Avaliação do potencial da aplicabilidade de geradores termoelétricos na gestão técnica de edifícios

As preocupações a nível ambiental relacionadas com o elevado consumo energético, que tem vindo a sofrer um aumento ao longo dos anos, tornaram-se um assunto a ser colocado no topo das prioridades por parte das organizações ambientalistas e governamentais. Sendo os edifícios um dos sectores que mais contribui para este cenário, torna-se necessário reduzir o consumo energético nos mesmos, fazendo uma gestão técnica mais eficiente da energia por eles consumida. Um controlo mais eficiente de sistemas de climatização ou iluminação, pode traduzir-se em grandes poupanças energéticas. Para isso, a automatização de edifícios tem vindo a tornar-se uma prática mais comum, onde através de uma rede de sensores é feito um controlo dos diversos equipamentos utilizados por estes sistemas. Estas redes sensoriais recorrem em geral a baterias para se manterem em constante funcionamento. No entanto o seu período de vida útil torna-se por vezes reduzido, dependendo da aplicação a que se destinam. Torna-se assim pertinente procurar uma solução alternativa a este problema, contribuindo o presente trabalho para o efeito. Neste trabalho, pretendeu-se estudar e caracterizar um conversor termoelétrico, estudando a possibilidade de substituição de baterias de pequenos dispositivos electrónicos pelos mesmos. Os conversores termoelétricos são pequenos dispositivos que fazem uso da termoeletricidade, nomeadamente do efeito de Seebeck, produzindo energia através de pequenas diferenças de temperatura que se encontrem no ambiente. Foram realizados diversos ensaios com o objectivo de simular diferentes condições de funcionamento do conversor, caracterizando-o da melhor forma possível. Conclui-se ser possível obter valores de potência satisfatórios, assumindo-se como viável a sua utilização em dispositivos com baixos consumos energéticos.The environmental concerns related to the high energy consumption, which has experienced an increase over the years, have become a subject to be placed on the top priority by the environmentalists and government organizations. Buildings are one of the sectors that most contribute to this scenario, it becomes necessary to reduce the energy consumption in them, making a more efficient technical management of energy consumed. More efficient control of HVAC and lighting systems can result in large energy savings. For this, building automation has become a more common practice, using a sensor network to check various equipments used by these systems. These sensory networks usually make use of batteries to remain in constant operation. However the period of its useful life it is sometimes reduced, depending on the intended application. It thus becomes possible to pursue an alternative solution to this problem, this paper contributes to the effect. In this work, it was intended to study and characterize a thermoelectric converter, studying the possibility of replacing the batteries of small electronic devices for them. Thermoelectric converters are small devices that make use of thermoelectricity, particularly the Seebeck effect, producing energy from small temperature differences found in the environment. Several tests were performed in order to simulate different operating conditions of the converter, characterizing it as best as possible. It was concluded to be possible to obtain satisfactory values of power, taking as feasible their use in devices with low energy consumption

AXL as a modulator of sunitinib response in glioblastoma cell lines

Receptor tyrosine kinase (RTK) targeted therapy has been explored for glioblastoma treatment. However, it is unclear which RTK inhibitors are the most effective and there are no predictive biomarkers available. We recently identified the RTK AXL as a putative target for the pan-RTK inhibitors cediranib and sunitinib, which are under clinical trials for glioblastoma patients. Here, we provide evidence that AXL activity can modulate sunitinib response in glioblastoma cell lines. We found that AXL knockdown conferred lower sensitivity to sunitinib by rescuing migratory defects and inhibiting apoptosis in cells expressing high AXL basal levels. Accordingly, overactivation of AXL by its ligand GAS6 rendered AXL positive glioblastoma cells more sensitive to sunitinib. AXL knockdown induced a cellular rewiring of several growth signaling pathways through activation of RTKs, such as EGFR, as well as intracellular pathways such as MAPK and AKT. The combination of sunitinib with a specific AKT inhibitor reverted the resistance of AXL-silenced cells to sunitinib. Together, our results suggest that sunitinib inhibits AXL and AXL activation status modulates therapy response of glioblastoma cells to sunitinib. Moreover, it indicates that combining sunitinib therapy with AKT pathway inhibitors could overcome sunitinib resistance.This work was funded by Fundacao para a Ciencia e Tecnologia (FCT), Portugal (project: PTDC/SAU-TOX/114549/2009). Olga Martinho is a recipient of a Post-Doc fellowship (UMINHO/BPD/32/2013) from QREN. We would like to acknowledge Dr. Shuang-En Chuang from the National Health Research Institute, Taiwan, for providing AXL vectors, and Dr. Raquel Andrade for critical review of the manuscript

Photonic superdiffusive motion in resonance radiation trapping

In this work we consider the relation between the jump length probability density function and the line shape function in resonance radiation trapping in atomic vapors. The two-sided jump length probability density function suitable for a unidimensional formulation of radiative transfer is also derived. As a side result, a procedure to obtain the Maxwell distribution of velocities from the Maxwell-Boltzmann distribution of speeds was obtained. General relations that give the asymptotic jump length behavior and the Lévy flight parameter niu for any line shape are obtained. The results are applied to generalized Doppler, generalized Lorentz, and Voigt line shape functions. It is concluded that the lighter the tail of the line shape function, the less heavy the tail of the jump length probability density function, although this tail is always heavy, with niu <= 1

A contribution for the automatic sleep classification based on the Itakura-Saito spectral distance

Sleep staging is a crucial step before the scoring the sleep apnoea, in subjects that are tested for this condition. These patients undergo a whole night polysomnography recording that includes EEG, EOG, ECG, EMG and respiratory signals. Sleep staging refers to the quantification of its depth. Despite the commercial sleep software being able to stage the sleep, there is a general lack of confidence amongst health practitioners of these machine results. Generally the sleep scoring is done over the visual inspection of the overnight patient EEG recording, which takes the attention of an expert medical practitioner over a couple of hours. This contributes to a waiting list of two years for patients of the Portuguese Health Service. In this work we have used a spectral comparison method called Itakura distance to be able to make a distinction between sleepy and awake epochs in a night EEG recording, therefore automatically doing the staging. We have used the data from 20 patients of Hospital Pulido Valente, which had been previously visually expert scored. Our technique results were promising, in a way that Itakura distance can, by itself, distinguish with a good degree of certainty the N2, N3 and awake states. Pre-processing stages for artefact reduction and baseline removal using Wavelets were applied.publishersversionpublishe

Importance of rotary systems in dental care by undergraduate students in patients of a public health service of Belo Horizonte

Background: The aim of this study was to evaluate the fracture rates of ProTaper rotary files used in the endodontics extension clinic of the Undergraduate Dentistry Course of the Pontifical Catholic University of Minas Gerais during the prior eight years. Material and Methods: Control record data regarding file usage by students were collected and analyzed by semester. For each period, the total number of patient consultations, the frequency of file use, the occurrence of fractures and the file numbers for which fractures occurred were noted. Descriptive statistics, including frequency of file fractures were calculated for all file types. The chi-square test was used to evaluate differences in the frequency of file fractures between all file types. Results: The study results revealed that during the examined period, there were 1006 consultations and 7993 uses of files. A total of 30 file fractures were recorded throughout this period; thus, fractures occurred in 0.37% of total file uses and 2.98% of all consultations. The most frequently used files were S1, S2 and F1, and these files also accounted for the most fractures. However, no differences in the frequency of file fractures were observed between the file types ( p >0.05). Conclusions: The low fracture rates observed in this study indicate that the examined instruments can be used to safely provide dental care to patients

Evaluation of three different rotary systems during endodontic retreatment: analysis by scanning electron microscopy

Background: Endodontic therapy is considered a series of important and interdependent steps, and failure of any of these steps may compromise the treatment outcome. This study aimed to evaluate the effectiveness of three different rotary systems in removing obturation materials during endodontic retreatment using scanning electron microscopy (SEM) analysis. Material and Methods: Thirty-six endodontically treated teeth were selected and divided into 3 groups of 10 and 1 control group with 6 dental elements. The groups were divided according to the rotary system used for removing gutta-percha, as follows: G1: ProTaper system; G2: K3 system; G3: Mtwo system; and G4: Control group. Thereafter, the roots were split and the sections were observed under SEM, for analysis and counting of clear dentinal tubules, creating the variable “degree of dentinal tubule patency” (0: intensely clear; 1: moderately clear; 2: slightly clear; 3: completely blocked). The data were subjected to the Friedman and Kruskal-Wallis statistical tests. Results: No differences were observed in the “degree of dentinal tubule patency” neither between the root thirds (to each evaluated group) nor between the groups (to each evaluated third). Nevertheless, when the three root thirds were grouped (providing evaluation of all root extension), the “degree of dentinal tubule patency” was lower in G1 than in G3 ( p <0.05), but showed no differences neither between G1 and G2 nor G2 and G3. Conclusions: No technique was able to completely remove the canal obturation material, despite G1 having shown better results, although without significant difference to G

Santuários católicos: o caso da Senhora dos Milagres em Pindelo dos Milagres

Os santuários católicos, nomeadamente nos meios rurais de Portugal, têm um papel importante na preservação da fé das populações e, sobretudo, no bem-estar das pessoas que habitam nestas zonas. De facto, as promessas feitas nestes santuários e as deslocações a estes lugares para oração são um bálsamo para as diversas dificuldades encontradas no dia-a-dia, nos mais diversos níveis da vida quotidiana. A manutenção com vitalidade destes santuários é, no entanto, um desafio para as populações e para a Igreja Católica, nomeadamente em virtude da perda de população que se tem verificado em muitas zonas Portuguesas do interior. Neste contexto, o objetivo deste texto é analisar as diversas interligações dos santuários católicos nas diversas partes do mundo, realçando as origens e a importância para as populações do santuário da Nossa Senhora dos Milagres em Pindelo dos Milagres (São Pedro do Sul).Catholic sanctuaries, especially in Portugal's rural areas, play an important role in preserving the faith of the people and, above all, in the well-being of the people living in these areas. In fact, the promises made in these shrines and the journeys to these places for prayer are a balm for the various difficulties encountered in everyday life at the most diverse levels of daily life. The maintenance of these sanctuaries with vitality is, however, a challenge for the population and for the Catholic Church, especially due to the loss of population that has occurred in many Portuguese areas of the interior. In this context, the purpose of this text is to analyze the different interconnections of Catholic shrines in different parts of the world, highlighting the origins and importance of the sanctuary of Our Lady of Miracles in Pindelo dos Milagres (São Pedro do Sul).info:eu-repo/semantics/publishedVersio

Relating network rigidity, time scale hierarchies, and expression noise in gene networks

Fluctuation-dissipation theorems can be used to predict characteristics of noise from characteristics of the macroscopic response of a system. In the case of gene networks, feedback control determines the "network rigidity," defined as resistance to slow external changes. We propose an effective Fokker-Planck equation that relates gene expression noise to topology and to time scales of the gene network. We distinguish between two situations referred to as normal and inverted time hierarchies. The noise can be buffered by network feedback in the first situation, whereas it can be topology independent in the latter.USP/COFECUBUSP-COFECUB [115/09

Stromal myofibroblasts in oral leukoplakia and oral squamous cell carcinoma

Objectives: Oral leukoplakia (OL) is the main potentially malignant disorder and oral squamous cell carcinoma (OSCC) is the most common malignancy of the oral mucosa. Stromal myofibroblasts play an important role in tumor invasion and metastasis, due to its ability to modify the extracellular matrix. This study aimed to evaluate the presence of stromal myofibroblasts in OL and OSCC. Differences in the presence of myofibroblasts among OL with distinct grades of epithelial dysplasia as well as between histologically high- and low-invasive OSCC were also assessed. Study D esign: A total of 30 OL and 41 OSCC from archival formalin-fixed, paraffin-embedded specimens were evaluated. 10 samples of normal oral mucosa were used as a control. Myofibroblasts were identified by immunohistochemical detection of alpha smooth muscle actin and its presence was classified as negative, scanty or abundant. Differences in the presence of myofibroblasts among OL with distinct grades of epithelial dysplasia as well as between high- and low-invasive OSCC were analyzed using the Mann-Whitney test. Results: Myofibroblasts were not detected in normal oral mucosa and OL, whatever its histological grade. In OSCC, the presence of stromal myofibroblasts was classified as negative in 11 (26.8%), scanty in 15 (36.6%), and abundant in 15 samples (36.6%). The presence of stromal myofibroblasts was statistically higher in high-invasive OSCC than in low-invasive OSCC (p<0.05). Conclusions: Stromal myofibroblasts were not detected in OL, indicating that these cells are not important during oral carcinogenesis. Nevertheless, stromal myofibroblasts were heterogeneously detected in OSCC and its presence was higher in tumors with a more diffuse histological pattern of invasion. These findings suggest that myofibroblasts are associated with the creation of a permissive environment for tumor invasion in OSC