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   5154篇
  免费   891篇
  国内免费   6篇
耳鼻咽喉   31篇
儿科学   134篇
妇产科学   730篇
基础医学   175篇
口腔科学   21篇
临床医学   2982篇
内科学   564篇
皮肤病学   48篇
神经病学   266篇
特种医学   37篇
外科学   258篇
综合类   56篇
一般理论   1篇
预防医学   424篇
眼科学   36篇
药学   80篇
中国医学   5篇
肿瘤学   203篇
  2024年   14篇
  2023年   180篇
  2022年   35篇
  2021年   81篇
  2020年   140篇
  2019年   66篇
  2018年   193篇
  2017年   236篇
  2016年   297篇
  2015年   265篇
  2014年   322篇
  2013年   373篇
  2012年   159篇
  2011年   253篇
  2010年   248篇
  2009年   374篇
  2008年   239篇
  2007年   208篇
  2006年   191篇
  2005年   175篇
  2004年   180篇
  2003年   147篇
  2002年   122篇
  2001年   118篇
  2000年   59篇
  1999年   128篇
  1998年   140篇
  1997年   122篇
  1996年   117篇
  1995年   114篇
  1994年   82篇
  1993年   59篇
  1992年   67篇
  1991年   71篇
  1990年   75篇
  1989年   51篇
  1988年   33篇
  1987年   26篇
  1986年   28篇
  1985年   44篇
  1984年   26篇
  1983年   27篇
  1982年   20篇
  1981年   21篇
  1980年   16篇
  1979年   11篇
  1978年   21篇
  1977年   10篇
  1976年   14篇
  1973年   7篇
排序方式: 共有6051条查询结果,搜索用时 15 毫秒
71.
Two hundred healthy, unpremedicated children, ages 1–10 years, scheduled for elective outpatient surgery were studied in order to examine the effect of minimizing preoperative fasting on perioperative blood glucose concentrations in paediatric patients. None of the patients ingested solids after midnight. On the day of surgery, the children were assigned to one of two groups. Group A children (n= 113) were not allowed any liquids for at least 6 h prior to surgery (NPO). Children in Group B (n= 87) ingested 10 ml·kg?1 of apple juice 2–4 h prior to the induction of anaesthesia. All patients received lactated Ringer's solution intraoperatively, unless BG at induction was < 50 mg·dl?1 (2.8 m·mol·l?1) in which case dextrose 2.5% in lactated Ringer's solution was administered. None of the patients who received apple juice was hypoglycaemic during induction of anaesthesia. However, two children in the NPO group had blood glucose values ± 50 mg·dl?1 (2.8 m·mol·l?1) at the time of induction of anaesthesia. Thirteen (11%) patients in Group A and 6 (7%) patients in Group B showed either no change or a further decrease in their postoperative BG concentration as compared with their induction values. Two of 43 patients in Group A and 2 of 41 patients in Group B had gastric fluid volumes > 0.4 ml/kg. All patients in both groups had gastric pH < 2.5. This study shows that gastric fluid volume and pH following a 2–4 h fast are not different from the values measured in children who were subjected to a traditional fasting period of 6 h or longer. Moreover, apple juice consumed 2–4 h prior to surgery neither buffers gastric pH nor does it modify intraoperative glucose homeostasis in children.  相似文献   
72.
73.
74.
Care of the newborn diagnosed with a congenital malignancy is a challenge for the neonatal intensive-care unit nurse. Malignancies found in infants differ from those found in older children. Nursing care of the neonate suspected or diagnosed with a congenital malignancy includes standard practices and problem identification as well as interventions unique to the patient with cancer. This article reviews the incidence, diagnosis, treatment, and nursing management of neoplasms diagnosed in neonates.  相似文献   
75.
Duodenal ulcer     
In 1958 the Yale freshman class gave blood samples as part of a study intended to determine the predictive value of plasma pepsinogen (PP) for the subsequent development of duodenal ulcer (DU). We report a long-term follow-up of this cohort. A selfadministered questionnaire designed to ascertain information about the development of peptic ulcers, and the presence of risk factors was mailed to 861 subjects with active addresses. A second questionnaire was mailed to each respondent's physician(s) to verify the diagnosis of DU. Completed questionnaires were returned, after three mailings, by 604 (70%) of the subjects. They reported 18 documented DUs, 15 since 1958, for an incidence of 1.1/1000 person years. Only smoking (P<0.05) and undergraduate physical inactivity (P<0.01) were identified as risk factors for DU. Family history; blood type; blood antigen secretor status; ingestion of coffee, alcohol, milk, salicylates, soda, or tea; and COPD were not identified as risk factors for DU. Patients with DU had higher mean PP values than those who did not (391.6±99.6 vs 346.6±106.7, mean ±sd) but this was not statistically significant (P>0.05). The predictive value of an elevated PP(>450) for the development of DU was 7.9%, but a low or normal PP predicted the absence of a DU in 97.5% of subjects over a 22-year span. We conclude that in a selected population followed for 22 years there is a low incidence of DU, supporting the general belief that duodenal ulcer is declining, that smoking and undergraduate physical inactivity are risk factors for duodenal ulcer, and that a low or normal PP may be useful as a predictor for a low susceptibility to duodenal ulcer disease.Dr. J. Chuong acknowledges the support of the Robert Wood Johnson Clinical Scholar Program, and the Daland Fellowship in Clinical Medicine of the American Philosophical Society.  相似文献   
76.
77.
78.
79.
80.
Radioiodine labelled 17-iodo-heptadecanoic acid (IHA) is used for non-invasive study of myocardial metabolism in coronary heart disease and cardiomyopathy. Yet in the interpretation of in vivo myocardial tracer kinetics, it is controversial whether the intracellular degradation of IHA or the removal of iodide across cellular membranes is the rate-limiting step in iodide release from the myocardium. In five patients undergoing coronary sinus catheterization, a mixture of about 40 kBq of [123I] NaI was injected into the left coronary artery. During the following 15-min period, frequent blood samples were taken from the aorta and the coronary sinus. In the aqueous phase of the venous blood, 14CO2 and inorganic 131I appeared nearly in parallel, with a peak time of 4–5 min. Moreover, as shown by the AV difference, there was no significant back diffusion of IHA and no significant non-specific deiodination detectable over the period of observation. There was myocardial retention of inorganic iodide (123I) injected into the left coronary artery. The data strongly support the premise that lipid turnover through -oxidation is the rate-limiting step in the externally measured release of iodide after IHA injection, provided that recirculating inorganic radioactive iodide is corrected for. In addition, 15 volunteers were studied using [11C]palmitic acid and [123I]IHA using PET and dynamic planar camera scintigraphy with iodide correction. There was no significant difference between the mean values of the elimination half-times, and also no significant correlation between half-times of both fatty acids for single individuals.  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