2,689 research outputs found
Multifunctional nanocarriers for lung drug delivery
Nanocarriers have been increasingly proposed for lung drug delivery applications. The strategy of combining the intrinsic and more general advantages of the nanostructures with specificities that improve the therapeutic outcomes of particular clinical situations is frequent. These include the surface engineering of the carriers by means of altering the material structure (i.e., chemical modifications), the addition of specific ligands so that predefined targets are reached, or even the tuning of the carrier properties to respond to specific stimuli. The devised strategies are mainly directed at three distinct areas of lung drug delivery, encompassing the delivery of proteins and protein-based materials, either for local or systemic application, the delivery of antibiotics, and the delivery of anticancer drugs-the latter two comprising local delivery approaches. This review addresses the applications of nanocarriers aimed at lung drug delivery of active biological and pharmaceutical ingredients, focusing with particular interest on nanocarriers that exhibit multifunctional properties. A final section addresses the expectations regarding the future use of nanocarriers in the area.UID/Multi/04326/2019; PD/BD/137064/2018info:eu-repo/semantics/publishedVersio
Design de uma estrutura de aprendizagem para aplicativos móveis abertos
Produção no âmbito da Tese de Doutoramento em Educação, especialidade de Educação a Distância e eLearning.Através da metodologia de pesquisa baseada em design, está sendo conduzida uma investigação sobre o desenho de uma estrutura de aprendizado sobre a utilização e desenvolvimento de recursos educacionais abertos, com foco em aplicativos abertos para dispositivos Smartphone. Como resultado da investigação, espera-se que seja projetado e implantado um curso aberto, disponível para qualquer pessoa que queira aprender sobre integração de tecnologia aberta na educação, sobre como usar e construir,
no contexto educacional específico de cada pessoa, aplicativos para Smartphone. Os conteúdos deste curso são eles próprios Recursos Educacionais Abertos, assim como a linguagem de programação selecionada para promover o desenvolvimento de aplicativos é também uma linguagem de programação aberta. As etapas tomadas desde o início da investigação até a interação do terceiro design de curso são descritas neste artigo, juntamente com alguns raciocínios sobre os dados coletados.Thru Design Based Research methodology it’s being conducted an investigation regarding the design of a
learning framework about the utilization and development of open educational resources, with focus on open
applications for Smartphone devices. As a result of the investigation is expected to be designed and deployed an open course, available for any person who wants to learn about open technology integration in education, on how to use and build, in each person’s particular educational context, applications for Smartphone. The contents of this course are themselves Open Educational Resources as well as the programing language selected to promote application development is also an open programming language. The steps taken from the beginning of the investigation until the third course design interation are described in this article, along with some reasoning about the data collected.info:eu-repo/semantics/publishedVersio
Forensic reconstruction of Ictalurus punctatus invasion routes using on-line fishermen records
In this work, the presence of the channel catfish Ictalurus punctatus in the Portuguese section of the Guadiana drainage (Iberian Peninsula) is confirmed based on morphological and molecular species identification. The spatial and temporal dispersal of this non-native catfish was also reconstructed for the Guadiana drainage, based mostly on online fishermen records with minor contributions from the few scientific reports available. The obtained records (mainly from angling fora) span the period since the species\u27 first reported presence in Iberia (1980s) up to the present, and support a westward invasion pattern of non-native fish (NNF) reported for the Iberian fish invasion hotspot. The invasion pathway is driven mainly by natural dispersal downstream at a rate between 8 and 42 km per year. Yet, at least four introduction events within the Guadiana drainage can unambiguously be assigned to human translocations after the initial human-mediated introduction. The present study reinforces the usefulness and relevance of using validated on-line fishermen records, provides a more complete and updated distribution range of NNF species and enables assessment of their dispersal patterns. This is of particular importance because it allows near real-time monitoring of NNF dispersal, including first occurrences of NNF, at minimal cost
Spatial patterns of species composition and richness in iberian freshwater fish:a macroecological approach
Tese de doutoramento, Biologia (Ecologia), 2010, Universidade de Lisboa, Faculdade de CiênciasDisponível no documentoFundação para a Ciência e Tecnologia (FCT), (SFRH/BD/10330/2002); Museo Nacional de Ciencias Naturales (CSIC, Madrid), programa Synthesys (European Community Research Infrastructure Action under the FP6); Instituto de Conservação da Natureza e Biodiversidad
Sexual reproduction vs. clonal propagation in the recovery of a seagrass meadow after an extreme weather event
Marine flowering plants can reproduce sexually and clonally, and the relative contribution of these two modes can be dependent on the environmental conditions. Zostera marina, a seagrass widely distributed in the northern hemisphere, can form annual and perennial meadows with different proportions of sexual versus clonal propagation depending on the environmental disturbance regime. We study the hypothesis that the contribution of sexual propagation varies during the recovery of a seagrass meadow. In this case study, we compare the proportion of sexual versus clonal propagation of a perennial Z. marina meadow before its disappearance due to winter storms and after recovery. Before disturbance, genotypic diversity was high, indicating frequent sexual reproduction events likely to create an abundant seed bank. Seedling germination allowed the population to recover after the extreme disturbance. As months passed, seedlings became rare and finally absent, giving place to adult shoots. In an advanced stage of colonization, the shoots colonized the area by vegetative growth, which lowered the genotypic diversity. Despite this reduction over time, the genotypic diversity of the new meadow is still high, demonstrating the importance of sexual reproduction in meadow recovery and persistence.info:eu-repo/semantics/publishedVersio
How authentic leadership promotes individual creativity: The mediating role of affective commitment
This study sought to provide a more comprehensive understanding of how authentic leadership can affect employees’ individual creativity through affective commitment’s mediating role. The sample included 177 leader-follower dyads from 26 private, small and medium-sized enterprises. Followers reported their levels of affective commitment and perceptions of authentic leadership, and leaders assessed each follower’s level of creativity. The results show that authentic leadership has a positive impact on affective commitment and creativity. Moreover, affective commitment fully mediates the relationship between perceived authentic leadership and individual creativity. Organizations can thus increase employees’ affective commitment and creativity by encouraging their managers to adopt more authentic leadership styles. Additional studies with larger samples are needed to determine more clearly not only authentic leadership’s influence on individual creativity but also other psychosocial and personal variables’ effects on that relationship.info:eu-repo/semantics/publishedVersio
EDUCAST – USE OF VÍDEO AT HIGHER TEACHING INSTITUTIONS, THE CASE OF UNIVERSIDADE DE ÉVORA
Partindo de um projeto da FCCN, que dotou algumas instituições de ensino Portuguesas de um kit de gravação de vídeo, portátil e de utilização simples, a Universidade de Évora, umas das instituições contempladas, tem utilizado esse kit para a gravação de diversos momentos da sua atividade letiva.
Na Universidade de Évora esta tecnologia tem vindo a ser utilizada em diferentes momentos, com especial incidência no suporte da sua oferta formativa em regime e-learning.
Após um ano de atividade em cursos online e de um período semelhante de utilização do kit Educast, reflete-se neste agora acerca da utilização desta tecnologia como um recurso multimédia educativo ao dispor da comunidade académica da Universidade de Évora e o seu impacto na atividade ensino/aprendizagem
Capacity limits of crosstalk-limited multi-core fiber systems
Space division multiplexing (SDM) is mainly seen as a way to increase data
throughput and handle the fact that the data capacity of single mode single core fiber (SMSCF) is reaching its limit. Transmissions with capacities in the order of petabit per second
have already been demonstrated using multi-core fibers (MCFs) with single mode
transmission in each core. The performance of these systems is limited by the intercore
crosstalk (ICXT). This dissertation analyzes the impact of the ICXT as a constraining
element of the capacity of coherent detection optical communication networks that use
the flexible grid over the C-band. The total capacity of the link, which is given by the
number of cores allowed of a weakly-coupled (WC) MCF for each modulation format, is
imposed by the maximum mean ICXT power acceptable for the connection. Link
impairments such as the wavelength dependence of ICXT power over the transmission
band and the nonlinear interference (NLI) noise due to MCF non-linear effects are also
considered in the analysis. The total data capacities for metro networks, regional networks
and long-distance networks are assessed for a W-profile MCF supported communication
links. Considering the impairments of the link as the wavelength dependence of ICXT
power over the transmission band and the NLI effects, the total capacities of 483.84 Tb/s
by 32-QAM, 430 Tb/s by 32-QAM and 206.08 Tb/s by 4-QAM are achieved for the metro
(represented with a link distance of 50 km), regional (represented with a link distance of
500 km) and long-distance networks (represented with a link distance of 5000 km),
respectively.A multiplexagem por divisão no espaço usando fibras ópticas multi-núcleo tem sido
extensivamente proposta para conseguir transmissão de capacidade ultra-elevada e lidar
com o facto de que fibra composta por um núcleo estar perto de atingir o seu limite. Já
foram demonstradas transmissões com capacidades na ordem dos petabit por segundo
usando fibras multi-núcleo. O desempenho destes sistemas, é, no limite, imposto pela
diafonia entre núcleos e por isso é feita uma análise da diafonia em sistemas coerentes
que utilizam a grelha flexível na banda C. A capacidade do sistema é dada pelo número
de núcleos permitidos nas fibras multi-núcleo fracamente acopladas para cada formato de
modulação que é imposta pela potência média máxima da diafonia entre núcleos para uma
dada distância. Os constrangimentos da ligação, como a dependência do comprimento de
onda da potência da diafonia entre núcleos na banda de transmissão e o efeito da
interferência não linear, são considerados. A capacidade de redes metropolitanas,
regionais e de longa distância são avaliadas para as fibras multi-núcleo de perfil
fracamente acopladas. Considerando os constrangimentos da ligação como a dependência
do comprimento de onda da potência da diafonia entre núcleos na banda de transmissão
e os efeitos não lineares, a capacidade total de 483.84 Tb/s usando o formato de
modulação 32-QAM , 430 Tb/s usando o formato de modulação 32-QAM e 206.08 Tbs/s
e usando o formato de modulação 4-QAM é alcançada para as redes metropolitanas (50
km), regionais (500 km) e de longa distância (5000 km), respectivamente
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