6,586 research outputs found

    Charge breaking bounds in the Zee model

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    We study the possibility that charge breaking minima occur in the Zee model. We reach very different conclusions from those attained in simpler, two Higgs doublet models, and the reason for this is traced back to the existence of cubic terms in the potential. A scan of the Zee model's parameter space shows that CB is restricted to a narrow region of values of the parameters

    The Era of Antimicrobial Peptides: Use of Hepcidins to Prevent or Treat Bacterial Infections and Iron Disorders

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    The current treatments applied in aquaculture to limit disease dissemination are mostly based on the use of antibiotics, either as prophylactic or therapeutic agents, with vaccines being available for a limited number of fish species and pathogens. Antimicrobial peptides are considered as promising novel substances to be used in aquaculture, due to their antimicrobial and immunomodulatory activities. Hepcidin, the major iron metabolism regulator, is found as a single gene in most mammals, but in certain fish species, including the European sea bass (Dicentrarchus labrax), two different hepcidin types are found, with specialized roles: the single type 1 hepcidin is involved in iron homeostasis trough the regulation of ferroportin, the only known iron exporter; and the various type 2 hepcidins present antimicrobial activity against a number of different pathogens. In this study, we tested the administration of sea bass derived hepcidins in models of infection and iron overload. Administration with hamp2 substantially reduced fish mortalities and bacterial loads, presenting itself as a viable alternative to the use of antibiotics. On the other hand, hamp1 seems to attenuate the effects of iron overload. Further studies are necessary to test the potential protective effects of hamp2 against other pathogens, as well as to understand how hamp2 stimulate the inflammatory responses, leading to an increased fish survival upon infection.This work was funded by the structured program of R&D&I ATLANTIDA - Platform for the monitoring of the North Atlantic Ocean and tools for the sustainable exploitation of the marine resources (NORTE-01-0145-FEDER-000040), supported by the North Portugal Regional Operational Programme (NORTE2020), through the European Regional Development Fund (ERDF). CB is supported by a Ph.D. fellowship (SFRH/BD/ 114899/2016) financed by FCT - Fundação para a Ciência e a Tecnologia/ Ministério da Ciência, Tecnologia e Ensino Superior

    The prognostic impact of magnesium in acute heart failure is different according to the presence of diabetes mellitus

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    Background: Hypermagnesemia predicts mortality in chronic heart failure (HF); however, in acute HF, magnesium does not seem to be outcome-associated. Diabetes mellitus (DM) frequently associates with altered magnesium status. We hypothesized that DM might influence the prognostic impact of magnesium in acute HF. Methods: This is a retrospective cohort study of hospitalized patients with acute HF. Patients without data on admission serum magnesium were excluded. Follow-up: 1 year from hospital admission. Primary end point: all-cause mortality. Patients were divided according to median serum magnesium (1.64 mEq/L). The Kaplan-Meier survival method was used to determine survival curves according to magnesium levels. The analysis was stratified according to the presence of DM. A multivariable Cox regression analysis was used to study the prognostic impact of magnesium. Results: We studied 606 patients. The mean age was 76 ± 12 years, 44.1% were male, 50.7% had DM, and 232 (38.3%) died during follow-up. Median magnesium was 1.64 (1.48-1.79) mEq/L. Patients with magnesium ≥1.64 mEq/L had higher 1-year mortality [141 (46.4%) vs 91 (30.1%), P < .001]. After adjustments for age, sex, history of atrial fibrillation, systolic blood pressure, heart rate, ischemic etiology, B-type natriuretic peptide, estimated glomerular filtration rate, alcohol consumption, antihyperglycaemic agents or glycated hemoglobin, admission glycemia, New York Heart Association class IV, and severe left ventricle systolic dysfunction, serum magnesium ≥1.64 mEq/L was associated with higher mortality only in patients with DM: HR 1.89 (95% confidence interval: 1.19-3.00), P = .007, and 1.27 (95% confidence interval: 0.83-1.94) and P = .26 for non-DM patients. The results were similar if magnesium was analyzed as a continuous variable. Per 0.1 mEq/L increase in magnesium levels, patients with DM had 13% increased risk of 1-year mortality. Conclusions: Higher magnesium levels were associated with worse prognosis only in HF patients with DM.info:eu-repo/semantics/publishedVersio

    Carbon stars in the X-shooter Spectral Library

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    We provide a new collection of spectra of 35 carbon stars obtained with the ESO/VLT X-shooter instrument as part of the X-shooter Spectral Library project. The spectra extend from 0.3μ\mum to 2.4μ\mum with a resolving power above \sim 8000. The sample contains stars with a broad range of (J-K) color and pulsation properties located in the Milky Way and the Magellanic Clouds. We show that the distribution of spectral properties of carbon stars at a given (J-K) color becomes bimodal (in our sample) when (J-K) is larger than about 1.5. We describe the two families of spectra that emerge, characterized by the presence or absence of the absorption feature at 1.53μ\mum, generally associated with HCN and C2_2H2_2. This feature appears essentially only in large-amplitude variables, though not in all observations. Associated spectral signatures that we interpret as the result of veiling by circumstellar matter, indicate that the 1.53μ\mum feature might point to episodes of dust production in carbon-rich Miras.Comment: 29 pages, 21 figures, 9 tables, Accepted for publication in A&

    Enterocolite Necrosante

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    Objectivo — Estudar a epidemiologia da enterocolite necrosante (ECN) na Unidade de Cuidados Intensivos Neonatais do Hospital de Dona Estefânia. Material e métodos — Foram revistos os processos clínicos dos recém-nascidos (RN) com ECN admitidos na UCIN do Hospital de Dona Estefânia no período compreendido entre 1 de Janeiro de 1990 e 31 de Dezembro de 1994 (5 anos). Foi feita a comparação entre alguns dos resultados obtidos neste período e os encontrados em estudo anterior (1985-1989). Na classificação da ECN foram utilizados os critérios de Bell modificados (1986). Resultados - Durante o período do estudo houve 34 RN com ECN correspondendo a 2,5% das admissões. Seis RN foram transferidos de outras unidades por ECN, para eventual intervenção cirúrgica. Vinte e um RN (61,8%) eram prétermo (RNPT) e 52,9% muito baixo peso (RNMBP). Vinte e quatro crianças, 11 das quais RNMBP, nasceram na maternidade do Hospital (incidência de ECN de 1,5 por mil nados-vivos; incidência de ECN no RNMBP de 6,5%). A idade média de início dos sintomas foi de 57 horas no RN de termo e 15 dias no RNPT (p = 0.000). Dezassete crianças tinham ECN grau I; quatro grau II; e treze grau III. (8 III A e 5 III B). Foram operados 35,3% dos RN, 58,3% dos quais no grau III A. Comparando os dois períodos, verificou-se que, nos últimos 5 anos, houve um menor número de ECN de grau avançado e de RN submetidos a intervenção cirúrgica, tendo esta ocorrido mais frequentemente no grau III A. Constatou-se uma descida da mortalidade superior a 50% do primeiro para o segundo período (32,1% vs 14,7%). Conclusão — A ECN é uma doença grave, predominante no RNPT. A acuidade do diagnóstico precoce traduz-se num menor número de intervenções cirúrgicas. A intervenção cirúrgica precoce — antes de ser diagnosticado pneumoperitoneu — contribui para reduzir a mortalidade

    Efeitos dos antibióticos rifampicina e cefotaxima no desenvolvimento de calos de maracuja-amarelo (Passiflora edulis f. Flavicarpa).

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    Este trabalho teve como objetivo verificar o efeito de antibióticos adicionados ao meio decultura ou em banho de imersão dos explantes no controle da contaminação e no desenvolvimento dos calos de maracujá-amarelo
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