A quantitative framework for analyzing epicardial activation patterns during ventricular fibrillation

We have developed a method for quantifying the complexity of activation patterns observed during ventricular fibrillation (VF) that is based on our previously reported methodology for decomposing epicardial mapping data into a set of isolated wavefronts. One-half second datasets are acquired from a 21 x 24 array of unipolar electrodes (1 mm spacing), and the wavefronts are isolated. A correlation technique is used to compute the similarity between all possible pairs of the isolated wavefronts. From these data, the wavefronts are sorted into clusters, each of which represents a recurring wavefront morphology. We define multiplicity (M) as the number of clusters needed to account for 90% of the total activations in the VF episode. M measures the complexity of the rhythm. In repetitive patterns (e.g., sinus rhythm), M = 1, indicating that the same morphology repeatedly activates the mapped region. Typically, in VF, M > 1, with larger numbers representing more complex, disorganized patterns. As an example, we computed M at 5, 10, 15, and 20 sec after electrical induction of VF in six pigs. M decreased significantly (p < 0.001), suggesting increasing organization during this period.     

Reaction of layered carbon fluorides CxF (x = 2.5-3.6) and hydrogen

The layered carbon fluorides C_xF (x = 2.5, 2.8, 3.6), generally classified as fluorine-graphite intercalation compounds, were heat-treated in hydrogen gas. These fluorides are more reactive with hydrogen compared to (CF)_n and (C₂F)_n. Reduction of C_xF to graphite-like carbon starts at about 573 K, and proceeds gradually along with the elevation of temperature. Fluorine atoms in C_xF are eliminated as HF in the reduction process without being substituted by hydrogen atoms. Systematic difference was not found in the average crystallite sizes of the carbon material prepared from C_xF by the reduction with hydrogen and that by the pyrolysis in vacuum. On the other hand, interlayer distance and fluorine content of the former are smaller than those of the latter. In the case that the C_xF precursor maintains a large particle size, the reduced carbon as well as the pyrolytically prepared carbon possesses a foam-like shape due to the exfoliation during the heat treatment.     

Terpendole E and its Derivative Inhibit STLC‐ and GSK‐1‐Resistant Eg5

Terpendole E is first natural product found to inhibit mitotic kinesin Eg5, but its inhibitory mechanism remains to be revealed. Here, we report the effects of terpendole E and 11ketopaspaline (a new natural terpendole E analogue) on the Eg5–microtubule interaction and in several Eg5 mutants. 11‐Ketopaspaline is a shunt product from terpendole E, and it shows potent inhibitory activity against the microtubule‐stimulated ATPase activity of Eg5. Unlike other Eg5 inhibitors, such as S‐trityl‐L ‐cysteine (STLC) and GSK‐1, both terpendole E and 11‐ketopaspaline only partially inhibited Eg5–microtubule interaction. Furthermore, terpendole E and 11‐ketopaspaline inhibited several Eg5 mutants that are resistant to STLC (Eg5^D130A, Eg5^L214A) or GSK‐1 (Eg5^I299F, Eg5^A356T), but with the same extent of inhibition against wild‐type Eg5. Because Eg5^D130A and Eg5^L214A show cross‐resistance to most known Eg5 inhibitors, which bind the L5 loop, these results suggest that terpendole E and its analogues have a different binding site and/or inhibitory mechanism to those for L5 loop‐binding type Eg5 inhibitors.     

Photo-rechargeability of film electrodes prepared by pulsed laser deposition

The film electrodes of TiO₂, which have two functions of opto-electric conversion and storage of electrochemical energy, were prepared by pulsed laser deposition. To investigate the relationship between the photo-rechargeability and the surface structure, the TiO₂ film electrodes with different surface morphology were prepared by changing the inert gas pressure during the deposition. The photo-charged quantity was found to be proportional to the third power of the rms of surface roughness. The results suggest that not only the surface but also the interstices between crystal grains near the surface contribute to the photo-charging with low photo-emf.     

Multimedia services in the HDTV MUSE system

Experimental equipment to investigate multimedia service functions for application to MUSE (multiple sub-Nyquist sampling encoding) HDTV broadcasting has been developed. This system is called the multimedia MUSE system. Programs have also been produced to evaluate service functions of the system taking into account the capacity of the transmission path. This paper describes the configuration of the multimedia MUSE System, service examples, and evaluation of transmission capacity making use of test programs. Our studies reveal that multimedia broadcasting services can be provided when storage memory is installed for achieving interactive viewing and multimedia programs are appropriately configured. In addition, the services described here will provide the basic concept for multimedia broadcasting in future digital broadcasts     

Three-dimensional organization of collagen fibrils during corneal stromal wound healing after excimer laser keratectomy

PURPOSE: To investigate the structural changes in corneal stromal collagen fibrils after excimer laser keratectomy in relation to the degree of corneal haze. SETTING: University of Tokyo Hospital, Tokyo, Japan. METHODS: Corneal haze was quantitatively measured by analyzing the light scattering in Scheimpflug images of the corneas of white rabbits after excimer laser keratectomy. Collagen fibril structure was examined using scanning electron microscopy after chemical digestion with sodium hydroxide solution; the same specimens were examined by transmission electron microscopy after re-embedding. RESULTS: Corneal haze reached a peak 4 weeks after excimer laser keratectomy and then gradually decreased. The collagen fibrils of the normal cornea were regularly arranged parallel to the surface of the cornea, with small interfibrillar distances. After excimer laser keratectomy, the arrangement was highly disordered, with increased interfibrillar distances. These structural changes were most prominent 4 weeks after excimer laser keratectomy. CONCLUSION: The structural changes in the collagen fibrils of the corneal stroma, especially the increase in interfibrillar distances and the disordered arrangement, were associated with corneal haze after excimer laser keratectomy.     

Inhibition of experimental autoimmune uveoretinitis by transforming growth factor-beta 1 in B10. A mice

Experimental autoimmune uveoretinitis (EAU) in mice, an organ specific autoimmune disease, has been investigated as an animal model for human endogenous uveitis. In this study, we report on the immunosuppressive effect of transforming growth factor-beta 1 (TGF-beta 1) on the development of EAU in mice. Inhibition by TGF-beta 1 of proliferation of interphotoreceptor retinoid-binding protein (IRBP)-specific T cell lines in B10.A mice against IRBP antigen was dose-dependent. However, when spleen cells used as the antigen presenting cell were first cultured with TGF-beta 1, this anti-proliferation effect was abolished. When IRBP-immunized mice were injected intraperitoneally with TGF-beta 1, dose-dependent suppression of EAU was obtained. The proliferation response of lymph node cells from TGF-beta 1 injected mice with IRBP-induced EAU was suppressed compared with phosphate buffered saline (PBS)-injected mice. These findings suggest that TGF-beta 1 may be a cytokine that plays a role in suppressing IRBP induced EAU in mice.     

Desensitization of the GABAA receptor shifts the dynamic range of retinal horizontal cells due to light and dark adaptation

The effects of the GABAergic pathway on the dynamic range of the light response of cone-driven horizontal cells (HCs) in the carp retina were investigated using conventional intracellular recordings and computer simulations. The amplitude of the HC responses to repetitive test flashes was altered by background illumination in control Ringer's solution, but was not changed following the application of picrotoxin or bicuculline, which suggests that GABAA receptors mediate the subsequent change in light response. This phenomenon was simulated by introducing the desensitization mechanism of the GABAA receptor into a cone-HC network model. These results suggest that desensitization of the GABAA receptor shifts the dynamic range of the HCs due to light and dark adaptation.     

High speed data collection system for magnetic field imaging by CTtechnique

A method of high-speed data collection used in imaging the magnetic-field distribution leaking from magnetic devices along any plane is proposed. The method uses the computed tomography (CT) technique. A high-speed data collection system developed for demonstrating the method is described. An image of the magnetic field is reconstructed from projection data provided by the voltage induced in the sensors of a line conductor and a rectangular coil moving in the plane of observation. Rotational scanning of the sensors is used for collecting the projections so that data-acquisition time can be reduced. To demonstrate the performance of the system, the reconstructed images of the magnetic-field distributions made by some permanent magnets are shown