• The Journal of the Korean dental association
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• v.26 no.5 s.228
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• pp.441-456
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• 1988

지난 수 십년간 기계적인 측면에서의 교정장치나 치료술식은 급속한 발전을 하여왔으나 생물학적 관점에서의 현대 교정학은 아직도 낙후된 수준에 머물러 있다. 이러한 관점에서 기초의학을 기반으로 세포의 생물학적 잠재력을 극대화시켜 임상적 효율성을 증진시키기 위한 일련의 연구들이 진행되고 있다. 그중에서 전기적 자극에 의한 골성장기전의 개념을 이용하는 분야는 가장 활발히 연구되고 있는 분야 중의 하나이다. 전기자극 중 가장 유용한 수단인 전자기장 이용법의 발달과정에 대해 알아보고 전기적 자극에 의한 골세포 반응의 작용기전에 대한 많은 자료를 종합, 분석하여 그 가설적인 모형을 세우고 아울러 교정 임상에서 이러한 개념의 적용가능성과 그 범위에 대해 조명해 본다. 앞으로 이 분야에 대한 계속적인 연구로 머지않아 실제 임상에 활용되는 단계에 이르게 되길 기대한다.

• The Korean Journal of Zoology
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• v.37 no.2
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• pp.161-173
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• 1994

면역효소법을 이용하여 3종의 한국산 개구리 참개구리(Rono nigromaculuto), 옴개구리(R. rugosa), 북방산개구리(R. 겨대bowskii)의 뇌에서 GnRH 뉴우런의 분포 부위와 GnRH의 종류 등을 연구하였다. 1차 항체로는 anti-rat GnRH, anti-salmon GnRH anti-chicken 11 GnRH 항체를 사용하였다. 3종의 개구리에서 mGnRH cGnRH 11와 sGnRH가 이둔 동정되었으나 3가지 항체에 대한 각 종의 면역 반응성은 종에 따라 달리 나타났다 mGnRH는 옴개구리와 참개구리에서, sGnRH는 북방산개구리에서 강한 면역 반응을 나타냈으며 cGnRH 11는 3종의 개구리에서 중간 정도의 면역 반응을 나타냈다. 각각의 GnRH의 상대적인 양에는 차이가 있으나 일부 경우를 제외하고는 뇌의 동일한 지역에 분포하였다. 참개구리에서는 GnRH가 중격 내측핵(NMS), Broca band 핵(NDB)에 집단으로 분포하였다. 북방산개구리에서는 GnRH가 중격 내측핵, Broca bnad 핵에서 등쪽에서 배쪽으로 길게 선상으로 가장 협소하게 분포하였으며, 번식기와 직전(1월-3월)에만 면역 반응을 나타냈다. 옴개구리의 뇌에서 가장 광범위한 지역, 즉 종뇌의 중격 내측핵, Broca band 핵, 아래 교차 지역(SCA)과 간뇌에 GnRH 신경세포가 분포하였으며. 제3뇌실 맥락얼기에서 mGnRH 신경세포가 처음으로 동정되었다. 3종에서 공통적으로 중격 내측핵과 Broca band 핵에서 유래한 신경섬유는 복측 시상하부를 거쳐 정중융기에 이르렀다. 이러한 결과는 GnRH가 뇌하수체에서 생식소 자극 호르몬의 분비 조절에 밀접한 관계가 있음을 뜻한다.

• The Korean Journal of Pesticide Science
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• v.16 no.3
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• pp.261-266
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• 2012

It is common to use many experiment animals to evaluate the toxicity of chemicals including pesticides. For protecting animal, the concepts of 3R (Reduction, Replacement, Refinement) were introduced and in vitro alternatives methods actively have been developed all over the world. Many experimental animals for toxicological tests have been used, so that it is important to establish the alternative methods. In this study, the alternative method using reconstituted human skin model (Keraskin$^{TM}$) was conducted for classification of skin irritation on pesticides. Sixteen formulations selected on the basis of the degree of irritation were treated by Keraskin$^{TM}$ test. The percent of cell viability was measured into the culture medium collected after treatment of the pesticides for 24-72 hrs. The skin irritations of formulations were evaluated by the cell viability. In this study, The 4 formulations with mild irritation in rabbits were evaluated as nonirritant, the 6 formulations with moderate and severe irritation were evaluated as irritant in human skin model test. We suggest that the alternative test using Keraskin$^{TM}$ model could be used as toxicity evaluation for primary irritation index (P.I.I.) score of greater than or equal to 2.1 of pesticides. The further studies should be required to apply for hazardous assessment of pesticides on alternative skin irritation methods because of the interindividual variability of the sensitivity of skin irritation on pesticides.

• Journal of the Institute of Electronics Engineers of Korea SC
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• v.44 no.1
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• pp.100-107
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• 2007

AABR(automated auditory brainstem response) test is used for the screening purpose of hearing ability of neonates. In this paper, algorithm using Rolle's theorem is suggested for automatic detection of the ensemble averaged ABR waveform. The ABR waveforms were recorded from 55 normal-hearing ears of neonates at screening levels varying from 30 to 60 dBnHL. Recorded signals were analyzed by expert audiologist and by the proposed algorithm. The results showed that the proposed algorithm correctly identified latencies of the major ABR waves (III, V) with latent difference below 0.2 ms. No significant differences were found between the two methods. We also analyzed the ABR signals using derivative algorithm and compared the results with proposed algorithm. The number of detected candidate waves using the proposed algorithm was 47 % less than that of the existing one. The proposed method had lower relative errors (0.01 % error at 60dBnHL) compared to the existing one. By using proposed algorithm, clinicians can detect and label waves III and V more objectively and quantitatively than the manual detection method.

• Korean journal of applied entomology
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• v.53 no.1
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• pp.65-71
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• 2014

Frankliniella occidentalis is attracted to flowers and is a major pest of chrysanthemums. Even when some chrysanthemum plants are not flowering, the ones that have already flowered attract F. occidentalis. Therefore, we investigated the efficacy of chrysanthemum as a trap plant that attract F. occidentalis by using an olfactometer. The numbers of F. occidentalis collected from the flowers of pink, wihte and yellow standard chrysanthemums on a tray with wet paper during the flowering period were 18.4, 56.6, and 52.6 respectively; the numbers of F. occidentalis collected from leaves were 7.8, 16.6, and 15.4 respectively. the numbers of F. occidentalis collected from the buds of pink, white and yellow standard chrysanthemums were 15.2, 45.8, and 41.6 respectively; the numbers of F. occidentalis collected from the leaves were 2, 8.8 and 3.4 respectively. In the Y-tube olfactometer test, the number of F. occidentalis attracted to the 2-way arms of the Y-tube was not significantly different for the yellow, red, violet and white flowers. In the four-choice olfactometer test, when the same visual cues and odor cues were provided, the frequency of F. occidentalis was higher in the yellow (10.7) flowers than in the red (1.3), violet (3.7) and white (2.0) flowers. When visual cues with disturbed odor cues, F. occidentalis preferred yellow (10.0) color over red (3.3), violet (1.3) and white (3.0) colors. When the same visual and odor cues, except for yellow visual cues, were provided, F. occidentalis preferred white (8.3) color over red (4.7), violet (4.7) and yellow (2.0) colors. Therefore, F. occidentalis were attracted to buds before the flowering of chrysanthemum plants and attracted to yellow flowers after the flowering.

• Clinical and Experimental Pediatrics
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• v.48 no.8
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• pp.881-885
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• 2005

Purpose : Airway dehydration and subsequent hyperosmolarity of periciliary fluid are considered critical events in exercise-induced bronchoconstriction. The aim of this study was to establish if a hyperosmolar challenge could induce activation of eosinophils. Methods : Human eosinophilic leukaemic cell lines, EoL-1 cells were incubated with hyperosmolar solutions for 15 minutes. Activation of EoL-1 cells was monitored by degranulation and superoxide anion production. In addition, we examined surface expression of CD69 and ICAM-1. Results : Hyperosmolar stimuli didn't induce superoxide anion production and degranulation. In addition, EoL-1 cells cultured with hyperosmolar medium at 930 mOsm/kg $H_2O$ resulted in no significant increment in fluorescent intensity of CD69 and ICAM-1 expression compared with results for cells incubated with isomolar medium. Conclusion : We found that hyperosmolar stimuli don't cause activation of EoL-1 cells, but further studies are required to determine the role of eosinophil in the mechanism of exercise-induced asthma.

• Korean Journal of Food Science and Technology
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• v.44 no.2
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• pp.251-256
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• 2012

Stilbenes are known as antioxidants and some of them demonstrate anti-pigmentation activity. The purpose of the present study was to investigate whether two stilbene compounds produced by biotransformation of the extract of $Morus$ $alba$ root show skin irritation and sensitization. In skin irritation test, 1% oxyresveratrol (OXY), and 5% OXY, and 1% oxyresveratrol-3-$O$-glucoside (OXY-3) showed a P.I.I score of 0, 0.04, and 0, respectively. Accordingly, the two stilbenes were evaluated to be virtually 'non-irritant' materials. In a skin sensitization study by GPMT, 1% OXY, 5% OXY, and 1% OXY-3 did not cause edema and erythema at 24 h and 48 h after topical application and exhibited a sensitization score of 0 and a rate of 0%. Consequently, it was confirmed that OXY and OXY-3 had no contact allergic sensitization in GPMT. Therefore, OXY and OXY-3 might be potential candidates as skin-whitening agents without posing any serious side effects.

• Journal of Biomedical Engineering Research
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• v.16 no.4
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• pp.425-430
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• 1995

The correlation technique has been widely used in ctRl data processing. The proposed CLT (clus- tering threshold) technique is a modified CCT (correlation coefficient threshold) technique and has many advantages compared with the conventional CCT technique. The CLT technique is explained by the following two steps. First, once the correlation coefficient map above the proper TH value is obtained using the CCT technique which is discrete and includes splash noise data, then the spurious pixels are rejected and the real neural activity pixels extracted using an nxn matrix box. Second, a clustering operation is performed by the two correction rules. The real neuronal activated pixels can be clustered and the false spurious pixels can be suppressed by the proposed CLT technique. The proposed CLT technique used in the post processing in ctRl has advantages over other existing techniques. It is especially proved to be robust in noisy environment.

• Progress in Medical Physics
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• v.9 no.2
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• pp.95-104
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• 1998

The dynamic properties of the 3rd-order neuron of the retina was investigated by using conventional intracellular recording techniques. Experiments were performed in the superfused retina-eyecup preparation of the channel catfish, Ictalurus punctatus. The cornea, iris, lens, and vitreous were removed by absorption with Kimwipe tissue under the dissection microscope thereby exposing the retina in a hemi -eyecup. The electrical signal was amplified by electrometer, viewed on oscilloscope. Regular signals from the cells were recorded on a penwriter and stored by data recorder and computer. Full-field, spot or annular light stimuli were generated on a computer monitor and focused onto the retina. Baclofen hyperpolarized the dark membrane potential, suppressed sustained component and enhanced transient component of the ON-sustained cell with a large transient component, but did not affect the surround antagonism of the cell. Baclofen selectively suppressed responses evoked by moving bar light stimuli on the ON-OFF transient cell. The results suggest that transient cells have directional selectivity in the inner retina. These dynamic properties of amacrine and ganglion cells were modulated by baclofen. Therefore, it is presumed that there is baclofen-induced directional selectivity in ON-OFF transient cells in the catfish retina.

• Economic and Environmental Geology
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• v.46 no.1
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• pp.71-84
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• 2013

Most gas hydrates (GH) occur in ocean sediments. Global GH reserves are estimated to be $10^{13}{\sim}20{\times}10^{15}m^3$, which is nearly 1,000 times the amount of current world energy consumption. Methane hydrate (MH) has the potential to be developed into future natural gas resources to replace traditional oil and gas resources, and thus MH production technologies such as depressurization, inhibitor injection, thermal stimulation, and $CO_2-CH_4$ substitution need to be further developed. MH production, which is expected to be in test production until 2014 in Korea, is focused on the development of GH production technologies for use in the commercial production of methane gas. This study compares MH production technology and its ability to meet the twin goals of being both effective and environmentally friendly while taking into consideration the complex phenomena of GH decomposition.