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   1356篇
  免费   69篇
  国内免费   2篇
耳鼻咽喉   4篇
儿科学   55篇
妇产科学   32篇
基础医学   168篇
口腔科学   33篇
临床医学   116篇
内科学   199篇
皮肤病学   34篇
神经病学   140篇
特种医学   46篇
外国民族医学   1篇
外科学   154篇
综合类   57篇
一般理论   1篇
预防医学   173篇
眼科学   15篇
药学   84篇
中国医学   14篇
肿瘤学   101篇
  2024年   3篇
  2023年   22篇
  2022年   58篇
  2021年   81篇
  2020年   52篇
  2019年   49篇
  2018年   66篇
  2017年   45篇
  2016年   32篇
  2015年   44篇
  2014年   57篇
  2013年   69篇
  2012年   100篇
  2011年   115篇
  2010年   56篇
  2009年   52篇
  2008年   68篇
  2007年   77篇
  2006年   66篇
  2005年   49篇
  2004年   36篇
  2003年   25篇
  2002年   32篇
  2001年   14篇
  2000年   7篇
  1999年   6篇
  1998年   8篇
  1996年   4篇
  1995年   4篇
  1992年   7篇
  1991年   8篇
  1990年   13篇
  1989年   5篇
  1988年   3篇
  1987年   5篇
  1986年   3篇
  1985年   5篇
  1984年   3篇
  1982年   3篇
  1979年   5篇
  1977年   7篇
  1974年   13篇
  1973年   4篇
  1972年   8篇
  1971年   8篇
  1970年   4篇
  1969年   4篇
  1967年   4篇
  1966年   2篇
  1965年   2篇
排序方式: 共有1427条查询结果,搜索用时 0 毫秒
181.
Enlarged Virchow–Robin spaces along the medullary perforators on brain magnetic resonance images (MRIs) of a 4–year–old, neurologically intact child with seizures are described. The differential diagnosis of cystic spaces in the centrum semiovale is discussed. The sparse MRI literature on bright signal intensities in childhood is reviewed.  相似文献   
182.
Diagnostic interpretation of intraoperative transesophageal echocardiography (TEE) examinations may vary, particularly when the echocardiographer is also the anesthesiologist. We therefore evaluated the concordance of TEE interpretation as part of a process of continuous quality improvement (CQI). Ten cardiac anesthesiologists participating in a CQI program conducted 154 comprehensive TEE examinations, each consisting of 16 major fields describing cardiac anatomy and function. These examinations were subsequently interpreted off-line by two primary echocardiographers (a radiologist and a cardiologist). Agreement was assessed using the kappa coefficient and percent agreement. Overall kappa and percent agreement were 0.58 and 83% for anesthesiologists versus radiologist, 0.57 and 80% for anesthesiologists versus cardiologist, and 0.60 and 82% for radiologist versus cardiologist. Anesthesiologists with longer than 5 yr of TEE experience had higher levels of agreement with the radiologist when assessing the aorta, right atrium, pulmonary vein flow, transmitral flow, and fractional area change. Cardiac anesthesiologists supported by a CQI program interpret TEE examinations at a level comparable with physicians whose primary practice is echocardiography. Thus, the anesthesiologist and the intraoperative echocardiographer need not be mutually exclusive. IMPLICATIONS: Interpretation of intraoperative transesophageal echocardiograms can be reliably performed by cardiac anesthesiologists.  相似文献   
183.
OBJECTIVE: To investigate associations between suicidal behaviours, including suicidal ideation and attempts, and poor peer and parental relationships in a nationally representative sample of Canadian adolescents aged 12 to 13 years. METHODS: We used Statistics Canada's National Longitudinal Survey of Children and Youth as the dataset. This cross-sectional sample included 1049 girls and 1041 boys aged 12 to 13 years. We obtained answers to self-report questionnaires that included measures of peer relationships, parental nurturance, and parental rejection, as well as information regarding suicidal ideation and attempts. Unadjusted and adjusted logistic regression models were used for the analysis. We included depression in the multiple logistic regression analysis. Analyses were run separately for boys and girls. RESULTS: The unadjusted logistic regression models found that, among early adolescent boys and girls, depression, poor peer relationships, decreased parental nurturance, and increased parental rejection were all significantly associated with suicidal ideation and attempts. However, after adjusting for all other variables in the multiple logistic regression models, poor peer relationships were no longer significantly associated with suicidal ideation among early adolescent boys and were only weakly associated among early adolescent girls. CONCLUSIONS: Poor parental relationships and depression were more powerfully associated with suicidal ideation and attempts than were peer relationships in a nationally representative sample of boys and girls aged 12 to 13 years, and these factors may be important early intervention targets.  相似文献   
184.
The case records 50 patients with abdominal pain and hyperamylasemia were studied in detail. Ten cases of gallstone induced hyperamylasemia, in which no evidence of pancreatitis was found at operation, were excluded. The etiological factors in the remaining group of forty cases of acute pancreatitis, in a community practicing alcohol abstinence, were reviewed. Both alcoholic and idiopathic pancreatitis were insignificant factors in the etiology of acute pancreatitis. Eighty percent of cases of acute pancreatitis were due to biliary tract disease. A younger age-group and female preponderance, as well as biochemical evidence of cholestasis, was observed in this group. An inverse relationship between preoperative serum amylase levels and the severity of the disease was noted. A more aggressive diagnostic work-up is, however, warranted to identify these cases, for which early surgery is advocated. There was no mortality in operated cases of biliary pancreatitis.  相似文献   
185.
1 The effect of surgery under general anaesthesia on drug metabolism was investigated in man. The activity of hepatic drug-metabolizing enzymes was evaluated by measurement of antipyrine clearance, before surgery and 3 days after surgery, in eighteen patients. 2 In those patients in whom the operation lasted 2 h or less, the postoperative clearance of antipyrine was significantly (P less than 0.05) increased by 48%; in those patients in whom the operation lasted 2--4 h, it was non-significantly decreased by 36%; in those patients in whom the operation lasted more than 4 h, it was significantly decreased by 47% (P less than 0.01). 3 It is concluded (a) that short operations are followed by increased activity of hepatic drug-metabolizing enzymes, whereas (b) protracted operations are followed by decreased activity. It is suggested (a) that the former effect may be a consequence of enzyme induction by drugs used for premedication and anaesthesia, whereas (b) the latter effect may be the result of major surgical trauma.  相似文献   
186.
187.
188.
189.
ABSTRACT: Tissue typing performed on the lymphocytes of 41 Patients, including: 23 patients with ichthyosis (15 of autosomal dominant and 8 of the x-linded variety; 8 patients with tuberous sclerosis (epiloia); and 10 patients with acroder-matitis enteropathica (AEP). In adddition, tissue typing was performed for a control group of 80 healthy unrelated subjects of the same ethnic origin as the patients. A significant increase of A2 antigen or its crossreacting antigen A28 was detected among the three diseases studied. A significant increase of HLA-A2 antigen was found in autosomal dominant ichthyosis, while the x-linked variety showed significant association with HLA-Cw2. A significant association with HLA-A28 antigen was noticed in both epiloia and AEP. The suggested mechanisms of such association may be refferred to as incidental genetic linkage with mutants causing disease or deficiency.  相似文献   
190.
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