全文获取类型
收费全文 | 686篇 |
免费 | 54篇 |
国内免费 | 32篇 |
专业分类
耳鼻咽喉 | 3篇 |
儿科学 | 28篇 |
妇产科学 | 8篇 |
基础医学 | 92篇 |
口腔科学 | 15篇 |
临床医学 | 100篇 |
内科学 | 144篇 |
皮肤病学 | 2篇 |
神经病学 | 56篇 |
特种医学 | 61篇 |
外科学 | 64篇 |
综合类 | 22篇 |
预防医学 | 44篇 |
眼科学 | 14篇 |
药学 | 92篇 |
中国医学 | 1篇 |
肿瘤学 | 26篇 |
出版年
2021年 | 9篇 |
2019年 | 7篇 |
2018年 | 8篇 |
2017年 | 6篇 |
2016年 | 11篇 |
2015年 | 7篇 |
2014年 | 17篇 |
2013年 | 21篇 |
2012年 | 17篇 |
2011年 | 29篇 |
2010年 | 22篇 |
2009年 | 26篇 |
2008年 | 28篇 |
2007年 | 28篇 |
2006年 | 19篇 |
2005年 | 20篇 |
2004年 | 9篇 |
2003年 | 13篇 |
2002年 | 19篇 |
2001年 | 19篇 |
2000年 | 12篇 |
1999年 | 19篇 |
1998年 | 18篇 |
1997年 | 17篇 |
1996年 | 16篇 |
1995年 | 15篇 |
1994年 | 20篇 |
1993年 | 15篇 |
1992年 | 20篇 |
1991年 | 21篇 |
1990年 | 19篇 |
1989年 | 25篇 |
1988年 | 22篇 |
1987年 | 25篇 |
1986年 | 20篇 |
1985年 | 17篇 |
1984年 | 8篇 |
1983年 | 8篇 |
1982年 | 7篇 |
1981年 | 10篇 |
1979年 | 6篇 |
1977年 | 9篇 |
1975年 | 5篇 |
1972年 | 7篇 |
1971年 | 6篇 |
1969年 | 7篇 |
1968年 | 12篇 |
1967年 | 5篇 |
1966年 | 5篇 |
1965年 | 7篇 |
排序方式: 共有772条查询结果,搜索用时 15 毫秒
1.
Neuroimaging in Pineal Tumors 总被引:4,自引:0,他引:4
F Reis MD AV Faria MD PhD VA Zanardi MD PhD JR Menezes MD F Cendes MD PhD LS Queiroz MD PhD 《Journal of neuroimaging》2006,16(1):52-58
BACKGROUND AND PURPOSE: The authors report radiological findings in 11 tumors in the pineal region, which were histologically diagnosed as germinomas, pineocytomas pineoblastomas, ependymomas, teratomas, and astrocytomas. METHODS: Computed tomography (CT) was performed in seven patients and magnetic resonance imaging (MRI) was performed in all patients. RESULTS: CT showed a solid or solid/cystic mass with variable contrast enhancement. MRI showed a heterogeneous mass, with hypointense signal on T1 and iso/hyperintense signal on T2-weighted images (WI) and gadolinium enhancement. Extension to adjacent structures occurred in five patients and spread through the cerebral spinal fluid (CSF) in two. CONCLUSIONS: Pineal region tumors have no pathognomonic imaging pattern. MRI and CT are complementary in diagnosis and are important to determine localization, extension, and meningeal spread. 相似文献
2.
3.
P M Dougherty J Palecek V Paleckova L S Sorkin W D Willis 《The Journal of neuroscience》1992,12(8):3025-3041
The role of excitatory amino acids (EAAs) in the excitation of monkey spinothalamic tract (STT) neurons following activation of cutaneous primary afferent fibers by noxious and non-noxious stimuli was investigated. The responses of STT neurons to either NMDA or non-NMDA EAA ligands were blocked by infusion of specific antagonists through a microdialysis fiber into the region surrounding the cells. Our results show that blockade of non-NMDA receptors results in a nearly complete elimination of the responses of STT neurons to all stimuli. Blockade of NMDA receptors results in an attenuation of the responses to noxious stimuli but, in addition, prevents the development of the sensitization of STT neurons that is often observed after intradermal injection of capsaicin. These observations further support a role of EAAs in the transmission of sensory information from primary afferent fibers to dorsal horn neurons and a role for NMDA receptors in the generation of hyperalgesia. 相似文献
4.
Buflomedil hydrochloride is a vasoactive drug with a variety of pharmacodynamic properties. Importantly, it seems to improve nutritional blood flow in ischaemic tissue of patients with peripheral and/or cerebral vascular disease by a combination of pharmacological effects: inhibition of alpha-adrenoceptors, inhibition of platelet aggregation, improved erythrocyte deformability, nonspecific and weak calcium antagonistic effects, and oxygen sparing activity. Therapeutic trials with buflomedil in patients with peripheral vascular diseases have shown that it increases walking distances in those with intermittent claudication and heals trophic lesions and reduces rest pain in many patients with more severe vasculopathies. In open clinical trials a good to very good clinical response was achieved in 57 to 87% of those treated. In comparative studies buflomedil 600 mg/day orally was shown to be significantly superior to placebo and comparable in efficacy to pentoxifylline (oxpentifylline) and naftidrofuryl. In patients with symptoms presumed to be due to cerebrovascular insufficiencies and elderly patients with senile dementia, buflomedil 450 to 600 mg/day alleviated symptoms associated with impairment of cognitive and psychometric function and was significantly superior to placebo and slightly more effective than drugs such as cinnarizine, flunarizine and co-dergocrine mesylate. Overall, buflomedil at dosages of up to 600 mg/day has been very well tolerated and discontinuation of therapy has rarely been necessary. Thus, buflomedil would seem to be a useful adjunct to conservative treatment in patients with mild-to-moderate peripheral vascular disease and/or cerebrovascular insufficiency, and well worth a try in patients with more severe peripheral disease unable to undergo surgery. However, a few well-designed long term studies are needed to fully define its overall place in therapy. 相似文献
5.
6.
7.
An electron microscopical study has been carried out to evaluate the effect of neonatal thymectomy on the hypophysis of germ-free mice at different times after the operation. The results fully confirm the previous findings in neonatally thymectomized, conventional mice. Also neonatal thymectomy in germ-free mice results in degranulation of growth hormone-producing cells in the anterior pituitary gland. A large number of these cells show an enlarged endoplasmic reticulum with formation of cisternae and loss of hormone granuli. This alteration of growth hormone-producing cells is similar to that observed in other cells of the hypophysis after removal of other target glands such as thyroid or gonads. The changes in the growth hormone-producing cells in neonatally thymectomized germ-free mice occur even in the first days after birth, when the number of differentiated growth hormone-producing cells is still very low.
Some thymectomized germ-free mice showed symptoms of the wasting syndrome but the alterations in their hypophysis were not more pronounced than those observed in thymectomized germ-free but nonwasting mice. The data fit well our suggestion that the perinatal thymus is under hypophysial control and that immunological maturation depends on endocrine function.
相似文献8.
Hormones and the immunological capacity. III. The immunodeficiency disease of the hypopituitary Snell-Bogg dwarf mouse 总被引:2,自引:0,他引:2
下载免费PDF全文
![点击此处可从《Clinical and experimental immunology》网站下载免费的PDF全文](/ch/ext_images/free.gif)
The naturally occurring immunodeficiency syndrome of the hypopituitary Snell-Bagg dwarf mice has been characterized. The immunopathological aspects of this syndrome derive primarily from an arrested ontogenetic development of the thymus. The alteration of the thymus function is caused by the failure of the pituitary to produce certain hormones, especially somatotropic hormone. The relation of this syndrome of the dwarf mouse to human immunodeficiency diseases and endocrinopathies is discussed. 相似文献
9.
10.
Jiang WZ Jin NY Li ZJ Zhang LS Wang HW Zhang YJ Han WY 《第二军医大学学报》2006,27(4):434-434
To express the core protein of HIV-1 of Chinese prevalent strain (HIV-1 (CN)) in Pichia pastoris, the fulllength gag gene was inserted into the secretory expression vector pHILS1. Linearized recombinant plasmid pHILGAG by Sail was electrotransformed into the yeast strain GS115, and the yeast transformants were identified by PCR. To induce the interest protein to be expressed, the PCR positive transformants were inoculated in the medium of BMGY and BMMY, mRNA of the strain was detected by RT-PCR, and the expressed protein was analyzed by SDS-PAGE, Western blotting and thin layer scanning. mRNA (1.3 kb) was amplified by RT-PCR. SDS-PAGE and Western blotting analysis showed that the molecular mass of the expressed protein was 55 kD, which was similar to the expected value, and the expressed protein could react with McAb to HIV-1 p24. Thin layer scanning analysis demonstrated that the whole amount of the expressed protein was approximately 13 % of the soluble protein in the supernatant. The recombinant yeast had good genetic stability. The optimal expression conditions of the engineering yeast were as follows: BMMY medium, 80-90% of dissolved oxygen, 1% methanol, and 3-day-cultivation course. Gag proteins were expressed under the optimal expression condition and purified via gel filtration chromatography. The purity of the interest protein was up to 85 %. After the purified proteins were inoculated into BALB/c mice, the anti-HIV-1 antibodies in the immunized mice could be detected by Western blotting. 相似文献