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   4754211篇
  免费   379515篇
  国内免费   15307篇
耳鼻咽喉   68485篇
儿科学   149228篇
妇产科学   126164篇
基础医学   712642篇
口腔科学   135128篇
临床医学   429905篇
内科学   855400篇
皮肤病学   114826篇
神经病学   397706篇
特种医学   191003篇
外国民族医学   1106篇
外科学   726025篇
综合类   138878篇
一般理论   2729篇
预防医学   394222篇
眼科学   114375篇
药学   344948篇
  24篇
中国医学   12462篇
肿瘤学   233777篇
  2021年   43941篇
  2019年   57799篇
  2018年   73133篇
  2017年   55968篇
  2016年   62192篇
  2015年   75247篇
  2014年   110523篇
  2013年   176262篇
  2012年   132235篇
  2011年   138217篇
  2010年   127377篇
  2009年   128859篇
  2008年   124428篇
  2007年   133492篇
  2006年   141910篇
  2005年   136500篇
  2004年   137011篇
  2003年   127171篇
  2002年   117296篇
  2001年   186711篇
  2000年   184012篇
  1999年   165112篇
  1998年   69215篇
  1997年   64418篇
  1996年   62239篇
  1995年   63394篇
  1994年   57414篇
  1993年   53163篇
  1992年   124924篇
  1991年   119982篇
  1990年   114865篇
  1989年   111914篇
  1988年   103563篇
  1987年   101623篇
  1986年   96523篇
  1985年   94033篇
  1984年   76737篇
  1983年   67517篇
  1982年   51208篇
  1981年   47236篇
  1980年   44532篇
  1979年   68008篇
  1978年   53029篇
  1977年   46937篇
  1976年   43161篇
  1975年   43705篇
  1974年   49605篇
  1973年   47574篇
  1972年   44814篇
  1971年   41281篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
1.
American Indian and Alaska Native (AIAN) individuals are diverse culturally and geographically but share a high prevalence of chronic illness, largely because of obstacles to high-quality health care. The authors comprehensively examined cancer incidence and mortality among non-Hispanic AIAN individuals, compared with non-Hispanic White individuals for context, using population-based data from the National Cancer Institute, the Centers for Disease Control and Prevention, and the North American Association of Central Cancer Registries. Overall cancer rates among AIAN individuals were 2% higher than among White individuals for incidence (2014 through 2018, confined to Purchased/Referred Care Delivery Area counties to reduce racial misclassification) but 18% higher for mortality (2015 through 2019). However, disparities varied widely by cancer type and geographic region. For example, breast and prostate cancer mortality rates are 8% and 31% higher, respectively, in AIAN individuals than in White individuals despite lower incidence and the availability of early detection tests for these cancers. The burden among AIAN individuals is highest for infection-related cancers (liver, stomach, and cervix), for kidney cancer, and for colorectal cancer among indigenous Alaskans (91.3 vs. 35.5 cases per 100,000 for White Alaskans), who have the highest rates in the world. Steep increases for early onset colorectal cancer, from 18.8 cases per 100,000 Native Alaskans aged 20–49 years during 1998 through 2002 to 34.8 cases per 100,000 during 2014 through 2018, exacerbated this disparity. Death rates for infection-related cancers (liver, stomach, and cervix), as well as kidney cancer, were approximately two-fold higher among AIAN individuals compared with White individuals. These findings highlight the need for more effective strategies to reduce the prevalence of chronic oncogenic infections and improve access to high-quality cancer screening and treatment for AIAN individuals. Mitigating the disparate burden will require expanded financial support of tribal health care as well as increased collaboration and engagement with this marginalized population.  相似文献   
2.
3.
4.
AIDS and Behavior - Although misperceived norms often drive personal health behaviors, we do not know about this phenomenon in the context of antiretroviral therapy (ART) adherence. We conducted a...  相似文献   
5.
Spindler  L.  Alam  A.  Fathallah  N.  Rentien  A.-L.  Draullette  M.  Pommaret  E.  Thierry  M.-L.  Mituialy  A. El  Abbes  L.  Aubert  M.  Benfredj  P.  Far  E. Safa  Beaussier  H.  de Parades  V. 《Techniques in coloproctology》2022,26(2):143-146
Techniques in Coloproctology - The aim of our study was to assess the efficacy of sinus laser therapy (SiLaT) for the treatment of pilonidal disease. All adult patients treated with SiLaT in our...  相似文献   
6.
Clinical Rheumatology - This study aimed to assess treatment patterns and frequency of inadequate response associated with advanced therapy initiation among patients with ankylosing spondylitis...  相似文献   
7.
The International Journal of Cardiovascular Imaging - Global longitudinal strain (GLS) has proven to be a powerful prognostic marker in various patient populations, but the prognostic value of...  相似文献   
8.
Numerous studies showed that postural balance improves through light touch on a stable surface highlighting the importance of haptic information, seemingly downplaying the mechanical contributions of the support. The present study examined the mechanical effects of canes for assisting balance in healthy individuals challenged by standing on a beam. Sixteen participants supported themselves with two canes, one in each hand, and applied minimal, preferred, or maximum force onto the canes. They positioned the canes in the frontal plane or in a tripod configuration. Statistical analysis used a linear mixed model to evaluate the effects on the center of pressure and the center of mass. The canes significantly reduced the variability of the center of pressure and the center of mass to the same level as when standing on the ground. Increasing the exerted force beyond the preferred level yielded no further benefits, although in the preferred force condition, participants exploited the altered mechanics by resting their arms on the canes. The tripod configuration allowed for larger variability of the center of pressure in the task-irrelevant anterior–posterior dimension. High forces had a destabilizing effect on the canes: the displacement of the hand on the cane handle increased with the force. Given this static instability, these results show that using canes can provide not only mechanical benefits but also challenges. From a control perspective, effort can be reduced by resting the arms on the canes and by channeling noise in the task-irrelevant dimensions. However, larger forces exerted onto the canes can also have destabilizing effects and the instability of the canes needs to be counteracted, possibly by arm and shoulder stiffness. Insights into the variety of mechanical effects is important for the design of canes and the instructions of how to use them.  相似文献   
9.
The International Journal of Cardiovascular Imaging - This study investigated the impact of bicuspid aortic valve (BAV) on valve morphology and motion as well as proximal and aortic hemodynamics...  相似文献   
10.

There are few published procedures for teaching athletic skills to children with autism spectrum disorder (ASD). This study used a multiple baseline across participants design to evaluate the effects of prompting, demand fading, and differential reinforcement, on the basketball shooting skills of four school-aged boys diagnosed with ASD. During baseline, all four boys rarely made correct and accurate baskets at the regulation height and distance for their age-group in youth basketball. Following intervention, all four boys increased their percentage of correct shots and accuracy, compared to baseline, and their shooting skills transferred to the game of “P-I-G” with peers.

  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