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   18684篇
  免费   1240篇
  国内免费   123篇
耳鼻咽喉   193篇
儿科学   283篇
妇产科学   265篇
基础医学   2518篇
口腔科学   437篇
临床医学   1718篇
内科学   3737篇
皮肤病学   506篇
神经病学   2188篇
特种医学   1213篇
外国民族医学   1篇
外科学   3560篇
综合类   112篇
一般理论   5篇
预防医学   611篇
眼科学   204篇
药学   1187篇
中国医学   13篇
肿瘤学   1296篇
  2023年   155篇
  2022年   113篇
  2021年   440篇
  2020年   345篇
  2019年   457篇
  2018年   519篇
  2017年   429篇
  2016年   519篇
  2015年   645篇
  2014年   789篇
  2013年   882篇
  2012年   1496篇
  2011年   1598篇
  2010年   977篇
  2009年   900篇
  2008年   1339篇
  2007年   1362篇
  2006年   1274篇
  2005年   1195篇
  2004年   1085篇
  2003年   989篇
  2002年   924篇
  2001年   204篇
  2000年   142篇
  1999年   175篇
  1998年   125篇
  1997年   158篇
  1996年   65篇
  1995年   91篇
  1994年   72篇
  1993年   54篇
  1992年   65篇
  1991年   50篇
  1990年   49篇
  1989年   43篇
  1988年   39篇
  1987年   34篇
  1986年   34篇
  1985年   23篇
  1984年   19篇
  1983年   15篇
  1982年   10篇
  1980年   10篇
  1979年   9篇
  1978年   11篇
  1975年   12篇
  1974年   10篇
  1973年   9篇
  1972年   7篇
  1970年   7篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
51.
Journal of Neurology - The original keywords were not sufficiently precise in describing the article content. Therefore, the key words were amended to include hemicraniectomy and malignant edema.  相似文献   
52.
Environmental pollution in the form of particulate matter <2.5 μm (PM2.5) is a major risk factor for diseases such as lung cancer, chronic respiratory infections, and major cardiovascular diseases. Our goal was to show that PM2.5 eliciting a proinflammatory response activates the immune-pineal axis, reducing the pineal synthesis and increasing the extrapineal synthesis of melatonin. Herein, we report that the exposure of rats to polluted air for 6 hours reduced nocturnal plasma melatonin levels and increased lung melatonin levels. Melatonin synthesis in the lung reduced lipid peroxidation and increased PM2.5 engulfment and cell viability by activating high-affinity melatonin receptors. Diesel exhaust particles (DEPs) promoted the synthesis of melatonin in a cultured cell line (RAW 264.7 cells) and rat alveolar macrophages via the expression of the gene encoding for AANAT through a mechanism dependent on activation of the NFκB pathway. Expression of the genes encoding AANAT, MT1, and MT2 was negatively correlated with cellular necroptosis, as disclosed by analysis of Gene Expression Omnibus (GEO) microarray data from the human alveolar macrophages of nonsmoking subjects. The enrichment score for antioxidant genes obtained from lung gene expression data (GTEx) was significantly correlated with the levels of AANAT and MT1 but not the MT2 melatonin receptor. Collectively, these data provide a systemic and mechanistic rationale for coordination of the pineal and extrapineal synthesis of melatonin by a standard damage-associated stimulus, which activates the immune-pineal axis and provides a new framework for understanding the effects of air pollution on lung diseases.  相似文献   
53.
The ability to execute a motor plan involves spatiotemporally precise oscillatory activity in primary motor (M1) regions, in concert with recruitment of “higher order” attentional mechanisms for orienting toward current task goals. While current evidence implicates gamma oscillatory activity in M1 as central to the execution of a movement, far less is known about top‐down attentional modulation of this response. Herein, we utilized magnetoencephalography (MEG) during a Posner attention‐reorienting task to investigate top‐down modulation of M1 gamma responses by frontal attention networks in 63 healthy adult participants. MEG data were evaluated in the time–frequency domain and significant oscillatory responses were imaged using a beamformer. Robust increases in theta activity were found in bilateral inferior frontal gyri (IFG), with significantly stronger responses evident in trials that required attentional reorienting relative to those that did not. Additionally, strong gamma oscillations (60–80 Hz) were detected in M1 during movement execution, with similar responses elicited irrespective of attentional reorienting. Whole‐brain voxel‐wise correlations between validity difference scores (i.e., attention reorienting trials—nonreorienting trials) in frontal theta activity and movement‐locked gamma oscillations revealed a robust relationship in the contralateral sensorimotor cortex, supplementary motor area, and right cerebellum, suggesting modulation of these sensorimotor network gamma responses by attentional reorienting. Importantly, the validity difference effect in this distributed motor network was predictive of overall motor function measured outside the scanner and further, based on a mediation analysis this relationship was fully mediated by the reallocation response in the right IFG. These data are the first to characterize the top‐down modulation of movement‐related gamma responses during attentional reorienting and movement execution.  相似文献   
54.
Weiss  Markus  Machotta  Andreas 《Der Anaesthesist》2022,71(4):255-263
Die Anaesthesiologie - Im Jahr 1989 haben die Vereinten Nationen die „United Nations Convention on the Rights of the Child“ (UNCRC) beschlossen und u. a. für Kinder der...  相似文献   
55.
56.
PurposeTo compare hepatic hypertrophy in the contralateral lobe achieved by unilobar transarterial radioembolization (TARE) versus portal vein embolization (PVE) in a swine model.MethodsAfter an escalation study to determine the optimum dose to achieve hypertrophy after unilobar TARE in 4 animals, 16 pigs were treated by TARE (yttrium-90 resin microspheres) or PVE (lipiodol/n-butyl cyanoacrylate). Liver volume was calculated based on CT before treatment and during 6 months of follow-up. Independent t-test (P < .05) was used to compare hypertrophy. The relationship between hypertrophy after TARE and absorbed dose was calculated using the Pearson correlation.ResultsAt 2 and 4 weeks after treatment, a significantly higher degree of future liver remnant hypertrophy was observed in the PVE group versus the TARE group, with a median volume gain of 31% (interquartile range [IQR]: 16%–66%) for PVE versus 23% (IQR: 6%–36%) for TARE after 2 weeks and 51% (IQR: 47%–69%) for PVE versus 29% (IQR: 20%–50%) for TARE after 4 weeks. After 3 and 6 months, hypertrophy converged without a statistically significant difference, with a volume gain of 103% (IQR: 86%–119%) for PVE versus 82% (IQR: 70%–96%) for TARE after 3 months and 115% (IQR: 70%–46%) for PVE versus 86% (IQR: 58%–111%) for TARE after 6 months. A strong correlation was observed between radiation dose (median 162 Gy, IQR: 139–175) and hypertrophy.ConclusionsPVE resulted in rapid hypertrophy within 1 month of the procedure, followed by a plateau, whereas TARE resulted in comparable hypertrophy by 3–6 months. TARE-induced hypertrophy correlated with radiation absorbed dose.  相似文献   
57.
58.
Die Anaesthesiologie - Der Postpunktionskopfschmerz („postdural puncture headache“, PDPH) zählt zu den wesentlichen Komplikationen der peripartalen neuroaxialen Analgesie. Als...  相似文献   
59.
60.
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