PVP2009-77360 PROPOSAL OF RATIONAL DETERMINATION OF FRACTURE TOUGHNESS LOWER-BOUND CURVES BY MASTER CURVE APPROACH

ABSTRACT The Master Curve gives the relation between the median of fracture toughness and temperature in ductile-brittle transition temperature region. The procedure to determine the Master Curve is provided in the current ASTM E1921 standard. Considering the substitution of the alternative lower-bound curves based on the Master Curve approach for the recursive KIc curves in the present codes, the statistical characteristic should be well incorporated into the determination of the lower-bound curves. The appendix in the ASTM standard provides the procedure to derive the lower-bound curves, however, it seems to be addressed without sufficient consideration on statistical reliability. In this study, we proposed a rational determination method of fracture toughness lower-bound curves based on the Master Curve approach. The method took account of the effect of sample size in the determination of the tolerance bound curve. The adequacy of the proposed method was then verified by comparing with a fracture toughness database for RPV steels. The method allows the application of the Master Curve using fewer specimens, which can coexist with the present surveillance program. INTRODUCTION The Master Curve gives the relation between the median of fracture toughness and temperature in ductile-brittle transition temperature region. The Master Curve method rests on several assumptions. One of the key assumptions of the Master Curve is that the scatter in fracture toughness is captured by the weakest link statistics with a three-parameter Weibull distribution with a slope of 4. The statistical mode

Surgery for Diverticular Disease of the Colon

Surgery for complications of colonic diverticulum was evaluated on the basis of a result of clinical experience for the 15 patients. 1) Average age was 48.9 years, and right-side oriented lesions were more often seen in younger patients. The men and women ratio was 1.5 to 1.0. 2) The reasons for surgery were disticulitis in 7 (46.7%), perforation in 3 (20.0%) and abscess and fistula formation in 2 (13.3%), respectively. 3) Complications on the left side were much more severe than those on the right side and also seen more often in older patients

Malignant Potential in the Analysis of DNA Ploidy Pattern in Patients with Colorectal Cancer

Recently the measurement of cellular DNA content has been focused on knowing the extent of cancer extension and biological behaviour of the tumor cells as well as on producting occurrence of recurrence and the survival time in patients with carcinomas of various organs. And also it is well known that tumor markers such as CEA, CA19-9 and CA72-2 are of great value in predicting recurrence in the follow-up study. It is common that colorectal cancers show well differentiated carcinoma which demonstrates relatively fair prognosis. However, some revealed aggressive and rapid extension of carcinoma, indicating a poor prognosis. The purpose of this study is to certify the significance of the measurement of cellular DNA content for assessing biologic behavior of colorectal cancer in comparison with clinicopathologic factors which have been used for assessment of their prognosis. Development of flow cytometer enabled us to measure the nuclear DNA content with ease, speed and producibility. Furthermore, prevalence of flow cytometric technique makes it possible to know more accurate outcome. When assessed biologically aggressive behavior of tumor cells, potent chemotherapy and extensive surgery are mandatory for improvement of the outcome. It is necessary to search for the method of the accurate assessment of the outcome for patients with carcinomas. The purpose of this study is to clarify the validity of nuclear DNA measurement for assessment of the prognosis in patients with colorectal cancer in comparison with clinicopathologic factors

Surgery for Gastric Cancer in Younger Patients

Twenty-five patients with gastric cancer were clinically evaluated in terms of a clinicopathological pattern in younger patients. 1) Female was more predominant than male. 2) The main tumor location was the cardia and the gross appearance was Borrmann IV of undifferentiated carcinoma in the majority. 3) Less hepatic metastases were seen in younger patients, whereas, the common extension in younger patients was peritoneal dissemination and serosal invasion. 4) The surgical outcome was satisfactory as far as a curative operation be performed. On the contrary, the result of non-curative operation was extremely pessimistic. Recently great strides in the surgical outcome of gastric cancer have been achieved in combination with adjuvant therapy of immunochemotherapy. Improvement of surgical outcome is attributable to the standarized operative procedure with reasonable node dissection. It is common that carcinomas in various organs affect older patients, not usually younger ones. The purpose of this study is to clarify the clinicopathologic features of gastric cancer in younger patients on the basis of our result of clinical experience

Qualitative investigation of the factors that generate ambivalent feelings in women who give birth after receiving negative results from non-invasive prenatal testing

Background: Women who receive negative results from non-invasive prenatal genetic testing (NIPT) may find that they later have mixed or ambivalent feelings, for example, feelings of accepting NIPT and regretting undergoing the test. This study aimed to investigate the factors generating ambivalent feelings among women who gave birth after having received negative results from NIPT. Methods: A questionnaire was sent to women who received a negative NIPT result, and a contents analysis was conducted focusing on ambivalent expressions for those 1562 women who responded the questionnaire. The qualitative data gathered from the questionnaire were analyzed using the N-Vivo software package. Results: Environmental factors, genetic counseling-related factors, and increased anticipatory anxiety, affected the feeling of ambivalence among pregnant women. Furthermore, pregnant women desired more information regarding the detailed prognosis for individuals with Down syndrome and living with them and/or termination, assuming the possibility that they were positive. Conclusions: Three major interrelated factors affected the feeling of ambivalence in women. Highlighting and discussing such factors during genetic counseling may resolve some of these ambivalences, thereby enhancing the quality of decisions made by pregnant women

The Validily of Tracheal Surgery for the Aged

Surgery for tracheal stenotic lesions in older patients over age 70 was evaluated in comparison with younger patients under age 69 on the basis of our clinical experience. The causes of tracheal lesions were mainly malignant diseases in spite of varying variety of etiology in the younger patients. The outcome of surgical treatment in the older ones was not inferior to that in the younger ones as far as postoperative complications were prevented. In conclusion, it is emphasized that the surgical treatment of choice is essential for palliation of symptoms and expectance of high quality of life

Esophageal Carcinomas with Synchronous and Metachronous Primary Malignant Carcinomas in Other Organs

Seventeen patients with 10 synchronous and 7 metachronous double cancers with carcinomas of the esophagus were surgically treated in the First Department of Surgery, Nagasaki University School of Medicine. All patients were men with an average of age 68.5. The incidence of double cancers with carcinoma of the esophagus accounted for 12.7% in a total of 134 of this series. The three triple cancers were included. Of the three, one was synchronous triple cancers in the esophagus, the stomach and the colon. The outcome was not necessarily satisfactory. Two had recurrence 3 and 5 months after surgery, but one is still alive for 33 months, free from carcinoma

Significance of Needle Aspiration Biopsy for Breast Cancer

The results of aspiration biopsy cytology were clinically evaluated on the basis of clinical experience with 608 patients with breast cancer at the First Department of Surgery, Nagasaki University School of Medicine. Aspiration biopsy is of clinical value in making a diagnosis of small-sized tumors. There was no detrimental outcome to promote tumor-cell spread locally as well as to give rise to distant metastasis into the other organ. One should be aware of a no cell finding in relation to scirrhous carcinoma and intraductal papillomatosis. Emphasis is placed on recommendation of open biopsy without repeated aspiration maneuver

Mab21l2 Is Essential for Embryonic Heart and Liver Development

During mouse embryogenesis, proper formation of the heart and liver is especially important and is crucial for embryonic viability. In this study, we showed that Mab21l2 was expressed in the trabecular and compact myocardium, and that deletion of Mab21l2 resulted in a reduction of the trabecular myocardium and thinning of the compact myocardium. Mab21l2-deficient embryonic hearts had decreased expression of genes that regulate cell proliferation and apoptosis of cardiomyocytes. These results show that Mab21l2 functions during heart development by regulating the expression of such genes. Mab21l2 was also expressed in the septum transversum mesenchyme (STM). Epicardial progenitor cells are localized to the anterior surface of the STM (proepicardium), and proepicardial cells migrate onto the surface of the heart and form the epicardium, which plays an important role in heart development. The rest of the STM is essential for the growth and survival of hepatoblasts, which are bipotential progenitors for hepatocytes and cholangiocytes. Proepicardial cells in Mab21l2-deficient embryos had defects in cell proliferation, which led to a small proepicardium, in which α4 integrin expression, which is essential for the migration of proepicardial cells, was down-regulated, suggesting that defects occurred in its migration. In Mab21l2-deficient embryos, epicardial formation was defective, suggesting that Mab21l2 plays important roles in epicardial formation through the regulation of the cell proliferation of proepicardial cells and the migratory process of proepicardial cells. Mab21l2-deficient embryos also exhibited hypoplasia of the STM surrounding hepatoblasts and decreased hepatoblast proliferation with a resultant loss of defective morphogenesis of the liver. These findings demonstrate that Mab21l2 plays a crucial role in both heart and liver development through STM formation