Achievable throughput with Block Diagonalization on OFDM indoor demonstrator

The proceeding at: 21st European Signal Processing Conference (EUSIPCO 2013), took place 2013, September 09-13, in Marrakech, Septiembre 2013.Block Diagonalization (BD) is a linear precoding transmission technique able to achieve full multiplexing gain in multiple antenna systems. In this work we present a Multiple-Input Multiple-Output (MIMO) implementation based on Orthogonal Frequency Division Multiplexing (OFDM) made up of a transmitter with 4 antennas and 2 users equipped with 2 antennas each one, which allows us to evaluate the performance of BD in indoor scenarios. First, the theoretic achievable rates are obtained for the measured channel in an offline evaluation. After that, the bit error rate performance is evaluated regarding the system sum throughput. To the best of our knowledge, this is the first time that BD performance is validated using a multiuser MIMO testbed.This work has been partially funded by research projects COMONSENS (CSD2008-000 1 0), and GRE3N (TEC20 11-29006-C03-02).Publicad

Safety assessment of chronic oral exposure to iron oxide nanoparticles

Iron oxide nanoparticles with engineered physical and biochemical properties are finding a rapidly increasing number of biomedical applications. However, a wide variety of safety concerns, especially those related to oral exposure, still need to be addressed for iron oxide nanoparticles in order to reach clinical practice. Here, we report on the effects of chronic oral exposure to low doses of γ-Fe2O3 nanoparticles in growing chickens. Animal observation, weight, and diet intake reveal no adverse signs, symptoms, or mortality. No nanoparticle accumulation was observed in liver, spleen, and duodenum, with feces as the main excretion route. Liver iron level and duodenal villi morphology reflect the bioavailability of the iron released from the partial transformation of γ-Fe2O3 nanoparticles in the acid gastric environment. Duodenal gene expression studies related to the absorption of iron from γ-Fe2O3 nanoparticles indicate the enhancement of a ferric over ferrous pathway supporting the role of mucins. Our findings reveal that oral administration of iron oxide nanoparticles is a safe route for drug delivery at low nanoparticle doses.Peer Reviewe

The QUIJOTE experiment: project overview and first results

QUIJOTE (Q-U-I JOint TEnerife) is a new polarimeter aimed to characterize the polarization of the Cosmic Microwave Background and other Galactic and extragalactic signals at medium and large angular scales in the frequency range 10-40 GHz. The multi-frequency (10-20~GHz) instrument, mounted on the first QUIJOTE telescope, saw first light on November 2012 from the Teide Observatory (2400~m a.s.l). During 2014 the second telescope has been installed at this observatory. A second instrument at 30~GHz will be ready for commissioning at this telescope during summer 2015, and a third additional instrument at 40~GHz is now being developed. These instruments will have nominal sensitivities to detect the B-mode polarization due to the primordial gravitational-wave component if the tensor-to-scalar ratio is larger than r=0.05.Comment: To appear in "Highlights of Spanish Astrophysics VIII", Proceedings of the XI Scientific Meeting of the Spanish Astronomical Society, Teruel, Spain (2014

Safety assessment of chronic oral exposure to iron oxide nanoparticles

Iron oxide nanoparticles with engineered physical and biochemical properties are finding a rapidly increasing number of biomedical applications. However, a wide variety of safety concerns, especially those related to oral exposure, still need to be addressed for iron oxide nanoparticles in order to reach clinical practice. Here, we report on the effects of chronic oral exposure to low doses of γ-Fe2O3 nanoparticles in growing chickens. Animal observation, weight, and diet intake reveal no adverse signs, symptoms, or mortality. No nanoparticle accumulation was observed in liver, spleen, and duodenum, with feces as the main excretion route. Liver iron level and duodenal villi morphology reflect the bioavailability of the iron released from the partial transformation of γ-Fe2O3 nanoparticles in the acid gastric environment. Duodenal gene expression studies related to the absorption of iron from γ-Fe2O3 nanoparticles indicate the enhancement of a ferric over ferrous pathway supporting the role of mucins. Our findings reveal that oral administration of iron oxide nanoparticles is a safe route for drug delivery at low nanoparticle doses.Peer Reviewe

CARIES DENTAL Y SU RELACIÓN CON HÁBITOS ALIMENTICIOS EN NIÑOS DE 6 A 10 AÑOS EN LA ESCUELA MIXTA “REPÚBLICA DE CHILE” Y EN LA “ESCUELA DE VARONES ARZOBISPO SERRANO”, EN EL CANTÓN CUENCA PROVINCIA DEL AZUAY- ECUADOR, PERÍODO 2013

El objetivo de esta investigación fue determinar la prevalencia de caries dental y su relación con hábitos alimenticios por lo que se realizó un estudio descriptivo de corte transversal a niños de edades comprendidas entre 6 a 10 años de la Escuela Mixta “República de Chile” y Escuela de Varones “Arzobispo Serrano”. Muestra 1000 niños a quienes se les realizó un examen bucodental para determinar la frecuencia de caries dental y una encuesta dirigida a 1000 padres de familia para conocer los hábitos alimenticios de los niños. Se pudo constatar que de los 1000 individuos evaluados, 925 presentan caries dental que representa el 92,5% de la muestra. La frecuencia de caries es mayor en el sexo masculino afectando a 518 individuos que representan el 56% sobre un 44% en el sexo femenino con 407 niñas afectadas. A su vez los grupos etarios mayormente afectados por caries son a los 6 años en ambos sexos con 26% en niños y 25% niñas. Los resultados permitieron determinar que la frecuencia de caries dental tiene directa relación con los hábitos alimenticios, ya que la dieta en su mayoría está basada en el consumo de alimentos cariogénicos, con el 38,8% y el 61,5% para el sexo femenino y masculino respectivamente. Además se constató que el nivel de higiene bucal es deficiente en el grupo etario de 8 años por la poca frecuencia del cepillado de sus dientes realizándolo solo 1 vez al día

Deciphering conformational selectivity in the A(2A) adenosine G protein-coupled receptor by free energy simulations

Transmembranal G Protein-Coupled Receptors (GPCRs) transduce extracellular chemical signals to the cell, via conformational change from a resting (inactive) to an active (canonically bound to a G-protein) conformation. Receptor activation is normally modulated by extracellular ligand binding, but mutations in the receptor can also shift this equilibrium by stabilizing different conformational states. In this work, we built structure-energetic relationships of receptor activation based on original thermodynamic cycles that represent the conformational equilibrium of the prototypical A(2A) adenosine receptor (AR). These cycles were solved with efficient free energy perturbation (FEP) protocols, allowing to distinguish the pharmacological profile of different series of A(2A)AR agonists with different efficacies. The modulatory effects of point mutations on the basal activity of the receptor or on ligand efficacies could also be detected. This methodology can guide GPCR ligand design with tailored pharmacological properties, or allow the identification of mutations that modulate receptor activation with potential clinical implications

Identification of V6.51L as a selectivity hotspot in stereoselective A(2B) adenosine receptor antagonist recognition

The four adenosine receptors (ARs) A(1)AR, A(2A)AR, A(2B)AR(,) and A(3)AR are G protein-coupled receptors (GPCRs) for which an exceptional amount of experimental and structural data is available. Still, limited success has been achieved in getting new chemical modulators on the market. As such, there is a clear interest in the design of novel selective chemical entities for this family of receptors. In this work, we investigate the selective recognition of ISAM-140, a recently reported A(2B)AR reference antagonist. A combination of semipreparative chiral HPLC, circular dichroism and X-ray crystallography was used to separate and unequivocally assign the configuration of each enantiomer. Subsequently affinity evaluation for both A(2A) and A(2B) receptors demonstrate the stereospecific and selective recognition of (S)-ISAM140 to the A(2B)AR. The molecular modeling suggested that the structural determinants of this selectivity profile would be residue V250(6.51) in A(2B)AR, which is a leucine in all other ARs including the closely related A(2A)AR. This was herein confirmed by radioligand binding assays and rigorous free energy perturbation (FEP) calculations performed on the L249V(6.51) mutant A(2A)AR receptor. Taken together, this study provides further insights in the binding mode of these A(2B)AR antagonists, paving the way for future ligand optimization