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   366篇
  免费   22篇
  国内免费   3篇
耳鼻咽喉   15篇
儿科学   9篇
妇产科学   4篇
基础医学   55篇
口腔科学   6篇
临床医学   35篇
内科学   97篇
皮肤病学   9篇
神经病学   32篇
特种医学   7篇
外科学   34篇
预防医学   42篇
药学   20篇
中国医学   3篇
肿瘤学   23篇
  2023年   12篇
  2022年   2篇
  2021年   16篇
  2020年   10篇
  2019年   13篇
  2018年   24篇
  2017年   13篇
  2016年   13篇
  2015年   13篇
  2014年   15篇
  2013年   20篇
  2012年   31篇
  2011年   48篇
  2010年   12篇
  2009年   10篇
  2008年   14篇
  2007年   19篇
  2006年   18篇
  2005年   18篇
  2004年   17篇
  2003年   23篇
  2002年   26篇
  2000年   1篇
  1998年   1篇
  1995年   1篇
  1993年   1篇
排序方式: 共有391条查询结果,搜索用时 946 毫秒
11.
12.
13.
14.
International Urology and Nephrology - Free calcium is the gold standard for diagnosis of calcium disorders, although calcium assessment is routinely performed by albumin-adjusted calcium. Our...  相似文献   
15.
16.
Aging is a key risk factor for cognitive decline and age-related neurodegenerative disorders. Also, an age-related decrease in sex steroid hormones may have a negative impact on the formation of neurofibrillary tangles(NFTs); these hormones can regulate Tau phosphorylation and the principal kinase GSK3β involved in this process. Hormone replacement therapy decreases NFTs, but it increases the risk of some types of cancer. However, other synthetic hormones such as tibolone(TIB) have been used for hormone replacement therapy. The aim of this work was to evaluate the long-term effects of TIB(0.01 mg/kg and 1 mg/kg, intragastrically for 12 weeks) on the content of total and hyperphosphorylated Tau(PHF-1) proteins and the regulation of GSK3β/Akt/PI3 K pathway and CDK5/p35/p25 complexes in the hippocampus of aged male mice. We observed that the content of PHF-1 decreased with TIB administration. In contrast, no changes were observed in the active form of GSK3β or PI3 K. TIB decreased the expression of the total and phosphorylated form of Akt while increased that of p110 and p85. The content of CDK5 was differentially modified with TIB: it was increased at low doses and decreased at high doses. When we analyzed the content of CDK5 activators, an increase was found on p35; however, the content of p25 decreased with administration of low dose of TIB. Our results suggest a possible mechanism of action of TIB in the hippocampus of aged male mice. Through the regulation of Tau and GSK3β/Akt/PI3 K pathway, and CDK5/p35/p25 complexes, TIB may modulate neuronal plasticity and regulate learning and memory processes.  相似文献   
17.
IntroductionThe aim of this study was to determine the prevalence of benign paroxysmal positional vertigo (BPPV) in patients diagnosed with endolymphatic hydrops (EH) and to analyze whether this association is a factor for poor prognosis in these patients.Material and methodsA retrospective study was carried out in our department among the patients definitively diagnosed as having Ménière's disease according to the criteria of the American Academy of Otolaryngology and BPPV by the usual triggering manoeuvres.ResultsThe prevalence of BPPV in our patients with EH was 5.1%. The rate of cure with the repositioning manoeuvres is 90.9%, however success with the first manoeuvre was only 63.36%. Recurrences occurred in up to 22.22%. We found a lower success rate with the first manoeuvre in relation to the rest of the patients with BPPV without EH. This difference is statistically significant (P=0.042).DiscussionWe did not find that these patients to have a lower rate of cure with the repositioning manoeuvres or a higher rate of recurrence. But in our protocol the first manoeuvre had a lower success rate than in the rest of the patients.  相似文献   
18.
BACKGROUND: The reduction in cervical cancer mortality in developed countries has been attributed to well-organized, population-based prevention and control programs that incorporate screening with the Papanicolaou (Pap) smear. In Mexico, there has been a decrease in cervical cancer mortality, but it is unclear what factors have prompted this reduction. METHODS: Using data from national indicators, we determined the correlation between cervical cancer mortality rates and Pap coverage, birthrate, and gross national product, using a linear regression model. We determined relative risk of dying of cervical cancer according to place of residence (rural/urban, region) using a Poisson model. We also estimated Pap smear coverage using national survey data and evaluated the validity and reproducibility of Pap smear diagnosis. RESULTS: An increase in Pap coverage (beta= -0.069) and a decrease in birthrate (beta=0.054) correlate with decreasing cervical cancer mortality in Mexico. Self-reported Pap smear rates in the last 12 months vary from 27.4% to 48.1%. Women who live in the central (relative risk, 1.04) and especially the southern (relative risk, 1.47) parts of Mexico have a greater relative risk of dying of cervical cancer than those who live in the north. There is a high incidence of false negatives in cervical cytology laboratories in Mexico; the percentage of false negatives varies from 3.33% to 53.13%. CONCLUSIONS: The decrease in cervical cancer mortality observed in Mexico is proportional to increasing Pap coverage and decreasing birthrate. Accreditation of cervical cytology laboratories is needed to improve diagnostic precision.  相似文献   
19.
Leaf and (unripe and ripe) berry essential oils of Juniperus oxycedrus ssp. badia (H. Gay) Debeaux grown wild in Spain have been analysed by capillary GC and GC-MS in combination with retention indices. A seasonal investigation of both leaf and berry oils was also performed. Among the approximately 80 constituents investigated (representing 90-98% of the oils) 60-68 were identified (80-97% of the oil composition). The leaf oils were mainly composed of alpha-pinene (40-57%) and manoyl oxide (5-10%). The (unripe) berry oils were dominated by alpha-pinene (65%) with moderate amounts of myrcene, limonene, germacrene D or gamma-muurolene. Several differences in yields and chemical composition from a qualitative and quantitative point of view were detected when comparing all the oil samples analysed. In addition, two oil samples were examined, but found inactive, against the replication of HIV-1(III(B)) and HIV-2(ROD) in cell culture, whereas the samples were toxic for the cells at a 50% cytotoxic concentration of 106 and 123 microg/ml, respectively.  相似文献   
20.
Plasmablastic lymphoma of the oral cavity and jaws   总被引:3,自引:0,他引:3  
  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