Continuous extraction strategies for monoclonal antibodies: From macro- to micro- scale

Aqueous two-phase extraction (ATPE) have shown to be a valuable option for the downstream processing of biopharmaceuticals, combining a high biocompatibility and selectivity with an easy and reliable scale up. Moreover, ATPE can overcome some of the technical drawbacks currently encountered using established purification platforms, such as batch operation, diffusional limitations and scale-related problems. We have developed a continuous ATPE process incorporating three different steps (extraction, back-extraction and washing) for the capture of monoclonal antibodies (mAbs). The ATPE process was set up and validated in a pump mixer-settler battery and successfully applied to a Chinese hamster ovary and a PER.C6® cell supernatant. The limited predictive design of ATPE, however, has restrict its applicability to current downstream processing. Microscale process techniques have recently emerged as effective tools for expediting bioprocess design in a cost-effective manner. ATPE in a microfluidic platform was therefore designed and tested for mAbs extraction, as an effective tool to accelerate bioprocess design and optimization. Furthermore, this platform has the potential of combining the process efficiency of ATPS with the reduced times and volumes associated with microfluidics, as well as the possibility to multiplex and parallel process in real downstream processes. In this way, we have develop a microfluidic channel-based toolbox for the rapid screening of antibody extraction conditions. Several microfluidic structures have been designed including a multiplexed structure that allows a simple negative-pressure driven rapid screening of up to 8 continuous extraction conditions simultaneously, using less than 20 μL of each phase forming solution per experiment. Results obtained from this device can be further applied in a second microfluidic structure (Figure 1) that integrates multiple-step continuous extraction protocols

Active methodologies in incoming programming classes

Innovative approaches in teaching programming have been required to improve the success of incoming programming students. This work presents the initial results of a teaching strategy implemented in the Algorithms subject of a Computer Science course. Ninety-five students, enrolled in this subject during the first semester of the course, participated in the research. The reported activity is related with active methodologies of teaching and Problem-Based Learning, being developed on the first day of class in groups of up to five students. The activity was based in two actions: 1) answering a questionnaire associating computing elements to daily life routines; and, 2) even without programming concepts knowledge, develop a smartphone application. Each group received a questionnaire containing 19 questions, divided into four blocks. What can be perceived with the accomplishment of this work, was the enthusiasm, motivation and engagement of the students who, even being unknown from each other, organized themselves in the groups and researched the necessary strategies to complete the challenge. The teacher acted as an advisor in the teaching process, conducting the experiment in order to lead students to find the solution.This work has been supported by FCT - Fundação para a Ciência e Tecnologia within the Projects Scopes: UIDB/05757/2020 and UIDB/00319/2020.info:eu-repo/semantics/publishedVersio

Técnicas para melhorar a durabilidade da construção em terra

Umas das principais fragilidades da construção em terra é a sua durabilidade face à ação da água, seja pelas chuvas, inundações ou ascensão da água por capilaridade, situações que acontecem sobretudo em países com elevado índice de pluviosidade. Contudo, as construções vernaculares têm demonstrado que é possível construir de forma durável, apesar de este conhecimento parecer ter sido esquecido ao longo dos anos. Por outro lado também têm sido desenvolvidas novas tecnologias para compactação, estabilização e impermeabilização de solos para melhorar a durabilidade da construção em terra. Todavia, a sustentabilidade da solução construtiva pode ser comprometida pelo uso excessivo de cimento ou materiais excessivamente impermeabilizantes. Neste artigo, pretende-se identificar e avaliar estratégias para proteção face à ação da água que têm sido utilizadas desde a Antiguidade até aos nossos dias. Deste modo, será possível perceber como inúmeros edifícios construídos em terra foram preservados ao longo de séculos, resistindo a condições climáticas severas

Sugar reduction in fruit nectar: comparison of children and adults's perception.

Human beings have an innate preference for sweet products. A cost-effective strategy to reduce sugar intake in the short term is reducing added sugars of processed foods. However, in order to be effective, sugar reduction should not be perceived by consumers. Preference for sweet taste is different in children and adults, which suggests that recommendations for sugar reduction may differ for products targeted at each segment. In this context, the objectives of the present study were to determine children and adults’ difference thresholds for added sugar in grape nectar, and to determine their hedonic perception towards nectars with reduced sugar content.SLACA, 12. De 4 a 7 de Novembro de 2017. Ref. 70421

Study and characterization of heat modified wood portuguese species

A modificação térmica tem-se revelado um método eficaz na melhoria da durabilidade de elementos de madeira. Até ao momento, as aplicações da madeira termicamente modificada (MTM) têm sido limitadas a revestimentos já que o tratamento térmico de tratamento conduz a uma redução significativa das resistências mecânicas da madeira. Contudo, este tratamento térmico poderá valorizar e potenciar a utilização de espécies de madeira menos utilizadas na construção, como são o Eucalipto e o Pinho bravo nacional. Com o objetivo de avaliar o efeito do tratamento térmico nas espécies referidas e, complementarmente, na madeira de Faia e Freixo, realizou-se uma campanha experimental composta por ensaios de caracterização mecânica (compressão paralela às fibras e flexão) e de estabilidade dimensional (retração, inchamento e teor de água de equilíbrio (TAE)). Para efeitos de comparação, todos os ensaios envolveram séries de provetes de cada espécie de madeira natural e MTM. Os resultados obtidos são coerentes com a bibliografia disponível, o aumento da estabilidade dimensional, assim como a diminuição do TAE e das propriedades mecânicas de flexão foram verificadas, permitindo, assim, avaliar a influência da modificação térmica nas propriedades de espécies de madeira presentes em Portugal.The thermal modification has proved to be an effective method to improve the durability of wood elements. Until the moment, applications of thermally modified wood (MTM) have been limited to non-structural applications, because the heat treatment leads to a significant reduction in the mechanical performance of wood. However, this heat treatment can promote the use of less used wood species in construction, as the national Eucalyptus and Pine. In order to evaluate the effect of heat treatment on the species of Pine, Eucalyptus, Beech and Ash, was held an experimental program that consisted in mechanical characterization tests (compression parallel to grain and flexion) and tests of dimensional stability (shrinkage, swelling and equilibrium moisture content (EMC)). For comparison, all tests were made with samples of non-modified and thermally modified wood. The results are consistent with the available literature, the dimensional stability increased, as well as the reduction of TAE and mechanical properties, allowing the evaluation of the thermal modification on the properties of wood species present in Portugal

Using the methodology problem-based learning to teaching programming to freshman students

This work registers the initial results of a teaching strategy implemented with students entering the Algorithms discipline with a higher degree in Computing. This discipline offered to first-year students records cases of dropout and evasion. Thus, it is necessary to implement teaching strategies to provide engagement, interest, and motivation with the subjects worked on. The main objective is apply an active methodology problem-based learning in programming teaching. In this work participated 177 students in the years 2019-2 (47), 2020-1/2020-2 (83), and 2021-2 (47), enrolled in the first period of the course. The methodology adopted for the development of this study consisted of: use of questionnaires to measure prior knowledge about computing concepts; group discussion of the answers recorded in the questionnaire; development of an APP for smartphone; use of the PBL (Problem-based learning) methodology as a learning strategy. It is an activity related to the active teaching and learning methodology of problem-based learning that is being developed on the first day of class in groups of up to five students. The strategy consisted of two actions: 1) answering a questionnaire associating everyday computing elements; and 2) even though the programming concepts were not presented, the groups were challenged to develop a smartphone application. Each group received a questionnaire containing 19 questions divided into four blocks. What can be seen from the completion of this work was the enthusiasm, motivation, and engagement of the students, who, even though they were newcomers, organized themselves into groups and researched the necessary strategies to complete the challenge. When measuring the knowledge obtained through the application of a questionnaire relating to the content (with the participation of 62% of students), it was found that 81% of the participants obtained the necessary grade for approval of that content. Following the strategy of an active methodology of learning and teaching that favors the protagonism and autonomy of the student, we concluded that strategy was benefic for to the students, and the teacher acted as a guide in the teaching process, directing what should be researched to find the solution and serving as a tutor in the resolution of the problem presented. Preliminarily, part of this study was presented at the 2nd International Computer Programming Education Conference.info:eu-repo/semantics/publishedVersio

Efficient graphene-based photodetector with two cavities

We present an efficient graphene-based photodetector with two Fabri-P\'erot cavities. It is shown that the absorption can reach almost 100% around a given frequency, which is determined by the two-cavity lengths. It is also shown that hysteresis in the absorbance is possible, with the transmittance amplitude of the mirrors working as an external driving field. The role of non-linear contributions to the optical susceptibility of graphene is discussed.Comment: 10 pages, 8 figures. published version: minor revisio

Light scattering by a medium with a spatially modulated optical conductivity: the case of graphene

We describe light scattering from a graphene sheet having a modulated optical conductivity. We show that such modulation enables the excitation of surface plasmon-polaritons by an electromagnetic wave impinging at normal incidence. The resulting surface plasmon-polaritons are responsible for a substantial increase of electromagnetic radiation absorption by the graphene sheet. The origin of the modulation can be due either to a periodic strain field or to adatoms (or absorbed molecules) with a modulated adsorption profile.Comment: http://iopscience.iop.org/0953-8984/24/24/24530

Spectral high resolution feature selection for retrieval of combustion temperature profiles

Proceeding of: 7th International Conference on Intelligent Data Engineering and Automated Learning, IDEAL 2006 (Burgos, Spain, September 20-23, 2006)The use of high spectral resolution measurements to obtain a retrieval of certain physical properties related with the radiative transfer of energy leads a priori to a better accuracy. But this improvement in accuracy is not easy to achieve due to the great amount of data which makes difficult any treatment over it and it's redundancies. To solve this problem, a pick selection based on principal component analysis has been adopted in order to make the mandatory feature selection over the different channels. In this paper, the capability to retrieve the temperature profile in a combustion environment using neural networks jointly with this spectral high resolution feature selection method is studied.Publicad