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   1459篇
  免费   90篇
  国内免费   8篇
耳鼻咽喉   25篇
儿科学   81篇
妇产科学   108篇
基础医学   163篇
口腔科学   81篇
临床医学   136篇
内科学   319篇
皮肤病学   15篇
神经病学   74篇
特种医学   53篇
外科学   268篇
综合类   22篇
一般理论   1篇
预防医学   50篇
眼科学   29篇
药学   64篇
中国医学   2篇
肿瘤学   66篇
  2024年   3篇
  2023年   14篇
  2022年   16篇
  2021年   50篇
  2020年   24篇
  2019年   56篇
  2018年   42篇
  2017年   45篇
  2016年   67篇
  2015年   57篇
  2014年   57篇
  2013年   84篇
  2012年   105篇
  2011年   75篇
  2010年   53篇
  2009年   51篇
  2008年   93篇
  2007年   116篇
  2006年   101篇
  2005年   86篇
  2004年   47篇
  2003年   41篇
  2002年   47篇
  2001年   30篇
  2000年   19篇
  1999年   35篇
  1998年   10篇
  1996年   5篇
  1994年   5篇
  1993年   4篇
  1992年   13篇
  1991年   14篇
  1990年   10篇
  1989年   5篇
  1987年   6篇
  1986年   4篇
  1985年   3篇
  1984年   7篇
  1983年   3篇
  1980年   3篇
  1978年   4篇
  1976年   2篇
  1975年   2篇
  1974年   3篇
  1973年   7篇
  1972年   4篇
  1971年   6篇
  1970年   4篇
  1969年   3篇
  1968年   3篇
排序方式: 共有1557条查询结果,搜索用时 23 毫秒
11.
We examined the effect of a new xanthine derivative, HWA448, on antigen-induced bronchoconstriction in actively sensitized guinea pigs. Guinea pigs were sensitized by intraperitoneal injection of bovine serum albumin (BSA) on two occasions, separated by 10 days. Two weeks after the second injection, the animal was placed in a two-chambered whole body plethysmograph and specific airway resistance (SRaw) was monitored for 10 min after an aerosol inhalation of BSA. HWA448 prevented the increase in SRaw after challenge (at 5 and 20 mg/kg i.p.). Aminophylline also prevented the increase in SRaw at 20 mg/kg, but not at a 5-mg/kg dose. The concentration of HWA448, which produced 50% relaxation of the tracheal rings constricted with 0.1 mM of histamine, was 49.9 microM as compared with 18.2 microM in aminophylline. HWA448 has a protective effect on antigen-induced bronchoconstriction in guinea pigs and may be a useful agent in the therapy of bronchial asthma.  相似文献   
12.
A developmental bone substitute, composed of a chitosan-bonded hydroxyapatite paste and having various possible applications in medical and dental treatments, was evaluated with regard to its osteoconductive properties. Radiographic examination revealed that a bone-like irregular radiopacity appeared in the region of the embedded paste. This was judged histopathologically as the formation of bone tissue with chondral tissue. These data suggest that the paste has osteoconductive properties, and may, therefore, prove clinically useful as a bioactive bone substitute.  相似文献   
13.
Gynaecomastia in adolescents is a benign glandular proliferation of the male breast. Secondary causes of gynaecomastia in adolescents are relatively rare and may result from a wide variety of rare pathological conditions. Among these, klinefelter syndrome, complete androgen resistance, adrenal tumours and oestrogen-secreting testicular tumours, hypogonadism, hyperthyroidism, kidney disease and medications play a role in aetiology. The aim of our study is to review the demographic characteristics, hormone profile, aetiological characteristics of paediatric gynaecomastia patients admitted to a single center and to determine the frequency of pathological gynaecomastia. Forty-three male patients with gynaecomastia who applied to the paediatric endocrinology outpatient clinic were included in our study. Demographic characteristics, physical examination findings, hormone profile, breast ultrasonography and karyotype results of the patients were recorded. There were 43 male patients in our study. Thirty-six (83.7%) of the patients were pubertal gynaecomastia, 7 (16.2%) were pathological gynaecomastia. Three of the patients with pathological gynaecomastia were prepubertal gynaecomastia, 2 had klinefelter syndrome, 1 had hypergonadotropic hypogonadism after acute lymphoblastic leukaemia treatment and 1 had gynaecomastia after spirololactone use. Careful evaluation of patients with gynaecomastia is especially important in detecting pathological types. We reported the rare prepubertal gynaecomastia and klinefelter frequency in our study.  相似文献   
14.
We examined a major organ function during 3 h biventricular assisted circulation after acute myocardial infarction model in the pig. In left ventricular circulation, the outflow cannula was placed in the ascending aorta and an inflow cannula through the mitral valve in the left ventricle. A pump (pulsatile group, Zeon Medical, Inc., Tokyo, Japan and nonpulsatile group, Nikkiso HPM-15, Nikkiso, Inc., Tokyo, Japan) was connected to each cannula. In right ventricular circulation, the outflow cannula was placed in the pulmonary artery and an inflow cannula in the right ventricle. The right ventricular circulation was supported by a nonpulsatile pump (Nikkiso HPM-15). The items measured were the regional blood flows of the cortex and medulla in the kidney, white matter and gray mater in brain, and liver; renal arterial flow; carotid arterial flow; portal vein flow; common hepatic arterial flow; arterial ketone body ratio (AKBR); and lactate/pyrubic acid (L/P). In the pulsatile group, the renal cortical blood flow increased, and the medulla blood flow decreased. On the other hand, in the nonpulsatile group, both regional blood flows decreased. That means that in the pulsatile assisted group intrarenal redistribution improved rather than in the nonpulsatile assisted group. In addition the liver regional blood flow, AKBR, and L/P showed significant differences between the pulsatile and nonpulsatile groups. On the other hand, the white matter and gray matter regional blood flows and carotid arterial flow did not show significant differences between the groups. The results of our study indicated that pulsatile circulation produced superior circulation in the kidney and liver, and microcirculation on the cell level was superior as well in early treatment of acute heart failure.  相似文献   
15.
16.
17.
18.
19.
Abstract

A Wada procedure was performed on a bilingual seizure surgery candidate. Immediately after the injection of barbiturate into the right internal carotid artery the patient spontaneously switched from counting in English (the language he indicated that he used most often) to Spanish (the language he learned first). He named in Spanish spontaneously as well. After injection of the left ICA the patient exhibited a global aphasia, with no evidence for differential recovery of language as the aphasia cleared. These observations are discussed in relation to the hypothesis that a language learned later in life may be more likely to be bilaterally represented than the first language learned.  相似文献   
20.
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