Spontaneous vesicles of sodium dihexadecylphosphate in HEPES buffer

The formation of spontaneous vesicles of dihexadecylphosphate (DHP) in a HEPES buffered solution at pH 7.4, the size, morphology and melting temperature, obtained by cryogenic transmission electron microscopy (cryo-TEM) and differential scanning calorimetry (DSC), are reported. The vesicles were formed by simply mixing a 5.0 mM lipid-solvent mixture at a temperature (75 degrees C) safely above the higher melting temperature T-m = 70.4 degrees C of DHP. The vesicle diameter ranges from 100 to 332 nm and their geometry is spherical, faceted or oblong. T-m increases from 66.8 to 70.4 as DHP concentration is raised from 0.6 to 5.0 mM. (c) 2008 Elsevier B.V. All rights reserved.

Muon transverse polarization in the K-l2 gamma decay in the standard model

The muon transverse polarization in the K+-->mu(+)nugamma process induced by the electromagnetic final state interaction is calculated in the framework of the standard model. It is shown that one loop contributions lead to a nonvanishing muon transverse polarization. The value of the muon transverse polarization averaged over the kinematical region of E(gamma)greater than or equal to20 MeV is equal to 5.63x10(-4).

Spontaneous CP violation in the 3-3-1 model with right-handed neutrinos

We implement the mechanism of spontaneous CP violation in the 3-3-1 model with right-handed neutrinos and recognize their sources of CP violation. Our main result is that the mechanism works already in the minimal version of the model and new sources of CP violation emerges as an effect of new physics at energies higher than the electroweak scale.

Dynamically induced spontaneous symmetry breaking in 3-3-1 models

We show that in SU(3)(C) circle times SU(3)(L) circle times U(1)(N) (3-3-1) models embedded with a singlet scalar playing the role of the axion, after imposing scale invariance, the breaking of Peccei-Quinn symmetry occurs through the one-loop effective potential for the singlet field. We, then, analyze the structure of spontaneous symmetry breaking by studying the new scalar potential for the model, and verify that electroweak symmetry breaking is tightly connected to the 3-3-1 breaking by the strong constraints among their vacuum expectation values. This offers a valuable guide to write down the correct pattern of symmetry breaking for multi-scalar theories. We also obtained that the accompanying massive pseudo-scalar, instead of acquiring mass of order of Peccei-Quinn scale as we would expect, develops a mass at a much lower scale, a consequence solely of the breaking via Coleman-Weinberg mechanism. (c) 2005 Published by Elsevier B.V.

Vacuum polarization effects in hyperon-rich dense matter - a nonperturbative treatment

We derive the equation of state (EOS) for electrically charged neutral dense matter using the quantum hadrodynamics (QHD) model. This is carried out in a non-perturbative manner including quantum corrections for baryons through a realignment of vacuum with baryon-antibaryon condensates. This yields the results of relativistic Hartree approximation of summing over baryonic tadpole diagrams. The quantum corrections from the scalar meson is also taken into account in a similar way. This leads to a softening of the EOS for the hyperonic matter. The formalism also allows Lis to make a self-consistent calculation of the in-medium sigma meson mass. The effects of such quantum corrections on the composition of charged neutral dense matter is considered. The effect of the resulting EOS on the structure of neutron stars is also studied.

Lepton transverse polarization in the B -> Dl nu(l) decay due to the electromagnetic final state interaction

The effect of lepton transverse polarization in B-0-->D(-)l(+)nu(l), B+-->(D) over bar (0)l(+)nu(l) decays (l=tau,mu) is analyzed within the framework of the standard model in the leading order of heavy quark effective theory. It is shown that a nonzero transverse polarization appears due to the electromagnetic final state interaction. The diagrams with intermediate D,D* mesons contributing to the nonvanishing P-T are considered. Regarding only the contribution of these mesons, the values of the tau-lepton transverse polarization averaged over the physical region in the B-0-->D(-)tau(+)nu(l) and B+-->(D) over bar (0)tau(+)nu(l) decays are equal to 2.60x10(-3) and -1.59x10(-3), respectively. In the case of muon decay modes the values of [P-T] are equal to 2.97x10(-4) and -6.79x10(-4).

Spontaneous breaking of the lepton number and invisible majoron in a 3-3-1 model

In this work we implement the spontaneous breaking of lepton number in version II of the 3-3-1 models and study their phenomenological consequences. The main result of this work is that our majoron is invisible even though it belongs to a triplet representation by the 3-3-1 symmetry.

Vacuum Polarization Tensor for QED in the Light Front Gauge

The use of light front coordinates in quantum field theories (QFT) always brought some problems and controversies. In this work we explore some aspects of its formalism with respect to the employment of dimensional regularization in the computation of the photon's self-energy at the one-loop level and how the fermion propagator has an important role in the outcoming results.

Spontaneous symmetry breaking of Bose-Fermi mixtures in double-well potentials

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Measurement of the Polarization of the Upsilon(1S) and Upsilon(2S) States in pp Collisions at s=1.96 TeV

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Measurement of the Polarization of W Bosons with Large Transverse Momenta in W plus jets Events at the LHC

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Induced polarization, resistivity, and self-potential: a case history of contamination evaluation due to landfill leakage

This article compares the efficiency of induced polarization (IP) and resistivity in characterizing a contamination plume due to landfill leakage in a typical tropical environment. The resistivity survey revealed denser electrical current flow that induced lower resistivity values due to the high ionic content. The increased ionic concentration diminished the distance of the ionic charges close to the membrane, causing a decrease in the IP phenomena. In addition, the self-potential (SP) method was used to characterize the preferential flow direction of the area. The SP method proved to be effective at determining the flow direction; it is also fast and economical. In this study, the resistivity results were better correlated with the presence of contamination (lower resistivity) than the IP (lower chargeability) data.

Electrochemical stability and corrosion resistance of Ti-Mo alloys for biomedical applications

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Cervicovaginal aerobic microflora of women with spontaneous abortion or preterm delivery in Araraquara-Brazil

Rotina bacteriológica do conteúdo vaginal e cervical de 22 mulheres com histórico de aborto recente ou ruptura precoce das membranas foi realizada. Chlamydia trachomatis, Streptococcus pyogenes, Streptococcus agalactiae, Candida sp e Gardnerella vaginalis foram isolados em 54,5% (12) das pacientes. Apesar de Ureaplasma urealyticum ter sido frequentemente encontrado (45,5%), somente em 5 das 22 mulheres foi o único microrganismo presente nos materiais analisados. Esses resultados chamam a atenção para a importância de investigação quantitativa bem como qualitativa da microbiota genital em gestantes, tendo em vista ter consequências na gestação.

Effects of desflurane, sevoflurane and isoflurane on pulmonary shunt in dogs during spontaneous ventilation

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)