONS: This study clearly demonstrates the benefits of high-resolution OCT for identifying living tissue structure and morphology. Compared with the current gold standard histology, OCT offers non-destructive tissue imaging, enabling high-resolution evaluation of living tissue morphology and structure as it evolves.  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