-
[show abstract]
[hide abstract]
ABSTRACT: Recurrence following liver transplantation for hepatitis C virus (HCV), which is universal, affects long-term outcomes. Treatment with interferon (IFN) and ribavirin (RBV), the only widely available options at this time, have been faced with low tolerability and overall unsatisfactory results in deceased donor liver transplantation (DDLT). However, its place after living donor liver transplantation (LDLT) remains a matter of debate. Since most LDLT cases are performed in a planned manner at a lower Model for End-stage Liver Disease (MELD) score compared to DDLT, we have aggressively applied preemptive INF/RBV in our series.
We studied 122 adult recipients who underwent LDLT for HCV-related end-stage liver disease. The preemptive IFN/RBV protocol initiated treatment promptly after improvement in the patient's general condition with a low-dose IFN alpha2b and RBV (400 mg/d) followed by a gradual increase in the INFalpha2b dosage. Finally, we applied pegylated IFN (1.5 ug/kg/wk) and RBV (800 mg/d). The treatment was continued for 12 months after serum HCV-RNA became negative, which was defined as the end-of-treatment response (ETR). The response was considered to be a sustained viral response (SVR) if there were negative serologic results without antiviral treatment for another 6 months. Splenectomy was performed at the time of LDLT to improve tolerability to INF/RBV. The median age of the patients was 55 yrs (range = 23-66), with male dominance (87 males and 35 females). Median MELD score was 14 (range = 6-48). The series included 72 patients with hepatocellular carcinomas, and six with HIV coinfections. In 98 cases, HCV genotype was 1b.
Overall survival at 5 years was 79%. Cumulative response rates under the protocol were ETR 56% and SVR 44% at 5 years.
Preemptive IFN/RBV therapy after LDLT for HCV is feasible with acceptable outcomes.
Transplantation Proceedings 04/2012; 44(3):791-3. · 1.00 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: We report a case of intrahepatic cholangiocarcinoma with biliary lithiasis arising 47 years after surgery for a congenital biliary dilatation (CBD). A 62-year-old woman was admitted for the investigation of a liver tumor. She had undergone a choledochoduodenostomy at the age of 15 years for CBD and resection of an extrahepatic bile duct with choledochojejunostomy because of cholangitis at the age of 55 years. An enhanced computed tomography (CT) revealed a liver tumor 50 mm in diameter in the S6 region with surrounding lymph node swelling and intrahepatic metastatic lesions in the S8 region. A drip infusion cholangiographic CT showed biliary lithiases in the left liver. An extended right hepatectomy and lymph node dissection was considered but was abandoned because of suspicions of liver functional insufficiency as a result of biliary lithiasis. She underwent biliary lithotomy through a percutaneous transhepatic cholangioscopy and subsequent systemic chemotherapy.
Bioscience trends 04/2012; 6(2):98-102. · 0.97 Impact Factor
-
J J Gao,
P P Song,
S Tamura, K Hasegawa,
Y Sugawara,
N Kokudo,
K Uchida,
R Orii,
F H Qi,
J H Dong,
W Tang
[show abstract]
[hide abstract]
ABSTRACT: Japan-China Joint Medical Workshop (2012) on standardization of perioperative management on hepato-biliary-pancreatic surgery was held by the Center for Medical Standards Research, IRCA-BSSA Group in Japan on April 15-16, 2012. Experts in the fields of surgery, anesthesia, pharmacy, and public health from 21 health institutions from Japan and China presented their research achievements and shared their medical experience of perioperative management on hepato-biliary-pancreatic surgery, which should facilitate building of guidelines for hepatocellular carcinoma and be expected to promote standardized management of liver cancer in Asia.
Drug discoveries & therapeutics. 04/2012; 6(2):108-11.
-
T. Kobayashi,
A. Isayama,
K. Yokokura,
M. Shimono, K. Hasegawa,
M. Sawahata,
S. Suzuki,
M. Terakado,
S. Hiranai,
F. Sato, [......],
J. Hinata,
Y. Sato,
M. Ohzeki,
K. Takahashi,
K. Kajiwara,
Y. Oda,
A. Kasugai,
K. Sakamoto,
K. Hoshino,
S. Moriyama
[show abstract]
[hide abstract]
ABSTRACT: A new gyrotron operation technique to increase oscillation efficiency was developed using the JT-60 electron cyclotron range of frequency (ECRF) system. In order to increase the efficiency without a significant increase in the anode leakage current by trapped electrons that limits the efficiency of gyrotrons with a collector potential depression technology, we actively optimized the electron pitch factor by controlling only the anode voltage within ~0.1 s after the start of the gyrotron operation, and a high-efficiency oscillation in the so-called hard-self-excitation region was achieved from the start of the oscillation. As an application of this technique in the JT-60 ECRF system, the gyrotron output power of 1.5 MW for 4 s, which is the longest pulse length in the world at an output power of 1.5 MW, was recorded with a successful reduction in the collector heat load by 20% as compared with the conventional operation. The reduced collector heat load at the 1.5 MW operation was acceptable for a steady-state operation. Further progress was made with respect to the expansion of the long-pulse capability of the ECRF system. A new gyrotron with an improved mode converter was developed in order to demonstrate a reduction in the stray radiation in the gyrotron; such radiation has thus far hindered long-pulse operations by causing an unacceptable heat load. We confirmed that the stray radiation was reduced to 1/3 of that of the original gyrotron; this reduced heat load is acceptable for steady-state operation. A conditioning operation of the improved gyrotron proceeds up to 31 s at 1 MW. This progress significantly contributes to an enhancement in the high-power and long-pulse capability of the ECRF system used in JT-60SA, where a total output power of 9 MW for 100 s is planned.
Nuclear Fusion 09/2011; 51(10):103037. · 4.09 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: This paper proposes a new dc-voltage-balancing circuit for a five-level diode-clamped inverter intended for a medium-voltage motor drive with a three-phase diode rectifier used as the front end. This circuit consists of two unidirectional choppers and a single coupled inductor with two galvanically isolated windings. The inductor produces no net dc magnetic flux because the individual dc magnetic fluxes generated by the two windings are canceled out with each other. This makes the inductor compact by a factor of six, compared with the balancing circuit including two noncoupled inductors. Moreover, introducing phase-shift control to the new balancing circuit makes it possible to adjust the midpoint voltage. As a result, the dc mean voltages of all the four split dc capacitors can be balanced, independent of inverter control. Experimental results obtained from a 200-V 5.5-kW downscaled model verify the effectiveness of the new balancing circuit.
IEEE Transactions on Industry Applications 05/2011; · 1.66 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: In recent years, systematic knowledge-creation is being watched in medical fields, and knowledge creation is successfully being adopted to improve clinical pathways and electronic medical charts. It is possible to provide more efficient and effective medical service with the sharing and use of information or knowledge in all medical organizations, though sometimes medical organizations may offer medical service that does not coincide with patient characteristics if the organization only pursues efficiency. In this study, it was hypothesized that Moshiokuri among nurses results in the generation of knowledge associated with patient characteristics. We examined knowledge creation among nurses by an in-depth analysis of Moshiokuri in hospitals equipped with clinical-pathways and electronic medical charts.
Computer and Information Science (ICIS), 2010 IEEE/ACIS 9th International Conference on; 09/2010
-
[show abstract]
[hide abstract]
ABSTRACT: In radiotherapy simulations, Monte Carlo-based radiotherapy simulation is applied to a high accurate calculation of dose distributions in a patient or optimization of the beam delivery system. Geant4 toolkit has come to be utilized to build a Monte Carlo simulator for that purpose. It needs the volume rendering capability to display a complex volume data by a visualizer. However, there is no volume rendering capability in the visualization system in Geant4. A volume visualization driver for Geant4 is described in this paper, which is available to display a complex patient image and a dose distribution calculated in a Geant4-based radiotherapy simulation with an external volume visualizer. The volume visualization driver extracts a patient data set, calculated dose distributions, particle trajectories and geometrical information of beam delivery modules in the simulation, and then saves their information as a data file. With that data file, the external volume visualizer is able easily to display results of the simulation.
Nuclear Science Symposium Conference Record (NSS/MIC), 2009 IEEE; 12/2009
-
[show abstract]
[hide abstract]
ABSTRACT: We propose a method of sampling regular and irregular-grid volume data for visualization. The method is based on the Metropolis algorithm that is a type of Monte Carlo technique. Our method enables `importance sampling' of local regions of interest in the visualization by generating sample points intensively in regions where a user-specified transfer function takes the peak values. The generated sample-point distribution is independent of the grid structure of the given volume data. Therefore, our method is applicable to irregular grids as well as regular grids. In this paper, we also demonstrate features of adaptive sampling in our method. We visualize volume data by projecting the generated sample points onto the 2D image plane. In this research, we propose to improve efficiency of the Monte Carlo volume graphics by using space partition of volumic MPU.
Intelligent Information Hiding and Multimedia Signal Processing, 2009. IIH-MSP '09. Fifth International Conference on; 10/2009
-
[show abstract]
[hide abstract]
ABSTRACT: This paper describes a 6.6-kV adjustable-speed motor drive for pumps and blowers without transformer. The power conversion system consists of a front-end diode rectifier, a five-level diode-clamped pulsewidth modulation (PWM) inverter with a voltage balancing circuit, and a hybrid active filter for harmonic-current mitigation of the diode rectifier. The control of the inverter is characterized by superimposing a third-harmonic zero-sequence voltage on each of the three-phase reference voltages to achieve the so-called overmodulation and reduce the switching stress of insulated gate bipolar transistors (IGBTs). A 200-V 5.5-kW downscale model is designed, constructed, and tested with focus on the five-level PWM inverter and the voltage balancing circuit. Experimental results obtained from the 200-V downscale model verify the viability and effectiveness of the 6.6-kV adjustable-speed motor drive, showing that the four split dc capacitor voltages are well balanced in all the operating conditions and that the switching stress of the IGBTs is reduced at low modulation indexes.
IEEE Transactions on Power Electronics 04/2009; · 4.65 Impact Factor
-
K Miyamoto,
K Iori,
K Sakamoto,
H Narita,
A Kimura,
M Taniguchi,
S Qiao, K Hasegawa,
K Shimada,
H Namatame,
S Blügel
[show abstract]
[hide abstract]
ABSTRACT: Spin- and angle-resolved photoemission spectroscopy has been applied to the study of the surface and bulk electronic structures of a face-centered cubic (fcc) Co thin film. We have experimentally resolved a negatively spin-polarized surface resonance state of fcc Co/Cu(001) at 0.4 eV below the Fermi energy. Moreover, we have found that the surface resonance state exhibits a strong spin–orbit interaction through an investigation of magnetic dichroism in the angular distribution spectrum of Co/Cu(001).
New Journal of Physics 12/2008; 10(12):125032. · 4.18 Impact Factor
-
[show abstract]
[hide abstract]
ABSTRACT: AIS (ship-borne automatic identification system) is a system that enables a ship to get information about encountered ships, such as their position, course, speed, name etc. automatically by VHF radio transmission. The system is expected to contribute the improvement of marine traffic control and safety. In some congested waterways overloaded/conflicted transmission of AIS is a potential problem in the planning stage. We have developed a simulator that simulates AIS communication for real or simulated marine traffic flow considering the movement of each ship. AIS communication is evaluated under various AIS transmitting conditions and for various aspects using thus developed AIS simulator.
ITS Telecommunications, 2008. ITST 2008. 8th International Conference on; 11/2008
-
[show abstract]
[hide abstract]
ABSTRACT: To achieve a high throughput performance constantly, a H-ARQ (hybrid-automatic repeat request) scheme which controls the retransmission size is important. RB-HARQ (reliability-based HARQ) has been proposed as the control scheme of the retransmission size. However, in RB-HARQ, simulations must be needed beforehand and a receiver must memorize results of simulations. In this paper, we propose a H-ARQ scheme with controlling retransmission size by BLER (block error rate) which can be obtained by results of CRC (cyclic redundancy check) decoding. We show that a throughput performance of the proposed scheme is equivalent to that of RB-HARQ and the proposed scheme does not need simulations which must be needed in RB-HARQ.
Personal, Indoor and Mobile Radio Communications, 2007. PIMRC 2007. IEEE 18th International Symposium on; 10/2007
-
M. Yamamoto, K. Hasegawa,
M. Nomura,
A. Schnase,
F. Tamura,
S. Anami,
E. Ezura,
K. Hara,
C. Ohmori,
A. Takagi,
M. Toda,
M. Yoshii
[show abstract]
[hide abstract]
ABSTRACT: We have performed particle tracking simulation of J- PARC RCS to study the synchronization process. A frequency offset is added to the original rf frequency pattern to shift the bunch center, under the condition that the offset value should be 'adiabatic' with respect to the synchrotron motion. Since the synchrotron frequency of the J-PARC RCS is substantially changed during acceleration, the particle tracking simulation helps to decide the limit of the frequency offset which can be employed.
Particle Accelerator Conference, 2007. PAC. IEEE; 07/2007
-
[show abstract]
[hide abstract]
ABSTRACT: The required alignment accuracy in the J-PARC linac is 0.1 mm in transverse direction. In the DTL/SDTL section, the fine alignment was carried out by using an optical alignment telescope along with the cavity installation. The displacement of the DTL by the unit tank connection was monitored by a laser tracker to obtain the tolerable displacement between unit tanks. The heights of cavities and magnets were compensated form the local settlement of the linac tunnel.
Particle Accelerator Conference, 2007. PAC. IEEE; 07/2007
-
[show abstract]
[hide abstract]
ABSTRACT: J-PARC linear accelerator components have been installed. Before the beam commissioning, a precise survey for alignment has been performed. The reference points were set up on the tunnel wall to built a survey network. Based on the survey results, the magnets in the straight section were re-aligned finely. Then, the results of the displacement are confirmed to be tolerable for the beam commissioning.
Particle Accelerator Conference, 2007. PAC. IEEE; 07/2007
-
M. Ikegami,
H. Tanaka,
Z. Igarashi,
S. Sato,
T. Morishita,
H. Asano,
T. Ito,
H. Sako,
T. Kobayashi,
A. Ueno, K. Hasegawa
[show abstract]
[hide abstract]
ABSTRACT: In the beam commissioning of J-PARC (Japan Proton Accelerator Research Complex) Linac, the RF amplitude and phase tuning has been performed for its DTL (Drift Tube Linac). The tuning has been performed with a "phase- scan" method, monitoring the output beam energy from each DTL tank. Comparing the obtained phase dependence of the output beam energy with those from the modeling, we have tuned the RF phase and amplitude for DTL tanks mostly within the required tuning accuracy of 1 deg in phase and 1 % in amplitude, although further analysis is required to quantitatively evaluate the achieved tuning accuracy.
Particle Accelerator Conference, 2007. PAC. IEEE; 07/2007
-
[show abstract]
[hide abstract]
ABSTRACT: In the beam commissioning of J-PARC (Japan Proton Accelerator Research Complex) linac, three simulations codes are used to model the accelerator. We have compared the modeling with the experimental results obtained in the beam commissioning to date, where a basic agreement has been confirmed between the modeling and the actual beam behavior.
Particle Accelerator Conference, 2007. PAC. IEEE; 07/2007
-
[show abstract]
[hide abstract]
ABSTRACT: We have been fabricated the several ACS modules step by step: the first buncher, the second buncher, the low- beta accelerating module, and so on. This paper reports the improvement of the frequency and summarizes these RF measurement results. The data of the frequency fluctuation from brazing or stacking have been accumulated, and then the second buncher could be tuned correctly, although the frequency of the first buncher was lower than the target design. In the present fabrication process, about 0.1 to 0.2 MHz fluctuation should be corrected at each measurement step. As the result, the frequency could be tuned to the range of the movable tuner.
Particle Accelerator Conference, 2007. PAC. IEEE; 07/2007
-
M. Yamamoto, K. Hasegawa,
M. Nomura,
A. Schnase,
F. Tamura,
S. Anami,
E. Ezura,
K. Hara,
C. Ohmori,
A. Takagi,
M. Toda,
M. Yoshii
[show abstract]
[hide abstract]
ABSTRACT: We have been testing the RF cavities for the J-PARC RCS, so that we can operate the cavities without severe problems. Before some MA cores were damaged, then we found such cores have low ribbon resistance. After that we have tested the cavities loaded with cores which have improved ribbon resistance.
Particle Accelerator Conference, 2007. PAC. IEEE; 07/2007
-
M. Yoshii,
S. Anami,
E. Ezura,
K. Hara,
Y. Hashimoto,
C. Ohmori,
A. Takagi,
M. Toda,
K. Haga, K. Hasegawa,
M. Nomura,
A. Schnase,
F. Tamura,
M. Yamamoto
[show abstract]
[hide abstract]
ABSTRACT: The rapid cycling synchrotron (RCS) radio frequency accelerating systems have been prepared for the beam commissioning scheduled in the middle of September 2007. Installations of cavities, power supplies and amplifiers were carried out. Also, the systems have been checked for the combined operations. For the main synchrotron (50 GeV-MR) accelerating systems, the high power examinations and final adjustments are ongoing. Installations are planned for September 2007. Here, we report on various issues that had been found and solved during the examination and installation period.
Particle Accelerator Conference, 2007. PAC. IEEE; 07/2007
