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   64526篇
  免费   4556篇
  国内免费   145篇
耳鼻咽喉   486篇
儿科学   2422篇
妇产科学   2075篇
基础医学   7661篇
口腔科学   847篇
临床医学   10238篇
内科学   12202篇
皮肤病学   1035篇
神经病学   6370篇
特种医学   1237篇
外国民族医学   34篇
外科学   6428篇
综合类   794篇
一般理论   86篇
预防医学   8444篇
眼科学   762篇
药学   3671篇
  1篇
中国医学   100篇
肿瘤学   4334篇
  2023年   326篇
  2022年   463篇
  2021年   1144篇
  2020年   806篇
  2019年   1286篇
  2018年   1444篇
  2017年   1062篇
  2016年   1184篇
  2015年   1288篇
  2014年   1797篇
  2013年   2894篇
  2012年   4158篇
  2011年   4432篇
  2010年   2380篇
  2009年   2229篇
  2008年   3969篇
  2007年   4403篇
  2006年   4287篇
  2005年   4087篇
  2004年   3926篇
  2003年   3796篇
  2002年   3537篇
  2001年   837篇
  2000年   757篇
  1999年   779篇
  1998年   809篇
  1997年   671篇
  1996年   601篇
  1995年   511篇
  1994年   477篇
  1993年   467篇
  1992年   529篇
  1991年   529篇
  1990年   490篇
  1989年   433篇
  1988年   391篇
  1987年   385篇
  1986年   363篇
  1985年   383篇
  1984年   356篇
  1983年   341篇
  1982年   358篇
  1981年   338篇
  1980年   261篇
  1979年   273篇
  1978年   229篇
  1977年   234篇
  1976年   202篇
  1975年   211篇
  1974年   196篇
排序方式: 共有10000条查询结果,搜索用时 781 毫秒
81.
Advancement Flaps: A Basic Theme with Many Variations   总被引:1,自引:0,他引:1  
Krishnan Ravi  MD    Garman Mary  MD    Nunez-Gussman Janna  MD    Orengo Ida  MD 《Dermatologic surgery》2005,31(S2):986-994
Background. The advancement flap involves the linear advancement of tissue in one direction. Despite its straightforwardness and simple concept, it can be used to close a variety of defects, ranging from small defects on the scalp or extremities to large, complicated defects involving cosmetic units on the face.
Objectives. To provide a basic and useful review for the indications, advantages, disadvantages, and techniques for the use of advancement flaps in the reconstruction of defects in dermatologic surgery.
Materials and Methods. We performed a literature search for articles discussing advancement flaps and compiled a brief review of our findings.
Results. The movement of the advancement flap must be balanced by the blood supply of the flap. The excision of Burow's triangles along various aspects of the advancement flap can increase movement and improve cosmesis of the flap. The types of advancement flaps discussed include the single advancement flap, double advancement flap, A-T flap (O-T flap), Burow's triangle flap (Burow's wedge flap), crescenteric advancement flap, island pedicle flap (V-Y flap), helical rim advancement flap, and facelift flap.
Conclusion. Advancement flaps are versatile and useful basic flaps for repairing defects.  相似文献   
82.
Work stress, burnout, and diminished empathy are prevalent issues for health‐care professionals. Mindfulness meditation (MM) is one commonly used strategy to manage stress. Measuring salivary cortisol allows for the assessment of serum cortisol level, a known stress level indicator. This study evaluated the association of subject‐reported stress symptoms and salivary cortisol in health‐care professionals, in an 8‐week MM program, with data collected prospectively at baseline and 8 weeks after program completion. Questionnaires [Profile of Mood States—Short Form (POMS‐SF), Maslach Burnout Inventory (MBI), and Interpersonal Reactivity Index (IRI)] measured mood, burnout and empathy. A paired t‐test between groups for pre/post‐salivary cortisol yielded no significant change. The POMS‐SF was most sensitive to change (mean increase 12.4; p = 0.020). Emotional exhaustion, measured in the MBI, was also affected by MM (mean decrease 4.54; p = 0.001). Changes in empathy may not have been captured due to either absence of effect of MM on empathy, subject number or scale sensitivity. Baseline and 8‐week correlations between salivary cortisol and survey results, and correlations between changes in these measures, were weak and not statistically significant. Nevertheless, psychometric results present a strong case for additional clinical trials of MM to reduce stress for health‐care professionals. Copyright © 2005 John Wiley & Sons, Ltd.  相似文献   
83.
84.
A previously reported paradigm in which rats run down a runway for food reward followed by morphine injection was analyzed to assess the utility of the paradigm in studies of opiate reinforcement. One experiment replicated the original report that post-trial morphine caused both an increase in runway speed and a decrease in food consumption (taste aversion) over successive trials, and showed in addition that the increase in runway speed did not occur as a result of food deprivation alone, but required the animals to have consumed food in the goal box. A second study using the quaternary opiate antagonist methyl naltrexone to block the peripheral effects of morphine suggested that the increase in runway speed has a peripheral locus while the taste aversion has a central one. A third experiment in which morphine was microinjected into either the lateral ventricle or the ventral tegmental area supported these observations, in that intracranial morphine failed to result in an increased runway speed, but did produce taste aversion after microinjection into either site. These findings also suggest that the increase in runway speed caused by post-trial morphine in this experiment has a peripheral locus of effect, which is probably distinct from the central effect that supports morphine self-administration and conditioned place preference. Offprint requests to: W.A.CorrigallThe views expressed in this publication are those of the authors and do not necessarily reflect those of the Addiction Research Foundation  相似文献   
85.
The surgical risk of colectomy in patients with cirrhosis   总被引:5,自引:1,他引:4  
The records of 54 patients with documented cirrhosis who underwent colectomy between January 1970 and January 1984 were studied to assess the operative risk and to determine the preoperative predictive risk factors. In-hospital mortality was 24 percent (13 patients), and postoperative complications occurred in 48 percent (26 patients). The risk of surgical intervention was significantly increased if encephalopathy, ascites, anemia, or hypoalbuminemia was present before operation. A simple operative risk index involving the presence of encephalopathy and ascites and the levels of hemoglobin and albumin is proposed to help distinguish a low-risk subgroup in whom postoperative mortality was 12.8 percent from a high-risk subgroup in whom postoperative mortality was 53.3 percent.  相似文献   
86.
87.
Our clinical experience with patients in Zimbabwe suggests that an arthropathy may be a feature of HIV disease. This takes two forms: the first is a reactive arthropathy usually affecting the large, lower limb joints with no other clinical features of a connective tissue disease. The second form is seen in association with features of complete or incomplete Reiter's syndrome with involvement of large and small peripheral joints (having an asymmetric distribution). Although this arthropathy may been seen in association with HIV positive asymptomatic disease and often is the reason for first presentation at hospital, the majority of our patients have clinical features of persistent generalized lymphadenopathy, plus or minus features of constitutional illness (such as fever, weight loss, and diarrhea). A small percentage of our patients have arthropathy in association with secondary systemic infection. Other locomotor conditions have been observed, although their numbers are too small to determine whether or not they truly are related to HIV disease. In Zimbabwe there is no association between the development of HIV-associated arthropathy and the presence of HLA-B27.  相似文献   
88.
89.
90.
Antigenic characterization of urothelial cells cultured from normal adult ureter was performed. These cells were cultured using a simplified isolation and culture technique and a commercially available serum-free medium. The cells growing in these cultures had epithelioid morphology and normal quantities of DNA. The antigen expression on these cultured normal urothelial cells was evaluated using a panel of monoclonal antibodies: 5G6.4, AN43, URO-5, anti-keratin and anti-blood group antibodies, and 425 (anti-epidermal growth factor receptor). Lower levels of anti-A and AN43 binding on cultured cells were observed than are seen on urothelial cells in sections of normal ureter, while the binding of anti-blood group H, 5G6.4, and URO-5 was unchanged. Binding of anti-epidermal growth factor receptor antibody 425 was improved if the cells were grown in medium lacking epidermal growth factor. These results confirm the urothelial origin of these cultured urothelial cells but indicate that some antigenic differences between cultured normal urothelial cells and urothelial cells in situ in the normal ureter exist.  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