Progress and achievements of the BA activities in Rokkasho

In Rokkasho Japan, the International Fusion Energy Research Center (IFERC) project and the International Fusion Materials Irradiation Facility/Engineering Validation and Engineering Design Activities (IFMIF/EVEDA) project are on going under the Broader Approach framework. The IFERC project consists of three sub-projects; a fusion demonstration reactor (DEMO) Design and R&D Coordination Center, a Computational Simulation Center (CSC), and an ITER Remote Experimentation Center (REC). DEMO Design activity has been conducted by the IFERC project team in Rokkasho and home teams in EU and JA. In the DEMO R&D activity, five R&D tasks mainly of the blanket materials are carried out intensively. A supercomputer with 1.23 Pflops of LINPAC performance has been installed in December 2011, the operation started in January 2012. Discussion of overall plan of REC has started in 2012 between EU and Japan. In the IFMIF/EVEDA project, an IFMIF prototype accelerator system up to 9 MeV with 125 mA CW deuteron beam will be installed and tested in Rokkasho. Major components of the accelerator are under development or fabrication in EU. The first component of the accelerator, an injector with an ECR ion source, will be delivered to Rokkasho in March 2013.     

A functionally graded titanium/hydroxyapatite film obtained by sputtering

A functionally graded film of titanium/hydroxyapatite (HA) was prepared on a titanium substrate using a radio frequency magnetron sputtering. The ratio of titanium to HA was controlled by moving the target shutter. The film was composed of five layers, with overall film thickness of 1 m. The HA was concentrated close to the surface, while the titanium concentration increased with proximity to the substrate. The bonding strength between the film and the substrate was 15.2 MPa in a pull-out test and the critical load from a scratch test was 58.85 mN. The corresponding values of a pure HA sputtered film were 8.0 MPa and 38.47 mN, respectively. The bonding strength of a pure HA plasma spray coating was 10.4 MPa in the pull-out test. The graded film and the pure HA film were sputter-coated to a thickness of 1 m on titanium columns (10 mm in length and 4 mm in diameter). These columns were implanted in diaphyses of the femora of six adult dogs and a push-out test was carried out after 2, 4, and 12 weeks. After 12 weeks, the push-out strengths of the graded film, the pure HA film and the non-coated columns were 3.7, 3.5, and 1.0 MPa.     

Measurement of nonlinear distortion in light-emitting diodes

The 2nd- and 3rd-order nonlinear distortion levels of light-emitting diodes used for analogue optical communication have been measured and found to be typically ?40 and ?75 dB, respectively. A method using three independent signal sources was employed in the measurement.     

Deformation characteristics in Β phase Ti-Nb alloys

Deformation modes in Β-phase Ti-Nb alloys containing from 36 to 52 wt pct Nb have been investigated as a function of composition, crystallographic orientation, or deformation temperature using both two surface trace analysis and transmission electron microscopy. 332 (113) twinning occurs in the low niobium content alloys independent of orientation and temperature. With increasing niobium content, 332<113> twinning or (111) slip occurs dependent on orientation and temperature. The operative twinning systems are explained by considering both the polarization of twinning shear and the Schmid factor. The 332 (113) twinning is suppressed in the high niobium content alloys and also suppressed by aging or oxygen addition in the low niobium content alloy. These characteristics have previously been observed in Β phase Ti-V and Ti-Mo alloys. The occurrence of 332 (113) twinning in Β-phase Ti alloys is related to the instability of Β phase. Formerly Graduate Student of Tohoku University     

添加音素持续时间信息到频谱模型的说话人辨认研究

传统的声音识别系统通过短时声音频谱信息来辨识说话人,这种方法在某些条件下具有较好的性能。但是由于有些说话人特征隐藏在较长的语音片段中,通过添加长时信息可能会进一步提高系统的性能。在文中,音素持续时间信息被添加到传统模型上,以提高说话人辨识率。频谱信息是通过短时分析获得的,但音素持续时间的提取却属于长时分析,它需要更多的语音数据。通过大量语音数据探讨了音素持续时间信息对说话人辨识的有效性,提出2种方法来解决数据量小所引起的问题。实验结果表明,当说话人的声音模型被恰当建立时,即使在语音数据量小的情况下,音素持续时间信息对说话人辨识率的提高也是有效的。     

Antimicrobial Activities of LL-37 Fragment Mutant-Poly (Lactic-Co-Glycolic) Acid Conjugate against Staphylococcus aureus,Escherichia coli,and Candida albicans

Various peptides and their derivatives have been reported to exhibit antimicrobial activities. Although these activities have been examined against microorganisms, novel methods have recently emerged for conjugation of the biomaterials to improve their activities. Here, we prepared CKR12-PLGA, in which CKR12 (a mutated fragment of human cathelicidin peptide, LL-37) was conjugated with poly (lactic-co-glycolic) acid (PLGA), and compared the antimicrobial and antifungal activities of the conjugated peptide with those of FK13 (a small fragment of LL-37) and CKR12 alone. The prepared CKR12-PLGA was characterized by dynamic light scattering and measurement of the zeta potential, critical micellar concentration, and antimicrobial activities of the fragments and conjugate. Although CKR12 showed higher antibacterial activities than FK13 against Staphylococcus aureus and Escherichia coli, the antifungal activity of CKR12 was lower than that of FK13. CKR12-PLGA showed higher antibacterial activities against S. aureus and E. coli and higher antifungal activity against Candida albicans compared to those of FK13. Additionally, CKR12-PLGA showed no hemolytic activity in erythrocytes, and scanning and transmission electron microscopy suggested that CKR12-PLGA killed and disrupted the surface structure of microbial cells. Conjugation of antimicrobial peptide fragment analogues was a successful approach for obtaining increased microbial activity with minimized cytotoxicity.     

The proliferative activity in oral epithelial dysplasia analyzed by proliferating cell nuclear antigen immunostaining and argyrophilic nucleolar organizer region staining

The proliferative activity of leukoplakia without dysplastic change (LP), epithelial dysplasia (ED), and squamous cell carcinoma (SCC) in the oral mucosa was examined by means of proliferating cell nuclear antigen (PCNA) immunostaining, silver-binding argyrophilic nucleolar organizer region (AgNOR) staining, and the frequency of mitotic figures. Significant differences in the labeling index of PCNA immunostaining (PI) and mitotic index (MI) were noted between LP and ED and between ED and SCC. The mean numbers of AgNORs (AI) significantly differed between ED and SCC. There was a significant positive correlation between PI and MI in samples of ED. However, there was no significant correlation between AI and other indexes. The number and the distribution of PCNA-positive cells in ED varied among samples. Five samples with higher PI and MI indexes than the mean values were selected from those of dysplasia based on the correlation between PI and MI. Their histological features symptomatic of oral ED as defined by the World Health Organization (WHO) Collaborating Centre in 1978, were investigated and compared with 10 samples with lower indexes. Histological findings, such as "loss of polarity of the basal cells," "an increased nuclear-cytoplasmic ratio," "cellular pleomorphism," and "enlarged nucleoli," were significant histological features of these five samples. This study showed that the four histological components described previously and the increased number of mitotic figures used as the index of proliferating activity were the main histological components related to severe ED of oral mucosa. They will provide a useful means of deciding the histopathological grade of oral ED.     

Efficient and compact green laser for micro‐projector applications

Abstract— Efficient and compact green lasers are keystone components for micro‐projector applications in mobile devices. An architecture that consists of an infrared‐producing DBR (distributed Bragg reflector) laser with a frequency‐doubling crystal is used to synthesize a green laser that has high electrical‐to‐optical conversion efficiency and can be modulated at speeds required for scanner‐based projectors. The design and performance of a green‐laser package that uses adaptive optics to overcome the challenge of maintaining alignment between the waveguides of the DBR laser and the frequency‐doubling crystal over temperature and lifetime is described. The adaptive optics technology that is employed uses the piezo‐based smooth impact drive mechanism (SIDM) actuators that offer a very small step size and a range of travel adequate for the alignment operation. The laser is shown to be compact (0.7 cm³ in volume) and capable of a wall‐plug efficiency approaching 10% (at 100‐mW green power). It was demonstrated that the adaptive optics enables operation over a wide temperature range (10–60°C) and provides the capability for low‐cost assembly of the device.     

Dissolution effect and cytotoxicity of diamond-like carbon coatings on orthodontic archwires

Nickel–titanium (NiTi) has been used for implants in orthodontics due to the unique properties such as shape memory effect and superelasticity. However, NiTi alloys are eroded in the oral cavity because they are immersed by saliva with enzymolysis. Their reactions lead corrosion and nickel release into the body. The higher concentrations of Ni release may generate harmful reactions. Ni release causes allergenic, toxic and carcinogenic reactions. It is well known that diamond-like carbon (DLC) films have excellent properties, such as extreme hardness, low friction coefficients, high wear resistance. In addition, DLC film has many other superior properties as a protective coating for biomedical applications such as biocompatibility and chemical inertness. Therefore, DLC film has received enormous attention as a biocompatible coating. In this study, DLC film coated NiTi orthodontic archwires to protect Ni release into the oral cavity. Each wire was immersed in physiological saline at the temperature 37 °C for 6 months. The release concentration of Ni ions was detected using microwave induced plasma mass spectrometry (MIP-MS) with the resolution of ppb level. The toxic effect of Ni release was studied the cell growth using squamous carcinoma cells. These cells were seeded in 24 well culture plates and materials were immersed in each well directly. The concentration of Ni ions in the solutions had been reduced one-sixth by DLC films when compared with non-coated wire. This study indicated that DLC films have the protective effect of the diffusion and the non-cytotoxicity in corrosive environment.     

Adsorptive properties of albumin, fibrinogen, and γ-globulin on fluorinated diamond-like carbon films coated on PTFE

Fluorinated diamond-like carbon (F-DLC) films were deposited on polytetrafluoroethylene (PTFE) using radio frequency (RF) plasma-enhanced chemical vapor deposition (CVD) by changing the ratio of tetrafluoromethane (CF₄) and methane (CH₄). To enhance the adhesion strength of the F-DLC film to the PTFE substrate, the PTFE surface was modified with a N₂ plasma pre-treatment. XPS analysis of the films showed that the C–C bond decreased with increases in the CF₄ ratio, whereas the C–F bond increased with the CF₄ ratio. The F/C ratio of the film also increased with the CF₄ ratio. The pull-out test showed that the adhesion strengths of the films (CF₄-0–60%) were improved with the plasma pre-treatment. In the film without the plasma pre-treatment, adhesion strength increased with the CF₄ ratio. In contrast, in the case with the plasma pre-treatment, the adhesion strength of the F-DLC film decreased with the increased CF₄ ratio. Regarding the adsorption of albumin, fibrinogen, and γ-globulin, the amount of adsorbed albumin on the film decreased with an increasing CF₄ ratio, and the amount of adsorbed fibrinogen and γ-globulin increased with the CF₄ ratio. The CF₄-0% DLC film showed the most adsorbed albumin and the least adsorbed fibrinogen and γ-globulin. This indicates that the CF₄-0% DLC film has higher anti-thrombogenicity than the F-DLC film.