Proteome profiling of vitreoretinal diseases by cluster analysis

Vitreous samples collected in retinopathic surgeries have diverse properties, making proteomics analysis difficult. We report a cluster analysis to evade this difficulty. Vitreous and subretinal fluid samples were collected from 60 patients during surgical operation of non‐proliferative diabetic retinopathy, proliferative diabetic retinopathy, proliferative vitreoretinopathy, and rhegmatogenous retinal detachment. For controls, we collected vitreous fluid from patients of idiopathic macular hole, epiretinal, and from a healthy postmortem donor. Proteins from these samples were subjected to quantitative proteomics using two‐dimensional gel electrophoresis. We selected 105 proteins robustly expressed among ca. 400 protein spots and subjected them to permutation test. By using permutation test analysis we observed unique variations in the expression of some of these proteins in vitreoretinal diseases when compared to the control and to each other: (i) the levels of inflammation‐associated proteins such as alpha1‐antitrypsin, apolipoprotein A4, albumin, and transferrin were significantly higher in all four types of vitreoretinal diseases, and (ii) each vitreoretinal disease elevated a unique set of proteins, which can be interpreted based on the pathology of retinopathy. Our protocol will be effective for the study of protein expression in other types of clinical samples of diverse properties.     

Monolithically integrated high-speed light source using 1.3-µm wavelength DFB-DC-PBH laser

The first monolithic high-speech light source, consisting of an InGaAsP/InP DFB laser, metal-insulator-semiconductor field-effect transistors, and a monitoring photodiode, has been fabricated. Small-signal modulation bandwidth up to 4 GHz was successfully achieved. The device design, fabrication procedures, and operating characteristics for the integrated light source are described.     

Design of hybrid type’s optical pickup actuator for system stability in high density reading and recording

Recently, there has been a trend to have large capacity and high data transfer rate in optical disk drive. Pickup actuator also should have high performance for satisfying this trend. Since moving magnet type actuator has more simple and robust structure than moving coil type one, we designed moving magnet type to accomplish high flexible mode frequency. However, the driving sensitivity of moving magnet type actuator was low because of its characteristics as following. At first, moving parts including magnets are heavy and electromagnetic (EM) circuits are not closed-loop owing to yoke composed of paramagnetic materials. Therefore, in order to increase the driving sensitivity without the degradation of the other dynamic characteristics, EM circuits were redesigned by adding solenoid coils on existing mechanism. As a result, the hybrid type actuator composed of moving magnet type and moving coil type was suggested to obtain high sensitivities and high flexible mode frequency. Design variables of EM circuits and structure parts were decided through parametric study and design of experiments procedure. Optimization algorithm using variable metric method was used to improve performance. Based on these results, the final model was presented.     

热处理温度对莫来石-铝矾土-氮化硅复合材料性能的影响

以莫来石、铝矾土、氮化硅为主要原料,铝酸钙水泥、硅微粉为结合剂,研究了不同热处理温度对莫来石-铝矾土-氮化硅复合材料性能的影响。结果表明:随着热处理温度的提高,莫来石-铝矾土-氮化硅复合材料的热膨胀系数在1400℃时出现最小值2.59×10-6℃-1;体积密度随着热处理温度的提高呈现先减小后增大再减小的变化规律;线变化率随热处理温度的提高呈现收缩先增大后减小的变化规律;常温抗折强度随着热处理温度的提高先增大后减小;常温耐压强度随着热处理温度的提高而增大。     

Design and operation of gas–liquid slug flow in miniaturized channels for rapid mass transfer

The influences of operating parameters such as channel size, flow rate, and void fraction on the mass transfer rate in the gas–liquid slug flow are investigated to establish a design method to determine the parameters for rapid mass transfer. From the experimental results, the turnover index, including the slug linear velocity, its length, and the channel size that represents the turnover frequency of the internal circulation flow, is proposed. For PTFE tube in which no liquid film exists in slug flow, a master curve is derived from the relationship between the mass transfer coefficient and the turnover index. For each channel material, the Sherwood number is also roughly correlated with the Peclet number. These correlations make it possible to arbitrarily determine a set of operating parameters to achieve the desired mass transfer rate. However, the turnover index and the Peclet number include the slug length, which cannot be controlled directly. The relationship between the slug length and the operating parameters is also investigated. The slug volume mainly depends on the inner diameter (i.d.) of a union tee. At a fixed union tee i.d., the slug length is controlled through the exit i.d. of the channel connected to the union tee and the void fraction. Thus, the final slug length depends on the union tee and exit channel inner diameters. At low flow rates, the gas and liquid collision angle is significant in determining the slug length.     

Application of silicon polymer as positive photosensitive material

A new positive-working photosensitive system of silicon polymer, containing silylether groups in the main chain and a photo-induced acid precursor was investigated. The silicon polymer is hydrolized by a photogenerated acid and degraded to low molecular weight compounds. Thus the effect of solubility inhibition of the polymer is diminished. The higher photosensitivity of this system as compared with 1,2-quinone diazide compounds is due to the catalytic reaction of the acid on the hydrolysis of the silicon polymer. The chemical structure around silylether groups in the polymer, in particular more hydrophilic and less steric structures, affects the rate of hydrolysis and thus the photosensitivity. Among various types of photo-induced acid precursors examined, e.g., s-triazine and 1,3,4-oxadiazole compounds substituted by trihalomethyl groups were effective.     

Degradation of toluene and acetaldehyde with Pt-loaded TiO2 catalyst and parabolic trough concentrator

Photocatalytic degradation of volatile organic compounds (VOCs) with Pt-loaded TiO₂ was analyzed at elevated temperatures in the laboratory experiments (40–190 °C) and in the field experiments (30–230 °C). The temperature of catalyst coated on the sunlight receiver was easily elevated to around 200 °C by parabolic trough concentrator (1 m × 1 m). When gaseous toluene (15 ppm) or acetaldehyde (400 ppm) was passed through the reactor, 79% of toluene or 93% of acetaldehyde was removed continuously. In the similar condition, bare TiO₂ was rapidly deactivated by the formation of byproducts. The combination of sunlight concentrator and Pt–TiO₂ catalyst exhibited the enhancement of complete degradation of VOCs, the inhibition of deactivation, and the reactivation of photocatalyst. The contributions of photocatalytic and catalytic activities of Pt–TiO₂ were analyzed by using UV lamp and electric heater. Acetaldehyde is thermocatalytically degraded by photodeposited Pt on TiO₂ at 70–190 °C without UV irradiation, however the UV irradiation is necessary for the complete oxidation of acetaldehyde into CO₂. It is inferred that the degradation of VOCs is enhanced by the combined effect of Pt thermocatalyst and Pt–TiO₂ photocatalyst.     

Application of graft-type poly(ether ether ketone)-based polymer electrolyte membranes to electrochemical devices – Fuel cells and electrolytic enrichment of tritium

The polymer electrolyte membrane consisting of poly(styrenesulfonic acid)-grafted poly(ether ether ketone) (PEEK-PEM) was investigated for application to two electrochemical devices; a fuel cell and electrolytic enrichment of tritium. For fuel cells, high temperature operation has been required from the viewpoints of simplification of cooling systems, heat recovery systems and so forth, and durability is one critical issue affecting practical use. We performed a long term durability test for PEEK-PEM (ion exchange capacity = 2.4 mmol/g, conductivity = 0.15 S/cm) under the condition of 110 °C and 50% relative humidity, and achieved a lifetime of 1500 h at a constant current of 0.3 A/cm². The cell voltage maintained 97% of initial voltage after 1300 h of operation. There have been only a few reports that PEMs exhibit longer lifetime than 1000 h at temperatures above 100 °C. For quantitative evaluation of tritium concentration in low-level tritiated water such as environmental water, the tritium enrichment by a solid polymer electrolysis (SPE) method is required prior to the tritium concentration measurements. The SPE device composed of PEEK-PEMs with IECs of 0.9–1.2 mmol/g showed a tritium enrichment ratio of 1.35 at 30 °C, which is 20% higher than that of Nafion. Higher tritium enrichment ratios in PEEK-PEM are explained by the smaller amount of transported water. The water transport coefficient in PEEK-PEM is ～1, which is a half value of Nafion. In addition, the water transport coefficient of PEEK-PEM shows less temperature dependence, at least, up to 60 °C. These features have advantages in electrolytic enrichment of tritium for practical use.     

Molecular orbital analysis of frontier orbitals for molecular electronics: a case study of unimolecular rectifier and photovoltaic cell

Recently, unimolecular devices have attracted significant attention as a ‘post-silicon technology’ to enable the fabrication of future nanoscale electronic devices. In this paper, we describe a candidate molecule for a rectifier function using porphyrin polymer and a photovoltaic cell using fullerene-based supramolecule. We have investigated the geometric and electronic structure of these organic molecules using an ab initio quantum mechanical calculation. These results for the porphyrin polymers show that the localization of the unoccupied orbital state on the acceptor moiety mostly depends on their structures. The calculated results for the electronic structure of a naphthalocyanine–fullerene supramolecule manifest that the HOMO’s were localized on the donor sub-unit and the LUMO’s were localized on theacceptor sub-unit.