Embryoid bodies (EBs) generated from human embryonic stem cells (hESCs) include spontaneously induced endodermal lineage cells (ELCs). Activin-A plays important roles in the endoderm differentiation of hESCs. Despite studies on the generation of ELCs from hESCs with treatment of Actvin-A, it was unclear for localization and pattern of ELCs by Activin-A during differentiation of hESCs. Accordingly in this study, we knew that Actvin-A increased the cystic EBs formation, including the highly enriched AFP (endoderm lineage specific marker)-expressing cells in the surface of cystic EBs. To induce the EBs formation from undifferentiated hESCs, cells were transferred onto petri-dish and cultured in suspension condition without bFGF removed hESC media (EB media) for 3 days. Next to investigate the effect of Activin-A, EBs were subsequently cultured in EB media supplement with 100 ng/ml Activin-A for 3 days. After 5～7 days of Activin-A treatment, cystic EBs began to appear which increased in numbers reaching ～60% of initially formed EBs over 5 days. Endoderm lineage marker, AFP were highly expressed and specifically localized at the surface region of cystic EBs comparison with normal EBs. We next attached the cystic EBs onto gelatin-coated plates and cultured for 5 days. In the results of real-time PCR and immunocytochemistry analysis, AFP-expressing cells migrated and localized at the outgrowth region of attached cystic EBs. To obtain the AFP-expressing cells of the outgrowth region, we manually isolated by using micro- dissection and cultured them. These cells strongly express AFP over 70% of isolated cells post re-plating. Here, we first showed an expression pattern of specifically localized ELCs by Activin-A during differentiation of hESCs. From this observation, we could highly purified ELCs from undifferentiated hESCs. Taken together, our system will provide a novel and efficient option to generate ELCs from hESCs.

본 연구에서는 스마트 최상층 면진시스템을 적용한 고층건물의 풍응답 제어성능을 검토해보았다. 이를 위하여 77층 초고층 건물을 예제구조물로 선택하였고 풍동실험을 통해서 얻은 풍하중을 사용하여 수치해석을 수행하였다. 예제구조물의 최상층은 FPS 및 MR 감쇠기로 구성된 스마트 면진시스템을 이용하여 주구조물과 분리된다. 주구조물의 동적응답을 저감시키는 것이 스마트 최상층 면진시스템의 가장 중요한 목표이지만 면진된 최상층의 과도한 응답은 구조물을 불안정하게 만들 수 있다. 따라서, 본 연구에서는 면진된 최상층과 주구조물을 효과적으로 제어하기 위하여 스카이훅제어기를 제어알고리즘으로 사용하였다. 제안된 스마트 최상층 면진시스템의 제어성능을 검토하기 위하여 일반적인 수동 최상층 면진시스템의 제어성능과 비교하였다. 수치해석결과 제안된 스마트 최상층 면진시스템을 이용하면 일반적인 수동 최상층 면진시스템에 비해서 면진층의 변위를 효과적으로 줄이면서도 구조물의 응답을 저감시킬 수 있음을 확인할 수 있었다.

Xylanase를 생산하는 호알칼리성 균주를 토양으로부터 분리하여 동정하였다. 토양으로부터 분리한 호알칼리성 균주 3000여종 중 xylanase 활성이 가장 높은 균주인 strain DK-2386 균주를 선별하였다. Gram 염색과 SEM을 통한 형태학적 특성을 관찰하였으며, Methods for General and Molecular Bacteriology와 Bergey's manual of systematic bacteriology, 그리고 Biochemical tests for identification of medical bacteria에 준하여 생화학적 특성을 확인한 결과 배양액의 색은 붉은 빛을 나타내었으며, Gram양성 간균, 내생포자형성, catalase 양성, oxidase 양성, 혐기성 양성, glucose로부터 gas 형성 양성, casein 가수분해 양성, starch 가수분해 양성, CMC 가수분해 양성, xylan 가수분해 양성, nitrate 환원능 양성이며 10% NaCl 농도에서도 생육하는 것을 확인하였다. 균체의 지방산 조성 분석 결과 C15:0 ISO 27.35%와 C15:0 ANTEISO 31.54%, C16:0 9.70%로 이루어져 Bacillus속으로 동정되었으며, 16S rDNA 염기서열 분석결과 B. agaradhaerens와 100%의 유사성을 갖는 것을 확인하였다. (사)한국종균협회로부터 분양받은 Bacillus agaradhaerens 40952, B. alcalophilus와 strain DK-2386 균주사이의 생화학적 특성을 비교한 결과 B. agaradhaerens와 속과 종이 같으나 미세하게 특성이 다른 균주로 판단되어 B. agaradhaerens DK-2386이라 명명하였다.

The isolation of preantral follicles from the ovaries of bovine was performed under mechanical and enzymatic methods. A significant increase in the total number of follicles retrieved was detected when tissue chopper was used. Micro-dissection could supply good quality, larger sized follicles (400 to ) but with the lowest yield (). The isolated preantral and early antral follicles were cultured for 14 days. Follicles isolated by the mechanical method had a greater growth during a culture period than follicles collected enzymatically. Morphologically normal bovine oocytes from early antral follicles after 14 days culture were 59.6% after culture and after 24 h of maturation culture, 12.9% of in vitro-grown oocytes reached the second metaphase. In conclusion, this study showed that mechanical method can be used effectively to isolate intact preantral follicles from bovine ovaries.

팽화홍삼으로부터 용매추출, 용매분획 및 silica gel column chromatography를 반복하여 두 개의 화합물을 분리하였다. 이들 두 화합물의 결정특성, 녹는점, 비선광도, Infrared spectrum 분석 결과, TLC에서의 Rf값, HPLC에서의 retention time 및 NMR 데이터를 측정하여 고찰한 결과 두 개의 화합물은 20(S)-ginsenoside Rg3와 ginsenoside Rg5임을 확인할 수 있었다. 특히 1H- 및 13C-NMR 데이터를 HSQC 및 HMBC와 같은 2D-NMR 실험을 통하여 더욱 정확하게 동정하였다.

본 논문에서는 비선형 지진격리교량의 최적 설계 방법을 제시하였다. 최적설계를 위한 목적함수로는 교각과 지진격리장치의 파괴확률을 고려하였으며, 상충하는 두 목적함수를 동시에 최적화하는 다수의 해를 효율적으로 검색하고자 유전자 알고리즘에 기반한 다목적 최적화기법을 도입하였다. 또한, 최적화 과정에서 요구되는 다수의 비선형 시간이력해석을 수행하지 않고도 교량의 확률적 응답을 효율적으로 예측할 수 있는 추계학적 선형화 방법을 접목하였다. 제시하는 방법의 효율성을 검증하기 위한 수치 예로서 실제 교량인 남한강교를 고려하였고, 제안하는 방법과 기존 비선형 시간이력해석을 이용한 생애주기비용 기반 설계법을 각각 적용하여 내진성능을 비교하였다. 내진성능을 비교한 결과, 제시하는 방법이 기존의 비용에 기반한 최적설계보다 우수한 성능 및 경제성을 보임을 검증하였다. 또한, 다양한 지진하중에 대해서도 제안된 방법이 보다 개선된 성능을 보임을 확인하였다.

호열성 미생물을 검토하기 위하여 전국 각지로부터 토양과 두엄을 채취하여 그로부터 호열성 미생물을 분리하였다. 토양과 두엄으로부터 분리된 호열성 미생물 1250여 균주를 선별하였고, 이들을 대상으로 미생물이 생산하는 효소활성을 검토하여 호열성 전분 분해 효소를 생산하는 1주의 미생물을 확인하였다. 확인된 1주의 미생물을 strain 2719라 명명하였다. Strain 2719 균주는 형태학적으로 gram 양성 간균의 특징을 나타냈고, 균주의 표면은 매끄럽지 않았으며, 비교적 다양한 길이를 가지고 있었다. 또한 다른 gram 양성 간균들에 비해서 많은 수의 균사들이 각 균주들 사이에 복잡하게 얽혀있었다. 생화학적 특성을 확인한 결과 catalase 양성, glucose 발효, arabinose 발효, mannitol 발효, casein·gelatin·starch 가수분해의 특징을 가지고 있었으며, 이는 Bacillus sp.로 추정되었다. 생육 pH의 범위는 pH 6-pH 8 범위에서 생육이 가능했으며, 생육 온도의 범위는 50-70oC였다. 16S rDNA sequence 분석결과 Bacillus thermoglucosidasius의 16S rDNA와 99.52%가 일치하였으나, sequence의 일부분이 다른 부분이 있고, 생육 특성에서 약간의 차이를 보였다. 또한 gene bank에 등록되어 있는 균주들의 16S rDNA sequence들과 비교하여도 일치하는 균주는 확인되지 않았다. 이와 같은 실험결과에 따라 2719 균주는 기존에 발표되지는 않았으나, Bacillus thermoglucosidasius와 매우 유사한 균주로 판단되어 Bacillus thermoglucosidasius 2719로 명명하였다.

새로운 항진균성 항생물질개발을 목적으로 고추탄저병균인 Colletotrichum gloeosporioides에 대한 항생활성을 가지는 미생물을 토양으로부터 분리하여 동정한 결과, Bacillus sp. CJ-1로 동정하였다. 항생물질의 생산을 위한 배양조건을 검토한 결과, glucose 1.5% (w/v), yeast extract 0.5% (w/v), pH 6.0의 배지를 사용하여 35℃에서 72시간 진탕 배양하였을 때 항진균활성이

마늘의 항균력에 저항성을 갖는 유산균을 분리하기 위해서 마늘 추출물이 첨가된 배지에서 생육하는 112 균주를 김치, 젓갈, 장아찌류로부터 분리하였다. 이 중에서 14균주에 대해서 내산성 및 내담즙성 그리고, 가축 병원성 세균인 Salmonella choleraesuis, Escherichia coli, Staphylococcus aureus, Shigella flesneri에 대해 항균력을 조사한 결과, 파김치 유래의 P'GW50-2 균주가 가장 우수한 특성을 지니고 있어 생균제로 이용 가능한 균주로 선발하였다. 선발된 균주는 16S rRNA 유전자의 염기서열 분석결과 Lactobacillus plantarum으로 동정되었고 L. plantarum TJ-LP-002으로 명명하였다. L. plantarum TJ-LP-002는 Bacillus cereus, S. aureus, Clostridium perfringens와 같은 Gram 양성균과 Aeromonas hydrophila, E. coli, Pseudomonas, Salmonella, Shigella와 같은 Gram 음성균에 대해서 비교적 넓은 항균활성을 나타내었다.

A dark brownish pigment from fruit body of Auricularia auricula was isolated and characterized in this report. The pigment was obtained with a yield of 0.61%(w/w) by alkaline extraction and subsequent purification steps. It showed the positive FeCl3 test which was the indication of phenolic compounds. A synthetic melanin showed a similar spectrometric characteristics to the pigment extract regarding a characteristic UV absorption between 200-250 nm and infrared absorptions profiles in the finger print region including absorption peaks at 1701 and 1624 cm-1. Its element analysis indicated that its atomic copmposition is close to that of DOPA melanin (eumelanin). With the result of its antioxidant activity in the TNBT (5-thio-2-nitrobenzoic acid) assay, we concluded that the dark brownish pigment from A. auricula is a melanin-like compound having a powerful antioxidative activity.

The toxicity of materials derived from root of Asiasarum heterotropoides against early third instar larvae from susceptible Culex pipiens pallens, Aedes aegypti, and Ochlerotatus togoi was examined using direct contact mortality bioassays. Results were compared with those following the treatment with two currently used mosquito larvicides, temephos and fenthion. The bioactive principles of A. heterotropoides root were identified as asarinin, asarone, methyleugenol, pellitorine, and pentadecane by spectroscopic analysis. As judged by 24 h LC50 values, pellitorine (2.08-2.38 ppm) was the most toxic compound, followed by asarinin (10.49-16.49 ppm) and asarone (22.38-26.99 ppm). These compounds were less toxic than either temephos (0.16-0.20) or fenthion (LC50, 0.23-0.29). Weak activity was produced by methyleugenol (53.30-58.52 ppm) and pentadecane (96.71-99.19 ppm). A. heterotropoides root-derived materials, particularly pellitorine, merit further study as potential mosquito larvicides for protection from humans and domestic animals from vector-borne diseases and nuisance caused by mosquitoes.

Entomopathogenic fungi were isolated directly from a cadaver of adult M. saltuarius (infected with white fungi) supporting fungal sporulation, to develop biological control of pine wilt disease vector, M. saltuarius which was the most abundant in the middle to northern part of Korea and caused enormous damage to native pine tree in Korea, Japan and other regions of Asia. Pathogenicity of each fungus was tested using oak longicorn beetle, Moechotypa diphysis, as substitutive insect. As the result, only one of them showed pathogenic to adults of M. diphysis, with up to 100% mortality within 13 days of inoculation. Selected fungus was named as MsW1 and identified by Beauveria bassiana using microscopic examination, B. bassiana-specific PCR primers and genetic sequencing of the ITS region analysis. Pathogenicity test were conducted with various concentration of conidial suspensions of this isolate on M. saltuarius (3rd instar larvae and adults). Mortality rates varied from 57.1% to 100.0% and from 16.7% to 100.0% of M. saltuarius (3rd instar larvae and adults), respectively at 30 days. This is the first report of natural infection of M. saltuarius by B. bassiana.

In agricultural fields, the entomopathogenic fungal species have been investigated for their potential as the biological control agents due to their role of natural enemies for insects. Until recent times, most of the studies for these fungi have been based on isolation from insect cadaver or soil. However, these methods, especially isolation from soil, might cause a problem involving differential isolation of the each entomopathogenic fungi. The purpose of this study is to determine the optimal isolation medium for entomopathogenic fungi using dodine, chitin, and skim milk. The growth rates of entomopathogenic fungi and non-entomopathogenic fungi were compared on dodine agar medium. The medium for this experiment was modified Veen semiselective medium which consisted of based on SDA (Sabouraund Dextrose Agar), 100 mg/ml for chloramphenicol, 50 mg/ml for streptomycin and adjusted dodine to 40, 50, 70 and 100 mg/ml. As a result, optimal concentration of dodine for isolation of entomopathogenic fungi was 50 mg/ml and 168 positive entomopathogenic fungi were isolated in 470 soil samples and 11 cadavers of insect. In addition, the isolates had significantly greater chitinase and protease activity than non-entomopathogenic fungi. The isolation method described represents a valuable tool for rapid and simple isolation of entomopathogenic fungi. These positive entomopathogenic fungi may have potential against variety pests in agriculture.

Matsumuraeses phaseoli and M. falcana cannot be classified with the external morphological characters. Although differences in the morphology of male genitalia and in the mitochondrial DNA sequence of cytochrome oxidase I between the two species have been found, there is no information that the two species are biologically different species till now. We, therefore in this study, tried to cross the two species to observe postzygotic incompatibility in the next hybrid generations and to know whether the two species are 'biological species' or not. In crossing between the parents, two kinds of F1 hybrids were produced successfully. In inter- and intra-breeding between F1 hybrids, two lines crossed with females of F1 hybrid produced by females of M. phaseoli could not produce F2 adults to show inviability of larvae. The other two lines produced F2 adults successfully and the F2 adults produced F3 larvae in inbreeding. In back-crossing between parents and F1 hybrids, the two lines of 8 breeding lines, in which females of F1 hybrid were produced by females of M. phaseoli, could not produce the next generation of larvae. The other six lines produced F2 adults successfully. The results indicated that maternal factors of F1 hybrid produced by M. phaseoli females contributed to create the incompatibility between the F1 females and other lines. In conclusion, the results showed a postzygotic reproductive isolation between M. phaseoli and M. falcana in part.

Pluripotent embryonic stem (ES) cells isolated from inner cell mass (ICM) of blastocyst-stage embryos are capable of differentiating into various cell lineages and demonstrate germ-line transmission in experimentally produced chimeras. These cells have a great potential as tools for transgenic animal production, screening of newly-developed drugs, and cell therapy. Miniature pigs, selectively bred pigs for small size, offer several advantages over large breed pigs in biomedical research including human disease model and xenotransplantation. In the present study, factors affecting primary culture of somatic cell nuclear transfer blastocysts from miniature pigs for isolation of ES cells were investigated. Formation of primary colonies occurred only on STO cells in human ES medium. In contrast, no ICM outgrowth was observed on mouse embryonic fibroblasts (MEF) in porcine ES medium. Plating intact blastocysts and isolated ICM resulted in comparable attachment on feeder layer and primary colony formation. After subculture of ES-like colonies, two putative ES cell lines were isolated. Colonies of putative ES cells morphologically resembled murine ES cells. These cells were maintained in culture up to three passages, but lost by spontaneous differentiation. The present study demonstrates factors involved in the early stage of nuclear transfer ES cell isolation in miniature pigs. However, long-term maintenance and characterization of nuclear transfer ES cells in miniature pigs are remained to be done in further studies.

기존의 교량받침으로 많이 사용되고 있는 폴리우레탄 디스크를 적용한 POT형식에 C형 강재감쇠장치를 추가적으로 적용한 새로운 형태의 지진격리장치에 대한 명확한 정적 성능검증과 동적특성을 파악하기 위하여 최대 극한 수직하중 시험, 최대 회전 시험, 동적재하 시험 및 동적재하 극한 반복시험을 시행하였다. 해석적 결과와 성능시험 결과를 비교분석한 결과, 충분한 감쇠능력을 보유하고있을 뿐만 아니라, 설계기준에도 적합하다는 결론을 얻을 수 있었다. 또한, EDC 및 유효강성값의 시험치가 이론치와 유사하여 시험 결과값의 분석이 유효함을 보였다.

본 연구에서는 원전 주제어실의 층 지진격리시스템에 대한 지진동 저감성능과 적용성을 평가하기 위해서 실험연구를 수행하였다. 층 지진격리시스템에 적용하기 위해서 납-고무 베어링(LRB)과 마찰진자장치(FPS)를 설계하고 제작하였다. 제어 캐비닛과 액세스 플로어로 구성된 원전 주제어실 부분 실험모형을 제작하여 납-고무 베어링과 마찰진자장치를 각각 설치하여 진동대 실험을 수행하여 지진응답특성을 비교, 평가하였다. 실험을 위해서 원전 주제어실의 운전기준지진(OBE)과 안전정지지진(SSE)의 수평방향 층응답 스펙트럼을 이용하여 인공지진 시간이력을 만들어서 진동대 실험에 사용하였다. 입력지진에 대한 실험모형의 지진응답은 마찰진자장치를 적용한 경우 상대적으로 우수한 지진동 저감특성을 나타냈다.

In this study, GSTs gene homology fragment from Mongolian wheatgrass(Agropyron mongolicum Keng) was isolated using homology-based method. one partials gene sequences have been obtained by reverse transcription polymerase chain reaction (RT-PCR). Sequence analysis using Software of DNAman and DNAuser etc, and showed that the cDNA sequences was 344 base pairs, encoding 62 amino acids. The partial gene had C-terminal conserved domains of substrate binding pocket (H-site) of GSTs superfamily. Homology comparison with GSTs gene amino acid sequences in other plants showed that it was 91% identical to 19E50 of wheat, 90% to pk0078 and 88% to gstf6. It was named as MwGSTs.