全文获取类型
收费全文 | 5672篇 |
免费 | 332篇 |
国内免费 | 43篇 |
专业分类
耳鼻咽喉 | 31篇 |
儿科学 | 167篇 |
妇产科学 | 122篇 |
基础医学 | 856篇 |
口腔科学 | 30篇 |
临床医学 | 498篇 |
内科学 | 1447篇 |
皮肤病学 | 112篇 |
神经病学 | 717篇 |
特种医学 | 111篇 |
外科学 | 409篇 |
综合类 | 10篇 |
一般理论 | 1篇 |
预防医学 | 291篇 |
眼科学 | 46篇 |
药学 | 446篇 |
中国医学 | 13篇 |
肿瘤学 | 740篇 |
出版年
2024年 | 1篇 |
2023年 | 37篇 |
2022年 | 102篇 |
2021年 | 140篇 |
2020年 | 85篇 |
2019年 | 115篇 |
2018年 | 132篇 |
2017年 | 113篇 |
2016年 | 141篇 |
2015年 | 155篇 |
2014年 | 198篇 |
2013年 | 259篇 |
2012年 | 413篇 |
2011年 | 436篇 |
2010年 | 256篇 |
2009年 | 233篇 |
2008年 | 401篇 |
2007年 | 388篇 |
2006年 | 388篇 |
2005年 | 387篇 |
2004年 | 393篇 |
2003年 | 326篇 |
2002年 | 289篇 |
2001年 | 52篇 |
2000年 | 37篇 |
1999年 | 57篇 |
1998年 | 77篇 |
1997年 | 65篇 |
1996年 | 51篇 |
1995年 | 50篇 |
1994年 | 44篇 |
1993年 | 37篇 |
1992年 | 25篇 |
1991年 | 29篇 |
1990年 | 20篇 |
1989年 | 18篇 |
1988年 | 13篇 |
1987年 | 12篇 |
1986年 | 7篇 |
1985年 | 13篇 |
1984年 | 15篇 |
1983年 | 11篇 |
1982年 | 8篇 |
1981年 | 4篇 |
1980年 | 10篇 |
1979年 | 2篇 |
1977年 | 1篇 |
1966年 | 1篇 |
排序方式: 共有6047条查询结果,搜索用时 31 毫秒
121.
Addolorata Carcagnì Patrizia Presbitero 《Catheterization and cardiovascular interventions》2004,62(3):409-414
Anatomical atrial septal defect (ASD) diameter measured by transesophageal echocardiography (TEE) underestimates the Amplatzer septal occluder (ASO) size for ASD closure. The aim of this study is to investigate whether a new echocardiographic diameter (procedural ASD diameter) may enable precise measurements of ASO device size. Fifty adult patients with secundum ASD were evaluated by TEE for percutaneous closure. The procedural ASD diameter was measured using the steadier rim borders where thickness was 2.5 mm. Out of the 50 patients, 12 were considered unsuitable for Amplatzer device closure. The other 38 patients underwent percutaneous closure. The mean anatomical ASD diameter was 14.8 +/- 7.0 mm, the mean procedural ASD diameter measured 19.5 +/- 8.1 mm, and the mean stretched balloon diameter (SBD) was 20.0 +/- 8.0 mm. ASO device size was 20.1 +/- 8.0 mm. At linear regression analysis, a high correlation (r = 0.99) was found between procedural ASD diameter and SBD. Procedural ASD diameter correlates with SBD and may allow reliable prediction of Amplatzer device in an adult population undergoing percutaneous ASD closure. 相似文献
122.
Boschi A Tinelli C Ortolani P Moscatelli G Morigi G Arlotti M 《AIDS (London, England)》2004,18(18):2381-2389
OBJECTIVE: To evaluate the safety of treatment interruption guided by CD4+ cell count in HIV-infected patients followed up prospectively. METHODS: Patients on highly active antiretroviral therapy with CD4+ cell counts > 500 x 10(6) cells/l discontinued therapy with instructions to start therapy again before their CD4+ count dropped below 200 x 10(6) cells/l. Any patients who resumed therapy would be eligible to interrupt treatment again once their CD4+ cell count increased above 500 x 10(6) cells/l. RESULTS: Data on 71 HIV infected patients is reported. Their median nadir CD4+ cell count before antiretroviral treatment was 352 x 10(6) cells/l [interquartile range (IQR), 294-445 x 10(6) cells/l]. The median CD4+ cell count at the time of first interruption was 790 x 10(6) cells/l (IQR, 657-1041 x 10(6) cells/l). The median follow-up after starting the first treatment interruption was 28.3 months (IQR, 21.4-37.0 months). During the follow-up 49 patients restarted therapy and 22 patients remain off therapy; 24 patients have interrupted therapy twice, nine patients have interrupted therapy three times and six patients four times. No AIDS-defining illnesses occurred during the follow-up. The median duration of the first interruption was 15 months (IQR, 6-26 months). The overall reduction of time on therapy was 71.1%. The duration of the first interruption and the reduction of time on therapy were related to nadir CD4+ cell count. The patients who resumed HAART rapidly regained CD4+ cells and achieved viral suppression. CONCLUSION: If carefully monitored, treatment interruptions guided by CD4+ cell count in patients with an initially high CD4+ cell counts are clinically safe, decrease exposure to the drugs and do not reduce the efficacy of therapy when this is re-started. 相似文献
123.
Guido Cimoli Monica Valenti Elvira Noviello Silvio Parodi Alessandra Mazzoni Elisabetta Rovini Fabio De Sessa Patrizia Russo 《Journal of cancer research and clinical oncology》1995,121(3):155-163
Human ovarian cancer cells A2780, selected for resistance to doxorubicin (A2780-DX3), are crossresistant to various other topoisomerase-II-targeted drugs but not to vinblastine. The parental cell line was very sensitive to doxorubicin-, mitoxantrone- or etoposide (VP16)-induced DNA single-strand breaks, under deproteinizing conditions. In contrast, little or no DNA strand breakage was seen in resistant A2780-DX3 cells, even at very high concentrations, indicating a good correlation, with cytotoxicity. No significant alterations in cellular drug uptake were observed in DX3 cells. Further studies showed that the nuclei isolated from resistant cells were also resistant to mitoxantroneor VP16-induced single-strand breaks, indicating that nuclear modifications in resistant cells are responsible for this resistance. Catalytic activity in crude nuclear extracts from wild-type and DX3 cells was almost equal. However, an assay that specifically measures generation of 5-protein-linked breaks in32P-labeled 3 DNA revealed that, DNA cleavage activity in nuclear extract from the DX3 cell line is profoundly resistant to a stimulation by VP16. These data indicate that stimulation of topoisomerase-II-mediated DNA cleavage is responsible for topoisomerase-II-targeted drugcytotoxicity rather than loss of normal topoisomerase catalytic function. These data support the hypothesis that A2780-DX3 cells display an atypical multidrug resistance.Abbreviations
MDR
multidrug resistance
-
SSB
Single-strand break 相似文献
124.
Human alloantigen-specific anergic cells induced by a combination of CTLA4-Ig and CsA maintain anti-leukemia and anti-viral cytotoxic responses 总被引:4,自引:0,他引:4
Comoli P Locatelli F Moretta A Montagna D Calcaterra V Cometa A Basso S Zecca M Maccario R 《Bone marrow transplantation》2001,27(12):1263-1273
The success of allogeneic hematopoietic stem cell transplantation from HLA-disparate donors depends on the development of new strategies for graft-versus-host disease prevention able to target specifically donor antihost alloreactivity, while preserving GVL and antiviral immune surveillance. Recent experimental and clinical work has shown the feasibility of an approach based on induction of anergy to host alloantigens through blockade of B7/CD28 costimulatory signal in donor T cells, but data on the impact of this strategy on the recovery of the immune system are still lacking. We devised an ex vivo method for induction of host alloantigen-specific unresponsiveness based on treatment with the B7/CD28 blocking agent CTLA4-Ig associated with CsA. We then proceeded to assess the maintenance of an effective immune response towards viral pathogens and tumor cells after CTLA4-Ig/CsA treatment, by measuring the frequency of CTL precursors directed against CMV- and EBV-infected targets, and against autologous leukemic blasts. We demonstrated that (1) CTLA4-Ig and CsA can act synergistically in inducing a state of unresponsiveness to alloantigens; (2) the number of leukemia-reactive, EBV-specific and CMV-specific CTLp is not impaired by CTLA4-Ig/CsA treatment. Our data provide the first direct in vitro evidence that it is possible to preserve antiviral and antileukemia effector cells after blockade of CD28/B7 interaction during MLR. 相似文献
125.
Antonella Tinari Paolo Monini Magda Marchetti Maria Grazia Ammendolia Patrizia Leone Barbara Ensoli 《Ultrastructural pathology》2013,37(5):301-310
The human herpesvirus 8 (HHV-8), also known as Kaposi's sarcoma-associated herpesvirus, is a gamma herpesvirus associated with AIDS-related body cavity-based lymphomas (BCBL), also called primary effusion lymphomas (PEL). These are a rare form of non-Hodgkin lymphomas in which HHV-8 is present, often associated with Epstein-Barr virus (EBV) infection. HHV-8 is also present in a latent state or in a state of low-level persistence in different primary effusion lymphoma-derived cell lines, such BCBL-1 cells, that lack EBV infection. This cell line was induced to produce mature virions by treatment with 12- O -tetradecanoyl phorbol-13-acetate (TPA) and the characteristic ultrastructural features of HHV-8 lytic replication were identified and compared to those of the other members of Herpesviridae family. 相似文献
126.
Roberto Ronca Patrizia Alessi Daniela Coltrini Emanuela Di Salle Arianna Giacomini Daria Leali Michela Corsini Mirella Belleri Chiara Tobia Cecilia Garlanda Elisa Bonomi Regina Tardanico William Vermi Marco Presta 《The Journal of pathology》2013,230(2):228-238
Fibroblast growth factors (FGFs) exert autocrine/paracrine functions in prostate cancer by stimulating angiogenesis and tumour growth. Here dihydrotestosterone (DHT) up‐regulates FGF2 and FGF8b production in murine TRAMP‐C2 prostate cancer cells, activating a FGF‐dependent autocrine loop of stimulation. The soluble pattern recognition receptor long pentraxin‐3 (PTX3) acts as a natural FGF antagonist that binds FGF2 and FGF8b via its N‐terminal domain. We demonstrate that recombinant PTX3 protein and the PTX3‐derived pentapeptide Ac‐ARPCA‐NH2 abolish the mitogenic response of murine TRAMP‐C2 cells and human LNCaP prostate cancer cells to DHT and FGFs. Also, PTX3 hampers the angiogenic activity of DHT‐activated TRAMP‐C2 cells on the chick embryo chorioallantoic membrane (CAM). Accordingly, human PTX3 overexpression inhibits the mitogenic activity exerted by DHT or FGFs on hPTX3_TRAMP‐C2 cell transfectants and their angiogenic activity. Also, hPTX3_TRAMP‐C2 cells show a dramatic decrease of their angiogenic and tumourigenic potential when grafted in syngeneic or immunodeficient athymic male mice. A similar inhibitory effect is observed when TRAMP‐C2 cells overexpress only the FGF‐binding N‐terminal PTX3 domain. In keeping with the anti‐tumour activity of PTX3 in experimental prostate cancer, immunohistochemical analysis of prostate needle biopsies from primary prostate adenocarcinoma patients shows that parenchymal PTX3 expression, abundant in basal cells of normal glands, is lost in high‐grade prostatic intraepithelial neoplasia and in invasive tumour areas. These results identify PTX3 as a potent FGF antagonist endowed with anti‐angiogenic and anti‐neoplastic activity in prostate cancer. Copyright © 2013 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd. 相似文献
127.
Norma Maugeri Mattia Baldini Patrizia Rovere-Querini Attilio Maseri Maria Grazia Sabbadini 《Autoimmunity》2013,46(4):386-388
Ischemia is a leading causes of morbidity in giant cell arteritis (GCA). We studied circulating platelets and leukocytes in patients with GCA and with polymyalgia rheumatica. Normal healthy donors (>60 a) served as controls. Patients had a significantly greater fraction of platelets expressing P-selectin, of platelet–Nph and platelet–Mo aggregates, and of Nph and Mo expressing tissue factor. These differences were correlated with the percentage of platelets expressing P-selectin and were not influenced by clinical features or by systemic inflammation. Activated circulating leukocytes and platelets could contribute to indolent vessel inflammation and possibly to thromboembolic events in patients with systemic large vessel vasculitis. 相似文献
128.
129.
130.