Re-evaluation of Radiation-Energy Transfer to an Extraction Solvent in a Minor-Actinide-Separation Process Based on Consideration of Radiation Permeability

ABSTRACT

Absorbed-dose estimation is essential for evaluation of the radiation tolerance of minor-actinide-separation processes. We propose a dose-evaluation method based on radiation permeability, with comparisons of heterogeneous structures seen in the solvent-extraction process, such as emulsions forming in the mixture of the organic and aqueous phases. A demonstration of radiation-energy-transfer simulation is performed with a focus on the minor-actinide-recovery process from high-level liquid waste with the aid of the Monte Carlo radiation-transport code PHITS. The simulation results indicate that the dose absorbed by the extraction solvent from alpha radiation depends upon the emulsion structure, and that from beta and gamma radiation depends upon the mixer-settler-apparatus size. Non-negligible contributions of well-permeable gamma rays were indicated in terms of the plant operation of the minor-actinide-separation process.     

Mathematical modelling of MAG welding

The development of laser welding technology has enabled the mass production of thin-walled structures, including steel sandwich panels. The technology of joining plating panels with stiffeners by welding allows us to create joints with a specific geometry and material properties. In comparison with other types of joints, laser welds are characterized by their specific behaviour under cyclic load and, as a consequence, a different model of fatigue damage. The basis of fatigue analysis of laser-welded joints was the determination of stress concentrations in the notches. For this purpose, a numerical finite element method model of a laser-welded joint was created. The article presents the main aspects of the numerical model and the results concerning the influence of the modelling method on the strain and stress distribution in the notches. For the weld root notch, the theoretical results have been compared with experimental data of strain distributions obtained by the laser extensometry grid technique.     

Reduced Claudin-12 Expression Predicts Poor Prognosis in Cervical Cancer

Background: Within the claudin (CLDN) family, CLDN12 mRNA expression is altered in various types of cancer, but its clinicopathological relevance has yet to be established due to the absence of specific antibodies (Abs) with broad applications. Methods: We generated a monoclonal Ab (mAb) against human/mouse CLDN12 and verified its specificity. By performing immunohistochemical staining and semiquantification, we evaluated the relationship between CLDN12 expression and clinicopathological parameters in tissues from 138 cases of cervical cancer. Results: Western blot and immunohistochemical analyses revealed that the established mAb selectively recognized the CLDN12 protein. Twenty six of the 138 cases (18.8%) showed low CLDN12 expression, and the disease-specific survival (DSS) and recurrence-free survival rates were significantly decreased compared with those in the high CLDN12 expression group. We also demonstrated, via univariable and multivariable analyses, that the low CLDN12 expression represents a significant prognostic factor for the DSS of cervical cancer patients (HR 3.412, p = 0.002 and HR 2.615, p = 0.029, respectively). Conclusions: It can be concluded that a reduced CLDN12 expression predicts a poor outcome for cervical cancer. The novel anti-CLDN12 mAb could be a valuable tool to evaluate the biological relevance of the CLDN12 expression in diverse cancer types and other diseases.     

High permittivity BaTiO3 and BaTiO3-polymer nanocomposites enabled by cold sintering with a new transient chemistry: Ba(OH)2∙8H2O

Cold sintering process (CSP) offers a promising strategy for the fabrication of innovative and advanced high permittivity dielectric nanocomposite materials. Here, we introduce Ba(OH)₂?8H₂O hydrated flux as a new transient chemistry that enables the densification of BaTiO₃ in a single step at a temperature as low as 150 °C. This remarkably low temperature is near its Curie transition of 125 °C, associated with a displacive phase transition. The cold sintered BaTiO₃ shows a relative density of 95 % and a room temperature relative permittivity over 1000. This new hydrated flux permits the fabrication of a unique dense BaTiO₃-polymer nanocomposite with a high volume fraction of ceramics ((1-x) BaTiO₃ – x PTFE, with x = 0.05). The composite exhibits a relative permittivity of approximately 800, at least an order of magnitude higher than previous reports on polymer composites with BaTiO₃ nanoparticle fillers that are typically well below 100. Unique high permittivity dielectric nanocomposites with enhanced resistivities can now be designed using polymers to engineer grain boundaries and CSP as a processing method opening up new possibilities in dielectric materials design.     

An improved EZ-GCD algorithm for multivariate polynomials

The EZ-GCD algorithm often has the bad-zero problem, which has a remarkable influence on polynomials with higher-degree terms. In this paper, by applying special ideals, the EZ-GCD algorithm for sparse polynomials is improved. This improved algorithm greatly reduces computational complexity because of the sparseness of polynomials. The author expects that the use of these ideals will be useful as a resolution for obtaining a GCD of sparse multivariate polynomials with higher-degree terms.     

Tracking control properties of human-robotic systems based on impedance control

Human-robotic systems that include interaction between human operators and robots should be designed with careful consideration for the dynamic property and control ability of a human operator. This paper performs manual tracking control tests on a human-robotic system using an impedance-controlled robot, and investigates control characteristics of a human operator according to the robot impedance properties. Experimental results demonstrate that humans try to maintain dynamic properties of an overall system as constant as possible by adjusting their own impedance properties. Then, a new training system using a neural network for operating a human-robotic system is constructed on the basis of the experimental findings in the human tracking control properties.     

m-Calpain (calcium-activated neutral proteinase) in Alzheimer''s disease brains

The possible association between the emergence of cytopathogenic HIV-1 variants and disturbance of the cytokine production in the course of HIV-1 infection was studied in 18 infected patients. The cytopathogenicity of the isolates was studied in a microassay based on the use of HIV-1-infectible Hela-CD4 cells carrying the bacterial LacZ gene under the control of the HIV-LTR (P4 cells). In addition, the production of cytokines by heparinized whole blood (HWB) obtained the same day from HIV-1(+) patients was measured. TNF-alpha was determined in a one-step procedure combining HWB culture in the presence of LPS+PHA for 24 h and detection of cytokines in the same wells. In separate experiments HWB was cultured in the presence of LPS+PHA for 48 h, then the supernatants were collected and stored until assayed by ELISa for IFN-gamma and IL-4. Higher TNF-alpha levels were found in activated HWB of patients with cytopathic strains (n = 9) than in patients with non-cytopathic strains (n = 9, p = 0.02) assessed with P4 cells. A defective production of type 1 cytokine (IFN-gamma) and no increased secretion of type 2 cytokines (IL-4) was observed in patients with cytopathic strains. IFN-gamma/IL-4 ratios were significantly lower in patients with cytopathic strains (n = 9) than in other patients (n = 9, p = 0.009). The results show that the disarray of cytokine production, as assessed with whole blood culture, is associated with the cytopathogenicity of HIV-1 isolates in HIV-1-infected individuals.     

Physiologic stress responses to laparoscopic cholecystectomy. A comparison of the gasless and pneumoperitoneal procedures

BACKGROUND: Differences in the physiological stress response to pneumoperitoneal (PP) and gasless abdominal wall-lifting (AWL) procedures used for laparoscopic cholecystectomy have not been properly evaluated. METHODS: We compared leukocyte count, interleukin-6 (IL-6) levels, arterial blood gases, creatinine clearance, plasma renin activity, cardiothoracic ratio, and clinical outcome in 27 patients without systemic complications who underwent laparoscopic cholecystectomy, including 11 by AWL and 16 by PP. RESULTS: Transient leukocytosis and high IL-6 levels were observed at POD 1 (postoperative day) in both groups, but both values returned to baseline by POD 2. IL-6 levels correlated significantly with operation time (p < 0.01). Changes in blood gases, creatinine clearance, plasma renin activity, and cardiothoracic ratio were not different for the two groups. The clinical outcome was similar for both groups. CONCLUSIONS: Our results indicate that both PP and AWL are appropriate for patients without serious complications.     

Relation between passive smoking at home and dietary intake

Recent attempts to protect hematopoietic progenitor cells from cytarabine (ara-C)-induced toxicity by transfer of the cytidine deaminase (CDD) gene resulted in efficient in vitro inducibility of ara-C resistance. Another enzyme involved in intracellular ara-CTP inactivation is the deoxycytidylate deaminase (dCMPD). We therefore transfected the human dCMPD cDNA gene into murine fibroblasts and investigated the relationship of forced dCMPD expression and resistance induction to ara-C. Several cell lines were established which demonstrated a 1.7-3.5-fold increase in cellular dCMPD activity and an up to 2-fold increase in the IC50 value of ara-C. However, increases in dCMPD activities did not show a positive linear correlation with the induction of ara-C resistance. In addition, CD34 + hematopoietic progenitor cells revealed the highest endogenous dCMPD enzyme levels among different human hematopoietic cells. Thus, despite the documented role for dCMPD in ara-CTP inactivation of certain cell types, these results suggest that the dCMPD gene may prove less useful than the CDD gene as a therapeutic target in attempts to attenuate ara-C-induced bone marrow toxicity.