Vanishing chiral couplings in the large-N_C resonance theory

The construction of a resonance theory involving hadrons requires implementing the information from higher scales into the couplings of the effective Lagrangian. We consider the large-Nc chiral resonance theory incorporating scalars and pseudoscalars, and we find that, by imposing LO short-distance constraints on form factors of QCD currents constructed within this theory, the chiral low-energy constants satisfy resonance saturation at NLO in the 1/Nc expansion.Comment: 5 pages, 2 figures. Version published in Physical Review D. Some equations to facilitate the discussion have been adde

Hadron structure in tau -> KKpi nu_tau decays

We analyse the hadronization structure of both vector and axial-vector currents leading to tau -> KKpi nu_tau decays. At leading order in the 1/Nc expansion, and considering only the contribution of the lightest resonances, we work out, within the framework of the resonance chiral Lagrangian, the structure of the local vertices involved in those processes. The couplings in the resonance theory are constrained by imposing the asymptotic behaviour of vector and axial-vector spectral functions ruled by QCD. In this way we predict the hadron spectra and conclude that, contrarily to previous assertions, the vector contribution dominates by far over the axial-vector one in all KKpi charge channels.Comment: 32 pages, 7 figure

One-loop Renormalization of Resonance Chiral Theory with Scalar and Pseudoscalar Resonances

The divergent part of the generating functional of the Resonance Chiral Theory is evaluated up to one loop when one multiplet of scalar an pseudoscalar resonances are included and interaction terms which couple up to two resonances are considered. Hence we obtain the renormalization of the couplings of the initial Lagrangian and, moreover, the complete list of operators that make this theory finite, at this order.Comment: 4 pages, no figures. Talk given at the High-Energy Physics International Conference on Quantum Chromodynamics, 2-9 July (2005), Montpellier (France). To appear in the Proceeding

Quality classification of Spanish olive oils by untargeted gas chromatography coupled to hybrid quadrupole–time of flight mass spectrometry with atmospheric pressure chemical ionization and metabolomics-based statistical approach

The novel atmospheric pressure chemical ionization (APCI) source has been used in combination with gas chromatography (GC) coupled to hybrid quadrupole time-of-flight (QTOF) mass spectrometry (MS) for determination of volatile components of olive oil, enhancing its potential for classification of olive oil samples according to their quality using a metabolomics-based approach. The full-spectrum acquisition has allowed the detection of volatile organic compounds (VOCs) in olive oil samples, including extra virgin, virgin and lampante qualities. A dynamic headspace extraction with cartridge solvent elution was applied. The metabolomics strategy consisted of three different steps: a full mass spectral alignment of GC-MS data using MzMine 2.0, a multivariate analysis using Ez-Info and the creation of the statistical model with combinations of responses for molecular fragments. The model was finally validated using blind samples, obtaining an accuracy in oil classification of 70 % taking the official established method, “PANEL TEST” as reference.The authors acknowledge the financial support of Generalitat Valenciana, as research group of excellence (PROMETEO II/2014/023) and Collaborative Research on Environment and Food-Safety (ISIC/2012/016). This work and C. Sales grant has been supported by Universitat Jaume I research promotion plans (P1-1B2013-70

Hadronic matrix elements for TAUOLA: 3 pi and KKpi channels

We emphasize that the motivation for including our hadronic matrix elements in TAUOLA is not only theoretical. We also show that our expressions describe better the tau to 3pi ALEPH data and are able to fit BABAR data on the isovector component of e^+e^- -> KKpi. The theoretical foundations of our framework are the large-N_C limit of QCD, the chiral structure exhibited at low energies and the proper asymptotic behaviour, ruled by QCD, that is demanded to the associated form factors.Comment: 6 pages, 2 figures. To appear in the Proceedings of TAU 08: 10th International TAU Conference, September 22-25, 2008. BINP Novosibirsk (Russia). To be published by Elsevier in Nuclear Physics B (Proceedings Supplement

On the structure of two-point Green-functions at next-to-leading order in 1/Nc

The structure of the two-point QCD Green-functions is studied in this note in the limit of large number of colours. Their general form at next-to-leading order in 1/Nc is derived keeping the infinite resonance summation and without relying on a particular realization of the hadronic action. It is found that the contributions from chiral operators without resonance fields of order p^4 or higher are irrelevant for the computation of the correlators and, hence, they can be dropped at the beginning of the calculation. The possibility of a more general cancelation of these local terms at the level of the generating functional is discussed.Comment: 6 pages, 1 figur

Tailoring hierarchical meso- macroporous 3D scaffolds: from nano to macro

Bone tissue regeneration requires the use of 3D scaffolds which mimic the architecture of the natural extracellular matrix, creating an adequate microenvironment for bone cell growth. Such 3D scaffolds need surface properties suitable for biological recognition in the early stage of cell adhesion, necessary to ensure complete cell colonization, retained cell functionality, and subsequently bone regeneration. Herein, hierarchical 3D scaffolds based on new hydroxyapatite/mesoporous glass nanocomposite bioceramic (MGHA) exhibiting different scales of porosity have been synthesized. These 3D scaffolds possess: (i) highly ordered mesopores with diameters of 10 nm; (ii) macropores with diameters in the 30-80 mu m range with interconnections of 1-10 mu m; and (iii) large macropores of ca. 500 mu m. To improve their surface properties, 3D scaffolds were modified through direct functionalization with amine propyl groups, which notably improve preosteoblast adhesion, proliferation (2.3 fold), differentiation (4.8 fold) and further cell colonization of these scaffolds. The observed enhancement can be related to these amine groups which favour early adhesion, e. g., based on nonspecific protein adsorption as was demonstrated by ellipsometry. These results suggest that the combination of hierarchical structure design and amine surface modification of hydroxyapatite/mesoporous nanocomposite scaffolds yields a double increase in cell proliferation, as well as a quadruple increase in cell differentiation, demonstrating the potential of these nanocomposite materials for bone tissue regeneration purposes

τ−→ηπ−π0ντ\tau^-\to\eta\pi^-\pi^0\nu_\tau and σ(e+e−→ηπ+π−)\sigma(e^+e^-\to \eta\pi^+\pi^-) at low energies

We analyze the hadronization structure of $\tau \to \eta \pi^- \pi^0 \nu_\tau$ decays. In the isospin limit only the vector current contributes to this process. We compute the relevant form factor within Resonance Chiral Theory, at leading order in the $1/N_C$ expansion, and considering only the contribution of the lightest vector resonances. The couplings in the resonance theory are constrained by imposing the asymptotic behaviour of vector spectral functions ruled by $QCD$. We reproduce the branching ratio of this mode and predict the low-energy behaviour of $\sigma\left(e^+e^-\to\eta\pi^+\pi^-\right)$ using isospin symmetry.Comment: 4 pages, 3 figures. To appear in the Proceedings of the QCD10 (25th anniversary) 15th International QCD Conference. 28th June - 3rd July 2010 Montpellier (France) (Nucl. Phys. Proc. Suppl.

Form Factors in the radiative pion decay

We perform an analysis of the form factors that rule the structure-dependent amplitude in the radiative pion decay. The resonance contributions to pion -> e nu_e gamma decays are computed through the proper construction of the vector and axial-vector form factors by setting the QCD driven asymptotic properties of the three-point Green functions VVP and VAP, and by demanding the smoothing of the form factors at high transfer of momentum. A comparison between theoretical and experimental determinations of the form factors is also carried out. We also consider and evaluate the role played by a non-standard tensor form factor. We conclude that, at present and due to the hadronic incertitudes, the search for New Physics in this process is not feasible.Comment: 14 pages, no figures. Typos corrected. Accepted for publication in The European Physical Journal

Effects of bleaching on osteoclast activity and their modulation by osteostatin and fibroblast growth factor 2

Hypothesis: Dental bleaching with H2O2 is a common daily practice in dentistry to correct discoloration of anterior teeth. The aim of this study has been to determine whether this treatment of human teeth affects growth, differentiation and activity of osteoclast-like cells, as well as the putative modulatory action of osteostatin and fibroblast growth factor 2 (FGF-2). Experiments: Previously to the in vitro assays, structural, physical-chemical and morphological features of teeth after bleaching were studied. Osteoclast-like cells were cultured on human dentin disks, pre-treated or not with 38% H2O2 bleaching gel, in the presence or absence of osteostatin (100 nM) or FGF-2 (1 ng/ml). Cell proliferation and viability, intracellular content of reactive oxygen species (ROS), pro-inflammatory cytokine (IL-6 and TNF alpha) secretion and resorption activity were evaluated. Findings: Bleaching treatment failed to affect either the structural or the chemical features of both enamel and dentin, except for slight morphological changes, increased porosity in the most superficial parts (enamel), and a moderate increase in the wettability degree. In this scenario, bleaching produced an increased osteoclast-like cell proliferation but decreased cell viability and cytokine secretion, while it augmented resorption activity on dentin. The presence of either osteostatin or FGF-2 reduced the osteoclast-like cell proliferation induced by bleaching. FGF-2 enhanced ROS content, whereas osteostatin decreased ROS but increased TNF alpha secretion. The bleaching effect on resorption activity was increased by osteostatin, but this effect was less evident with FGF-2. Conclusions: These findings further confirm the deleterious effects of tooth bleaching by affecting osteoclast growth and function as well as different modulatory actions of osteostatin and FGF-2. (C) 2015 Elsevier Inc. All rights reserved