Soret effect and photochemical reaction in liquids with laser-induced local heating.

We report a theoretical model and experimental results for laser-induced local heating in liquids, and propose a method to detect and quantify the contributions of photochemical and Soret effects in several different situations. The time-dependent thermal and mass diffusion equations in the presence and absence of laser excitation are solved. The two effects can produce similar transients for the laser-on refractive index gradient, but very different laser-off behavior. The Soret effect, also called thermal diffusion, and photochemical reaction contributions in photochemically reacting aqueous Cr(VI)-diphenylcarbazide, Eosin Y, and Eosin Y-doped micellar solutions, are decoupled in this work. The extensive use of lasers in various optical techniques suggests that the results may have significance extending from physical-chemical to biological applications.

Influence of Incorporating Zirconium- and Barium-based Radiopaque Filler Into Experimental and Commercial Infiltrants.

OBJECTIVES: To evaluate how adding different concentrations of particles (barium or zirconium oxide 25%/45% by weight) to a commercial infiltrant (Icon) and an experimental infiltrant influences cohesive strength (CS), degree of conversion (DC), water sorption (WS), solubility (SL), radiopacity, and penetration depth. METHODS AND MATERIALS: Microtensile CS (n=10) was evaluated using a universal testing machine. DC (n=5) was evaluated in a Fourier-transform infrared spectrometer. Polymerized samples were dissected, weighed, and stored to obtain the final mass for WS and SL tests (n=10). Radiopacity analysis (n=5) was performed using a digital radiography system. Penetration depth analysis (n=5) was performed by confocal laser scanning microscopy. Analyses were performed using the R program, with a significance level of 5%, except for the penetration depth analyses, which were evaluated only qualitatively. RESULTS: The groups with 45% zirconium showed greater CS values, regardless of the infiltrant. Among the groups with no particle addition, those of the experimental infiltrant presented higher DC than those of Icon. The experimental infiltrant presented lower WS than Icon. All groups had SL below the ISO recommended levels. Radiopacity higher than 2.24 mmAl (enamel radiopacity) was observed only in the groups with 45% zirconium. All the groups achieved similar penetration depth, but the groups containing experimental infiltrant appear to have had longer tag extensions. CONCLUSIONS: Addition of 45% of zirconium presented good results for CS and WS, as well as SL below the ISO recommended standard, adequate radiopacity, and penetration depth similar to the other groups.

Time-resolved thermal mirror technique with top-hat cw laser excitation.

A theoretical model was developed for time-resolved thermal mirror spectroscopy under top-hat cw laser excitation that induced a nanoscale surface displacement of a low absorption sample. An additional phase shift to the electrical field of a TEM(00) probe beam reflected from the surface displacement was derived, and Fresnel diffraction theory was used to calculate the propagation of the probe beam. With the theory, optical and thermal properties of three glasses were measured, and found to be consistent with literature values. With a top-hat excitation, an experimental apparatus was developed for either a single thermal mirror or a single thermal lens measurement. Furthermore, the apparatus was used for concurrent measurements of thermal mirror and thermal lens. More physical properties could be measured using the concurrent measurements.

Optical pseudomotors for soft x-ray beamlines.

Optical elements of soft x-ray beamlines usually have motorized translations and rotations that allow for the fine alignment of the beamline. This is to steer the photon beam at some positions and to correct the focus on slits or on sample. Generally, each degree of freedom of a mirror induces a change of several parameters of the beam. Inversely, several motions are required to actuate on a single optical parameter, keeping the others unchanged. We define optical pseudomotors as combinations of physical motions of the optical elements of a beamline, which allow modifying one optical parameter without affecting the others. We describe a method to obtain analytic relationships between physical motions of mirrors and the corresponding variations of the beam parameters. This method has been implemented and tested at two beamlines at ALBA, where it is used to control the focus of the photon beam and its position independently.

Longitudinal study of periodontal condition in students of the Dental School the University of Buenos Aires Argentina.

The aim of the present study was to describe, clinically and radiographically, the gingivoperiodontal condition of students (young adults) entering the Dental School and reassess it 2 years later. Four hundred and seventy-five students, 147 male and 328 female (mean: 19.66 years) were studied (Initial examination: IE); two years later, 240 students 76 male and 164 female were reevaluated (Final examination: FE). The clinical examination include Plaque Index (P1I), Gingival Index (GI), Bleeding on Probing (BOP), Probing Pocket Depth (PPD), and Attachment Level (AL). Alveolar bone level was measured on bite wing radiographs. At the IE, 46.5% of the sites had no visual signs of inflammation and 65.3% did not bleed on probing, however 91% of the students had at least one site with BOP. (Prevalence). Of the total sites probed 99.47% had crevices between 1 to 4 mm. 92% had AL between 0 to 1 mm. And only 7.9% had AL > 1 mm. 49.6% of the students had at least one site with AL > 1 mm. Prevalence of alveolar bones loss > 2 mm. was 2.95% and in no case measurements exceeded 3 mm. Distal of teeth 16 and 36 showed the highest P1I, GI, PPD and AL, therefore these teeth showed the highest risk of pathology in the population studied. In the final examination 70.5% of the sites had GI 0 and 73% did not bleed on probing. 90.4% of the students had at least one site with BOP. No statistically significant difference in PPD nor in AL was found between IE and FE. In this population of young adults prevalence of gingivitis was high but severity was low. Prevalence of loss of attachment was near 50% but only 7.9% of the sites had AL > 1 mm. After studying dentistry for two years the prevalence of gingivitis was similar but the severity was lower. Periodontal condition was not substantially modified.

Two color multichannel heterodyne interferometer set up for high spatial resolution electron density profile measurements in TJ-II.

A high spatial resolution two color [CO(2), λ=10.6 µm/Nd:YAG (Nd:YAG denotes neodymium-doped yttrium aluminum garnet), and λ=1.064 µm] expanded-beam multichannel heterodyne interferometer has been installed on the TJ-II stellarator. Careful design of the optical system has allowed complete control on the evolution of both Gaussian beams along the interferometer, as well as the evaluation and optimization of the spatial resolution to be expected in the measurements. Five CO(2) (measurement) channels and three Nd:YAG (vibration compensation) channels have been used to illuminate the plasma with a probe beam of 100 mm size. An optimum interpolation method has been applied to recover both interferometric phasefronts prior to mechanical vibration subtraction. The first results of the installed diagnostic are presented in this paper.

Calibration of a high spatial resolution laser two-color heterodyne interferometer for density profile measurements in the TJ-II stellarator.

A high spatial resolution two-color (CO(2), lambda=10.6 microm, He-Ne, lambda=633 nm) interferometer for density profile measurements in the TJ-II stellarator is under development and installation, based in the currently operational single channel two-color heterodyne interferometer. To achieve the objectives of 32 channels, with 4-5 mm lateral separation between plasma chords, careful design and calibration of the interferometric waveforms for both the measurement and vibration compensation wavelengths are undertaken. The first step has been to set up in our laboratories an expanded-beam heterodyne/homodyne interferometer to evaluate the quality of both interferometric wavefronts, a reported source of poor vibration compensation and thus low resolution in the density profile measurements. This novel interferometric setup has allowed us to calibrate the spatial resolution in the profile measurements resulting in approximately 2 mm lateral resolution in the reconstruction of the interferometric wavefront.

[Inflammatory response and apoptosis in acute pulmonary injury]. / Respuesta inflamatoria y apoptosis en la lesión pulmonar aguda.

One of the principal mechanisms of pulmonary injury in acute respiratory distress is due to the effects of the precipitated inflammatory response. The damage produced to the alveolar epithelium and underlying endothelium depends on the sequestration and activation of inflammatory cells, which in turn exert their actions through mediators. On the other hand, apoptosis is a mechanism responsible for epithelial damage and regulation of inflammation. Response of the lung tissue subjected to mechanical ventilation stimulus is added to the previous mechanisms. All these processes flow into a series of common pathways of cellular activation. Knowledge of these mechanisms could serve to identify which patients would benefit from a specific treatment before applying therapies that act indiscriminately in the inflammatory response.

Doenças de bezerros. II. Epidemiologia da anaplasmose no Estado de Sergipe / Diseases of calves: anaplasmose epidemiology in the State of Sergipe, Brazil

Este estudo representa parte de um trabalho sobre doenças de bezerros nas regiöes produtoras de leite do Estado de Sergipe. Foi realizado levantamento epidemiológico para determinar a prevalência de anaplasmose, através do "anaplasmosis card-test" e do método de Giemsa em 2593 bezerros de até um ano de idade. Foram testadas amostras colhidas de 116 propriedades, distribuídas por 15 municípios das regiöes climáticas árida, semi-árida, transiçäo semi-árida e transiçäo subúmida. A prevalência da infecçäo foi de 16,3 por cento e frequência de 12,3 por cento de animais com corpúsculo de inclusäo