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Porous-stabilized rare-earth barium copper oxide (REBCO) tape is an effective structure to solve a trade-off between the current-limiting and recovery performances of the resistive-type superconducting fault current limiters (RSFCLs). In the present study, a current-transfer-type porous-stabilized REBCO tape was proposed to suppress hot spots on the tape, which caused a recovery delay. In this type of REBCO tape, two porous stabilizers with different roles are utilized. The boiling heat transfer performance is improved with one of the porous stabilizers fixed with insulating epoxy on the tape while the current is transferred to the other porous stabilizer to decrease the Joule heating in the hot spot. To design the structure of the current-transfer-type porous-stabilized REBCO tape, the heat transfer performance with a porous medium and insulating epoxy was evaluated. The results indicated that there were suitable specifications for the porous medium and insulating epoxy for high heat transfer performance. The recovery performance of the current-transfer-type porous-stabilized REBCO tape was evaluated with the prototype using the selected porous stabilizer and insulating epoxy. The experimental results showed that the tolerable Joule heating was dramatically improved via current transfer to the porous stabilizer owing to the suppression of the temperature rise of the hot spot. The recovery time was shortened to 0.8 s. The present study showed one way to suppress the hot spots with a simple structure while maintaining the high electrical resistance of the REBCO tape.

Rare-earth barium copper oxide (REBCO) tape is used for resistive type superconducting fault current limiters (RSFCLs) owing to its quick response and simple structure. To shorten the recovery time, film boiling on the REBCO tape should be suppressed as it exhibits poor heat transfer performance. To address the aforementioned issue, this study utilized low thermal conductivity materials as the thermal/electrical interface material for porous-stabilized REBCO tape. The experimental results showed that the cooling and recovery performances were dramatically improved by utilizing an insulating epoxy, which has a thermal conductivity of 0.6 W/mK. Based on the visualization of the boiling behavior, the liquid-solid contact between liquid nitrogen and the REBCO tape was promoted by the insulating epoxy, in which the film boiling was easily broken.

Heat transfer performance of divertor cooling device EVAPORON-4, which was developed in order to remove a high heat flux of 10 MW/m2 under low pumping power conditions, is evaluated. Uni-directional porous media used in EVAPORON-4 make it possible to promote evaporative heat transfer in microchannels of the porous medium due to its high effective thermal conductivity. In this study, we evaluate effect of soldering the uni-directional porous medium onto a grooved heat transfer surface on boiling and evaporative heat transfer performance. The heat transfer experiments prove that the boiling heat transfer performance is highly enhanced by soldering the porous medium onto the grooved surface due to the promotion of evaporation in the uni-directional porous medium and that the critical heat flux is also further increased. In particular, a high heat flux of 9.1 MW/m2, which is not critical heat flux, is achieved at 1.0 L/min and the liquid subcooling of 70 K. The pumping power characteristics also verify the evaporation promotion in the uni-directional porous medium and clarify the issues of EVAPORON-4 including the porous structure.

Ultrasonic welding (UW) is a candidate for easy and simple fabrication of lap joints of high-temperature superconducting (HTS) tapes. Our previous study applied UW to both silver-sheathed BSCCO tapes and copper-stabilized REBCO tapes with indium foil inserted in-between. However, the fabrication was performed with limited joining conditions and critical current, I C, degradation was confirmed in some of the BSCCO tape joints. In this study, we evaluated the joining-condition dependence of joint resistance and I C to improve UW-joined HTS tape performance. Various UW samples using BSCCO and REBCO tapes were prepared with different thicknesses of indium foil, ultrasonic vibration amplitude, joining pressure, joining time, and metal plate arrangement. The results showed that HTS tapes layered between metal plates on the top and bottom can avoid I C degradation even with higher joining energy, however thinner indium foil induced degradation in the BSCCO samples. Through this study, we found the value of joint resistivity only depended on the joining energy per unit joint area. The achieved joint resistivities were 14.0 nΩcm2 for the silver-sheathed BSCCO tapes and 36.1 nΩcm2 for the copper-stabilized REBCO tapes though it was strongly influenced by interface resistivity of the REBCO tape itself.

In recent years, heat flux is becoming much higher according to the downsizing of electronics, and accurate thermal design and high efficient cooling technique are required for higher reliability of electronics. Heat spreader is one of the key technology of high heat flux electronics. Conventionally, heat spreading angle in the heat spreaders is assumed as 45 degrees. However, the angle depends on surrounding condition. Additionally, for efficient use of the heat spreaders, contact thermal resistance is also important. However, heat spreading angle and contact thermal resistance under high heat flux condition have not been discussed in details. In this paper, contact thermal resistance and heat spreading angle in the heat spreaders under high heat flux condition are discussed.

This paper describes comparison of thermal properties between Si power MOSFET and SiC power MOSFET. Conventionally, Si power MOSFET has been widely used in power electronics area. On the other hand, SiC power MOSFET has wide band gap, and is gaining attention as a new generation power device. However, thermal properties of SiC power MOSFET has not been clear. For appropriate thermal management of SiC power MOSFET, heat generation tendency and temperature rise of the device should be investigated. In this paper, we conducted numerical simulation to investigate thermal properties of SiC power MOSFET. Electro-Thermal Analysis was employed as simulation method. We compared temperature between Si power MOSFET and SiC power MOSFET, and discussed difference of heat generation and temperature between these two devices.

This study evaluates boiling and evaporative heat transfer performance of a heat sink called EVAPORON-4 utilizing uni-directional porous media in order to remove high heat generation of 300–500 W/cm2 from a chip of the next generation SiC-/GaN-based on-vehicle inverter. The unidirectional porous heat sink has three functions such as direct supply of cooling liquid to a heat transfer surface, promotion of evaporation, and passive vapor discharge. The porous medium is made of oxygen free copper and the porosity is 19.6 %. The small pore holes of 0.5 mm in diameter work for the liquid supply and the large holes of 2.6 mm for the vapor discharge. In order to discharge the vapor through the vapor discharge pore holes, the porous heat sink is set onto a grooved heat transfer surface. As a result, the porous heat sink achieves high cooling performance of approximately 850 W/cm2 at the pumping power of 2.6 W in case of the liquid subcooling of 40 K and the flow rate of 2.0 L/min (102 kg/m2/s).

Molten-salt used as a coolant in fusion reactors plays a significant role in the design of advanced reactors. Investigation of thermal behavior is necessary in an actual environment of a facility where heat transfer enhancement takes place under a high Pr number fluid flow such as in case of FLiBe. For the development of a facility, it is necessary to be able to monitor fluid motion of a basic heat transfer promoter such as a sphere-packed pipe (SPP). In the present study, to discern the complex flow structures in SPP, digital holographic PTV visualization is carried out by a refractive index-matching method using a sodium iodide (NaI) solution employed as a working fluid. Hologram fringe images of particles behind the spheres can be observed, and the particles’ positions can be reconstructed by a digital hologram. Consequently, 3-D velocity-fields around the spheres are obtained by the reconstructed particles’ positions. The velocity between pebbles is found to be faster than that in other regions.

We review current accomplishments and ongoing work in Task 1–3 “Flow Control and Thermofluid Modeling” of the US-JAPAN “TITAN” Program. This encompasses construction of a new MHD lead–lithium loop at UCLA and planning, preparation and pre-experimental analysis for first experiments, including tests of high-temperature ultrasound Doppler velocimeter and studies of the behavior and electroinsulating properties of the foam-based silicon carbide flow channel insert in the flowing liquid metal in a magnetic field. First results of magnetohydrodynamic experiments on flow transitions from 3D to 2D are also presented and discussed.

Glass-ceramic LiFePO 4 was synthesized through the crystallization of glass powder prepared by melting low-cost raw materials in ambient air. To obtain the homogeneous precursor glass, the addition of a small amount of Nb 2 O 5 was effective. Ferric ions in the precursor glass were reduced and precipitated as LiFePO 4 through the heat treatment of a mixture of the glass powder and a carbon source. The obtained glass-ceramic particles contained a LiFePO 4 crystalline phase and a carbon-containing surface amorphous layer with a thickness of about 20 nm. A lithium-ion rechargeable battery fabricated with the glass-ceramic powder showed better high-rate performance than that of a battery made using commercial LiFePO 4 ceramic powder. The better performance of the battery with the glass-ceramic is attributed to the existence of the surface amorphous layer. This synthesis process, consisting of glass melting in air and the subsequent crystallization of glass powder, has the potential to be used for the large-scale continuous production of high-performance LiFePO 4 .

We grew pure ErBa 2 Cu 3 O 7− δ (ErBCO) films and ErBCO films with BaSnO 3 (BSO) doping as artificial pinning centers (APCs) by pulse laser deposition on SrTiO 3 substrates, and the effects of oxygen pressure on crystallinity, critical temperature ( T C ) and microstructure of ErBCO films were investigated. In a previous study, we grew ErBCO films with BaNb 2 O 6 (BNO) by controlling the growth temperature under a constant oxygen pressure of 400mTorr and confirmed the effect of BNO as APCs. We observed the tendency which diameter of nanorods became small and pinning force was strong at lower growth temperature. However, crystallinity and T C of ErBCO films degraded at low growth temperature. So, it is very important to improve crystallinity and T C by a novel method. In this study, we focused on oxygen pressure, and aimed at improvement of crystallinity and T C by controlling oxygen pressure.

By changing the composition ratio in Flibe to decrease its melting temperature, it becomes possible to design the TBM under the temperature design limits for ferritic steel. The accompanied demerit...

Summary Background Human mast cells express both FcɛRIα and FcγRIα. IgE up-regulates FcɛRIα expression, but IgG1 does not up-regulate FcγRIα expression. The transmembrane domain (TM) of FcγRIα determines the stability of cell surface expression of this receptor. Objective The aim of this study was to clarify the roles of the TM and cytoplasmic domain (CY) of FcɛRIα in IgE-mediated FcɛRI up-regulation. Methods Chimeric receptors created by domain shuffling between FcɛRIα and FcγRIα were transduced into human mast cell line HMC-1. Cell surface expression of the chimeric receptors and the effect of IgE or IgG1 on chimeric receptor expression were examined by FACS. The association of the chimeric receptors with FcRγ was investigated by immunoprecipitation. Results The results showed that the TM and CY of FcɛRIα are not essential for IgE-mediated up-regulation of surface FcɛRI. Conclusion The extracellular domain of each Fc receptor determines the diversity of Ig-regulated Fc receptor expression.

The NDT method using electromagnetic waves has availability for crack detection in large pipes or structures in nuclear power plants. The purpose of this study is then, to develop a new method to determine the crack size and location with high speed and accuracy. Through this study, it has been shown that the transmitted wave carries a lot of information on crack depth and the obtained signals of reflected wave below the cut-off frequency depend on the crack position. Experimental results indicate that there exists attractive possibility in the new NDT method.

The interaction energy between rutile TiO 2 (1 1 0) surface and CO 2 molecule has been investigated by ab initio quantum chemical calculations in order to increase the adsorption energy between the surface and the adsorbate by a chemical modification of the surface. In this work, we propose a novel approach for chemical modifications by utilizing the ab initio calculations. The interaction energy between a surface and a molecule can be decomposed into several physically meaningful terms such as electrostatic, polarization and charge transfer interactions by the Kitaura-Morokuma analysis. In the case when the charge transfer interaction from the molecule to surface is dominant, replacing several Ti atoms by the element that has larger electron negativity than the Ti atom will be appropriate. Such modification will promote the charge transfer from molecule to surface, which will leads to the increase in the stabilization energy. We represent TiO 2 surface by a Ti 7 O 22 H 16 cluster in which dangling bonds are terminated by hydrogen atoms. Geometry optimizations as well as the Kitaura-Morokuma analysis are performed within the RHF level for the CO 2 and Ti 7 O 22 H 1 6 system. In the CO 3 form adsorption geometry, the charge transfer interaction energy from the cluster to CO 2 is found to be dominant among the component interactions. It is demonstrated that replacement of two Ti atoms by two Ca atoms drastically promotes the charge transfer in accord with our proposal and consequently, the total adsorption energy increases. The mechanism of the increase in the charge transfer interaction as well as CO 2 adsorption on the TiO 2 cluster is discussed by investigating the spacial distribution of the HOMO electron density of the cluster.

Critical current density ( J C ) of REBa 2 Cu 3 O 7− δ (REBCO) films deteriorates in a magnetic field. One of the methods to solve the J C deterioration is to introduce artificial pinning centers (APCs) such as nanorods into the REBCO films. When many nanorods with a small diameter grew up than less rods with large diameter in REBCO films, the nanorod are considered to act as APCs. Therefore, we focused on controlling the rod diameter in order to realize the higher number density of nanorods in REBCO films. BaNb 2 O 6 (BNO) was introduced in ErBCO films. In order to decrease the diameter of nanorods, we think it is necessary to control migration length of Nb atoms at the film surface of the ErBCO. As a result, it was observed in TEM image that diameter of nanorods was changed by varying substrate temperature and decreased with decreasing the substrate temperature.

An improved magnetic field analysis by using tensor reluctivity is presented. The conventional numerical modeling of materials can not exactly express the phase difference between the magnetic flux density and the magnetic field intensity. We therefore define the magnetic tensor reluctivity under an alternating and rotating flux condition, and calculate it from measured data, which are obtained by using two-dimensional magnetic measuring apparatus. This method is applied to a three-phase transformer model core made of oriented steel. As a result, it is shown that our new method is applicable to the strong anisotropic problems and rotating magnetic field problems. >

In the conventional magnetic field analyses that are applied to such things as rotating machines, the magnetic properties of the arbitrary direction have been modelled by using the magnetic properties of the easy axis and its perpendicular direction. Such kind of numerical modeling can not exactly show the phase difference between the magnetic flux density B and the magnetic field strength H in the case of a rotating magnetic flux excitation. In this paper, the B- and H-values are measured as vector quantities under the rotating magnetic flux excitation. The magnetic properties of the material are expressed by the magnetic reluctivity tensor based on the measured results. This new expression is applied to the rotating magnetic field problem. As a result, it is shown that our new method is applicable to the problem in the case of the rotating magnetic flux excitation. >

In conventional magnetic measurements, magnetization characteristics are measured under excitation in a single direction, and consequently the results represent the magnetization characteristics in the measured direction. However, these characteristics cannot be applied to analyses which assume a rotating magnetic field. In order to analyze such fields, we measured the magnetization characteristics as vector values using a two-dimensional magnetic measurement apparatus. This paper presents a magnetic reluctivity tensor expression for the two-dimensional magnetization characteristics in finite element analysis. We show that the expression is an effective tool for the analysis of rotating magnetic fields.

Despite its importance, a thermodynamic approach to determining the glass-forming ability (GFA) of bulk metallic glass (BMG) remains a goal to be achieved. We examined the GFA of water-quenched Pd-P-based and Pt${}_{60}$Ni${}_{15}$P${}_{25}$ BMG's in which their molten alloys were sufficiently treated with a dehydrated ${\mathrm{B}}_{2}$O${}_{3}$ flux prior to and during quenching to room temperature. This allowed us to envisage the applicability of the classical steady-state homogeneous nucleation theory because the suppression of heterogeneous nucleation worked effectively. GFA was examined by comparing the critical cooling rate ${R}_{c}^{h}$ for glass formation with the maximum diameter ${d}_{max}$ of glass. To calculate ${R}_{c}^{h}$, the homogeneous nucleation rate ${I}_{\mathrm{ss}}$($T$), and the growth rate ${u}_{c}$($T$) were estimated as functions of the undercooling temperature of molten alloys. Then, the free energy difference \ensuremath{\Delta}${G}_{L\ensuremath{-}x}$($T$) between the liquid and crystalline phases, and the viscosity $\ensuremath{\eta}(T)$ of the liquid were experimentally determined while the surface energy ${\ensuremath{\sigma}}_{\mathrm{sL}}(T)$ at the liquid-nucleus interface was estimated by calculation. The ${d}_{max}$ of rod BMG's correlated strongly to ${R}_{c}^{h}$ through the relation ${R}_{c}^{h}$ \ensuremath{\approx} ${d}_{max}^{\ensuremath{-}3}$/10 mm${}^{3}$ Ks${}^{\ensuremath{-}1}$.

A significant increase of mRNA expression of thymic stromal lymphopoietin (TSLP) has been reported in the bronchial mast cells (MCs) of asthmatic subjects; however, the mechanism underlying the upregulation of TSLP mRNA and protein remains unknown. FcepsilonRI-mediated activation of human MCs upregulated TSLP mRNA expression by 5.2+/-2.9-fold, while activation of the MCs using lipopolysaccharide and polyriboinosinic:polyribocytidylic acid failed to upregulate TSLP. Stimulation of MCs with interleukin (IL)-4 alone did not affect the TSLP mRNA expression, while pre-incubation of MCs with IL-4 for 48 h significantly enhanced the FcepsilonRI-mediated TSLP mRNA expression (by 53.7+/-15.9-fold; p0.05) and the amount of TSLP in the cell pellets increased significantly from 23.4+/-4.3 pg mL(-1) to 121.5+/-3.7 pg mL(-1) (p0.0001). However, the released TSLP was rapidly degraded by proteases that were released by MCs. We identified the population of cells expressing TSLP in the lungs of 16 asthmatic and 11 control subjects by immunohistochemistry. The percentage of TSLP-positive MCs in the total population of MCs was significantly increased in asthmatic airways (p0.0001). Thus, MCs are able to store TSLP intracellularly and to produce TSLP following aggregation of FcepsilonRI in the presence of IL-4.

The karyotypic relationships of skunks (Mephitidae) with other major clades of carnivores are not yet established. Here, multi-directional chromosome painting was used to reveal the karyological relationships among skunks and between Mephitidae (skunks) and Procyonidae (raccoons). Representative species from three genera of Mephitidae (Mephitis mephitis, 2n = 50; Mephitis macroura, 2n = 50; Conepatus leuconotus, 2n = 46; Spilogale gracilis, 2n = 60) and one species of Procyonidae (Procyon lotor, 2n = 38) were studied. Chromosomal homology was mapped by hybridization of five sets of whole-chromosome paints derived from stone marten (Martes foina, 2n = 38), cat, skunks (M. mephitis; M. macroura) and human. The karyotype of the raccoon is highly conserved and identical to the hypothetical ancestral musteloid karyotype, suggesting that procyonids have a particular importance for establishing the karyological evolution within the caniforms. Ten fission events and five fusion events are necessary to generate the ancestral skunk karyotype from the ancestral carnivore karyotype. Our results show that Mephitidae joins Canidae and Ursidae as the third family of carnivores that are characterized by a high rate of karyotype evolution. Shared derived chromosomal fusion of stone marten chromosomes 6 and 14 phylogenetically links the American hog-nosed skunk and eastern spotted skunk.

Human mast cells express both Fc epsilon RI alpha and Fc gamma RI alpha. IgE up-regulates Fc epsilon RI alpha expression, but IgG1 does not up-regulate Fc gamma RI alpha expression. The transmembrane domain (TM) of Fc gamma RI alpha determines the stability of cell surface expression of this receptor.The aim of this study was to clarify the roles of the TM and cytoplasmic domain (CY) of Fc epsilon RI alpha in IgE-mediated Fc epsilon RI up-regulation.Chimeric receptors created by domain shuffling between Fc epsilon RI alpha and Fc gamma RI alpha were transduced into human mast cell line HMC-1. Cell surface expression of the chimeric receptors and the effect of IgE or IgG1 on chimeric receptor expression were examined by FACS. The association of the chimeric receptors with FcR gamma was investigated by immunoprecipitation.The results showed that the TM and CY of Fc epsilon RI alpha are not essential for IgE-mediated up-regulation of surface Fc epsilon RI.The extracellular domain of each Fc receptor determines the diversity of Ig-regulated Fc receptor expression.

The constitutive equation of magnetic materials and the associated magnetic field analysis are presented. The B- and H-values have been measured as vector relationships under the influence of a rotating field, using the two-dimensional magnetic measurement apparatus. The magnetic properties are represented by a tensor expression as a function of magnetic reluctivities. This expression is then applied to the rotating field analysis. The off-diagonal terms of the magnetic reluctivity tensor when the axis ratio is 1.0 are antisymmetric. The calculated results with the tensor expression of the H-loop and of the phase difference are in good agreement with the measured results. >

In this paper, the Leidenfrost phenomena and water mist cooling are described from the viewpoint of surface conditions of heat transfer interfaces. The effect of nano-scale structures on boiling heat transfer phenomena is researched. It is clarified that the Leidenfrost phenomena on a substrate with adhered nanoscale carbons (nano carbons) are different from the one in case of a normal heat transfer interface. The photographs taken by a high-speed camera show that the boiling on a substrate with nano carbons takes the different form in comparison with the one on a normal interface. In case that the surface temperature of a copper substrate is about 140 degree C, a water droplet has a neck of water between itself and the substrate with nano carbons. On the other hand, the nucleate boiling is observed on a normal copper substrate. From the relation between evaporation time and initial surface temperature, heat transfer enhancement can be achieved under the nucleate boiling conditions. Also, the critical heat flux of water mist cooling could be enhanced by adhering nano carbons on heat-transfer interfaces. It is supposed that the wettability between water and copper is improved by the nano carbons.Copyright © 2005 by ASME

This paper evaluates the control performance of a speed sensorless induction motor control method for railway vehicles traction, compared to vector control system with pulse generators as speed sensors, from the view points of flux behavior. The speed sensorless strategy is based on the rotor flux induced voltage and is expected its high performance as well vector control system with pulse generators. The control performance is verified from the viewpoint of the rotor flux, because the speed sensor is used for controlling the rotor flux with the indirect vector control strategy. This paper provides the way how to evaluate the speed sensorless control on the railway vehicle traction system. First, the proposed speed sensorless control strategy for railway vehicles is presented. Then, its basic control characteristic is evaluated by numerical simulation and further control functions that are peculiar to the railway traction application are rated by the experiments

For railway vehicle traction purpose, slip frequency of induction traction motors are controlled with detecting rotor frequency by pulse generators or PGs as the speed sensors. Applying the speed sensor less control method to the railway vehicle traction to eliminate the PGs, we expect to improve cost efficiency and reliability of the traction control system. Though speed sensor-less control methods are popular in general industrial application purpose, some novel control functions may be added and its compatibility is verified to cope with the problem particular in railway vehicle traction application. In this paper, we present the result of the application to railway vehicle traction control with theoretical study and tests.

This paper deals with the numerical expression of the rational magnetic properties on a silicon steel sheet that are called two-dimensional magnetic properties. In the past, the magnetic properties were estimated by scalar values in the measuring direction under the condition of an alternating magnetic field excitation. These properties cannot exactly take into account the phase difference between the magnetic flux density B and the magnetic field strength H in the case of rotating magnetic field excitation. We therefore investigate the expression of the magnetic properties by using the permeability tensor. The calculated results by using the permeability tensor correspond to measured results very well.

This paper presents a position control method to suppress torsional vibrations of 2 mass resonant systems without using position sensor on the arm portion. Instead of using a position sensor, the reaction torque caused by the shaft torsion is utilized for the suppression of the vibration. In this paper, the reaction torque is estimated by an observer using motor portion parameters and state variables. The feedback of the reaction torque makes it possible to control the "resonance ratio", which is a novel concept for vibration controls. The proposed control system is based on both the conventional PD control and the resonance ratio control, and the controller gain determination method is discussed. The validity of the proposed method is also confirmed by several experiments. >

Malignant peripheral nerve sheath tumors(MPNSTs) of the acoustic nerve are very rare. Only seven cases of MPNST arising from the acoustic nerve have been reported. The authors present a case of MPNST with divergent cartilage and melanotic differentiation of the acoustic nerve. The patient was a 69 year old man admitted to our neurosurgical service in January 1999 complaining of left facial nerve palsy and hearing difficulty of his left ear. The initial CT showed a tumor at the left cerebellopontine angle region. On MRI the tumor was depicted as low intensity on T 1-weighted image and high intensity on T 2-weighted image, the mass was heterogeneously enhanced after administration of Gd-DTPA. The partial removal of the tumor was performed in January 1999. He was discharged February 1999. But he was admitted again because of progressive cerebellar ataxia. MRI showed the rapid regrowth of the residual tumor. In March 1999, complete removal of the tumor was performed. Histopathological analysis revealed a malignant spindle cell neoplasm with divergent cartilage and melanotic differentiation. We review the relevant literature concerning MPNST of the acoustic nerve and discuss the clinical features of malignant eighth cranial nerve tumor.

No case of histopathologically confirmed delayed cerebral radiation necrosis (DCRN) that occurred twice at different regions and times in the same patient has been previously reported. We present a patient with such a rare clinical course and who is surviving long-term (over 13 years) with a history of a distant metastasis of a malignant tumour. To diagnose DCRN preoperatively was very difficult. However, surgical extirpation seemed to be effective for DCRN. The patient is still in a good performance status after surgery.

We reported an autopsy case of cerebral infarction with primary lung cancer. The patient was a 50-year-old man. Despite having been treated with warfarin potassium and ticlopidine hydrochloride, he relapsed cerebral infarction. His laboratory data on admission showed that lupus anticoagulant was positive, together with a high value of beta-thromboglobulin, thrombin-antithrombin III complex, markers of platelet and coagulation activation, CEA and CA 19-9. The autopsy finding revealed a primary papillary adenocarcinoma in the right lower lung, multiple cerebral infarction, renal infarction, pulmonary infarction and splenic infarction. The atherosclerotic changes were mild in the whole tissues and findings of vasculitis were not observed. Recurrence of cerebral infarction was effectively suppressed with the addition of steroid therapy to antithrombotic therapy. This case was considered as catastrophic antiphospholipid syndrome. It is necessary to differentiate antiphospholipid syndrome in case of the abnormal coagulation and fibrinolytic factors with recurrent cerebral infarction. Moreover, systemic examinations are important, because malignant tumor may exist on the background of the case.

Temporary vessel occlusion (TO) for aneurysmal clipping is an effective technique to facilitate dissection between aneurysm and parent vessels, and to place a permanent clip at the aneurysmal neck precisely. However, several unsolved problems remain regarding the overall safety and risk resulting from this technique. The authors examined a series of patients in whom mannitol 500 ml, tocopherol acetate 500 mg, and phenytoin 500 mg were administered intravenously as ischemic protection during TO for the aneurysmal clipping. The study comprises a nonconcurrent retrospective analysis of 144 consecutive aneurysm clippings performed with the aid of intentional TO at the Hiroshima Prefectural Hospital from 1985 to 1995. To identify technical and patient-specific risk factors for perioperative stroke, factors studied included duration, location of the temporary clip application, number of occlusive episodes, patient sex, age, and preoperative neurological status, timing of operation, as well as postoperative, temporary or permanent, neurological deficits (ND) due to TO were used. Overall frequency of postoperative ND due to TO manifested clinically and radiologically were 9.0% and 9.7%, respectively. In both univariate and multivariate analysis there were no significant factors relevant to the ND. However, duration of the temporary occlusion time over 20 minutes was the factor most influential on the ND due to TO. Duration of the temporary occlusion time was shown to have no link with outcome. Based on our findings the authors conclude that temporary vessel occlusion within 20 minutes with anti-ischemic drugs is a relatively safe adjunct to aneurysmal surgery.

A surgery for an case acute of a ruptured aneurysm with idiopathic thrombocytopenic purpura (ITP) is very rare. We encountered a case of a ruptured basilar artery (BA) superior cerebellar artery (SCA) aneurysm associated with ITP. A successful operation was carried out while the patient was in the acute stage. The patient was a 63-year-old female. She has been suffering from ITP for two years, when she experienced a sudden severe headache and vomitting on May 5, 1995. She was referred to our hospital as a case of subarachnoid hemorrhage estimated to be in group 2 according to the Fisher grade. Her neurological condition caused by the subarachnoid hemorrhage was grade 2 according to HuntKosnik classification, and she was classified according to WFNS as grade 1. The number of platelets was, however, 2.3 x 10(4)/mm3 on admission. Cerebral angiography showed the aneurysm at the bifurcation of BA and SCA. The administration of platelet transfusion, betamethasone and gamma-globulin induced an increase of the number of platelets to 8.7 x 10(4) mm3 just before the operation. Neck clipping for the aneurysm was performed using platelet transfusion via the right pterional approach 25 hours after the onset. No tendency to bleed was recognized during the operation. The number of platelets was kept constantly at the level between 16.9 x 10(4)/mm3 and 22.0 x 10(4)/mm3 during the postoperative course with the administration of betamethasone. The postoperative course was good with no manifestations of delayed ischemic neurological deficits.

Compression of the crus cerebri against the free edge of the tentorium contralateral to a supratentorial mass, the so-called Kernohan's notch, can be a cause of false localizing sign. Kernohan's notch has been thoroughly studied clinically and pathologically, but not radiographically. The authors describe a case of left chronic subdural hematoma, which resulted in left hemiparesis caused by Kernohan's notch. Injury to the contralateral cerebral peduncle was clearly shown by magnetic resonance imaging (MRI) performed in the postoperative period. A 43-year-old man was transferred to our hospital in deep coma with dilated pupils, unreactive to light. Computed tomography (CT) scans obtained on admission revealed a left chronic subdural hematoma and a midline shift to the right. After drainage and irrigation of the left chronic subdural hematoma through a single burr hole, his clinical condition improved gradually. But 1 month after the operation, mild left hemiparesis still persisted. MRI T2-weighted images demonstrated an abnormally increased signal area in the right cerebral peduncle. T1-weighted coronal images showed the anatomical relationship between the hypointense lesion in the right cerebral peduncle and tentorial edge. Three-dimensional-MRI (3D-MRI) clearly demonstrated the surface image of Kernohan's notch. We emphasize the utility of 3D-MRI for detecting evidence of brain stem injury, such as Kerno han's notch.

We describe a case of intracranial hypotension syndrome due to overdrainage of cerebrospinal fluid presented with hearing loss after ventriculoperitoneal shunting procedure. A 69-year-old man suffering from subarachnoid hemorrhage presented with an angiogram showing two aneurysms, one of the right internal carotid and one of the middle cerebral artery. Neck clipping was performed. One month later, he developed normal pressure hydrocephalus (NPH), which was treated by ventriculoperitoneal (NPH), which was treated by ventriculoperitoneal shunting procedure using low pressure Pudenz system. Trias of NPH were improved by insertion of shunt system. However, he complained of hearing loss which was worsened by upright position and improved by lying down. Such kinds of phenomenon were demonstrated by audiogram showing that the transitory decrease of hearing and electrocochleography showing the elongation of N1 latency at upright position. These data suggested that his hearing loss was caused by inner ear or auditory nerve lesion. After the shunt system was replaced into the antisiphon device, his hearing disturbance improved. Axial computed tomography of bone window at the level of orbitomeatal line demonstrated widely perilymphatic duct on both sides. This finding suggested that the fluctuation of intracranial pressure was easily transmitted into the cochlear through the widened perilymphatic duct, resulting in hearing disturbance.

We report a case of Rathke's cleft cyst associated with anterior communicating artery aneurysm. The patient was 60-year-old woman who developed visual disturbance two months before admission to our hospital. Visual acuity on the right was 0.06 and on the left was 0.08. The visual fields showed a complete temporal hemianopsia on the left eye and an incomplete temporal hemianopsia of the right eye with a central defect of the temporal visual field. CT and MR imagings showed an intra- and suprasellar mass lesion with no enhancement. Angiography showed bilateral A1 elevations and anterior communicating artery aneurysm. The operation was performed through interhemispheric approach. Suprasellar cystic mass compressed upward the optic nerves and chiasm, and aneurysmal dome stuck in the central region of chiasm. This anatomical disorders affected to the optic chiasm resulted in a rare visual field defect. Neck clipping of aneurysm and opening of the cyst were performed. A diagnosis of Rathke's cleft cyst was made. Following surgery, her visual fields resolved but she suffered from diabetes insipidus.