Effects of Isotopically Controlled Boron Addition on Microstructure of Nickel Irradiated at the Below Core Canister of FFTF

Nickel specimens doped with several levels of ^B were irradiated in the Fast Flux Test Facility(FFTF) for the purpose of examining the applicability of boron addition to the study of helium production effects. It was found that the boron has its chemical and transmutative effetcs, the former suppressing and the latter enhancing void nucleation. It seems that reliable estimation of helium effects is possible by well designed experiments seprating some side effects of boron from its transmutation effects

Development of Controlled Temperature-Cycle Irradiation Technique in JMTR

The effects of cyclic temperature changes during neutron irradiation upon radiation induced microstructure evolution and resulting property changes of materials is very important from both fundamental and engineering viewpoints. Therefore, a technique that allows us to do the controlled temperature-cycle irradiation was developed in the Japan Materials Testing Reactor (JMTR). The technique meets the following requirements : (1) the temperature-cycle irradiation is to be performed under three different conditions by changing lower and upper temperatures; 200 --- 400℃, 300 --- 400℃ and 300 --- 450℃. (2) the number and period of the temperature-cycles are to be six for 24-day full irradiation and approximately 44 h/44 h at the lower/upper temperatures. (3) the temperatures of each specimen assembly are to be maintained at the lower temperatures before start-up of the reactor and at the upper temperatures during shut-down until the complete absence of reactor power. In this paper, the details of the irradiation rig, successful results and several problems to be overcome for future improvement are presented

Surface morphology of tungsten exposed to helium plasma at temperatures below fuzz formation threshold 1073 K

Impact of crystal orientation on the surface morphology of the helium plasma exposed tungsten has been investigated on the linear device PSI-2. A nanoscale undulating surface structure having a periodic arrangement is formed for temperatures below 1073 K, in contrast to the fuzz nanostructure formation in a higher temperature range. The crests of undulation align with the  〈1 0 0〉  direction. The interval of the undulation is narrowest at the crystal grainof {1 1 0} surface. The interval becomes wider as the crystal grain surface tilts away from the {1 1 0} surface, and the undulating surface structure is not formed near the {1 0 0} surface. The height of undulations is 8 nm, independently of the interval of the undulations, and it corresponds to the depth of the layer heavily damaged due to helium plasma exposure

Left Hemihepatectomy for Hepatocellular Carcinoma Following Esophagectomy with Retrosternal Gastric Tube Reconstruction for Esophageal Cancer

Approximately 4% of patients with esophageal cancer develop a second primary malignancy in the upper gastrointestinal trunk. However, hepatectomy following esophagectomy for esophageal cancer has rarely been reported. We report the case of a 70-year-old man who underwent an esophagectomy for esophageal cancer with retrosternal gastric tube reconstruction. Nine years later, he developed hepatocellular carcinoma with tumor thrombus involving the left portal vein, and was successfully treated with left hemihepatectomy. Special attention should be paid to avoiding incidental injury of the gastric tube as well as the right gastroepiploic artery during the hepatectomy

Pathophysiology and Treatment of Diabetic Cardiomyopathy and Heart Failure in Patients with Diabetes Mellitus

There is a close relationship between diabetes mellitus and heart failure, and diabetes is an independent risk factor for heart failure. Diabetes and heart failure are linked by not only the complication of ischemic heart disease, but also by metabolic disorders such as glucose toxicity and lipotoxicity based on insulin resistance. Cardiac dysfunction in the absence of coronary artery disease, hypertension, and valvular disease is called diabetic cardiomyopathy. Diabetes-induced hyperglycemia and hyperinsulinemia lead to capillary damage, myocardial fibrosis, and myocardial hypertrophy with mitochondrial dysfunction. Lipotoxicity with extensive fat deposits or lipid droplets is observed on cardiomyocytes. Furthermore, increased oxidative stress and inflammation cause cardiac fibrosis and hypertrophy. Treatment with a sodium glucose cotransporter 2 (SGLT2) inhibitor is currently one of the most effective treatments for heart failure associated with diabetes. However, an effective treatment for lipotoxicity of the myocardium has not yet been established, and the establishment of an effective treatment is needed in the future. This review provides an overview of heart failure in diabetic patients for the clinical practice of clinicians

Proposal Of Propulsion Unit Based On Earthworm Setae For Underwater Excavation Robot

In this paper, we developed a propulsion unit with bristles imitating the setae of earthworm. This propulsion unit is installed in SEAVO: sub-seafloor excavation robot. To realize underwater excavation by SEAVO, it is necessary to move the soft and fluid sedimentary layer of seafloor surface. As a solution, we focused on the setae of earthworm which live in mud and soft soil. Then, we developed the propulsion unit with bristles imitating the earthworm's setae and measured the performance of the bristlesattached propulsion unit. Comparing the measurement result of the bristles-attached propulsion unit with the previous propulsion unit, we confirmed the usefulness of the bristles-attached propulsion unit

Vasopressin-oxytocin–type signaling is ancient and has a conserved water homeostasis role in euryhaline marine planarians

Vasopressin/oxytocin (VP/OT)–related peptides are essential for mammalian antidiuresis, sociosexual behavior, and reproduction. However, the evolutionary origin of this peptide system is still uncertain. Here, we identify orthologous genes to those for VP/OT in Platyhelminthes, intertidal planarians that have a simple bilaterian body structure but lack a coelom and body-fluid circulatory system. We report a comprehensive characterization of the neuropeptide derived from this VP/OT-type gene, identifying its functional receptor, and name it the “platytocin” system. Our experiments with these euryhaline planarians, living where environmental salinities fluctuate due to evaporation and rainfall, suggest that platytocin functions as an “antidiuretic hormone” and also organizes diverse actions including reproduction and chemosensory-associated behavior. We propose that bilaterians acquired physiological adaptations to amphibious lives by such regulation of the body fluids. This neuropeptide-secreting system clearly became indispensable for life even without the development of a vascular circulatory system or relevant synapses

Characterization of Ion Cyclotron Wall Conditioning Using Material Probes in LHD

The ion cyclotron wall conditioning (ICWC) is one of the conditioning methods to reduce impurities and to remove tritium from the plasma facing components. Among the advantages of ICWC are the possible operation under strong magnetic field for fully torus area based on the charge exchange damage observed in thin SS samples arranged on a hexahxedron block holder with three different facings, the areas influenced by ICWC is estimated. On the plasma facing area of the material holder, high density of helium bubbles is observed by transmission electron microscope (TEM). But the other areas show no observable damage. The fact that the bubble were observed only in a sample facing the plasma implies that the effective particles, most probably charge exchange neutrals come to the wall straightly Thus, cleaning of the surfaces un-exposed to plasma directly and those in shadow area is difficult by ICWC