Green processing of porous chitin structures for biomedical applications combining ionic liquids and supercritical fluid technology

The application of green chemistry principles in the processing of materials for advanced technologies is a steadily increasing field of research. In this work porous chitin-based materials were developed by combining the processing of chitin using ionic liquids (ILs)as a green solvent together with the use of super- critical fluid technology(SCF) as clean technology.Chitin was dissolved in 1-butyl-3-imidazolium acetate,followed by regeneration of the polymer in ethanol in specific moulds.The IL was removed using Soxhlet extraction and successive steps of extraction with SCF using carbon dioxide/ethanol ratios of 50/ 50 and70/30.The developed porous chitin-based structures (ChIL)can be classified as mesoporous materials,with very low density and high porosity.The cytotoxicity of ChIL extracts was investigated using L929 fibroblast like cells,and the results demonstrated that the produced materials have extremely lowcytotoxicityl evels.Therefore,the findings suggest that the porous chitin structures may be potential candidates for a number of biomedical applications,including tissue engineering.Fundação para a Ciência e Tecnologia (FCT)S.S.S. and A.R.C.D. thank the Portuguese Foundation for Science and Technology (FCT) for post-doctoral fellowships (SFRH/BPD/ 45307/2008 and SFRH/BDP/34994/2007, respectively). This work was partially supported by the FCT (Project PTDC/QUI/68804/ 2006) and was carried out under the scope of the European NoE EXPERTISSUES (NMP3-CT-2004-500283)

Study of the electrochemical reduction of amoebicide Teclozan and its amperometric determination in pharmaceutical formulations

Neste trabalho, a redução eletroquímica do amebicida Teclozan (TEC) foi estudada sobre um eletrodo de carbono vítreo em meio de acetonitrila. Eletrólises com potencial controlado foram realizadas visando, tanto a determinação do número de elétrons envolvidos na redução do fármaco, quanto a identificação dos produtos eletrogerados, os quais foram isolados por extração líquido-líquido e caracterizados por 1H RMN. Foi verificado que o TEC apresenta dois picos voltamétricos, cada um associado à quebra redutiva de duas ligações C-Cl. Em presença de um doador de prótons, foi observado que o primeiro pico voltamétrico em −1,8 V corresponde principalmente à redução dos grupamentos -CHCl2 a -CH2Cl; enquanto o segundo pico em −2,2 V é responsável pela redução dos grupos -CH2Cl a CH3, fornecendo como único produto o derivado totalmente desalogenado do TEC, com rendimentos entre 82 e 97%. Este trabalho descreve também o desenvolvimento de um método eletroanalítico baseado na detecção amperométrica do TEC em condições hidrodinâmicas, o qual forneceu um limite de detecção de 8,9 × 10-6 mol L-1.The electrochemical reduction of amoebicide Teclozan (TEC) was studied on a glassy carbon electrode in acetonitrile. Controlled-potential electrolyses were performed for coulometric and preparative purposes. The electrogenerated products were isolated by liquid-liquid extraction and characterized by 1H NMR. It was observed that TEC presents two voltammetric peaks, each one associated with the cleavage of two C-Cl bonds. In presence of a proton donor it was observed that the first peak at −1.8 V promotes mainly the reduction of the groups CHCl2 to CH2Cl and the second one at −2.2 V promotes the reduction of the groups CH2Cl to CH3 giving as the sole product the completely dechlorinated TEC derivative with yields between 82 and 97%. In addition, a comparative study between the analytical performance of voltammetric techniques and amperometric detection of TEC in hydrodynamic conditions was performed. The amperometric detection was more sensitive than all evaluated voltammetric techniques, providing a detection limit of 8.9 × 10-6 mol L-1.FAPESP; CAPES; FC

A new method for testing antimicrobial activity of filamentous fungi

Tbls work was supporled by a FCT projecl (PTDC/AGR-AAM/099556/2008)

Caloric restriction rescues yeast cells from alpha-synuclein toxicity through autophagic control of proteostasis

α-Synuclein (SNCA) is a presynaptic protein that is associated with the pathophysiology of synucleinopathies, including Parkinson's disease. SNCA is a naturally aggregation-prone protein, which may be degraded by the ubiquitin-proteasome system (UPS) and by lysosomal degradation pathways. Besides being a target of the proteolytic systems, SNCA can also alter the function of these pathways further, contributing to the progression of neurodegeneration. Deterioration of UPS and autophagy activities with aging further aggravates this toxic cycle. Caloric restriction (CR) is still the most effective non-genetic intervention promoting lifespan extension. It is known that CR-mediated lifespan extension is linked to the regulation of proteolytic systems, but the mechanisms underlying CR rescue of SNCA toxicity remain poorly understood. This study shows that CR balances UPS and autophagy activities during aging. CR enhances UPS activity, reversing the decline of the UPS activity promoted by SNCA, and keeps autophagy at homeostatic levels. Maintenance of autophagy at homeostatic levels appears to be relevant for UPS activity and for the mechanism underlying rescue of cells from SNCA-mediated toxicity by CR.BSM and HP are supported by fellowships from the Fundação para a Ciência e Tecnologia (FCT, Portugal) (SFRH/BPD/90533/2012 and SFRH/BD/133087/2017, respectively).info:eu-repo/semantics/publishedVersio

Identificando Características de Organizações Intensivas em Conhecimento em Universidades: Um Estudo de Caso nas Instituições do Sistema ACAFE de Santa Catarina - Brasil

O estudo identifica características de organizações intensivas em conhecimento em universidades. Parte-se do pressuposto de que organizações que desenvolvem atividades na área de educação são, em princípio, organizações intensivas em conhecimento. Para mapear as características que possam confirmar tal pressuposto, estruturou-se o estudo em 4 dimensões: organização e gestão, infra-estrutura, pessoas e tecnologia, através das quais elaborou-se o instrumento de pesquisa. O estudo foi desenvolvido através de um survey utilizando o trabalho de ANGELONI (2002), denominado Modelo Alternativo de Organização do Conhecimento . Os resultados atenderam as expectativas, mesmo apresentando alguns desvios em razão de o assunto tratado ser relativamente novo para as empresas e, mais especificamente para instituições de ensino superior. Conclui-se que as pesquisas acerca da gestão do conhecimento em IES, ainda são incipientes, acreditando-se que os resultados apresentados contribuirão para novas pesquisas e para que as IESs iniciem processos de suas transformações em organizações intensivas em conhecimento

Separation of non-ferrous frations of shredded end-of-life vehicles for valorising its alloys

Worldwide the end-of-life vehicles (ELV) generate millions of tons of waste, requiring an adequate and efficient management. The non-ferrous fraction contains essentially aluminium, magnesium and copper alloys, being valorised by metallurgical processors to obtain new metals and alloys. However most of the recovered metals are downcycled, as is the case of aluminium where the recycled products are essentially used to produce less purity casting alloys. New or improved separation technologies are therefore necessary in order to allow an accurate separation of alloys or alloy groups, increasing the value of the non-ferrous streams. In this paper, the composition of the non-ferrous fractions of ELV shredders are assessed with particular relevance for the aluminium and magnesium alloys. Essentially, the main cast and wrought alloys are characterized and their markets and applications are discussed. Based on waste composition, several physical separation and sorting technologies can be applied to improve the products quality, which are here depicted and discussed. Physical processing includes operations such as eddy current and heavy media separations. For sorting alloys contained in the non-ferrous stream, other sensor-based technologies are being developed, such as electromagnetic sensing and novel laser induced breakdown spectroscopy systems, constituting an important contribution for boosting the non-ferrous metals recycling rates

Método GASMoC: uma técnica para detetar bacilos álcool ácido-resistentes sem fenol

FCT_UIDB/05608/2020. FCT_UIDP/05608/2020.A técnica de Ziehl-Neelsen (ZN) permite detetar bacilos álcoolácido resistentes (BAAR), tal como Mycobacterium tuberculosis (agente causador da tuberculose). Nesta técnica, a carbol-fucsina (CF) penetra a parede das BAAR conferindo-lhes uma tonalidade rosa que é mantida quando utilizada uma solução descorante, devido ao envelope celular que lhes confere resistência álcool-ácida2. Assim, as BAAR são demonstradas a rosa sobre um fundo azul. A CF implica o uso de fenol que liberta vapores, cuja inalação pode resultar em graves efeitos para a sua saúde a curto e a longo prazo. Alguns autores comprovaram a capacidade da fucsina básica aquosa (FBA) aquecida, como alternativa, para corar BAAR. Assim sendo, pretende-se com o presente estudo determinar a capacidade de deteção da técnica de Ziehl-Neelsen sem o uso de fenol.info:eu-repo/semantics/publishedVersio

Isolation of Chitinolytic Bacteria from European Sea Bass Gut Microbiota Fed Diets with Distinct Insect Meals

SIMPLE SUMMARY: The ever-growing human population is increasingly demanding more fish. As a response, aquaculture has become the fastest growing industry in its sector. Alternatives to fish meal, an unsustainable commodity used as the main protein source for carnivorous species, are urgently needed in aquafeeds. Recently, in Europe, seven insect species have been approved as potential ingredients for animal feeds, including fish feed. However, chitin, one of the components of an insect’s exoskeleton, is indigestible for several economically valuable fish species, decreasing fish performance upon inclusion. This work aimed to isolate, from the European sea bass gastrointestinal tract, probiotic bacteria capable of producing chitinases to improve the use of diets containing high levels of insect meal. Based on the enhanced adaptability of gut microbial communities and the selective pressure of chitin-enriched diets on fish gut microbiota, bacteria were first isolated from the gastrointestinal tract of European sea bass fed chitin-enriched diets. Isolates were then comprehensively screened in vitro for important traits such as their ability to utilize chitin, gut-survival aptitude, and biosafety-related issues required to be considered eligible as probiotics by the European Food Safety Authority (EFSA). ABSTRACT: Insect meal (IM), recently authorized for use in aquafeeds, positions itself as a promising commodity for aquafeed inclusion. However, insects are also rich in chitin, a structural polysaccharide present in the exoskeleton, which is not digested by fish, resulting in lower fish performance. Through the application of a dietary pressure, this study aimed to modulate European sea bass gut microbiota towards the enrichment of chitinolytic bacteria to allow the isolation of novel probiotics capable of improving the use of IM-containing diets, overcoming chitin drawbacks. Five isoproteic (44%) and isolipidic (18%) diets were used: a fish meal (FM)-based diet (diet CTR), a chitin-supplemented diet (diet CHIT5), and three diets with either 25% of Hermetia illucens and Tenebrio molitor larvae meals (HM25 and TM25, respectively) or H. illucens exuviae meal (diet HEM25) as partial FM substitutes. After an 8-week feeding trial, the results showed a clear modulatory effect towards spore-forming bacteria by HM25 and HEM25 diets, with the latter being responsible for the majority of the chitinolytic fish isolates (FIs) obtained. Sequential evaluation of the FI hemolytic activity, antibiotic resistance, total chitinolytic activity, sporulation, and survival in gastrointestinal-like conditions identified FI645 and FI658 as the most promising chitinolytic probiotics for in vivo application

Determining factors of functioning in hemodialysis patients using the international classification of functioning, disability and health

Background: Hemodialysis (HD) treatment affects functioning, physical activity level, clinical biomarkers, and body composition. However, the association between these variables with functioning, considering International Classification of Functioning, Disability and Health (ICF) domains remains unclear. Thus, the aim of this study was to investigate the possible association between physical activity, biomarkers, and body composition with functioning in HD patients in reference to the ICF. Methods: Eighty HD patients performed different tests grouped according to ICF domain: Body structure and function – handgrip strength (HS), 5-repetition sit-to-stand test, and 60-s sit-to-stand test (5-STS, 60-STS, respectively); Activity – short physical performance battery (SPPB); and Participation – participation scale questionnaire. Physical activity [Human Activity Profile questionnaire (HAP)], body composition (Dual-energy X-ray absorptiometry), Parathormone (PTH), and alkaline phosphatase were analyzed as possible variables associated with ICF domains. Data analyses were performed using simple and multiple regression models adjusted for age, duration of HD, and diuresis volume. Results: In the body structure and function domain, appendicular lean mass, PTH level, and age were associated with HS ( R2 = 0.558); HAP and PTH were associated with 5-STS ( R2 = 0.263); and HAP, PTH, duration of HD, and age were associated with 60-STS ( R2 = 0.337). In the activity domain, HAP, PTH, alkaline phosphatase, duration of HD, age, and body fat were associated with SPPB ( R2 = 0.689). Finally, only HAP was associated with the participation scale ( R2 = 0.067). Conclusion: Physical activity and PTH levels are determinant protagonists of functioning in all ICF domains in hemodialysis patients