133 research outputs found

    Cellular death of two non-saccharomyces wine-related yeasts during mixed fermentations with saccharomyces cerevisiae

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    The early death of two non-Saccharomyces wine strains (H. guilliermondii and H. uvarum) during mixed fermentations with S. cerevisiae was studied under enological growth conditions. Several microvinifications were performed in synthetic grape juice, either with single non- Saccharomyces or with mixed S. cerevisiae/non-Saccharomyces inocula. In all mixed cultures, non-Saccharomyces yeasts grew together with S. cerevisiae during the first 1–3 days (depending on the initial inoculum concentration) and then, suddenly, non-Saccharomyces cells began to die off, regardless of the ethanol concentrations present. Conversely, in both non-Saccharomyces single cultures the number of viable cells remained high (ranging 107–108 CFU ml− 1) even when cultures reached significant ethanol concentrations (up to 60–70 g l− 1). Thus, at least for these yeast strains, it seems that ethanol is not the main death-inducing factor. Furthermore, mixed cultures performed with different S. cerevisiae/ H. guilliermondii inoculum ratios (3 :1; 1:2; 1: 10; 1 : 100) revealed that H. guilliermondii death increases for higher inoculum ratios. In order to investigate if the nature of the yeast–yeast interaction was related or not with a cell–cell contact-mediated mechanism, cell-free supernatants obtained from 3 and 6 day-old mixed cultures were inoculated with H. guilliermondii pure cultures. Under these conditions, cells still died and much higher death rates were found for the 6 days than for the 3 day-old supernatants. This strongly indicates that one or more toxic compounds produced by S. cerevisiae triggers the early death of the H. guilliermondii cells in mixed cultures with S. cerevisiae. Finally, although it has not been yet possible to identify the nature of the toxic compounds involved in this phenomenon we must emphasise that the S. cerevisiae strain used in the present work is killer sensitive with respect to the classical killer toxins, K1, K2 and K28, whereas the H. guilliermondii and H. uvarum strains are killer neutral

    Exploring psychoacoustic indicators to assess close proximity tyre-road noise

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    Road traffic noise is associated with several health problems and welfare; such as sleep disturbances and annoyance. Accordingly, it becomes essential to characterize road noise not only based on acoustic indicators, but also based on psychoacoustic indicators. The acoustic indicators are required to assure compliance with European legislation and to define vehicle detection thresholds, the psychoacoustic indicators describe better annoyance rates. In this context, this work aimed to explore tyre-road noise measurements acquired on eight road pavements at eight speeds, from the point of view of psychoacoustics. In the analysis three psychoacoustic indicators (Loudness, Sharpness, Roughness) and one acoustic indicator (LAmax) were determined on 64 tyre-road noise samples acquired through the Close Proximity Method (CPX). It was confirmed that all psychoacoustic indicators are appropriated to describe tyre-road noise.This work was financed by FEDER grants through the Operational Competitiveness Program – COMPETE and ON.2 – Novo Norte (Programa Operacional Regional do Norte 2007/2013) integrated in the structural funds QREN and the project PEst-OE/ECI/UI4047/2014 supported by Portuguese Foundation for Science and Technology

    Estimulación eléctrica en la reparación ósea de defectos creados en cráneos de conejos

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    Electrical stimulation has been used in different conditions for tissue regeneration. The aim of this study was to analyze the tissue response of defects created in rabbit skulls to electrical stimulation. Two groups were formed, each with 9 New Zealand rabbits; two 5 mm defects were made, one in each parietal, with one being randomly filled with autogenous bone extracted as particles and the other maintained only with blood clotting. The rabbits were euthanized at 8 weeks and 15 weeks to then study the samples collected histologically. In the 8-week analysis bone formation was observed in the defects in the test and control filled with bone graft, whereas the defects with clotting presented a very early stage of bone formation with abundant connective tissue. At 15 weeks an advanced stage of bone regeneration was identified in the defects with bone graft, whereas no significant differences were found in the electrically stimulated defects. In conclusion, electrical stimulus does not alter the sequence of bone formation; new studies could help establish patterns and influences of the stimulus on bone regeneration.Electrical stimulation has been used in different conditions for tissue regeneration. The aim of this study was to analyze the tissue response of defects created in rabbit skulls to electrical stimulation. Two groups were formed, each with 9 New Zealand r33311461150sem informaçãosem informaçãoLa estimulación eléctrica ha sido empleada en diferentes condiciones para la regeneración de tejidos. El objetivo de esta investigación es analizar la respuesta tisular de defectos creados en cráneo de conejos a la estimulación eléctrica. Se formaron 2 g

    Maspin expression in normal skin and usual cutaneous carcinomas

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    Maspin is a serine protease inhibitor whose gene is located on 3q27. Several lines of evidence point towards its putative role as tumor suppressor gene and angiogenesis inhibitor; however, there are compelling data showing that maspin is also expressed in the nuclear compartment and might be associated with the differentiation of specific cell lineages. No systematic study of maspin expression in normal skin and usual skin carcinomas have been published so far. We semiquantitatively analyzed the distribution and immunoreactivity pattern of maspin in 14 squamous cell carcinomas (SCCs) and 16 basal cell carcinomas (BCCs) and in the adjacent normal epidermis of all cases. We also examined the correlation of maspin expression with histological type, grade, vascular invasion, perineural infiltration, and mitotic counting. Cytoplasmic expression of maspin was observed in suprabasal, prickle, and granular cell layers of normal epidermis; cells of the germinative hair matrix, Henle's and Huxley's layers, and cuticle of hair follicles; mature sebaceous cells and sweat gland's secretory cells. Nuclear expression was detected in some basal/myoepithelial cells of the sweat glands and scattered mature sebaceous cells. All SCCs but one grade IV SCC showed maspin expression, and it was correlated with the differentiation of these neoplasms. BCCs presented variable maspin expression, while metatypical carcinomas showed moderate to intense maspin expression, nodular BCCs variable contents of maspin and displayed a peculiar distribution, confined to the center of the neoplastic nodules. Two BCCs and one SCC showed maspin nuclear expression. No correlation with other clinical pathological features was observed. Our findings do not support the role of maspin as a tumor suppressor gene and suggest that this serpin is probably associated with specific lines of differentiation

    The transcription factor FOXO3a is a crucial cellular target of gefitinib (Iressa) in breast cancer cells

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    Gefitinib is a specific inhibitor of the epidermal growth factor receptor (EGFR) that causes growth delay in cancer cell lines and human tumor xenografts expressing high levels of EGFR. An understanding of the downstream cellular targets of gefitinib will allow the discovery of biomarkers for predicting outcomes and monitoring anti-EGFR therapies and provide information for key targets for therapeutic intervention. In this study, we investigated the role of FOXO3a in gefitinib action and resistance. Using two gefitinib-sensitive (i.e., BT474 and SKBR3) as well as three other resistant breast carcinoma cell lines (i.e., MCF-7, MDA-MB-231, and MDA-MB-453), we showed that gefitinib targets the transcription factor FOXO3a to mediate cell cycle arrest and cell death in sensitive breast cancer cells. In the sensitive cells, gefitinib treatment causes cell cycle arrest predominantly at the G(0)-G(1) phase and apoptosis, which is associated with FOXO3a dephosphorylation at Akt sites and nuclear translocation, whereas in the resistant cells, FOXO3a stays phosphorylated and remains in the cytoplasm. The nuclear accumulation of FOXO3a in response to gefitinib was confirmed in tumor tissue sections from breast cancer patients presurgically treated with gefitinib as monotherapy. We also showed that knockdown of FOXO3a expression using small interfering RNA (siRNA) can rescue sensitive BT474 cells from gefitinib-induced cell-proliferative arrest, whereas reintroduction of active FOXO3a in resistant MDA-MB-231 cells can at least partially restore cell-proliferative arrest and sensitivity to gefitinib. These results suggest that the FOXO3a dephosphorylation and nuclear localization have a direct role in mediating the gefitinib-induced proliferative arrest and in determining sensitivity to gefitinib.Supported by the German Cancer Aide Foundation (J. Krol)and the Association of International Cancer Research (R. Francis).Andrew Sunters and Andreas Polychronic were fellows funded by CancerResearch UK. Andre Albergaria is a recipient of a grant from Fundação para a Ciência e a Tecnologia, Portugal. This work was sponsored by theBreast Cancer Research Trust and Cancer Research U

    Perceção do risco para peões através do ruído rodoviário

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    Neste trabalho estudou-se a influência do ruído proveniente do tráfego rodoviário na perceção do risco e a forma como varáveis que para ele contribuem (e.g. velocidade e tipo de pavimento) conseguem influenciar a tomada de decisão dos peões numa situação de atravessamento de uma rodovia. Recorreu-se à apresentação de estímulos auditivos em ambiente simulado constituídos por amostras de ruído de tráfego rodoviário adquiridas através do método da passagem controlada (CPB) a um conjunto de participantes. A experiência realizada permitiu concluir que o nível de ruído do tráfego rodoviário apresenta grande importância na forma como os peões avaliam uma potencial situação de risco numa passagem para peões, sendo que quanto mais intenso for o ruído do tráfego mais conservadora é a opção tomada pelos peões.FCT – Fundação para a Ciência e Tecnologia e contém informação proveniente dos projetos PEst-OE/ECI/UI4047/2014, PEst-OE/EEI/UI0319/2014 financiados no âmbito do Programa Operacional Temático Fatores de Competitividade (COMPETE) e comparticipados pelo Fundo Comunitário Europeu FEDER, do projeto PTDC/ECM-TRA 3568/2014 cofinanciado pelo Programa Operacional Competitividade e Internacionalização e pelo projeto NORTE-07-0162-FEDER-000076- cave@CCG, ON.2 – Programa Operacional Regional do Norte

    Pedestrians behaviour at unsignalized crosswalks: comparison of results based on simulated urban environments with field observations

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    [Excerpt] Introduction: Walking is the cleanest mode of transportation on earth, but the it is still one of the most dangerous. Knowing the pedestrians’ behavior in conflict zones is an essential step to reduce pedestrian crashes. The methods for this kind of analysis pass through sophisticated simulation methods, such as the virtual environments. This research is a part of the project AnPeB, the first approach done to the pedestrians’ behavior analysis on a pair of virtual urban environments recently developed, comparing the data collected through their implementation with field observations. [...]This work is part of the activities of the research project AnPeB – Analysis of pedestrians behavior based on simulated urban environments and its incorporation in risk modelling (PTDC/ECM-TRA/3568/2014), was funded under the Promover a Produção Científica e Desenvolvimento Tecnológico e a Constituição de Redes Temáticas (3599-PPCDT) project and supported by the European Community Fund FEDER and the doctoral scholarship SFRH/BD/131638/2017 funded by the Fundação para a Ciência e a Tecnologia

    Tyre/road noise annoyance assessment through virtual sounds

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    Road-traffic noise is the most significant source of environmental noise. Among the several different sources of noise emission from vehicles, tyre/road noise at speeds above 40 km/h is the most prevalent. Its negative impact on health is now better known and may be mitigated by optimising road surface characteristics. Experimental data linking the characteristics of the road surface to levels of annoyance regarding noise remain scarce. Moreover, assessing annoyance by experimental means using real sounds is complex and could impede study interactions with a wide set of variables. In this chapter we describe, discuss and present the results of a straightforward method to assess tyre/road noise and related annoyance, based on the virtual sounds made by vehicles, with no interferences
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