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   6188篇
  免费   1031篇
  国内免费   8篇
耳鼻咽喉   49篇
儿科学   252篇
妇产科学   141篇
基础医学   913篇
口腔科学   149篇
临床医学   882篇
内科学   1065篇
皮肤病学   60篇
神经病学   745篇
特种医学   247篇
外国民族医学   1篇
外科学   714篇
综合类   506篇
一般理论   3篇
预防医学   485篇
眼科学   120篇
药学   602篇
中国医学   2篇
肿瘤学   291篇
  2021年   77篇
  2020年   48篇
  2019年   77篇
  2018年   107篇
  2017年   74篇
  2016年   75篇
  2015年   109篇
  2014年   143篇
  2013年   189篇
  2012年   264篇
  2011年   282篇
  2010年   148篇
  2009年   145篇
  2008年   226篇
  2007年   252篇
  2006年   277篇
  2005年   278篇
  2004年   251篇
  2003年   240篇
  2002年   247篇
  2001年   212篇
  2000年   219篇
  1999年   207篇
  1998年   118篇
  1997年   79篇
  1996年   104篇
  1995年   80篇
  1994年   69篇
  1993年   74篇
  1992年   151篇
  1991年   168篇
  1990年   127篇
  1989年   152篇
  1988年   141篇
  1987年   180篇
  1986年   139篇
  1985年   142篇
  1984年   120篇
  1983年   107篇
  1982年   82篇
  1981年   89篇
  1980年   101篇
  1979年   100篇
  1978年   65篇
  1977年   67篇
  1976年   56篇
  1975年   56篇
  1974年   67篇
  1972年   66篇
  1970年   48篇
排序方式: 共有7227条查询结果,搜索用时 31 毫秒
31.
To investigate the pathophysiology of nonpharmacologically induced panic attacks, 18 drug-free agoraphobic patients and 13 matched healthy subjects underwent structured exposure to phobic situations. Heart rate, blood pressure, and plasma free 3-methoxy-4-hydroxyphenylglycol (MHPG), cortisol, growth hormone, and prolactin levels were measured before, during, and after exposure. Fifteen patients experienced situational panic attacks during exposure. Panicking patients displayed significantly greater increases in heart rate but not blood pressure or plasma free MHPG or cortisol in comparison with the healthy subjects. Growth hormone and prolactin responses tended to be smaller in the patients. If brain noradrenergic hyperactivity occurs during situational panic attacks, it may be too brief or too restricted in regional localization to affect MHPG levels in plasma. Chronically recurrent attacks may cause an adaptation of neuroendocrine mechanisms activated by anxiety or stress.  相似文献   
32.
33.
The management of injuries--a review of deaths in hospital   总被引:1,自引:0,他引:1  
A prospective review was undertaken of the management of 111 consecutive patients who died in hospital after admission for treatment of injuries. A standard set of data relating to each patient was reviewed by each member of a trauma death audit committee and then by the whole committee. Autopsy reports were available on all patients. Conclusions were drawn concerning defective aspects of patient management and possible avoidance of each death. Injury severity was assessed using the Trauma Score (TS) and Injury Severity Score (ISS). The possibly avoidable death (PAD) rate was 17%. The most common defects in management were related to inadequate fluid resuscitation and delays in definitive management. The greatest contributions to the PAD rate were from inadequate fluid resuscitation, delays and inadequate perception of the severity of injuries or significance of clinical deterioration. Increasing age was related to a higher frequency of PAD. PAD rate in the presence of severe head injury was 8%, but was 63% in the absence of a severe head injury. It is concluded that review of all trauma deaths is an achievable, beneficial and essential part of a hospital-based integrated trauma service. TS and ISS are not sufficiently sensitive to justify their use in selecting deaths for review. Improved blood volume replacement, earlier and more direct management and supervision by senior specialist staff, and elimination of causes of delay in patient management should all decrease the death rate from injuries particularly in patients without severe head injury.  相似文献   
34.
Indian Journal of Thoracic and Cardiovascular Surgery -  相似文献   
35.
Results from 120 patients managed with a Sacks-Vine gastrostomy tube were analyzed. In our experience, this device can be successfully placed in almost all cases (96%), and has a low rate for procedure-related mortality (0.8%) and major (4.4%) and minor (12.4%) complications. Advantages and problems associated with this feeding catheter are discussed. The Sacks-Vine gastrostomy tube is a reasonable alternative to other catheters placed by different methods.  相似文献   
36.
37.
38.
This study reviewed a series of patients with Crohn's disease managed by surgeons of the Department of Colon and Rectal Surgery, St Vincent's Hospital, Melbourne, since 1978. There were 306 patients: 171 males and 135 females. The mean age at diagnosis was 33.4 years (range 11–93). The distribution of the disease was small bowel 32.3%, small bowel and colon 26.5%, colon 39.9%, and anal disease alone 1.6%. A total of 416 abdominal operations were performed on 204 patients. The commonest indications for surgery were failed medical therapy (21.9%), small bowel obstruction (15.9%), enteric tistula (10.1%), and intra-abdominal abscess (10.1%). The most frequently performed procedures were ileocolic resection with anastomosis (28.8%), small bowel resection (9.4%), and total colectomy and ileostomy (7.0%). Postoperative complications included anastomotic leaks in 4.0%. intra-abdominal abscess formation in 3.6%, and enterocutaneous fistulae developed in 6%. Three patients died during the review period. During follow up (mean 84.4). 30% of patients developed recurrence requiring further surgery at a mean of 72.7 months postoperatively. The most frequent site for a recurrence was the pre-anastomotic terminal ileum (61.7%). In conclusion. the majority of patients with Crohn's disease will require resectional surgery at some stage. This can be performed with a low mortality and morbidity, and a recurrence rate of around 5% per year.  相似文献   
39.
Schizophrenic patients, nonschizophrenic patients, and nonpsychiatric controls were compared in their demonstration of clockwise circling (CC), and in lateral eye movement responses to verbal and spatial questions. Only schizophrenic subjects who did not evidence CC showed inappropriate left hemisphere arousal to spatial stimuli. A tendency was noted for CC to occur more frequently among paranoid than nonparanoid schizophrenics. The results, taken together with other recent findings, suggest that the absence of CC may correlate with a more severe form of schizophrenia, and one more likely to be characterized by overarousal of the left cerebral hemisphere.  相似文献   
40.
We have obtained multislice magnetic resonance (MR) images of the eye and calculated ocular dimensions along the three cardinal axes: antero-posterior (A-P), equatorial, and vertical. We found no difference in the shape of hyperopic (average refractive error: +3.72 D) and emmetropic eyes, both of which had an equatorial diameter longer than the A-P and vertical diameters. Myopic eyes (average refractive error: -6.54 D) were larger than hyperopic eyes, and most had the same spheroelliptical shape as that of the emmetropic and hyperopic eyes. The results suggest that during myopic progression an overall enlargement or a radial volume expansion has occurred.  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