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   2517篇
  免费   190篇
  国内免费   45篇
耳鼻咽喉   23篇
儿科学   102篇
妇产科学   41篇
基础医学   210篇
口腔科学   42篇
临床医学   323篇
内科学   386篇
皮肤病学   49篇
神经病学   70篇
特种医学   303篇
外科学   342篇
综合类   208篇
预防医学   244篇
眼科学   18篇
药学   215篇
  2篇
中国医学   32篇
肿瘤学   142篇
  2022年   32篇
  2021年   35篇
  2020年   33篇
  2018年   29篇
  2017年   25篇
  2016年   23篇
  2015年   41篇
  2014年   56篇
  2013年   85篇
  2012年   89篇
  2011年   97篇
  2010年   100篇
  2009年   112篇
  2008年   82篇
  2007年   102篇
  2006年   102篇
  2005年   74篇
  2004年   81篇
  2003年   80篇
  2002年   73篇
  2001年   48篇
  2000年   37篇
  1999年   48篇
  1998年   95篇
  1997年   88篇
  1996年   76篇
  1995年   75篇
  1994年   47篇
  1993年   65篇
  1992年   27篇
  1991年   34篇
  1990年   23篇
  1989年   40篇
  1988年   51篇
  1987年   49篇
  1986年   42篇
  1985年   43篇
  1984年   31篇
  1983年   32篇
  1982年   20篇
  1980年   21篇
  1977年   20篇
  1976年   19篇
  1963年   17篇
  1959年   22篇
  1958年   29篇
  1957年   19篇
  1956年   30篇
  1955年   42篇
  1954年   35篇
排序方式: 共有2752条查询结果,搜索用时 223 毫秒
1.
2.
In the “basic” approach, medical expenses are catastrophic if they exceed a prespecified percentage of consumption or income; the approach tells us if expenses cause a large percentage reduction in living standards. The ability‐to‐pay (ATP) approach defines expenses as catastrophic if they exceed a prespecified percentage of consumption less expenses on nonmedical necessities or an allowance for them. The paper argues that the ATP approach does not tell us whether expenses are large enough to undermine a household's ability to purchase nonmedical necessities. The paper compares the income‐based and consumption‐based variants of the basic approach, and shows that if the individual is a borrower after a health shock, the income‐based ratio will exceed the consumption‐based ratio, and both will exceed the more theoretically correct Flores et al. ratio; whereas if the individual continues to be a saver after a health shock, the ordering is reversed and the income‐based ratio may not overestimate Flores et al.'s ratio. Last, the paper proposes a lifetime money metric utility (LMMU) approach defining medical expenses as catastrophic in terms of their lifetime consequences. Under certain assumptions, the LMMU and Flores et al. approaches are identical, and neither requires data on how households finance their medical expenses.  相似文献   
3.
A cluster randomized experiment was undertaken testing two sets of interventions encouraging enrollment in the Individually Paying Program (IPP), the voluntary component of the Philippines' social health insurance program. In early 2011, 1037 unenrolled IPP‐eligible families in 179 randomly selected intervention municipalities were given an information kit and offered a 50% premium subsidy valid until the end of 2011; 383 IPP‐eligible families in 64 control municipalities were not. In February 2012, the 787 families in the intervention sites who were still IPP‐eligible but had not enrolled had their vouchers extended, were resent the enrollment kits and received SMS reminders. Half the group also received a ‘handholding’ intervention: in the endline interview, the enumerator offered to help complete the enrollment form, deliver it to the insurer's office in the provincial capital, and mail the membership cards. The main intervention raised the enrollment rate by 3 percentage points (ppts) (p = 0.11), with an 8 ppt larger effect (p < 0.01) among city‐dwellers, consistent with travel time to the insurance office affecting enrollment. The handholding intervention raised enrollment by 29 ppts (p < 0.01), with a smaller effect (p < 0.01) among city‐dwellers, likely because of shorter travel times, and higher education levels facilitating unaided completion of the enrollment form. Copyright © The World Bank Health Economics © 2015 John Wiley & Sons, Ltd.  相似文献   
4.
Background Beating heart surgery has now become the commonest technique of doing Coronary Artery Bypass Graft Surgery (CABG) in our country. It is being used even in such high risk situations like diffuse coronary disease and Critical Left Main stem Stenosis (LMCS) with good results. The aim of this study is to retrospectively review our results in Off-Pump Coronary Artery Bypass Surgery (OPCAB) in patients with critical left main stem stenosis. Methods This study is a retrospective analysis of the data of patients who underwent primary coronary artery bypass surgery. During the period from April 2003 to September 2005 a total of 64 patients underwent OPCAB procedure for critical LMCS. During the same period 10 patients underwent CABG on Cardio Pulmonary Bypass (CPB). The age range was 36–77yrs. The sex distribution was M: F 53∶10. Ten patients were done as emergency. 2 of them were on Intra Aortic Balloon Pump (IABP) support preoperatively. 10 patients were high risk with a Euro score of ≥5. Results Left Internal Mammary Artery (LIMA) was used in 78% of cases. Average grafts per patient was 2.96. The median ventilation time was 5.91 hrs. New IABP insertion in postoperative period was required in 1 patient. One patient was reexplored for bleeding. There was one perioperative myocardial infarction. 57% of patients did not need any blood transfusion. There was no conversion to CPB. There was no operative mortality. Inotropes were used in ten cases. Conclusions OPCAB is a safe method of revascularization in patients with critical LMCS. Preoperative IABP is useful in patients with cardiogenic shock. However, there is a place for CPB in patients needing additional procedures like Mitral Valve repair (MV repair) or Dor's procedure or when the vessels are very diffusely diseased. Those patients who are unstable despite IABP support may be managed by Beating heart On Pump (BHOP) technique.  相似文献   
5.
Patients treated with high doses of interleukin-2 (IL-2) because of cancer, develop hemodynamic and vasopermeability changes, that resemble those observed in sepsis. These patients thus provide a unique opportunity to study the early events in the development of septic shock. We analysed the changes that occurred in the contact system of coagulation in plasma from 4 patients, who together received seven 12-day cycles of high doses of IL-2. Levels of factor XII and prekallikrein during the cycles progressively fell to 50 and 30% of their initial levels, respectively, whereas significant increases in plasma factor XIIa- and kallikrein-C1-inhibitor complexes were not observed (in 3 out of 211 samples slightly increased levels of both complexes were found). The reductions in factor XII and prekallikrein were only in part due to protein leakage, since levels were still significantly lower, i.e., 80 and 50%, respectively, when corrected for albumin decreases. Levels of high molecular weight kininogen (HMWK) also decreased during IL-2 therapy, however, this decrease paralleled that of albumin. SDS-PAGE analysis of plasma HMWK did not reveal increased cleavage of this protein. The reduction of factor XII and prekallikrein, corrected for protein leakage, significantly correlated with albumin levels and inversely with daily cumulative weight gain in the patients. Thus, we demonstrate that factor XII and prekallikrein decrease during IL-2 therapy. As these decreases, already observed after 1 day treatment, were disproportional to that of albumin, a negative acute phase reactant, and correlated with signs of the vascular leak syndrome, we favor the explanation that they reflected activation rather than a decreased synthesis of the contact system proteins.(ABSTRACT TRUNCATED AT 250 WORDS)  相似文献   
6.
7.
8.
9.
Heat shock proteins are diverse and essential components of cell physiology. Their expression is elevated in the cell undergoing stress, where they protect the cell from death by necrosis or apoptosis and accelerate recovery. Significant advances have been made in studies relevant to plastic surgery regarding these proteins and their manipulation. This review introduces the heat shock proteins and appraises these studies in skin, ultraviolet light exposure, neoplasia, wound healing, ageing, burns, and reconstructive surgery.  相似文献   
10.
氟西汀与阿米替林治疗105例抑郁障碍病人的双盲对照试验   总被引:6,自引:4,他引:2  
目的:评价国产氟西汀的抗抑郁作用及安全性。方法:采用随机、双盲对照、多中心研究,分为国产氟西汀组57例(男性22例,女性35例;年龄40±s13a),口服氟西汀20mg,qd,阿米替林57例(男性27例,女性30例;年龄40±14a),口服阿米替林75mg,bid,疗程6wk。结果:氟西汀治疗抑郁障碍的疗效与阿米替林相当,总有效率分别为85%及92%(P>0.05);氟西汀组的主要副作用有口干、便秘、恶心、心动过速等,但较之阿米替林程度轻且发生率低。结论:氟西汀的抗抑郁作用与阿米替林相当,副作用少,服用方便。  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