Publicaciones 2011-2020

@article{RN346,
title = {Neuroprotective Effect of a New 7,8-Dihydroxycoumarin-Based Fe2+/Cu2+ Chelator in Cell and Animal Models of Parkinson's Disease},
author = { P. Aguirre and O. Garcia-Beltran and V. Tapia and Y. Munoz and B.K. Cassels and M. Nunez},
url = {/brokenurl#<Go to ISI>://WOS:000392459400021},
doi = {10.1021/acschemneuro.6b00309},
issn = {1948-7193},
year = {2017},
date = {2017-01-01},
journal = {Acs Chemical Neuroscience},
volume = {8},
number = {1},
pages = {178-185},
abstract = {Disturbed iron homeostasis, often coupled to mitochondrial dysfunction, plays an important role in the progression of common neurodegenerative diseases such as Parkinson's disease (PD). Recent studies have underlined the relevance of iron chelation therapy for the treatment of these diseases. Here we describe the synthesis, chemical, and biological characterization of the multifunctional chelator 7,8-dihydroxy-4-((methylamino)methyl)-2H-chromen-2-one (DHC12). Metal selectivity of DHC12 was Cu2+ similar to Fe2+ > Zn2+ > Fe3+. No binding capacity was detected for Hg2+, co(2+), ca(2+), Mnz+, Mg2+, Ni2+, Pb2+ or Cd2+. DHC12 accessed cells colocalizing with Mitotracker Orange, an indication of mitochondrial targeting. In addition, DHC12 chelated mitochondrial and cytoplasmic labile iron. Upon mitochondrial complex I inhibition, DHC12 protected plasma membrane and mitochondria against lipid peroxidation, as detected by the reduced formation of 4-hydroxynonenal adducts and oxidation of C11-BODIPY581/891. DHC12 also blocked the decrease in mitochondrial membrane potential, detected by tetrarnethylrhodamine distribution. DHC12 inhibited MAO-A and MAO-B activity. Oral administration of DHC12 to mice (0.25 mg/kg body weight) protected substantia nigra pars compacta (SNpc) neurons against MPTP-induced death. Taken together, our results support the concept that DHC12 is a mitochondrial-targeted neuroprotective iron-copper chelator and MAO-B inhibitor with potent antioxidant and mitochondria protective activities. Oral administration of low doses of DHC12 is a promising therapeutic strategy for the treatment of diseases with a mitochondrial iron accumulation component, such as PD.},
keywords = {activity, antioxidant antioxidant, basal brain chelator, complex content, coumarin-based coumarins, disease, ganglia, i, inhibitory-activity, iron iron-copper lipid-peroxidation, model, mouse neurodegeneration neurodegeneration, neuroprotection, niptp oxidative parkinsons stress, with},
pubstate = {published},
tppubtype = {article}
}

@article{RN305,
title = {Calculations of the Light Absorption Spectra of Porphyrinoid Chromophores for Dye-Sensitized Solar Cells},
author = { R. Mera-Adasme and W.H. Xu and D. Sundholm and F. Mendizabal},
url = {/brokenurl#<Go to ISI>://WOS:000385180600020},
doi = {10.1039/c6cp04627d},
issn = {1463-9076},
year = {2016},
date = {2016-01-01},
journal = {Physical Chemistry Chemical Physics},
volume = {18},
number = {40},
pages = {27877-27884},
abstract = {Solar power is a strong alternative to the currently used fossil fuels in order to satisfy the world's energy needs. Among them, dye-sensitized solar cells (DSSC) represent a low-cost option. Efficient and cheap dyes are currently needed to make DSSCs competitive. Computational chemistry can be used to guide the design of new light-absorbing chromophores. Here, we have computationally studied the lowest excited states of ZnPBAT, which is a recently synthesized porphyrinoid chromophore with high light-absorption efficiency. The calculations have been performed at ab initio correlated levels of theory employing second-order coupled clusters (CC2) and algebraic diagrammatic construction using second order (ADC(2)) methods and by performing density functional theory (DFT) calculations using the time-dependent DFT (TDDFT) approach for excitation energies. The ultraviolet-visible (UV-vis) spectrum calculated at the ADC(2) and CC2 levels agrees well with the experimental one. The calculations show that ZnPBAT has six electronic transitions in the visible range of the absorption spectrum. The ab initio correlated calculations and previously reported experimental data have been used to assess the performance of several well-known density functionals that have been employed in the present TDDFT study. Solvent effects have been estimated by using the conductor-like screening model (COSMO). The influence of the addition of a TiO2 cluster to the chromophore systems has also been investigated. The results indicate that both CAM-B3LYP and Becke's "half-and-half'' (BHLYP) density functionals are appropriate for the studies of excitation energies in the blue range of the visible spectrum for these kinds of porphyrinoid chromophores, whereas the excitation energies of the Q band calculated at the ab initio correlated level are more accurate than those obtained in the present TDDFT calculations. The inclusion of solvent effects has a modest influence on the spectrum of the protonated form of the studied chromophores, whereas solvent models are crucial when studying the absorption spectrum of the anionic chromophore. The calculated UV-vis spectrum for the chromophore anion is not significantly affected by attaching a TiO2 cluster to it.},
keywords = {adsorption, approximation, basis-sets, correlation-energy, dft, efficiency hartree-fock, model, organic-dyes, performance, screening},
pubstate = {published},
tppubtype = {article}
}

@article{RN270,
title = {Accuracy and Reliability of Chile's National Air Quality Information System for Measuring Particulate Matter: Beta Attenuation Monitoring Issue},
author = { A.R. Toro and C. Campos and C. Molina and R.G.E. Morales and M.A. Leiva},
url = {/brokenurl#<Go to ISI>://WOS:000357909800013},
doi = {10.1016/j.envint.2015.02.009},
issn = {0160-4120},
year = {2015},
date = {2015-01-01},
journal = {Environment International},
volume = {82},
pages = {101-109},
publisher = {2015 Elsevier Ltd.},
abstract = {A critical analysis of Chile's National Air Quality Information System (NAQIS) is presented, focusing on particulate matter (PM) measurement. This paper examines the complexity, availability and reliability of monitoring station information, the implementation of control systems, the quality assurance protocols of the monitoring station data and the reliability of the measurement systems in areas highly polluted by particulate matter. From information available on the NAQIS website, it is possible to confirm that the PM2.5 (PM10) data available on the site correspond to 30.8% (69.2%) of the total information available from the monitoring stations. There is a lack of information regarding the measurement systems used to quantify air pollutants, most of the available data registers contain gaps, almost all of the information is categorized as "preliminary information" and neither standard operating procedures (operational and validation) nor assurance audits or quality control of the measurements are reported. In contrast, events that cause saturation of the monitoring detectors located in northern and southern Chile have been observed using beta attenuation monitoring. In these cases, it can only be concluded that the PM content is equal to or greater than the saturation concentration registered by the monitors and that the air quality indexes obtained from these measurements are underestimated. This occurrence has been observed in 12 (20) public and private stations where PM2.5 (PM10) is measured. The shortcomings of the NAQIS data have important repercussions for the conclusions obtained from the data and for how the data are used. However, these issues represent opportunities for improving the system to widen its use, incorporate comparison protocols between equipment install new stations and standardize the control system and quality assurance.},
keywords = {environmental chemistry, matter, megacities, model, monitoring, network, particulate pm10 pollution, quality santiago, system, temuco},
pubstate = {published},
tppubtype = {article}
}

@article{RN264,
title = {Micro-Raman Spectral Identification of Manganese Oxides Black Pigments in an Archaeological Context in Northern Chile},
author = { M. Sepulveda and S. Gutierrez and M. Campos-Vallette and V.G. Standen and B.T. Arriaza and J.J. Carcamo},
url = {/brokenurl#<Go to ISI>://WOS:000362260500001},
doi = {UNSP 32, 10.1186/s40494-015-0061-2},
issn = {2050-7445},
year = {2015},
date = {2015-01-01},
journal = {Heritage Science},
volume = {3},
abstract = {The micro-Raman spectroscopy was used to identify manganese oxides, pyrolusite, manganite and cryptomelane in archaeological sites in northern Atacama Desert, Chile. The present micro-Raman data allow us to compare and expand the origins of raw materials used by archaic groups of the Atacama Desert. In the Andean highlands, pyrolusite and manganite were identified while in the coastal lowlands manganite and cryptomelane were found. The present results complement the data obtained from the lithic materials and rock art painting analyses pointing to a better understanding of the daily life of ancient populations and minerals use in this region.},
keywords = {archaeological art, atacama black contexts, desert, diagnosis, manganese micro-raman minerals, model, oxides, pigment, rock site spectroscopy},
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{RN153,
title = {Raman and Surface Enhanced Raman Scattering of a Black Dyed Silk},
author = { T. Aguayo and C. Garrido and E. Clavijo and J.S. Gomez-Jeria and C.A. Monasterio and M. Icaza and F.E. Moraga and M. Campos-Vallette},
url = {/brokenurl#<Go to ISI>://WOS:000323784900005},
doi = {10.1002/jrs.4348},
issn = {0377-0486},
year = {2013},
date = {2013-01-01},
journal = {Journal of Raman Spectroscopy},
volume = {44},
number = {9},
pages = {1238-1245},
publisher = {2013 John Wiley & Sons, Ltd.},
abstract = {The Raman and surface enhanced Raman scattering (SERS) spectra of a black dyed silk sample (BDS) were registered. The spectral analysis was performed on the basis of Raman and SERS spectral data of isolated samples of Bombyx mori silk fibroin, its motif peptide component (GAGAGS) and the synthetic reactive black 5 dye (RB5). The macro FT-Raman spectrum of the silk sample is consistent with a silk II-Cp crystalline fraction of Bombyx mori silk fibroin; the SERS spectrum is highly consistent with conformational modifications of the fibroin due to the interactions with the Ag nanoparticles. The GAGAGS peptide sequence dominates the Raman spectrum of the silk. The SERS spectrum of the peptide suggests a random coil conformation imposed by the surface interaction; the serine residue in the new conformation is exposed to the surface. Quantum chemical calculations for a model of the GAGAGS-Ag surface predict a nearly extended conformation at the Ag surface. The Raman spectrum of the dye was analysed, and a complete band assignment was proposed; it was not possible to propose a preferential orientation or organization of the molecule on the metal surface. Quantum chemical calculations for a model of the dye interacting with a silver surface predict a rather coplanar orientation of the RB5 on the Ag metal surface. The Raman spectrum of the BDS sample is dominated by signals from the dye; the general spectral behaviour indicates that the dye mainly interacts with the silk through the sulphone (-SO2-) and sulphonate (-SO2-O-) groups. Besides the presence of dye signals, mainly ascribed to the sulphone and sulphonate bands, the SERS spectrum of the BDS sample also displays bands belonging to the amino acids alanine, glycine, serine and particularly tyrosine.},
keywords = {aromatic-hydrocarbons, art, dye, fibroin, gagags, microscopy, model, nmr polycyclic raman, resonance sers, silk, spectroscopy},
pubstate = {published},
tppubtype = {article}
}