• KSBB Journal
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• 제22권4호
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• pp.222-227
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• 2007

바이오디젤 (지방산 메틸에스테르)은 디젤 엔진의 대체에너지로서 현재 페트로디젤과 일정 수준으로 혼합하여 사용되고 있다. 바이오디젤의 생산에는 다양한 방법 및 공정이 개발되어 적용되고 있는데, 이 중 알칼리 촉매를 이용한 전이에스테르화 반응은 짧은 반응시간에도 높은 순도의 바이오디젤을 생산할 수 있다. 본 연구에서는 제주도산 유채유를 대상으로 알칼리 촉매 (KOH)를 사용하여 반응표면 분석법을 적용하여 전이에스테르화 반응의 최적조건을 탐색하였다. 바이오디젤 생산 인자의 최적조건은 반응온도 59.7$^{\circ}C$, 촉매량 1.18%, 유지 대 메탄을 몰비 1:8.75, 그리고 반응시간 15.18분에서 생산물 중 약 97% 이상의 지방산 메틸에스테르 함량을 확보하였다.

• Korean Chemical Engineering Research
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• 제58권1호
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• pp.122-126
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• 2020

본 연구에서는 폴리디메틸실록산(PDMS)과 모세관-미세몰딩(MIMIC) 기술을 활용하여 마이크로패턴 채널 시스템을 제작하고, 단일 세포 수준에서 극성화 패턴으로 형성되는 분자 신호를 고해상도 세포 이미징을 통해 분석하였다. 이 과정에서 혈소판유래성장인자(PDGF)가 처리된 세포에서는 세포 이동에 중요한 세 종류의 신호인 포스포이노시티드 3-인산화효소(PI3K), Rac 및 액틴(Actin) 신호가 선두(front)영역에서 후미(rear)영역에 비해 강하게 활성화 하는 데 반해, 마이오신 경쇄(MLC) 신호는 비특이적 경향성을 보여주었다. 본 연구 결과는 향후 마이크로패턴의 미세환경에서 세포 극성화 신호와 세포 이동과의 상관 관계를 연구하는 데 중요한 도움이 될 것으로 사료된다.

• 한국환경보건학회지
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• 제43권5호
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• pp.382-392
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• 2017

Objectives: The purpose of this study is to obtain basic data on the development of a risk communication model through an investigation of risk perception for radon and identify effective risk communication channels. Methods: A questionnaire was used to evaluate differences in perception level according to respective communication channels. A chi-squared test was used to analyze the difference in pre- and post-risk communication by communication channel. One-way ANOVA was used to analyze the difference in the radon risk perception rate for each communication channel. Results: All of the communication channels resulted in increased radon risk perception, but there was no statistical difference between them in terms of perception (p>0.05). However, based on previous findings that it is effective to use a multi-channel approach, it is considered that communication channels based on duplicate avenues is most appropriate. Conclusions: It is expected that this study will be used as basic data to better understand the formation of public opinion about radon risk and to understand the social reaction to each risk factor.

• 한국물환경학회지
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• 제34권6호
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• pp.602-620
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• 2018

Korean benthic macroinvertebrate community from 959 sites and 14 environmental factors that could affect the biological distribution were surveyed and analyzed. The 438 taxa were divided into six groups according to TWINSPAN. Based on the environmental factor values corresponding to each taxon, the average and range of environmental factors for each biological group tended to increase or decrease in eight environmental factors (altitude, slope, current velocity, fraction of fine particles in substrates, turbidity, $BOD_5$, T-N and T-P). As a result of discriminant analysis (hit ratio: 69.6 %), environmental factors that significantly influence the distribution of each biological group were $BOD_5$, altitude, catchment area, T-N, T-P and fraction of fine particles in substrates. The discriminant functions 1 and 2 classified the existing six biological groups (clustered by TWINSPAN) into five (group 1: highland highly sensitive group; group 2: lowland sensitive group, group; 3 and 4: lowland slightly tolerant group; group 5: lowland tolerant group; group 6: lowland highly tolerant group). Most of the benthic macroinvertebrates were identified in the species level. However, a few others were identified in genus or family level, too. Even the organisms belonging to the same genus or family may prefer different environmental factors in the species level, the identification of characteristic of the habitat environment preferred by organism and species level identification of these organisms are utmost. The results of this study may be used as basic information on environmental factors which can be considered in preservation and restoration research for biodiversity.

• Fisheries and Aquatic Sciences
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• 제26권12호
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• pp.752-761
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• 2023

Genetic diversity serves as the basis for selecting and genetically enhancing any culturable species in aquaculture. Here, two different strains of wild (River Ravi and River Kabul) and six captive-bred strains of Labeo rohita from various provinces were se- lected, and genetic diversity among them was evaluated using three different microsatellite markers, i.e., Lr-28, Lr-29, and Lr-37, and one mitochondrial CO1 (Cytochrome c oxidase subunit 1) gene. Different strains of L. rohita were collected, and part of their caudal fin was cut and preserved in ethanol for DNA extraction and determination of genetic diversity among them. Results in- dicated that selected markers were polymorphic with polymorphic information content (PIC) content values above 0.5 with the highest in Lr-28 followed by Lr-29 and then Lr-37. The observed heterozygosity (Ho) of all strains was higher (Avg: 0.731) but less than the expected heterozygosity (He). Moreover, TMs and WRs showed the highest He, while TKs showed the lowest, He. Over- all, inbreeding coefficient (FIS) values observed for all strains with selected markers were positive. The DNA barcoding with the CO1 gene revealed genetic variation among various strains, as demonstrated by the clades in the phylogenetic tree separating the strains into two distinct clusters that then divided into sub-clusters. In conclusion, TMs showed the highest heterozygosity as compared to other strains. Overall results provide the baseline data for the initiation of the genetic improvement program.

• International Journal of Fuzzy Logic and Intelligent Systems
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• 제7권2호
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• pp.109-114
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• 2007

Fingerprints have been widely used in the biometric authentication because of its performance, uniqueness and universality. Lately, the speed of identification has become a very important aspect in the fingerprint-based security applications. Also, the reliability still remains the main issue in the fingerprint identification. A fast and reliable fingerprint matching algorithm based on the process of the 'self-nonself' discrimination in the biological immune system was proposed. The proposed algorithm is organized by two-matching stages. The 1st matching stage utilized the self-space and MHC detector string set that are generated from the information of the minutiae and the values of the directional field. The 2nd matching stage was made based on the local-structure of the minutiae. The proposed matching algorithm reduces matching time while maintaining the reliability of the matching algorithm.

• Animal cells and systems
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• 제5권4호
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• pp.313-317
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• 2001

The sequential assessment model describes a fight between two conspecific as an ongoing statistical sampling process, which makes it possible to predict fight length or repetition number of a behavioral element depending on relative RHP (resource holding potential: e.g. weight or fighting ability). We staged contests between males of common freshwater gobies to test some predictions of this model. Fights proceeded in a consistent sequence of phases. Most contests began with two contestants adopting lateral display, and then escalated to intense physical contacts. The length of contests was negatively correlated with weight difference between the contestants. The duration of complete phases was, however, independent of weight, and the prior information gained during complete phases did not appear to affect subsequent phases of the fight. Our results show that the contests of common freshwater gobies are well predicted by the sequential assessment model.

• 생물정신의학
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• 제22권2호
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• pp.29-33
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• 2015

The brain maintains homeostasis and normal microenvironment through dynamic interactions of neurons and neuroglial cells to perform the proper information processing and normal cognitive functions. Recent post-mortem investigations and animal model studies demonstrated that the various brain areas such as cerebral cortex, hippocampus and amygdala have abnormalities in neuroglial numbers and functions in subjects with mental illnesses including schizophrenia, dementia and mood disorders like major depression and bipolar disorder. These findings highlight the putative role and involvement of neuroglial cells in mental disorders. Herein I discuss the physiological roles of neuroglial cells such as astrocytes, oligodendrocytes, and microglia in maintaining normal brain functions and their abnormalities in relation to mental disorders. Finally, all these findings could serve as a useful starting point for potential therapeutic concept and drug development to cure unnatural behaviors and abnormal cognitive functions observed in mental disorders.

• 생물정신의학
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• 제2권2호
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• pp.301-305
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• 1995

Subcortical dementia may occur as a complication of cerebral malaria via deep white matter demyelination with encephalitis and diffuse small vessel vasculitis. In subcortical dementia, impairment in attention and frontal executive function are predominant. Patients are often inert, indifferent, and uninterested. They appear characteristically 'slowed up' with a marked deficit in the retrieval of information. Changes in mood, personality, and social conduct are very common. We describe a case of subcortical dementia, who has definite changes in brain MRI after cerebral malaria.

• 식물분류학회지
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• 제46권2호
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• pp.163-174
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• 2016

Gnetum (Gnetaceae, Gnetales) is a gymnosperm genus with ca. 35 species distributed in tropical forests around the world. Due to its dioecious habit and lack of diagnostic characters from vegetative tissue, the identification of Gnetum species is not easy without seeds or reproductive structures. To identify and verify their phylogenetic positions, we applied DNA barcoding to Cambodian Gnetum collections gathered between 2010 and 2015, with previously designed cp matK gene primers. We newly sequenced partial matK sequences from 72 Gnetum collections, 43 out of 72 from Cambodia, and analyzed 115 Gnetum accessions using the neighbor-joining method. The resulting neighbor-joining tree categorized Cambodian Gnetum samples into three clades of species: G. macrostachyum, G. montanum, and G. aff. gracilipes. The recognition of G. aff. gracilipes in Cambodia is reported here for the first time. Taxonomic information for the three recognized Cambodian Gnetum species is provided and the benefits of the taxonomic reevaluation assisted by DNA barcoding are emphasized in this work.