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   429篇
  免费   12篇
儿科学   22篇
妇产科学   25篇
基础医学   33篇
口腔科学   4篇
临床医学   22篇
内科学   113篇
皮肤病学   15篇
神经病学   23篇
特种医学   5篇
外科学   112篇
综合类   12篇
预防医学   20篇
眼科学   12篇
药学   9篇
中国医学   5篇
肿瘤学   9篇
  2023年   3篇
  2022年   2篇
  2021年   4篇
  2020年   3篇
  2019年   41篇
  2018年   29篇
  2017年   29篇
  2016年   2篇
  2015年   2篇
  2014年   3篇
  2013年   12篇
  2012年   6篇
  2011年   4篇
  2010年   6篇
  2009年   8篇
  2008年   8篇
  2007年   3篇
  2006年   2篇
  2005年   4篇
  2004年   3篇
  2003年   2篇
  2002年   2篇
  2001年   2篇
  2000年   2篇
  1999年   1篇
  1998年   2篇
  1997年   1篇
  1996年   2篇
  1995年   1篇
  1994年   1篇
  1990年   1篇
  1988年   1篇
  1985年   23篇
  1984年   26篇
  1983年   16篇
  1982年   25篇
  1981年   17篇
  1980年   24篇
  1979年   21篇
  1978年   26篇
  1977年   11篇
  1976年   23篇
  1975年   10篇
  1974年   10篇
  1973年   16篇
  1972年   1篇
排序方式: 共有441条查询结果,搜索用时 505 毫秒
1.
癫痫大发作儿童生活质量的研究   总被引:2,自引:0,他引:2  
应用癫痫患者生活质量量表,以问卷方式,对91例患儿进行生活质量的研究,并与正常儿童比较及探讨影响因素。结果,患儿生活质量明显低于正常儿童,主要因对发作恐慎、担心长期用药、存在认知障碍及社会交往困难;此外,生活质量与学习成绩也有关。即使发作已被控制,患儿生活质量并无明显改善。因而对患儿除药物治疗外,应加强非药物的心理治疗及提高学习能力,才能提高癫痫患儿的生活质量。  相似文献   
2.
Twenty-five patients were treated for retained, recurrent, or primary common duct stones by permanent drainage of the biliary tract with external choledochoduodenostomy. Twenty-one patients had common duct stones which became evident two to fifty years after the initial biliary tract procedure and which may represent stones formed in the common duct. Three recent patients had a clinical history of primary common duct stones, had stones which were soluble in chloroform-methanol solution, and had hepatic bile which was lithogenic as determined by evaluating the molar percentage of cholesterol, phospholipid, and bile salt in bile samples obtained at the time of choledochoduodenostomy. These data suggest that further stone formation is possible and that permanent bypass of the sphincter of Oddi is indicated to prevent recurrent bile duct obstruction. Long-term evaluation of the results of external choledochoduodenostomy indicates that the procedure is safe and effective in the prevention of recurrent biliary tract calculi.  相似文献   
3.
4.
5.

Introduction

Retrospective data indicates that dehydration in acute ischemic stroke patients may be common, even though these patients frequently have elevated blood pressure. We sought to evaluate clinical and laboratory measures of intravascular volume status compared to more objective measures using ultrasound measurements of the inferior vena cava (IVC).

Methods

This was a prospective observation study of acute ischemic stroke patients in the emergency department. Patients with NIH stroke scale ≥4 within 12?h of symptom onset were included. A trained ultrasonographer performed bi-dimensional imaging of the IVC with passive respiration to determine the percent inspiratory collapse and maximum diameter. We defined low intravascular volume as >50% IVC collapse and a maximal diameter?<?2.1?cm. Analysis was limited to patients with confirmed ischemic stroke.

Results

There were 42 patients, of whom 31 had confirmed acute ischemic stroke. The mean age was 65?±?15?years, 52% were female, and 71% were hypertensive. The median NIH stroke scale score was 7 (IQR 5–15). Based on IVC ultrasound, low intravascular volume was present in 63% (95% CI 44–80%) of patients. A higher proportion of hypertensive patients had low intrasvascular volume (72% vs. 33%). There was poor correlation between IVC assessment of intrasvascular volume and blinded clinician assessment or laboratory markers of dehydration.

Conclusion

The majority of ED acute ischemic stroke patients in this sample were hypertensive and demonstrated low intravascular volume based on IVC ultrasound.  相似文献   
6.
Methicillin-resistant Staphylococcus aureus (MRSA) has become endemic in Detroit, accounting for 50% of bacteremias in heroin abusers. To identify the salient epidemiologic and clinical features of MRSA bacteremia, case-control studies were performed comparing 28 cases of MRSA bacteremia to 28 cases of methicillin-sensitive S. aureus (MSSA) bacteremia in intravenous drug abusers. Infective endocarditis was diagnosed in 46.4% (13 of 28). In endocarditis and nonendocarditis bacteremia alike, the duration of fever, length of hospitalization, need for surgery, and mortality rates were similar. A history of recent antimicrobial therapy, especially cephalosporins, was more common in the MRSA group (p = 0.006). Complications including neurologic, renal, vascular, and musculoskeletal manifestations were more common in the MSSA endocarditis patients than MRSA endocarditis patients, although this difference was not significant. Complications related to antibiotic therapy were similar for both groups. The case-control studies indicate that MRSA and MSSA are similar in their virulence as measured by duration of hospitalization, duration of fever, complications, and mortality.  相似文献   
7.
8.
Grand means of time‐varying signals (waveforms) across subjects in magnetoencephalography (MEG) and electroencephalography (EEG) are commonly computed as arithmetic averages and compared between conditions, for example, by subtraction. However, the prerequisite for these operations, homogeneity of the variance of the waveforms in time, and for most common parametric statistical tests also between conditions, is rarely met. We suggest that the heteroscedasticity observed instead results because waveforms may differ by factors and additive terms and follow a mixed model. We propose to apply the asinh‐transformation to stabilize the variance in such cases. We demonstrate the homogeneous variance and the normal distributions of data achieved by this transformation using simulated waveforms, and we apply it to real MEG data and show its benefits. The asinh‐transformation is thus an essential and useful processing step prior to computing and comparing grand mean waveforms in MEG and EEG.  相似文献   
9.
目的 分析京杭大运河江苏丹阳段及丹金溧漕河沿线钉螺时空分布特征,为动态评估该区域钉螺扩散风险提供科学依据。方法 收集2012-2017年研究区域内水网型血吸虫病流行区螺情数据,采用缓冲区分析、空间自相关分析、热点分析及标准差椭圆分析法,探索京杭大运河丹阳段及丹金溧漕河沿线钉螺时空变化趋势。结果 2012-2017年,研究区域内有螺环境数呈上升趋势;有螺环境主要分布于丹金溧漕河1 000 m缓冲区内,特别是京杭大运河与丹金溧漕河交汇处的老九曲河沿线。2014、2016、2017年,研究区域内钉螺分布存在空间自相关,热点区域主要为丹金溧漕河与京杭大运河交汇处;钉螺分布整体呈东北-西南方向,随着时间变化逐渐向南北方向转变。结论 京杭大运河丹阳段及丹金溧漕河沿线钉螺空间分布复杂,存在从上游向下游扩散的风险,需加强该区域的灭螺工作。  相似文献   
10.
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