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   439篇
  免费   19篇
  国内免费   29篇
耳鼻咽喉   2篇
儿科学   26篇
妇产科学   5篇
基础医学   35篇
口腔科学   11篇
临床医学   52篇
内科学   86篇
皮肤病学   15篇
神经病学   21篇
特种医学   59篇
外科学   48篇
综合类   59篇
预防医学   12篇
眼科学   2篇
药学   32篇
肿瘤学   22篇
  2022年   2篇
  2021年   4篇
  2019年   2篇
  2016年   4篇
  2015年   6篇
  2014年   12篇
  2013年   20篇
  2012年   10篇
  2011年   10篇
  2010年   20篇
  2009年   18篇
  2008年   19篇
  2007年   23篇
  2006年   27篇
  2005年   15篇
  2004年   12篇
  2003年   7篇
  2002年   6篇
  2001年   8篇
  2000年   7篇
  1999年   7篇
  1998年   29篇
  1997年   35篇
  1996年   30篇
  1995年   18篇
  1994年   13篇
  1993年   18篇
  1992年   5篇
  1990年   4篇
  1989年   11篇
  1988年   8篇
  1987年   10篇
  1986年   3篇
  1985年   13篇
  1984年   3篇
  1983年   4篇
  1982年   5篇
  1981年   7篇
  1980年   2篇
  1979年   2篇
  1978年   4篇
  1977年   2篇
  1975年   5篇
  1974年   3篇
  1973年   1篇
  1972年   2篇
  1971年   1篇
  1970年   3篇
  1969年   3篇
  1967年   1篇
排序方式: 共有487条查询结果,搜索用时 12 毫秒
61.
Persistent primitive sciatic artery   总被引:1,自引:0,他引:1  
  相似文献   
62.
We describe three cases of fetal intracranial teratoma diagnosed by ultrasound and review the literature. Sonographic features include cranial enlargement, gross distortion of normal cerebral architecture by a hyperechoic, multicystic mass, and polyhydramnios. Despite early diagnosis, the cesarean section rate is high and the overall prognosis is dismal.  相似文献   
63.
64.
The purpose of these studies was to determine the molecular basis of the phenotypic mosaicism that is a defining feature of paroxysmal nocturnal hemoglobinuria (PNH). Analysis of T cell clones from a female patient revealed four distinct phenotypes based on surface expression of glycosyl phosphatidylinositol-anchored proteins (GPI-AP). When PIG-A (the gene that is mutant in PNH) from these clones was analyzed, four discrete somatic mutations were identified. Analysis of X chromosomal inactivation among the abnormal T cell clones was consistent with polyclonality. Together, these studies demonstrate that the phenotypic mosaicism that is characteristic of PNH is a consequence of genotypic mosaicism and that, at least in this case, PNH is a polyclonal rather than a monoclonal disease. That four distinct somatic mutations were present in a single patient suggests that in conditions that predispose to PNH PIG-A may be hypermutable.  相似文献   
65.
SP Adler  ; MM McVoy 《Transfusion》1989,29(8):667-671
Antibody responses to cytomegalovirus (CMV) after red cell (RBC) transfusion were studied in 84 seropositive surgery patients and 82 seropositive oncology patients. The surgery patients were randomized to receive RBCs stored either 3 to 8 or 20 to 42 days after donation. Of 38 patients receiving RBCs stored 8 days or less, 3 developed a rise in titer (4-fold increase) of IgG antibody to CMV 8 to 12 weeks after transfusion. This rate of response (8%) did not differ significantly (p = 0.23) from that (16%) in the 46 patients receiving RBCs stored 20 to 42 days. Seropositive oncology patients were randomized to receive RBCs from seronegative or random donors. Five (19%) of 27 oncology patients receiving seronegative RBCs and 13 (23%) of 55 patients receiving random RBCs (mean, 2 seropositive RBC units/patient) developed a rise in titer of antibody to CMV. No CMV morbidity occurred in either patient group. For both patient groups, a rise in titer of antibody to CMV was associated with the number of transfused RBC units. These results confirm that CMV-seronegative RBCs are unnecessary for infrequently transfused seropositive patients. They also suggest that multiple transfusions of stored RBCs are as immunosuppressive as multiple transfusions of RBCs used within a few days after donation.  相似文献   
66.
67.
Carriage of nuclear dehydrogenating clostridia has been associated with colon cancer and implicated in its aetiology. This study has compared the carriage of these organisms in a British population at high risk for the development of colon cancer with a low risk Nigerian population. Clostridia were found in all of the stools from both populations. Nuclear dehydrogenating clostridia were only found in the stools of the British subjects (32%). These results support the suggestion that the carriage rate of nuclear dehydrogenating clostridia in a population is related to the risk of colon cancer.  相似文献   
68.
A combined experience of 37 cases of subacute hepatic failure encountered in five major gastroenterology centres over a period of ten years is discussed. Majority (65%) were males with average age of 38 years. Maximum (54%) were in 5th decade. Jaundice (100%), abdominal distention (38.7%), swelling feet (64%), fever (54%), abdominal pain (54%), exhaustion (78.3%) were the major presenting features. Jaundice and ascites were present in all cases. Pedal oedema (78.3%), hepatomegaly (54%), splenomegaly (32.4%) and encephalopathy (27%) were the other important clinical features. Hypoalbuminemia and prolonged prothrombin time were significant laboratory findings in addition to hyperbilirubinemia and elevated ALT and AST. Hbs Ag was detected in 46%. Major complications encountered were renal failure (48.7%), spontaneous bacterial peritonitis (43.2%), other infections (43.2%), encephalopathy (43.2%) and upper gastrointestinal bleed (22%). 54% died during stay in hospital. To conclude subacute hepatic failure is potentially fatal condition.KEY WORDS: Subacute hepatic failure, HBsAg, Jaundice  相似文献   
69.
Two hundred and twenty one cases of viperine envenomation, who presented to hospital without specific treatment, seen over an twenty five years period, have been presented. Mild, moderate and severe envenomation was encountered in 33 per cent, 47 per cent and 20 per cent respectively. Bites on feet and ankles were seen in 85.5 per cent of cases. The average time interval between bite and hospitalisation was 4.8 hours, range being 15 minutes to 7 days. Local swelling was observed in 97.7 per cent, hematuria in 62 per cent, mucosal haemorrhages in 24.8 per cent and haematemesis in 19 per cent of patients. Average Antisnake Venom (ASV) required in mild, moderate and severe envenomation was 50 ml, 147.5 ml and 324 ml respectively. Major complications observed were renal failure in 10, intracompartmental syndrome in 3, intracerebral bleed and septicaemia in 2 each. One patient each developed finger gangrene, osteomyelitis, perirenal haematoma, sinus bradycardia and uncontrolled bleeding. Blood transfusion was required in 32 patients. Reactions to ASV were seen in 12 patients and overall there were 5 deaths.KEY WORDS: Antisnake venom, Viperine envenomation  相似文献   
70.
Background: Obesity/overweight is a recognized risk factor for a host of disorders. The disease risk stratification is commonly based on the Quetelets Index (Body Mass Index-BMI), a surrogate measure of fatness. The currently used BMI cut-offs to classify people as overweight or obese in Armed Forces have been defined in studies on Caucasian populations. However, because of differences in body structure and composition in different ethnic, socioeconomic, cultural and regional groups the correspondence between BMI and body fat content varies between populations. We conducted this pilot study in the Indian Navy to define BMI cut-offs for overweight and obesity using body fat content derived from Skin Fold Thickness as the standard.  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