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   264364篇
  免费   10196篇
  国内免费   167篇
耳鼻咽喉   2420篇
儿科学   9368篇
妇产科学   4957篇
基础医学   29229篇
口腔科学   3746篇
临床医学   23284篇
内科学   47207篇
皮肤病学   2142篇
神经病学   23482篇
特种医学   11867篇
外国民族医学   10篇
外科学   40746篇
综合类   4248篇
一般理论   71篇
预防医学   28220篇
眼科学   4675篇
药学   16782篇
  1篇
中国医学   713篇
肿瘤学   21559篇
  2021年   1226篇
  2020年   839篇
  2019年   1283篇
  2018年   23267篇
  2017年   18353篇
  2016年   20628篇
  2015年   2280篇
  2014年   2595篇
  2013年   3555篇
  2012年   10654篇
  2011年   24953篇
  2010年   20831篇
  2009年   13519篇
  2008年   22848篇
  2007年   25339篇
  2006年   4259篇
  2005年   5930篇
  2004年   6874篇
  2003年   7585篇
  2002年   5666篇
  2001年   3254篇
  2000年   3500篇
  1999年   2881篇
  1998年   1362篇
  1997年   1147篇
  1996年   1025篇
  1995年   977篇
  1994年   982篇
  1993年   880篇
  1992年   2321篇
  1991年   2288篇
  1990年   2184篇
  1989年   2100篇
  1988年   1985篇
  1987年   1980篇
  1986年   1881篇
  1985年   1859篇
  1984年   1543篇
  1983年   1374篇
  1982年   953篇
  1981年   794篇
  1980年   746篇
  1979年   1338篇
  1978年   962篇
  1977年   838篇
  1976年   792篇
  1975年   788篇
  1974年   963篇
  1973年   842篇
  1972年   801篇
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
71.
72.

Background  

The fibromyalgia syndrome (FMS) is suggested to be a manifestation of depression or affective spectrum disorder. We measured the cognitive style of patients with FMS to assess personality styles in 44 patients with fibromyalgia syndrome (FMS) by comparing them with 43 patients with major depressive disorder (MDD) and 41 healthy controls (HC).  相似文献   
73.
74.
Hollingworth described chewing gum as ‘a technique of relaxation’. Recent research has examined this issue and there is evidence that chewing gum can prevent the adverse effects of acute stress. There are also plausible biological mechanisms that could explain such effects. It is now important to examine chewing gum and chronic stress and the present study involved a survey of this topic. The survey covered the ‘stress process’, collecting data on exposure to stressful events, levels of perceived stress and health outcomes. Frequency of chewing gum was also recorded. Potential confounding factors (demographics, personality and health-related behaviours) were also recorded. The web-based survey was completed by a community sample of 2,248 full-time workers (68% female. Mean age: 35 years, range 18–74 years). Sixty-one per cent of the sample were gum chewers. The results showed that chewing gum was associated with lower levels of perceived stress (both at work and life in general). Gum chewers were also less likely to be depressed and to have seen their doctor for high blood pressure or high cholesterol. Chewing gum was associated with lower levels of alcohol consumption and with cigarette smoking. Gum chewers were also more likely to be neurotic extraverts. Those who chewed gum were also more likely to be exposed to negative factors at work. Logistic regression analyses showed that the effects of chewing gum on stress and health remained significant when these confounding factors were controlled for. These results suggest that chewing gum may be a simple way of preventing stress and the negative health outcomes that are often associated with it. Intervention studies are now required and the mechanisms underlying the effects reported here need further investigation. Copyright © 2009 John Wiley & Sons, Ltd.  相似文献   
75.
76.
77.
Introduction Choroid plexus cysts can lead to isolation of the lateral ventricles and distension of the third ventricle. We present an ultrasonographic video documentation of an infant with variably shaped and localized choroid plexus cyst of the third ventricle. Case report An infant had periods of increased intracranial pressure with changing dilatation of the first to third ventricle. Cerebral ultrasonography of the not crying boy demonstrated a choroid plexus cyst limply hanging down from the roof of the third ventricle to the beginning of the aqueduct of Sylvius. During crying, the cyst prolapsed from the third into left lateral ventricle and was strangled by the foramen of Monro. Endoscopic cyst fenestration and third ventriculostomy continuously solved the problem of intermittent hydrocephalus occlusus. Conclusion Depending not only on localization and size but also on cyst form and cerebrospinal fluid pressure, a single choroid plexus cyst can cause various obstructions of cerebrospinal fluid pathways.  相似文献   
78.
Introduction Iniencephaly, a neural tube defect involving occiput and inion and combined with rachischisis of the cervical, thoracic spine, and retroflexion position of the head is a very rare congenital abnormality of the fetus–newborn with a 0.1–10 of 10,000 prevalence. This abnormality’s prognosis is thought to be dismal. This abnormality can be associated with other abnormalities such as anencephaly, encephalocele, hydrocephalus, cyclopia, absence of the mandible, cleft lip and palate, cardiovascular disorders, diaphragmatic hernia, renal abnormalities, overgrowth of the arms compared to the legs, and club food and gastrointestinal atresia. Discussion Most of the patients are dead born, and the others die in a few hours. There are only six previously documented long-term survivors. In our case, our patient with iniencephalic signs and findings is still living. She is 2 years old now. We think that this patient presents a mild form of iniencephaly.  相似文献   
79.
Background and aims Since the introduction of endovascular aortic aneurysm repair (EVAR) for aortic aneurysms, the number of juxtarenal aortic aneurysms (JRA) has been growing steadily due to selection bias (neck morphology for EVAR). This case-match study compares the perioperative outcome and midterm results of suprarenally clamped JRA with infrarenal aortic aneurysms (AAA). Methods From 1997 to 2004, patients who received open surgery with suprarenal clamping for JRA were included in the study and compared to matched patients with infrarenal clamping (AAA). Measurements analyzed were the in-hospital mortality and morbidity. Midterm results were obtained through clinical investigation and magnetic resonance angiography imaging. Results Thirty-five patients (mean age, 68.4 years; 30 male and 5 female) received suprarenal cross-clamping for JRA. The overall in-hospital mortality for JRA and for the controls (AAA) with elective aortic repair was 4.5% (6.1% JRA; 3% AAA, p = 0.058). The morbidity of JRA was elevated according to the rate of pulmonary complications (p = 0.021) and the need for re-operation (p = 0.019). The mean follow-up time was 2.3 years (range, 8–96 months). At follow-up, 28 patients (80%) from the JRA group and 29 patients from the AAA group (82.9%) were alive. Conclusion Open aortic surgery for JRA with the need for suprarenal cross-clamping shows a slightly elevated in-hospital mortality rate without statistical significance and equal midterm mortality results in comparison with infrarenally clamped aortic aneurysms.  相似文献   
80.

Background  

Liver transplantation in presence of diffuse portal vein thrombosis is possible by using caval blood as portal inflow, through cavo-portal transposition. However, clinical results are heterogeneous and experimental studies are needed, but similar hemodynamic conditions are difficult to obtain, especially in small animals. Herein we describe a new simple model of cavo-portal transposition in rat.  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