• 한국토양비료학회지
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• 제23권1호
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• pp.60-66
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• 1990

영남지역(嶺南地域)의 수종(數種) 토양통(土壤統)에서 경작여부(耕作與否)에 따른 토착(土着) 대두근류균(大豆根瘤菌)의 분포특성(分布特性)을 구명(究明)하였다. 이를 위하여, 토양통(土壤統)이 서로 다른 5개(個) 지점(地點)의 경작지(耕作地)와 미경작지(未耕作地) 토양(土壤)의 대두(大豆) 접종효과(接種效果)(Soil inoculum potential)와 토착근류균(土着根瘤菌)의 취락형태적(聚落形態的) 분포특성(分布特性)을 조사(調査)하였는데 그 결과(結果)는 다음과 같았다. 1. 영남지역(嶺南地域)에 분포(分布)한 토착(土着) 대두근류균(大豆根瘤菌)의 밀도(密度)는 경작지(耕作地)의 경우 $10^4Cells/g$. soil 이상(以上)이었으나 미경작지(未耕作地)에서는 경미(輕微)하였다. 2. 경작지(耕作地) 토양(土壤)의 대두(大豆) 접종효과(接種效果)(Soil inoculum potential)는 NifTAL의 우수근류근(優秀根瘤菌) 접종제(接種劑) TAL 보다 좋았고, 대두근류균(大豆根瘤菌)의 질소고정(窒素固定) 특성면(特性面)에서 근류(根瘤) 무게가 근류수(根瘤數)를 보상(報償)하였다. 3. 토착(土着) 대두근류균(大豆根瘤菌)의 취락형태별(聚落形態別) 분포(分布)는 경작여부(耕作與否)에 따라 상이(相異)하였는데, "Dry"형(形) 기경지(旣耕地)에서, "Wet"형(形)은 미경작지(未耕作地)에서 각각(各各) 우점경향(優占傾向)을 보였다. 4. 토착(土着) 대두근류균(大豆根瘤菌)의 취락형태별(聚落形態別) 공생효과(共生效果)는 "Dry"형(形)이 "Wet"형(形)보다 좋았다. 따라서 숙전(熟田)에서의 대두생육(大豆生育)은 "Dry"형(形) 토착(土着) 대두근류균(大豆根瘤菌)의 밀도(密度)에 크게 영향(影響)을 받을 것으로 판단(判斷)되었다.

• 한국수정란이식학회지
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• 제32권4호
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• pp.343-351
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• 2017

Porcine spermatogonial stem cells (SSCs) prefer three-dimensional (3D) culture systems to 2D ones for the maintenance of self-renewal. Of the many 3D culture systems, agar-based hydrogels are candidates for supporting porcine SSC self-renewal, and there are various types of agar powder that can be used. In this study, we sought to identify an agar-based 3D hydrogel system that exhibited strong efficacy in the maintenance of porcine SSC self-renewal. First, 3D hydrogels with different mechanics were prepared with various concentrations of Bacto agar, lysogeny broth (LB) agar, and agarose powder, and the 3D hydrogel with the strongest alkaline phosphatase (AP) activity and greatest increase in colony size was identified for the different types of agar powder. Second, among the porcine SSCs cultured in the different 3D hydrogels, we analyzed the colony formation, morphology, and size; AP activity; and transcription and translation of porcine SSC-related genes, and these were compared to determine the optimal 3D hydrogel system for the maintenance of porcine SSC self-renewal. We found that 0.6% (w/v) Bacto agar-, 1% (w/v) LB agar-, and 0.2% (w/v) agarose-based 3D hydrogels showed the strongest maintenance of AP activity and the most pronounced increase in colony size in the culture of porcine SSCs. Moreover, among these hydrogels, the strongest transcription and translation of porcine SSC-related genes and largest colony size were detected in porcine SSCs cultured in the 0.2% (w/v) agarose-based 3D hydrogel, whereas there were no significant differences in colony formation and morphology. These results demonstrate that the 0.2% (w/v) agarose-based 3D hydrogel can be effectively used for the maintenance of porcine SSC self-renewal.

• 한국표면공학회지
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• 제36권5호
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• pp.379-385
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• 2003

The surface morphology, the glossiness and the hardness of Zn-Cr and Zn-Cr-X(X:Co, Mn) alloy electrodeposits were investigated by using chloride bath with EDTA additive and flow cell system. The surface morphology of Zn-Cr alloy and Zn-Cr-Mn alloy changed from fine needle shape crystalline structure to colony structure of fine granular crystallites with increasing current density in the range of 20-100 $A/dm^2$. The surface morphology of Zn-Cr-Co alloy deposited from low Co concentration bath(2.5-10 g/$\ell$) was similar to that of Zn-Cr alloy, while that of Zn-Cr-Co alloy deposited from high cobalt concentration bath was fine granular crystalline structure in the same range of current density. The glossiness of Zn-Cr and Zn-Cr-Mn alloy increased noticeably with increasing current density, while that of Zn-Cr-Mn alloy decreased with increasing Mn concentration of bath in high current density region. The glossiness of Zn-Cr-Co alloy deposited from low Co concentration bath increased with current density while that of the alloy from high Co concentration bath decreased with increasing current density. The hardness of Zn-Cr and Zn-Cr-X alloy increased noticeably with current density.

• 한국치위생학회지
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• 제7권2호
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• pp.189-196
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• 2007

A study of the J health college dept of dental hygiene practice vistant a total of 35 supragingival calculus and subgingival calculus picking SEM observation and bacteria identification of the result are followings. 1. As observed by dental calculus SEM, the surface roughness appeared as peaks, valleys, and pits. 2. About bacteteria morphology blood agar plate small green zone partial hemolysis colony streptococcus observation 3. Isolated colony gram stain gram are positive display 4. Supragingival calculus at Lactococcus lactis spp. Leuconostoc spp. Streptococcus mitis, Aerococcus viridans bacteria 1, 3, 3, 16 species detection 5. Subgingival calculus at Aerococcus viridans, Leuconostoc spp. bacteria 5, 1 species detection.

• KSBB Journal
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• 제11권1호
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• pp.115-123
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• 1996

zooglan생합성에 필수적인 gene cluster를 clone하기 위해 2종류의 변이주가 분리되었다. Zoogloea ramigera 115는 협막형 다당(주로 zooglan)을 생산한다. 115 균주로 접합시키고 생산물을 용이하게 분리하기 위하여 반복된 원심분리와 선별을 통해 협막을 만들지 않는 slime형 생산균주를 분리하였다. 세포외 다당 생산 능력이 결여된 변이주를 전통적인 transposon(Tn5) 기술을 사용하여 얻었고 달라진 colony 형태와 celluflour결합 성질에 의해 선별하였다. 이들 변이주들은 범용숙주범위 cosmid vector안에 건설된 Z.ramigera 115slime gene library 와 helper plasmid로의 3양친 접합에 의해 보상되었다.

• 한국작물학회지
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• 제45권2호
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• pp.143-149
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• 2000

From the soils of soybean fields in Cotton Branch Station (CBS) and Pine Tree Station (PTS), Arkansas, USA, various single spore isloates of sudden death syndrome (SDS) pathogen were obtained on modified Nash ＆ Snyder's medium (MNSM) with dilution plating technique and transferred to potato dextrose agar (PDA) medium to identify the cultural colony shape. The colony shapes of these isolates resembled F. solani isolate 171 which was white and chalky shaped on MNSM and most of them had unique form of morphology which produced white margin and blue center colony on PDA. Although, some of these isolates had more dark blue or showed slightly different color, all isolates that were selected randomly for green-house inoculation assay produced typical foliar symptoms on leaves of soybean, Hartz 6686. To determine the genetic differences among the isolates, mitochondrial DNA restriction fragment length polymorphism (RFLP) was conducted with fourty isolates from both fields, using mtDNA probes, 2U18 and 4U40, derived from Colletotrichum orbiculare. We obtained distinctive RFLPs in each treatment of restriction enzyme, EcoRI and HaeⅢ. Isolates, 11-2-5 and 14-3-1-1, from CBS and isolates, 104-3-1-2 and 701-1-5-1, from PTS showed different band patterns from 171 in both or in either treatment of restriction enzymes. Even if some of these isolates showed heterogeneous, they were more closer to 171 than PN603. And, also, rest of the thirty-six isolates had exactly same polymorphisms as 171 in each treatment of restriction enzyme. Although, some of the isolates showed the different morphological shape on PDA and slightly different band patterns on RFLPs, all of the isolates selected on MNSM due to their distinctive colony shape from other fungi produced the typical foliar symptoms on soybean leaves in greenhouse inoculation assay. It might be suggested that these isolates were not genetically different from check isolate 171 and they were unique strain of F. solani.

• 생태와환경
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• 제38권3호통권113호
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• pp.420-428
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• 2005

유해조류의 대발생을 제어하기 위하여 개발되었던 박테리아, 백운몰개, 송사리 등의 직접 및 배양여액이 배양중인 단독형 (solitary) 남조 M. aeruginosa의 성장 및 형태에 어떠한 영향을 주는지 파악하기 위하여 대수기 조류세포에 생물제재를 농도별로 처리하였다. 실험에 사용된 3가지 생물제재의 적접처리시 남조 M. aeruginosa를 효과적으로 감소시켰으며, 특히 2종의 어류는 모두 처리 5일째 조류세포를 완전히 제어하였다. 생물제재의 직접 또는 여액에 의한 조류세포의 군체형성은 생물제재의 종류, 처리유형, 처리농도 등에 따라 차이를 보였는데, 어류의 경우, 여액 처리농도가 높을수록 높은 군체 및 군체당 높은 세포수를 나타냈으나, 살조세균은 농도에 따른 유의한 차이를 보이지 않았다. 결국, 유해조류의 제어를 위한 생물제재의 현장 적용은 남조 M. aeruginosa의 군체형성을 유도함으로서 새로운 조류대발생의 원인이 될 수 있기 때문에 새로운 생물제재나 적용기법 등의 개발이 필요하다고 판단되었다.

• 한국재료학회지
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• 제12권5호
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• pp.407-413
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• 2002

Eutectic high chromium cast irons containing 17%Cr and 26%Cr were produced for this research by making each of them solidify unidirectionally. Abrasion wear test against SiC or $Al_2$O$_3$bonded paper was carried out using test pieces cut cross-sectionally at several distances from the chill face of castings. The wear resistance was evaluated in connection with the parameters such as eutectic colony size($E_w$), area fraction of boundary region of the colony($S_B$) where comparatively large massive chromium carbides are crystallized and, average diameter of chromium carbides in the boundary region($D_c$). The wear rate($R_w$), which is a gradient of straight line of wear loss versus testing time, was influenced by the type and the particle size of the abrasives. The $R_w$ value against SiC was found to be larger than that against A1$_2$O$_3$under the similar abrasive particle size. In the case of SiC, the $R_w$ value increased with an increase in the particle size. The $R_w$ value also increased as the eutectic colony size decreased, and that of the 17%Cr iron was larger than that of the 26%Cr iron at the same $E_w$ value. Both of the $S_B$ and $D_c$ values were closely related to the $R_w$ value regardless of chromium content of the specimens. The $R_w$ values of the annealed specimens were greater than those of the as-cast specimens because of softened matrix structures. As for the relationship between wear rate and macro-hardness of the specimens, the hardness resulting in the minimum wear rate was found to be at 550 HV30.

• 미생물학회지
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• 제29권5호
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• pp.314-318
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• 1991

We investigated the effect of Triton X-100 on the growth and morphology of Trichoderma koningii by comparing various parameters representing the frowth of mold in the presence or absence of Triton X-100. The specific growth rate and doubling time of T. koningii were not affected by the addition of 0.05% Triton X-100 in batch culture. However, in the presence of Triton X-100, cultures reached its stationary phase earlier and showed reduced level in total yield of biomass. The addition of Triton X-100 into solid medium also resulted in decrease in the colony radial growth rate and this response was correlated with the formation of mycelia which showed increase in branching and septation in the presence of Triton X-100.

• 한국가축번식학회지
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• 제25권3호
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• pp.219-225
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• 2001

토끼 배아세포(Embryonic Stem Cell)를 분리하기 위해 토끼 1-cell embryo를 채란하여 in vitro에서 blastocyst까지 배양한 후 mouse embryonic fibroblasts(MEF), rabbit embryonic fibroblasts(REF) 및 STO cell expressing Leukemia Inhibition Factor gene(SNL) feeder cell과 공배양하였다. 외관상 충실한 토끼 배아세포 8 개를 확보하였고 분리된 토끼 ES cell의 모양은 주위에 분화된 세포가 없는 전형적인 colony모양으로 성장하고 액체질소에 동결보존 및 3∼5차례의 계대배양 후에도 이러한 모양은 계속 유지되었다. 충분히 자란 dish를 1 : 2로 계대배양을 한 후 다시 confluent하게 자라는 데에 걸리는 시간(doubling time)은 빠른 경우 84시간으로 나타났다. 분리 된 토끼 ES cell은 gelatin이 coating되지 않은 culture dish에 이식 배양하였을 때 부유상태로 증식하면서 내부에 강이 생기고 외배엽과 내배엽이 형성하는 전형적인 Embryoid body 모양을 나타내어 분리된 ES cell이 미분화상태의 stem cell임이 확인되었다. 본 연구를 통해 토끼에서의 수정란 배양을 통해 토끼 배아세포를 분리하여 특성을 규명하였다 현재까지의 연구성과로는 토끼 수정란의 배양기술을 완벽하게 개발했다는 점과 토끼에서 ES cell을 분리하여 앞으로 유전자 조작의 가능성을 열어 놓은 것이다. 토끼 ES cell system이 완벽히 확립되도록 분리된 ES cell에 대한 미분화상태의 연구 및 미분화상태를 식별할 수 있는 marker등에 대한 연구에 이용될 것이고 복제토끼 및 형질전환토끼의 생산 등을 위한 연구에 이용될 수 있다.