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   68506篇
  免费   7002篇
  国内免费   2731篇
耳鼻咽喉   331篇
儿科学   904篇
妇产科学   619篇
基础医学   2975篇
口腔科学   601篇
临床医学   4188篇
内科学   7544篇
皮肤病学   824篇
神经病学   1588篇
特种医学   1031篇
外国民族医学   6篇
外科学   4309篇
综合类   15706篇
现状与发展   7篇
一般理论   2篇
预防医学   3253篇
眼科学   496篇
药学   7253篇
  93篇
中国医学   25326篇
肿瘤学   1183篇
  2024年   241篇
  2023年   1223篇
  2022年   2013篇
  2021年   3021篇
  2020年   2864篇
  2019年   4104篇
  2018年   3219篇
  2017年   3285篇
  2016年   2444篇
  2015年   2280篇
  2014年   5408篇
  2013年   4353篇
  2012年   5318篇
  2011年   5163篇
  2010年   4359篇
  2009年   3147篇
  2008年   2574篇
  2007年   2848篇
  2006年   2198篇
  2005年   1837篇
  2004年   1433篇
  2003年   1234篇
  2002年   1069篇
  2001年   938篇
  2000年   774篇
  1999年   523篇
  1998年   365篇
  1997年   372篇
  1996年   282篇
  1995年   245篇
  1994年   213篇
  1993年   118篇
  1992年   132篇
  1991年   130篇
  1990年   82篇
  1989年   64篇
  1988年   64篇
  1985年   641篇
  1984年   1039篇
  1983年   794篇
  1982年   793篇
  1981年   778篇
  1980年   712篇
  1979年   700篇
  1978年   620篇
  1977年   416篇
  1976年   526篇
  1975年   431篇
  1974年   413篇
  1973年   340篇
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
91.
王彬  周欢  吴深涛 《天津中医药》2019,36(8):767-770
"代谢性高血压"是目前普遍存在的高血压类型,"浊毒蕴血"和"脉络阻滞"是高血压进程中相互影响、密不可分的病理环节,从改善血液质量和疏解脉道阻滞入手,真正把握高血压及其靶器官损害的病机实质,是临床开展高血压合并代谢紊乱整合调节的突破口,通过"化浊解毒-复血之纯粹,调和营卫-解脉之阻滞"诸法,以期为当前社会背景下中医药针对高血压的泛血管保护理念提供实践基础。  相似文献   
92.
93.
94.
95.
96.
97.
ObjectivesTo describe recent trends in advanced imaging and hospitalization of emergency department (ED) syncope patients, both considered “low-value”, and examine trend changes before and after the publication of American College Emergency Physician (ACEP) syncope guidelines in 2007, compared to conditions that had no changes in guideline recommendations.MethodsWe analyzed 2002–2015 National Hospital Ambulatory Medical Care Survey data using an interrupted-time series with comparison series design. The primary outcomes were advanced imaging among ED visits with principal diagnosis of syncope and headache and hospitalization for ED visits with principal diagnosis of syncope, chest pain, dysrhythmia, and pneumonia. We adjusted annual imaging and hospitalization rates using survey-weighted multivariable logistic regression, controlling for demographic and visit characteristics. Using adjusted outcomes as datapoints, we compared linear trends and trend changes of annual imaging and hospitalization rates before and after 2007 with aggregate-level multivariable linear regression.ResultsFrom 2002 to 2007, advanced imaging rates for syncope increased from 27.2% to 42.1% but had no significant trend after 2007 (trend change: ?3.1%; 95%CI ?4.7, ?1.6). Hospitalization rates remained at approximately 37% from 2002 to 2007 but declined to 25.7% by 2015 (trend change: ?2.2%; 95%CI ?3.0, ?1.4). Similar trend changes occurred among control conditions versus syncope, including advanced imaging for headache (difference in trend change: ?0.6%; 95%CI ?2.8, 1.6) and hospitalizations for chest pain, dysrhythmia, and pneumonia (differences in trend changes: 0.1% [95%CI ?1.9, 2.0]; ?0.9% [95%CI ?3.1, 1.3]; and ?1.2% [95%CI ?5.3, 2.9], respectively).ConclusionsBefore and after the release of 2007 ACEP syncope guidelines, trends in advanced imaging and hospitalization for ED syncope visits had similar changes compared to control conditions. Changes in syncope care may, therefore, reflect broader practice shifts rather than a direct association with the 2007 ACEP guideline. Moreover, utilization of advanced imaging remains prevalent. To reduce low-value care, policymakers should augment society guidelines with additional policy changes such as reportable quality measures.  相似文献   
98.
Objective: To investigate apoptotic effects of berberine, a significant alkaloids component existing in Rhizoma coptidis, and its possible acting mechanism in insulinoma cells. Methods: Different concentrations of berberine were used to treat mouse insulinoma(MIN6) cells for various period of time. The viability and apoptosis of the cells were analyzed using methylthiazolyldiphenvl-tetrazolium bromide assay, flow cytometry and enzyme-linked immuno sorbent assay. Changes in the relating pro-and anti-apoptosis proteins were detected by western-blotting. Results: The half-maximal inhibitory concentration(IC50) of berberine was 5.7 μmol/L on MIN6 cells viability for 16 h. Berberine caused a 20% reduction(P0.05) in cell number after only 4-h incubation; which reached 50% after 24 h(P0.01). Berberine treatment for 16 h significantly increased the level of DNA fragmentation. The flow cytometry showed the apoptotic rate increased 2.9-and 4.6-fold after treating with berberine(5 μmol/L) for 8 and 16 h, while 3-and 8.7-fold after 10 μmol/L treatment for 8 and 16 h(P0.01). Berberine treatment dramatically elevated the expression ratio of Bax to Bcl-2. Meanwhile, berberine notably increased the apoptosis-inducing factors and cytochrome C transforming from the mitochondria to the cytoplasm. Apoptotic protease-activating factor 1(Apaf-1) was subsequently activated after cytochrome C release. Furthermore, caspase-3 and poly adenosine diphosphate-ribose polymerase were also activated to trigger apoptosis cascade. Conclusion: High concentration(5 and 10 μmol/L) of berberine could induce the apoptosis of MIN6 cells through cytochrome C/Apaf-1/caspase-3 and apoptosis inducing factor(AIF) pathway.  相似文献   
99.
基于调控肠道菌群探讨中药防治脑卒中   总被引:3,自引:3,他引:0  
肠道菌群是一个独特的生态系统,被称为人体"被遗忘的器官",被誉为人类的"第二基因组"。肠道菌群失调与许多中枢神经系统疾病相关,例如帕金森病、阿尔茨海默症、精神分裂症及多发性硬化等。脑卒中具有高的发病率、复发率、死亡率和致残率的特点。肠道菌群在脑卒中的发生、发展中起着关键的作用,可通过影响机体的吸收、代谢、血压、血糖、血脂及动脉粥样斑块等因素,进一步影响脑卒中的发病。中医认为脾胃气血流注失度、阴阳盛衰失衡,机体生理功能失调,化生"风、火、痰、虚、瘀"等病理产物,可致中风的发生。脾胃主腐熟运化水谷,肠道菌群影响饮食的消化吸收,现代研究的肠道菌群功能与中医之脾胃功能失调相关。因此,调整肠道菌群的稳态,可作为一个潜在的干预靶点预防和治疗缺血性脑卒中。中药干预脑卒中已经取得了很好的疗效,是否与调节肠道菌群有关,值得未来做进一步的研究。同时对中药有效成分(小檗碱、黄芩苷、白藜芦醇等),中药单方(丹参、红景天等)和中药组方(补阳还五汤、脑心通胶囊、补中益气汤等)防治脑缺血的研究进展进行综述,为缺血性脑卒中的预防和开发提供新的途径和思路。  相似文献   
100.
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