全文获取类型
收费全文 | 1507篇 |
免费 | 129篇 |
国内免费 | 65篇 |
专业分类
耳鼻咽喉 | 10篇 |
儿科学 | 70篇 |
妇产科学 | 16篇 |
基础医学 | 190篇 |
口腔科学 | 36篇 |
临床医学 | 219篇 |
内科学 | 357篇 |
皮肤病学 | 24篇 |
神经病学 | 26篇 |
特种医学 | 289篇 |
外科学 | 229篇 |
综合类 | 40篇 |
预防医学 | 75篇 |
眼科学 | 16篇 |
药学 | 62篇 |
肿瘤学 | 42篇 |
出版年
2021年 | 18篇 |
2020年 | 7篇 |
2019年 | 14篇 |
2018年 | 15篇 |
2017年 | 12篇 |
2016年 | 16篇 |
2015年 | 26篇 |
2014年 | 24篇 |
2013年 | 41篇 |
2012年 | 33篇 |
2011年 | 37篇 |
2010年 | 56篇 |
2009年 | 51篇 |
2008年 | 41篇 |
2007年 | 72篇 |
2006年 | 46篇 |
2005年 | 35篇 |
2004年 | 33篇 |
2003年 | 27篇 |
2002年 | 27篇 |
2001年 | 22篇 |
2000年 | 38篇 |
1999年 | 40篇 |
1998年 | 68篇 |
1997年 | 80篇 |
1996年 | 78篇 |
1995年 | 75篇 |
1994年 | 51篇 |
1993年 | 55篇 |
1992年 | 25篇 |
1991年 | 30篇 |
1990年 | 24篇 |
1989年 | 57篇 |
1988年 | 41篇 |
1987年 | 56篇 |
1986年 | 30篇 |
1985年 | 37篇 |
1984年 | 29篇 |
1983年 | 31篇 |
1982年 | 24篇 |
1981年 | 25篇 |
1980年 | 26篇 |
1979年 | 9篇 |
1978年 | 18篇 |
1977年 | 16篇 |
1976年 | 6篇 |
1975年 | 8篇 |
1973年 | 10篇 |
1969年 | 8篇 |
1966年 | 6篇 |
排序方式: 共有1701条查询结果,搜索用时 93 毫秒
71.
Dvorak AM; Tepper RI; Weller PF; Morgan ES; Estrella P; Monahan-Earley RA; Galli SJ 《Blood》1994,83(12):3600-3612
We used light and electron microscopy to analyze the eyelid inflammation that develops in transgenic mice that overexpress interleukin-4 (IL-4; Tepper et al, Cell 62:457, 1990). Analysis of alkaline Giemsa-stained plastic sections examined by light microscopy (Dvorak et al, J Exp Med 132:558, 1970), as well as by routine transmission electron microscopy, indicated that the mast cells in the inflammatory eyelid lesions were undergoing piecemeal degranulation, a form of secretion in which the cells' cytoplasmic granules exhibit characteristic morphologic changes that are thought to be associated with the prolonged, vesicle-mediated release of the granules' constituents. Moreover, by using a newly reported enzyme affinity-gold method, which stains histamine based on binding to diamine oxidase-gold (Dvorak et al, J Histochem Cytochem 41:787, 1993), we show that these activated mast cells had released much of their histamine content. The eyelid lesions also exhibited increased numbers of mast cells; interstitial fibrosis, particularly around cutaneous nerves and blood vessels; activated fibroblasts; focal axonal damage; venules with endothelial cells containing numerous vesiculo-vacuolar organelles; and infiltrates of neutrophils and eosinophils. Our findings illustrate that overexpression of the IL-4 gene in vivo can result in eyelid lesions associated with piecemeal degranulation of mast cells, as well as tissue fibrosis and a variety of other pathologic changes. These results also represent the first direct morphologic evidence for histamine secretion by mast cells in vivo. 相似文献
72.
Alves Pereira Ivanio Maldonado Cocco José Feijó Azevedo Valderillo Guerra Generoso Bautista-Molano Wilson Casasola Julio César Vega Morales David Soriano Enrique Roberto Gil Diana Rocío Zazzetti Federico Aldunate Leandro Holdsworth Elizabeth Anita Massey Olivia Lobosco Steve Lawson Fabio 《Clinical rheumatology》2020,39(6):1813-1822
Clinical Rheumatology - Discordance (misalignment) regarding treatment satisfaction may exist in real-life clinical practice between patients and their physicians. We aimed to assess physician and... 相似文献
73.
74.
75.
Waldmann TA; Goldman CK; Bongiovanni KF; Sharrow SO; Davey MP; Cease KB; Greenberg SJ; Longo DL 《Blood》1988,72(5):1805-1816
Human T-cell lymphotropic virus I (HTLV-I)-induced adult T-cell leukemia (ATL) cells constitutively express interleukin-2 (IL-2) receptors identified by the anti-Tac monoclonal antibody (MoAb), whereas normal resting cells do not. This observation provided the scientific basis for a trial of intravenous anti-Tac in the treatment of nine patients with ATL. The patients did not suffer untoward reactions and did not have a reduction in the normal formed elements of the blood, and only one of the nine produced antibodies to the anti-Tac MoAb. Three patients had transient mixed, partial, or complete remissions lasting from 1 to more than 8 months after anti-Tac therapy, as assessed by routine hematologic tests, immunofluorescence analysis of circulating cells, and molecular genetic analysis of HTLV-I provirus integration and of the T-cell receptor gene rearrangement. The precise mechanism of the antitumor effects is unclear; however, the use of a MoAb that prevents the interaction of IL-2 with its receptor on ATL cells provides a rational approach for the treatment of this malignancy. 相似文献
76.
Efficient gene delivery to multipotential hematopoietic stem cells would greatly facilitate the development of effective gene therapy for certain hematopoietic disorders. We have recently described a rapid multiparameter sorting procedure for significantly enriching stem cells with competitive long-term lymphomyeloid repopulating ability (CRU) from 5-fluorouracil (5-FU)-treated mouse bone marrow. The sorted cells have now been tested as targets for retrovirus-mediated delivery of a marker gene, NeoR. They were cocultured for 4 days with fibroblasts producing a high titer of retrovirus in medium containing combinations of the hematopoietic growth factors interleukin-3 (IL-3), IL-6, c-kit ligand (KL), and leukemia inhibitory factor (LIF) and then injected into lethally irradiated recipients, together with sufficient "compromised" bone marrow cells to provide short-term support. Over 80% of the transplanted mice displayed high levels (> or = 20%) of donor- derived leukocytes when analyzed 4 to 6 months later. Proviral DNA was detected in 87% of these animals and, in half of them, the majority of the hematopoietic cells were marked. Thus, infection of the stem cells was most effective. The tissue and cellular distribution of greater than 100 unique clones in 55 mice showed that most sorted stem cells had lymphoid as well as myeloid repopulating potential. Secondary transplantation provided strong evidence for infection of very primitive stem cells because, in several instances, different secondary recipients displayed in their marrow, spleen, thymus and day 14 spleen colony-forming cells the same proviral integration pattern as the primary recipient. Neither primary engraftment nor marking efficiency varied for stem cells cultured in IL-3 + IL-6, IL-3 + IL-6 + KL, IL-3 + IL-6 + LIF, or all four factors, but those cultured in IL-3 + IL-6 + LIF appeared to have lower secondary engraftment potential. Provirus expression was detected in 72% of the strongly marked mice, albeit often at low levels. Highly efficient retroviral marking of purified lymphomyeloid repopulating stem cells should enhance studies of stem cell biology and facilitate analysis of genes controlling hematopoietic differentiation and transformation. 相似文献
77.
Di Quinzio MK Oliva K Holdsworth SJ Ayhan M Walker SP Rice GE Georgiou HM Permezel M 《The Australian & New Zealand journal of obstetrics & gynaecology》2007,47(1):9-15
AIM: Cervico-vaginal fluid (CVF) may provide insight into the biochemical pathways of human reproduction and parturition. The aim of this study was to establish a 2-D electrophoretic map of human CVF in healthy, pregnant women at term. METHODS: CVF was collected, concentrated and processed by routine 2-D polyacrylamide gel electrophoresis using pH 4-7-immobilised pH gradient strips and 8-16% gradient polyacrylamide gels. Imaged gels were analysed, yielding more than 400 proteins. A total of 157 proteins were common to all gels with a subgroup of the most abundant proteins being excised and characterised either by MALDI or by electrospray ion-trap mass spectrometry. RESULTS: Twenty-one proteins were successfully identified, yielding 15 different proteins. These included blood transport proteins (albumin and transthyretin); a structural protein (beta-actin); proteins involved in fatty acid metabolism (fatty acid-binding protein and acetyl-CoA-binding protein); a calcium-binding protein (annexin III); an anti-inflammatory cytokine (interleukin-1 receptor antagonist); proteinase inhibitors (alpha-1-antitrypsin, monocyte/neutrophil elastase inhibitor, squamous cell carcinoma antigen-1 and cystatin A); and enzymes involved in oxidative stress defence (thioredoxin, peroxiredoxin 2, glutathione S-transferase P and copper,zinc superoxide dismutase). CONCLUSION: CVF is a complex body fluid consisting of both endogenous and environmental proteins. The putative role of some of these proteins in the human reproductive tract is discussed. 相似文献
78.
79.
小鼠皮肤超氧化物歧化酶活性与枸杞多糖的干预 总被引:1,自引:0,他引:1
目的:观察枸杞多糖对皮肤胶原代谢和自由基产生的影响,探讨其抗皮肤衰老的作用。方法:实验于2005-06/2006-05在广东医学院整形外科研究所完成。①实验材料:清洁级昆明小鼠60只,月龄2个月,体质量16~24g,雌雄各半。②实验分组:将小鼠随机分为正常对照组、衰老模型组和抗衰老模型组,每组20只。③实验干预:模型组每日用D-半乳糖溶液皮下注射制造衰老模型,用量和时间为80mg/(kg·d)7d,120mg/(kg·d)14d,140mg/(kg·d)14d,180mg/(kg·d)7d。正常对照组每日注射同体积的生理盐水。抗衰老模型组在注射D-半乳糖期间以枸杞多糖灌胃,剂量为20mg/(kg·d),正常对照组和衰老组则以同体积的生理盐水代之灌胃。④实验评估:42d后切取小鼠颈背部皮肤,测定超氧化物歧化酶活力、羟脯氨酸和丙二醛含量。结果:56只小鼠进入结果分析(4只死亡)。①小鼠皮肤超氧化物歧化酶活力:与正常对照组相比,衰老组和抗衰老组小鼠皮肤超氧化物歧化酶活力降低,差异有显著性意义(P<0.01);抗衰老组与衰老模型组比较,超氧化物歧化酶活力增加,差异有显著性意义(P<0.01)。②与正常对照组相比,衰老组和抗衰老组小鼠皮肤羟脯氨酸和丙二醛含量增加,差异有显著性意义(P<0.01);抗衰老组与衰老组比较,羟脯氨酸和丙二醛含量均降低,差异有显著性意义(P<0.01)。结论:枸杞多糖改善皮肤老化的作用与提高小鼠皮肤超氧化物歧化酶活力,降低羟脯氨酸、丙二醛含量,影响胶原代谢有关。 相似文献
80.