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        검색결과 16

        1.
        2020.02 KCI 등재 구독 인증기관 무료, 개인회원 유료
        잭업 드릴링 리그 (Jack-up drilling rigs)는 해양자원개발 분야 중 석유 및 가스 탐사 산업에서 널리 사용되는 대표적인 해양구조 물이다. 이러한 잭업 구조물은 대체로 얕은 수심에서 사용하도록 설계되었지만 에너지 산업의 추세로 대수심 및 가혹한 환경 조건에서도 사용이 가능한 설계가 요구되고 있다. 이러한 잭업구조물의 운영환경 확장에 따라서 과도한 설계를 최소화하고 신뢰성 반영된 설계법이 요구되었다. 기존의 해양구조물 산업에서 잭업 구조물의 설계법은 사용(혹은 허용)응력 설계 (WSD: Working (or Allowable) Stress Design) 방법을 사용하여 설계가 되고 있었다. 이러한 설치환경변화에 따라서 충분한 신뢰성을 확보가 가능한 하중 및 저항계수 (LRFD: Load and Resistance Factored Design) 방법을 최근 개발되었고 규정화가 되었다. LRFD 방법은 통계적 기반으로 한 한계상태설계 개념으로 잭업구조 물의 구성구조부재의 하중과 전산수치해석을 이용한 강도의 불확성을 하중 및 저항 계수로 표현하는 설계법이다. 개발된 LRFD 방법은 실제 잭업구조물 설계의 적합성 판단을 위하여 기존의 WSD 방법과의 정량적인 비교 분석이 반드시 필요하다. 따라서 본 연구는 기존의 WSD와 LRFD 방법으로 이용하여 실 잭업 구조물의 레그 구조를 대상으로 상용유한요소해석코드를 이용하여 정량적인 UC (Unity Check) 값을 기반으로 비교 분석하였다. 분석된 결과로 다양한 환경하중조건 하에서 LRFD 방법을 사용하여 잭업구조물의 레그(Leg) 설계에서 상 당히 합리적인 UC 값을 가지고 기존 대표적인 WSD기법 중에 하나인 API-RP 코드 대비 약 31 % 차이가 분석되었다. 따라서 LRFD 설계 방법이 WSD 방법에 비해 구조 최적화 및 합리적인 설계에 더 유리하다는 것을 확인할 수 있었다.
        4,200원
        3.
        2014.06 구독 인증기관·개인회원 무료
        We have used bulked segregant analysis to screen the strain-specific DNA marker associated thermophilic strain of Pleurotus eryngii. Bulked genomic DNAs of Pleurotus eryngii were amplified by randomly amplified polymorphic DNA (RAPD) using OP-A, OP-B, OP-L, OP-P, OP-R and OP-S primers to screen the strain-specific DNA marker. A unique DNA fragment of 550 bp was amplified with OP-S07 primer from the thermophilic strain and sequenced. A sequence characterized amplified region (SCAR) marker was designed on the basis of the determined sequence and named as OP-S07-1. The PCR analysis with the OP-S07-1 primer showed that this SCAR marker clearly distinguish the thermophilic strains from the control strains.
        4.
        2012.10 구독 인증기관·개인회원 무료
        Allomyrina dichotoma is a typical pet beetles in Korea. From 2010, similar symptoms of milky spore disease were found collectively in grubs of the species reared in insect farms. They shared a specific symptom that the skin of last instar larvae was changed softer with opaque white and infested grubs eventually died. To clarify the cause of the symptom, we collected the larvae of A. dichotoma from five farms and examined intestinal bacterial florae of them using pyrosequencing technique. From those results, a member of Paenibacillus was found only in the larvae showing the symptom of disease. Through PCR analysis using a Paenibacillus specific primer set, we obtained the partial 16S rRNA gene sequence and confirmed the microbe as Paenibacillus sp. For detailed characterizing, a whole guts was extracted from each larva showing the sign of the disease and incubated at 70℃ for 15 min to isolate spore forming bacteria. After then, each content of guts was cultured on MYPGPNAL agar medium (12.5 μg/ml of nalidixic acid) at 30℃. The 16S rRNA gene sequence analysis for six isolate showed that they were closely related to P. rigui (97.5~98.0% similarity) and to P. chinjuensis (95.9~96.6% similarity). Additional tests including API test and cellular fatty acid composition analysis were performed, but the strain couldn’t be identified at species level, suggesting it may represent novel species of the genus Paenibacillus.
        5.
        2008.05 구독 인증기관·개인회원 무료
        We determined the complete mitogenome of the oriental mayfly, Ephemera orientalis (Ephemeroptera: Ephemeridae) and the dragonfly Davidius lunatus (Odonata: Gomphidae). The 16,463-bp long E. orientalis and the 15,912 bp long D. lunatus mitogenome contains gene arrangement and content identical to the most common type found in a diverse insect order. Most individual E. orientalis and D. lunatus mt genes were well within the size found in the respective genes of other insects. The initiation codon for the D. lunatus COI gene was typical as ATA, whereas no typical start codon was found in the start region of E. orientalis COI gene. The A+T-rich regions of both mitogenomes have a few unusual feature. The A+T-rich region of E. orientalis contains a tandem repeat composed of two identical copies of 55 bp long, whereas that of D. lunatus contains a tandem repeat composed of duplicated identical 261-bp copies and one partial copy of the repeat. Also, the A+T-rich region of E. orientalis contains a single sequence and that of D. lunatus contains nine sequences, along with the tandem triplicate sequences, that has the potential to form stem-and-loop structures, flanked by the conserved sequences, “TA(A)TA” at the 5’ end and “G(A)nT’ at the 3’ end. Furthermore, the A+T-rich region of D. lunatus contains two tRNA-like structures, tRNALeu(UUR)-like sequence and tRNATyr-like sequence that have proper anticodon TAA and clover-leaf structure that were previously found in the hymenopteran insects.
        6.
        2017.05 서비스 종료(열람 제한)
        Background : Korean mountain ginseng (Panax ginseng C.A. Meyer) are difficult to industrially apply because of its scarcity and high cost. Advances in plant biotechnology have made it possible to produce mountain ginseng on a large scale using adventitious root cultures in bio-reactors. This study was conducted to develop a cosmetic emulsion using ginsenoside and physiological activity - enhanced raw materials by fermentation process. Methods and Results : Wild ginseng adventitious roots were fermented with Pediococcus pentosaceus HLJG 0702 (KACC 81017BP). ginsenoside contents was analysed by using HPLC. Antioxidant activity was measured by DPPH and ABTS radical scavenging activity and whitening effect was measured by tyrosinase inhibitory activity. After microfluidizer processing was performed to prepare emulsions with homogenized particles, particle size and distribution were measured through a transmission electron microscop e(TEM). Particle stability compares pH, viscosity, light and zeta potential. When fermented with Pediococcus pentosaceus HLJG 0702, the highest change rates of Rg3, Rk1 and Rg5 were shown and the antioxidant activity was increased. The whitening effect was 73.2 ± 0.9% when treated at 100 ㎍/㎖, 1.5 times higher than the control. The optimum particle size and distribution were shown to be 418.0 ± 14.9 ㎚ for 6 times treatment with 0 - 10 times microfluidizer treatment. Stability was about 3% in pH, viscosity and light test. the zeta potential was found to be homogeneous at –33.33 mV. Conclusion : Pediococcus pentosaceus HLJG 0702 Fermented Wild ginseng adventitious roots were found to have effective ingredients and improved physiological activity. We have also developed emulsions that exhibit optimal particle size and distribution
        7.
        2016.10 서비스 종료(열람 제한)
        Background : The minor saponins produced by the hydrolysis of a major saponins sugar. The minor saponins has high absorption and efficacy compared to major saponin. The acid treatment, heat treatment and fermentation with minor saponin research has been actively conducted. This study was performed in order to investigate the bioconversion of ginsenoside Rg5 of fermented wild ginseng adventitious roots by using lactic acid bacteria. Methods and Results : 20g adventitious roots of ginseng was added to water (10-fold v/w). 10% (v/v) of lactic acid bacteria (Pediococcus pentosaceus HLJG0702[KACC 81017BP]) were inoculated with wild ginseng adventitious roots. For the fermentation process the inoculated samples were transferred to culture room for 1, 3 and 5 days. The fermented samples were dried at room temperature and extracted with 70% ethanol. Extract was concentrated completely at 50 ℃ and Rg5 was analysed by using HPLC. Results showed no significant difference the dry weight of non-fermented and fermented wild ginseng adventitious roots. During the fermentation process, the pH changed from 5.7 to 4.2. HPLC analysis showed higher ginsenoside Rg5 (39.588 mg/g) at 3 days. Conclusion : The fermentation of ginseng root can increase the Rg5 contents and minor saponin composition. This process may be used to enhance the minor saponin thereby increasing in fermented property of wild ginseng adventitious roots.
        8.
        2016.10 서비스 종료(열람 제한)
        Background : Korean mountain ginseng(Panax ginseng C.A. Meyer) are difficult to clinically apply because of its scarcity and high cost. Advances in plant biotechnology have made it possible to produce mountain ginseng extracts on a large scale using adventitious root cultures in bio-reactors. This study investigated the variations of ginsenoside compounds composition and biological activities of wild ginseng adventitious roots by fermentation process. Methods and Results : Wild ginseng adventitious roots with five days fermentation using four strain of bacteria(Leuconostoc mesenteroides(KACC 15744), Bacillus circulans(KACC 15822), Bacillus licheniformis(KACC 15823), Bacillus subtilis subsp. inaquosorum(KACC 17047)). Ginsenoside contents was analysed by using HPLC. To examine the antioxidant activity associated with biological functions, radical scavenging analyses DPPH, ABTS and SOD-like activity analyses were conducted. The total phenolic and flavonoid contents were evaluated to determine the antioxidant activity increment. The result showed increased total ginsenoside contents by fermentation process. In particular, B. licheniformis showed the highest ginsenoside contents. Regarding ginseng fermented with B. licheniformis, values of 70.6 ± 1.4%, 44.3 ± 1.7%, and 88.4 ± 1.3% were measured using DPPH, ABTS, and SOD-like antioxdiant activity analyses, respectively. The total phenolic contents in ginseng fermented with B. licheniformis was 184.5 ± 0.9 ㎍·GAE/㎖, and the total flavonoid contents was 108.5 ± 1.8 ㎍·QE/㎖ in ginseng fermented with L. mesenteroides. Conclusion : The high activity of β-glucosidase was selected bacteria. The four types of lactic acid bacteria examined, the use of B. licheniformis to ferment ginseng resulted in greatest increase in biological activities and ginsenoside contents.
        9.
        2015.09 서비스 종료(열람 제한)
        DGCR8 is a RNA-binding protein working with DROSHA to produce pre-microRNA in the nucleus, while DICER does not only mature microRNA but also endogenous siRNAs in the cytoplasm. Here, we have produced Dgcr8 conditional knock-out mice using progesterone receptor (PR)-Cre (Dgcr8flox/flox; PRcre/+ mice, Dgcr8d/d) and demonstrated that canonical microRNAs dependent of DROSHA-DGCR8 complex are required for uterine development as well as female fertility in mice. Adult Dgcr8d/d females did not undergo regular reproductive cycle and produce any pups when housed with fertile males, whereas administration of exogenous gonadotropins induced normal ovulation with corpus luteal formation in these mice. Ovulated oocytes from Dgcr8d/d mice had comparable fertilization potentials and were normally developed to the blastocyst after fertilization as compared to those in control Dgcr8f/f mice. Interestingly, PR-Cre-dependent Dgcr8 deletion showed aberrant infiltration of acute inflammatory immune cells to female reproductive organs only when Dgcr8d/d mice were mated with male mice. With respect to uterine development, gross morphology, histology, and weight of Dgcr8d/d uterus were similar to those of control at 3-week-old age. However, multiple uterine abnormalities were noticeable at 4-week-old age when PR expression is significantly increased, and these deformities became severe onwards. Gland formation and myometrial layers were significantly reduced, and stromal cell compartment did not expand and became atrophic during uterine development in these mice. These results were consistent with aberrantly reduced cell proliferation in stromal cell compartments of Dgcr8d/d mice. Collectively, our results suggest that DGCR8 dependent-canonical microRNAs are essential for development and physiology of the uterus with respect to morphogenesis, proper immune modulation, reproductive cycle, and steroid hormone responsiveness in mice.
        12.
        2013.08 서비스 종료(열람 제한)
        Olive flounder (Paralichthys olivaceus) is a most important aquaculture species in Korea. Like most marine fishes, olive flounders are stomachless at first feeding and aquired gastric function during the metamorphosis, so food was mainly digested by pancreatic enzyme from first feeding to premetamorphosis. However, comprehensive analysis of pancreatic and gastric digestive enzyme of olive flounder at early developmental period is still unclear. In the expression study of pancreatic and gastric digestive enzyme by real-time PCR at early developmental stage, pancreatic enzyme such as chymotrypsinogen 2, preproelastase 2 and 4, pancreatic protein somatomedin-B domain (PPSB) mRNA expression were initiated at first feeding and strongly expressed in the pancreas developmental stage, while gastric digestive enzyme signal was not at all detected during same period. Although, trypsinogens were secreted from pancreas and have similar amino acid sequence, trypsinogen 3 expression induction was detected both pancreas and stomach developmental stage, while trypsinogen 2 expression was significantly increased only post-metamorphosis period. Pepsinogen mRNA expression was only detected at metamorphosis according to stomach differentiation. Lipid digestive enzyme, lipase and intestine fatty acid binding protein 1 (I-FABP 1), were already reached a certain level at beginning of hatching and more increased during early developmental stage and then gradually decreased before metamorphosis. These results suggested that feed ingestion of olive flounder was exclusive charged by pancreatic digestive enyme, lipid digestive enzyme and trypsinogen 3 from first feeding and then fully swiched by gastric digestive enzyme and trypsinogen 2 from metamorphosis period.
        13.
        2013.08 서비스 종료(열람 제한)
        For the study of population genetic structure with mtDNA, it is essential to measure genetic diversity at each mtDNA regions. Also, to evaluate the variation according to the each region should follow as well as to see if there are differences. In this study, we delved into the variations and dendrogram among samples of seven mtDNA regions (NDⅡ, NDⅤ, NDⅣ, NDⅣL, NDⅥ, NDⅠ, 12SrRNA) from wild Pacific abalone, Haliotis discus hannai collected in Yeosu, Korea. The region with the highest genetic variation was NDⅣ region (Haplotype diversity = 1.0000, Nucleotide diversity = 0.010823) with two to five times higher variation than the others. Furthermore, the study to see if there is a difference between the regions of samples showed that similar aspects of dendrogram in NDⅡ and NDⅠ(divergence of 90% and 87%), which forms a group with hd4, 7, 8 and 10 at bootstrap support, based on 1000 replications. Also, pair-wise FST between clusters within the regions showed high values; 0.4061 (P=0.0000), 0.4805 (P=0.0000) respectively. Therefore we can infer that it is the most efficient and accurate way to analyze the region of NDⅣ with the highest variation in addition to the regions of NDⅡ and NDⅠ, which formed clusters with high bootstrap value, for study of population genetic structure in this species.
        15.
        2003.02 KCI 등재 서비스 종료(열람 제한)
        Nonghobyeo', was derived from a mutant of Milyang 95, by pure line selection method, which was developed from the single cross between Chukei 1016 and Milyang 79, by the rice breeding team of National Yeongnam Agricultural Experiment Station (NYAES) in 19