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   2420644篇
  免费   199958篇
  国内免费   4264篇
耳鼻咽喉   35383篇
儿科学   74474篇
妇产科学   64881篇
基础医学   343259篇
口腔科学   68724篇
临床医学   219260篇
内科学   477176篇
皮肤病学   49461篇
神经病学   204956篇
特种医学   98065篇
外国民族医学   887篇
外科学   367176篇
综合类   56671篇
现状与发展   1篇
一般理论   1021篇
预防医学   194329篇
眼科学   57137篇
药学   179429篇
  4篇
中国医学   4422篇
肿瘤学   128150篇
  2018年   24736篇
  2016年   21039篇
  2015年   25030篇
  2014年   35720篇
  2013年   53525篇
  2012年   71365篇
  2011年   74780篇
  2010年   44464篇
  2009年   42850篇
  2008年   71108篇
  2007年   75441篇
  2006年   76264篇
  2005年   74079篇
  2004年   71317篇
  2003年   68540篇
  2002年   67285篇
  2001年   112734篇
  2000年   116781篇
  1999年   98663篇
  1998年   28223篇
  1997年   25949篇
  1996年   25799篇
  1995年   24965篇
  1994年   23475篇
  1993年   21942篇
  1992年   79765篇
  1991年   76707篇
  1990年   73871篇
  1989年   71086篇
  1988年   66088篇
  1987年   65048篇
  1986年   61531篇
  1985年   58621篇
  1984年   44421篇
  1983年   37853篇
  1982年   23143篇
  1981年   20569篇
  1980年   19280篇
  1979年   41505篇
  1978年   29232篇
  1977年   24509篇
  1976年   23002篇
  1975年   24198篇
  1974年   29900篇
  1973年   28304篇
  1972年   26444篇
  1971年   24311篇
  1970年   22865篇
  1969年   21269篇
  1968年   19270篇
排序方式: 共有10000条查询结果,搜索用时 264 毫秒
131.
132.
133.
134.
135.
136.
137.
Objective: Report measured resting energy expenditure (REE) in wheelchair rugby athletes and evaluate agreement between REE and the prediction models of Chun, Cunningham, Harris-Benedict, Mifflin, Nightingale and Gorgey, and Owen.

Design: Cohort-based validation study.

Setting. Paralympic team training camp.

Participants: Fourteen internationally competitive athletes who play wheelchair rugby, 13 of whom had cervical spinal cord injuries (SCI).

Outcome Measures: A portable metabolic analyzer was used to measure REE following an overnight fast and dual-energy X-ray absorptiometry (DXA) was used to assess lean body mass for the prediction equations.

Results: REE in the current sample was 1735?±?257?kcal?×?day?1 ranging from 1324 to 2068?kcal?×?day?1 Bhambhani Y. Physiology of wheelchair racing in athletes with spinal cord injury. Sports Med 2002;32(1):2351.[Crossref], [PubMed], [Web of Science ®] [Google Scholar]. Bland–Altman analyses revealed negative mean bias but similar limits of agreement between measured REE and scores predicted by Chun, Cunningham, Mifflin, Nightingale and Gorgey, and Owen models in elite athletes who play wheelchair rugby.

Conclusion: Prediction models regressed on persons with and without SCI under-predicted REE of competitive wheelchair rugby athletes. This outcome may be explained by the higher REE/fat-free mass (FFM) ratio of current athletes compared to less active samples. Findings from the current study will help practitioners to determine nutrient intake needs on training days of varied intensity.  相似文献   
138.
139.
Hypertrophic lichen planus (HLP) is a T‐cell‐mediated process typically presenting with hypertrophic or verrucous plaques on the lower limbs. We report the case of a 24‐year‐old woman with a history of HLP since age 3 years presenting with rapid malignant transformation of one lesion into a large squamous cell carcinoma (SCC). Subsequent examination revealed progressive, widespread metastatic involvement, and the patient ultimately died from her disease. SCC associated with HLP is rare, with a review of the literature revealing fewer than 50 cases. This case highlights the need to be aware of suspicious changes in HLP and to educate patients as to when to be reevaluated.  相似文献   
140.
The serrated pathway (SP) can be viewed as two parallel, but partially overlapping, arrays of colorectal precursor lesions, and their respective endpoint carcinomas, that are distinct from those of the conventional adenoma–carcinoma sequence (APC‐pathway). In this review we focus at the outset on the clinical impact, pathological features, molecular genetics and biological behaviours of the various SP cancers. Then we summarize the clinicopathological features, classification and molecular profiles of the two main precursor lesions that anchor the respective pathways: (i) sessile serrated adenoma/polyp (SSA/P), also called sessile serrated lesion (SSL), and (ii) traditional serrated adenoma (TSA). Activating mutations of the RAS–RAF–MAPK pathway initiate and sustain the lesions of the SP, and CpG island methylation of the promoter regions of tumour suppressor and DNA repair genes play the major role in their neoplastic progression. The SP includes microsatellite stable (MSS) carcinomas that are among the most biologically aggressive colorectal carcinomas (CRC), and also accounts for the great preponderance of sporadic hypermutated, mismatch repair (MMR)‐deficient or microsatellite instable (MSI) CRC. The identification, removal and appropriate classification of at‐risk SP precursors and surveillance of individuals who harbour these lesions present a challenge and opportunity for CRC prevention and mortality reduction.  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