APPLICATION OF OUTER SURFACE IRRADIATED LASER STRESS IMPROVEMENT PROCESS (L-SIP) TO PRESSURIZER AS RESIDUAL STRESS IMPROVEMENT METHOD FOR ALLOY 600 PWSCC MITIGATION

ABSTRACT Improvement of residual stress is effective in a countermeasure to deal with the stress corrosion cracks in pipe welds. A irradiated laser stress improvement process (L-SIP) will be introduced as a method to improve residual stress inside steel pipes. This work method is to improve inner surface residual stress from tensile stress to compressive stress by irradiating laser beam around the welds of steel pipe and utilizing the temperature differences between inner and outer surface. Recently this method is applied to PWR pressurizer surge nozzle on TRUGA unit 2. INTRODUCTION In the welds of steel pipes at nuclear power plant or thermal power plant, stress corrosion crack (SCC) is regarded as a damage mode. Stress corrosion crack is caused by tensile residual stress, materials and environment (including water quality and temperature, etc.). It is very difficult to improve the material and environment of pipes in operation plant. Therefore, the residual stress improvement work method is used as a simplified method. In order to improve residual stress, some ways of peening including shot peening are applied. In the welds of steel pipes, it is often impossible to apply them to inner surface of pipes where stress corrosion crack occurs due to the inaccessibility. To date, the use of laser beam as a maintenance technology for nuclear power plants have been studied (1)(2)(3)(4) , it is one of the applicable method from outside of the pipe. This study will report the first application to nuclear power plant in order to improve the inner residual stress of pressurizer surge nozzle

A Case of Giant Mesenteric Cyst Originating from the Small Intestine

A 62-year-old man was admitted to Showa University Fujigaoka Hospital because of a giant mass that was discovered approximately 8 weeks after the development of obvious symptoms, namely upper abdominal pain, vomiting, and progressive distension. Ultrasonography revealed a giant cystic mass that was occupying the right upper abdomen, and contrast-enhanced computed tomography revealed a huge, relatively well-defined, and low-density cystic mass that measured 10cm in diameter. Radical resection of the tumor was performed via open laparotomy, along with segmental small intestine resection to address potential invasion into adjacent tissues. Histological findings of the resected specimen indicated mesenteric cyst. The patient\u27s postoperative recovery was uneventful and he was discharged after 11 days. At the 12-month follow-up, the patient was in good health with no signs of recurrence

The inhibitory effects of a RANKL-binding peptide on articular and periarticular bone loss in a murine model of collagen-induced arthritis: a bone histomorphometric study

Showing the effects of OP3-4 on the proliferation and differentiation of cartilage cell line ATDC5. A Results of proliferation assay on day 1 with the noninduction medium. B Alcian blue-positive area ratio in the cartilage induction medium on day 10. **p <0.01 vs. vehicle control, #p <0.05 vs. 100 ÎźM OP3-4. (JPEG 384 kb

Prediction and Treatment of Difficult Cases in Colorectal Endoscopic Submucosal Dissection

Purpose. The aim of this study was to examine the characteristics of difficult cases and the learning curve in colorectal endoscopic submucosal dissection (ESD). Methods. We studied 518 colorectal tumors treated by ESD. Patients were divided into 2 groups such as the difficult ESD group and non-difficult ESD group in view of procedure time and procedure speed, respectively. The clinical features in each group were analyzed, and we also examined cases with severe fibrosis. Furthermore, we divided all cases into 5 periods according to experience of ESDs and investigated the rates of difficult and perforation cases. Results. In view of both procedure time and procedure speed, there were significant differences about mean tumor size, rates of severe fibrosis and perforation, and en bloc resection rate between the two groups. Severe fibrosis was detected in protruding tumors >40 mm in diameter. With respect to the learning curve, the rate of difficult and perforation cases decreased significantly in the late periods compared to the first period. Conclusions. Large tumor size, high rates of severe fibrosis and perforation, and low rate of en bloc resection are related with difficult ESD cases. The increasing of experiences can decrease the rate of difficult cases and perforation

Defective function of GABA-containing synaptic vesicles in mice lacking the AP-3B clathrin adaptor

AP-3 is a member of the adaptor protein (AP) complex family that regulates the vesicular transport of cargo proteins in the secretory and endocytic pathways. There are two isoforms of AP-3: the ubiquitously expressed AP-3A and the neuron-specific AP-3B. Although the physiological role of AP-3A has recently been elucidated, that of AP-3B remains unsolved. To address this question, we generated mice lacking μ3B, a subunit of AP-3B. μ3B−/− mice suffered from spontaneous epileptic seizures. Morphological abnormalities were observed at synapses in these mice. Biochemical studies demonstrated the impairment of γ-aminobutyric acid (GABA) release because of, at least in part, the reduction of vesicular GABA transporter in μ3B−/− mice. This facilitated the induction of long-term potentiation in the hippocampus and the abnormal propagation of neuronal excitability via the temporoammonic pathway. Thus, AP-3B plays a critical role in the normal formation and function of a subset of synaptic vesicles. This work adds a new aspect to the pathogenesis of epilepsy