Publications by authors named "Jandir Hickmann"

Background: Gold nanoparticles (AuNPs) can inhibit pivotal pathological changes in experimental asthma, but their effect on steroid-insensitive asthma is unclear. The current study assessed the effectiveness of nebulized AuNPs in a murine model of glucocorticoid (GC)-resistant asthma.

Methods: A/J mice were sensitized and subjected to intranasal instillations of ovalbumin (OVA) once a week for nine weeks.

View Article and Find Full Text PDF

Extreme or rogue waves are large and unexpected waves appearing with higher probability than predicted by Gaussian statistics. Although their formation is explained by both linear and nonlinear wave propagation, nonlinearity has been considered a necessary ingredient to generate super rogue waves, i.e.

View Article and Find Full Text PDF

Cyclo-Gly-Pro (CGP) attenuates nociception, however its effects on salivary glands remain unclear. In this study, we investigated the acute effects of CGP on salivary flow and composition, and on the submandibular gland composition, compared with morphine. Besides, we characterized the effects of naloxone (a non-selective opioid receptor antagonist) on CGP- and morphine-induced salivary and glandular alterations in mice.

View Article and Find Full Text PDF

In this Letter we numerically and experimentally demonstrated that a lattice with an optical vortex distributed over the entire lattice can be generated in the Fourier space using three higher-order Laguerre-Gauss beams placed at the vertices of an equilateral triangle in real space. In this scheme the optical vortice's lattice presents a topological defect in its central region. Probing the net topological charge of the whole lattice, we found that it corresponds to the topological charge associated with the orbital angular momentum of each beam in real space.

View Article and Find Full Text PDF

Although gold nanoparticles have been shown to exhibit a range of beneficial biological properties, including antiinflammatory and anti-oxidant effects, their putative impact on allergic asthma has not been addressed. In this study, we evaluated the potential of nasal-instilled gold nanoparticles to prevent allergen-induced asthma in distinct murine models of this disease. Swiss-Webster (outbred) and A/J (inbred) mice were sensitized with ovalbumin and then treated with intranasal injections of gold nanoparticles (6 and 60 μg/kg), 1 h before ovalbumin challenges.

View Article and Find Full Text PDF

Interactions between cells and microenvironments are essential to cellular functions such as survival, exocytosis and differentiation. Cell adhesion to the extracellular matrix (ECM) evokes a variety of biophysical changes in cellular organization, including modification of the cytoskeleton and plasma membrane. In fact, the cytoskeleton and plasma membrane are structures that mediate adherent contacts with the ECM; therefore, they are closely correlated.

View Article and Find Full Text PDF

We study square and triangular optical lattice formation using a diffraction technique with light-possessing orbital angular momentum (OAM). We demonstrate that it is possible to use Fraunhofer diffraction of light by a square aperture to unveil OAM about two times bigger than would be possible with a triangular aperture. We notice that the pattern remains truncated until a topological charge (TC) equal to 20 with good precision.

View Article and Find Full Text PDF

We analytically and experimentally study the Fraunhofer diffraction of an optical vortex beam possessing noninteger values of the azimuthal index. We show that the Fraunhofer diffraction of this beam presents the birth of a vortex at α=n+ε, where n is an integer number and ε is a small fraction. We discuss this behavior on the basis of the born vortex movement from a position of low intensity to high intensity when α is increased of an integer number in fractional steps of ε.

View Article and Find Full Text PDF

We engineer an intensity square lattice using the Fraunhofer diffraction of a Laguerre-Gauss beam by a square aperture. We verify numerically and experimentally that a perfect optical intensity lattice takes place only for even values of the topological charge. We explain the origin of this behavior based on the decomposition of the patterns.

View Article and Find Full Text PDF

We study the Fraunhofer diffraction problem while taking into account the orbital angular momentum of light. In this case, the phase singularity of the light beam is incident on the slit in two different cases: in one, it is incident slightly above the slit, and in the other it is centered on the slit. We observed that the symmetry and the fringe formation in the interference pattern strongly depend on the amount of orbital angular momentum and the slit position in relation to the beam.

View Article and Find Full Text PDF

Ghost interference is experimentally investigated by varying the pseudothermal light source's transverse size and coherence width. Our results show that by increasing the transverse size of the source the quality of the interference pattern is improved, while the visibility is reduced. On the other hand, by increasing the coherence width of the source, the visibility of the interference pattern is improved, while the quality is reduced.

View Article and Find Full Text PDF

We study Zener tunneling in two-dimensional photonic lattices and derive, for the case of hexagonal symmetry, the generalized Landau-Zener-Majorana model describing resonant interaction between high-symmetry points of the photonic spectral bands. We demonstrate that this effect can be employed for the generation of Floquet-Bloch modes and verify the model by direct numerical simulations of the tunneling effect.

View Article and Find Full Text PDF

We discuss the interband light tunneling in a two-dimensional periodic photonic structure, as studied recently in experiments for optically induced photonic lattices [Trompeter, Phys. Rev. Lett.

View Article and Find Full Text PDF

We have experimentally measured the birefringence in bulk two-dimensional hexagonal photonic crystals in transparent spectral regions above and below the fundamental band gap. Data is presented for structures with different numbers of layers and two different air-filling fractions. We have used these data to design a photonic crystal quarter waveplate and provide independent experimental demonstrations of its operation.

View Article and Find Full Text PDF

We identify a new four-wave mixing process in which two nearly collinear pump beams produce phase-dependent gain into a weak bisector signal beam in a self-defocusing Kerr medium. Phase matching is achieved by weak-wave advancement caused by cross-phase modulation between the pump and signal beams. We relate this process to the inverse of spatial modulational instability and suggest a time-domain analog.

View Article and Find Full Text PDF