Yasuyuki Watanabe

Single center experience of cell-free and concentrated ascites reinfusion therapy in malignancy related ascites.

Cell‐Free and Concentrated Ascites Reinfusion Therapy (CART) is expected to improve patients’ symptoms related to ascites. Use of a patients own proteins in ascites might reduce the risk of infection. However, several reports have described that reinfusion of concentrated ascites might elevate body temperature. The aim of this study is to examine the safety and efficacy of the CART system performed exclusively on patients with malignancies. In this retrospective cohort observational study, we examined 81 CART processes performed on 24 patients with malignancies. Data were collected from medical records and records during processing of ascites. We investigated the effectiveness and adverse events during the procedures. The amount of ascites processed was 2.6u2009±u20091.4u2009L on average. The concentration ratio was 9.31u2009±u20095.45 on average. We found an increase in the urine volume after the procedure, which was significantly related to the amount of reinfused protein. The body temperature increased by 0.44°C. Systolic blood pressure decreased by 4u2009mmu2009Hg after paracentesis, but no significant difference was found between the pressure before paracentesis and after reinfusion. In platelet counts, no significant change was observed. After all, no clinically significant adverse event was confirmed during CART procedures. Results show that CART can be performed safely even on patients with malignancy‐related ascites and that the procedure might improve diuresis.

Successful Treatment by Double Filtrate Plasmapheresis in a Pregnant Woman With the Rare P Blood Group and a History of Multiple Early Miscarriages

Abstract:u2002 Individuals of P type, a rare blood group, have anti‐PP1Pk antibody in their serum, which causes spontaneous abortion in the early stages. We report a patient of p type suffering from multiple spontaneous abortions. We also review previously reported cases from published work. A 36‐year‐old woman (gravida 2, para 0) was referred to our hospital because of habitual abortion. At the third pregnancy, we started double filtration plasmapheresis (DFPP) from 7u2003weeks 3u2003days to remove the antibody. We attained rapid decline in the titer and normal fetal growth. Gradual tapering of the DFPP frequency caused neither a rebound of the titer nor growth retardation. During the course, she experienced only one episode of catheter infection as an adverse effect. At 37u2003weeks 3u2003days, after 57 DFPP repetitions, a 2496u2003g girl was delivered by cesarean section. The infant suffered neither from anemia nor from severe jaundice. A review of previous reports indicates that the titer of the pathogenic antibody should be kept as low as possible from the early gestational stage in P‐incompatible habitual abortion cases, otherwise the case typically comes to an unfavorable outcome. Plasma exchanges with fresh plasma potentially induce contamination by either known or unknown pathogens. Such risks are reduced using DFPP because the volume of albumin solution that replaces fresh plasma is less than that by plasma exchange. The present case, along with previous reports, shows that DFPP is an effective therapy for treating P‐incompatible pregnancy.u2003

Microgravity experiments for a visual feedback control of a space robot capturing a target

We propose an experimental system of a space robot in the microgravity environment at the Japan Microgravity Center where microgravity (less than 10/sup -5/ g for 10 sec) is generated by a free-fall of 490 m. In the environment, we performed experiments for a visual feedback control of a space robot capturing a target. To measure the position of the target and the motion of the robot, two CCD cameras are used and their images are processed by the tracking vision. After the introduction of the experimental system, we establish two computational methods to identify the 3D position and orientation of the robot base, and show the experiments and their results to evaluate the proposed methods.

Effects of growth interruption on structure of MBE grown GaAs/AlAs hetero-interfaces studied by x-ray diffraction

Abstract The effects of “growth interruption” on the structure of an MBE grown GaAs/AlAs superlattice were studied by X-ray diffraction measurements using anomalous scattering for gallium and arsenic atoms. The results revealed that “Growth Interruption” improves the distribution of periods of the superlattice and that the period is decreased due to the re-evaporation of Ga-As layers during the interruption.

A space robot of the center-of-mass invariant structure

We propose a free-flying space robot whose center-of-mass is fixed to the base body and invariant to changes of the configuration. The space robot with such a structure, named center-of-mass invariant structure, has the following characteristics: (1) an experimental system on the ground is simply built, (2) the computational cost of the generalized Jacobian matrix is reduced, and (3) motions in 2D planes are holonomic. We developed a prototype of the space robot with the center-of-mass invariant structure. The result of a preliminary experiment is to be shown.

NH3 flow rates dependence of crystallinity in GaN thin films grown by reactive close-spaced method at low temperature

Gallium nitride (GaN) thin films were grown on (0 0 0 1) sapphire using a direct reaction of NH 3 (ammonia) and metallic Ga (gallium) diluted with metallic Bi (bismuth) in a conventional resistance heated reactor. The growth of GaN thin films was carried out for 6 h at 750 C under low pressure. In this study, the flow rate of NH 3 was varied from 10 to 100 seem. The crystallinity, optical and electrical properties of the GaN films were measured to investigate the NH 3 flow rate dependence of the films grown. The NH 3 flow rate influenced the quality of the GaN thin films. At the NH 3 flow rate of 60 seem. we obtained a good quality of GaN films which exhibited a full width at half maximum of 10 aremin from the X-ray rocking curve, a neutral-donor bound exciton (I 2 line) emission in 13K photoluminescence (PL), an electron mobility of 45 cm 2 /V-s and concentration of 2 × 10 19 cm -3 at 300K.

Acceleration-level analysis on velocity-based motion control of kinematically redundant manipulators

Acceleration-level control of kinematically redundant manipulators has its peculiar problems such as the instability of the local torque optimization and the end-motion joint velocities. A large number of studies on the problems have been carried out and one of the most promising solutions is the acceleration-level control based on a velocity-level method which never causes the problems. In the conventional approach, the joint accelerations to accomplish a task is derived from the acceleration-level kinematic equation, whereas the velocity-based control uses the joint accelerations obtained by time differentiation of the solution to the velocity-level kinematic equation. In this paper, control methods based on the task-priority concept which accomplish primary and secondary tasks are investigated at the acceleration level. The velocity-level solution is analytically differentiated by time and compared with the simple acceleration-level solution, which clarifies the difference between the velocity-based control and the simple acceleration-level control.

Site of ruthenium in icosahedral AlMnRuSi

Abstract In order to investigate the sites occupied by ruthenium atoms in the Al76Mn14Ru7Si3 and Al68Mn20Ru8Si4 icosahedral alloys, the differential structure factors (DSF) and the differential pair distribution functions (DPDF) concerning ruthenium were obtained by the anomalous X-ray scattering technique with synchrotron radiation. On the assumption that ruthenium atoms occupy aluminum or manganese sites in the atomic structure model (Mackay-type; Quasiperiodic Configuration of Icosahedral Clusters (QCIC) model) of the Alue5f8Mn icosahedral phase, it is concluded that the ruthenium atoms are preferentially substituted at manganese sites which almost correspond to the vertices of the three-dimensional Penrose tiling (3D-PT) in i-Al76 Mn14 Ru7 Sii3. In the case of i-Al68 Mn20 Ru8 Si4, ruthenium atoms are substituted for two kinds of atomic sites, one of which is the manganese site and the other is that of aluminum atoms at the innermost shell of Mackay icosahedra.

Room temperature, very sensitive bolometer using doubly clamped microelectromechanical oscillators

We have proposed a room temperature, all electrical driving and detecting, very sensitive bolometer using a doubly clamped microelectromechanical (MEMS) oscillator. We fabricated GaAs MEMS oscillators, which were excited and detected both by piezoelectric effect. The device detects the shift in the resonance frequency caused by heating and works as a very sensitive bolometer. When the oscillator was driven slightly below the nonlinear hysteretic regime for the mechanical oscillations, the bolometer showed a voltage responsivity about 3,300 V/W, while keeping low noise spectral density of about 60 nV/Hz-1/2, demonstrating a noise equivalent power (NEP) of below 20 pW/Hz-1/2 at room temperature. Further improvement in NEP is expected by optimizing the sample structure. The observed effect can be used for realizing high-sensitivity terahertz bolometer for room-temperature operation.