63 research outputs found
Isolation and Characterization of Novel Iron-Sulphur Proteins from DvH Involved in Cell Division
Firstly, isolated from Desulfovibrio gigas, the Orange Protein presents a unique type of mixed metal sulphur cluster composed by two different metals, molybdenum and copper. This protein forms a complex with other proteins, that has recently been proposed to be involved in anaerobic cell division of D. vulgaris Hildenborough.
In this Master thesis, DVU2103 ATPase from D. vulgaris Hildenborough was purified and biochemically characterized. Since the metal cluster present in this protein has been proven to be oxygen sensitive, the purification was performed under anoxic environment. The protein was co-purified with other proteins of the orp operon, DVU2108 and possibly DVU2104, as a protein complex (heterotrimer) confirming that this complex has physiological meaning. The protein complex was purified with an average yield of 58 ± 28 μg, and presents 5.3 ± 0.3 Fe atoms/Total protein. DVU2103 complex presents a broad absorption band at 400 nm in its visible spectrum characteristic of [4Fe-4S] clusters and ICP-AES analysis confirm the presence of either one or two [4Fe4S] clusters. As-isolated protein is mainly EPR active presenting a rhombic signal, with g values of 2.06, 1.89 and 1.85, that switches to an axial signal when reduced with dithionite. Dithionite, unlike ascorbate, is responsible for the full reduction of the metallic centre. Studies to determine the apparent molecular mass of the complex revealed that ATP affects its conformational structure, making it more compact, and oxic conditions lead to the destruction of the [Fe-S] cluster, with concomitant formation of a larger oligomer. ATPase activity of “DVU2103” complex was tested under anoxic and oxic conditions, showing that the protein has a higher activity under the former. Considering that the exposure to oxygen leads to the destruction of the [Fe-S] cluster, it can be concluded that it is essential for higher activity.
In this thesis the homologous expression and purification of DVU2108 in D. vulgaris Hildenborough was also performed. No Mo/Cu heterometallic cluster was detected in this protein after purification under anoxic conditions, nevertheless Fe/protein ratio of 1 was estimated for this sample
In depth study of charge compensation mechanism in novel 2D layered anode materials for Lithium and Sodium Ion Batteries
The development of high-performance electrode materials has become a critical area of research in the lithium and sodium-ion battery (LIBs and SIBs) community to meet the high energy and power density demands of the current and future electrical energy storage applications. So far, the progress in the development of suitable anode materials has been mostly limited to carbon-based materials, metal sulphides and oxides to a minor extent. Overall, these electrodes show room for improvement given their low voltage, low gravimetric density and poor long-term cyclability. Thus, at this juncture, alternative anodes to these with an excellent rate performance and a high capacity with long cyclability must be sought. The discovery of graphene initiated a surge of interest in other two-dimensional (2D) atomically thin materials, such as transition metal dichalcogenides (TMDs). These types of materials have been studied as promising materials for a broad range of applications for decades. The rising interest in these materials is due to their earth-abundant presence in nature, excellent mechanical properties, ability to tune interlayer spacing, good performance when large current densities are applied, long life capability and wide operation range temperatures. Although the excellent theoretical properties of these materials have not yet been reached, TMDs are a group of very promising materials to be used in energy storage. This thesis is a proof of concept to study the viability of two different TMD materials (WTe2 and TaTe2) as anode materials for both LIBs and SIBs. With this study, we will shed a light on the charge compensation mechanisms for these materials during lithium and sodium ion intercalation. The structure of the materials studied in this work was characterised using XRD, SEM and TEM. Their electrochemical response was tested using electrochemical techniques such as galvanostatic cycling, CV and EIS to probe ion (de)intercalation into the electrode crystal structure. Moreover, electrochemical tests were coupled with operando synchrotron XRD and XANES spectroscopy to understand the structural evolution upon ion insertion and extraction
Participação social de adolescentes em situação de acolhimento institucional
According to the Statute of Children and Adolescents (ECA) of 1990, the institutional care is a provisional and exceptional measure used transiently until there is family reintegration. When is not possible this reintegration, placement in a substitute family becomes an alternative, since it is the fundamental right of children and adolescents living in the community and family. The present study aims to investigate the social participation of adolescents in a Foster Home in the city of João Pessoa - PB. This is a descriptive study, with qualitative approach whose participants were adolescents between 12 and 18 who are in residential care situation in that Foster Home and agreed to participate voluntarily and signed the Informed Consent Form. For the research, it was used as data collection tool a semi-structured interview with script prepared by the researcher. After completion of the collection, it was made the analysis of empirical data that had as a parameter the own categories that have emerged of such data. As were built, analyzed and discussed the categories and forward to the responses from the guiding questions, three topics have been defined. It was found that teenagers participate in sports activities and training courses as well as attend services of health and social care. Some teens said they miss hanging out with friends, play, taking other courses and practice other sports. Only two teenagers claim to have contact with their family that occurs sporadically. Therefore, this research craves to contribute to a possible reassessment of the service provided by Foster Home and suggests empirical evaluation and research of the expansion applied in other residential care shelters in the state of Paraíba in order to collect comparative data for improve these institutions so that, increasingly, provide quality care to children and adolescentsDe acordo com o Estatuto da Criança e do Adolescente (ECA) de 1990 o acolhimento institucional é uma medida provisória e excepcional, utilizada de forma transitória até que ocorra a reintegração familiar. Não sendo possível esta reintegração, a colocação em família substituta torna-se uma alternativa, uma vez que é direito fundamental da criança e do adolescente o convívio na comunidade e com a família. O presente estudo tem como objetivo investigar a participação social de adolescentes de uma Casa Lar do município de João Pessoa-PB. Trata-se de um estudo descritivo, com abordagem de natureza qualitativa, cujos participantes foram adolescentes entre 12 e 18 anos que estão em situação de acolhimento institucional na referida Casa Lar, que aceitaram participar da pesquisa de forma voluntária e assinaram o Termo de Assentimento Livre e Esclarecido. Para a realização da pesquisa, foi utilizado como instrumento de coleta de dados a entrevista semiestruturada, com roteiro elaborado pela pesquisadora. Após a finalização da coleta, foi realizada a análise dos dados empíricos, tendo como parâmetro as próprias categorias que surgiram desses dados. Conforme foram construídas, analisadas e discutidas as categorias e frente às respostas obtidas às questões norteadoras, foram definidos três eixos temáticos. Foi verificado que os adolescentes participam de atividades esportivas e cursos profissionalizantes, como também frequentam serviços da área de saúde e da assistência social. Alguns adolescentes afirmaram sentir falta de sair com amigos, brincar, realizar outros cursos e praticar outros esportes. Apenas dois adolescentes afirmam ter contato com a família, e acontece de forma esporádica. Almeja-se que essa pesquisa contribua para uma possível reavaliação do serviço prestado pela Casa Lar e sugere-se avaliação empírica e expansão da pesquisa aplicada em outros abrigos de acolhimento institucional na região paraibana, a fim de coletar dados comparativos, visando o aprimoramento destas instituições para que, cada vez mais, prestem atenção de qualidade às crianças e adolescentes
Boosting the Usage of Green Energy for EV Charging in Smart Buildings Managed by an Aggregator Through a Novel Renewable Usage Index
The growing trend of electric vehicles (EVs) and building integrated photovoltaics (BIPVs) is
a promising means to reduce related climate change issues. EV loads can be managed via an aggregator to
maximize the usage of green energy produced by photovoltaic units (PV) through smart charging strategies
that exploit controllable EV demand connected to BIPV. Previous works have focused on the EV charging
coordination in a smart BIPV, although without an optimization that encourages EV charging with the
energy produced by the PV units. This paper proposes an aggregation strategy that maximizes a green
energy index (GEI) for the smart charging coordination of EVs, which takes advantage of periods with
high PV availability to charge the EV batteries; moreover, a post-processing stage for the GEI provides
EV owners with information about the percentage of charged energy, period by period, that comes from
PV generation. The results for a case study with 510 EVs integrated with 17 smart BIPVs show that the
strategy effectively optimizes the usage of the energy produced by the PV units to charge the EVs, contributes
to reduce non-renewable energy consumption of the building sector, and satisfies the EV owners’ energy
requirements for transportation.This work was supported in part by the Coordination for the Improvement of Higher Education Personnel (CAPES); in part by the Brazilian National Council for Scientific and Technological Development (CNPq) under Grant 305318/2016-0; in part by the Sao Paulo Research Foundation (FAPESP) under Grant 2018/08008-4, Grant 2017/02831-8, and Grant 2018/23617-7; and in part by the Portuguese Foundation for Science and Technology (FCT), under Project PTDC/EEI-EEE/28983/2017 [Coordinated ENErgy Resource manaGEment under uncerTainty considering electrIc vehiCles and demand flexibility in distribution networks (CENERGETIC)], Project CEECIND/02814/2017, and Project UIDB/000760/2020.info:eu-repo/semantics/publishedVersio
Voltage hysteresis during lithiation/delithiation of graphite associated with meta-stable carbon stackings
Cell voltage is a fundamental quantity used to monitor and control Li-ion batteries. The open circuit voltage (OCV) is of particular interest as it is believed to be a thermodynamic quantity, free of kinetic effects and history and, therefore, “simple” to interpret. Here we show that the OCV characteristics of graphite show hysteresis between charge and discharge that do not solely originate from Li dynamics and that the OCV is in fact history dependent. Combining first-principles calculations with temperature-controlled electrochemical measurements, we identify a residual hysteresis that persists even at elevated temperatures of greater than 50 °C due to differences in the phase succession between charge and discharge. Experimental entropy profiling, as well as energies and volume changes determined from first-principles calculations, suggest that the residual hysteresis is associated with different host lattice stackings of carbon and is related to Li disorder across planes in stage II configurations
Efecto de lo videojuego sobre el rendimiento de la prueba de conocimiento a los estudiantes de la disciplina " práctica profesional y ética en fisioterapia " de la Universidad de Brasilia
O presente estudo teve como objetivo avaliar o efeito de longo prazo do vídeo game educacional (VGE) no desempenho em teste de conhecimentos específicos (TCE), opinião de satisfação com a disciplina (SAT) e percepção de aprendizagem dos conteúdos (PA) de uma disciplina da graduação em fisioterapia da Universidade de Brasília. Trata-se de um ensaio clínico randomizado com dois grupos: Grupo Experimental (GE): aulas presencias e uso semanal do VGE extraclasse; Grupo Controle (GC): apenas aulas presenciais. As aulas presenciais ocorreram uma vez por semana com ambos os grupos presentes. Os alunos do GE precisaram acessar a plataforma do VGE uma vez por semana. Após 17 semanas foram aplicados os instrumentos de avaliação das variáveis dependentes: (I) TCE; (2) SAT; (3) PA. Utilizamos o teste t Student para comparar as médias do TCE entre os grupos e frequências absolutas e relativas para reportar as escalas SAT e PA. Os dados foram analisados com nível de significância 5%. A amostra foi composta por um total de 71 alunos (22,83 [±3,35] anos de idade), sendo 62 indivíduos do sexo feminino (87,3%) e 09 do sexo masculinos (12,7%). Houve diferença estatisticamente significante entre GE e GC no TCE (p = 0.006), apresentando o GE maior média que o GC. Em relação aos desfechos secundários O GE apresentou 100% das respostas nas categorias 4 e 5, enquanto, o GC também apresentou respostas na categoria 3. Os resultados da pesquisa indicaram que o VGE foi capaz de melhorar o desempenho em teste de conhecimentos específicos. Os resultados de opinião parecem indicar que a utilização do VGE pode aumentar a satisfação com a disciplina e a percepção de aprendizados do conteúdo.The current study had the objective of evaluate the long term effect of the educational video game (EVG) in the specific knowledge test (SKT) performance, opinion of satisfaction with the discipline (SAT) and learning perception of the subject matter (LP) of a graduation discipline in the Physiotherapy course of the University of Brasília (UNB). This study is a randomized clinical trial with two groups: Experimental Group (EG): Attending instead presential classes with extra time for EVG. Control Group (CG): only attending regular timeclasses. The classes occurred once a week with the presence of both groups. Students allocated in EG needed to access the EVG platform once a week. After 17 weeks, the assessment tools were applied for the dependent variables: (I) SKT, (2) SAT and (3) LP. The Student t test was used to compare the SKT means between groups and for the absolute and relative frequencies, were used to report SAT and LP scales. The data was analyzed with statistical significance of 5%. The sample consisted of a total of 71 students (22,83 [±3,35] years old), including 62 females (87,3%) and 9 males (12,7%) individuals. There was a significant statistical difference between EG and CG in SKT (p=0.006), with the EG having higher means than CG. Regarding the secondary endpoints EG had 100% answers in categories 4 and 5, while the GC also showed responses in category 3. The study results points that de EVG was able to improve the performance in the SKT. The SAT results may indicate that the use of the EVG can increase the satisfaction with the discipline and the learning perception of the subject matter.El estudio tuvo como objetivo evaluar el efecto a largo plazo del videojuego educativo (VJE) en la realización de la prueba de conocimientos específicos (TCE), opinión de la satisfacción con la disciplina (SAT) y la percepción de los contenidos de aprendizaje (PCA) del curso de graduación en fisioterapia en la Universidad de Brasilia. Se trata de un ensayo clínico aleatorizado con dos grupos: grupo experimental (GE): clases presenciales y uso semanal de VJE extra clase; Grupo control (GC): sólo las clases presenciales. Las clases ocurrieran una vez por semana con los dos grupos presentes. Los estudiantes del grupo GE necesitaban acesar a la plataforma VJE una vez a la semana. Después de 17 semanas, se aplicaron los instrumentos de evaluación de las variables dependientes: TCE (I); (2) SAT; (3) PCA. Se utilizó el Test t de Student para comparar las medias del TCE entre los grupos y las frecuencias absolutas y relativas, para informar las escalas del SAT y PCA. Los datos se analizaron con nivel de significación de 5%. La muestra estuvo constituida por un total de 71 estudiantes (22,83 [± 3,35] años), 62 mujeres (87,3%) y 09 hombres (12,7%). No hubo diferencias significativas entre GE y GC en el TCE (p = 0,006), con GE teniendo medias superiores a GC. Mientras los criterios de valoración secundarios GE tuvo 100% de las respuestas en las categorías 4 y 5, mientras que el GC también mostró respuestas en la categoría 3. Los resultados indicaron que el VJE fue capaz de mejorar el rendimiento en la prueba de conocimientos específicos. Los resultados de laopiniones parecen indicar que la utilización del VJE puede aumentar la satisfacción con la disciplina y la percepción de los contenidos de aprendizaje
On demand manufacturing of patient-specific liquid capsules via co-ordinated 3D printing and liquid dispensing
A method for the production of liquid capsules with the potential of modifying drug dose and release is presented. For the first time, the co-ordinated use of fused deposition modelling (FDM), 3D printing and liquid dispensing to fabricate individualised dosage form on demand in a fully automated fashion has been demonstrated. Polymethacrylate shells (Eudragit EPO and RL) for immediate and extended release were fabricated using FDM 3D printing and simultaneously filled using a computer-controlled liquid dispenser loaded with model drug solution (theophylline) or suspension (dipyridamole). The impact of printing modes: simultaneous shell printing and filling (single-phase) or sequential 3D printing of shell bottom, filling and shell cap (multi-phase), nozzle size, syringe volume, and shell structure has been reported. The use of shell thickness of 1.6 mm, and concentric architecture allowed successful containment of liquid core whilst maintaining the release properties of the 3D printed liquid capsule. The linear relationship between the theoretical and the actual volumes from the dispenser reflected its potential for accurate dosing (R = 0.9985). Modifying the shell thickness of Eudragit RL capsule allowed a controlled extended drug release without the need for formulation change. Owing to its low cost and versatility, this approach can be adapted to wide spectrum of liquid formulations such as small and large molecule solutions and obviate the need for compatibility with the high temperature of FDM 3D printing process. In a clinical setting, health care staff will be able to instantly manufacture in small volumes liquid capsules with individualised dose contents and release pattern in response to specific patient's needs. [Abstract copyright: Copyright © 2017. Published by Elsevier B.V.
Spinning of Endless Bioactive Silicate Glass Fibres for Fibre Reinforcement Applications
Bioactive glasses have been used for many years in the human body as bone substitute. Since bioactive glasses are not readily available in the form of endless thin fibres with diameters below 20 µm, their use is limited to mainly non-load-bearing applications in the form of particles or granules. In this study, the spinnability of four bioactive silicate glasses was evaluated in terms of crystallisation behaviour, characteristic processing temperatures and viscosity determined by thermal analysis. The glass melts were drawn into fibres and their mechanical strength was measured by single fibre tensile tests before and after the surface treatment with different silanes. The degradation of the bioactive glasses was observed in simulated body fluid and pure water by recording the changes of the pH value and the ion concentration by inductively coupled plasma optical emission spectrometry; further, the glass degradation process was monitored by scanning electron microscopy. Additionally, first in vitro experiments using murine pre-osteoblast cell line MC3T3E1 were carried out in order to evaluate the interaction with the glass fibre surface. The results achieved in this work show up the potential of the manufacturing of endless bioactive glass fibres with appropriate mechanical strength to be applied as reinforcing fibres in new innovative medical implants
Normativa de Produção Orgânica no Brasil : a percepção dos agricultores familiares do assentamento da Chapadinha, Sobradinho (DF)
O presente trabalho tem como objetivo determinar o grau de conhecimentos e aderência dos produtores familiares do assentamento rural Chapadinha, em Sobradinho (DF), às normativas de produção orgânica estabelecidas no Brasil. A metodologia de pesquisa utilizada contou com entrevistas abertas que pretenderam avaliar as percepções e conhecimentos dos produtores sobre as normativas mais importantes para a produção orgânica no Brasil: Lei n. 10831/2003; Decreto n. 6323/2007 e a IN n. 46/2011; as normas foram integradas em três unidades de análise: diretrizes dos sistemas e produção, processo de comercialização e mecanismos de controle. O trabalho aponta que a documentação constitui o maior gargalo no processo de certificação de pequenos produtores, pois estes requisitos são complexos, além de que é escassa a capacitação relacionada com o correto entendimento desses documentos. Com relação ao processo de comercialização e os mecanismos de controle identificou-se que os produtores apresentaram um grau de conhecimento incompleto relacionado a alguns dos parâmetros da normativa, prejudicando o tempo para a certificação, sendo necessária maior orientação técnica e acompanhamento.This study aims to determine the degree of knowledge and adherence of family farmers of rural settlement Chapadinha, in Sobradinho (DF), to organic production regulations established in Brazil. The research methodology used included open interviews that intended to assess the perceptions and knowledge of the producers on the most important regulations for organic production in Brazil: Law 10831/2003, Decree 6323/2007 and the Normative Instruction 46/2011; these standards had been integrated into three units of analysis: guidelines of systems and production, marketing processes and control mechanisms. The paper points out that the documentation is the biggest bottleneck in smallholder certification process, as these requirements are complex, and there is less training related to the proper understanding of these documents. In relation to the marketing process and control mechanisms it was identified that the producers have a degree of incomplete knowledge related to some of the rules of the parameters related to these aspects, damaging time for certification, requiring greater technical guidance and monitoring
O Estresse na equipe de enfermagem em unidades de urgência e emergência
Objetivo: identificar fatores geradores de estresse na equipe de enfermagem atuante em unidade de emergência hospitalar. Método: Estudo descritivo, com abordagem qualitativa. Entrevistou-se dez técnicos de enfermagem e dois enfermeiros atuantes em uma unidade de urgência e emergência no período de outubro a novembro de 2010. Resultados: Os dados foram submetidos a análise de conteúdo, emergindo três categorias. A primeira enfoca a presença de familiares no ambiente de trabalho como fatores estressores na equipe. Na segunda categoria são abordados aspectos relacionados ao medo do desconhecido, do inesperado gerando estresse no trabalho; e, na terceira, descrevem-se as interrelações decorrentes do processo de trabalho geradoras de estresse na equipe. Conclusão: O estudo mostra a relevância da temática relativa à saúde mental dos trabalhadores da equipe de enfermagem em urgência e emergência. Assim, poderão adotar estratégias que visam melhorar as condições de trabalho dos profissionais da equipe de enfermagem, priorizando o cuidado dos trabalhadores em busca da qualidade de vida. Descritores: Enfermagem, Esgotamento profissional, Cuidados de Enfermagem
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