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   1054篇
  免费   110篇
  国内免费   12篇
耳鼻咽喉   68篇
儿科学   29篇
妇产科学   48篇
基础医学   123篇
口腔科学   86篇
临床医学   170篇
内科学   223篇
皮肤病学   12篇
神经病学   79篇
特种医学   49篇
外科学   93篇
综合类   26篇
预防医学   61篇
眼科学   16篇
药学   71篇
肿瘤学   22篇
  2021年   10篇
  2019年   13篇
  2018年   8篇
  2017年   12篇
  2016年   12篇
  2015年   13篇
  2014年   23篇
  2013年   21篇
  2012年   47篇
  2011年   46篇
  2010年   26篇
  2009年   24篇
  2008年   45篇
  2007年   49篇
  2006年   44篇
  2005年   40篇
  2004年   32篇
  2003年   28篇
  2002年   38篇
  2001年   36篇
  2000年   37篇
  1999年   45篇
  1998年   19篇
  1997年   22篇
  1996年   9篇
  1994年   17篇
  1993年   12篇
  1992年   37篇
  1991年   27篇
  1990年   19篇
  1989年   30篇
  1988年   22篇
  1987年   27篇
  1986年   24篇
  1985年   24篇
  1984年   15篇
  1983年   19篇
  1982年   13篇
  1980年   12篇
  1979年   11篇
  1978年   11篇
  1977年   8篇
  1976年   11篇
  1973年   13篇
  1972年   14篇
  1970年   8篇
  1969年   9篇
  1968年   7篇
  1967年   9篇
  1966年   10篇
排序方式: 共有1176条查询结果,搜索用时 15 毫秒
101.

Background

Hearing impairment is common among older adults and affects cognitive assessments for identification of dementia which rely on good hearing function. We developed and validated a version of the Montreal Cognitive Assessment (MoCA) for people with hearing impairment.

Methods

We adapted existing MoCA 8.1 items for people with hearing impairment by presenting instructions and stimuli in written rather than spoken format. One Attention domain and two Language domain items required substitution by alternative items. Three and four candidate items respectively were constructed and field-tested along with the items adapted to written form. We used a combination of individual item analysis and item substitution to select the set of alternative items to be included in the final form of the MoCA-H in place of the excluded original items. We then evaluated the performance and reliability of the final tool, including making any required adjustments for demographic factors.

Results

One hundred and fifty-nine hearing-impaired participants, including 76 with normal cognition and 83 with dementia, completed the adapted version of the MoCA. A further 97 participants with normal hearing completed the standard MoCA as well as the novel items developed for the MoCA-H to assess score equivalence between the existing and alternative MoCA items and for independence from hearing impairment. Twenty-eight participants were retested between 2–4 weeks after initial testing. After the selection of optimal item set, the final MoCA-H had an area under the curve of 0.973 (95% CI 0.952–0.994). At a cut-point of 24 points or less sensitivity and specificity for dementia was 92.8% and 90.8%, respectively. The intraclass correlation for test–retest reliability was 0.92 (95%CI 0.78–0.97).

Conclusion

The MoCA-H is a sensitive and reliable means of identifying dementia among adults with acquired hearing impairment.  相似文献   
102.
103.
104.
105.
Gellan gum (GG)‐based hydrogels are advantageous in tissue engineering not only due to their ability to retain large quantities of water and provide a similar environment to that of natural extracellular matrix (ECM), but also because they can gelify in situ in seconds. Their mechanical properties can be fine‐tuned to mimic natural tissues such as the nucleus pulposus (NP). This study produced different formulations of GG hydrogels by mixing varying amounts of methacrylated (GG‐MA) and high‐acyl gellan gums (HA‐GG) for applications as acellular and cellular NP substitutes. The hydrogels were physicochemically characterized by dynamic mechanical analysis. Degradation and swelling abilities were assessed by soaking in a phosphate buffered saline solution for up to 170 h. Results showed that as HA‐GG content increased, the modulus of the hydrogels decreased. Moreover, increases in HA‐GG content induced greater weight loss in the GG‐MA/HA‐GG formulation compared to GG‐MA hydrogel. Potential cytotoxicity of the hydrogel was assessed by culturing rabbit NP cells up to 7 days. An MTS assay was performed by seeding rabbit NP cells onto the surface of 3D hydrogel disc formulations. Viability of rabbit NP cells encapsulated within the different hydrogel formulations was also evaluated by Calcein‐AM and ATP assays. Results showed that tunable GG‐MA/HA‐GG hydrogels were non‐cytotoxic and supported viability of rabbit NP cells. Copyright © 2012 John Wiley & Sons, Ltd.  相似文献   
106.
107.
An elevated peripheral leucocyte count is associated with an increased risk of myocardial infarction and progression of coronary artery disease. The aim of this study was to determine neutrophil count and activation, measured as an increase in plasma neutrophil elastase, in patients with stable ischaemic heart disease, insulin-dependent diabetes mellitus and essential hypertension compared with a comparable group of control subjects. Neutrophil count and neutrophil elastase were raised significantly for patients with ischaemic heart disease (p less than 0.005; p less than 0.002), diabetes mellitus (p less than 0.001; p less than 0.01) and hypertension (p less than 0.05; p less than 0.0001) respectively compared to the control subjects. Neutrophil elastase did not correlate with subject age or leucocyte count. This study confirms the association between leucocyte count and vascular disease, and is consistent with neutrophil activation contributing to the progression of vascular disease.  相似文献   
108.
目的:肾移植的成功与否关键在于及时发现和正确处理排斥反应。探讨无创伤性形态学和血流动力学检查手段彩色多普勒超声在移植肾急性排斥反应中的作用,为临床评估肾移植效果及移植肾功能提供客观的辅助性数据。方法:选择2004-01/2005-12在南京医科大学附属第一医院、江苏省人民医院行同种异体移植肾患者57例,其中经穿刺活检证实或最后临床诊断为急性移植肾排斥反应者22例,未发生排斥反应等并发症的移植肾功能正常者35例,患者均知情同意。采用Philips EnVisor彩色多普勒超声血流显像仪,对急性排斥反应肾移植患者进行二维超声和彩色多普勒血流显像检测,观察排斥反应患者甲基强的松龙冲击治疗前后移植肾脏的大小、形态结构、肾内血管树分布、血流灌注以及各级动脉血流参数(阻力指数,搏动指数)等指标的变化,并与移植肾功能正常患者进行比较。结果:急性排斥反应组2例患者发生严重并发症死亡,进入结果分析急性排斥反应组20例,移植肾功能正常组35例。①发生急性排斥反应时肾移植患者移植肾体积明显大于肾功能正常组(P<0.01);肾实质增厚,皮髓质界限模糊。给予甲基强的松龙冲击治疗后急性排斥反应组患者肾脏厚径显著小于治疗前(P<0.05);肾实质回声减低,皮髓质交界变清。②发生急性排斥反应时肾移植患者移植肾血流阻力指数、搏动指数均显著高于移植肾功能正常组(P<0.01)。治疗后急性排斥反应组患者肾血流阻力指数、搏动指数均显著低于治疗前(P<0.01),与移植肾功能正常组差异无显著性意义(P>0.05)。结论:彩色多普勒超声作为一种简便、经济的无创性技术,对移植肾血流阻力指数、搏动指数的追踪观察可为临床上评估肾移植效果提供较可靠的客观依据,对移植肾急性排斥反应的早期诊断有较高的评估价值。  相似文献   
109.
110.
The pharmacokinetics of midazolam in paediatric patients   总被引:14,自引:0,他引:14  
A serum concentration profile study on midazolam in children was done. Fifty six children aged 3-10 years took part. The routes investigated were intravenous, intramuscular, rectal and oral at 0.15 mg.kg-1, and the oral at 0.45 mg.kg-1 and 1 mg.kg-1. Serum concentration levels for 5 h were studied using gas liquid chromatography. The volume of distribution, Vss, was 1.29 l.kg-1, the elimination half-life 1.17 h and the serum clearance 9.11 ml.kg-1.min-1. Peak serum concentrations for the intramuscular, rectal and oral routes were at 15 min, 30 min and 53 min respectively. Bioavailability was 87%, 18%, 27% respectively at a dose of 0.15 mg.kg-1. The oral route bioavailability halved to 15% at the two higher doses. Bioequivalence was present between the 0.15 mg.kg-1 intramuscular dose and the 0.45 mg.kg-1 oral dose from 45 to 120 min.  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