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   4436篇
  免费   221篇
  国内免费   27篇
耳鼻咽喉   68篇
儿科学   84篇
妇产科学   54篇
基础医学   604篇
口腔科学   91篇
临床医学   268篇
内科学   1025篇
皮肤病学   170篇
神经病学   267篇
特种医学   126篇
外科学   908篇
综合类   9篇
预防医学   82篇
眼科学   33篇
药学   330篇
中国医学   6篇
肿瘤学   559篇
  2023年   32篇
  2022年   46篇
  2021年   90篇
  2020年   38篇
  2019年   75篇
  2018年   97篇
  2017年   74篇
  2016年   78篇
  2015年   105篇
  2014年   104篇
  2013年   161篇
  2012年   253篇
  2011年   251篇
  2010年   175篇
  2009年   143篇
  2008年   278篇
  2007年   277篇
  2006年   303篇
  2005年   354篇
  2004年   332篇
  2003年   284篇
  2002年   344篇
  2001年   51篇
  2000年   41篇
  1999年   74篇
  1998年   102篇
  1997年   75篇
  1996年   70篇
  1995年   51篇
  1994年   39篇
  1993年   42篇
  1992年   21篇
  1991年   27篇
  1990年   13篇
  1989年   16篇
  1988年   16篇
  1987年   13篇
  1986年   11篇
  1985年   14篇
  1984年   9篇
  1983年   20篇
  1982年   12篇
  1981年   18篇
  1980年   8篇
  1979年   7篇
  1978年   7篇
  1973年   3篇
  1971年   4篇
  1969年   3篇
  1964年   4篇
排序方式: 共有4684条查询结果,搜索用时 0 毫秒
51.
Summary Postmortem coronary angiography was performed in 20 beagles and 15 mongrels, and the origin and distribution of the sinus node arteries (SNAs) were subsequently investigated using soft X-ray radiography, the tissue clearing method, and histological examination. In 19 of 20 beagles, the SNAs consisted of a single atrial branch originating from the right coronary artery, and the distribution pattern of the atrial branch seemed to be uniform. In contrast, the following three different patterns were recognized in the atrial branches forming the SNAs of mongrels: (1) distribution by two atrial branches, i.e., one originating from the right coronary artery and the other from the left circumflex artery, (2) dual distribution by two atrial branches originating from the right coronary artery, and (3) distribution by a single atrial branch originating from the right coronary artery or from the left circumflex artery. In 26 of the 30 dogs which were histologically examined, the SNAs ran outside of the sinus node and were not centrally located. In the beagles, the proximal atrial branch from the right coronary artery reached the atrioventricuolar node area and supplied blood to the atrioventricular node together with the arterial branches derived from the anterior septal artery and posterior septal artery. In addition, the arterial branch of the SNAs reached the atrioventricular junction area. These findings should contribute to clinical, pharmacological, and pathological studies of the cardiovascular system, including studies on cardiac arrhythmias in beagles.  相似文献   
52.
Plasmapheresis for the treatment of hypertriglyceridemia has previously been performed in patients with sudden onset severe hypertriglyceridemia and acute pancreatitis; however, only a few reports of this procedure have been published. We report here on a case showing severe hypertriglyceridemia during asparaginase (Asp) treatment for acute lymphocytic leukemia (ALL), and give an overview of a lipid‐lowering apheresis therapy. To prevent the complication of pancreatitis due to hypertriglyceridemia, we performed plasma exchange (PE) three times using fresh frozen plasma. PE remarkably reduced both serum triglyceride and total cholesterol levels from 5430 mg/dL to 403 mg/dL and from 623 mg/dL to 204 mg/dL, respectively. The causes of severe hyperlipidemia in this patient were considered to include: the Asp treatment for ALL, and a genetic background with a heterozygote of familial lipoprotein lipase (LPL) defect syndrome, because the patient's plasma LPL level after intravenous heparin injection was low at 137 ng/mL. Hence, PE using fresh frozen plasma may be useful not only to remove lipoproteins, but also to supply defective factors, such as LPL, in similar cases.  相似文献   
53.
Incidence of human parvovirus B19 DNA detection in blood donors   总被引:2,自引:0,他引:2  
Summary. 1000 serum samples from blood donors were tested for human parvovirus B19 (B19) DNA by a nested PCR assay: six samples were positive for B19 DNA. The frequency was 1/167 (0-6%), considerably higher than previous surveys (0-004-0-03%). Five of the six samples were also positive for anti-B19 IgM, indicating an acute phase of infection. It is recommended to screen for B19 DNA in blood products to prevent transfusion mediated viral infection for those susceptible such as immunocompromised patients and pregnant women.  相似文献   
54.
Summary While mural thrombus accompanied by an abdominal aortic aneurysm (AAA) is not rare, the growth rate of such a thrombus has not yet been adequately documented. We present here a very rare case of a 62-year-old female patient with an AAA in whom the mural thrombus in the aneurysm grew very rapidly over a short period. We could follow the growth of the mural thrombus in the AAA by two-dimensional (2-D) abdominal echography. Patients with an AAA must be closely monitored by this technique which is able to detect the presence of the thrombus and allow evaluation of its growth.  相似文献   
55.
OBJECTIVES: This study evaluated the sensitivity and the related factors in iodine-123-beta-methyl-p-iodophenyl-pentadecanoic acid (BMIPP) scintigraphy to detect stable angina. METHODS: The subjects were 198 patients with stable angina who underwent BMIPP before percutaneous coronary intervention or coronary bypass graft surgery. Patients with unstable angina, myocardial infarction, congestive heart failure, cardiomyopathy and vasospastic angina were excluded. After investigation of the sensitivity of BMIPP, the patients with single-vessel disease without collateral flow were classified into the normal (123)I-BMIPP uptake group (normal group)or decreased (123)I-BMIPP uptake group (decreased group), and various factors were compared between the two groups. RESULTS: Sensitivity was 61% overall, 58% in single-vessel disease, 69% in double-vessel disease, 53% in triple-vessel disease, 43% in only left main vessel disease, and 89% in left main and other vessel disease (NS). In single-vessel disease, the sensitivity was 40% in 75% coronary artery stenosis, 58% in 90% stenosis, 89% in 99% stenosis, and 69% in total occlusion (p = 0.003). Comparing the deoreased and normal groups, diabetes mellitus was more frequent in the normal group (14.6% vs 39.5%), minimal lumen diameter was smaller (0.75 +/- 0.37 vs 0.98 +/- 0.49 mm) and lesion length was longer in the decreased group (15.4 +/- 4.9 vs 11.6 +/- 5.5 mm). Logistic multivariate analysis showed that the independent factors were diabetes mellitus [odds ratio 0.20, 95% confidence interval (CI) 0.04-0.87, p = 0.03], minimal lumen diameter (odds ratio 0.10, 95% CI 0.02-0.48, p = 0.003) and lesion length (odds ratio 1.12, 95% CI 1.00-1.25, p = 0.03). CONCLUSIONS: BMIPP is useful in stable angina patients because of the acceptable sensitivity. Diabetes mellitus, minimal lumen diameter and lesion length were independent factors associated with decreased BMIPP uptake.  相似文献   
56.
This report describes a patient with a single coronary artery in whom the right coronary artery originated from the distal left circumflex artery. Single coronary artery is a rare congenital anomaly of the coronary circulation which is often associated with other congenital cardiac malformations. This anomaly is thought to be clinically significant especially in patients with atrial fibrillation, although no other associated cardiac anomaly was detected.  相似文献   
57.
A case of 22 mm hypervascular nodule in segment two of the liver but without hepatitis B or C virus infection in a 32-year-old Japanese woman with a history of alcohol abuse is presented. Imaging studies such as contrast-enhanced ultrasound, computed tomography and magnetic resonance imaging showed hypervascularity in the early phase and venous washout in the late phase. Histologically, stellate scar-like fibrous septa, pericellular fibrosis, fatty change, neutrophilic infiltration, slight increase of cell density, and diffuse capillarization of the sinusoids together with small unpaired arteries were observed. The nodule was diagnosed as focal nodular hyperplasia-like lesion in alcoholic liver cirrhosis.  相似文献   
58.
59.
60.
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