Determinación de carbamatos en zumo mediante electroforesis capilar empleando líquidos iónicos

Leído en julio de 2013El objetivo principal de este trabajo es el desarrollo de un nuevo método de análisis sensible y selectivo para un grupo de plaguicidas pertenecientes a la familia de los carbamatos (CRBs). Al ser la mayoría de los CRBs neutros hasta valores de pH bastante elevados, ha sido necesario recurrir al empleo de la cromatografía electrocinética micelar (MEKC), basada en la formación de micelas en el tampón electroforético para conseguir la separación de este tipo de compuestos no cargados. Para ello se ha introducido un líquido iónico, (1-Dodecil-3-metilimidazoliumtetrafluoroborato), como medio organizado alternativo a los más comúnmente empleados en electroforesis capilar como son los surfactantes dodecil sulfato sódico (SDS) y bromuro cetiltrimetil amonio (CTAB). Para el tratamiento de muestra se hace uso de la microextracción líquido-líquido dispersiva (DLLME), la cual presenta la ventaja de ser eficaz, rápida y sencilla, además de reducir el consumo de disolventes orgánicos y de residuos. El procedimiento propuesto será caracterizado y validado para una matriz alimentaria, concretamente zumos de frutas.Universidad de Granada. Departamento de Química Analítica. Máster Universitario en Biotecnología, curso 2012-2013Grupo de Investigación: Calidad en química analítica alimentaria, ambiental y clínica (FQM - 302

La presencia de la Historia de la Química en los manuales de 4º de E.S.O.

La enseñanza renovada de las ciencias contempla con especial interés temáticas que tradicionalmente han sido consideradas como pertenecientes al entorno de la ciencia. Entre ellas la Historia de la Ciencia ha adquirido un lugar preferente. En este trabajo se han analizado las exposiciones que hacen los libros de texto actuales de Física y Química de 4º ESO acerca de la Historia de la Química. Para ello se han seleccionado un total de 8 manuales, que han arrojado unos resultados que hemos analizado y discutido. Se ha estudiado en ellos la importancia concedida a la Historia, así como los tipos de presentación y sus finalidades didácticas. Se advierte un moderado empleo de la Historia. Lo habitual es que haya unas 8-10 referencias por manual. Sin embargo, en el R.D. de Enseñanzas Mínimas no aparece ninguna alusión a esta temática. Hay tópicos y personajes objeto de una especial atención, como átomo, tabla periódica, y Mendeleiev. Aparecen sobre todo en forma de reconstrucción histórica, normalmente en el texto principal, aunque también lo hacen ubicados en la introducción a un tema o en forma de recuadro.Contemporary science teaching now envisages with special interest contents that were previously regarded as more peripheral. Of these contents, the History of Science now holds a privileged position. This research analyzed a set of eight secondary school Physics and Chemistry textbooks at the tenth-grade level with a special focus on the sections explaining the History of Science. The results obtained highlight the importance given to history as well as the types of presentation and their didactic objectives. It was found that there was a moderate use of history in these textbooks with an average of 8-10 references per textbook. Nevertheless, the R. D. de Enseñanzas Mínimas does not include any mention of the History of Science. In the textbooks analyzed, the topics of particular interest were the atom, the periodic table, and Mendeleyev. They generally appear in the form a historical reconstruction in the main text though in some of the textbooks, this information is located in the introduction to one of the chapters or in a text box.Universidad de Granada. Departamento de Didáctica de las Ciencias Experimentales. Máster Universitario de Profesorado de Educación Secundaria, Formación Profesional, Bachillerato e Idiomas, especialidad de Física-Química. Curso 2013-201

Does Backgrounds Color Influence the Appearance of Gingiva-Colored Resin-Based Composites?

This research was funded by the Spanish Ministry of Science, Innovation and Universities, grant number PGC2018-101904-A-100, the Government of Andalusia, grant number P20-00200, the University of Granada, grant number A.TEP.280.UGR18, and the APC was funded by the grant number PGC2018-101904-A-100.Dental materials are mainly tested in vitro, so laboratory conditions must reproduce the oral environment to ensure the validity of their results. This study aimed to evaluate the influence of backgrounds on the color of gingiva-colored resin-based composites (GCRBC). Three discs of each of 20 shades of GCRBCs and each thickness (1 and 2 mm) were prepared. Diffuse reflectance was measured on-air and over three natural teeth (0M3/B1, 3M3/B3, and 5M3/B4 shades of Vita 3D Master/Vita Classical guides, respectively) using a calibrated spectroradiometer, CIE D65 illuminant and the CIE 45 degrees/0 degrees geometry. CIEDE2000 color difference formula and its 50:50% perceptibility and acceptability thresholds have been used to calculate and interpret the results. It can be stated that the background influences the color of all GCRBCs tested, although the effect is more pronounced for 1 mm thick samples. L*, a* and b* coordinates values of GCRBCs on air were significantly different from those obtained on natural teeth backgrounds, and the total color differences were greater than the acceptability thresholds. Since GCRBCs are placed on a dental substrate in clinical conditions, it is not advisable to perform color measurements of GCRBCs on-air because of the high color differences found. This recommendation is especially relevant for thin specimens.Spanish Government PGC2018-101904-A-100Government of Andalusia P20-00200University of Granada A.TEP.280.UGR1

Color stability and degree of conversion of gingiva-colored resin-based composites

Objectives: To evaluate gingiva-colored resin-based composites' (GCRBC) color stability and degree of conversion (DC%). Methods: Eight discs (8 1 mm) of 20 shades of GCRBC were prepared. Color coordinates were measured against a gray background with a calibrated spectroradiometer, CIE D65 illuminant and the CIE 45 /0 geometry at baseline and after 30 days of storage in distilled water, coffee, and red wine. Color differences (ΔE00) between final and baseline conditions were calculated. An ATR-FTIR spectrometer with a diamond tip was used to calculate DC%. The results were analyzed statistically using ANOVA and Tukey post-hoc test. The level of significance was p < 0.05. Results: DC% and color stability correlated with each other and with the GCRBC brand. DC% ranged between 43% and 96%, highest values correspond to flowable composites. All composites have experienced color changes after immersion in water, wine and coffee. However, the magnitude of the color change has varied widely depending on the immersion medium and the GCRBC. Color changes generated by the wine were, globally, greater than those induced by coffee (p < 0.001) and above the acceptability thresholds. Conclusions: The DC% of GCRBCs is sufficient to achieve adequate biocompatibility and physicomechanical properties, but the high susceptibility to staining could compromise aesthetic long-term results. Clinical Significance: The degree of conversion and the color stability of gingivacolored resin-based composites correlated with each other. All composites have experienced color changes after immersion in water, wine and coffee. Color changes generated by wine were, globally, greater than those induced by coffee and above the acceptability thresholds that could compromise aesthetic long-term results.Junta de Andalucía, Grant/Award Number: P20-00200; Universidad de GranadaGrant/Award Number: CBU

Optical behavior of 3D-printed dental restorative resins: Influence of thickness and printing angle

The authors also acknowledge Detax GmbH, Formlabs Inc. and GC Corporation for providing the polymer-based 3D printing restorative resins used in this study.Objectives To evaluate the influence of thickness and printing angle on the optical properties of 3D-printed dental restorative resins. Methods Four 3D printing resin systems were evaluated: DFT-Detax Freeprint Temp; FP- Formlabs Permanent Crown; FP- Formlabs Temporary CB; and GCT- GC Temporary-. Samples from each material were printed at 0° and 90°, and polished up to 0.5, 1.0, 1.5 and 2.0 mm thickness. Scattering (S), absorption (K) and albedo (a) coefficients, transmittance (T%), light reflectivity (RI) and infinite optical thickness ( ) were calculated using Kubelka-Munk’s model. Data were statistically analyzed using Kruskal–Wallis¸ Mann-Whitney tests, and VAF coefficient. Results The spectral distribution on S, K, T%, RI, were wavelength dependent. Although the spectral behaviors were similar for all the specimens evaluated, the values of S, K, T% and presented significant differences between specimen thicknesses for all the materials used and for both printing orientations. Values for S and K increased, and T% and decreased. Significant differences between 0° and 90° were found for RI values at 0.5 and 1.0 mm thick samples, for S and K at 2.0 mm, for at 0.5 and 1.0 mm for DFT, and at 0.5 mm for FT. Conclusions Optical properties of 3D-printed restorative resins vary between thicknesses, and could be affected by the building orientation. Therefore, these factors should be considered in order to improve the biomimetic potential of 3D-printed dental restorative resins. Clinical significance Understanding the optical behavior of the 3D-printed restorative resins is essential to optimize their clinical performance.FEDER/ Government of Andalusia P20-00200support from the FEDER/ Government of Andalusia P20-00200 and State of Rio Grande do Sul, FAPERGS (grant #19/2551-0001721-9)Funding for open access charge: Universidad de Granada / CBU

The influence of printing angle on color and translucency of 3D printed resins for dental restorations

Objectives: To evaluate the influence of printing orientation on color and translucency of 3D printing restorative resins. Methods: Four 3D printing resin systems in the available shades (DFT-Detax Freeprint Temp- A1, A2,A3; FPFormlabs Permanent Crown- A2,A3,B1,C2; FT- Formlabs Temporary CB- A2,A3,B1,C2; GCT-GC TemporaryLight, Medium) were evaluated. Three samples (10x10x1.2 mm) from each material were printed at two different printing orientations (0 degrees and 90 degrees) and polished to 1.00 +/- 0,01 mm of thickness. Spectral reflectance was measured against black background using a calibrated spectroradiometer, CIE D65 standard illuminant and the 45 degrees/0 degrees geometry. Color and translucency differences were evaluated using CIEDE2000 metric (AE00) and 50:50% perceptibility (PT00 and TPT00) and acceptability (AT00 and TAT00) thresholds. Results: In general, color changes due to printing orientation at (0 degrees and 90 degrees) were mainly produced by AL* or AC* . AE00 were above PT00 for all DFT shades, FP-B1, FP-C2, FT-A2 and FT-B1. Only for DFT-1, AE00 was above AT00. ARTP00 values were above TPT00 for DFT-A1, DFT-A3, FP-B1 and FT-B1, but lower than TAT00. The direction of the changes in translucency (ARTP00) depends on the material and shade. Significance: The selection of building orientation (0 degrees and 90 degrees) for the 3D printed resins influence the visual color and translucency and therefore their esthetic appearance. These aspects should be considered when printing dental restorations using the evaluated materials.FEDER/Government of Andalusia P20-00200Spanish Government PGC2018-101904-A-100State of Rio Grande do Sul, FAPERGS 19/2551-0001721-9Universidad de Granada/CBU

Relevant optical properties for gingiva-colored resin-based composites

The authors acknowledge funding support from the Spanish Ministry of Science, Innovation and Universities (PGC2018-101904-A-100) and from the i+D+I Government of Andalusia 2020, Spain (P20-00200).Objectives: To evaluate the optical properties of gingiva-colored resin-based composites (GCRBCs). Methods: Five discs (8 mm diameter x 1mm height) of 17 shades of GCRBCs were prepared. Diffuse reflectance was measured against white and black backgrounds using a calibrated spectroradiometer, CIE D65 illuminant and the CIE 45⁰/0⁰ geometry. Relative translucency parameter was calculated using ΔE00 (RTP00). Translucency differences were evaluated using published data of 50:50% translucency perceptibility (TPT00) and acceptability (TAT00) thresholds. Scattering (S) and absorption (K) coefficients and transmittance (T%) were calculated using Kubelka–Munk’s equations. Data were statistically analyzed using Kruskal–Wallis, Mann–Whitney tests, and VAF coefficient. Results: The RTP00 values of the 17 evaluated shades ranged from 8.69 to 21.34. There were perceptible translucency differences (TPT00=0.62) between different shades of the same brand and between composites designated with the same shade of different brands. Spectral distributions of S, K and T were wavelength- dependent. Although the spectral behavior of the S and K coefficients and T% were similar for all the gingival composites evaluated, the values of these parameters presented statistically significant differences between shades, which would justify the differences found in the relative translucency parameter. Conclusions: The optical properties S, K and T% of GCRBCs were significantly different, resulting in perceptible translucency differences between the same shade of different commercial brands and between different shades of the same brand. Clinical significance: Translucency differences of gingiva-colored composites may significantly influence their masking ability affecting the clinician’s choice of restorative material.Spanish Ministry of Science, Innovation and Universities (PGC2018-101904-A-100)i+D+I Government of Andalusia 2020, Spain (P20-00200

The Chemogenetic Receptor Ligand Clozapine N-Oxide Induces<em> in vivo</em> Neuroreceptor Occupancy and Reduces Striatal Glutamate Levels

Chemogenetic studies with the ligand clozapine N-oxide (CNO) are predicated upon the assumption that CNO is devoid of actions at natural neuroreceptors. However, recent evidence shows that CNO may be converted back to clozapine (CLZ) in vivo, which could yield plasma concentrations that may be sufficient to occupy inter alia dopamine D2=3 and serotonin 5HT2A receptors in living brain. To test this phenomenon, we measured striatal dopamine D2=3 receptor occupancy with [18F]fallypride PET and serotonin 5HT2A occupancy ex vivo using [18F]MH.MZ. We found a CNO dosedependent effect on the availability of both neuroreceptor sites. In parallel MR spectroscopy experiments, we found that CNO reduced creatine C phosphcreatine (CrCPCr) and increased N-acetylaspartate C N-acetylaspartylglutamate (NAACNAAG) signals in the prefrontal cortex, and also reduced the glutamate signal in dorsal striatum, with peak effect at 2 mg/kg. Thus, our findings suggest that conversion of CNO to CLZ in living rats imparts significant occupancy at endogenous neuroreceptors and significant changes to neurometabolite levels

The clinical heterogeneity of coenzyme Q10 deficiency results from genotypic differences in the Coq9 gene

Primary coenzyme Q10 (CoQ10) deficiency is due to mutations in genes involved in CoQ biosynthesis. The disease has been associated with five major phenotypes, but a genotype–phenotype correlation is unclear. Here, we compare two mouse models with a genetic modification in Coq9 gene (Coq9Q95X and Coq9R239X), and their responses to 2,4‐dihydroxybenzoic acid (2,4‐diHB). Coq9R239X mice manifest severe widespread CoQ deficiency associated with fatal encephalomyopathy and respond to 2,4‐diHB increasing CoQ levels. In contrast, Coq9Q95X mice exhibit mild CoQ deficiency manifesting with reduction in CI+III activity and mitochondrial respiration in skeletal muscle, and late‐onset mild mitochondrial myopathy, which does not respond to 2,4‐diHB. We show that these differences are due to the levels of COQ biosynthetic proteins, suggesting that the presence of a truncated version of COQ9 protein in Coq9R239X mice destabilizes the CoQ multiprotein complex. Our study points out the importance of the multiprotein complex for CoQ biosynthesis in mammals, which may provide new insights to understand the genotype–phenotype heterogeneity associated with human CoQ deficiency and may have a potential impact on the treatment of this mitochondrial disorder.This work was supported by grants from the Marie Curie International Reintegration Grant Programme (COQMITMEL-266691 to LCL) within the Seventh European Community Framework Programme, from Ministerio de Economía y Competitividad, Spain (SAF2009-08315 and SAF2013-47761-R to LCL), from the Consejería de Economía, Innovación, Ciencia y Empleo, Junta de Andalucía (P10-CTS-6133 to LCL), and from the ‘CEIBioTic’ (20F12/1 to LCL). MLS is a predoctral fellow from the Consejería de Economía, Innovación, Ciencia y Empleo, Junta de Andalucía. LCL is supported by the ‘Ramón y Cajal’ National Programme, Ministerio de Economía y Competitividad, Spain (RYC-2011-07643). MAT is supported by a predoctoral grant from the University of Granada. EJC is supported by the Research Program of the University of Granada. CMQ is supported by NICHD Grants 5K23 HDO65871-05 and P01 HD080642-01, and by a MDA grant. The proteomic analysis was performed in the CSIC/UAB Proteomics Facility of IIBB-CSIC that belongs to ProteoRed, PRB2-ISCIII, supported by Grant PT13/0001

Validation of a Hyperspectral Imaging System for Color Measurement of In-Vivo Dental Structures

A full comprehension of colorimetric relationships within and between teeth is key for aesthetic success of a dental restoration. In this sense, hyperspectral imaging can provide point-wise reliable measurements of the tooth surface, which can serve for this purpose. The aim of this study was to use a hyperspectral imaging system for the colorimetric characterization of 4 in-vivo maxillary anterior teeth and to cross-check the results with similar studies carried out with other measuring systems in order to validate the proposed capturing protocol. Hyperspectral reflectance images (Specim IQ), of the upper central (UCI) and lateral incisors (ULI), were captured on 30 participants. CIE-L*a*b* values were calculated for the incisal (I), middle (M) and cervical (C) third of each target tooth. Delta E-ab* and Delta E-00 total color differences were computed between different tooth areas and adjacent teeth, and evaluated according to the perceptibility (PT) and acceptability (AT) thresholds for dentistry. Non-perceptible color differences were found between UCIs and ULIs. Mean color differences between UCI and ULI exceeded AT (Delta E-ab* = 7.39-7.42; Delta E-00 = 5.71-5.74) in all cases. Large chromatic variations between I, M and C areas of the same tooth were registered (Delta E-ab* = 5.01-6.07 and Delta E-00 = 4.07-5.03; Delta E-ab* = 5.80-8.16 and Delta E-00 = 4.37-5.15; and Delta E-ab* = 5.42-5.92 and Delta E-00 = 3.87-4.16 between C and M, C and I and M and I, respectively). The use of a hyperspectral camera has proven to be a reliable and effective method for color evaluation of in-vivo natural teeth.MCIN/AEI/ERDF "Una manera de hacer Europa" PGC2018-101904-A-I00 PID2021128317OB-I00Junta de Andalucia RDI P20-00200OTRI 474