Publicaciones 2011-2020

@article{RN395,
title = {Solution, Solid-State Two Step Synthesis and Optical Properties of Zno and Sno2 Nanoparticles and Their Nanocomposites with Sio2},
author = { C. Diaz and M.L. Valenzuela and M. Segovia and K. Correa and R. De La Campa and A.P. Soto},
url = {/brokenurl#<Go to ISI>://WOS:000425608200006},
doi = {10.1007/s10876-017-1324-8},
issn = {1040-7278},
year = {2018},
date = {2018-01-01},
journal = {Journal of Cluster Science},
volume = {29},
number = {2},
pages = {251-266},
abstract = {Nanostructure luminescent ZnO and SnO2 materials are prepared by a two-step solid-state method based on the solution preparation of the macromolecular precursors ZnCl2 center dot Chitosan and SnCl2 center dot Chitosan having different ratios (1:1, 1:5 and 1:10), their pyrolysis under air at 800 A degrees C. The pyrolytic ZnO and SnO2 nanomaterials show a dependence of the particle size, morphology and luminescent properties with the ratio [metal/polymer] in the MCl2 center dot Chitosan precursors. Thus, ZnO semiconductor materials exhibit luminescence spectra with several emission at 440 nm corresponds to a radiative transition of an electron from the shallow donor level of oxygen vacancies, and the zinc interstitial, to the valence band. On the other hand, the photoluminescence spectrum of the nanostructured SnO2 shows an intense blue luminescence at a wavelength of 420 nm which may be attributed to oxygen-related defects that have been introduced during the growth process of the nanoparticles. Additionally, whereas SnO2 was successfully incorporated into SiO2 structure (SnO2//SiO2) by pyrolysis of solid-state mixtures of the precursors SnCl2 center dot Chitosan in the presence of SiO2, the same reaction carried out with ZnCl2 center dot Chitosan precursors led to a mixture of Zn2SiO4 and SiO2. Thus, this new methodology yields nanostructured semiconductor materials, ZnO and SnO2, suitable for optoelectronic and sensor solid-state devices.},
keywords = {center chitin, chitosan, crystal-structure, dot fine-structure, kinetics, mechanisms, nanostructures, photoluminescence, sio2, size sno2 solid-state synthesis, zinc-oxide, zno},
pubstate = {published},
tppubtype = {article}
}

@article{hugo2017functional,
title = {Functional Roles of T3.37 and S5.46 in the Activation Mechanism of the Dopamine D1 Receptor},
author = { E.A. Hugo and B.K. Cassels and A. Fierro},
url = {/brokenurl#<Go to ISI>://WOS:000399406500014},
doi = {10.1007/s00894-017-3313-0},
issn = {1610-2940},
year = {2017},
date = {2017-01-01},
journal = {Journal of Molecular Modeling},
volume = {23},
number = {4},
abstract = {The activation mechanism of dopamine receptors is unknown. The amino acids S5.42, S5.43, and S5.46 located in helix 5 appear to be crucial, but their specific roles in receptor activation have not been studied. We modeled the D1 dopamine receptor using the crystal structures of the D3 dopamine and beta 2 adrenergic receptors. Molecular dynamics simulations show that the interaction of dopamine with the D1 receptor leads to the formation of a hydrogen-bond network with its catechol group and helices 3, 5, and 6, including water molecules. The para hydroxyl group of dopamine binds directly to S5.42 and N6.55, the latter also interacting with S5.43. Unexpectedly, S5.46 does not interact directly with the catechol; instead, it interacts through a water molecule with S5.42 and directly with T3.37. The formation of this hydrogen-bond network, part of which was previously observed in docking studies with dopamine agonists, triggers the opening of the E6.30-R3.60 ionic lock associated with the activation of GPCRs. These changes do not occur in the unbonded (apo) receptor or when it is in a complex with the antagonist 3-methoxy- 5,6,7,8,9,14-hexahydrodibenz[d, g]azecine. Our results provide valuable insight into the T3.37-S5.46-water-S5.43-ligand interaction, which may be crucial to the activation of the D1 dopamine receptor and should be considered during the design of novel agonists.},
keywords = {crystal-structure, d-1, d1 dopamine dopamine, dynamics, identification, interactions, models, molecular pharmacophore, receptor, recognition residues, s5.46, serine structures},
pubstate = {published},
tppubtype = {article}
}

@article{RN314,
title = {Effect of the Selenium Content in the Optical Properties of the Kesterite Cu2znsns4-Xsex Phases},
author = { F. Lopez-Vergara and A. Gald\'{a}mez and P. Barahona and V. Manriquez},
url = {/brokenurl#<Go to ISI>://WOS:000393079900028},
doi = {10.4067/S0717-97072016000400028},
issn = {0717-9707},
year = {2016},
date = {2016-01-01},
journal = {Journal of the Chilean Chemical Society},
volume = {61},
number = {4},
pages = {3291-3294},
abstract = {Polycrystalline Cu2ZnSnS4-XSeX (X=1, 2, 3) compounds were synthesized by conventional solid-state reactions. The samples were characterized by powder X-ray diffraction (XRD), energy-dispersive X-ray analysis (SEM-EDS), Raman spectroscopy, diffuse reflectance UV-vis and Photoluminescence. All of phases crystallize in the tetragonal kesterite-type structure. The powder X-ray diffraction (XRD) patterns were indexed in the space group vertical bar (4) over bar No secondary phases were detected in XRD patterns. The results from diffuse reflectance show band gap between 1.26 - 1.17 eV, when S is gradually replaced by Se. The PL spectrum of Cu2ZnSnS4- xSex phases shows nearly symmetrical band, which shifted linearly to the lower energy with increasing Se content. The selenized (CZTSSe) phases are promising candidates to be used as absorbing material in solar cells},
keywords = {crystal-structure, film photovoltaics solar-cells, solid-solutions, thin-films},
pubstate = {published},
tppubtype = {article}
}

@article{RN192,
title = {Synthesis of Coumarin Derivatives as Fluorescent Probes for Membrane and Cell Dynamics Studies},
author = { O. Garcia-Beltran and O. Yanez and J. Caballero and A. Gald\'{a}mez and N. Mena and M. Nunez and B.K. Cassels},
url = {/brokenurl#<Go to ISI>://WOS:000335487400009},
doi = {10.1016/j.ejmech.2014.02.016},
issn = {0223-5234},
year = {2014},
date = {2014-01-01},
journal = {European Journal of Medicinal Chemistry},
volume = {76},
pages = {79-86},
publisher = {2014 Elsevier Masson SAS.},
abstract = {Three coumarin-derived fluorescent probes, 3-acetyl-7-[(6-bromohexyl)oxy]-2H-chromen-2-one (FM1), 7-[(6-bromohexyl)oxy]-4-methyl-2H-chromen-2-one (FM2) and ethyl 2-7-[(6-bromohexyl)oxy]-2-oxo-2H-chromen-4-ylacetate (FM3), are described, with their photophysical constants. The compounds were tested in preliminary studies employing epifluorescence microscopy demonstrating that they allow the imaging of human neuroblastoma SH-SY5Y cell membranes. The structure of FM3 was confirmed by X-ray crystallographic analysis. Molecular dynamics (MD) simulations were used to characterize the localization and interactions of the studied compounds with a lipid bilayer model of 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine (POPC).},
keywords = {biological-membranes, carboxylic-acids, cell coumarins, crystal-structure, decarboxylation depth, dynamics, energy-transfer, hydrogen-bond, membranes, model, molecular molecular-dynamics, probes, proteins, resonance},
pubstate = {published},
tppubtype = {article}
}

@article{RN142,
title = {Theoretical Study of Complexes of the Type [Pt-3(M-L)(3)(L ')(3)]-X (L=Co,So2,Cnh; L '=Ph3,Cnh; X=Tl+, Hg-0, Mph3+ (M = Cu, Au, Ag))},
author = { F. Mendizabal and D. Donoso and R. Salazar},
url = {/brokenurl#<Go to ISI>://WOS:000331236900014},
issn = {0717-9707},
year = {2013},
date = {2013-01-01},
journal = {Journal of the Chilean Chemical Society},
volume = {58},
number = {1},
pages = {1562-1570},
abstract = {The interaction between the [Pt-3(mu-L)(3)(L')(3)] cluster (L = CO, SO2, CNH; L' = PH3, CNH) and a series of fragments X (Tl+, Hg(0), AuPH3+, CuPH3+ and AgPH3+) was studied using ab initio methodology. The calculations suggest that the complexes formed are stable. We have studied these complexes at the HF, MP2, B3LYP and PBE levels of theory. The magnitude of the interaction energies and Pt-3-MPH3+ distances indicate a substantial covalent character of the bond. On the other hand, in [Pt-3(mu-L)(3)(L')(3)]-X (Tl+ and Hg) the energy magnitudes are in the order of metallophilic interaction, which indicates that the dispersion and ionic terms are found as the main contribution to stability. These results have been confirmed by orbital diagrams. In addition, the Fukui index of electrophilic attack and electrophilicity index on the [Pt-3(mu-L)(3)(L')(3)] clusters were used to explore possible sites that may play a role in chemical reactivity.},
keywords = {approximation, chemical-reactivity, chemistry cluster clusters, complexes, crystal-structure, electronegativity, electrophilicity index, interactions, metallic platinum pseudopotentials, reactivity, units},
pubstate = {published},
tppubtype = {article}
}

@article{RN19h,
title = {Esr, Electrochemical, Molecular Modeling and Biological Evaluation of 4-Substituted and 1,4-Disubstituted 7-Nitroquinoxalin-2-Ones as Potential Anti-Trypanosoma Cruzi Agents},
author = { B. Aguilera-Venegas and C. Olea-Azar and E. Norambuena and V.J. Aran and F. Mendizabal and M. Lapier and J.D. Maya and U. Kemmerling and R. Lopez-Munoz},
url = {/brokenurl#<Go to ISI>://WOS:000288046600012},
doi = {10.1016/j.saa.2010.12.017},
issn = {1386-1425},
year = {2011},
date = {2011-01-01},
journal = {Spectrochimica Acta Part a-Molecular and Biomolecular Spectroscopy},
volume = {78},
number = {3},
pages = {1004-1012},
publisher = {2010 Elsevier B.V.},
abstract = {Electrochemical and ESR studies were carried out in this work with the aim of characterizing the reduction mechanisms of 4-substituted and 1,4-disubstituted 7-nitroquinoxalin-2-ones by means of cyclic voltammetry in DMSO as aprotic solvent. Two reduction mechanisms were found for these compounds: the first, for compounds bearing a labile hydrogen by following a self-protonation mechanism (ECE steps), and the second, for compounds without labile hydrogen, based on a purely electrochemical reduction mechanism (typical of nitroheterocycles). The electrochemical results were corroborated using ESR spectroscopy allowing us to propose the hyperfine splitting pattern of the nitro-radical, which was later corroborated by the ESR simulation spectra. All these compounds were assayed as growth inhibitors against Trypanosoma cruzi: first, on the non-proliferative (and infective) form of the parasite (trypomastigote stage), and then, the ones that displayed activity, were assayed on the non-infective form (epimastigote stage). Thus, we found four new compounds highly active against T. cruzi. Finally, molecular modeling studies suggest the inhibition of the trypanothione reductase like one of the possible mechanisms involved in the trypanocidal action.},
keywords = {anion, behavior binding-site, chagas chagas-disease, complexes, crystal-structure, disease, epimastigote, esr, glutathione-reductase, modeling, molecular nifurtimox, nitro nitroquinoxaline, radical-anion, reductase, superoxide trypanothione trypomastigote},
pubstate = {published},
tppubtype = {article}
}