[en] The effects of toluene on the sensitivity to seizures induced by aminophylline were investigated. Mice were pretreated with an ip injection of corn oil or toluene (100-500 mg/kg) followed by a timed intravenous infusion of aminophylline at various time intervals to assess the seizure thresholds and lethal doses. Toluene increased seizure susceptibility to aminophylline in a dose- and time-dependent manner. Toluene-induced enhancement of seizure susceptibility to aminophylline occurred as early as 30 min and persisted for at least 3 days after a single administration of toluene (500 mg/kg). Treatment of benzaldehyde, one of toluene's metabolites, also showed an increase in the susceptibility to aminophylline. The enhancing effect was also observed in caffeine-induced seizures 1 h, but not 1 day after toluene treatment. These results suggest that individuals with toluene exposure may increase the risk for convulsive and even lethal complications associated with the therapeutic use of aminophylline

[en] The influence of annealing on the AgGaS₂ films grown by pulsed laser deposition has been investigated. The X-ray diffraction results show the AgGaS₂ films were found with preferential orientation (1 1 2) normal to the surface and silver droplets were diminished after the post-annealing. Photoluminescence (PL) measurements reveled the exciton energy is slightly red shifted that is possibly due to the thermal strain effect. The binding energy of the shallow donors is ∼28 meV determined from temperature dependent PL spectra. In addition, the A-exciton and the B/C-exciton could be observed in the transmittance spectra at room temperature

[en] Liu chaotic systems exhibit two- or four-scroll attractors and are observed in a variety of engineering phenomena, including rigid body motion, brushless DC motor system and so forth. This study applies the Lyapunov stability theorem to identify the sufficient conditions for the asymptotic stability of the equilibrium points of Liu chaotic systems. A linear balanced feedback gain control method is then employed to design a controller to achieve the global synchronization of two identical four-scroll Liu chaotic systems. The feasibility and effectiveness of the proposed chaos stability and synchronization schemes are verified via numerical simulations.

[en] An analysis of stability and chaotic dynamics is presented by a single-axis rate gyro subjected to linear feedback control loops. This rate gyro is supposed to be mounted on a space vehicle which undergoes an uncertain angular velocity ω_Z(t) around its spin axis and simultaneously acceleration ω-bar _X(t) occurs with respect to the output axis. The necessary and sufficient conditions of stability and degeneracy conditions for the autonomous case, whose vehicle undergoes a steady rotation, were provided by Routh-Hurwitz theory. The stability of the nonlinear nonautonomous system was investigated by Liapunov stability and instability theorems. As the electrical time constant is much smaller than the mechanical time constant, the singularly perturbed system can be obtained by the singular perturbation theory. The Liapunov stability of this system by studying the reduced and boundary-layer systems was also analyzed. Using the Melinikov technique, we can give criteria for the existence of chaos in the gyro motion when the vehicle undergoes perturbed harmonic rotation about its spin and output axes

[en] The decorporative efficacy and antioxidative action of prompt and delayed consecutive administration of catecholicpolyaminopolycarboxylate ligands, 7601 and 9501 for radiothorium in mice were investigated. DTPA and Vitamin E were used as positive controls. The competitive abilities of 7601 and 9501 to mobilize the thorium with BSA were studied. Their inhibition effects on superoxide anionas radicals were measured with electron spin resonance. The results showed that 7601 and 9501 are able to effectively prevent the internal radiation injury induced radiothorium, attributing to their double functions of pronounced removal effectiveness and antioxidative action. Their protective effects were better than DTPA and Vitamin E. The mechanisms of protective effects of 7601 and 9501 for internal radiation injury was close related to competitive ability of chelating agent to chelate the thorium with BSA and oxygen free radical scavenging activities

[en] This Letter introduces linear balanced feedback control scheme to design controller for the synchronization of two identical chaotic systems based on Lyapunov stability theory and constrained extreme approach. The technique is applied to synchronizing two identical four-scroll chaotic systems and guiding balanced feedback gains design. In accordance with the result of the analysis, an adaptive control scheme is proposed for chaos synchronization when the parametric variations of the response system are uncertain. The feasibility and effectiveness of the proposed synchronization scheme are verified via numerical simulations

[en] Cascaded photonic crystal fiber (PCF) tapers in a monolithic fiber obtained by post-processing techniques such as hole inflation and tapering have been manufactured. An ultraviolet-extended supercontinuum (SC) generation down to 352 nm wavelength pumped at 1064 nm in cascading PCF tapers has been obtained. High spectral flatness (5 dB) has been achieved in the entire visible window. (letter)

[en] Aiming at studying the dynamic performances of herringbone-grooved gas bearings, a model is built to analysis the relationship between herringbone-grooved gas bearings parameters and its performances such as friction torque, stiffness, stamping, etc. In this model, the hydrodynamic effect of compressible fluid and the shunting effect of herringbone groove are taken into account, and the partial derivative method which based on local integral finite difference method is used to calculate the modal at the same time. The result shows that when the average gap and the length-diameter ratio are decreasing, the rotate speed and eccentricity ratio will be increasing and the hydrodynamic effect of the gas bearing will be enhanced. Increasing groove angle, decreasing width-ridge ratio or aggrandizing length-groove ratio can improve its load capacity. The parameters such as rotate speed and eccentricity ratio are the most important factors which affect the dynamic characteristics of herringbone-groove gas bearing greatly. Then the analysis method is verified through an experiment systematically. In the experiment, the moment balance method is used. The experiment result shows that the result of model is correct s and reliable. (paper)

[en] In this paper, a PMMA (polymethylmethacrylate) microfluidic device with filtration features fabricated by hot embossing and thermal bonding was used to separate RBCs (red blood cells) from whole rat blood. The filtration features are composed of 20 µm deep and 300 µm wide main channels, 15 µm high and 25 µm wide micro-dams which were fabricated in main channels and an array of orthogonal side channels for perfusion flow to collect RBCs. As rat blood advances through the main channels, a perfusion flow through the side channels washes away RBCs which are sufficiently small to enter the gaps between the micro-dams and the cover plate. A silicon mold fabricated by dry etching was used to produce three-dimensional filtration features on PMMA substrates. Oxygen plasma treatment was used to increase the adhesive ability of PMMA surfaces, which enables thermal bonding at 86 °C and 0.75 MPa. The distortion of microchannels and micro-dams has been minimized, which makes the value of the gap between the micro-dam and the cover plate appropriate for cell filtration

[en] Poor main magnetic field (B₀) homogeneity (H_B) leads to artifacts and signal losses in magnetic resonance imaging (MRI). The American College of Radiology's MRI quality control manual mandates annual checks of H_B, suggesting tests using spectral linewidth and phase-difference (Δφ) maps. A new method, the bandwidth-difference (ΔBW) method, which compares the distortion for small and large BW acquisitions to determine the H_B, is proposed. The ΔBW method has the advantage that it can be used to measure multiple diameters of spherical volumes (DSV) in a single phantom. A phantom has been developed to exploit this method and results obtained with it are compared to those using three standard methods. Small receiver BW in the presence of poor H_B leads to geometric distortions because gradients are reduced to the level of the B₀ inhomogeneities. Data were acquired using seven MRI systems from different manufacturers, ranging in field strength from 0.2 to 3.0 T. Fast gradient echo pulse sequences were scanned twice using small and large BWs. H_B was measured from the shift of landmarks between the two BW acquisitions. Results were compared with data from the full width at half maximum (FWHM) method, the Δφ method and one manufacturer's resonant frequency mapping data. The FWHM method was available on two systems and the Δφ method was available on one. The ΔBW method could be performed in all scanners investigated. The H_B measured ranged 0.11-0.32 ppm to 6.7-12.9 ppm for DSV of 13-22.6 cm. Direct comparisons of the data obtained using the ΔBW method showed good agreement with data obtained using the FWHM method. Data obtained using the ΔBW method compared favorably with the manufacturer's resonant frequency map. The ΔBW method produces measurements of H_B at various DSV values that can be obtained from a single set of phantom images. The accuracy of ΔBW B₀ homogeneity measurements are comparable to the other methods tested