The intrinsic fluorescence of FAD and its application in analytical chemistry: a review

This review (with 106 references) mainly deals with the analytical applications of flavin-adenine dinucleotide (FAD) fluorescence. In the first section, the spectroscopic properties of this compound are reviewed at the light of his different acid-base, oxidation and structural forms; the chemical and spectroscopic properties of flavin mononucleotide (FMN) and other flavins will be also briefly discussed. The second section discusses how the properties of FAD fluorescence changes in flavoenzymes (FvEs), again considering the different chemical and structural forms; the glucose oxidase (GOx) and the choline oxidase (ChOx) cases will be commented. Since almost certainly the most reported analytical application of FAD fluorescence is as an auto-indicator in enzymatic methods catalysed by FvE oxidoreductases, it is important to know how the concentrations of the different forms of FAD changes along the reaction and, consequently, the fluorescence and the analytical signals. An approach to do this will be presented in section 3. The fourth part of the paper compiles the analytical applications which have been reported until now based in these fluorescence properties. Finally, some suggestions about tentative future research are also given

Direct minimally invasive enzymatic determination of tyramine in cheese using digital imaging

An enzymatic method for the direct (without pretreatment) minimally invasive tyramine determination in cheese is proposed. Colorimetric test strips containing tyramine oxidase (TAO), peroxidase and 3, 3', 5, 5'-tetramethylbenzidine (Q-TAO), allow tyramine determination through the RGB chromatic coordinates of the observed blue colour (LOD = 2.6·10-6 M, LOQ = 8.7·10-6 M, RSD% (n = 5; 1.8·10-4 M) = 3.2%). The strips are inserted in the sample for 2 min and then the RGB coordinates are measured using a smartphone. Previously, these Q-TAO strips have been also optimized for tyramine determination in cheese extract. To do that, a spectrophotometric method in solution for tyramine determination in cheese extracts has been developed, which included an in-depth study of the indicating reaction; this study has allowed to gain new information about the spectroscopic properties of different TMB species and, which it is more important, to detect cross-reactions between TAO and TMB species. A mathematical model has also been developed which relate the RGB signals obtained with the tyramine concentrations, the instrumental characteristics of the smartphone and the spectroscopic properties of the absorbing product of the enzymatic reaction. © 2021 Elsevier B.V

Health aspects of physical education in the Community of Madrid (Spain)

Casi el 50% del alumnado tiene alguna enfermedad crónica. El desarrollo corporal es normal, la adaptación cardiovascular no es mala pero mejorable. La actividad física resulta insuficiente, la valoración de la condición física es inadecuada. Las instalaciones deportivas escolares en los centros públicos son claramente deficientes desde el punto de vista de la salud. Por último, en ninguno de los centros, el profesorado había recogido estos datos antes de la elaboración de esta investigación, salvo adaptaciones curriculares concretas pedidas por el alumnado. Es necesario buscar nuevas metodologías que estén ajustadas a criterios de salud y coordinadas con los servicios de saludThe results of this study, note that almost 50 % of students claim to have a chronic disease, vision problems are the most predominant. On the other hand, we can see that the physical development is suited to the average population; cardiovascular adaptation of students is not bad but should be better. In addition, school physical activity is insufficient, the assessment of the physical condition is inadequate and in public schools, school sports facilities are clearly deficient from the point of view of health. Finally, it is noted that none of the schools, the teachers had collected this data before making this research, except specific curricular adaptations requested by the student. It is necessary that teachers look for new work methods that comply with health criteria and that are coordinated with health service

Fluorescence of the Flavin group in choline oxidase. Insights and analytical applications for the determination of choline and betaine aldehyde

Choline oxidase (ChOx) is a flavoenzyme catalysing the oxidation of choline (Ch) to betaine aldehyde (BA) and glycine betaine (GB). In this paper a fundamental study of the intrinsic fluorescence properties of ChOx due to Flavin Adenine Dinucleotide (FAD) is presented and some analytical applications are studied in detail. Firstly, an unusual alteration in the excitation spectra, in comparison with the absorption spectra, has been observed as a function of the pH. This is ascribed to a change of polarity in the excited state. Secondly, the evolution of the fluorescence spectra during the reaction seems to indicate that the reaction takes place in two consecutive, but partially overlapped, steps and each of them follows a different mechanism. Thirdly, the chemical system can be used to determine the Ch concentration in the range from 5×10-6 M to 5×10-5 M (univariate and multivariate calibration) in the presence of BA as interference, and the joint Ch+BA concentration in the range 5×10-6-5×10-4 M (multivariate calibration) with mean errors under 10%//a semiquantitative determination of the BA concentration can be deduced by difference. Finally, Ch has been successfully determined in an infant milk sample

Smartphone-interrogated test supports for the enzymatic determination of putrescine and cadaverine in food

Diamino-oxidase (DAO), horseradish peroxidase (HRP), and tetramethylbenzidine (TMB) have been immobilized into cellulose to obtain circular cellulose test supports (CCTSs) for the determination of cadaverine (Cad) and putrescine (Put). During the enzymatic reaction, TMB is oxidized and a blue spot is obtained. This color (RGB coordinates) is measured with a smartphone and a commercial application. The highest sensitivity is provided by the component R and a linear response is observed for low biogenic amine (BA) concentrations, but a second-order polynomial response better fits the experimental results for a wider concentration range. This has been successfully explained with a model developed to explain the RGB values obtained in this type of analytical system. Optimization studies enable CCTSs to be obtained for Put and Cad determination, which could be used (kept at 4 °C) for at least 45 days if a stabilizer (StabilCoat™ or StabilGuard™) is added during its synthesis. In these conditions, the R coordinate follows the model up to at least 4 × 10-4 M Put and/or Cad (both analytes give the same response). The method permits the Put and Cad determination from 5 × 10-5 M up to 4 × 10-4 M (RSD = 3%, n = 3). The CCTSs have been applied to Put + Cad determination in a tuna sample without any interference by other biogenic amines. The concentration found statistically agrees with that obtained using a HPLC-MS-validated method

Caveolin-1 is required for TGF-β-induced transactivation of the EGF receptor pathway in hepatocytes through the activation of the metalloprotease TACE/ADAM17

Transforming growth factor-beta (TGF-β) plays a dual role in hepatocytes, inducing both pro- and anti-apoptotic responses, whose balance decides cell fate. Survival signals are mediated by the epidermal growth factor receptor (EGFR) pathway, which is activated by TGF-β in these cells. Caveolin-1 (Cav1) is a structural protein of caveolae linked to TGF-β receptors trafficking and signaling. Previous results have indicated that in hepatocytes, Cav1 is required for TGF-β-induced anti-apoptotic signals, but the molecular mechanism is not fully understood yet. In this work, we show that immortalized Cav1(-/-) hepatocytes were more sensitive to the pro-apoptotic effects induced by TGF-β, showing a higher activation of caspase-3, higher decrease in cell viability and prolonged increase through time of intracellular reactive oxygen species (ROS). These results were coincident with attenuation of TGF-β-induced survival signals in Cav1(-/-) hepatocytes, such as AKT and ERK1/2 phosphorylation and NFκ-B activation. Transactivation of the EGFR pathway by TGF-β was impaired in Cav1(-/-) hepatocytes, which correlated with lack of activation of TACE/ADAM17, the metalloprotease responsible for the shedding of EGFR ligands. Reconstitution of Cav1 in Cav1(-/-) hepatocytes rescued wild-type phenotype features, both in terms of EGFR transactivation and TACE/ADAM17 activation. TACE/ADAM17 was localized in detergent-resistant membrane (DRM) fractions in Cav1(+/+) cells, which was not the case in Cav1(-/-) cells. Disorganization of lipid rafts after treatment with cholesterol-binding agents caused loss of TACE/ADAM17 activation after TGF-β treatment. In conclusion, in hepatocytes, Cav1 is required for TGF-β-mediated activation of the metalloprotease TACE/ADAM17 that is responsible for shedding of EGFR ligands and activation of the EGFR pathway, which counteracts the TGF-β pro-apoptotic effects. Therefore, Cav1 contributes to the pro-tumorigenic effects of TGF-β in liver cancer cells.This work was supported by grants from: (1) the Ministry of Economy and Competitiveness (MINECO), Spain (BFU2012-35538 and ISCIII-RTICC: RD12-0036-0029 to IF; SAF2013-43713 to PM-S; BFU2012-33932 to GE; SAF2011-25047 and CSD2009-00016 to MAdP); (2) AGAUR-Generalitat de Catalunya (2009SGR-312 to IF); and (3) People Programme (Marie Curie Actions) of the European Union’s Seventh Framework Programme (FP7/2007-2013) under REA grant agreement no. PITN-GA-2012-316549 (IT LIVER) to IF JM-C and RM-V were recipients of pre-doctoral fellowships from the FPU program (Ministry of Education, Culture and Sport, Spain) and the FPI program (associated to SAF201125047, MINECO, Spain), respectively. We acknowledge the review and suggestions of Dr. Christoph Meyer (University of Heidelberg, Mannheim, Germany).S

Blood Bacterial Profiles Associated With Human Immunodeficiency Virus Infection and Immune Recovery

[EN] Human immunodeficiency virus (HIV) infection impairs mucosal immunity and leads to bacterial translocation, fueling chronic inflammation and disease progression. While this is well established, questions remain about the compositional profile of the translocated bacteria, and to what extent it is influenced by antiretroviral therapy (ART). Using 16S ribosomal DNA targeted sequencing and shotgun proteomics, we showed that HIV increases bacterial translocation from the gut to the blood. HIV increased alpha diversity in the blood, which was dominated by aerobic bacteria belonging to Micrococcaceae (Actinobacteria) and Pseudomonadaceae (Proteobacteria) families, and the number of circulating bacterial proteins was also increased. Forty-eight weeks of ART attenuated this phenomenon. We found that enrichment with Lactobacillales order, and depletion of Actinobacteria class and Moraxellaceae and Corynebacteriacae families, were significantly associated with greater immune recovery and correlated with several inflammatory markers. Our findings suggest that the molecular cross talk between the host and the translocated bacterial products could influence ART-mediated immune recovery.This work was supported by the Instituto de Salud Carlos III (Plan Estatal de I+D+i 2013–2016, projects PI15/00345 and PI18/00154); the Fundación Asociación Española Contra el Cáncer within the European Research Era-NET aligning national/regional translational cancer research programs and activities program (grant AC17/00019) and cofinanced by the European Development Regional Fund; and Plan Estatal de I+D+i 2013–2016 (grant PT17/0019 to the Proteomics Facility of the Spanish National Center for BIotechnology)

Development of novel low-mass module concepts based on MALTA monolithic pixel sensors

The MALTA CMOS monolithic silicon pixel sensors has been developed in the Tower 180 nm CMOS imaging process. It includes an asynchronous readout scheme and complies with the ATLAS inner tracker requirements for the HL-LHC. Several 4-chip MALTA modules have been built using Al wedge wire bonding to demonstrate the direct transfer of data from chip-to-chip and to read out the data of the entire module via one chip only. Novel technologies such as Anisotropic Conductive Films (ACF) and nanowires have been investigated to build a compact module. A lightweight flex with 17 {\mu}m trace spacing has been designed, allowing compact packaging with a direct attachment of the chip connection pads to the flex using these interconnection technologies. This contribution shows the current state of our work towards a flexible, low material, dense and reliable packaging and modularization of pixel detectors.Comment: 5 pages + 1 page references,8 figure

Personalized Respiratory Medicine: Exploring the Horizon, Addressing the Issues. Summary of a BRN-AJRCCM Workshop Held in Barcelona on June 12, 2014.

This Pulmonary Perspective summarizes the content and main conclusions of an international workshop on personalized respiratory medicine coorganized by the Barcelona Respiratory Network (www.brn.cat)and the AJRCCM in June 2014. It discusses (1) its definition and historical, social, legal, and ethical aspects; (2) the view from different disciplines, including basic science, epidemiology, bioinformatics,and network/systems medicine; (3) the bottlenecks and opportunities identified by some currently ongoing projects; and (4) the implications for the individual, the healthcare system and the pharmaceutical industry. The authors hope that, although it is not a systematic review on the subject,this document can be a useful reference for researchers, clinicians, healthcare managers, policy-makers,and industry parties interested in personalized respiratory medicine

Aplicación de la metodologia de aula invertida 'Team Based Learning' en cinco assignaturas en la Facultad de Química a través de un proyecto de aprendizaje reflexivo/experiencial

La metodología de Aula Inversa "Team Based Learing" (TBL) se ha aplicado en 5 asignaturas en la Facultat de Química de la Universitat de Barcelona. El proyecto se ha desarrollado en un entorno reflexivo/experiencial en el que los profesores (10 en total)han actuado como profesores y observadores. Este funcionamiento les ha permitido adquirir una experiencia que facilitará la futura aplicación de la metodología TBL, la cual ha sido valorada positivamente por docentes y estudiantes