14 research outputs found

    New properties of a bioinspired pyridine benzimidazole compound as a novel differential staining agent for endoplasmic reticulum and Golgi apparatus in fluorescence live cell imaging

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    IndexaciĂłn: Scopus.In this study, we explored new properties of the bioinspired pyridine benzimidazole compound B2 (2,4-di-tert-butyl-6-(3H-imidazo[4,5-c]pyridine-2-yl)phenol) regarding its potential use as a differential biomarker. For that, we performed 1D 1HNMR (TOCSY), UV-Vis absorption spectra in different organic solvents, voltammetry profile (including a scan-rate study), and TD-DFT calculations that including NBO analyses, to provide valuable information about B2 structure and luminescence. In our study, we found that the B2 structure is highly stable, where the presence of an intramolecular hydrogen bond (IHB) seems to have a crucial role in the stability of luminescence, and its emission can be assigned as fluorescence. In fact, we found that the relatively large Stokes Shift observed for B2 (around 175 nm) may be attributed to the stability of the B2 geometry and the strength of its IHB. On the other hand, we determined that B2 is biocompatible by cytotoxicity experiments in HeLa cells, an epithelial cell line. Furthermore, in cellular assays we found that B2 could be internalized by passive diffusion in absence of artificial permeabilization at short incubation times (15 min to 30 min). Fluorescence microscopy studies confirmed that B2 accumulates in the endoplasmic reticulum (ER) and Golgi apparatus, two organelles involved in the secretory pathway. Finally, we determined that B2 exhibited no noticeable blinking or bleaching after 1 h of continuous exposure. Thus, B2 provides a biocompatible, rapid, simple, and efficient way to fluorescently label particular organelles, producing similar results to that obtained with other well-established but more complex methods. © 2018 Llancalahuen, Fuentes, Carreño, ZĂșñiga, PĂĄez-HernĂĄndez, GacitĂșa, Polanco, Preite, Arratia-PĂ©rez and Otero.https://www.frontiersin.org/articles/10.3389/fchem.2018.00345/ful

    Two New Fluorinated Phenol Derivatives Pyridine Schiff Bases: Synthesis, Spectral, Theoretical Characterization, Inclusion in Epichlorohydrin-ÎČ-Cyclodextrin Polymer, and Antifungal Effect

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    It has been reported that the structure of the Schiff bases is fundamental for their function in biomedical applications. Pyridine Schiff bases are characterized by the presence of a pyridine and a phenolic ring, connected by an azomethine group. In this case, the nitrogen present in the pyridine is responsible for antifungal effects, where the phenolic ring may be also participating in this bioactivity. In this study, we synthesized two new pyridine Schiff Bases: (E)-2-[(3-Amino-pyridin-4-ylimino)-methyl]-4,6-difluoro-phenol (F1) and (E)- 2-[(3-Amino-pyridin-4-ylimino)-methyl]-6-fluoro-phenol (F2), which only differ in the fluorine substitutions in the phenolic ring. We fully characterized both F1 and F2 by FTIR, UV-vis, 1H; 13C; 19F-NMR, DEPT, HHCOSY, TOCSY, and cyclic voltammetry, as well as by computational studies (DFT), and NBO analysis. In addition, we assessed the antifungal activity of both F1 (two fluorine substitution at positions 4 and 6 in the phenolic ring) and F2 (one fluorine substitution at position 6 in the phenolic ring) against yeasts. We found that only F1 exerted a clear antifungal activity, showing that, for these kind of Schiff bases, the phenolic ring substitutions can modulate biological properties. In addition, we included F1 and F2 into in epichlorohydrin-ÎČ-cyclodextrin polymer (ÎČCD), where the Schiff bases remained inside the ÎČCD as determined by the ki, TGA, DSC, and SBET. We found that the inclusion in ÎČCD improved the solubility in aqueous media and the antifungal activity of both F1 and F2, revealing antimicrobial effects normally hidden by the presence of common solvents (e.g., DMSO) with some cellular inhibitory activity. The study of structural prerequisites for antimicrobial activity, and the inclusion in polymers to improve solubility, is important for the design of new drugs

    Una herencia en Manaos (anotaciones sobre historia ambiental, ecologĂ­a polĂ­tica y agroecologĂ­a en una perspectiva latinoamericana)

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    Este artĂ­culo pretende explorar algunas vinculaciones de la agroecologĂ­a con la historia ambiental, en sus escalas macro y micro, y con la ecologĂ­a polĂ­tica. Una clave de interpretaciĂłn es un interrogante sobre la identidad latinoamericana, que es percibida como articulaciĂłn y sedimentaciĂłn de varias herencias diferentes,en la cultura, la tecnologĂ­a, los paisajes y la naturaleza

    OLIGOMER CHAIN LENGTH EFFECT ON THE NUCLEATION AND GROWTH MECHANISMS (NGM) OF POLYTHIOPHENE

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    Charge Storage and Solar Rechargeable Battery Devices Based on Electrodes Electrochemically Modified with Conducting Polymer Nanowires

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    In this work, the use of nanostructured conducting polymer deposits on energy-storing devices is described. The cathode and the anode are electrochemically modified with nanowires of polypyrrole and poly(3,4-ethylenedioxythiophene), respectively, prepared after the use of a mesoporous silica template. The effect of aqueous or ionic liquid medium is assayed during battery characterization studies. The nanostructured device greatly surpasses the performance of the bulk configuration in terms of specific capacity, energy, and power. Moreover, compared with devices found in the literature with similar designs, the nanostructured device prepared here shows better battery characteristics, including cyclability. Finally, considering the semi-conducting properties of the components, the device was adapted to the design of a solar-rechargeable device by the inclusion of a titanium oxide layer and cis-bis(isothiocyanate)-bis(2,2′-bipyridyl-4,4′-dicarboxylate) ruthenium (II) dye. The device proved that the nanostructured design is also appropriate for the implementation of solar-rechargeable battery, although its performance still requires further optimization

    Variable surface charge of humic acid-ferrihydrite composite: Influence of electrolytes on ciprofloxacin adsorption.

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    Antimicrobial compounds are found in a range of environments as pollutants. Here, we evaluated the influence of two common anions, NO3- and PO43-, on ciprofloxacin adsorption on humic acid/ferrihydrite composite (HADIG/Fh), synthetic ferrihydrite (Fh), and humic acid (HA-DIG) under controlled pH (7.0), ionic strength (0.1 M) and temperature (25 degrees C). All materials were characterized by isoelectric point (IEP), while the composite and the iron oxide were characterized by Miissbauer spectroscopy. Kinetic and isotherm adsorption studies were carried out using cyclic voltammetry (in KH2PO4) and square wave voltammetry (in KNO3). The application of kinetic models for both anions revealed Fh to fit to a pseudo second order model (R-2 = 0.941); while HA-DIG (R-2 = 0.950) and HA-DIG/Fh (R-2 = 0.993) were fitted to pseudo first order models. The adsorption results showed a high dependency electrolyte, especially in Fh, where different shape curves (H-type in KNO3 and Ctype in KH2PO4) and maximum experimental adsorbed amount C m were observed. This finding is supported by the distinct IEP values and change in sign of surface charge between the two ions. Finally, results suggest that HA-DIG could be potentially used in environmental remediation to remove antibiotics from natural matrices, though the risk of antibiotic transportation increased with depth in the soil profile.Comision Nacional de Investigacion Cientifica y Tecnologica (CONICYT) CONICYT FONDECYT 1130094 Puente 2018 P1811 Dicyt-USACH 021742PA Proyecto Fondo Fortalecimiento USA1799 Basal Funding for Scientific and Technological Centers of Excellence FB0807 CEDENNA CONICYT PIA/ANILLO ACM 17000

    Nanostructured TiO2 and PEDOT Electrodes with Photovoltaic Application

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    In this work, nanostructured TiO2 and poly-3,4-ethylenedioxythiophene (PEDOT) layers were electrochemically prepared over transparent electrodes. Morphological characterization evidenced the presence of nanostructures as planed with 50-nm-wide TiO2 rod formations followed by 30-nm-wide PEDOT wires. Different characterizations were made to the deposits, establishing their composition and optic properties of the deposits. Finally, photovoltaic cells were prepared using this modified electrode, proving that the presence of PEDOT nanowires in the cell achieves almost double the efficiency of its bulk analogue

    Synthesis, characterization and computational studies of (E)-2-{[(2-aminopyridin-3-yl)imino]-methyl}-4,6-di-tert-butylphenol

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    (E)-2-{[(2-Aminopyridin-3-yl)imino]-methyl}-4,6-di-tert-butyl-phenol ( 3: ), a ligand containing an intramolecular hydrogen bond, was prepared according to a previous literature report, with modifications, and was characterized by UV-vis, FTIR, ÂčH-NMR, 13C-NMR, HHCOSY, TOCSY and cyclic voltammetry. Computational analyses at the level of DFT and TD-DFT were performed to study its electronic and molecular structures. The results of these analyses elucidated the behaviors of the UV-vis and electrochemical data. Analysis of the transitions in the computed spectrum showed that the most important band is primarily composed of a HOMO→LUMO transition, designated as an intraligand (IL) charge transfer

    Sobreviviendo a la educaciĂłn on line : manual para utilizar recursos de Internet en el aula

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    Manual dirigido al profesorado de EducaciĂłn Infantil y Primaria para la utilizaciĂłn de recursos educativos a travĂ©s de Internet. Aporta claves acerca de problemas como el paradigma en la educaciĂłn no presencial o semi-presencial, los modelos de trabajo en este tipo de entornos de enseñanza-aprendizaje, las habilidades que los docentes deben potenciar, las herramientas que existen y existirĂĄn al margen de los cambios tecnolĂłgicos y algunas estrategias para desarrollar actividades en entornos virtuales. Pretende conducir al lector por temas que van desde los planteamientos generales acerca del uso de las tecnologĂ­as en el aula, a ideas concretas de actividades aplicables a los diversos cursos de la enseñanza.Castilla y LeĂłnBiblioteca de EducaciĂłn del Ministerio de EducaciĂłn, Cultura y Deporte; Calle San AgustĂ­n 5 -3 Planta; 28014 Madrid; Tel. +34917748000; [email protected]
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