1,721,190 research outputs found
GLOBAL-LOCAL ITERATIVE METHODS FOR EQUIVALENT DIFFUSION-THEORY PARAMETERS IN NODAL CALCULATION
No full textTo get the equivalent assemblywise flux weighted constants (FWCs) for use in the coarse-mesh nodal analysis, the global/local iterative homogenization procedures, including the procedures based on variational principles, are developed in this study. The nodal expansion method is employed in the global core analysis and the fine-mesh finite difference method in the local assembly calculation. To achieve fast and stable convergence, the mixed boundary condition is imposed on the assembly surface in local assembly calculation, where we modulate the surface flux using the assemblywise fundamental mode eigenfunction. The results of numerical tests using the assemblywise FWCs are compared with the reference solutions for the PWR and BWR problems. In the PWR problems, there is no strong need for the global/local iterative homogenization. However, in the BWR problems, the iterative procedures we developed remarkably improve the accuracy of the assembly power distribution. Especially the surface flux should be modulated in the local calculation, when there exists high heterogeneity at the node surface as in BWR. The procedures based on the variational principles provide similar trend in accuracy to the direct iterative procedures
Altered IL-7Rα expression with aging and the potential implications of IL-7 therapy on CD8+ T-cell immune responses
No full textWe investigated the effects of aging on the IL-7-mediated CD8(+) T-cell survival pathway and of IL-7 therapy on T-cell immunity. Cells expressing IL-7 receptor (IL-7R) alpha(high) and alpha(low) were identified in a CD45RA(+) effector memory (EMCD45RA+, CD45RA(+)CCR7(-)) CD8(+) T-cell subset. Elderly subjects (65 years and older) had an increased frequency of EMCD45RA+, IL7R alpha(low) CD8(+) T cells, leading to decreased STAT5 phosphorylation and survival responses to IL-7 compared with young subjects (40 years and younger). These EMCD45RA+ IL-7R alpha(low) cells were largely antigen experienced (CD27(-)CD28(-)), replicatively senescent (CD57(+)), and perforin(high) CD8+ T cells that had decreased IL-7R alpha mRNA, independent of guanine and adenine binding protein alpha (GABP alpha) and growth factor independence-1 (GFI1) expression. In measuring T-cell receptor (TCR) repertoires of EMCD45RA+ CD8(+) T cells, the elderly had a limited repertoire in IL-7R alpha(high) and IL-7R alpha(low) cells, whereas the young had a diverse repertoire in IL-Mahigh but not in IL-7R alpha(low) cells. These findings suggest that aging affects IL7% expression by EMCD45RA+ CD8(+) T cells, leading to impaired signaling and survival responses to IL-7, and that IL-7 therapy may improve the survival of EMCD45RA+ CD8(+) T cells with a diverse TCR repertoire in the young but not in the elderly.Y
Role of Syndecan-4 in the cellular invasion of Orientia tsutsugamushi
No full textCell surface heparan sulfate proteoglycans (HSPGs) play a critical role in the cellular invasion of intracellular bacteria and are presumed to have a role in the infection of host cells by Orientia tsutsugamushi. Previously, we showed that O. tsutsugamushi infection decreased markedly after treating host cells with heparinase, which suggests that HSPGs play an important role in oriential infection. We tested oriential infection in REF-Syn4 cells over-expressing syndecan-4, and in REF-Syn4AS cells in which the expression of syndecan-4 was down regulated by transfecting with anti-sense syndecan-4 cDNA. Oriential infection was found to be dependent on the expression level of syndecan-4 on the cell surface. Furthermore, the infectivity of O. tsutsugamushi was specifically reduced by treating O. tsutsugamushi with the purified recombinant core protein of syndecan-4 (Syn4E). These results suggest that the core protein of syndecan-4 and the heparin/heparan sulfate chain of syndecan play an important role in oriential infection by O. tsutsugamushi. (C) 2004 Elsevier Ltd. All rights reserved.N
Co-operative Strategy for an Interactive Robot Soccer System by Reinforcement Learning Method
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Incidence and Risk of Depressive Disorder in Patients with Retinitis Pigmentosa
No full textImportance: There is a lack of large-scale clinical studies exploring mental health among patients with retinitis pigmentosa (RP). Additionally, few studies have evaluated the associations of visual impairment with mental health in young patients. Objective: To investigate the association between depressive disorder and RP. Design, Setting, and Participants: This was a retrospective, nationwide, population-based cohort study using data obtained from the Health Insurance Review and Assessment service in Korea between 2008 and 2022. A total of 10879 individuals who were newly diagnosed with RP between January 2011 and December 2021, as verified by both the RP registration code (National Registry of Rare and Intractable Disease in Korea code V209) and diagnostic code (International Statistical Classification of Diseases, 10th Revision code H35.51), were included. Data analysis was performed from October 2023 to January 2024. Exposure: Diagnosis of RP. Main Outcomes and Measures: Participants were categorized into 3 groups based on age at diagnosis (<20, 20-39, and ≥40 years). The incidence of depressive disorder in RP was determined after excluding those diagnosed with depressive disorder prior to RP diagnosis. Age- and sex-adjusted standardized incidence ratios (SIRs) of depressive disorder in patients with RP compared with the general population were calculated. Subgroup analyses by sex and age group were conducted. Results: A total of 10879 patients (638 aged <20 years, 2233 aged 20-39 years, and 8008 aged ≥40 years; 5710 [52.5%] female) newly diagnosed with RP between 2011 and 2021 were included. The 10-year cumulative incidence of depressive disorder was 17.67% (95% CI, 16.57%-18.84%) in patients with RP. Subgroup analysis showed higher incidence of depressive disorder in female patients (hazard ratio [HR], 1.46; 95% CI, 1.29-1.65; P <.001) and those aged 40 years or older (HR, 1.93; 95% CI, 1.63-2.29; P <.001). The overall SIR of depressive disorder in patients with RP was 1.19 (95% CI, 1.12-1.27; P <.001), indicating a higher risk of depressive disorder compared with that in the general population. Both male and female patients with RP showed increased incidence rates of depressive disorder (17.53 [95% CI, 15.91-19.27] and 25.57 [95% CI, 23.58-27.67] per 1000 person-years, respectively) and increased SIRs of depressive disorder (1.21 [95% CI, 1.10-1.33] and 1.18 [95% CI, 1.09-1.28], respectively) (all P <.001) compared with the general population. Subgroup analysis by age group showed that the SIR peaked in patients in their 20s (1.50; 95% CI, 1.17-1.90; P =.006) and aged 60 years or older (1.25; 95% CI, 1.14-1.37; P <.001). Conclusions and Relevance: Individuals diagnosed with RP had a higher risk of developing depressive disorder. These findings support consideration of providing emotional and social support to patients with RP
Uveitis Risk After the First Dose of COVID-19 Vaccination Based on Uveitis History: Matched Cohort and Crossover Case Series Study
No full textPurpose: To investigate the risk of noninfectious uveitis following the first dose of coronavirus disease 2019 (COVID-19) vaccination based on the uveitis history. Design: Retrospective matched cohort and crossover case series study. Methods: A random sample of 7 917 457 individuals who received COVID-19 vaccine between January 2021 and March 2022 in Korea, and had no recorded history of COVID-19 were categorized into the control and uveitis groups based on their uveitis history. After performing 3:1 propensity score matching, we assessed the cumulative incidence and risk of noninfectious uveitis in the 180 days after COVID-19 vaccination. Additionally, we performed a crossover case series analysis to compare the pre- and postvaccination incidence rate ratios (IRRs) of uveitis in individuals with and without a history of uveitis. Results: In the matched cohort analysis, uveitis group had a significantly higher cumulative incidence of uveitis (15.4%) than control group (0.10%). The uveitis group exhibited increased risks of all uveitis types, anterior, and nonanterior uveitis in the first 60 days (hazard ratio [HR]: 169, 158, and 253, respectively) and in days 61 to 180 (HR: 166, 164, and 143, respectively) after vaccination. In the crossover case series analysis, uveitis occurred with relatively equal frequency in 20-day intervals during the 180 days before and after vaccination, regardless of uveitis history. For uveitis group, the adjusted IRRs for early and late postvaccination events were 0.92 (95% CI, 0.88-0.96) and 0.83 (95% CI, 0.80-0.85), respectively. Conclusions: COVID-19 vaccination did not increase the risk of uveitis, regardless of uveitis history
FUNCTION OF NAD GLYCOHYDROLASE IN ADP-RIBOSE UPTAKE FROM NAD BY HUMAN ERYTHROCYTES
No full textThe function of the ectoenzyme NAD glycohydrolase (NADase) in ADP-ribose uptake from extracellular NAD was studied in human erythrocytes that express relatively high NADase activity (adult erythrocytes) and erythrocytes expressing very low activity (newborn erythrocytes). The rates of ADP-ribose uptake from NAD in human erythrocytes were correlated with their NADase activities. In contrast, there was no significant difference in the rates of ADP-ribose uptake among these cells when incubated with ADP-ribose. These results indicate that ecto-NADase may have a role as supplier of ADP-ribose for its uptake into the cells and that the cleavage of NAD by NADase is necessary for the ADP-ribose uptake by human erythrocytes. From ADP-ribose uptake studies at 37-degrees-C a K(m) of 0.7 +/- 0.05 muM and a V(max) of 2.04 +/- 0.1 pmol/min per mul cell water was found for the uptake of [H-3]ADP-ribose. The thiol-reactive reagents p-chloromercuribenzene sulfonic acid and N-ethylmaleimide inhibited the uptake ADP-ribose with IC50 values of 50 +/- 4 and 750 +/- 25 mM, respectively. Since efflux of [H-3]ADP-ribose was negligible, the ADP-ribose transport system appears to be unidirectional. The unidirectionality was supported by the evidence that transported ADP-ribose was rapidly degraded to AMP which is impermeable to the membrane.
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