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   23326篇
  免费   2457篇
  国内免费   206篇
耳鼻咽喉   207篇
儿科学   729篇
妇产科学   673篇
基础医学   2937篇
口腔科学   429篇
临床医学   2689篇
内科学   4222篇
皮肤病学   247篇
神经病学   1595篇
特种医学   682篇
外科学   2952篇
综合类   1835篇
现状与发展   1篇
一般理论   43篇
预防医学   2882篇
眼科学   441篇
药学   1915篇
  3篇
中国医学   399篇
肿瘤学   1108篇
  2023年   133篇
  2022年   224篇
  2021年   542篇
  2020年   366篇
  2019年   389篇
  2018年   408篇
  2017年   401篇
  2016年   326篇
  2015年   474篇
  2014年   634篇
  2013年   931篇
  2012年   1242篇
  2011年   1383篇
  2010年   918篇
  2009年   807篇
  2008年   1167篇
  2007年   1219篇
  2006年   1048篇
  2005年   1010篇
  2004年   879篇
  2003年   849篇
  2002年   751篇
  2001年   670篇
  2000年   710篇
  1999年   567篇
  1998年   268篇
  1997年   227篇
  1996年   247篇
  1995年   213篇
  1994年   171篇
  1993年   170篇
  1992年   443篇
  1991年   483篇
  1990年   445篇
  1989年   417篇
  1988年   365篇
  1987年   389篇
  1986年   359篇
  1985年   344篇
  1984年   285篇
  1983年   243篇
  1982年   156篇
  1981年   150篇
  1979年   196篇
  1978年   147篇
  1977年   148篇
  1974年   185篇
  1973年   166篇
  1972年   133篇
  1970年   134篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
1.
2.
3.
沙苑子本草考证   总被引:1,自引:0,他引:1  
张婷婷  柯创  秦路平  吴建军 《中草药》2020,51(16):4348-4354
沙苑子为我国常用中药,药用历史悠久。通过查阅本草文献,对沙苑子名称、基原、功效、产地及伪品5个方面进行考证,得知其名称演变大致经过"白蒺藜""沙苑蒺藜""沙苑子"3个阶段;历代本草记载沙苑子基原为扁茎黄芪的干燥成熟种子,古今应用品种基本一致;沙苑子补肾固精功效的记载自宋《本草衍义》起逐渐清晰明确;沙苑子道地产区自宋时起为陕西沙苑,明清时期产地逐渐转到陕西潼关、山西等地,建国后以陕西省为主向北扩散,以陕西潼关为佳;沙苑子建国前有马薸子、色微绿伪品及紫云英子等混伪品,建国后有紫云英、猪屎豆、华黄芪和直立黄芪的种子等混伪品。为沙苑子正本清源,并为其进一步深入开发提供参考。  相似文献   
4.
5.
6.
7.
In both adults and children with diabetes, technologies such as continuous subcutaneous insulin infusion using insulin pumps and continuous glucose monitoring can help improve diabetes control, reduce hypoglycaemia and improve quality of life. Access to these technologies in the UK is very variable. Some technologies are recommended by the National Institute for Health and Care Excellence, while others have not been appraised, and new technologies are emerging all the time. Additionally, different guidelines for adults and children further complicate access to diabetes technology in the transition from paediatric to adult care. Against this background, Diabetes UK and NHS England have brought together a multidisciplinary group of experts, including clinicians and people with diabetes, to develop this consensus guideline, combining the different technologies into a common pathway to aid clinical and policy decision‐making. We created a pathway that supports the incremental addition of technology as monotherapy and then dual therapy in the same way that we incrementally add in therapeutic agents to support people with Type 2 diabetes to achieve their personalized glycaemic targets. The pathway emphasizes the importance of structured education, specialist support and appropriate access to psychological therapies, as essential pillars for optimized use of diabetes‐related technology, and recommends the re‐evaluation of its use when the individual is unable either to use the technology appropriately or to achieve the intended outcomes. This pathway is endorsed by UK‐wide clinical and patient associations and we recommend that providers and commissioners use it to ensure the right individual with diabetes has access to the right technology in a timely way to help achieve better outcomes.  相似文献   
8.
Recent work suggests that while voluntary episodic memory declines with age, involuntary episodic memory, which comes to mind spontaneously without intention, remains relatively intact. However, the neurophysiology underlying these differences has yet to be established. The current study used electroencephalography (EEG) to investigate voluntary and involuntary retrieval in older and younger adults. Participants first encoded sounds, half of which were paired with pictures, the other half unpaired. EEG was then recorded as they listened to the sounds, with participants in the involuntary group performing a sound localization cover task, and those in the voluntary group additionally attempting to recall the associated pictures. Participants later reported which sounds brought the paired picture to mind during the localization task. Reaction times on the localization task were slower for voluntary than involuntary retrieval and for paired than unpaired sounds, possibly reflecting increased attentional demands of voluntary retrieval and interference from reactivation of the associated pictures respectively. For the EEG analyses, young adults showed greater alpha event-related desynchronization (ERD) during voluntary than involuntary retrieval at frontal and occipital sites, while older adults showed pronounced alpha ERD regardless of intention. Additionally, older adults showed greater ERD for paired than unpaired sounds at occipital sites, likely reflecting visual reactivation of the associated pictures. Young adults did not show this alpha ERD memory effect. Taken together, these data suggest that involuntary memory is largely preserved with age, but this may be due to older adults' greater recruitment of top-down control even when demand for such control is limited.  相似文献   
9.
王黎黎  王芬  柯善高  夏夷  钟明 《安徽医药》2016,37(3):314-317
目的 探讨腰硬联合(CSEA)及患者自控镇痛(PCEA)对产程及分娩结局的影响。方法 随机选取2014年1~12月足月待产、无妊娠合并症和并发症初产妇996例,其中503例产妇于活跃期实施CSEA+PCEA镇痛(分娩镇痛组),493例未行分娩镇痛(对照组),分别记录并比较两组产妇各产程时间、子宫收缩、镇痛效果、运动神经阻滞程度、产程中缩宫素的使用率、产后出血率、羊水Ⅲ度污染率、新生儿Apgar评分、产钳助产和剖宫产率。结果 分娩镇痛组第一产程、第二产程较对照组有所延长,差异有统计学意义(P<0.05);第三产程无明显改变;子宫收缩力减弱;分娩镇痛组较对照组镇痛效果显著,差异有统计学意义(P<0.05);运动阻滞程度低;缩宫素使用率、产后出血率、羊水Ⅲ度污染率、及新生儿Apgar评分及产钳助产和剖宫产率两组比较,差异均无统计学意义(P>0.05)。结论 腰硬联合分娩镇痛可能会使第一产程、第二产程延长,对子宫收缩力有一定的影响,但并未增加缩宫素的使用率及产钳助产和剖宫产率,其镇痛效果显著,运动阻滞程度低,对分娩结局无不良影响。  相似文献   
10.
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