Hydrogen Behavior in Ti-Added Reduced Activation Ferritic-Martensitic Steels

Kang‑Mook Ryu,Dae Geon Lee,Joonoh Moon,Chang‑Hoon Lee,Tae‑Ho Lee,Jae Sang Lee,Dong‑Woo Suh 대한금속·재료학회 2021 METALS AND MATERIALS International Vol.27 No.3

Hydrogen behavior and corresponding mechanical degradation were examined in TaTi-RAFM and EUROFER97 steels. Increased Ta content with Ti addition decelerates the hydrogen diffusion but increases the solubility in the lattice. It ismainly led by the higher fraction of Ta-rich MC carbides and dislocation density in TaTi-RAFM steel. Overall activationenergy of hydrogen trapping of investigated steels is evaluated to be 25.3 ~ 25.6 kJ/mol in the tempered condition. The activationenergy increases to nearly 30 kJ/mol when the steels are re-austenitized and quenched. Higher activation energy withincreased dislocation density indicates that the dislocation provides for trap site with higher activation energy than Ta-richMC carbide. Mechanical degradation by hydrogen with respect to the yield strength, tensile strength and uniform elongationcould not be observed in all investigated steels. The presence of hydrogen only has influence on the loss of post-uniformelongation. For a given charging time, the loss of post-uniform elongation is more remarkable in TaTi-RAFM steel due tothe larger hydrogen uptake.

상염색체우성 다낭신의 임상경과 및 합병증

이상주,이영모,이한규,최대은,박기현,이강욱,신영태 충남대학교 의학연구소 2001 충남의대잡지 Vol.28 No.2

Autosomal dominant polycystic kidney disease(ADPKD) is one of most common hereditary disorder. It is potentially fatal and the major mobilities are hypertension and renal failure. To elucidate clinical characteristics and outcomes of ADPKD, 67 ADPKD patients were analyzed retrospectively. The male to female ratio was 48 years for males and 42 years for females. The factors leading to the dignosis of ADPKD were flank or abdominal pain (46%), palpable abdominal mass (24%), incidental findings (18%), gross hematuria and headache. Urinalysis result showed hematuria (31%), proteinuria (19%), pyuria (18%). Among renal complications hypertension (67%) was the most common. Other complications were urolithiasis (16%) upper urinary tract infection (9%), cyst infection (7%). Azotemia was observed in 24% of cases. Echocardiography showed left ventricular hypertrophy in 24% and valvular regurgitation in 18% of cases, but there was no mital valve prolapse. Cerebrovascular events occurred in 6 cases (2 cases of intervertebral hemorrhage and 4 cases of cerebral infarction). Hipatic cyst were observed in 64% of cases. Eighteen cases culminated in end stage renal failure (ESRF) at an of 47. According to this study, the most common complications of ADPKD was hypertension (67%), ESRF (27%), and cerebrovascular event (9%). Hypertension was more frequently observed in increased creatinine group than normal.

자생 차(Camellia sinensis L.)의 육묘 방법에 관한 연구

이용호,이종성,강남대,송근우,강동주,고영옥,정대수 동아대학교 2001 大學院論文集 Vol.26 No.-

These experiments were conducted to studies on methods raising seedling in Native Tea Trees(Camellia sinensis L.). this experiment was conducted for 2years from 1999 to 2000 in Kyeongnam Provincial Rural Development Administration(R.D.A) The results were summarized as follows: 1. Germination percentage, mature seedling percentage, tiller, leaf number, leaf length and dry weight become higher Cup Pot Φ16cm treatment plot, plant height and leaf area was high some Net Pot Φ15cm treatment plot. 2. The growth of underground and aboveground show a good result all Cup Pot Φ16cm treatment plot. 3. The T/R rate of Cup Pot Φ16cm treatment plot were found 100% and Cup Pot Φ15cm treatment plot were found 114%. 4. The economic gains become higher Cup Pot Φ16cm.

횡문근융해증과 급성 신부전 및 범발성 혈관내 응고장애를 동반한 열사병 1예

최대은,박수진,권오경,이한규,이영모,이상주,나기량,이강욱,신영태 충남대학교 의학연구소 2003 충남의대잡지 Vol.30 No.2

Heat stroke is a life-threatening illness characterized by an elevated core body temperature that rises above 40% and central nervous system dysfunctions that results in delirium, convulsions, or coma. Heat stroke is subdivided into two forms, classic and exertional. Since strenuous exercise is one of the major exacerbating and precipitating factors, the incidence of exertional heat stroke is high among young adult, especially military personnel undergoing military training. Exertional heat stroke commonly causes rhabdomyolysis, lactic acidosis, acute renal failure, shock and pulmonary edema. We report a case of heat stroke with rhabdomyolysis, acute renal failure, disseminated intravascular coagulopathy(DIC) after strenuous exercise. A 18 year old man was admitted to the hospital because of loss of consciousness. He was a wrestler and he had tried to lose 6kg in weight by jogging and strenuous exercise on that summer day with hot temperature. The development of this illness was favoured by much clothes inappropriate for that environmental condition with a purpose to enhance sweating, and by restricted intake of water and food. On admission, the blood pressure was 80/50mmHg, and body temperature was 39.4℃ with stuporous mentality. Laboratory finding were as follows : in complete blood cell count, hemoglobin was 16.7g/dL and platelet count was 158,000/ mm³. In blood chemistry, AST 1061U/L, ALT 201U/L, BUN 30mg/dL, Cr 2.2mg/dL, LDH 941IU/L, CK 696IU/L were resulted. In arterial blood gas analysis, pH 7.39, pCO₂ 30mmHg pO₂ 86mmHg, HCO₃ 18.4mEq/L, O₂ saturation 96.7% were resulted. In urinalysis, specific gravity 1.025, protein 3+, erythrocyte 2+ were resulted. In brain imaging study, brain CT finding was normal. After appropriate treatments with rapid cooling, hydration and supportive care, he improved with alert mental status. On 2nd hospital day, in laboratory result, thrombocytopenia and coagulopathy were appeared and renal insufficiency was aggravated. So he was treated with platelet concentrate and fresh frosen plasma for DIC, and enough hydration for appropriate urine volume preservation. After all, On 22nd hospital day, he fully recovered and discharged. Nowadays, with followed for some duration, he is wellbeing with no complications.

[환경] 음용 원수의 염소소독에 의한 소독부산물 생성패턴에 관한 연구 Ⅱ

이강진(Kang Jin Lee1),홍지은(Jee Eun Hong),표희수(Heesoo Pyo),박송자(Song-Ja Park),유제강(Je Kang Yoo),이대운(Dae Woon Lee) 한국분석과학회 2004 분석과학 Vol.17 No.1

혈액 투석 환자에서 중심정맥 협착에 대한 스텐트 삽입술 : Wallstent Placement

임대승,노상필,이유선,정승현,김보영,이정우,강정아,김정희,이민수,정준용,최시완,정진옥,성인환,이강욱,신영태 충남대학교 의과대학 의학연구소 2002 충남의대잡지 Vol.29 No.1

Stenosis of central vein is a common complication arising after percutaneous subclavian vein catheter insertion performed for temporary vascular access in chronic renal failure patients undergoing hemodialysis. There are several treatment methods for the condition like percutaneous angioplasty(PTA), stent insertion, and surgery, but recent trend is toward PTA and stents. Among the patients diagnosed with chronic renal failure from March 1993 to May 2002 and undergoing hemodialysis through AV fistula, the 14 Patients in whom central vein stenosis arose were selected for the study. A total of 28 percutaneous interventions(5 PTA and 23 stent placement) were performed, and restenosis rate and the time taken till the restenosis in de novo lesions and instant lesions were compared. All 28 cases were operated successfully. The 14 cases that received both anigioplasty and stent placement initially. (de novo lesion : 14 cases), Among the 10 cases with de novo lesion that followed up more than 1 year, 3 cases are currently undergoing hemodialysis without restenosis, and the remaining 7 cases have recurred stenosis with the mean time to restenosis of 10.9 months. In the 7 cases in whom stenosis recurred, 11 interventions were done(instent lesion: 11 cases). 4 of these were using only ballon angioplasty with 100% restenosis rate and the mean time of 3 months until restenosis. The remaining 7 cases were using both balloon angioplasty and stent placement, also with 100% restenosis rate but with the mean time of 12 months until restenosis, which was later than the group receiving only balloon angioplasty. In treating the patients with central vein stenosis, stent placement seems to be more advantageous over PTA in terms of restenosis rate and the mean duration of patency. In the case of instent lesion, inserting the stent for the second time after stenosis recurred lengthened the duration of patency compared to performing balloon angioplasty alone.

Toluene, Xylene, Trichloroethylene 투여가 흰쥐의 시상하부와 뇌하수체의 GnRH, GnRH Receptor, Pit-1 유전자 발현에 미치는 영향

기노석,이종태,강대성,김대환,이채관,이헌,전진호,김정호,이채언 大韓産業醫學會 1998 대한직업환경의학회지 Vol.10 No.2

The workplace exposure of chemicals has steadily increased, therefore the concern for subsequent effect on reproductive outcome has been an important issue in occupational medicine. In previous studies, higher rates of spontaneous abortion, reduced fertility and menstrual disorder among women, and an impairement of sperm quantity and quality among men have been associated with a wide variety of chemical agents. This study was conducted to evaluate the effects of toluene, xylene and trichloroethylene(TCE) injection on the mRNA levels of GnRH, GnRH receptor and Pit-1 genes in male rats hypothalamus and pituitary and the effects on the plasma levels of FSH, LH, prolactin and testosterone. Sprague-Dawley male rats were divided into five groups of five each according to concentration of toluene, xylene and TCE. The rats were injected subcutaneously to 0, 50, 100, 200, 400 mg/kg body weight/day of toluene, xylene and TCE, respectively for 6 days. Rat brains were excised and hypothalamus and pituitary were separated. Reverse transcription-polymerase chain reaction (RT-PCR) and RNase protection assay(RPA) were used to evaluate the GnRH, GnRH receptor and Pit-1 mRNA levels. Plasma concentrations of FSH, LH, prolactin and testosterone were assayed by radioimmunoassay(RIA). The results were as follows; 1. GnRH, GnRH receptor and Pit-1 mRNA levels in toluene and xylene injected groups, and GnRH receptor mRNA levels in TCE injected group were lowered dose-dependently. Especially, GnRH receptor and Pit-1 mRNA levels in 200mg/kg of toluene injected group, and GnRH, GnRH receptor and Pit-1 mRNA levels in 400mg/kg of toluene injected group were significantly lower than control group (p<0.05). GnRH receptor and Pit-1 mRNA levels in 400mg/kg of xylene injected group, and GnRH receptor mRNA levels in 400mg/kg of TCE injected group were significantly lower than control group(p<0.05). 2. The plasma levels of prolactin and testosterone in 400mg/kg of toluene injected group, and LH in 100, 200 and 400mg/kg of xylene injected group, and testosterone in 400 mg/kg of TCE injected group were significantly lower than control group(p<0.05). In conclusion, we speculated that toluene and xylene affected reproductive system secondarily through hypothalamus-pituitary axis, and TCE affected directly through steroidogenesis. And we recommended that further study for assessment of the reproductive toxicity of mixed organic solvent exposures should be conducted.

간세포암과 감별이 어려웠던 악성중피종 치험 1예

김선문,허원석,채경훈,강윤세,정재훈,김연수,박기오,문희석,이엄석,김석현,성재규,이병석,이헌영,신경숙,조준식,송인상,강대영 충남대학교 의학연구소 2003 충남의대잡지 Vol.30 No.2

Malignant peritoneal mesothelioma is a rare neoplasm that arises from the mesothelium of a serosal cavity and is a rapidly fatal disease with a median survival of 4 to 12 months for untreated cases. Recently, we experienced a case with malignant peritoneal mesothelioma who was suspected hepatocelluar carcioma by abdominal CT scan and was confirmed by biopsy including immunohistochemical stain(calretinin) after surgery. We performed tumor excisions and wedge resection of the liver(segment Ⅷ)and inserted Tencoff catheter in abdominal cavity at 25th day of post-operation. We treated with intraperitoneal paclitaxel(25mg/m^(2)/day for 5 days) six courses monthly. She was well tolerable and is still living without any evidence of recurrence for 14th month of post-operation.

플라톤의 『Meno￣n』에서의 가설(Hypothesis)적 방법

이강대 圓光大學校 社會思想硏究所 1993 社會思想硏究 Vol.3 No.-

過量의 鹽分攝取가 白鼠腎臟 動脈에 미치는 影響에 對한 病理學的 硏究

李忠植,姜大榮 충남대학교 의과대학 지역사회의학연구소 1984 충남의대잡지 Vol.11 No.1

There are considerable data which indicate that the high salt intake is important or necessary to the development of hypertension in man and animals, and the low-salt diet is effective lowering the blood pressure. This study is made to evaluate the morphologic changes of small arteries on high-salt diet and salt-restrction in rats. Male albino rats were fed different amount of salt (0.06;%, 0.4%, 4. 0%, 8.0% of NaCI) for 2-20 weeks and changes of arterial calibers of different sized arteries are studied. The results were as follows: 1. In salt-fed groups, the arterial walls reveal medial thickening due to hyperplasia of smoo muscle cells, especially in medium-(4.0%) and high-salt(8.0%) groups. 2. There is no significant differences of external-to-luminal diameter(ED/LD among three rena arterial types with each experimental group(p>0.1). 3. In salt-fed groups, increment of ED/LD ratio in comparison to the control group is significant in all arterial types of medium-and high-salt groups (p<0.01), but insignificant in low-salt(0.4%) group (p>0.05). 4. Restriction of salt intake after 10 weeks salt feeding did not reverse altered ED/LD ratio in all arterial types (p>0.05). In summary, the results obtained by present study indicate that intake of a large amount of salts bring about hyperplastic thickening of the wall of renal arterial system with comparative narrowing of the lumen, and that these changes persist even after the restrictction of salt intake.