Fabrication and High-Temperature Compressive Behavior of Unique Multi-Sheet Stacked Block Ni–Cr–Al Metallic Foam

Kyu‑Sik Kim,Tae‑Hoon Kang,박만호,Kee‑Ahn Lee 대한금속·재료학회 2021 METALS AND MATERIALS International Vol.27 No.5

Large unique block Ni–Cr–Al superalloy foam was fabricated using a combination method of powder-alloying, multi-sheetstacking, and hot compression processes. Subsequently, the compressive properties and deformation behaviors of multi-sheetstacked block metallic foam were investigated from room temperature to 1073 K. The analysis of the resulting structuralcharacteristics of the block foam showed that the interfaces between the sheets have complex strut interactions, such ascontacted (deformed) and intersected struts. The relative density was measured as 2.93% for sheet foam and 4.90% for blockfoam. The compressive deformation of sheet and block Ni–Cr–Al foams showed the typical compressive stress–strain curvesof plastically deformable metallic foams regardless of foam type. However, different deformation behaviors in the plateauregions were detected based on the type of foam. It is noteworthy that the yield strength of block foam showed a relativelylower value than that of sheet foam, even though the block foam had higher relative density. The existence of unique interfacesin the multi-sheet stacked block foam may have affected strength and plastic deformation. Finally, distinct compressivebehaviors related to the structural and microstructural characteristics of block Ni–Cr–Al foam are discussed.

복막유착의 원인 규명과 예방을 위한 실험적 연구

강대영,송규상,노승무,조준식,이태용 충남대학교 의과대학 지역사회의학연구소 1999 충남의대잡지 Vol.26 No.1

Postoperative peritoneal adhesion is the most common cause of intestinal obstruction, and intestinal obstruction is one of the most difficult problems in abdominal surgery. In this experimental study for developing peritoneal adhesion model and its prevention, we divided rats into 5 groups; the talc powder treated group, the cotton-fluff treated group, the talc+fluff treated group, the ischemia group and the control group. There were 16 rats in each group. We made incisions on the midabdomen of the rats and administered talc powder, cotton fluff and talc powder+fluff into the peritoneal cavity respectively. In the ischemia group, we clamped the root of superior mesenteric artery for two minutes to induce ischemia on the small bowel of the rat. We counted the number of the peritoneal adhesive sites in peritoneal cavity on the 7th, 14th , 21st and 42nd postoperative day after peritoneal adhesion induced operation, and observed the characters of the adhesion state. The average number of the peritoneal adhesions were 1.25 per one rat in the talc powder group, 1.44 in the fluff group, 1.31 in the talc+fluff group and 1.31 in the ischemia group compared with 0.94 per one rat in the control group performed sham operation. 91.6% of the all adhesions were observed on the peritoneum of the previous incision sites and only 8.4% of the adhesions were adhered to the peritoneal surface of non-incision sites. The data of this study suggest that peritoneal injury and inflammatory reaction is the major cause of peritoneal adhesion. Also this study indicates that foreign bodies can develop peritoneal adhesion, but the effect is much lower than that of peritoneal injury with inflammatoty reaction.

독성물질의 세포사 기전 및 세포사 유발물질의 검색법 개발에 관한 연구(Ⅰ) : 독성물질로 인한 파킨슨병 모델에서의 세포사 기전 연구 Study on the cell-death mechanisms of toxin-induced parkinsonism

강태석,김종민,서경원,김영옥,김준규,오재호,이윤동,김규봉,오정자,송연정,임종준,전범석,문전옥,최광식 식품의약품안전청 2000 식품의약품안전청 연보 Vol.4 No.-

MPTP 독성물질이 도파민성 신경세포에 선택적으로 작용하여 산화성 손상에 의한 신경세포사를 일으키는 것을 이용하여 파킨슨병의 동물모델을 만들고, 이를 통해서 아폼토시스를 비롯한 포사의 기전에 대한 연구 및 너코틴의 신경세포 보호효과 여부를 판정하는 실험을 병행하고자 하였다. 파킨슨꾐의 동물모델을 MPTf 독성 물질을 이용하여 확립하였으며, MPTP(30mgag, i.p.)를 투여한 후 1, 2,3, 4, 5일째 흑질 조직을 채춰하여 tarm로 박걸하여 tyrosine hydroxylase 면역조직화학염색을 수행하여 cell countif우한 결과, control은 57.635ce11s, 1일째 친.OfDells,2일째 57.9±6cells,3일릴 없.3±죠ells, 4일째 49.0츠3cells, 5일째 39.4±Scells료 4, 3일째 뚜렷한 신경세포 수의 감소를 보였다. 신경세포사 기전 규명을 위한 아폼토시스 분걱에서는 벼PTP 투여 후 1, 2, 3, 4, 5일째 조직을 채취하여 Hoechst staining, TUNEL staining을 수곡하였는데 양성 반응을 보인 신경세포는 관찰되지 않아. 아폼토시스로 인한 세포사가 관찰되지 않았다. bIPTP 파킨슨병 동물모델에서 nicotine 보호효과 탐색에 관한 실험은 nicat푸e 0.2mgAg을 5일 퐁안 투여 후 리『fP(30mgag)를 CS7Bt/6 마은스에 복강 내주사로 nicotine과 병용 투여한 후 1, 2, 3, 4, 5일째 뇌를 적출하땄다. 신경세포사가 뚜렷이 관찰되기 시작하는 4, 5일째의 신경세포 수의 감소 정도를 20. 30% 정도 약화시키는 경향을 보였으나, nicotine 보호효과에 대한 추가 실헝이 현재 수행 중에 있다. The cause of Parkinson's disease (PD) is largely unknown. However, free radical toxicit? may plaf a role ip. the degeneration of substantia nigra, which is the Hajorfocus of pathological damages in PD. Recently, a neuroprotective effect of nicotine in PD has been suggested. Therefore, the mechanism of neurodegenerafion and protective potential o( nicotine in PD were investigated in the experimental modeB of Pll using a neurotoxin, C57BL/6mice were administered with 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP, 30 mg/kg,j.p.). The degree of neurodegenerafion was determined by immunohistochemical stainiHB oftyrosine hydroxylase (TH). TH-positive cells on nigral sections were found 56.0 ±4, 57.9 ±6,52.315ce11s, 49.0±3cells, and 39,4±Scells at days 1, 2, 3, 4, 5, respectively (controls : 57.6±Scells). Hoechst and TUNEL staining showed no evidence of apoptosis. The exandnation on themice co-adrunistered with nicotine(0.2mgAg) and MPTP(30mgag) revealed a tendency ofnicotine protective effects. At days 4 and 5, the degree of TH-positive cells was decreased by20-30%, In corclusiffn, the role of apoptosis was not evidenced in this MPTP modeB of PB.The possible proteccon by nicotine should be elucidated with further studies.

당뇨병 백서의 간세포에서 Glucokinase 활성도 및 유전자 발현에 대한 인슐린의 영향

강성이,팽정령,서광식,안규정,우정택,김성운,양인명,김진우,김영설,김광원,최영길 경희대학교 유전공학연구소 1993 遺傳工學論文集 Vol.5 No.-

목적 당대사의 조절 상태에 따른 생체 변화를 분자 수준에서 이해하고자 식이 조건을 달리한 정상 백서와 화학적으로 유도된 당뇨병 백서의 간조직에서 혈당수준과 인슐린치료 정도에 따라 나타나는 글루코키나제 활성도 및 유전자 발현을 분석하였다. 방법 스트렙토조토신 정맥투여 후 당뇨병의 유발을 확인하고, 인슐린을 1일 3회 3일간 복강내로 투여하여 상태를 안정시킨 후, 인슐린 투여군은 인슐린 투여 6시간이내에 그리고 인슐린 비투여군은 24시간 후 단두하여 채혈하고 복강을 열어 간조직을 채취하였다. 채취한 간조직에서 글루코키나제 활성도는 인산화된 포도당에서 NADH의 형성을 형광분광계로 측정하였으며, 글루코키나제 유전자 mRNA발현은 Northern 분석법을 이용하였다. 성적 정상 백서에서 공복상태와 식이를 섭취한 경우에 간조직의 글루코키나제 효소의 활성은 차이가 없었으나, 글루코키나제 유전자 mRNA 발현은 증가되었다. 당뇨병이 유발된 백서의 간조직에서 글루코키나제 효소의 활성 및 글루코키나제 유전자의 mRNA 발현은 정상 백서에 비하여 낮았다. 인슐린 투쳐 후 글루코키나제 효소의 활성 및 글루코키나제 유전자의 mRNA 발현이 증가되었고, 특히 혈당이 정상화된 경우에서 글루코키나제 유전자의 mRNA 발현이 증가도었다. 결론 인슐린에 의한 간조직에서 글루코키나제 효소의 활성 및 글루코키나제 유전자의 mRNA을 증가를 볼수 있었다. 당뇨병 백서에서 인슐린 투여 후에 혈당조절이 안된 경우 간조직의 글루코키나제 유전자의 mRNA 발현이 증가가 없는 것으로 보아 글루코키나제 mRNA의 발현에는 인슐린 이외의 다른 요소가 관여할 것으로 생각된다. The liver-specific hexokinase isoenzyme, referred to as glucokinase, is thought to play a key reglulatory role in hepatic glucose metabolism. The glucokinase gene is, therefore, of interest both because of its tissue-specific expression and because of the several regulatory processes that can be analyzed. The level of hepatic glucokinase activity appears to be determined essentially by regulation of the rate of enzyme synthesis, with insulin playing a leading role as an inducer. We investigated the role of insulin for the induction of glucokinase in the liver of diabetic rats. Experimental diabetes was induced by injection of streptozotocin 7 days before the experiment. Regular insulin was given by three days intraperitoneal injection at 8-h interval. The glucokinase mRNA in the liver was estimated by Nothern blot assay, as well as by fluorometric enzyme activity assay. Glucokinase activity was not reduced in the liver of normal fasting rats as compared to normal fed rats. And glucokinase activity was reduced in the liver of diabetic rats as compared to normal rats. In diabetic rats treated with insulin, glucokinase enzyme activity were increased. But glucokinase mRNA expression was only increased in normoglycemic diabetic rat with treated with insulin as compared to hyperglycemic rat. These data indicate that insulin stimulates hepatic glucokinase enzyme activity and mRNA expression. But other hormonal or metabolic factors may be contribute to regulation of glucokinase mRNA expression.

Cyclophosphamide가 Mouse 肝臟의 燐酸鹽 分解酵素 活性에 미치는 影響

강성준,이군자,정호삼,이규식 한양대학교 의과대학 1985 한양의대 학술지 Vol.5 No.2

Cyclophosphamide which is known as a widely used anticancer drug is very effective against a lymphosarcoma, leukemia and nonneoplasmic diseases such as rhematoid arthritis and lupus erythematosus. Cyclophosphamide acts on a DNA as a alkylating agent inhibiting the cell division and growth. And it is also known that metabolites of cyclophosphamide damages the liver cell. The authors have, therefore, undertaken to pursue the effect of cyclophosphamide on the phosphatase activity in the liver. Albino mice, DDY strain, weighing 20gm were used as experimental animals. The experimental animals were administered daily with 200gm of cyclophosphamide per kilogram of body weight were divided into 7-day treatment group and 10-day treatment group. The specimens obtained from the liver were fixed with 10% formalin and sliced at 16 μm thickness in a frozen cryostat. The activity of alkaline phosphatase was observed by the Gomori's method and activity of the adenosine triphosphatase was observed by the Wachstein-Meisel's method for histochemical study. The results were as follows. 1. Alkaline phosphatase activity of the hepatic lobule was moderately positive at the periportal and intermediate zone of the 7-day cyclophosphamide treatment group and trace activity of alkaline phosphatase was observed at the periportal and intermediate zone of the 10-day cyclophosphamide treatment group. 2. Adenosine triphosphatase activity of the hepatic lobule was moderately positive at the periportal, central and intermediate zone of the 7-day cyclophosphamide treatment group and weakly positive at the central and periportal zone of the 10-day cyclophosphamide treatment group.

인슐린 비의존형 당뇨병성 케톤산증 환자의 마취경험 : 증례보고 A case report

강규식,김난설,김지은 순천향의학연구소 2004 Journal of Soonchunhyang Medical Science Vol.10 No.2

The most serious acute complication of DM is diabetic ketoacidosis (DKA). Medical and surgical illnesses account for 50% of episodes of DKA. Infection, myocardial infarction, cerebral vascular accidents, gastrointestinal bleeding, trauma, pancreatitis, and burns are the most common medical causes. The mortality rate from DKA has been reduced to less than 5%. Patients with insulin-dependent diabetes mellitus (IDDM) are more prone to DKA than those with noninsulin-dependent diabetes mellitus (NIDDM). Older diabetics account for approximately 75% of patients who present with DKA. The signs and symptoms of DKA result from hyperglycemia or ketoacidosis. We report a case of anesthetic management of a patient with noninsuline-dependent diabetic ketoacidosis after trauma.

졸-겔 공정에 의한 실리카-지르코니아 복합 분말 합성

강성,박규섭,배동식 국립7개대학공동논문집간행위원회 2005 공업기술연구 Vol.5 No.-

Silica-zirconia composite nanoparticles have been synthesized by a metal alkoxide hydrolysis and condensation. The size and composition of the synthesized particles can be controlled by manipulating the relative rates of the hydrolysis and condensation reaction of precursor. The average size of range of synthesized silica-zirconia composite nanoparticles was about in the size range of 30-100nm. The effects of synthesis parameters, such as the molar ratio of water to precursor and the molar ratio of water to surfactant, are discussed.

Rat의 복강내에 투여한 5-fluorouracil-polyglycolic acid 제형이 장기에 미치는 영향에 관한 연구

강대영,송규상,최정목,노승무,정경수,오정연,김진향,양준묵,최선웅,이진호,조준식,민병무,김용백,김창식,박근성,김승영,김학용,인현빈 충남대학교 의과대학 지역사회의학연구소 1998 충남의대잡지 Vol.25 No.1

For more effective intraperitoneal chemotherapy, the authers made 5-fluorouracil-polyglycolic acid composite disks(FU-PGA disks) with 5-fluorouracil and polyglycolic acid, a biodegradable polymer. We inserted the FU-PGA disk into the peritoneal cavites of Sprague-Dawley male rats, the control and three experimental groups; one FU-PGA disk insert group(300mg/kg), two FU-PGA disk insert group(600mg/kg), and three FU-PGA disk insert group(900mg/kg). The control group received a similar number of PGA disk inserts. A pharmacokinetic study was performed to measure the 5-fluorouracil concentration in the peritoneal fluid, blood, and tissues(liver, kidney and heart) at 24 hours, 72hours and 168 hours after insertion of the FU-PGA disk. Light and electron microscopic studies were done. The results were as follows: 1) The number of white blood cells and platelets decreased after FU-PGA insertion. The degree was proportional to the duration and amounts inserted. The change in the number of red blood cells varied slightly. 2) Light microscopically, slight changes were noted at 168 hours in the 3 disk insert group (900mg/kg). Mild fatty change and hepatocyte degeneration around the central veins of the liver were noted, with vacuolar degeneration in the proximal convoluted tubules of the kidney. 3) Electron microscopically,the liver showed focal increases of lipid droplets in the hepatocytes, and irregular nuclear membrane with focal nucleolar segregation of the fibrillar and granular elements. Also the double membranous structure of the hepatocytes and Kupffer cells was widened with bleb formation. The kidney showed wide separation of the nuclear double membrane in the proximal convoluted tubular cells and mesangial cells, with vacuolation and myelin figure formation in the mitochondria of the proximal convoluted tubular cells, at 72 hours and 168 hours in the 2 to 3 FU-PGA insert groups. The heart showed focal loss of cristae,vacuolation and myelin figure formation in the mitochondria of the 2 to 3 FU-PGA insert groups. In conclusion, despite the large amont of FU-PGA inserted, the histopathological changes in the liver, kidney and heart were slight, and consonant with the very low amount of 5-fluorouracil concentrations detected in the liver, kidney and heart. The above results suggest that the FU-PGA composite can serve as a new device for releasing drugs in a controlled manner and easily targeted to intraperitoneal organs. This device can improve the efficacy of intraperitoneal chemotherapy for gastric cancer.

후복막강 부신경절종 적출시 Nicardipine과 Esmolol을 사용한 마취관리 : 증례보고 A case report

강규식,김덕,김천숙 순천향의학연구소 2004 Journal of Soonchunhyang Medical Science Vol.10 No.2

Paragangliomas are tumors arising from the neuroendocrine elements (Chief cells) of the paraganglia. Paragangliomas are uncommon tumors and are infrequently found in the extraadrenal retroperitoneum. We investigated and treated a patient with retroperitoneal paraganglioma, which was found incidentally at abdominal computer tomograhy. It was confirmed by pathological study. We report a case of retroperitoneal paraganglioma successfully managed intraoperatively with an infusion of nicardipine and an intermittent esmolol injection.

누두흉 환자에서 Nuss 금속막대 제거 전 · 후 폐 역학 변화

강규식,백남순,김천숙,안기량,권진형,김지은,유시현 순천향의학연구소 2003 Journal of Soonchunhyang Medical Science Vol.9 No.1

Nuss operation is one of the surgical procedure for pectus excavatum and it's method is the insertion of convex steel bar under the sternum through small bilateral thoracic incision. As the patients is growing, the thorax can be compressed gradually by steel bar. So Nuss bar needs to be removed two years after Nuss operation. This study was undertaken to assess the effect on the repiratory mechanics before and after the removal of the Nuss bar. Twenty patients with previous Nuss operation were allocated for the removal of Nuss bar. Lung mechanics (dynamic lung compliance, static lung compliance, and airway resistance), hemodynamic change (heart rate, systolic pressure, and diastolic pressure), and pulmonary gas exchange (arterial oxygen tension, arterial carbon dioxide tension, pulse oximeter saturation, and end tidal carbon dioxide tension) were measured before and after removal of Nuss bar. Respiratory mechanics (dynamic and static lung compliance, inspiratory airway resistance), pulmonary gas exchange and hemodynamic parameter were unchanged before and after the removal of Nuss bar. We concluded that lung mechanics were not changed before and after the removal of Nuss bar in the patients with pectus excavatum and the 95% patients were satisfied with operation.