全文获取类型
收费全文 | 208799篇 |
免费 | 19843篇 |
国内免费 | 13379篇 |
专业分类
耳鼻咽喉 | 1907篇 |
儿科学 | 2748篇 |
妇产科学 | 2155篇 |
基础医学 | 21725篇 |
口腔科学 | 3797篇 |
临床医学 | 26955篇 |
内科学 | 26974篇 |
皮肤病学 | 2990篇 |
神经病学 | 8491篇 |
特种医学 | 8359篇 |
外国民族医学 | 65篇 |
外科学 | 18002篇 |
综合类 | 40552篇 |
现状与发展 | 65篇 |
一般理论 | 15篇 |
预防医学 | 17795篇 |
眼科学 | 5870篇 |
药学 | 23623篇 |
296篇 | |
中国医学 | 14521篇 |
肿瘤学 | 15116篇 |
出版年
2024年 | 724篇 |
2023年 | 2950篇 |
2022年 | 7516篇 |
2021年 | 9745篇 |
2020年 | 7678篇 |
2019年 | 6113篇 |
2018年 | 6331篇 |
2017年 | 6661篇 |
2016年 | 6113篇 |
2015年 | 9732篇 |
2014年 | 12075篇 |
2013年 | 12228篇 |
2012年 | 18200篇 |
2011年 | 19287篇 |
2010年 | 14088篇 |
2009年 | 11859篇 |
2008年 | 13603篇 |
2007年 | 12999篇 |
2006年 | 11760篇 |
2005年 | 10375篇 |
2004年 | 7249篇 |
2003年 | 6907篇 |
2002年 | 5710篇 |
2001年 | 4203篇 |
2000年 | 3519篇 |
1999年 | 2858篇 |
1998年 | 1720篇 |
1997年 | 1663篇 |
1996年 | 1324篇 |
1995年 | 1159篇 |
1994年 | 1084篇 |
1993年 | 674篇 |
1992年 | 684篇 |
1991年 | 642篇 |
1990年 | 550篇 |
1989年 | 460篇 |
1988年 | 371篇 |
1987年 | 361篇 |
1986年 | 255篇 |
1985年 | 185篇 |
1984年 | 100篇 |
1983年 | 80篇 |
1982年 | 53篇 |
1981年 | 38篇 |
1980年 | 34篇 |
1979年 | 29篇 |
1978年 | 8篇 |
1975年 | 11篇 |
1974年 | 7篇 |
1973年 | 15篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
31.
NADPH-Diaphorase-Positive Neurons in Primate Cerebral Cortex Colocalize with GABA and Calcium-Binding Proteins 总被引:3,自引:3,他引:0
Neurons in the monkey cerebral cortex containing nicotinamideadenine dinucleotide phosphate-diaphorase (NADPH-d) can he dividedinto two distinct types, both nonpyramidal. Type I neurons havea large soma (diameter 2050 µm), a dense NADPH-dhistochemical reaction. and are distributed throughout the cortex,but mainly in the subcortical white matter, and are mostly aspiny.Type II cells have a small soma (< 20 µm) with lightNADPH-d reactivity and are distributed primarily in the supragranularlayers, particularly layers II and upper III. The numericaldensity of type II cells is much greater than that of type I.Type I neurons also stain for GABA and a few intracortical typeI cells contain calbindin. All type II cells found here arecolocalized with both GABA and calbindin. Neither type I nortype II cells are stained for parvalbumin. Together with previous observations that almost all corticalNADPH-d cells in various subprimates are like type I cells,we suggest that type II cells may form a group of NADPH-d-richneurons differentiated in higher mammalian cortex from a subpopulationof calbindin-containing GABAergic interneurons, and these nitricoxide-synthesizing cells may play a role in control of intracorticalneuronal activity characteristic of higher cerebral functionsin advanced mammals. 相似文献
32.
33.
Jiyou Li Yuquan Xie Guizhi Shi Heling Sun Xinhua Ji Maolin Jin Boqin Yang Mingsheng Wang 《中国癌症研究》1992,4(2):10-12
In order to investigate the antagonistic effect of Glycyrrhiza Uralensis Fish (GUF) and Chelidonium maJus L (CML) on gastrccarcinogenesis
induced by MNNG in Wastar rats, we treated the rats with MNNG alone (group 1) and with MNNG plus GUF and CML (group 2 and
3) respectively. The incidence of infiltrating adenocarcinoma of the glandular stomach and duodenum in group 2 was significantly
lower than that in group 1 (26.7% vs. 67.8%). The differentiation and aggressivenees of carcinomas occured in group 2 were
much better and mild than those in group 1. Present study also demonstrated that the inhibitory effect of CML on proliferation
of human stomach carcinoma cell line MGC-803 was very remarkable; in addition, GUF and CML were able to antagonise the mutagenic
activation of MNNG. These results suggest that GUF and CML may be empoyed in prevention of gastric carcinoma. 相似文献
34.
35.
本文对103名高龄老人进行营养情况调查、心理状况调查和体测量,结果表明:高龄老人体质指数大于26者很少,只要老龄人的各种营养素达到供给量标准,心理状态乐观满意,且不吸烟不酗酒者,则可长命百岁。 相似文献
36.
Summary The vestibulospinal level of vestibular function is commonly neglected in the evaluation of vertiginous patients. We have now developed a new posture equilibrometer. A transducer is placed on the head of the subject being tested. With this meter we can record body swaying, X (left-right) and Y (fore-aft) components of angular displacement, angular velocity, and angular acceleration. A detailed analysis of the data can be made by having patients keep their eyes either open or closed during the Romberg test. The head is turned left or right in this test, while the eyes are opened and closed in the Mann test. The posture equilibrometer has enabled us to evaluate more precisely vestibulospinal function and sensory interactions.
Offprint request to: N. C. Zhong 相似文献
37.
38.
We have adapted the simple and sensitive McAb-antigen spot test (AST) for evaluating the efficacy of anti-Leishmania chemotherapy. Serum samples from 37 kala-azar patients were tested by McAb-AST, and all showed definite positive reactions before treatment. After a course of antimony treatment, 20 turned negative, coupled with the disappearance of clinical symptoms; another 12 cases responded with weak positivity accompanied by an improvement of clinical manifestations; and the remaining 5 antimony-resistant patients showed strong positive reactions, with their conditions gradually worsening. Furthermore, all 6 cases in which the diagnosis was missed by the bone marrow smear method turned McAb-AST negative after chemotherapy. These results suggest that McAb-AST can be used to evaluate the efficacy of chemotherapy as well as to avoid missed diagnosis by the bone marrow smear method. 相似文献
39.
The purpose of the present study was to determine the reliability of several selected signs of trauma from occlusion and their relations with severity of periodontitis. 32 moderate to advanced chronic periodontitis patients participated in the study. All teeth present were evaluated for various abnormal occlusal contacts, signs of trauma from occlusion, and the severity of periodontitis. Standardized periapical radiographs were also taken for each tooth. The results demonstrated that: (1) no significant difference occurred in probing pocket depth (PD), clinical attachment loss (AL), or percentage of alveolar bone height (BH) between teeth with and without various abnormal occlusal contacts, i.e., premature contacts in centric relation occlusion, non-working contacts in lateral excursions, premature contacts of anterior teeth or posterior protrusive tooth contacts; (2) teeth with either significant mobility, functional mobility, or radiographically widened periodontal ligament space (PDLS) had deeper PD, more AL and lower BH than teeth without these signs, while teeth with pronounced wear or radiographically thickened lamina dura had less AL than teeth without these findings; (3) 2 combined indices, i.e., the trauma from occlusion index (TOI) and the adaptability index (AI), were proposed for the identification of occlusal trauma and the response of periodontium to excessive biting forces in heavy function, respectively; TOI-positive teeth exhibit deeper PD, more AL and less osseous support than TOI-negative teeth; however, AI-positive teeth had less AL and more osseous support than AI-negative teeth; (4) with identical attachment level, TOI-positive teeth had less osseous support than TOI-negative teeth while the magnitude of difference became greater with an increase of attachment loss. 相似文献
40.
VEGF和p53在胰腺癌中的表达及意义 总被引:1,自引:0,他引:1
目的 探讨胰腺癌组织中血管内皮生长因子 (VEGF)及p5 3蛋白的表达及其临床病理意义。方法 采用SP免疫组织化学方法 ,对 46例胰腺癌组织中VEGF及 p5 3蛋白的表达进行检测。结果 VEGF与 p5 3表达率分别为 65 .2 %和 5 8.7%。p5 3表达与VEGF表达呈明显正相关(P <0 .0 5 )。VEGF表达与胰腺癌淋巴结转移 (P <0 .0 5 )和远处转移 (P <0 .0 1)显著相关 ,而与肿瘤大小 ,病理学分级无关 ,p5 3表达与胰腺癌远处转移 (P <0 .0 5 )显著相关 ,而与肿瘤大小 ,病理学分级及淋巴结转移无关。结论 在胰腺癌中 ,VEGF表达与 p5 3蛋白的表达呈正相关 ,在胰腺癌的转移中起重要作用 相似文献