Endoscopic treatment of vesicoureteral reflux in patients with myelodysplasia

PURPOSE: We assessed the usefulness of and indications for endoscopic treatment of vesicoureteral reflux in myelodysplasia patients. MATERIALS AND METHODS: A total of 26 patients treated with intermittent catheterization was divided into 11 (16 ureters) with and 15 without vesicoureteral reflux. In 9 patients (13 ureters) endoscopic correction was performed with 3% atelo-collagen and without anesthesia at the outpatient clinic. In each ureter we obtained the sum of scores for 4 risk factors for upper urinary tract deterioration: bladder compliance less than 10 ml./cm. water, grade 2 to 3 bladder deformity, detrusor-sphincter dyssynergia and urethral closure pressure 50 cm. water or greater. RESULTS: No reflux was demonstrated immediately after the initial collagen injection but cystography 3 to 6 months later showed recurrent reflux in 5 ureters (38%). Repeat injection cured the reflux, with results persisting for an average of 17 months. Mean risk factor score for patients without vesicoureteral reflux was significantly lower than that for patients with reflux. In patients treated with intermittent catheterization and anticholinergic agents the mean score for ureters with an increased or unchanged reflux grade was significantly greater than for those with a decreased grade. CONCLUSIONS: Endoscopic treatment of reflux appears to be safe and useful in patients with myelodysplasia. The treatment is preferable in those with high risk factor scores due to the possibility of increased reflux grade in such patients.     

Robust parameter-estimation using the bootstrap method for the2-parameter Weibull distribution

This paper proposes bootstrap robust estimation methods for the Weibull parameters; it applies bootstrap estimators of order statistics to the parametric estimation procedure. Estimates of the Weibull parameters are equivalent to the estimates using the extreme value distribution. Therefore, the bootstrap estimators of order statistics for the parameters of the extreme value distribution are examined. Accuracy and robustness for outliers are examined by Monte Carlo experiments which indicate adequate efficiency of the proposed reliability estimators for data with some outliers     

Flexible generation mix under multi objectives and uncertainties

Criteria for evaluating flexibility of a generation mix are presented, and an efficient computational algorithm for determining a flexible generation mix considering uncertainties in the power system expansion planning is developed. The flexible generation mix problem is formulated as a multiobjective optimization problem and solved by the dynamic programming technique in which type of generation plant is selected as a stage and generation capacity is selected as a state. The proposed method can treat easily not only the uncertainties but also many constraints of generation planning such as integer solutions of generation capacities, reliability constraints, and so on. The effectiveness and feasibility of the proposed method are demonstrated on a typical power system model     

Determination of horseradish peroxidase concentration using the chemiluminescence of Cypridina luciferin analogue, 2-methyl-6-(p-methoxyphenyl)-3,7-dihydroimidazo[1,2-a]pyrazin-3-one

The chemiluminescence of the Cypridina luciferin analogue, 2-methyl-6-(p-methoxyphenyl)-3,7-dihydroimidazo[1,2-a]pyrazin++ +-3-one (MCLA) was observed at 462 nm in the presence of horseradish peroxidase (HRP) and the total spectrum of light emitted was found to depend linearly on HRP concentration. Methods for the determination of HRP concentration using the chemiluminescence was investigated. HRP could be detected in the range from 100 pmol/L to 100 nmol/L under the optimum condition, H2O2 (10 mmol/L) and MCLA (10 mumol/L) at pH 5.8.     

Pseudo-binary system Bi2O3-TeO2 in air

The phase equilibria in the pseudo-binary system Bi₂O₃-TeO₂ at 600° 950° C in air were examined by solid-state reaction techniques and X-ray powder diffraction method. Four pseudo-binary compounds appeared, i.e., -Bi₂O₃ type solid solution having a compositional range of (1-x)Bi₂O₃·xTeO₂ wherex=0 0.4 a new compound Bi₆Te₂O₁₅ which has an orthorhombic cell of a=2.27(4) nm, b=1.06(1) nm and c = 0.539(8) nm, 2Bi₂O₃ · 3TeO₂, and an unidentified phase Bi₂O₃·2TeO₂. The formation of the phase Bi₆Te₂O₁₅, in which all the Te ions are hexavalent, was confirmed by the thermogravimetry and by the Mössbauer spectra. The liquidus curves for whole system were determined by DTA method.     

X-ray CDF study on the behaviour of the amorphous chain under extension

The behaviour of the amorphous chain in vulcanized natural rubber (NR) and styrene-butadiene rubber (SBR) under extension is studied by means of the cylindrical distribution function (CDF) derived from wide angle X-ray scattering (WAXS). In the case of the highly stretched vulcanized NR where the orientation-induced crystallization took place, the observed WAXS intensity was separated into a crystalline peak component and a broad amorphous one from which the CDF was obtained. The CDF calculated from the broad component shows that some of the amorphous segments of the highly stretched vulcanized NR are extended as fully as the crystalline chains and that the fraction of the segments increases with increasing extension. In the case of SBR, such fully stretched segments as in the case of the vulcanized NR show higher degree of an interchain packing order than those in the vulcanized NR.     

Molecular association complex of urea with polyethylene: 3. Structural studies of the complex

The crystal structure of urea-polyethylene complex in the hexagonal form, obtained by one of our preparation methods, is analysed by X-ray power diffractometry. In this analysis, the fixed molecular parameters of urea are used, and three models with respect to rotational disorder of the guest polyethylene molecule are assumed. It is shown that the host lattice structure constructed by urea molecules is essentially the same as that of urea-n-paraffin complex. Effects of the disorder structure of the guest on X-ray scattering of the complex are presented. However, there is a difficulty in identifying the disorder structure by X-ray analysis. With the aid of a potential energy calculation between the hexagonal urea tunnel and the guest molecule, a rotational disorder model is preferred.     

The hydrogen-electrode reaction in the isotopically mixed system—II. Evaluation of the electrolytic separation factor of deuterium from the rest potential of the hydrogen electrode in the deuterium-containing system

The rest potential, E_r, of the hydrogen electrode in deuterium-containing hydrogen and a solution of light water as referred to the reversible hydrogen electrode in the light hydrogen and the same solution is formulated as a function of deuterium content of the gaseous hydrogen and the deuterium separation factor, S_b, in the hydrogen ionization reaction. It is shown that the relation is not significantly affected by the operative mechanism of the hydrogen-electrode reaction. Consequently, the relation provides a convenient method of evaluating S_b from the observation of E_r.

Experiments were carried out on Pt, Ni, Au and Ag in the system composed of deuterium-containing hydrogen and light water. The value of S_b as evaluated from E_r was practically independent of the deuterium content in the gaseous hydrogen. The values obtained were 1·1 for Pt in acidic and alkaline solutions, 1·6 for Ni in alkaline solution, 1·2 for Au and 1·5 for Ag, both in acidic solution. These values multiplied by the partition coefficient of deuterium between hydrogen and water (4·0 at room temperature) give approximate values of the deuterium separation factor in the hydrogen evolution reaction.     

Evaluation of hydrogen absorption properties of Ti–0.2 mass% Pd alloy in fluoride solutions

The hydrogen absorption properties of Ti–0.2 mass% Pd (Ti–0.2Pd) alloy in 2.0% and 0.2% acidulated phosphate fluoride (APF) and neutral 2.0% NaF solutions (25 °C) has been evaluated by hydrogen thermal desorption analysis. During the early stage of immersion (120 h) in the 2.0% APF solution, the amount of absorbed hydrogen was lower than 500 mass ppm. A thermal desorption of hydrogen primary appearing with a peak at 500–600 °C and a broad desorption ranging from 100 to 400 °C were observed. In the 0.2% APF solution, the amount of absorbed hydrogen saturated at 100–200 mass ppm; the thermal desorption of hydrogen appeared with a single peak at 550 °C. In the 2.0% NaF solution, hydrogen absorption was negligible even after 1000 h of immersion, although corrosion pits were observed. The results of the present study suggest that the hydrogen absorption of Ti–0.2Pd alloy, as compared with commercial pure titanium, is suppressed in fluoride solutions.     

Measurement of self-diffusion coefficients in Li ionic conductors by using the short-lived radiotracer of 8Li

For the effective use of short-lived radioactive beams, soon to be available at the Tokai Radioactive Ion Accelerator Complex, the authors have developed a radiotracer method for diffusion studies in solids. The experimental test was performed by the measurement of the diffusion coefficients of Li in a sample of the compound βLiAl using an α-emitting radiotracer of ⁸Li (T_1/2=0.84 s). It was found that the time-dependent yields of the α particles from the diffusing ⁸Li that was initially implanted in the sample could be used as a measure of the diffusivity of the tracer in a nondestructive way. The method was applied to measure the self-diffusion coefficients of Li in βLiGa, and for investigating how the Li diffusion in the Li ionic conductors is affected by the concentration of atomic defects (i.e., the existence of the atomic vacancies of Li and the defects in Ga sites that are replaced by Li).