Characterization of the isothermal phases transformations and the respectives products in three eutectoid steels for railroad application.

Artigos recentemente publicados v?m destacando a import?ncia do conhecimento sobre a cin?tica de transforma??o de fases em a?os eutet?ides aplicados em ferrovias, visando o aprimoramento de processos de fabrica??o e de soldagem. Nesse sentido, o presente trabalho apresenta um estudo de caracteriza??o da cin?tica de decomposi??o isot?rmica da austenita em tr?s a?os atualmente utilizados no mundo para a fabrica??o de trilhos ferrovi?rios, sendo dois de classifica??o premium e um de classifica??o standard. Os a?os estudados foram caracterizados em seu estado de entrega e, por meio de ensaios de dilatometria, as temperaturas cr?ticas de austenitiza??o e os intervalos de tempo de decomposi??o da austenita foram medidos. Diagramas tempo-temperatura-transforma??o (TTT) foram determinados. A influ?ncia de alguns par?metros como o espa?amento interlamelar perl?tico original e o tamanho de gr?o austen?tico pr?vio sobre as transforma??es de fases e sobre as microestruturas resultantes, foram discutidos. Mostrou-se ainda que, a partir de tratamentos isot?rmicos bem planejados, ? poss?vel a obten??o de uma microestrutura majoritariamente bain?tica em a?os eutetoides com composi??es qu?micas relativamente simples.Recently published papers have been enhancing the importance of understanding about the kinetics of phase transformation in eutectoid steels applied to railways, aiming the improvement of the manufacturing and the welding processes. In this sense, this work presents a characterization study on the austenite?s isothermal decomposition kinetics in three steels currently used worldwide in the manufacturing of railway tracks, being two of then premium and the other standard. The steels studied were characterized at initial state and, through dilatometry, the austenitization critical temperatures and the austenite decomposition?s time intervals were measured. Time-temperature-transformation (TTT) diagrams were determined. The influence of some parameters such as the original pearlite interlamellar spacing and the prior austenitic grain?s size on the phase transformations and the resulting microstructures, was discussed. The study also showed that stemming from well-planned isothermal treatments, it is possible to obtain a mostly-bainitic microstructure in eutectoid steels of fairly simple chemical compositions

Silicon-hydroxyapatite bioactive coatings (Si-HA) from diatomaceous earth and silica. Study of adhesion and proliferation of osteoblast-like cells

The aim of this study consisted on investigating the influence of silicon substituted hydroxyapatite (Si–HA) coatings over the human osteoblast-like cell line (SaOS-2) behaviour. Diatomaceous earth and silica, together with commercial hydroxyapatite were respectively the silicon and HA sources used to produce the Si–HA coatings. HA coatings with 0 wt% of silicon were used as control of the experiment. Pulsed laser deposition (PLD) was the selected technique to deposit the coatings. The Si–HA thin films were characterized by Fourier Transformed Infrared Spectroscopy (FTIR) demonstrating the efficient transfer of Si to the HA structure. The in vitro cell culture was established to assess the cell attachment, proliferation and osteoblastic activity respectively by, Scanning Electron Microscopy (SEM), DNA and alkaline phosphatase (ALP) quantification. The SEM analysis demonstrated a similar adhesion behaviour of the cells on the tested materials and the maintenance of the typical osteoblastic morphology along the time of culture. The Si–HA coatings did not evidence any type of cytotoxic behaviour when compared with HA coatings. Moreover, both the proliferation rate and osteoblastic activity results showed a slightly better performance on the Si–HA coatings from diatoms than on the Si–HA from silica.This work was supported by the UE-Interreg IIIA (SP1.P151/03) Proteus project and Xunta de Galicia ( Projects: 2006/12 and PGIDITO5PXIC30301PN)

Gut microbiota modulation accounts for the neuroprotective properties of anthocyanins

High-fat (HF) diets are thought to disrupt the profile of the gut microbiota in a manner that may contribute to the neuroinflammation and neurobehavioral changes observed in obesity. Accordingly, we hypothesize that by preventing HF-diet induced dysbiosis it is possible to prevent neuroinflammation and the consequent neurological disorders. Anthocyanins are flavonoids found in berries that exhibit anti-neuroinflammatory properties in the context of obesity. Here, we demonstrate that the blackberry anthocyanin-rich extract (BE) can modulate gut microbiota composition and counteract some of the features of HF-diet induced dysbiosis. In addition, we show that the modifications in gut microbial environment are partially linked with the anti-neuroinflammatory properties of BE. Through fecal metabolome analysis, we unravel the mechanism by which BE participates in the bilateral communication between the gut and the brain. BE alters host tryptophan metabolism, increasing the production of the neuroprotective metabolite kynurenic acid. These findings strongly suggest that dietary manipulation of the gut microbiota with anthocyanins can attenuate the neurologic complications of obesity, thus expanding the classification of psychobiotics to anthocyanins

Effectiveness of the Brazilian Visceral Leishmaniasis Surveillance and Control Programme in reducing the prevalence and incidence of Leishmania infantum infection.

Background Control strategies adopted by the Brazilian Visceral Leishmaniasis Surveillance and Control Programme (VLSCP) include identifying and culling seropositive infected dogs, early diagnosis and treatment of human cases, chemical control of the vector and population awareness. This study evaluated the effectiveness of the VLSCP on the prevalence and incidence rates of Leishmania infantum in children residing in areas under different VLSCP intervention times. Methods A quasi-experimental epidemiological study with a panel (two cross-sectional) and a concurrent cohort was performed in three areas of Belo Horizonte, southeast Brazil. The first cross-sectional study (I) was carried out with 1875 children, 478 of which were enrolled in the cohort study. In the second cross-sectional study (II), 413 additional children were included, totalizing 891 children. Laboratory diagnosis was performed by ELISA-rK39. Analyses included multilevel logistic and Poisson regression models. Results The incidence rates of L. infantum infection were: 14.4% in the area where VLSCP intervention was initiated in 2006 (AI2006); 21.1% in the area where intervention was initiated in 2008 (AI2008); and 11.6% in the area where intervention was initiated in 2010 (AI2010 - control area). A follow-up period of 24 months showed that the persons-time incidence rates in AI2006, AI2008, and AI2010 were: 6.2/100, 10/100, and 5.6/100 persons/24 months, respectively. The final prevalence rates of infection (cross-sectional II - in 2012), compared to the initial rates (cross-sectional I - in 2010), increased 83.7% in AI2006, 74.1% in AI2008, and decreased 5% in AI2010. Analysis of the effectiveness revealed that children residing in AI2008 are more likely to be infected (OR = 1.84; 95% CI: 1.06-3.23) and present a higher risk of infection (IRR = 1.76; 95% CI: 1.05-2.95) compared to those in AI2010. No statistically significant differences were observed in asymptomatic infection (OR and IRR) in AI2006 compared to AI2010. Conclusions The VLSCP was not effective at controlling L. infantum infection in areas where interventions had respectively been carried out for six and four years. However, it is unclear what the consequences in terms of human infection and diseases would be in the absence of the VLSCP. Efforts to improve the effectiveness of control measures remain a necessary priority

Automated Detection of Cortical Lesions in Multiple Sclerosis Patients with 7T MRI

The automated detection of cortical lesions (CLs) in patients with multiple sclerosis (MS) is a challenging task that, despite its clinical relevance, has received very little attention. Accurate detection of the small and scarce lesions requires specialized sequences and high or ultra- high field MRI. For supervised training based on multimodal structural MRI at 7T, two experts generated ground truth segmentation masks of 60 patients with 2014 CLs. We implemented a simplified 3D U-Net with three resolution levels (3D U-Net-). By increasing the complexity of the task (adding brain tissue segmentation), while randomly dropping input channels during training, we improved the performance compared to the baseline. Considering a minimum lesion size of 0.75 μL, we achieved a lesion-wise cortical lesion detection rate of 67% and a false positive rate of 42%. However, 393 (24%) of the lesions reported as false positives were post-hoc confirmed as potential or definite lesions by an expert. This indicates the potential of the proposed method to support experts in the tedious process of CL manual segmentation

Environmental variables, habitat discontinuity and life history shaping the genetic structure of Pomatoschistus marmoratus

Coastal lagoons are semi-isolated ecosystems exposed to wide fluctuations of environmental conditions and showing habitat fragmentation. These features may play an important role in separating species into different populations, even at small spatial scales. In this study, we evaluate the concordance between mitochondrial (previous published data) and nuclear data analyzing the genetic variability of Pomatoschistus marmoratus in five localities, inside and outside the Mar Menor coastal lagoon (SE Spain) using eight microsatellites. High genetic diversity and similar levels of allele richness were observed across all loci and localities, although significant genic and genotypic differentiation was found between populations inside and outside the lagoon. In contrast to the FST values obtained from previous mitochondrial DNA analyses (control region), the microsatellite data exhibited significant differentiation among samples inside the Mar Menor and between lagoonal and marine samples. This pattern was corroborated using Cavalli-Sforza genetic distances. The habitat fragmentation inside the coastal lagoon and among lagoon and marine localities could be acting as a barrier to gene flow and contributing to the observed genetic structure. Our results from generalized additive models point a significant link between extreme lagoonal environmental conditions (mainly maximum salinity) and P. marmoratus genetic composition. Thereby, these environmental features could be also acting on genetic structure of coastal lagoon populations of P. marmoratus favoring their genetic divergence. The mating strategy of P. marmoratus could be also influencing our results obtained from mitochondrial and nuclear DNA. Therefore, a special consideration must be done in the selection of the DNA markers depending on the reproductive strategy of the species

Estratégias de coping utilizadas por familiares de indivíduos em tratamento hemodialítico

This descriptive, qualitative study aims to identify the coping strategies used most by the family members of patients with chronic kidney disease receiving hemodialysis. The data were collected through interviews, with the Coping Strategies Inventory questionnaire administered to ten family members, and were submitted to descriptive statistics and to thematic content analysis. The strategy used most was escape-avoidance, demonstrating that the family members prefer not to face the situation. The second most-used strategy was social support, ratified by the fact that they stated that they talk with other persons and professionals, seeking information about the problem, and because they accept the support received positively. The third was problem resolution, represented by the attitude of accepting responsibility for the care, either through strong affective bonds or through a feeling of responsibility established prior to the disease. The families use coping strategies of different intensities, while, nevertheless, indicating involvement and major participation in the care for the patient.Estudio cualitativo, que trató de identificar las estrategias de afrontamiento empleadas por las familias de los pacientes con insuficiencia renal crónica en hemodiálisis. Se aplicó el Inventario de Estrategias de Afrontamiento y una questión abierta con diez familiares. Los datos cuantitativos fueron sometidos a procedimientos estatísticos y análisis de contenido cualitativo. La estrategia de mayor utilización fue el escape y evitación (oito), lo que demuestra que los miembros de las familisa preferían no tener que enfrentar esta situación. La siguiente estrategia fue utilizada más apoyo social, ya hablé con otras personas y profesionales que buscan información sobre el problema, y aceptar el apoyo positivo recibido. A terceira foi resolução de problemas, representada pela atitude em assumir o cuidado, seja pelo forte vínculo afetivo ou pelo sentimento de responsabilidade já estabelecido antes da doença. Familias de las estrategias de afrontamiento empleadas con diferentes intensidades, pero mostrando una gran implicación y la participación en el cuidado del paciente crónico.Estudo descritivo, de natureza quali-quantitativa, que objetivou identificar as estratégias de enfrentamento mais utilizadas por familiares de pacientes com doença renal crônica em hemodiálise. Os dados foram coletados por meio de entrevista, com aplicação do Inventário de Estratégias de Coping a dez familiares, e submetidos à estatística descritiva e à análise de conteúdo temática. A estratégia mais utilizada foi fuga e esquiva, demonstrando que os familiares preferiam não enfrentar a situação. A segunda estratégia mais usada foi suporte social, ratificada ao afirmarem que conversaram com outras pessoas e profissionais buscando informações sobre o problema, e por aceitarem positivamente o apoio recebido. A terceira foi resolução de problemas, representada pela atitude em assumir o cuidado, seja pelo forte vínculo afetivo ou pelo sentimento de responsabilidade já estabelecido antes da doença. As famílias empregaram estratégias de enfrentamento com intensidades diferentes, porém indicando envolvimento e grande participação no cuidado ao doente.Universidade Federal de São Paulo (UNIFESP)aff2Universidade Estadual de MaringáUEMUNIFESPSciEL

Mule Regulates the Intestinal Stem Cell Niche via the Wnt Pathway and Targets EphB3 for Proteasomal and Lysosomal Degradation

The E3 ubiquitin ligase Mule is often overexpressed in human colorectal cancers, but its role in gut tumorigenesis is unknown. Here, we show in vivo that Mule controls murine intestinal stem and progenitor cell proliferation by modulating Wnt signaling via c-Myc. Mule also regulates protein levels of the receptor tyrosine kinase EphB3 by targeting it for proteasomal and lysosomal degradation. In the intestine, EphB/ephrinB interactions position cells along the crypt-villus axis and compartmentalize incipient colorectal tumors. Our study thus unveils an important new avenue by which Mule acts as an intestinal tumor suppressor by regulation of the intestinal stem cell niche