Microstructure‑Strengthening Interrelationship of an Ultrasonically Treated Hypereutectic Al–Si (A390) Alloy

Soo‑Bae Kim,Young‑Hee Cho,Jae‑Gil Jung,Woon‑Ha Yoon,Young‑Kook Lee,Jung‑Moo Lee 대한금속·재료학회 2018 METALS AND MATERIALS International Vol.24 No.6

Ultrasonic melt treatment (UST) was applied to an A390 hypereutectic Al–Si alloy in a temperature range of 750–800 °Cand its influence on the solidification structure and the consequent increase in strength was investigated. UST at such a hightemperature, which is about 100 °C above the liquidus temperature, had little effect on the grain refinement but enhanced thehomogeneity of the microstructure with the uniform distribution of constituent phases (e.g. primary Si, α-Al and intermetallics)significantly refined. With the microstructural homogeneity, quantitative analysis confirmed that UST was found tosuppress the formation of Cu-bearing phases, i.e., Q-Al5Cu2Mg8Si6, Al2Cuphases that form in the final stage of solidificationwhile notably increasing the average Cu contents in the matrix from 1.29 to 2.06 wt%. A tensile test exhibits an increasein the yield strength of the as-cast alloy from 185 to 208 MPa, which is mainly associated with the solute increment withinthe matrix. The important role of UST in the microstructure evolution during solidification is discussed and the mechanismcovering the microstructure-strengthening interrelationship of the ultrasonically treated A390 alloy is proposed.

The HBV DNA Amounts in Serum Have No relationship with ALT level and Hetergeneous Population Coexits in Chronic Hepatitis B Virus Infection

Chun, Yoon-Keun,Ha, Joo-hun,Hong-Jung-Woo,Oh, Soo-Myung,Kim, Sung-Soo 경희대학교 동서의학연구소 1999 INTERNATIONAL SYMPOSIUM ON EAST-WEST MEDICINE Vol.1999 No.1

Yoon-Keun Chun¹,Joohun Ha□Hong-Jung Woo□, Soo Myung Oh□,Sung Soo Kim□ ¹Department of Molecular Biology, College of Medicine,²Department of Surgery, college of Medicine,³Department of Internal Medicine, College of Oriental Medicine,and ⁴East-Weat Medical Reserch Institute,Kyung Hee University, Seoul, Korea. The HBV DNA Amounts in Serum Have No relationship with ALT level and Hetergeneous Population Coexits in Chronic Hepatitis B Virus Infection. Proceedings of International Symposium on East-West Medicine, Seoul. 212-230, 1999. -Hepatitis B is caused by hepadnavirus. Hepatitis B virus replicates through 3.5kb pregenomic RNA intermediate which is regulated by core promoter. Pathogenesis of hepatitis B virus has been bilieved the result of host immune response. But recently many studies have reported that high level of viral replication caused by mutation in core promoter might result in severs hepatitis. But these studies were performed in vitro, not in vivo. So there is yet debate about which factor, viral of host factor, is more important in pathogenesis of hepatitis B virus. So we measured real viral replication level in 204 chronic hepatitis B patients by quantifying HBV DNA from sera by our novel PCR-based more sensitive method, and compared these results with ALT level measured from same sera, which indicates liver cell damage. Surprisingly there are no significant correlation between HBV DNA quantity and ALT level. Then we cloned core promoter region. In SSCP, we found that many viral mutants coexist in one patient. Base on SSCP result, we chose main viral core promoter type in each patients, which is thought to determine overall viral replication level in this patient. Main type of core promoter region of each 41 patients were directly sequenced. And with these we measured promoter activity by luciferase assay system and compared promoter activity with on another. We found tha there were some differences in promoter activity according to core promoter sequences. And we constructed replication-competent viral constructs with core promoter from 41 patients and Transfected these into HepG2 cell and measured HBV DNA by southern blot. There were also differences in HBV DNA quantity according to core promoter sequences. On these all results we investigated correlation between the effect of HBV core promoter on viral replication in vitro and HBN DNA quantity, ALT level from sera of each patients. We found there is no significant correlation among them. As a result, we concluded that in determining severity chronic hepatitis B patients, host factors of each patient is more important rather than replicative activity of virus itself.

급성전골수성백혈병에서 백혈구성분채집술에 이은 치명적인 뇌출혈 2예

오윤정,박소윤,김윤정,한동석,김현수,최진혁,남동기,임호영,김효철,주희재 아주대학교 의과학연구소 1998 아주의학 Vol.3 No.1

The aim of this study is to report 2 cases of acute promyelocytic leukemia who died from intracranial hemorrhage following leukapheresis and to provide proper preventive measures against hemorrhage following leukapheresis. From 1994 to 1997, a total of twenty-six patients with leukemia underwent leukapheresis to control hyperleukocytosis at Ajou University Hospital. Two patients with acute promyelocytic leukemia received all-trans retinoic acid but developed drug-induced hyperleukocytosis. Shortly after leukapheresis, they died from intracranial hemorrhage. The risk factors for fatal hemorrhage are thought to be coexisting disseminated intravascular coagulation(DIC), thrombocytopenia aggravated by leukapheresis, exacerbated coagulopathy related to mechanical trauma through leukapheresis and the excess use of citrate during leukapheresis. To reduce the risk of the bleeding associated with leukapheresis, it is necessary to replace platelet sufficiently before and after leukapheresis and to give calcium to correct coagulopathy induced by excess citrate which is used as anticoagulant as well as the correction of disseminated intravascular coagulation.

정신분열병에 대한 리스페리돈의 효과 및 안정성

이민수,김용구,김영훈,연병길,오병훈,윤도준,윤진상,이철,정희연,강병조,김광수,김동언,김명정,김상훈,김희철,나철,노승호,민경준,박기창,박두병,백기청,백인호,손봉기,손진욱,양병환,양창국,우행원,이정호,이종범,이홍식,임기영,전태연,정영조,정영철,정인과,정인원,지익성,채정호,한상익,한선호,한진희,서광윤 大韓神經精神醫學會 1998 신경정신의학 Vol.37 No.1

연구목적 : 본 시험의 목적은 임상시험 시작전에 연구자들을 대상으로 PANSS Workshop을 통하여 PANSS, ESRS에 대한 국내에서의 표준화 작업을 구축하고 새로운 정신병 치료제인 리스페리돈의 효과와 안정성을 재확인하여 리스페리돈 사용에 대한 적정화를 이루는데 있다. 연구방법 : 1996년 4월부터 1996년 9월까지 국내 39개 대학병원 정신과에 입원중인 혹은 증상이 악화되어 입원하는 정신분열병 환자 377명을 대상으로 다시설 개방 연구를 시행하였다. 1주일간의 약물 배설기간을 가진후, 리스페리돈을 8주간 투여하였고, 기준점, 1주, 2주, 4주, 그리고 8주후에 평가되었다. 용량은 제1일에는 리스페리돈 1mg씩 1일 2회, 제2일에는 2mg씩 1일 2회, 제3∼7일에는 3mg씩 1일 2회 투여하였다. 이후 환자의 임상상태에 따라 임의로 증량할 수 있으며, 최대 일일 16mg을 초과하지 않도록 하였다. 추체외로 증상을 조절하기 위한 투약을 허용하였다. 임상증상 및 부작용의 평가는 PANSS(Positive and Negative Syndrome Scale), CGI(Clinical Global Impression) 그리고 ESRS(Extrapyramidal Symptom Rating Scale)을 사용하였다. 연구결과 : 377명중 343명(91%)이 8주간의 연구를 완결하였다. 치료 종결시점인 8주후 PANSS 총점수가 20% 이상 호전된 경우를 약물 반응군으로 정의할때, 약물반응군은 81.3%였다. 리스페리돈에 반응하는 예측인자로는 발병연령, 이전의 입원 횟수, 유병기간이 관련 있었다. 리스페리돈은 1주후부터 PANSS양성, 음성, 및 일반정신병리 점수상에 유의한 호전을 보여 효과가 빨랐다. CGI의 경우도 기준점에 비해 1주후부터 유의한 감소를 나타내었다. ESRS의 경우, 파킨슨 평가점수는 기준점과 비교해 투여 1주, 2주, 4주후 유의하게 증가되었다가 8주후 기준점과 차이가 없었다. Dystonia 평가점수는 1주후만 유의한 증가를 보였으며, dyskinesia 평가점수는 유의한 차이가 없었다. 혈압, 맥박수의 생명징후 및 일반 혈액학 검사, 생화학적 검사, 심전도 검사에서 유의한 변화는 없었다. 결 론 : 이상의 다시설 개방 임상 연구를 통해 리스페리돈은 정신분열병 환자에서 양성증상뿐만 아니라 음성증상 및 전반적인 증상에도 효과적인 것으로 사료된다. 보다 명확한 평가를 위해서는 다른 항정신병약물과의 이중맹검 연구가 필요할 것으로 생각되며, 또한 장기적 치료에 대한 평가도 함께 이루어져야 하겠다. Objective : The purpose of this study was to investigate the efficacy and safety of risperidone in the treatment of Korean schizophrenic patients. Method : This multicenter open study included 377 schizophrenic patients drawn from 39 university hospitals. After a wash-out period of 1 week, the schizophrenic patients were treated with risperidone for 8 weeks and evaluated at 5 points ; at baseline, and 1, 2, 4 and 8 weeks of treatment. The dose was increased from 2mg/day(1mg twice daily) to 6mg/day(3mg twice daily) during the first week and adjusted to a maximum of 16mg/day over the next 7 weeks according to the patient's clinical response. Medication to control extrapyramidal symptoms was permitted. The psychiatric and neurological status of the patients was assessed by PANSS, CGI, and ESRS scales. Results : 343(91%) of 377 patients completed the 8-week trial period. Clinical improvement, as defined by a 20% or more reduction in total PANSS score at end point, was shown by 81.3% of patients. The predictors of response to risperidone were associated older age, shorter duration of illness, fewer previous hospitalization. Risperidone had rapid onset of action ; a significant decrease of the total PANSS and three PANSS factor(positive, negative, general), and CGI was already noticed at the end of first week. For the ESRS, parkinsonism rating scores were significantly increased until week 4 comparing with baseline. Dystonia rating scores were significantly increased until week 1, and dyskinesia rating scores were not significantly changed during the study. Laboratory parameters including vital sign, EKG, hematological, and biochemical values showed no significant changes during the trial. Conclusions : This study suggests that risperidone is generally safe and effective against both the positive and negative symptoms in our group of patients.

상백피 추출물이 당뇨쥐의 혈당 및 효소에 미치는 영향

윤수홍,정소영,하헌 한국위생과학회 2001 한국위생과학회지 Vol.7 No.2

The purpose of this study was to investigate the effects of the water extract of Mori Radicis Cortex(MRC) on blood glucose level and glutamic oxaloacetic transaminase(GOT), glutamic pyruvic transaminase(GPT), alkaline phosphatase(ALP) and lactate dehydrogenage(LDH) activities in streptozotocin(STZ) induced diabetic rats. Four groups of male Sprague-Dawley were a control group, STZ-diabetic group, Mori Radicis Cortex group and Mori Radicis Cortex + DTZ group. There was a significant decrease of glucose level elevated in diabetic rats treated with STZ, as compared with control group. The water extract of Mori Radicis Cortex recovered significantly above enzyme activities damaged by streptozotocin treatment. These results suggested that the water extract of Mori Radicis Cortex may be a potential antiglycemic and liver protective agents.

사회복지정보화의 패러다임 : 시론적 논의와 적용 Preliminary Discussion and Application

정윤수,김미원 명지대학교 사회과학연구소 2004 사회과학논총 Vol.21 No.-

변연성 발육성 치아종 : A Case of Peripheral Developing Odontoma

윤정훈,임경수,손홍범 조선대학교 구강생물학연구소 2003 Oral Biology Research (Oral Biol Res) Vol.27 No.1

A peripheral odontoma is a relatively rare lesion and is thought to represent the soft tissue counterpart of the central or intraosseous odontoma. Although several odontogenic tumors can occur peripherally, only a few cases of peripheral odontomas involving the gingival tissues have been reported. No earlier stage of peripheral odontoma or peripheral developing odontoma has been described. Here, we report a case of a peripheral developing odontoma occurring in the gingiva of a 4-rear-old Korean boy. Microscopic sections showed several nodules of developing rudimentary tooth germ-like structures in the gingival tissue. It seems likely that this case arise from remnants of the dental lamina located in the gingiva, since the clinical and histologic presentation lends support to the peripheral origin of this tumor.

직교 변환을 이용한 블라인드 등화 알고리즘에 관한 연구

윤태성,정수영 國立 昌原大學校 産業技術硏究所 1999 産技硏論文集 Vol.13 No.-

In this study, we proposed the frequency domain Sato and CMA (Constant Modulus Algorithm) blind equalization algorithms that have the improved convergence speed characteristics using the orthogonal transforms (DFT, DCT-Discrete Fourier/Cosine Transform). And then, the convergence characteristics of the frequency domain CMA/Sato (DFT-CMA, DCT-CMA/DFT-Sato, DCT-Sato) are compared with those of the conventional LMS based CMA/Sato blind algorithms for the real data and the complex data(4QAM, 16QAM). Simulation results show that the frequency domain Sato and CMA blind equalization algorithms have better convergence speed, especially when the distortion of the communication channel increases, than the conventional CMA.

지방자치와 주민참여

정윤수 연세대학교 동서문제연구원 2000 東西硏究 JOURNAL OF EAST AND WEST STUDIES Vol.12 No.1

우리 나라는 1991년에 기초자치단체와 광역자치단체에 지방의회를 구성하고 1995년에는 자치단체장 선거를 실시하여 본격적인 지방자치시대를 맞이하였다. 이에 따라 지방자치의 정착에 중요한 역할을 할 주민참여의 바람직한 형태에 대한 관심이 높아졌다. 본 논문은 현재 우리 나라 주민참여의 문제점을 살펴보고 개선 방안을 제시하였다. 분석결과 주민들의 낮은 참여율, 주민참여의 대표성 확보의 어려움, 참여과정상의 비효율과 혼란, 그리고 공무원의 잘못된 인식 등이 문제점으로 나타났다. 이러한 문제점을 개선하기 위한 방안으로 주민참여 활성화를 위한 제도적 틀 정비, 주민조직을 통한 참여기회의 확대, 자생적 주민조직의 재정 문제 해결, 행정공개의 확대 등을 제시하였다.

고실 사구종 1례

신현수,윤태현,장희종,남정권 대한이비인후과학회 1998 대한이비인후과학회지 두경부외과학 Vol.41 No.3