Genetic variants of innate immune receptors and infections after liver transplantation.

Infection is the leading cause of complication after liver transplantation, causing morbidity and mortality in the first months after surgery. Allograft rejection is mediated through adaptive immunological responses, and thus immunosuppressive therapy is necessary after transplantation. In this setting, the presence of genetic variants of innate immunity receptors may increase the risk of post-transplant infection, in comparison with patients carrying wild-type alleles. Numerous studies have investigated the role of genetic variants of innate immune receptors and the risk of complication after liver transplantation, but their results are discordant. Toll-like receptors and mannose-binding lectin are arguably the most important studied molecules; however, many other receptors could increase the risk of infection after transplantation. In this article, we review the published studies analyzing the impact of genetic variants in the innate immune system on the development of infectious complications after liver transplantation

In situ measurements and thermo-mechanical simulation of Ti–6Al–4V laser solid forming processes

Residual stresses and distortions are two technical obstacles for popularizing the additive manufacturing (AM) technology. The evolution of the stresses in AM components during the thermal cycles of the metal depositing process is not yet clear, and more accurate in situ measurements are necessary to calibrate and validate the numerical tools developed for its simulation. In this work a fully coupled thermo-mechanical analysis to simulate the laser solid forming (LSF) process is carried out. At the same time, an exhaustive experimental campaign is launched to measure the temperature evolution at different locations, as well as the distortions and both the stress and strain fields. The thermal and mechanical responses of single-wall coupons under different process parameters are recorded and compared with the numerical models. Good agreement between the numerical results and the experimental measurements is obtained. Sensitivity analysis demonstrates that the AM process is significantly affected by the laser power and the feeding rate, while poorly influenced by the scanning speed.Peer ReviewedPostprint (author's final draft

Finite element analysis and experimental validation of the thermomechanical behavior in laser solid forming of Ti-6Al-4V

A three-dimensional (3D) thermomechanical coupled model for Laser Solid Forming (LSF) of Ti-6Al-4V alloy has been calibrated through experiments of 40-layers metal deposition using different scanning strategies. The sensitivity analysis of the mechanical parameters shows that the thermal expansion coefficient as well as the elastic limit of Ti-6Al-4V have a great impact on the mechanical behavior. Using the validated model and optimal mechanical parameters, the evolution of thermo-mechanical fields in LSF has been analyzed. It has been found that the stresses and distortions develop in two stages, after the deposition of the first layer and during the cooling phase after the manufacturing of the component. The cooling phase is the responsible of 70% of the residual stresses and 60% of the total distortions. The analyses indicate that by controlling the initial substrate temperature (pre-heating phase) and the final cooling phase it is possible to mitigate both distortion and residual stresses. Hence, the influence of different pre-heating procedures on the mechanical fields has been analyzed. The results show that increasing the pre-heating temperature of the substrate is the most effective way to reduce the distortions and residual stresses in Additive Manufacturing

In situ measurements and thermo-mechanical simulation of Ti–6Al–4V laser solid forming processes

Residual stresses and distortions are two technical obstacles for popularizing the additive manufacturing (AM) technology. The evolution of the stresses in AM components during the thermal cycles of the metal depositing process is not yet clear, and more accurate in situ measurements are necessary to calibrate and validate the numerical tools developed for its simulation. In this work a fully coupled thermo-mechanical analysis to simulate the laser solid forming (LSF) process is carried out. At the same time, an exhaustive experimental campaign is launched to measure the temperature evolution at different locations, as well as the distortions and both the stress and strain fields. The thermal and mechanical responses of single-wall coupons under different process parameters are recorded and compared with the numerical models. Good agreement between the numerical results and the experimental measurements is obtained. Sensitivity analysis demonstrates that the AM process is significantly affected by the laser power and the feeding rate, while poorly influenced by the scanning speed

Percepções dos alunos de Enfermagem sobre flipped classroom e avaliação contínua na sala de aula de Gestão de Enfermagem

Introduction: Although the training of nurses in administration and leadership has an important repercussion on the present and the future of the profession, teaching methods are still traditional in many cases. Flipped classroom is a widely used method in nursing education but studies about its application to Nursing Administration and Management are limited. Method: Qualitative study by means of anonymous survey (dichotomous and open questions). Results: 92 % of students were shown to be satisfied with the teaching methodology and 92.9 % with the assessment. Only 31.5 % had used it previously but 83 % would like to use it in more subjects. The students showed that the methodology used had improved their opinion about the content and had increased their perception its usefulness. Conclusion: The participating students have been shown to be satisfied with flipped method and continuous assessment. These teaching strategies can help motivate nursing students towards the subject of Nursing Administration and Management, which can encourage them to pursue postgraduate training and professional practice in this area.Introducción: Si bien la formación de enfermeros en Administración y Gestión tiene una importante repercusión en el presente y el futuro de la profesión, los métodos de enseñanza siguen siendo tradicionales en muchos casos. El aula invertida es un método ampliamente utilizado en la educación de enfermería, pero los estudios sobre su aplicación a la administración y gestión de enfermería son limitados. Método: Estudio cualitativo mediante cuestionario anónimo (preguntas dicotómicas y abiertas). Resultados: El 92 % de los estudiantes se mostró satisfecho con la metodología de enseñanza y el 92,9 % con la evaluación. Solo el 31,5 % lo había usado anteriormente, pero al 83 % le gustaría usarlo en más sujetos. Los estudiantes demostraron que la metodología utilizada había mejorado su opinión sobre el contenido y había aumentado su percepción útil del mismo. Conclusión: Los estudiantes participantes han demostrado estar satisfechos con el método de aula invertida. Estas estrategias de enseñanza pueden ayudar a motivar a los estudiantes de enfermería hacia la asignatura de Administración y Gestión de los Servicios de Enfermería, lo que puede animarlos a realizar una formación de posgrado y una práctica profesional en esta área.Introdução: Embora a educação de Enfermagem em Administração e Gestão tenha um grande impacto no presente e futuro da profissão, os métodos de ensino continuam a ser tradicionais em muitos casos. A sala de aula invertida é um método amplamente utilizado na educação em Enfermagem, mas os estudos sobre a sua aplicação à Administração e Gestão de Enfermagem são limitados. Método: Estudo qualitativo utilizando um questionário anônimo (perguntas dicotômicas e abertas). Resultados: 92% dos estudantes ficaram satisfeitos com a metodologia de ensino e 92,9% com a avaliação. Apenas 31,5% já o tinha utilizado antes, mas 83% gostariam de  utilizá-lo em mais assuntos. Os estudantes mostraram que a metodologia utilizada havia melhorado a sua opinião sobre o conteúdo e aumentado a sua percepção útil do conteúdo. Conclusão: Os estudantes participantes mostraram-se satisfeitos com o método invertido e com a avaliação contínua. Estas estratégias de ensino podem ajudar a motivar os estudantes de Enfermagem para a disciplina de Administração e Gestão de Enfermagem, o que pode encorajá-los a empreender uma educação de pós-graduação e prática profissional nesta área

Universal Texture of Quark and Lepton Mass Matrices and a Discrete Symmetry Z_3

Recent neutrino data have been favourable to a nearly bimaximal mixing, which suggests a simple form of the neutrino mass matrix. Stimulated by this matrix form, a possibility that all the mass matrices of quarks and leptons have the same form as in the neutrinos is investigated. The mass matrix form is constrained by a discrete symmetry Z_3 and a permutation symmetry S_2. The model, of course, leads to a nearly bimaximal mixing for the lepton sectors, while, for the quark sectors, it can lead to reasonable values of the CKM mixing matrix and masses.Comment: 24 pages, RevTEX, no figure, some references and comments were adde

Causes of death in a contemporary cohort of patients with invasive aspergillosis

Information regarding the processes leading to death in patients with invasive aspergillosis (IA) is lacking. We sought to determine the causes of death in these patients, the role that IA played in the cause, and the timing of death. The factors associated with IA-related mortality are also analyzed. We conducted a multicenter study (2008-2011) of cases of proven and probable IA. The causes of death and whether mortality was judged to be IA-related or IA-unrelated were determined by consensus using a six-member review panel. A multivariate analysis was performed to determine risk factors for IA-related death. Of 152 patients with IA, 92 (60.5%) died. Mortality was judged to be IA-related in 62 cases and IA-unrelated in 30. The most common cause of IA-related death was respiratory failure (50/62 patients), caused primarily by Aspergillus infection, although also by concomitant infections or severe comorbidities. Progression of underlying disease and bacteremic shock were the most frequent causes of IA-unrelated death. IA-related mortality accounted for 98% and 87% of deaths within the first 14 and 21 days, respectively. Liver disease (HR 4.54; 95% CI, 1.69-12.23) was independently associated with IA-related mortality, whereas voriconazole treatment was associated with reduced risk of death (HR 0.43; 95% CI, 0.20-0.93). In conclusion, better management of lung injury after IA diagnosis is the main challenge for physicians to improve IA outcomes. There are significant differences in causes and timing between IA-related and IA-unrelated mortality and these should be considered in future research to assess the quality of IA car

Effects of new physics in neutrino oscillations in matter

A new flavor changing electron neutrino interaction with matter would always dominate the nu_e oscillation probability at sufficiently high neutrino energies. Being suppressed by theta_{13}, the energy scale at which the new effect starts to be relevant may be within the reach of realistic experiments, where the peculiar dependence of the signal with energy could give rise to a clear signature in the nu_e --> nu_tau channel. The latter could be observed by means of a coarse large magnetized detector by exploiting tau --> mu decays. We discuss the possibility of identifying or constraining such effects with a high energy neutrino factory. We also comment on the model independent limits on them.Comment: 11 pages, 5 figure

Stigmatization is common in patients with non-alcoholic fatty liver disease and correlates with quality of life

Background and aims: Stigmatization is a well-documented problem of some diseases. Perceived stigma is common in alcohol-related liver disease and hepatitis C, but little information exists on stigma in patients with non-alcoholic fatty liver disease (NAFLD). Aim of the study was to investigate frequency and characteristics of perceived stigma among patients with NAFLD. Methods: One-hundred and ninety-seven patients seen at the liver clinic were included: a study group of 144 patients with NAFLD, 50 with cirrhosis (34 compensated, 16 decompensated), and a control group of 53 patients with alcohol-related cirrhosis. Demographic, clinical, and laboratory data were collected. Quality-of-life was assessed by chronic liver disease questionnaire (CLDQ). Perceived stigma was assessed using a specific questionnaire for patients with liver diseases categorized in 4 domains: stereotypes, discrimination, shame, and social isolation. Results: Perceived stigma was common in patients with NAFLD (99 patients, 69%) and affected all 4 domains assessed. The frequency was slightly higher, yet not significant, in patients with NAFLD cirrhosis vs those without (72% vs 67%, respectively; p = 0.576). In patients without cirrhosis perceived stigma was unrelated to stage of disease, since frequency was similar in patients with no or mild fibrosis compared to those with moderate/severe fibrosis (66% vs 68%, respectively). There were no differences in perceived stigma between patients with compensated cirrhosis and these with decompensated cirrhosis. Among patients with cirrhosis, stigmatization was more common in alcohol-related vs NAFLD-cirrhosis, yet differences were only significant in two domains. In patients with NAFLD, perceived stigma correlated with poor quality-of-life, but not with demographic or clinical variables. Conclusions: Perceived stigmatization is common among patients with NAFLD independently of disease stage, is associated with impaired quality-of-life, and may be responsible for stereotypes, discrimination, shame, and social isolation, which may affect human and social rights of affected patients

Discrete Flavor Symmetry, Dynamical Mass Textures, and Grand Unification

Discrete flavor symmetry is explored for an intrinsic property of mass matrix forms of quarks and leptons. In this paper we investigate the S3 permutation symmetry and derive the general forms of mass matrices in various types of S3 theories. We also exhibit particular realizations of previous ansatze of mass matrices, which have often been applied in the literature to the standard model Yukawa sector. Discrete flavor symmetry is also advantageous for vanishing matrix elements being dynamically generated in the vacuum of scalar potential. This is due to the fact that group operations are discrete. While zero elements themselves do not explain mass hierarchies, we introduce an abelian flavor symmetry. A non-trivial issue is whether successful quantum numbers can be assigned so that they are compatible with other (non-abelian) flavor symmetries. We show typical examples of charge assignments which not only produce hierarchical orders of mass eigenvalues but also prohibit non-renormalizable operators which disturb the hierarchies in first-order estimation. As an explicit application, a flavor model is constructed in grand unification scheme with S3 and U(1) (or Z_N) flavor symmetries.Comment: 40 pages, references adde