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   66717篇
  免费   7075篇
  国内免费   5017篇
耳鼻咽喉   566篇
儿科学   1005篇
妇产科学   738篇
基础医学   7469篇
口腔科学   1361篇
临床医学   9074篇
内科学   9266篇
皮肤病学   614篇
神经病学   2888篇
特种医学   2326篇
外国民族医学   29篇
外科学   6049篇
综合类   12845篇
现状与发展   19篇
一般理论   5篇
预防医学   5229篇
眼科学   1761篇
药学   7408篇
  85篇
中国医学   4319篇
肿瘤学   5753篇
  2024年   257篇
  2023年   1145篇
  2022年   2922篇
  2021年   3988篇
  2020年   3208篇
  2019年   2297篇
  2018年   2444篇
  2017年   2299篇
  2016年   2120篇
  2015年   3374篇
  2014年   4066篇
  2013年   3699篇
  2012年   5351篇
  2011年   5675篇
  2010年   3804篇
  2009年   3024篇
  2008年   3530篇
  2007年   3559篇
  2006年   3354篇
  2005年   3287篇
  2004年   2018篇
  2003年   1809篇
  2002年   1520篇
  2001年   1285篇
  2000年   1256篇
  1999年   1357篇
  1998年   905篇
  1997年   866篇
  1996年   681篇
  1995年   661篇
  1994年   512篇
  1993年   302篇
  1992年   378篇
  1991年   344篇
  1990年   281篇
  1989年   255篇
  1988年   233篇
  1987年   182篇
  1986年   164篇
  1985年   115篇
  1984年   70篇
  1983年   55篇
  1982年   47篇
  1981年   31篇
  1980年   18篇
  1979年   30篇
  1978年   6篇
  1975年   3篇
  1971年   5篇
  1969年   5篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
1.
Cao  Jie  Xie  Chengyu  Hou  Zhiru 《Ecotoxicology (London, England)》2022,31(2):259-270
Ecotoxicology - Soil heavy metal pollution evaluations are a necessary measure for mine ecological control projects. In this study, the heavy metals Pb, Zn and Cd were studied in mining areas,...  相似文献   
2.
痛情绪是指因疼痛引发的情绪和情感体验,是疾病过程中最常见的一种情绪。痛情绪相关神经机制非常复杂,但主要与单胺类神经递质、神经肽和某些神经环路有关,笔者将结合目前研究现状分别从以上两方面展开,就痛情绪相关单胺类神经递质和神经肽在受体分类、脑区通路、共疾病以及各神经递质之间的联系和痛情绪相关神经环路中各个蛋白的作用机制等方面进行探讨。  相似文献   
3.
Neoadjuvant programmed cell death protein 1 (PD-1) blockade exhibits promising efficacy in patients with mismatch repair deficient (dMMR) colorectal cancer (CRC). However, discrepancies between radiological and histological findings have been reported in the PICC phase II trial (NCT 03926338). Therefore, we strived to discern radiological features associated with pathological complete response (pCR) based on computed tomography (CT) images. Data were obtained from the PICC trial that included 36 tumors from 34 locally advanced dMMR CRC patients, who received neoadjuvant PD-1 blockade for 3 months. Among the 36 tumors, 28 (77.8%) tumors achieved pCR. There were no statistically significant differences in tumor longitudinal diameter, the percentage change in tumor longitudinal diameter from baseline, primary tumor sidedness, clinical stage, extramural venous invasion status, intratumoral calcification, peritumoral fat infiltration, intestinal fistula and tumor necrosis between the pCR and non-pCR tumors. Otherwise, tumors with pCR had smaller posttreatment tumor maximum thickness (median: 10 mm vs 13 mm, P = .004) and higher percentage decrease in tumor maximum thickness from baseline (52.9% vs 21.6%, P = .005) compared to non-pCR tumors. Additionally, a higher proportion of the absence of vascular sign (P = .003, odds ratio [OR] = 25.870 [95% CI, 1.357-493.110]), nodular sign (P < .001, OR = 189.000 [95% CI, 10.464-3413.803]) and extramural enhancement sign (P = .003, OR = 21.667 [2.848-164.830]) was observed in tumors with pCR. In conclusion, these CT-defined radiological features may have the potential to serve as valuable tools for clinicians in identifying patients who have achieved pCR after neoadjuvant PD-1 blockade, particularly in individuals who are willing to adopt a watch-and-wait strategy.  相似文献   
4.
Zedoary tumeric (Curcumae Rhizoma, Ezhu in Chinese) has a long history of application and has great potential in the treatment of liver cancer. The anti liver cancer effect of zedoary tumeric depends on the combined action of multiple pharmacodynamic substances. In order to clarify the specific mechanism of zedoary tumeric against liver cancer, this paper first analyzes the mechanism of its single pharmacodynamic substance against liver cancer, and then verifies the joint anti liver cancer mechanism of its "pharmacodynamic group". By searching the research on the anti hepatoma effect of active components of zedoary tumeric in recent years, we found that pharmacodynamic substances, including curcumol, zedoarondiol, curcumenol, curzerenone, curdione, curcumin, germacrone, β-elemene, can act on multi-target and multi-channel to play an anti hepatoma role. For example, curcumin can regulate miR, GLO1, CD133, VEGF, YAP, LIN28B, GPR81, HCAR-1, P53 and PI3K/Akt/mTOR, HSP70/TLR4 and NF-κB. Wnt/TGF/EMT, Nrf2/Keap1, JAK/STAT and other pathways play an anti hepatoma role. Network pharmacological analysis showed that the core targets of the "pharmacodynamic group" for anti-life cancer are AKT1, EGFR, MAPK8, etc, and the core pathways are neuroactive live receiver interaction, nitrogen metabolism, HIF-1 signaling pathway, etc. At the same time, by comparing and analyzing the relationship between the specific mechanisms of pharmacodynamic substance and "pharmacodynamic group", it is found that they have great reference significance in target, pathway, biological function, determination of core pharmacodynamic components, formation of core target protein interaction, in-depth research of single pharmacodynamic substance, increasing curative effect and so on. By analyzing the internal mechanism of zedoary tumeric pharmacodynamic substance and "pharmacodynamic group" in the treatment of liver cancer, this paper intends to provide some ideas and references for the deeper pharmacological research of zedoary tumeric and the relationship between pharmacodynamic substance and "pharmacodynamic group".  相似文献   
5.
Bone mineral density (BMD) is a highly heritable predictor of osteoporotic fracture. GWAS have identified hundreds of loci influencing BMD, but few have been functionally analyzed. In this study, we show that SNPs within a BMD locus on chromosome 14q32.32 alter splicing and expression of PAR-1a/microtubule affinity regulating kinase 3 (MARK3), a conserved serine/threonine kinase known to regulate bioenergetics, cell division, and polarity. Mice lacking Mark3 either globally or selectively in osteoblasts have increased bone mass at maturity. RNA profiling from Mark3-deficient osteoblasts suggested changes in the expression of components of the Notch signaling pathway. Mark3-deficient osteoblasts exhibited greater matrix mineralization compared with controls that was accompanied by reduced Jag1/Hes1 expression and diminished downstream JNK signaling. Overexpression of Jag1 in Mark3-deficient osteoblasts both in vitro and in vivo normalized mineralization capacity and bone mass, respectively. Together, these findings reveal a mechanism whereby genetically regulated alterations in Mark3 expression perturb cell signaling in osteoblasts to influence bone mass.  相似文献   
6.
目的探讨脑卒中患者急性应激障碍发生现状及影响因素。方法采用斯坦福急性应激反应问卷对349例脑卒中住院患者进行调查。结果共163例(46.70%)患者发生急性应激障碍;Logistic回归分析结果显示,患者性格、是否存在偏瘫及是否吞咽功能障碍是脑卒中患者发生急性应激障碍的主要影响因素(P0.05,P0.01)。结论脑卒中患者急性应激障碍发生率较高,内向性格及存在偏瘫和吞咽功能障碍的患者更容易发生急性应激障碍。医护人员应及时为高危患者提供个体化治疗及预见性护理,防止脑卒中患者发生急性应激障碍。  相似文献   
7.
8.
背景 恶性肿瘤给家庭、社会带来了沉重的医疗、经济负担,极易导致部分家庭“因病致贫”或放弃治疗,目前相关研究多集中于单一病种、分散地域的研究,仍缺乏对于全国范围与多病种恶性肿瘤住院费用变化及结构构成的考量。目的 分析2013-2017年我国4种恶性肿瘤住院费用水平以及影响住院费用的主要项目和结构变动情况,为控制医疗费用上涨、深化新医改提供参考依据。方法 本研究数据来源于《2014中国卫生和计划生育统计年鉴》《2015中国卫生和计划生育统计年鉴》《2016中国卫生和计划生育统计年鉴》《2017中国卫生和计划生育统计年鉴》以及《2018中国卫生健康统计年鉴》,样本跨度为2013-2017年。统计“30种疾病人均住院费用”中的胃恶性肿瘤、肺恶性肿瘤、食管恶性肿瘤以及膀胱恶性肿瘤的数据,4种恶性肿瘤的人均住院费用包括药费、检查费、治疗费、手术费和手术材料费。2019年4-8月,采用结构变动度法分析我国2013-2017年4种恶性肿瘤的住院费用的结构变动情况〔结构变动值(VSV)、结构变动度(DSV)、结构变动贡献率〕。结果 2013-2017年,4种恶性肿瘤的人均住院费用逐年上升,其中胃恶性肿瘤的人均住院费用始终最高,且肺恶性肿瘤的人均住院费用上升幅度最大。2013-2017年,在4种恶性肿瘤住院各项费用的占比中,药费占比最高且总体逐年下降。从4种恶性肿瘤住院各项费用的实际变化来看,药费在2013-2014年有所上升,2014-2017年逐年下降;检查费在2013-2014年下降,2014-2017年缓慢上升;手术费与手术材料费在2013-2017年逐年上升。2013-2017年,在4种恶性肿瘤住院各项费用中均是药费的VSV最大;4种恶性肿瘤药费、检查费的VSV均呈负向变化,手术费和手术材料费的VSV均呈正向变化,治疗费的VSV增减均不明显。2013-2017年,4种恶性肿瘤住院费用的DSV从大到小依次为肺恶性肿瘤、胃恶性肿瘤、食管恶性肿瘤、膀胱恶性肿瘤。2013-2017年,4种恶性肿瘤住院各项费用中均是药费的结构变动贡献率最大,治疗费的结构变动贡献率最小;除药费外,胃恶性肿瘤、肺恶性肿瘤住院各项费用中均是手术材料费和手术费的结构变动贡献率次之,食管恶性肿瘤住院各项费用中手术费、检查费的结构变动贡献率次之,膀胱恶性肿瘤住院各项费用中检查费、手术材料费的结构变动贡献率次之。结论 2013-2017年我国4种恶性肿瘤手术费的结构变动贡献率虽然较为理想,但药费、治疗费仍是住院费用结构的重点调整对象;同时为有效降低恶性肿瘤的人均住院费用,应当加强控制手术材料费与检查费;而胃恶性肿瘤与肺恶性肿瘤患者的疾病经济负担严重,若要缓解应加强疾病的早期预防与住院费用管控。  相似文献   
9.
目的探讨雨课堂在临床流行病学教学中的作用和效果。方法采用随机对照法在本科阶段无流行病学学习经历的临床专业硕士研究生中,使用雨课堂线上课前预习及课后随堂练习的功能,用于评价雨课堂线上功能的辅助教学效果。结果应用雨课堂线上功能干预组与对照组在基线、阶段小测和末考卷面成绩均无统计学差异;但对于主动学习,雨课堂参与度较高的学生成绩提高明显。结论雨课堂有利于理论性较强课程的学习,但是仍不能忽略课堂教学师生互动过程。  相似文献   
10.
Owing to the frequent incidence of blast-induced traumatic brain injury (bTBI) in recent military conflicts, there is an urgent need to develop effective therapies for bTBI-related pathologies. Blood-brain barrier (BBB) breakdown has been reported to occur after primary blast exposure, making restoration of BBB function and integrity a promising therapeutic target. We tested the hypothesis that treatment with dexamethasone (DEX) after primary blast injury potentiates recovery of an in vitro BBB model consisting of mouse brain endothelial cells (bEnd.3). DEX treatment resulted in complete recovery of transendothelial electrical resistance and hydraulic conductivity 1 day after injury, compared with 3 days for vehicle-treated injured cultures. Administration of RU486 (mifepristone) inhibited effects of DEX, confirming that barrier restoration was mediated by glucocorticoid receptor signaling. Potentiated recovery with DEX treatment was accompanied by stronger zonula occludens (ZO)-1 tight junction immunostaining and expression, suggesting that increased ZO-1 expression was a structural correlate to BBB recovery after blast. Interestingly, augmented ZO-1 protein expression was associated with specific upregulation of the α+ isoform but not the α isoform. This is the first study to provide a mechanistic basis for potentiated functional recovery of an in vitro BBB model because of glucocorticoid treatment after primary blast injury.  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