• The Korean Journal of Pharmacology
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• v.30 no.1
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• pp.67-73
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• 1994

Na-Ca exchange transports calcium ion either into (reverse mode Na-Ca exchange) or out of the cell (forward mode Na-Ca exchange) according to the direction of driving force produced by the changes in ratio of intra- and extra-cellular Na concentrations. Thus, Na-Ca exchange is regarded as the regulator of myocardial contraction. However, the existence of reverse mode Na-Ca exchange and its role in myocardial contraction is still questioned. Present study was performed to identify the presence of reverse mode Na-Ca exchange and its possible involvement in the regulation of myocardial contraction in rat heart. Using the left atria of rat, contraction was induced by electrical field stimulation (EFS, 0.5 msec duration and supramaximal voltage). Changing of the stimulation frequencies from resting 4 Hz to 0.4, 1 or 8 Hz caused typical negative staircase effect in twitch tension, but $^{45}Ca$ uptake showed bimodal increase. When the stimulation frequency was abruptly changed from 4 Hz to 0.4 Hz the atrial twitch tension showed three phased-enhancement, that is, the initial rapid increase (the first phase) followed by rapid decrease (the second phase) and stabilization (the third phase). $^{45}Ca$ uptake was equivalent to tension, i.e. initial significant increase in first 30 second and then decrease. Benzamil treatment abolished the first phase of increase in a dose dependent manner from $10^{-5}\;to\;3{\times}10^{-4}M.$ Bay k 8644 $(3{\times}10^{-5}M)$ treatment enhanced the inotropy induced by frequency reduction and abolished the second and third phase decreases. Benzamil treatment also suppressed the contraction stimulated by Bay K 8644. Although the contraction at 4 Hz stimulation was completely abolished by verapamil $3{\times}10^{-5}\;M$ pretreatment, the contraction reappeared as soon as the stimulation frequency was changed into 0.4 or 1 Hz and interstingly,$^{45}Ca$ uptake were significantly higher than no treatment. From these results, it is concluded that reduction of stimulation frequency causes calcium influx by the reverse mode Na-Ca exchange, resulting in initial rapid increase of twitch tension. then it turns into forward mode exchange to efflux the calcium, resulting in decrease of the twitch tension in left atria of rat.

• The Proceeding of the Korean Institute of Electromagnetic Engineering and Science
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• v.8 no.1
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• pp.2-28
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• 1997

기습이란 공격개념이 전쟁의 역사를 장식해 왔으며 현대전에서는 공중공격이 가장 효과적인 기습수단으로 사용되고 있다. 공중 공격에 대한 구체적 방어수단은 조기경보망과 각종 대공방어무기 체계이다. 레이다는 방공망과 방공무기의 '전천후 원거리 눈'의 역할을 기대하는 목적으로 출발하고 발달하여 왔다. 레이다 기술은 그시대의 최신 첨단기술을 가장 먼저 수용하고 또 자극하는 다양한 모습 으로 나타나 보인다. 레이다는 가장 막강한 정보수집수단으로 성장하여 군사용뿐만이 아니라 민수응용 으로 그 많은 역할을 해 왓으며 앞으로도 계속될 전망이다. 레이다의 발달에는 항공기 및 공중공격진술 의 발전과 밀접한 관계를 가지고 있다. 공간을 날아다니는 것은 무엇이든 레이다의 대상표적이고 위협 상황이기 때문이다. 이러한 관점에서 레이다 발달배경, 레이다의 과거와 현재, 그리고 앞으로의 발전방 향을 조명해 보기로 한다.

• Korean Journal of Pharmacognosy
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• v.8 no.3
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• pp.115-119
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• 1977

Black pepper (Piper nigrum L.) among several irritating spices tested was highly effective on the duration of hexobarbital hypnosis in mice. Pretreatment of mice with the methanolic extract of black pepper (60mg/kg i.p.) prolonged markedly the duration of hexobarbital sleeping time. Three consecutive daily administrations of the same dose of black pepper extract, however, shortened (37%) the duration of hexobarbital sleeping time. The ether soluble fraction of black pepper extract caused most potent effects on the duration of hexobarbital hypnosis. From the above results, it was postulated that the lipid soluble components of black pepper might considerably change the drug action and metabolism by altering drug metabolizing enzyme systems.

• Journal of Embryo Transfer
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• v.19 no.3
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• pp.229-237
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• 2004

The main objective of this study was to examine the effects of serum and gonadotropins supplement during in vitro maturation(IVM) of bovine oocytes on nuclear maturation and embryo development, and we also examine the cell number. 1 . The first polar body(PB) extrusion rates of Korean native cow(KNC) oocytes matured in medium with FBS or gonadotropins were similar among treatment groups. The development rate to the blastocyst stage was significantly higher in the group of both supplement FBS and gonadotropins(26.0％) than in the group of non-supplement(9.9％) and gonadotropins (12.0％). The numbers of inner cell mass (ICM) and trophectoderm (TE) cells and total cell numbers of blastocysts were highest in the group of both supplement FBS and gonadotropins, and the number of ICM cells was increased by FBS supplementation (p<0.05). 2. The PB extrusion rates of KNC oocytes matured in medium with FBS in the different duration of IVM was significantly higher in the 0-18hr(63.1％) and in the 9-18hr(63.4％) group than in the 0-9hr.(37.4％) group (p<0.05). The embryo development rates did not differ among treatment groups. The numbers of TE cells and total cell numbers of blastocysts were similar among treatment groups, but the number of ICM cells of the 0-18h. group were significantly higher than the other treatment groups (p<0.05). The results indicate that although TCM199 alone can support bovine oocyte maturation and development to the blastocyst stage, a high quality of blastocysts can be produced from oocytes matured in medium containing serum and gonadotropins.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.7
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• pp.158-165
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• 2019

Although evaluation of writing disabilities identification and timely intervention are required, clinicians adopt a manual scoring method and there is a possibility of error due to subjective evaluation. In this study, the size ratio and position of letters are digitized and quantified through image processing of offline handwritten characters. We tried to evaluate objectively and accurately the performance of writing through comparison with existing methods. From November 12th to 16th, 2018, 20 adults without neurological injury were selected. They used a pencil to follow the 10 words, 2 sentence stimuli after keeping the usual habit, and we collected the writing test data. The results showed that the height of the word was 1.2 times larger than the width and it tilted to the lower left. The spacing interval was 9mm on average. In the Paired T test, a high correlation was showed between our system and existing methods in the word and sentence 2. This demonstrated the possibility as a testing tool. This study evaluated objectively and precisely writing performance of offline handwritten characters through image processing and provided preliminary data for performance standards. In the future, it can be suggested as a basic data on writing diagnosis of various ages.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.48 no.4
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• pp.303-312
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• 2022

In this study, Cyperus rotundus (C. rotundus) was fractionated into ethyl acetate to identify α-cyperone, a representative indicator, and its ethyl acetate fraction were evaluated to confirm the possibilityas a functional cosmetic ingredient. As a result of HPLC analysis, it was confirmed that the content of α-cyperone was 5.243%. In order to verify the inflammatory relief effect of the ethyl acetate fraction from C. rotundus (EAFC) and α-cyperone, it was confirmed that nitric oxide (NO) production inhibitory ability in RAW 264.7 macrophages induced an inflammatory reaction with lipopolysaccharide (LPS). Real-time qPCR analysis confirmed inhibition of mRNA expression level of inflammatory factors, IL-1β, IL-6, TNF-α, COX-2 and iNOS. As a results of conducting a clinical study using a simple cosmetic formulation containing EAFC, it was confirmed that the skin irritation stimulated by sodium lauryl sulfate (SLS) was calming and relieving itching. Through these results, it is believed that the C. rotundus can be used as a natural cosmetic ingredient that has the effect of inhibiting inflammation and relieving itching.

• Korean Journal of Food Science and Technology
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• v.29 no.2
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• pp.314-319
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• 1997

The objectives of this study were to examine the effect of storage time, temperature, pH, and NaCl concentration on hydroperoxide lyase and lipoxygenase activities, and to establish important informations to the production of typical cucumber flavor. Conditions affecting lipoxygenase and hydroperoxide lyase would be important for cucumber flavor production. Maximum activity was observed at pH 5.0 for hydroperoxide lyase and pH 5.5 for lipoxygenase. Both enzymes were relatively stable at $40\;to\;50^{\circ}C$ for 6days storage time. Maximum activity of both enzymes was observed with 0.2 M NaCl at pH 5.0. Activities were stimulated with concentrations of NaCl from 0.05 to 0.2 M. Hydroperoxide lyase and lipoxygenase activities were decreased at concentration of NaCl greater than 0.2 M.

• Journal of the Korean earth science society
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• v.31 no.3
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• pp.246-258
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• 2010

A convective circulation box was redesigned after analyzing reasons why adolescent elementary school students could not derive a convective circulation concept from the convection circulation box experiments. Even though students were in the formal operational period of Piaget, the adolescents felt difficult to understand a concept of the natural phenomena they have never seen before. Thus, we designed a method to help students increase their scientific understandings about the concept through developing a miniature convective circulation box. Findings indicated that an application of redesigned convective circulation box in the classroom experiment significantly increased the students' understanding about the convective circulations of land and sea breezes, and as well as their participation in the activities. In addition, the redesigned convective circulation box motivated students to develop their scientific thinking skills by allowing them to decide where to put visible incenses inside the box and to directly observe the smoke currents circulation formed accordingly. Redesigning and using a convective circulationbox as a miniature of natural phenomenon helps students avoid having misconceptions. The biggest merits of the box are that it is observable in all directions, it provides much clearer convective circulations comparing to the extant box, and it requires low production costs.

• Tuberculosis and Respiratory Diseases
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• v.48 no.6
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• pp.898-908
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• 2000

Background : Eotaxin a CC chemokine specific for eosinophils, is implicated in the pathogenesis of asthma by recruiting eosinophils into the airways. Theophylline has been used for the treatment of asthma and recently was proposed to have an anti-inflammatory action. The aim of this study is to examine whether theophylline may inhibit the eosinophilic airway inflammation by reducing the expression of eotaxin. Methods : The expression of eotaxin mRNA was assessed by Northern analysis in A549 cells 4 h after stimulation with TNF-$\alpha$ or IL-1$\beta$. And then, theophylline was added to A549 cells stimulated with 0.1 ng/mL IL-1$\beta$. Results : Eotaxin mRNA expression rates induced by 0.1, 1, 10 ng/mL TNF-$\alpha$ as compared with $\beta$-actin, were 7%, 22%. 28%, respectively. Eotaxin mRNA expression rates induced by 0.01, 0.1, 1, 10 ng/mL IL-1$\beta$, as compared with $\beta$-actin, were 10%, 42%, 63%, 72%, respectively. Eotaxin mRNA expression rates after the addition of 0, 0.001, 0.01, 0.1 ${\mu}M$ dexamethasone induced by 10 ng/mL TNF-$\alpha$ as compared with $\beta$-actin, were 27%, 18%, 8%, respectively. Eotaxin mRNA expression rate after the addition of 0, 0.001, 0.01, 0.1 ${\mu}M$ dexamethasone induced by 0.1 ng/mL IL-1$\beta$ as compared with $\beta$-actin, were 43%, 47%, 12%, 8%, respectively. Eotaxin mRNA expression rates after the addition of 0, 0.001, 0.01, 0.1, 1, 10 mM theophylline induced by 0.1 ng/mL IL-1$\beta$, as compared with $\beta$-actin, were 48%, 40%, 33%, 22%, 16%, 14%, respectively. Conclusion : These results suggest that theophylline may reduce eosinophil infiltration of the airway at least in part by reducing the expression of eotaxin under the conditions of these experiments.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.21 no.8
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• pp.36-43
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• 2020

The extracts of antioxidants, torreya nucifera and alphinia henryi, were tested for properties as a fragrance material and applied to a mask pack formulation to study the fragrance properties. The DPPH antioxidant test of hot water and ethanol extract confirmed that the ethanol extract had superior antioxidant efficacy compared to the hot water extract. It was confirmed that the optimal mixing ratio as a raw material for the mask pack of torreya nucifera and alphinia henryi was 3:7 as a result of the DPPH antioxidant test. As a result of the cytotoxicity test, the cell viability was good as it showed 103.30% at 0.5 ug/mL, 104.25% at 1 ug/mL, 102.56% at 5 ug/mL, and 99.17% at 10 ug/mL compared to the untreated group. As a result of the patch test on the mask pack formulation, the skin irritation index of 0.02 was judged as a non-irritation product in the skin irritation primary stimulation human application test. In the evaluation of skin moisturizing, it showed a significant increase rate of 19.178% compared to before the sample adaptation. Evaluation of the change over time in the sheet mask pack formulation confirmed the formulation stability without viscosity and pH change for 12 weeks at low temperature(4℃), room temperature(25℃), and high temperature(45℃).