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   245661篇
  免费   21158篇
  国内免费   14629篇
耳鼻咽喉   2216篇
儿科学   3095篇
妇产科学   4905篇
基础医学   28641篇
口腔科学   4276篇
临床医学   31485篇
内科学   40212篇
皮肤病学   2870篇
神经病学   13661篇
特种医学   8641篇
外国民族医学   100篇
外科学   26982篇
综合类   34916篇
现状与发展   49篇
一般理论   45篇
预防医学   15327篇
眼科学   6726篇
药学   24782篇
  190篇
中国医学   11267篇
肿瘤学   21062篇
  2024年   790篇
  2023年   3676篇
  2022年   9228篇
  2021年   12029篇
  2020年   8826篇
  2019年   7894篇
  2018年   8269篇
  2017年   7228篇
  2016年   6851篇
  2015年   10342篇
  2014年   12988篇
  2013年   12113篇
  2012年   17784篇
  2011年   19413篇
  2010年   11847篇
  2009年   9455篇
  2008年   12830篇
  2007年   12857篇
  2006年   12392篇
  2005年   12466篇
  2004年   8613篇
  2003年   7643篇
  2002年   6611篇
  2001年   5999篇
  2000年   6123篇
  1999年   6416篇
  1998年   3655篇
  1997年   3674篇
  1996年   2792篇
  1995年   2582篇
  1994年   2231篇
  1993年   1496篇
  1992年   2289篇
  1991年   1997篇
  1990年   1664篇
  1989年   1455篇
  1988年   1264篇
  1987年   1176篇
  1986年   941篇
  1985年   748篇
  1984年   491篇
  1983年   381篇
  1982年   225篇
  1981年   201篇
  1980年   191篇
  1979年   243篇
  1978年   141篇
  1977年   112篇
  1976年   97篇
  1974年   116篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
41.
To study the pathological and histochemical characteristics of lesions in piglet livers infected with Taenia saginata asiatica (T. saginata asiatica) throughout the different stages, piglets were fed with eggs of T. saginata asiatica and raised in isolation in an animal center to establish the T. saginata asiatica infection model with normal piglets as control. The pathological changes in the piglet livers were observed after the infection using liver sections stained with hematoxylin and eosin. Histochemical methods were used to check the changes in lipid, glycogen and protein content in the liver. The data collected by image analysis were analyzed statistically with Statistical Package for the Social Science. The results show that T. saginata asiatica-exposed piglets were indeed infected. Inflammatory reactions began on the fourth day and progressed rapidly. Kupffer cell hyperplasia, hepatic hydropic degeneration and ballooning degeneration were found in the 10th–20th days after infection. Hepatic central veins and hepatic sinusoids were dilated and congested. Spotty necrosis occurred in some local liver tissues. In the 40th–60th days, granulomatous reactions and mild hepatocirrhosis were the main lesions. In the 70th–80th days, hepatocirrhosis and bile duct proliferation were observed in the liver. In the different stages, lipid drops were increased while glycogen and protein levels were decreased to some degree. There was a significant difference in metabolism between the infected group and the control group (P < 0.01). It is concluded that pigs are the favorable intermediate host of T. saginata asiatica and its infection can result in serious pathological and histochemical lesions in host organs. Translated from Journal of Guiyang Medical College, 2006, 31(4): 296–300 [译自: 贵阳医学院学报]  相似文献   
42.
故障1故障现象:病人呼吸回路漏气。可能原因:1.手控时APL阀未关闭,2.钠石灰罐安装不严密,3.螺纹管损坏或接头松动,4.活瓣罩未拧紧,5.手动/自动转换开关失灵。解决方法:1.关闭半紧闭APL阀,2.重新安装半紧闭APL阀,3.更换新管或重新安装管路,4.重新拧紧活瓣罩。故障2故障现象:呼气  相似文献   
43.
44.
文章回顾了医患关系的历史和现状,将医患关系的发展划分为四个时期,即萌芽成长期、成熟定型期、空前和谐期、转轨变型期,着重指出了转轨变型期医患关系不和谐的现状。分析了医患关系不和谐的成因,首先是体制、机制方面的原因;第二是医疗机构和医务人员方面的原因;第三是社会转轨变型期的各种社会矛盾在医患关系上的体现。探讨了构建和谐医患关系的途径:建立公平高效的医疗卫生体系是前提;崇尚医德,提高医术是基础;交流和沟通是关键;依法执业是保障。  相似文献   
45.
46.
We analyzed performance and efficiency of the left ventricular myocardium on the basis of two new energetic parameters. The myocardial energy consumed during one cardiac cycle is related to performed work on the one hand (E1) and to the stress-time-integral on the other (E2). E1 was obtained by analysis of the pressure-volume integral divided by left ventricular muscle mass. E2 was obtained as follows: the stress-time integral was analyzed from pressure-volume data and wall thickness using an ellipsoidal calculation model. In order to transfer the stress-time integral into energy units, the value was multiplied by a constant factor which was obtained in experimental myothermal studies. In ten patients with coronary heart disease undergoing diagnostic heart catheterization, angiocardiography was performed before and after oral administration of nitroglycerin (1.6 mg). Total energy consumption (2E1 + E2) per gram myocardium per beat decreased from 6.1 +/- 1.3 mcal/g to 4.7 +/- 1.4 mcal/g (P less than 0.01), and myocardial efficiency (E1/[2E1 + E2]) increased from 27.0 +/- 3.1% to 28.4 +/- 4.3% (N.S.) on the average. This analysis explains quantitatively the beneficial effect of nitro-preparations on myocardial function and energetics.  相似文献   
47.
Type IIIC tibial fractures are complex injuries involving extensive bone and soft-tissue devascularization that result in a high percentage of complications and ultimate amputation. An emergency free flap transfer not only may salvage the limb but also may improve the aesthetic and functional results of reconstruction by placing the injured structures in a well-vascularized bed. Two cases of type IIIC tibial fracture were treated in this manner, and we present our experience with a 30-month follow-up of one patient and a 6-month follow-up of another patient.  相似文献   
48.
49.
神经肽Y(NPY)是广泛分布于中枢神经系统和外周神经各部位的神经肽类物质。本实验观察NPY在体外对几种免疫细胞活性的直接作用。结果表明,NPY对小鼠T淋巴细胞丝裂原反应性和NK细胞的杀伤活性均无明显影响(P>0.05),对巨噬细胞分泌溶菌酶有明显抑制作用(P<0.05);而对B淋巴细胞丝裂原反应性则有明显的促进作用(P<0.05)。上述结果提示,NPY对部分免疫细胞功能的影响因细胞种类而异。  相似文献   
50.
The MR imaging features of a paraganglioma of the cauda equina with associated spinal cord cysts are presented. MR imaging showed the tumor to be isointense with the spinal cord on all pulse sequences and to enhance homogeneously. The intramedullary cysts had increased signal intensity on proton density- and T2-weighted images, and involved the cervical and thoracic regions.  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