IWAVE-An adaptive filter approach to phase lock and the dynamic characterization of pseudo-harmonic waves.

We present a novel adaptive filtering approach to the dynamic characterization of waves of varying frequencies and amplitudes embedded in arbitrary noise backgrounds. This method, known as IWAVE (Iterative Wave Action angle Variable Estimator), possesses critical advantages over conventional techniques, making it a useful new tool in the dynamic characterization of a wide range of data containing embedded oscillating signals. After a review of existing techniques, we present the IWAVE algorithm, derive its key characteristics, and provide tests of its performance using simulated and real world data.

Fast-framing camera based observations of spheromak-like plasmoid collision and merging process using two magnetized coaxial plasma guns.

We have been conducting compact toroid (CT) collision and merging experiments by using two magnetized coaxial plasma guns. As is well known, an actual CT/plasmoid moves macroscopically in a confining magnetic field. Therefore, three-dimensional measurements are important in understanding the behavior of the CTs. To observe the macroscopic process, we adopted a fast-framing camera (ULTRA Cam HS-106E) developed by NAC Image Technology. The characteristics of this camera are as follows: a CCD color sensor, capable of capturing 120 images during one sequence with a frame rate of up to 1.25 MHz. Using this camera, we captured the global motion of a CT inside the magnetic field and the collision of two CTs at the mid-plane of the experimental device. Additionally, by using a color sensor, we captured the global change in the plasma emission of visible light during the CT collision/merging process. As a result of these measurements, we determined the CT's global motion and the changes in the CT's shape and visible emission. The detailed system setup and experimental results are presented and discussed.

Effects of para-nonylphenol on 92 kDa gelatinase secretion by human peripheral lymphocytes and U937 cells in vitro.

Much attention has focused on environmental estrogenic chemicals such as para-nonylphenol which disrupt various tissues via the estrogen receptor. We studied effects of para-nonylphenol on gelatinase secretion by human lymphocytes in vitro. para-Nonylphenol (0.05-50 microM) dose dependently suppressed 92 kDa gelatinase secretion. The suppressive effect of 25 and 50 microM para-nonylphenol was completely blocked by tamoxifen. We also studied the effects of para-nonylphenol (0.05-50 microM) on 92 kDa gelatinase secretion by human leukemia U937 cells. para-Nonylphenol suppressed 92 kDa gelatinase secretion in a dose-dependent manner. The suppressive effect of 50 microM para-nonylphenol was completely blocked by tamoxifen. Estradiol did not significantly suppress 92 kDa gelatinase secretion. Our results suggest that para-nonylphenol suppressed 92 kDa gelatinase secretion via the estrogen receptor, however, para-nonylphenol interacts with the estrogen receptor in a manner distinct from estradiol. As this assay system is simple and rapid, it may prove useful to evaluate toxic effects of para-nonylphenol on human blood cells.

Cytochrome P-450-butyl peroxide complex detected by ESR.

ESR measurements were performed for the reaction systems composed of t- or n-butylhydroperoxide and cytochrome P-450 (UT-2), purified from rat liver microsomes. On addition of n-butylhydroperoxide to the P-450 at pH 7.4, ESR signal due to a ferric low-spin species (g1 = 2.29, g2 = 2.24 and g3 = 1.96) was recorded. The observed g-parameters agreed well with those of a model thiolate-heme-iron(III)-peroxide complex, Fe(III)TPP(-S-TGE) (-OO-t-butyl) (g1 = 2.285, g2 = 2.198 and g3 = 1.959). In terms of the g-parameters, the new P-450 complex was concluded to be a P-450-butyl peroxide adduct, in which a butyl peroxide anion ligates at the sixth position of heme iron(III).

[Mechanical ventilation in rats]. / Ventilación mecánica en ratas.

In order to create an experimental model of mechanical ventilation that allows functional respiratory studies and different studies related to thorax surgery in small animals, young adult Sprague-Dawley male rats were anesthetised with sodium thiopental and a tracheostomy with a tephlonated catheter was performed. The carotid artery was canulated for arterial blood gas samples, and the cardiovascular system was controlled permanently. A continuous flow time cicled neonatal ventilator, Loosco Amsterdan Infant Ventilator M.K.2, was used for mechanical ventilation. Conventional ventilation with different volumes and pressures were tested. Good adaptation and tolerance and normal blood gases were found with a rate of 60/min; flow rate 0.2 l/min; I:E 1:2; PEED 0 cm H2O; PIP 6.7 +/- 0.5 (mean +/- SD) cm H2O and sharp waves. We conclude that with these very old neonatal ventilators it is possible to ventilate very small experimental animals easily, and allow to small laboratories to do respiratory functional studies or experimental surgery of the thorax.

[Monitoring theophylline in premature newborn infants]. / Monitorización de la teofilina en el recién nacido prematuro.

In order to defined the PO theophylline dose which produced effective theophylline concentrations between 4-10 micrograms/ml in prematures babies, we analized the theophylline pharmacokinetic of 6 adequate weight for gestational age female prematures, aged 31-34 gestational weeks, to which we administered PO 5 mg/kg of theophylline as the attack dose, following by a PO maintained dose of 2.5 mg/kg/12 h. In steady-state we did the pharmacokinetic studies after the administration of one dose. We found that only maintenance doses of 2.5 mg/kg/12 h produced therapeutic theophylline concentrations. Considering the pharmacokinetic data, we conclude that PO maintenance dose of 3 mg/kg/12 h of theophylline will be necessary to reach effective theophylline concentration.

[Pharmacokinetics of theophylline in children with acute asthmatic crisis]. / Farmacocinética de la teofilina en niños con crisis asmática aguda.

In order to defined the theophylline dose which produce effective theophylline concentrations with less number of plasmatic controls, we analyzed the theophylline pharmacokinetics of 18 boys and girls between 3-12 year olds of Tarragona, to which we administered 6 mg/kg/6 h of aminophylline by IV intermittent infusion (30 min), following by rapid-release PO aminophylline at the same dose and intervals. In steady-state we did the pharmacokinetic studies at 1 h, 4 h and 6 h after the administration of one dose. The maintenance dose obtained was administered PO as slow-release theophylline, with later controls of theophylline concentration. We found that maintenance dose of 24.1 +/- 4.7 mg/kg/day (mean +/- SD) allowed theophylline concentration between therapeutic levels in the population studied.