88 research outputs found

    Interfacial stabilization of enzymes in microemulsions

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    One of the major constrains to the use of enzymes in industrial processes is their insufficient stability under processing conditions, namely high temperatures, presence of ultrasounds, among others. Herein, we investigated the use of oil-in-water proteinaceous (BSA) microemulsions as a novel methodology for the stabilization of laccase from ascomycete Micelliophthora thermophila. The immobilization of laccase onto the produced microemulsions benefitiated its stability under ultrasonic conditions. The half life time of immobilized laccase was 2.4-fold higher (from 23 to 56 minutes) than laccase in the free form. This technique show promising potentialities for the stabilization of enzymes used onto a variety of processes, namely textile bleaching, surface hydrolysis, among others

    Applying differential dynamic logic to reconïŹgurable biological networks

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    Qualitative and quantitative modeling frameworks are widely used for analysis of biological regulatory networks, the former giving a preliminary overview of the system’s global dynamics and the latter pro- viding more detailed solutions. Another approach is to model biological regulatory networks as hybrid systems, i.e., systems which can display both continuous and discrete dynamic behaviors. Actually, the development of synthetic biology has shown that this is a suitable way to think about biological systems, which can often be constructed as networks with discrete controllers, and present hybrid behaviors. In this paper we discuss this approach as a special case of the reconïŹgurability paradigm, well studied in Computer Science (CS). In CS there are well developed computational tools to reason about hybrid systems. We argue that it is worth applying such tools in a biological context. One interesting tool is differential dynamic logic ( d L ), which has recently been developed by Platzer and applied to many case-studies. In this paper we discuss some simple examples of biological regulatory networks to illustrate how d L can be used as an alternative, or also as a complement to methods already used

    Moringa oleifera L. screening: SFE-CO2 optimisation and chemical composition of seed, leaf, and root extracts as potential cosmetic ingredients

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    Moringa oleifera L. tree (Mo) has emerged as a rich alternative source of bioactive compounds to design cosmetic formulations. Supercritical carbon dioxide fluid extraction (SFE-CO2) was successfully applied on the screening of Mo seed, leaf, and root extracts. The extraction yield was evaluated by response surface methodology (RSM), for pressure and temperature ranges of 117–273 bar and 41–60 C, respectively, using a design of experiments (DOE). The pressure significantly affected the results (a = 0.05), with the highest extraction efficiency obtained at conditions above 195 bar. The extracts’ composition, evaluated by gas chromatography-mass spectrometer (GC-MS), revealed an increasing correlation between the pressure, total extract solubility, and mass of extract at a constant temperature, due to the higher extraction yield. Seed extracts presented more than 80% of oleic acid in relative composition (8.04 mgcompound gplantpart -1). Leaf extracts performed well for the obtainment of linolenic acid (>20%; 3.10 mg g-1), nonacosane (>22%; 0.46 mg g-1), and -tocopherol (>20%; 0.21 mg g-1). Mo root resulted in higher relative composition for sterol molecules, despite its very low affinity with CO2. The most promising bioactive compounds, oleic acid and -tocopherol, were more abundant when operating at 250 bar at 45 C and 195 bar at 55 C, for Mo seed and leaf SFE-CO2 extracts, respectively.This work was financially supported by LA/P/0045/2020 (ALiCE), UIDB/50020/2020 and UIDP/50020/2020 (LSRE-LCM), UIDB/00690/2020 and UIDP/00690/2020 (CIMO) and LA/P/0007/2021 (SusTEC), funded by national funds through the Fundação para a CiĂȘncia e Tecnologia FCT/MCTES (PIDDAC). JĂșlia CristiĂȘ Kessler acknowledges her PhD scholarship (ref. 2020.06656.BD) from FCT.info:eu-repo/semantics/publishedVersio

    Sonochemical and hydrodynamic cavitation reactors for laccase/hydrogen peroxide cotton bleaching

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    Article in pressThe main goal of this work is to develop a novel and environmental-friendly technology for cotton bleaching with reduced processing costs. This work exploits a combined laccase–hydrogen peroxide process assisted by ultrasound. For this purpose, specific reactors were studied, namely ultrasonic power generator type K8 (850 kHz) and ultrasonic bath equipment Ultrasonic cleaner USC600TH (45 kHz). The optimal operating conditions for bleaching were chosen considering the highest levels of hydroxyl radical production and the lowest energy input. The capacity to produce hydroxyl radicals by hydrodynamic cavitation was also assessed in two homogenizers, EmulsiFlex¼-C3 and APV-2000. Laccase nanoemulsions were produced by high pressure homogenization using BSA (bovine serum albumin) as emulsifier. The bleaching efficiency of these formulations was tested and the results showed higher whiteness values when compared to free laccase. The combination of laccase–hydrogen peroxide process with ultrasound energy produced higher whiteness levels than those obtained by conventional methods. The amount of hydrogen peroxide was reduced 50% as well as the energy consumption in terms of temperature (reduction of 40 °C) and operating time (reduction of 90 min).The author Idalina Goncalves would like to acknowledge the Cottonbleach project (FP7-SME-2008-2; 243529-2-cottonbleach) for the funding. The author Carla Silva would like to acknowledge FCT - Fundacao para a Ciencia e a Tecnologia for the grant SFRH/BPD/46515/2008

    Valorization of Amaranth (Amaranthus cruentus) grain extracts for the development of alginate-based active films

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    This research work investigates the development of alginate-based films incorporating phenolic compounds extracted from Amaranthus cruentus grain using different solvents. Alginate, glycerol, and amaranth grain phenolic compounds at various concentrations were used to produce the films. An experimental Central Composite Rotatable Design (CCRD) was used to evaluate the effect of these variables on different film’s properties, i.e., water vapor permeability, hydrophobicity, moisture content, solubility, thermal, mechanical, and optical properties. This study demonstrated that high phenolic compound content and antioxidant capacity were obtained from amaranth grain using ethanol as the extraction solvent. Alginate films incorporating amaranth phenolic compounds were successfully manufactured, and this study can be used to tailor the formulation of alginate films containing amaranth phenolic compounds, depending on their final food application. For example, less flexible but more resistant and water-soluble films can be produced by increasing the alginate concentration, which was confirmed by a Principal Component Analysis (PCA) and Partial Least Squares (PLS) analysis. This study showed that active alginate films with amaranth phenolic compounds can be tailored to be used as food packaging material with potential antioxidant activity.This research was funded by Portuguese Foundation for Science and Technology (FCT) under the scope of the strategic funding of UIDB/04469/2020 unit, and by LABBELS—Associate Laboratory in Biotechnology, Bioengineering and Microelectromechnaical Systems (LA/P/0029/2020). Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq), Brazil, is also acknowledged for the doctoral grant to L.M.C. (IF/00300/2015).info:eu-repo/semantics/publishedVersio

    Design of novel BSA/hyaluronic acid nanodispersions for transdermal pharma purposes

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    A novel transdermal hyaluronic acid (HA) conjugated with bovine serum albumin (BSA) was developed in the form of solid-in-oil (S/O) nanodispersion (129.7 nm mean diameter). Ex vivo skin penetration analysis by fluorescence and confocal observation of histological skin sections revealed the ability of BSA/HA nanodispersions to cross the stratum corneum and penetrate into the dermis. Furthermore, no significant toxicity was found in fibroblast and keratinocyte cells in vitro. These results proved the potential of the developed nanodispersion for transdermal delivery of hyaluronic acid constituting a high value to biopharmaceutical and cosmetics industries.We thank Matadouro Central Carnes de Entre Douro e Minho, Lda, for their support on pig samples. The histological studies were supported by the Department of Histology from Life and Health Sciences Research Institute (ICVS), University of Minho. The confocal 3D images were performed by Department of Chemistry and Kanbar Laboratory for Nanomaterials Bar-Ilan University Center for Advanced Materials and Nanotechnology. C.S. would like to thank Fundacao para a Ciencia e a Tecnologia for their funding (SFRH/BPD/46515/2008). T.M. would like to thank Fundacao para a Ciencia e a Tecnologia for their funding (SFRH/BPD/47555/2008)

    Scenarios for the future Brazilian power sector based on a multi-criteria assessment

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    The Brazilian power generation sector faces a paradigm change driven by, on one hand, a shift from a hydropower dominated mix and, on the other hand, international goals for reducing greenhouse gas emissions. The objective of this work is to evaluate five scenarios for the Brazilian power sector until 2050 using a multi-criteria decision analysis tool. These scenarios include a baseline trend and low carbon policy scenarios based on carbon taxes and carbon emission limits. To support the applied methodology, a questionnaire was elaborated to integrate the perceptions of experts on the scenario evaluation process. Considering the results from multi-criteria analysis, scenario preference followed the order of increasing share of renewables in the power sector. The preferable option for the future Brazilian power sector is a scenario where wind and biomass have a major contribution. The robustness of the multi-criteria tool applied in this study was tested by a sensitivity analysis. This analysis demonstrated that, regardless of the respondents' preferences and backgrounds, scenarios with higher shares of fossil fuel sources are the least preferable option, while scenarios with major contributions from wind and biomass are the preferable option to supply electricity in Brazil through 2050.The research that allowed the publication of this paper has been produced with the financial assistance of the European Union in the context of the CLIMACAP project (EuropeAid/131944/C/SER/Multi) and of the U.S. Agency for International Development and U.S. Environmental Protection Agency in the context of the LAMP project (under Interagency Agreements DW89923040 and DW89923951US). The contents of this publication are the sole responsibility of the authors and can in no way be taken to reflect the views of the European Union or the U.S. government. The authors would like to thank the feedback and efforts from all CLIMACAP and LAMP project partners for enabling the research results reported in this article. This research was also supported by a Marie Curie International Research Staff Exchange Scheme Fellowship within the 7th European Union Framework Programme, under project NETEP-European Brazilian Network on Energy Planning (PIRSES-GA-2013-612263).info:eu-repo/semantics/publishedVersio

    TiO2/graphene and TiO2/graphene oxide nanocomposites for photocatalytic applications: A computer modeling and experimental study

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    Supplementary data related to this article can be found at http://dx. doi.org/10.1016/j.compositesb.2018.03.015.This work reports a computational study, focused on graphene (G) and graphene oxide (GO) interfaces with titanium dioxide (TiO2), and an experimental assay on the photocatalytic activity of TiO2/G and TiO2/GO nanocomposites in the degradation of two different pollutants: methylene blue and ciprofloxacin. Both carbon nanostructures were compared due to their different chemical structure: GO is a G derivative with oxygen functional groups which should promote a closer chemical interaction with TiO2 nanoparticles. Computational models of the fundamental properties of the composites indicated potentially improved photocatalytic activity compared to TiO2, namely lower band gaps and charge carrier segregation at the interfaces. These fundamental properties match qualitatively experimental results on methylene blue, which was more effectively degraded by TiO2/G and TiO2/GO nanocomposites than by pure TiO2 under UV light. In contrast, the same nanocomposites were found to be less efficient to degrade ciprofloxacin than pure TiO2 under visible and UV light. Therefore, this work showcases the relevance of an efficient matching between the catalyst and the molecular properties and structure of the pollutant.This work was supported by the Portuguese Foundation for Science and Technology (FCT) in the framework of the Strategic Project PESTC/FIS/UI607/2014 and PEST-C/QUI/UIO686/2014 and the CICECO Aveiro Institute of Materials, POCI-01-0145-FEDER-007679 (FCT ref. UID/CTM/50011/2013). Access to computing facilities provided by the Project “Search-ON2: Revitalization of HPC infrastructure of UMinho” (NORTE-07-0162-FEDER-000086) is also acknowledged. P. M. Martins and Luciana Pereira thanks the FCT for grants SFRH/BD/98616/2013 and SFRH/BPD/110235/2015, respectively. MMF for a program CiĂȘncia 2008 fellowship. The authors thank ïŹnancial support from the Basque Government Industry Department under the ELKARTEK Program. P.A.A.P. Marques thanks the grant IF/00917/2013/CP1162/ CT0016. Acknowledges also to FCT under the scope of the strategic funding of UID/BIO/04469/2013 unit and COMPETE 2020 (POCI-010145-FEDER-006684) and BioTecNorte operation (NORTE-01-0145FEDER-000004) funded by the European Regional Development Fund under the scope of Norte2020 - Programa Operacional Regional do Norte.info:eu-repo/semantics/publishedVersio

    Chemical and organoleptic properties of bread enriched with Rosmarinus officinalis L.: the potential of natural extracts obtained through green extraction methodologies as food ingredients

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    The potential of R. officinalis L. (RO) extracts as a source of aromas was accessed by hydrodistillation (HD) and supercritical fluid extraction using carbon dioxide (SFE-CO2), followed by a series of analysis: quantification by GC-MS, sensory perception and description, and cytotoxicity against Vero cells. The extracts shown abundancy of α-pinene, eucalyptol, S-verbenone and camphor, contributing for the green, fresh, citric, and woody as main sensory notes. The odour threshold (ODT) value (less than 3.0 × 10 3 ÎŒg⋅mL 1) and the cytotoxic potential (ca. 220 ÎŒg∙mL 1) defined the concentration range for food application. The most promising extract was added to bread doughs and the final volatile profile was characterised by GC-MS through HS-SPME over time. Among the 34 compounds found, furfural showed an evident contribution in the bread crust aroma, which persisted over four hours of storage, contributing to a pleasant bread fragrance according to the evaluators. This study aims to represent a stepping stone for the use of natural aromas as ingredients for the development of innovative food products.This work was funded by the European Regional Development Fund (ERDF) through the Regional Operational Program North 2020, within the scope of Project Mobilizador Norte-01-0247-FEDER-024479: ValorNatural Âź. This work was also supported by LA/P/0045/2020 (ALiCE), UIDB/50020/2020 and UIDP/50020/2020 (LSRE-LCM), and UIDB/ 00690/2020 (CIMO) funded by national funds through FCT/MCTES (PIDDAC). L. Barros and R. Calhelha also thank the national funding by FCT, P.I. through the institutional scientific employment and individual program-contract, and JĂșlia Cristiˆe Kessler acknowledges her Ph.D scholarship (ref. 2020.06656.BD) by FCT.info:eu-repo/semantics/publishedVersio
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