A novel strategy of acrylamide mitigation in fried potatoes using asparaginase and high pressure technology

The potentiality of high pressure processing (HPP) to possibly enhance diffusion of asparaginase into raw potato sticks, and consequently on reduction of acrylamide levels in fried potatoes was evaluated. Raw potato sticks were immersed in asparaginase (10,000 ASNU/L) and immediately subjected to 0.1, 100, 200 and 400 MPa for 5 min, with total enzymatic reaction times of 5, 10 and 20 min and room temperature. Pressurized raw potato sticks became softer, more flexible, and required lower energy for cutting (up to 47% less); the roughness of potato surface and moisture content were slightly reduced; and the concentration of soluble solids in the exterior solutions increased, indicative of a leaching effect. Due to changes induced by asparaginase and/or HPP on raw potatoes, fried potatoes exhibited higher weight loss after frying, and higher hardness (crispness). The combined treatment with asparaginase and HPP showed to reduce acrylamide levels by 26 -47%, while with asparaginase or HPP alone there was no significant reduction.publishe

Microfluidic immunosensor for rapid and highly-sensitive salivary cortisol quantification

This paper presents a novel poly(dimethylsiloxane) (PDMS) microfluidic immunosensor that integrates a complementary metal-oxide-semiconductor (CMOS) optical detection system for a rapid and highly-sensitive quantification of salivary cortisol. The simple and non-invasive method of saliva sampling provides an interesting alternative to the blood, allowing a fast sampling at short intervals, relevant for many clinical diagnostic applications. The developed approach is based on the covalent immobilization of a coating antibody (Ab), a polyclonal anti-IgG, onto a treated PDMS surface. The coating Ab binds the capture Ab, an IgG specific for cortisol, allowing its correct orientation. Horseradish peroxidase (HRP)-labelled cortisol is added to compete with the cortisol in the sample, for the capture Ab binding sites. The HRP-labelled cortisol, bonded to the capture Ab, is measured through the HRP enzyme and the tetramethylbenzidine (TMB) substrate reaction. The cortisol quantification is performed by colorimetric detection of HRP-labelled cortisol, through optical absorption at 450 nm, using a CMOS silicon photodiode as the photodetector. Under the developed optimized conditions presented here, e.g., microfluidic channels geometry, immobilization method and immunoassay conditions, the immunosensor shows a linear range of detection between 0.01-20 ng/mL, a limit of detection (LOD) of 18 pg/mL and an analysis time of 35 min, featuring a great potential for point-of-care applications requiring continuous monitoring of the salivary cortisol levels during a circadian cycle.FCT with the reference project UID/EEA/04436/2013, by FEDER funds through the COMPETE 2020 – Programa Operacional Competitividade e Internacionalização (POCI) with the reference project POCI-01-0145-FEDER-006941. V C Pinto thanks the FCT for the SFRH/BD/81526/2011 PhD grant. P J Sousa thanks the FCT for the SFRH/BD/81562/2011 PhD grant. S.O. Catarino thanks the FCT for the SFRH/BPD/108889/2015 grant, supported by national funds from Ministérios da Ciência, Tecnologia e Ensino Superior and by FSE through the POCH - Programa Operacional Capital Humanoinfo:eu-repo/semantics/publishedVersio

A dual channel naphthyl-BODIPY probe for the detection of cations in mixed aqueous solution

The development of chemosensors for the sensing of metal ions is one of the most active research fields with great potential for environmental, physiological and medicinal applications, especially in the case of Pd2+, Hg2+ and the trivalent cations Fe3+ and Al3+. For example, mercury is one of the most toxic metal ions, even at very low concentrations. Accumulation of mercury over time in humans leads to cognitive and motion disorders and Minamata disease. On the other hand, trivalent metal cations such as Fe3+ and Al3+ play crucial roles in physiological processes and its abnormal levels in human tissues and cells could induce anemia, diabetes, Alzheimer´s and Parkinson’s diseases. Therefore, the efficient detection of these cations is a timeless topic in several areas of investigation. We report herein the chromo-fluorogenic behavior toward metal cations of a new BODIPY probe bearing a 4-N,N-dimethylnaphthyl group attached to the meso position of the BODIPY core and a formyl group in position 2. This receptor is a dual channel probe that can be used for the chromogenic and fluorogenic detection, in mixed aqueous solutions, of trivalent (Fe3+and Al3+) and divalent cations (Hg2+and Pd2+) with biological and medicinal relevance.The authors acknowledge Fundação para a Ciência e Tecnologia (Portugal) for funding through CQUM (Pest-C/QUI/UI0686/2019) and project PTDC/QUI COL/28052/2017. The NMR spectrometer Bruker Avance III 400 is part of the National NMR Network (REDE/1517/RMN/2005)

Anion Colorimetric Chemosensor Based on a Benzimidazole-Functionalized BODIPY Derivative

A BODIPY derivative bearing a benzimidazole unit at position 2 and an electron donor group (anthracene) at the meso position was synthetized and characterized by the usual spectroscopic techniques. The evaluation of the compound as a colorimetric chemosensor was performed in solutions of acetonitrile/water (75:25) in the presence of several anions (HSO4−, NO3−, H2PO4−, CN−, BzO−, ClO4−, Br−, F−, I− and CH3CO2−) with biomedical and environmental relevance. The in-vestigated BODIPY derivative demonstrated a selective color change from pink to yellow upon interaction with a hydrogen sulfate anion (HSO4−).The authors acknowledge Fundação para a Ciência e Tecnologia-FCT (Portugal) for funding through CQUM (UID/QUI/00686/2020) and project PTDC/QUI-COL/28052/2017 and a PhD grant to. R. C. R. Gonçalves (SFRH/BD/05278/2020). The NMR spectrometer Bruker Avance III 400 was part of the National NMR Network and was purchased within the framework of the National Program for Scientific Re-equipment, contract REDE/1517/RMN/2005, with funds from POCI 2010 (FEDER) and FCT

Synthesis, characterization and evaluation of a carbazolyl-BODIPY as a fluorimetric chemosensor for F-

BODIPY dyes have received great attention in the last few years as optical chemosensors since they can recognize metal ions in solutions through optical signals (colorimetric and/or fluorimetric). In this context, our research group reports the synthesis of a carbazolyl-BODIPY derivative and its respective characterization by 1H NMR spectroscopy and mass spectrometry. Furthermore, a preliminary study of the chemosensory capacity of this BODIPY derivative was carried out in acetonitrile solution in the presence of several anions and a highly selective fluorimetric response was obtained for F-

A meso-triphenylamine-BODIPY derivative for the optical chemosensing of metal ions

The design and synthesis of organic molecules for recognition of biologically/environmentally important metal ions has emerged as a highly regarded research field. The BODIPY (4,4-difluoro-4-bora-3a,4a-diaza-s-indacene) core is a versatile signaling molecule that can be fine-tuned with functional groups to create selective binding sites to improve its optical proper-ties. As an extension of the work developed in our research group, we report the synthesis and characterization of a BODIPY functionalized with triphenylamino and a formyl group at the meso and 2-position, respectively, for the highly selective detection of Cu2+ and Fe3+. The preliminary study of the BODIPY derivative as optical chemosensor was carried out in acetonitrile solution in the presence of different cations, and interactions with Cu2+ and Fe3+ induced a perceptible color change. UV-visible titrations showed changes in the absorption spectra upon the addition of three equivalents of each cation, with the appearance of a new absorption band at 693 nm.This research was funded by Foundation for Science and Technology (FCT) for financial support to CQ/UM (UID/QUI/00686/2020) and project PTDC/QUI-COL/28052/2017. Thanks are also due to Fundação para a Ciência e Tecnologia (Portugal) for financial support to the Portuguese NMR network (PTNMR, Bruker Avance III 400-Univ. Minho)

Synthesis and characterization of a meso-anthracene-BODIPY derivative for colorimetric recognition of Cu2+ and Fe3+

: Ions exist widely in biological and environmental media, and the scarcity or excess of these species can have adverse consequences. BODIPY dyes appear as heterocyclic organic compounds capable of recognizing metal ions in solution and in cells, through optical signals (colorimetric and/or fluorimetric), and their photophysical properties can be adjusted through the func-tionalization of the BODIPY core. In continuation of the work developed recently, our research group reports the synthesis of a meso-anthracene-BODIPY derivative and the respective charac-terization by 1H and 13C nuclear magnetic resonance (NMR) and UV-Vis absorption spectrosco-pies. The preliminary study of the chemosensory capacity of the BODIPY derivative was also car-ried out in the presence of several cations in acetonitrile solution, which shows a selective colori-metric response for Cu2+ and Fe3+.This research was funded by the Foundation for Science and Technology (FCT) for financial support to CQ/UM (UIDB/QUI/00686/2020) and project PTDC/QUI-COL/28052/2017. Thanks are also due to Fundação para a Ciencia e Tecnologia (Portugal) for financial support to the Portuguese NMR Network (PTNMR, Bruker Avance III 400-Univ. Minho)

Hybrid structures made of polyurethane/graphene nanocomposite foams embedded within aluminum opencell foam

This paper focuses on the development of hybrid structures containing two different classes of porous materials, nanocomposite foams made of polyurethane combined with graphene-based materials, and aluminum open-cell foams (Al-OC). Prior to the hybrid structures preparation, the nanocomposite foam formulation was optimized. The optimization consisted of studying the effect of the addition of graphene oxide (GO) and graphene nanoplatelets (GNPs) at different loadings (1.0, 2.5 and 5.0 wt%) during the polyurethane foam (PUF) formation, and their effect on the final nanocomposite properties. Globally, the results showed enhanced mechanical, acoustic and fire-retardant properties of the PUF nanocomposites when compared with pristine PUF. In a later step, the hybrid structure was prepared by embedding the Al-OC foam with the optimized nanocomposite formulation (prepared with 2.5 wt% of GNPs (PUF/GNPs2.5)). The process of filling the pores of the Al-OC was successfully achieved, with the resulting hybrid structure retaining low thermal conductivity values, around 0.038 W∙m−1∙K−1, and presenting an improved sound absorption coefficient, especially for mid to high frequencies, with respect to the individual foams. Furthermore, the new hybrid structure also displayed better mechanical properties (the stress corresponding to 10% of deformation was improved in more than 10 and 1.3 times comparatively to PUF/GNPs2.5 and Al-OC, respectively).publishe

Multimodal emotion evaluation: a physiological model for cost-effective emotion classification

Emotional responses are associated with distinct body alterations and are crucial to foster adaptive responses, well-being, and survival. Emotion identification may improve peoples' emotion regulation strategies and interaction with multiple life contexts. Several studies have investigated emotion classification systems, but most of them are based on the analysis of only one, a few, or isolated physiological signals. Understanding how informative the individual signals are and how their combination works would allow to develop more cost-effective, informative, and objective systems for emotion detection, processing, and interpretation. In the present work, electrocardiogram, electromyogram, and electrodermal activity were processed in order to find a physiological model of emotions. Both a unimodal and a multimodal approach were used to analyze what signal, or combination of signals, may better describe an emotional response, using a sample of 55 healthy subjects. The method was divided in: (1) signal preprocessing; (2) feature extraction; (3) classification using random forest and neural networks. Results suggest that the electrocardiogram (ECG) signal is the most effective for emotion classification. Yet, the combination of all signals provides the best emotion identification performance, with all signals providing crucial information for the system. This physiological model of emotions has important research and clinical implications, by providing valuable information about the value and weight of physiological signals for emotional classification, which can critically drive effective evaluation, monitoring and intervention, regarding emotional processing and regulation, considering multiple contexts.publishe