1,791 research outputs found
Balancing charge-transfer strength and triplet states for deep-blue thermally activated delayed fluorescence with an unconventional electron rich dibenzothiophene acceptor
Manipulation of the emission properties of deep-blue emitters exhibiting thermally activated delayed fluorescence (TADF) through molecular design is challenging. We present an effective strategy to probe deeper into the role of localized (LE) and charge transfer (CT) states in the reverse intersystem crossing (RISC) mechanism. In a series of donor–acceptor–donor (D–A–D) blue emitters the dibenzothiophene functionality is used as an unconventional acceptor, while derivatives of 9,10-dihydro-9,9-dimethylacridine are used as electron-donors. tert-Butyl and methoxy substituents in the para-positions of the donor greatly enhance the donor strength, which allows exploration of different energy alignments among CT and LE triplet states. In the tert-butyl substituted compound the low energy triplet is localized on the acceptor unit, with the RISC mechanism (kRISC = 0.17 × 105 s−1) likely involving the mixture of CT and LE triplet states that are separated by less than 0.09 eV. An optimized organic light-emitting diode (OLED) based on the tBu-compound presents a maximum external quantum efficiency of 10.5% and deep-blue emission with Commission Internationale de l'Eclairage coordinates of (0.133, 0.129). However, when methoxy substituents are used, the low-energy triplet state moves away from the emissive 1CT singlet increasing the energy gap to 0.24 eV. Despite a larger ΔEST, a faster RISC rate (kRISC = 2.28 × 105 s−1) is observed due to the upper-state RISC occurring from the high-energy triplet state localized on the D (or A) units. This work shows the importance of fine-tuning the electronic interactions of the donor and acceptor units to control the TADF mechanism and achieve a deep-blue TADF OLED
Guia para o estabelecimento de critérios microbiológicos em géneros alimentícios
Autoria/Colaboração: Ana Lúcia Baltazar – ESTeSC; Ana Santos – VETDIAGNOS, Lda.; Maria Cecília Alexandre – ERSAR; António Lopes João – CMMV-Exército Português; Marta Ferreira – ATIVE, Lda.; Carla Novais – FFUP; Maria Cândida Marramaque – ANIL; Carlos Brandão – ESHTE; Patrícia Antunes – FCNAUP; Catarina Leitão Proença – CFPSA; Paulo Fernandes – INSA, I.P.; Cátia Martins Vaz – Dan Cake Portugal, S.A.; Pedro Caiado de Sousa – DGAV; Elisa Carrilho – ASAE; Rita Amaral Ferreira – Eurest Portugal, Lda.; Fátima Cordeiro – DGAV; Rita Temtem – LRVSA_Madeira; Helena Barroso – ISCSEM; Roberto Brazão – INSA, I.P.; Liliana Carvalho – Câmara Municipal de Braga; Silvia Viegas – INSA, I.P.; Luís Amaro – Ordem dos Nutricionistas; Sónia Pedro – IPMA, I.P.; Luísa Oliveira – INSA, I.P.; Sandra Quinteira – ESSVA-CESPU; Manuela Sol – ASAE; Verónica Ribeiro – CMMV-Exército Português; Márcia Reto – ASAE.O conteúdo desta publicação é da responsabilidade do Grupo de Trabalho Ocorrência Microbiológica na Cadeia Alimentar (GTOMCA), do Programa PortFIR, não representando, em termos jurídicos, a posição oficial das entidades e empresas que o compõem. Assim, estas não assumem qualquer responsabilidade ou obrigação por eventuais erros ou imprecisões que possam existir e a responsabilidade pela interpretação e uso do documento é exclusivamente do leitor.O objetivo do Guia é compilar, complementar e disponibilizar um conjunto informação existente relativa aos critérios microbiológicos ao longo de todas as etapas da cadeia alimentar, não incluindo a produção primária, visando apoiar e facilitar a sua aplicação.
O presente guia apresenta alguns exemplos de critérios microbiológicos aplicáveis ao longo da cadeia alimentar, a nível internacional, não dispensando a consulta da legislação em vigor.
O presente documento destina-se a apoiar, entre outros, os operadores da indústria alimentar, da restauração, de laboratórios de controlo da qualidade, a comunidade científica e as entidades oficiais que atuem neste âmbito de atividade, sem prejuízo da aplicação de outros requisitos normativos e regulamentares.N/
Molecular analysis of an odorant-binding protein gene in two sympatric species of Lutzomyia longipalpis s.l.
New Horizons for Black Holes and Branes
We initiate a systematic scan of the landscape of black holes in any
spacetime dimension using the recently proposed blackfold effective worldvolume
theory. We focus primarily on asymptotically flat stationary vacuum solutions,
where we uncover large classes of new black holes. These include helical black
strings and black rings, black odd-spheres, for which the horizon is a product
of a large and a small sphere, and non-uniform black cylinders. More exotic
possibilities are also outlined. The blackfold description recovers correctly
the ultraspinning Myers-Perry black holes as ellipsoidal even-ball
configurations where the velocity field approaches the speed of light at the
boundary of the ball. Helical black ring solutions provide the first instance
of asymptotically flat black holes in more than four dimensions with a single
spatial U(1) isometry. They also imply infinite rational non-uniqueness in
ultraspinning regimes, where they maximize the entropy among all stationary
single-horizon solutions. Moreover, static blackfolds are possible with the
geometry of minimal surfaces. The absence of compact embedded minimal surfaces
in Euclidean space is consistent with the uniqueness theorem of static black
holes.Comment: 54 pages, 7 figures; v2 added references, added comments in the
subsection discussing the physical properties of helical black rings; v3
added references, fixed minor typo
Evolution of Chagas’ disease in Brazil. Epidemiological perspective and challenges for the future: a critical review
Aims: This paper aimed to provide a critical review of the evolution of Chagas’ disease in Brazil, its magnitude, historical development and management, and challenges for the future.
Methods: A literature search was performed using PubMed, SciELO and Google Scholar and throughout collected articles’ references. Narrative analysis was structured around five main themes identified: vector transmission, control program, and transfusion, oral and congenital transmission.
Results: In Brazil, the Chagas’ disease Control Program was fully implemented in the 1980s, when it reached practically all the endemic areas, and in 1991, the Southern Cone Initiative was created, aiming to eliminate the disease transmission through eliminating the Triatoma infestans and controlling blood banks. As a result, the prevalence of chagasic donors in blood banks reduced from 4.4% in the 80s to 0.2% in 2005. In 2006, PAHO certified the interruption of transmission of Chagas’ disease through this vector in Brazil. However, there are still challenges, such as the domiciliation of new vector species, the need for medical care of the infected individuals, the prevention of alternative mechanisms of transmission, the loss of political concern regarding the disease and, the weakening of the control program.
Conclusion: Despite the progress towards control, there are still many challenges ahead to maintain and expand such control and minimise the risk of re-emergence
Tartrate-resistant acid phosphate as biomarker of bone turnover over the lifespan and different physiologic stages in sheep
Currently, the best resources for assessment of bone tissue using imaging techniques are expensive and available in few medical facilities, thus serum or urinary bone turnover biomarkers could be useful as early indicators of prognosis. However, there is a wide range of variability in bone turnover markers due to several factors, such as different ages and metabolic stages, thus it is important to have as much data published on the subject as possible. The aim of this study was therefore to generate a reference range for alkaline phosphatase (ALP) and tartrate-resistant acid phosphatase (TRAP) and validate the already published data.National Council for Scientific and Technological Development (CNPq - Brazil) PhD scholarship 202248/2015–1.info:eu-repo/semantics/publishedVersio
Inventory of Chondrichthyes and Actinopterygii species collected in the central coast of São Paulo State, Brazil
Guia para o estabelecimento de critérios microbiológicos em géneros alimentícios
O objetivo do Guia é compilar, complementar e disponibilizar um conjunto informação existente relativa aos critérios microbiológicos ao longo de todas as etapas da cadeia alimentar, não incluindo a produção primária, visando apoiar e facilitar a sua aplicação. O presente guia apresenta alguns exemplos de critérios microbiológicos aplicáveis ao longo da cadeia alimentar, a nível internacional, não dispensando a consulta da legislação em vigor. O presente documento destina-se a apoiar, entre outros, os operadores da indústria alimentar, da restauração, de laboratórios de controlo da qualidade, a comunidade científica e as entidades oficiais que atuem neste âmbito de atividade, sem prejuízo da aplicação de outros requisitos normativos e regulamentares.Autoria/Colaboração: Ana Lúcia Baltazar - ESTeSC; Ana Santos - VETDIAGNOS, Lda.; Maria Cecília Alexandre - ERSAR; António Lopes João - CMMV-Exército Português; Marta Ferreira - ATIVE, Lda.; Carla Novais - FFUP; Maria Cândida Marramaque - ANIL; Carlos Brandão - ESHTE; Patrícia Antunes - FCNAUP; Catarina Leitão Proença - CFPSA; Paulo Fernandes - INSA, I.P.; Cátia Martins Vaz - Dan Cake Portugal, S.A.; Pedro Caiado de Sousa - DGAV; Elisa Carrilho - ASAE; Rita Amaral Ferreira - Eurest Portugal, Lda.; Fátima Cordeiro - DGAV; Rita Temtem - LRVSA_Madeira; Helena Barroso - ISCSEM; Roberto Brazão - INSA, I.P.; Liliana Carvalho - Câmara Municipal de Braga; Silvia Viegas - INSA, I.P.; Luís Amaro - Ordem dos Nutricionistas; Sónia Pedro - IPMA, I.P.; Luísa Oliveira - INSA, I.P.; Sandra Quinteira - ESSVA-CESPU; Manuela Sol - ASAE; Verónica Ribeiro - CMMV-Exército Português; Márcia Reto - ASAE.O conteúdo desta publicação é da responsabilidade do Grupo de Trabalho Ocorrência Microbiológica na Cadeia Alimentar (GTOMCA), do Programa PortFIR, não representando, em termos jurídicos, a posição oficial das entidades e empresas que o compõem. Assim, estas não assumem qualquer responsabilidade ou obrigação por eventuais erros ou imprecisões que possam existir e a responsabilidade pela interpretação e uso do documento é exclusivamente do leitor.Ligação para o registo no repositório INSA.Editor: Instituto Nacional de Saúde Doutor Ricardo Jorge, I
TRY plant trait database - enhanced coverage and open access
Plant traits-the morphological, anatomical, physiological, biochemical and phenological characteristics of plants-determine how plants respond to environmental factors, affect other trophic levels, and influence ecosystem properties and their benefits and detriments to people. Plant trait data thus represent the basis for a vast area of research spanning from evolutionary biology, community and functional ecology, to biodiversity conservation, ecosystem and landscape management, restoration, biogeography and earth system modelling. Since its foundation in 2007, the TRY database of plant traits has grown continuously. It now provides unprecedented data coverage under an open access data policy and is the main plant trait database used by the research community worldwide. Increasingly, the TRY database also supports new frontiers of trait-based plant research, including the identification of data gaps and the subsequent mobilization or measurement of new data. To support this development, in this article we evaluate the extent of the trait data compiled in TRY and analyse emerging patterns of data coverage and representativeness. Best species coverage is achieved for categorical traits-almost complete coverage for 'plant growth form'. However, most traits relevant for ecology and vegetation modelling are characterized by continuous intraspecific variation and trait-environmental relationships. These traits have to be measured on individual plants in their respective environment. Despite unprecedented data coverage, we observe a humbling lack of completeness and representativeness of these continuous traits in many aspects. We, therefore, conclude that reducing data gaps and biases in the TRY database remains a key challenge and requires a coordinated approach to data mobilization and trait measurements. This can only be achieved in collaboration with other initiatives
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