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The degradation and recovery behavior of device performance on GaAlAs LEDs (Light emitting diodes) irradiated by 2-MeV electrons and 70-MeV protons are investigated. The reverse current increases after irradiation, while the capacitance decreases. The device performance degradation is proportional with fluence. For electron irradiation, fluence rate is also effective for degradation. Low fluence rate shows more large degradation compared to high fluence rate resulting from heat impact in bulk. DLTS measurement reveals the DX center in epitaxial substrate, and this spectrum increases with fluence. The radiation damage of proton is larger than that of electron irradiation, which is caused by the difference of mass and possibility of nuclear collision for the formation of lattice defects. After irradiation, the device performance recovers by thermal annealing.

The 500?keV negative-ion based neutral beam injector for JT-60U started operations in 1996. The availability of the negative ion based neutral beam injection system has been improved gradually by modifying the ion source and optimizing its operation parameters. Recently, the extension of the pulse duration up to 30?s has been intended to study quasi-steady state plasma on JT-60U. The most serious issue is to reduce the heat load on the grids for long pulse operation. Two modifications have been proposed to reduce the heat load. One is to suppress the spread of beamlet-bundle which may be caused by beamlet-beamlet interaction in the multi-aperture grid due to the space charge force. Indeed, the investigation of the beam deflection, which was measured by the infrared camera on the target plate set 3.5?m away from the grid, indicates that the spread of beamlet-bundle is in proportion to the current density. Field-shaping plates were attached on the extraction grid to modify the local electric field. The plate thickness was optimized to steer the beamlet deflection. The other is to reduce the stripping loss, where the electron of the negative ion beam is stripped and accelerated in the accelerator and then collides with the grids. The ion source was modified to reduce the pressure in the accelerator column to suppress the beam-ion stripping loss. To date, long pulse injection of 19?s of 1.5-1.6?MW at a high energy beam of 360?keV, 9-10?A for D?has been obtained by one ion source with these modifications.

The origin of longitudinal beam non-uniformity, which is one of the key issues in large caesium (Cs)-seeded negative ion sources for fusion application, was experimentally investigated in the JAERI 10 A negative ion source. A sufficient caesium was seeded in the negative ion source to enhance the negative ion production. The beam intensity with Cs was typically four times higher than that without Cs, and was relatively high in the upper region where the electron temperature and plasma density were relatively high. This distribution was significantly different from that without Cs. From the correlation between the beam intensity and the plasma parameters, it was found that the beam non-uniformity was due to the localization of the plasma.

The present objective of the 1?MeV electrostatic accelerator R&D for the ITER NB system is the acceleration of ampere class negative ion beams at the required current density (200?A?m?2) up to the beam energy of 1?MeV. To produce such high current density H?ions, the KAMABOKO negative ion source was operated under high power arc discharge (?40?kW) and with Caesium seeding for enhancement of the negative ion surface production. The H?ion beams of 146?A?m?2(total ion current: 0.2?A) have been obtained stably at the beam energy of 836?keV (pulse length: ?0.2?s). The pulse length was limited due to the power density of the beams, which is more than twice as high as those of the existing negative ion based NB systems (JT-60U and LHD). A preliminary measurement of beam optics showed a beamlet divergence of ?5?mrad even in the beams of such high power density. The Bremsstrahlung generation as a consequence of electron acceleration was estimated. A discussion then follows for photoelectron production and possible breakdowns in insulators for the acceleration of higher current negative ions.

Major issues of neutral beam (NB) injector power supplies are high-speed switching, regulation and transmission of dc ultra-high voltage (UHV) and suppression of surge energy input to the beam source at high voltage breakdown. A gate turn-off thyristor inverter type power supply where the control is performed on the low voltage ac side was designed for the ITER NB. Based on the remarkable progress of a high power IEGT (injection enhanced gate transistor), the design of the inverter has been modified to increase efficiency and compactness using such new elements. The power loss in the inverter is reduced to 0.5?MW from 1.6?MW by adopting the IEGT inverter system at the same frequency of 150?Hz. Further, power supply performance has been studied for higher frequency operation of the inverter at 300?Hz. It was confirmed that the voltage regulation was stable even when the filter capacitor was reduced to 1/5 of the original value by circuit simulation. For the transmission line of the dc UHV with intermediate voltages, a disc shape multi-conductor bushing with a transmission line test chamber has been developed. The dimensions of the bushing are 1.8?m (diameter) and 140?mm (thickness) at the edge. Electric fields at the conductor surface and insulator surface were designed to be lower than 5?kV?mm?1and 7?kV?mm?1, respectively. An electric field at the bottom of the ground potential outer conductor was designed to be lower than 1.2?kV?mm?1to prevent particle levitation which triggers breakdown. The prototype transmission line has passed the lightning impulse test up to 1300?kV. A dc UHV up to 1175?kV was successfully sustained for 300?s. To prevent electric damage of the beam source at high voltage breakdown, core snubbers using Fe-based nanocrystalline soft magnetic materials have been adopted to dissipate the surge energy.

R&D pertaining to a 1 MeV accelerator and a large negative ion source has been carried out at the Japan Atomic Energy Research Institute for the ITER neutral beam system. The R&D is, at present, progressing towards: (1) 1 MeV acceleration of H⁻ ion beams at the ITER relevant current density of 200 A m⁻² and (2) improvement of uniform negative ion production over wide extraction area in large negative ion sources. Recently, H⁻ ion beams of 1 MeV and 140 mA level have been generated with a substantial beam current density (100 A m⁻²). In the uniformity study, it was clarified that the electron temperature in the ion extraction region was locally high (>1 eV), which resulted in the destruction of negative ions at a high reaction rate. Interception of fast electrons leaking through a transverse magnetic field called ‘magnetic filter’ has been found to be effective in lowering the local electron temperature, followed by an improvement of negative ion beam profile.

AbstractTwo pilot facilities of advanced negative-ion-based neutral beam injection heating system have been working successfully on the JT-60U tokamak and the LHD heliotron in Japan. These were the first applications of negative-ion technology to the production of high current neutral beam for plasma heating as well as current drive. High energy deuterium beam of 400 keV (5.8 MW) was injected in JT-60U for efficient current drive, and high power hydrogen beam of 9.0 MW (160 keV) was injected in LHD producing high performance plasmas. These results demonstrate the feasibility of negative ion beam system for future fusion reactors such as ITER.

AbstractThe negative-ion based neutral beam injection system developed by JAERI for JT-60U has been intended to generate a 500 keV and 10 MW beam for 10 seconds with two ion sources. Technical efforts to decrease heat loads on the accelerator grids, to improve non-uniformity of the source plasma, to increase voltage holding of the accelerator, and to optimize the operational parameters have been conducted intensively. A step-down control of the filament voltage was very effective to keep the acceleration current constant during the pulse duration. To suppress degradation of voltage holding of the accelerator, protection spark gaps of ~178 kV for each stage, its gap length is 73 mm, were confirmed to be effective.As results of these improvements, as of June 2002, the maximum injection power has reached 6.2 MW, and a pulse length has attained 10 seconds of the design value with a 2.6 MW beam.

The injection performance of the negative-ion based NBI (N-NBI) system for JT-60U has been improved by correcting beamlet deflection and improving spatial uniformity of negative ion production. Beamlet deflection at the peripheral region of the grid segment due to the distorted electric field at the bottom of the extractor has been observed. This was corrected by modifying the surface geometry at the extractor to form a flat electric field. Moreover, beamlet deflection due to beamlet–beamlet repulsion caused by space charge was also compensated for by extruding the edge of the bottom extractor. This resulted in a reduction of the heat loading on the NBI port limiter. As a result of the improvement above, continuous injection of a 2.6 MW H⁰ beam at 355 keV has been achieved for 10 s. Thus, long pulse injection up to the nominal pulse duration of JT-60U was demonstrated. This has opened up the prospect of long pulse operation of the negative-ion based NBI system for a steady-state tokamak reactor. So far, a maximum injection power of 5.8 MW at 400 keV, with a deuterium beam, and 6.2 MW at 381 keV, with a hydrogen beam, have been achieved in the JT-60U N-NBI. Uniformity of negative ion production was improved by tuning the filament emission current so as to direct more arc power into the region where less negative ion current was extracted.

Abstract: A 57-year-old man was referred to our hospital because of acute cardiac failure and acute renal insufficiency. Laboratory data showed elevation of serum immune complex levels and antineutrophil cytoplasmic antibody (ANCA) titers, with cytoplasmic pattern (C-ANCA) on indirect immunofluorescence (IIF), and proteinase 3 specificity (PR3-ANCA) on solid-phase enzyme-linked immunosorbent assay (ELISA). Hemodialysis therapy was initiated, and this relieved the symptoms of cardiac failure. Echocardiography revealed three-grade aortic insufficiency and two large floating vegetations on the aortic valve. Considering the risk of embolism, we immediately performed aortic valve replacement and surgically removed the vegetations, subsequently giving antibiotic therapy. Six weeks after the operation, the patient's renal function showed marked improvement and the serological abnormalities, except for ANCA titers, had normalized, resulting in no need for dialysis. A renal biopsy specimen revealed diffuse proliferative glomerulonephritis (GN) with crescents including more than 50% of glomeruli, and granular deposits of IgM, C3, and C1q on immunofluorescence. ANCA titers remained high, but the patient's renal function has been stable, indicating a discrepancy between ANCA titers and his clinical course. In this patient, treatment by immediate surgical intervention, performed during the acute phase with active GN and highly reduced renal function, led to dramatic renal recovery. This case suggests that surgical removal of vegetations in the early stage of crescentic GN may result in a good renal outcome in patients with rapidly progressive GN associated with endocarditis. Although it has been suggested that ANCA may have some relationship to GN in endocarditis, in this patient, its pathogenetic significance is questionable.

The bcl-2 gene becomes transcriptionally deregulated in the majority of low-grade non-Hodgkin lymphomas as a result of t(14;18) translocations that place the bcl-2 gene at 18q21 into juxtaposition with the Ig heavy- chain locus at 14q32. This chromosomal translocation or similar bcl-2 gene rearrangements involving the Ig light-chain genes have been reported to occur in some cases of B-cell chronic lymphocytic leukemia (B-CLL). We analyzed the structure, methylation, and expression of the bcl-2 gene in 20 cases of B-CLL or closely related variants of this lymphoproliferative disorder, including at least 16 typical examples of CD5+ B-CLL. None of the 20 specimens had evidence of bcl-2 gene rearrangements, based on Southern blot analysis using three different bcl-2 probes. However, immunoblot analysis using antibodies specific for the Bcl-2 protein showed that 14 of 20 cases (70%) contained levels of p26-Bcl-2 that were equal to or greater than those found in a t(14;18)-bearing lymphoma cell line. Furthermore, in 19 of 20 cases (95%), the Bcl-2 protein was present at levels that were 1.7- to 25- fold higher than in normal peripheral blood lymphocytes. These differences in the relative levels of Bcl-2 protein among cases of B- CLL appeared to be functionally significant, in that a preliminary analysis of 3 representative cases showed that CLL cells with higher levels of Bcl-2 protein survived longer in culture and were delayed in their onset of DNA degradation relative to CLL cells with lower Bcl-2 protein levels. Evaluation of the methylation status of the bcl-2 gene using the isoschizomers Msp I and Hpa II, and a probe corresponding to the first major exon of the gene showed complete demethylation of both copies of the bcl-2 gene in a region corresponding to a 2.4-kb Msp I fragment in all 20 cases of B-CLL. In contrast, analysis of 6 of 6 B- cell lines that harbor a t(14;18) was consistent with hypomethylation of only one of the two bcl-2 alleles. Neither copy of the bcl-2 gene was demethylated in this region in 5 of 5 lymphoid cell lines that lack this translocation. However, hypomethylation of the bcl-2 gene did not necessarily correlate with the relative levels of Bcl-2 protein present in the B-CLL cells, suggesting that additional mechanisms for regulating bcl-2 expression are involved.(ABSTRACT TRUNCATED AT 400 WORDS)

The synaptic connections between histaminergic neurons and substance P (SP) afferents in the caudal magnocellular nucleus (CM) of the hypothalamus were examined using an immunoelectron microscopic mirror method. SP-immunoreactive (SP-IR) terminals made synaptic contacts with the somata, somatic spines and dendrites of histidine decarboxylase immunoreactive (HDC-IR) neurons. This suggests that SP afferents exert monosynaptic influence on the central histaminergic neuronal system.

Proton energy spectra from (p, xp) reactions on98Mo and106Pd have been measured at incident energies of 12, 14, and 16 MeV to investigate the incident energy dependence of preequilibrium (p, p′) process. The (p, xp) energy spectrum for60Ni has also been measured at an incident energy of 18 MeV to confirm the mass number dependence. These spectra were compared with a calculation based on the exciton model in which the square of the average effective matrix element ¦M¦2 was assumed to beKA−3E−1 and isospin conservation was taken into account. The calculated spectra using a constantK-value (430 MeV3) were in good agreement with all the measured ones. The role of isospin conservation in preequilibrium process was discussed through the present analyses.

R & D's on high power negative ion source at JAERI are reviewed. A method of cesium injection into volume source has drastically progressed in development of the high current source. The H- ion current was enhanced up to 10 A only by seeding cesium of a few hundreds mg into a volume production type magnetically filtered multicusp source. Reductions of the optimum gas pressure and the electron current were also observed in the operation of cesium seeded sources. These effects are helpful in stable ac-celeration of the ion beams. High energy negative ion beam acceleration was demonstrated in the cesium seeded sources. So far, we have succeeded to accelerate 0.13 A H- ion beam up to 350 keV for 1 s with good beam optics of the divergence ωl/e ∼ 5 mrad. Two methods of the beam focussing were attempted; i.e. aperture displacement and curved grids extraction. The beam focussing by aperture displacement was found to be useful for the high power beam steering, while the beam merge experiment were being progressed for the further application. On a basses of these R & D's, the high power negative ion source for the negative-ion based NB system appeared to be reasonable, high efficiency, and realistic.

The design of a negative-ion-based NBI system for JT-60U rated to inject neutral beams of 500 keV, 10 MW for 10 seconds is described. The neutral beam is injected tangentially from a beamline with two ion sources. The ion source is a cesium-seeded multicusp volume source. The acceleration current per source is 22 A with deuterium at a current density of 13 mA/cm2. The operating pressure of the plasma generator is less than 0.3 Pa. A three-stage multi-aperture electrostatic acceleration system is adopted as the accelerator. Residual ions are deflected horizontally by the combined magnetic fields produced by the deflecting coils and the stray field from the tokamak. The deflecting magnetic field is swept with a frequency of 2 Hz. An acceleration power supply of 490 kV, 64 A is inverter type power supply. The freauency of the inverters is 150 Hz. The system will be completed in 1996. The system will be the first negative-ion-based NBI system in the world.

Interactions of the Bcl-2 protein with itself and other members of the Bcl-2 family, including Bcl-X-L, Bcl-X-S, Mcl-1, and Bax, were explored with a yeast two-hybrid system. Fusion proteins were created by linking Bcl-2 family proteins to a LexA DNA-binding domain or a B42 trans-activation domain. Protein-protein interactions were examined by expression of these fusion proteins in Saccharomyces cerevisiae having a lacZ (beta-galactosidase) gene under control of a LexA-dependent operator. This approach gave evidence for Bcl-2 protein homodimerization. Bcl-2 also interacted with Bcl-X-L and Mcl-1 and with the dominant inhibitors Bax and Bcl-X-S. Bcl-X-L displayed the same pattern of combinatorial interactions with Bcl-2 family proteins as Bcl-2. Use of deletion mutants of Bcl-2 suggested that Bcl-2 homodimerization involves interactions between two distinct regions within the Bcl-2 protein, since a LexA protein containing Bcl-2 amino acids 83-218 mediated functional interactions with a B42 fusion protein containing Bcl-2 amino acids 1-81 but did not complement a B42 fusion protein containing Bcl-2 amino acids 83-218. In contrast to LexA/Bcl-2 fusion proteins, expression of a LexA/Bax protein was lethal to yeast. This cytotoxicity could be abrogated by B42 fusion proteins containing Bcl-2, Bcl-X-L, or Mcl-1 but not those containing Bcl-X-S (an alternatively spliced form of Bcl-X that lacks a well-conserved 63-amino acid region). The findings suggest a model whereby Bax and Bcl-X-S differentially regulate Bcl-2 function, and indicate that requirements for Bcl-2/Bax heterodimerization may be different from those for Bcl-2/Bcl-2 homodimerization.

The Bcl-2 protein is a suppressor of programmed cell death that homodimerizes with itself and forms heterodimers with a homologous protein Bax, a promoter of cell death. Expression of Bax in Saccharomyces cerevisiae as a membrane-bound fusion protein results in a lethal phenotype that is suppressible by co-expression of Bcl-2. Functional analysis of deletion mutants of human Bcl-2 in yeast demonstrated the presence of at least three conserved domains that are required to suppress Bax-mediated cytotoxicity, termed domains A (amino acids 11-33), B (amino acids 138-154), and C (amino acids 188-196). In vitro binding experiments using GST-Bcl-2 fusion proteins demonstrated that Bcl-2(delta B) and Bcl-2(delta C) deletion mutants had a markedly impaired ability to heterodimerize with Bax but retained the ability to homodimerize with wild-type Bcl-2. In contrast, Bcl-2(delta A) and an NH2-terminal deletion mutant Bcl-2(delta 1-82) retained Bax binding activity in vitro but failed to suppress Bax-mediated cytotoxicity in yeast. Sequences downstream of domain C in the region 197-218 also were shown to be required for Bax-binding in vitro and anti-death function in yeast. Analysis of Bcl-2/Bcl-2 homodimerization using both in vitro binding assays as well as a yeast two-hybrid method provided evidence in support of a head-to-tail model for Bcl-2/Bcl-2 homodimerization and revealed that sequences within the NH2-terminal A domain interact with a structure that requires the presence of both the carboxyl B and C domains in combination. In addition to further delineating structural features within Bcl-2 that are required for homo-dimerization, the findings reported here support the hypothesis that Bcl-2 promotes cell survival by binding directly to Bax but suggest that ability to bind Bax can be insufficient for anti-cell death function.

The Escherichia coli cytoplasmic membrane protein, p12, stimulates the protein translocation activity reconstituted with SecY, SecE and SecA. The gene encoding p12, which is located at 69 min on the E. coli chromosome, was deleted to examine the role of p12 in protein translocation in vivo. The deletion strain exhibited cold‐sensitive growth. Pulse‐chase experiments revealed that precursors of outer membrane protein A, maltose binding protein and beta‐lactamase accumulated at 20 degrees C but not at 37 degrees C. The deletion strain harboring a plasmid which carries the gene encoding p12 under the control of the araBAD promoter was able to grow in the cold when p12 was expressed with the addition of arabinose. Furthermore, the accumulated precursors were rapidly processed to the mature forms upon the expression of p12. Immunoblot analysis revealed the steady‐state accumulation of precursor proteins at 20 degrees C, whereas the accumulation was only marginal at 37 degrees C, indicating that the function of p12 is more critical at 20 degrees C than at 37 degrees C. Finally, proteoliposomes were reconstituted with or without p12 to demonstrate that the stimulation of the activity by p12 increases with a decrease in temperature. From these results, we concluded that p12 is directly involved in protein translocation in E. coli and plays a critical role in the cold. We propose the more systematic name, SecG, for p12.

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Hemoglobin Shimonoseki, discovered in western Japan in 1960, has been further characterized as a mutant with abnormal α-polypeptide chains on the basis of: (1) The presence of a minor hemoglobin component migrating cathodally at pH 8.6 to Hb A2, presumably α2Shσ2A2. (2) Hybridization studies. (3) Fingerprinting of isolated α-polypeptide chains. Hemoglobin Sh is characterized by the substitution of arginine for glutamine at residue 54 and can therefore be designated as α254Argβ2A.

We present computed tomographic (CT) and sonographic findings of heterotopic gastric mucosa incidentally found in a 63-year-old male. CT showed a slightly high density area in the gallbladder, which was intermediately enhanced early after bolus injection of contrast medium. Ultrasonography showed an echogenic sessile polyp. Histologically, the tumor consisted of gastric fundic glands containing parietal cells and chief cells.

We study numerically the onset of chaos and thermalization in the Banks-Fischler-Shenker-Susskind (BFSS) matrix model with and without fermions, considering Lyapunov exponents, entanglement generation, and quasinormal ringing. We approximate the real-time dynamics in terms of the most general Gaussian density matrices with parameters which obey self-consistent equations of motion, thus extending the applicability of real-time simulations beyond the classical limit. Initial values of these Gaussian density matrices are optimized to be as close as possible to the thermal equilibrium state of the system. Thus attempting to bridge between the low-energy regime with a calculable holographic description and the classical regime at high energies, we find that quantum corrections to classical dynamics tend to decrease the Lyapunov exponents, which is essential for consistency with the Maldacena-Shenker-Stanford bound at low temperatures. The entanglement entropy is found to exhibit an expected "scrambling" behavior--rapid initial growth followed by saturation. At least at high temperatures the entanglement saturation time appears to be governed by classical Lyapunov exponents. Decay of quasinormal modes is found to be characterized by the shortest timescale of all. We also find that while the bosonic matrix model becomes nonchaotic in the low-temperature regime, for the full BFSS model with fermions the leading Lyapunov exponent, entanglement saturation time, and decay rate of quasinormal modes all remain finite and nonzero down to the lowest temperatures. [ABSTRACT FROM AUTHOR]

Summary: We report a case of agranulocytosis induced by ritodrine and discuss the pathophysiology of this disorder.

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