649 research outputs found

    Thin film instability with thermal noise

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    We study the effects of stochastic thermal fluctuations on the instability of the free surface of a flat liquid film upon a solid substrate. These fluctuations are represented as a standard Brownian motion that can be added to the deterministic equation for the film thickness within the lubrication approximation. Here, we consider that while the noise term is white in time, it is coloured in space. This allows for the introduction of a finite correlation length in the description of the randomized intermolecular interaction. Together with the expected spatial periodicity of the flow, we find a dimensionless parameter, β\beta, that accounts for the relative importance of the spatial correlation. We perform here the linear stability analysis (LSA) of the film under the influence of both terms, and find the corresponding power spectra for the amplitudes of the normal modes of the instability. We compare this theoretical result with the numerical simulations of the complete non-linear problem, and find a good agreement for early times. For late times, we find that the stochastic LSA predictions on the dominant wavelength remains basically valid. We also use the theoretical spectra to fit experimental data from a nanometric melted copper film, and find the corresponding times of the evolution as well as the values of the parameter, β\beta

    Efeitos hemorreológicos das hemácias e suas implicações na saúde

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    La reología es una disciplina científica que se dedica al estudio de la deformación y flujo de la materia o, más precisamente, de los fluidos. En particular, la hemorreología se ocupa del comportamiento del flujo de la sangre completa, además de la deformabilidad de los elementos individuales que la componen (es decir, glóbulos rojos, glóbulos blancos y plaquetas). Debido a su importancia fisiopatológica, la medición de la deformabilidad de los glóbulos rojos ha sido el foco de numerosos estudios en las últimas décadas y en especial su rol en la regulación del suministro de O2 . El objetivo de esta revisión fue resumir la información actualmente disponible sobre la reología de la sangre, con especial énfasis en la influencia de la deformabilidad de los glóbulos rojos, destacando su relación con diversas enfermedades humanas tales como trastornos hereditarios de la membrana (esferocitosis, eliptocitosis, ovalocitosis y estomatocitosis), trastornos metabólicos (diabetes y cambios en la membrana inducidos por el estrés oxidativo) y losasociados a enfermedades críticas. Se exponen brevemente las técnicas microfluídicas que han sido identificadas como métodos de gran potencial en el desarrollo de modelos experimentales dinámicos de última generación. Su uso podría dilucidar la importancia de las alteraciones de la membrana de los eritrocitos en condiciones patológicas y las consecuencias de dichas alteraciones en la dinámica del flujo de la microcirculación.Rheology is a scientific discipline dealing with the flow and deformation behavior of materials, with the materials under consideration being solids or more precisely, fluids. In particular, hemorheology is concerned with the behaviour of the flow of whole blood and also the deformability of the individual elements that make it up (i.e. red blood cells, white blood cells and platelets). Due to its pathophysiological importance, the measurement of red blood cell deformability has been the focus of numerous studies in recent decades and in particular the role of red blood cells in the regulation of O2 supply. The aim of this review was to summarise the currently available information on blood rheology with special emphasis on the influence of red blood cell deformability, highlighting its relationship with various human diseases such as hereditary membrane disorders (e.g. spherocytosis, elliptocytosis, ovalocytosis and stomatocytosis), metabolic disorders (e.g. diabetes and membrane changes induced by oxidative stress) and those associated with critical illnesses. The microfluidic techniques that have been identified are briefly presented here as key methods to develop the state-of-the-art in dynamic experimental models to elucidate the importance of erythrocyte membrane alterations in pathological conditions as well as the role that such alterations play in the dynamics of microcirculation flow.Reologia é uma disciplina científica que se dedica ao estudo da deformação e fluxo da matéria ou, mais especificamente, dos fluidos. A hemorreologia trata, em particular, do comportamento do fluxo do sangue total, além da deformabilidade dos elementos individuais que o compõem (ou seja, glóbulos vermelhos, glóbulos brancos e plaquetas). Devido à sua importância fisiopatológica, a mensuração da deformabilidade das hemácias tem sido foco de inúmeros estudos nas últimas décadas e, principalmente, o papel das hemácias na regulação do suprimento de O2. O objetivo desta revisão era resumir as informações atualmente disponíveis sobre a reologia do sangue com ênfase especial na influência da deformabilidade dos glóbulos vermelhos, destacando sua relação com várias doenças humanas, como distúrbios hereditários da membrana (esferocitose, eliptocitose, ovalocitose e estomatocitose), distúrbios metabólicos (diabetes e alterações na membrana induzidas por estresse oxidativo) e aqueles associados a doenças críticas. Técnicas microfluídicas são brevemente discutidas, as quais têm sido identificadas como métodos de grande potencial no desenvolvimento de modelos experimentais dinâmicos de última geração. Seu uso poderia elucidar a importância das alterações da membrana eritrocitária nas condições patológicas e as consequências de tais alterações na dinâmica do fluxo da microcirculação.Fil: Feldman, Leonardo. Universidad Nacional del Centro de la Pcia.de Bs.as.. Facultad de Ciencias de la Salud.; Argentina. Clinica Modelo; ArgentinaFil: Diez, Javier Alberto. Universidad Nacional del Centro de la Provincia de Buenos Aires. Centro de Investigaciones en Física e Ingeniería del Centro de la Provincia de Buenos Aires. - Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tandil. Centro de Investigaciones en Física e Ingeniería del Centro de la Provincia de Buenos Aires. - Provincia de Buenos Aires. Gobernación. Comisión de Investigaciones Científicas. Centro de Investigaciones en Física e Ingeniería del Centro de la Provincia de Buenos Aires; ArgentinaFil: Najle, Roberto. Universidad Nacional del Centro de la Provincia de Buenos Aires. Facultad de Ciencias Veterinarias; ArgentinaFil: Gonzalez, Alejandro Guillermo. Universidad Nacional del Centro de la Provincia de Buenos Aires. Centro de Investigaciones en Física e Ingeniería del Centro de la Provincia de Buenos Aires. - Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tandil. Centro de Investigaciones en Física e Ingeniería del Centro de la Provincia de Buenos Aires. - Provincia de Buenos Aires. Gobernación. Comisión de Investigaciones Científicas. Centro de Investigaciones en Física e Ingeniería del Centro de la Provincia de Buenos Aires; Argentin

    Molecular Identification of Trypanosma cruzi discrete Typing Units in end-Stage Chronic Chagas Heart Disease and Reactivation after Heart Transplantation

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    One hundred years after the discovery of Chagas disease, it remains a major neglected tropical disease. Chronic Chagas heart disease is the most severe manifestation. Heart trasplantation is the proper treatment for end-stage heart failure. T. cruzi strains cluster into 6 discrete typing units assosiated with different geographical distribution, transmission cycles and varying disease symptoms.In the southern cone of South America, T. cruzi II, V and VI popuations appear to be assosiated with Chagas disease and T. cruzi I with sylvatic cycles.Fil: Burgos, Juan Miguel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - la Plata. Instituto de Investigaciones Biotecnológicas. Instituto de Invest. Biotec. (subsede San Martin) | Universidad Nacional de San Martin. Instituto de Investigaciones Biotecnológicas. Instituto de Invest. Biotec. (subsede San Martin); Argentina. Laboratorio Biología Molecular de Enfermedad de Chagas; ArgentinaFil: Diez, Mirta. Universidad Favaloro; ArgentinaFil: Vigliano, Carlos. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Favaloro; ArgentinaFil: Bisio, Margarita María Catalina. Gobierno de la Ciudad de Buenos Aires. Instituto Multidisciplinario de Investigaciones en Patologías Pediátricas. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto Multidisciplinario de Investigaciones en Patologías Pediátricas; ArgentinaFil: Risso, Marikena Guadalupe. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Investigaciones Bioquímicas de Buenos Aires. Fundación Instituto Leloir. Instituto de Investigaciones Bioquímicas de Buenos Aires; ArgentinaFil: Duffi, Tomas. Laboratorio Biología Molecular de Enfermedad de Chagas; ArgentinaFil: Cura, Carolina Inés. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Investigación en Ingeniería Genética y Biología Molecular "Dr. Héctor N. Torres". Grupo Vinculado al INGEBI- Laboratorio de Biocatálisis y Biotransformaciones - LBB - UNQUI; ArgentinaFil: Brusés, Bettina Laura. Universidad Nacional del Nordeste. Instituto de Medicina Regional; ArgentinaFil: Favaloro, Liliana Ethel. Universidad Favaloro; ArgentinaFil: Leguizamon, María Susana. Dirección Nacional de Instituto de Investigación.Administración Nacional de Laboratorios e Institutos de Salud "Dr. Carlos G. Malbrán"; ArgentinaFil: Lucero, Raúl Horacio. Universidad Nacional del Nordeste. Instituto de Medicina Regional; ArgentinaFil: Laguens, Rubén. Universidad Favaloro; ArgentinaFil: Levin, Mariano Jorge. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Investigación en Ingeniería Genética y Biología Molecular "Dr. Héctor N. Torres". Grupo Vinculado al INGEBI- Laboratorio de Biocatálisis y Biotransformaciones - LBB - UNQUI; ArgentinaFil: Favaloro, Roberto René. Universidad Favaloro; ArgentinaFil: Schijman, Alejandro Gabriel. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Laboratorio Biología Molecular de Enfermedad de Chagas; Argentin

    Accurate Real-Time PCR Strategy for Monitoring Bloodstream Parasitic Loads in Chagas Disease Patients

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    Infection with the parasite Trypanosoma cruzi (T. cruzi), causing American trypanosomiasis or Chagas disease, remains a major public health concern in 21 endemic countries of America, with an estimated prevalence of 8 million infected people. Chagas disease shows a variable clinical course, ranging from asymptomatic to chronic stages with low parasitaemias, whose severest form is heart disease. Diagnosis at the asymptomatic and chronic stages is based on serological detection of anti-T. cruzi antibodies, because conventional parasitological methods lack sensitivity. Current chemotherapies are more effective in recent infections than in the chronic adult population. The criterion of cure relies on serological conversion to negative, which may occur only years after treatment, requiring long-term follow-up. In this context, we aimed to develop a real-time PCR assay targeted to repetitive sequences of T. cruzi for sensitive quantitation of parasitic load in peripheral blood of infected patients. It was applied to monitor treatment response of infected children, allowing rapid evaluation of drug efficacy as well as detection of treatment failure. It was also used for early diagnosis of chagasic reactivation in end-stage heart disease patients who received immunosuppressive drugs after cardiac transplantation. This laboratory strategy may constitute a novel parasitological tool for prompt and sensitive evaluation of anti-parasitic treatment of Chagas disease

    Intensidade da dor após aplicação de somatropina humana recombinante: estudo comparativo de não-inferioridade, randomizado e cruzado/Pain intensity after application of recombinant human somatropin: a comparative study of non-inferiority, randomized and crossed

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    Objetivo: Baixa estatura patológica é uma condição idiopática na faixa etária pediátrica, com consequências psicológicas e cardiometabólicas. A adesão é um fator determinante para o sucesso no tratamento da deficiência de hormônio do crescimento, e a ocorrência de dor no local de aplicação pode levar a não adesão ao tratamento. O objetivo principal deste estudo de não inferioridade foi avaliar a intensidade da dor após a aplicação e o secundário, a segurança de duas formulações da somatropina humana recombinante. Método: Estudo clínico randomizado, duplo-cego, controlado e cruzado. Sádios adultos com fototipo Fitzpatrick 2 a 4 foram randomizados para receber duas formulações de somatropina, teste (T) e comparador (R).Foram administrados 4UI na dose única durante dois dias consecutivos em braços alternados, na sequência TR ou RT. A intensidade do dor foi atingida pelo EVA (escala visual analógica) de 0 a 10 cm e a segurança, pela incidência de eventos adversos (EA). Resultados: 68 participantes foram randomizados e 66 concluíram o estudo. Em relação ao dor, foi demonstrada não inferioridade entre os medicamentos T e R, tanto no momento da aplicação, quanto no escore acumulado (p = 0,1586 e 0,0545, IC90%), e na estratificação por sequência (p = 0 , 8733 e 0,8186, IC90%) e período (p = 0,5105 e 0,2158, IC90%). Não houve diferença significativa na frequência de EA entre os controles. Conclusão: A intensidade do dor induzida foi semelhante entre os testes de teste e comparador.Eventos adversos incidem também em ambos os controles. NCT03634514 Resultados: 68 participantes foram randomizados e 66 concluíram o estudo. Em relação ao dor, foi demonstrada não inferioridade entre os medicamentos T e R, tanto no momento da aplicação, quanto no escore acumulado (p = 0,1586 e 0,0545, IC90%), e na estratificação por sequência (p = 0,8733 e 0,8186, IC90%) e período (p = 0,5105 e 0,2158, IC90%). Não houve diferença significativa na frequência de EA entre os controles. Conclusão: A intensidade do dor induzida foi semelhante entre os testes de teste e comparador. Eventos adversos incidem também em ambos os controles. NCT03634514 Resultados: 68 participantes foram randomizados e 66 concluíram o estudo. Em relação ao dor, foi demonstrada não inferioridade entre os medicamentos T e R, tanto no momento da aplicação, quanto no escore acumulado (p = 0,1586 e 0,0545, IC90%), e na estratificação por sequência (p = 0,8733 e 0,8186, IC90%) e período (p = 0,5105 e 0,2158, IC90%). Não houve diferença significativa na frequência de EA entre os controles. Conclusão: A intensidade do dor induzida foi semelhante entre os testes de teste e comparador. Eventos adversos incidem também em ambos os controles. NCT03634514 e estratificação por sequência (p = 0,8733 e 0,8186, IC90%) e período (p = 0,5105 e 0,2158, IC90%). Não houve diferença significativa na frequência de EA entre os controles. Conclusão: A intensidade do dor induzida foi semelhante entre os testes de teste e comparador. Eventos adversos também ocorrem nos dois controles. NCT03634514 e estratificação por sequência (p = 0,8733 e 0,8186, IC90%) e período (p = 0,5105 e 0,2158, IC90%). Não houve diferença significativa na frequência de EA entre os controles. Conclusão: A intensidade do dor induzida foi semelhante entre os testes de teste e comparador. Eventos adversos também ocorrem nos dois controles. NCT0363451

    Antimicrobial resistance among migrants in Europe: a systematic review and meta-analysis

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    BACKGROUND: Rates of antimicrobial resistance (AMR) are rising globally and there is concern that increased migration is contributing to the burden of antibiotic resistance in Europe. However, the effect of migration on the burden of AMR in Europe has not yet been comprehensively examined. Therefore, we did a systematic review and meta-analysis to identify and synthesise data for AMR carriage or infection in migrants to Europe to examine differences in patterns of AMR across migrant groups and in different settings. METHODS: For this systematic review and meta-analysis, we searched MEDLINE, Embase, PubMed, and Scopus with no language restrictions from Jan 1, 2000, to Jan 18, 2017, for primary data from observational studies reporting antibacterial resistance in common bacterial pathogens among migrants to 21 European Union-15 and European Economic Area countries. To be eligible for inclusion, studies had to report data on carriage or infection with laboratory-confirmed antibiotic-resistant organisms in migrant populations. We extracted data from eligible studies and assessed quality using piloted, standardised forms. We did not examine drug resistance in tuberculosis and excluded articles solely reporting on this parameter. We also excluded articles in which migrant status was determined by ethnicity, country of birth of participants' parents, or was not defined, and articles in which data were not disaggregated by migrant status. Outcomes were carriage of or infection with antibiotic-resistant organisms. We used random-effects models to calculate the pooled prevalence of each outcome. The study protocol is registered with PROSPERO, number CRD42016043681. FINDINGS: We identified 2274 articles, of which 23 observational studies reporting on antibiotic resistance in 2319 migrants were included. The pooled prevalence of any AMR carriage or AMR infection in migrants was 25·4% (95% CI 19·1-31·8; I2 =98%), including meticillin-resistant Staphylococcus aureus (7·8%, 4·8-10·7; I2 =92%) and antibiotic-resistant Gram-negative bacteria (27·2%, 17·6-36·8; I2 =94%). The pooled prevalence of any AMR carriage or infection was higher in refugees and asylum seekers (33·0%, 18·3-47·6; I2 =98%) than in other migrant groups (6·6%, 1·8-11·3; I2 =92%). The pooled prevalence of antibiotic-resistant organisms was slightly higher in high-migrant community settings (33·1%, 11·1-55·1; I2 =96%) than in migrants in hospitals (24·3%, 16·1-32·6; I2 =98%). We did not find evidence of high rates of transmission of AMR from migrant to host populations. INTERPRETATION: Migrants are exposed to conditions favouring the emergence of drug resistance during transit and in host countries in Europe. Increased antibiotic resistance among refugees and asylum seekers and in high-migrant community settings (such as refugee camps and detention facilities) highlights the need for improved living conditions, access to health care, and initiatives to facilitate detection of and appropriate high-quality treatment for antibiotic-resistant infections during transit and in host countries. Protocols for the prevention and control of infection and for antibiotic surveillance need to be integrated in all aspects of health care, which should be accessible for all migrant groups, and should target determinants of AMR before, during, and after migration. FUNDING: UK National Institute for Health Research Imperial Biomedical Research Centre, Imperial College Healthcare Charity, the Wellcome Trust, and UK National Institute for Health Research Health Protection Research Unit in Healthcare-associated Infections and Antimictobial Resistance at Imperial College London

    Effect of aliskiren on post-discharge outcomes among diabetic and non-diabetic patients hospitalized for heart failure: insights from the ASTRONAUT trial

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    Aims The objective of the Aliskiren Trial on Acute Heart Failure Outcomes (ASTRONAUT) was to determine whether aliskiren, a direct renin inhibitor, would improve post-discharge outcomes in patients with hospitalization for heart failure (HHF) with reduced ejection fraction. Pre-specified subgroup analyses suggested potential heterogeneity in post-discharge outcomes with aliskiren in patients with and without baseline diabetes mellitus (DM). Methods and results ASTRONAUT included 953 patients without DM (aliskiren 489; placebo 464) and 662 patients with DM (aliskiren 319; placebo 343) (as reported by study investigators). Study endpoints included the first occurrence of cardiovascular death or HHF within 6 and 12 months, all-cause death within 6 and 12 months, and change from baseline in N-terminal pro-B-type natriuretic peptide (NT-proBNP) at 1, 6, and 12 months. Data regarding risk of hyperkalaemia, renal impairment, and hypotension, and changes in additional serum biomarkers were collected. The effect of aliskiren on cardiovascular death or HHF within 6 months (primary endpoint) did not significantly differ by baseline DM status (P = 0.08 for interaction), but reached statistical significance at 12 months (non-DM: HR: 0.80, 95% CI: 0.64-0.99; DM: HR: 1.16, 95% CI: 0.91-1.47; P = 0.03 for interaction). Risk of 12-month all-cause death with aliskiren significantly differed by the presence of baseline DM (non-DM: HR: 0.69, 95% CI: 0.50-0.94; DM: HR: 1.64, 95% CI: 1.15-2.33; P < 0.01 for interaction). Among non-diabetics, aliskiren significantly reduced NT-proBNP through 6 months and plasma troponin I and aldosterone through 12 months, as compared to placebo. Among diabetic patients, aliskiren reduced plasma troponin I and aldosterone relative to placebo through 1 month only. There was a trend towards differing risk of post-baseline potassium ≥6 mmol/L with aliskiren by underlying DM status (non-DM: HR: 1.17, 95% CI: 0.71-1.93; DM: HR: 2.39, 95% CI: 1.30-4.42; P = 0.07 for interaction). Conclusion This pre-specified subgroup analysis from the ASTRONAUT trial generates the hypothesis that the addition of aliskiren to standard HHF therapy in non-diabetic patients is generally well-tolerated and improves post-discharge outcomes and biomarker profiles. In contrast, diabetic patients receiving aliskiren appear to have worse post-discharge outcomes. Future prospective investigations are needed to confirm potential benefits of renin inhibition in a large cohort of HHF patients without D

    Optimasi Portofolio Resiko Menggunakan Model Markowitz MVO Dikaitkan dengan Keterbatasan Manusia dalam Memprediksi Masa Depan dalam Perspektif Al-Qur`an

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    Risk portfolio on modern finance has become increasingly technical, requiring the use of sophisticated mathematical tools in both research and practice. Since companies cannot insure themselves completely against risk, as human incompetence in predicting the future precisely that written in Al-Quran surah Luqman verse 34, they have to manage it to yield an optimal portfolio. The objective here is to minimize the variance among all portfolios, or alternatively, to maximize expected return among all portfolios that has at least a certain expected return. Furthermore, this study focuses on optimizing risk portfolio so called Markowitz MVO (Mean-Variance Optimization). Some theoretical frameworks for analysis are arithmetic mean, geometric mean, variance, covariance, linear programming, and quadratic programming. Moreover, finding a minimum variance portfolio produces a convex quadratic programming, that is minimizing the objective function ðð¥with constraintsð ð 𥠥 ðandð´ð¥ = ð. The outcome of this research is the solution of optimal risk portofolio in some investments that could be finished smoothly using MATLAB R2007b software together with its graphic analysis

    An embedding technique to determine ττ backgrounds in proton-proton collision data

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    An embedding technique is presented to estimate standard model tau tau backgrounds from data with minimal simulation input. In the data, the muons are removed from reconstructed mu mu events and replaced with simulated tau leptons with the same kinematic properties. In this way, a set of hybrid events is obtained that does not rely on simulation except for the decay of the tau leptons. The challenges in describing the underlying event or the production of associated jets in the simulation are avoided. The technique described in this paper was developed for CMS. Its validation and the inherent uncertainties are also discussed. The demonstration of the performance of the technique is based on a sample of proton-proton collisions collected by CMS in 2017 at root s = 13 TeV corresponding to an integrated luminosity of 41.5 fb(-1).Peer reviewe

    Measurement of t(t)over-bar normalised multi-differential cross sections in pp collisions at root s=13 TeV, and simultaneous determination of the strong coupling strength, top quark pole mass, and parton distribution functions

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