全文获取类型
收费全文 | 29501篇 |
免费 | 1362篇 |
国内免费 | 200篇 |
专业分类
耳鼻咽喉 | 323篇 |
儿科学 | 545篇 |
妇产科学 | 704篇 |
基础医学 | 3408篇 |
口腔科学 | 1522篇 |
临床医学 | 2236篇 |
内科学 | 7986篇 |
皮肤病学 | 443篇 |
神经病学 | 2728篇 |
特种医学 | 1115篇 |
外科学 | 4238篇 |
综合类 | 112篇 |
一般理论 | 7篇 |
预防医学 | 1556篇 |
眼科学 | 433篇 |
药学 | 1634篇 |
中国医学 | 119篇 |
肿瘤学 | 1954篇 |
出版年
2023年 | 175篇 |
2022年 | 421篇 |
2021年 | 805篇 |
2020年 | 457篇 |
2019年 | 632篇 |
2018年 | 818篇 |
2017年 | 574篇 |
2016年 | 698篇 |
2015年 | 804篇 |
2014年 | 1106篇 |
2013年 | 1492篇 |
2012年 | 2278篇 |
2011年 | 2446篇 |
2010年 | 1407篇 |
2009年 | 1247篇 |
2008年 | 2125篇 |
2007年 | 2180篇 |
2006年 | 2008篇 |
2005年 | 2023篇 |
2004年 | 1799篇 |
2003年 | 1554篇 |
2002年 | 1446篇 |
2001年 | 188篇 |
2000年 | 121篇 |
1999年 | 169篇 |
1998年 | 240篇 |
1997年 | 190篇 |
1996年 | 186篇 |
1995年 | 146篇 |
1994年 | 136篇 |
1993年 | 91篇 |
1992年 | 101篇 |
1991年 | 91篇 |
1990年 | 74篇 |
1989年 | 80篇 |
1988年 | 74篇 |
1987年 | 52篇 |
1986年 | 53篇 |
1985年 | 46篇 |
1984年 | 85篇 |
1983年 | 54篇 |
1982年 | 72篇 |
1981年 | 47篇 |
1980年 | 28篇 |
1979年 | 27篇 |
1978年 | 28篇 |
1977年 | 30篇 |
1976年 | 21篇 |
1974年 | 18篇 |
1973年 | 22篇 |
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
171.
Bone-specific antibodies in sera from patients with celiac disease: characterization and implications in osteoporosis 总被引:5,自引:0,他引:5
Sugai E Cherñavsky A Pedreira S Smecuol E Vazquez H Niveloni S Mazure R Mauriro E Rabinovich GA Bai JC 《Journal of clinical immunology》2002,22(6):353-362
Osteopenia and osteoporosis are well-known complications detected in celiac disease patients with still obscure pathogenesis. In the present study we investigated the presence of circulating anti-bone autoantibodies in patients with celiac disease and explored their role in the associated bone disease. We evaluated serum samples from 33 patients at the time of diagnosis and from 20 of them after treatment. Sera from patients with inflammatory bowel disease (n = 9), nonceliac osteoporotic (n = 18), and healthy individuals (n = 10) were used as controls. The presence of IgA specific anti-bone antibodies was first investigated using indirect immunofluorescence on cryosections of fetal rat tibia (20-day pregnancy). Furthermore, samples were homogenized and total tissue extracts were subjected to Western blot analysis to confirm immunoreactivity. At diagnosis, sera from 51.5% (17/33) of celiac patients had antibodies that recognized antigenic structures in chondrocytes and the extracellular matrix along mature cartilage, bone interface, and perichondrium of fetal rat bone. Among controls, only two osteoporotic patients showed very low titles of anti-bone autoantibodies. The immunostaining was localized in areas where an active mineralization process occurred and was similar to the distribution of the native bone tissue transglutaminase. The frequency of patients with positive baseline titers of anti-bone antibodies diminished significantly after treatment (P = 0.048). Western blot assays confirmed the presence of autoantibodies in sera from patients with a positive immunofluorescence staining. Autoantibodies recognized a major protein band on tissue extracts with a molecular weight of 77–80 kDa, which could be displaced when sera were preadsorbed with human recombinant tissue transglutaminase. We provide original evidence that patients with celiac disease have IgA-type circulating autoantibodies against intra- and extracellular structures of fetal rat tibia. Our findings suggest that these antibodies recognize bone tissue transglutaminase as the autoantigen, and based on the localization of the immunoreactivity we speculate that they might have an active role in the pathophysiology of celiac disease-associated bone complications. 相似文献
172.
Mauro Congia Fulvia Frau Rosanna Lampis Rita Frau Roberto Mele Francesco Cucca Francesco Muntoni Susanna Porcu Francesca Boi Licinio Contu Giorgio La Nasa Marina Mulargia Mario Pirastu Antonio Cao Stefano De Virgillis 《Tissue antigens》1992,39(2):78-83
This study characterizes by serological and molecular methods the HLA class I and class II alleles in a group of celiac disease children, their parents and a control group of Sardinian descent. We found the DR3-DQw2 haplotype in all patients which was, in almost all cases (84%), associated with the HLA-A30, B18, DR3, DRw52, DQw2 extended haplotype named "Sardinian haplotype" because of its frequency (12-15%) in this Caucasian population. This is the first time that this DQw2-linked haplotype has been reported with such a high frequency in CD. However, no different distribution of "Sardinian haplotype" was found comparing CD patients with 91 haplotyped DQw2-positive controls. This finding indicates that the DQw2 antigen in Sardinians is almost always associated with the A30, B18, DR3, DRw52, DQw2 extended haplotype. The DQA1 and DQB1 second exon sequence analysis of the B18,DR3 and B8,DR3 haplotypes showed the DQA1*0501 and DQB1*0201 alleles which shared the already published sequences. DPB1 subtyping showed the DPB1*0301 allele more frequently (p less than 0.005) in CD patients but this difference was no longer significant when patients and controls, both heterozygous for the DR3-DQw2 haplotype, were compared. We suggest that the divergent HLA extended haplotypes and DP allele associated with CD, described in different Caucasian populations, can be explained by the particular DQw2 linkage disequilibrium in each population. 相似文献
173.
Borsari V Giavaresi G Fini M Torricelli P Tschon M Chiesa R Chiusoli L Salito A Volpert A Giardino R 《Biomaterials》2005,26(24):4948-4955
A new implant surface has been developed with the purpose of avoiding as much stress shielding as possible, and thus prolong the prosthesis lifespan. The aim of this study was to investigate the in vitro effect of this new ultra-high roughness and dense Titanium (Ti) surface (PG60, Ra = 74 microm) in comparison with medium (TI01, Ra = 18 microm) and high (TI60, Ra = 40 microm) roughness and open porous coatings; all the coatings were obtained by vacuum plasma spraying. MG63 osteoblast-like cells were seeded on the tested materials and polystyrene, as control, for 3 and 7 days. Cells proliferated on the material surfaces similarly to the control. Alkaline phosphatase activity had lower values for TI60 than TI01 (p < 0.0005) and PG60 (p < 0.005). Osteocalcin levels measured on TI60 were significantly (p < 0.0005) lower in comparison with TI01 and PG60 at 7 days. Procollagen-I synthesis reduced with increasing roughness and the lowest data was found for PG60. While at 3 days Transforming Growth Factor beta1 levels augmented with increasing roughness, at 7 days TI60, the high roughness surface, was significantly lower than PG60 (p < 0.005) and TI01 (p < 0.001). All tested materials showed significantly higher Interleukin-6 levels than those of polystyrene at both experimental times. Nitric Oxide activity on TI01 was significantly (p < 0.05) higher than on TI60 and polystyrene. In conclusion, the new ultra-high roughness and dense coating PG60 provided a good biological response, even though, at least in vitro, it behaved similarly to the coatings already used in orthopaedics. 相似文献
174.
The mechanism of the force response to stretch in human skinned muscle fibres with different myosin isoforms 总被引:5,自引:1,他引:5
Marco Linari Roberto Bottinelli Maria Antonietta Pellegrino Massimo Reconditi Carlo Reggiani Vincenzo Lombardi 《The Journal of physiology》2004,554(2):335-352
Force enhancement during lengthening of an active muscle, a condition that normally occurs during locomotion in vivo , is attributed to recruitment of myosin heads that exhibit fast attachment to and detachment from actin in a cycle that does not imply ATP splitting. We investigated the kinetic and mechanical features of this cycle in Ca2+ activated single skinned fibres from human skeletal muscles containing different myosin heavy chain (MHC) isoforms, identified with single-fibre gel electrophoresis. Fibres were activated by using a new set-up that allows development of most of the tension following a temperature jump from 0–1°C to the test temperature (∼12°C). In this way we could prevent the development of sarcomere non-uniformity and record sarcomere length changes with a striation follower in any phase of the mechanical protocol. We found that: (i) fibres with fast MHC isoforms develop 40–70% larger isometric forces than those with slow isoforms, as a result of both a larger fraction of force-generating myosin heads and a higher force per head; (ii) in both slow and fast fibres, force enhancement by stretch is due to recruitment of myosin head attachments, without increase in strain per head above the value generated by the isometric heads; and (iii) the extent of recruitment is larger in slow fibres than in fast fibres, so that the steady force and power output elicited by lengthening become similar, indicating that mechanical and kinetic properties of the actin–myosin interactions under stretch become independent of the MHC isoform. 相似文献
175.
Francesca Oliviero Paola Galozzi Anna Scanu Francesca Galuppini Vanni Lazzarin Silvia Brocco Giampietro Ravagnan Paolo Sfriso Roberta Ramonda Paolo Spinella Leonardo Punzi Gianmaria Pennelli Roberto Luisetto 《Nutrients》2021,13(3)
Background: Polydatin is a stilbenoid with important antioxidant, anti-inflammatory, and immunomodulating properties. The aim of this study was to assess the anti-inflammatory preventive effect of polydatin in the mouse model of acute arthritis induced by calcium pyrophosphate (CPP) crystals. Methods: Acute arthritis was induced by the injection of a suspension of sterile CPP crystals into the ankle joint of Balb/c mice. Animals were randomized to receive polydatin or colchicine (the control drug) according to a prophylactic and a therapeutic protocol. The primary outcome was the variation of ankle swelling obtained after crystal injection and treatment, while histological parameters such as leukocyte infiltration, IL-1ß and CXCL1 levels and tissue expression were considered as secondary outcomes. Results: Prophylactic treatment with PD significantly diminished ankle swelling after 48 h from crystal injection. Secondary outcomes such as leukocyte infiltration, necrosis, edema, and synovitis were also decreased. PD caused a reduction in circulating levels of IL-1ß and CXCL1, as well as their tissue expression. By contrast, the therapeutic administration of PD did not have any beneficial effect. Conclusions: PD can effectively prevent acute inflammatory response to crystals in the mouse model of CPP crystal-induced arthritis. These results suggest that this bioactive compound might be used in the prevention of crystal-induced acute attacks in humans. 相似文献
176.
Alma Martelli Lorenzo Flori Era Gorica Eugenia Piragine Anella Saviano Giuseppe Annunziata Matteo Nicola Dario Di Minno Roberto Ciampaglia Ilenia Calcaterra Francesco Maione Gian Carlo Tenore Ettore Novellino Vincenzo Calderone 《Nutrients》2021,13(5)
Preservation of vascular endothelium integrity and functionality represents an unmet medical need. Indeed, endothelial dysfunction leads to decreased nitric oxide biosynthesis, which is prodromic of hypertension and hypercoagulability. In this panorama, the nutraceutical supplement Taurisolo®, a polyphenolic extract from Aglianico cultivar grape, rich in catechin and procyanidins, was evaluated as a vasoprotective, vasorelaxing, anti-hypertensive and anti-coagulant agent in: cell lines, isolated vessels, in vivo models of chronic hypertension and hypercoagulability, and in clinical tests of endothelial reactivity. Taurisolo® demonstrated to fully protect vascular cell viability from oxidative stimulus at 100 µg/mL and evoke vasorelaxing effects (Emax = 80.6% ± 1.9 and pEC50 = 1.19 ± 0.03) by activation of the Sirtuins-AMPK-pathway. Moreover, Taurisolo®, chronically administered at 20 mg/Kg/die in in vivo experiments, inhibited the onset of cardiac hypertrophy (heart weight/rat weight = 3.96 ± 0.09 vs. 4.30 ± 0.03), hypercoagulability (decrease of fibrinogen vs. control: p < 0.01) and hypertension (mean of Psys: 200 ± 2 vs. control 234 ± 2 mmHg) and improved endothelial function (Emax = 88.9% ± 1.5 vs. control 59.6% ± 3.6; flow-mediated dilation in healthy volunteers after 400 mg twice daily for 8 weeks vs. baseline: p = 0.019). In conclusion, Taurisolo® preserves the vascular function against ox-inflamm-ageing process and the consequent cardiovascular accidents. 相似文献
177.
Xavier Nogués Francisca Sánchez-Martinez Xavier Castells Adolfo Díez-Pérez Rosa Ana Sabaté Irene Petit Ariadna Brasé Juan Pablo Horcajada Roberto Güerri-Fernández Julio Pascual 《Journal of the American Medical Directors Association》2021,22(5):939-942
A Coronavirus Disease 2019 (COVID-19)–specific Hospital-at-Home was implemented in a 400-bed tertiary hospital in Barcelona, Spain. Senior or immune-compromised physicians oversaw patient care. The alternative to inpatient care more than doubled beds available for hospitalization and decreased the risk of transmission among patients and health care professionals. Mild cases from either the emergency department or after hospital discharge were deemed suitable for admission to the Hospital-at-Home. More than half of all patients had pneumonia. Standardized protocols and management criteria were provided. Only 6% of cases required referral for inpatient hospitalization. These results are promising and may provide valuable insight for centers undertaking Hospital-at-Home initiatives or in the case of new COVID-19 outbreaks. 相似文献
178.
Alfred K. Cheung Tara I. Chang William C. Cushman Susan L. Furth Fan Fan Hou Joachim H. Ix Gregory A. Knoll Paul Muntner Roberto Pecoits-Filho Mark J. Sarnak Sheldon W. Tobe Charles R.V. Tomson Lyubov Lytvyn Jonathan C. Craig David J. Tunnicliffe Martin Howell Marcello Tonelli Michael Cheung Johannes F.E. Mann 《Kidney international》2021,99(3):559-569
179.
Luvero Daniela Filippini Maurizio Salvatore Stefano Pieralli Annalisa Farinelli Miriam Angioli Roberto 《Lasers in medical science》2021,36(9):1837-1843
Lasers in Medical Science - Childbirth is a great change in woman life because of hormonal, physical and psychological alterations that are associated with this process. Dyspareunia and perineal... 相似文献
180.
Di Rienzo Alessandro Colasanti Roberto Gladi Maurizio Dobran Mauro Della Costanza Martina Capece Mara Veccia Salvatore Iacoangeli Maurizio 《Neurosurgical review》2021,44(3):1523-1532
Neurosurgical Review - The optimal management of cranioplasty infections remains a matter of debate. Most authors have suggested that the infected bone/implant removal is mandatory, combined with... 相似文献