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Three-dimensional printing techniques have been widely used in the fabrication of new materials applied to energy, sensing and electronics due to unique advantages, such as fast prototyping, reduced waste generation, and multiple fabrication designs. In this paper, the production of a conductive 3D-printing filament composed of Ni(OH)2 microparticles and graphene within a polylactic acid matrix (Ni-G-PLA) is reported. The nanocomposite was characterized by thermogravimetric, energy-dispersive X-ray spectroscopic, scanning electronic microscopic, Raman spectroscopic and electrochemical techniques. Characteristics such as printability (using fused deposition modelling), electrical conductivity and mechanical stability of the polymer nanocomposite were evaluated before and after 3D printing. The novel 3D-printed disposable electrode was applied for selective detection of glucose (enzyme-less sensor) with a detection limit of 2.4 μmol L−1, free from the interference of ascorbic acid, urea and uric acid, compounds typically found in biological samples. The sensor was assembled in a portable electrochemical system that enables fast (160 injection h−1), precise (RSD

New materials have been widely investigated for ionizing radiation dosimetry for medical procedures. Carbon-doped alumina (α-Al2O3:C) have been reported to be excellent thermoluminescent (TL) and optically stimulated luminescence (OSL) radiation dosimeters. In the present study, we have synthetized nano and micro-sized α-Al2O3:C polycrystals, doped with different percentages of carbon atoms aiming to compare their efficiency as TL dosimeters. The dosimetric characteristics for X ray and gamma fields were investigated. Samples doped with different amounts of carbon atoms were sintered under different atmosphere conditions, at temperatures ranging from 1300 °C to 1750 °C. Among the investigated samples, the micro-sized alumina doped with 0.01% of carbon and sintered at 1700 °C under reducing atmosphere, has presented a very high TL output. The main TL peak is centered at 250 °C and has a linear behavior with photon dose in the dose range of 0.02-to-5000 mGy, with correlation coefficient very close to one (0.99991). Samples produced by using nanosized alumina have shown much lower TL output when compared to the samples with microsized alumina. The micro-sized alumina obtained by the methodology used in this work is a suitable candidate to be explored for application in X and Gamma radiation dosimetry.

Due to their differentiated structure and properties, nanoporous metals gain great attention in several areas, such as catalysis and energy storage. The effects of magnetic fields on electrochemical processes affect the theoretical and practical performance of the capacitors. This work describes the effect of a external magnetic field on the electrochemical performance of nickel ferrite nanoparticles prepared by the proteic sol–gel method. Here the electrochemical capacitance and the cyclability of the electrodes modified by the NiFe2O4 nanoparticles are compared without the intervention of any magnetic field and with the presence of a magnetic field of 200 mT flow density. Our experimental data showed that the studied material under an external magnetic field has a much better electrochemical performance when compared with the one without the application of a magnetic field. A magnetic field can improve the capacitance, reduce the charge transfer resistance and enhance the discharge performance. The improvement in the capacitance of the magnetized electrode increases 29.3 % in the current density of 1 A g−1, and the cyclability increases around 69.1 % when compared to the tested electrode without the magnetic field. Therefore, our results show an alternative way to improve the electrochemical performance of energy storage materials.

In this paper, thermoluminescence (TL) properties such as glow curves analysis, dose response linearity and some dosimetric characteristics of pure and carbon doped lanthanum aluminate (LaAlO 3 ) produced by different syntheses using the solid state reaction method are investigated, after exposure to different UV radiation doses. The effect of different syntheses on the TL glow curves structures is also investigated and discussed. TL glow-curve deconvolution (CGD) methods and the Chen’s peak shape methods were used to analyze the sets of TL glow curves. The kinetic parameters of TL single peaks were computed. Additionally, the life times ( τ ) of electrons in trap for all samples were determined and calculated. A good linear dose response over the dose range from 0.21 to 1.26 mJ/cm 2 has been attributed to both samples (B and C).

Made available in DSpace on 2022-04-29T07:25:55Z (GMT). No. of bitstreams: 0 Previous issue date: 2015-07-25 Financiadora de Estudos e Projetos Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) Abstract Bulk Co-doped ZnO (Zn1-xCoxO) samples were prepared and studied with particular emphasis on their compositions, structures, and magnetic properties. A detailed microstructural analysis was conducted to investigate the nature of Co incorporation into the wurtzite ZnO matrix. The Zn1-xCoxO ceramic samples were prepared using the standard solid-state reaction method with different Co molar concentrations of up to 30%. A Co solubility limit of approximately 23% was determined. For samples with Co concentrations greater than 23%, a segregated phase identified as Zn-doped CoO (Co1-yZnyO with y = 0.23) was observed. The magnetic characterization for the single-phase samples revealed a paramagnetic behavior with antiferromagnetic coupling of Co2+ ions within the ZnO matrix. In order to get more insight about the magnetic results Monte Carlo simulations were conducted for different magnetic couplings and different Co distributions over the volume of the samples. We discussed the observed magnetic behavior of our samples by considering the main theories regarding the magnetic properties of dilute magnetic oxides. An inhomogeneous distribution of Co ions within the grains was inferred from the microstructural and magnetic characterization. Universidade Federal de Alfenas Universidade Federal de Ouro Preto Departamento de Engenharia de Materiais, Universidade Federal de São Carlos University of Valencia, Materials Science Institute Universidade Federal de Uberlândia Instituto de Física, Universidade de São Paulo Centro de Desenvolvimento de Tecnologia Nuclear/CNEN Departamento de Física, Instituto de Geociências e Ciências Exatas, Universidade Estadual Paulista Departamento de Física, Instituto de Geociências e Ciências Exatas, Universidade Estadual Paulista Financiadora de Estudos e Projetos: 134/08 CNPq: 476870/2011-9 Financiadora de Estudos e Projetos: MAT2012-33483 CAPES: PNPD-2011

U–Mo alloys are a promising alternative in high-density fuel materials for use in research and test reactors, due to its resistance to swelling associated with the presence of the metastable γ-phase in the microstructure. It has been reported that increasing additions of Mo cause a beneficial delay in the decomposition of the γ-phase in U–Mo alloys during isothermal heat treatments. Analyses emphasized high temperature aging (>400 °C), where the microstructural evolution features were followed by low resolution light microcopy, but little information is available for lower temperature treatments. High resolution microstructural characterization techniques allow a more in depth analysis of the decomposition, as already shown for U–Nb alloys. In this work, phase transitions resulting from the decomposition of the γ-phase, or its variants, were investigated in as-cast U–Mo alloys with 5, 7 and 10 wt.% Mo, aged at 300 and 500 °C. Characterization techniques employed light microscopy, hardness, high resolution FE-SEM and EFM, which establishes contrasts for domains with different physical properties. The ageing of Mo-segregated regions, typical of the as-cast state, allowed the consideration of a broad range of Mo contents. For the low Mo regions, results were similar to those reported for U–Nb alloys, involving transformation twins and disorder-ordering mechanisms in the low temperature ageing and the formation of a non-lamellar constituent (NL3) in the high temperature ageing. The precipitation of oriented acicular or Widmanstatten γ′ platelets over a γ-phase matrix was observed for the hypereutectoid compositions of the U–Mo system, while the interdendritic regions with Mo contents close to the eutectoid composition were initially untransformed. This indicates a maximum in the γ stabilizing effect for the eutectoid composition, in opposition to the commonly accepted increased stabilizing effect for raised Mo additions.

ObjectiveTo quantify modification of functional capacity in a three-year period in a group of patients with rheumatoid arthritis (RA) using HAQ and EPM-ROM inventories.MethodsForty patients with RA on methotrexate (MTX) as disease-modifying antirheumatic drug (DMARD) were followed for up to three years. The functional status was assessed at the beginning and end of the period by HAQ and EPM-ROM.ResultsThirty-two patients were retrieved, with initial HAQ score of 1.14±0.49 (mean±SD) and EPM-ROM score of 5.8±2.75. After an average period of three years, the HAQ score was 1.13±0.49 and EPM-ROM score, 6.81±3.66. In the subgroup of seven patients submitted to orthopedic surgery, HAQ score decreased from 0.84±0.72 to 1.64±0.56 and the EPM-ROM score, from 5.8±1.80 to 8.3±0.74. In the subgroup of non-operated patients, HAQ score varied from 1.2±0.45 to 1.07±0.70 and EPM-ROM score, from 5.7±3.06 to 6.4±3.90.ConclusionIn a group of RA patients in use of only MTX as DMARD, there was little change on HAQ score and EPM-ROM scores over the average period of three years. Worsening functional capacity was observed in the group of operated patients in comparison to the not operated ones. This fact alerts us to the need for use of broader therapeutic regimens availability of musculoskeletal surgeries in a timely manner in patients with RA.

LaAlO3 single crystals grown under hydrothermal conditions and co-doped with Ce and Dy atoms have been recently reported to show high thermoluminescent (TL) outputs for ultraviolet (UV) radiation fields ( Oliveira et al., 2011 ). Due to this property, they have been considered for further investigation for applications in UV dosimetry. Encouraged by these results, we start an investigation about the TL properties of polycrystalline LaAlO3 grown by an alternative method. In this method, equimolar amounts of Al2O3 and La2O3 are sintered, producing polycrystalline LaAlO3 powder. Polycrystals doped with amounts of carbon ranging from 0.0 to 5.0 at.% were synthesized by sintering under hydrogen reducing atmosphere. After irradiation with a UV commercial lamp, the best TL outputs were observed for the undoped sample. The recorded TL glow curves show a main TL peak centered at 175 °C. The TL emission spectrum show a broad emission peak centered at 634 nm and another three narrow peaks centered at 724 nm, 738 nm and 754 nm, respectively. The undoped material show a huge TL output response for UV spectral irradiances ranging from 0.04 to 1.68 mJ cm−2 that can be fitted by a 2nd order polynomial regression. The investigation demonstrates that undoped polycrystalline LaAlO3 crystals sintered under reducing atmosphere are very attractive to be investigated as high sensitivity ultraviolet TL dosimeters.

The main current therapies for inflammatory bowel diseases (IBD) are aimed at controlling the exacerbated inflammation in the gut. Although these therapies have been successful, they are not curative and it is not possible to predict whether a beneficial response will occur or which patients will be refractory to the treatment. Total body irradiation (TBI) associated with chemotherapy is the first choice in the treatment of some hematological disorders and is an applicable option in the preparation of patients with hematologic diseases for hematopoietic stem cell transplantation. Then, in this study we investigated the association of TBI as immunosuppressive therapy and bone marrow cell (BMC) transplantation as a strategy to induce colitis recovery and immune reconstitution in the TNBS model of intestinal inflammation. TNBS mice treated with TBI associated with BMC transplantation presented elevated gain of weight and an overall better outcome of the disease when compared to those treated only with TBI. In addition, TBI associated or not with BMC reduced the frequency of inflammatory cells in the gut and restored the goblet cell counts. These results were accompanied by a down regulation in the production of inflammatory cytokines in the colon of mice treated with TBI alone or in association with BMC transplantation. The BMC infused were able to repopulate the ablated immune system and accumulate in the site of inflammation. However, although both treatments ( TBI or TBI + BMC ) were able to reduce gut inflammation, TBI alone was not enough to fully restore mice weight and these animals presented an extremely reduced survival rate when their immune system was not promptly reconstituted with BMC transplantation. Finally, these evidences suggest that the BMC transplantation is an efficient strategy to reduce the harmful effects of TBI in the colitis treatment, suggesting that radiotherapy may be an important immunosuppressive therapy in patients with IBD, by modulating the local inflammatory response.

This work investigates the actions of LASSBio-1289, (E)-N-methyl-N'-(thiophen-3-methylene)benzo[d][1,3]dioxole-5-carbohydrazide, on monocrotaline (MCT)-induced pulmonary arterial hypertension (PAH) in rats. Two weeks following the MCT injection, LASSBio-1289 (50 or 75mg/kg, p.o.) or vehicle was administrated once daily for 14 days. LASSBio-1289 (75 mg/kg) treatment caused a significant decrease in right ventricular systolic pressure (31.89±0.82 mmHg) compared to the MCT-vehicle group (52.74±6.19 mmHg; P

Although several reports have demonstrated physiological and behavioral changes in adult rats due to neonatal immune challenges, little is known about their effects in adolescence. Since neonatal exposure to lipopolysaccharide (LPS) alters the neural substrates involved in cognitive disorders, we tested the hypothesis that it may also alter the response to novel environments in adolescent rats. At 3 and 5 days of age, male Wistar rats received intraperitoneal injections of either vehicle solution or E. coli LPS (0.05mg/kg) or were left undisturbed. In the mid-adolescent period, between 40 and 46 days of age, the rats were exposed to the following behavioral tests: elevated plus-maze, open-field, novel-object exploration task, hole-board and the modified Porsolt forced swim test. The results showed that, in comparison with control animals, LPS-treated rats exhibited (1) less anxiety-related behaviors and enhanced patterns of locomotion and rearing in the plus-maze and the open-field tests, (2) high levels of exploration of both objects in the novel-object task and of corner and central holes in hole-board test, and (3) more time spent diving, an active behavior in the forced swim test. The present findings suggest that neonatal LPS exposure has long-lasting effects on the behavior profile adolescent rats exhibit in response to novelty. This behavioral pattern, characterized by heightened exploratory activity in novel environments, also suggests that early immune stimulation may contribute to the development of impulsive behavior in adolescent rats.

The influence of grain-boundaries on uranium and oxygen diffusion in polycrystalline UO2 has been investigated. Our results show that between 1498°C and 1697°C, in H2 atmosphere, uranium diffusion in UO2 grain-boundaries is about five orders of magnitude greater than uranium volume diffusion, in the same experimental conditions. Between 605°C and 750°C, in H2/N2/H2O atmosphere, the oxygen diffusion coefficients measured in polycrystalline and single crystalline UO2 are similar, and correspond to the volume diffusion.