Estimation of the Hydromotive Source Pressure from Ejecting Beats of the Left Ventricle

The relationship between peak isovolumic developed pressure (Pmax) and end-diastolic volume can indicate ventricular contractility. Therefore, we propose a practical method to estimate Pmax from the pressure curve of an ejecting contraction of left ventricle. For the estimation, we first considered the left ventricle a linear time varying hydromotive pressure source (HMP(t)) coupled in series with an internal impedance. To formulate the HMP(t) we Fourier analyzed isovolumic pressure curves obtained under various conditions in six dogs. Since the higher order harmonics were found to be very small, HMP(t) could be described simply as where Pd = end-diastolic pressure and w = 2/T in which T is duration of contraction. Finally, HMP(t) for ejecting contraction was estimated by fitting the equation to the isovolumic portions of the pressure curve of ejecting contractions. The estimated Pmax values correlated well with actually observed Pmax values (r = 0.951, N = 24). We conclude that the proposed technique can be used to estimate Pmax from a single ejecting beat.     

STUDIES ON FROZEN BEER PRECIPITATES II. CHEMICAL STRUCTURE OF THE β-GLUCAN ISOLATED FROM THE PRECIPITATES

A nitrogen-free non-starchy polysaccharide was isolated from frozen beer precipitate by repeated precipitation with ethanol, and further fractionated with ammonium sulphate into a pentose-free fraction (G-1) and a pentose-containing fraction (G-2). The G-1 fraction, which constituted about 90% of the non-starchy polysaccharide, was composed solely of glucose residues united by β-linkages, as evidenced by the specific rotation (-12°) and the infrared absorption spectrum. The G-1 glucan gave glucose, celloblose, and laminaribiose on partial acid hydrolysis. Hydrolysis of the methylated G-1 glucan gave 2,3,6-tri-O-methyl-D-glucose and 2,4,6-tri-O-methyl-D-glucose together with trace amounts of 2,3,4,6-tetra-O-methyl-D-glucose and di-O-methyl-D-glucose (paper chromatography). Gas chromatography of the methanolysate of the methylated G-1 glucan indicated the presence of methyl 2,3,6-tri-O-methyl-D-glucopyranoside and methyl 2,4,6-tri-O-methyl-D-glucopyranoside with a proportion of 3:1. The G-1 glucan consumed 0·8 mole periodate per anhydroglucose residue on periodate oxidation. These results indicate that the G-1 glucan is a β-glucan of essentially linear structure containing β-1,4- and β-1,3-linked glucopyranose residues in proportions of 3:1 to 4:1. The molecular weight of the G-1 glucan was estimated as 114,000.     

Effect of styrene grafting on diffusion and solubility of gases in polyethylene

Diffusion and solubility coefficient data of gases for styrene-grafted high-density polyethylene obtained by γ-irradiation are reported. Diffusion coefficients were determined by the time lag method. Solubility coefficients were determined by a new, more accurate static method. Densities and volume fractions of grafted polystyrene were calculated from the observed values of extent of grafting and density of the graft copolymer films. The solubility coefficients obey simple additivity in terms of volume fraction of side-chain polystyrene and amorphous polyethylene. However, behavior of the diffusion coefficients is more complex. Inasmuch as diffusion is a kinetic process, it is influenced by morphology. The experimental results reported here, together with x-ray diffraction and DSC data, provide a basis for discussing the morphology of the graft copolymers.     

Gyrotron Backward Wave Oscillator Experiments with a Relativistic Electron Beam Using an X-Band Rectangular Waveguide

A mildly relativistic electron beam (500keV, 200A, 10ns) injected into an X-band rectangular waveguide immersed in a uniform axial magnetic field (4-10kG) produced magnetically tunable microwave radiation in the 9-13 GHz frequency range with an estimated output power of 1MW. The frequency range and tunability of the radiated microwave agreed with a theoretical model for a gyrotron backward wave oscillator taking into account the low energy component of the beam electron.     

Preparation of ZnS thin films from solution mist by laser irradiation

A new type of laser chemical vapour deposition process, in which the reactants are incorporated in the mist of the solvent, is proposed. It is applicable to prepare high-quality thin films from reactants having a low vapour pressure. By using a continuous wave CO₂ laser, ZnS thin films, consisting of c-axis oriented ultrafine microcrystallites, have been prepared.     

Sporadic diarrhea caused by Vibrio cholerae non-O1 and characteristics of the isolates

In 1996, we examined five domestic and eight imported cases of sporadic diarrhea caused by Vibrio cholerae non-O1 in Tokyo. The domestic cases occurred during the summer, from June to September, while the imported cases were seen throughout the year. The major clinical symptoms of the patients were watery diarrhea (100%) with an average frequency of 5.5 times/day, abdominal pain (77%), vomiting (31%) and fever (15%). A total of 13 strains isolated from these 13 cases had the typical biochemical characteristics of Vibrio cholerae, and were classified into 11 kinds of serovars (O2, O5, O8, O9, O12, O14, O27, O51, O88, O97, and O161). All strains produced hemolysin, and two strains produced NAG-ST, while no strain produced cholera toxin.