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   11087篇
  免费   569篇
  国内免费   105篇
耳鼻咽喉   103篇
儿科学   255篇
妇产科学   109篇
基础医学   1065篇
口腔科学   160篇
临床医学   775篇
内科学   3068篇
皮肤病学   151篇
神经病学   662篇
特种医学   401篇
外科学   2236篇
综合类   61篇
预防医学   261篇
眼科学   151篇
药学   714篇
中国医学   17篇
肿瘤学   1572篇
  2023年   87篇
  2022年   174篇
  2021年   301篇
  2020年   188篇
  2019年   234篇
  2018年   277篇
  2017年   245篇
  2016年   284篇
  2015年   311篇
  2014年   367篇
  2013年   440篇
  2012年   734篇
  2011年   765篇
  2010年   450篇
  2009年   367篇
  2008年   610篇
  2007年   653篇
  2006年   679篇
  2005年   689篇
  2004年   658篇
  2003年   656篇
  2002年   648篇
  2001年   176篇
  2000年   162篇
  1999年   182篇
  1998年   117篇
  1997年   98篇
  1996年   94篇
  1995年   81篇
  1994年   86篇
  1993年   71篇
  1992年   82篇
  1991年   103篇
  1990年   68篇
  1989年   87篇
  1988年   89篇
  1987年   57篇
  1986年   52篇
  1985年   38篇
  1984年   34篇
  1983年   37篇
  1982年   16篇
  1980年   14篇
  1979年   36篇
  1978年   14篇
  1975年   9篇
  1973年   13篇
  1971年   17篇
  1969年   16篇
  1966年   17篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
101.
Brain natriuretic peptide (BNP) is a novel peptide that has actions similar to atrial natriuretic peptide (ANP). The present study investigated BNP localization in the heart, ANP and BNP contents in several organs, and ANP and BNP clearance through these organs. In the morphological study, it was shown that porcine BNP-like immunoreactivity was mainly distributed in the granules of the atrium. The content of porcine BNP-like immunoreactivity in the atrium was extremely high, about 100-fold greater than in the ventricle. From the determination of porcine BNP and ANP contents of such organs as the heart, kidney and liver and also plasma, it was shown that porcine BNP concentration was approximately one order of magnitude lower than that of ANP, and clearance rates of ANP and porcine BNP from these organs were similar and not significantly different between the organs. These results suggest that the modes of secretion and degradation of porcine BNP are not the same as those of ANP.  相似文献   
102.
Corynebacterium propinquum, which is included in Corynebacterium group ANF-3, exists as a commensal in the oral flora. This organism has not yet been fully recognized as a respiratory pathogen. We previously reported that the first case with respiratory infection caused by C. propinquum. On the other hand, Corynebacterium pseudodiphtheriticum is recognized as a causative organism in respiratory infections. Recently we experienced two cases with C. propinquum respiratory infections in our hospital. Three types of the onset such as a community-acquired infection, a hospital-acquired infection, and a nursing home acquired infections were observed. Our analysis indicated that gram staining of the purulent sputum is an essential tool to evaluate whether C. propinquum is a respiratory pathogen or not, because this organism is a commensal bacteria.  相似文献   
103.
104.
Animal studies suggest that some angiotensin converting enzyme inhibitors augment endothelium-dependent vasorelaxation. We aimed to determine if captopril augments endothelium-dependent vasodilation in middle-aged hypertensive patients. By using strain-gauge plethysmography, forearm vasodilation evoked with intra-arterial acetylcholine (4, 8, 16, and 24 micrograms/min) or nitroprusside (0.2, 0.4, 0.8, and 1.2 micrograms/min) was examined before and after captopril administration (25 mg per os). Before captopril, forearm vasodilation with acetylcholine was less in hypertensive patients (n = 12) than in age-matched (n = 7) or young (n = 7) normotensive subjects, but forearm vasodilation with nitroprusside did not differ among the three groups. Captopril improved forearm vasodilation in hypertensive patients (n = 7) with acetylcholine but nitroprusside did not. In contrast, nifedipine (10 mg per os) did not alter forearm vasodilation with acetylcholine or nitroprusside in hypertensive patients (n = 5). The decreases in mean blood pressure caused by captopril and nifedipine in hypertensive subjects were comparable. Captopril did not alter forearm vasodilation with acetylcholine or nitroprusside in young normotensive subjects (n = 7). These results suggest that captopril in hypertensive patients may acutely improve impaired endothelium-dependent forearm vasodilation that does not result from reduction in blood pressure per se.  相似文献   
105.
106.
Summary 1255 cases of leukemia-lymphoma were tested between 1972 and 1984 by multiple marker analysis. Routine leukemia phenotyping was performed using standard morphological and cytochemical techniques in combination with clinical and histo-pathological information; the main emphasis was put on immunological surface marker analysis using erythrocyte rosette assays, TdT and a large panel of poly- and monoclonal antibody tests. The 1255 cases were divided into these major types and subtypes: 349 cases of ALL and related immature T- and Burkitt-lymphomas (cALL, pre B-ALL, B-ALL and Burkitt-lymphomas, T-ALL and immature, mostly leukemic T-lymphomas, Null-ALL), 454 cases of mature T- and B-cell malignancies (T-CLL, mycosis fungoides, Sezary-syndrome, T-lymphomas, B-CLL, hairy cell leukemia, multiple myeloma, B-lymphomas), 263 cases of acute myeloid leukemias (AML, AMMoL/AMoL), 182 cases of chronic myeloid leukemias (CML in chronic phase, CMoL, CML in blast crisis), 6 cases of erythroleukemia and 1 case of megakaryoblastic leukemia. A simplified classification scheme which has been used in our laboratories is presented. Phenotyping is of diagnostic, prognostic and therapeutic relevance, most evidently for patients with ALL. Routine leukemia phenotyping should be performed with highly standardized techniques and reagents and by combining information from several fields in the multiple marker analysis. New areas of leukemia research might become very useful for the routine procedure of phenotyping.Abbreviations ALL acute lymphoblastic leukemia - AML acute myeloblastic leukemia - AMMoL acute myelomonoblastic leukemia - AMoL acute monoblastic leukemia - cALL common ALL - CLL chronic lymphocytic leukemia - CML chronic myelocytic leukemia - CML-BC CML in blastic crisis - CMoL chronic monocytic leukemia  相似文献   
107.
108.
An orally effective, nonpeptide vasopressin V1 receptor antagonist, OPC-21268 was produced for possible human use. We investigated the effects of OPC-21268 on the vascular effects of intra-arterially infused arginine vasopressin in human forearm vessels. The brachial artery was cannulated for drug infusions and direct measurement of arterial pressure. Forearm blood flow was measured by a strain gauge plethysmograph, and forearm vascular resistance was calculated. Arginine vasopressin was infused intra-arterially at doses of 0.02, 0.06, 0.09, 0.2, 0.6, and 1.2 ng/kg/min. The lower doses of arginine vasopressin increased, whereas the higher doses of arginine vasopressin decreased forearm vascular resistance (p less than 0.01). Intra-arterial infusion of phenylephrine at doses of 0.2, 0.4, and 2.4 micrograms/min increased forearm vascular resistance dose-dependently (p less than 0.01). OPC-21268 (50 mg for two, 100 mg for six, and 200 mg for two subjects) given orally did not alter resting arterial pressure, forearm vascular resistance, or heart rate. OPC-21268 decreased vasoconstrictor responses to arginine vasopressin at doses of 0.02 (p less than 0.02) and 0.09 (p less than 0.05) ng/kg/min and augmented vasodilator responses to arginine vasopressin at a dose of 1.2 ng/kg/min (p less than 0.01). However, the vasoconstrictor responses to phenylephrine were not altered by OPC-21268. These results demonstrated that OPC-21268 effectively and specifically antagonized the V1 receptor-mediated vasoconstriction in human forearm resistance vessels. These results suggest that OPC-21268 may be useful therapeutically to antagonize the vasoconstriction caused by arginine vasopressin in some pathological states.  相似文献   
109.
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