라미부딘과 HBIg 1주일 단기 병합요법은 간이식 후 B형 간염 재발 방지에 HBIg 장기 고용량 투여요법만큼 효과적인가?

김성주,장재권,이석구,도재혁,백승운,최문석,조재원,고광철,이풍렬,이종철,최규완,박상종,이준혁,김재준,임윤정,안병훈 대한소화기학회 2001 대한소화기학회지 Vol.37 No.1

Background/Aims : The aim of this study was to evaluate whether the regimen consisted of lamivudine and one-week HBIg for HBV prophylaxis after liver transplantation is as effective as long-term therapy of high dose HBIg. Methods: Sixty-one patients with HBV infection were randomly divided into two groups: HBIg group of 31 patients and combination group of 30 patients. In the HBIg group, HBIg was given according to the standard dosing schedule. In the combination group, lamivudine was given indefinitely from at least 4 weeks before transplantation, and 10,000 IU of HBIg was given during anhepatic phase and 6 consecutive days. Results: The two groups were not different in HBeAg and HBV DNA positivity. In the HBIg group, the median follow-up of 20 long-term survivors was 12.7 months (range: 4.0 - 48.2) and that of 23 survivors in the combination group was 22.3 months (4.2 - 42.2). Hepatitis B recurred in a patient of the HBIg group and 2 of the combination group. The recurrence-free survival rate of long-term survivors was 66.7% (95% C.I., 39.5% - 93.9%) in the HBIg group and 76.0% (58.6% - 93.4%) in the combination group after 40 months. Conclusions: The combined therapy of lamivudine and one-week HBIg has an effect equivalent to long-term therapy of high dose HBIg in HBV prophylaxis after liver transplantation at a much lower cost.

열선 화학 기상 증착법에 의한 실리콘 박막 및 태양전지 특성

김상균(Kim, Sang-Kyun),이정철(Lee, Jeong Chul),전상원(Jeon, Sang Won),임충현(Lim, Chung Hyun),안세진(Ahn, Sae Jin),윤재호(Yun, Jae Ho),김석기(Kim, Seok Ki),송진수(Song, Jinsoo),박성주(Park, S-J),윤경훈(Yoon, Kyung Hoon) 한국신재생에너지학회 2005 한국신재생에너지학회 학술대회논문집 Vol.2005 No.06

최근 열선 화학 기상 증착법(HWCVD)은 낮은 온도에서 TFT용 Poly Si 중착을 할 수 있다는 점과 실리콘 박막을 빠른 속도로 증착할 수 있다는 점에서 각광을 받고 있다. 본 연구에서는 HWCVD를 이용하여 태양전지를 제조하고 그 특성을 평가하였다. 조건에 따른 실리콘 박막의 특성 변화를 알기 위해 corning glass 및 실리콘 wafer에 다양한 조건에서 단위 박막(intrinsic layer)을 증착하였고 이 결과를 바탕으로 p/i/n 구조의 태양전지를 제조하였다. Ta 열선 온도는 1700-2000도였고 가스 원료인 SiH₄와 수소의 비율을 조절하면서 그 영향을 관찰하였다. 태양전지의 경우 p충과 n충은 PECVD로 증착하였으며 단위박막 및 태양전지 i충 증착시 기판과 열선간의 거리는 7cm, 기판 온도는 200?C와 250?C로 고정하였고 작업압력은 30mTorr였다. 단위 박막 특성 평가를 위해 암/광 전도도, SEM, Raman Scattering, FT-IR등을 사용하였으며 태양전지 특성 평가를 위해 I-V 및 Spectral response를 측정하였다. 열선 온도가 증가함에 따라 증착속도 및 결정화 분율은 증가하였다. 특히 비정질에서 결정질로 전이되는 구간은 매우 좁았으며 여러 분석 방법에서 일치되는 결과를 보였다. SiH₄ 유량이 늘어날수록 비정질이 결정질로 바뀌는 열선 온도가 증가하였으며 기판 온도가 낮을 경우 또한 결정으로 바뀌는 열선 온도가 증가하였다. 태양전지의 경우 열선 온도가 증가함에 따라 V_{oc} 및 W가 낮아졌으며 J_{sc}, 는 증가하는 경향을 보였으며 결정질 비율이 증가하는 것을 관찰할 수 있었다. 이러한 경향은 quantum efficiency 결과에서도 확인할 수 있었다.

골형성부전증 10예의 임상적 특징

이형숙,김현주,조재현,이승원,김현아,최준혁,송영준,김대중,이관우,정윤석 대한내분비학회 2003 Endocrinology and metabolism Vol.18 No.5

연구배경 및 방법: 골형성부전증은 비교적 희귀한 유전병으로 교원질 대사 장애로 인한 골의 취약성과 다발성 골절 및 척추측만증 등을 특징으로 한다. 유전방식과 표현형의 발현 정도에 따라 다양한 임상 양상을 보이며, 임상적 중증도에 따라 4가지 형태로 분류된다. 지금까지 국내 보고는 분만과정이나 태아 진찰시 골격이상으로 발견된 증례보고가 주였다. 저자들은 비교적 경미한 임상 양상을 보이는 예를 포함한 다수의 골형성부전증 환자들의 전반적인 임상적 특징에 대해 보고하는 바이다. 결과: 2001년 6월부터 2003년 2월까지 골형성부전증으로 진단받은 6 가계, 10예를 대상으로 하였다. 평균 나이는 27.3(5∼56)세였고 소아가 2예였다. 모두 상염색체 우성으로 유전되었으며, 제 I형이 4예, 제 III형이 4예, 그리고 제 IV형이 2예였다. 전 예에서 다수의 골절 경험이 있었고, 골밀도 저하와 골피질 두께 감소 소견이 관찰되었다. 전신의 평균 골밀도는 0.690(0.421∼1.039) g/cm²였다. 골형성지표로 측정된 sAlk는 소아의 경우만 증가되어 있었고, 골흡수지표로 측정된 uDPD의 평균치는 12.9(4.4∼36.3) nM/mM Cr으로 증가된 소견을 보였다. mobility score는 대부분 3,4단계에 속해 있었다. 중증형일수록 진단 시의 mobility score가 낮은 경향을 보였다. 결론: 한국인 골형성부전증 환자의 임상적 특징을 살펴본 결과 기존의 보고된 II형 외에도 I, III, IV형이 다양하게 존재함을 알 수 있었으며, 모든 예에서 상염색체 우성으로 유전됨을 확인할 수 있었다. 또한 모든 예에서 증가된 골흡수로 인한 골밀도 저하와 골절을 확인할 수 있었다. Osteogenesis Imperfecta (OI) is a relatively rare hereditary disease, which is characterized by multiple bone fractures and spine scoliosis, due to the fragility of bone, and is often associated with blue sclerae, deafness and dentinogenesis imperfecta. Four types of OI can be distinguished, according to the clinical findings. Although mutations affecting type I collagen are responsible for the disease in most patients, the mechanism by which the genetic defects cause abnormal bone development remains to be fully understood. Here, the clinical characteristics of 10 OI patient cases are reported, with a review of the literature. All the cases, including 4 type I, 4 type III and 2 type IV, inherited OI as an autosomal dominant trait. All the subjects had multiple old fractures and decreased bone densities. In this study, the biochemical marker of bone formation, serum alkaline phosphatase, was found to be increased only in the pediatric OI patients, while the biochemical marker of bone resorption, urinary deoxypyridinoline, was increased in all cases. The mobility score was found to correlate with the severity of the type on diagnosis (J Kor Soc Endocrinol 18:496∼503, 2003).

용탕단조법으로 제조한 AISI 304 와이어 강화 AM60 Mg 복합재의 특성 연구 (2) : 와이어의 다중 네킹 현상 및 기구 Multiple Necking Phenomena and Mechanism of Reinforcement Wires

김재중,김낙준 대한금속재료학회(대한금속학회) 2000 대한금속·재료학회지 Vol.38 No.6

The multiple-necking phenomenon and mechanism of reinforcement wires in AM60 Mg composites reinforced with AISI 304 wires has been investigated in the present study. AM60 Mg composite reinforced with AISI 304 wires exhibits ductility greater than the ductility of wire itself due to the occurrence of multiple-necking along the length of wire. As the volume fraction of AISI 304 wires decreases, the number of wire necking and the ductility of composites increase. It has been shown that the multiple-necking phenomenon is closely related to wires necking, interface reaction, and volume fraction of reinforcement. This phenomenon is also related to diameter of wires, strain rate, structure of metal, and interface strength. The multiple-necking results from local strain hardening of the matrix surrounding the neck, enabling the matrix to decrease neck growth by attraction force. Because multiple-necking plays an important role in the ductility and deformation behavior of composite, further works is needed to characterize the causes of this phenomenon in other metal/metal composites system.

정밀주조된 A356 Al 합금의 미세조직과 기계적 성질과 미치는 HIPping의 영향

김낙준,이민하,김재중,김경훈,이성학,이의휘 대한금속재료학회 2002 대한금속·재료학회지 Vol.40 No.2

The effects of HIPping on high-cycle fatigue properties of investment cast A356 Al alloys were investigated in this study. Tensile and high-cycle fatigue tests were conducted for cast alloys, two of which were HIPped, and then the test data were analyzed in relation with microstructures, tensile and fracture properties, and fatigue fracture mode. Eutectic Si particles were homogeneously dispersed in the matrix of the cast A356 Al alloys, but there were many large pores formed as cast defects. The high-cycle fatigue results indicated that fatigue strength of the HIPped alloys was higher than that of the non-HIPped alloys because of the significant reduction in volume fraction of pores by HiPping. In the non-HIPped specimens, fatigue cracks initiated at large pores adjacent to the specimen surface and then propagated down to several hundreds micrometers depth while coalescing with other large pores. On the other hand, the HIPped specimens, where pores did not affect the fatigue substantially, fatigue cracks propagated along eutectic Si particles formed at solidification cell boundaries, thereby showing improved fatigue strength by 40∼50% over the non-HIPped specimens.

Abnormal Ventricular Looping and Abnormal Laterality of the Atrial Chambers are the Main Morphogenetic Mechanisms of Cardiac Lesions in Cultured Rat Embryos Treated with Retinoic Acid

You Mie Lee Korean Academy of Medical Science 1998 Journal of Korean medical science Vol.13 No.2

소화성 궤양 출혈에서 열탐침 지혈법 후 재출혈의 위험인자

김영호,이석호,이상구,손희정,이규택,최규완,백승운,이종균,이준혁,고광철,이종철,김재준,류광현,이풍렬 대한소화기내시경학회 2000 Clinical Endoscopy Vol.20 No.6

Background/Aims: The precise rebleeding rate and risk factors of rebleeding after heat probe thermocoagulation in peptic ulcer patients with bleeding are not clear and still need to be evaluated. If we could identify the pre-dictors for rebleeding, the mortality rate might be loweted with early retreatment or surgery in these high risk group. Methods: The 94 patients in whom heat probe was applied were enrolled and the 18 patients with bleeding tendencies. Initial hemostasis was defined as hemostasis persisting for 24 hours post-treatment and permanent hemostasis as absence of bleeding for 7 days after therapy. Rebleedig was defined as oozing or spurting hemorrhage in the ulcer base and/or unstable vital signs and continuting tarry or bloody stool or hematemesis after therapy. Results: In 35 patients with active bleeding sign, initial hemostasis was obtained in 30 (85.7%) patients. After having achieved initial hemostasis, 9 (30.0%) patients rebled. In 41 ulcer patients with non-bleeding visible vessel, 40 cases (97.6%) achieved successful pre-vention of rebleeding. No evident complication was observed. With univariate analysis, bleeding ulcer patients with spurting and oozing hemorrhage had a higher re-bleeding rate than those with non-bleeding visible vessel. Conclusions: The heat probe thermocoagulaton is relative safe and effective procedure to protect bleeding in pectic ulcer patients with non-bleeding visible vessel, but insufficient to hemostasis in bleeding peptic ulcer patients with spurting or oozing in ulcer base. Spurting and oozing hemorrhage are the only risk factors of rebleeding after initial hemostasis with heat probe thermocoagulation in peptic ulcer patients with bleeding.

TFT용 유리에 증착된 DLC film의 자외선 차단효과

김문협,노재승,오세진,이성수,김성진 금오공과대학교 산업기술개발연구원 2000 産業技術開發硏究 Vol.16 No.-

Diamond-like carbon films were deposited on TFT glass substrates using radio frequency plasma enhanced chemical deposition. Experiments were carried out using methane gas mixture with hydrogen gas. This study was investigated on the UV shielding effect of the diamond like carbon films deposited on the soda lime glass coated with indium tin oxide by UV spectrum analysis. In addition, bonding structure of diamond like carbon films was investigated by Raman spectra. The deposition rate of diamond like carbon films was increased with deposition time. Optical band gap calculated by UV spectra decreased with increase of deposition time and DC self bias.

폐결핵환자의 최근 단기화학요법에 대한 임상적 고찰

김재원,정혜영,박효숙,조동일,유재인,유남수,박윤기,배성근 최신의학사 1981 最新醫學 Vol.24 No.1

가스터빈 블레이드 온도 특성 및 코팅층 건전성 평가를 위한 적외선 열화상 카메라 기법 활용

김재열,심재기,최승현,최진호 한국공작기계학회 2008 한국공작기계학회 추계학술대회논문집 Vol.2008 No.-

Key part of main equipment in a gas turbine may be likely to be damaged due to operation under high temperature, high pressure, high-speed rotation, etc. Accordingly, the cost for maintenance increases and the damaged parts may cause generation to stop. The number of parts for maintenance also increases, but diagnostics technology for the maintenance actually does not catch up with the demand. Blades are made of precipitation hardening Ni superalloy IN738 and the like for keeping hot strength. The surface of a blade is thermal-sprayed, using powder with main compositions such as Ni, Cr, Al, etc. in order to inhibit hot oxidation. Conventional regular maintenance of the coating layer of a blade is made by FPI(Fluorescent Penetrant Inspection) and MTP(Magnetic Particle Testing). Such methods, however, are complicated and take long time and also require much cost. In this study, defect diagnostics were tested for the coating layer of an industrial gas turbine blade, using an infraredthermography camera. Since the infrared thermography method can check a temperature distribution on a wide range of area by means of non-contact, it can advantageously save expenses and time as compared to conventional test methods. For the infrared thermography method, however, thermo-load must be applied onto a tested specimen and it is difficult to quantify the measured data. To solve the problems, this essay includes description about producing a specimen of a gas turbine blade (bucket), applying thermo-load onto the produced specimen, photographing thermography images by an infrared thermography camera, analyzing the thermography images, and pre-testing for analyzing defects on the coating layer of the gas turbine blade.