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   831篇
  免费   100篇
  国内免费   8篇
耳鼻咽喉   3篇
儿科学   69篇
妇产科学   17篇
基础医学   125篇
口腔科学   30篇
临床医学   87篇
内科学   180篇
皮肤病学   19篇
神经病学   33篇
特种医学   133篇
外科学   58篇
综合类   50篇
预防医学   48篇
眼科学   31篇
药学   25篇
肿瘤学   31篇
  2022年   5篇
  2021年   5篇
  2020年   9篇
  2019年   9篇
  2018年   20篇
  2017年   8篇
  2016年   22篇
  2015年   22篇
  2014年   28篇
  2013年   45篇
  2012年   20篇
  2011年   14篇
  2010年   43篇
  2009年   47篇
  2008年   19篇
  2007年   32篇
  2006年   18篇
  2005年   18篇
  2004年   11篇
  2003年   15篇
  2002年   10篇
  2001年   14篇
  2000年   8篇
  1999年   9篇
  1998年   41篇
  1997年   47篇
  1996年   42篇
  1995年   38篇
  1994年   25篇
  1993年   29篇
  1992年   9篇
  1991年   22篇
  1990年   18篇
  1989年   23篇
  1988年   19篇
  1987年   15篇
  1986年   18篇
  1985年   20篇
  1984年   9篇
  1983年   15篇
  1982年   7篇
  1981年   16篇
  1980年   8篇
  1979年   7篇
  1977年   13篇
  1976年   11篇
  1973年   4篇
  1972年   5篇
  1971年   5篇
  1966年   5篇
排序方式: 共有939条查询结果,搜索用时 15 毫秒
41.
42.

Background

Reliable estimates of the population proportion eligible to donate blood are needed by blood collection agencies to model the likely impact of changes in eligibility criteria and inform targeted population-level education, recruitment, and retention strategies. In Australia, the sole estimate was calculated 10+ years ago. With several subsequent changes to the eligibility criteria, an updated estimate is required.

Study Design and Methods

We conducted a cross-sectional national population survey to estimate eligibility for blood donation. Respondents were aged 18+ and resident in Australia. Results were weighted to obtain a representative sample of the population.

Results

Estimated population prevalence of blood donation eligibility for those aged 18–74 was 57.3% (95% CI 55.3–59.3). The remaining 42.7% (95% CI 40.7–44.7) were either temporarily (25.3%, 95% CI 23.5–27.2) or permanently ineligible (17.4%, 95% CI 16.1–18.9). Of those eligible at the time of the survey, that is, with the UK geographic deferral for variant Creutzfeldt-Jakob disease included, (52.9%, 95% CI 50.8–54.9), 14.2% (95% CI 12.3–16.3) reported donating blood within the previous 2 years. Eligibility was higher among men (62.6%, 95% CI 59.6–65.6) than women (52.8%, 95% CI 50.1–55.6). The most common exclusion factor was iron deficiency/anemia within the last 6 months; 3.8% (95% CI 3.2–4.6) of the sample were ineligible due to this factor alone.

Discussion

We estimate that approximately 10.5 million people (57.3% of 18–74-year-olds) are eligible to donate blood in Australia. Only 14.2% of those eligible at the time of survey reported donating blood within the previous 2 years, indicating a large untapped pool of potentially eligible blood donors.  相似文献   
43.
44.

Background

In the Netherlands, screening for chlamydia (the most prevalent sexually transmitted infection worldwide) is a relatively simple and free procedure. Via an invitation letter sent by the public health services (PHS), people are asked to visit a website to request a test kit. They can then do a chlamydia test at home, send it anonymously to a laboratory, and, within two weeks, they can review their test results online and be treated by their general practitioner or the PHS. Unfortunately, the participation rates are low and the process is believed to be not (cost-) effective.

Objective

The objective of this study was to assess whether the low participation rate of screening for chlamydia at home, via an invitation letter asking to visit a website and request a test kit, could be improved by optimizing the invitation letter through systematically applied behavior change theories and evidence.

Methods

The original letter and a revised letter were randomly sent out to 13,551 citizens, 16 to 29 years old, in a Dutch municipality. Using behavior change theories, the revised letter sought to increase motivation to conduct chlamydia screening tests. The revised letter was tailored to beliefs that were found in earlier studies: risk perception, advantages and disadvantages (attitude), moral norm, social influence, and response- and self-efficacy. Revisions to the new letter also sought to avoid possible unwanted resistance caused when people feel pressured, and included prompts to trigger the desired behavior.

Results

No significant differences in test package requests were found between the two letters. There were also no differences between the original and revised letters in the rates of returned tests (11.80%, 581/4922 vs 11.07%, 549/4961) or positive test results (4.8%, 23/484 vs 4.1%, 19/460). It is evident that the new letter did not improve participation compared to the original letter.

Conclusions

It is clear that the approach of inviting the target population through a letter does not lead to higher participation rates for chlamydia screening. Other approaches have to be developed and pilot tested.  相似文献   
45.
46.
47.
由于治疗方法的进步,近80%的儿童和青少年癌症患者能够长期生存。在美国,约有270000例儿童癌症的幸存者,即每640名20至39岁成年人中就有一名幸存者。大量的幸存者有利于儿童癌症治疗后长期健康结果的研究。现在可以明确的是,化疗和放疗所致的儿童各器官系统损害在临床上可能潜伏多年。为了全面了解治疗儿童癌症而继发的健康问题,重要的是衡量三项长期结果:健康状况、死亡率和患病率。这三项中,关于前两项已有相当好的研究报道。在一项对20227例癌症5年生存者的回顾性分析中,Mertens等发现以下原因导致的超额死亡率具有统计学意义:继发癌症(…  相似文献   
48.
目的探讨高脂血症性急性胰腺炎(HAP)和非高脂血症性急性胰腺炎的特点及临床救治效果。方法回顾分析我院在2013年1月至2013年12月收治的99例急性胰腺炎的临床资料,根据患者有无高脂血症将其分为HAP组(高脂血症患者)和对照组(无高脂血症的AP患者);患者均接受标准化临床治疗,比较2组患者病情、血浆生化指标、治疗转归、住院时间与费用、复发等情况。结果 HAP组重度胰腺炎比例(13.6%)明显高于对照组(7.8%),HAP组血糖和尿酸均显著高于对照组,其中HAP组血糖平均值达到对照组的171%,而HAP组的血淀粉酶却仅为对照组的44.5%;HAP组1年内的复发率(13.6%)显著高对于照组(2.6%),P0.01差异有统计学意义。结论高血脂对急性胰腺炎的病情、表现和治疗结果均有明显影响,应引起高度重视。  相似文献   
49.
No previously published studies have described double-lumen hemodialysis/apheresis catheters for use with continuous-flow apheresis collection of peripheral stem cell (PSC). We prospectively evaluated experiences with these catheters during both PSC collection and transplantation. Because of previously-described successful experiences with single-lumen apheresis catheters placed in the inferior vena cava, all catheters evaluated in this study were placed in this anatomic location. Our experience demonstrated high rates of thrombotic occlusion (65%) and catheter-related infections (15%). This method of access should not be considered optimal in its present state of use. Further investigation into preferred catheter design, anatomic location, and thrombosis prophylaxis during continuous-flow apheresis is warranted.  相似文献   
50.
We evaluated the association of body mass index (BMI) with migraine and migraine specifics in a cross-sectional study of 63 467 women aged ≥ 45 years, of whom 12 613 (19.9%) reported any history of migraine and 9195 had active migraine. Compared with women without migraine and a BMI < 23 kg/m2, women with a BMI ≥ 35 kg/m2 had adjusted odds ratios (ORs) (95% confidence intervals) of 1.03 (0.95, 1.12) for any history of migraine. Findings were similar for active migraineurs. Women with a BMI of ≥ 35 kg/m2 had increased risk for low and high migraine frequency, with the highest estimate for women who reported daily migraine. Compared with women with the lowest associated risk (migraine frequency < 6 times/year; BMI between 27.0 and 29.9 kg/m2), women with a BMI ≥ 35 kg/m2 had an OR of daily migraine of 3.11 (1.12, 8.67). Among the women with active migraine, a BMI ≥ 35 kg/m2 was associated with increased risk of phonophobia and photophobia and decreased risk of a unilateral pain characteristic and migraine aura. Our data confirm previous findings that the association between BMI with migraine is limited to migraine frequency and specific migraine features.  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