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A 3D printed drug delivery implant formed from a dynamic supramolecular polyurethane formulation
Using a novel molecular design approach, we have prepared a thermo-responsive supramolecular polyurethane as a matrix material for use in drug eluting implants. The dynamic supramolecular polyurethane (SPU) is able to self-assemble through hydrogen bonding and π-π stacking interactions, resulting in an addressable polymer network with a relatively low processing temperature. The mechanical properties of the SPU demonstrated the material was self-supporting, stiff, yet flexible thus making it suitable for hot-melt extrusion processing, inclusive of related 3D printing approaches. Cell-based toxicity assays revealed the SPU to be non-toxic and therefore a viable candidate as a biocompatible polymer for implant applications. To this end, the SPU was formulated with paracetamol (16 %w/w) and 4 wt% or 8 wt% poly(ethylene glycol) (PEG) as an excipient and hot melt extruded at 100 °C to afford a 3D printed prototype implant to explore the extended drug release required for an implant and the potential manipulation of the release profile. Furthermore, rheological, infra-red spectroscopy, powder X-ray diffraction and scanning electron microscopy studies revealed the chemical and physical properties and compatibility of the formulation components. Successful release of paracetamol was achieved from in vitro dissolution studies and it was predicted that the drug would be released over a period of up to 8.5 months with hydrophilic PEG being able to influence the release rate. This extended release time is consistent with applications of this novel dynamic polymer as a drug eluting implant matrix
Impacto das mudanças climáticas sobre a produção de cana-de-açúcar no Estado de Goiás.
A elevação do preço do petróleo, o apelo mundial pela redução das emissões de gases de efeito estufa e a produção de energia renovável viabilizaram o aumento da produção de álcool e criaram a necessidade de identificação de áreas de expansão do cultivo da cana-de-açúcar no Brasil. Por outro lado, o último relatório do IPCC apresenta informações conclusivas sobre ocorrências de alterações do clima e elevação das temperaturas. Neste sentido, estudos para identificar a vulnerabilidade dos sistemas agrÃcolas e quantificar o impacto das mudanças climáticas sobre as culturas agrÃcolas tornaram-se uma necessidade. O objetivo deste trabalho foi simular o efeito das mudanças climáticas sobre a produção de cana-de-açúcar, variedade RB72454, cultivada em três localidades de Goiás, admitindo-se a elevação da temperatura em 1,8°C, 2,4°C e 4,0°C. Os resultados mostraram elevação na produtividade média, mesmo no cenário pessimista (4,0°C), nos municÃpios de Goiânia e JataÃ, em 3% e 4%, respectivamente; enquanto em Goianésia, observou-se uma redução de 6% na produtividade.CBA 2009
IN-SHOE PRESSURE DISTRIBUTION DURING FENCING LUNGE
Fencing is a sport involving sharp backward and forward movements interspersed with several slower gliding steps in which lower limb agility is crucial to good movements and correct body positioning. Thus, while the upper extremity uses the weapon, the legs and feet work to get the fencer in position to it. From a biomechanical point of view, particularly stressed are the feet. Incidence of foot injury in fencing is high, and there have been many cases reported of metatarsal stress fractures, capsulitis, plantar fasciitis, and interdigital neuromas. Although it would be useful to accurately evaluate the high pressure points so that overall lower limb salvage may be improved, to our knowledge, no information about the force and pressure distribution beneath the foot of fencers performing technical actions is available. The purpose of this study was, therefore, to evaluate dynamic in-shoe plantar pressure during fencing lunge. Six right-handed foilists of national level (age: 24k5.5) were the subjects of this study. Each athlete was asked to perform the following technical actions: simple lunge; step forward-lunge; step backward-lunge; jump forward-lunge. Data for at least six trials per condition was collected. The Fscan in-shoe pressure measurement system was used to measure plantar pressure during all trials. The system uses an ultra-thin flexible and trimmable sensor with 960sensing locations distributed evenly across the entire plantar surface. These footsensors can be customized to the individual needs and sizing of each subject. The parameters examined included the centre of pressure path, time-pressure relationships, and the force and pressure in three regions of the foot (rear, mid, and forepart).Despite the apparent intersubject similarities in performing the actions, clear differences were observed in most of the examined parameters. In contrast to the above finding, the variability within-subject was low indicating a high consistency in movement execution, As expected, in all the technical actions, an asymmetrical load was placed on the lower extremities, with the right foot of the athletes particularly subjected to stress in the forward actions. The results showed that the majority of the right foot pressure was localized in the forefoot and especially over the head of the first and second metatarsal and hallux. High pressure levels, as those found here, applied too often and over a long periods of time can cause structural damage to the foot. Shoe and plantar orthosis designers should attempt to reduce such risks designing sager footwear and proper shoe inserts
Metodologia para avaliação de impactos de mudanças climáticas na demanda de água para a agricultura irrigada em nÃvel de bacia hidrográfica.
Propomos uma metodologia para avaliação de impactos das mudanças climáticas na demanda de água para irrigação em nÃvel de bacia hidrográfica, utilizando integração de modelos, na Bacia do Jaguaribe, no Estado do Ceará. Foi empregado o sistema integrado de modelagem regional Providing Regional Climates for Impact Studies (Precis), submetido ao método de redução de escala dinâmica, utilizando-se o modelo climático regional HadRM3P com as condições de contorno do modelo global HadAM3P, do Hadley Centre. Foi utilizado um conjunto de climatologia de base do modelo de 1961 a 1990 e de projeções climáticas futuras (2040) com resolução de 0,44º x 0,44º. As coordenadas geográficas da região em estudo foram consideradas para interpolação, num sistema de informação geográfica abrangendo área de 6.415,10km2. A evapotranspiração de referência foi estimada pelo método simplificado de Penman-Monteith FAO, utilizando-se dados mÃnimos. O aumento da necessidade hÃdrica bruta média foi estimado em 33,62% e 37,87% respectivamente para o ano de 2040, conforme o cenário analisado (A2 e B2).Editores técnicos: Maria Fernanda Moura, Giampaolo Queiroz Pellegrino, Lineu Neiva Rodrigues
Diretrizes para escolha de um Sistema de Gerenciamento de Conteúdos.
O objetivo deste documento é apresentar as diretrizes básicas para escolha de um CMS tomando por base a experiência adquirida com o desenvolvimento do Agritempo.bitstream/CNPTIA/10192/1/comtec53.pdfAcesso em: 28 maio 2008
director profile of a nematic between two concentric cylinders with inhomogeneous boundary conditions
The tilt angle profile in a nematic cell limited by two concentric cylindrical surfaces with inhomogeneous distribution of easy axes is investigated in the one-constant approximation. The results are presented in terms of the Green function approach by considering the strong anchoring case and the presence of an external electric field for small distortions
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