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   44947篇
  免费   2538篇
  国内免费   193篇
耳鼻咽喉   462篇
儿科学   1018篇
妇产科学   778篇
基础医学   8337篇
口腔科学   1072篇
临床医学   3617篇
内科学   8642篇
皮肤病学   1244篇
神经病学   4721篇
特种医学   2059篇
外国民族医学   3篇
外科学   6168篇
综合类   258篇
一般理论   16篇
预防医学   2180篇
眼科学   865篇
药学   3276篇
中国医学   41篇
肿瘤学   2921篇
  2022年   189篇
  2021年   458篇
  2020年   398篇
  2019年   624篇
  2018年   741篇
  2017年   585篇
  2016年   751篇
  2015年   904篇
  2014年   1122篇
  2013年   1604篇
  2012年   2221篇
  2011年   2354篇
  2010年   1589篇
  2009年   1526篇
  2008年   2490篇
  2007年   2583篇
  2006年   2446篇
  2005年   2559篇
  2004年   2383篇
  2003年   2403篇
  2002年   2468篇
  2001年   608篇
  2000年   562篇
  1999年   675篇
  1998年   685篇
  1997年   559篇
  1996年   486篇
  1995年   448篇
  1994年   382篇
  1993年   357篇
  1992年   336篇
  1991年   334篇
  1990年   295篇
  1989年   282篇
  1988年   283篇
  1987年   248篇
  1986年   229篇
  1985年   272篇
  1984年   270篇
  1983年   254篇
  1982年   262篇
  1981年   241篇
  1980年   196篇
  1979年   180篇
  1978年   225篇
  1977年   187篇
  1976年   194篇
  1974年   188篇
  1933年   176篇
  1932年   186篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
1.
2.
3.
4.
Clinical Oral Investigations - The aims of this study are to assess different saliva substitutes for their efficacy to lubricate the oral cavity, and to relate this oral lubrication to the ability...  相似文献   
5.
ABSTRACT

Objective: The purpose of this study was to examine the influence of a total knee arthroplasty (TKA) on linked cranial and caudal structures.

Methods: Thirty-five (14f/21m) subjects participated in this study: 15 subjects (9f, 6m) pre- and post- TKA and a control group of 20 subjects (5f, 15m). The measurements included: jaw condyle position and movement, back scan, plantar pressure distribution, and body sway.

Results: There were no significant differences in electronic position analysis of the jaw; however, the protrusion of the TKA group improved (p = 0.001). The test group had a more anteriorly inclined thoracic spine and a less pronounced lumbar lordosis. Before and after surgery, the body sway in the test group was larger.

Conclusion: The TKA affected most prominently the static mechanisms of the postural control and the spine position. The trajectories of the mandible during protrusion also changed slightly.  相似文献   
6.
7.
The recognition that neurogenesis does not stop with adolescence has spun off research towards the reduction of brain disorders by enhancing brain regeneration. Adult neurogenesis is one of the tougher problems of developmental biology as it requires the generation of complex intracellular and pericellular anatomies, amidst the danger of neuroinflammation. We here review how a multitude of regulatory pathways optimized for early neurogenesis has to be revamped into a new choreography of time dependencies. Distinct pathways need to be regulated, ranging from neural growth factor induced differentiation to mitochondrial bioenergetics, reactive oxygen metabolism, and apoptosis. Requiring much Gibbs energy consumption, brain depends on aerobic energy metabolism, hence on mitochondrial activity. Mitochondrial fission and fusion, movement and perhaps even mitoptosis, thereby come into play. All these network processes are interlinked and involve a plethora of molecules. We recommend a deep thinking approach to adult neurobiology.  相似文献   
8.
9.
10.
Trabecular bone score (TBS) is used for fracture prediction in adults, but its utility in children is limited by absence of appropriate reference values. We aimed to develop reference ranges for TBS by age, sex, and population ancestry for youth ages 5 to 20 years. We also investigated the association between height, body mass index (BMI), and TBS, agreement between TBS and lumbar spine areal bone mineral density (aBMD) and bone mineral apparent density (BMAD) Z-scores, tracking of TBS Z-scores over time, and precision of TBS measurements. We performed secondary analysis of spine dual-energy X-ray absorptiometry (DXA) scans from the Bone Mineral Density in Childhood Study (BMDCS), a mixed longitudinal cohort of healthy children (n = 2014) evaluated at five US centers. TBS was derived using a dedicated TBS algorithm accounting for tissue thickness rather than BMI. TBS increased only during ages corresponding to pubertal development with an earlier increase in females than males. There were no differences in TBS between African Americans and non-African Americans. We provide sex-specific TBS reference ranges and LMS values for calculation of TBS Z-scores by age and means and SD for calculation of Z-scores by pubertal stage. TBS Z-scores were positively associated with height Z-scores at some ages. TBS Z-scores explained only 27% and 17% of the variance of spine aBMD and BMAD Z-scores. Tracking of TBS Z-scores over 6 years was lower (r = 0.47) than for aBMD or BMAD Z-scores (r = 0.74 to 0.79), and precision error of TBS (2.87%) was greater than for aBMD (0.85%) and BMAD (1.22%). In sum, TBS Z-scores provide information distinct from spine aBMD and BMAD Z-scores. Our robust reference ranges for TBS in a well-characterized pediatric cohort and precision error estimates provide essential tools for clinical assessment using TBS and determination of its value in predicting bone fragility in childhood and adolescence. © 2022 American Society for Bone and Mineral Research (ASBMR).  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