• 한국생물공학회:학술대회논문집
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• 한국생물공학회 2005년도 생물공학의 동향(XVI)
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• pp.439-439
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• 2005

• 대한치과기공학회지
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• 제29권2호
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• pp.213-223
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• 2007

The success of a porcelain fused to metal (PFM) restoration depends upon the quality of the porcelain-metal bond. The adhesion between metal substructure and dental porcelain is related to the diffusion of oxygen to the reaction layer formed on cast-metal surface during firing. The purposed of this investigation was to study the effects of gold based bonding agent on Ni-Cr alloy-ceramic adhesion between porcelain matrix, gold based bonding agent and metal substructure interface. gold based bonding agent have been applied as an intermediate layer between a metal substructure and a ceramic coating. gold based bonding agent(Aurofilm NP, Metalor, Swiss) was applied on Ni-Cr alloy surface by four method. Surfaces only air abraded with 110${\beta}\neq$ Al2O3 particles were used as control. metal ceramic adhesion was evaluated by a biaxial flexure test(N=5) and volume fraction of adherent porcelain was determined by SEM/EDS analysis. Result of this study suggest that the layering sequence of gold based bonding agent is very important and can improve porcelain adherence to PFM.

• 한국분말재료학회지
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• 제25권5호
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• pp.420-425
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• 2018

Core-shell structured nanoparticles are garnering attention because these nanoparticles are expected to have a wide range of applications. The objective of the present study is to improve the coating efficiency of gold shell formed on the surface of silica nanoparticles for $SiO_2@Au$ core-shell structure. For the efficient coating of gold shell, we attempt an in-situ synthesis method such that the nuclei of the gold nanoparticles are generated and grown on the surface of silica nanoparticles. This method can effectively form a gold shell as compared to the conventional method of attaching gold nanoparticles to silica particles. It is considered possible to form a dense gold shell because the problems caused by electrostatic repulsion between the gold nanoparticles in the conventional method are eliminated.

• Journal of Plant Biotechnology
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• 제29권4호
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• pp.223-228
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• 2002

본 연구실에서 개발된 particle inflow gun (PIG)은 조작이 간편하고, 사용비용도 저렴하며, 식물 세포 내의 유전자 도입효율이 높은 특징을 갖고 있다. PIG 장비를 이용하여 벼 캘러스 내로의 유전자 도입 조건을 검토하기 위해서 사용된 vector는 pIG121Hm으로서 T-DNA 내부에 intron GUS ($\beta$-glucuronidase)와 hygromycin 및 kanamycin 저항성 유전자를 포함하고 있다. 또한 벼 캘러스 내에 물리적으로 DNA를 도입할 때에 DNA 도입 효율과 관계가 높은 요인들을 GUS의 발현빈도를 통하여 조사하였다. 그 결과 gold particle에 DNA를 부착하는 과정에 사용되는 spermidine과 calcium chloride의 경우 무첨가구에 비해 16 mM의 spermidine과 1.5 M의 calcium chloride 첨가구에서 GUS 발현율이 각각 2배, 3배 증가하였다. 그리고 1회 분사되는 gold particles양이 2 mg의 경우 가장 높은 GUS 발현율을 보여주었으며, 또한 PIG장비의 분사거리와 헬륨의 압력은 벼의 배양세포의 경우 12cm의 분사거리에서 3.5 bar (50 psi)의 헬륨압력으로 분사하였을 때 GUS 발현율이 가장 높았다. 이상의 결과에서 PIG 장비를 이용한 유전자 도입은 본 연구에서 검토한 최적의 조건을 이용하였을 경우 기존에 많이 사용되고 있는 Biolistic Gun (Bio-Rad 사)과 거의 비슷한 유전자 도입효율을 보여 주었다. 특히 PIG 장비의 경우 조작이 매우 간편하고, 분사에 사용되는 일회용 부품이 필요하지 않기 때문에 대량의 반복실험을 필요로 하는 연구에서 손쉽게 사용되리라 기대된다.

• 한국재료학회:학술대회논문집
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• 한국재료학회 2012년도 춘계학술발표대회
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• pp.107.1-107.1
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• 2012

Because of beautiful glossy and color, the value of gold leverage is very high in Europe. For improve the quality of white gold, we performed heat treatment on 14K white gold alloys at various age-hardening conditions. Age-hardening behavior and the related phase transformation changes were studied to elucidate the hardening mechanism of 14K white gold alloys. For solid solution treatment [ST], casted 14K white gold alloy specimens were treated at high temperature ($750^{\circ}C$) during 30 minute, and the specimens dropped to water for quenching immediately. For Age-hardening treatment [AT], the specimens were treated at various temperatures ($250^{\circ}C{\sim}300^{\circ}C$). After the heat treatment, we observed increased hardness from 144 Hv to 214 Hv by Vicker's hardness tester. Variation of the grain size measured by optical microscopy (OM) and scanning electron microscopy (SEM) images. By electron probe micro-analysis (EPMA) mapping analysis, we investigated that irregular particles were changed uniformly. After heat treatment, 14K white gold alloys showed improved hardness and became uniformity of grain size by age-hardening treatment.

• 한국분말재료학회지
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• 제14권3호
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• pp.165-172
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• 2007

The purpose of this study was to analyze the sintering characteristics of gold and silver nanoparticles. In this study, gold and silver nanoparticles were prepared by using Inert Gas Cndensation (IGC). The sintering temperatures for gold and silver nanoparticles were $100{\sim}1000^{\circ}C\;and\'100{\sim}500^{\circ}C$, respectively. The sintering characteristics of gold and silver nanoparticles prepared by IGC were evaluated by X-ray diffraction(XRD), transmission electron microscopy (TEM), and scanning electron microscopy (SEM). Gold and silver nanoparticles with the size of $1{\sim}100\;nm\;and\;10{\sim}100\;nm$, respectively, were obtained. The size of sintered gold and silver nanoparticles increased with an increase in the sintering temperature. XRD data showed that silver nanoparticles were similar with polycrystal single-phase.

• 식물병연구
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• 제20권1호
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• pp.15-20
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• 2014

A rapid, user-friendly and simple immune-chromatographic dipstick kit named 'rapid immune-gold strip' (RIGS) kit was developed in a novel single strip format to detect on-site detection of Tomato spotted wilt virus (TSWV). Immunoglobulin G (IgG) from polyclonal antisera raised in rabbits against TSWV was purified through protein-A affinity chromatography and then the purified TSWV-IgG was conjugated to colloidal gold nano-particles which served as a test line on nitrocellulose membrane. Protein A that non-specifically binds to TSWV antibody was used as a control line on the same strip. The diagnosis process with the TSWV-RIGS involves simply grinding the suspect plant sample in a bag that contains the extraction buffer and inserting the strip the bag. Results can be seen in 2-5 minutes. The flow of the complexes of gold particles coated with TSWV-IgG and a crude sap from TSWV-infected pepper, tobacco and tomato plants resulted in intensive color formed on the test lines proportional to the concentrations of TSWV. The RIGS-TSWV kit did not show any cross-reactions against other tomato-infecting viruses unrelated to TSWV. These results indicate that the TSWV-RIGS kit is highly sensitive and is not required for laboratory training and experience prior to testing. The TSWV-RIGS kit is suitable for on-site detection of suspect TSWV-infected plants as well as for laboratory diagnosis.

• 한국식물병리학회:학술대회논문집
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• 한국식물병리학회 2003년도 정기총회 및 추계학술발표회
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• pp.75.2-75
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• 2003

To develop an effective protection strategy against tomato bushy stunt virus (TBSV), tobacco plants expressing single-chain Fv antibodies (scFv), were established. A previous had shown that the replication activity of viral replicase was inhibited by the selected scFvs. Moreover, no systemic symptom was found after virus inoculation on leaves of wt N. benthamiana infiltrated with an Agrobacterium suspension resulting i3l expression of the scFvs. However, control plants showed systemic symptoms. In this study the localization of the scFvs within two transgenic plant lines, (CP28H3, CP-P55) was demonstrated using immunogold labelling. The gold particles, indicating the presence of scFv, were mostly found In the cytoplasm of the plant cells including chloroplasts and in the cell walls. However, they were hardly found in the vacuole, nucleoplasm and intercellular spaces. Gold particles often accumulated in either the cytosol or chloroplasts showing a specific labeling, There was no difference in type of gold labeling between both transgenic lines. The localization of the scFv in the cytoplasm further conforms the inhibition of the RNA-dependent RNA polymerase (RdRp) by the selected scFv because it is known that the RdRp is localized to membraneous cytosolic structures.

• 한국식물병리학회지
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• 제14권3호
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• pp.229-239
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• 1998

Antibodies were raised against fusion proteins of the N-terminus and a region containing the GDNQ (Gly-Asp-Asn-Gln) polymerase motif of the L (polymerase) protein of sonchus yellow net virus (SYNV). Immunoblot analyses using these antibodies revealed the presence of the L protein in purified SYNV preparations and in nuclear extracts from infected tobacco. The serological analyses and detection in a polyacrylamide gels suggested that the L protein is present in at least a 20 fold lower abundance than the G, N, M1 and M2 proteins, and has size corresponding to a molecular weight of over 200 kDa as predicted from nucleotide sequence data. Electron microscopy with gold-labelled antibodies was used to localize the N, M2, and G proteins of SYNV in thin sections of infected tissue. When sections of SYNV-infected tissue were treated with antisera against total SYNV proteins and N protein, gold label could be detected in both the viroplasms and in virus particles. With the anti-M2 protein antiserum, the gold label was strongly localized in the viroplasms but only limited labelling of the virus particle sonly. Limited labelling of the L protein was observed in the viroplasms and the virus particles, presumably because of the low abundance of L protein in the tissues.

• Plant Resources
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• 제8권3호
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• pp.175-180
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• 2005

Thin sections of cellulose fibers were incubated with an endo- and an exoglucanase labeled with gold particles of differing sizes. The hydrolytic sites were then visualized under transmission electron microscopy (TEM). The potential interaction between the ${\beta}$-1, 4-glucan substrates and the endo- and the exoglucanases was investigated using cellulosic and lignocellulosic substrates. The simultaneous visualization was very successful in distinguishing preferred substrates for each cellulase in lignocellulosic substrates. When plant lignocellulose was preincubated with endocellulase, density of the gold labeling greatly increased suggesting that preliminary exposure of lignocellulosic material to endocellulase may have enhanced the accessibility of the substrate to endocellulase and exocellulase. This result provided a plausible explanation for the observed endo/exo cellulase co-hydrolysis.