Matériaux 2D TMDC pour la génération d'hydrogène par photo-décomposition de l'eau

Le stockage de l'énergie solaire en énergie chimique est une approche hautement souhaitable pour résoudre le défi énergétique. Les cellules photo-électrochimiques combinent la collecte de l'énergie solaire et la décomposition de l'eau. Les nanofeuillets semiconducteur 2D de di-chalcogenures de métaux de transition (TMDC) sont considérés comme des matériaux attrayants pour l'élaboration de photocatalyseur efficace pour la conversion de l'énergie solaire en hydrogène. Malgré les propriétés optoélectroniques uniques des TMDC, la passivation de défauts de surface présents en concentration élevée est un défi important pour le développement de cette classe de matériaux. Dans ce contexte, le présent travail a concerné l'élaboration d'un photocatalyseur 2D TMDC pour la photo-décomposition de l'eau. Le développement de photocatalyseurs de haute performance a été examiné suivant deux axes principaux. Un premier axe de recherche consiste à passiver les défauts de surface des nanofeuillets 2D p-WSe2 à l'aide de complexes Mo-S pour diminuer la recombinaison des porteurs de charge photo-générés et améliorer l'activité photocatalytique. Nous avons démontré que des couches ultra minces de complexes thio et oxo-thio-Mo moléculaires représentent une classe idéale de catalyseurs, bien adaptée pour fonctionnaliser les matériaux 2D car ils sont stables dans des environnements aqueux, bon marché, respectueux de l'environnement. Des densités de courant de -2 mA cm-2 à -0.2 V par rapport à l'électrode d'hydrogène (NHE) ont été obtenues pour la nouvelle photocathode p-WSe2/ MoxSy. En plus d'offrir une activité électro-catalytique élevée, les films complexes Mo se sont révélés capables de guérir les défauts de surface. Les contributions respectives aux effets catalytiques et cicatrisants observées expérimentalement pour les divers complexes moléculaires de Mo impliquaient la forte adsorption sur les défauts ponctuels du substrat 2D WSe2 de complexes de Mo tels que (MoS4)2-, (MoOS3)2- et (Mo2S6O2)2-. Il a été démontré que ces couches de co-catalyseur Mo-S formés à un pH bien défini présentent un comportement n-semi-conducteur et l'ingénierie des bandes formées avec p-WSe2 s'est révélée appropriée pour assurer la séparation des charges et la migration efficace des électrons photo-induits pour la RDH, représentant un exemple de couche de passivation multi-composant avec de multiples propriétés. Un deuxième axe de travail concerne l'optimisation de la nanostructure du film de WSe2 comme objectif l'obtention d'une surface spécifique élevée et des parois de pores composées de quelques monofeuillets. Des films de WSe2 nanostructurés de haute surface et à bonne collecte de porteurs de charge ont été obtenus par co-assemblage des nanofeuillets de WSe2 et des nanofeuillets d'oxyde de graphène réduit (rGO) avec un rapport de nanofeuillets rGO/WSe2 optimal. Après dépôt de la couche ultra mince de co-catalyseur les nouvelles nanojunctions de rGO-WSe2/MoxSy ont présenté des photocourants jusqu'à -5 mA cm-2 à -0.2 V vs NHE. Des rendements quantiques d'environ 10% ont été obtenus pour des films de nanoplaquettes de WSe2 de 70 nm d'épaisseur en présence de rGO et catalyseur MoxSy. Le potentiel de notre procédé d'auto-assemblage en présence de nanofeuillets de TMDC et de rGO a été illustré avec l'obtention de microstructure optimisée de films de p-MoS2, p-WSe2 et p-WS2. Dans une perspective à plus long terme, les photoelectrodes basées sur des nanofeuillets de TMDC sont des candidats intéressants pour la conception de cellules tandem offrant des valeurs de band-gap (Eg) et présentant des potentiels de dégagement d'hydrogène modulables.Collecting and storing solar energy in chemical energy is a highly desirable approach to solve energy challenge. The great potential of a photoelectrochemical cell technology combines the harvesting of solar energy with the water splitting into a single device. 2D semiconducting nanosheets of Transition Metal Di-Chalcogenides (TMDC) are seen as an attractive material to design an efficient photocatalyst for the conversion of solar energy into hydrogen. Despite the unique optoelectronic properties of the TMDCs, the passivation of surface defects in high concentration is a remaining challenge for the development of this class of materials. In this context, the present work has aimed the elaboration of thin 2D TMDC photocatalyst for solar water splitting. The development of high performance photocatalysts was evaluated following two main axis. A first strategy consists in the surface defects passivation of 2D p-WSe2 nanosheets using Mo-S complexes to decrease the photogenerated charge carrier recombination and improve photocatalytic activity. We demonstrated these Mo thio and oxo-thio- molecular complexes films as an ideal class of catalysts, well-suited to functionalize 2D materials since they are stable in aqueous environments, cheap and environmentally benign. Current densities of -2 mA cm-2 at -0.2 V vs NHE electrode were obtained for the new p-WSe2/MoxSy photocathode. Besides developing high electro-catalytic activity, the Mo complexes films were shown to display ability to heal surface defects. The respective contributions in catalytic and healing effects observed experimentally for the various molecular Mo complexes involved strong adsorption on point defects of the 2D WSe2 substrate of Mo complexes such as (MoS4)2-, (MoOS3)2-and (Mo2S6O2)2-. The Mo complexes films spontaneously formed at well-defined pH were demonstrated to present n-semi-conducting behaviour and band engineering formed with p-WSe2 showed to be suitable for ensuring charge separation and efficient migration of the photo-induced electrons for the Hydrogen Evolution Reaction, thus representing an example of multicomponent passivation layer exhibiting multiple properties. A second strategy focus in the nanostructure optimization of WSe2 with high specific surface area and pore walls composed of few layers. Nanostructured WSe2 films of high surface area and good charge carrier collection were obtained by co-assembling WSe2 nanosheets and reduced graphene oxide (rGO) nanosheets with an optimal rGO/WSe2 nanosheet ratio. After deposition of co-catalyst thin layer, the new layered nanojunctions of rGO-WSe2/MoxSy exhibited photocurrents up to -5 mA cm-2 at -0.2V vs NHE. Incident-photon-to-current efficiency conversion of 10% were achieved for WSe2 nanoflakes of 70 nm thickness in presence of rGO and MoxSy co-catalyst. The potential of our self-assembly process in the presence of TMDC and rGO nanosheets has been illustrated with the obtention of optimized microstructures of p-MoS2, p-WSe2 and p-WS2. In a long-term perspective, photoelectrodes based on TMDC nanosheets are interesting candidates for the design of tandem cells offering modular band-gap (Eg) values and hydrogen onset potentials

Liquid crystal phase and waterlike anomalies in a core-softened shoulder-dumbbells system

Using molecular dynamics we investigate the thermodynamics, dynamics and structure of 250 diatomic molecules interacting by a core-softened potential. This system exhibits thermodynamics, dynamics and structural anomalies: a maximum in density-temperature plane at constante pressure and maximum and minimum points in the diffusivity and translational order parameter against density at constant temperature. Starting with very dense systems and decreasing density the mobility at low temperatures first increases, reach a maximum, then decreases, reach a minimum and finally increases. In the pressure-temperature phase diagram the line of maximum translational order parameter is located outside the line of diffusivity extrema that is enclosing the temperature of maximum density line. We compare our results with the monomeric system showing that the anisotropy due to the dumbbell leads to a much larger solid phase and to the appearance of a liquid crystal phase. the double ranged thermodynamic and dynamic anomalies.Comment: 14 pages, 5 figure

Triage at the Emergency Department: association between triage levels and patient outcome

OBJECTIVEIdentify association between sociodemographic, clinical and triage categories with protocol outcomes developed at Hospital São Paulo (HSP).METHODSRetrospective cohort study conducted with patients older than 18 years submitted to the triage protocol in August 2012. Logistic regression was used to associate the risk categories to outcomes (p-value ≤0,05).RESULTSMen with older age and those treated in clinical specialties had higher rates of hospitalization and death. Patients in the high-priority group had hospitalization and mortality rates five and 10.6 times, respectively (p < 0.0001).CONCLUSIONThe high-priority group experienced higher hospitalization and mortality rates. The protocol was able to detect patients with more urgent conditions and to identify risk factors for hospitalization and death.OBJETIVOIdentificar la asociación entre variables sociodemográficas, clínicas y categorías de cribado con resultados del protocolo desarrollado en el Hospital São Paulo (HSP). MÉTODOEstudio de cohorte retrospectivo llevado a cabo con pacientes mayores de 18 años sometidos al protocolo de cribado en agosto de 2012. Se utilizó la regresión logística para asociar las categorías de riesgo a los resultados (p-valor≤0,05).RESULTADOSHombres con edad más avanzada y atendidos por las especialidades clínicas presentaron mayores índices de estancia hospitalaria y defunción. Pacientes con alta prioridad presentaron índice de estancia hospitalaria y defunción cinco y 10,6 veces mayor, respectivamente (pOBJETIVOIdentificar a associação entre variáveis sociodemográficas, clínicas e categorias de triagem com desfechos do protocolo desenvolvido no Hospital São Paulo (HSP).MÉTODOEstudo de coorte retrospectivo realizado com pacientes maiores de 18 anos submetidos ao protocolo de triagem em agosto de 2012. Utilizou-se regressão logística para associar as categorias de risco aos desfechos (p-valor≤0,05).RESULTADOSHomens com idade mais avançada e atendidos pelas especialidades clínicas apresentaram maiores taxas de internação e óbito. Pacientes com alta prioridade apresentaram taxa de internação e óbitos cinco e 10,6 vezes maior, respectivamente (

Development and validation of an informative booklet on bed bath

OBJECTIVE: To develop and validate an informative booklet on bed bath for coronary patients. METHOD: The informative booklet was developed based on the experience of researchers and literature. The booklet was subjected to content validation for ten nurses, using the Delphi technique. The final version of the booklet has been validated with 35 patients admitted to the coronary care unit and who had experienced at least once the bed bath, using Likert scale. RESULTS: The informative booklet was developed containing information about bed bath and the reasons that patients need this procedure. In the first phase were required four rounds to obtain consensus among nurses. In the second phase, it was observed that the average of the responses were above 4, thus, the booklet was considered as validated. CONCLUSION: This study developed and validated an informative booklet on bed bath for coronary patients.OBJETIVO: Construir e validar um manual informativo sobre o banho no leito para pacientes com síndrome coronária aguda. MÉTODOS: O manual informativo foi desenvolvido com base na experiência profissional dos pesquisadores e em levantamento bibliográfico. A versão preliminar do manual foi submetida à validação de conteúdo por dez enfermeiros, utilizando a Técnica de Delphi. A versão final do manual foi validada com 35 pacientes internados na unidade coronariana e que haviam vivenciado ao menos uma vez o banho no leito utilizando escala do tipo Likert. RESULTADOS: O manual informativo foi construído contendo informações sobre o banho no leito e as razões da necessidade deste procedimento. Na primeira fase foram necessárias quatro rodadas para o consenso entre os enfermeiros. Na segunda fase, foi observada uma média de escore superior a 4, sendo considerado como validado. CONCLUSÃO: Foi construído e validado um manual informativo sobre o banho no leito para pacientes com síndrome coronária aguda.Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Universidade Federal de São Paulo (UNIFESP) Escola Paulista de EnfermagemUNIFESP, EPESciEL

Perícias psicológicas e psiquiátricas nos processos de família

Divulgação dos SUMÁRIOS das obras recentemente incorporadas ao acervo da Biblioteca Ministro Oscar Saraiva do STJ. Em respeito à Lei de Direitos Autorais, não disponibilizamos a obra na íntegra.Localização na estante: 347.6:340.63(81) B277

A Utilização do Jogo Didático “Dominó Vegetal’’ Como Instrumento Alternativo para o Ensino de Briófitas e Pteridófitas na Disciplina de Ciências (Relato de Experiência) / The Use of the 'Plant Domino' Didactic Game as an Alternative Instrument for Teaching Briophytes and Pteridophytes in the Discipline of Science (Experience Report)

Os recursos didáticos são todos os instrumentos que contribuem e facilitam a aprendizagem do discente, incluído neste, os jogos didáticos são grandes promissores da aprendizagem, uma vez que, possibilita a explicação e revisão do conteúdo abordado de uma forma mais simples e atrativa. Tendo em vista isto, o presente trabalho mostra a importância e contribuição do uso do Jogo Didático “Dominó Vegetal”, como ferramenta educativa e facilitadora no aprimoramento dos conteúdos de Briófitas e Pteridófitas. O trabalho foi realizado na Escola Estadual Aldinar Gonçalves de Carvalho, localizada no município de Araguatins – TO, em uma turma do 7º ano na segunda fase do ensino fundamental II, através do período de regência do Programa Residência Pedagógica. Vale ressaltar, que além do uso do jogo didático, expor os assuntos em sala de aula, possibilitando uma argumentação e valorizando os conhecimentos prévios e os questionamentos feitos pelos alunos, possibilita a reconstrução do conhecimento de uma forma mais dinâmica e interativa

COVID-19: comentários em redes sociais oficiais do Ministério da Saúde sobre ação Brasil Conta Comigo

Objetivo: Desvelar o conteúdo dos comentários em postagens oficiais do Ministério da Saúde, de convocação de profissionais de saúde para enfrentamento à COVID-19.Método: Estudo qualitativo, realizado com 2823 comentários, obtidos a partir do acesso virtual às redes sociais oficiais do Ministério da Saúde no Facebook, Instagram e Twitter. Para processamento do corpus textual, utilizou-se o software Interface de R pourles Analyses Multidimensionnelles de Textes et de Questionnaires e realizou-se a análise multivariada por Classificação Hierárquica Descendente.Resultados: Foram obtidas cinco categorias: “dificuldades nas etapas para capacitação”, “aspectos financeiros envolvidos na convocação”, “condições trabalhistas no enfrentamento à pandemia”, “obrigatoriedade de capacitação x possível convocação”, “visibilidade e valorização da odontologia no combate à COVID-19”.Conclusão: Os comentários contemplaram o acesso à capacitação, a remuneração e condições trabalhistas, a obrigatoriedade para capacitação, possível convocação para atuar na linha de frente no combate à COVID-19 e reinvindicação por maior valorização da odontologia. Palavras-chave: Infecções por coronavirus. Redes sociais online. Pessoal de saúde

Patch-like, two dimensional WSe2-based hetero-structures activated by a healing catalyst for H2 photocatalytic generation

2D photoactive materials may offer interesting opportunities in photocatalytic devices since they combine strong light absorption and shortening of charge carriers’ diffusion path. Because of their high surface defect concentration and the formation of a majority of edge/plane vs plane/plane contacts between the anisotropic building blocks, surface defect passivation and improvement of charge carrier transport are critical for the large development of high surface area, 2D photo-catalysts. Here, we propose a hetero-structure nanoporous network with a patch-like coating as high performance 2D photo-catalysts. The hetero-structured building blocks are composed of a photo-active WSe2 nanoflake in direct contact with both a conducting rGO nanosheet and an ultrathin layer of healing catalyst. The resulting nanoporous film achieves a H2 evolution photocurrent density up to 5 mA cm−2 demonstrating that the patch-like hetero-structures represent an effective strategy to simultaneously improve hole collection, defect passivation and charge transfer. These hetero-structures made of an ultrathin healing catalyst layer represent promising building blocks for the bottom-up fabrication of high surface area photocathodes particularly for 2D photo-catalysts displaying high defect concentration