• 제목/요약/키워드: Light Stimulus

검색결과 125건 처리시간 0.031초

Photoresponsive Hydrogels as Drug Delivery Systems

  • Abueva, Celine DG.;Chung, Phil-Sang;Ryu, Hyun-Seok;Park, So-Young;Woo, Seung Hoon
    • Medical Lasers
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    • 제9권1호
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    • pp.6-11
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    • 2020
  • Hydrogels have been developed and used in tissue engineering and regenerative medicine to deliver therapeutics to injured or diseased tissue because of their versatility and properties that can be tailored to match the natural extracellular matrix. Hydrogels can be made with a variety of physical and chemical properties combined with light responsiveness ideal for applications in different fields of medicine that require the spatiotemporal control of therapeutics. Light, as a stimulus, is relatively inexpensive, contact-free, noninvasive with high spatial resolution and temporal control, convenient and easy to use, and allows deep tissue penetration that is relatively harmless. Photoresponsive hydrogels are ideal candidates for on-demand drug delivery systems that are capable of sustained and controlled drug release, minimizing the side effects, and ensuring the activity and efficient delivery of drugs to the target tissue.

녹색광 밝기에 따른 심리·생리(심박변이) 반응 및 영향 분석 (Analysis of Psychological, Physiological(Heart Rate Variability) Response & Influence Consequent on Green Light Brightness)

  • 정찬웅;임오연;이진숙
    • 조명전기설비학회논문지
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    • 제30권3호
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    • pp.9-20
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    • 2016
  • This study compared the effect of green light consequent on maximum brightness 85 lx and intial brightness 15 lx, and its accompanying psychological, physiological response. 1) As a result of psychology(general stress evaluation, Symptom Checklist-90-Revision) evaluation, all stress evaluation items mostly showed a decrease, and they are comparatively positively evaluated in minimum brightness 15 lx comparing to maximum brightness 85 lx. 2) Physiological (Heart Rate Variability) evaluation result was included in stable range in all cardiovascular system variables after light stimulus in time of comparison with the standard range; in addition, the Heart Rate Variability evaluation result was found to be stable in all cardiovascular system variables except Low Frequency in minimum brightness 15 lx comparing to maximum brightness 85 lx. 3) Green light was found not to appear as a stimulating factor in the human body in time of space projection, being found to be effective in stability of mind and body, and reduction in stress. Thus, it was found that green light functioned as an emotional, relaxing tranquilizer by working on the sympathetic nervous system.

편백나무로 제작된 힐링 침대에서의 색체 자극이 스트레스 완화에 미치는 효과 (The Effect of Stress Reduction on Color Stimulus Using Healing Bed in Cypress Tree)

  • 신선혜;유미;오승용;김주리;송의선;문명철;임승택;박희준;권대규
    • 재활복지공학회논문지
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    • 제10권2호
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    • pp.163-170
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    • 2016
  • 본 연구에서는 삼림욕을 즐기는 것과 같은 편안한 상태의 휴식을 유도하기 위하여 편백나무를 이용하여 힐링 침대 시스템과 색체자극을 위한 LED 감성 모듈을 개발하였고, 8가지 조명과 3가지 색온도의 색체 자극에 따른 휴식이 스트레스 완화에 미치는 효과를 비교 분석하였다. 피험자는 건강한 20대 성인 남여 7명(age $23.3{\pm}0.7yr$; height $165{\pm};10cm$ body mass $59{\pm}10kg$)을 대상으로 하였으며, 8가지 색상(red, orange, yellow, green, blue, indigo, violet, white)과 3가지 색온도(3,000K, 5,000K, 8,000K)에 따른 휴식 시 심박변이도, 피험자의 주관적 인지평가를 진행하였다. 그 결과, 심박변이도의 경우 한색계열인 green, blue, indigo의 조명과 3000K의 낮은 온도 조명이 부교감신경을 활성화시켜 심리적으로 안정되는 결과를 얻었으며, 피험자가 주관적으로 느끼는 인지시간의 결과 동일 시간을 자극받았을 지라도 green 색상과 3,000K 온도 자극 시 인지 시간이 가장 느렸으며, 감성어휘 평가에서는 orange 색상과 3,000K온도에서 가장 높은 점수를 얻었다. 따라서, 본 연구 결과 3,000K의 낮은 온도자극과 green 색상 자극 시 심리정 안정이 가장 높은 결과를 얻었으며, 추후 연구에서는 작업 환경에 따른 조명 자극 시 피로도 회복과 뇌파 변화를 비교 분석 할 것이다.

망막-시상하부 경로의 광반응 특성 (Photoresponsive properties of the retinohypothalamic tract)

  • 이배환;;;;손진훈
    • 감성과학
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    • 제10권2호
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    • pp.253-261
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    • 2007
  • 빛은 인간과 동물에서 일주 리듬과 신경내분비 활동을 조절하는 자극이다. 망막-시상하부 경로는 주/야 주기와 신경내분비 활동에 관여한다. 특히 멜라토닌 분비는 빛에 의해 영향을 받으며, 다양한 측면의 건강 문제와 관련이 있다는 것이 알려져 왔다. 본 논문은 생물학적 리듬과 신경내분비 활동에 있어서 빛이 수행하는 역할과, 빛과 건강 문제와의 관련성, 망막-시상하부 경로의 특성을 소개하고자 한다.

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의복과 메이크업의 콘트라스트 배색에 따른 조화감 연구 (A Study on the Harmony for Contrast Coloration of Clothing and Makeup)

  • 정수진
    • 한국생활과학회지
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    • 제16권3호
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    • pp.601-613
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    • 2007
  • In this research, 128 stimuli of contrast coloration of lipstick and clothing were evaluated to the degree of harmony in the coordination of makeup and clothing color depending on the combination of eyeshadow color(brown, violet), lipstick color(red, orange, and purple), lipstick tone(vivid, light, dull, and dark), clothing style(formal, casual), and clothing tone(vivid, light, dull, and dark). Sets of stimulus and response scales were used as experimental materials. The subjects were 768 female undergraduates living in Gyeongsangnam-do. As to the brown eyeshadow, dull lipstick and light, dull clothing, vivid, dull, dark lipstick and dark clothing among the combinations of red lipstick and blue green clothing, dull lipstick and light, dull, dark clothing, dark lipstick and dull, dark clothing among the combinations of orange lipstick and purplish blue clothing were evaluated as harmonious coloration regardless of the clothing style. As to the violet eyeshadow, combinations of red lipstick and blue green clothing and combinations of red purple lipstick and yellow green clothing wide come out range of disharmony. Thus, the degree of harmony in the contrast coloration can be perceived to be different depending on how the color and tone of clothing and lipstick are coordinate.

광자극에 대한 Amoeba 의 반응양상과 phosphatase 의 특성 및 활성도 변화 (The Characterization and Activity Changes of Phosphatases in Amoeba sp. to the Light Stimuli and Its Response Pattern)

  • Chang, Nam-Kee;Chai-Seong Lim;Jin-Ho Bae
    • The Korean Journal of Ecology
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    • 제14권1호
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    • pp.101-111
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    • 1991
  • Amoeba sp. was cultured under the light and the dark conditions, and the activity of phosphatases was investigated. There was a linear correlation between the early reaction time and the activity of phosphatases when phosphatases were incubated at 30℃. Then the activity of acid phosphatase was about 2 times higher than that of alkaline phosphatase. The activity of phosphatase was optimal at pH 5.0 in acidic part and at pH 8.0 in alkaline part, respectively. The optimal temperature of phosphatases was near the 40℃. The isozyme patterns of cytoplasmic acid phosphatase were compared with those of membraneous one. Both the isozyme patterns were shown to bo polymorphic on the polyacyamide gel, but different band patterns were observed in the isozymes of the cytoplasmic and the membraneous acid phosphatases. The number of Amoeba sp. under the light stimulus for 48 hours decreased negative exponentially from the illumination. The activity of acid and alkaline phosphatases under the illumination of light incresed 1.7 and 1.5 times higher, respectively, than the activity of those under the dark condition. This result apperars to be related to the mechanism of the autophosphorylation.

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촉각과 온각 자극에 따른 악력, 상지 기민성, 그리고 손 기능의 차이 (The Difference of Grip Strength, Upper Limb Dexterity, and Hand Function according to Light Touch and Thermal Sensory Stimulus)

  • 이현숙;김성중;유재호
    • 한국산학기술학회논문지
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    • 제12권6호
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    • pp.2644-2651
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    • 2011
  • 본 연구의 목적은 촉각과 온각 자극에 따른 악력, 상지 기민성, 그리고 손 기능 변화의 차이 를 비교 분석하여 움직임에 가장 영향력 있는 자극의 종류를 규명하는 것이었다. 건강한 성인 남성 40명을 대상으로 하였고 신체적 특성을 파악한 뒤 악력과 상지 기민성 및 손 기능을 측정하였다. 이 후 부드러운 솔을 이용하여 촉각 입력을 발현한 뒤 재측정 하였으며 다음날 핫팩을 이용하여 온각 자극 발현 뒤 재측정하였다. 연구 결과 악력과 상지 기민성 검사의 모든 변인에서 통계적으로 유의한 차이가 나타났고(p<.001), Lifting small objects를 제외한 모든 손 기능 변인에서 통계적으로 유의한 차이가 나타났다(p<.01). 결론적으로 자극의 입력은 악력, 기민성, 그리고 손 기능을 증가시킨다. 또한 자극의 종류에 따른 영향에서 온각 자극 입력은 촉각 자극 입력보다 악력, 기민성, 그리고 손 기능을 더욱 증가시킨다. 따라서 재활치료 및 산업 현장에서 상지와 손의 기능 촉진을 위해서는 적절한 자극의 적용이 도움이 될 것이며 앞으로 자극의 빈도와 강도에 대한 연구가 더욱 필요할 것으로 생각된다.

LED 광색의 삼속성에 따른 피로도와 선호도 분석 (The Analysis of Fatigueness and Preference for Three Appearance Attributes of LED Light Color)

  • 백창환;김연진;김홍석;박승옥
    • 조명전기설비학회논문지
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    • 제25권1호
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    • pp.18-29
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    • 2011
  • Light emitting diode(LED) technology has been increasingly developed and larger color gamut by LED illuminations can be reproduced; therefore more efficient LED lighting design can be accomplished under a consideration of color emotion. Fifty-two LED colors which are uniformly distributed on the uniform chromaticity space are evaluated in terms of fatigueness and preference and their relation to three color-appearance attributes(lightness, chroma and hue) are investigated. As a result, 23 human observers likely to prefer and feel comfortable, when lightness of a given LED color stimulus increases as well as its chroma decreases. The highest fatigueness score is observed in red color series and the most preferred LED color is found in green color series. In addition, fatigueness and preference show a strong negative linear relation and their Pearson correlation is higher than -0.8.

유기박막의 외부자극 특성 (External Stimulus Properties of Organic Thin Films)

  • 강용철;이우선;박태곤;권영수;조수영;이경섭
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 1997년도 춘계학술대회 논문집
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    • pp.213-216
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    • 1997
  • The Maxwell displacement current was investigated in the connection with phase diagram of monolayers on a water surface. We measwed the displacement current of 8A5H monolayers on the water surface. The displacement current generated during 8A5H monolayers compression. Also, displacement current pulses were found to be generated when isomerizations were induced in 8A5H monolayers by irradiation with ultraviolet light ($lambda_1=340nm$) and visible light($lambda_2=450nm$).

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A Multi-photodiode Array-based Retinal Implant IC with On/off Stimulation Strategy to Improve Spatial Resolution

  • Park, Jeong Hoan;Shim, Shinyong;Jeong, Joonsoo;Kim, Sung June
    • JSTS:Journal of Semiconductor Technology and Science
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    • 제17권1호
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    • pp.35-41
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    • 2017
  • We propose a novel multi-photodiode array (MPDA) based retinal implant IC with on/off stimulation strategy for a visual prosthesis with improved spatial resolution. An active pixel sensor combined with a comparator enables generation of biphasic current pulses when light intensity meets a threshold condition. The threshold is tuned by changing the discharging time of the active pixel sensor for various light intensity environments. A prototype of the 30-channel retinal implant IC was fabricated with a unit pixel area of $0.021mm^2$, and the stimulus level up to $354{\mu}A$ was measured with the threshold ranging from 400 lx to 13120 lx.