Randomized clinical study of injectable dextrin-based hydrogel as a carrier of a synthetic bone substitute.

OBJECTIVES: This study aimed to improve the performance and mode of administration of a glass-reinforced hydroxyapatite synthetic bone substitute, Bonelike by Biosckin® (BL®), by association with a dextrin-based hydrogel, DEXGEL, to achieve an injectable and moldable device named DEXGEL Bone. METHODS: Twelve participants requiring pre-molar tooth extraction and implant placement were enrolled in this study. BL® granules (250-500 µm) were administered to 6 randomized participants whereas the other 6 received DEXGEL Bone. After 6 months, a bone biopsy of the grafted area was collected for histological and histomorphometric evaluation, prior to implant placement. The performance of DEXGEL Bone and BL® treatments on alveolar preservation were further analyzed by computed tomography and Hounsfield density analysis. Primary implant stability was analyzed by implant stability coefficient technique. RESULTS: The healing of defects was free of any local or systemic complications. Both treatments showed good osseointegration with no signs of adverse reaction. DEXGEL Bone exhibited increased granule resorption (p = 0.029) accompanied by a tendency for more new bone ingrowth (although not statistically significant) compared to the BL® group. The addition of DEXGEL to BL® granules did not compromise bone volume or density, being even beneficial for implant primary stability (p = 0.017). CONCLUSIONS: The hydrogel-reinforced biomaterial exhibited an easier handling, a better defect filling, and benefits in implant stability. CLINICAL RELEVANCE: This study validates DEXGEL Bone safety and performance as an injectable carrier of granular bone substitutes for alveolar ridge preservation. TRIAL REGISTRATION: European Databank on Medical Devices (EUDAMED) No. CIV-PT-18-01-02,705; Registo Nacional de Estudos Clínicos, RNEC, No. 30122.

A Review on Biological Processes for Pharmaceuticals Wastes Abatement-A Growing Threat to Modern Society.

Over the last decades, the production and consumption of pharmaceuticals and health care products grew manifold, allowing an increase in life expectancy and a better life quality for humans and animals, in general. However, the growth in pharmaceuticals production and consumption comes with an increase in waste production, which creates a number of challenges as well as opportunities for the waste management industries. The conventional current technologies used to treat effluents have shown to be inefficient to remove or just to reduce the concentrations of these types of pollutants to the legal limits. The present review provides a thorough state-of-the-art overview on the use of biological processes in the rehabilitation of ecosystems contaminated with the pharmaceutical compounds most commonly detected in the environment and eventually more studied by the scientific community. Among the different biological processes, special attention is given to biosorption and biodegradation.

Recovery of Rare Earth Elements from Wastewater Towards a Circular Economy.

The use of rare earth elements is a growing trend in diverse industrial activities, leading to the need for eco-friendly approaches to their efficient recovery and reuse. The aim of this work is the development of an environmentally friendly and competitive technology for the recovery of those elements from wastewater. Kinetic and equilibria batch assays were performed with zeolite, with and without bacterial biofilm, to entrap rare earth ions from aqueous solution. Continuous assays were also performed in column setups. Over 90% removal of lanthanum and cerium was achieved using zeolite as sorbent, with and without biofilm, decreasing to 70% and 80%, respectively, when suspended Bacillus cereus was used. Desorption from the zeolite reached over 60%, regardless of the tested conditions. When in continuous flow in columns, the removal yield was similar for all of the rare earth elements tested. Lanthanum and cerium were the elements most easily removed by all tested sorbents when tested in single- or multi-solute solutions, in batch and column assays. Rare earth removal from wastewater in open setups is possible, as well as their recovery by desorption processes, allowing a continuous mode of operation.

Pilot-scale sorption studies of diethylketone in the presence of Cd2+ and Ni2.

The effect of pH on the sorption capacity of vermiculite towards cadmium and nickel was tested in batch systems and it was shown that the sorption percentages increase with an increase in the mass of vermiculite and with an increase in the initial pH. Maximum sorption percentages were obtained for a pH of 8 and 4 g of vermiculite (86.5% for Cd2+ and 86.1% for Ni2+, for solutions with 100 mg/L of metal). As a consequence, it was possible to establish a range of optimal pH for biosorption processes, by combining the so determined optimal sorption pH of vermiculite with the optimal growth pH of Streptococcus equisimilis, a bacterium used to treat contaminated water. Pilot-scale experiments with a S. equisimilis biofilm supported on vermiculite were conducted in closed-loop conditions, aiming to treat large volumes of diethylketone aqueous solutions, eventually containing Cd2+ or Ni2+. The excellent capacity of this joint system to simultaneously biodegrade diethylketone and biosorb Cd2+ or Ni2+was proved. The removal percentage and the uptake increase through time, even with the replacement of the initial solution by new ones. The breakthrough curves that best describe the results achieved for Cd2+ and Ni2+ are respectively the Adams-Bohart and the Yoon and Nelson model.

Sorption studies of diethylketone in the presence of Al3+, Cd2+, Ni2+ and Mn2+, from lab-scale to pilot scale.

The toxic effects of diethylketone (DEK) in aqueous solution with different concentrations of Al3+, Cd2+, Ni2+ and Mn2+ were evaluated at lab-scale. It was established that Streptococcus equisimilis is able to efficiently remove DEK with different concentrations with heavy metals. It was proved that this joint-system has excellent capacity to biodegrade high concentrations of DEK in the presence of Al3+, Cd2+, Ni2+ and Mn2+. With the exception of Al3+, the uptake for all metals increased as the initial concentration of each metal in the mixed solution increased. The breakthrough curves are best described by the Adams and Bohart model for Cd2+, by the Yoon and Nelson model for Ni2+ and by the Wolborska model for Mn2+.

Bioremoval of diethylketone by the synergistic combination of microorganisms and clays: uptake, removal and kinetic studies.

The performance of two bacteria, Arthrobacter viscosus and Streptococcus equisimilis, and the effect of the interaction of these bacteria with four different clays on the retention of diethylketone were investigated in batch experiments. The uptake, the removal percentages and the kinetics of the processes were determined. S. equisimilis, by itself, had the best performance in terms of removal percentage, for all the initial diethylketone concentrations tested: 200, 350 and 700 mg/L. The uptake values are similar for both bacteria. A possible mechanism to explain the removal of diethylketone includes its degradation by bacteria, followed by the adsorption of the intermediates/sub-products by the functional groups present on the cells' surfaces. The assays performed with bacteria and clays indicated that the uptake values are similar despite of the clay used, for the same microorganism and mass of clay, but in general, higher values are reached when S. equisimilis is used, compared to A. viscosus. Kinetic data were described by pseudo-first- and pseudo-second-order models.

Kinetics of biodegradation of diethylketone by Arthrobacter viscosus.

The performance of an Arthrobacter viscosus culture to remove diethylketone from aqueous solutions was evaluated. The effect of initial concentration of diethylketone on the growth of the bacteria was evaluated for the range of concentration between 0 and 4.8 g/l, aiming to evaluate a possible toxicological effect. The maximum specific growth rate achieved is 0.221 h(-1) at 1.6 g/l of initial diethylketone concentration, suggesting that for higher concentrations an inhibitory effect on the growth occurs. The removal percentages obtained were approximately 88%, for all the initial concentrations tested. The kinetic parameters were estimated using four growth kinetic models for biodegradation of organic compounds available in the literature. The experimental data found is well fitted by the Haldane model (R (2) = 1) as compared to Monod model (R (2) = 0.99), Powell (R (2) = 0.82) and Loung model (R (2) = 0.95). The biodegradation of diethylketone using concentrated biomass was studied for an initial diethylketone concentration ranging from 0.8-3.9 g/l in a batch with recirculation mode of operation. The biodegradation rate found followed the pseudo-second order kinetics and the resulting kinetic parameters are reported. The removal percentages obtained were approximately 100%, for all the initial concentrations tested, suggesting that the increment on the biomass concentration allows better results in terms of removal of diethylketone. This study showed that these bacteria are very effective for the removal of diethylketone from aqueous solutions.

A tomada de consciência e o grupo focal na transformação das representações sociais do envelhecimento: uma pesquisa de intervenção / Focus groups and the grasp of consciousness in the Transformation of social representations of ageing: a proposal for intervention

Existe um consenso nos estudos das representações sociais da velhice: declínio, doenças e perdas (físicas, familiares e da capacidade de trabalho), de um lado e, de outro, a valorização da experiência do idoso e das questões sócio-políticas a ele relacionadas. Na Psicologia do envelhecimento, 3 aspectos são salientados: o declínio do suporte familiar ao idoso, a experiência e valores relacionados ao envelhecer e a defesa de trabalhos sobre a capacitação dos cuidadores, majoritariamente centrados no aspecto físico do envelhecimento. Assumimos o desafio proposto por Fávero (2005) de criar uma situação que engendrasse uma transformação das representações sociais da velhice nos cuidadores de uma instituição para idosos. Teórico-metodológicamente, três aportes foram essenciais: o grupo focal, os atos da fala e a tomada de consciência no sentido desenvolvimental piagetiniano. Tomamos, como sugere esta autora, o sujeito humano na sua identidade única e particular sem apartá-lo do coletivo, considerando sua capacidade de reorganização interna. Participaram do estudo, 7 sujeitos entre 32 e 52 anos, 6 mulheres e 1 homem, funcionários de uma instituição para idosos independentes, que foram convidados a participar de um grupo focado no envelhecimento e no sujeito idoso, visando: a identificação das representações sociais, as premissas do paradigma que lhe dá suporte; a tomada de consciência a respeito de tais representações e premissas, as implicações destas para a prática pessoal e/ou profissional e as possibilidades de sua re-elaboração. Catorze sessões de grupo foram desenvolvidas e registradas em áudio. Suas transcrições foram submetidas à análise dos atos da fala. Os resultados apontaram dois focos - o envelhecimento visto como experiência negativa e a ênfase nas perdas físicas, intelectuais e sociais – sustentados por um paradigma calcado na relação aspecto físico, beleza e afetividade, indicando uma articulação entre as representações sociais do envelhecimento e aquelas de gênero. A tomada de consciência dos sujeitos levou, num primeiro momento, à justificativa desses focos e num segundo, a reformulação do dito paradigma, ou seja, a mudança de determinados aspectos das representações sociais do envelhecimento. Os resultados das análises dos atos da fala apontaram mudanças das representações sociais nos seguintes aspectos: o reconhecimento das diferenças entre a velhice feminina e masculina, com ênfase nas...AU)

Enfermedades marcadoras de sida en un grupo de pacientes africanos con infección por VIH/sida / Infections and other opportunistic processes in a group of African patients with HIV infection/AIDS

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