Publications by authors named "Takuya Hashimoto"

Background: Standard liver volume (SLV) is an important concept in adult living liver donor transplantation. The purpose of this study was to re-evaluate and modify the authors' previous formula for predicting total liver volume (TLV).

Methods: The TLV of 301 Japanese living donors was measured by computed tomography.

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A titanium BINOLate catalyzed asymmetric 1,3-dipolar cycloaddition reaction between alpha-substituted acroleins and alkyl diazoacetates has been developed. With this methodology in hand, chiral 2-pyrazolines containing a quaternary stereogenic center were obtained in high to excellent enantioselectivities (up to 95% ee). The synthetic utility of the optically enriched 2-pyrazoline thus obtained was demonstrated in the short synthesis of manzacidin A.

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A mu-oxo-type chiral bis-Ti(IV) oxide (S,S)-1 can be successfully utilized in the asymmetric 1,3-dipolar cycloaddition reactions between various nitrones 2 and acrolein to give the corresponding isoxazolidines with high to excellent enantioselectivities. For instance, the reaction between nitrone 2 (R = t-Bu) and acrolein in the presence of 10 mol % of bis-Ti(IV) catalyst (S,S)-1 in dichloromethane at -40 degrees C gave the corresponding endo cycloadduct with 97% ee.

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Background: The usefulness of cryopreserved superior vena cava (SVC) grafts for venous reconstruction remains to be evaluated in right liver and right lateral sector transplantation.

Methods: Reconstruction of the hepatic vein was performed when the congested area in the liver graft was significant. A vein graft with a suitable shape and length meeting the demands for the venoplasty was selected, and SVC grafts were used in 20 recipients.

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The incidence of hepatic venous stenosis is higher in partial liver transplantation. New methods for hepatic venous reconstruction in left liver transplantation, which secure wide anastomosis, were devised and are reported here. In the graft, the right side of the middle hepatic vein or the left side of the left hepatic vein was cut longitudinally and a rectangular-shaped vein patch was attached for venoplasty.

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A right lateral sector graft (RLSG) was devised to overcome graft-size disparity in living donor liver transplantation (LDLT). When the RLSG has a middle hepatic vein (MHV) tributary, which drains a significant part of segment VI, the MHV tributary (V6) should be reconstructed to avoid congestion of the RLSG. In the donor operation, congestive area of segment VI was identified by 5 minutes of simultaneous clamping of V6 and the hepatic artery to the right lateral sector.

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Hypothesis: Biliary reconstruction of the small bile duct is difficult, and bilioenteric reconstruction without mucosa-to-mucosa alignment would be a simple and useful maneuver in this situation; however, the long-term results of this surgical technique remain to be evaluated.

Objective: To evaluate the usefulness of bilioenteric reconstruction without mucosa-to-mucosa alignment from the standpoint of the long-term results.

Design: Retrospective review.

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Early diagnosis of the malfunction of a mechanical artificial heart implanted in a patient who has been discharged from hospital is very important. We have developed an electro-stethoscope system that enables the malfunction of an artificial heart to be detected from the analysis of sound signals from the artificial heart. The sound data can be transmitted to a hospital via a mobile telephone or the Internet, so that doctors can examine the condition of the artificial heart.

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An artificial chaperone, which can decrease the protein aggregation and increase the reactivation yield of denatured protein in a fashion similar to natural chaperone, was newly developed using stimuli-responsive polymers. It has previously been reported that the addition of poly(propylene oxide)-phenyl-poly(ethylene glycol) (PPOn-Ph-PEG) with the unit number of PPO (n) 33 could enhance the refolding of bovine carbonic anhydrase (Kuboi et al. J.

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In this study, we developed a new miniature motor-driven pulsatile left ventricular assist device (LVAD) for implantation into a Japanese patient of average build by means of computer-aided design and manufacturing (CAD/CAM) technology. A specially designed miniature ball-screw and a high-performance brushless DC motor were used in an artificial heart actuator to allow miniaturization. A blood pump chamber (stroke volume 55 ml) and an inflow and outflow port were designed by computational fluid dynamics (CFD) analysis.

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A new, chiral bis-Ti(IV) oxide of type 3 has been designed and can be utilized for strong activation of aldehyde carbonyls, thereby allowing a new catalytic enantioselective allylation of aldehydes with allyltributyltin. The chiral bis-Ti(IV) catalyst (S,S)-3 can be readily prepared either by treatment of bis(triisopropoxy)titanium oxide with (S)-BINOL or by treatment of ((S)-binaphthoxy)isopropoxytitanium chloride with silver(I) oxide. Treatment of hydrocinnamaldehyde with allyltributyltin under the influence of chiral bis-Ti(IV) oxide (S,S)-3 generated in situ (10 mol %) in CH(2)Cl(2) afforded an allylation product in 84 % yield and with 99 % ee.

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A new, chiral bis-Ti(IV) oxide of type 1 was successfully designed and can be utilized for strong activation of aldehyde carbonyls, thereby allowing a new catalytic enantioselective allylation of aldehydes with allyltributyltin. The chiral bis-Ti(IV) catalyst (S,S)-1 can be readily prepared either by treatment of bis(triisopropoxy)titanium oxide with (S)-binaphthol or by reaction of ((S)-binaphthoxy)isopropoxytitanium chloride with silver(I) oxide. Reaction of hydrocinnamaldehyde with allyltributyltin (1.

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Thrombus formation is a critical issue when designing a long-term implantable left ventricular assist system (LVAS). Fluid dynamic characteristics of blood flow are one of the main factors that cause thrombus formation. In this study, we optimized the fluid dynamics of a sac blood pump in our LVAS to ensure minimization of shear-related blood damage that could lead to thrombus formation.

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Atom positions and anisotropic Debye-Waller factors of the rhombohedral phase of LaCrO(3) have been refined simultaneously with the low-order structure factors, using a structure-analysis method of convergent-beam electron diffraction (CBED) proposed by Tsuda & Tanaka [Acta Cryst. (1999), A55, 939-954]. The method is based on the least-squares fitting between full dynamical calculations and energy-filtered intensities of two-dimensional higher-order Laue-zone (HOLZ) and zeroth-order Laue-zone (ZOLZ) CBED patterns.

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An implantable secondary battery is one of the key components in a total artificial heart system. Because a 2 year cycle life is required, the cycle life of the secondary battery as well as its charge and discharge properties are important parameters for selection of an appropriate battery. We carried out cycle life tests on four kinds of rechargeable batteries (a Ni-MH secondary battery, a Ni-Cd secondary battery, a Li-ion battery with a graphite anode, and a Li-ion battery with a nongraphitizable carbon electrode) to determine their suitability as implanted back-up batteries.

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