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   1494篇
  免费   104篇
  国内免费   1篇
耳鼻咽喉   9篇
儿科学   48篇
妇产科学   37篇
基础医学   156篇
口腔科学   24篇
临床医学   266篇
内科学   271篇
皮肤病学   16篇
神经病学   157篇
特种医学   31篇
外科学   106篇
综合类   29篇
一般理论   3篇
预防医学   295篇
眼科学   21篇
药学   77篇
中国医学   1篇
肿瘤学   52篇
  2023年   9篇
  2022年   24篇
  2021年   72篇
  2020年   32篇
  2019年   39篇
  2018年   37篇
  2017年   31篇
  2016年   40篇
  2015年   32篇
  2014年   49篇
  2013年   81篇
  2012年   127篇
  2011年   124篇
  2010年   69篇
  2009年   50篇
  2008年   100篇
  2007年   96篇
  2006年   83篇
  2005年   76篇
  2004年   81篇
  2003年   84篇
  2002年   67篇
  2001年   8篇
  2000年   9篇
  1999年   12篇
  1998年   13篇
  1997年   12篇
  1996年   13篇
  1995年   9篇
  1994年   8篇
  1993年   5篇
  1992年   6篇
  1991年   7篇
  1990年   8篇
  1989年   8篇
  1987年   6篇
  1986年   9篇
  1985年   3篇
  1984年   6篇
  1983年   7篇
  1982年   4篇
  1981年   4篇
  1980年   5篇
  1978年   2篇
  1977年   5篇
  1975年   8篇
  1974年   3篇
  1973年   4篇
  1971年   2篇
  1967年   2篇
排序方式: 共有1599条查询结果,搜索用时 625 毫秒
1.
OBJECTIVE: In light of recent terrorist events and the potential threat of smallpox as a biological agent, we present information concerning smallpox to better inform the otolaryngologist concerning this disease and its prevention. STUDY DESIGN: We performed a review of the smallpox and smallpox vaccination literature over the past 200 years using MEDLINE, PREMEDLINE, Centers for Disease Control and Prevention Internet site, World Health Organization Internet site, and references found in previous publications not found in MEDLINE or PREMEDLINE. Our search focused on the pathogenesis, clinical presentation, course, unique manifestations in the head and neck, diagnosis, and treatment of smallpox, as well as the method of smallpox vaccination, vaccination contraindications, and complications. RESULTS: Smallpox is a viral disease with a high mortality rate. Its clinical course, manifestations, and methods of prevention are carefully analyzed in light of otolaryngology practice. CONCLUSION: Smallpox manifestations in the head and neck often presented as acute airway obstruction and also as long-term sequelae such as ectropion, nasal vestibular stenosis, conductive hearing loss, and blindness. Most chronic sequelae involve the head and neck. Smallpox vaccination is effective but not without potential serious risks.  相似文献   
2.
3.
4.
In 1995, the National League for Nursing commissioned a Panel on Interdisciplinary/Transdisciplinary Education. The focus of the Panel's work was to examine educational issues that transcend the health professions and to make recommendations for future implementation of an interdisciplinary approach to addressing them. This article is being simultaneously published by several professional journals. The goal is to seek as much feedback as possible.  相似文献   
5.
6.
OBJECTIVES: The purpose of this study was to determine quality of life (QOL) and exercise performance (EP) in patients with persistent atrial fibrillation (AF) converted to sinus rhythm (SR) compared with those remaining in or reverting to AF. BACKGROUND: Restoration of SR in patients with AF improving QOL and EP remains controversial. METHODS: Patients with persistent AF were randomized double-blind to amiodarone, sotalol, or placebo. Those not achieving SR at day 28 were cardioverted and classified into SR or AF groups at 8 weeks (n = 624) and 1 year (n = 556). The QOL (SF-36), symptom checklist (SCL), specific activity scale (SAS), AF severity scale (AFSS), and EP were assessed. RESULTS: Favorable changes were seen in SR patients at 8 weeks in physical functioning (p < 0.001), physical role limitations (p = 0.03), general health (p = 0.002), and vitality (p < 0.001), and at 1 year in general health (p = 0.007) and social functioning (p = 0.02). Changes in the scores for SCL severity (p = 0.01), functional capacity (p = 0.003), and AFSS symptom burden (p < 0.001) at 8 weeks and in SCL severity (p < 0.01) and AF symptom burden (p < 0.001) at 1 year showed significant improvements in SR versus AF. Symptomatic patients were more likely to have improvement. The EP in SR versus AF was greater from baseline to 8 weeks (p = 0.01) and to 1 year (p = 0.02). The EP correlated with physical functioning and functional capacity except in the AF group at 1 year. CONCLUSIONS: In patients with persistent AF, restoration and maintenance of SR was associated with improvements in QOL measures and EP. There was a strong correlation between QOL measures and EP.  相似文献   
7.
1. Phospholipase A2 (PLA2) cleaves phospholipids to produce a lyso-phospholipid and free fatty acid and, in view of the biological activity of the products, PLA2 may play a role in many disease states. Lyso-phospholipids and free arachidonic acid increase in ischaemic myocardium, indicating that ischaemia activates the enzyme. 2. Plasma PLA2 activity was measured in patients with acute myocardial infarction, based on the release of labelled arachidonic acid from Escherichia coli cell membrane. Fourteen males (peak serum creatine phosphokinase (CK) above twice upper normal) were studied on day 1 (within 6 h of chest pain onset), days 2-4, and days 6-9. Normal age matched males (n = 13) were also studied. 3. Plasma PLA2 in patients with uncomplicated myocardial infarction (n = 12) was, initially, 1.14 +/- 0.10 (s.e.m.) nmol/min per mL plasma, similar to that in the normal group (1.52 +/- 0.14). On days 2-4, PLA2 activity increased to 1.94 +/- 0.18 (P less than 0.001) and this activity was correlated with the earlier peak CK level (P less than 0.02). On days 6-9, PLA2 activity was 1.49 +/- 0.13 while in two patients who developed complications and underwent open-heart surgery between the last two measurements, there were further increases to 4.22 and 4.04 nmol/min per mL. 4. The increase in plasma PLA2 in uncomplicated myocardial infarction is likely to be due to release from the damaged myocardium; whether it contributes to pathophysiology is uncertain.  相似文献   
8.
A potential public health concern is the reported detection of the human T-lymphotropic virus (HTLV) tax gene in the lymphocytes of up to 11% of a low-risk group of New York City blood donors (NYBD). This study aimed to independently confirm the prevalence of HTLV tax sequences in 293 NYBD. All NYBD tested negative for antibodies to HTLV types 1 and 2 and HTLV Tax. HTLV tax sequences were not detected in the NYBD lymphocytes. These data demonstrate the lack of HTLV-1 tax in this group of NYBD at low risk for HTLV infection.  相似文献   
9.
Mixing pharmaceutical preparations of soluble neutral regular insulin solution (NRI) and neutral protamine Hagedorn (NPH) crystalline insulin suspension leads to a reduction in the measurable amount of soluble insulin in the formulation supernatant. However in spite of the loss in soluble insulin, the time-actions of these components have been shown, in clinical trials, to be unaffected. The interaction between these different physical forms of insulin has been studied using reversed-phase HPLC, isothermal titrating calorimetry, and Doppler electrophoretic light scattering analysis. Sorbent surface and solution perturbation studies revealed that the NRI adsorbs to the surface of the NPH crystal with an equilibrium constant ranging from 104 M–1 to 107 M–!, depending on the protamine concentration, pH, ionic strength, and temperature. This adsorption behavior suggests that the binding is mediated by electrostatic interactions arising between the positively-charged NPH crystal and the negatively-charged NRI hexamer. Doppler electrophoretic light scattering results, used to probe the pH-dependent surface charge of NPH and soluble insulin hexamer, support the conclusion that electrostatic interactions mediate the adsorption process. Adsorption studies under physiological conditions indicate that the elevated temperature and ionic strength, in a subcutaneous depot, are sufficient to lead to the dissociation of the NRI/NPH complex that exists in these NPH mixture formulations.  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