• Title/Summary/Keyword: Microscopic Level

검색결과 385건 처리시간 0.025초

한국 미디어 정치경제학의 한계와 가능성 탐색 (The Limits and Possibilities of Political-economy Paradigm in Korean Media Studies)

  • 임영호
    • 한국언론정보학보
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    • 제70권
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    • pp.9-34
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    • 2015
  • 미디어 환경에서 급격한 변화가 전개되면서 구조적 접근의 중요성은 높아가고 있다. 그럼에도 불구하고 한국의 미디어 정치경제학은 대내외의 시대 흐름을 포착하지 못한 채 이전의 낡은 틀 안에 갇혀 제 역할을 하지 못하고 있다. 특히 정치경제학은 경제에 관한 설명에서 출발하는데도, 외연 확장에만 치중해 정작 체계적인 경제 이론을 발전시키는 데 소홀했다. 이 글은 국내 미디어 정치경제학의 이론적 한계를 검토하면서 지향해야 할 방향과 연구 의제를 제안한다. 미디어 정치경제학의 자기 혁신을 위해서는 이론의 미시적 토대인 가치 법칙과 거시적 분석 틀을 모두 재검토할 필요가 있다. 특히 스마이드의 수용자 상품론과 정보재 논쟁 등의 논의는 정치경제학의 미시적 토대를 발전시키는 데 큰 잠재력을 갖고 있다. 나아가 미디어 정치경제학은 구체적 사례 분석에서 자본의 원리를 재확인하는 동어 반복적 논리를 벗어나 자본의 구체적 작동 양상을 규명하는 거시적 구조 분석 틀을 개발해야 한다. 자본 축적 과정의 추이, 기술 혁신에 따른 생산력 발전 과정, 노동 양식 변화, 생산 유통 소비 부문 간의 관계, 미디어 산업의 축적 체제 유형화 등이 이러한 작업의 예다.

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납(Pb)이 배양 섬유모세포에 미치는 세포독성에 관한 연구 (A Study on the Cytotoxicity of Lead in Cultured Fibroblasts)

  • 정연태;최민규;김정중;문연자;김재민;백순기
    • 한국환경성돌연변이발암원학회지
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    • 제15권2호
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    • pp.122-130
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    • 1995
  • In order to evaluate the cytotoxicity of lead in cultures of Balb/c mouse 3T3 cell line, various cytotoxic assays were carried out after expose cells to various concentrations of lead nitrate. Cytotoxic assays using this study were included NR assay, MTT assay, measurement of LDH and protein, synthetic rate of DNA and UDS. Intrace!!ular Ca$^{2+}$ level was also measured. Light and electron microscopic studies were done for morphological changes of lead-treated cell cultures. The results were as follows; 1. The absorbances of NR and MTT were decreased dose-dependently, and NR, and MTT, values of lead nitrate were 3.4 mM and 1.5 mM, respectively. 2. Amount of LDH released into the medium was increased in dose-dependently and LDH activity at 5 mM concentration of lead nitrate was increased to 335 % of control. 3. Amount of total protein was decreased dose-dependently, and which was half of control at 2 mM concentration of lead nitrate. 4. The synthetic rate of DNA was decreased dose-dependently, and also which was remarkably decreased at 3 mM and 5 mM concentrations of lead nitrate. 5. The synthetic rate of UDS was increased at 1 mM concentration of lead nitrate, but which was remarkably decreased at 3 mM and 5 mM concentrations of lead nitrate. 6. Intrace!lular Ca$^{2+}$ level was remarkably increased at 1 mM concentration of lead nitrate, compared with control. 7. In light microscopy, number of cells and processes were decreased according to the increase of dosage of lead nitrate. Electron microscopic findings showed that many vacuoles and cisternal dilatation of rough endoplasmic reticulum were seen in the cytoplasm at 1 mM concentration of lead nittale. From the above results, high dosage treatment of lead nitrate (>3 mM) damaged genetic malerials and it also showed cytotoxicity in mouse 3T3 cell line cultures by injury of cell organelles and Ca$^{2+}$ channel.

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The Signaling of UV-induced Apoptosis in Melanocytes

  • Kim, Dong-Seok;Kim, Sook--Young;Park, Kyoung-Chan
    • Journal of Photoscience
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    • 제9권2호
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    • pp.217-220
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    • 2002
  • Ultraviolet B (UVB) radiation may activate or deteriorate cultured human epidermal melanocytes, depending on the doses and culture conditions. In this study, we examined whether apoptosis of melanocytes can be induced by physiologic doses of UVB irradiation. PI staining for DNA condensation and flow cytometric analyses demonstrated the apoptotic cell death of melanocytes after UVB irradiation. The level of p53 and Bax revealed a dose-dependent increase with increasing dose of UVB, but the level of Bcl-2 remained unchanged. Confocal microscopic examination showed that Bax moved trom a diffuse to a punctate distribution after UVB irradiation. However, there were no changes in the pattern of Bcl-2. We next examined the downstream targets of apoptosis. Our results showed that a precursor form of caspase-3 disappeared with increasing doses of UVB. We also observed cleavage of poly(ADP-ribose) polymerase (PARP) after UVB irradiation. In addition, UVB irradiation resulted in a remarkable activation of c-Jun N-terminal kinase (JNK). These results indicate that UVB may induce apoptosis via JNK activation in human melanocytes.

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숙지황(熟地黃)이 난소적출(卵巢摘出)로 폐경(閉經)이 유발(誘發)된 흰쥐에 미치는 영향(影響) (Effects of the Rehmanniae Radix Preparat on Ovariectomized Rats)

  • 조수인
    • 대한본초학회지
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    • 제20권4호
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    • pp.61-67
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    • 2005
  • Objectives : Obese and osteoporosis are diseases characterized by bone loss and morbidity with osteoporotic fracture is increasing in elderly. The present study was carried out to determine the effects of Rehmanniae Radix Preparat(RRP) on the postmenopausal obese. Methods : The variance of body weight, femoral bone weight, serum level of cholesterol and microscopic view of tibia were investigated. Animals were observed for 8 weeks, and vehicle and extracts of prescriptions were administered ad libitum. Results : Body weight increased significantly in 6 weeks after ovariectomy, and the weight of RRP administered group decreased significantly. RRP decreased the serum level of cholesterol. Conclusions : According to above results, RRP can be used for prevention and curing the postmenopausal obese.

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APPLICATION OF HISTOGRAM OUTLIER ANALYSIS ON THE IMAGE DEGRADATION MODEL FOR BEST FOCAL POINT SELECTION

  • Shin, Hyun-Kyung
    • Journal of applied mathematics & informatics
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    • 제27권1_2호
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    • pp.175-182
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    • 2009
  • Microscopic imaging system often requires the algorithm to adjust location of camera lenses automatically in machine level. An effort to detect the best focal point is naturally interpreted as a mathematical inverse problem [1]. Following Wiener's point of view [2], we interpret the focus level of images as the quantified factor appeared in image degradation model: g = $f{\ast}H+{\eta}$, a standard mathematical model for understanding signal or image degradation process [3]. In this paper we propose a simple, very fast and robust method to compare the degradation parameters among the multiple images given by introducing outlier analysis of histogram.

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액체 상태에서의 현상에 대한 예비 초등교사의 설명 (Perspective Primary Teachers' Explanations of Liquid-State Phenomena)

  • 노석구
    • 한국초등과학교육학회지:초등과학교육
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    • 제27권4호
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    • pp.371-384
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    • 2008
  • The purposes of this study were to investigate perspective teachers' conceptions of liquid-state and get implications for the direction of science curriculum or professional development. The instrument was composed of seven questions focusing on aspects of liquid-state phenomena. The results showed that the participants have various alternative concepts about liquid-state. The problem revealed in almost every question was their macroscopic explanations for the phenomena. In addition, it appeared that the participants seemed to understand phenomena in terminology level, but they didn't know basic reasons or fundamental concepts about the phenomena. It is required to change the curriculum or instructional methods in secondary school and teacher education programs to anchor the scientific concepts on molecular or microscopic level.

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Acoustic Emission on Failure Analysis of Rubber-Modified Epoxy Resin

  • Lee Deok-Bo
    • Fibers and Polymers
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    • 제5권4호
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    • pp.259-263
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    • 2004
  • Rubber-modified epoxy resins have been employed as adhesive and matrix materials for glass and corbon-fiber composites. The behavior of fracture around a crack tip for rubber-modified epoxy resin is investigated through the acoustic emission (AE) analysis of compact tension specimens. Damage zone and rubber particles distributed around a crack tip were observed by a polarized optical microscope and an atomic force microscope (AFM). The damage zone in front of pre-crack tip in rubber-modified specimen $(15wt\%\; rubber)$ began to form at about $13\%$ level of the fracture load and grew in size until $57\%$ load level. After that, the crack propagated in a stick-slip manner. Based on time-frequency analysis of AE signals and microscopic observation of damage zone, it was thought that AE signals with frequency bands of 0.15-0.20 MHz and 0.20­0.30 MHz were generated from cavitation in the damage zone and crack propagation, respectively.

Recombinant Human Epidermal Growth Factor (DWP401)의 마우스를 이용한 피하투여 아급성독성시험 (A 13 Week Subcutaneous Toxicity Study of Recombinant Human Epidermal Growth Factor (DWP401) in Mice)

  • 송시환;강부현;신천철;김희연;강진석;심점순;한상섭;노정구
    • Biomolecules & Therapeutics
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    • 제4권2호
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    • pp.138-147
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    • 1996
  • DWP401, a recombinant human epidermal growth factor, was subcutaneously administered to ICR mice at the dose levels of 0, 0.04, 0.2 and 1.0 mg/kg/day (15rats/sex/group) in order to evaluate the subchronic toxicity. General observations, examinations for food and water consumption, ophthalmoscopy and urinalysis were carried out during the study. For the complete gross and microscopic examinations, 10 mice/ sex/group were sacrificed at the ends of the dosing period, and the remaining animals were sacrificed with a 5 week recovery period. Examinations for hematology and blood biochemistry were also carried out at the time of recovery period. Based on the results, it was thought that the target tissue or organs were mesothelial cell, injection site, spleen, adrenal gland, ovary and transitional epithelial cell of urinary tract, and no observed toxic level of DWP401 was 0.04 mg/kg while definite toxic dose level might be 0.2 mg/kg.

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한국, 일본, 러시아 용암동굴 형성층의 형광X선 분석과 편광현미경적 연구 (XRF Analysis and Polarizing Microscopic Study of the Lava Cave Formation, Korea, Japan and Russia)

  • Sawa, Isao;Furuyama, Katsuhiko;Ohashi, Tsuyoshi;Kim, Chang-Sik;Kashima, Naruhiko
    • 동굴
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    • 제74호
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    • pp.23-31
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    • 2006
  • (1) Kaeusetgul Cave in Kimnyong-Ri, Jeju-Do, Korea. Kaeuset-gul Cave (KC) is situated in NNE area of the Manjang-gul cave (125m a.s.l.). Kaeuset-gul Cave lies at $126^{\circ}45'22"$ E in longitude and $33^{\circ}33'09"$ N in latitude. The coast belong Kimnyeong-Ri, Kujwa-eup, Jeju-Do. Altitude of the cave-entrance is 10m and length of the cave is 90m. Lava hand-specimens of KC are studied by X-ray fluorescence analysis (XRF). Average major chemical components of specimens from KC is as follows (wt.%); $SiO_2=47.03$, $TiO_2=3.16$, $Al_2O_3=18.41$, FeO*=13.53, MnO=0.14, MgO=5.05, CaO=8.66, $Na_2O=2.81$, $K_2O=0.67$, $P_2O_5=0.55$ in KC. Polarizing microscopic studyindicates that these specimens are described of alkali-basalt. (2) Tachibori Fuketsu (Cave) in Shizuoka Prefecture, Fuji Volcano, Japan Tachibori Fuketsu lies attoward the south in skirt of the Fuji volcano, $138^{\circ}42'04"$ east longitude and $35^{\circ}18'00"$ north latitude. The location of cave entrance is 2745, Awakura, Fujinomiya-shi, Shizuoka Prefecture. The above sea level and length of Tachibori Fuketsu are 1,170m and 82m. Average major chemical components of specimens from cave areas follows (Total 100 wt.%) ; ($SiO_2$=50.52, $TiO_2$=1.69, $Al_2O_3$=15.47, FeO*=13.13, MnO=0.20, MgO=5.97, CaO=9.17, $Na_2O$=2.52, $K_2O$=0.94 and $P_2O_5=0.40).$ Polarizing microscopic study indicates that these specimens may belong to tholeiite-basalt series. According to polarizing microscopic study, Au (Augite), P1 (Plagioclase), and O1 (Olivine) are contained as phenocryst minerals. (3) Gorely Cave in Kamchatka Peninsula, Russia Gorely caldera is located at the southeastern part of Kamchatka Peninsula, about 75km southwest of Petropavlovsk-Kamchatskiy.. Gorely lava caves are situated in NHE area of Mt. Gorely volcano (1829m a.s.1.). One of lava cave (Go-9612=K-1) lies at $158^{\circ}00'22"$ east longitude and $52^{\circ}36'18"$ north latitude. The elevation of cave entrance is about 990m a.s.1. and the main cave extends in the NNW direction for about 50m by 15m wide and 5m in depth. The cave of K-3is near the K-1 cave. "@Lava hand-specimens K-1 and K-3 caves are studied by X-ray fluorescence analysis and polarizing microscopic observation. Average major chemical components of specimens from these caves are as follows (wt.%) ;($SiO_2$=55.12, $TiO_2$=1.25, $Al_2O_3$=16.07, T-FeO* =9.41, MnO=0.16, MgO=5.01, CaO=7.21, $Na_2O$=3.39, $K_2O$=1.92, $P_2O_5$=0.45) and these values indicate that the Gorely basaltic andesite belong to high alumina basalt. Polarizing microscopic study indicates that these specimens are described of Augite andesite.

연쇄상구균 감염후 급성 사구체신염에서 육안적 혈뇨와 현미경적 혈뇨에 따른 임상양상의 비교 (The Comparative Study of Clinical Manifestations in Acute Poststreptococcal Glomerulonephritis with Gross Hematuria or Microscopic Hematuria)

  • 박수화;정은수;심창은;김기혁;이종국
    • Childhood Kidney Diseases
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    • 제8권2호
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    • pp.159-165
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    • 2004
  • 목적: 본 연구는 지난 3여년간 연쇄상구균 감염후 사구체신염으로 진단 받은 환아들 중 초기에 육안적 혈뇨를 보인 환아들의 임상양상을 관찰하고 현미경적 혈뇨만을 보인 환아들과의 차이를 비교하여 경과 예측에 도움이 되고자 한다. 방법: 2000년 1월부터 2003년 4월까지 인제대학교부속 일산 백병원과 국민건강보험공단 일산병원에서 연쇄상구균 감염후 사구체신염으로 진단받은 환아 39례를 대상으로 하였다. 결과: 대상 환아들의 평균 발병 연령은 8.85세 남녀 비는 1.1:1이었으며, 육안적 혈뇨를 보인 환아들(A군)은 17례, 현미경적 혈뇨만을 보인 환아들(B군)은 22례이었다. 두 군간의 부종, 핍뇨, 상기도 감염의 기왕력등의 빈도의 차이는 없었으나, 고혈압의 빈도는 A군 17례중 3례(17.6%), B군 22례중 11례(50.0%)로 B군에서 높았다. 검사 소견상 백혈구수, BUN, creatinine, ASO치는 차이가 없었으나 혈청 보체치 C3와 C4는 B군에서 낮게 측정되었고 단백뇨의 정도를 나타내는 소변 내 단백/creatinine의 비와 24시간 소변내 단백량은 A군에서 높은 수치를 보였다. 그러나 질환에 의한 합병증의 발생이나 사망은 없었다. 결론: 초기에 육안적 혈뇨를 가진 환아들(A군)은 현미경적 혈뇨만을 보였던 환아들(B군)보다 고혈압의 빈도는 낮았으며, 단백뇨의 양은 많았다. 그러나 두 군간의 임상경과 및 예후의 유의한 차이는 없었으며 대상 환아 전례에서 임상적인 호전을 보였다.

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