52 research outputs found

    Dynamics of liquid crystalline domains in magnetic field

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    We study microscopic single domains nucleating and growing within the coexistence region of the Isotropic (I) and Nematic (N) phases in magnetic field. By rapidly switching on the magnetic field the time needed to align the nuclei of sufficiently large size is measured, and is found to decrease with the square of the magnetic field. When the field is removed the disordering time is observed to last on a longer time scale. The growth rate of the nematic domains at constant temperature within the coexistence region is found to increase when a magnetic field is applied.Comment: 10 pages, 5 figures, unpublishe

    Fatigue behavior of foreign object damaged 7075 heat treated aluminum alloy coated with PVD WC/C

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    AbstractThe effect of a physically vapor deposited (PVD) WC/C coating on the fatigue behavior of as produced and foreign object damaged (FOD) solution heat treated and aged 7075 aluminum alloy was studied. Coated and uncoated samples were tested under rotating bending to determine the fatigue strengths between 104 and 106 cycles in both damaged and smooth condition. FOD was produced with single shots of small hard steel spheres impacting at 100 m/s in the minimum cross section. SEM was used to characterize the features of the fracture surfaces

    Five-year retrospective italian multicenter study of visceral leishmaniasis treatment

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    The treatment of visceral leishmaniasis (VL) is poorly standardized in Italy in spite of the existing evidence. All consecutive patients with VL admitted at 15 Italian centers as inpatients or outpatients between January 2004 and December 2008 were retrospectively considered; outcome data at 1 year after treatment were obtained for all but 1 patient. Demographic characteristics, underlying diseases, diagnostic procedures, treatment regimens and outcomes, as well as side effects were recorded. A confirmed diagnosis of VL was reported for 166 patients: 120 (72.3%) immunocompetent, 21 (12.6%) patients with immune deficiencies other than HIV infection, and 25 (15.1%) coinfected with HIV. Liposomal amphotericin B (L-AmB) was the drug almost universally used for treatment, administered to 153 (92.2%) patients. Thirty-seven different regimens, including L-AmB were used. The mean doses were 29.4 \ub1 7.9 mg/kg in immunocompetent patients, 32.9 \ub1 8.6 mg/kg in patients with non-HIV-related immunodeficiencies, and 40.8 \ub1 6.7 mg/kg in HIV-infected patients (P < 0.001). The mean numbers of infusion days were 7.8 \ub1 3.1 in immunocompetent patients, 9.6 \ub1 3.9 in non-HIV-immunodeficient patients, and 12.0 \ub1 3.4 in HIV-infected patients (P < 0.001). Mild and reversible adverse events were observed in 12.2% of cases. Responsive patients were 154 (93.3%). Successes were 98.4% among immunocompetent patients, 90.5% among non-HIV-immunodeficient patients, and 72.0% among HIV-infected patients. Among predictors of primary response to treatment, HIV infection and age held independent associations in the final multivariate models, whereas the doses and duration of L-AmB treatment were not significantly associated. Longer treatments and higher doses of L-AmB were not able to significantly modify treatment outcomes either in the immunocompetent or in the immunocompromised population

    Prevalence of M75 Streptococcus Pyogenes strains harboring slaa gene in patients affected by pediatric obstructive sleep apnea syndrome in Central Italy

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    Recently we reported an association between pediatric obstructive sleep apnea syndrome (OSAS) and Group A streptococcus (GAS) sub-acute chronic tonsil colonization. We showed that GAS may contribute to tonsil hyperplasia via a streptolysin O (SLO)-dependent cysteinyl leukotrienes (CysLTs) production, which can trigger T and B cell proliferation. In the present study, we characterized the GAS strains isolated from pediatric OSAS patients in comparison with a panel of age and sex matched GAS strains unrelated to OSAS, but isolated in the same area and during the same period ranging from 2009 to 2013. We found that slaA gene, previously reported to be associated to CysLTs production pathway, was significantly associated to GAS OSAS strains. Moreover, the most numerous group (32%) of the GAS OSAS strains belonged to M75 type, and 6 out of 7 of these strains harbored the slaA gene. Multilocus Sequence Typing (MLST) experiments demonstrated that the clone emm75/ST49/ smeZ, slaA was associated to OSAS cases. In conclusion, we found an association between slaA gene and the GAS OSAS strains, and we showed that the clone emm75/ST49 harboring genes smeZ and slaA was exclusively isolated from patients affected by OSAS, thus suggesting that this genotype might be associated to the pathogenesis of OSAS, although further studies are needed to elucidate the possible role of SlaA in tonsil hypertrophy development

    Paediatric obstructive sleep apnoea syndrome (OSAS) is associated with tonsil colonisation by Streptococcus pyogenes

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    The involvement of pathogenic bacteria in obstructive sleep apnoea syndrome (OSAS) has yet to be elucidated. We investigated the possible role of group A streptococcus (GAS) in OSAS pathogenesis. In 40 tonsillectomized patients affected by OSAS and 80 healthy controls, significant (p < 0.0001) association of GAS with paediatric OSAS was found. Supernatant from streptolysin O (SLO)-producing GAS induced production of cysteinyl leukotrienes (CysLTs) in tonsil mononuclear cells (TMCs). CysLTs-treated TMCs showed significant (p < 0.05) proliferation of CD4+ T, CD19+ and CD19+CD27+CD38+ B lymphocytes. We discovered a SLO-dependent activation of CysLTs production through a pathway involving TOLL-like receptor 4 (TLR4), TIR-domain-containing adapter-inducing interferon-β (TRIF), Myeloid differentiation primary response gene 88 (MyD88), and p38 MAP Kinase. In conclusion, we hypothesise that GAS may contribute to paediatric tonsillar hyperplasia through CysLTs production induced by SLO, and this might explain its association with OSA

    Chromosome conformation signatures define predictive markers of inadequate response to methotrexate in early rheumatoid arthritis

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    The authors would like to thank members of OBD Reference Facility Benjamin Foulkes, Chloe Bird, Emily Corfeld and Matthew Salter for expedient processing of clinical samples on the EpiSwitch™ platform and Magdalena Jeznach and Willem Westra for help with preparation of the manuscript. The study employed samples from the SERA Biobank used with permission and approval of the SERA Approval Group. We gratefully acknowledge the invaluable contribution of the clinicians and operating team in SERA. We would also like to thank Prof. Raju Kucherlapati (Harvard Medical School), and Prof. Jane Mellor (Oxford Univ.), Prof. John O’Shea (National Institute of Health) and Prof. John Isaacs (New Castle Univ.) for their independent and critical review of our study. A list of Scottish Early Rheumatoid Arthritis (SERA) inception cohort investigators is provided in Additional fle 1: Additional Note. Funding This work was funded by Oxford BioDynamics.Peer reviewedPublisher PD

    Is Rotavirus a hepatotropic virus?

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    Doubly periodic instability pattern in a smectic-A liquid crystal

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    Contains fulltext : 116957.pdf (preprint version ) (Open Access

    Relapsing fever in a traveller from Senegal: determination of Borrelia species using molecular methods

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    We describe a case of a febrile patient returning from Senegal in which haemoscopic and molecular investigation confirmed tick-borne relapsing fever (TBRF), suggesting Borrelia crocidurae as the causative agent. This case emphasises the need to include TBRF in the differential diagnosis of fever following a journey from endemic countries, including malarial areas
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