Copper Alloy Design for Preventing Sulfur-Induced Embrittlement in Copper.

This study presents an experimental approach to address sulfur-induced embrittlement in copper alloys. Building on recent theoretical insights, we identified specific solute elements, such as silicon and silver, known for their strong binding affinity with vacancies. Through experimental validation, we demonstrated the effectiveness of Si and Ag in preventing sulfur-induced embrittlement in copper, even though they are not typical sulfide formers such as zirconium. Additionally, our findings highlight the advantages of these elements over traditional solutes, such as their high solubility and propensity to accumulate along grain boundaries. This approach may have the potential to be applied to other metals prone to sulfur-induced embrittlement, including nickel, iron, and cobalt, offering broader implications for materials engineering strategies and alloy development.

ESTIMATION OF EXPOSURE DOSES FOR THE SAFE MANAGEMENT OF NORM WASTE DISPOSAL.

Naturally occurring radioactive materials (NORM) wastes with different radiological characteristics are generated in several industries. The appropriate options for NORM waste management including disposal options should be discussed and established based on the act and regulation guidelines. Several studies calculated the exposure dose and mass of NORM waste to be disposed in landfill site by considering the activity concentration level and exposure dose. In 2012, the Korean government promulgated an act on the safety control of NORM around living environments to protect human health and the environment. For the successful implementation of this act, we suggest a reference design for a landfill for the disposal of NORM waste. Based on this reference landfill, we estimate the maximum exposure doses and the relative impact of each pathway to exposure dose for three scenarios: a reference scenario, an ingestion pathway exclusion scenario, and a low leach rate scenario. Also, we estimate the possible quantity of NORM waste disposal into a landfill as a function of the activity concentration level of U series, Th series and 40K and two kinds of exposure dose levels, 1 and 0.3 mSv/y. The results of this study can be used to support the establishment of technical bases of the management strategy for the safe disposal of NORM waste.

[Primary squamous cell carcinoma of the ascending colon: report of a case and Korean literature review].

Primary squamous cell carcinoma of the colon is an extremely rare malignancy. A 48-year-old male visited our hospital for screening colonoscopy. Colonoscopic examination showed a 1 cm sized sessile polyp in the ascending colon. The patient underwent endoscopic mucosal resection (EMR) without any complication. The pathologic findings were compatible with squamous differentiation of tumor cells in inflammatory colonic mucosa. The tumor was confined to the mucosa and the margins of the excised tissue were found to be free of the tumor. There were no other primary sites and no distant metastases in the extensive evaluation using a whole body CT scan and PET-CT. Additional surgical resection was not done. Follow-up colonoscopy performed eight month later showed a whitish scar without evidence of local recurrence and follow-up PET-CT demonstrated no evidence of recurrence. Herein, we report a case of primary squamous cell carcinoma of the ascending colon presenting as a sessile polyp which was removed by EMR.

AIDS-related gastrointestinal kaposi sarcoma in Korea: a case report and review of the literature.

Kaposi sarcoma (KS) is a vascular neoplasm, which is fairly prevalent in acquired immunodeficiency syndrome (AIDS) patients. Mucocutaneous and lymph node involvements are characteristic features of KS in AIDS patients. The involvement of gastrointestinal tract occurs in 40% of KS patients and leads to significant morbidity and mortality. In the highly active antiretroviral therapy (HAART) era, the rate of AIDS related KS has fallen with control of human immunodeficiency virus (HIV) viremia. However, it is still recognized as the primary AIDS-defining illness, and the proportion of AIDS diagnoses made due to KS ranged from 4.1% to 7.5%. In Korea, AIDS-related KS has been report in low rate incidence. Its gastrointestinal involvements are rarely reported. To date, five cases have been recorded in Korea. Herein, we present an additional case of gastrointestinal KS as the AIDS-defining illness and review of the Korean medical literature.

[The trend of eradication rate of Helicobacter pylori infection and clinical factors that affect the eradication of first-line therapy].

BACKGROUND/AIMS: Although triple combination therapy containing a proton pump inhibitor (PPI) and two antibiotics is considered as a standard regimen for the first-line anti-Helicobacter pylori treatment, the recent trend of eradication rates following this therapy has been declined in the last few years. The purpose of this study was to investigate the trend of H. pylori eradication rates over the last 9 years and to evaluate are clinical factors affecting eradication rates. METHODS: From January 2001 to June 2009, H. pylori eradication rates in 709 patients with documented H. pylori infection who received triple combination therapy for 7 days were retrospectively evaluated according to years and various clinical factors. H. pylori status was evaluated by 13C urea breath test 4-6 weeks after completion of treatment. results: The overall H. pylori eradication rate was 77.0%. The annual eradication rates from year 2001 to 2009 were 78.9%, 72.5%, 81.0%, 75.0%, 79.1%, 77.1%, 77.8%, 77.8%, and 75.0% by per-protocol analysis. There was no decreasing tendency of the eradiation rate over 9 years (p=0.974). There was no statistical difference in the eradication rates according to age, sex, smoking, alcohol, NSAIDs, underlying diseases, endoscopic diagnosis, and PPI. However, the eradication rate was lower in patients who took aspirin (OR=0.509, 95% CI=0.292-0.887, p=0.001) and antibiotics within 6 months (OR=0.347, 95% CI=0.183-0.658, p=0.001). CONCLUSIONS: The H. pylori eradication rate has not changed at Gwangju-Chonnam province in Korea for recent 9 years. Lower eradication rate in aspirin and antibiotics users warrants further attention.

[Hypertriglyceridemia-induced pancreatitis treated with insulin in a nondiabetic patient].

Heparin and/or insulin stimulate lipoprotein lipase and are known to decrease serum triglyceride level. However, their efficacy in hypertriglyceridemia-induced acute pancreatitis in nondiabetic patients is not well documented. We report a case of hypertriglyceridemia-induced pancreatitis in 43-year-old nondiabetic woman in whom treatment with insulin was accompanied by reduction in serum triglyceride level and the resolution of pancreatitis. She presented to the emergency department with abdominal pain and biochemical evidence of acute pancreatitis. Her medical history was unremarkable. There was no history of alcohol consumption, and biliary imaging was not remarkable. Subsequent laboratory investigation revealed marked hypertriglyceridemia (1,951 mg/dL), impaired fasting glucose, and normal HbAlc level. The Ransons score and APATCH II score were 1 and 4. Abdominal CT showed diffuse enlargement of pancreas, peripancreatic fat infiltration, and multiple fluid collections around the pancreas. We treated the patient with the infusion of 5% dextrose and 1.5 unit/hr regular insulin to reduce serum triglyceride level. The level of serum triglyceride was decreased to 305 mg/dL on day 5. During the remainder of hospitalization, her clinical symptoms and laboratory values gradually improved.

[Analysis of the clinical characteristics and prognostic factors of ruptured hepatocellular carcinoma].

BACKGROUND/AIMS: Spontaneous rupture of hepatocellular carcinoma (HCC) is a rare but life-threatening complication. Although the prevalence rate and mortality of HCC has been reportedly high in Korea, studies on ruptured HCC are limited. The aim of this study was to determine the clinical characteristics and prognostic factors of ruptured HCC. METHODS: Among 886 cases with HCC that had been diagnosed at Chonnam National University Hospital from January 2002 to December 2007, 62 cases (7.0%) with ruptured HCC were studied retrospectively regarding their clinical characteristics and prognostic factors. RESULTS: Transarterial embolization was performed in 56 cases (90.3%) to control bleeding, with a hemostasis success rate of 89.3%. The survival time after the rupture of HCC was 8.0+/-1.7 months (mean+/-SD), although it was longer in HCC cases that were first diagnosed in a ruptured state or ruptured with a small amount of bleeding than in those that ruptured during follow-up after diagnosis or with a large amount of bleeding, respectively. The 30-day mortality rate in patients with a ruptured HCC was 43.5%, and the early deaths were independently associated with the presence of hepatic encephalopathy (odds ratio, OR=44.7; 95% confidence interval, CI=1.9-1051.1; P=0.018), serum bilirubin >3.0 mg/dL (OR=36.7; 95% CI=1.3-1068.5; P=0.036), and the massive or diffuse type of tumor morphology (OR=53.5; 95% CI=3.0-964.2; P=0.007). CONCLUSIONS: The prognosis in patients with ruptured HCCs was poor with a 30-day mortality of 43.5%. The early deaths after the rupture of HCC were associated with elevated serum bilirubin levels, hepatic encephalopathy, and the massive or diffuse type of tumor morphology.