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Pulsed power technology has possibility to be able to provide a new method for tissue ablation. Applying a pulsed high electric field with nanosecond duration time onto a cancer cell can induce apoptosis into that. In this method, a frequency component of the electric field applied to the cell is an important factor. This paper focuses on the investigation of frequency characteristics of a difference of a cell death caused by applying the pulsed high electric field. The budding yeast that is a eukaryotic cell has been used as a model organism of a human cell. Difference of the cell death of the yeast for frequencies of the pulsed electric field by using molecular probes, propidium iodide, Annexin-V, and FLICA has been investigated. The frequency of the pulsed electric field was changed from 200 kHz to 70 MHz. The low frequencies, 200 kHz and 3.5 MHz, under 45 MHz yielded both necrosis and apoptosis in the cells. The electric field of frequency of 200 kHz with an intensity of 30 kV/cm only induced necrosis by breakdown in most cells. At the frequencies of 200 kHz with 16 kV/cm and 3.5 MHz, both apoptosis and necrosis occurred. The apoptotic pathway at 3.5 MHz went via caspase. At the frequency of 70 MHz, only apoptosis, not necrosis, was induced in the cells. However, the apoptosis via caspase was not dominant for the cell death. A signal for the cell death passed through other pathway of apoptosis, which was different from that of 3.5 MHz. At 45 MHz, the cell death did not occur. 45 MHz is the boundary where necrosis occurs, and the apoptotic pathway is different.

Poly(vinyl alcohol) [PVA, -(CH2CH(OH))n-] forms the crystalline complexes I and II with iodine ions (I3−) when PVA is immersed in the KI/I2 aqueous solutions of 0.1–0.5 and 1–3 mol/l concentration, respectively. On the basis of the X-ray diffraction and the ultraviolet-visible, IR and Raman spectral data, we have found that the immersion of PVA films into the iodine aqueous solutions containing the different type of counter ions (K+, Na+, Li+, H+, or Cs+) creates the various types of the crystal modification. When PVA sample was immersed in the solution of relatively low concentration, all the types of counter ion gave the complex I structure. When the concentration of the solution was increased to 1–3 mol/l, the sample immersed for several hours showed the formation of the complex II. In the case of H+ ion, the longer immersion was found to give a new crystal form or complex III with the different packing mode of PVA and I3− ions as determined by the X-ray structure analysis. In the cases of Na+ and Li+ ions, the complex II was disordered by the longer immersion in such a highly-concentrated solution. As clarified by the infrared spectral data, the hydrogen bonds of O–H ⋯ I type are formed in the iodine complex, the strength of which was found also to be different depending on the type of counter ion species. In this way, the present paper has revealed the important role of the counter cations on the formation and stability of the PVA-iodine complexes for the first time.

Poly(vinyl alcohol) (PVA) is known to form the crystalline complexes with iodine ions, in which the linear I3– ions form the columnar arrays and are connected to the neighboring PVA chains of planar-zigzag conformation through the charge transfer between OH groups and I3– ions. In order to clarify the effective OH segmental length necessary for the formation of such an iodine complex along the chain axis, the complex formation behavior has been investigated systematically for a series of ethylene–vinyl alcohol (EVOH) random copolymers on the basis of the experimental data of 2D X-ray diffraction, visible-ultraviolet (UV–Vis) absorption spectra, Raman spectra, and infrared spectra. By comparing the observed X-ray diffraction patterns, the EVOH copolymers with VOH content near 100 mol % were found to take the relatively regular complex II structure, while the EVOH copolymers of 70–50 VOH mol % were found to take the structure of complex I, in which the PVA zigzag chains are packed together randomly with and...

We have investigated sterilization of packaging foods. In sterilization methods of the packaging foods, there is pulsed discharge sterilization and high frequency pulsed electric field sterilization. The pulsed discharge sterilization is suitable for solid fresh foods. The high frequency pulsed electric field sterilization is suitable for liquid fresh foods. However, many liquid fresh foods are difficult to sterilize by the pulsed electric field for having high electrical conductivity like containing salt. In this study, sterilizing properties of the brine of the high conductivity by nanosecond pulsed electric field have been investigated. Target microorganism was Saccharomyces cerevisiae that is detected generally in foods. In experiments, the salinity and temperature of the brine with S. cerevisiae was changed as parameters. As experimental results, by applying the pulsed electric field in the sample temperature of 50 °C, processing time to reduce the number of S. cerevisiae two digits has been about one-fifth of that of the room temperature. In the evaluation of the sterilization ratio by difference of the salinity, the sterilization ratio at the salinity of 3 % has been more than that of 0.3 %.

In this paper, a novel method for the discrete optimization problem is proposed based on the UCB algorithm. Definition of the neighborhood in the search space of the problem easily affects the performance of the existing algorithms because they do not well take into account the dilemma of exploitation and exploration. To optimize the balance of exploitation and exploration, we divide the search space into several grids to reconsider the discrete optimization problem as a Multi-Armed Bandit Problem, and therefore the UCB algorithm is directly introduced for the balancing. We proposed a UCB-grid area search and conducted numerical experiments on the 0-1 Knapsack Problem. Our method showed stable results in different environments.

Discounted UCB1-tuned was proposed as one of the methods to choose the action in a multi-armed bandit problem. This algorithm is an optimized selection method for balancing between the exploration and the exploitation, by using weighted value and weighted variance. In this paper, we proposed the method to apply Discounted UCB1-tuned to Q-learning, and experimentally evaluated its performance in the continuous state spaces shortest path problem.

Nitrogen (N)-doped ZnO layers were grown using diethylzinc (DEZ), water (H 2 O) and monomethylhydrazine (MMHy) as Zn, O and N precursors, respectively. Raman spectra revealed N-related vibrational modes at 275, 510, 582 and 643 cm −1 in addition to the host phonons of ZnO. The intensity of these additional modes was increased with increasing the amount of MMHy. These ZnO samples were thermally annealed under an oxygen ambient to activate N as an acceptor. By increasing the annealing temperature, the intensity of additional modes was decreased, which indicates the dissociation and re-evaporation of N complexes. By capacitance–voltage ( C – V ) measurements, it was observed that the capacitance was increased by increasing the positive bias voltage for N-doped as-grown ZnO layer, which indicates that this layer is n-type with donor concentration of 1×10 16 cm −3 . In contrast, the capacitance was decreased by increasing the positive bias voltage for N-doped ZnO layer annealed at 800 °C. In addition, the neutral acceptor-bound exciton (A 0 X) emission and donor–acceptor pair (DAP) emission were observed in N-doped ZnO layer annealed above 800 °C by low-temperature photoluminescence (PL) measurements.

ZnO layer was epitaxially grown on GaN template by atomic layer epitaxy (ALE) using Diethylzinc (DEZ) and H2O at the growth temperature of 250 °C. By reflection high-energy electron diffraction (RHEED) measurements, spotty pattern was observed for the ZnO layer directly grown on c-plane sapphire substrate, while streaky pattern was observed for that grown on GaN template. Full-width at half-maximum (FWHM) value of (0002) X-ray rocking curve of ZnO layer was greatly reduced from 4.96° to 0.103° by using GaN template. By photoluminescence (PL) measurements, only the near bandedge emissions were observed. FWHM of the neutral-donor-bound-exciton (D0X) emission line was reduced from 18.7 to 16.1 meV by using GaN template. (© 2004 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)

Atomic layer growth of ZnO thin films was achieved using diethylzinc (DEZ) and H 2 O as reactant gases. Self-limiting growth occurred at substrate temperatures ranging from 206 to 268 °C. Self-limiting growth was also achieved for a certain region of the DEZ flow rate. It was found that the crystal growth orientation of the films was strongly dependent on the substrate temperature and the DEZ flow rate. The low temperature photoluminescence spectra exhibit dominant band edge emission at around 3.36 eV.

Low-resistivity and high-stability ZnO films were grown by photo-atomic layer deposition (photo-ALD) technique using boron as an n-type dopant. The effect of the UV-irradiation was quantitatively evaluated by controlling the intensity of the incident light. The growth mechanism of ZnO films under UV-irradiation was investigated by varying the UV-irradiation period. In addition to the UV-irradiation, n-type doping using B 2 H 6 was carried out. By optimizing the introduction cycle of B 2 H 6 , the lowest resistivity of 6.9×10 −4 Ω cm was obtained. Furthermore, ZnO films grown by photo-ALD exhibit excellent stability in the electrical properties under air exposure.

A trehalose synthase (TSase) that catalyzes the synthesis of trehalose from d -glucose and α- d -glucose 1-phosphate (α- d -glucose 1-P) was detected in a basidiomycete, Grifola frondosa . TSase was purified 106-fold to homogeneity with 36% recovery by ammonium sulfate precipitation and several steps of column chromatography. The native enzyme appears to be a dimer since it has apparent molecular masses of 120 kDa, as determined by gel filtration column chromatography, and 60 kDa, as determined by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Although TSase catalyzed the phosphorolysis of trehalose to d -glucose and α- d -glucose 1-P, in addition to the synthesis of trehalose from the two substrates, the TSase equilibrium strongly favors trehalose synthesis. The optimum temperatures for phosphorolysis and synthesis of trehalose were 32.5 to 35°C and 35 to 37.5°C, respectively. The optimum pHs for these reactions were 6.5 and 6.5 to 6.8, respectively. The substrate specificity of TSase was very strict: among eight disaccharides examined, only trehalose was phosphorolyzed, and only α- d -glucose 1-P served as a donor substrate with d -glucose as the acceptor in trehalose synthesis. Two efficient enzymatic systems for the synthesis of trehalose from sucrose were identified. In system I, the α- d -glucose 1-P liberated by 1.05 U of sucrose phosphorylase was linked with d -glucose by 1.05 U of TSase, generating trehalose at the initial synthesis rate of 18 mmol/h in a final yield of 90 mol% under optimum conditions (300 mM each sucrose and glucose, 20 mM inorganic phosphate, 37.5°C, and pH 6.5). In system II, we added 1.05 U of glucose isomerase and 20 mM MgSO 4 to the reaction mixture of system I to convert fructose, a by-product of the sucrose phosphorylase reaction, into glucose. This system generated trehalose at the synthesis rate of 4.5 mmol/h in the same final yield.

Low-resistivity ZnO films were grown by photo atomic layer deposition (photo-ALD) technique using diethylzinc (DEZ) and H2O as reactant gases. Self-limiting growth was achieved for the temperature range from 105°C to 235°C. It was found that UV light irradiation was very effective to increase the electron concentration of the films and the electron concentration of 5 × 1020 cm−3 was achieved even in undoped ZnO. Thus, the resistivity of the films grown with UV irradiation was one order of magnitude less than that grown without UV irradiation. The minimum resistivity of 6.9 × 10−4Ω cm was obtained by photo- ALD method without any intentional doping.

Polycrystalline Cu(InGa)Se2 (CIGS) thin-film solar cells using evaporated InxSey and ZnInxSey buffer layers are prepared. The purpose of this work is to replace the chemical bath deposited CdS buffer layer with a continuously evaporated buffer layer. In this study, a major effort is made to improve the performance of CIGS thin-film solar cells with these buffer layers. The relationship between the cell performance and the substrate temperature for these buffer layers is demonstrated. Even at the high substrate temperature of about 550°C for the buffer layer, efficiencies of more than 11% were obtained. Furthermore, the I−V characteristics of the cells using these buffer layers are compared with cells using CdS buffer layers fabricated by chemical bath deposition method. We have achieved relatively high efficiencies of over 15% using both the ZnInxSey and the CdS buffer layers.

We investigated of PSA in 57 patients who underwent the prostate biopsy in our hospital during 1994. Serum PSA level were determined with a Markit-M kit. Sensitivity and specificity for prostate cancer at the current standard value of PSA of 3.6 ng/ml (with our PSA kit) were 74.2% and 61.5%, respectively. There were six cases of prostate cancer with PSA values in the 1.5-3.6 ng/ml ceange 6, and 5 of these cases were stage B. Judging from these results, it seems quite necessary to perform prostate biopsy or intense management even if the PSA value is 1. 5-3.6 ng/ml.

Heavily carbon-doped p-GaAs layers with a hole concentration of 1.5 × 10 21 −3.4 × 10 18 cm -3 were grown by metalorganic molecular beam epitaxy (MOMBE). The carrier concentration agrees well with the carbon concentration measured by SIMS, which suggests 100% of electrical activation of the incorporated carbon as an acceptor. The p-n diodes with carbon-doped p-GaAs show good rectification. The lattice constant of GaAs decreases with increasing carbon concentration. The carbon-doped InGaAs with a hole concentration of 2.6 × 10 20 cm -3 , lattice-matched with a GaAs substrate, was obtained for the first time. The effective bandgap narrowing in heavily doped GaAs was also studied by photoluminescence. The measured bandgap with a hole concentration of 10 20 cm -3 is about 100 meV lower than that of intrinsic GaAs. Finally, the static and high-frequency characteristics of heterojunction bipolar transistors with carbon-doped p-GaAs were calculated.

FexSey films were prepared on GaAs(001) substrates by a selenization of Fe films using molecular beam epitaxy equipment. Structural and magnetic properties of FexSey thin films during their selenization process were studied. The selenized films obtained consisted of polycrystalline grains of 100–700 nm. A magnetic anisotropy of in-plane/perpendicular to the films was weakened by increasing the selenization ratio of the samples, which was interesting in contrast to the fact that the grain size of the films became larger.

FeSe thin films were prepared on GaAs(100) substrate by the selenization of Fe films using molecular-beam epitaxy. FeSe compound thin films were obtained at a substrate temperature above 380 degrees C. From the depth profiles of Fe and Se in the selenized film measured by Auger electron spectroscopy, it was confirmed that an FeSe layer with a constant ratio of Fe/Se was formed. The measured composition ratio of Fe/Se in the film was 1/3. It was different from the composition in Fe3Se4 or Fe7Se8, which is a stable bulk FeSe compound. From the measured M-H curve, it was found that the obtained FeSe film consisted of two phases with different magnetic properties. (C) 1997 American Institute of Physics.

The dependence of magnetization dynamics and magneto-impedance effect in positively magnetostrictive Fe/sub 77.5/Si/sub 7.5/B/sub 15/ amorphous wires on annealing conditions was studied. The observed MI ratio of the annealed samples was as much as 36% and optimum annealing conditions were suggested. The locus of the magnetization vector of the annealed wire indicated that the circumferential magnetization proceeded easily in the annealed wire. It was also suggested that the effect of oxidation should be considered for samples annealed in air.

The autosomal dominant macrothrombocytopenia with leukocyte inclusions, May-Hegglin anomaly (MHA), Sebastian syndrome (SBS), and Fechtner syndrome (FTNS), are rare platelet disorders characterized by a triad of giant platelets, thrombocytopenia, and characteristic Dohle body-like leukocyte inclusions. The locus for these disorders was previously mapped on chromosome 22q12.3–q13.2 and the disease gene was recently identified as MYH9, the gene encoding the nonmuscle myosin heavy chain-A. To elucidate the spectrum of MYH9 mutations responsible for the disorders and to investigate genotype–phenotype correlation, we examined MYH9 mutations in an additional 11 families and 3 sporadic patients with the disorders from Japan, Korea, and China. All 14 patients had heterozygous MYH9 mutations, including three known mutations and six novel mutations (three missense and three deletion mutations). Two cases had Alport manifestations including deafness, nephritis, and cataracts and had R1165C and E1841K mutations, respectively. However, taken together with three previous reports, including ours, the data do not show clear phenotype–genotype relationships. Thus, MHA, SBS, and FTNS appear to represent a class of allelic disorders with variable phenotypic diversity.

Background Clinical and pathological features of familial prostate cancer patients were examined. Methods We compared 7 pairs (14 patients) of familial prostate cancer patients (Group F) with those of 1741 prostate cancer patients diagnosed in around Gunma Prefecture between 1987 and 1993 (Group G). Relative survival rates were compared because the average age was different in two groups. Results In Group F and Group G, age at diagnosis ranged from 54 to 86 and 47 to 97 years old, and the averages were 68.1 +/- 8.5 (S.D.) and 74.2 +/- 8.3, respectively. The average age tended to be younger in Group F. The ratio of early stage cancer tended to be higher and that of poorly differentiated cancer tended to be lower in Group F. The 3- and 5-year relative survival rate was 82.4% and 57.6% in Group F, and 84.3% and 73.9% in Group G, respectively. The 5-year survival rate tended to be lower in Group F, but almost no difference was observed between two groups on the whole. In Group F, of 6 patients whose causes of death were clear, 4 (66.7%) died of prostate cancer, while in Group G, of 398 patients whose causes of death were elaar, 224 (56.3%) died of prostate cancer. Family history of other cancer sites was positive in 3 of 6 families in Group F. Conclusions Familial prostate cancer patients tended to be young, in early stage and low ratio of poorly differentiated cancer.

A Lamb wave propagating through a crystal induces refractive-index variations in the crystal due to its photo-elastic effect; this crystal forms a phase cyclic structure. Therefore, if an incident light is transmitted into this crystal, light diffraction and mode transformation occur. In this study, we theoretically and experimentally examined light-wave propagation in a crystal in which Lamb waves had caused cyclic variations in the refractive index. In the experiment, it was verified that the Lamb wave power required for 100% mode conversion is 4 mW/mm in a LiTaO3 substrate with a Lamb wave wavelength of 132 µm and a substrate thickness of 50 µm.

A GaAs pseudo-heterojunction bipolar transistor with a heavily carbon-doped base grown by metalorganic molecular beam epitaxy was fabricated, and the highest dc current gain of 1.7 was obtained, which evidences band-gap narrowing in the base. However, hole injection from the base to the emitter still cannot be ignored, and the use of a heavily carbon-doped InGaAs base is proposed to improve transistor characteristics.

Solar cells based on Cu(InGa)Se2 (CIGS) thin films fabricated by selenization/sulfurization were investigated. We have concentrated on studying the heterojunction quality to improve the efficiency and stability of n-ZnO/i-(atomic layer deposition :ALD)ZnO buffer-layer/p-CIGS structure devices. The effect of heat treatment for CIGS absorbers was studied. It is found that the heat-treatment can remove entities, e.g., excess In x S y , from the surface of CIGSS, which causes interdiffusion in the (ALD)ZnO buffer layer and decreases V oc and FF. We achieved 13.9% efficiency (V oc: 510 mV, FF: 0.736, J sc: 36.9 mA/cm2) without the use of Cd-related material. Reversible light-soaking and current-injection effects were observed clearly in i-(ALD)ZnO/CIGS-based solar cells. These phenomena can be controlled by changing the CIGS surface conditions. Devices treated with NH4OH as well as deionized water in an ultrasonic bath prior to the growth of buffer layers are not sensitive to light illumination or application of bias voltage in the dark. The origin of the light-soaking/current-injection effect is assumed to be at/near the CIGS surface or grain boundaries.

The minority electron transport in p-type GaAs with hole concentrations greater than 1020 cm-3 was investigated using the Monte Carlo method. It is found that electron-hole and the plasmon scatterings play a dominant role in heavily doped p-type GaAs. The estimated electron mobility and diffusion length are in good agreement with the experimentally obtained values. Based on the above, the static and high-frequency characteristics of AlGaAs/GaAs HBT's were analyzed. The band gap narrowing and the Auger recombination are found to induce substantial effects on the current gain. The maximum frequency of oscillation of 440 GHz and the propagation delay time of 1.5 ps/gate are predicted for the base doping of 1×1021 cm-3.

The potential of metalorganic molecular beam epitaxy (MOMBE) for the growth of extremely low resistivity p-tape GaAs and GaAlAs has been investigated. The acceptor is carbon which is incorporated from trimethylgallium. The hole concentration was controlled in the range 10 19 -10 21 cm -3 by changing the growth temperature. The highest hole concentrations of 1.5×10 21 and 2.5×10 21 cm -3 have been obtained for GaAs and GaAlAs with the Al mole fraction of 0.35, respectively, which are higher than any other values reported for p-type epitaxial GaAs and GaAlAs thin films. The growth mechanism and detailed electrical properties have been discussed. It was found that the behavior of carbon as an acceptor is much more suitable than that of beryllium for device applications, which require thin layers with ultra low resistivity.

Band gap narrowing in heavily doped p-type GaAs is estimated by photoluminescence measurement. Measured values agree well with the theoretical results. Monte Carlo simulation of minority electron transport demonstrates that plasmon scattering plays an essential role in heavily doped p-type GaAs. Theoretical calculations, including these heavy doping effects, on heterojunction bipolar transistors (HBT's) show that maximum oscillatiorn frequency of over 300 GHz is expected by increasing the hole concentration of the base layer to 1×1021 cm-3.

We have investigated the potential of metalorganic molecular beam epitaxy (MOMBE) for the growth of extremely low resistivity p-type GaAs and GaAlAs. Heavily doped GaAs and GaAlAs epilayers with a carrier concentration of 5 × 1020-1 × 1021cm-3 were successfully grown by MOMBE. The acceptor was carbon which was incorporated from TMG. The thermal diffusion coefficient was much lower than that of Be, and the lattice constant did not vary with increasing carrier concentration. The behavior of carbon as an acceptor is very suitable for device applications, which require thin layers with ultra-low resistivity.

p‐type GaAs with doping levels of up to 5.8×1020 cm−3 has been grown by metalorganic molecular‐beam epitaxy (MOMBE) using carbon (C) as a dopant. The mobility and minority‐carrier diffusion length of the C‐doped MOMBE layers were comparable to those of Be‐doped MBE layers. The diffusion coefficient of C at 900 °C was estimated to be 6×10−15 cm2 /s which is about two orders of magnitude less than that of Be (1×10−12 cm2 /s). In addition, the lattice constant of C‐doped GaAs was found to be 5.6533 A which completely matches that of the substrate, while the lattice constant of Be‐doped GaAs decreases to 5.6467 A at a doping level of 2×1020 cm−3 as reported by Lievin et al. [Inst. Phys. Conf. Ser. No. 79, 595 (1985)].