• 한국동물번식학회:학술대회논문집
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• 한국동물번식학회 2001년도 발생공학 국제심포지움 및 학술대회 발표자료집
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• pp.47-47
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• 2001

One of the problems associated with in vitro culture of primordial germ cells (PGCs) is the large loss of cells during the initial period of culture. This study characterized the initial loss and determined the effectiveness of two classes of apoptosis inhibitors, protease inhibitors and antioxidants, on the ability of porcine PGCs to survive in culture. Results from electron microscopic analysis and in situ DNA fragmentation assay indicated that porcine PGCs rapidly undergo apoptosis when placed in culture. Additionally,？ 2-macroglobulin, a protease inhibitor and cytokine carrier, and N-acetylcysteine, an antioxidant, increased the survival of PGCs in vitro. While other protease inhibitors tested did not affect survival of PGCs, all antioxidants tested improved survival of PGCs (p〈0.05). Further results indicated that the beneficial effect of the antioxidants was critical only during the initial period of culture. Finally, it was determined that in short-term culture, in the absence of feeder layers, antioxidants could partially replace the effect(s) of growth factors and reduce apoptosis. Collectively, these results indicate that the addition of ？2-macroglobulin and antioxidants can increase the number of PGCs in vitro by suppressing apoptosis.

• 한국문화재보존과학회:학술대회논문집
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• 한국문화재보존과학회 2004년도 제20회 발표논문집
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• pp.109-114
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• 2004

The purpose of this study lies in analyzing the characteristics of the carbonized textile fabrics and to know the carbonizing mechanism. Samples were Jiyo excavated from the grave of Mrs. Hansan Lee as the wife of Jinju Kang at Daeduk-gu, Daejon, and black fragements assumed as of the outside material of cotton skirt and black dusts collected out of Jikryung for official dress. The composition and status of the fiber were clarified by means of Microscopic FT-IR and both cross sectioanl and side parts of the fiber were observed using the technique of scanning electron microscopy(SEM). Finally EDS analysis was carried out to qualitatively analyze inorganic ingredients contained in the carbonized fiber. As a result of FT-IR measurement, characteristic peak was very strong around $1625cm^{-1}$ and could be found even between 2500 and $2300cm^{-1}$ because of a high-molecule pigmental substance, melanine. When SEM photography was applied to the fractions, the tissues were identified as silk fiborine through the observation of their side and cross sectional parts. SEM-EDS measurement indicated that both the cotton skirt and Jikryung for official dress contained a high proportion of inorganic substances such as Si, Ca suggesting the existence of silicide and calcium carbonate.

• 복식
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• 제58권9호
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• pp.129-141
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• 2008

Jikgeum(woven with supplementary golden wefts) hyungbae(rank badge) of danryung(official uniform) excavated from Im Backryung'tomb($1498{\sim}1546$) of the Joseon dynasty($1392{\sim}1910$) at Goyang, Gyunggi-Do in 2007, was in a critical condition because of serious collapse of substrate in metal thread. For conservation of hyungbae, metal thread was examined by different scientific methods(Light Microscope, Scanning Electron Microscope and Energy Dispersive X-Rray Spectrometry(SEM-EDS), Fourier Transform Infrared Spectroscopy(FT-IR)). Analytical data showed that metal thread was gilt membrane strip composed of gold leaves and proteinaceous substrate which was probably parchment. To protect collapse of substrate, 1% solution of Paraloid B-72 was infilterated into substrate for consolidation of substrate and it was adhered to warp of fabric in hyungbae, before wet cleaning. After wet cleaning, the most of the gold leaves were restored, which was confirmed by both the examination with the naked eye and the microscopic examination.

• 대한소아치과학회지
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• 제24권2호
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• pp.383-404
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• 1997

In this study, we tried to compare the effect of glass inserts on marginal leakage of composite resin restoration by comparing with that of several filling methods. The results obtained from this experiment were as follows ; 1. The degree of microleakage measured in glass inserts group was generally lower than that of the other groups. Statistical analysis showed significant intergroup difference between glass inserts and one complete unit, pre-polymerized composite resin ball(P<.05), but no significant difference between groups of glass inserts and increments(P>.05). 2. Scanning electron microscopic observation showed relatively large gap around resin-tooth interface in specimens restored the method of using the one complete unit and pre-polymerized composite resin ball whereas a denser and tighter was observed in increments and glass inserts group. Generally the gingival margin was shown to have better bonds than the occlusal margin in specimen of all groups. 3. In the present experiment, methods using the techniques of glass inserts and increments were evaluated to be superior to those of one complete unit, pre-polymerized composite resin ball in the aspect of microleakage. However, the result of this study could not determine the superiority of the use of glass inserts over incremental method. Besides the physical properties observed in this study, the practical aspect of clinical convenience should be considered in determining the selection of material.

• 미생물학회지
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• 제25권3호
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• pp.238-243
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• 1987

본 실험에서는 숲속 토양으로부터 산성조건에서 생장이가능한 내산성 균주를 분리 동정하였다. 분리된 균주는 형태적 관찰과 박층 크로마토그래피에 의한 세포벽 분석과 ISP 분류 기준에 따른 생리적 실험을 통하여 동정하였으며, 이 균주의 포자는 형태가 간상형이고 표면구조는 매끈한 형태였다. 포자의 배열형태는 compact spiral 구조였으며 이 균주는 명확한 포자낭벽을 갖고 있지 않았고, 세포벽 분석결과에 따르면 Streptomyces 속에 속하는 것으로 밝혀졌다. 또한 중성조건에서 생장이 우수하나 산성조건에서도 생장이 가능한 내산성 균주로써, Nonomura의 분류 기준에 의하면 Streptomyces mirabilis인 것으로 동정되었다.

• Journal of Microbiology and Biotechnology
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• 제16권10호
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• pp.1597-1604
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• 2006

To screen for an anti-yeast substance (AYS), many bacteria were isolated from soil and a strain AY2000 was selected. The strain AY2000 was identified as Rahnella aquatilis by morphology, biochemical properties, and 16S r-RNA nucleotide sequence analyses. The strain AY2000 showed anti-yeast activity against Candida albicans and Saccharomyces cerevisiae, whereas R. aquatilis ATCC33071 as a type strain did not show the activity against the yeasts under the same condition. The growth of yeast cell was significantly inhibited by AYS produced by the strain AY2000, as shown by optical density and MTT assay. The minimum inhibitory concentration (MIC) of the AYS against S. cerevisiae and C. albicans at $28^{\circ}C\;was\;20{\mu}g/ml\;and\;60{\mu}g/ml$, respectively. The MIC of AYS against hyphae of C. albicans at $37^{\circ}C\;was\;600{\mu}g/ml$. Scanning electron microscopic analysis revealed that yeast cells treated with AYS had an irregular form with a wrinkled and rough surface.

• Restorative Dentistry and Endodontics
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• 제19권1호
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• pp.97-105
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• 1994

The purpose of this study was to evaluate the smear layer removing efficiency of two root canal preparation techniques. Twelve single-rooted teeth were used in two groups of six each. Group 1 was biomechanically prepared by hand using a K-file with a high volume of normal saline irrigation. Group 2 was. prepared by using ultrasonically activated K-file with a constant high volume of normal saline irrigation. After the experimental procedures, each root was split saggitally. The removing efficiency of the preparation methods were assessed in terms of surface condition of the canal walls at three levels, those coronal, middle, and apical thirds. On the basis of remaining debris, presence of smear layer, and patency of dentinal tubules, each canal was evaluated according to a scale form 0 to 2. A statistical analysis was used to indicated any significant differences in surface condition between the two methods. There was no statistical significance between hand instrumentation and ultrasonic instrumentation at the cervical third but removing efficiency of ultrasonic instrumentation was superior. No statistically significant differences were obhserved for middle or apical third.

• 한국동물위생학회지
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• 제39권4호
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• pp.271-276
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• 2016

Horsehair or gordian worms (Nematomorpha) were identified with 22 genera (Gordiida) and 5 marine species (Nectonema) until now. During juvenile phase in development, they gain parasitic activity in arthropods. In this study, a gordian worm was detected in the feces of a dog living in Nonsan-si, Chungcheongnam-do, Korea. Using this worm, we evaluated the morphological characteristics by light microscopic analysis. Furthermore, the morphological classification was re-evaluated by scanning and transverse electron microscopes. The worm was determined that it is male adult having a bi-lobed tail and male gonads in cross sections. Based on the morphological characteristics including cross sections of body and areole on the cuticle, the parasite was also identified as Gordius sp. (Nematomorpha: Gordiidae).

• 방사성폐기물학회지
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• 제21권1호
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• pp.1-8
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• 2023

The major concern in the deep geological disposal of spent nuclear fuels include sulfide-induced corrosion and stress corrosion cracking of copper canisters. Sulfur diffusion into copper canisters may induce copper embrittlement by causing Cu₂S particle formation along grain boundaries; these sulfide particles can act as crack initiation sites and eventually cause embrittlement. To prevent the formation of Cu₂S along grain boundaries and sulfur-induced copper embrittlement, copper alloys are designed in this study. Alloying elements that can act as chemical anchors to suppress sulfur diffusion and the formation of Cu₂S along grain boundaries are investigated based on the understanding of the microscopic mechanism of sulfur diffusion and Cu₂S precipitation along grain boundaries. Copper alloy ingots are experimentally manufactured to validate the alloying elements. Microstructural analysis using scanning electron microscopy with energy dispersive spectroscopy demonstrates that Cu₂S particles are not formed at grain boundaries but randomly distributed within grains in all the vacuum arc-melted Cu alloys (Cu-Si, Cu-Ag, and Cu-Zr). Further studies will be conducted to evaluate the mechanical and corrosion properties of the developed Cu alloys.

• Childhood Kidney Diseases
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• 제5권1호
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• pp.1-8
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• 2001

목 적 : 혈뇨의 가족력을 가지는 무증상성 혈뇨의 가장 흔한 기저질환 중의 하나로 알려져 있는 비박형 기저막 신증(Thin glomerular basement membrane disease)은 흔한 빈도수에 비해 임상적 양상이나 병리학적 소견에 대해서는 국내에서 체계적으로 잘 보고되어 있지 않다. 본 인구에서는 비박형 기저막 신증 환아들을 대상으의 임상적 및 병리학적 소견을 분석하였다. 대상 및 방법 : 1990년부터 2000년까지 무증상성 혈뇨를 주소로 내원한 환아 중 신장조직검사를 시행하여 비박형 기저막 신증으로 진단된 26명의 환아들을 대상으로 하여 임상적 및 병리학적 소견들의 특징을 분석하였다. 결 과 : 대상 환아들의 혈뇨의 발현시기는 9.4${\pm}$3.2세(3.0-15.8세)였고, 신생검 당시의 나이는 평균 11.1${\pm}$2.2세(4.7-16.3세)였다. 이중 성별에 따른 차이는 남아가 8례, 여아가 18례의 여아에서 더 많았다. 환아의 부모와 형제를 대상으로 실시한 요검사상 혈뇨의 가족력이 나타난 겅우는 8례(30.7$\%$) 였다. 입원 당시의 임상적 소견을 살펴보면, 육안적 혈뇨를 가진 경우가 3례(11.5$\%$), 현미경적 혈뇨 23례(88.5$\%$), 단백뇨 1례(3.8$\%$)로 대부분의 환아에서 현미경적 혈뇨가 주된 소견이었다. 임상경과의 관찰도중 현미경적 혈뇨는 전례에서 지속되었다. 신조직 검사상 광학현미경 소견에서는 이상소견이 거의 나타나지 않았으며, 면역형광현미경 소견에서는 대부분에서 면역글로불린과 보체의 침착을 관찰할 수 없었고 일부에서 메산지움에 IgM, C3와 fibrinogen의 침착이 관찰되었다. 전자 현미경 소견으로는 사구체 기저막의 두께는 180.9${\pm}$35.8nm로 얇아져 있었다. 결 론 : 본 연구에서 비박형 기저막 신증은 현미경적 혈뇨를 주소로 내원한 소아의 흔한 원인이며 혈뇨의 가족력이 있는 경우는 약 30$\%$에서 관찰되었다. 임상경과는 대부분 좋은 것으로 나타났다.