• 제목/요약/키워드: Class D

검색결과 1,985건 처리시간 0.029초

Three Non-Aspartate Amino Acid Mutations in the ComA Response Regulator Receiver Motif Severely Decrease Surfactin Production, Competence Development, and Spore Formation in Bacillus subtilis

  • Wang, Xiaoyu;Luo, Chuping;Liu, Youzhou;Nie, Yafeng;Liu, Yongfeng;Zhang, Rongsheng;Chen, Zhiyi
    • Journal of Microbiology and Biotechnology
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    • 제20권2호
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    • pp.301-310
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    • 2010
  • Bacillus subtilis strains produce a broad spectrum of bioactive peptides. The lipopeptide surfactin belongs to one well-known class, which includes amphiphilic membrane-active biosurfactants and peptide antibiotics. Both the srfA promoter and the ComP-ComA signal transduction system are an important part of the factor that results in the production of surfactin. Bs-M49, obtained by means of low-energy ion implantation in wild-type Bs-916, produced significantly lower levels of surfactin, and had no obvious effects against R. solani. Occasionally, we found strain Bs-M49 decreased spore formation and the development of competence. Blast comparison of the sequences from Bs-916 and M49 indicate that there is no difference in the srfA operon promoter PsrfA, but there are differences in the coding sequence of the comA gene. These differences result in three missense mutations within the M49 ComA protein. RT-PCR analyses results showed that the expression levels of selected genes involved in competence and sporulation in both the wild-type Bs-916 and mutant M49 strains were significantly different. When we integrated the comA ORF into the chromosome of M49 at the amyE locus, M49 restored hemolytic activity and antifungal activity. Then, HPLC analyses results also showed the comA-complemented strain had a similar ability to produce surf actin with wild-type strain Bs-916. These data suggested that the mutation of three key amino acids in ComA greatly affected the biological activity of Bacillus subtilis. ComA protein 3D structure prediction and motif search prediction indicated that ComA has two obvious motifs common to response regulator proteins, which are the N-terminal response regulator receiver motif and the C-terminal helix-turn-helix motif. The three residues in the ComA N-terminal portion may be involved in phosphorylation activation mechanism. These structural prediction results implicate that three mutated residues in the ComA protein may play an important role in the formation of a salt-bridge to the phosphoryl group keeping active conformation to subsequent regulation of the expression of downstream genes.

TFDEA를 이용한 무인항공기 기술예측에 관한 연구 (A Study on Technology Forecasting of Unmanned Aerial Vehicles (UAVs) Using TFDEA)

  • 정병기;김현철;이춘주
    • 기술혁신학회지
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    • 제19권4호
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    • pp.799-821
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    • 2016
  • 무인항공기는 현대 전장 환경에서 감시정찰을 위한 필수요소이며, 전장의 복잡성과 불확실성이 증가함에 따라 그 중요성은 더욱 커지고 있다. 본 연구에서는 1982년부터 2014년까지 개발된 96대의 군용 무인항공기를 대상으로 비모수적이며 비통계적 기술예측 방법인 TFDEA를 이용한 기술예측을 실시하였다. 2001년에 최초로 소개된 이후 Inman 외(2006) 등은 TFDEA가 SOA 분석에서 회귀분석과 같은 전통적인 계량방법론보다 예측력이 우수함을 실증하였다. 본 연구에서는 무인항공기에 대한 기술예측 결과 연간 평균기술변화율이 4.06%로 향상되었으며, 개발된 대부분의 무인항공기는 첨단기술 프론티어(SOA) 보다 낮은 수준이었다. 이는 무인항공기를 개발하는 대부분의 국가가 기술적으로 중진국이고, 기술적 선진국인 북미와 유럽의 국가들이 세계 무인항공기 시장의 60% 이상을 장악하고 있다는 것에 기인한다고 볼 수 있다. 본 연구는 TFDEA의 적용분야를 미래체계로서 관심의 대상인 무인화 기술개발 분야로 확대하여 기술혁신의 특성을 분석함으로써 미래 무인항공기의 개발과 기술발전에 관한 기술예측의 기법으로서 적용가능성을 확인하였다. 특히 군의 작전요구성능과 연구개발관리에 필요한 정량적 지표를 설정하는데 활용할 수 있을 것으로 평가된다.

한국(韓國)에 있어서의 요충감염상(蟯虫感染相) (Pattern on Enterobius vermicularis in Korea)

  • 이준상;김규호;유종철;홍경숙;이혜정;임한종
    • 농촌의학ㆍ지역보건
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    • 제3권1호
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    • pp.18-26
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    • 1978
  • Enterobius vermicularis (pinworm) infestation in present day Korea has become one of nationwide problems. But, the incidence of pinworm infestation having been reported by many workers was almostly the data for specific groups. The incidence of pinworm infestation for 208 families of 760(male; 30, female;420) middle class inhabitant of Seoul, 238 subrural inhabitants in Gyeonggi Province and 150(male;77, female;73) rural primary students in three different districts were examined by modified Gralam's scotch-tape swab method. The results are summarized as follows; 1. The incidence of nationwide infestation a. The nationwide incidence of pinworm infestation of the 1,148 specimens examined was 28.7% (male; 27.5%, female; 29.6%). b. The highest incidence was found among 5-14 years of age. c. In comparison of the incidence by the area, the highest incidence was found among subrural area, next among rural area and the lowest among urban area. 2, Urban area a. The incidence of the 760 inhabitants examined was 23.2% (male; 24.1%, female; 22. 3%). b. The incidence of the parents group was 12.2% and children group was 30. 30.3%. c. In the parents who hold one or more pinworm poitive cases among children, the incidence of father group was 13.2% and mother group was 29.7%.3. Subrural area a. The incidence of the 238 inhabitants examined was 42.9% (male, 40.8%, female; 44.4%). b. The cumulative positive rate of anal swabs showed increasing tendency. c. Worm collection rates after chemotherapy of 98 inhabitants were 54, 0%. d. In scotch tape anal swab only one times, diagnostic value was 74.0%. e. Mother group infested with pinworm seemed to play an important role for the high incidence in individual family. f. In comparison of the incidence by the examination method, the highest incidence was found among scotch tape method. 4. Rural area The incidence of the 150 primary students examined was 34. 5% (male ; 24. 7%, female; 43.8%).

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Human Impact on Diversity and Abundance of Baboon (Papio kindae)-edible Fleshy-fruited Trees in Miombo Forests of the Kundelungu National Park, D.R. Congo

  • Kazaba, Paul Kaseya;Numbi, Desire Mujike;Muledi, Jonathan Ilunga;Shutcha, Mylor Ngoy;Tshikung, Didier Kambol;Sowunmi, Akindayo Abiodun;Aweto, Albert Orodena
    • Journal of Forest and Environmental Science
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    • 제36권3호
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    • pp.175-186
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    • 2020
  • This study approaches, from a floristic perspective, the under-researched human-primate competition for forest resources. Investigating the human impact on fruit trees edible for Kinda baboons (Papio kindae Lönnberg), we have collated dietary data on a free-ranging troop and floristic information on two forest sites of the Kundelungu National Park (KNP), Democratic Republic of Congo: the relatively intact Integral Zone (IZ) and the human-disturbed Annex Zone (AZ). Trees with DBH≥10 cm have been identified, counted and measured throughout 22 sample plots (11 per site), each measuring 1,000 ㎡. A total of seven woody species whose fruits are eaten by Kinda baboons were recorded. Four of them, namely the Sycamore fig Ficus sycomorus L., the Mobola plum Parinari curatellifolia Planch. ex Benth, the Kudu berry Pseudolachnostylis maprouneifolia Pax and the Monkey orange Strychnos innocua Delile were found in both sites, while the Large-leaved jackal-berry Diosyros kirkii Hiern and the Buffalo thorn Ziziphus mucronata Willd. were exclusively in the IZ, and Strychnos cocculoides Baker only in the AZ. Compared to the IZ, the AZ had lower values of stem density, species richness and diversity indices, suggesting a negative human impact on baboon-edible trees, in line with our hypothesis. Moreover, as was expected, human activities decreased the abundance of larger baboon-edible fruit trees. However, the size-class distribution of P. curatellifolia depicted a reverse J-curve in the AZ. The abundant younger P. curatellifolia trees remaining in that human-disturbed site constitute an important food stock for baboons, if well preserved. These results also illustrate the critical role of rangers' patrols, formerly more frequent (and presumably efficient) in the IZ than in the AZ of the Park. Their implications on baboons and miombo forests are discussed from both the research and conservation perspectives.

자기치유 공학재료: II. 무기재료 (Self-healing Engineering Materials: II. Inorganic Materials)

  • 김민희;강동은;윤지환;최은지;심상은;윤주호;김일
    • 청정기술
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    • 제17권2호
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    • pp.85-96
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    • 2011
  • 자기치유재료란 장기간 사용에 의한 기계적 충격에 의해 발생된 손상을 치료할 수 있는 능력을 발휘하도록 구조적, 화학적으로 개질시킨 스마트 재료의 하나이다. 사용에 손상이 일어난 부위를 본질적으로 치유할 수 있는 재료(고분자, 세라믹, 금속 등)를 사용함으로써 부품의 수명을 길게 할 수 있고, 장기간 사용에 의한 분해로 야기되는 효율의 감소를 막을 수 있으며, 재료의 파괴에 의한 비용지출을 막을 수 있어 여러 산업 공정의 생산단가를 낮출 수 있다. 최근 차량용 자기치유 페인트가 가능하다는 니싼의 발표 이후 재료의 자기치유능력에 대한 관심이 고조되고 있다. 본 총설에서는 앞서 발표한 자기치유 유기재료에 이어 금속, 세라믹, 콘크리트 등 무기 재료의 자기치유방법에 대해서 알아보고, 향후의 방향을 제시하고자 한다.

수종의 생분해성 차폐막의 생채분해도, 생채친화도 및 조직재생유도 능력에 관한 실험적 연구 (EVALUATION OF BIODEGRADABILITY, BIOCOMPATIBILITY AND TISSUE REGENERATIVE CAPACITY OF SYNTHETIC BIODEGRADABLE MEMBRANES IN BEAGLE DOGS)

  • 설양조;김태일;이재일;배철민;이승진;정종평
    • Journal of Periodontal and Implant Science
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    • 제25권3호
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    • pp.603-613
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    • 1995
  • The purpose of this investigation was to evaluate on the biodegradability, biocompatibility and tissue regenerative capacity of synthetic bioabsorbable membranes in beagle dogs. For animal study, 9 adult beagle dogs were used to examination, on the surgical implantation of membranes and histological analysis. In each animal, the 3rd and 4th premolars of the both sides of the mandible were selected as test teeth. Two types of bioresorbable membranes including "Guidor membrane", "S-membranes" were used to examining for biological activity, and also Gore-tex membranes was used for positive control. Surgically created defects were made in 2 premolars of both sides of the mandible at $3{\times}4mm^2$ in size and tested membranes were implanted in the defected area. A plaque control regimen was instituted with daily tooth brushing with a 0.1% chlorhexidine digluconate during experimental periods. All the experimental animals were sacrificed after 2, 4, and 8 weeks from surgery and undecalcified slides were prepared using the "sawing and grinding" technique described by Donath and Breuner". In biodegradability, all the membranes were started their biodegradation from two weeks after implantation and gradually demolished of their frame morphology from eight weeks. However, demolition of membranes in 8 weeks after implantation was highest in Guidor membranes and followed by S-membranes. Biocompatibilityof two kinds of biodegradable membranes including Guidor and S-mambrane were shown to be well tolerated to the surrounding tissue, and were minimal accumulation of inflammatory cell infiltration around the implanted membranes to compare with Gore-tex membrane. Regeneration of defected alveolar bone was initiated from two weeks of membrane implantation and new bone formation was gradually increased from that time. However, pattern of new bone formation on the defected areas of two kinds of biodegrable membranes was almost similar and quite competitive comparing with Gore-tex membrane. These results implicate that bioresorbable membranes should be highly useful tool for guided tissue regeneration of periodontal defects.

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A Study of Shilla(新羅)′s Naeoe(內衣), Danoe(短衣)

  • 권준희;조우현
    • 복식
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    • 제52권2호
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    • pp.103-113
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    • 2002
  • Heungdukwang'(興德王) costume ordinance(834A.D.) is a very important written historical record because it reveals Tongil Shills's(統一新羅) costume. But among the clothing pieces that appeared in Heundukwang'(興德王) costume ordinance, classification of Naeoe(內衣) and Danoe(短衣) is not clear. This study focuses on the categorization of Naeoe(內衣) and Danoe(短衣). Upper garments included among costume ordinance were Pyooe(表衣), Naeoe(內衣) and Danoe(短衣), Pyooe(表衣) and aeoe(內衣) were unisex, while Danoe(短衣) was worn only by women excluding the lower class. Pyooe(表衣) is applicable to Po(袍), Naeoe(內衣) is aplicable to Yu(유). Shilla'(新羅) upper garments appearing in visual records are as follows: -With the exception of Pyooe(表衣), the length of men's upper garments were between hip and knee length. These upper garments featured V-neck and round neck styles with the left side of the garments folded over the right side. -Again excluding Pyooe(表衣), women's upper garments were similar to men's upper garments having V-neck and round necklines. We know this to be true from the relics found during the excavations of Hwangsungdong and Yonggangdong, as well as from the women in the stone reliefs of Sangju. Although we know the shape of necklines. the length of upper garments remained a mystery because women of that tome tucked in their upper garments into the skirts and/or wore an over garment. However a clay doll found around Bulguksa(佛國寺) wearing a knee length garment with V-neck. The upper garment was opened in the front and was worn over another garment with same length and round neckline. At that time, The upper garments found in China and Japan. were not much different than those found in Shilla (新羅). They also included garments that were waist length, had peach-shaped necklines, or were worn over head. Shilla's(新羅) traditional upper garment was between hip and knee length, but with the introduction and influence of Chinese costume. upper garments with a length coming down to the high waist line began to appear. In addition to Chinese influence, because Shilla's(新羅) women wore the upper garment first and then the lower garment, a long upper garment was not necessary. These shorter upper garments came to be known as 'Danoe(短衣)'When we perceive clothing. we look at silhouette first and then the details. Silhouette is much determined by length and neckline or the front of the garment determines the details, So we need to attention to the basis of ancient dress classifications. These classifications were according to first length [Po(袍), Yu(유)] and then neckline [Danryoung(團領), Jingryoung(首領)]. As a result. Naeoe(內衣) and Danoe(短衣) are classified by the length. The length (內衣) was between hip and knee length while Daneoe(短衣) was waist length. Danoe(短衣) was worn by putting the bottom of it inside skirt naeoe(內衣) was worn over a skirt or plant. But both had V-neck and round neck styles, and styles with the left side of the garments folded over the right side.

Molecular Cloning and Function Analysis of an Anthocyanidin Synthase Gene from Ginkgo biloba, and Its Expression in Abiotic Stress Responses

  • Xu, Feng;Cheng, Hua;Cai, Rong;Li, Lin Ling;Chang, Jie;Zhu, Jun;Zhang, Feng Xia;Chen, Liu Ji;Wang, Yan;Cheng, Shu Han;Cheng, Shui Yuan
    • Molecules and Cells
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    • 제26권6호
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    • pp.536-547
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    • 2008
  • Anthocyanidin synthase (ANS, leucoanthocyanidin oxygenase), a 2-oxoglutarate iron-dependent oxygenase, catalyzed the penultimate step in the biosynthesis of the anthocyanin class of flavonoids, from the colorless leucoanthocyanidins to the colored anthocyanidins. The full-length cDNA and genomic DNA sequences of ANS gene (designated as GbANS) were isolated from Ginkgo biloba for the first time. The full-length cDNA of GbANS contained a 1062-bp open reading frame (ORF) encoding a 354-amino-acid protein. The genomic DNA analysis showed that GbANS gene had three exons and two introns. The deduced GbANS protein showed high identities to other plant ANSs. The conserved amino acids (H-X-D) ligating ferrous iron and residues (R-X-S) participating in 2-oxoglutarate binding were found in GbANS at the similar positions like other ANSs. Southern blot analysis indicated that GbANS belonged to a multi-gene family. The expression analysis by real-time PCR showed that GbANS expressed in a tissue-specific manner in G. biloba. GbANS was also found to be up-regulated by all of the six tested abiotic stresses, UV-B, abscisic acid, sucrose, salicylic acid, cold and ethylene, consistent with the promoter region analysis of GbANS. The recombinant protein was successfully expressed in E. coli strain with pET-28a vector. The in vitro enzyme activity assay by HPLC indicated that recombinant GbANS protein could catalyze the formation the cyanidin from leucocyanidin and conversion of dihydroquercetin to quercetin, suggesting GbANS is a bifunctional enzyme within the anthocyanidin and flavonol biosynthetic pathway.

선박용 디젤엔진 추진축에서 빙 충격 토크 기진에 의한 과도 비틀림 진동 응답 (Transient Torsional Vibration Response due to Ice Impact Torque Excitation on Marine Diesel Engine Propulsion Shafting)

  • 로날드디.바로;엄기탁;이돈출
    • 한국소음진동공학회논문집
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    • 제25권5호
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    • pp.321-328
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    • 2015
  • 최근 극지 선박의 수요가 늘어나고 있고 IACS(국제선급연합)에서는 대빙 선박에 대한 새로운 기준이 적용되고 있다. 이 선박에서는 추진시스템에 대한 대빙 설계 기준으로 빙 충격 토크는 프로펠러 날개 수를 중심으로 한 조화 함수로 규정되어 있다. 그러나 실 상황에서는 이러한 주기적인 기진 토크보다는 불규칙한 빙의 충격 토크가 발생할 수 있는 확률이 오히려 크다. 이 논문에서는 비틀림진동이 비교적 큰 6개의 실린더를 갖는 디젤엔진을 주 기관으로 한 추진시스템의 안정성을 검토하고자 한다. 특히 불규칙한 빙 충격 토크와 디젤엔진에서 발생하는 진동토크를 동시에 고려하여 비틀림진동의 공진점을 통과할 과도 비틀림 진동 응답을 이론적으로 해석하였다. 여기서 빙 충격토크는 빙이 프로펠러에 부딪칠 때를 여러 유형별로 가상하여 선급에서 규정된 방법에 의해서 구하였다. 전체적인 시스템의 과도응답 해석은 직접적분방법의 하나인 뉴마크(Newmark) 법을 이용하였다.

휨인성을 고려한 강섬유보강 숏크리트 거동의 수치해석적 연구 (A Numerical Study on the Behavior of Steel Fiber Reinforced Shotcrete in Consideration of Flexural Toughness)

  • 조병욱;유광호;김수만;임두철;이상돈;박연준
    • 터널과지하공간
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    • 제17권5호
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    • pp.411-427
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    • 2007
  • 타당성 있는 터널의 설계 및 경제적 시공을 위해서는 터널해석의 신뢰성이 확보되어야 한다. 이를 위해서는 암반과 지보재의 상호 작용을 포함하여 시공 전반에 걸친 깊은 이해가 필요하다. 본 논문에서는 파괴 이후에도 지보력을 상실하지 않는 강섬유보강 숏크리트의 거동을 적절히 모델링하는 기법을 소개하였다. 강지보재의 지보 효과를 알아보기 위해 3차원 해석을 수행하였으며, 이를 통하여 새로운 하중분담율이 산정되었다. 소성모멘트한계만을 사용한 경우(PML 모델) 숏크리트에 비정상적으로 발생하던 높은 인장응력을 없앨 수 있었고, 파괴 후의 연성 거동을 모사할 수 있었으나 축력의 영향이 고려되지 못하여 실제 거동과의 괴리를 메우기에는 다소 미흡하였다. 따라서 축력과 모멘트 한계를 동시에 고려할 수 있는 방법이 필요하였는데, FLAC의 내장 모델인 liner 모델을 통하여 이러한 거동이 모사될 수 있었다. Liner 모델에서는 강섬유 보강 숏크리트의 일축압축 강도와 더불어 최대 및 잔류 인장강도도 지정이 가능하다. 이 두 가지 모델을 이용하여 4등급 및 5등급 암반에 굴착되는 2차로 터널에 대하여 해석을 수행하였다. 또한 종래에 사용되던 탄성 beam 모델을 이용한 해석도 병행하여 그 결과를 비교하였다. 탄성 beam 모델을 제외한 두 가지 모델은 탄성 beam 모델에서는 반영될 수 없었던 휨인성을 고려할 수 있었다.