Effect of irradiation hardening on brittle fracture performance of box-shaped blanket fabricated by F-82H

Fusion reactor blankets designed for DEMO are based on a water cooled ceramic breeder. The unstable fracture of the box-shaped blanket would occur by the superimposition of three factors as follows: (1) it is the reduction of fracture toughness for structural materials, such as F-82H, caused by the significant irradiation hardening, (2) it is the formation of cracks which act as the initiation point of the fracture, and (3) it is the excessive tensile load caused by the inner pressure to In-Box loss of coolant accident (LOCA). In the present study, application of Weibull stress criterion to fracture assessment is to investigate the effect of irradiation hardening on the brittle fracture performance of box-shaped blanket fabricated by F-82H. Both structural analysis of the box-shaped blanket simulating In-Box LOCA and deformation behavior analysis of irradiated toughness specimens were conducted by elastic-plastic finite element analysis (FEA). Weibull stress values calculated from FEA of irradiated toughness specimens were higher than those from FEA of irradiated structural components. It, therefore, is considered that the irradiation hardening of structural materials would not promote the brittle fracture at the corner of rectangular coolant tubes of the blankets caused by the load of In-Box LOCA

Effects of work-matched moderate- and high-intensity warm-up on power output during 2-min supramaximal cycling

We tested the hypothesis that compared with a moderate-intensity warm-up, a work-matched high-intensity warm-up improves final-sprint power output during the last 30 s of a 120-s supramaximal exercise that mimics the final sprint during events such as the 800-m run, 1,500-m speed skate, or Keirin (cycling race). Nine active young males performed a 120-s supramaximal cycling exercise consisting of 90 s of constantworkload cycling at a workload that corresponds to 110% peak oxygen uptake (VO2peak) followed by 30 s ofmaximal cycling. This exercise was preceded by 1) no warm-up (control), 2) a 10-min cycling warm-up at a workload of 40% VO2peak (moderate-intensity), or 3) a 5-min cycling warm-up at a workload of 80% VO2peak (high-intensity). Total work was matched between the two warm-up conditions. Both warm-ups increased 5-s peak (observed within 10 s at the beginning of maximal cycling) and 30-s mean power output during the final 30-s maximal cycling compared to no warm-up. Moreover, the high-intensity warm-up provided a greater peak(577±169 vs. 541±175 W, P=0.01) but not mean (482±109 vs. 470±135W, P=1.00) power output than the moderate-intensity warm-up. Both VO2 during the 90-s constant workload cycling and the post-warm-up blood lactate concentration were higher following the high-intensity than moderate-intensity warm-up (all P≤0.05). We show that work-matched moderate- (~40% VO2peak) and high- (~80% VO2peak) intensity warmups both improve final sprint (~30 s) performance during the late stage of a 120-s supramaximal exercise bout, and that a high-intensity warm-up provides greater improvement of short-duration (<10 s) maximal sprinting performance

Alpha-adducin G460W polymorphism, urinary sodium excretion, and blood pressure in community-based samples

BackgroundThere is limited evidence on the gene–environmental interaction among α-adducin G460W gene polymorphism, sodium intake, and blood pressure (BP) levels in a general population. One hypothesis is that the association between G460W polymorphism and BP is more evident among persons with higher sodium intake than those with lower sodium intake.MethodsWe conducted a population-based cross-sectional study of 2823 men and women aged 30 to 74 years in a Japanese rural community to examine the association of the α-adducin G460W polymorphism with BP levels stratified by salt intake, as estimated by 24-h urine collection and dietary questionnaire.ResultsThere was no difference in systolic or diastolic BP levels among the GG, GW, and WW groups for women, but for men, mean systolic BP tended to be higher in the WW group than in the GG group. When we stratified men according to sodium excretion/intake, mean systolic BP was significantly higher in the WW group than in the GG group among men with higher urinary sodium excretion (138.8 v 133.6 mm Hg, P = .02) and tended to be higher among men with higher previous sodium intake. No genetic association was found among women or among men with lower urinary sodium excretion or lower sodium intake.ConclusionsThe α-adducin WW genotype was associated with higher systolic BP among men with a higher sodium intake

Caregiver Burden for Impaired Elderly Japanese with Prevalent Stroke and Dementia under Long-Term Care Insurance System

Background: Limited data are available on caregiver burden for stroke and dementia patients. We examined the associations of prevalent stroke and dementia with family caregiver burden in Japanese general populations. Methods: A total of 916 Japanese home caregivers, whose family members were covered by long-term care insurance, responded to the caregiver burden questionnaire. The questionnaire included the caregiver\u27s age, sex and employment status, the patient-caregiver relationship, the patient\u27s history of stroke, symptoms of dementia, care levels under long-term care insurance and the Zarit Caregiver Burden Interview. Results: The mean total score from the Zarit Caregiver Burden Interview was 12% higher in patients with stroke than in those without (p = 0.02) and 40% higher in those with dementia than in those without (p < 0.001). Compared with nonstroke patients without dementia, the mean total score was 21% higher in stroke patients without dementia (p = 0.01), 49% higher in nonstroke patients with dementia (p < 0.001) and 55% higher in stroke patients with dementia (p < 0.001). After adjustment for the caregiver\u27s age, sex and employment status, the patient-caregiver relationship, and the patient\u27s care level and community, the higher scores remained statistically significant for nonstroke patients with dementia and for stroke patients with dementia but not for stroke patients without dementia. Conclusions: Prevalent stroke and, more strongly, dementia were associated with increased family caregiver burden. Among patients with dementia, the presence of stroke did not enhance caregiver burden further

Perceived Workplace Interpersonal Support Among Workers of the Fukushima Daiichi Nuclear Power Plants Following the 2011 Accident: The Fukushima Nuclear Energy Workers’ Support (NEWS) Project Study

ObjectiveThe 2011 Fukushima Daiichi nuclear accident was the worst nuclear disaster since Chernobyl. The Daiichi workers faced multiple stressors (workplace trauma, victim experiences, and public criticism deriving from their company’s post-disaster management). Literatures suggest the importance of workplace interpersonal support (WIS) in enhancing psychological health among disaster workers. We sought to elucidate the role of their demographics, disaster-related experiences, and post-traumatic stress symptoms on perceived WIS.MethodsWe analyzed self-report questionnaires of 885 workers 2-3 months post-disaster. We used sociodemographic and disaster exposure-related variables and post-traumatic stress symptoms (measured by the Impact of Event Scale-Revised) as independent variables. We asked whether WIS from colleagues, supervisors, or subordinates was perceived as helpful, and used yes or no responses as a dependent variable. Logistic regression analyses were performed to assess correlates of WIS.ResultsOf the participants, one-third (34.7%) reported WIS. WIS was associated with younger age (20-28 years [vs 49-], adjusted odds ratio [aOR]: 3.25, 95% CI: 1.99-5.32), supervisory work status (aOR: 2.30, 95% CI: 1.35-3.92), and discrimination or slur experience (aOR: 1.65, 95% CI: 1.08-2.53).ConclusionsEducational programs focusing on WIS might be beneficial to promote psychological well-being among nuclear disaster workers, especially younger workers, supervisors, and workers with discrimination experiences. (Disaster Med Public Health Preparedness. 2018;12:460–463

Association between markers of arterial stiffness and atrial fibrillation in the Circulatory Risk in Communities Study (CIRCS).

Background and aims:Limited evidence is available on the association between markers of arterial stiffness and the prevalence of atrial fibrillation among Asian populations. Therefore, we examined those associations in the Japanese population.Methods:We conducted a cross-sectional population-based study of 4264 men and women aged 40-79 years. The augmentation index (AI), a marker of arterial stiffness, was calculated as the ratio of central pulse pressure/brachial pulse pressure, where the AI and central aortic pressure were measured by an automated tonometer: the HEM-9000AI device (Omron Healthcare co., Kyoto, Japan). Atrial fibrillation was estimated by the Minnesota codes using resting electrocardiograph (ECG).Results:The prevalence of atrial fibrillation and total arrhythmia were higher with larger AI values. These associations did not change after adjustment for known cardiovascular risk factors. The multivariable odd ratios (95% confidence intervals) in the highest versus lowest tertiles of AI were 3.4 (1.4-8.6, p for trend = 0.008) for atrial fibrillation and 1.8 (1.2-2.7, p for trend = 0.004) for total arrhythmia. There was no association of central or brachial pulse pressure levels with the prevalence of atrial fibrillation or total arrhythmia.ConclusionAI values, but not brachial or central pulse pressures, were positively associated with the prevalence of atrial fibrillation and total arrhythmia, independent of cardiovascular risk factors

Development of the photomultiplier tube readout system for the first Large-Sized Telescope of the Cherenkov Telescope Array

The Cherenkov Telescope Array (CTA) is the next generation ground-based very high energy gamma-ray observatory. The Large-Sized Telescope (LST) of CTA targets 20 GeV -- 1 TeV gamma rays and has 1855 photomultiplier tubes (PMTs) installed in the focal plane camera. With the 23 m mirror dish, the night sky background (NSB) rate amounts to several hundreds MHz per pixel. In order to record clean images of gamma-ray showers with minimal NSB contamination, a fast sampling of the signal waveform is required so that the signal integration time can be as short as the Cherenkov light flash duration (a few ns). We have developed a readout board which samples waveforms of seven PMTs per board at a GHz rate. Since a GHz FADC has a high power consumption, leading to large heat dissipation, we adopted the analog memory ASIC "DRS4". The sampler has 1024 capacitors per channel and can sample the waveform at a GHz rate. Four channels of a chip are cascaded to obtain deeper sampling depth with 4096 capacitors. After a trigger is generated in a mezzanine on the board, the waveform stored in the capacitor array is subsequently digitized with a low speed (33 MHz) ADC and transferred via the FPGA-based Gigabit Ethernet to a data acquisition system. Both a low power consumption (2.64 W per channel) and high speed sampling with a bandwidth of $>$300 MHz have been achieved. In addition, in order to increase the dynamic range of the readout we adopted a two gain system achieving from 0.2 up to 2000 photoelectrons in total. We finalized the board design for the first LST and proceeded to mass production. Performance of produced boards are being checked with a series of quality control (QC) tests. We report the readout board specifications and QC results.Comment: In Proceedings of the 34th International Cosmic Ray Conference (ICRC2015), The Hague, The Netherlands. All CTA contributions at arXiv:1508.0589

Dietary fiber intake and risk of incident disabling dementia: the Circulatory Risk in Communities Study

OBJECTIVES: It has been hypothesized that dietary fiber intake has a beneficial impact on prevention of dementia, but the epidemiological evidence is scant. We sought to examine whether dietary fiber intake is inversely associated with risk of dementia requiring care under the national insurance (disabling dementia). METHODS: The study setting was the Circulatory Risk in Communities Study, involving 3739 Japanese individuals aged 40-64 years at the dietary surveys (1985-99). Dietary fiber intake was estimated using the 24-hour dietary recall method. Incident disabling dementia was followed up from 1999 through 2020. Disabling dementia was further classified into that with or without a history of stroke. Hazard ratios of disabling dementia according to quartiles of total, soluble, and insoluble fiber intake were calculated using the Cox proportional hazards model. RESULTS: During a median 19.7-year follow-up, a total of 670 cases of disabling dementia developed. Dietary fiber intake was inversely associated with risk of dementia: the multivariate hazards ratios (95% confidence intervals) were 0.83 (0.67-1.04), 0.81 (0.65-1.02), and 0.74 (0.57-0.96) for individuals with the second, third, and highest quartiles of dietary fiber intake, respectively, as compared with the lowest quartile (P for trend = 0.03). The inverse association was more evident for soluble fiber intake and was confined to dementia without a history of stroke. As for fiber-containing foods, potatoes, but not vegetables or fruits, showed a similar association. CONCLUSIONS: Dietary fiber intake, especially soluble fiber, was inversely associated with risk of disabling dementia in a general Japanese population

An association between systolic blood pressure and stroke among patients with impaired consciousness in out-of-hospital emergency settings

Background: Stroke is difficult to diagnose when consciousness is disturbed. However few reports have discussed the clinical predictors of stroke in out-of-hospital emergency settings. This study aims to evaluate the association between initial systolic blood pressure (SBP) value measured by emergency medical service (EMS) and diagnosis of stroke among impaired consciousness patients. Methods: We included all patients aged 18 years or older who were treated and transported by EMS, and had impaired consciousness (Japan Coma Scale ≧ 1) in Osaka City (2.7 million), Japan from January 1, 1998 through December 31, 2007. Data were prospectively collected by EMS personnel using a study-specific case report form. Multiple logistic regressions assessed the relationship between initial SBP and stroke and its subtypes adjusted for possible confounding factors. Results: During these 10 years, a total of 1,840,784 emergency patients who were treated and transported by EMS were documented during the study period in Osaka City. Out of 128,678 with impaired consciousness, 106,706 who had prehospital SBP measurements in the field were eligible for our analyses. The proportion of patients with severe impaired consciousness significantly increased from 14.5% in the =200 mmHg SBP group (P for trend =200 mmHg group versus the SBP 101-120 mmHg group was 5.26 (95% CI 4.93 to 5.60). The AOR of the SBP > =200 mmHg group versus the SBP 101-120 mmHg group was 9.76 in subarachnoid hemorrhage (SAH), 16.16 in intracranial hemorrhage (ICH), and 1.52 in ischemic stroke (IS), and the AOR of SAH and ICH was greater than that of IS. Conclusions: Elevated SBP among emergency patients with impaired consciousness in the field was associated with increased diagnosis of stroke

Diurnal pattern of salivary cortisol and progression of aortic stiffness: Longitudinal study.

Background The positive direct relation between stress and the development of cardiovascular disease has increasingly been recognized. However, the link between hypothalamic-pituitary-adrenal (HPA) dysregulation and subclinical cardiovascular disease has not been studied longitudinally. We investigated the relation of diurnal salivary cortisol, as a biological marker of stress levels, with progression of aortic stiffness over five years. Methods A total of 3281 people (mean age 65.5) in the Whitehall II prospective study provided six saliva samples on a single weekday. We assessed the diurnal salivary cortisol using the daytime slope and bedtime level. Aortic stiffness was measured by carotid-femoral pulse wave velocity (PWV) at baseline (2007-2009) and five years later (2012-2013). Linear mixed models were used to estimate the association of diurnal salivary cortisol with baseline PWV and five-year longitudinal changes. Results Diurnal salivary cortisol were not associated with PWV at baseline. Among women but not men, a 1-SD shallower salivary cortisol slope at baseline was associated with a five-year increase in PWV (β = 0.199; 95% CI = 0.040, 0.358 m/s) and higher bedtime cortisol level (β = 0.208, 95% CI = 0.062, 0.354 m/s). Conclusions Dysregulation of the HPA axis measured using salivary cortisol (shallower slope, higher bedtime level) predicted the rate of progression of aortic stiffness among women