The N*(1520) ---> Delta pi Amplitudes Extracted from the gamma p ---> pi+ pi- p Reaction and Comparison to Quark Models

The gamma p ---> pi+ pi- p reaction, in combination with data from the pi N ---> pi pi N reaction, allows one to obtain the s- and d-wave amplitudes for the N*(1520) decay into Delta pi with absolute sign with respect to the N*(1520) ---> N gamma helicity amplitudes. In addition one obtains the novel information on the q dependence of the amplitudes. This dependence fits exactly with the predictions of the non-relativistic constituent quark models. The absolute values provided by these models agree only qualitatively, and a discussion is done on the reasons for it and possible ways to improve.Comment: 12 pages, 1 figure, TeX, Version 3.141 [PD VMS 3.4/CERN 1.0

Double Pion Photoproduction on the Nucleon: Study of the Isospin Channels

A model for the gamma p ----> pion+ pion- p reaction developed earlier is extended to account for all isospin channels. The model includes N, Delta(1232), N^*(1440) and N^*(1520) as intermediate baryonic states and the rho-meson as an intermediate two pion resonance. Although many terms contribute to the cross section, some channels exhibit particular sensitivity to certain mechanisms of resonance excitation or decay and the reactions provide novel information on such mechanisms. In particular the gamma N ----> N^*(1520) ----> Delta(1232) pion process affects all the channels and is a key ingredient in the interpretation of the data. Comparison is made with all available data and the agreement is good in some channels. The remaining discrepancies in some other channels are discussed.Comment: 23 pages, 13 figures. TeX, Version 3.141 [PD VMS 3.4/CERN 1.0

Genetic identification and pedigree control on horses through microsatellite DNA sequences

Ponencia publicada en ITEA, vol.104El Laboratorio Central de Veterinaria de Algete (LCV) ha sido nombrado centro de referencia para la realización de análisis de marcadores genéticos y la homologación de las técnicas para la identificación y el control de filiación en équidos, con el fin de garantizar las genealogías de los animales inscritos en los libros genealógicos (Real Decreto 662/2007). A partir de ese momento, se ha desarrollado un protocolo de trabajo que cubre la totalidad de los pasos a seguir desde la recogida de muestras en el campo hasta la recepción final de los resultados por parte de la asociación de ganaderos. La metodología empleada utiliza los medios más avanzados y tiene establecidos una serie de puntos de control para poder detectar los errores que pudieran producirse tanto en la recogida de muestras como en la transmisión de la información que a éstas debe acompañar para su posterior análisis. La optimización de la metodología empleada posibilita procesar un número elevado de muestras en un corto espacio de tiempo con una gran fiabilidad en los resultados obtenidos. El análisis al que se someten las muestras incluye 18 marcadores microsatélite de ADN, amplificados en una reacción única de PCR, elegidos de la lista propuesta por la ISAG (Intenational Society for Animal Genetics). Se dispone, además, de dos paneles adicionales compuestos de 22 y 8 nuevos marcadores respectivamente, que son utilizados en los casos en que se necesita una mayor capacidad de exclusión o para llevar a cabo estudios de genealogías con datos de progenitores procedentes de otros laboratorios donde utilicen estos marcadores, algo bastante habitual en las razas equinas en las que existe gran movimiento de animales entre distintos países.Central Veterinary Laboratory of Algete (LCV) has been appointed as a referral center for the analysis of genetic markers and certification of techniques for the identification and genealogical control in horses, in order to guarantee the genealogies of the animals entered in studbooks (Royal Decree 662/2007). Since then, it has developed a working protocol covering all the steps to follow from the collection of samples in the field until receipt of the final results by the breeders’ association. The methodology uses the most advanced and has established a series of checkpoints in order to detect any errors that may occur in both the sample collection and transmission of information that must accompany them for later analysis. The optimization methodology enables to process a large number of samples in a short time with great reliability in the results. The analysis that the samples are submitted includes 18 microsatellite DNA markers, amplified in a single PCR reaction, chosen from the list proposed by the ISAG (International Society for Animal Genetics). It also provides two additional panels composed of 8 and 22 new markers, respectively, which are used in cases where there is a need for increased capacity of exclusion or to conduct studies pedigrees with data from parents from other laboratories where use these markers, which is quite common in horse races where there is great movement of animals between countries

Virtual versus Real Nuclear Compton Scattering in the Delta(1232) Region

In this paper we calculate the cross section for Virtual Compton Scattering off nuclei in the delta resonance region. We also calculate the background for the process from Coherent Bremsstrahlung in nuclei and explore the regions where the Virtual Compton Scattering cross section dominates. The study also shows that it is possible to extract the cross section for Real Compton Scattering from the Virtual Compton one in a wide range of scattering angles.Comment: latex , 11 pages, ps.gz file, 16 figure

PLA/PCL electrospun membranes of tailored fibres diameter as drug delivery systems

[EN] The main electrospinning parameters, i.e., polymer concentration in the injectable solution, solvents used and their proportion, flow rate, voltage and distance to collector were herein systematically modified to analyse their particular influence in fibres diameter of electrospun membranes of poly(lactic acid), polycaprolactone and their mixture. As a result of this analysis, the procedures to obtain membranes of these polymers and blend with under- and above-micron-sized fibres were established, in which the solvents ratio (chloroform/methanol and dichloromethane/dimethylformamide) and voltage were found to play the major role. Moreover, the plausible differential effect of these fibres diameters (0.8 and 1.8 ¿m) in the controlled release of a molecule of interest was explored, using bovine serum albumin (BSA), proving that the most effective configuration for BSA release among those studied was the PLA-PCL combination in membranes of above-micron fibres diameter.The authors acknowledge Spanish Ministerio de Economia y Competitividad through DPI2015-65401-C3-2-R project, and the assistance and advice of the Electron Microscopy Service of the Universitat Politecnica de Valencia (Spain).Herrero-Herrero, M.; Gómez-Tejedor, J.; Vallés Lluch, A. (2018). PLA/PCL electrospun membranes of tailored fibres diameter as drug delivery systems. European Polymer Journal. 99:445-455. https://doi.org/10.1016/j.eurpolymj.2017.12.045S4454559

An in vitro experimental model to predict the mechanical behaviour of macroporous scaffolds implanted in articular cartilage

A model is proposed to assess mechanical behaviour of tissue engineering scaffolds and predict their performance in vivo during tissue regeneration. To simulate the growth of tissue inside the pores of the scaffold, the scaffold is swollen with a Poly (Vinyl alcohol) solution and subjected to repeated freezing and thawing cycles. In this way the Poly (Vinyl alcohol) becomes a gel whose stiffness increases with the number of freezing and thawing cycles. Mechanical properties of the construct immersed in water are shown to be determined, in large extent, by the water mobility constraints imposed by the gel filling the pores. This is similar to the way that water mobility determines mechanical properties of highly hydrated tissues, such as articular cartilage. As a consequence, the apparent elastic modulus of the scaffold in compression tests is much higher than those of the empty scaffold or the gel. Thus this experimental model allows assessing fatigue behaviour of the scaffolds under long-term dynamic loading in a realistic way, without recourse to animal experimentation.The UPV group acknowledges the support of the Spanish MICINN through project MAT2010-21611-C03-01. CIBER-BBN is an initiative funded by the VI National R&D&i Plan 2008-2011, Iniciativa Ingenio 2010, Consolider Program. CIBER Actions are financed by the Instituto de Salud Carlos III with assistance from the European Regional Development Fund. The authors thank the microscopy service of Universitat Politecnica de Valencia for useful help and advice and Ricardo Perez Feito for technical assistance in the experimental set up.Vikingsson, LKA.; Gallego Ferrer, G.; Gómez-Tejedor, JA.; Gómez Ribelles, JL. (2014). An in vitro experimental model to predict the mechanical behaviour of macroporous scaffolds implanted in articular cartilage. Journal of the Mechanical Behavior of Biomedical Materials. 32:125-131. https://doi.org/10.1016/j.jmbbm.2013.12.024S1251313

Vector meson production and nucleon resonance analysis in a coupled-channel approach for energies m_N < sqrt(s) < 2 GeV II: photon-induced results

We present a nucleon resonance analysis by simultaneously considering all pion- and photon-induced experimental data on the final states gamma N, pi N, 2 pi N, eta N, K Lambda, K Sigma, and omega N for energies from the nucleon mass up to sqrt(s) = 2 GeV. In this analysis we find strong evidence for the resonances P_{31}(1750), P_{13}(1900), P_{33}(1920), and D_{13}(1950). The omega N production mechanism is dominated by large P_{11}(1710) and P_{13}(1900) contributions. In this second part we present the results on the photoproduction reactions and the electromagnetic properties of the resonances. The inclusion of all important final states up to sqrt(s) = 2 GeV allows for estimates on the importance of the individual states for the GDH sum rule.Comment: 41 pages, 26 figures, discussion extended, typos corrected, references updated, to appear in Phys. Rev.

Macroporous thin membranes for cell transplant in regenerative medicine

The aim of this paper is to present a method to produce macroporous thin membranes made of poly (ethyl acrylate-co-hydroxyethyl acrylate) copolymer network with varying cross-linking density for cell transplantation and prosthesis fabrication. The manufacture process is based on template techniques and anisotropic pore collapse. Pore collapse was produced by swelling the membrane in acetone and subsequently drying and changing the solvent by water to produce 100 microns thick porous membranes. These very thin membranes are porous enough to hold cells to be transplanted to the organism or to be colonized by ingrowth from neighboring tissues in the organism, and they present sufficient tearing stress to be sutured with surgical thread. The obtained pore morphology was observed by Scanning Electron Microscope, and confocal laser microscopy. Mechanical properties were characterized by stress-strain experiments in tension and tearing strength measurements. Morphology and mechanical properties were related to the different initial thickness of the scaffold and the cross-linking density of the polymer network. Seeding efficiency and proliferation of mesenchymal stem cells inside the pore structure were determined at 2 hours, 1, 7, 14 and 21 days from seeding.This work was funded by the Spanish Ministry of Economy and Competitiveness (MINECO) through the project MAT2013-46467-C4-1-R (including the FEDER financial support). J.R.R. acknowledges funding of his PhD by the Generalitat Valenciana through VALi+d grant (ACIF/2010/238). CIBER-BBN is an initiative funded by the VI National R&D&i Plan 2008-2011, Iniciativa Ingenio 2010, Consolider Program, CIBER Actions and financed by the Instituto de Salud Carlos III with assistance from the European Regional Development Fund. The authors acknowledge too the advice of Dr. Daniel Kelly, Dr. Conor Buckley and Dr. Yurong Liu about the isolation and expansion of porcine MSCs. The authors acknowledge the assistance and advice of Electron Microscopy Service of the UPV.Antolinos Turpín, CM.; Morales Román, RM.; Ródenas Rochina, J.; Gómez Ribelles, JL.; Gómez-Tejedor, JA. (2015). Macroporous thin membranes for cell transplant in regenerative medicine. Biomaterials. 67:254-263. https://doi.org/10.1016/j.biomaterials.2015.07.032S2542636

Chiral perturbation theory calculation for pn -> dpipi at threshold

We investigate the reaction pn -> dpipi in the framework of Chiral Perturbation Theory. For the first time a complete calculation of the leading order contributions is presented. We identify various diagrams that are of equal importance as compared to those recognized in earlier works. The diagrams at leading order behave as expected by the power counting. Also for the first time the nucleon-nucleon interaction in the initial, intermediate and final state is included consistently and found to be very important. This study provides a theoretical basis for a controlled evaluation of the non-resonant contributions in two-pion production reactions in nucleon-nucleon collisions.Comment: 24 pages, 3 figures, 3 table

Evaluation of the polarization observables I^S and I^C in the reaction gamma p --> pi^0 eta p

We evaluate the polarization observables I^S and I^C for the reaction gamma p --> pi^0 eta p, using a chiral unitary framework developed earlier. The I^S and I^C observables have been recently measured for the first time by the CBELSA/TAPS collaboration. The theoretical predictions of I^S and I^C, given for altogether 18 angle dependent functions, are in good agreement with the measurements. Also, the asymmetry dSigma/dcos(theta) evaluated here agrees with the data. We show the importance of the Delta(1700)D33 resonance and its S-wave decay into eta Delta(1232). The result can be considered as a further confirmation of the dynamical nature of this resonance. At the highest energies, deviations of the predictions from the data start to become noticeable, which leaves room for additional processes and resonances such as a Delta(1940)D33. We also point out how to further improve the calculation.Comment: Version accepted for publication by the European Physical Journal A, 9 pages, 7 figure