Very large stochastic resonance gains in finite sets of interacting identical subsystems driven by subthreshold rectangular pulses.

We study the phenomenon of nonlinear stochastic resonance (SR) in a complex noisy system formed by a finite number of interacting subunits driven by rectangular pulsed time periodic forces. We find that very large SR gains are obtained for subthreshold driving forces with frequencies much larger than the values observed in simpler one-dimensional systems. These effects are explained using simple considerations.

Voice therapy used to test a basic protocol for multidimensional assessment of dysphonia.

The aim of this study was the elaboration of a basic voice protocol to discover which combination of tests and measures (multidimensional evaluation) provide decisive and essential data for the diagnosis of voice pathology and its prognosis. Voices of 21 patients with dysphonia and 21 subjects in a control group were evaluated and compared. Vocal function was assessed using a multiparametric set of videolaryngostroboscopic, perceptual, acoustic, spectrographic, aerodynamic, and subjective basic measurements (Multidimensional "Teatinos" Protocol).

Patterns in inhibitory networks of simple map neurons.

We study the dynamics of networks of inhibitory map-based bursting neurons. Linear analysis allows us to understand how the patterns of bursting are determined by network topology and how they depend on the strength of synaptic connections, when inhibition is balanced. Two kinds of patterns are found depending on the symmetry of the network: slow cyclic patterns riding on subthreshold oscillations where almost all neurons contribute bursts in a sparse manner and fast patterns of bursts in which only one of two mutually exclusive groups of neurons take part.

Hypomorphic mutations in the gene encoding a key Fanconi anemia protein, FANCD2, sustain a significant group of FA-D2 patients with severe phenotype.

FANCD2 is an evolutionarily conserved Fanconi anemia (FA) gene that plays a key role in DNA double-strand-type damage responses. Using complementation assays and immunoblotting, a consortium of American and European groups assigned 29 patients with FA from 23 families and 4 additional unrelated patients to complementation group FA-D2. This amounts to 3%-6% of FA-affected patients registered in various data sets.

Electronic and molecular structures of trigonal truxene-core systems conjugated to peripheral fluorene branches. Spectroscopic and theoretical study.

An analysis is performed on the molecular and electronic features in a series of trigonal molecules constituted by a central truxene core which is ramified with three oligofluorene moieties of different lengths. Arms and core are studied independently and upon threefold unification. Special emphasis is paid to the modulation of the conjugational properties in relation to substitution, molecular dimension, ring aromaticity, intermolecular forces, oxidation state, etc.

Vibrational fingerprint of the structural tuning in push-pull organic chromophores with quinoid or proaromatic spacers.

The Raman spectra of a series of push-pull molecules containing probenzenoid or quinoid spacers which are substituted with 1,3-dithiol-2-ylidene as donor and dicyano-methylene or barbituric acid as acceptors have been analyzed. The experimental spectra have been assigned and interpreted according to density functional theory calculations. Correlations between the Raman spectra of the isolated spacers and of the substituted molecules have been done.

[Neurohormonal blockade in patients with heart failure at discharge from hospital].

With the objective to value the degree of fulfillment of the pharmacological processing in patients with heart failure was designed the study of therapeutic adherence in heart failure (ATICA). During the period of inclusion educational, social, demographic data have been obtained, personal antecedents, analytic and physical exploration of the patients. These data mentioned are the ones that are reflected in the present pilot study.

CD4 count and viral load time-courses in patients treated with highly active antiretroviral therapy and association with the CDC staging system.

Objectives: The aim of the study was to analyse CD4 cell count and viral load dynamics in patients undergoing antiretroviral therapy and their association with the Centers for Disease Control and Prevention (CDC) classification system.

Methods: CD4 cell count and viral load were determined in 2982 patients who were classified according to clinical and immunological CDC stages. Measurements were carried out at baseline and at the 3rd, 6th and 12th months.

Limitations of a simplification antiretroviral strategy for HIV-infected patients with decreasing adherence to a protease inhibitor regimen.

Purpose: To determine the long-term efficacy of a simplification strategy in the clinical setting when used to improve adherence.

Method: Prospective study of 70 patients included in a regimen with ddI plus 3TC plus an NNRTI, after viral suppression with a PI-containing regimen, due to decreasing adherence. Adherence to PI was calculated as the percentage of doses taken last week before inclusion, and patients were stratified as high and low adherence (95% and <95% of doses).

Severity of the toxicity associated with combinations that include didanosine plus stavudine in HIV-infected experienced patients.

Background: The combination of didanosine (ddI) and stavudine (d4T) is no longer recommended as a first-line treatment because of toxicity, but it may be useful in experienced patients.

Methods: Retrospective chart review of experienced patients on ddI plus d4T was conducted at a single institution, recording the development of adverse events as well as their severity and action taken. The risk of developing severe toxicities was estimated by Kaplan-Meier analysis.

Octopolar chromophores based on donor- and acceptor-substituted 1,3,5-tris(phenylethynyl)benzenes: impact of meta-conjugation on the molecular and electronic structure by means of spectroscopy and theory.

The molecular and electronic structures of a series of all-meta-substituted phenylacetylene mesitylenes peripherally substituted with donor or acceptor (D-A) groups are studied. The impact of meta- and para-substitution patterns is also analyzed by employing Raman and optical spectroscopies in conjunction with theoretical calculations. Outer phenyl rings display a partial quinoid character induced by two different motifs: (i) outer phenyls --> triple bond charge transfer for the cases where these phenyls are substituted with electron-donors; (ii) double electron withdrawing effect in the molecules with the peripheral phenyls substituted with electron acceptors.

Structure-property relationships in push-pull amino/cyanovinyl end-capped oligothiophenes: quantum chemical and experimental studies.

A series of push-pull chromophores built around thiophene-based pi-conjugating spacers and bearing various types of amino donors and cyanovinyl acceptors have been analyzed by means of UV-vis-NIR, IR, and Raman spectroscopic measurements in the solid state as well as in solution. The intramolecular charge transfer (ICT) of these pi-conjugated systems has also been tested by analyzing the ability of the solute molecules to undergo shifts in their fluorescence emission maxima with increasing solvent polarity. These push-pull oligomers also display an attractive electrochemical behavior since they generate stable species both upon oxidation and reduction.

Structural implications of ring shape, dimension, and metal atom insertion in nanosized cyclic oligothiophenes: joint Raman and density functional theory study.

This paper reports on a combined spectroscopic and density functional theory study on a series of cyclo(diacetylenes-oligothiophenes) with different shapes and dimensions. The case of a macrocycle fragmented by the insertion of Pt metallic atoms is illustrated as well. The analysis covers the neutral and oxidized samples.

Exploration of ground and excited electronic states of aromatic and quinoid S,S-dioxide terthiophenes. Complementary systems for enhanced electronic organic materials.

We analyze the electronic and molecular structures for the ground and excited electronic states of aromatic terthiophene (3T), the quinodimethane 3',4'-dibutyl-5,5' '-bis(dicyanomethylene)-5,5' '-dihydro-2,2':5',2' '-terthiophene (3Q), and isologues with the middle ring S-oxidized (3TO2, 3QO2). These represent extremes of electron rich and deficient ground states, often exhibiting complementary properties. Oxidizing the central sulfur atom affects the molecular structure, electron affinity, and photophysical properties of both pi systems.

Hematopoietic dysfunction in a mouse model for Fanconi anemia group D1.

We have investigated the hematopoietic phenotype of mice with a hypomorphic mutation in the Brca2/Fancd1 gene (Brca2(Delta27/Delta27) mutation). In contrast to observations made in other Fanconi anemia (FA) mouse models, low numbers of hematopoietic colony-forming cells (CFCs) were noted in Brca2(Delta27/Delta27) mice, either young or adult. Additionally, a high incidence of spontaneous chromosomal instability was observed in Brca2(Delta27/Delta27) bone marrow (BM) cells, but not in Brca2(+/Delta27) or Fanca(-/-) BM cells.

Synthesis and characterization of a novel terthiophene-based quinodimethane bearing a 3,4-ethylenedioxythiophene central unit.

The synthesis and a combined spectroscopic and density functional theoretical characterization of a 3',4'-ethylenedioxy-5,5' '-bis(dicyanomethylene)-5,5' '-dihydro-2,2':5',2' '-terthiophene analogue of 7,7,8,8-tetracyanoquinodimethane (TCNQ) are presented. Electrochemical data show that this novel trimer can be both reversibly reduced and oxidized at relatively low potentials. Quantum-chemical calculations show that the compound exhibits a quinoidal structure in its ground electronic state and that a certain degree of intramolecular charge transfer takes place from the central terthienyl moiety toward both =C(CN)2 end-caps.

Alternated quinoid/aromatic units in terthiophenes building blocks for electroactive narrow band gap polymers. Extended spectroscopic, solid state, electrochemical, and theoretical study.

We report here the synthesis of three novel pi-conjugated heterocyclic mixed trimers that contain two electron-donating 3,4-ethylenedioxy-2-thienyl (EDOT) units covalently attached to a central proquinoid electron-accepting thienopyrazine moiety (two of these narrow-HOMO-LUMO gap D-A-D compounds also bear hexyl side chains attached either to the outermost alpha positions of the EDOT end rings or to the beta positions of the pyrazine fused ring). The modification of the terthiophene structure upon EDO, pyrazine, and hexyl substitutions has been treated in detail with spectroscopic and theoretical arguments. Solid-state properties reveal the occurrence of short intramolecular contacts between heteroatoms of adjacent rings.

Multidisciplinary physicochemical analysis of oligothiophenes end-capped by nitriles: electrochemistry, UV-vis-near-IR, IR, and Raman spectroscopies and quantum chemistry.

In this article, we investigate a series of alpha,omega-dicyano end-capped oligothiophenes NC(C(4)H(2)S)(n)()CN ranging in length from the dimer to the hexamer (n = 2-6), in the neutral state as pure solids, by means of Fourier transform IR and Fourier transform Raman (FT-Raman) spectroscopies. The cyclic voltammetry analysis of the compounds in dichloromethane reveals that most of them show two oxidation and two reduction waves (i.e.

Pilot scale mineralization of organic acids by electro-Fenton process plus sunlight exposure.

The viability of the electro-Fenton degradation of aqueous solutions of benzoic acid, 2,4-dichlorophenoxyacetic acid and oxalic acid has been studied at 20 A using a pilot flow reactor containing an anode and an oxygen diffusion cathode, both of 100 cm(2) section. Pollutants were preferentially oxidized by hydroxyl radicals formed in solution from reaction of Fe(2+) with electrogenerated H(2)O(2), allowing mineralization of benzoic acid and 2,4-D. For oxalic acid no electrochemical mineralization was observed.

Hybrid organic semiconductors including chalcogen atoms in pi-conjugated skeletons. Tuning of optical, redox, and vibrational properties by heavy atom conjugation.

In this work, the interactions between heteroatoms (S, Se, and Te) and conjugated skeletons are analyzed. The study is carried out by using electronic absorption and fluorescence spectroscopies, electrochemistry, vibrational Raman spectroscopy, and theoretical calculations in the framework of DFT and TD-DFT theories. Optical spectra are described in terms of one-electron promotions between orbitals around the energy gap.

Quasispecies as predictive response factors for antiviral treatment in patients with chronic hepatitis C.

The object of this study was to evaluate the viral factor, especially the quasispecies, as predictive of sustained virologic response. We studied the quasispecies, genotype, viral load, and hepatitis C (HCV) cAg in 41 patients with chronic hepatitis C treated with interferon and in 84 with interferon and ribavirin. In the interferon group, responders presented a lower viral load.

Validation of a specific questionnaire on psychological and social repercussions of the lipodystrophy syndrome in HIV-infected patients.

Objective: To validate a questionnaire to identify psychosocial repercussions of the lipodystrophy syndrome (LD) in HIV-infected patients.

Methods: A questionnaire containing 35 items in 6 subscales [body image, anxiety, depression, social support, social distress, quality of life (QoL)] was consecutively administered to 128 patients with LD, 25 naive patients or on therapy without LD, and to 15 HIV negative patients from January to July '04. Reliability was assessed using Cronbach's alpha and the intraclass correlation coefficient (ICC).

Nitric oxide reduces adenosine transporter ENT1 gene (SLC29A1) promoter activity in human fetal endothelium from gestational diabetes.

Human umbilical vein endothelial cells (HUVEC) from gestational diabetes exhibit reduced adenosine uptake and increased nitric oxide (NO) synthesis. Adenosine transport via human equilibrative nucleoside transporters 1 (hENT1) is reduced by NO by unknown mechanisms in HUVEC. We examined whether gestational diabetes-reduced adenosine transport results from lower hENT1 gene (SLC29A1) expression.