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   1736222篇
  免费   137282篇
  国内免费   3080篇
耳鼻咽喉   23909篇
儿科学   56862篇
妇产科学   49405篇
基础医学   245833篇
口腔科学   52229篇
临床医学   149828篇
内科学   346942篇
皮肤病学   38466篇
神经病学   141060篇
特种医学   67663篇
外国民族医学   476篇
外科学   259364篇
综合类   40592篇
现状与发展   3篇
一般理论   587篇
预防医学   136511篇
眼科学   39433篇
药学   130844篇
  3篇
中国医学   3690篇
肿瘤学   92884篇
  2018年   19821篇
  2017年   14676篇
  2016年   15811篇
  2015年   18306篇
  2014年   25071篇
  2013年   37572篇
  2012年   52331篇
  2011年   55219篇
  2010年   31853篇
  2009年   29614篇
  2008年   51029篇
  2007年   53652篇
  2006年   53807篇
  2005年   52398篇
  2004年   50875篇
  2003年   48393篇
  2002年   47101篇
  2001年   78814篇
  2000年   81840篇
  1999年   69182篇
  1998年   18427篇
  1997年   16871篇
  1996年   16753篇
  1995年   16426篇
  1994年   15389篇
  1993年   14486篇
  1992年   56484篇
  1991年   54653篇
  1990年   53390篇
  1989年   51517篇
  1988年   47839篇
  1987年   47121篇
  1986年   44849篇
  1985年   43320篇
  1984年   32366篇
  1983年   27876篇
  1982年   16336篇
  1981年   14630篇
  1979年   30818篇
  1978年   21319篇
  1977年   17942篇
  1976年   16878篇
  1975年   17824篇
  1974年   21792篇
  1973年   20982篇
  1972年   19116篇
  1971年   18060篇
  1970年   16566篇
  1969年   15555篇
  1968年   14210篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
991.
A case of Ewing's tumour of rib presenting as chest mass is reported. The role of computed tomography and chest ultrasound in evaluating such patients is discussed along with a brief review of literature.  相似文献   
992.
993.
Histological sections of brain from patients showing evidence of advanced pathology of Alzheimer disease (AD) were examined for the presence of herpes simplex type-1 (HSV-1) nucleic acids by a sensitive in-situ hybridization technique. Samples from neurologically normal patients were examined in parallel. Sensitivity of the assay was verified by the detection of HSV-1 nucleic acids in neurons of trigeminal ganglia taken from cases of AD and normal controls. This indicated that the hybridization reaction was sufficiently sensitive to detect latent HSV-1 infections. Positive hybridization in the brain was only detected in a confirmed case of herpes simplex virus encephalitis. These results appear to confirm previous reports that HSV-1 infection is not directly involved in the pathology associated with AD.  相似文献   
994.
Apexcardiography was employed to make a noninvasive assessment of left ventricular diastolic function in 80 patients with extensive myocardial infarction. In half the patients, there were impairments in cardiac diastole as manifested by its altered phase structure and some changed parameters indirectly indicating a rise in left ventricular end diastolic pressure and a fall in myocardial relation rates and diastolic compliance. Prior 10-day administration of tocopherol and nicotinamide to 45 patients caused a decrease in the severity of diastolic abnormalities in those in whom the latter had been abnormal. The use of membrane protectors resulted in lower incidence of complications and improved outcome of the disease.  相似文献   
995.
Despite extensive investigation, the pathogenesis of the adult respiratory distress syndrome (ARDS) remains uncertain. As yet, there is no clear explanation of why some patients at risk for ARDS develop the syndrome, whereas others do not. Neutrophils and complement fragments have been implicated in the acute lung injury, but it is clear from published data that evidence of complement activation alone predicts neither the development nor the severity of ARDS. We investigated whether the combination of endotoxin, a leukocyte-priming agent, and complement fragments, leukocyte-stimulating agents, was associated with the development of ARDS. Ninety-eight patients were identified as being either at risk for the development of ARDS or having ARDS, and serial blood samples were obtained. There was no correlation between C5 fragments and the development of ARDS. C3 fragment levels were increased in 89% of the patients with ARDS, but they were also increased in 62% of patients at risk. Endotoxin was detected in 74% of the plasma samples obtained from patients at risk who subsequent developed ARDS and in 64% of the plasma samples obtained from the patients with ARDS. In contrast, only 22% of the plasma samples obtained from the patients at risk who did not develop ARDS had measurable endotoxin. We suggest that the combination of endotoxin and complement fragments may be one mechanism involved in the development of ARDS.  相似文献   
996.
In 422 patients admitted from the emergency department (ED) for suspected acute myocardial infarction, the hypothesis that chest pain that persists on arrival in the ED or recurs during the initial ED evaluation is a useful predictor of acute myocardial infarction (AMI) and complications of coronary ischemia was tested. Compared with patients whose chest pain spontaneously ceased before arrival in the ED, patients whose chest pain persisted or recurred during the initial ED evaluation had a 2.3 times greater risk of interventions (P less than .001), a 1.7 times greater risk of complications (P = .045), a 3.8 times greater risk of life-threatening complications (P = .04), and a 2.4 times greater risk of AMI (P = .005). A third group of patients with suspected AMI never experienced chest pain. This group of patients who never experienced chest pain had a three times higher risk of death (P = .02) compared with patients whose chest pain persisted or recurred in the ED, and a 2.1 times greater risk of intervention (P = .01), a 5.2 times greater risk of life-threatening complication (P = .015), and a 7.9 times greater risk of death (P = .025) compared with patients whose chest pain resolved before arrival in the ED. It was concluded that patients with chest pain that resolves spontaneously before arrival to the ED have a better in-hospital prognosis than any other group.  相似文献   
997.
998.
G Rao  H R Madoff 《Chest》1989,95(1):244-245
A 64-year-old woman presented in shock. The computed tomography (CT) scan confirmed rupture of the left diaphragm with strangulation. Three days after surgery, the patient developed herniation of abdominal contents on the right side with cardiorespiratory collapse. Marlex mesh was used to repair on the right side. Postoperatively, she needed partial gastrectomy for massive duodenal ulcer bleeding. A dual chamber pacemaker was used to correct the complete heart block.  相似文献   
999.
A 37-year-old woman receiving long-term hemodialysis was admitted to the hospital with a fever of unknown origin (6 weeks of unexplained, persistent, low-grade fever). Although she had received vancomycin hydrochloride 5 days before the onset of fever, the drug was not suspected as the cause because of the duration of fever, the administration of vancomycin on prior occasions without incident, and the lack of allergic stigmata. After hospitalization, vancomycin and gentamicin sulfate were administered empirically. Immediately thereafter, her temperature rose to 40 degrees C, and over the ensuing 24 hours, eosinophilia and a maculopapular rash developed that resolved entirely when antibiotic therapy was stopped and low-dose steroid therapy was instituted. The prolonged hypersensitivity reaction after a single dose of vancomycin is consistent with the greatly extended half-life of this drug in the population with end-stage renal disease and should alert physicians to the possibility of such persistent idiosyncratic reactions in this group.  相似文献   
1000.
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