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   9792篇
  免费   561篇
  国内免费   36篇
耳鼻咽喉   91篇
儿科学   443篇
妇产科学   214篇
基础医学   884篇
口腔科学   236篇
临床医学   682篇
内科学   2081篇
皮肤病学   212篇
神经病学   674篇
特种医学   216篇
外科学   2215篇
综合类   215篇
一般理论   2篇
预防医学   379篇
眼科学   290篇
药学   747篇
中国医学   55篇
肿瘤学   753篇
  2023年   93篇
  2022年   60篇
  2021年   404篇
  2020年   249篇
  2019年   317篇
  2018年   430篇
  2017年   275篇
  2016年   356篇
  2015年   321篇
  2014年   493篇
  2013年   583篇
  2012年   926篇
  2011年   850篇
  2010年   499篇
  2009年   425篇
  2008年   544篇
  2007年   571篇
  2006年   484篇
  2005年   441篇
  2004年   356篇
  2003年   296篇
  2002年   221篇
  2001年   132篇
  2000年   111篇
  1999年   95篇
  1998年   56篇
  1997年   55篇
  1996年   38篇
  1995年   36篇
  1994年   29篇
  1993年   22篇
  1992年   72篇
  1991年   66篇
  1990年   40篇
  1989年   48篇
  1988年   42篇
  1987年   38篇
  1986年   31篇
  1985年   48篇
  1984年   30篇
  1983年   24篇
  1982年   13篇
  1981年   15篇
  1980年   17篇
  1979年   18篇
  1978年   13篇
  1977年   13篇
  1976年   13篇
  1974年   18篇
  1972年   10篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
1.
2.
3.
4.

Background

Regional anaesthesia for upper limb surgery is routinely performed with brachial plexus blocks. A retroclavicular brachial plexus block has recently been described, but has not been adequately compared with another approach. This randomised controlled single-blinded trial tested the hypothesis that the retroclavicular approach, when compared with the supraclavicular approach, would increase the success rate.

Methods

One hundred and twenty ASA physical status 1–3 patients undergoing distal upper limb surgery were randomised to receive an ultrasound-guided retroclavicular or supraclavicular brachial plexus block with 30 mL of a 1:1 mixture of mepivacaine 1% and ropivacaine 0.5%, using a single-injection technique without needle tip repositioning. The primary outcome was block success rate 30 min after local anaesthetic injection, defined as a composite score of 14 of 16 points, inclusive of sensory and motor components. Secondary outcomes included needling time, time to first opioid request, oxycodone consumption, and pain scores (numeric rating scale, 0–10) at 24 h postoperatively.

Results

Success rates were 98.3% [95% confidence interval (CI): 90.8%, 99.9%] and 98.3% [95% CI: 90.9%, 99.9%] in the supraclavicular and retroclavicular groups, respectively (P=0.99). The mean needling time was reduced in the supraclavicular group [supraclavicular: 5.0 (95% CI: 4.7, 5.4) min; retroclavicular: 6.0 (95% CI: 5.4, 6.6) min; P=0.006]. The mean time to first opioid request was similar between groups [supraclavicular: 439 (95% CI: 399, 479) min; retroclavicular: 447 (95% CI: 397, 498) min; P=0.19] as were oxycodone consumption [supraclavicular: 10.0 (95% CI: 6.5, 13.5 mg; retroclavicular: 7.9 (95% CI: 4.8, 11.0) mg; P=0.80] and pain scores at 24 h postoperatively [supraclavicular: 1.2 (95% CI: 2.1, 2.7); retroclavicular: 1.5 (95% CI: 1.6, 2.4); P=0.09].

Conclusions

Ultrasound-guided retroclavicular and supraclavicular brachial plexus blocks share identical success rates, while providing similar pain relief. Reduced needling time in the supraclavicular approach is not clinically relevant.

Clinical trial registration

NCT02641613.  相似文献   
5.
Objectives: Atopic dermatitis (AD) is a chronic, relapsing skin condition, with signs and symptoms that impact patients’ lives and are best measured from the patient perspective. Therefore, there is a need for AD-specific questionnaires that are consistent with Food and Drug Administration guidance and best measurement practices, assessing sign and symptom severity and associated impacts, to support treatment efficacy in regulated trials. The objectives were to develop patient-reported outcome (PRO) questionnaires assessing sign and symptom severity, as well as impacts of moderate-to-severe adult AD.

Methods: A targeted literature review and meetings with clinical experts (dermatologists) were conducted to identify AD-related sign, symptom, and impact concepts. Results were harmonized and used to construct two draft PRO questionnaires: the Atopic Dermatitis Symptom Scale (ADerm-SS; 11 items) and the Atopic Dermatitis Impact Scale (ADerm-IS; 10 items). The content validity and questionnaire content were evaluated via qualitative concept elicitation/cognitive debriefing interviews with adult patients with moderate-to-severe AD.

Results: From the literature (n?=?13 articles), 13 sign and symptom and 43 impact concepts were identified, while 21 sign and symptom and 48 impacts were elicited from experts (n?=?3). During the patient interviews (n?=?15), 19 sign and symptom and 41 impact concepts were reported, the majority of which were evaluated by the ADerm-SS and ADerm-IS, thus substantiating the content of both questionnaires. Additionally, patients interpreted both questionnaires as intended by the developers.

Conclusions: The ADerm-SS and ADerm-IS can be regarded as content-valid PRO questionnaires for moderate-to-severe AD.  相似文献   

6.
7.
Abstract

Cardiac troponins (cTn) are currently the standard of care for the diagnosis of acute coronary syndromes (ACS) in patients presenting to the emergency department (ED) with chest pain (CP). However, their plasma kinetics necessitate a prolonged ED stay or overnight hospital admission, especially in those presenting early after CP onset. Moreover, ruling out ACS in low-risk patients requires prolonged ED observation or overnight hospital admission to allow serial measurements of c-Tn, adding cost. Heart-type fatty acid-binding protein (H-FABP) is a novel marker of myocardial injury with putative advantages over cTn. Being present in abundance in the myocellular cytoplasm, it is released rapidly (<1?h) after the onset of myocardial injury and could potentially play an important role in both earlier diagnosis of high-risk patients presenting early after CP onset, as well as in risk-stratifying low-risk patients rapidly. Like cTn, H-FABP also has a potential role as a prognostic marker in other conditions where the myocardial injury occurs, such as acute congestive heart failure (CHF) and acute pulmonary embolism (PE). This review provides an overview of the evidence examining the role of H-FABP in early diagnosis and risk stratification of patients with CP and in non-ACS conditions associated with myocardial injury.
  • Key messages
  • Heart-type fatty acid-binding protein is a biomarker that is elevated early in myocardial injury

  • The routine use in the emergency department complements the use of troponins in ruling out acute coronary syndromes in patients presenting early with chest pain

  • It also is useful in risk stratifying patients with other conditions such as heart failure and acute pulmonary embolism.

  相似文献   
8.
Journal of Neuro-Oncology - Intracranial meningiomas rarely present with multiple lesions. To the best of our knowledge, current literature regarding meningiomatosis (MM) is mostly comprised of...  相似文献   
9.
10.
Uptake of colorectal cancer screening remains suboptimal. Mailed fecal immunochemical testing (FIT) offers promise for increasing screening rates, but optimal strategies for implementation have not been well synthesized. In June 2019, the Centers for Disease Control and Prevention convened a meeting of subject matter experts and stakeholders to answer key questions regarding mailed FIT implementation in the United States. Points of agreement included: 1) primers, such as texts, telephone calls, and printed mailings before mailed FIT, appear to contribute to effectiveness; 2) invitation letters should be brief and easy to read, and the signatory should be tailored based on setting; 3) instructions for FIT completion should be simple and address challenges that may lead to failed laboratory processing, such as notation of collection date; 4) reminders delivered to initial noncompleters should be used to increase the FIT return rate; 5) data infrastructure should identify eligible patients and track each step in the outreach process, from primer delivery through abnormal FIT follow-up; 6) protocols and procedures such as navigation should be in place to promote colonoscopy after abnormal FIT; 7) a high-quality, 1-sample FIT should be used; 8) sustainability requires a program champion and organizational support for the work, including sufficient funding and external policies (such as quality reporting requirements) to drive commitment to program investment; and 9) the cost effectiveness of mailed FIT has been established. Participants concluded that mailed FIT is an effective and efficient strategy with great potential for increasing colorectal cancer screening in diverse health care settings if more widely implemented.  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