Ketamine이 돼지 관상동맥의 Ca(2+)Channel과 K(+)Channel에 미치는 영향

김경현,김교상,서정국,유희구,염종훈,신우중,김경현 대한마취과학회 1997 Korean Journal of Anesthesiology Vol.32 No.4

Background: Ketamine produces increasing in heart rate and arterial blood pressure, in vivo. However, the direct effects of ketamine itself on the porcine coronary arteries are not well determined. In this study, the direct effects of ketamine on the porcine coronary artery responses to vasoactive agents that operate through Ca2+ channel, K+ channels and endothelium related mechanisms were investigated, in vitro. Methods: Adult porcine hearts(n=12) were obtained from a slaughter house. Coronary arteries were perfused and dissected with 4oC Krebs solution, and were cut into vessel rings and prepared with and without the endothelium(3∼4mm in length). The ring segments were suspended in tissue bath(5ml) filled with Krebs solution at 37oC and bubbled with 95% O2-5% CO2 gas mixture. The effect of ketamine(5 10 5, 10 4, 2 10 4M) on vascular smooth muscle tone caused by Ca2+[voltage operated channel(VOC), receptor operated channel(ROC)] and K+channels(Ca2+activated K+ currents, ATP-sensitive K+ currents) regulationwere studied with Ca2+ free solution and K+channel blocker. Results: Ketamine induced vasorelaxation of porcine coronary rings that were precontracted by KCl(50 mM) or acetylcholine(3 10 7M). The changes of vascular tone in endothelium intact and removed group did not show statistical significance. In ketamine pretreated group(Ca2+ free solution), after ketamine pretreatment, the last vascular tone was same as that relaxed by ketamine. The other group that without pretreatment of ketamine, the last vascular tone was same as that precontracted with KCl or acetylcholine. In the TEA pretreated group, the porcine coronary artery relaxation was reversed. However, pretreatment with glybenclamide, the porcine coronary artery relaxation was not reversed. Conclusions: Ketamine induced vasorelaxation of the porcine coronary artery as concentration relating manner, in vitro. The vasorelaxation induced by ketamine was not associated with endothelium. Furthermore, an antagonism of Ca2+ channels(VOC, ROC) and activation of Ca2+ activated K+ channels may be responsible for the porcine coronary arterial relaxing effect of ketamine. (Korean J Anesthesiol 1997; 32: 504∼509)

Al-Cu 계 합금에서 Pb 및 Bi 첨가가 피삭특성에 미치는 영향

김경현,정인상 대한금속재료학회(대한금속학회) 1990 대한금속·재료학회지 Vol.28 No.3

The machinability of Al alloys can be improved by addition of selected elements such as Pb, Bi, Sn, Cd and In. However, these elements have not only different melting points and densities but also form miscibility gap with Aluminium. This kind of phenomenon induces severe gravity segregation. The aim of this study is to observe the effect of several additives such as Pb, Bi on the machinability of Al-Cu alloys. Pb, Bi particles were finer with increasing of cooling rate and Ar bubbling pressure, and were coarsened with longer holding time after stirring. Due to the coarseness of particles with descending by gravitation, the more addition of Pb and Bi, the particle size becomes coarser. As the contents of additional elements increased, cutting properties were remarkably enhanced such as smaller cutting force and lower bite temperature without degradation of tensile properties. It is also found that the Al alloy is the optimum for free-cutting when 0.4% of Pb and Bi are added to Al-Cu alloys.

문화는 무엇을 할 수 있는가 3 미국에서 성장한 한 문화학도의 자유주의 문화 담론에 대한 문제제기 - 서태지와 미국 언더그라운드 , 그리고 문화평론가 이재현

김경현 사회평론 1996 사회평론 길 Vol.96 No.8

N/A

Anti-pruritic effects of bee venom in compound 48/80-induced mouse scratching behavior model

김경현,이우람,안현진,김정연,한상미,박관규 한국양봉학회 2014 한국양봉학회 학술대회 자료집 Vol.2014 No.4

MBE로 성장된 Al_0.25Ga_0.75As/In_0.2Ga_0.8As pHEMT 에피구조의 RTA에 따른 전도 특성

김경현,홍성의,백문철,조경익,최상식,양전욱,심규환,Kim, Kyung-Hyun,Hong, Sung-Ui,Paek, Moon-Cheol,Cho, Kyung-Ik,Choi, Sang-Sik,Yang, Jeon-Wook,Shim, Kyu-Hwan 한국전기전자재료학회 2006 전기전자재료학회논문지 Vol.19 No.7

We have investigated $Al_{0.25}Ga_{0.75}As/In_{0.2}Ga_{0.8}As$ structures for pseudomorphic high electron mobility transistor(pHEMT), which were grown by molecular beam epitaxy(MBE) and consequently annealed by rapid thermal anneal(RTA), using Hall measurement, photoluminescence, and transmission electron microscopy (TEM). According to intensity and full-width at half maximum maintained stable at the same energy level, the quantized energy level in $Al_{0.25}Ga_{0.75}As/In_{0.2}Ga_{0.8}As$ quantum wells was independent of the RTA conditions. However, the Hall mobility was decreased from $6,326cm^2/V.s\;to\;2,790cm^2/V.s\;and\;2,078cm^2/V.s$ after heat treatment respectively at $500^{\circ}C\;and\;600^{\circ}C$. The heat treatment which is indispensable during the fabrication procedure would cause catastrophic degradation in electrical transport properties. TEM observation revealed atomically non-uniform interfaces, but no dislocations were generated or propagated. From theoretical consideration about the mobility changes owing to inter-diffusion, the degraded mobility could be directly correlated to the interface scattering as long as samples were annealed below $600^{\circ}C$ lot 1 min.

소아시아 그리스인의 로마 원로원 숭배

김경현 한국서양고대역사문화학회 2017 서양고대사연구 Vol.50 No.-

역사가 타키투스에 의하면, 티베리우스 황제는 황제숭배와 관련해 선임황제인 아우구스투스와 다른 정책을 취했다. 그는 원칙적으로 자신을 생전에 신격화하는 데 강한 거부감을 갖고 있었던 데다, 아우구스투스와 비슷한 예우를 받을 자격이 없다는 겸양의 이유에서였다. 그럼에도 불구하고, 그는 자신과 모후 리비아 (아우구스투스의 미망인)를 숭배하겠다는 아시아 속주의 요청을 조건부로 수용했다. 원로원을 함께 숭배하라는 단서가 바로 그것이었다. 즉위 초부터 원로원에 대해 명실상부하게 겸허함을 보였던 그의 태도에 비추어 볼 때 그것은 납득할 만한 일이었다. 하지만 그런 절충안이 다른 속주로 파급되는 것은 원치 않아, 아시아 속주와 비슷한 황제숭배를 제안한 스페인 속주의 요구를 단호히 거부했다. 그런데 원로원 숭배에 관한 비문헌 증거들 (주화 및 금석문)은 일견 위의 문헌증거와는 다른 양상을 가리키는 듯하다. 그래서 그 증거들을 망라적으로 수집한 포르니에 이어 키에나스트는 다음과 같이 주장했다. 원로원 숭배는 아시아 속주 뿐 아니라 제국 전역에 확산되었으며, 게다가 서기 2~3세기에 이르러서야 더 활력을 띠었다는 것이다. 필자의 이 글은 문제의 비문헌 증거를 위 두 연구자들과는 다른 방식으로 분석해, 오히려 타키투스의 증언이 대체로 유효함을 보여주고자 한다. 두 연구자가 비문헌 증거에서 원로원 숭배의 근거로 간주했던 두 개의 관용구 (theos synkletos와 hiera synkletos) 가운데, 후자는 ‘신적 숭배’라기보다 ‘의례적인 경칭’에 불과하다는 것이 필자의 생각이다. 비문에서 원로원을 가리키는 단순한 라틴어 명사 senatus가 그리스어로 번역될 때, 그저 synkletos라는 명사만이 아니라 그 앞에 관례적으로 hiera라는 형용사가 추가되곤 한 사실에 주목할 필요가 있다. 이는 원로원에 대한 신적 숭배가 더 이상 공식적으로 지속되지 않았지만, 기억의 관성 때문에 hiera라는 경어적 표현을 덧붙이는 정도의 예우가 남았던 것이다. 문헌증거가 시사하듯, 속주에서의 원로원 숭배는 티베리우스 황제의 독특한 절충안이었을 뿐 아니라, 특히 서기 2~3세기경 로마 원로원의 권한과 기능이 거의 유명무실해진 점을 감안할 때, 두 선행 연구자의 가정을 수긍하기 어렵다. 황제숭배의 일환으로서 원로원 숭배가 정식으로 지켜진 것은, 주화들에서 theos synkletos라는 세김글이 집중적으로 확인되는 서기 1세기 동안, 특히 네로 황제 치세까지였다고 짐작된다. hiera synkletos라는 새김글이 주로 지역 종교의 숭배대상인 신들 (제우스, 아테나, 아폴론, 헤라클레스, 아프로디테, 키벨레 외에, 도시 tyche 등)과 함께 나타나는 반면, 황제, 황후, 로마 여신과 함께 그려진 주화들이 주로 서기 1세기에 분포한다는 점도 그와 관련해 주목할 점이다. 비문헌 증거를 필자처럼 해석하면, 그 결과는 속주의 원로원 숭배에 관한 문헌증거와 대체로 부합한다. This paper discusses anew the temporal span as well as the geographic scope of the cult of Senate among the Greeks under Roman domination with a view to producing a different conclusion from those of two preceding researchers, Forni (1954) and Kienast (1985). There are two, literary and non-literary categories of evidence, and the latter (consisting of inscriptions and coins) is exhaustively and conveniently catalogued in Forni. The literary evidence, solely coming from Tacitus' Annales (passim in Book 4), is both meager and stingy, though very explicit concerning how at first the cult of Senate came into existence. According to Tacitus, when the Greek cities of Province Asia had applied for divine worship of the living emperor, Tiberius granted the petition on the condition that the Senate should be also worshipped together with himself and Augusta Livia (Augustus' widow and his mother also then alive). This idiosyncratic compromise is very much understandable, for Tiberius took the policy of governance with the Senate, at least during the first years of his reign. Yet, again Tacitus tells us, he did not want to see this expediency propagated elsewhere, as when he rejected a similar petition from the Spanish cities. Tacitus did not care at all to pursue the vicissitudes of the cult in the books that follow. Thus it can be presumed that the cult of Senate was a peculiarity in Province Asia, and that it could not last for long. Yet, non-literary evidences, prima facie, give us a different picture, if we regard the phrases such as theos synkletos (divine senate) and hiera synkletos (sacred senate) as typical of the cult of Senate, as both Forni and Kienast did. For 70 odd inscriptions mentioning hiera synkletos were found throughout the entire Roman empire, while the 539 coins containing the legends theos synkletos (divine senate) and hiera synkletos were produced in the provinces of Asia Minor and adjacent areas. Furthermore, the coins ranged heavily during the 2nd and 3rd centuries A. D., which is a rather singular phenomenon, considering that the Senate had become nothing but a name. This picture from the non-literary evidences was adopted by both Froni and Kienast with disregard to Tacitus. And particularly Forni even came to suggest, without any evidence, that the cult of Senate could have been established among the Greeks during the Republican period just like the cult of dea Roma. This paper attempts to prove that Tacitus is correct as far as the cult of Senae is concerned and that the non-literary evidences need to be handled more carefully than had been by Forni and Kienast. The different premise of this author is that the phrase hiera synkletos may not testify to the cult of Senate, but remain merely an honorary cliche among the Greeks indicating the Roman senate, as is exemplified by the inscriptions where the Latin phrase senatus populusque Romanus was translated into the Greek hiera synkletos kai demos Romanion. With this premise applied to the coin legends, we may get a picture different from that of Forni and Kieast: hiera synkletos on the coins mostly ranging from 2nd and 3rd centuries A. D. may not be signifying the continuance of the cult of Senate, but should be construed merely as a fossilized remnant of a foregone cult. Another remarkable aspect of the numismatic evidences is that the coins with the other legend (theos synkletos) ranged mostly from Tiberius till Nero, thus pointing to the possibility that the cult of Senate itself was a phenomenon very much peculiar to the Julio-Claudian dynasty. And the author also attempts to rebut the assumption of Forni that the cult of Senate could have emerged during the Republican period, by explaining how the Greek municipal communities mostly tended to find individual senators as their benefactors and patrons (hence the so-called civic patronage) during the last two centuries B.C. In the final analysis, concerning the temporal span and geographical limit of th...

pragmatike historia와 tyche -폴리비오스의 역사이론과 서술의 실제-

김경현 한국사학사학회 2009 韓國史學史學報 Vol.0 No.20

This paper discusses the question of consistency between theoretical premises and narrative practice in Histories of Polybius, the Greek historian who has been numbered together with his predecessor Thucydides in the top class of ancient historiography. For, while modelling Thucydides in setting the purpose of historical research and writing for providing practical lessons for future men of state-affairs (pragmata), he advanced further in formulating the methodological principles and the requirements for would-be historian. Thus, he was the first to conceptualize the pragmatike historia, and has been duly acknowledged as such. The second chapter of this paper attempts to exhibit the cardinal aspects of the pragmatike historia. According to the historian, the genre of history he chose to write is different from that of the so-called genealogike historia: while Polybius himself does record mostly what he has seen and heard in person, thus likelier to be more faithful to the historical truth, the latter, usually tracing back to the remote past far beyond historian's ken, thus unavoidably dependent upon what has been transmitted through the writings of predecessors, by and large regardless of the truth. And Polybius tries to expound the methodology of research to the readers, as occasions are given throughout Histories. apodeiksis and aitiologia are its key-words: the former signifies the principle of analytically demonstrating facts by means of various evidences and testimony, the latter the causative explanation of historical events. The famous analysis of the Roman constitution and the military system as the secrets of Rome's success Polybius presents in the book VI of Histories epitomizes his rationalistic approach to history. And the confidence in human knowledge's continuous expansion his contemporaries are witnessing particularly in the field of ecumenical geography, reflects the historian's rationalism in a way very much reminiscent of the 18th century's European intellectual optimism. Yet, does the narrative of Histories abide by the methodological principles? The third chapter answers to this question by testing one of the most prominent features of Polybius' narrative, namely the use of the term tyche. (the total appearance is 137 times) That the historian makes frequent recourses to it prima facie contradicts diametrically the conclusion just drawn in the previous chapter, for usual connotations of the term (chance, fortune, and fate) seemingly do replace, rather than supplement, the rational causation of events. The author of this paper firstly proposes classify the usage of tyche in Histories into three categories: etiological tyche, moral (or punitive) tyche, and teleological (or providential) tyche. As for the etiological tyche, there is no need to further our discussion, for the historian himself concedes its indispensability due to human perception's limitation in cases where natural elements affect or multiple factors converge to produce historical circumstance beyond the expectation of historical agents. In the meantime, the remaining two categories are a different matter, if they are meant to be significant as of more than a conventional way of expression. For their premise is that a transcendental power intervenes in human affairs to punish the moral deviant or, to speak tyche operating on a far grander scale, to lead the entire oikumene according to a predestined plan (for example, a cycle of rise and fall). However, the final analysis of the concrete ways the historian refers to tyche, whether moral or providential, shows that the reference of tyche are nothing but a rhetorical and convenient way of expression. That moral tyche can't be by any means an objective force affecting human actions is revealed by its inconsistent nature. That is, the historian applies the operation of moral tyche solely to the figures alleged to be villains, while representing as outstanding exceptions to the rule ... This paper discusses the question of consistency between theoretical premises and narrative practice in Histories of Polybius, the Greek historian who has been numbered together with his predecessor Thucydides in the top class of ancient historiography. For, while modelling Thucydides in setting the purpose of historical research and writing for providing practical lessons for future men of state-affairs (pragmata), he advanced further in formulating the methodological principles and the requirements for would-be historian. Thus, he was the first to conceptualize the pragmatike historia, and has been duly acknowledged as such. The second chapter of this paper attempts to exhibit the cardinal aspects of the pragmatike historia. According to the historian, the genre of history he chose to write is different from that of the so-called genealogike historia: while Polybius himself does record mostly what he has seen and heard in person, thus likelier to be more faithful to the historical truth, the latter, usually tracing back to the remote past far beyond historian's ken, thus unavoidably dependent upon what has been transmitted through the writings of predecessors, by and large regardless of the truth. And Polybius tries to expound the methodology of research to the readers, as occasions are given throughout Histories. apodeiksis and aitiologia are its key-words: the former signifies the principle of analytically demonstrating facts by means of various evidences and testimony, the latter the causative explanation of historical events. The famous analysis of the Roman constitution and the military system as the secrets of Rome's success Polybius presents in the book VI of Histories epitomizes his rationalistic approach to history. And the confidence in human knowledge's continuous expansion his contemporaries are witnessing particularly in the field of ecumenical geography, reflects the historian's rationalism in a way very much reminiscent of the 18th century's European intellectual optimism. Yet, does the narrative of Histories abide by the methodological principles? The third chapter answers to this question by testing one of the most prominent features of Polybius' narrative, namely the use of the term tyche. (the total appearance is 137 times) That the historian makes frequent recourses to it prima facie contradicts diametrically the conclusion just drawn in the previous chapter, for usual connotations of the term (chance, fortune, and fate) seemingly do replace, rather than supplement, the rational causation of events. The author of this paper firstly proposes classify the usage of tyche in Histories into three categories: etiological tyche, moral (or punitive) tyche, and teleological (or providential) tyche. As for the etiological tyche, there is no need to further our discussion, for the historian himself concedes its indispensability due to human perception's limitation in cases where natural elements affect or multiple factors converge to produce historical circumstance beyond the expectation of historical agents. In the meantime, the remaining two categories are a different matter, if they are meant to be significant as of more than a conventional way of expression. For their premise is that a transcendental power intervenes in human affairs to punish the moral deviant or, to speak tyche operating on a far grander scale, to lead the entire oikumene according to a predestined plan (for example, a cycle of rise and fall). However, the final analysis of the concrete ways the historian refers to tyche, whether moral or providential, shows that the reference of tyche are nothing but a rhetorical and convenient way of expression. That moral tyche can't be by any means an objective force affecting human actions is revealed by its inconsistent nature. That is, the historian applies the operation of moral tyche solely to the figures alleged to be villains, while representing as outstanding exceptions to the rule his...

할리카르나소스의 디오니시오스, 『투키디데스론』(peri Thoukididou)

김경현 한국서양고대역사문화학회 2021 서양고대사연구 Vol.61 No.-

박한상 사건 TV 다큐멘터리를 본 한 미국유학생의 긴급반론 : 홍정욱과 박한상은 얼마나 다른가 - 신세대 미국유학생들을 위한 변명

김경현 사회평론 1994 사회평론 길 Vol.94 No.9

수도권 통행 특성을 고려한 통행시간가치 산정 연구

김경현,이장호,윤일수 대한교통학회 2017 대한교통학회지 Vol.35 No.6

교통시설 투자사업에 대한 타당성조사 시 가장 큰 비율을 차지하는 편익항목은 통행시간 절감편익이며, 이는 통행시간가치를 이용하여 산정한다. 현재 예비타당성조사 표준 지침(5판)에서는 1999년 전국 지역 간 통행 조사 자료를 기반으로 산정된 업무통행 대비 비업무통행 통행시간가치의 비율을 이용하여 비업무통행 통행에 대한 시간가치를 산정하였으며, 여기에 수도권 통행목적 비율과 재차인원을 적용하여 수도권에 대한 통행시간가치를 산정하였다. 수도권 통행은 전국 지역 간 통행과 다른 통행특성을 가지고 있다. 수도권 통행의 경우 복합 대중교통수단을 이용한 환승이 빈번하게 발생하고 있으며, 통근통행에 장시간을 소요하고 있다. 따라서 본 연구에서는 타당성조사 관련 지침의 통행시간가치 산정방법을 개선함으로써 수도권의 통행 특성을 반영한 통행시간가치를 산정하였다. 수도권 통행 특성 반영을 위하여 기존 비업무통행에 포함된 통근통행을 분리하여 통근통행에 대한 통행시간가치를 별도로 산정하였다. 통근통행 모형과 비업무 통행 모형에 대한 우도비 검정통계량 검정 결과 두 모형은 통계적으로 유의미한 차이가 있는 것으로 분석되었다. 또한 수도권 통합요금제 시행에 따른 통행 여건을 반영하기 위하여 대중교통 통합 모형을 구축하였다. 대중교통 통합모형의 버스와 지하철의 계수 비교결과 두 수단간 계수는 통계적으로 유의미한 차이가 없는 것으로 분석되었다. Travel time reduction benefit is the most important benefit item in the feasibility study of transportation infrastructure investment projects and calculated by using the value of travel time. The current feasibility study guideline (5th edition) calculate the value of non-business ravel time in a metropolitan area, using the ratio of the value of non-business travel time to business travel time calculated based on the nationwide inter-regional traffic survey data of 1999. The characteristics of metropolitan trips are different from those of nationwide regional trips. Metropolitan trips have frequent transfers between multiple public transits and long-time commuter trips. Therefore, this research aims to calculate the value of travel time reflecting traffic characteristics in a metropolitan area by improving the limitation of current calculation methods. To reflect these characteristics, this research extracts commuter trips from non-business trips and calculates the value of travel time for commuter trips. The results of the likelihood ratio test for the commuter trip model and the non-business trip model are found to be statistically significant. An integrated public transportation model was also estimated in this study to reflect the trip conditions of the Seoul metropolitan area integrated fare system. The results of comparing coefficients between bus and subway in the integrated public transit model indicated that there were no statistically significant differences between the two modes.