全文获取类型
收费全文 | 78751篇 |
免费 | 6862篇 |
国内免费 | 3589篇 |
专业分类
耳鼻咽喉 | 920篇 |
儿科学 | 872篇 |
妇产科学 | 1348篇 |
基础医学 | 11066篇 |
口腔科学 | 1749篇 |
临床医学 | 7715篇 |
内科学 | 13565篇 |
皮肤病学 | 1197篇 |
神经病学 | 5188篇 |
特种医学 | 2587篇 |
外国民族医学 | 15篇 |
外科学 | 10366篇 |
综合类 | 9423篇 |
现状与发展 | 5篇 |
一般理论 | 5篇 |
预防医学 | 4706篇 |
眼科学 | 2090篇 |
药学 | 7756篇 |
21篇 | |
中国医学 | 2372篇 |
肿瘤学 | 6236篇 |
出版年
2024年 | 69篇 |
2023年 | 519篇 |
2022年 | 1252篇 |
2021年 | 1690篇 |
2020年 | 1251篇 |
2019年 | 1394篇 |
2018年 | 1890篇 |
2017年 | 1622篇 |
2016年 | 1579篇 |
2015年 | 2095篇 |
2014年 | 2643篇 |
2013年 | 2953篇 |
2012年 | 4273篇 |
2011年 | 4062篇 |
2010年 | 2721篇 |
2009年 | 2436篇 |
2008年 | 3263篇 |
2007年 | 3461篇 |
2006年 | 3337篇 |
2005年 | 2960篇 |
2004年 | 2517篇 |
2003年 | 2591篇 |
2002年 | 2336篇 |
2001年 | 5493篇 |
2000年 | 5272篇 |
1999年 | 4568篇 |
1998年 | 1713篇 |
1997年 | 1376篇 |
1996年 | 876篇 |
1995年 | 766篇 |
1994年 | 657篇 |
1993年 | 548篇 |
1992年 | 2076篇 |
1991年 | 1802篇 |
1990年 | 1653篇 |
1989年 | 1578篇 |
1988年 | 1365篇 |
1987年 | 1260篇 |
1986年 | 1110篇 |
1985年 | 940篇 |
1984年 | 604篇 |
1983年 | 476篇 |
1982年 | 254篇 |
1981年 | 189篇 |
1980年 | 144篇 |
1979年 | 281篇 |
1978年 | 77篇 |
1974年 | 75篇 |
1973年 | 95篇 |
1972年 | 71篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
111.
目的:了解某社区常住人口恶性肿瘤平均年发病率是否高于周边人群,重点是白血病平均年发病率。方法:采用回顾性调查法及个案调查表收集该社区1998年6月~2004年9月常住人口中的确诊恶性肿瘤病人22例,将该社区恶性肿瘤平均年发病率与南山区在该时段恶性肿瘤平均的发病率进行比较。结果:1998年6月~2004年9月南山区常住人口恶性肿瘤平均年发病66.1/10万,某社区常住人口恶性肿瘤平均年发病率29.9/10万,两地差异有统计学意义(F=0.0001,P〈0.05);南山区常住人口白血病平均年发病率2.79/10万,某社区常住人口白血病平均年发病率4.07/10万,两者无统计学意义差异(F=0.467,P〉0.05)。结论:该社区常住人口恶性肿瘤及白血病平均年发病水平低于南山区全区水平。 相似文献
112.
根尖诱导成形术(apexficaotion,AP)是指牙根未完全形成之前,在消除感染或尖周炎症的基础上,用药物诱导根尖部牙髓和俄根尖周组织,使牙根继续发育并使根尖形成,行永久性充填。2002年-2005年我科将Vitapex糊剂用于儿童患牙行根尖诱导成形术,效果较好:现将护理配合介绍如下。 相似文献
113.
114.
Chai Ben-Fu柴本甫Shanghai Institute of Traunatology Orthopedics ShanghaiTang Xue-ming汤雪明Shanghai Second Medical College Shanghai 《中华医学杂志(英文版)》1986,99(2):126-132
Transmission electron microscopic investigation
of standardized fractures of radii in 50 rabbits re
vealed that fibroblasts took part in the formation of
bony callus. The osteogenetic role played by the
fibroblasts can be categorized into the following 5
aspects: a. Fibroblasts synthesize and secrete Type
collagen fibrils and induce deposition of calcium
salt crystals in the collagen fibrils. b. Fibroblasts
produce matrix vesicles in their surroundings. These
matrix vesicles become calcified and turn into floccu-
lent calcospherules which coalesce and fuse into bone
tissues. c. Fibroblasts harbor calcium granules in
their mitochondria, thus providing calcium for calci-
fication of the intercellular matrix and bone forma
tion between the cells. d. Fibroblasts can transform
directly into osteocytes; there is bone formation
around the fibroblasts, the bone tissues surround the
fibroblast in the form of bony lacuna, then the fibro-
blast in the lacuna transforms into osteocyte. e.
Fibroblasts can undergo degenerative changes leading
to decease and replacement by bone tissues. 相似文献
115.
X J Zhang K R Kunkel F Jahoor R R Wolfe 《JPEN. Journal of parenteral and enteral nutrition》1991,15(4):394-399
We have investigated the role of basal insulin concentration on leucine kinetics (determined by means of 1-[13C]leucine) and energy metabolism (determined by indirect calorimetry) in eight septic patients by reducing insulin (and glucagon) secretion by somatostatin infusion. Basal glucagon concentration was elevated (744 +/- 381 pg/mL), and insulin concentration was normal (10 +/- 4 microU/mL). Basal resting energy expenditure (REE) was 151 +/- 8% that of predicted basal energy expenditure, and leucine appearance (Ra), oxidation, and nonoxidative disposal rates were all elevated above the normal ranges. Somatostatin infusion reduced insulin concentration by 52% and glucagon concentration by 64%. This resulted in a significant increase in the rate of leucine oxidation from 0.96 +/- 0.08 to 1.18 +/- 0.14 mumol/kg/min (p less than 0.01), and nonoxidative leucine disposal decreased from 2.95 +/- 0.18 to 2.67 +/- 0.17 mumol/kg/min (p less than 0.01). Somatostatin infusion also caused significant increases in REE and fat oxidation from 1310 +/- 100 to 1505 +/- 128 kcal/m2/day (p less than 0.05) and from 1.72 +/- 0.24 to 2.41 +/- 0.41 mg/kg/min, respectively, and a slight decrease of carbohydrate oxidation from 1.51 +/- 0.49 to 1.31 +/- 0.49 mg/kg/min. These metabolic responses can be attributed to the reduction in insulin concentration, because they are in the opposite direction of changes that would occur as a consequence of a reduction in glucagon concentration. We conclude that the basal insulin plays an important role in attenuating net protein loss and energy expenditure. 相似文献
116.
117.
几种手性药物对映体的HPLC分离与生物样品分析 总被引:2,自引:0,他引:2
使用CHIRAL-AGP柱,通过优化色谱条件,以HPLC法对3种手性药物SFZ-47〔(±)-3H-1,2-二氢-2-(4-甲基苯胺基)-甲基-1-吡咯里嗪酮〕,KMBZ-009〔(±)-反式-4-苯基-5-(邻氯苄基)-吡咯烷酮-2〕和地丙苯酮〔(±)-2′-(2-羟基-3-(特戊胺基)丙氧基)-3-苯基苯丙基酮〕进行了对映体的直接分离,达到良好的分离效果.在此基础上测试了动物血浆样品中SFZ-47的对映体,对其药物动力学的对映体选择性进行了初步研究. 相似文献
118.
119.
Abstract: A pulsatile impeller assist heart and a total heart were tested as a chronic left ventricular assist device in 5 calves and an acute biventricular assist device in 4 pigs respectively, to evaluate their blood compatibility. During the left ventricular assist experiments, the indicators for hemolysis, thrombogenesis, renal dysfunction, and hepatic dysfunction were measured preoperatively, at the beginning of the pumping, 6 h postoperatively, and every following day. The results demonstrated that the impeller assist heart causes no severe blood damage nor organ dysfunction in the experiments lasting up to 11 days. In biventricular assist experiments, the number of red blood cells, white blood cells, platelets, and the he-matocrit, hemoglobin, free hemoglobin, and lactate dehy-drogenase levels were tested preoperatively at the beginning of the pumping and every 2 h postoperatively. The data remained in acceptable ranges during experiments lasting 6 h. It is confirmed that the authors' impeller assist heart and total heart have the advantages of simplicity, implantability, and pulsatility with good blood compatibility. 相似文献
120.