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   198066篇
  免费   2874篇
  国内免费   1744篇
耳鼻咽喉   1359篇
儿科学   6925篇
妇产科学   3322篇
基础医学   19447篇
口腔科学   1966篇
临床医学   15337篇
内科学   34495篇
皮肤病学   941篇
神经病学   17671篇
特种医学   9618篇
外国民族医学   15篇
外科学   31292篇
综合类   5691篇
现状与发展   6篇
一般理论   2篇
预防医学   19513篇
眼科学   3291篇
药学   11789篇
  13篇
中国医学   1622篇
肿瘤学   18369篇
  2024年   62篇
  2023年   318篇
  2022年   773篇
  2021年   1029篇
  2020年   812篇
  2019年   693篇
  2018年   22619篇
  2017年   17970篇
  2016年   20095篇
  2015年   1849篇
  2014年   2050篇
  2013年   1781篇
  2012年   8573篇
  2011年   22617篇
  2010年   19752篇
  2009年   12309篇
  2008年   20627篇
  2007年   22789篇
  2006年   1686篇
  2005年   3419篇
  2004年   4081篇
  2003年   5053篇
  2002年   3117篇
  2001年   840篇
  2000年   1099篇
  1999年   868篇
  1998年   642篇
  1997年   650篇
  1996年   430篇
  1995年   435篇
  1994年   354篇
  1993年   249篇
  1992年   343篇
  1991年   335篇
  1990年   363篇
  1989年   312篇
  1988年   246篇
  1987年   210篇
  1986年   167篇
  1985年   181篇
  1984年   76篇
  1983年   79篇
  1982年   47篇
  1981年   34篇
  1980年   49篇
  1974年   39篇
  1969年   33篇
  1938年   60篇
  1932年   56篇
  1930年   46篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
101.
102.
103.
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   
104.
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   
105.

Background  

Ankylosing spondylitis is a chronic inflammatory rheumatic disorder which usually begins in early adulthood. The diagnosis is often delayed by many years. MR imaging has become the preferred imaging method for detection of early inflammation of the axial skeleton in ankylosing spondylitis.  相似文献   
106.
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   
107.
Background To our best knowledge, Panton–Valentine leucocidin (PVL)-positive methicillin-sensitive Staphylococcus aureus (MSSA) has not been described yet as cause for severe pyomyositis. Case report We present a 23-year-old apparently healthy male patient without any typical predisposing findings who developed severe pyomyositis secondary to an operated pilonidal cyst. In the follow-up, the patient showed signs of immunocompromisation. The causative agent for purulent infection of multiple muscles was a MSSA strain harbouring PVL toxin. Results In the reported case, aggressive antibiotic and surgical treatment with additional application of immunoglobulins has lead to recovery from the disease without relapse. Conclusions PVL-positive S. aureus are associated with skin diseases, multiple abscesses and often complicated by severe sepsis and necrotising pneumonia. Under such circumstances, the mortality rate can reach up to 75%. In addition, the PVL toxin can cause immunocompromisation and might be therefore involved in the aetiology of pyomyositis. Aggressive antibiotic and surgical treatment with additional application of immunoglobulins is recommended for treatment.  相似文献   
108.

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   
109.

Background  

Health service policy in the United Kingdom emphasises the importance of self-care by patients with chronic conditions. Written information for patients about their condition is seen as an important aid to help patients look after themselves. From a discourse analysis perspective written texts such as patient information leaflets do not simply describe the reality of a medical condition and its management but by drawing on some sorts of knowledge and evidence rather than others help construct the reality of that condition. This study explored patient information leaflets on osteoarthritis (OA) to see how OA was constructed and to consider the implications for self-care.  相似文献   
110.
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