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   1443361篇
  免费   119540篇
  国内免费   6620篇
耳鼻咽喉   18155篇
儿科学   45829篇
妇产科学   38332篇
基础医学   197408篇
口腔科学   38336篇
临床医学   131570篇
内科学   299908篇
皮肤病学   33487篇
神经病学   120792篇
特种医学   58906篇
外国民族医学   277篇
外科学   224953篇
综合类   33241篇
现状与发展   3篇
一般理论   571篇
预防医学   116117篇
眼科学   30704篇
药学   101142篇
  7篇
中国医学   2385篇
肿瘤学   77398篇
  2018年   15329篇
  2017年   12112篇
  2016年   14403篇
  2015年   16321篇
  2014年   22814篇
  2013年   34232篇
  2012年   42791篇
  2011年   45868篇
  2010年   28375篇
  2009年   27694篇
  2008年   43127篇
  2007年   46100篇
  2006年   47081篇
  2005年   45890篇
  2004年   43699篇
  2003年   42736篇
  2002年   40306篇
  2001年   67040篇
  2000年   68658篇
  1999年   57604篇
  1998年   18131篇
  1997年   16162篇
  1996年   16953篇
  1995年   17102篇
  1994年   15819篇
  1993年   14889篇
  1992年   47644篇
  1991年   46280篇
  1990年   44457篇
  1989年   42281篇
  1988年   39195篇
  1987年   38483篇
  1986年   36269篇
  1985年   35127篇
  1984年   27039篇
  1983年   22793篇
  1982年   14786篇
  1981年   13315篇
  1980年   12505篇
  1979年   23927篇
  1978年   17567篇
  1977年   14813篇
  1976年   13565篇
  1975年   14077篇
  1974年   16394篇
  1973年   15639篇
  1972年   14359篇
  1971年   13145篇
  1970年   11993篇
  1969年   11193篇
排序方式: 共有10000条查询结果,搜索用时 46 毫秒
81.
82.
To understand in situ behavior of osteocytes, we characterized a model of osteocytes in their native bone matrix and demonstrated real-time biologic activity of osteocytes while bending the bone matrix. Using 43 male Sprague-Dawley rats, dumbbell-shaped explants were harvested from stainless steel femoral implants after 6-12 weeks and incubated in culture medium or fixed. Sixteen specimens were used to determine bone volume density (BV/TV), volumetric bone mineral density (BMD) and histology for different implantation periods. Osteocyte viability was evaluated by L-lactate dehydrogenase (LDH) activity in 12 cultured explants. Confocal microscopy was used to assess tracer diffusion in three explants and changes in osteocyte pH of a mechanically loaded explant. From 6 to 12 weeks, explant BV/TV and volumetric BMD trended up 92.5% and 101%, respectively. They were significantly and highly correlated. Tissues were uniformly intramembranous and all bone cell types were present. Explants maintained LDH activity through culture day 8. Diffusion at 200 microM was limited to 1,209 Da. Explants appeared capable of reproducing complex bone biology. This model may be useful in understanding osteocyte mechanotransduction in the context of a physiologically relevant bone matrix.  相似文献   
83.
We report the case of a patient with a 13-year history of pemphigus vulgaris (PV) treated with immunosuppressive agents, prednisone and mycophenolate mofetil who had developed lesions of Kaposi's sarcoma (KS) on a sole plaque of PV that had been previously treated with intralesional injections of steroids. The lesions were surgically removed and polymerase chain reaction (PCR) demonstrated human herpesvirus-8 (HHV-8) DNA. There were neither recurrences nor later dissemination of KS following gradual decrease of the immunosuppressive therapy. We suggest that the treatment with intralesional steroids may have influenced the local reactivation of a latent infection of the virus, determining the appearance of this localized KS.  相似文献   
84.
Thoraxtrauma     
Chest injuries can be sustained in isolation or in association with multiple injuries. Life-threatening complications may ensue because organs that are vital to survival of the organism are situated within the thoracic cavity. These complications include airway obstruction, tension pneumothorax, wide open pneumothorax, flail chest, cardiac tamponade and massive hemothorax. The mortality of patients hospitalized with chest injury can be as high as 10%. Clinical examination and awareness of the possibility of other injuries (high level of suspicion) are essential, and standard chest X-ray, ultrasound and thoracic computed tomography may also be needed for the diagnosis. The first part of this serial paper on the management of chest injuries focuses on anatomical aspects, pathophysiology and symptoms, but mainly on the indications for the standard diagnostic procedures and further high-tech examinations.  相似文献   
85.
Relationship-centered care reflects both knowing and feeling: the knowledge that physician and patient bring from their respective domains of expertise, and the physician’s and patient’s experience, expression, and perception of emotions during the medical encounter. These processes are conveyed and reciprocated in the care process through verbal and nonverbal communication. We suggest that the emotional context of care is especially related to nonverbal communication and that emotion-related communication skills, including sending and receiving nonverbal messages and emotional self-awareness, are critical elements of high-quality care. Although nonverbal behavior has received far less study than other care processes, the current review argues that it holds significance for the therapeutic relationship and influences important outcomes including satisfaction, adherence, and clinical outcomes of care.  相似文献   
86.
Successful efforts in improving breastfeeding initiation rates at an urban teaching hospital prompted the hospital to create a lactation consultant (LC) position in the outpatient setting to focus on breastfeeding duration. This article reviews the complexity of the clinic setting, with the challenges and benefits of the consultant's first year in one of the hospital's outpatient clinics. Preliminary data collected by the consultant suggest that patients counseled by the LC in the outpatient clinic setting have longer breastfeeding duration rates.  相似文献   
87.
OBJECTIVE: To compare infants' discomfort, nursing-time and caregiver preference, and assess the clinical efficiency (as a secondary outcome) of hood versus facemask nebulization in infants with evolving bronchopulmonary dysplasia (BPD) in the neonatal intensive care unit. STUDY DESIGN: A prospective, open, randomized, controlled crossover clinical trial. In total, 10 infants with BPD who were on inhaled beta-agonist bronchodilators and corticosteroids were randomly assigned to receive their nebulized treatments either by a facemask, or by a hood for 2-3 days, and then crossover to receive the same treatments with the other technique for another 2-3 days. Infants' discomfort, nursing-time, caregiver preference and clinical efficiency were compared. RESULTS: At baseline there was no significant clinical difference between the groups. Nurse-time required for administering the hood nebulization (mean+/-s.e.m.: 1.9+/-0.1 min) was significantly shorter than the time for mask nebulization (12.0+/-0.6 min, P<0.0001). Infants' discomfort score was significantly lower (0.1+/-0.04) for hood versus mask nebulization (2.5+/-0.2, P<0.0001). Nurses and parents unequivocally preferred the hood treatment. During both mask and hood nebulization therapies (2-3 days) clinical efficiency was comparable. While both methods caused an immediate (20 min post) clinical improvement, the immediate respiratory assessment change score was significantly greater for the hood versus the mask nebulization (0.62+/-0.27 versus 0.13+/-0.14, P<0.05). CONCLUSIONS: Nebulization of aerosolized medications in infants with evolving BPD by hood was less time-consuming for caregivers and was much better tolerated by the infants while being at least as effective as the conventional facemask nebulization.  相似文献   
88.
89.
90.
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