• 한국식품조리과학회지
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• 제31권3호
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• pp.288-295
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• 2015

In this study, we investigate the physicochemical characteristics of dried bracken (Pteridium aquilinum Kuhn) harvested in Namhae. The moisture, ash, crude protein and crude lipid content was $10.79{\pm}0.31%$, $6.16{\pm}0.04%$, $33.20{\pm}0.40%$ and $2.45{\pm}0.27%$, respectively. The total mineral (Ca, Fe, K, Mg, Na, Mn) content was $36720.1{\pm}495.7mg/kg$, with K being the highest at $31890.0{\pm}503.8mg/kg$. The total free amino acid content was 704.41 mg/100 g, the amount of methionine, citrulline and sarcosine being higher than the others. The water and 50% ethanol extracts from the dried bracken were evaluated for the total poly phenolic compound content, antioxidant activity and xanthine oxidase and ${\alpha}$-glucosidase inhibitory activity. The total polyphenol content in the 50% ethanol extract ($1574.86{\pm}18.31mg/100g$) was higher than in the water extract ($1240.24{\pm}16.32mg/100g$). The DPPH and ABT radical scavenging activity was increased according to the concentration of bracken extract, and the activity in the 50% ethanol extract was higher than in the water extract. In addition, the xanthine oxidase and ${\alpha}$-glucosidase inhibitory activity was also higher in the 50% ethanol extract than in the water extract. In conclusion, bracken has great antioxidative and antidiabetic effects and can be used as a preventive agent for oxidation and diabetes.

• Molecules and Cells
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• 제23권3호
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• pp.304-315
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• 2007

Fusarium graminearum causes a serious scab disease of small grains in Korea. The nucleotide sequence of the genomic RNA of a double-stranded RNA (dsRNA) virus, Fusarium graminearum virus-DK21 (FgV-DK21), from F. graminearum strain DK21, which is associated with hypovirulence in F. graminearum, was determined and compared to the genome sequences of other mycoviruses, including Cryponectria hypoviruses. The FgV-DK21 dsRNA consists of 6,624 nucleotides, excluding the 3'-terminal poly(A) tail. The viral genome has 53- and 46-nucleotide 5' and 3' untranslated regions (UTRs), respectively, and five putative open reading frames. A phylogenetic analysis of the deduced amino acid sequence of ORF1, which encodes a putative RNA-dependent RNA polymerase, and those of other mycoviruses revealed that this organism forms a distinct virus clade with other hypoviruses, and is more distantly related to other mycoviruses (3.8 to 24.0% identity). However, pairwise sequence comparisons of the nucleotide and deduced amino acid sequences of ORFs 2 through 5 revealed no close relationships to other protein sequences currently available in GenBank. Analyses of RNA accumulation by Northern blot and primer extension indicated that these putative gene products are expressed from at least two different subgenomic RNAs (sgRNAs), in contrast to the cases in other hypoviruses. This study suggests the existence of a new, as yet unassigned, genus of mycoviruses that exhibits a potex-like genome organization and sgRNA accumulation.

• 한국축산식품학회지
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• 제43권5호
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• pp.901-913
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• 2023

This study aimed to investigate changes in the quality of meat aged using Jeju scoria earthenware. Water-holding properties, pH, color, tenderization, fatty acid composition, and free amino acid characteristics of aged pork loin were evaluated to determine the effects of wet and dry (normal and Jeju Scoria) aging methods and aging time (0, 10, 20, 30, and 40 days) on meat quality. The aging methods altered pH and CIE L^* after 10 days of aging. However, the aging method did not alter the pH and CIE L^* of the aged pork loin after 10 days of aging. The shear force was significantly lower in the Scoria aging method than in the wet aging method after 10 and 20 days of aging. Both the normal and Scoria aging methods increased aging loss compared to the wet aging method, which could be attributed to longer air exposure times of the two non-packaged aging methods than in the packaged aging method. The scoria aging method had significantly higher contents and ratios of saturated (SFA) to mono-unsaturated fatty acids but lower ratios of poly-unsaturated fatty acids to SFA than the wet aging method. The content of most free amino acids significantly increased with aging time, especially those related to the sweet, and umami categories. In summary, this study suggests that the Scoria aging method provides positive aspects of eating quality, such as improvement of meat tenderness and taste, including umami, with minimum changes in the overall meat quality.

• 한국재료학회:학술대회논문집
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• 한국재료학회 2011년도 춘계학술발표대회
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• pp.244.2-244.2
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• 2011

We introduce a novel and robust method for the preparation of nanocomposite multilayers, which allows the excellent photoluminescent (PL) properties as well as the accurate control over the composition and dimensions of multilayers. By exchanging the oleic acid stabilizers of CdSe@ZnS quantum dots (QDs) synthesized in organic solvent with 2-bromo-2-methylpropionic acid (BMPA) in the same solvent, these nanoparticles were be alternately deposited by nucleophilic substitution reaction with highly branched poly(amidoamine) dendrimer (PAMA) through layer-by-layer (LbL) assembly process. Our approach does not need to be transformed into the water-dispersible nanoparticles with electrostatic or hydrogen-bonding groups, which can deteriorate their inherent properties, for the built-up of multilayers. The nanocomposite multilayers including QDs exhibited the strong PL properties achieving densely packed surface coverage as well as long-term PL stability under atmospheric conditions in comparison with those of conventional LbL multilayers based on electrostatic interaction. Furthermore, we demonstrate that the flexible multilayer films with optical properties can be easily prepared using nucleophilic substitution reaction between bromo and amino groups in organic media. This robust and tailored method opens a new route for the design of functional film devices based on nanocomposite multilayers.

• Bulletin of the Korean Chemical Society
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• 제31권11호
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• pp.3103-3108
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• 2010

Conducting polymers (CPs) are widely used as matrixes for the entrapment of enzymes in analytical chemistry and biosensing devices. However, enzyme-catalyzed polymerization of CPs is rarely used for immunosensing due to the difficulties involved in the quantitative analysis of colloidal CPs in solution phase. In this study, an enzyme-amplified electrocatalytic immunosensor employing a CP as a redox marker has been developed. A polyanionic polymer matrix, $\alpha$-amino-$\omega$-thiol terminated poly(acrylic acid), was employed for precipitation of CP. The acrylic acid group acts as a polyanionic template. The thiol terminus of the polymer was used to produce self-assembled monolayers (SAMs) on Au electrodes and the amine terminus was employed for immobilization of biomolecules. In an enzymeamplified sandwich type immunosensor, the polyaniline (PANI) produced enzymatically is attracted by the electrostatic force of the matrix polymer. The precipitated PANI was characterized by electrochemical methods.

• 통합자연과학논문집
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• 제3권2호
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• pp.72-77
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• 2010

Alginate lyases, also known as alginases or alginate depolymerases, catalyze the degradation of alginate by a ${\beta}$-elimination mechanism that has yet to be fully elucidated. Alginate is a copolymer of ${\alpha}$-L-guluronate (G) and its C5 epimer ${\beta}$-D-mannuronate (M), arranged as homopolymeric G blocks, M blocks, alternating GM or random heteropolymeric G/M stretches. Almost all alginate lyases depolymerize alginate in an endolytical fashion via a ${\beta}$-elimination reaction. The alginate lyase Atu3025 from Agrobacterium tumefaciens strain C58, consisting of 776 amino-acid residues, is a novel exotype alginate lyase classified into polysaccharide lyase family 15. Till now there is no crystal structure available for this class of proteins. Since there is no template with high sequence identity, three-dimensional coordinates for exotype alginate lyase (PL 15 family) were determined using modeling methods (Comparitive modeling and Fold recognition). The structures were modeled using the X-ray coordinates from Heparinase protein family (PDB code: 3E7J). This enzyme (Atu3025) displays enzymatic activity for both poly-M and poly-G alginate. Since poly-M is widespread; docking of a tri-mannuronate against the modeled structure was performed. We identified some of those residues which are crucial for lyase activity. The results from this study should guide future mutagenesis studies and also provides a starting point for further proceedings.

• 폴리머
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• 제29권5호
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• pp.518-521
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• 2005

생분해성 고분자와 수화젤의 약물 전달 시스템과 조직 공학을 포함하는 다양한 생의학적인 응용이 점차 확대되고 있다. 하이드록실 pendant group을 갖고 있는 폴리아미노산의 하나인 PHEA는 뛰어난 생분해성과 우수한 생체적합성을 갖는 고분자로 알려져 있다 PHEA 및 그 유도고분자를 제조하고 이를 다양한 생의학적인 응용에 적용하는 연구가 진행되어 왔다. 본 연구에서는 유기용매에서 가교제인 HMDI를 사용하여 PHEA 수화젤을 제조하였다. PHEA는 아스팔트산의 열 축중합에 의해 합성한 polysuccinimide와 ethanolamine과의 고분자 반응으로부터 제조하였다. 제조한 수화젤에 대한 서로 다른 수용액과 pH용액에서의 팽윤 거동을 조사하였고, SEM을 통한 수화젤의 모폴로지와 가수분해 거동을 관찰하였다.

• 폴리머
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• 제29권1호
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• pp.36-40
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• 2005

폴리(아미노산)유도체는 약물전달시스템의 약물전달체로 많이 연구되고 있으며 그 중 Polysuccinimide(PSI)는 생체적합성과 생분해성 등의 물리화학적 특성을 이용하여 약물전달체로 이용할 수 있는 가능성을 지닌 고분자이다. 축합중합을 이용하여 아스파르트산이 고리를 형성함으로써 PSI를 중합하였다. 이 때 PSI의 중합 최적조건을 관찰하기 위하여 시간과 촉매함량의 변화에 따른 평균분자량의 변화를 확인하였다. 또한 친수성과 소수성으로 이루어진 고분자 미셀을 제조하기 위하여 친수성 사슬인 메톡시폴리(에틸렌 글리콜((MPEG)을 결합시켰다. 합성한 고분자는 1H-NMR, FT-IR 및 GPC를 통하여 특성을 확인하였으며, ELS와 AFM을 통해 미셀의 형성에 대한 특성을 분석하였다. 미셀의 평균크기는 90~130 nm로 측정되었다. 본 연구를 통하여 PSI를 주사슬로 하는 가지 공중합체가 미셀 형태의 약물전달용 전달체로서 가능성을 가지고 있음을 확인할 수 있었다.

• 한국양식학회지
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• 제20권1호
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• pp.65-72
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• 2007

우리나라 주요 담수어종인 미꾸라지(Misgurnus mizolepis)로 부터 apolipoprotein A-I (apoA-I) cDNA를 분리하고 그 구조, 분자 계통 및 발현 특징을 분석하였다. 미꾸라지 apoA-I cDNA는 254개의 아미노산을 암호화하고 있는 762 bp의 ORF를 포함하고 있었으며 아울러 24 bp의 5'UTR 및 293 bp의 3'UTR(종결 코돈 및 poly A tail 제외)를 갖고 있었다. 미꾸라지 apoA-I은 여타 척추동물 apoA-I과의 다중배열 시 염기서열에서는 많은 차이를 나타내었지만 단백질의 구조적 특징은 높은 상동성을 보였고, 또한 척추동물의 apoA-I들과의 분자계통을 분석한 결과, 종래 알려진 분류학적 위치와 비교적 잘 일치하였다. 미꾸라지 apoA-I mRNA는 RT-PCR 분석을 통해 간 및 뇌 조직에서 분석한 다른 조직보다 유의적으로 높게 발현하는 것으로 나타났고, 특히 간에서 가장 높은 발현을 보였다. 수정시부터 부화 후 14일까지 초기 발생 및 치어에서의 apoA-I mRNA 발현을 조사한 결과 수정 8시간째부터 급격한 발현의 증가가 시작되어 이후 지속적으로 높은 발현 수준을 유지하였다.

• 한국식품영양과학회지
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• 제21권2호
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• pp.187-194
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• 1992

Rhizopus oryzae CJ-2114의 polygalacturonase 생성을 위한 최적조건은 수분이 60% 함유된 밀기울 배지에 1% albumin, 0.2% (NH$_4$)$_2$C$_2$O$_4$, 1% sorbitol을 첨가하여 96시간 배양시 최대활성을 나타내었으며, Sep-hadex G-75 및 G-150을 사용한 gel filtration과 DEAE-cellulose에 의한 이온교환 크로마토그라피를 통하여 이 효소를 11.13배 정제할 수 있었고, 수율은 40.3% 였다. 정제효소는 polyacrylamide gel 전기 영동에 의하여 단일밴드로 확인되었으며 분자량은 SDS-polyacryl-amide 전기영동에 의하여 47,000정도로 측정되었다. 효소의 결정구조는 표면이 거친 기둥모양을 형성하고 있었으며 아미노산 조상은 17종류로써 glutamic acid 함량이 198.74mg/g enzyme로 가장 많았다.