계통오차 분석 활동이 실험 오차와 실험 지도에 대한 교사의 인식에 미치는 영향

박대현 서울대학교 대학원 2020 국내박사

초중등학교의 탐구 실험에서 교과서에 수록된 참값을 얻기는 매우 어렵다. 교사들은 실험환경의 미비함과 실험의 미숙함 때문에 실험 오차가 발생하는 것을 당연하다고 간주하며, 오차의 원인과 보정에 별로 관심을 보이지 않는다. 그렇지만 오차의 원인을 찾고 오차를 줄이려는 노력은 실험방법과 실험도구의 특성을 이해하여 실험에 숙달하게 만들고, 실험자가 실험에 관련된 과학의 본성과 배경 이론을 이해하는 데 있어서 중요하다. 선행연구에 의하면 실험수업은 과학적 탐구능력 향상이라는 과학교육의 목표를 달성하기에 효율적인 교수법으로 인정받고 있지만, 학교에서는 실험수업이 이루어지는 횟수가 적고 실험수업이 지식을 습득하는 데 초점이 맞추어져 진행되고 있다. 실험 수업의 중요성이 강조되고 있지만 학교에서 실험수업이 잘 이루어지지 않는 이유는 실험을 어렵게 만드는 환경요인과 실험수업에서 교사들이 겪는 어려움 때문이다. 실험수업에 관한 선행연구에 의하면 교사들은 실험결과에 오차가 있을 때 그 원인을 자세히 찾기보다 실험환경이 좋지 않고 학생들이 실험에 미숙하기 때문에 오차가 생기는 것으로 여긴다. 하지만 오차의 원인을 피하기 어려운 환경과 학생의 미숙함으로만 여기고 넘어간다면 실험수업은 과학적 탐구능력의 향상이라는 본래의 목표를 달성하지 못하고 의미를 잃게 된다. 이 연구에서는 실험환경이 상대적으로 잘 갖추어진 학교에도 실험수업에 대한 동일한 어려움이 있는지 알아보기 위해 과학고등학교에 근무하는 물리 교사들을 대상으로 실험 오차와 실험 지도에 대해 어떤 인식을 가지고 있는지 면담하였다. 연구에 참여한 교사들은 세 명으로 모두 과학고등학교에서 물리를 담당하고 있으며, 교직 경력이 20년 이상, 10년 이상, 5년 미만인 교사를 한 명씩 선택했다. 우선 교사들은 실험값이 정밀하지 않고 정확하지 않은 어려움을 겪고 있었고, 정밀한 실험도구를 사용함으로써 이 문제를 해결하였다. 그리고 실험수업에서 학생들이 오차의 원인을 찾아내더라도 오차를 보정하는 과정을 진행하지 않았으며, 실험키트를 사용하는 실험에서는 오차의 원인을 찾을 수 없는 경우도 있었다. 그리고 계통오차를 보정하는 것에 어려움을 겪고 있었다. 중등학교 물리실험 수업의 일차 목표는 대체로 실험결과를 이론과 비교하면서 이론의 타당성을 확인하는 것과 실험 능력을 향상시켜 학생 주도의 탐구설계 능력을 올리는 것이다. 그러나 실험도구와 실험과정에 드러나지 않는 체계적 오차가 있고 그것을 보정하지 않는다면 이런 목표를 달성하기 어렵다. 이 연구에서는 체계적 오차, 다시 말해, 계통오차의 원인을 이해하고 보정하는 활동을 통해 교사들이 오차 보정의 중요성을 확인하고 실험수업을 진행하는 태도에 변화가 있는지 조사했다. 실험 오차에는 몇 종류가 있는데, 우연오차나 실험자의 과실로 일어나는 오차는 개인의 실험 숙련도와 관련되므로 오랜 경험이나 정밀한 실험도구를 통해 해결될 수 있다. 그러나 계통오차는 실험기구에 내재된 체계적 오류이므로 실험자의 경험보다는 실험도구의 작동에 대한 이해가 중요하다. 그러므로 계통오차의 이해는, 우연오차보다, 오차가 실험에서 차지하는 역할과 오차 처리의 중요성을 교사들이 인식하게 하여 실험 지도의 태도 변화를 유도하는 데에 효과적일 수 있다. 교사들이 계통오차를 이해하는 데에 효과가 있을 실험 주제를 찾기 위해, 물리학 실험 교과서에 수록된 실험 도구를 조사하고, 실험 도구와 관련된 계통오차가 발생할 가능성이 큰 실험들을 찾았다. 모든 실험에서 계통오차를 찾아서 제거하기는 어려울 뿐만 아니라 계통오차의 제거 자체가 이 연구의 목표는 아니므로 계통오차를 발견하고 분석하고 보정하는 과정을 수행하기 용이한 실험 주제를 역학, 전자기, 빛과 파동, 현대물리 단원에서 한 개씩 선택했다. 연구자는 실험설계에 대한 이해에 도움이 되도록 스마트 기기, 오픈소스 하드웨어, 범용기기들을 사용하여 물리실험들을 설계했고, 연구참여자들이 이 실험들을 수행하여 계통오차를 분석해보도록 했다. 연구참여자들이 계통오차 분석 활동을 수행해 본 뒤에는 면담을 통해 참여자들이 이 실험을 수행하면서 오차에 대한 인식에 어떤 변화가 일어났는지 알아보았다. 연구참여자들은 계통오차 분석 활동을 통해 실험을 지도할 때 오차의 발생은 피할 수 없는 것이라는 자신의 기존 관념을 바꾸었으며, 계통오차에 대한 이해가 실험에 사용하는 도구를 고려해서 실험을 지도하도록 영향을 주었다고 하였다. 또한, 본 연구에서 진행한 활동이 오차에 대한 이해와 오차 처리가 갖는 교육적 의미를 환기하는 데 도움을 주었다는 소감을 밝혔다. 이 연구에서 계통오차의 원인은 사용한 실험도구의 종류에 따라서 분류할 수도 있었다. 스마트 기기를 사용한 실험에서는 기기의 작동 방식이 계통오차의 원인이 되었으며, 범용기기나 오픈소스 하드웨어를 사용한 실험에서는 이상적 조건으로 생각하고 사용한 실험도구의 물리량이 계통오차의 원인이 되었다. 이 결과를 바탕으로 계통오차의 원인을 찾고 측정값을 보정하는 과정을 순서도로 제시했으며, 순서도를 이용하여 계통 오차를 체계적으로 찾아내는 과정을 예시로 들고, 계통오차 분석활동을 교사 대상 실험연수로 활용할 수 있는 모형을 제안하였다. 연구를 요약하면 다음과 같다. 교사들은 일반적으로 실험에서 오차를 당연하게 여기며 오차의 원인을 찾아 보정하는 것을 어려워한다. 그러나 실험결과가 이론에서 크게 벗어나는데도 그것의 원인을 오차에 돌리면서 정작 오차의 분석에는 소홀하다면 실험교육이 과학의 본성을 외면하는 상황이 된다. 그러므로 오차의 본성을 탐구함으로써 교사들의 인식을 쇄신하기 위한 활동이 필요하다. 우연오차는 체계적이지 않지만, 계통오차는 기기 자체에 내재되어 있으므로 오차의 원인을 체계적으로 찾아내고 영향을 분석하기에 용이하다. 따라서 연구자는 적당한 실험 주제와 기기를 이용하여 계통오차를 찾아내고 분석하여 이해하는 것을 목표로 하는 계통오차 분석 활동을 설계하고 교사들에게 수행하게 했다. 그리고 이 활동을 경험한 물리 교사들의 오차에 대한 인식이 활동 전후로 어떻게 바뀌었는지 면담을 통해 확인했고, 교사의 이런 경험이 학생들에게 실험을 지도할 때 태도 변화에도 연결될 수 있음을 알았다. 이 연구의 결과를 확대하여 교사연수에 적용하면 교사들이 오차 처리의 중요성과 이론과 실험의 관계를 인식하고 실험수업을 통해 과학의 본성을 지도하는 데에 도움이 되리라 믿는다. It is very difficult to obtain the conventional true value of textbooks in inquiry experiments of elementary and secondary schools. Teachers consider that the experimental error is very large due to the lack of experimental equipment and environment, and immaturity of experiment. And teachers show little interest in the cause and correction of errors. However, efforts to find the cause of the error and reduce the error are important in understanding the characteristics of the experimental method and the experimental tools to make the mastery of the experiment, and for the experimenter to understand the nature of science and background theory related to the experiment. According to previous studies, laboratory instruction is recognized as an effective teaching method to achieve the goal of scientific education, which is to improve scientific inquiry ability. However, in the school, the frequency of laboratory instructions is small, and the laboratory instructions are focused on acquiring knowledge. The reason why laboratory instructions are not conducted well in school is because of the environmental factors that make experiments difficult and the difficulties experienced by teachers in laboratory instructions. According to previous studies on laboratory instructions, when there is an error in the experimental results, teachers think that, rather than finding the cause in detail, the error occurs because the experimental equipments are poor and students are unskilled in experimenting. However, if the cause of the error is regarded only as the experimental environment and the inexperienced students, the laboratory instruction loses meaning without achieving the original goal of improving scientific inquiry ability. In this study, we interviewed physics teachers working in science high schools to see if there were the same difficulties in laboratory instructions even in schools with relatively good experimental environments. In addition, we analyzed the perception of experimental error and laboratory instructions. First, even if the teachers followed the experiment according to the textbook, the experiment result was imprecise and inaccurate, and the problem was solved by using precise experimental tools. In the laboratory instructions, even if students found the cause of the error, the process of correcting the error did not proceed. In some cases, the cause of the error could not be found in the experiment using the experimental kit. And teachers were having difficulty about correcting systematic errors. The primary goal of secondary school physics experiment is to compare the experimental results with theories to confirm the validity of the theory and to improve students' scientific inquiry ability. However, there are systematic errors that are not revealed in the experimental tools and process, and it is difficult to achieve this goal without correcting them. We investigated whether teachers perceived the importance of error correction and whether there was a change in attitude about conducting laboratory instructions, through the activities of understanding and correcting the causes of systematic errors. There are several types of experimental errors, random errors or careless errors are related to the individual's experimental skill, and can be resolved through long experience or precise experimental tools. However, compared to the random errors, the systematic error is a systematically inherent in the experimental apparatus, so it is important to understand the operation of the experimental tool rather than the experimenter's experience. In addition, understanding of systematic errors, rather than random errors, can be effective in inducing changes in teachers' attitudes of laboratory instructions by recognizing the role of errors in experiment and the importance of error correction. In order to find an experimental topic that would be effective for teachers to understand systematic errors, we examined the experimental tools contained in the physics experiment textbooks, and found experiments that are likely to cause systematic errors related to the experimental tools. Since it is difficult to find and eliminate systematic errors in all experiments, and the elimination of systematic errors itself is not the goal of this study, we chose an experimental topic that facilitates the process of discovering, analyzing, and correcting systematic errors. Each topic was selected from mechanics, electromagnetics, light and wave, and modern physics. we designed physics experiments for exploring systematic errors using smart measuring instruments, open source hardware, and general-purpose measuring instruments, and asked teachers to perform these experiments. Three teachers participated in this study, taking charge of physics at science high school. Participants in the study had teaching careers of 20 years or more, 10 years or more, and less than 5 years, respectively. We could also classify the causes of systematic errors according to the type of experimental tools used when designing experiments using smart devices, open source, and general-purpose devices. In the experiments using smart devices, the operating principle of the devices caused the systematic errors. In the experiments using general-purpose equipments or open source hardwares, the physical quantity of the experimental tools used as an ideal condition was the cause of systematic error. After participants performed these experiments, interviews were conducted to find out what changes occurred in the perception of errors. Participants in this study changed their existing notion that the occurrence of errors was inevitable in the experiments through the exploring systematic errors. They also said that the understanding of systematic errors influenced to consider the tools used in the laboratory instructions. And they expressed that it gave an educational meaning emphasizing the importance of understanding and correcting errors. In this study, we found that the systematic errors can be largely divided into two types according to the experimental apparatus, due to the operating principle of the apparatus itself and due to the limitation of the experimental environment. Based on these results, we presented in the flowchart the process of finding the cause of systematic errors and correcting the measured values. The study is summarized as follows. Teachers generally do not doubt occurrence of errors in experiments, they think that it is difficult to correct the errors. However, when the experimental results deviate from the theory, if the error analysis is neglected, the laboratory instructions turns away from the nature of science. Therefore, teachers' activities are needed to explore the nature of error and recognize its importance. Although the random error is not systematic, since the systematic error is inherent in the device itself, it is easy to systematically find the cause of the error and analyze the effect. Therefore, we designed a physics experiments aimed at finding, analyzing, and understanding the systematic errors using appropriate experimental topics and devices, and let teachers perform them. After that, we interviewed to see how teachers' perceptions of experimental errors have changed. And we found that experience of these physic experiments can also affect the teachers' perception of the laboratory instructions. We expect that, if the results of this study are expanded and applied to in-service training programs for experiments, teachers will be able to recognize the relationship between theory and experiment, and it will help students understand the nature of science through laboratory instructions.

The effects of experimenter habituation and trial and error experiences on emulation in typically developing toddlers

Rothstein, Mindy Bunya Columbia University 2010 해외박사(DDOD)

소속기관이 구독 중이 아닌 경우 오후 4시부터 익일 오전 9시까지 원문보기가 가능합니다.

I tested for the presence of emulation in typically developing toddlers. I also set out to determine whether incidental learning as "trial and error" manipulations of experimental apparatuses would induce emulation in the children who had not demonstrated emulation. Using a comparison design to compare the performance of two groups, in Experiment 1 I analyzed the performance of typically developing 2-year-olds (ages 24--36 months) who were habituated to the experimenter prior to being tested for emulation with those who were not habituated to the experimenter prior to testing. The results demonstrated that habituated 2-year-olds emulated, while non-habituated 2-year-olds did not. Based on these findings, I recruited new participants (ages 18--23 months) who I habituated to me and tested them for emulation. Those (eight experimental participants and eight control participants) not demonstrating emulation received a "trial and error" treatment package. Using a time-lagged experimental-control with a nested single case multiple probe design across participants, I compared experimental and control groups while controlling for maturation to determine the presence of emulation and the effectiveness of a trial and error treatment package. Results demonstrated that the trial and error treatment package successfully induced emulation in experimental participants while the control participants (who had not received the treatment package) still did not emulate. After the experimental participants learned to emulate, the control participants were also given the trial and error treatment package, which induced emulation in them as well. Key words: Imitation, Emulation, Developmental Cusps.

Resistance is not futile: An experimental analogue of "resistance" effects on the consultant's therapeutic behavior in the treatment of disruptive students

Cautilli, Joseph Temple University 2005 해외박사(DDOD)

소속기관이 구독 중이 아닌 경우 오후 4시부터 익일 오전 9시까지 원문보기가 가능합니다.

This study presents an experimental analogue of resistance in the consultation process. Using a reversal design, the experimenter measured the ecological effects of teacher resistant behaviors on consultant therapeutic behavior. The study defined therapeutic behaviors as teaching, confronting and problem identification, analysis, and evaluation statements as outlined by Bergan and Kratochwill (1990). In this study, the author instructed four school psychology students and one student from a masters program in behavior analysis that this was a study of resistance in the consultation process with teachers. The experimenter instructed the participants that analysis of the sessions would determine if any resistance occurred and how they managed it. The teacher was a double agent, in the sense that s/he was working with the experimenter. The study measured participants' behavior on therapeutic statements made to the teachers during varying levels of resistant statements made by teachers. The experimenter met with teachers on weekly basis. Overall, the participants had between 12-15 sessions (variation due to missed sessions by the consultant) with the teacher. The team consisting of the experimenter and teacher met weekly to discuss the previous sessions data and what do in the next session. The experimenter instructed the teachers on the type of session that they were supposed to provide: when to be resistant and when to be nonresistant in the study. When a stable baseline occurred, the experimenter instructed the teachers to become resistant. The resistance continued for several (3-4) active sessions. After this phase, the experimenter instructed the teachers to become compliant again for several (3-4) sessions. When the experimenter observed stability in the data, the experimenter instructed the teachers to become resistant until the end of the study (between 2-3 sessions). The experimenter measured intervention integrity by coding teachers' behaviors to determine if they were resistant in resistant phases and not resistant in the nonresistant phases. At the end of each session, consultants coded their overall rating of their beliefs of the teacher's skill level, warmth, and ability. It is clear that in the A phases of intervention, the participants emitted more therapeutic statements than during the B phases. In addition, looking at the participants' perception of their own effectiveness as consultants and their perception of the warmth and competence of consultees' behavior, the participants were more confident in themselves and rated the consultees as more effective in the A phases than in the B phases. The data supports the notion that the intervention affected the participants' number of therapeutic statements. We found that all participants decreased therapeutic questioning in response to consultees' resistance. In addition, the resistance also led to increased number of missed sessions by the participants and greater negative perceptions of the consultees by the participants. (Abstract shortened by UMI.).

中學校 科學 實驗 學習의 效果的인 指導 方案에 관한 硏究

김중헌 漢陽大學校 敎育大學院 1994 국내석사

We're in this Together: An Experimental Test of Communal Appraisal and Coping Intentions

Bright, Emma ProQuest Dissertations & Theses University of Cali 2019 해외박사(DDOD)

소속기관이 구독 중이 아닌 경우 오후 4시부터 익일 오전 9시까지 원문보기가 가능합니다.

Background: The extensive literature on stress and coping primarily focuses on intra-individual processes. The vital role of close relationships in influencing psychosocial, physiological, and behavioral adaptation to stressors warrants greater attention. The construct of communal coping involves two processes: an appraisal of the stressor as shared (i.e., "our problem" as opposed to "my/your problem") and cooperative efforts to manage the stressor (Lyons, Mickelson, Sullivan, & Coyne, 1998). Research suggests that communal coping is associated with greater relationship satisfaction, more positive relationship processes, and lower engagement in unhealthy behaviors. However, the current body of literature is entirely correlational and has yet to eliminate third variable or reverse causality explanations. Intended to provide a more definitive test of the effects of communal coping, the present controlled experiment was designed to test the effects of induced communal appraisal and coping intentions on relevant psychosocial, physiological, and behavioral outcomes.Method: Adults currently in an intimate relationship (N = 133) were randomized to write about a conflict in their relationship from a communal perspective as the couple's problem, a non-communal perspective as the participant's problem, or a non-communal perspective as the partner's problem over two in-person laboratory sessions. Participants completed psychosocial, relational, and behavioral measures within each writing session and one week prior to and following the writing sessions. The present study examined differences between experimental conditions in primary outcomes (negative affect, relationship satisfaction, physical symptoms, alcohol use, heart rate) and secondary outcomes (perceived stress, sleep, interpersonal approach behaviors) over time, as well as moderators (dispositional communion, attitudes toward emotional expression).Results: Experimental condition produced a statistically significant effect on change in state partner-directed negative affect from Session 1 pre-induction to Session 2 post-induction, with greater decreases in state partner-directed negative affect for participants in the Communal Coping condition than participants in the Non-Communal Partner condition. Participants in the Communal Coping condition had increases in physical symptoms, whereas participants in the Non-Communal Partner condition had decreases in self-reported physical symptoms. Experimental condition had no significant effect on relationship satisfaction, heart rate reactivity or recovery, interpersonal approach behaviors, and sleep. Dispositional communion significantly moderated the effect of experimental condition on within-session state individual negative affect and perceived stress, as well as perceived stress at one-week follow-up, such that participants with greater dispositional communion assigned to the Communal Coping condition experienced greater improvement on those variables than did participants in the Non-Communal conditions. Attitudes toward emotional expression significantly moderated the relationship between experimental condition and change in alcohol use from baseline to follow-up, participants in the Non-Communal Partner condition with more positive attitudes toward emotional expression had greater increases in alcohol use from baseline to follow-up than participants in the Communal Coping condition.Conclusions: Taken collectively, the findings suggest that experimentally-induced communal appraisal and coping intentions may benefit individuals during relationship conflicts, particularly by buffering against negative partner-directed affect, individual negative affect, and perceived stress. However, induced communal coping produced an increase in physical symptoms, and further research is needed to examine the potential costs of coping communally.

코카인에 의한 백서 심근병변에 대한 조직학적 연구

김애란 梨花女子大學校 1990 국내박사

마약 사용자가 급격히 늘어감에 따라 최근 몇 년 사이로 코카인이 심장에 미치는 영향에 대한 관심이 높아지고 있으나 실제로 코카인 단독 투여후 심장에 어떠한 영향을 미치는지에 대해서는 아직 논란이 많다. 이에 저자는 코카인 단독 투여후 처치기간과 투여총량이 심근변화에 미치는 형태학적 변화를 관찰하여 인체에서 보고된 여러 심장병의 원인과 그 기전을 파악하고자 이 실험을 시도하게 되었다. 실험동물은 체중 200그램내외의 웅성백서 80마리를 사용하여 정상대조군(제I군), 코카인 소량 투여군(제II군, 30mg/kg/day), 대량 투여군(제III군, 45mg/kg/day)으로 나누어 8주간 매주 도살하여 적출한 심근 조직편을 가지고 H & E 염색 및 특수염색을 하여 광학현미경으로 검색하였고 또 격주로 전자현미경으로 검색하여 심근의 형태학적 변화를 관찰하여 다음과 같은 결론을 얻었다. 1. 심근의 조직학적 변화로는 정도의 차이는 있으나 H & E 염색상 심근의 수축대(contraction band)가 제II군에서는 3, 4주에, 그리고 제III군에서는 2, 3주에 가장 심하게 관찰되었다. 2. 호산성 괴사(eosinophilic necrosis)는 제II군에서는 7, 8주에 국소적으로, 제III군에서는 국소적 및 미만성으로 2주부터 경도 및 중등도로 나타나기 시작했다. 임파구성 심근 염증(lymphocytic myocarditis)은 제II군으로는 6주부터, 제III군에서는 2주부터 경도 및 중등도의 염증세포 침윤이 관찰되었고 모든 심근의 변화에 제III군에서 제II군 보다 심한 변화를 보였다. 3. 심근의 특수염색 소견으로는 허혈성 변성(ischemic change)이 실험초부터 국소적 혹은 미만성으로 관찰되었으며 제II군보다 제III군에서, 기간이 길어질수록 증가함을 관찰할 수 있었다. 심근에 선문(striation)의 소실은 투여량이나 기간에 관계없이 경도로 산발적인 분포를 보였으며 당원(glycogen)의 소실이 현저히 나타났고 간질 섬유 증식은 기간이 길어질수록 증가되었다. 4. 관상동맥의 분지에서는 뚜렷한 내막증식은 없었으며 동맥벽의 섬유소(fiber) 및 공포(vacuole) 등으로 인한 비후를 볼 수 있었으며 이는 특수염색상이나 전자현미경으로 확인되었다. 5. 심근 섬유의 전자현미경적 소견은 초기에 미토콘드리아의 종창 및 막 파괴를 보였으며 수축대의 무형질의 진한 내용물(amorphous dense material), 근섬유의 파괴, 개재 판(intercalate disk)의 손상등이 제II군, 특히 제III군에서 잘 관찰되었다. 이상의 결론을 종합해 보면 코카인 투여에 의한 심근 섬유의 변화는 수축대, 허혈성 변성, 호산성 괴사 및 임파구성 염증반응이 특징적이었으며 처치량이 증가함에 따라, 투여기간이 길수록 경도로 증가함을 관찰할 수 있었다. As the usage of narcotics, especially that of cocaine increases, cocaine-associated cardiotoxicity is also observed to increase. For example, illicit use of cocaine has been associated with sudden death (Wetli and Wright, 1979; Mittleman and Wetli, 1984), myocardial infarction with or without anatomically normal coronary artery (Coleman, et al, 1982; Pasternack, et al, 1985; Howard, et al, 1985; Weiss, 1986), myocarditis (Isner, et al, 1986; Simpson and Edwards, 1986; Virmani, et al, 1987; Isner, et al, 1985), chronic heart failure (Wiener, et al, 1986; Karch and Billingham, 1988), fatal arrythmia (Isner, et al, 1985), but very little is known about how cocaine alone affect the heart. This experimental study was aimed to observe the morphological changes of the myocardium induced by cocaine in rats and thereby clarify the pathophysiology of cocaine-associated cardiotoxicity in humankind. The experiment was conducted by using 80 albino Sprague Dawley male rats which were divided into three groups: The group I (16 rats) was used as the control group with normal saline; the group II (32 rats) was given daily intraperitoneal injection of 30mg/kg of 0.3% cocaine, and the group III (32 rats) was given daily intraperitoneal injection of 45mg/kg of the same cocaine. The experiment continued for 8 weeks and each of the 4 rats was sacrificed every week for the light microscopic examination of the heart (H & E stain, 5 different special stains) and every other week for the electron microscopic examination. The results were as follows: 1. Light microscopically, myocardial contraction band appeared both in the cocaine treated groups, but it appeared at 3 to 4th week in the group II and disappeared as the experiment continued whereas in group III, it appeared at 2 to 3rd week and persisted through out the experiment. 2. Eosinophilic necrosis was observed at 7 to 8th week in group II whereas in group III, it appeared mildly to moderately at 2nd week. Lymphocytic myocarditis began about 6th week in group II as compared to about 2nd week in the group III. All the myocardial findings were more intensly noted in group III than in group II and as the duration of the experiment prolonged. 3. The special stain of the myocardium revealed focal to mildly diffuse ischemic changes from the beginning of the experiment. The changes were more intense in group III than in group II and the myocardial changes increased as the duration of the experiment prolonged. The loss of the striation of myofibrils showed mild to diffuse distribution with no relation to the dosage nor duration. The loss of glycogen was typical as the duration of cocaine administration increased along with interstitial fibrotic proliferation. 4. There were no evidences of intimal proliferation nor atherosclerotic changes in coronary arteries in both groups, but mild hypertrophy of the vessel wall was noted due to the collagen proliferation and vacuoles in both cocaine treated groups. No evidence of intimal proliferation and thrombus was confirmed by the use of special staining and electron microscopy. 5. Electron microscopic findings in group II and group III showed early mitochondrial swelling and mitochondrial membrane destruction as well as amorphous dense material in contraction band which soon followed by the destruction of myofibrils and intercalate disk. These findings were more intense with group III than in group II. All in all, typical findings of the cocaine induced myocardial changes included early alteration of mitochondria with contraction band, ischemic changes, eosinophilic necrosis and lymphocytic myocarditis which in generalization, intensified in group III than in group II, and as the experiment prolonged.

하악골신장술시 불화나트륨 투여의 초기효과에 대한 실험적 연구

정동희 경희대학교 2000 국내박사

Distraction osteogenesis is a surgical-orthopedic technique to lengthen a bone by separating or distracting a fracture callus. The purpose of this study was to observe the effects of sodium fluoride on the bony repair and regeneration processes after distraction osteogenesis in dogs. Four adult dogs were employed for this experiment. Four dogs were divided into experimental and control groups. The distraction was undertaken at the rate of 0.75mm a day for 15 consecutive days to yield 12.25mm lengthening of mandibular corpus. One mg NaF/kg of body weight/day were given orally to the experimental group. The animals were euthanized at two and four weeks after the completion of distraction, and radiologic, histologic, and histomorphometric examinations were achieved. The results were as follows ; 1. At two weeks after completion of distraction, the active osteoblasts lining the osteoid at the surface of trabecular bony spicules and active new bone formation were observed in the both groups. However, the cellular activity and new bone formation were more prominent in the experimental group. 2. At four weeks after completion of distraction, the continuous osteoid and new bone formation and active osteoblasts were observed in the experimental group. But these phenomena were decreased in the control group. These results imply that sodium fluoride has the stimulation effects on the osteoid production of the osteoblasts during the healing process after distraction osteogenesis more continuously.

CD244 in the pathogenesis of experimental autoimmune encephalomyelitis : Implication of natural killer cells in autoimmune disease

빙소진 제주대학교 대학원 2016 국내박사

초음파장에서 빛을 발산하는 기포의 반경 및 스펙트럼에 관한 연구

전진석 中央大學校 2000 국내박사

Adriamycin이 백서 심근과 폐조직에 미치는 형태학적 및 심근 Myoglobin변화에 관한 실험적 연구=

김영진 이화여자대학교 1987 국내박사