1,990 research outputs found

    Chiral symmetry restoration and the critical end point in QCD

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    Abstract: In a system of quark matter we study the chiralphasetransition,thebehaviorofthechiralandquark number susceptibility and the CEP at finite temperature andchemicalpotential.Thisisdonewithintheframework oftwo-flavorNambuandJona-Lasiniomodel.Wehavecalculatedthechiralquarkcondensateandthequarknumber densityand,withthis,wehavefoundthephasetransition type.Withthesequantitieswehavedeterminedthephase diagramforQCDandtheCEP. Keywords:chiralphasetransition,criticalendpoint,dynamicalmass,criticalbehavior,dynamicalchiralsymmetrybreakin

    Accounting for ocean connectivity and hydroclimate in fish recruitment fluctuations within transboundary metapopulations

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    International audienceMarine resources stewardships are progressively becoming more receptive to an effective incorporation of both ecosystem and environmental complexities into the analytical frameworks of fisheries assessment. Understanding and predicting marine fish production for spatially and demographically complex populations in changing environmental conditions is however still a difficult task. Indeed, fisheries assessment is mostly based on deterministic models that lack realistic parameterizations of the intricate biological and physical processes shaping recruitment, a cornerstone in population dynamics. We use here a large metapopulation of a harvested fish, the European hake (Merluccius merluccius), managed across transnational boundaries in the northwestern Mediterranean, to model fish recruitment dynamics in terms of physics-dependent drivers related to dispersal and survival. The connectivity among nearby subpopulations is evaluated by simulating multi-annual Lagrangian indices of larval retention, imports, and self-recruitment. Along with a proxy of the regional hydroclimate influencing early life stages survival, we then statistically determine the relative contribution of dispersal and hydroclimate for recruitment across contiguous management units. We show that inter-annual variability of recruitment is well reproduced by hydroclimatic influences and synthetic connectivity estimates. Self-recruitment (i.e., the ratio of retained locally produced larvae to the total number of incoming larvae) is the most powerful metric as it integrates the roles of retained local recruits and immigrants from surrounding subpopulations and is able to capture circulation patterns affecting recruitment at the scale of management units. We also reveal that the climatic impact on recruitment is spatially structured at regional scale due to contrasting biophysical processes not related to dispersal. Self-recruitment calculated for each management unit explains between 19% and 32.9% of the variance of recruitment variability, that is much larger than the one explained by spawning stock biomass alone, supporting an increase of consideration of connectivity processes into stocks assessment. By acknowledging the structural and ecological complexity of marine populations, this study provides the scientific basis to link spatial management and temporal assessment within large marine metapopulations. Our results suggest that fisheries management could be improved by combining information of physical oceanography (from observing systems and operational models), opening new opportunities such as the development of short-term projections and dynamic spatial management

    Clinical picture, management and risk stratification in patients with cardiogenic shock: does gender matter?

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    Background: Early recognition and risk stratification are crucial in cardiogenic shock (CS). A lower adherence to recommendations has been described in women with cardiovascular diseases. Little information exists about disparities in clinical picture, management and performance of risk stratification tools according to gender in patients with CS. Methods: Data from the multicenter Red-Shock registry were used. All consecutive patients with CS were included. Both CardShock and IABP-SHOCK II risk scores were calculated. The primary end-point was in-hospital mortality. The discriminative ability of both scores according to gender was assessed by binary logistic regression, calculating Receiver operating characteristic (ROC) curves and the corresponding area under the curve (AUC). Results: A total of 793 patients were included, of whom 222 (28%) were female. Women were significantly older and had a lower proportion of chronic obstructive pulmonary disease and prior myocardial infarction. CS was less often related to acute coronary syndromes (ACS) in women. The use of vasoactive drugs, renal replacement therapy, invasive ventilation, therapeutic hypothermia and mechanical circulatory support was similar between both groups. In-hospital mortality was 346/793 (43.6%). Mortality was not significantly different according to gender (p = 0.194). Cardshock risk score showed a good ability for predicting in-hospital mortality both in man (AUC 0.69) and women (AUC 0.735). Likewise, the IABP-II successfully predicted in-hospital mortality in both groups (man: AUC 0.693; women: AUC 0.722). Conclusions: No significant differences were observed regarding management and in-hospital mortality according to gender. Both the CardShock and IABP-II risk scores depicted a good ability for predicting mortality also in women with CS

    Especificación de un modelo para el estudio de la percepción de utilidad

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    A model is a data management, production and transfer system organized in explanatory trends of past, current and future relationships. The emphasis on each suggests decision making and strategy execution. The objective of this work was to specify a model for of the perception of utility. An exploratory and cross-sectional study was conducted with a selection of 186 students from a public university in central Mexico, considering their participation in the system of professional practices and social service in local organizations. The validity of the instrument that found a one-dimensional variable that explained 43% of the variance was established, but the research design limited the results to the research scenario, suggesting the extension of the work

    Noninvasive Biomarkers for the Diagnosis of Liver Fibrosis and Cirrhosis

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    The clinical importance of monitoring liver fibrosis lies in the morbidity and mortality of the chronic liver diseases in relation to the stage and progression of fibrosis. Whether the fibrosis stabilizes or regresses depends on the specific treatment. Liver biopsy, the current standard for the diagnosis, has implicit limitations due to sampling heterogeneity. There are noninvasive imaging methods, such as transient elastography that measures the stiffness of the liver, but it has some limitations (feasibility and unreliability), particularly in obese patients. FibroTest is the most widely used noninvasive serological method worldwide which is efficacious in the extreme stages of fibrosis, but these methods cannot discern intermediate stages. Liver fibrosis is a dynamic response that involves multiple cellular and molecular events with an excessive deposit of extracellular matrix. Even though there is much information on the pathophysiology of fibrosis, that knowledge is still incomplete, greatly hindering the development of both an accurate treatment and a noninvasive diagnostic method with adequate sensitivity for all the stages of fibrosis. It is known that IGFBP participates in liver homeostasis, and thus these proteins can be used as serum biomarkers during the progression of liver fibrosis in chronic hepatitis C

    Humans with inherited MyD88 and IRAK-4 deficiencies are predisposed to hypoxemic COVID-19 pneumonia

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    X-linked recessive deficiency of TLR7, a MyD88- and IRAK-4–dependent endosomal ssRNA sensor, impairs SARS-CoV-2 recognition and type I IFN production in plasmacytoid dendritic cells (pDCs), thereby underlying hypoxemic COVID-19 pneumonia with high penetrance. We report 22 unvaccinated patients with autosomal recessive MyD88 or IRAK-4 deficiency infected with SARS-CoV-2 (mean age: 10.9 yr; 2 mo to 24 yr), originating from 17 kindreds from eight countries on three continents. 16 patients were hospitalized: six with moderate, four with severe, and six with critical pneumonia, one of whom died. The risk of hypoxemic pneumonia increased with age. The risk of invasive mechanical ventilation was also much greater than in age-matched controls from the general population (OR: 74.7, 95% CI: 26.8–207.8, P < 0.001). The patients’ susceptibility to SARS-CoV-2 can be attributed to impaired TLR7-dependent type I IFN production by pDCs, which do not sense SARS-CoV-2 correctly. Patients with inherited MyD88 or IRAK-4 deficiency were long thought to be selectively vulnerable to pyogenic bacteria, but also have a high risk of hypoxemic COVID-19 pneumonia

    Autoantibodies against the immunodominant sCha epitope discriminate the risk of sudden death in chronic Chagas cardiomyopathy

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    In Chagas disease (ChD) caused by Trypanosoma cruzi, new biomarkers to predict chronic cardiac pathology are urgently needed. Previous studies in chagasic patients with mild symptomatology showed that antibodies against the immunodominant R3 epitope of sCha, a fragment of the human basic helix-loop-helix transcription factor like 5, correlated with cardiac pathology. To validate sCha as a biomarker and to understand the origin of anti-sCha antibodies, we conducted a multicenter study with several cohorts of chagasic patients with severe cardiac symptomatology. We found that levels of antibodies against sCha discriminated the high risk of sudden death, indicating they could be useful for ChD prognosis. We investigated the origin of the antibodies and performed an alanine scan of the R3 epitope. We identified a minimal epitope MRQLD, and a BLAST search retrieved several T. cruzi antigens. Five of the hits had known or putative functions, of which phosphonopyruvate decarboxylase showed the highest cross-reactivity with sCha, confirming the role of molecular mimicry in the development of anti-sCha antibodies. Altogether, we demonstrate that the development of antibodies against sCha, which originated by molecular mimicry with T. cruzi antigens, could discriminate electrocardiographic alterations associated with a high risk of sudden death.Ministerio de Economía y competitividad and Fondo Europeo de Desarrollo Regional (SAF2015-63868-R (MINECO/FEDER) to N.G., and SAF2016-75988-R (MINECO/FEDER) to M.F.); Ministerio de Ciencia, Innovación y Universidades-Agencia Estatal de Investigación and Fondo Europeo de Desarrollo Regional (PGC2018-096132-BI00 (MICINN/FEDER) to N.G.); Universidad Autónoma de Madrid-Banco de Santander Inter-University Cooperation Grant with Latin América (CEAL-AL/2015-12 to N.G.); Red de Investigación de Centros de Enfermedades Tropicales (RICET RD12/0018/0004 to M.F.); and Comunidad de Madrid (S-2010/BMD-2332 to M.F.). CBMSO institutional grants from Fundación Ramón Areces and Banco de Santande

    IV consenso mexicano sobre Helicobacter pylori

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    Desde el último consenso mexicano para el diagnóstico y tratamiento de la infección por Helicobacter pylori (H. pylori) en el 2007, han existido avances importantes al respecto. Por tal motivo, la Asociación Mexicana de Gastroenterología convocó a 20 expertos para la realización del «IV consenso mexicano sobre H. pylori». Durante febrero y junio del 2017 se organizaron 4 mesas de trabajo, una revisión de la literatura y 3 rondas de votaciones donde se establecieron 32 enunciados para discusión y consenso. Dentro de las recomendaciones se destaca el reconocer a México como un país con riesgo de cáncer gástrico bajo a intermedio a pesar de la alta prevalencia de infección por H. pylori. Se corrobora que enfermedad ulcerosa péptica, presencia de lesiones premalignas, antecedentes de cáncer gástrico y linfoma asociado a la mucosa deben considerarse indicaciones claras para erradicación. La relación del H. pylori con los síntomas dispépticos sigue siendo controversial. La triple terapia de erradicación con amoxicilina, claritromicina y un inhibidor de la bomba de protones ya no debe ser considerada la primera línea de tratamiento. En su lugar, se proponen 2 opciones: la terapia cuádruple con bismuto (inhibidor de la bomba de protones, subcitrato de bismuto, tetraciclina y metronidazol) y la terapia cuádruple sin bismuto (inhibidor de la bomba de protones, amoxicilina, claritromicina y metronidazol). Se establece la necesidad de la realización de sensibilidad antimicrobiana ante la falla a 2 tratamientos de erradicación. Finalmente, se proponen campañas de educación respecto al diagnóstico y tratamiento del H. pylori para médicos de primer contacto y población general. Abstract Important advances have been made since the last Mexican consensus on the diagnosis and treatment of Helicobacter pylori (H. pylori) infection was published in 2007. Therefore, the Asociación Mexicana de Gastroenterología summoned 20 experts to produce ‘‘The Fourth Mexican Consensus on Helicobacter pylori’’. From February to June 2017, 4 working groups were organized, a literature review was performed, and 3 voting rounds were carried out, resulting in the formulation of 32 statements for discussion and consensus. From the ensuing recommendations, it was striking that Mexico is a country with an intermediate-to-low risk for gastric cancer, despite having a high prevalence of H. pylori infection. It was also corroborated that peptic ulcer disease, premalignant lesions, and histories of gastric cancer and mucosaassociated lymphoid tissue lymphoma should be considered clear indications for eradication. The relation of H. pylori to dyspeptic symptoms continues to be controversial. Eradication triple therapy with amoxicillin, clarithromycin, and a proton pump inhibitor should no longer be considered first-line treatment, with the following 2 options proposed to take its place: quadruple therapy with bismuth (proton pump inhibitor, bismuth subcitrate, tetracycline, and metronidazole) and quadruple therapy without bismuth (proton pump inhibitor, amoxicillin, clarithromycin, and metronidazole). The need for antimicrobial sensitivity testing when 2 eradication treatments have failed was also established. Finally, the promotion of educational campaigns on the diagnosis and treatment of H. pylori for both primary care physicians and the general population were proposed
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