• 생명과학회지
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• 제30권1호
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• pp.64-69
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• 2020

꿀벌(Apis mellifera)에는 많은 항균성 펩티드가 있습니다. 그러나 아직 많은 종류의 펩티드를 기능을 알려지지 않았다. 따라서, 알려지지 않은 기능성 펩티드의 특성화가 필요하다. 그래서 우리는 새로운 항균성 펩티드(AMP)를 분석 하였다. 우리는 Apis mellifera에서 total RNA를 분리하고 Illumina HiSeq 2500 차세대 시퀀싱(NGS) 기술을 사용하여 15,314 개의 펩티드 서열을 생성하여 새로운 AMP를 선발 하였다. AMP로서 기능을 가지는 AMP를 선발 하기 위해 AMP 서열의 특성 과 특징을 분석을 기초로 하여 알려지지 않은 펩티드 및 알려진 44 개의 펩티드가 확인 되었다. 그 중에서도 AMP5라는 특성화 되지 않은 펩티드를 선발 하였다. AMP5는 표피, 지방체, 독낭에서 발현된다. 항균 활성을 분석하기 위해 Gram-negative bacteria Escherichia coli KACC 10005 및 Bacillus thuringiensis KACC 10168에 대한 항균 활성을 합성한 AMP5 처리하여 시험 하였다. AMP5는 Gram-negative bacteria Escherichia coli에 대한 항균 활성을 나타냈다(MIC₅₀ = 22.04±0.66 μM). 일벌에 Escherichia coli을 주사했을 때 AMP5는 체내에서 항균성 펩티드로 발현이 높아졌다. 이러한 결과는 Escherichia coli에 대한 항균 활성을 나타냄을 확인하였다.

• 한국정보과학회논문지:정보통신
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• 제31권4호
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• pp.375-383
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• 2004

최근에 사용 편이성으로 인해 다양한 무선 이동 네트워크들이 널리 보급되면서, 무선 네트워크성능을 향상시키기 위한 연구가 활발히 진행되고 있다. 무선 네트워크에서의 패킷 손실은 유선 네트워크의 혼잡이 아닌, 전파 오류로 인해 빈번히 발생되기 때문에, 시뮬레이션에서 무선 네트워크의 성능을 정확히 평가하기 위해서는 알맞은 무선 채널 모델을 채택해야 한다. 적합한 채널 모델은 사용 주파수 영역, 신호출력, 방해물 존재 유무, 평가하는 프로토콜의 비트 오류에 대한 민감성 둥 여러 가지 변수를 고려하여 선택해야 한다. 본 논문에서는 센서(Sensor) 채널의 고 전파 오류 특성을 분석하고, 센서 채널에 알맞은 채널 모델을 결정한다. 또한 센서 네트워크에서 수집한 비트 오류 데이타와 다양한 이론적 무선 채널 모델링 방식을 이용하여 링크계층 FEC(Forward Error Correction) 알고리즘과 TCP 성능 변화를 평가한다. 10일간의 센서 채널 트레이스와의 비교 분석에 의하면, CM(Chaotic Map) 모델은 센서 채널의 BER 편차와 PER(Packet Error Rate) 같을 각각 3배와 10배 이내의 오차 범위에서, 다른 모델은 수십 배 이상 오차범위에서 예측한다. FEC 알고리즘과 세가지 TCP (Tahoe, Reno, 그리고 Vegas) 시뮬레이션 실험에서도 CM 모델은 트레이스와 유사한 성능 변화를, 다른 모델은 최대 10배 이상의 오차를 보인다.

• Journal of Microbiology and Biotechnology
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• 제28권11호
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• pp.1883-1895
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• 2018

Alcohol dependence is a global public health problem, yet the mechanisms of alcohol dependence are incompletely understood. The traditional view has been that ethanol alters various neurotransmitters and their receptors in the brain and causes the addiction. However, an increasing amount of experimental evidence suggests that gut microbiota also influence brain functions via gut-to-brain interactions, and may therefore induce the development of alcohol use disorders. In this study, a rat model of alcohol dependence and withdrawal was employed, the gut microbiota composition was analyzed by high-throughput 16S rRNA gene sequencing, and the metagenome function was predicted by PICRUSt software. The results suggested that chronic alcohol consumption did not significantly alter the diversity and richness of gut microbiota in the jejunum and colon, but rather markedly changed the microbiota composition structure in the colon. The phyla Bacteroidetes and eight genera including Bacteroidales S24-7, Ruminococcaceae, Parabacteroides, Butyricimonas, et al were drastically increased, however the genus Lactobacillus and gauvreauii in the colon were significantly decreased in the alcohol dependence group compared with the withdrawal and control groups. The microbial functional prediction analysis revealed that the proportions of amino acid metabolism, polyketide sugar unit biosynthesis and peroxisome were significantly increased in the AD group. This study demonstrated that chronic alcohol consumption has a dramatic effect on the microbiota composition structure in the colon but few effects on the jejunum. Inducement of colonic microbiota dysbiosis due to alcohol abuse seems to be a factor of alcohol dependence, which suggests that modulating colonic microbiota composition might be a potentially new target for treating alcohol addiction.

• Asian-Australasian Journal of Animal Sciences
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• 제33권1호
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• pp.166-176
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• 2020

Objective: An experiment was conducted to determine the effects of L-arginine (L-Arg) and N-carbamoylglutamic acid (NCG) on the growth, metabolism, immunity and community of cecal bacterial flora of weanling and young rabbits. Methods: Eighteen normal-grade male weanling Japanese White rabbits (JWR) were selected and randomly divided into 6 groups with or without L-Arg and NCG supplementation. The whole feeding process was divided into weanling stage (day 37 to 65) and young stage (day 66 to 85). The effects of L-Arg and NCG on the growth, metabolism, immunity and development of the ileum and jejunum were compared via nutrient metabolism experiments and histological assessment. The different communities of cecal bacterial flora affected by L-Arg and NCG were assessed using high-throughput sequencing technology and bioinformatics analysis. Results: The addition of L-Arg and NCG enhanced the growth of weanling and young rabbit by increasing the nitrogen metabolism, protein efficiency ratio, and biological value, as well as feed intake and daily weight gain. Both L-Arg and NCG increased the concentration of immunoglobulin A (IgA), IgM, and IgG. NCG was superior to L-Arg in promoting intestinal villus development by increasing villus height, villus height/crypt depth index, and reducing the crypt depth. The effects of L-Arg and NCG on the cecal bacterial flora were mainly concentrated in different genera, including Parabacteroides, Roseburia, dgA-11_gut_group, Alistipes, Bacteroides, and Ruminococcaceae_UCG-005. These bacteria function mainly in amino acid transport and metabolism, energy production and conversion, lipid transport and metabolism, recombination and repair, cell cycle control, cell division, and cell motility. Conclusion: L-Arg and NCG can promote the growth and immunity of weanling and young JWR, as well as effecting the jejunum and ileum villi. L-Arg and NCG have different effects in the promotion of nutrient utilization, relieving inflammation and enhancing adaptability through regulating microbial community.

• 한국항해학회지
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• 제21권3호
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• pp.1-18
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• 1997

From the beginning of 1990s , also in the shipping industry, especially liner shipping industry competition has been more intensive and difference of the service quality among shipping companies has been learned . On the other hand, a shipping company has some limitations to do its international mission for itself just by broadening service area. For this reason, the necessity for the global strategi alliance among the shipping companies, which is orginally aimed at sharing of facilities and organixation, has been developed. Through strategic alliance, liner shipping companies do not need to input the additional capitals to increase the material assets such as vessel capacity and spread the risk by the enlargement of the market. Also, they can secure the competitive edge through efficient utilizaton of assets. The purpose of strategic alliance of Hanjin Shipping Ltd., can be summarized as follows ; broadening of service area, cost reduction through vessel sharing, realization of rationalized shipping service by terminal and equipment or facilities sharing. Liner strategic alliances are agreement among liner companies to pol their equipment , andterminals for joint operations and services in which each alliance partner continues to serve its market using jointly operated or used inland feeders,inland terminals, port terminals, and mainline fleets of ship as well as joint pools of containers and equipment. Strategic alliances are generally more formal agreements than consortia and impose longer term and far reaching obligation on their members. It also acts as one in developing and advancing the strategic aims of the alliance members. The most important objective for liner strategic alliances is cost reduction and improvement in capital asset utilization. Main aims of strategic alliance drawn in this paper, can be enumerated follows : 1. improvements in service frequency and quality : 2. improvements in vessel and equipment utilization and thereby reductions in fixed and variable cost ; 3. improvements in market shares and high value cargo booking ; 4. reductions in intermodal storage and port terminal throughput costs ; 5. improvements in negotiating powers with ports and feeder transport providers ; 6. reduction in financial and other fixed costs such as insurance; 7. coordination and integration of MIS and EDI systems and service for greater efficiency and market penetration ; and, 8. improvements in logistic chain management and economic of scale by equipment depot, terminal, and vessel sharing.

• 한국재료학회지
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• 제16권4호
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• pp.225-230
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• 2006

Nanoimprint lithography (NIL) is a novel method of fabricating nanometer scale patterns. It is a simple process with low cost, high throughput and resolution. NIL creates patterns by mechanical deformation of an imprint resist and physical contact process. The imprint resist is typically a monomer or polymer formulation that is cured by heat or UV light during the imprinting process. Stiction between the resist and the stamp is resulted from this physical contact process. Stiction issue is more important in the stamps including narrow pattern size and wide area. Therefore, the antistiction layer coating is very effective to prevent this problem and ensure successful NIL. In this paper, an antistiction layer was deposited and characterized by PECVD (plasma enhanced chemical vapor deposition) method for metal stamps. Deposition rates of an antistiction layer on Si and Ni substrates were in proportion to deposited time and 3.4 nm/min and 2.5 nm/min, respectively. A 50 nm thick antistiction layer showed 90% relative transmittance at 365 nm wavelength. Contact angle result showed good hydrophobicity over 105 degree. $CF_2$ and $CF_3$ peaks were founded in ATR-FTIR analysis. The thicknesses and the contact angle of a 50 nm thick antistiction film were slightly changed during chemical resistance test using acetone and sulfuric acid. To evaluate the deposited antistiction layer, a 50 nm thick film was coated on a stainless steel stamp made by wet etching process. A PMMA substrate was successfully imprinting without pattern degradations by the stainless steel stamp with an antistiction layer. The test result shows that antistiction layer coating is very effective for NIL.

• 청정기술
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• 제17권4호
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• pp.389-394
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• 2011

바이오가스로부터 이산화탄소와 질소를 제거하기 위한 흡착공정은 많이 논의되고 있다. 특히 흡착공정 중에서 압력변동흡착(Pressure swing adsorption)공정은 에너지소모가 적고 가격이 경제적이기 때문에 기체의 분리와 정제를 위한 공정으로 적절하다. 물리적 흡착을 사용하는 PSA공정은 흡착과 탈착이 가능하다. 각 cycle단계의 구성은 가압, 주입 및 흡착, 압력 균등화, 감압 및 세정으로 이루어져있다. 본 실험에서 PSA공정은 이산화탄소와 질소를 제거하기 위한 흡착제로 zeolite 13X와 carbon molecular sieve (CMS)로 구성되어 있으며, 혼합 가스의 농도는 $CH_4/CO_2/N_2$ (75:21:4 vol%)의 비율을 갖고 있다. 각각 zeolite 13X와 CMS는 선택적으로 혼합가스로부터 질소와 이산화탄소를 흡착하여 분리하고 제거한다. 또한 CMS의 경우는 빠르게 분산되는 이산화탄소의 처리량이 높다. 상부탱크, 하부탱크, 주입탱크의 가스 조성은 TCD 검출기를 이용하는 gas chromatography (GC)에 의해서 측정되었다.

• 한국미생물·생명공학회지
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• 제42권1호
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• pp.41-50
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• 2014

수소생산 유효세균을 유지하기 위해 열처리한 혐기소화슬러지를 접종원으로 하여 PVA 담체를 활용한 고정화와 비고정화 방법에 의한 수소생산능 및 세균 군집을 비교분석 하였다. 고정화에 의한 수소생산성은 비고정화 방법과 비교하여 수소생산성에 영향을 미치지 않았다. 그러나 고정화 방법은 유기물 분해결과 발생하는 유기산 축적 및 pH 강하 등의 환경변화에 있어 세균의 성장과 활성에 안정적 환경을 제공할 수 있는 가능성을 나타내었다. DGGE 분석에 의한 세균군집분석에서는 비고정화와 고정화 반응조간에 형성된 세균군집이 차이가 있는 것으로 나타났으며, 상대적으로 고정화 반응조내의 유효 수소생산 세균 군집이 좀 더 안정적으로 유지되는 것으로 확인되었다. Droplet digital PCR에 의한 6종의 유효한 수소생산 세균 절대정량 분석결과, encapsulation에 관계없이 두 반응기에서의 우점세균수는 유사하였다. Firmicutes, Clostridium, Enterobacter, Ruminococcus 및 Escherichia가 $1{\times}10^5-1{\times}10^6$ copy number of ml-sample 수준에서 존재하였다.

• Journal of Microbiology and Biotechnology
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• 제32권4호
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• pp.405-418
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• 2022

Simotang oral liquid (SMT) is a traditional Chinese medicine (TCM) consisting of four natural plants and is used to alleviate gastrointestinal side effects after chemotherapy and functional dyspepsia (FD). However, the mechanism by which SMT helps cure these gastrointestinal diseases is still unknown. Here, we discovered that SMT could alleviate gastrointestinal side effects after chemotherapy by altering gut microbiota. C57BL/6J mice were treated with cisplatin (DDP) and SMT, and biological samples were collected. Pathological changes in the small intestine were observed, and the intestinal injury score was assessed. The expression levels of the inflammatory factors IL-1β and IL-6 and the adhesive factors Occludin and ZO-1 in mouse blood or small intestine tissue were also detected. Moreover, the gut microbiota was analyzed by high-throughput sequencing of 16S rRNA amplicons. SMT was found to effectively reduce gastrointestinal mucositis after DDP injection, which lowered inflammation and tightened the intestinal epithelial cells. Gut microbiota analysis showed that the abundance of the anti-inflammatory microbiota was downregulated and that the inflammatory microbiota was upregulated in DDP-treated mice. SMT upregulated anti-inflammatory and anticancer microbiota abundance, while the inflammatory microbiota was downregulated. An antibiotic cocktail (ABX) was also used to delete mice gut microbiota to test the importance of gut microbiota, and we found that SMT could not alleviate gastrointestinal mucositis after DDP injection, showing that gut microbiota might be an important mediator of SMT treatment. Our study provides evidence that SMT might moderate gastrointestinal mucositis after chemotherapy by altering gut microbiota.

• Animal Bioscience
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• 제35권11호
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• pp.1698-1710
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• 2022

Objective: Raw potato starch (RPS) is resistant to digestion, escapes absorption, and is metabolized by intestinal microflora in the large intestine and acts as their energy source. In this study, we compared the effect of different concentrations of RPS on the intestinal bacterial community of weaned piglets. Methods: Male weaned piglets (25-days-old, 7.03±0.49 kg) were either fed a corn/soybean-based control diet (CON, n = 6) or two treatment diets supplemented with 5% RPS (RPS5, n = 4) or 10% RPS (RPS10, n = 4) for 20 days and their fecal samples were collected. The day 0 and 20 samples were analyzed using a 16S rRNA gene sequencing technology, followed by total genomic DNA extraction, library construction, and high-throughput sequencing. After statistical analysis, five phyla and 45 genera accounting for over 0.5% of the reads in any of the three groups were further analyzed. Furthermore, short-chain fatty acids (SCFAs) in the day 20 fecal samples were analyzed using gas chromatography. Results: Significant changes were not observed in the bacterial composition at the phylum level even after 20 d post feeding (dpf); however, the abundance of Intestinimonas and Barnesiella decreased in both RPS treatment groups compared to the CON group. Consumption of 5% RPS increased the abundance of Roseburia (p<0.05) and decreased the abundance of Clostridium (p<0.01) and Mediterraneibacter (p< 0.05). In contrast, consumption of 10% RPS increased the abundance of Olsenella (p<0.05) and decreased the abundance of Campylobacter (p<0.05), Kineothrix (p<0.05), Paraprevotella (p<0.05), and Vallitalea (p<0.05). Additionally, acetate (p<0.01), butyrate (p<0.05), valerate (p = 0.01), and total SCFAs (p = 0.01) were upregulated in the RPS5 treatment group Conclusion: Feeding 5% RPS altered bacterial community composition and promoted gut health in weaned piglets. Thus, resistant starch as a feed additive may prevent diarrhea in piglets during weaning.