Daniel Pereira

Infliximab prevents increased systolic blood pressure and upregulates the AKT/eNOS pathway in the aorta of spontaneously hypertensive rats

High systolic blood pressure caused by endothelial dysfunction is a comorbidity of metabolic syndrome that is mediated by local inflammatory signals. Insulin-induced vasorelaxation due to endothelial nitric oxide synthase (eNOS) activation is highly dependent on the activation of the upstream insulin-stimulated serine/threonine kinase (AKT) and is severely impaired in obese, hypertensive rodents and humans. Neutralisation of circulating tumor necrosis factor-α (TNFα) with infliximab improves glucose homeostasis, but the consequences of this pharmacological strategy on systolic blood pressure and eNOS activation are unknown. To address this issue, we assessed the temporal changes in the systolic pressure of spontaneously hypertensive rats (SHR) treated with infliximab. We also assessed the activation of critical proteins that mediate insulin activity and TNFα-mediated insulin resistance in the aorta and cardiac left ventricle. Our data demonstrate that infliximab prevents the upregulation of both systolic pressure and left ventricle hypertrophy in SHR. These effects paralleled an increase in AKT/eNOS phosphorylation and a reduction in the phosphorylation of inhibitor of nuclear factor-κB (Iκβ) and c-Jun N-terminal kinase (JNK) in the aorta. Overall, our study revealed the cardiovascular benefits of infliximab in SHR. In addition, the present findings further suggested that the reduction of systolic pressure and left ventricle hypertrophy by infliximab are secondary effects to the reduction of endothelial inflammation and the recovery of AKT/eNOS pathway activation.

Near-fatal pulmonary embolism in an experimental model: hemodynamic, gasometric and capnographic variables

INTRODUCTIONnExperimental studies on pulmonary embolism (PE) are usually performed under mechanical ventilation. Most patients with suspicion of PE enter the Emergency Services in spontaneous breathing and environmental air. Thus, under these conditions, measurements of hemodynamic, gasometric and capnographic variables contribute largely to a more specific comprehension of cardiopulmonary and gasometric alterations in the acute phase of the disease. Studies which evaluated animals under conditions are lacking.nnnOBJECTIVEnThis study aimed to submit animals under spontaneous ventilation and without supplemental oxygen to PE.nnnMETHODSnPE was induced in six pigs using autologous blood clots, and cardiorespiratory and gasometric records were performed before and after PE. The values of near fatal mean pulmonary arterial pressure (MPAP) were previously determined.nnnRESULTSnThe presence of obstructive shock could be evidenced by increased MPAP (from 17.8 ± 3.5 to 41.7 ± 3.3 mmHg) (P<0.0001) and decreased cardiac output (from 4.9 ± 1.0 to 2.7 ± 1.0 L/min) (P<0.003). Consequently, metabolic acidosis occurred (Lac art) (from 2.4 ± 0.6 to 5.7 ± 1.8 mmol/L)(P<0.0001). It was observed hypoxemia (from 73.5 ± 12.7 to 40.3 ± 4.6 mmHg) (P<0.0001); however, PaCO2 did not vary (from 44.9 ± 4.4 to 48.2 ± 6.0 mmHg) (NS). There were significant increases in both P(a-et)CO2 (from 4.8 ± 2.8 to 37.2 ± 5.8 mmHg) and P(A-a)O2 (from 8.2 ± 8.9 to 37.2 ± 10.3 mmHg) (both P<0.0001). There was also a significant increase in the total alveolar minute volume (from 4.0 ± 0.9 to 10.6 ± 2.9 L/min) (P<0.0001).nnnCONCLUSIONSnIn this model, the near fatal MPAP was from 2 to 2.5 times the basal MPAP; and the capnographic variables, associated with arterial and venous gasometry, showed effective in discriminating an acute obstructive profile.

Characterization of new FIR laser lines from CHD/sub 2/OH

In this work, we report new optically pumped far-infrared (FIR) laser lines from CHD/sub 2/OH. A waveguide CO/sub 2/ laser of wide tunability (290 MHz) was used as pump source, and a Fabry-Pe/spl acute/rot open cavity was used as a FIR laser resonator. Optoacoustic absorption spectra were used as a guide to search for new FIR laser lines. We could observe 15 new laser lines in the range from 116.4 to 401.4 /spl mu/m. The lines were characterized according to wavelength, relative polarization, relative intensity, and optimum working pressure. The transferred Lamb-dip technique was used to measure the frequency absorption transition both for the new and previously reported laser lines.

Frequency doubled and stabilized all-solid-state Ti:sapphire lasers

We describe in detail the design, construction, and characterization of an efficient frequency doubled and stabilized all-solid-state Ti: sapphire laser. The laser frequency has been locked to the resonance of a Fabry-Perot cavity, and doubled in a Brewster-cut potassium niobate crystal placed inside a power enhancement cavity. Up to 200 mW of single frequency blue light with fast frequency instabilities of 40-kHz rms and a drift of 10 MHz/hour has been generated. The spectral distributions of amplitude and frequency noise for the free-running laser have been measured and compared with the case of pumping from an argon ion laser. Our laser is well suited in atomic physics for high resolution spectroscopy and for laser cooling and trapping using transitions in the blue-violet region, as we demonstrate with the calcium resonant transition, at 423 nm.

Single-frequency blue light source based on optically injected diode lasers

We describe a diode-laser-based system capable of generating >50 mW of single-frequency radiation near 425 nm. An alternative extended cavity diode laser injection seeds a semiconductor amplifier, whose output is frequency doubled by a nonlinear crystal placed in a power enhancement cavity. This system is particularly well suited for high-resolution spectroscopy in the blue region, and for laser cooling and trapping of calcium atoms.

Desenvolvimento de software de análise gráfica para planos de radioproteção

In this work we developed a software that calculates the external doses in a plant radioactive, and presented graphically in contour dose (isodoses) using the geometric method. It was created to help the lessons of radioprotection, but can be used to review plans for radioprotection. The software was written for version 6.0 of the application Mathematica® from Wolfram Research for the algebraic and numerical calculation, but can be easily translated into Maple®, Matlab® or Delphi®. To demonstrate its application, this software is used to prepare the plan for radioprotection of a laboratory that uses a gas isotopic laser (14CO2).

Characterization of new FIR laser lines from CD/sub 3/-rocking and asymmetric CD/sub 3/ deformation modes of /sup 13/CD/sub 3/OD

In this paper, we report new optically pumped far-infrared (FIR) laser lines from the in-plane CD/sub 3/-rocking and asymmetric CD/sub 3/ deformation absorption vibrational bands of /sup 13/CD/sub 3/OD. A waveguide CO/sub 2/ laser of wide tunability (290 MHz) was used as the pump source, and a Fabry-Perot open cavity as the FIR laser resonator. Optoacoustic absorption spectrum was used as a guide to search for new FIR laser lines. We could observe 13 new laser lines in the range 103-491 /spl mu/m. The lines were characterized according to wavelength, relative polarization, relative intensity, and optimum working pressure. The transferred lamb-dip technique was used to measure the frequency absorption transition for both new and previously reported laser lines.

Deceleration of a calcium atomic beam with a frequency-doubled diode laser

A calcium atomic beam has been decelerated by a single extended-cavity diode laser, frequency doubled to 423 nm. A potassium niobate crystal is placed in an external power buildup cavity, and the second-harmonic laser beam, counterpropagating with the atomic beam, is tuned into resonance with the strong 1S0–1P1 transition of calcium. For input power of 78 mW at 846 nm, we generate 22 mW at 423 nm after correction for the reflectivity of our cavity output coupler. To keep the atoms always in resonance during the deceleration process, the Zeeman tuning technique was used.

An enhanced parallel port interface for controlling and monitoring experiments

In this paper we present a circuit for enhanced parallel port (EPP) interfacing that is of low cost and great versatility for general use for data communication in research laboratories. The communication is bi-directional and its speed is higher than 500 Kbytes s-1 . This circuit has an address decoder, which permits individual communication with eight items of equipment of 8 and 16 bits, with an extra status bit. The addressing system also allows insertion of up to 16 such interfacing circuits into the same computer EPP output, each of which can be independently reached.

Calcium magneto-optical trap loaded from a decelerated atomic beam

We describe a new system for laser cooling and trapping of neutral Calcium atoms employing the 1S0 -1 P1 resonant transition at 423 nm. An on-axis magneto-optical trap (MOT) is loaded from a Zeeman decelerated atomic beam. When a single laser is used, in order to avoid perturbation of the trap by the deceleration laser beam, this one has been tightly focused near the MOT center, with a waist size much smaller than the atomic cloud. In order to test the efficiency of this novel technique, we have then employed a second, independent decelerating laser, with a profile mode matched to the atomic beam. For an oven temperature of 580±C this system can load 1.2 (2) x 107 atoms in 16 (1) ms. By the spatial extension of the atomic cloud the one dimension rms velocity was estimated to be 136 (12) cm/s, corresponding to a temperature of 9 (2) mK. The variation of the number of trapped atoms as a function of laser detuning and intensity, trap magnetic field gradient and oven temperature is analyzed. Spatial structures of the trapped atoms, like stable rings created by vortex forces, have been observed. This is the first time that these structures, already observed in alkali-metal elements, are reported in MOTs of alkaline-earth elements.