Tracking the Oxygen Status in the Cell Nucleus with a Hoechst‐Tagged Phosphorescent Ruthenium Complex

Molecular oxygen in living cells is distributed and consumed inhomogeneously, depending on the activity of each organelle. Therefore, tractable methods that can be used to monitor the oxygen status in each organelle are needed to understand cellular function. Here we report the design of a new oxygen‐sensing probe for use in the cell nucleus. We prepared “Ru‐Hoechsts”, each consisting of a phosphorescent ruthenium complex linked to a Hoechst 33258 moiety, and characterized their properties as oxygen sensors. The Hoechst unit shows strong DNA‐binding properties in the nucleus, and the ruthenium complex shows oxygen‐dependent phosphorescence. Thus, Ru‐Hoechsts accumulated in the cell nucleus and showed oxygen‐dependent signals that could be monitored. Of the Ru‐Hoechsts prepared in this study, Ru‐Hoechst b , in which the ruthenium complex and the Hoechst unit were linked through a hexyl chain, showed the most suitable properties for monitoring the oxygen status. Ru‐Hoechsts are probes with high potential for visualizing oxygen fluctuations in the nucleus.     

Individual monitoring for internal contamination with plutonium compounds at JAEA-NCL

This paper provides an outline of an individual monitoring programme for internal contamination with Pu compounds and some of the knowledge obtained from experience of inhalation incidents that occurred over the past few decades at the Japan Atomic Energy Agency, Nuclear Fuel Cycle Engineering Laboratories (JAEA-NCL). Most of the incidents resulted in minor exposure doses, being an average of 0.1 mSv at a mixed oxide plant and 1.5 mSv at a reprocessing plant. Only two incidents involving three workers resulted in exposure over the regulatory dose limits of that time. The maximum exposure dose, an effective dose equivalent of 90 mSv, was assessed for a worker involved in the incident that took place at the reprocessing plant in 1993. Only faecal measurements have been used in final dose assessments because alternative monitoring data have rarely been available. Further investigations on the physicochemical properties specific to Pu compounds in workplaces have therefore been needed to improve not only the accuracy of internal dose assessments but also the nasal swab method useful in deciding medical intervention.     

Computations on Metallofullerenes Derivatized during Extraction: La@C80-C6H3Cl2 and La@C82-C6H3Cl2

Recently, an extraction of la metallofullerenes from soot using 1,2,4-trichlorobenzene has been reported for La@C₈₀ and La@C₈₂. In both cases, the cages were derivatized by the solvent (forming La@C₈₀-C₆H₃Cl₂ and La@C₈₂-C₆H₃Cl₂) and the following X-ray analysis disclosed rather unexpected cages: C₈₀(C _2v ;3) and C₈₂(C _3v ;7). In order to explain the challenging observations, a two-step computational treatment is presented. The first step deals with the high-temperature gas-phase formation of the underivatized endohedrals while the second step models the reaction with the solvent. The Gibbs free energies were evaluated for representative temperatures and the computational scheme was able to confirm high relative populations for the observed derivatized cages.     

Optical properties of epitaxial plzt thin films

In the epitaxial (Pb_1?x , La _x )(Zr_1?y , Ti _y )_1?x/4O₃ [PLZT] films, the composition dependence of the refractive index and electric-optic (EO) coefficient near the morphotropic phase boundary (MPB) composition was investigated. A (100/001)-oriented PLZT 10/65/35 epitaxial film is found to have isotropic optical properties. Highly (100/001)-oriented epitaxial PLZT films with compositions near the MPB on Nb–SrTiO₃ substrates were fabricated using a sol–gel process. The value of birefringence from 4?×?10^?3 to 5?×?10^?4 in PLZT epitaxial film was smaller than that of lithium niobate single crystal. The refractive index decreases with increasing lanthanum content. The difference in the refractive index obtained depended upon the lanthanum content up to 2%. This value is adequate for fabrication of waveguide structures. The EO coefficient of PLZT 9/65/35 thin films was 45 pm/V, which is larger than that of lithium niobate single crystal. A very small polarization dependence of the EO coefficient was also observed.     

In Vitro Tumor Cell-Binding Assay to Select High-Binding Antibody and Predict Therapy Response for Personalized 64Cu-Intraperitoneal Radioimmunotherapy against Peritoneal Dissemination of Pancreatic Cancer: A Feasibility Study

Peritoneal dissemination of pancreatic cancer has a poor prognosis. We have reported that intraperitoneal radioimmunotherapy using a ⁶⁴Cu-labeled antibody (⁶⁴Cu-ipRIT) is a promising adjuvant therapy option to prevent this complication. To achieve personalized ⁶⁴Cu-ipRIT, we developed a new in vitro tumor cell-binding assay (⁶⁴Cu-TuBA) system with a panel containing nine candidate ⁶⁴Cu-labeled antibodies targeting seven antigens (EGFR, HER2, HER3, TfR, EpCAM, LAT1, and CD98), which are reportedly overexpressed in patients with pancreatic cancer. We investigated the feasibility of ⁶⁴Cu-TuBA to select the highest-binding antibody for individual cancer cell lines and predict the treatment response in vivo for ⁶⁴Cu-ipRIT. ⁶⁴Cu-TuBA was performed using six human pancreatic cancer cell lines. For three cell lines, an in vivo treatment study was performed with ⁶⁴Cu-ipRIT using high-, middle-, or low-binding antibodies in each peritoneal dissemination mouse model. The high-binding antibodies significantly prolonged survival in each mouse model, while low-and middle-binding antibodies were ineffective. There was a correlation between in vitro cell binding and in vivo therapeutic efficacy. Our findings suggest that ⁶⁴Cu-TuBA can be used for patient selection to enable personalized ⁶⁴Cu-ipRIT. Tumor cells isolated from surgically resected tumor tissues would be suitable for analysis with the ⁶⁴Cu-TuBA system in future clinical studies.     

Application of high strength MnMoNi steel to pressure vessels for nuclear power plant

Recent increase in output of nuclear power plant has been attained by enlargement of major components such as pressure vessels. Such large components have almost reached a size limit from the points of manufacturing capacity and cost in both forgemasters and fabricaters. In order to solve this problem, it must be beneficial to apply design by use of material of higher strength, which brings reduction of pressure vessel thickness and weight. The Japan Steel Works Ltd. (JSW) has many manufacturing experiences of large integrated forgings made from high strength MnMoNi steel with tensile strength level of 620 MPa for steam generator (SG) pressure vessel, and has performed confirmation tests of its material properties. This paper describes the confirmation test results such as tensile and impact properties, nil-ductility transition temperature (NDT-T), static and dynamic fracture toughness, weldability including under-clad cracking (UCC) sensitivity, as well as metallurgical factors which influence on such material properties.     

Automatic parameter learning method for agent activation spreading network by evolutionary computation

Artificial Life and Robotics - A variety of planning research is being actively conducted in multiple research fields. The focus of these studies is to flexibly utilize both immediate and...