• 제목/요약/키워드: Two-dimensional

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세기조절방사선치료(IMRT)의 Commissioning 및 정도관리: AAPM TG119 적용 (Intensity Modulated Radiation Therapy Commissioning and Quality Assurance: Implementation of AAPM TG119)

  • 안우상;조병철
    • 한국의학물리학회지:의학물리
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    • 제22권2호
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    • pp.99-105
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    • 2011
  • 본 연구에서는 미국의학물리학회(AAPM)에서 제안된 세기조절방사선치료(IMRT)의 commissioning 및 정도관리를 위해 제안된 일련의 시험을 통해 본원의 세기조절방사선치료의 정확도를 평가하고 정도관리 절차를 수립하고자 하였다. TG119에 제시된 5가지 세기조절방사선치료의 표적체적: multi-target, 두경부, 전립선, 및 두 가지의 C-shape (easy&hard)을 대상으로 CT 스캔된 팬텀을 이용하여 치료계획시스템에서 IMRT 치료계획을 수행하였다. 얻어진 치료계획을 dynamic sliding window 전달방식으로 팬텀에 조사하였다. 절대 선량은 표적 및 위험장기 부위에 이온 전리함(CC13, IBA)을 이용하여 측정하고, 2차원 상대 선량분포는 EBT2 필름을 사용하여 측정하였다. 측정된 값들은 해당하는 치료계획시스템 계산값과 비교하여 오차의 평균 및 표준편차를 구하였다. 이를 바탕으로 TG119에 제시된 신뢰구간을 계산하여 제시된 값과 비교하였다. 이온 전리함을 이용한 측정 결과에서 표적 및 위험장기에 대한 계산값과 측정값 사이의 평균오차는 각각 $1.2{\pm}1.1%$$1.2{\pm}0.7%$이었고, 95% 신뢰구간은 각각 3.4%와 2.6%으로 TG119에서 제시하고 있는 4.5%와 4.7% 이내에 있었다. 필름을 이용한 측정 결과에서는 허용기준 3%/3 mm를 통과하는 감마인덱스는 평균$ 97.7{\pm}0.8%$로 95% 신뢰구간은 3.9%로 TG119에서 제시하고 있는 7.0% 이내에 있었다. 따라서 TG119에서 제시된 일련의 표준화된 시험을 통해 본원의 세기조절방사선치료의 commissioning 및 정도관리를 평가할 수 있었다. 이온 전리함을 이용한 절대 선량에 대한 action level은 표적과 위험장기에서 각각 ${\pm}4%$${\pm}3%$로, EBT2 필름을 이용한 2차원 상대선량분포는 허용기준 3%/3 mm 기준으로 감마인덱스 1이하를 통과하는 비율이 96%로 정할 수 있었다. 이를 통해 TG119에서 제시된 일련의 표준화된 시험을 통해 각 기관의 IMRT 정확도 평가에 대한 객관적인 지표로 이용될 수 있을 것으로 기대된다.

고등학생의 건강 및 삶의 질에 대한 진단적 연구 - PRECEDE 모형을 근간으로 - (A Diagnostic Study on High School Students' Health and Quality of Life - Based on the PRECEDE model -)

  • 유재순;홍여신
    • 한국간호교육학회지
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    • 제3권
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    • pp.78-98
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    • 1997
  • Health education, as the most fundamental concept for national health promotion, alms for developing the self-care ability of the general public. High school days are regarded as the period when most important physical, mental and social developments occur, and most health-related behaviors are formed. School health education is one of the major learning resources influencing health potential in the home and community as well as for the individual student. High school health education in Korea has a fundamental systemic flaw in that health-related subjects are divided and taught under various subjects areas at school. In order to achieve the goal of school health education, it is essential to make a systematic assessment of the learner's concerns connected with his health and life, and the factors affecting them. So far, most of the research projects that had been carried out for improving high school health education were limited in their concerns to a particular aspect of health. Even though some had been done in view of comprehensive school health education, they failed to Include a health assessment of the learner. Therefore, in this study the high school students' concerns related to health and life were investigated in the first place on the basis of the PRECEDE model, developed by Green and others for the purpose of a comprehensive diagnostic research on high school health education. This study was done in two steps : one was the basic study for developing research instrument and the other was the main one. The former was conducted at five high schools in Seoul and Cheongju for 2 months-beginning in March, 1996. The students were asked to respond to questions related to their health and lives in unstructured open-ended question forms. On the basis of analysis of the basic study, the diagnostic instruments for the quality of life, health problems, health behavior and educational factors were constructed to be used for the collection of data for main study. An expert panel and the pilot study were used to improve content validity and reliability of the instruments. The reliability of the instruments was measured at between .7697 and .9611 by the Cronbach $\alpha$. The data for this study were collected from the sample consisted of the junior and senior classes of twenty general and vocational high schools in Seoul and Cheongju for two months period beginning in July, 1996. In analyzing the data, both t-test and $X^2$-test were done by using SAS-$PC^+$ Program to compare data between the sexes of the high school students and the types of high school. A canonical correlation analysis was carried out to determine the relationships among the diagnostic variables, and a multivariate multiple regression analysis was conducted by using LISREL 8.03 to ascertain the influences of variables on the high school students' health and quality of life. The results were as follows : 1) The findings of the hypothesis tests (1) The canonical correlation between the educational diagnosis variables and behavioral, epidemiological, social diagnosis variables was .7221, which was significant at the level of p<.001. (2) The canonical correlation between the educational diagnosis variables and the behavior variables was .6851, which also was significant (p<.001). (3) The canonical correlation between the behavioral diagnosis variables and the epidemiological variables was 4295, which was significant (p<.001). (4) The canonical correlation between the epidemiological diagnosis variables and the social variables was .6005, which was also significant (p<.001). Therefore, the relationship between each diagnosis variable suggested by the PRECEDE model had been experimentally proven to be valid, supporting the conceptual framework of the study as appropriate for assessing the multi-dimensional factors affecting high school students' health and quality of life. Health behavior self-efficacy, the level of parents' interest and knowledge of health, and the level of the perception of school health education, all of which are the educational diagnostic variables, are the most influential variables in students' health and quality of life. In particular, health behavior self-efficacy, a causative factor, was one of the main influential variables in their health and quality of life. Other diagnostic variables suggested in the steps of the PRECEDE model were found to have reciprocal relations rather than a unidirectional causative relationship. The significance of this research is that it has diagnosed the needs of high school health education by the learner-centered assessment of variety of factors related to the health and the life of the students. This research findings suggest an integrated system of school health education to be contrived to enhance the effectiveness of the education by strengthening the influential factors such as self-efficacy to improve the health and quality of the lives of high school students.

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2차원 바코드를 이용한 오디오 워터마킹 알고리즘 (A digital Audio Watermarking Algorithm using 2D Barcode)

  • 배경율
    • 지능정보연구
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    • 제17권2호
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    • pp.97-107
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    • 2011
  • 본 논문에서는 2차원 바코드를 이용한 오디오 워터마킹 알고리즘을 제안하였다. 삽입되는 워터마크 정보로는 2차원 바코드인 QR 코드를 변형하여 이용하였다. 2차원 바코드가 1차원 바코드에 비하여 많은 정보를 표현할 수 있고, 코드자체가 에러 보정능력을 내재하고 있는 장점을 이용하여 워터마킹 알고리즘의 견고성을 높였다. 또한 부분적인 워터마크 정보의 손실에 대응하기 위하여 직교코드를 이용하여 삽입대역을 확산했으며, 삽입강도 0.7에서 50dB 이상의 우수한 품질을 확보할 수 있었다.

단층치료기를 이용한 방사선 치료의 환자별 정도관리 평가를 위한 감마인덱스의 정량화 방법 (A Method to Calculate a Pass Rate of the ${\gamma}$-index Analysis in Tomotherapy Delivery Quality Assurance (DQA))

  • 박달;김용호;김원택;김동원;김동현;전호상;남지호;임상욱
    • 한국의학물리학회지:의학물리
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    • 제21권4호
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    • pp.340-347
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    • 2010
  • 단층치료기(TomoTherapy$^{(R)}$)를 이용한 방사선 치료에서 환자별 정도관리인 DQA (delivery quality assurance)는 보통 이온 전리함과 필름을 이용한다. DQA의 결과는 치료계획장비인 TomoPS (Tomo Planning Station)를 이용하여 분석하게 되는데 필름을 이용한 2차원 선량분포의 비교는 감마인덱스 분석을 사용한다. 감마인덱스를 이용한 비교는 3%/3 mm와 같은 기준을 사용하여 이 기준을 통과한 비율(pass rate)이 허용 값보다 크게 되는지 확인한다. TomoPS는 pass rate 값을 정량적으로 계산해주는 기능이 없다. 본 논문에서는 TomoPS 감마인덱스 분석의 pass rate를 정량적으로 계산하는 방법을 제시하고 이를 계산해주는 프로그램인 PassRT를 개발하였다. PassRT의 검증을 위해 I'mRT MatriXX (IBA Dosimetry, Germany)를 사용하여 측정한 세기조절방사선 치료를 받은 환자의 환자별 정도관리 자료와 필름을 사용한 DQA 자료를 사용하였다. 두 가지 종류의 자료에 대해 PassRT로 계산한 pass rate를 OmniPro I'mRT (IBA Dosimetry, Germany)프로그램으로 계산한 pass rate와 비교하였다. MatriXX를 이용하여 측정한 자료의 비교결과 평균오차 0.00%, 표준편차 0.01%, 최대오차 0.04%였고, 필름의 결과는 평균오차 0.00%, 표준편차 0.02%, 최대오차 0.02%였다. 관심영역이 $24.3{\times}16.6cm^2$ 보다 작은 경우 본 논문에서 제시한 방법으로 감마인덱스 분석의 pass rate를 소수점 첫째자리 까지 정확하게 계산할 수 있어서 보다 정확한 단층치료기의 DQA에 도움이 될 것으로 생각된다.

콘빔 CT 및 MLC 로그데이터를 이용한 전달 선량 재구성 시 오차 분석 (Error Analysis of Delivered Dose Reconstruction Using Cone-beam CT and MLC Log Data)

  • 정광호;박소아;강세권;황태진;이미연;김경주;배훈식;오도훈
    • 한국의학물리학회지:의학물리
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    • 제21권4호
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    • pp.332-339
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    • 2010
  • 본 연구에서는 콘빔 단층촬영영상(cone beam CT; CBCT) 및 다엽 콜리메이터(multileaf collimator;MLC) 로그데이터를 이용한 적응형 방사선치료기법의 체계를 구축하고, 그 과정에서의 선량 계산 오차의 양상을 팬텀을 이용하여 분석하고자 하였다. Catphan-600 (The Phantom Laboratory, USA) 팬텀을 CT와 CBCT 촬영 후 CT 영상을 이용하여 간단한 단계별조사(step-and-shoot) 방식의 세기조절방사선치료(intensity-modulated radiation therapy; IMRT) 계획을 수립하였다. 이후 빔전달 시 생성된 MLC 로그데이터(Dynalog)를 이용하여 실제 전달된 세그먼트 별 모니터단위(MU) 가중치와 MLC 엽(leaf)의 위치를 구한 후 이를 다시 Pinnacle3에 넣고 선량을 재계산하였다. 초기 치료 계획은 치료 계획용 CT 영상($CT_{plan}$) 및 CBCT 영상($CBCT_{plan}$)에 대하여 계산되었으며, 재구성된 선량 역시 치료 계획용 CT 영상($CT_{recon}$) 및 CBCT 영상($CBCT_{recon}$)에 대하여 계산되었다. 각 선량 계산을 $CT_{plan}$을 기준으로 하여 2차원 선량분포, 감마 인덱스, 선량-부피 히스토그램(dose-volume histogram; DVH)을 이용하여 분석하였다. 2차원 선량분포 및 DVH 분석 모두에서 원래의 치료 계획보다 실제 전달된 선량이 다소 많은 것으로 나타났으나 임상적인 의미는 미미했다. 감마 인덱스의 경우 CBCT에 선량을 계산했을 때 치료 계획 정보나 재구성된 선량 정보를 이용한 경우 모두 오차가 크게 발생했다. 재구성된 선량은 빔의 경계 부분에서 오차가 크게 발생하였으나 그 영향은 CT 및 CBCT 영상 간 차이에 의한 것보다 작았다. CBCT 영상에 전달된 선량을 재구성하게 되면 두 영향이 복합적으로 작용하여 오차는 더 줄어들게 되지만 $CT_{plan}$$CBCT_{plan}$의 차이에 비하여 $CBCT_{plan}$$CBCT_{recon}$ 차이는 상대적으로 작아 전달된 선량의 오차를 평가할 때 불확실성이 커졌다. 그러므로 선량 계산 오차의 양상은 셋업 오차, CBCT 영상을 이용한 선량 계산 오차 및 재구성된 선량 계산의 오차로 나누어 분석될 필요가 있을 것이다.

의복단서, 지각자변인이 여자한복착용자의 인상형성에 미치는 영향(I) - 의복단서를 중심으로 - (Effect of Clothing cues and perceiver variables on Impression Formation of Female dressed in Korean Dress(Part I) - Focus on Clothing Cues -)

  • 박찬부
    • 복식
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    • 제32권
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    • pp.313-336
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    • 1997
  • Nineteen stimulus photograghs varied in hue and color scheme of one clothing style of Korean dress worn by a female were used to investigate the effect of color color scheme and structure on impression formation for Korean dress. Subjects were 77 male and 86 female undergraduate and graduate students. The stimuli c9onsisted of two sets(cool and warm) of four similar color schemes two sets (cool and warm in Chima color) of five contrasting color schemes and one extra stimulus triad 3 hue base. Structures were de-fined by color schemes of Kit.Korum toward the color schemes of Jokori and Chima. Stimu-lus photogragh selected from Korean dress fashion magazines was managed and varied in hues and color schemes to Kit Korum Jokori and Chima according to Korean Standard Color through scanning and Adobe photoshop 3.0 program and then pictured through slide printer(HR-6000). Each subject assessed 19 stimulus color photographs with incorporated 7 point semantic differential response scale. The data were analyzed by frequency mean factor analysis t-test ANOVA and Scheffe test. Results indicate impression ofrmations are af-fected by clothing cues. 1) Four factors emerged to account for dimensional structure of impressions of female features on Korean dress. These four factors were titled as(1) preference.evaluation (2) individuality.attention (3) youth and (4) friendshio. The preference.evaluation factor was the largest including eleven adjectives and accounting for 29.62% of the variances. 2) Almost every clothing cue(color, color scheme, structure) had some effects on im-pressions formed But the color of Chima did not form the effects on impression of prefer-ence.evaluation factor. The effect of related color scheme was the most influential clothing cue on impressions of preference.evalation factor and friendship factor whereas the ef-fect of contrasting color scheme was the most influential clothing cue on impressions of indi-viduality.attention factor and youth factor. The effect of cool color of Chima was the most influential clothing cue on impression of indi-viduality.attention factor whereas the effect of warm color of Chima was the most influen-tial clothing cue on impressions of youth factor and friendship factor. The effect of Jokori/Chima.Kit.Korum structure was the most influential clothing cue on impressions of pref-erence.evaluation factor and youth factor whereas the effect of Kit.Korum/Jokori.Chima structure was the most influential clothing cue on impressions of individuality.attention factor and friendship factor. 3) The interaction effects were appeared among clothing cues. Significant interaction effects between color schemes(similar and contrasting) and colors of Chima(cool and warm were appeared on impressions of prefer-ence.evaluation factor imdividuality.atten-tion factor and friendship factor, Significant interaction effects between color schemes (similar and contrasting) and structures (Jokori.Chima.Kit.Korum; Jokori.Kit.Koru-m/Chima;Jokori/Chima.Kit.Korum;Kit.Korum/Jokori.Chima) were appeared on impressions of preference.evaluation factor youth factor and friendship factor. Signifi-cant interaction effects between colors(cool and warm) and structures were appeared on impressions of individuality.attention factor youth factor and friendship factor. Sighifi-cant interaction effects between colors(cool and warm) and structures were appeared on impressions of individuality.attention factor youth factor and friendship factor. Significant interaction effects among clothing cues(color color schemes and structures) were appeared on all impression factors. The friendship factor was the most friquently affected impression factor by interaction effects among clothing cues. In summary the clothing was used as nonverbal cues in the effect on impression for-mation of female dressed in Korean dress. it concluded that color schemes worked as cen-tral traits and colors of Chima and structures worked as peripheral traits in the formation of impression of the female clothed in Korean dress. hence organizing our impressions with respect to the parts of the Korean dress in re-lation to the whole holistic perceptual pro-cess Gestalt approach was used and supported.

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고해상도 조영증강 삼차원 회손기울기 회상 영상을 이용한 측면연수경색 환자의 두개내 척추동맥 및 뒤아래소뇌동맥 평가 (High-Resolution Contrast-Enhanced 3D-Spoiled Gradient-Recalled Imaging for Evaluation of Intracranial Vertebral Artery and Posterior Inferior Cerebellar Artery in Lateral Medullary Infarction)

  • 윤영노;안성준;서상현;박아영;정태섭
    • Investigative Magnetic Resonance Imaging
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    • 제18권1호
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    • pp.17-24
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    • 2014
  • 목적: 측면연수경색 환자의 두개내 척추동맥 및 뒤아래소뇌동맥 평가에 있어 고해상도 조영증강 삼차원 회손기울기에 코 회상영상의 역할 규명하고자 한다. 대상과 방법: 임상시험심사위원회에서 승인한 측면연수경색으로 확진된 25명의 환자를 대상으로 하였다. 모든 환자는 3T 자기공명 영상을 이용한 고해상도 조영증강 삼차원 회손기울기에코 회상영상과 조영증강 자기공명 혈관조영술을 받았다. 두 명의 영상의학과 의사는 환자의 임상정보와 확산강조영상 없이 두개내 척추동맥 및 뒤아래소뇌동맥에 있는 동맥병변을 평가하였다. 두개내 척추동맥과 뒤아래소뇌동맥의 병변 동반유무에 따라 임상정보와 측면연수경색의 넓이, 소뇌경색 동반여부를 비교하였다. 결과: 총 25명의 환자 중 22명의 환자가 고해상도 조영증강 삼차원 회손기울기에코 회상영상으로 두개내 척추동맥 및 뒤아래소뇌동맥에서 박리, 죽종, 혈전색전증을 보였다. 그러나 그 중 12개의 뒤아래소뇌동맥의 병변은 조영증강 자기공명 혈관조영술에서 보이지 않았다. 추가적인 소뇌경색은 두개내 척추동맥과 뒤아래소뇌동맥에 병변이 있을 경우 두개내 척추동맥에만 병변이 있는 경우보다 빈번하게 나타났다. 결론: 고해상도 조영증강 삼차원 회손기울기에코 회상영상은 측면연수경색 환자의 두개내 척추동맥 및 뒤아래소뇌동맥의 병변평가에 도움을 줄 수 있다.

증강현실 영화포스터 제작연구 (Study for making movie poster applied Augmented Reality)

  • 이기호
    • 만화애니메이션 연구
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    • 통권48호
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    • pp.359-383
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    • 2017
  • 3000년 전 이집트에서 인류 최초의 포스터가 등장한 이후 인쇄술의 발명과 문명의 발전으로 포스터 제작기술이 가속화 되었다. 이에 발맞추어 포스터의 표현 또한 단순 문자 배열에서 예술적 감성을 함께 표현하려는 시도로 발전되었으며, 이제는 전문 디자이너의 영역으로 자리 잡은 하나의 예술 형식이 되었다. 하지만 포스터의 표현 방식에 대한 기술적 변화는 이차원적 발전에 머무르고 있으며, 현대의 멀티미디어를 기반으로 하는 ICT 환경변화와는 무관한 듯 인쇄에만 의존하고 있는 상황이다. 특히, 수많은 종류의 포스터 가운데 유일하게 영상물을 대상으로 하는 영화 포스터의 양식이 아직도 종이인쇄에 그치고 있고, 지금까지 여러 시도는 있어 왔지만 영화계는 여전히 ICT 접목에 대해서는 전혀 고려치 않는 듯 같다. 이 연구는 영화포스터의 대상이 영상물을 다루고 있다는 특징으로부터 시작하여 영화의 동적 이미지를 정적 포스터에 접목시키기 위해 증강현실을 도입하는 시도를 하였다. 국내 한 대학의 영상디자인전공 졸업작품에서 학생들의 영상작품홍보를 위한 각 작품들의 포스터를 일반 상업영화 포스터 형식으로 디자인하여 인쇄하였으며, 이 중 증강현실 적용에 적합하다고 판단되는 6작품을 선별하여 증강현실을 도입하고 전시하였다. 모바일 디바이스를 통해 포스터와 정합되어 나타나는 콘텐츠는 영상물의 한 장면이 포스터 위에서 재현되지만, 원래 포스터가 표현하고 있는 텍스트 정보 등은 그대로 유지되도록 하여, 마치 영화 "해리포터"에서 등장한 현상수배 포스터와 같이 움직이는 포스터를 구현할 수 있었다. 본 증강현실 포스터 제작을 위해 두 가지 다른 형식으로 제작된 기존 상업영화의 포스터에 증강현실을 도입해 봄으로써 AR 콘텐츠의 특징을 배가시킬 수 있는 방법을 찾아 본 작품에 적용할 수 있었다. 이를 통해 AR 표현이 적합한 포스터디자인을 알 수 있었으며, 증강현실 콘텐츠 제작의 정합과정에서 증강현실의 안정적 구동을 위한 기술적 표현에 대해 정리할 수 있었다.

Regulation of Tumor Neceosis Factor-${\alpha}$ Receptors and Signal Transduction Pathways

  • Han, Hyung-Mee
    • Toxicological Research
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    • 제8권2호
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    • pp.343-357
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    • 1992
  • Tumor necrosis factor-${\alpha}$(TNF), a polypeptide hormone secreted primarily by activated macrophages, was originally identified on the basis of its ability to cause hemorrhagic necrosis and tumor regression in vivo. Subsequently, TNF has been shown to be an important component of the host responses to infection and cancer and may mediate the wasting syndrome known as cachexia. These systemic actions of TNF are reflected in its diverse effects on target cells in vitro. TNF initiates its diverse cellular actions by binding to specific cell surface receptors. Although TNF receptors have been identified on most of animal cells, regulation of these receptors and the mechanisms which transduce TNF receptor binding into cellular responses are not well understood. Therefore, in the present study, the mechanisms how TNF receptors are being regulated and how TNF receptor binding is being transduced into cellular responses were investigated in rat liver plasma membranes (PM) and ME-180 human cervical carcinoma cell lines. $^{125}I$-TNF bound to high ($K_d=1.51{\pm}0.35nM$)affinity receptors in rat liver PM. Solubilization of PM with 1% Triton X-100 increased both high affinity (from $0.33{\pm}0.04\;to\;1.67{\pm}0.05$ pmoles/mg protein) and low affinity (from $1.92{\pm}0.16\;to\;7.57{\pm}0.50$ pmoles/mg protein) TNF binding without affecting the affinities for TNF, suggesting the presence of a large latent pool of TNF receptors. Affinity labeling of receptors whether from PM or solubilized PM resulted in cross-linking of $^{125}I$-TNF into $M_r$ 130 kDa, 90 kDa and 66kDa complexes. Thus, the properties of the latent TNF receptors were similar to those initially accessible to TNF. To determine if exposure of latent receptors is regulated by TNF, $^{125}I$-TNF binding to control and TNF-pretreated membranes were assayed. Specific binding was increased by pretreatment with TNF (P<0.05), demonstrating that hepatic PM contains latent TNF receptors whose exposure is promoted by TNF. Homologous up-regulation of TNF receptors may, in part, be responsible for sustained hepatic responsiveness during chronic exposure to TNF. As a next step, the post-receptor events induced by TNF were examined. Although the signal transduction pathways for TNF have not been delineated clearly, the actions of many other hormones are mediated by the reversible phosphorylation of specific enzymes or target proteins. The present study demonstrated that TNF induces phosphorylation of 28 kDa protein (p28). Two dimensional soidum dodecyl sulfate-polyacrylamide gel electrophoresis(SDS-PAGE) resolved the 28kDa phosphoprotein into two isoforms having pIs of 6.2 and 6.1. The pIs and relative molecular weight of p28 were consistent with those of a previously characterized mRNA cap binding protein. mRNA cap binding proteins are a class of translation initiation factors that recognize the 7-methylguanosine cap structure found on the 5' end of eukaryotic mRNAs. In vitro, these proteins are defined by their specific elution from affinity columns composed of 7-methylguanosine 5'-triphosphate($m^7$GTP)-Sepharose. Affinity purification of mRNA cap binding proteins from control and TNF treated ME-180 cells proved that TNF rapidly stimulates phosphorylation of an mRNA cap binding protein. Phosphorylation occurred in several cell types that are important in vitro models of TNF action. The mRNA cap binding protein phosphorylated in response to TNF treatment was purifice, sequenced, and identified as the proto-oncogene product eukaryotic initiation factor-4E(eIF-4E). These data show that phosphorylation of a key component of the cellular translational machinery is a common early event in the diverse cellular actions of TNF.

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평행식 진동탄환 암거 천공기의 연구(III)-견인력, 토크, 동력 및 모멘크에 관한 모형시험- (A Study on Balanced -type Oseillating Mole-Drainer(III)-Model Test for Draft Force, Torque, Power and Moment)

  • 김용환
    • Journal of Biosystems Engineering
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    • 제1권1호
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    • pp.1-6
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    • 1976
  • This paper is the third one of the study on balanced type oscillating mole-drainer, the first one was presented in No 9. Gyeongsang College Report and the second one in Vol. 17, No.4 of the KSAE. In the first part of this study, the characteristics of traction forces between the nonoscillating earth working equipments and oscillating ones was compared. A model of the balanced type oscillating mole-drainer, which composed of a mechanism that may reduce the machine vibration, was designed following the dimensional analysis and similitude technique. The model test was carried out to clarify the balancing mechanism of the oscillating parts and other parts of the machine. In the light of the results from the model tests, a prototype machine was made for experimental purpose. Results from the field test by a reported in the near future. In the second report, the model tests were carried out under the same soil conditions, i.e, . oscillating frequency, running velocity, and oscillating amplitude, etc. It was clear that use of balanced type oscillating model could substantially reduce the vibration of the whole system of the machine, when compared with the nonoscillating type model. In this paper(the third report), results of investigation on the traction force, power requirement, and moment. etc, is presented. Analysis of variance technique was used for analyzing the effect of the frequency, amplitude, and running velocity on the draft force, torque, power requirements, and moments. The results obtained from the model tests are as follows, 1) By practicing a balanced-type oscillating mole-drainer, it was possible to reduce the traction resistance by 55.1-61. 2 percent of traction resistance, however, was 1.75 - 1.95 times greater than the value of resistance which was induced by use of a mole-drainer with single bullet. The resistance of rear shank against soil was considered as a main causing factor of the above results. 2) As the oscillation frequency was increased, the traction resistance was decreased. Considering on the effect of oscillation the greater the amplitude, and the slower the running velocity was, the greater the reduction ratio of traction resistance was. 3) The ratio of the traction resistance of oscillating mole-drainer to that of non-oscillating one could be represented as a function of dimensionless variable (V/$Af$). The results from the tests were well agreed with the reported results from the experim ents on oscillation plow or hoe. 4) By taking a lower value of (V/$Af$), reducing the traction resistance was possible. This fact meant, however, that the efficiency of mole drain practice would be lower. 5) It was experimentally confirmed under the same condition of soil that the variable (R/$rD1^3$) could be represented as a function of a variable($V^2/gD$) when a non\ulcornerocillating mole-drainer was used. 6) When a oscillating mole-drainer was used, the variable(R/$rD_1^{3}$) could be represented as a function of two variables ($v^2/gD_1$) and (V^2/gD_1$). 7) The torque was not affected by a change of frequency. However, a relation of proportionality existed between torque and amplitude, running velocity, and ratio of bullet diameter. When a balanced type oscillating mole-drainer with two bullets was used, torque was increased by 52.8-78. 4 percent and total power requirement was also increased. 8) Total power requirement was increased linearly in accordance with the increasing frequency, 41.96 percent of total power was used for oscillating action. The magnitude of total power requirement was 1. 8-9. 4 times greater than that of a non-oscillating mechanism. In the view point of power requirement, it was not advisable to increase the frequency, amplitude, running velocity, and ratio of bullet diameter at the same time. 9) Only the positive moment occured in the rear shank. Change of the diameter of a rear bullet, could not affect the balancing against the soil resistance. It was necessary for rear bullet to have a large resistance against soil only when the rear bullet was in backward motion. 10) Within an extent of the experimental base, optimum limits for several design factors were A=0.5cm, $f$=22.5Hz, V=O. 05m/sec, and $\lambda$=1.0 By adapting these values traction resistance was reduced by 40 percent and vibration acceleration wa s reduced by 60 percent. Even though the total , power requirements for operating a balanced type oscillation mechanism was greater ~than that of non-oscillating one, using a oscillating mechanism would be more effective. Because a balanced type oscillating mechanism is used, tractive resistance will be reduced and then the lighter . tractive equipment could be used.

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