TiO2:WO3 composite humidity sensors doped with ZnO and CuO investigated by impedance spectroscopy

For impedance-type sensors based on semiconducting metal oxides, the overall conduction mechanisms strongly influence the magnitude and the direction of the sensor signal variation. For humidity, in particular, the electronic/ionic charge-transfer reactions that take place at the semiconductor surface can be used to monitor and control it. In recent years, various mechanisms have been proposed to explain the variations of electrical response to humidity. With the study of composite materials, we expect to obtain a better sensitivity of these sensors, when compared with the ones made out of only one metal oxide. This could be due to the fact that some of the positions initially occupied by the atoms of one of the metals are now occupied by atoms of the other metal: if a single covalent/ionic adsorption is decisive in the observed changes in the material's conductivity, then the electronegativity of the occupying metal atoms may be used to regulate the sensitivity. In this paper, TiO2:WO3 composite oxide bulk sensors, using 48.92 and 51.08% (w/w) of titanium and of tungsten atoms, respectively, doped with the same proportions of cooper and zinc oxides (7%), were prepared by a conventional sintering method, and their dependence of their complex impedance spectra, measured in the range 100 Hz–10 MHz, on the relative humidity (RH), operating temperature and on the measuring frequency is shown and explained

Efeitos do treinamento aeróbico em camundongos ateroscleróticos

A doença aterosclerótica é caracterizada por um processo inflamatório crônico que, por sua vez, pode acelerar a senescência de células vasculares e agravar a instalação de placas. O exercício aeróbico moderado melhora a função vascular prevenindo o agravamento do processo aterosclerótico. Camundongo apoE-/-, modelo experimental de aterosclerose espontânea, tem se mostrado uma valiosa ferramenta no estudo dessa doença. O objetivo deste estudo foi verificar a capacidade de treinamento dos camundongos apoE-/- e verificar a influência do treinamento físico na senescência de células vasculares e na lesão aterosclerótica. Camundongos apoE -/- (n=16) e C57BL/6 (n=16) machos de 4 ½ meses de idade foram divididos em grupo treinado e sedentário. O treino correspondeu a: 1 hora/dia, 50-70% da velocidade máxima de corrida, 5 vezes/semana, 5 semanas. Foram realizadas medidas de colesterol, pressão arterial (PA) e freqüência cardíaca (FC). Após o treino os animais foram eutanasiados, a aorta retirada e incubada em uma solução X-gal (pH 6.0) para caracterização colorimétrica (cor azul) da senescência e posterior quantificação de área de placa. Os dados estão expressos como média ± EPM. Para análise estatística foi usado ANOVA 2-vias, seguida do post hoc de Fisher, **p? 0,05. Foi encontrada senescência vascular nos animais apoE-/- e o treinamento aeróbico não reduziu a área de lesão aterosclerótica, embora observou-se uma tendência de redução de área de senescência de células vasculares. A capacidade de corrida dos grupos C57 e apoE-/- não foi diferente antes do programa de treinamento, no entanto, o mesmo aumentou a capacidade máxima de corrida dos animais quando comparado aos sedentários, com ganho percentual de 36 e 42% na velocidade máxima alcançada nos grupos C57 e apoE -/- treinados, respectivamente. Os animais apoE -/- apresentaram hipercolesterolemia (sedentário: 646±75##, treinado: 664±66## mg/dL) em relação aos C57 (sedentário: 161±16, treinado: 102±12 mg/dL), e o treino não influenciou o colesterol, FC e PA. Os camundongos apoE-/- apresentaram o mesmo ganho de performance física com o treino que os animais C57. Apesar da área de lesão de placa não ter sido reduzida com o treino, observou-se uma tendência de redução de senescência nos animais ateroscleróticos, sugerindo um possível efeito do treinamento aeróbico na redução do desenvolvimento precoce de senescência vascular

Antioxidant responses of edible and model plant species subjected to subtoxic zinc concentrations

Zinc (Zn) is a common heavy metal in polluted soils, as it is a widespread pollutant deriving both from natural sources and anthropogenic activities. The antioxidant tolerance/defence mechanisms against oxidative stress induced by subtoxic concentrations of Zn (50 and 150 μM ZnSO4) were studied in a widespread edible plant (lettuce; Lactuca sativa L.) and in an important model plant (Arabidopsis thaliana (L.) Heynh.). After 10 days (Arabidopsis) and 20 days (lettuce) of Zn exposure, Zn uptake/translocation was evaluated in both roots and shoots, while indicators of oxidative stress and stress intensity, total antioxidant capacity, and enzymatic and non-enzymatic antioxidative defence were measured in leaves. From an overall comparison of the two species, Zn root uptake in Arabidopsis subjected to 50 and 150 μM ZnSO4 was approximately 3- and 5-fold lower than in lettuce, while Zn translocation from roots to apical leaves was more efficient in Arabidopsis (23.7 vs 21.3% at 50 μM ZnSO4 and 19.3 vs 12.9% at 150 μM ZnSO4). Generally, a higher degree of Zn-induced oxidative stress (863.8 vs 21.3 μg g−1 FW H2O2 and 1.33 vs 0.75 μMg−1 FW MDAeq at 150 μM ZnSO4) and antioxidant response (441.2 vs 258.5mMg−1 FW TEAC and 91.0 vs 54.9% RSA at 150 μM ZnSO4) were found in lettuce. The aim of this study is understanding (a) if subtoxic Zn levels can affect Zn uptake and translocation in the studied species and (b) if this eventual Zn absorption can influence plant oxidative status/antioxidant response. Considering that soil contamination by Zn can affect crop production and quality, the results of this research could be important for environmental, nutritional and human health issues

Laparoscopic colorectal resection for a giant colonic diverticulum - video vignette

A giant colonic diverticulum (GCD) is a rare disease with less than 200 cases reported in the literature. By definition, a GCD is larger than 4cm in diameter with close sigmoid colon relationship in more than 90% of the cases. En bloc resection of the diverticulum with anterior sigmoid-rectal segment with primary anastomosis is the best treatment approach. The authors present a case of laparoscopic colorectal resection with partial cystectomy for a giant colonic diverticulum. A 62-years-old man with sigmoid colon diverticulosis and several episodes of diverticulitis presented at the office with a painless hypogastric/left iliac abdominal mass. CT scan showed a round 11 cm smooth walled structure filled with gas, adjacent to the sigmoid anti-mesenteric border and the urinary bladder. Four trocars were used for the laparoscopic approach. Step-by-step as follows: i. complete mobilization of colon splenic flexure. ii. Giant diverticulum dissection with partial bladder resection. iii. Bladder closure. iv. Sigmoid colon and intra-peritoneal rectum resection with primary anastomosis. The post-operative course was uneventful and the patient was discharged home on post-operative day 4. Vesical catheter was removed on post-operative day 10. Pathological specimen analysis confirmed the pre-operative diagnosis of a GCD. There is a consensus that this extremely rare diverticular disease complication should be approached with prompt standard resection due to high risk of diverticulum rupture. Laparoscopic approach seems to be feasible and safe despite of dissection higher complexity owing to the mega diverticulum. This article is protected by copyright. All rights reserved.info:eu-repo/semantics/publishedVersio

Advanced Directives and Living Will: A Case Report

Descreve-se o caso de uma mulher de 61 anos, com diagnóstico de neoplasia da mama em estadio IV. Na altura, recusou terapêutica. Recorre ao Serviço de Urgência, um ano após o diagnóstico, em mutismo, sendo que os exames complementares de diagnóstico revelaram uma lesão cerebral, interpretada como nova metástase. No seu processo clínico, tem uma diretiva antecipada de vontade. Este é um documento formal que explicita quais os cuidados que pretende ou não receber em final de vida. Apresentamos a descrição do caso, as indicações que a doente deixou expressas neste documento e uma reflexão acerca das diretivas antecipadas de vontade e de como estas devem ser integradas na prática clínica.info:eu-repo/semantics/publishedVersio

Characteristics of sleep habits among adolescents living in the city of Ribeirão Preto (SP)

Introduction: Adolescence is the period of transition between childhood and adult life, characterized by changes in physical, emotional, sexual and social development. Although during this phase most individuals are healthy, it is known that health status is related to behaviors and habits such as a healthy diet, the regular practice of physical activity and good sleep quality, which contribute to optimum physical and cognitive performanceObjective: To determine some sleep characteristics of adolescents living in the city of Ribeirão Preto (SP).Methods: this was a cross-sectional descriptive study conducted at 14 schools in the city of Ribeirão Preto (SP) including adolescents aged 10 to 19 years who answered a questionnaire about sleep habits. The chi-square test was used to determine differences between genders with the aid of the EPI-INFO 7 software, with the level of significance set at p<0.05.Results: A total of 535 adolescents (65% girls) were included in the study. Of these, 47.7% studied during the morning period and 10.3% had a job and studied in the evening period. Regarding sleep duration, 242 (45%) slept less than 9 hours per night during week days and 256 (48%) during the weekends (Saturday and Sunday), Of the total number of adolescents studied, 75.5% reported that they went to bed when they felt sleepy, 90% reported delay in falling asleep, 84.3% used some type of electronic equipment before going to sleep, and 44% reported that they woke up during the night. In the morning, 70.3% needed to be awakened, and 44.7% reported a delay in waking up. During the daytime, 70% felt somnolent and 34% reported that they slept during the day. Girls reported that they felt more daytime sleepiness (71.3%) and slept more during the day (62.1%) than boys (28.7% and 37.9%, respectively), with the difference being statistically significant (p < 0.05).Conclusions: Almost half the adolescents investigated sleep less than the minimum time considered ideal. Furthermore, the most of adolescents went to the bed when they felt sleepy, used electronic devices before to sleep, had difficulties to fall asleep, need to be awake in the morning and felt sleepy during the day. A substantial proportion of adolescents studied awoke at night and slept during the day. Compared to boys, girls felt sleepy and slept during the day significantly.

Crystallization and preliminary crystallographic studies of FoxE from Rhodobacter ferrooxidans SW2, an FeII oxidoreductase involved in photoferrotrophy

FoxE is a protein encoded by the foxEYZ operon of Rhodobacter ferrooxidans SW2 that is involved in Fe^II-based anoxygenic photosynthesis (`photoferrotrophy'). It is thought to reside in the periplasm, where it stimulates light-dependent Fe^II oxidation. It contains 259 residues, including two haem c-binding motifs. As no three-dimensional model is available and there is no structure with a similar sequence, crystals of FoxE were produced. They diffracted to 2.44 Å resolution using synchrotron radiation at the Fe edge. The phase problem was solved by SAD using SHELXC/D/E and the experimental maps confirmed the presence of two haems per molecule

Robotic implantation of intracerebral electrodes for deep brain stimulation

This dissertation objective is to contribute for the development of a robotic system towards neurosurgery assistance in Deep Brain Stimulation (DBS) stereotactic procedures. Being DBS neurosurgery typically a long, physically and cognitively demanding procedure; the introduction of a robotic assistant to hold, manipulate and position instrumentation would improve the medical team working conditions and lead to better surgery outcomes. Upon understanding how could the robot be used and what robotic systems were adequate to the task, we implemented a simulation environment to emulate several industrial robot manipulators and the operating room. It was also developed each robot geometric and differential kinematic equations, and control algorithms specifically oriented for DBS neurosurgery assistance. Taking into account the operating room arrangement, the robot characteristics and task requirements, we selected the most apt industrial robotic manipulator and further elaborated on its placement and orientation to achieve utmost performance.This work has been partially financed by projects FP7 Marie Curie ITN - NETT (project no289146), FCT FCOMP-01-0124-FEDER-022674, Pest-C/MAT-UI0013/2011 (FCT grant ref. UMINHO/BIC/8/2012) and FCT PhD grant (ref. SFRH/BD/86499/2012)

Development of new decorative coatings based on gold nanoparticles dispersed in an amorphous TiO2 dielectric matrix

The present work is devoted to the optical properties of Au:TiO2 thin films in order to clarify the role of the Au clusters inclusions in the TiO2 dielectric matrix. Three series of films containing about 30 at.% (29.2), 20 at. % (19.8) and 10 at.% (9.3) Au were deposited by dc reactive magnetron sputtering. On thermal annealing in the range from 300 to 800 °C in protective atmosphere, significant changes on the crystalline phases and clusters dimensions were detected. The most promising optical behavior was found for the film 20% Au:TiO2, where the films revealed some colour changes, evolving from several shades of grey to different tones of red. This change in the optical behaviour of the films was found to be correlated with a cluster size increase from 2 to 17 nm. For higher size values (>20 nm) the films, independently of the Au content, showed a golden appearance colour. The optical changes were confirmed by reflectivity and CIELab colour measurements. Regarding the films with 10 and 30 at.% Au, the results confirmed that there is an evident range of compositions and clusters size where the SPR is more evident. Sample A (10 at.% Au) it seems to be in the lower limit of the SPR showing a typical interferometric behavior on the reflectivity measurements, similar to the TiO2 optical behavior. Regarding the 30 at.% Au one, the results seems to indicate that the amount of gold particles and their grain size is in the upper limit to show a SPR activity.Fundação para a Ciência e Tecnologia (FCT) - PTDC/CTM/70037/200

Electron transfer process in microbial electrochemical technologies: the role of cell-surface exposed conductive proteins

Electroactive microorganisms have attracted significant interest for the development of novel biotechnological systems of low ecological footprint. These can be used for the sustainable production of energy, bioremediation of metal-contaminated environments and production of added-value products. Currently, almost 100 microorganisms from the Bacterial and Archaeal domains are considered electroactive, given their ability to efficiently interact with electrodes in microbial electrochemical technologies. Cell-surface exposed conductive proteins are key players in the electron transfer between cells and electrodes. Interestingly, it seems that among the electroactive organisms identified so far, these cell-surface proteins fall into one of four groups. In this review, the different types of cell-surface conductive proteins found in electroactive organisms will be overviewed, focusing on their structural and functional properties