全文获取类型
收费全文 | 4123篇 |
免费 | 254篇 |
国内免费 | 21篇 |
专业分类
耳鼻咽喉 | 44篇 |
儿科学 | 47篇 |
妇产科学 | 38篇 |
基础医学 | 667篇 |
口腔科学 | 172篇 |
临床医学 | 344篇 |
内科学 | 927篇 |
皮肤病学 | 111篇 |
神经病学 | 384篇 |
特种医学 | 170篇 |
外科学 | 570篇 |
综合类 | 22篇 |
预防医学 | 193篇 |
眼科学 | 43篇 |
药学 | 312篇 |
中国医学 | 5篇 |
肿瘤学 | 349篇 |
出版年
2023年 | 25篇 |
2022年 | 54篇 |
2021年 | 88篇 |
2020年 | 73篇 |
2019年 | 82篇 |
2018年 | 86篇 |
2017年 | 70篇 |
2016年 | 94篇 |
2015年 | 120篇 |
2014年 | 132篇 |
2013年 | 187篇 |
2012年 | 299篇 |
2011年 | 318篇 |
2010年 | 200篇 |
2009年 | 184篇 |
2008年 | 264篇 |
2007年 | 292篇 |
2006年 | 282篇 |
2005年 | 254篇 |
2004年 | 224篇 |
2003年 | 222篇 |
2002年 | 192篇 |
2001年 | 47篇 |
2000年 | 28篇 |
1999年 | 42篇 |
1998年 | 43篇 |
1997年 | 36篇 |
1996年 | 36篇 |
1995年 | 23篇 |
1994年 | 16篇 |
1993年 | 26篇 |
1992年 | 29篇 |
1991年 | 17篇 |
1990年 | 14篇 |
1989年 | 21篇 |
1988年 | 16篇 |
1987年 | 20篇 |
1986年 | 15篇 |
1985年 | 15篇 |
1984年 | 11篇 |
1983年 | 12篇 |
1982年 | 11篇 |
1981年 | 11篇 |
1979年 | 10篇 |
1978年 | 11篇 |
1977年 | 9篇 |
1976年 | 11篇 |
1974年 | 11篇 |
1973年 | 8篇 |
1968年 | 8篇 |
排序方式: 共有4398条查询结果,搜索用时 601 毫秒
1.
2.
3.
The experimental infection of immunocompetent and immunodeficient athymic mice with an avirulent encephalitogenic Toxoplasma strain (DX strain) was employed to study the ensuing encephalitic process by use of histological and immunocytochemical methods. In the acute phase of the infection Toxoplasma cysts and tachyzoites were accompanied by an infiltrate composed of macrophages, CD4+ and CD8+ T cells. In the chronic stage a granulomatous encephalitis developed. In contrast to immunocompetent NMRI mice, athymic nude NMRI mice died 3 weeks post-infection because of a generalized toxoplasmosis with predominant involvement of the brain. A salient feature of murine Toxoplasma encephalitis was up-regulation of class I and II major histocompatibility complex (MHC) gene products. Class I antigen was widely expressed on microglial cells and astrocytes. Class II antigen was only expressed on microglial cells despite a considerable astrogliosis. Our results indicate a differential expression of MHC-determined antigens on brain cells in acute and chronic murine Toxoplasma encephalitis. 相似文献
4.
Torsten T. Bauer Joachim Lorenz Klaus-Friedrich Bodmann Friedrich Vogel 《Medizinische Klinik》2005,26(13):355-360
Hintergrund:
Die nosokomiale Pneumonie gehört zu den häufigsten nosokomialen Infektionen und ist die häufigste auf der Intensivstation. Die nosokomiale Pneumonie ist mit einer signifikanten Mortalität und Morbidität assoziiert, und ihr Auftreten verschlechtert die Prognose des Patienten deutlich. Nach der Definition der DRGs auch im deutschen Krankenhaussystem ist die nosokomiale Pneumonie überwiegend Sache des Krankenhauses und kann somit nicht nur das Ergebnis der Patientenbehandlung, sondern auch das finanzielle Ergebnis des Krankenhauses beeinträchtigen. 相似文献5.
Dimmeler Stefanie; Tonn Torsten; Seeger Florian; Zeiher Andreas M. 《European heart journal》2007,28(17):2175
It obviously escaped the notion of Egeland and Brinchman thatthe protocols additionally differ with regard to the washingsteps and buffer components used in the 相似文献
6.
K. Bahlke T. Scholbach T. Rhein F. Deckert A. Tannapfel J. Hauss Prof. Dr. H. Witzigmann 《Gef?sschirurgie》2004,9(3):215-219
The celiac axis compression syndrome is a rare disease in adults. In childhood it is extremely uncommon. Vascular reasons or chronic irritation of the celiac ganglion are discussed as causes for this syndrome, leading to chronic abdominal pain. Lateral aortography is acknowledged to be the best method for diagnosis of the celiac axis compression syndrome. New duplex scanning methods are gaining more and more importance. The indication for surgery is the subject of controversy in the current literature. We present the case of a 15-year-old girl who recovered completely after transsection of the ligamentum arcuatum medianum and resection of the celiac ganglion. 相似文献
7.
Possible genetic defects in regulation of glycosaminoglycans in patients with diabetic nephropathy 总被引:1,自引:0,他引:1
T Deckert I M Horowitz A Kofoed-Enevoldsen L Kjellén M Deckert C Lykkelund F Burcharth 《Diabetes》1991,40(6):764-770
The hypothesis of genetic defects in glycosaminoglycan (GAG) regulation among patients with insulin-dependent diabetes mellitus (IDDM) and nephropathy was assessed by studies in tissue cultures of fibroblasts obtained from 7 patients with normal urinary albumin excretion, 11 patients with diabetic nephropathy, and 6 nondiabetic control subjects. The incorporation of [2H] glucosamine and [35S] sulfate into hyaluronic acid (HA), chondroitin sulfate and dermatan sulfate (CS + DS), and heparan sulfate (HS) was measured in cells, matrix, and medium and related to micrograms of tissue protein. Large interindividual variations were seen in all three groups, and the incorporation of [3H] glucosamine into HA, CS + DS, and HS and [35S] sulfate into CS + DS and HS were not significantly different between the three groups. However, the fractional incorporation of [3H]glucosamine into HS was significantly reduced in diabetic patients with nephropathy compared with control subjects. This was the case not only when related to the total amount of GAGs (P = 0.014) but also when related to HA (P = 0.014). No significant difference was seen between control subjects and normoalbuminuric diabetic patients. The degree of N-sulfation of HS was not significantly different between the experimental groups. The results suggest that patients with diabetic nephropathy may suffer from deficiencies of coordinate regulation in the biosynthesis of GAG in fibroblasts, which may lead to a reduced density of HS in the extracellular matrix. If these changes reflect alterations in the biosynthesis of GAG from endothelial, myomedial, and mesangial cells, this observation may be relevant for the pathogenesis of severe diabetic complications. 相似文献
8.
Hans Rommelspacher Lutz G. Schmidt Torsten May 《Alcoholism, clinical and experimental research》1991,15(3):553-559
Based on the hypothesis that condensation products of neurotransmitters with aldehydes are involved in the pathogenesis of alcoholism, aromatic beta-carbolines (norharman and harman) were measured in the blood plasma of alcoholics and nonalcoholics. The identity of the extracted compounds was confirmed by various elution conditions of the high performance liquid chromatography (HPLC), newly developed radioreceptor assays, and the mass spectrum of norharman. The levels of norharman and harman in nonalcoholics were unchanged after a load with ethanol (1 g/kg body weight). The norharman levels of the alcoholics were significantly higher than that of the nonalcoholic controls (99.5 +/- 26.6 pg/ml vs. 26.9 +/- 10.7 pg/ml; p less than 0.001) and did not change significantly during a 3-week detoxication period. In the subgroup of alcoholics with delirium or hallucinosis, a slight increase of norharman during detoxication could be detected while in alcoholics with vegetative withdrawal symptoms norharman levels dropped slightly over time (p = 0.07). No difference was found with respect to harman between nonalcoholics and alcoholics. These results suggest disturbed regulatory processes in the formation and/or metabolism of norharman in alcoholics. Further investigations are needed to reveal a possible marker function of norharman in alcoholic patients. 相似文献
9.
10.
High levels of functional endopeptidase 24.11 (CD10) activity on human thymocytes: preferential expression on immature subsets.
下载免费PDF全文
![点击此处可从《Immunology》网站下载免费的PDF全文](/ch/ext_images/free.gif)
B Mari J P Breittmayer S Guerin N Belhacene J F Peyron M Deckert B Rossi P Auberger 《Immunology》1994,82(3):433-438
Although it is now well established that cells of the immune system express most of the exopeptidases described so far, little information is available concerning the identification and the characterization of the peptidases associated with the surface of human thymocytes. In the present study we have focused on CD10 expression on thymocytes using both FACS and enzymatic analysis. Unfractionated intact human thymocytes were shown to express significant levels of CD10-specific enzymatic activity, as assessed by the hydrolysis of the neutral endopeptidase (NEP) substrate Suc-Ala-Ala-Phe-pNA and of D-Ala2-Leu-enkephalin, a typical NEP substrate. CD10 activity was abolished by specific NEP inhibitors, including thiorphan, retrothiorphan and phosphoramidon. Moreover, high performance liquid chromatography (HPLC) analysis showed that intact thymocytes and purified NEP hydrolysed thymopentin, a thymic factor known to induce the maturation of prothymocytes into thymocytes. Finally, CD 10/NEP was preferentially associated with CD3- CD3low and immature CD4- CD8- thymocytes. The data demonstrate for the first time that human thymocytes express functional NEP and suggest a role for this enzyme in the maturation of human thymocytes. 相似文献