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   736813篇
  免费   50326篇
  国内免费   1438篇
耳鼻咽喉   9613篇
儿科学   23876篇
妇产科学   17957篇
基础医学   114214篇
口腔科学   20913篇
临床医学   65889篇
内科学   141258篇
皮肤病学   16874篇
神经病学   52427篇
特种医学   27321篇
外国民族医学   77篇
外科学   109236篇
综合类   14936篇
现状与发展   2篇
一般理论   166篇
预防医学   52373篇
眼科学   17000篇
药学   55910篇
  3篇
中国医学   2422篇
肿瘤学   46110篇
  2021年   5989篇
  2019年   5854篇
  2018年   8395篇
  2017年   6558篇
  2016年   7398篇
  2015年   8095篇
  2014年   10966篇
  2013年   16243篇
  2012年   21934篇
  2011年   22965篇
  2010年   13620篇
  2009年   12684篇
  2008年   21294篇
  2007年   23036篇
  2006年   23289篇
  2005年   21768篇
  2004年   21348篇
  2003年   20214篇
  2002年   19780篇
  2001年   37299篇
  2000年   37956篇
  1999年   31336篇
  1998年   8297篇
  1997年   7002篇
  1996年   7293篇
  1995年   6897篇
  1994年   6363篇
  1992年   23741篇
  1991年   23598篇
  1990年   22947篇
  1989年   22728篇
  1988年   20631篇
  1987年   20023篇
  1986年   19007篇
  1985年   17806篇
  1984年   13048篇
  1983年   11026篇
  1982年   6036篇
  1979年   11769篇
  1978年   8297篇
  1977年   6985篇
  1976年   6716篇
  1975年   7396篇
  1974年   8660篇
  1973年   8285篇
  1972年   7803篇
  1971年   7298篇
  1970年   7015篇
  1969年   6459篇
  1968年   5914篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
101.
102.
Sebum excretion rate was measured by a photometric technique. We demonstrated a high correlation between sebum excretion rates on the left and right sides of the upper back and between back and forehead skin. Sebum excretion rate measurements overlying an open comedone (blackhead) were significantly lower than those obtained from normal skin. This observation demonstrates a functional obstruction to the outflow of sebum and would suggest that the lack of involvement of open comedones in inflammatory acne is not because of the maintenance of a free flow of sebum.  相似文献   
103.
A 65-year-old man with spontaneous rupture of the esophagus survived with a direct suture of the esophagus 15 hours after the onset of symptoms. Endoscopic examination of the esophagus was especially of great help in determining the surgical procedure in this patient, and we want to stress the importance of prompt diagnosis and immediate surgery for this disease.  相似文献   
104.
Effects of dexamethasone on central and peripheral ACTH systems in the rat   总被引:1,自引:0,他引:1  
To investigate the simultaneous effects of dexamethasone on peripheral and central adrenocorticotropic hormone (ACTH) systems, rats were treated with dexamethasone or saline for 4 days. Pituitary, plasma, hypothalamus and cerebrospinal fluid (CSF) were then collected and analyzed for ACTH immunoreactivity. Additionally, hypothalamic tissue extracts were analyzed for corticotropin-releasing hormone (CRH) immunoreactivity. Dexamethasone significantly lowered peripheral levels of ACTH as measured in pituitary and plasma. Hypothalamic ACTH content significantly increased while CSF ACTH significantly decreased with dexamethasone treatment. Hypothalamic CRH concentrations showed a small but statistically insignificant decrease. These results suggest that prolonged exposure to dexamethasone affects central as well as peripheral ACTH activity, corroborate our previous findings in rhesus monkeys of decreased CSF ACTH in response to prolonged dexamethasone treatment, suggest that dexamethasone may inhibit the release of ACTH from hypothalamic neurons into the CSF, and provide evidence that the effect of dexamethasone on pituitary ACTH content is of greater magnitude than its effect on hypothalamic CRH.  相似文献   
105.
Roentgen endovascular occlusion with spiral emboli was used in 240 patients with different diseases. The introduction of spiral emboli into the arteries of abdominal and retroperitoneal organs was fulfilled through usual angiographic catheters. Duration of the arterial occlusion was checked up in the following angiographic examinations and showed the devices described to be appropriate for a continuous arterial blockade. No complications resulting from the introduction of the spiral embolus were noted.  相似文献   
106.
Snoring means obstructive breathing during sleep, and its most exaggerated form is obstructive sleep apnea. Mild snoring may respond to simple self-help remedies. Heavy snoring responds well to the surgical removal or reconstruction of obstructive elements in the hypopharynx, nasopharynx or nasal passages.  相似文献   
107.
Seventy seven antral biopsies were collected from patients attending endoscopy clinic at King Khalid University Hospital, Riyadh, Saudi Arabia during a period of six months between December 1988 to May 1989. Of these 69 (89.6%) showed chronic gastritis as well as Helicobacter-like organisms (HLOs) in the biopsy specimens while 63 (81.8%) of biopsies grew Helicobacter pylori on culture. These findings indicate a good correlation between the histological diagnosis of chronic gastritis and isolation of H. pylori on culture.  相似文献   
108.
The authors suggest additional criteria evidencing inflammations in the gallbladder and colloid stability of the bile: bile acid absorption and cholesterol sedimentation coefficients. Derivation of these coefficients is based on biochemical examination of the bile with measurements of bile acid, cholesterol, and bilirubin concentrations in both portions. The results of examinations of 99 subjects evidence the diagnostic value and specificity of the characteristics, and availability of this method for clinical practice.  相似文献   
109.
A number of children who are admitted for inpatient psychiatric treatment have experienced significant trauma and abuse. It is important to evaluate them for the presence of a DD. The variety, complexity, and subtlety of the symptomatic presentation of childhood MPD makes differential diagnosis difficult, and it is probable that many cases have been missed in the past. Detailed historical information and extensive behavioral observations in a variety of settings can assist in establishing the diagnosis and in delineating areas for therapeutic intervention. Hospitalization may be necessary to conduct an adequate evaluation, develop a therapeutic alliance, safely manage behaviors that are injurious to the child or others, and/or to diffuse potentially volatile family situations. All members of a multidisciplinary inpatient team play important roles in the achievement of successful therapeutic intervention with dissociating children and their families. Skilled family therapy is often an important adjunct to therapeutic interventions focused on the child, particularly when the parent also has MPD. Knowledge of the psychodynamic issues involved in dissociation can be used to develop behavioral interventions that are successful in decreasing the child's need to dissociate, improving his or her overall functioning, and help him or her gain mastery over problematic behaviors.  相似文献   
110.
Genetic factors for the span of apprehension test: a study of normal twins.   总被引:1,自引:0,他引:1  
The Partial Report Span of Apprehension test has been found to detect cognitive deficits in some first degree relatives of schizophrenic patients. To assess the relative contribution of genetic vs. environmental factors on this measure, 19 monozygotic and 14 dizygotic female twin pairs, selected from a normal population, were tested on the Span of Apprehension test and an IQ test. Both Span of Apprehension test performance and IQ score had high heritabilities: 0.65 and 0.71, respectively. The mode of transmission for performance on the Span of Apprehension test appears to operate in a nonadditive manner. A multivariate behavioral-genetic model applied to the Span of Apprehension and IQ measures indicated that slightly less than half of the genetic effects important for the Span of Apprehension test are found in common with the genetic factors important for IQ. The phenotypic correlation between the Span of Apprehension and IQ measures can be attributed entirely to genetic factors. The influence of unique genetic components in the performance of the Span of Apprehension test in the general population heightens the promise of this measure as a genetic marker for schizophrenia.  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