Effectiveness factor for immobilized biocatalysts: two substratestwo products reactions

Immobilized enzymes are being increasingly used as biocatalysts in numerous processes to obtain high-value products for the pharmaceutical, flavour and fragrance industries (Gandhi et al., 2000). The major advantages of immobilization include the increase in enzyme stability, the possibility of enzyme reutilization and the easy separation of the biocatalysts from the reaction mixture. However, it is necessary to account for mass transfer limitations that, under some conditions, may arise in these systems (Gómez et al., 2003; Jeison et al., 2003). These resistances comprise the effects of intraparticle diffusion and external mass-transfer. Given the complexity of the kinetics of multisubstrate enzyme reactions, reactor modelling studies that account for mass-transfer phenomena are so far limited to single-substrate ones (Gómez et al., 2003). To compare the observed reaction rate with the reaction rate in the absence of mass-transfer limitations, an overall effectiveness factor is usually calculated (Gómez et al., 2003; Jeison et al., 2003). In this work, a model is developed to calculate the overall effectiveness factor for immobilized enzymes that carry out irreversible two substrates-two products reactions following kinetic mechanisms such as the Ternary Complex or the Ping-Pong Bi-Bi with inhibition by the second substrate. The model has two dimensionless parameters for each substrate – Thiele modulus (reaction/intraparticle diffusion), Biot number (film diffusion/intraparticle diffusion) – and one related to the reaction kinetics. Their influence on the effectiveness factor is analysed. The results obtained can be applied in the design and simulation of enzymatic reactors

University–industry partnerships for the provision of R&D services

Technology Transfer Offices (TTOs) are the main institutions responsible for the establishment of university–industry partnerships. R&D contracts exemplify the indirect mechanisms through which enterprises and universities collaborate on a win–win basis. This study addresses organizational and institutional aspects that act as drivers for the establishment of successful university–industry partnerships. First, a series of regression models explain the determinants of R&D contracts. These models include two main dimensions: the university and the technology transfer office. Second, further analysis empirically explores whether universities in regions with a favorable environment enjoy greater active involvement in this particular knowledge transfer mechanism. The empirical study analyzes 2010 data for Spanish public universities. Results indicate that successful R&D contracts depend on university and TTO characteristics, and the university's location. The paper also presents a set of managerial implications for improving the establishment of university–industry partnerships.Peer ReviewedPostprint (author's final draft

Assessment of potential prebiotic activity of pineapple by-products (peels and stems) extracts and maintenance of bioavailability through in vitro gastrointestinal tract system

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Analysis of a vegetable oil performance in a milling process by MQL Lubrication

In this work, we carried out a comparison between the dry machining of an aluminum block with conventional cutting oil and a block with vegetable oil. The two oils had different flow rates. Using the Taguchi method, it was possible to determine the matrices for optimizing the best parameters for each group of tests. Then, we studied the utility of using vegetable oil as a cutting lubricant. We found that the vegetable oil studied in this work had good properties in terms of reducing cutting temperatures but was less effective than conventional cutting oil in reducing the surface roughness of the machined part. Tribological tests were carried out to understand the influence of the selected lubricants in reducing friction and wear. After the sliding experiments, which were performed without lubrication in the presence of the same lubricants that were used in the machining tests and in the presence of distilled water, we concluded that vegetable oil has satisfactory lubricating properties that are similar to those of the conventional cutting fluid, indicating a potential for consideration as an effective alternative to the conventional cutting fluid, with economic, environmental, and health advantages.Financial support was provided by Portugal’s national funding FCT/MCTES (PIDDAC) to Centro de Investigação de Montanha (CIMO) (UIDB/00690/2020 and UIDP/00690/2020) and SusTEC (LA/P/0007/2020). Additionally, this work was partially supported by Portuguese FCT, under the reference projects UIDB/04077/2020, UIDB/00532/2020 and UIDB/04436/2020. This research was also partially funded by EXPL2021CIMO_01. Inês Afonso acknowledges the financial support of CIMO through EXPL2021CIMO_01

Predictors of the perceived risk of COVID-19 and adherence to confinement guidelines in the context of the COVID-19 pandemic

INTRODUCTION: Complete adherence to public health guidelines is essential to reduce the spread of COVID-19. Studies on the factors associated with increased/decreased adherence to these measures have the potential to inform public policies directed at increasing adherence, and thus helping to control the spread of the current pandemic. OBJECTIVES: This study aimed at assessing the demographic and psychosocial predictors of the perceived risk of the COVID-19 and adherence to confinement guidelines during the first mandatory lockdown in Portugal. METHODS: A convenience sample of 430 adults living in Portugal between March 19(th) and May 2(nd,) 2020 completed an online survey asking participants about the perceived risk of the COVID-19 and adherence to confinement guidelines. Participants also completed a sociodemographic questionnaire and measures of psychological function. Multiple regression analysis was performed. RESULTS: Teleworking and Risk and COVID-19 controllability were significant predictors of the perceived risk of COVID-19 as measured by the perceived risk of being infected with COVID-19. Teleworking participants and those perceiving COVID-19 as less controllable reported a higher perceived risk of being infected with COVID-19 than those who were not in telework and perceived COVID-19 as a controllable condition. Adherence to confinement guidelines was predicted by the mental health status and perceived risk of COVID-19. Participants who reported worse mental health status, who perceived COVID-19 as a dangerous condition, and who trusted the public health system reported greater adherence to confinement guidelines. CONCLUSIONS: The results of this study will be discussed considering their implications to public health policymaking to promote adherence to public health policies. DISCLOSURE: No significant relationships

Definição de parâmetros para o estudo da fadiga muscular em exercícios dinâmicos utilizando a metodologia acumulativa-normalizada por meio de eletromiografia

Dissertação (mestrado)—Universidade de Brasília, Faculdade de Tecnologia, Departamento de Engenharia Elétrica, 2018.Esta dissertação compreende o estudo da fadiga muscular, e aborda a determinação de parâmetros que possibilitem a avaliação objetiva da fadiga muscular em esforços físicos dinâmicos utilizando EMG-S (eletromiografia de superfície). O trabalho tem enfase na busca que parâmetros que permitam a repetibilidade da avaliação em diferentes voluntários e diferentes tipos de esforços físicos. Além de índices indicadores de fadiga já consolidados na literatura, usar-se-á um indicador demostrado pelo grupo de pesquisa da Universidade de Brasília, que mostrou bastante eficácia e sensibilidade quanto à evolução da fadiga muscular. Tanto para este parâmetro quanto para os outros abordou-se, além da verificação direta dos indicadores uma análise com indicadores acumulativos. As avaliações realizadas mostraram que, ajustando os parâmetros de processamento de sinais flexivelmente de acordo com cada sinal, tanto os novos quanto os parâmetros clássicos se mostram tão promissores na análise de exercícios dinâmicos como já observado na análise de exercícios isostáticos. Os modelos determinantes de indicadores de fadiga através de EMG-S mostraram um grau de reprodutibilidade alvissareiro em relação a diferentes pessoas, diferente exercício e diferentes músculos de estudo.This work comprises the study of muscle fatigue and addresses the determination of parameters that allow the objective evaluation of muscle fatigue in dynamic physical efforts using EMG-S(surface electromyography). The work focuses on the search for parameters that allow the repeatability of the evaluation in different volunteers and different types of physical efforts. In addition to indexes of fatigue already consolidated in the literature, an indicator will be used, demonstrated by the research group of the University of Brasília, which showed a great deal of efficacy and sensitivity regarding the evolution of muscular fatigue. For both this parameter and the others, it was approached, besides the direct verification of the indicators, an analysis with cumulative indicators. The evaluations showed that by adjusting the signal processing parameters flexibly according to each signal, both the new and the classical parameters are shown as promising in the analysis of dynamic exercises as already observed in the analysis of isotactic exercises. The determinant models of fatigue indicators through EMG-S showed a degree of reproducibility in relation to different people, different exercise and different study muscles

Knockdown of Selenocysteine-Specific Elongation Factor in \u3ci\u3eAmblyomma maculatum\u3c/i\u3e Alters the Pathogen Burden of \u3ci\u3eRickettsia parkeri\u3c/i\u3e with Epigenetic Control by the Sin3 Histone Deacetylase Corepressor Complex

Selenocysteine is the 21st naturally-occurring amino acid. Selenoproteins have diverse functions and many remain uncharacterized, but they are typically associated with antioxidant activity. The incorporation of selenocysteine into the nascent polypeptide chain recodes the TGA stop codon and this process depends upon a number of essential factors including the selenocysteine elongation factor (SEF). The transcriptional expression of SEF did not change significantly in tick midguts throughout the blood meal, but decreased in salivary glands to 20% at the end of the fast feeding phase. Since selenoprotein translation requires this specialized elongation factor, we targeted this gene for knockdown by RNAi to gain a global view of the role selenoproteins play in tick physiology. We found no significant differences in tick engorgement and embryogenesis but detected no antioxidant capacity in tick saliva. The transcriptional profile of selenoproteins in R. parkeri-infected Amblyomma maculatum revealed declined activity of selenoprotein M and catalase and increased activity of selenoprotein O, selenoprotein S, and selenoprotein T. Furthermore, the pathogen burden was significantly altered in SEF-knockdowns. We then determined the global impact of SEF-knockdown by RNA-seq, and mapped huge shifts in secretory gene expression that could be the result of downregulation of the Sin3 histone deacetylase corepressor complex

Analysis of a vegetable oil performance in a milling process by MQL lubrication

In this work, we carried out a comparison between the dry machining of an aluminum block with conventional cutting oil and a block with vegetable oil. The two oils had different flow rates. Using the Taguchi method, it was possible to determine the matrices for optimizing the best parameters for each group of tests. Then, we studied the utility of using vegetable oil as a cutting lubricant. We found that the vegetable oil studied in this work had good properties in terms of reducing cutting temperatures but was less effective than conventional cutting oil in reducing the surface roughness of the machined part. Tribological tests were carried out to understand the influence of the selected lubricants in reducing friction and wear. After the sliding experiments, which were performed without lubrication in the presence of the same lubricants that were used in the machining tests and in the presence of distilled water, we concluded that vegetable oil has satisfactory lubricating properties that are similar to those of the conventional cutting fluid, indicating a potential for consideration as an effective alternative to the conventional cutting fluid, with economic, environmental, and health advantages.Financial support was provided by Portugal’s national funding FCT/MCTES (PIDDAC) to Centro de Investigação de Montanha (CIMO) (UIDB/00690/2020 and UIDP/00690/2020) and SusTEC (LA/P/0007/2020). Additionally, this work was partially supported by Portuguese FCT, under the reference projects UIDB/04077/2020, UIDB/00532/2020 and UIDB/04436/2020. This research was also partially funded by EXPL2021CIMO_01. Inês Afonso acknowledges the financial support of CIMO through EXPL2021CIMO_01.info:eu-repo/semantics/publishedVersio