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   2339063篇
  免费   183322篇
  国内免费   7302篇
耳鼻咽喉   30237篇
儿科学   76298篇
妇产科学   64594篇
基础医学   333944篇
口腔科学   64983篇
临床医学   215797篇
内科学   466684篇
皮肤病学   53701篇
神经病学   190968篇
特种医学   91290篇
外国民族医学   522篇
外科学   348779篇
综合类   52600篇
现状与发展   5篇
一般理论   930篇
预防医学   192302篇
眼科学   51475篇
药学   167750篇
  9篇
中国医学   3909篇
肿瘤学   122910篇
  2018年   24010篇
  2016年   21667篇
  2015年   24478篇
  2014年   34090篇
  2013年   51780篇
  2012年   66273篇
  2011年   71145篇
  2010年   43012篇
  2009年   41716篇
  2008年   67007篇
  2007年   71612篇
  2006年   72156篇
  2005年   70245篇
  2004年   67207篇
  2003年   64994篇
  2002年   62454篇
  2001年   106406篇
  2000年   109032篇
  1999年   91701篇
  1998年   27252篇
  1997年   24562篇
  1996年   25563篇
  1995年   25152篇
  1994年   23393篇
  1993年   21992篇
  1992年   75227篇
  1991年   73585篇
  1990年   71190篇
  1989年   68253篇
  1988年   63318篇
  1987年   62292篇
  1986年   58918篇
  1985年   56571篇
  1984年   43061篇
  1983年   36992篇
  1982年   22745篇
  1981年   20571篇
  1980年   19374篇
  1979年   40061篇
  1978年   29269篇
  1977年   24652篇
  1976年   22667篇
  1975年   24151篇
  1974年   28900篇
  1973年   28053篇
  1972年   26154篇
  1971年   24301篇
  1970年   22570篇
  1969年   21249篇
  1968年   19856篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
951.
952.
Total energy expenditure (TEE) was measured by doubly labeled water in 13 preoperative patients undergoing elective coronary artery surgery and compared to resting energy expenditure (REE) measured by indirect calorimetry (IC) calculated from the Harris-Benedict (HB) formula or from formulas based on midarm circumference and arm muscle circumference. Mean REE measured by IC and calculated from the HB, midarm circumference, arm muscle circumference formulas were 62, 75, 62, and 69%, respectively, of TEE measured by doubly labeled water. REE measured by IC correlated significantly with that predicted by the HB (p = 0.006) but not the anthropometric formulas. The relationship between REE derived from anthropometric predictive formulas and REE measured by IC is altered in ischemic heart disease.  相似文献   
953.
After ingesting or inhaling laundry detergent powder, eight children required hospital admission. The predominant symptoms were stridor, drooling, and respiratory distress. All but one patient underwent endoscopy of the airways and the esophagus, five children were admitted to the intensive care unit, and four children required endotracheal intubation. Laundry detergent ingestions are generally considered to have minor consequences, and there exists a paucity of literature on the subject. Evidence of significant morbidity incurred because of ingestion or inhalation of sodium carbonate-containing laundry detergent powder is presented, together with a review of the existing literature.  相似文献   
954.
955.
Twenty two patients (age range: 1 month to 11 years) were treated for congenital diaphragmatic defects (excluding hiatus hernia) in the six year period 1983-8. Presenting features were failure to thrive (n = 7), abdominal pain and vomiting (n = 4), chronic respiratory symptoms (n = 3), and inability to wean from ventilatory support (n = 3). The defect was an incidental finding in five patients. Operative repair was performed with no mortality or serious postoperative morbidity. Dramatic improvement occurred in 15 of the 17 symptomatic patients. Awareness of the differential diagnosis should avoid delay in diagnosis or inappropriate treatment. Surgical correction is strongly recommended in all cases.  相似文献   
956.
957.
Five cases of unilateral vocal cord paralysis/paresis were diagnosed following extracorporeal membrane oxygenation for newborn respiratory failure. All were right sided and transient in nature. None of the five patients had other findings commonly associated with vocal cord palsy. The extracorporeal membrane oxygenation procedure requires surgical dissection in the carotid sheath on the right side of the neck, an area immediately adjacent to both the vagus and recurrent laryngeal nerve. It is speculated that vocal cord paralysis in these infants was acquired as a result of the extracorporeal membrane oxygenation cannulation. Although the vocal cord paralysis resolved in all cases, two patients had difficult courses after extracorporeal membrane oxygenation. Therefore, laryngoscopic examination should be considered for patients after extracorporeal membrane oxygenation.  相似文献   
958.
Tumor material from 91 patients with squamous cell carcinoma of the head and neck was transplanted subcutaneously in athymic nude mice. In the first (man to mouse) passage, the calculated mean probability of tumor take in a single mouse was 11%. The probability of growth in the first passage was significantly better for moderately and poorly differentiated tumors than for well-differentiated tumors. Also, the implantation of lymph node material resulted in a significantly better tumor take rate than material taken from a primary tumor. Transplantability was not dependent on the following characteristics: localization, T or N stage of the tumor, or the sex of the patients. Once growth was established, all variables studied had no influence on the probability of growth in the subsequent mouse passages. A relationship between tumor growth in nude mice and patient prognosis could not be found. When transplanting head and neck squamous cell carcinoma in nude mice, it has to be recognized that some tumor characteristics will influence the success of tumor growth.  相似文献   
959.
Usher syndrome: clinical findings and gene localization studies   总被引:3,自引:0,他引:3  
The issue of genetic heterogeneity is a critical problem in the localization of the gene(s) for Usher syndrome. Based on the data obtained on families studied to date, the differences between type I and type II Usher syndrome appear quite distinct with regard to auditory and vestibular function. Although the majority of families can be confidently diagnosed as typical type I or type II, clinical investigations revealed four families with findings that did not fit into either of the two more common subtypes. These findings emphasize the critical importance of an in-depth clinical analysis concomitant with the linkage investigation to assure accurate subtyping of Usher syndrome. Based on an analysis of only those families with definite type I or type II Usher syndrome, approximately 17% of the genome can be excluded as a potential site of the gene for type I, and 14% can be excluded as the site for the type II gene. This study will continue until the Usher gene(s) is successfully localized.  相似文献   
960.
This paper reports the results of an experimental study modeled after a study conducted by Kaplan et al. The hypothesis tested was: Adolescents who receive a social learning intervention (SLI) will show greater improvement in metabolic control of their diabetes than will adolescents who receive only traditional diabetes instruction. Thirty-four adolescents between the ages of 12 and 16 who attended a midwestern camp were randomly divided into two groups. Both groups attended a daily 1-hour teaching session about diabetes. Later each day, the experimental group received an SLI consisting of role modeling to help the subjects circumvent peer pressure. To determine metabolic control, HbA1 values were determined before and 3 1/2 months after the intervention. The control group showed no significant difference in HbA1 values, while the experimental group showed a decrease in metabolic control.  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