33 research outputs found
脳卒中患者における二重課題下での移乗動作能力低下は転倒と関連がある
入院中の脳卒中(テント上脳梗塞・脳出血)患者14例を対象に、移乗動作のみと、移乗動作に思考課題(数字の逆唱課題)を負荷した時との移乗動作を、脳卒中発症後に転倒歴のある7例とない7例で比較した. 移乗動作のperformanceは12項目で評価し、点数化した. 移乗動作のみの時には、転倒歴の有無と移乗動作のperformanceには関係はなかったが、数字逆唱課題負荷時には転倒歴のある群の移乗動作のperformanceは、負荷しない時より有意に不良であり、特にブレーキ・フットレスト管理での評価点数が低かった. この結果は、二重課題下での運動課題のperformanceが低下する脳卒中患者は、低下しない者より転倒リスクが高いことを示唆する. 以上より、移乗動作に思考課題を負荷すると移乗動作自立度判定の精度が向上することが示唆された.Performance of transfer of bed to wheel chair and wheel chair to bed was compared between under single task and dual task which were transfer and repeat the number in reverse sequence in hospitalized 14 stroke patients. The patients were separated to two groups that involved 7 patients had fall history(FALL) and other patients had not it(NON-FALL). The transfer performance was evaluated with 12 items. The performance was not significant difference between FALL and NON-FALL in single-task that was transfer. But the performance of transfer in FALL was significantly lower than that in NON-FALL in dual-task. The point of dual-task was significantly lower than that of single-task in management of brakes and the foot rest. These findings indicate that the performance of transfer is decreased by second cognitive task in stroke patient. The dual-task setting may be effective of assessment of performance of transfer in stroke patients
FUEL-CYCLE SCENARIO TO REDUCE RADIOACTIVE WASTE FROM LIGHT-WATER REACTOR
It is important to reduce the amount of trans-uranium (TRU) produced from the existing nuclear power plants to realize sustainable nuclear energy since the some TRU nuclides remain for a long time and have high radioactivity and radiotoxicity. One of the promising solutions is to transmute the TRU nuclides to those with lesser radioactivity and radiotoxicity in the existing nuclear reactors. In the current scheme, the TRU nuclides are transmuted in fast reactors and/or accelerator-driven-systems, however, this scenario seems unpromising in Japan: after the Fukushima Daiichi accident, it is required to reduce the production of TRU nuclides from the light-water reactors. In the previous studies, a concept of FORSETI was investigated, and a nuclear-fuel cycle simulation code ATRUNCYS was developed to study the low TRU production scenario. The FORSETI concept consists of two types of fuels: 1) UO2 fuels with high-assay low-enriched-uranium, and 2) MOX fuels with highly fissile concentrated plutonium reprocessed from the FORSETI-UO2 fuels. The current paper focuses on the following two scenarios: a) once-recycled scenario with the current fuel design, and b) once-recycled scenario with the FORSETI concept. The two scenarios were compared by using the ATRUNCYS code where the simulation studies showed that the amount, radioactivity, and radiotoxicity of resulting waste can be decreased in the FORSETI concept: In the case 1), the production of TRU nuclides decreased in the UO2 fuel; In the case 2), the fission rate increased and neutron-capture reactions of 240Pu and 241Pu decreased in the MOX fuels
FUEL-CYCLE SCENARIO TO REDUCE RADIOACTIVE WASTE FROM LIGHT-WATER REACTOR
It is important to reduce the amount of trans-uranium (TRU) produced from the existing nuclear power plants to realize sustainable nuclear energy since the some TRU nuclides remain for a long time and have high radioactivity and radiotoxicity. One of the promising solutions is to transmute the TRU nuclides to those with lesser radioactivity and radiotoxicity in the existing nuclear reactors. In the current scheme, the TRU nuclides are transmuted in fast reactors and/or accelerator-driven-systems, however, this scenario seems unpromising in Japan: after the Fukushima Daiichi accident, it is required to reduce the production of TRU nuclides from the light-water reactors. In the previous studies, a concept of FORSETI was investigated, and a nuclear-fuel cycle simulation code ATRUNCYS was developed to study the low TRU production scenario. The FORSETI concept consists of two types of fuels: 1) UO2 fuels with high-assay low-enriched-uranium, and 2) MOX fuels with highly fissile concentrated plutonium reprocessed from the FORSETI-UO2 fuels. The current paper focuses on the following two scenarios: a) once-recycled scenario with the current fuel design, and b) once-recycled scenario with the FORSETI concept. The two scenarios were compared by using the ATRUNCYS code where the simulation studies showed that the amount, radioactivity, and radiotoxicity of resulting waste can be decreased in the FORSETI concept: In the case 1), the production of TRU nuclides decreased in the UO2 fuel; In the case 2), the fission rate increased and neutron-capture reactions of 240Pu and 241Pu decreased in the MOX fuels
Normally-OFF Two-Dimensional Hole Gas Diamond MOSFETs Through Nitrogen-Ion Implantation
Diamond is a promising material for power applications owing to its excellent physical properties. Two-dimensional hole gas (2DHG) diamond metal-oxide- semiconductor field-effect transistors (MOSFETs) with hydrogen-terminated (C-H) channel have high current densities and high breakdown fields but often show normally-ON operation. From the viewpoint of safety, normally-OFF operation is required for power applications. In this letter, we used ion implantation to form a shallow and thin nitrogen-doped layer below the C-H channel region, which realized normally-OFF operation. Nitrogen-ion implanted length is fixed at 5 or 10 μm. Nitrogen is a deep donor (1.7 eV) and the nitrogen-doped layer prevents hole accumulation near the surface. The threshold voltage was as high as -2.5 V and no obvious dependence on the threshold voltage of nitrogenion implanted length is observed. The breakdown field was 2.7 MV/cm at room temperature. Of 64 devices with a common gate length, 75% showed normally-OFF operation. We confirmed the threshold voltage shift by a thin and shallow nitrogen-doped layer formed by ion implantation
Vertical-type two-dimensional hole gas diamond metal oxide semiconductor field-effect transistors
Power semiconductor devices require low on-resistivity and high breakdown voltages simultaneously. Vertical-type metal-oxide-semiconductor field-effect transistors (MOSFETs) meet these requirements, but have been incompleteness in diamond. Here we show vertical-type p-channel diamond MOSFETs with trench structures and drain current densities equivalent to those of n-channel wide bandgap devices for complementary inverters. We use two-dimensional hole gases induced by atomic layer deposited Al2O3 for the channel and drift layers, irrespective of their crystal orientations. The source and gate are on the planar surface, the drift layer is mainly on the sidewall and the drain is the p+ substrate. The maximum drain current density exceeds 200 mA mm−1 at a 12 µm source-drain distance. On/off ratios of over eight orders of magnitude are demonstrated and the drain current reaches the lower measurement limit in the off-state at room temperature using a nitrogen-doped n-type blocking layer formed using ion implantation and epitaxial growth
Dissociation mediates the relationship between peer victimization and hallucinatory experiences among early adolescents
Peer victimization increases the risk of experiencing psychotic symptoms among clinical and general populations, but the mechanism underlying this association remains unclear. Dissociation, which is related to peer victimization and hallucinatory experiences, has been demonstrated as a significant mediator in the relation between childhood victimization and hallucinatory experience among adult patients with psychosis. However, no studies have examined the mediating effect of dissociation in a general early adolescent population. We examined whether dissociation mediates the relationship between peer victimization and hallucinatory experiences among 10-year-old adolescents using a population-based cross-sectional survey of early adolescents and their main parent (Tokyo Early Adolescence Survey; N = 4478). We examined the mediating effect of dissociation, as well as external locus of control and depressive symptoms, on the relationship between peer victimization and hallucinatory experiences using path analysis. The model assuming mediation effects indicated good model fit (comparative fit index = .999; root mean square error of approximation = .015). The mediation effect between peer victimization and hallucination via dissociation (standardized indirect effect = .038, p < .001) was statistically significant, whereas the mediation effects of depressive symptoms (standardized indirect effect = −.0066, p = 0.318) and external locus of control (standardized indirect effect = .0024, p = 0.321) were not significant. These results suggest that dissociation is a mediator in the relation between peer victimization and hallucinatory experiences in early adolescence. For appropriate intervention strategies, assessing dissociation and peer victimization as they affect hallucinatory experiences is necessary