Sistema adaptativo no lineal

In this paper, we present a method to correct the amplitud distorsion produced by a non linear system. First of all it is shown how this correction can be achieved making use of a least square error criterium by means of a polynomical function. An adaptive method is also studied and a discussion of the convergence condition is made. Finally, as an example, the method is aplied to design the expansor which makes use of a mu law.Peer ReviewedPostprint (published version

The UPC Text-to-Speech System for Spanish and Catalan

This paper summarizes the text-to-speech system that has been developed in the Speech Group of the Universitat Politècnica de Catalunya (UPC). The system is composed of a core and different interfaces so that it is compatible for research, for telephone applications (either CTI boards or standard ISDN PC cards supporting CAPI), and Windows applications developed using Microsoft SAPI. The paper reviews the system making emphasis in the parts of the system which are language dependent and which allow the reading of bilingual text (Spanish and Catalan). The paper also presents new approaches in prosodic modeling (segmental duration modeling) and generation of the database of speech segments, which have been introduced last year.Peer ReviewedPostprint (published version

Lipid crystallization kinetics - roles of external factors influencing functionality of end products

The extent of crystallization and transformation of lipids, and their network formation, play decisive roles in determining physical properties (e.g., hardness, texture, rheology, and spreadability) of lipid-based food products. In these products, the lipid materials are present in rather complicated physical states such as mixtures of solid and liquid lipids or emulsified with water phases. In addition, various external influences are applied during actual production in a factory. Therefore, exploration of lipid crystallization under multiple external influences is necessary to improve the functionality of lipid-based food products

Cu(II) 4-phenoxybenzoate dimers and monomer coordinated by pyridines: synthesis and crystal structures

The complexes [Cu(PhOBz)2(dPy)]2 (PhOBz = 4-phenoxybenzoate; dPy = pyridine (1), 3-phenylpyridine (2), 4-benzylpyridine (3) and 4-phenylpyridine (4) and the complex [Cu(PhOBz)2(4-Phpy)2(H2O)] (5) were prepared and fully characterized. X-ray crystal structures of the five complexes have been determined. Complexes 1-4 consist of binuclear units where both Cu(II) are linked by four syn-syn carboxylate bridges, showing a paddle-wheel unit. The compound 5 is mononuclear and the metal center is coordinated to two PhOBz in monodentate form, two 4-Phpy ligands and one H2O molecule with slightly distorted square pyramidal geometry. Finally, the magnetic properties of compounds 3 and 5 have also been studied, confirming the different strength interactions between Cu(II) cations

Noninvasive assessment of an engineered bioactive graft in myocardial infarction: impact on cardiac function and scar healing

Cardiac tissue engineering, which combines cells and biomaterials, is promising for limiting the sequelae of myocardial infarction (MI). We assessed myocardial function and scar evolution after implanting an engineered bioactive impedance graft (EBIG) in a swine MI model. The EBIG comprises a scaffold of decellularized human pericardium, green fluorescent protein-labeled porcine adipose tissue-derived progenitor cells (pATPCs), and a customized-design electrical impedance spectroscopy (EIS) monitoring system. Cardiac function was evaluated noninvasively by using magnetic resonance imaging (MRI). Scar healing was evaluated by using the EIS system within the implanted graft. Additionally, infarct size, fibrosis, and inflammation were explored by histopathology. Upon sacrifice 1 month after the intervention, MRI detected a significant improvement in left ventricular ejection fraction (7.5%64.9% vs. 1.4%63.7%; p = .038) and stroke volume (11.565.9 ml vs. 364.5 ml; p = .019) in EBIG-treated animals. Noninvasive EIS data analysis showed differences in both impedance magnitude ratio (20.02 6 0.04 per day vs. 20.48 6 0.07 per day; p = .002) and phase angle slope (20.18°60.24° per day vs.23.52°60.84° per day; p = .004) in EBIG compared with control animals. Moreover, in EBIG-treated animals, the infarct size was 48% smaller (3.4%60.6% vs. 6.5%61%; p = .015), less inflammation was found by means of CD25+ lymphocytes (0.65 6 0.12 vs. 1.26 6 0.2; p = .006), and a lower collagen I/III ratio was detected (0.4960.06 vs. 1.6660.5; p = .019). An EBIG composed of acellular pericardium refilled with pATPCs significantly reduced infarct size and improved cardiac function in a preclinical model of MI. Noninvasive EIS monitoring was useful for tracking differential scar healing in EBIG-treated animals, which was confirmed by less inflammation and altered collagen deposit.Peer ReviewedPostprint (published version

Interatrial conduction block with retrograde activation of the left atrium and paroxysmal supraventricular tachyarrhythmias: influence of preventive antiarrhythmic treatment.

Patients with advanced interatrial conduction block with retrograde activation to the left atrium present a high incidence of supraventricular tachyarrhythmias. We report the value of preventive antiarrhythmic treatment in these patients

How random is your heart beat?

We measure the content of random uncorrelated noise in heart rate variability using a general method of noise level estimation using a coarse grained entropy. We show that usually - except for atrial fibrillation - the level of such noise is within 5 - 15% of the variance of the data and that the variability due to the linearly correlated processes is dominant in all cases analysed but atrial fibrillation. The nonlinear deterministic content of heart rate variability remains significant and may not be ignored.Comment: see http://urbanowicz.org.p

Syntheses, supramolecular architectures and photoluminescence properties of Zn(II) complexes based on 3,5-dihydroxybenzoic and pyridine/pyrazole derived ligands

Five new coordination compounds [Zn(μ‑3,5‑DHB)2(H2O)2]n (1a), [Zn(μ‑3,5‑DHB)(μ‑OH2) (H2O)2]n·(3,5‑DHB)n·(4H2O)n (1b), [Zn(3,5‑DHB)2(Isna)2]·2H2O (2), [Zn(3,5‑DHB)2(4‑Acpy)2]·3H2O (3) and [Zn (3,5‑DHB)2(3‑Mepz)2]·H2O (4) (3,5‑HDHB=3,5‑dihydroxybenzoic, Isna=isonicotinamide, 4‑Acpy=4‑acetylpyridine and 3‑Mepz=3‑methylpyrazole) were synthesized in water or water-methanol as solvents. All these compounds have been characterized by elemental analysis, FTIR-ATR and 1H NMR spectroscopies and Powder X-ray diffraction (PXRD). For compounds 1b-4, X-ray crystal structures have been determined. In these compounds, 3,5‑DHB ligand displays different coordination modes. Complex 1b is a coordination polymer, while the addition of the pyridine/pyrazole ligands in the reaction provokes the formation of monomeric compounds (2-4). Moreover, the crystal packing indicates that these complexes expand into 2D/ 3D network structures mainly by intermolecular hydrogen bond interactions. Finally, the photoluminescent properties of these complexes in solid state have also been investigated. The strong emission observed for 1b indicates that it may be a good candidate for photoluminescent devices