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      • SCOPUSKCI등재

        정상면역을 가진 성인에서 발생한 식도 방선균증

        김현수 ( Hyun Soo Kim ),천종운 ( Jong Woon Cheon ),김민수 ( Min Su Kim ),정창길 ( Chang Kil Jung ),김경록 ( Kyung Rok Kim ),최재원 ( Jae Won Choi ),강동우 ( Dong Woo Kang ),김선영 ( Sun Young Kim ) 대한소화기학회 2013 대한소화기학회지 Vol.61 No.2

        Hyun Soo Kim, Jong Woon Cheon, Min Su Kim, Chang Kil Jung, Kyung Rok Kim, Jae Won Choi, Dong Woo Kang and Sun Young Kim1 Departments of Internal Medicine and Pathology1, DongKang Medical Center, Ulsan, Korea Actinomycosis is a chronic suppurative disease and caused by Actinomycosis species, principally Actinomyces israelii, which are part of the normal inhabitant on the mucous membrane of the oropharynx, gastrointestinal tract, and urogenital tract. It usually affects cervicofacial, thoracic and abdominal tissue. Cervicofacial type has the highest percentage of occurrence with 50%. Actinomycosis frequently occurs following dental extraction, jaw surgery, chronic infection or poor oral hygiene. It may also be considered as an opportunistic infection in immunocompromised patients such as malignancy, human immunodeficiency virus infection, diabetes mellitus, steroid usage or alcoholism. But, actinomycosis rarely occurs in adults with normal immunity and rare in the esophagus. We report an unusual case of esophageal actinomycosis which was developed in a patient with normal immunity and improved by therapy with intravenous penicillin G followed oral amoxicillin, and we also reviewed the associated literature.

      • KCI등재

        조선조 김시습론과 절의론: 남효온, 윤춘년, 이이, 박세당의 김시습 전기를 중심으로

        김영수 ( Kim Young Soo ) 서울대학교 한국정치연구소 2020 韓國 政治 硏究 Vol.29 No.2

        본고의 목적은 김시습의 삶에 대한 후대의 평가를 통해 조선 전기의 절의론을 검토하려는 것이다. 김시습론은 남효온, 윤춘년, 이이, 박세당의 논의를 검토하고자 한다. 김시습의 삶을 바라보는 조선조의 핵심 패러다임은 유교적 절의론이다. 그런데 절의론의 구체적 내용을 보면, 유교가 현실정치에서 직면하는 긴장과 충돌임을 알 수 있다. 예컨대 조선조 절의론을 대표하는 정몽주, 길재, 김시습, 조광조 등의 공통점은 현실정치의 부조리에 저항했지만 좌절했다는 점이다. 그러나 이들은 유교의 순수가치에 헌신하다가 처형되거나 추방된 순교자들로서 인식되었고, 유교의 진정한 정신적 영웅으로 평가되었다. 그래서 이들 대부분은 유교의 전당인 문묘에 종사되었다. 이 때문에 김시습에 대한 절의론을 검토해보면 조선의 정치사상과 정치현실, 그리고 지식인의 정치참여의 성격을 구체적으로 이해하는 데 기여할 수 있을 것이다. 또한 광기와 풍자를 통한 김시습의 독특한 권력비판의 형식도 이해할 수 있을 것이다. The purpose of this paper is to examine not only the political fidelity, but also the tension between Confucianism and politics in Early Chosŏn Dynasty through understanding on Kim Si-sup’s life. Specifically, Nam Hyo-on, Yun Chun-Yeon, Yi, and Park Se-Dang’s will be reviewed. In Chosŏn Dynasty, political fidelity was the core paradigm to interpret Kim’s life, Then, the concrete contents of political fidelity suggest the fact that Confucianism faced tension and conflict in real politics. The most famous persons of political fidelity in Chosŏn Dynasty are Chung Mong-ju (鄭夢周), Gil-jae (吉再), Kim Si-sup, and Cho Kwang-jo (趙光祖). All of them resisted and failed in real politics. But they were recognized as the true spiritual heroes of Confucianism, because they were martyrs who had been devoted to the pure value of Confucianism and executed or deported by real politics. Therefore, this research will contribute to the concrete understanding of political ideology, political reality, and participation of intellectuals in Chosŏn dynasty. One also could understand Kim’s unique form of criticism on political power through his madness and satire.

      • KCI등재

        우적가 배경설화에 나타난 시험과 오도의 양상

        김영수(Kim Young-Soo) 비교민속학회 2003 비교민속학 Vol.25 No.-

        While we read the old documentary records, what we should be careful about is that we should approach and analyze the real material through doubt if it has a non-logical structure. And we should avoid the way of blind following and accepting to the opinion that pre-researchers has given. Why I had interest in the myth of U-Juck-Ga(遇賊歌 : The song made by a monk 〈named Young-jae〉 of Sin-ra dynasty. Its title means the song when he met sixty bandits) was the point that the bandits reward giving the property. And at once they were very impressed after listening to the one song, and as soon as they listened to the song they turned into the buddhist. So it describes a happening like a miracle. So I think that we can't explain the identity of bandits and the meaning of song without solving this kind of strange and non-logical meaning. The background myth of U-Juck-Ga has the structure of the personal seeking after truth of monk named Young-jae(永才). The entering to mountain of the monk Young-jae has not the meaning of small hiding(小隱 : To hide somewhere like a mountain for seeking after truth 〈accompanying not so much pain or hardship〉)or big hiding(大隱 : To hide somewhere like a mountain for seeking after truth 〈accompanying very much pain or hardship〉) but almost like the meaning of being scattered hiding(散隱 : To hide like a person who doesn't exist for seeking the truth 〈accompanying extreme pain and hardship〉) as the classical scholar Huh-am(虛庵 : The title of Jung-hi-ryang〈鄭希良〉, one classical scholar of Cho-sun dynasty) appointed. We should regard him as not the monk who had fame and sang a song very well but the monk who tried to turn to buddha with his 90-year-old body. The fact that the monk Young-jae was quite good at making the Hyang-Ga(鄕歌 : a poem and song especially thrived in the period of unified Sin-ra dynasty) is just a little detail of describing about him. And we should regard that the bandits already knew the name of the monk as that the fame of the monk was already well-known to bandits. The reason why they let him to make the Hyang-ga is not because of his good talent to make it. That he was quite good at making Hyang-ga means that he had not only very high virtue but also had a good talent to persuade someone when he made Hyang-ga. As it were, it is not just a simple song but a song which is quite easy to be understood about the doctrine of buddhism. If the bandits let the 90-year-old monk sing a song just because he is good at singing a song, then it is just the behavior of making fun of him, and the fact that the bandits turned into the buddhist through the monk Young-jae can't not but to have a big contradiction. The identity of the bandits might reflect the hard time of that period, and also can be his spiritual enemy for testing his body and soul. As the U-Juck-Ga has the meaning of reflecting oneself on passed days, for the wandering bandits who had no fame the monk Young-jae could be the changed people of buddha. and In the aspect of Young-jae himself the identity of the bandits could be the changed people for testing his body and soul.

      • KCI등재

        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.

      • KCI등재

        콩 단백 성분 및 연령이 암컷 흰쥐의 혈장 지질 농도와 인지질 지방산 패턴에 미치는 영향

        정은정(Eun-Jung Chung),김수연(Soo-Yeon Kim),김지영(Ji-Young Kim),안지영(Ji-Young Ahn),박정화(Jung-Wha Park),차명화(Myung-Hwa Cha),이양자(Yang-Cha Lee Kim) 한국식품영양과학회 2003 한국식품영양과학회지 Vol.32 No.2

        혈중 지질농도는 식이단백질 종류보다는 연령의 영향을 많이 받아, young군보다 old군의 총 콜레스테롤, TG, HDL-콜레스테롤, LDL+VLDL-콜레스테롤 및 AI 모두 높았다. 한편 콩 단백질군에서 HDL-콜레스테롤 수준이 증가하고, LDL+VLDL-콜레스테롤와 AI는 감소하여, 심혈관질환에 대한 콩 단백질의 유익한 효과를 확인할 수 있었다. 식이단백질에 의해 유의한 영향을 받은 혈장 인지질의 지방산조성중 22:0, 18:1ω9, ∑MUFA 조성은 카제인군에서 콩 단백질군 보다 높았으며, 반대로 ∑SFA 조성은 카제인군에서 낮았다. 연령에 의해 혈장 인지질 지방산 조성에 있어 유의한 차이를 보인 지방산 중 22:0, 18:1ω9, 22:1, 18:3ω3 및 22:4ω6는 young군에서 높은 반면에, 22:6ω3, ∑ω3, 18:2ω6, 20:4ω6, ∑ω6 및 ∑PUFA의 조성비율은 old군에서 높게 나타났다. 이와 같이 식이 단백질의 종류보다 연령의 영향력이 더 많이 나타난 것은 혈중 콜레스테롤 수준이 식이 단백질보다는 연령의 영향을 더 크게 받았기 때문으로 생각된다. 혈장 인지질 지방산의 대사지표 중 Δ7-desaturation index(16:0⇒16:1ω7)와 Δ9-desaturation index(18:0⇒18:1ω9)가 식이 단백질의 영향을 받아 카제인군에 비해 콩 단백질군에서 유의하게 낮았다. Δ7- 및 Δ9-desaturation index만이 식이 단백질의 영향을 받은 것은 식이 단백질보다 desaturase 활성에 더 큰 영향력을 미치는 콜레스테롤이 식이에 첨가되었기 때문이라 생각된다. Δ-4 desaturation index (22:4ω6⇒22:5ω6)는 young군에 비해 old군에서 높았으며, elongation index(20:4 ω6⇒22:4ω6)는 old군에서 낮았다. 대부분의 elongation과 desaturation 단계는 연령에 따라 유의한 차이를 보이지 못하였으나, ω3계 지방산의 전체적인 elongation-desaturation 단계를 나타내는 ∑products-fatty acid(ω3)/α-LNA(ω3) 비율이 old군에서 young군보다 유의하게 높아, 연령에 따른 PUFA 대사의 변화가 관찰되었다. 이상에서와 같이, 콩 단백질의 섭취로 흰쥐 혈장 인지질의 ∑MUFA 조성은 낮고 ∑SFA 조성은 높아 다른 지질 강화성분의 섭취와 유사한 결과를 나타내었다. 혈중 콜레스테롤 수준이 높은 old군에서 체내 막조직의 유동성을 유지하기 위해 PUFA의 합성 특히 ω3계 지방산의 elongation-desaturation이 증가하여 총 PUFA 조성이 young군보다 높았다. 연구결과로 이소플라본을 포함한 콩 단백질의 혈중 지질저하 기전에 대해 체계적인 설명은할 수 없지만, 콩 단백질이 혈장 지방산의 조성을 변화시킴으로써 간접적으로 심혈관계 질환에 대해 유익한 효과를 미침을 알 수 있었다. 한편, 이러한 혈관의 건강과 관련된 콩의 유익한 효과는 이소플라본과 같은 콩의 특정 성분의 단독효과라기보다는 콩 단백질과의 복합효과에 의한 것이라는 주장은 매우 설득력 있다고 생각된다. Effects of soy protein concentrate (SPC) containing isoflavone and casein diets on plasma phospholipid (PLs)-fatty acid patterns were investigated in 7- & 40- wk old female rats. Diets containing 16% SPC (soy/young: SY, soy/old: SO) and casein (casein/young: CY, casein/ old: CO) supplemented with 0.5% cholesterol were fed for 4 wks. Fatty acid compositions of plasma PLs were determined by TLC and GLC. Compared to the dietary protein effects, age effects on serum lipids were more profound. The levels of total cholesterol (Chol.), triglyceride, HDL-Chol., (LDL+VLDL)-Chol. and atherogenic index (AI) were higher in older groups (OC & OS) than younger groups (YC & YS). Soy groups had higher HDL-Chol. level and lower (LDL+VLDL)-Chol. and AI, compared with casein groups. The compositions of C22:0, C18:1ω9 and sum of MUFA in plasma PLs were significantly higher in casein group (CY & CO) than soy group (SY & SO), but those of sum of SFA were higher in soy group. The compositions of C22:0, C18:1ω9, C22:1, C18:3ω3 and C22:4ω6 were higher and those of C22:6ω3, sum ofω3, C18:2ω6 C20:4ω6, sum ofω6 and sum of PUFA were lower in plasma PLs of younger rats. The average P/S and ω3/ω6 ratio in older group was higher. The Δ-7 desaturation index (16:0⇒16:1ω7) and Δ-9 desaturation index (18:0⇒18 : 1ω9) were lower in soy group than casein group, while Δ-6 and Δ-5 desaturation index were not affected by dietary protein. The Δ-4 desaturation index (22:4ω6⇒22:5ω6) were higher and, elongation index (20:4ω6⇒22:4ω6) were lower in older group. The ratio of the products of ω3 fatty acid series/precursor of ω3 fatty acid series (C18:3) was significantly higher in older group, which in- dicated that age affected the plasma PUFA metabolism. On the other hand, older rats had higher serum cholesterol level compared with younger rats. Taken together, these changes in fatty acid composition might cause minimal changes in the membrane fluidity induced by the increase serum cholesterol level.

      • KCI등재

        한국인 직무 스트레스 측정도구의 개발 및 표준화

        장세진,고상백,강동묵,김성아,강명근,이철갑,정진주,조정진,손미아,채창호,김정원,김정일,김형수,노상철,박재범,우종민,김수영,김정연,하미나,박정선,이경용,김형렬,공정옥,김인아,김정수,박준호,현숙정,손동국 大韓産業醫學會 2005 대한직업환경의학회지 Vol.17 No.4

        Background and Purposes: Over the past three decades, numerous studies performed in Korea have reported that job stress is a determinant risk factor for chronic diseases and work disability. Every society has its own culture and occupational climate particular to their organizations, and hence experiences different occupational stress. An occupational stress measurement tool therefore needs to be developed to estimate it objectively. The purpose of this study is to develop and standardize the Korean Occupational Stress Scale (KOSS) which is considered to be unique and specific occupational stressors in Korean employees. Subjects and Methods: Data were obtained from the National Study for Development and Standardization of Occupational Stress (NSDSOS Project: 2002-2004). A total of 12,631 employees from a nationwide sample proportional to the Korean Standard Industrial Classification and the Korean Standard Occupational Classification were administered. The KOSS was developed for 2 years (2002-2004). In the first year, we collected 255 items from the most popular job stress measurement tools such as JCQ, ERI, NIOSH and OSI, and 44 items derived from the a qualitative study (depth interview). Forty-three items of KOSS, in the second year, were retained for use in the final version of the KOSS by using Delphi and factor analysis. Items were scored using conventional 1-2-3-4 Likert scores for the response categories. Results: We developed eight subscales by using factor analysis and validation process: physical environment (3 items), job demand (8 items), insufficient job control (5 items), interpersonal conflict (4 items), job insecurity (6 items), organizational system (7 items), lack of reward (6 items), and occupational climate (4 items). Together they explained 50.0% of total variance. Internal consistency alpha scores were ranged from 0.51 to 0.82. Twenty-four items of the short form of the KOSS (KOSS-SF) were also developed to estimate job stress in the work setting. Because the levels of the subscales of occupational stress were gender dependent, gender-specific standard norms for both the 43-item full version and the 24-item short form using a quartile for the subscales of KOSS were presented. Conclusion: The results of this study suggest that KOSS might be an appropriate measurement scale to estimate occupational stress of Korean employees. Further and more detailed study needs to be conducted to improve the validity of this scale.

      • 比較憲法에 관한 硏究 : 民主主義國家의 憲法과 共産主義國家의 憲法을 中心으로

        金水暎,黃革周,權光植,吳再煥,崔聖俊,金益鉉,金永休,王任東 朝鮮大學校 法政大學 1977 法政大論文集 Vol.4 No.-

        This paper aims to make clear the fundamental differences between the constitutions of two political systems, constitutional democracy and communism. (1) Fundamental Human Rights The recognition and the protection of fundamental liberties are the essences of the political system of constitutional democacy. The reality of individual liberties is the only reliable criterion that differentiates the two political systems, since the institutional apparatus of both government, assemblies, elections, parties, bureaucracies have become stereotyped to the point of identity. Recognition or nonrecognition of fundemental guaranties are closely related to the ideological telos of either system. In the constitutional democracy they crystallize the supreme values of human self-realization and dignity. In the communist states they are denied legitimacy not only because they may function as foci of opposition against monolithic power but also because they could obstruct the ideology of economic planning under collectivism. The idelolgical foundation and functional purpose of classical fundamentalism underwent a fa -reaching transformation in the Marxian society. The Russian Revolution preaches and practices the primacy of the collectivity over the individual. Instesd of being "inalienable" interpreted as obligations of the state toward the laboring masses. The attitude of Marxism in the U.S.S.R. and the so-called "People's Democracies" toward fundamental liberties is altogether different. All constitutions in the Soviet orbit contain elaborate statements on fundamental rights of the citizens, characteristically coupled with provisions concerning their duties toword the state and the community. Civil liberties in the classical sense, which the constitution of communist states merely summarizes, are overshadowed by the new social and economic rights. The guaranty of the civil rights proper is hedged in by the rubber clause that they are guaranteed " in conformity with the interests of the working class" and "in order to strenghthen the socialist system". Especially political rights of the suffrage are converted into compulsory mass participation in the political process directed by the party hierarchy. And its single party (communist party)was the straight negation of all political liberty. (2) Patterns of Governament In the modern democratic-constitutional state the essence of the power process consists in the attempt to establish an equilibrium between the various competitive plural forces within in state society, with due regard to the free unfolding of the human personality. In communist state, social control and political power are monopolized by a single power holder, subordinating the individual to the ideological requirements of the group domination the state. The basic difference between the two political systema conists in whether, in the various stages of the governmental process, political power, is distributed among and shared by several independent power holders or whether political power is concentrated in and monoploized by a single power holder, be it an individual person, and assembly, or a party. Assembly government system revived in the Stalin constitution of 1936 in the U.S.S.R. from where it spread, after the Second World War, to all satellite states, as well as East Germany, Red China, North Korea. No communist state fails to conform to this standard pattern. Assembly government, by its own biological laws. easily transforms itself into a regime in which a single power holder exercises the monopoly of political power. This may well be the intrinsic reason for the communist preference. By necessity the communist state is a plice state. Another indispensable instrument of social control is the single party. The governmental techniques of a communist regime are necessarily authoritarian. But the regime does much more than exclude the power addressees from their legitimate share in the formation of the will of the state. It attempts to mold the private life, the soul, the spirit and the mores of the citizens to a dominant ideology that the various instrumentalities of the power process force on the non-conformists.

      • KCI등재

        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.

      • KCI등재

        Caffeine이 지구성 운동 수행능력에 미치는 영향과 억제성 아미노산에 의하여 활성화되는 이온통로의 조절작용

        김은경,김영표,천병옥,이계영,김연정,임백빈,조영욱,김창주,김성수 대한스포츠의학회 1999 대한스포츠의학회지 Vol.17 No.1

        To investigate the effect and mechanism of caffeine on endurance exercise, two experiments were performed. First, to test caffeine effect on aerobic exercise, 200-300g Sprague-Dawley rats were used and three groups, control group, low caffeine injection group and high caffeine injection group, were divided. Blood smpling by heart puncture were done at rest, after 30 min treadmill exercise, and after maximal exercise. Blood glucose, free fatty acid concentration were detected and following results were obtained. Glucose concentration showed significant difference between groups(p=0.0305) and also significant changes were exhibited between time(p=0.0004). Free fatty acid concentration had no difference between groups. but had significance between times(p=0.00065). Exercise endurance performance time showed significant difference(p=0.02350 in high caffeine injection group compared to control group. In this experiments, endurance exercise capacity was increased by caffeine injection. Therefore, second experiment was performed to investigate the effect of caffeine on ion current induced inhibitory amino acid neurotransmitter. GABA and glycine. Single periaqueductal gray neuron was acutely dissociated and nystatin perforated patch clamp was performed under voltage clamping condition. Caffeine evoked outward current in PAG neuron dose dependent manner. 1mM of caffeine application had no response. but 3mM caffeine evoked about 32.5±8.539pA outward ion current and 10mM caffeine evoked about 215.46±19.4pA outward current. 10^-2mM GABA activated Cl ̄current and recorded by inward current. Caffeine inhibited GABA activated Cl ̄ current concentration dependent manner. 10^-2mM of caffeine had no effect on 1-^-2mM of GABA response. but 10^-1mM caffeine inhibited GABA activated Cl ̄ current about 5.74±2.13%, 1mM caffeine inhibited about 17.25±2.70%, 10mM caffeine inhibited GABA response about 45.31±7.71%. 10^-1mM of glycine activated Cl ̄ current and also recorded by inward current. Caffeine inhibited glycine activated Cl ̄ current concentration dependent manner. 10^-2mM caffeine decreased glycine activated Cl ̄ current about 4.61±1.650%, 10^-1mM caffeine decreased about 6.49±2.24%, 1mM caffeine decreased about 26.82±4.27%, and 10mM caffeine decreased glycine response about 94.47±1.39%. These results suggest that caffeine inhibite inhibitory amino acid, GABA and glycine, this response causes excitation of CNS and this seems to be the basic mechanism of increasing effect to aerobic exercise performance by caffeine.

      • KCI등재

        Effect of Ultrasonic Melt Treatment on Solidification Microstructure of Al–5Ti–1B Alloy Containing Numerous Inoculant Particles

        Soo‑Bae Kim,Jae‑Gil Jung,Young‑Hee Cho,Su‑Hyeon Kim,Kwangjun Euh,Jung‑Moo Lee 대한금속·재료학회 2022 METALS AND MATERIALS International Vol.28 No.7

        The effect of ultrasonic melt treatment (UST) on the solidification microstructure of an Al–5Ti–1B alloy containing highvolumefractions of Al3Tiand TiB2particles is investigated for various UST times with different melt holding times. Theas-cast Al–5Ti–1B alloy is composed of TiB2and polygonal Al3Tiparticles (present prior to UST), plate-like Al3Tiparticles,and Al grains (formed during UST and/or solidification). The UST causes a size reduction and homogeneous distributionof the TiB2-agglomerated region containing many submicron-sized TiB2particles pushed to the grain boundaries. The USTslightly decreases the size and improves the distribution of polygonal Al3Tiparticles enriched in the TiB2-agglomeratedregion. Unlike the TiB2and polygonal Al3Tiparticles, which exhibit a minor refining effect, the plate-like Al3Tiparticlesshow a significant refinement with UST application. The UST has a significant effect on the size distribution of Al grains byinducing the formation of medium-sized grains at the expense of small and large grains; however, it only has a slight effecton grain refinement. The degree of microstructure modification increases with increasing UST time but decreases with meltholding time after UST. The mechanisms for the refinement and dispersion of the TiB2and Al3Tiparticles and Al grains arediscussed considering fragmentation, nucleation, and growth behaviors induced by the UST and subsequent solidification.

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