• Title/Summary/Keyword: Metal Surface

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Solid-Phase Refolding of Poly-Lysine fusion Protein of hEGF and Angiogenin (Poly-lysine이 연결된 hEGF와 angiogenin의 융합단백질의 고체상 재접힘)

  • Park, Sang-Joong;Ryu, Kang;Suh, Chang-Woo;Chai, Young-Gyu;Kwon, Oh-Byung;Park, Seung-Kook;Lee, Eun-Kyu
    • KSBB Journal
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    • v.17 no.2
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    • pp.153-157
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    • 2002
  • A fusion protein, consisting of a human epidermal growth factor as the recognition domain and human angiogenin as the toxin domain, can be used as a targeted therapeutic against breast cancer cells among others. The fusion protein was expressed as an inclusion body in recombinant E. coli, yet when the conventional solution-phase refolding process was used the refolding yield was very low due to severe aggregation, probably because of the opposite surface charge resulting from the vastly different pl values of each domain. Accordingly the solid-phase refolding process, which exploits the ionic interactions between a solid matrix and the protein, was tried, however the ionic binding yield was also very low regardless of the resins and pH conditions used. Therefore, to provide a higher affinity toward the solid matrix, six Iysine residues were tagged to the N-terminus of the hEGF domain. When cation exchange resins, such as heparin- or CM-Sepharose, were used as the matrix, the adsorption capacity increased 2.5~3-fold and the subsequent refolding yield increased nearly 15-fold compared to the conventional process. A similat result was also obtained when an Ni-NTA metal affinity resin was used.

The Biocompatibility Of Cultured Bone Marrow Cells And Gingival Fibroblasts On The Titanium Surfaces (티타늄 배양에 대한 배양골수와 치은 섬유아세포의 생체적합성)

  • Oh, Choong-Young;Park, Joon-Bong;Kwon, Young-Hyuk;Lee, Man-Sup
    • Journal of Periodontal and Implant Science
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    • v.26 no.1
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    • pp.143-160
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    • 1996
  • The purpose of this study was to evaluate the response in aspect of attachment and growth rate of osteoblasts and growth rate of osteoblasts and human gingival fibroblasts to the commercially pure titanium(CP titanium)and titanium alloy(Ti-6AI-4V) that are used widely as implant materials, and to obtain the basic information to ideal implant materials. In the studly, commercially pure titanium in first test group, titanium alloy(Ti-6AI-4V) in second test group, cobalt-chrome-molybdenum alloy(Co-Cr-Mo alloy) in positive control group, and tissue culture polystyrene plate in negative control group were used. The results of this study were as follows. 1. Bone marrow cells cultured on CP titanium and Ti-6Al-4V showed significantly greater attachment and growth rate(p(0.05) compared to Co-Cr-Mo alloy in each time. 2. There were no significant differences(p>0.05) in attachment and growth rate of bone marrow cells cultured on CP titanium and Ti-6AI-4V or tissue culture plate. 3. Most bone marrow cells cultured on CP titanium, Ti-6Al-4V and tissue culture plate were attached well to each substratum in first 2days, and then, grew at higher growth rate. On the other hand, some cells cultured on Co-Cr-Mo alloy failed to attach in first 2 days, and then, attached cells grew at lower growth rate than other groups. 4. Attachment and growth rates of gingival fibroblasts cultured on CP titanium and Ti-6Al-4V showed no significant differences(p>0.05) compared to Co-Cr-Mo alloy in 2 days, but significantly greater increase(p<0.05) in 5 and 9 days. 5. There were no significantly differences(p>0.05) between growth rates on gingival fibroblasts cultured on CP titanium, Ti-6Al-4V and tissue culture plate in 2 and 5days, but a significant lower growth rate(p<0.05) on CP titanium and Ti-6Al-4V versus tissue culture plate. 6. Some gingival fibroblasts cultured on all specimen groups failed to attach, but attached cells grew well, especially on CP titanium, Ti-GAl-4V and tissue culture plate. 7. There were no significant differences(P>0.05) between growth rates of both bone marrow cells and gingival fibroblasts cultured on CP titanium and Ti-6AI-4V. As a result of this study, both commercially pure titanium and Ti-6AI-4V showed excellent biocompatibility and there was no significant difference in the cellular response to the both metals. Bone marrow cells cultured on each substratum showed significantly greater growth rate and responded sensitively to cytotoxic effects of metal surfaces compared to gingival fibroblasts. Considering cell response to the substrate, it was likely that the composition itself of titanium metals have no significant effect on the biocompatibility. Further study need to be done to evaluate the influence of surface characteristics on cellular responses.

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Rehabilitation of severely worn dentition using Monolithic surveyed restoration and electronic surveying in RPD metal framework fabrication: A case report (심한 마모를 가진 환자에서 전자 서베잉을 이용한 금관 및 국소의치 수복 증례)

  • Choi, Youngha;Kim, Hyeong-Seob;Kwon, Kung-Rock;Pae, Ahran;Noh, Kwantae;Paek, Janghyun;Hong, Seoungjin
    • The Journal of Korean Academy of Prosthodontics
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    • v.56 no.3
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    • pp.243-249
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    • 2018
  • Excessive tooth wear results in unacceptable damage to the occlusal surface and can cause pulpitis, occlusal disharmony, dysfunction, and unesthetic result. Patients with severe attrition have to be classified as several types relative to the vertical dimension of occlusion (VDO) and the interocclusal distance for the prosthetic space. The patient in this case was a 80 - year - old woman who lost support of posterior occlusion and collapsed of the occlusal plane due to confrontation of the opposing teeth, accompanied by an increase in the number of remaining bristles, resulting in a loss of intermaxillary space for prosthesis. In this case, treatment with increased vertical dimension may have stability if the increase in vertical occlusal height is minimized within the required range, and a stable occlusal contact is provided after an increased vertical occlusal height stabilization period. After the new VDO had been confirmed under interim fixed restorations, definitive fixed restorations were produced. Through these treatment processes, we obtain satisfactory results that are functional and aesthetically pleasing.

Full mouth Rehabilitation in a Patient with Occlusal Collapse with Vertical Dimension Increase (교합 붕괴 환자에서 수직 고경을 증가한 보철 수복 : 증례 보고)

  • Jo, Si-Hoon;Jeong, Su-Yang;Nam, Hyun-Seok;Song, Kwang-Yeob;Park, Ju-Mi;Ahn, Seung-Geun
    • Journal of Dental Rehabilitation and Applied Science
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    • v.26 no.4
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    • pp.477-482
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    • 2010
  • In a case of multiple posterior teeth loss, antagonistic teeth extrude to the edentulous space and compensatory occlusion on the remained anterior teeth leads to occlusal trauma. Extrusion of antagonistic teeth breaks down occlusion plane and loss of posterior support bring about severe wear of remained teeth. In this situation, it is needed to restore remained teeth and edentulous space by increasing vertical dimension to obtain prosthodontic rehabilitation space and to correct occlusion plane. In this case report, the patient had a masticatory problem with loss of posterior teeth support and an esthetic problem of shortened anterior teeth. Before the tooth preparation for the prosthodontic restoration, the patient used removable device for 2 months to increase vertical dimension reversibly. After that, he got provisional fixed restoration with irreversible tooth reduction and used it for 3 months. It had spent 5 month to evaluate the adaptation state on final restoration with incresed vertical dimension. The increasing amount was 3 mm, which was relatively in less degree and masticatory system adapted to the increased vertical dimension without any pathologic changes. Final restoration was made to have equal-intensity contacts on all teeth in a verifiable centric relations and immediate disclusion of all posterior contacts the moment the mandible moves in any direction from centric relation. In addition, metal occlusion surface on posterior teeth was applied to prevent excessive muscle activation, occlusal trauma and the porcelain fracture.

A study on the fatigue bending strength of quasi-isotropic CFRP laminates subjected to impact damage (축격손상을 받은 의사등방성 탄소섬유강화 복합재의 굽힘피로강도)

  • Park, Soo-Chul;Park, Seol-Hyeon;Jung, Jong-An;Cha, Cheon-Seok;Yang, Yong-Jun
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.18 no.10
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    • pp.688-695
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    • 2017
  • Compared to metal, CFRP has excellent mechanical characteristics in terms of intensity, hardness, and heat resistance as well as its light weight that it is used widely in various fields. Therefore, this material has been used recently in the aerospace field. On the other hand, the material has shortcomings in terms of its extreme vulnerability to damage occurring internally from an external impact. This study examined the intensity up to its destruction from repeated use with the internal impact of a CFRP laminated plate that had also been exposed to external impact obtain design data for the external plate of aircraft used in the aerospace field. For the experimental method, regarding the quasi-isotopic type CFRP specimen and orthotropic CFRP specimen that are produced with a different layer structure, steel spheres with a diameter of 5 mm were collided to observe the resulting impact damage. Through a 3-point flexural fatigue experiment, the progress of internal layer separation and impact damage was observed. Measurements of the flexural fatigue strength after the flexural fatigue experiment until internal damage occurs and the surface impacted by the steel spheres revealed the quasi-isotopic layer structure to have a higher intensity for both cases.

A study on the Artistic Formativeness Represented in the Materials of the Modern Fashion Design (현대패션 디자인 소재에 표현된 예술적 조형성에 관한 연구)

  • 이효진
    • Journal of the Korean Society of Costume
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    • v.32
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    • pp.163-182
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    • 1997
  • The purpose of this study was intended to analyze artistic formativeness represented in the modern fashion design materials. Nowadays the modern fashion design materials is characterized by variety. The fashion materials the most important of fashion is called a softwear in textile industry and emerged as a new field. Fashion design also escaped from the tra-ditional restraint and extended to pursue lib-eral clothes and the designer's creative inten-tion has resulted in conceptual and conven-tional alteration as a new mode of plastic ex-preseeion. As a results of analysis of the formative fea-ture of Art style represented in the modern fashion design materials. First Surrealism had been searching for a new way of confronting a social and rtistic environment that was stifling and repugnant to them. Accordingly the wide applicaytion of the various object due to the thought of Sur-realism through the modern fashion materials brought the diversification and individua-lization of the modern fashion design. Second Pop Art that is made modern mech-anic culture and commercialism brought the great transformation in the history of Art out of the existing style and the sense of ex-pression. And the plastic characteristics of Pop Art that has a gravity as modern fashion materials on a them of the elements of popular consumer's society. That is the common and cheap objects were introduced into fashion materials itself or pat-tern. Third Minimalism is a trend in art att-empting to seek essence of the object by presenting simple and disciplined expressions by minimal formative means. The features of external form are simplicity clarity unrelated composition and symmetrical structure. Mini-malism was a quest for basic elements repre-senting the fundamental esthetic values of art. The minimal expression in modern fashion materials mean fabrics with simple surface and is contained using simple geometric pattern or utilizing textiles without any patterns. Fourth Eroticism is a kind of psychological revolution in the development of human civilization and is deeply rooted in the cultural tradition of myth religion customs and art. So Eroticism must be distinguished from a mere animal reproduction. These erotic char-acteristics were holded the meanings of sexu-ality through the modern fashion materials. Especially it was expressed the sexual part of body was nakedly showed through trans-parent materials or semitransparent like metalic and opaque materials. Recently the various kinds of new materials such as paper vinyle plastic metal as well as human body were applied to new fashion de-sign. First of all the new materials will give modern fashion designers stimuli and inspi-ration. It can also express values of moderners to despise materialism and uniformed modern society and to recover humanity and self-actualization.

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Ellipsometric study of Mn-doped $Bi_4Ti_3O_{12}$ thin films

  • Yoon, Jae-Jin;Ghong, Tae-Ho;Jung, Yong-Woo;Kim, Young-Dong;Seong, Tae-Geun;Kang, Lee-Seung;Nahm, Sahn
    • Proceedings of the Korean Vacuum Society Conference
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    • 2010.08a
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    • pp.173-173
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    • 2010
  • $Bi_4Ti_3O_{12}$ ($B_4T_3$) is a unique ferroelectric material that has a relatively high dielectric constant, high Curie temperature, high breakdown strength, and large spontaneous polarization. As a result this material has been widely studied for many applications, including nonvolatile ferroelectric random memories, microelectronic mechanical systems, and nonlinear-optical devices. Several reports have appeared on the use of Mn dopants to improve the electrical properties of $B_4T_3$ thin films. Mn ions have frequently been used for this purpose in thin films and multilayer capacitors in situations where intrinsic oxygen vacancies are the major defects. However, no systematic study of the optical properties of $B_4T_3$ films has appeared to date. Here, we report optical data for these films, determined by spectroscopic ellipsometry (SE). We also report the effects of thermal annealing and Mn doping on the optical properties. The SE data were analyzed using a multilayer model that is consistent with the original sample structure, specifically surface roughness/$B_4T_3$ film/Pt/Ti/$SiO_2$/c-Si). The data are well described by the Tauc-Lorentz dispersion function, which can therefore be used to model the optical properties of these materials. Parameters for reconstructing the dielectric functions of these films are also reported. The SE data show that thermal annealing crystallizes $B_4T_3$ films, as confirmed by the appearance of $B_4T_3$ peaks in X-ray diffraction patterns. The bandgap of $B_4T_3$ red-shifts with increasing Mn concentration. We interpret this as evidence of the existence deep levels generated by the Mn transition-metal d states. These results will be useful in a number of contexts, including more detailed studies of the optical properties of these materials for engineering high-speed devices.

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The Distribution Characteristics and Contamination of Heavy Metals in Soil from Dalcheon Mine (달천광산 토양 내 중금속의 존재형태 및 오염도)

  • Suh, Ji-Won;Yoon, Hye-On;Jeong, Chan-Ho
    • Journal of the Mineralogical Society of Korea
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    • v.21 no.1
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    • pp.57-65
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    • 2008
  • The geochemical partitioning of arsenic in contaminated soils from a of wet land and tailing of the abandoned mine is examined. Chemical analysis and sequential extraction method by ultrasound-sonication extraction are applied to investigate the mobility and chemical existence conditions of arsenic as well as heavy metals. The results of this study showed that heavy metals concentration of tailings showed as a following order: Fe > As > Cu > Pb > Cr. The highest metal concentration was recognized in samples less than $63\;{\mu}m$ fraction in their particle sizes. Exchangeable and carbonate fractions in soil samples showed following Cu > As > Pb > Fe > Cr for tailings, and Fe > Pb > Cu > As > Cr for reservoir soils, respectively. Arsenic was bound as exchangeable fraction in tailings and its concentration appeared higher than those of the other metals. Thus, As can be easily dispersed into soil and water environments. The obtained results can be used to design soil remediation plan in the study area and require further detailed study to investigate severe environmental pollution of surface water as well as rivers with respect to heavy metals in terms of speciation analysis of toxic elements such as As and Cr.

Effect of air-contaminated TiN on the deposition characteristics of Cu film by MOCVD (공기 중에 노출된 MOCVD TiN 기판이 MOCVD Cu 증착에 미치는 효과)

  • Choe, Jeong-Hwan;Byeon, In-Jae;Yang, Hui-Jeong;Lee, Won-Hui;Lee, Jae-Gap
    • Korean Journal of Materials Research
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    • v.10 no.7
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    • pp.482-488
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    • 2000
  • The deposition characteristics of Cu film by MOCVD using (hfac)Cu(1,5-COD)(1,1,1,5,5,5-hexafluro-2,4-pentadionato Cu(I) 1,5-cryclooctadiene) as a precursor have been investigated in terms of substrate conditions. Two different substrates such as air-exposed TiN and non-contaminated TiN were used for the MOCVD of Cu. MOCVD of Cu on the air-exposed TiN affected the nucleation rate of Cu as well as its growth, resulting in the Cu films having poor interconnection between particles with relatively small grains. On the other hand, in-situ MOCVD of Cu led to the Cu films having a significantly improved interconnection between particles with larger grains, indicating the resistivity as low as $2.0{\mu}{\Omega}-cm$ for the films having more than 1900$\AA$ thickness. Moreover, better adhesion of Cu films to the TiN by using in-situ MOCVD has been obtained. Finally, initial coalescence mechanism of Cu was suggested in this paper in terms of different substrate conditions by observing the surface morphology of the Cu films deposited by MOCVD.

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Heterocyclic Amines Removal by Binding Ability of Lactic Acid Bacteria Isolated from Soybean Paste (된장에서 분리된 유산균의 결합력에 의한 Heterocyclic Amines 제거)

  • Lim, Sung-Mee
    • Korean Journal of Microbiology
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    • v.50 no.1
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    • pp.73-83
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    • 2014
  • The objective of the this study was to investigate the binding capacity and removal ability of lactic acid bacterial strains obtained from Korean soybean paste for mutagenic heterocyclic amines (HCAs) formed during cooking of protein-rich food at high temperature. Among 19 strains identified by carbohydrate fermentation and 16S rRNA sequencing, the live cell or cell-free culture supernatant of Lactobacillus acidophilus D11, Enterococcus faecium D12, Pediococcus acidilactici D19, L. acidophilus D38, Lactobacillus sakei D44, Enterococcus faecalis D66, and Lactobacillus plantarum D70 inhibited the mutagenesis caused by either 3-amino-1,4-dimethyl-5H-pyrido[4,3-b] indole (Trp-P-1) or 3-amino-1-methyl-5H-pyrido[4,3-b] indole (Trp-P-2) in Salmonella typhimurium TA98 and TA100. The bacterial cells of the isolated strains showed greater binding activity than the pure cell wall, exopolysaccharide, and pepetidoglycan. The carbohydrate moieties of the cell wall or protein molecules on the cell surface have a significant role in binding Trp-P-1 and Trp-P-2, since protease, heating, sodium metaperiodate, or acidic pH treatments significantly (P<0.05) reduced the binding efficacy of the tested bacteria. Addition of metal ions or sodium dodecyl sulfate decreased the binding ability of E. faecium D12, L. acidophilus D38, and E. faecalis D66. Therefore, the binding mechanisms of these strains may consist of ion-exchange and hydrophobic bonds. Especially, the high mutagen binding by L. acidophilus D38 and L. plantarum D70 may reduce the accumulation or absorption of Trp-P-1 and Trp-P-2 in the small intestine via increased excretion of a mutagen-bacteria complex.