• 대한의용생체공학회:학술대회논문집
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• 대한의용생체공학회 1995년도 추계학술대회
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• pp.26-33
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• 1995

Silicone Rubber (SR)-based potassium- and sodium-selective solid-state electrodes have been developed for the portable blood electrolyte analyzer system. The electrochemical performance of these electrodes have been evaluated with a static experimental setup and with the newly developed blood electrolyte analyzer system (model; HS603). It has been shown that their potentiometric properties are essentially comparable to those of PVC-based ion-selective electrodes, but with greatly improved lifetime (200 and 40 days for potassium and sodium sensors, respectively) and potential stability (within $\pm0.1$ mV). Clinical tests have been performed with real serum samples and the results have been compared with those obtained from Ciba-Corning BGA 288 system; correlations were excellent, proving its practical utility as a new commercial system.

• 대한화장품학회지
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• 제30권4호
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• pp.457-462
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• 2004

N-Acetyl-D-glucosamine (NAG)는 보습제로 사용되어지는 히아루론산의 구성물질인 뮤코 다당류의 일종이며, 특히 화장품으로서 응용은 보습제로서의 사용이 최초이다. 본 실험에서는 게나 새우의 껍데기에서 추출된 키틴을 탈아세틸화 하여 얻은 NAG를 화장품 원료로서 적용하고자 하였다. 현재 기능성 주름 원료로 알려진 레티놀(retinol)과 NAG를 비교하기 위하여 섬유아세포의 활성능력 및 콜라겐 생성촉진 효과를 비교 실험하였으며, 제형 내에서의 안정성을 위하여 HPLC로 역가를 측정하였다. 실험결과, 게의 껍질로부터 유도된 NAG는 피부에 자극을 전혀 주지 않으면서 섬유아세포의 세포활성 및 콜라겐의 생성을 촉진시키는 효과를 나타내었으며, 헤어리스 마우스를 대상으로 실험을 실시한 결과 피부층의 변화를 통하여 주름의 감소 효능을 볼 수 있었다.

• Water Engineering Research
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• 제6권3호
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• pp.131-147
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• 2005

Today, a trend that tries to return the artificial space of a river to a natural one is expanding. But in Korea, which lies in the monsoon climate zone, rivers endure flood damage every year. Moreover, climatic change from global warming causes severe variations in precipitation patterns. Until recently, river restoration practices in Korea have followed partial restoration. These restorative treatments transformed artificial structures of the stream to natural ones and introduced natural vegetation by imitating natural or semi-natural streams. Treatment transformed the riparian structure and increased the diversity of micro-topography and vegetation. Furthermore, restoration recovered species composition, increased species diversity, and inhibited the establishment of exotic species. In particular, the Suip stream, which was left to its natural process for approximately 50 years, recovered its natural features almost completely through passive restoration. An urban stream, the Yangjae, and a rural stream, the Dongmoon, were restored partially by applying ecological principles. On the contrary, technological treatment applied to recover flood damage induced species composition far from the natural vegetation and decreased species diversity. Additionally, this treatment increased exotic species. The same results were found also in benthic invertebrate and fish fauna. The above-mentioned results reflect the importance of ecological considerations in river management.

• 한국토양비료학회지
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• 제45권5호
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• pp.792-797
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• 2012

경남지역 논토양의 글로말린 함량과 미생물 특성과의 관계를 분석하기 위하여 2011년에 20개소를 선정하여 분석한 결과는 다음과 같다. 토양 글로말린 함량은 토양 유기물 함량 (r=0.595, p<0.01) 및 탈수소효소 활성 (r=0.663, p<0.01)과 정의상관 관계를 나타냈다. 또한, 글로말린 함량은 미생물 생체 탄소 함량 (r=0.710, p<0.001) 및 총 세균군집 (r=0.616, p<0.01)과 정의상관을 보였다. 그리고 글로말린 함량은 그람음성 세균의 군집 (r=0.561, p<0.05) 및 cy19:0/18:$1{\omega}7c$ (r=0.487, p<0.05)와 정의상관 관계를 나타냈다. 따라서 논토양에서 글로말린 함량은 지속가능한 친환경농업을 위해 토양 건강성의 지표로 활용할 수 있을 것으로 생각된다.

• 한국환경보건학회지
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• 제37권2호
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• pp.141-149
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• 2011

This study aimed for developing a two stage dual media filtration system. It has a sand and activated carbon layer above the under-drain system, and a sand layer above the middle-drain system for pretreatment. When retrofitting an old sand filter bed or designing a new one, this technology can substitute the existing sand filter bed without requiring a new plant site. The removal rate of total particle is 93, and 3~7 ${\mu}m$ and 5~15 ${\mu}m$ particles are all 97%. These high removal efficiencies of each pollutant due to adsorption and biological oxidation in activated carbon filter layer. The best backwashing method of two stage dual media filtration system is ascertained by air injection, air + water injection and water injection sequence. In this study, a pilot plant of two stage and dual filtration system was operated for 4 months in water treatment plant. The stability of turbidity was maintained below 1 NTU. The TOC, THMFP and HAAFP were removed about 90% by two stage and dual media filtration system, which is almost 2 times higher than existing water treatment plant.

• KSBB Journal
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• 제26권6호
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• pp.483-490
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• 2011

Bioactive peptides (BAP) showed excellent cosmetic activity than bio-materials such as caffeic acid (CA), gallic acid (GA), and nicotinic acid (NA). Caffeoyl tripeptide-1 (CT-1) is a BAP that is stabilized with Gly-His-Lys (GHK) tripeptide and CA by using Fmoc solid phase peptide synthesis. Digalloyl tetrapeptide-19 (DT-19) is stabilized by combining Lys-Glu-Cys-Gly with GA and nicotinoyl tripeptide-1 (NT-1) is synthesized by GHK and NA. According to experiments, CT-1 has an excellent anti-oxidant function even with a very small amount of 10 ppm CT-1. DT-19's tyrosinase inhibition activity has the better effect of about 28.57% in 0.01% and 33.33% in 0.005% of concentration and about 7.89% in 0.001% concentration than vitamin-C. In addition, NT-1 is safer than the NA. Almost BAPs like pal-KTTKS, acetyl hexapeptide, and copper tripeptide-1 have the anti-wrinkle effect while DT-19 and NT-1 are applicable for potential BAPs focused on the whitening effect. The three kinds of BAPs like CT-1, DT-19, and NT-1 consisting of amino acids are safe to the skin, and have more excellent stability than bio-materials which are found to be unstable and cause skin irritation. Due to the high biological activity of BAP in the field of skin care, its utilization will increase constantly.

• Journal of Plant Biotechnology
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• 제36권2호
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• pp.115-123
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• 2009

In recent years, several genetically modified (GM) crops have been developed worldwide through the recombinant DNA technology and commercialized by various agricultural biotechnological companies. Commercialization of GM crops will be required the assesment of risks associated with the release of GM crops. In advance of the commercial release of GM crops, developer should submit the several information on GM crops for approval. In this study, we carried out to provide the molecular data for the risk assessment of GM rice containing insect-resistant gene, modified Cry1Ac (CryIAc1). Through the molecular analysis with CryIAc1 induced GM rice, we confirmed the steady integration and expression of transgene, the transgene copy number, the adjacent region sequences of inserted gene into rice genome, and the transgene stability in progenies. For the qualitative PCR detection methods, specific primer pairs were designed on the basis of integration sequences, and construct- and event-specific detection markers were developed for leaf folder-resistant rice, Cr7-1 line. From these results, we demonstrated that the molecular data and the PCR detection methods of leaf folderresistant GM rice could be acceptable to conduct the biosafety and environment risk assessment.

• Bulletin of the Korean Chemical Society
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• 제35권12호
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• pp.3521-3526
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• 2014

A magnetic sonophotocatalyst $Fe_3O_4@SiO_2@TiO_2$ is synthesized for the enhanced biodegradability of organophosphate pesticide. The as-prepared catalysts were characterized using different techniques, such as X-ray diffraction (XRD) and transmission electron microscopy (TEM). The radial sonophotocatalytic activity of $Fe_3O_4@SiO_2@TiO_2$ nanocomposite was investigated, in which commercial dichlorvos (DDVP) was chosen as an object. The degradation efficiency was evaluated in terms of chemical oxygen demand (COD) and enhancement of biodegradability. The effect of different factors, such as reaction time, pH, the added amount of catalyst on $COD_{Cr}$ removal efficiency were investigated. The average $COD_{Cr}$ removal efficiency reached 63.13% after 240 min in 12 L sonophotocatalytic reactor (catalyst $0.2gL^{-1}$, pH 7.3). The synergistic effect occurs in the combined sonolysis and photocatalysis which is proved by the significant improvement in $COD_{Cr}$ removal efficiency compared with that of solo photocatalysis. Under this experimental condition, the $BOD_5/COD_{Cr}$ ratio rose from 0.131 to 0.411, showing a remarkable improvement in biodegradability. These results showed that sonophotocatalysis may be applied as pre-treatment of pesticide wastewater, and then for biological treatment. The synthesized magnetic nanocomposite had good photocatalytic performance and stability, as when it was used for the fifth time, the $COD_{Cr}$ removal efficiency was still about 62.38%.

• Biomolecules & Therapeutics
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• 제22권5호
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• pp.371-383
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• 2014

The nematode Caenorhabditis elegans (C. elegans) offers a unique opportunity for biological and basic medical researches due to its genetic tractability and well-defined developmental lineage. It also provides an exceptional model for genetic, molecular, and cellular analysis of human disease-related genes. Recently, C. elegans has been used as an ideal model for the identification and functional analysis of drugs (or small-molecules) in vivo. In this review, we describe conserved oncogenic signaling pathways (Wnt, Notch, and Ras) and their potential roles in the development of cancer stem cells. During C. elegans germline development, these signaling pathways regulate multiple cellular processes such as germline stem cell niche specification, germline stem cell maintenance, and germ cell fate specification. Therefore, the aberrant regulations of these signaling pathways can cause either loss of germline stem cells or overproliferation of a specific cell type, resulting in sterility. This sterility phenotype allows us to identify drugs that can modulate the oncogenic signaling pathways directly or indirectly through a high-throughput screening. Current in vivo or in vitro screening methods are largely focused on the specific core signaling components. However, this phenotype-based screening will identify drugs that possibly target upstream or downstream of core signaling pathways as well as exclude toxic effects. Although phenotype-based drug screening is ideal, the identification of drug targets is a major challenge. We here introduce a new technique, called Drug Affinity Responsive Target Stability (DARTS). This innovative method is able to identify the target of the identified drug. Importantly, signaling pathways and their regulators in C. elegans are highly conserved in most vertebrates, including humans. Therefore, C. elegans will provide a great opportunity to identify therapeutic drugs and their targets, as well as to understand mechanisms underlying the formation of cancer.

• 대한치과의사협회지
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• 제55권10호
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• pp.676-687
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• 2017

Objectives : The aim of this study was to evaluate the effects of a composite of bone substitute and collagen barrier membrane (bone patch) for local ridge augmentation at peri-implant dehiscence defects on the clinical efficacy and positional stability in dogs. Materials and methods : Implant placement and ridge augmentation procedure were performed at surgically created peri-implant dehiscence defects in canine mandible (n=6). Four treatment modalities were randomly applied: i) bone patch group, ii) Guided bone regeneration (GBR) without pin fixation group (bone graft and collagen membrane), iii) GBR with pin fixation group, and iv) negative control group. After 12 weeks, clinical, micro-CT and histological analyses were performed. Results : Histologic analysis showed that bone patch group had similar results to GBR group and GBR with fixation group in terms of new bone formation. Micro-CT analysis revealed similar results to histologic analysis in terms of total volume maintenance. Operating time was shorter in bone patch group compared to GBR group and GBR with fixation groups. Conclusions : GBR using bone patch could simplify the ridge augmentation procedure with reduced operating time and equivalent biological performance compared to the conventional procedure.