Interventional Algorithm in Gastrointestinal Bleeding-An Expert Consensus Multimodal Approach Based on a Multidisciplinary Team

The approach to the patient with gastrointestinal bleeding (GIB) can be very complex. A multidisciplinary panel of physicians with expertise in Gastroenterology, Anesthesiology, and Transfusion Medicine worked together to provide the best knowledge and guide clinical practitioners in the real setting of health institutions, characterized by disparate availability of human and technical resources. The authors propose a global and personalized approach according to different clinical scenarios to improve the outcomes of patients with GIB, for whom the reduction of inappropriate transfusions is crucial. The goal of this document is to provide clear and objective guidance through interventional algorithms toward a goal-directed approach according to the clinical situation and supported by the latest available scientific data on GIB management in different settings.info:eu-repo/semantics/publishedVersio

Characterization of Active Sites on Carbon Catalysts

A method based on the deconvolution of TPD spectra is proposed for the characterization of surface oxygen groups, which can act as the active sites on carbon catalysts. The method, which was previously used to characterize activated carbons oxidized in the gas phase, has been extended and applied to other materials, carbons oxidized in the liquid phase. It is shown that this method fits quite well the TPD experimental data of the original activated carbon as well as the gas-phase and liquid-phase oxidized materials and is suitable to estimate the amounts of each type of oxygen surface groups.info:eu-repo/semantics/publishedVersio

Highly N2-Selective Activated Carbon-Supported Pt-In Catalysts for the Reduction of Nitrites in Water

The catalytic reduction of nitrites over Pt-In catalysts supported on activated carbon has been studied in a semi-batch reactor, at room temperature and atmospheric pressure, and using hydrogen as the reducing agent. The influence of the indium content on the activity and selectivity was evaluated. Monometallic Pt catalysts are very active for nitrite reduction, but the addition of up to 1 wt% of indium significantly increases the nitrogen selectivity from 0 to 96%. The decrease in the accessible noble metal surface area reduces the amount of hydrogen available at the catalyst surface, this favoring the combination of nitrogen-containing intermediate molecules to promote the formation of N2 instead of being deeply hydrogenated into NH4+. Several activated carbon-supported Pt-In catalysts, activated under different calcination and reduction temperatures, have been also evaluated in nitrite reduction. The catalyst calcined and reduced at 400°C showed the best performance considering both the activity and the selectivity to nitrogen. This enhanced selectivity is ascribed to the formation of Pt-In alloy. The electronic properties of Pt change upon alloy formation, as it is demonstrated by XPS.This work was financially supported by Base-UIDB/50020/2020 and Programmatic-UIDP/50020/2020 Funding of LSRE-LCM, funded by natiunal funds through FCT/MCTES (PIDDAC). Financial support from Ministerio de Ciencia e Innovación (Spain, Project PID 2019-108453GB-C21 and PID 2020-116998RB-I00) is gratefully acknowledged

Catalytic and Photocatalytic Nitrate Reduction Over Pd-Cu Loaded Over Hybrid Materials of Multi-Walled Carbon Nanotubes and TiO2

TiO2 and carbon nanotube-TiO2 hybrid materials synthesized by sol-gel and loaded with 1%Pd−1%Cu (%wt.) were tested in the catalytic and photocatalytic reduction of nitrate in water in the presence of CO2 (buffer) and H2 (reducing agent). Characterization of the catalysts was performed by UV-Vis and fluorescence spectroscopy, X-ray diffraction, temperature programed reduction, N2 adsorption, and electron microscopy. The presence of light produced a positive effect in the kinetics of nitrate removal. Higher selectivity toward nitrogen formation was observed under dark condition, while the photo-activated reactions showed higher selectivity for the production of ammonium. The hybrid catalyst containing 20 %wt. of carbon nanotubes shows the best compromise between activity and selectivity. A mechanism for the photocatalytic abatement of nitrate in water in the presence of the hybrid materials was proposed, based in the action of carbon nanotubes as light harvesters, dispersing media for TiO2 particles and as charge carrier facilitators

Anesthesiology Consensus in the Management of the Airway

Os consensos na gestão clínica da via aérea em anestesiologia pretendem disponibilizar informação, baseada na evidência atual ou, na falta desta, na opinião de peritos, no que respeita à abordagem da via aérea difícil previsível ou não previsível. Reforçamos a importância da avaliação da via aérea e da identificação de potenciais problemas que possam condicionar dificuldade na sua abordagem e a adoção de uma estratégia segura que permita identificar e responder em crescendo de intervenção às dificuldades encontradas. Na impossibilidade de intubação traqueal (não intubo) otimizada e limitada a 4 tentativas, da impossibilidade de ventilar e oxigenar (não oxigeno) após 2 tentativas de usar um dispositivo supraglótico ou de uso de máscara facial inicialmente adequada é importante realizar, em tempo útil, uma cricotirotomia para assegurar oxigenação. As situações clínicas de exceção só com planos simples, conhecidos por todos e regularmente treinados e adaptados à nossa atividade clinica podem assegurar melhores “outcomes”. O registo destes eventos e a informação ao nosso doente da dificuldade encontrada e modo como foi resolvido o problema é essencial e constitui ainda um desafio a alargar a uma base nacional.info:eu-repo/semantics/publishedVersio

Thermogravimetric and reaction kinetic analysis of biomass samples from an energy plantation

The products of a Hungarian experimental plantation for energy crops were investigated. Young shoots of poplar clones (Populus x euramericana and Populus x interamericana), black locust (Robinia pseudoacacia), willow (Salix alba), and an herbaceous plant (Miscanthus sinensis) revealed unexpectedly similar thermal behavior in inert and oxidative atmospheres, as well. An 8-fold difference in the level of grinding did not result in substantial differences in the thermal decomposition. The effect of oxygen in the ambient gas was studied at low sample masses (0.2-0.4 mg) that excluded the overheating due to the high reaction heat of the combustion process. The presence of oxygen affects the decomposition from ca. 220 degreesC. Nevertheless, the extrapolated onset temperature of the hemicellulose decomposition is practically the same at 0, 5, and 21 V/V% oxygen. A group of 12 experiments, representing two grinding levels, three plant genera and four different heating programs were evaluated simultaneously by the method of least squares employing the model of independent pseudocomponents. All evaluated experiments were well described by the same set of kinetic parameters; only the parameters describing the peak area of the partial processes differed. A technique was recommended for the appropriate handling of the nonrandom errors in the simultaneous evaluation of experiment series

Materiales de carbón como catalizadores para la ozonización de contaminantes orgánicos en agua

[EN] A brief overview about the use of carbon materials as metal free ozonation catalysts is presented. Carbon materials (activated carbons, carbon xerogels, carbon nanofibers and carbon nanotubes) have been shown to be active catalysts in the ozonation of a wide range of organic pollutants. Carbon materials with surface basic properties (i.e. high electron density) and with large pores are the most promising for this process.[ES] En el presente trabajo se resume brevemente el uso de materiales de carbón como catalizadores libres de metales en el proceso de ozonización. Los materiales de carbón (carbones activados, xerogeles de carbón, nanofibras y nanotubos de carbono) han mostrado ser catalizadores activos para una gran variedad de contaminantes orgánicos en dicho proceso, siendo los más adecuados aquellos con propiedades superficiales básicas (alta densidad electrónica) y con mayor tamaño de poros.This work was partially supported by the European Community’s Seventh Framework Programme (FP7/2007-2013) under Grant Agreement No. 280658, by FEDER through COMPETE (project PEst-C/EQB/LA0020/2013), and by QREN, ON2 and FEDER (Project NORTE-07-0124-FEDER-0000015). A. G. acknowledges the Grant received from FCT (BD/45826/2008).Peer reviewe

Pressão nos aneurismas

Um aneurisma é uma área frágil na parede de um vaso sanguíneo que faz com que o vaso forme uma protuberância ou aumente de tamanho. Em situações limites, este enfraquecimento pode levar ao rompimento do vaso. O principal objetivo deste trabalho é o de compreender como ocorre a deformação do aneurisma quando sujeito a uma pressão interna semelhante à pressão sanguínea. O estado de deformação do aneurisma, permitirá definir quais as regiões é que estão sujeitas a deformações mais elevadas e que podem dar uma indicação de potencial rotura. Para realizar este estudo realizaram-se duas aproximações distintas, uma numérica e outra experimental. Para o estudo numérico utilizou-se o programa comercial de elementos finitos Ansys®. Neste caso, fez uma simulação considerando que material de que são constituídos os vasos sanguíneos têm um compartimento hiper-elástico e aplicou-se uma pressão interna constante. Para a fazer a análise experimental, foi desenvolvido um modelo in-vitro do aneurisma, para realização desse modelo recorreu-se a um sistema de prototipagem rápida utilizando uma impressora 3D, Solidoodle®. O material que foi utilizado para a criação do modelo tem um comportamento elástico próximo das paredes arteriais e designa- se por polidimetilsiloxano. Da análise dos resultados obtidos verificou-se que região em que ocorre uma deformação mais elevada encontra-se no topo do aneurisma, permitindo concluir-se que há uma forte probabilidade de ser nessa região que ocorra a rotura do aneurisma.info:eu-repo/semantics/publishedVersio