심혈관계 질환으로 관상질환 집중치료실에 입원한 환자들의 혜후 측정을 위한 APACHEⅢ점수 체계의 임상적 유용성

이공섭,이창선,최현주,홍종서,강지향,김도형,이민영,오인균,김병엽,김상억,김학찬,한승혜,이재용,지영우,안경주 대한순환기학회 2000 Korean Circulation Journal Vol.30 No.8

Effects of Pilger Rolling and Heat Treatment on Microstructure and Corrosion Resistance of Ag-electroplated 304 Stainless Steel Tubes

Hyun Park,Woo‑Jin Lee,Jae‑Han Son,Han‑Kyun Shin,Sung‑Kyu Hong,Hyo‑Jong Lee 대한금속·재료학회 2022 METALS AND MATERIALS International Vol.28 No.8

We introduce a cost-effective method that combines electroplating with metal cold working processes to manufacture compositetubes with robust corrosion resistance. First, a 3-step electroplating process was developed to form an adhesive anduniform Ag coating on the outer wall of a 304 stainless steel tube. The process consisted of a Ni-strike step for removing thepassivation layer of the initial 304 tube, Cu deposition for smoothing the surface by adding a buffer layer, and Ag deposition. To reinforce the interfacial adhesion between the electroplated layers and the 304 tube and increase the area of the Ag coating,a pilger rolling or pilger rolling + heat-treatment process was performed after the Ag electroplating process. Scanningelectron microscopy of the composite tubes after each process indicated that the as-deposited Ag coating changed fromhaving a rough to smooth surface after only pilger rolling and with additional heat treatment. Electron backscatter diffractionanalysis of the microstructures and textures of the tubes revealed that dynamic recrystallization occurred extensively duringpilger rolling, resulting in the formation of a relatively defect-free grain structure without heat treatment. Furthermore,electrochemical polarization curves determined that the Ag-coated composite tubes are superior to the uncoated 304 tubein terms of corrosion resistance under Cl−atmosphere, owing to the formation of a AgCl passivation layer during testing. Surface analysis of the composite tubes suggests that the properties of the AgCl passivation layer are related to the grainsize of the Ag coating and the density of plastic-deformation-induced defects.

정상 및 Phenylhydrazine으로 처치한 토끼 적혈구의 Adenosine Deaminase Isozymes의 활성도에 관하여

李鉉國,車鍾希,李奉宰,金良均,李根培 조선의대 1984 The Medical Journal of Chosun University Vol.9 No.1

Streptokinase와 Plasminogen의 활성 복합체에 대한 생화학적 특성

이현재,전형균,이해진,김태성,김연웅 慶尙大學校 1988 論文集 Vol.27 No.2

Fig 1과 Fig 2의 실험 결과에 의하면 streptokinase에 의한 plasminogen의 활성화 기작은 먼저 streptokinase와 plasminogen 결합하여 복합체를 만들고 그 다음 다른 분자의 streptokinase에 의한 plasminogen을 streptokinase에 의한 plasmin으로 활성화 한다고 생각되었다.그리고 원래 효소활성이 없는 streptokinase량이 plasminogen보다 과량으로 존재하게 되면 전체 esterolytic 활성도는 plasminogen 의 량에 의존하게 될 것이다.Fig 3의 실험에서 streptokinase plasminogen 복합체의 정량적인 구성 비율을 조사하였더니 plasminogen 1㎍에 0.5㎍의 streptokinase가 결합하였다. 이는 보고된 plasminogen의 분자량을 87.000(10) 그리고 streptokinase분자량이 47.000(6)으로 계산하면 각각 한 분자씩 결합하고 있음을 알 수 있었다. 이 결과는 Fig. 1의 결과를 보충할 수 있는 data이다. streptokinase plasminogen 복합체의 생화학적 특성을 조사하기 위하여 복합체만의 활성을 assay 할 수 있는 방법을 고안하였다. 실험결과 soybean trysin inhibitor를 사용하면 plasminogen의 활성화에 의하여 생성된 plasmin의 esterolytic 활성은 완벽하게 저해할 수 있었으나 streptokinase plasminogen 복합체의 활성은 저해하지 못하였으므로 soybean trypsin inhibitor를 첨가하여plasmin활성을 제거하여 순수한 복합체만의 활성을 측정할 수 있었다.(Fig.5).그러나 pancreatic tyrpsin inhibitor는 Plasmin 뿐만 아니라 streptokinase plasminogen복합체의 활성을 모두 저해할 수 있었으므로 이 inhibitor 는 복합체의 활성을 측정하는데 사용하지 않았다. (Fig.4). 두가지 inhibitor의 복합체에 대한 상이한 저해 효과는 복합체의 활성화 자리 (active site)에 두 inhibitor 가 결합하고난 후 기질이 출입할 수 있는 공간의 넓이에 의한 효과인 것으로 생각되었다 (Table 1).따라서 soybean trypsin inhibitor을 이용한 assay는 원래의 생화확적 특성에 영향이 없는 것으로 생각되었다. 복합체의 esterolytic 반응은 빠른 첫 번째 반응 그리고 그 이후 늦은 두 번째 반응으로 진행되는 biphasic한 형태를 보여 주었다(Fig.7).이 반응 기작은 알려진 serine protease들이 acyl중간체을 이용한 biphasic 반응 기작과 유사한 형태이었다. 활성화 자리에 위치하고 있는 여러 작용기들을 확인하기 위한 기초 실험으로써 pH에 따른 esterolytic활성을 측정한 결과 최대 활성을 보이는 pH는 7.5이었다.(Fig.8). 이 근처의 pKa 값을 가지고 아미노산은 histidine 종류을 생각할 수있을 것이다. The kinetic data suggest that streptokinase interacts with plasminogen to become an active complex which in turn. activates another molecule of plasminogen to plasmin. This complex was fromed stoichiometrically at 1:1 molar ratio. A series of experiment were carried out to find the condition that the streptokinase plasminogen complex activities free from plasmin could be monitered. The soybean trypsin inhibitor wsas used to assay the activity of streptokinase-plasminogen complex. The lack of inhibiton of esterase activity by soybean trypsin inhibitor was thought to be the size of the protein in active site. The esterolytic reaction by streptokinase-plasminogen complex showed biphasic pattern. The pH profile showed typical bell-shape and optimal pH for streptokinas-plasminogen complex showed biphasic pattern. The pH profile showed a typical bell-shape and optimal pH for streptokinas-plasminogen complex was 7.5.

Fe/Si(100) 2×1의 초기 계면에 대한 연구

이상균,장현덕,오진호,박종윤 성균관대학교 기초과학연구소 1995 論文集 Vol.46 No.1

Si(100) 2×1 표면 위에 SPE 법으로 성장된 철 실리사이드의 형성에 대해 연구하였다. 성장된 박막은 중착량과 열처리 온도에 따라 XPS와 RHEED를 사용하여 특징 지워졌다. 상온으로 유지되는 기판 위에 증착 직후의 Fe 층은 Stranski-Krastanov의 성장모드에 따라 성장하였다. low coverage(6분)로 증착한 후, 400℃로 열처리한 시료에서 spotty 2×2 RHEED 패턴이 관측되었다. 이는 매우 낮은 coverage에서도 실리사이드가 형성됨을 확인시켜 주는 결과이다. 또, medium coverage(45분)로 증착된 후, 400℃에서 열처리한 시료에서는 매우 streaky한 패턴이 관측되었다. 이 streaky 패턴은 적층 박막의 매끄러운 표면을 의미한다. 선호되는 박막의 적층 성향은 방위각 편향 β-FeSi_2[010]//Si<110>를 갖는 β-FeSi_2(100)/Si(100)이며, A-type으로 정의되어진다. high coverage에서는 여러 실리사이드가 형성되었으나 RHEED 패턴은 diffuse spot과 높은 background만이 관측되었다. 이는 형성된 실리사이드가 기판과 적층 성장을 하지 않음을 나타낸다. 청정한 Si(100) 2×1으로의 회복은 1100℃ 이상의 온도에서 실현되었다. The formation of the iron silicide grown on Si(100) 2×1 by SPE have been studied accordingly to the changes of Fe deposition amount and annealing temperature using XPS and RHEED. The as-deposited Fe layer was grown with a Stranski-Krastanov growth mode. At the low coverage, the spotty 2×2 RHEED pattern was observed at 400℃. Thus we confirm the formation of the β-FeSi_2 even at the low coverage. At the medium coverage, the RHEED pattern at 400℃ was very streaky 2×2. This well-developed streaky are characteristic of a smooth surface of an epitaxial film. The preferred epitaxial relationship was found to be β-FeSi_2(100)/Si(100) with β-FeSi_2[010]//Si<110>, which is referred to the A-type orientation. At the high coverage, several silicides were observed, but the RHEED pattern of diffuse spot and high background were observed, which means that the silicides did not form the epitaxy with the substrate. Clean Si(100) 2×1 was recovered after annealing at 1100℃.

구치부 반대교합의 조기치료에 대한 치험례

이은미,강동균,김태완,김영진,남순현,김현정 大韓小兒齒科學會 2008 大韓小兒齒科學會誌 Vol.35 No.2

구치부 반대교합은 유치열기와 혼합치열기에서 종종 나타나는 부정교합으로서,유병율은 7∼23%로 다양하게 나타난다. 이는 상악 치아의 협측 교두가 대합되는 하악 치아의 협측 교두의 설측에 교합하는 상태이며,하나의 치아 또는 한 치아군에서 나타날 수 있다. 구치부 반대교합의 경우, 보통 자발적 교정이 이루어지지 않으므로, 발견되는 즉시 치료해주는 것이 추천된다. 치성이나 기능성의 경우 성장함에 따라 골격성으로 이행하여 악골의 변형을 초래하고 교정적인 수단으로 개선이 불가능한 상태로 악화될 가능성도 있으므로 조기에 치료하는 것이 효과적이며,이러한 반대교합의 치료 방법으로는 하악의 변위를 유발하는 조기접촉을 제거하기 위한 교합조정,협소한 상악궁의 확장,치열궁내 비대칭을 치료하기 위한 개개 치아의 배열 등의 방법이 있다. 본 증례에서는 유치열기와 초기 혼합치열기 아동에서 구치부 반대교합이 관찰되어 치아의 선택적 삭제와 상악궁의 확장으로 반대교합을 교정한 후 정기적 검진시 양호한 결과가 관찰되기에 이를 보고하는 바이다. Posterior cross-bite is a relatively frequent malocclusion in primary and early mixed dentition and the reported prevalence of posterior cross-bite varies from 7% to 23%. It has been defined as a transverse discrepancy in arch relationship which the palatal cusp of the upper posterior teeth do not occlude in the central fossa of the opposing lower teeth, and can be manifested in a single tooth or in a group of teeth. Posterior cross-bite does not often self-correct and therefore immediate treatment is recommended. Occlusal adjustment to eliminate premature contact that causes mandibular deviation, expansion of narrow maxillary arch, arrangement of the individual teeth to treat asymmetry within the dental arch are the methods of treating cross-bite. In the present case, functional posterior cross-bite was observed in the primary and the early mixed dentition children. The children were treated by the slow maxillary expansion and occlusal adjustment. The outcome of periodic examinations after the correction of cross-bite was favorable.

인터넷 기업가치평가에 관한 연구

이균봉,손명현 釜山大學校 商科大學 2002 釜山商大論集 Vol.73 No.-

This study is to valuate the internet corporate listed on KOSDAQ. The traditional valuation method based on only historical accounting incomes is not fully adequate for evaluation of internet corporate. Though the initial growth rates of internet companies are very high in their early stages, their operating incomes are very low because of high marketing and investment expenditures. This study was conducted on the samples of 42 firms that have reported their ratios of sales changes in individual company level for 3 years listed on KOSDAQ in 2000. Black-Scholes' option pricing model and DCF model were used to test the difference between the estimated corporate value in this study and real stock price. The result of study is as follows : There is no difference between estimated stock price by option model and real stock price. The result shows the stock price estimated by DCF model didn't explain real stock price. The sensitivity analysis by variables in both model indicates that DCF model is more sensitive than option model. DCF model consist of 4 estimated variables, while option model has only one. It can be interpreted that DCF model produces bigger variable measurement errors compared to option model. But option model is more appropriate to value the internet company's stock price than DCF model.

체외충격파 쇄석술 시행 후 5년 뒤 발생한 요관 협착 및 농신장 1예

이현승,권균홍,조용건,김봉진,임창섭,김자영,허동,임학 고신대학교의과대학 2008 고신대학교 의과대학 학술지 Vol.23 No.4

A 40-years-old woman was admitted to this hospital with flank pain and high grade fever for 2 weeks. As a matter of her past history, extracorporeal shock wave lithotripsy (ESWL) was performed for treatment of renal stones 5 years ago. Her abdominal CT findings were hydronephrosis with pyonephrosis and renal stones. Antibiotics administered for 5 days had no effects on her symptom improvement. A right ureteral stricture was noticed by ultrasonography follow up. We inserted double J stent and continued antibiotics therapy for 10 days, and then her fever was disappeared and flank pain was improved. ESWL is one of the most important treatment of renal and ureteral stone. However, its complications should not be negligible including bleeding, pain, ureteral obstruction, infection and so on. Complications of ESWL can be divided into acute and chronic courses. When we treat pyelonephritis patient with past history of ESWL, possibility of ureteral stricture must also be considered. In this study we report a case of pyelonephritis caused by ureteral stricture, possibly as a chronic complication of ESWL performed 5 years earlier

복식자궁전적출술과 인공슬관절 치환술 환자에서 정맥내 자가통증조절이 수술 후 진통에 미치는 효과

최영균,남현옥,이정한,이근무,정순호,김영재,신치만 白中央醫療院 2005 仁濟醫學 Vol.26 No.1

Objective: Intravenous patient-controlled analgesia(IV PCA) is gaining wide spread popularity in the management of postoperative pain control. The purpose of this study is to evaluate the severity of pain after TAH and TKRA through comparing visual analogue scale(VAS) of pain of each patients who received identical IV PCA protocol, and to improve our IV PCA protocol. Methods: TAH group includes twenty female patients who were scheduled for TAH. TKRA group includes twenty female patients who were scheduled for TKRA. Each group received fentanyl 50㎍ about 30minutes before the end of surgery, followed by IV PCA with fentanyl 1500 ㎍, ketolorac 300mg, ondansteron 8mg, normal saline 56㎖(total 96ml, basal infusion rate 1㎖/hr, bolus dose 1㎖, lockout time 10 minutes). VAS scores were recorded at 1, 6, 12, 24, 48 hours postoperatively. Total bolus doses and patients' satisfaction were checked after the end of analgesia. Results: VAS scores of TKRA group were significantly higher than those of TAH group at 12, 24, 48 hours postoperatively. VAS scores of both group progressively decreased(P<0.05). Patients' satisfaction score showed no significant difference between two groups. Total bolus dose of TKRA group was significantly higher than that of TAH. Conclusion: The postoperative pain of TKRA was more severe than that of TAH. TKRA group needed more profound postoperative pain control than TAH group. We should consider the increase of early postoperative period analgesic doses to acquire optimal pain control of both group.

발열을 동반한 호중구감소증에서 Cefepime 단독투여와 Ceftazidime 및 Tobramycin 병합투여의 효능비교

정현욱,채제욱,강미라,양정채,문치숙,기현균,장현하,오원섭,김기현,백경란,이남용,송재훈 대한감염학회 2004 감염과 화학요법 Vol.36 No.6

목적 : 국내에서 발열을 동반한 호중구감소증이 있는 악성 종양환자에게 경험적 항생제로 베타락탐계 항생제와 아미노배당체의 병합요법의 사용이 일반적이다. Cefepime은 광범위 항균 작용을 가지고 있어, 그람 음성균 뿐만 아니라 그람 양성균에 대해서도 우수한 효과를 나타낸다. 재료 및 방법: 발열을 동반한 호중구감소증이 있는 악성 종양환자를 대상으로 무작위, 공개, 비교 연구를 시행하였다. 대상 환자를 무작위로 cefepime 단독요법군과 ceftazidime 및 tobramycin 병합요법군으로 나누어 투여하고 각각의 임상적 효능과 안전성을 비교하였다. 구강및 인후 점막염이 있는 환자에서 분리된 녹색 연쇄알 구균에 대한 항생제 내성 정도를 조사하였다. 결과 : 대상환자 89명 중 CA 투여군이 48예(53.9%), CT 투여군이 41예(46.1%)이었다. 발열의 유형별로 MDI는 18예(20.2%), CDI는 9예(10.1%), UF는 62예(69.7%)로 두 군 간에 차이가 없었다. CA 투여군과 CT 투여군의 임상적 호전률은 시험약 투여 후 2-4일째 각각 91.7%, 85.4% (P=0.31), 치료 종료 시 각각 91.7%, 100% (P=0.15)로 두 군간에 유의한 차이가 없었다. 치료 종료 시 CA 투여군과 CT 투여군의 세균학적 소실률은 모두 100%로 두 군간의 유의한 차이가 없었다(P=0.78). 점막염이 있는 환자로부터 녹색 연쇄알 구균이 분리된 경우는 25예(28.1%)이었으며, 분리된 녹색 연쇄알 구균은 penicillin, ceftriaxone, cefepime, vancomycin에 모두 감수성을 보였다. 약제 관련 이상 반응의 발생 빈도도 두 군간에 유의한 차이가 없었다. 결론 : 발열을 동반한 호중구감소증이 있는 악성 종양환자의 경험적 항생제로서 cefepime 단독요법은 ceftazidime 및 아미노배당체의 병합요법만큼 효과적이고 안전하였다. Background : Broad-spectrum antibiotic therapy has been recommended as an empirical regimen in cancer patients with febrile neutropenia. Cefepime is a fourth generation cephalosporin with good activity against both gram-positive cocci and gram-negative bacilli. Materials and Methods : To compare the efficacy and safety of cefepime alone with ceftazidime plus tobramycin as empirical regimen for adult cancer patients with febrile neutropenia, a randomized, open label, comparative trial was performed. If the patient showed clinical improvent 72 hours, antibiotic could be changed to oral ciprofloxacin. Clinical and microbiological responses were determined at 72 hours and at the end of therapy. To investigate the antimicrobial resistance of viridans streptococci, swab cultures were obtained from throat in all enrolled patients and antimicrobial susceptibility tests were performed by using microdilution method according to the NCCLS. Results : A total of 89 patients were enrolled. Forty-eight patients received cefepime alone (CA), and 41 patients received ceftazidime plus tobramycin (CT). Demographic and baseline clinical characteristics were similar in both groups (P>0.05). The initial clinical success rate at day 2-4 in group CA (91.7%) was similar with that in CT group (85.4%) (P=0.31). At the end of therapy, the final clinical success rate in CA group (91.7%) was similar to that in CT group (100%) (P=0.15). In 18 patients, with microbiologically defined infections, the eradication rate was 100% in both groups. Adverse events including liver dysfunction (21.3%) and renal dysfunction (2.2%), were similar in both groups (P=0.87). Viridans streptococci were isolated from the throat cultures in 25 cases, and all of these strains were susceptible to penicillin (MIC_(90) 0.12 ㎍/mL), cefepime (1 ㎍/mL), and vancomycin (0.12 ㎍/mL). Conclusion : Efficacy and safety of cefepime monotherapy was comparable to the combination of ceftazidime and tobramycin. It could be used as an alternative empirical regimen for treating cancer patients with febrile neutropenia.