全文获取类型
收费全文 | 8369篇 |
免费 | 666篇 |
国内免费 | 212篇 |
专业分类
耳鼻咽喉 | 231篇 |
儿科学 | 47篇 |
妇产科学 | 83篇 |
基础医学 | 724篇 |
口腔科学 | 471篇 |
临床医学 | 617篇 |
内科学 | 432篇 |
皮肤病学 | 32篇 |
神经病学 | 459篇 |
特种医学 | 793篇 |
外科学 | 862篇 |
综合类 | 966篇 |
现状与发展 | 1篇 |
一般理论 | 1篇 |
预防医学 | 674篇 |
眼科学 | 112篇 |
药学 | 1418篇 |
2篇 | |
中国医学 | 1117篇 |
肿瘤学 | 205篇 |
出版年
2024年 | 23篇 |
2023年 | 125篇 |
2022年 | 215篇 |
2021年 | 276篇 |
2020年 | 264篇 |
2019年 | 226篇 |
2018年 | 249篇 |
2017年 | 251篇 |
2016年 | 260篇 |
2015年 | 269篇 |
2014年 | 497篇 |
2013年 | 565篇 |
2012年 | 536篇 |
2011年 | 596篇 |
2010年 | 450篇 |
2009年 | 447篇 |
2008年 | 453篇 |
2007年 | 440篇 |
2006年 | 363篇 |
2005年 | 331篇 |
2004年 | 270篇 |
2003年 | 268篇 |
2002年 | 200篇 |
2001年 | 189篇 |
2000年 | 140篇 |
1999年 | 139篇 |
1998年 | 113篇 |
1997年 | 94篇 |
1996年 | 91篇 |
1995年 | 98篇 |
1994年 | 88篇 |
1993年 | 66篇 |
1992年 | 60篇 |
1991年 | 53篇 |
1990年 | 27篇 |
1989年 | 34篇 |
1988年 | 30篇 |
1987年 | 29篇 |
1986年 | 26篇 |
1985年 | 41篇 |
1984年 | 46篇 |
1983年 | 33篇 |
1982年 | 35篇 |
1981年 | 29篇 |
1980年 | 36篇 |
1979年 | 35篇 |
1978年 | 23篇 |
1977年 | 28篇 |
1976年 | 26篇 |
1974年 | 20篇 |
排序方式: 共有9247条查询结果,搜索用时 15 毫秒
51.
52.
摘要:目的:对民族药香青兰进行化学成分及药理活性的研究,对该药材的综合应用和深入研究奠定基础。方法:通过查阅1995-2022年知网、PubMed中的中英文文献与相关文献对香青兰进行综述。结果:经过系统的研究,发现香青兰的组成主要包含总黄酮和黄酮苷类、挥发油、三萜类和蛋白质等。这些成分有着多种药理作用,如抗缺氧、抗血栓和降血压。结论:香青兰对于治疗高血压,心脏病等有一定疗效。香青兰在蒙医临床中应用广泛。研究表明,香青兰的化学成分和药理作用已经取得了一定的进展,其作用范围广泛,对心血管疾病有显著的疗效。 相似文献
53.
Lai J Gouldstone A Butler JP Federspiel WJ Loring SH 《Respiratory physiology & neurobiology》2002,131(3):233-243
The pleural space is modeled in two dimensions as a thin layer of fluid separating a deformable membrane and a rigid surface containing a bump. We computed the steady-state membrane configuration and fluid pressure distribution during relative sliding of the two surfaces. For physiologically relevant values of membrane tension, shear flow-induced pressures near the bump and far-field pressure gradients are similar to those measured in vivo within the pleural space (e.g. Lai-Fook et al.) [J. Appl. Physiol.: Respirat. Environ. Exercise Physiol. 56 (1984) 1633-1639]. Deformation of the membrane over the bump suggests that the pressure field generated by the sliding motion promotes an even layer of fluid in the pleural space, preventing asperities from touching. Results also suggest a possible mechanism for pleural fluid redistribution during breathing, whereby irreversible fluid motion is associated with the deformability of the membrane. 相似文献
54.
Marina Rova Claire Burrell Marika Cohen 《Body, Movement and Dance in Psychotherapy: An International Journal for Theory, Research and Practice》2020,15(3):204-218
ABSTRACT In this reflective article we introduce Moving Space, a creative movement and art project supporting female Asylum Seekers as they move through the transient space of temporary accommodation. We explore how this cross-modal approach supports women to anchor experiences of displacement, loss and trauma through the use of embodied and visual creative process. Moreover, we argue that the transient nature of the therapeutic space brings into focus women’s resourcefulness and resilience despite the adversity and uncertainty they are experiencing. 相似文献
55.
Male wild (Cavia aperea) and domestic (C. porcellus) guinea pigs were tested in two-bottle choice tests for preferences between glucose solutions of different concentrations and de-ionized water. Wild males showed significant preferences for concentrations between 0.025 and 0.4 M glucose while domestic males preferred only the 0.2 M glucose solution to de-ionized water. C. aperea males also consumed significantly greater volumes of liquid per kg body during the glucose tests than did the C. porcellus males. These comparative results contrast sharply with those obtained by other authors with wild and domestic Norway rats. 相似文献
56.
The feeding behavior of rats sympathectomized by neonatal administration of guanethidine (GUA) and/or adult adrenal demedullation (MDL) was investigated. GUA treatment tended to decrease body weight gain and food intake, chiefly by decreasing meal size and increasing satiety ratios. It also attenuated the increase in food intake caused by 2-deoxy-D-glucose (2DG; 150, 300, 450 mg/kg, IP) but not by insulin (3, 6, 9 U/kg, IP). MDL altered meal patterns in the same manner as GUA treatment but the effects were of smaller magnitude. It did not influence the response to either glucoprivic challenge. Combined GUA treatment and MDL generally produced additive effects. These results suggest that the major sympathetic influence on feeding is through adrenergic innervation and not circulating catecholamines. The hypothesis that the alteration in feeding patterns produced by ventromedial hypothalamic lesions is due to decreased sympathetic activity was not supported. 相似文献
57.
The effects of imidacloprid (Advantage) on sheep keds (Melophagus ovinus Linné 1758) were studied in vivo and in vitro by means of direct observation (monitored on video tape) and by light and electron
microscopy. It was found that:
1. Imidacloprid acted rapidly on all motile stages of the sheep keds. Within 3–4 min after exposure they became immobile and
their legs and the abdomen started tetanic trembling movements for 15–30 min, leading to death.
2. The compound is apparently taken up by the body, since it also acted on those sheep keds that had been exclusively exposed
to imidacloprid-contaminated filter papers.
3. The compound is available and active for more than 1 month in the wool of sheep; even rainfall does not reduce its efficacy.
Body contact between treated mother sheep and their lambs protects them from infestation with these ectoparasites.
4. The compound initiates an ultimately lethal destruction of the ganglia, nerve chords and related muscle fibers, as can
be seen in electron micrographs.
Received: 7 October 2000 / Accepted: 18 October 2000 相似文献
58.
Keisuke Izumi Hisashi Otsuka Keizo Furuya Akiko Akagi 《Virchows Archiv : an international journal of pathology》1979,384(3):263-267
Summary The carcinogenicity of 1,2-dimethylhydrazine dihydrochloride (DMH) by oral, intragastric and subcutaneous administration was examined in 339 BALB/c mice. Subcutaneous injection of DMH induced intestinal tumors in the lower colon of all mice. After oral administration it induced a high incidence of vascular tumors in the liver and soft tissues, but colon tumors were found in only 2 mice when given at a high dosage. On intragastric administration, it induced a fairly high incidence both of colon and vascular tumors. The sites and incidences of vascular tumors and squamous cell carcinomas of the perianal glands were also described.This work was supported in part by a Grant-in Aid for Cancer Research from the Ministry of Education, Japan. 相似文献
59.
颈深筋膜及筋膜间隙的计算机三维重建 总被引:1,自引:0,他引:1
目的 :对颈深筋膜及深筋膜间隙进行计算机三维重建以显示其立体结构。方法 :用生物塑化技术制作薄层断面标本 ,在SGI工作站上 ,采用双线提取筋膜及间隙轮廓的方法对颈深筋膜及其间隙进行了三维重建。结果 :重建出咽后间隙、颈动脉间隙和内脏间隙及颈部的大血管和重要器官。重建结构均能单独显示、任意搭配显示或总体显示 ,可在三维空间位置上绕任意轴旋转任意角度。结构 :用双线法提取筋膜及间隙轮廓 ,能重建出筋膜间隙并能同时清楚显示间隙内的结构 ,为筋膜间隙的计算机三维重建提供了一种新的方法 相似文献
60.
Masumura K Kuniya K Kurobe T Fukuoka M Yatagai F Nohmi T 《Environmental and molecular mutagenesis》2002,40(3):207-215
Heavy-ion radiation accounts for the major component of absorbed cosmic radiation and is thus regarded as a significant risk during long-term manned space missions. To evaluate the genetic damage induced by heavy particle radiation, gpt delta transgenic mice were exposed to carbon particle irradiation and the induced mutations were compared with those induced by reference radiations, i.e., X-rays and gamma-rays. In the transgenic mouse model, deletions and point mutations were individually identified as Spi(-) and gpt mutations, respectively. Two days after 10 Gy of whole-body irradiation, the mutant frequencies (MFs) of Spi(-) and gpt were determined. Carbon particle irradiation significantly increased Spi(-) MF in the liver, spleen, and kidney but not in the testis, suggesting an organ-specific induction of mutations by heavy-ion irradiation. In the liver, the potency of inducing Spi(-) mutation was highest for carbon particles (3.3-fold increase) followed by X-rays (2.1-fold increase) and gamma-rays (1.3-fold increase), while the potency of inducing gpt mutations was highest for gamma-rays (3.3-fold increase) followed by X-rays (2.1-fold increase) and carbon particles (1.6-fold increase). DNA sequence analysis revealed that carbon particles induced deletions that were mainly more than 1,000 base pairs in size, whereas gamma-rays induced deletions of less than 100 base pairs and base substitutions. X-rays induced various-sized deletions and base substitutions. These results suggest that heavy-ion beam irradiation is effective at inducing deletions via DNA double-strand breaks but less effective than X-ray and gamma-ray irradiation at producing oxidative DNA damage by free radicals. 相似文献