• 감성과학
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• 제13권1호
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• pp.21-32
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• 2010

이 연구는 그림 자료의 근접성(고근접 vs. 저근접)에 따른 제시여부와 읽기모드(단순읽기 vs. 요약읽기)에 따른 학습자의 인지부하 차이를 검증하기 위한 것이다. 특히, 이 연구에서는 전기피부반응을 통하여 인지부하의 정도를 측정하였다. 실험참가자는 34명(통제집단=17명, 실험집단=17명)이었으며 고근접 조건과 저근접 조건에 대한 반복구획요인설계를 적용하였다. 또한 각 실험조건에서 측정된 과제난이도 지각점수를 공변량으로 투입하여 학습자의 사전지식에 의한 영향력을 통제하였다. 그림 자료의 근접성의 정도에 따라서 고근접 그림 자료와 저근접 그림 자료가 순차적으로 제시되었다. 처음에는 단순읽기 모드가 제시되었고 이후에 요약읽기를 수행하였다. 전기피부반응은 단순읽기와 요약읽기에서 모두 측정되었다. 이 연구의 종속변수는 전기피부반응과 지각된 난이도였다. 연구결과에 따르면 고근접 자료가 제시된 조건에서는 유의미한 차이를 발견할 수 없었다. 그러나 저근접 조건에서는 그림 자료의 제시여부 및 읽기모드 사이에서 유의미한 차이가 있었다. 즉, 저근접 조건에서는 텍스트만 제시하는 것보다는 그림 자료가 제시될 때 전기피부반응이 올라갔다. 또한 단순 읽기 보다 요약읽기에서 더 높은 전기피부반응이 측정되었다. 이 연구의 결과는 저근접 그림은 인지부하를 유발하는 요인이 될 수 있으며 읽기모드가 복잡해지면 인지부하가 높아질 수 있음을 보여주는 것이다. 동일한 자료를 활용한다고 하더라도 인지과정의 복잡성 정도에 따라서 인지부하가 달라질 수 있다는 것이다. 그러나 학습성취과 같은 과제수행 요인과 더 높은 난이도에서의 인지부하 측정에 대한 후속연구가 필요하다.

• Physical Therapy Rehabilitation Science
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• 제1권1호
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• pp.6-12
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• 2012

Objective: Coenzyme (CoQ10) is an enzymatic co factor used in normal cellular metabolism. Recent evidence shows that in people with heart disease it can reverse endothelial cell damage in the blood vessels. It is also a potent antioxidant. Design: One group pretest-posttest design. Methods: In the present study, endothelial function was evaluated using the response to occlusion and heat before and 2 weeks after administration of CoQ10, 300 mg/day. Thirty Eight subjects, who are physical therapy students, participated in a series of experiments to see if taking 300 mg of CoQ10 daily for 2 weeks would impact resting blood flow in the forearm skin and the blood flow response to 4 minutes of vascular occlusion and the response to local heat ($42^{\circ}C$) for 6 minutes. Results: The results showed that, for this population, there was no difference in the response to heat. However, the response to occlusion was improved after administration of CoQ10. Conclusions: It would appear that in a young population CoQ10 has no effect on the nitric oxide vasodilator pathway in skin but does influence other vasodilator pathways.

• Journal of Microbiology and Biotechnology
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• 제18권1호
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• pp.110-117
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• 2008

Three kinds of prenylated flavonols, icariside I, icariside II, and icaritin, were isolated from an icariin hydrolysate and their effects on melanogenesis evaluated based on mushroom tyrosinase inhibition and quantifying the melanin contents in melanocytes. Although none of the compounds had an effect on tyrosinase activity, icariside II and icaritin both effectively inhibited the melanin contents with an $IC_{50}$ of 10.53 and $11.13{\mu}M$, respectively. Whereas icariside II was obtained from a reaction with ${\beta}$-glucosidase and cellulase, the icariin was not completely converted into icariside II. Thus, for the high-purity production of icariside II, the reaction was optimized using the response surface methodology, where an enzyme concentration of 5.0mg/ml, pH 7, $37.5^{\circ}C$, and 8 h reaction time were selected as the central conditions for the central composite design (CCD) for the enzymatic hydrolysis of icariin into icariside II using cellulase. Empirical models were developed to describe the relationships between the operating factors and the response (icariside II yield). A statistical analysis indicated that all four factors had a significant effect (p<0.01) on the icariside II production. The coefficient of determination $(R^2)$ was good for the model (0.9853), and the optimum production conditions for icariside II was an enzyme concentration of 7.5mg/ml, pH 5, $50^{\circ}C$, and 12 h reaction time. A good agreement between the predicted and experimental data under the designed optimal conditions confirmed the usefulness of the model. A laboratory pilot scale was also successful.

• The Korean Journal of Physiology and Pharmacology
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• 제25권1호
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• pp.87-94
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• 2021

Skin photoaging occurs due to chronic exposure to solar ultraviolet radiation (UV), the main factor contributing to extrinsic skin aging. Clinical signs of photoaging include the formation of deep, coarse skin wrinkles and hyperpigmentation. Although melanogenesis and skin wrinkling occur in different skin cells and have different underlying mechanisms, their initiation involves intracellular calcium signaling via calcium ion channels. The ORAI1 channel initiates melanogenesis in melanocytes, and the TRPV1 channel initiates MMP-1 production in keratinocytes in response to UV stimulation. We aimed to develop a drug that may simultaneously inhibit ORAI1 and TRPV1 activity to help prevent photoaging. We synthesized nootkatol, a chemical derivative of valencene. TRPV1 and ORAI1 activities were measured using the whole-cell patch-clamp technique. Intracellular calcium concentration [Ca2+]i was measured using calcium-sensitive fluorescent dye (Fura-2 AM). UV-induced melanin formation and MMP-1 production were quantified in B16F10 melanoma cells and HaCaT cells, respectively. Our results indicate that nootkatol (90 μM) reduced TRPV1 current by 94% ± 2% at -60 mV and ORAI1 current by 97% ± 1% at -120 mV. Intracellular calcium signaling was significantly inhibited by nootkatol in response to ORAI1 activation in human primary melanocytes (51.6% ± 0.98% at 100 μM). Additionally, UV-induced melanin synthesis was reduced by 76.38% ± 5.90% in B16F10 melanoma cells, and UV-induced MMP-1 production was reduced by 59.33% ± 1.49% in HaCaT cells. In conclusion, nootkatol inhibits both TRPV1 and ORAI1 to prevent photoaging, and targeting ion channels may be a promising strategy for preventing photoaging.

• 한국실내디자인학회논문집
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• 제40호
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• pp.26-33
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• 2003

Contemporary architecture has two different movements that one is the utilization of digital technology and the other is the inclination to nature. After deconstructivism in architecture, the tendency of design shows the fusion between digitalism and organicism and as a consequence the phenomena of 'skin expression' has emerged which can be thought as 'organic digitalism' or 'digital organicism'. The definition of skin tendency in environmental design is the design of nature based on the technology. As a result, the surface becomes the design issue compared to structure and the momentum for new aesthetic value. There are post-structuralism, complex system theory and the organic architecture as theoretical background for the tendency of skin expression. Specially the ideas of post-structural philosophy has effected deeply to the formation of its movement and also offered the theoretical nutrition for digital architecture. The characteristics of the skin tendency can be analyzed as topological transformation, smooth continuum, deterritorialization, ecological response system, and tactility. These design characteristics has combined with conventional material and design vocabulary to transform and develope new spatial conception.

• 한국의류학회지
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• 제21권2호
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• pp.314-324
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• 1997

The purpose of this study was to evaluate the thermoregulatory response level on the heat and cold tolerance with investigating monthly changes of skin temperature in Koreans and to obtain the basal information for standard amount of clothing weight, indoor climate and working condition. Forty eight subjects in 5 age groups (6~11, 12~19, 20~44, 45~64, 65~76 years old) with both sexs were taken from Seoul and Kyunggi probince. All subjects were measured skin temperature, mean skin temperature, Total clothing weight in neutral condition in each month from June 1994 to May 1995. The results obtained are summarized as follows: 1. Skin temperature of all subjects was low on February, March and April, and was high on June, July and August. Temperatures of the torso (forehead and abdomen) and the lower limbs (leg and foot) were remarkably different. In general, most of skin temperatures except of hand, thigh and foot were higher in males. 2. Mean skin temperature was 0.5'c higher in males than female with ranging 32.5~34.5$^{\circ}C$ in males and 32.1~34.1$^{\circ}C$ in females. Also, mean skin temperature of 6~11 age group were higher than that of 45~ 64 age group in both sexs.

• 한국음향학회:학술대회논문집
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• 한국음향학회 1999년도 학술발표대회 논문집 제18권 1호
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• pp.269-273
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• 1999

Combination of mental stress task with noise background is a traditional tool employed in psychophysiology. However, intensity of background noise is a factor affecting both performance on test and psychophysiological responses associated with stress evoked by mental load in noisy environment. In the current study on 7 subjects we analyzed the influence of white noise (WN) intensity (55, 70, and 85 dB[A] ) on psychophysiological responses during word recognition test performed on noise background. There were recorded following physiological variables: electrodermal activity (EDA) , namely, skin conductance level (SCL), skin conductance response (SCR) amplitude (SCR-A), rise time and total number of SCRs (N-SCR); cardiovascular activity, e.g., heart rate (HR), respiratory sinus arrhythmia (RSA) index, pulse transit time (PTT), finger pulse volume (PV), skin temperature (SKT) and respiratory activity, such as respiration rate (RESP-R) and inspiration wane amplitude (RESP-A) during baseline resting state and 40 s long performance on 3 similar Korean word recognition tests with different WN intensity (55, 70, and 85 dB). Electrodermal responses (SCR-A, SCL, N-SCR) demonstrated gradual increment with increased intensity of noise, and this increase of response magnitude with higher intensity of noise was typical also for r skin temperature (phasic SKT decrease) and pulse volume (phasic and tonic PV decrease). However, some cardiovascular and respiratory responses did not exhibit same tendency of gradual increase of reactivity , namely HR, as well as RESP-R and RESP-A showed decrement of response magnitudes. Important finding in terms of cardiovascular reactivity was that 55 and 70dB evoked similar profiles, while 85dB WN resulted in significantly different profile of reactions, suggesting that there exists a threshold level after which intensive auditory stimulation elicits psychophyslological responses pattern of different quality. There are discussed potential autonomic mechanism involved in mediation of observed physiological responses.

• 대한화장품학회지
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• 제40권1호
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• pp.95-108
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• 2014

화장품은 일반인이 장기간 연용하는 제품으로 인체 피부에 대한 안전성이 매우 중요하다. 화장품에 의한 접촉피부염은 자극성 물질이 피부에 접촉 후 침투하여 유발하는 염증반응으로 활성화된 면역세포에서 염증을 매개하는 다양한 인자를 분비함으로써 시작된다. 본 연구에서는 국산 생약 추출물을 이용하여 RAW264.7 대식 세포에서 염증 관련 인자에 대한 영향을 통해 항염증 활성을 스크리닝 하였다. 51종의 국산 생약 추출물 중 측백, 측백엽(초), 향부자, 형개, 동과자, 산약, 산약(초), 상지, 송절, 택사의 에탄올 추출물 10종이 lipopolysaccharide(LPS)에 의해 유도된 세포독성을 감소시킴과 동시에 염증 관련 인자인 Nitric oxide (NO), interleukin (IL)-1${\beta}$, IL-6, tumor necrosis factor (TNF)-${\alpha}$의 생성을 억제하는 것을 확인하였다. 또한, 이들 생약 추출물은 인체피부에서도 자극을 유발하지 않음을 인체 첩포시험을 통해 검증하였다. 따라서, 항염증 활성이 확인된 10종 국산 생약 추출물은 피부 자극을 예방할 수 있는 화장품 소재로서의 활용이 가능할 것으로 사료된다.

• 한국산업정보학회논문지
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• 제20권3호
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• pp.11-18
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• 2015

오늘날 스트레스는 인간의 정신적, 신체적 건강을 위협하는 주된 요인 중의 하나이다. 본 논문에서는 대학생들에 대해 수업 전과 후에 측정한 심박변이도, 전기피부반응, 피부 온도가 스트레스 환경에서 생체 신호에 미치는 영향을 분석, 조사하였다. 본 연구에는 21세에서 27세 사이의 학생 30명이 참여하였으며, 이들의 평균 나이는 22.31세, 표준편차는 1.45세이다. 실험을 통해 시간영역과 주파수영역 모두에서 HRV의 제어 그룹에 대해 비교한 결과, 실험군에 대한 RMSSD(p=0.033), LF 첨두값(p=0.003), VLF(p=0.045)가 통계적으로 유의한 것으로 확인되었다. 평균 피부 전도도는 수업 후의 측정 결과(평균=5.993(uS), 표준편차=3.406)가 수업 전의 측정 결과(평균=3.039(uS), 표준편차=2.628)보다 평균적으로 97.2% 높게 나타났으며, 피부 온도는 수업 후의 측정 결과($34.835{\pm}0.305$)가 수업 전의 측정 결과($34.471{\pm}0.281$)보다 평균적으로 1.055% 높게 나타남을 알 수 있었다. 본 연구결과는 스트레스 관련 임상 연구에서 자율신경계의 반응을 조사하는 연구에 활용될 수 있을 것으로 사료된다.

• Archives of Plastic Surgery
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• 제48권5호
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• pp.569-569
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• 2021