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   568篇
  免费   20篇
耳鼻咽喉   4篇
儿科学   8篇
妇产科学   7篇
基础医学   56篇
口腔科学   6篇
临床医学   33篇
内科学   129篇
皮肤病学   97篇
神经病学   30篇
特种医学   41篇
外科学   92篇
综合类   9篇
预防医学   12篇
眼科学   2篇
药学   40篇
肿瘤学   22篇
  2024年   1篇
  2023年   5篇
  2022年   6篇
  2021年   16篇
  2020年   9篇
  2019年   14篇
  2018年   9篇
  2017年   10篇
  2016年   15篇
  2015年   9篇
  2014年   15篇
  2013年   25篇
  2012年   34篇
  2011年   36篇
  2010年   31篇
  2009年   23篇
  2008年   33篇
  2007年   33篇
  2006年   17篇
  2005年   23篇
  2004年   31篇
  2003年   18篇
  2002年   16篇
  2001年   9篇
  2000年   20篇
  1999年   16篇
  1998年   14篇
  1997年   9篇
  1996年   9篇
  1995年   2篇
  1994年   4篇
  1993年   6篇
  1992年   8篇
  1991年   3篇
  1990年   2篇
  1989年   8篇
  1988年   7篇
  1987年   5篇
  1986年   4篇
  1985年   3篇
  1984年   2篇
  1983年   4篇
  1982年   5篇
  1980年   2篇
  1978年   4篇
  1977年   2篇
  1976年   8篇
  1975年   2篇
  1973年   1篇
排序方式: 共有588条查询结果,搜索用时 15 毫秒
21.
Tobacco smoke exposure is the cause of exaggerated inflammatory responses and tissue destruction leading to chronic bronchitis and emphysema. A number of studies have used biochemical and immunological technologies to identify biomarkers of severity, risk and pharmacological target of disease. Recently, genomic and proteomic studies have been carried out to explore tobacco smoke-induced lung damage mechanisms. Eight of these studies, including 81 healthy non-smokers, 138 healthy smokers and 24 smokers with COPD, had open platform generated data available online and were reviewed in order to identify markers of smoke-induced damage by analyzing differential gene and protein expression in healthy individuals exposed to tobacco smoke in comparison with chronic obstructive pulmonary disease (COPD) smokers and healthy non-smokers. To this end the Ingenuity Pathways Analysis, a web-based application enables identifying the main biological functions and pathways, was used.The pathway most significantly associated with healthy smokers was the Nrf2-mediated Oxidative Stress Response (p-value < 0.01): out of the 22 genes/proteins identified in healthy smokers, 19 were up-regulated and three down-regulated, compared to non-smokers. Interestingly, four genes/proteins of the same pathway were differentially regulated in COPD, one up-regulated and three down-regulated, compared to healthy smokers. Moreover, in the comparison between COPD and healthy smokers, our analysis showed that the most relevant pathway was the Mitochondrial Dysfunction (p-value < 0.01) with 12 differentially regulated genes/proteins.This data-mining review supports the notion that Nrf2-regulated anti-oxidant genes play a central role in protection against tobacco smoke toxic effects and may be amenable to use as COPD risk biomarkers. Furthermore, this review suggests that mitochondrial dysfunction may be involved in the development of COPD.  相似文献   
22.
BACKGROUND: Preterm premature rupture of membranes (pPROM) complicates up to one-third of preterm deliveries. We studied the Amniotic Fluid Index (AFI) in order to ascertain its validity as a predictive variable of maternal-fetal outcome in pregnancies complicated by pPROM. STUDY DESIGN: One hundred and fourteen pregnant women with gestational age between 24 and 34 weeks' gestation at the time of pPROM. Patients were categorized into two groups on the basis of AFI value (AFI <5 cm=63 or AFI >or=5 cm=51) performed at the time of admission. RESULTS: AFI numeric values were significantly related to the following maternal-neonatal variables: high maternal body temperature (P7 at 5 min (P相似文献   
23.
RATIONALE: The aim of the present study was to assess, intraindividually, the relationship among slow eye movements, electroencephalogram (EEG) power, and subjective measures of sleepiness during a 40-hour sleep deprivation comparing 2 experimental conditions: eyes-open and eyes-closed. METHODS: Nineteen normal subjects participated in a sleep-deprivation protocol with recordings of the waking Cz-A1-2 EEG in 36 sessions at 1-hour intervals starting at 10:00 AM. Each session consisted of a 2-minute eyes-closed period, followed by a 4-minute eyes-open period. Electrooculogram, self-ratings (Karolinska Sleepiness Scale and Visual Analog Scale for Global Vigor), and tympanic temperature were also recorded. RESULTS: Changes in sleepiness and alertness are paralleled by increases in slow eye movements and theta and delta EEG power. The beginning of the rise of delta, theta, and slow eye movement activity corresponded to the nadir of temperature, peaking at 7:00AM. Cross-correlational analyses showed that changes in slow eye movements were strictly phase locked to those in slow-frequency EEG bands and in subjective measures. The comparison of time intervals that were equivalent with respect to circadian phase confirms the effects of the increased sleepiness on slow eye movement activity and on the other measures. The temporal concordance of the different physiologic and subjective measures is also reflected in the individual time courses. Individual and group analyses converged in indicating that slow eye movements can be considered reliable indexes of sleepiness but only in the eyes-closed condition. CONCLUSIONS: Results suggest that subjective and EEG changes associated with higher sleepiness are paralleled by an increase in slow eye movement activity, but this relationship exists almost exclusively with the eyes closed. Hence, its use in practical and operational contexts seems limited.  相似文献   
24.
25.
26.
27.
Neurosurgical Review - Traumatic brain injury (TBI) is the main cause of pediatric trauma death and disability worldwide. Recent studies have sought to identify biomarkers of TBI for the purpose of...  相似文献   
28.
29.
Neuroimaging in Pineal Tumors   总被引:4,自引:0,他引:4  
F Reis  MD  AV Faria  MD  PhD  VA Zanardi  MD  PhD  JR Menezes  MD  F Cendes  MD  PhD  LS Queiroz  MD  PhD 《Journal of neuroimaging》2006,16(1):52-58
BACKGROUND AND PURPOSE: The authors report radiological findings in 11 tumors in the pineal region, which were histologically diagnosed as germinomas, pineocytomas pineoblastomas, ependymomas, teratomas, and astrocytomas. METHODS: Computed tomography (CT) was performed in seven patients and magnetic resonance imaging (MRI) was performed in all patients. RESULTS: CT showed a solid or solid/cystic mass with variable contrast enhancement. MRI showed a heterogeneous mass, with hypointense signal on T1 and iso/hyperintense signal on T2-weighted images (WI) and gadolinium enhancement. Extension to adjacent structures occurred in five patients and spread through the cerebral spinal fluid (CSF) in two. CONCLUSIONS: Pineal region tumors have no pathognomonic imaging pattern. MRI and CT are complementary in diagnosis and are important to determine localization, extension, and meningeal spread.  相似文献   
30.
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