Pruritus in hemodialysis patients: Results from the Japanese Dialysis Outcomes and Practice Patterns Study (JDOPPS)

Pruritus affects many patients undergoing hemodialysis (HD). In this study, pruritus and its relationship to morbidity, quality of life (QoL), sleep quality, and patient laboratory measures were analyzed in a large sample of Japanese patients undergoing HD. Severity of patient‐reported pruritus symptoms experienced during a 4‐week period was collected from 6480 Japanese patients undergoing HD in three phases of the Dialysis Outcomes and Practice Patterns Study (DOPPS; 1996–2008; 60–65 study facilities/phase). Adjusted linear and logistic regressions were used to identify associations of pruritus with treatment parameters and QoL outcomes. Adjusted Cox regressions examined the influence of pruritus severity on mortality. Moderate to extreme pruritus was experienced by 44% of prevalent patients undergoing HD in the Japanese Dialysis Outcomes and Practice Patterns Study. Many patient characteristics were significantly associated with pruritus, but this did not explain the large differences in pruritus among facilities (20–70%). Pruritus was slightly less common in patients starting HD than in patients on dialysis >1 year. Patients with moderate to extreme pruritus were more likely to feel drained (adjusted odds ratio = 2.2–5.8, P < 0.0001), have poor sleep quality (adjusted odds ratio = 1.9–3.7, P < 0.0001), and have QoL mental and physical composite scores 2.3–6.7 points lower (P < 0.0001) than patients with no/mild pruritus. Pruritus in patients undergoing HD was associated with a 23% higher mortality risk (P = 0.09). The many poor outcomes associated with pruritus underscore the need for better therapeutic agents to provide relief for the 40–50% of prevalent patients undergoing HD substantially affected by pruritus. Pruritus in new patients with end‐stage renal disease likely results from uremia or pre‐existing conditions (not HD per se), indicating the need to understand development of pruritus before end‐stage renal disease.     

Electron emission mechanism of hydrogenated natural type IIb diamond (111)

Clarification of the electron emission mechanism of diamond has been one challenging topic in the field of vacuum nanoelectronics. Electric field of less than 5 V/µm is enough to extract electrons from diamond, which is orders of magnitude lower than the value required for electron emission from metal emitter in general. There have been number of studies on the clarification of electron emission mechanism, however, unified model has not been proposed. The difficulty largely lies in determining the origin of emitted electrons. In this study, we succeeded in clarifying the electron emission mechanism of hydrogenated natural type IIb diamond (111) surface by using combined x-ray photoemission spectroscopy/ultraviolet photoemission spectroscopy/field emission spectroscopy (XPS/UPS/FES) system. Obtained spectra clearly defined the origin of emitted electrons at the valence band maximum (VBM). As applied voltage was increased, the number of emitted electrons increased, however, the origin remained at VBM independent of the applied voltage.     

Experimental studies of fault location in PV module strings

Two methods for the fault location in PV module string were experimentally studied. One was the earth capacitance measurement (ECM) and the other was the time-domain reflectometry (TDR). By ECM, the disconnection position in the string was estimated by the earth capacitance value without the effects of the irradiance change, and the estimation error was small enough to determine the disconnection position in actual repair/maintenance operation. On the other hand, TDR could detect the degradation (series resistance increase) and the positions in the string by the change of response waveform.     

Vacuum freezing type ice slurry production using ethanol solution 1st report: Measurement of vapor–liquid equilibrium data of ethanol solution at 20 °C and at the freezing temperature

In this study, an original method for the production of ice slurry from ethanol solution without using a refrigerator is proposed. This system has advantages compared with similar existing systems using materials other than ethanol solution. In this paper, the vapor–liquid equilibrium data of ethanol solution at 20 °C and at the freezing temperature are measured, which is necessary to calculate the COP of this ice slurry producing system. In the experiments, two experimental methods are proposed to measure the saturated pressure and the vapor composition of ethanol solution. Each method has an advantage in their operating temperature range. As a result, the vapor–liquid equilibrium diagrams of ethanol solution at 20 °C and at the freezing temperature, and approximations of saturated pressure of various concentrations of ethanol solution for varying liquid temperature, are obtained.     

Zonotopes and the LP-Newton method

Although linear programming problems can be solved in polynomial time by the ellipsoid method and interior-point algorithms, there still remains a long-standing open problem of devising a strongly polynomial algorithm for linear programming (or of disproving the existence of such an algorithm). The present work is motivated by an attempt toward solving this problem. Linear programming problems can be formulated in terms of a zonotope, a kind of greedy polyhedron, on which linear optimization is made easily. We propose a method, called the LP-Newton method, for linear programming that is based on the zonotope formulation and the minimum-norm-point algorithm of Philip Wolfe. The LP-Newton method is a finite algorithm even for real-number input data with exact arithmetic computations. We show some preliminary computational results to examine the behavior of the LP-Newton method. Major part of this paper was presented as a plenary talk with the same title at ICOTA7 (December 12–15, 2007, Kobe, Japan) by the first author. The fourth author’s research was carried out while visiting RIMS in August 2007.     

Dynamic behavior of carbon nanotube field emitters observed by in situ transmission electron microscopy

We examined dynamic behavior of field-emitting carbon nanotubes (CNTs) by in situ transmission electron microscopy (TEM). CNTs employed in the present study were multi-wall CNTs prepared by chemical vapor deposition, double-wall and single-wall CNTs produced by arc discharge. Orientation of CNTs, being random when no electric field was applied, were aligned parallel to the electric field and returned reversibly to their original direction when the field was turned off. In addition to this reversible behavior without serious structural damage in CNTs, sublimation and violent oscillation of CNTs were observed. When CNTs were bundled, branching of the bundle by electric static force was also observed.     

Catalytic activity of aryl alcohol oxidase immobilized in 3D-mesoporous silicates

Aryl alcohol oxidase was immobilized on two mesoporous materials, MS-A and MS-B. The immobilization rate for the larger pore material MS-A (11.5 nm) was higher than for the smaller pore material MS-B (4.2 nm). Furthermore, the sol–gel silica encapsulation of MS-immobilized enzymes improved thermal stability.     

Efficient Nonlinear Absorbing Platinum(II) Acetylide Chromophores in Solid PMMA Matrices

Platinum(II) acetylides were incorporated into poly(methyl methacrylate) (PMMA) glasses to obtain solid‐state nonlinear optical devices. We report on device fabrication, structural, chemical, and mechanical properties, as well as the optical limiting capabilities of the final solids. Two different guest‐host systems are presented: 1) Dye molecules functionalized to be readily dispersed in methyl methacrylate (MMA) and subsequent in situ polymerization of the MMA yielding solid PMMA host matrices. 2) Dye molecules functionalized to copolymerize with MMA forming covalent bonds between the guest and the PMMA host matrix. A range of doped organic solids were prepared, reaching concentrations up to 13 wt% of the guest molecule. Raman spectra of the doped solid devices indicate that the chemical structure of the nonlinear dyes remains intact upon the polymerization of the solid matrix. Luminescence spectra confirm that the basic photophysical properties observed for the same solute molecules in THF are maintained also in the solid state. Optical power limiting (OPL) characterization reveal clamping levels for the dyes nonbonded to the solid host being less than 4 µJ at pulse energies up to 110 µJ at 532 nm (f/5 arrangement and 5 ns pulses), which is comparable to the performance of similar dyes in THF solutions. In contrast, the highly crosslinked solid possesses a higher clamping level (8 µJ) at the same nominal concentration.     

Numerical simulations of hypervelocity impact of asteroid/comet on the Earth

In this study, numerical simulations of asteroid/comet impact on the earth were carried out by using the hydrocode AUTODYN-2D (Century Dynamics Inc.). The ejected mass into the atmosphere originated from different sources was recorded at different altitudes as a function of time. It is claimed that the mass extinction at the Permian–Triassic (P/T) boundary was caused by an extraterrestrial impact and the following abrupt climate/environment change. The objective of this work is to substantiate the claim with numerical analysis. It is demonstrated that the materials from different origins are splashed into the atmosphere and that the crater size is a function of the diameter as well as the kinetic energy of the impactor. The effect of impact angle to the appearance of ejected materials is also investigated using two-dimensional plane strain model.