Photocurable Polymeric Blends for Surgical Application

The preparation of photocrosslinkable bioadhesives synthesized from oligomers of lactic acid and polycaprolactone (PCL), both functionalized with 2-isocyanoethyl acrylate (AOI), were studied. The obtained modified macromers of LA-AOI (mLA) and PCL-AOI (mCL) were chemically characterized by 1H NMR and used to formulate polymeric blends with different mass proportions, 1:1, 1:2 and 2:1, respectively. Subsequently, the produced blends were crosslinked, considering two UV irradiation times: 30 and 120 s. After their production, the thermal and mechanical properties of bioadhesives were assessed, where upon the rheology, gel content, hydrolytic degradation and dynamic contact angles were determined. Furthermore, the cytotoxic profile of bioadhesives was evaluated in contact with human dermal fibroblasts cells, whereas their antibacterial effect was studied monitoring Escherichia coli and S. aureus growth. Overall, flexible and resistant films were obtained, presenting promising features to be used as surgical bioadhesives.info:eu-repo/semantics/publishedVersio

Potential Fields as an External Force and Algorithmic Improvements in Deformable Models

Deformable Models are extensively used as a Pattern Recognition technique. They are curves defined within an image domain that can be moved under the influence of internal and external forces. Some trade-offs of standard deformable models algorithms are the selection of image energy function (external force), the location of initial snake and the attraction of contour points to local energy minima when the snake is being deformed. This paper proposes a new procedure using potential fields as external forces. In addition, standard Deformable Models algorithm has been enhanced with both this new external force and algorithmic improvements. The performance of the presented approach has been successfully proved to extract muscles from Magnetic Resonance Imaging (MRI) sequences of Iberian ham at different maturation stages in order to calculate their volume change. The main conclusions of this paper are the practical viability of potential fields used as external forces, as well as the validation of the algorithmic improvements developed. The feasibility of applying Computer Vision techniques, in conjunction with MRI, for determining automatically the optimal ripening time of the Iberian ham is a practical conclusion reached with the proposed approach

Magnetic Resonance Imaging, texture analysis and regression techniques to non-destructively predict the quality characteristics of meat pieces

The quality of meat products is traditionally assessed by chemical or sensorial analysis, which are time consuming, need specialized technicians and destroy the products. The development of new technologies to monitor meat pieces using non-destructive methods in order to establish their quality is earning importance in the last years. An increasing number of studies have been carried out on meat pieces combining Magnetic Resonance Imaging (MRI), texture descriptors and regression techniques to predict several physico-chemical or sensorial attributes of the meat, mainly different types of pig ham and loins. In spite of the importance of the problem, the conclusions of these works are still preliminary because they only use the most classical texture descriptors and regressors instead of stronger methods, and because the methodology used to measure the performance is optimistic. In this work, we test a wide range of texture analysis techniques and regression methods using a realistic methodology to predict several physico-chemical and sensorial attributes of different meat pieces of Iberian pigs. The texture descriptors include statistical techniques, like Haralick descriptors, local binary patterns, fractal features and frequential descriptors, like Gabor or wavelet features. The regression techniques include linear regressors, neural networks, deep learning, support vector machines, regression trees, ensembles, boosting machines and random forests, among others. We developed experiments using 15 texture feature vectors, 28 regressors over 4 datasets of Iberian pig meat pieces to predict 39 physico-chemical and sensorial attributes, summarizing16,380 experiments. There is not any combination of texture vector and regressor which provides the best result for all attributes tested. Nevertheless, all these experiments provided the following conclusions: (1) the regressor performance, measured using the squared correlation (R2), is from good to excellent (above 0.5625) for 29 out of 39 attributes tested; (2) the WAPE (Weighted Absolute Percent Error) is lower than 2% for 32 out of 37 attributes; (3) the dispersion in computer predictions around the true attributes is lower or similar than the dispersion in the labeling expert’s for the majority of attributes (85%); and (4) differences between predicted and true values are not statistically significant for 29 out of 37 attributes using the Wilcoxon ranksum statistical test. We can conclude that these results provide a high reliability for an automatic system to predict the quality of meat pieces, which may operate on-line in the meat industries in the futureThe authors wish to acknowledge the funding received from the FEDER-MICCIN Infrastructure Research Project (UNEX-10-1E-402), Junta de Extremadura economic support for research group (GRU15173 and GRU15113), from the Xunta de Galicia (Centro singular de investigación de Galicia accreditation 2016–2019) and from the European Union (European Regional Development Fund — ERDF)S

Mudança de estilo de vida e gestão do peso na diabetes: programa de formação de formadores 'Juntos é Mais Fácil'

Apesar de os efeitos positivos de um estilo de vida saudável na prevenção e terapêutica da diabetes mellitus tipo 2, a mudança comportamental é percecionada pelos profissionais de saúde como um processo difícil e complexo. Juntos é Mais Fácil é um programa de educação em grupo para a adoção de estilos de vida saudáveis em pessoas com diabetes, que decorreu entre 2011-2014 em 88 unidades de saúde em Portugal, com boa adesão dos participantes. O objetivo deste trabalho é apresentar os modelos teóricos e de intervenção que estiveram na base do seu desenvolvimento e aplicação (incluindo, entre outros, gestão de grupos, entrevista motivacional e modelo transteórico da mudança) e avaliar o conjunto de cursos de formação de formadores que decorreu como meio de preparação de 416 profissionais de saúde para a implementação do programa Juntos é Mais Fácil. Os questionários de avaliação da formação foram respondidos por 350 profissionais (84,1%) participantes nos cursos. 98,0% dos participantes fez uma apreciação global Muito Boa ou Boa da formação, e mais de 95,0% teve uma equivalente apreciação dos conteúdos, dos formadores e da organização. Este grande interesse manifestado encontra concordância com a menor satisfação expressa em relação à duração do curso e à vontade em prolongar o mesmo. Estratégias futuras para obviar a limitação de tempo passarão pela utilização de novas metodologias, nomeadamente o e-learning. Concluímos que vale a pena investir na capacitação de profissionais de saúde e de pessoas com diabetes, para fazer face ao enorme desafio que constitui a mudança comportamental

Conservation of holm oak (Quercus ilex) by in vitro culture

In vitro culture techniques are used to propagate tree species, as well as to conserve the species in the short and long term. In the present study, in vitro propagation and conservation of holm oak (Quercus ilex L.) were successfully achieved using juvenile material. Mature acorns were germinated under controlled conditions of moisture and temperature, and 3-month-old seedlings were used as source of explants for culture initiation. Micropropagation via axillary bud proliferation was achieved by culturing shoots in a vertical position on Woody Plant Medium containing different cytokinins and/or concentrations, which were changed every 2 weeks over a 6-week multiplication cycle, as follows: 0.1 mg L-1 benzyladenine (BA) for the first 2 weeks, 0.05 mg L-1 BA for the next 2 weeks, and 0.01 mg L-1 BA plus 0.1 mg L-1 zeatin for the last 2 weeks. Acceptable rooting rates were obtained by culturing microcuttings in Murashige & Skoog medium with half-strength macronutrients supplemented with 3 or 5 mg L-1 indole-3-butyric acid (IBA) in combination with 0.1 mg L-1 naphthalene acetic acid (NAA) for 15 days and subsequent transfer to auxin-free medium for 4 weeks

For the improvement of Heart Failure treatment in Portugal ‐ Consensus statement

Heart failure is a syndrome with high prevalence, morbidity and mortality, but awareness of the disease is poor among the general public and policy makers. This document, which was prepared by a group of experts consisting of cardiologists, internists and general practitioners, aims to set out in detail the problem of heart failure in Portugal at several levels: burden of the disease, diagnosis, treatment and monitoring. To this aim, different aspects of the management of the various stages of the disease are identified and discussed in detail, covering both outpatients and hospitalized patients. In order to optimize the medical care provided to these patients, various short‐, medium‐ and long‐term solutions and strategies are put forward that have the potential to improve the integration and use of available resources. The intention is to highlight strategies that are not based on a single model but can be adapted to different regional circumstances, in order to increase awareness and improve management of heart failure in Portugal.publishersversionpublishe

Unha enxeñeira ou científica en cada cole

Póster presentado na V XORNADA UNIVERSITARIA GALEGA EN XÉNERO. TRANSFORMANDO DENDE A UNIVERSIDADE. Vigo, 7 Xullo 2017Nesta comunicación, presentamos o proxecto Unha enxeñeira ou científica en cada cole organizado pola Oficina de Igualdade de Xénero da Universidade de Santiago de Compostela (USC) en colaboración co Concello de Santiago de Compostela. Esta iniciativa pretende incentivar a presenza de rapazas en carreiras relacionadas coas disciplinas STEM (ciencia, enxeñería, tecnoloxía e matemáticas), mediante actividades didácticas nos centros educativos que rachen cos estereotipos sexistas da nosa sociedade. A actividade didáctica consistiu na realización de dezanove obradoiros, dirixidos a nenas e nenos de 5º ou 6º de primaria e realizados nos meses de setembro e outubro de 2016. Os obradoiros foron impartidos por profesoras ou investigadoras da USC e do Centro de Supercomputación de Galicia (CESGA) para crear referentes femininos e incentivar a presenza de rapazas no ámbito científico tecnolóxico. Ademais, estes obradoiros amosaron a relación da ciencia e da tecnoloxía coa nosa vida cotiá e serviron para achegar ao alumnado a estas disciplinas dun xeito lúdicoConcello de Santiago de Compostel

Photocurable Polymeric Blends for Surgical Application

The preparation of photocrosslinkable bioadhesives synthesized from oligomers of lactic acid and polycaprolactone (PCL), both functionalized with 2-isocyanoethyl acrylate (AOI), were studied. The obtained modified macromers of LA-AOI (mLA) and PCL-AOI (mCL) were chemically characterized by 1H NMR and used to formulate polymeric blends with different mass proportions, 1:1, 1:2 and 2:1, respectively. Subsequently, the produced blends were crosslinked, considering two UV irradiation times: 30 and 120 s. After their production, the thermal and mechanical properties of bioadhesives were assessed, where upon the rheology, gel content, hydrolytic degradation and dynamic contact angles were determined. Furthermore, the cytotoxic profile of bioadhesives was evaluated in contact with human dermal fibroblasts cells, whereas their antibacterial effect was studied monitoring Escherichia coli and S. aureus growth. Overall, flexible and resistant films were obtained, presenting promising features to be used as surgical bioadhesives

Development of photocrosslinkable surgical adhesives

Dissertação de Mestrado Integrado em Engenharia Química apresentada à Faculdade de Ciências e TecnologiaOs adesivos cirúrgicos têm vindo a ser objeto de estudo ao longo dos anos, surgindo como uma alternativa a métodos mais tradicionais de tratamento e regeneração de tecidos biológicos. O desenvolvimento destes materiais constitui uma boa aposta em práticas cirúrgicas devido às inúmeras vantagens que apresentam, refletindo-se principalmente numa melhoria da qualidade de vida do paciente. De entre as principais características que tornam os bioadesivos tão atrativos, destaca-se a redução do trauma nos tecidos circundantes, traduzindo-se em melhores resultados estéticos, a rapidez e facilidade de aplicação e a possibilidade de serem biodegradáveis, podendo ser absorvidos pelo organismo. O avanço tecnológico tem promovido o desenvolvimento e o aumento da oferta de bioadesivos de emprego cirúrgico generalizado. Atualmente, estão disponíveis no mercado alguns adesivos e selantes, de origem natural e sintética, para as mais variadas aplicações clínicas. Porém, a libertação de subprodutos tóxicos, o fraco desempenho mecânico, a probabilidade de transmissão de doenças e o risco de infeções, têm restringido as suas utilizações por parte dos profissionais de saúde. Uma possível solução para estas desvantagens centra-se no desenvolvimento de adesivos com base em polímeros biodegradáveis e biocompatíveis, com grupos terminais foto-reticuláveis. Por sua vez, os adesivos foto-reticuláveis por meio da exposição à irradiação UV apresentam uma série de vantagens, nomeadamente uma elevada velocidade de reação de cura, um maior controlo da temperatura de polimerização e das propriedades finais dos materiais.O presente trabalho consistiu na síntese de copolímeros, a partir de poliésteres insaturados (UPs) e de oligómeros de ácido lático funcionalizados com metacrilato de 2-isocianoetilo (IEMA), para a preparação de novos adesivos cirúrgicos foto-reticuláveis. Foram testadas e desenvolvidas novas formulações de base UPs, tendo sido estudados diversos parâmetros do sistema, desde os diferentes tipos de polóis e ácidos carboxílicos usados bem como a percentagem de monómeros adicionada. Por sua vez, selecionou-se o macrómero de ácido lático modificado, devido às suas vantajosas propriedades recentemente estudadas e avaliadas na produção de bioadesivos. Posto isto, foram testadas três proporções estequiométricas diferentes, que após adição de um fotoiniciador biocompatível (Irgacure® 2959), permitiu a obtenção de matrizes flexíveis, resistentes e uniformes, ao fim de 2 minutos e 30 segundos de reticulação. Este compromisso foi considerado promissor para uma futura aplicação em contexto clínico.As análises ATR-FTIR e 1H RMN permitiram acompanhar o progresso das reações de síntese, funcionalização e foto-reticulação. Os materiais preparados foram ainda caracterizados pelas mais diversas técnicas, com o intuito de avaliar as propriedades químicas, físicas, térmicas, mecânicas e biológicas, possibilitando, desta forma, a sua validação como potenciais adesivos cirúrgicos.A técnica termogravimétrica indicou que os materiais são termicamente mais estáveis após foto-reticulação, apresentando estabilidade à temperatura fisiológica e exibindo temperaturas de degradação acima dos 200ºC. A análise térmica dinâmico-mecânica permitiu também identificar as transições térmicas nestes materiais. A capacidade de absorção de água dos adesivos, varia consoante a composição estequiométrica dos copolímeros e o grau de reticulação das matrizes. Quando incubados numa solução de PBS os adesivos revelaram-se hidroliticamente instáveis, verificando-se uma relação evidente com a sua capacidade de absorção de água e grau de reticulação. Esta instabilidade permitiu concluir que os filmes são biodegradáveis, com potencial de absorção por parte do organismo. Por fim, nos estudos de biocompatibilidade foi possível avaliar o comportamento dos materiais com e sem incorporação de um fármaco modelo nas suas estruturas. Selecionou-se para este fim a clorexidina (CHX), devido à sua função bactericida e bacteriostática, permitindo assim averiguar a sua influência na viabilidade celular e na atividade bacteriana, quando em contacto com os materiais. Relativamente aos adesivos sem fármaco adicionado, verificou-se que a grande maioria apresentava excelentes resultados, com valores de viabilidade celular muito perto dos 100%, mesmo para tempos de incubação de 7 dias, pelo que os respetivos materiais foram considerados biocompatíveis. Conclui-se também que a presença da CHX afetou a viabilidade das células. Por sua vez, os estudos da atividade bacteriana revelaram o expectável, isto é, que os adesivos apresentavam características bactericidas, úteis na minimização ou até na prevenção de infeções.Face aos resultados obtidos pode afirmar-se que os novos adesivos sintetizados apresentam características promissoras para a sua utilização em cirurgia. Não obstante, ainda serão necessários novos testes de caracterização, de modo a garantir a sua aplicabilidade de forma segura.Surgical adhesives have been an object of study over the years, appearing as an alternative to traditional methods in the treatment and regeneration of biological tissues. The development of these materials will promote the enhancement of surgical practices, due to their numerous advantages, which mainly reflect in an improvement in the patient's quality of life. Among the main characteristics that make the bioadhesive so attractive, the reduction of the trauma in the surrounding tissues must be highlighted, resulting in better aesthetic results, the speed and ease of application and the possibility of being biodegradable, which make them able of being absorbed by the organism. Technological advances have endorsed the development and the increase of the bioadhesive offer of generalized surgical employment. Currently, some natural and synthetic adhesives and sealants are available for the most varied clinical applications. However, the release of toxic byproducts, a poor mechanical performance, the probability of disease transmission and the risk of infections restricted their use by health professionals. One possible solution to these drawbacks is the development of adhesives based on biodegradable and biocompatible polymers with photocrosslinkable end groups. In turn, light-cured adhesives by exposure to UV irradiation have several advantages, namely a high curing reaction rate, a better control of the polymerization temperature and of the final properties of the materials.The present work consisted in the synthesis of copolymers, based on unsaturated polyesters (UPs) and lactic acid oligomers functionalized with 2-isocyanatoethyl methacrylate (IEMA), for the preparation of new photopolymerizable surgical adhesives.New UPs formulations were tested and developed, and several system parameters were studied, including different types of glycols and carboxylic acids used, as well as the percentage of monomers added. In turn, the modified lactic acid macromer was selected because of its advantageous properties recently studied and evaluated in the production of bioadhesives. Henceforth, three different stoichiometric proportions were tested, which, after the addition of a biocompatible photoinitiator (Irgacure® 2959), allowed to obtain flexible, resistant and uniform matrices after 2 minutes and 30 seconds of crosslinking. This commitment was considered promising for a future application in the clinical practice.The ATR-FTIR and 1H NMR analyzes allowed to monitor the progress of the synthesis, functionalization and photopolymerization reactions. The prepared materials were characterized by using the most diverse techniques, with the purpose of evaluating the chemical, physical, thermal, mechanical and biological properties, thus allowing their validation as potential surgical adhesives.The thermogravimetric technique indicated that the materials became more thermally stable after photopolymerization, exhibiting stability at physiological temperature and degradation at temperatures above 200°C. Dynamic-mechanical thermal analysis also allowed to identify the thermal transitions in these materials. The swelling capacity of the adhesives varies according to the stoichiometric composition of the copolymers and to the degree of crosslinking of the matrices. When incubated in a PBS solution, these adhesives showed to be hydrolytically unstable, which is consistent with an apparent connection to their swelling capacity and to their degree of crosslinking. This instability allows concluding that films are biodegradable, with a potential to be absorbed by the body.Finally, it was possible to evaluate the behavior of materials with and without incorporation of a model drug in their structures through biocompatibility studies. For this purpose, chlorhexidine was selected because of its bactericidal and bacteriostatic function, thus allowing to study its influence on cell viability and bacterial activity when in contact with the materials. Regarding the adhesives without drug, most of them showed excellent results, with cellular viability values of almost 100%, even for incubation times of 7 days, which showed that the prepared materials were biocompatible. It was also concluded that the presence of chlorhexidine affected the viability of the cells. In turn, the studies related to bacterial activity revealed as expected, that drug-loaded adhesives presented bactericidal characteristics, useful not only in minimization, but also in infection prevention.In light of the results obtained, it may be concluded that the new synthesized adhesives present promising characteristics for their use in surgery. Nevertheless, further characterization tests will still be required in order to ensure their safe applicability