• 한국식물학회:학술대회논문집
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• 한국식물학회 1999년도 제13회 식물생명공학심포지움 New Approaches to Understand Gene Function in Plants and Application to Plant Biotechnology
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• pp.57-62
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• 1999

Light-regulated translation of chloroplast mRNAs requires nuclear-encoded trans-acting factors that interact with the 5' untranslated region (UTR) of these mRNAs. A set of four proteins (60, 55, 47, and 38 kDa) that bind to the 5'-UTR of the psbA mRNA had been identified in C. reinhardtii. 47 kDa protein (RB47) was found to encode a chloroplast poly (A)-binding protein (cPABP) that specifically binds to the 5'-UTR of the psbA mRNA, and essential for translation of this mRNA, cDNA encoding 60 kDa protein (RB60) was isolated, and the amino acid sequence of the encoded protein was highly homologous to plants and mammalian protein disulfide isomerases (PDI), normally found in the endoplasmic reticulum (ER). Immunoblot analysis of C. reinhardtii proteins showed that anti-PDI recognized a distinct protein of 56 kDa in whole cell extract, whereas anti-rRB60 detected a 60 kDa protein. The ER-PDI was not retained on heparin-agarose resin whereas RB60 was retained. In vitro translation products of the RB60 cDNA can be transported into C. reinhardtii chloroplast in vitro. Immunoblot analysis of isolated pea chloroplasts indicated that higher plant also possess a RB60 homolog. In vitro RNA-binding studies showed that RB60 modulates the binding of cPABP to the 5'-UTR of the psbA mRNA by reversibly changing the redox status of cPABP using redox potential or ADP-dependent phosphorylation. Site-directed mutagenesis of -CGHC- catalytic site in thioredoxin-like domain of RB60 is an unique PDI located in the chloroplast of C. reinhardtii, and suggest that the chloroplast PDI may have evolved to utilize the redox-regulated thioredoxin like domain as a mechanism for regulating the light-activated translation of the psbA mRNA.

• 한국식물학회:학술대회논문집
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• 한국식물학회 1985년도 워크샵 및 심포지엄 북한산국립공원의 식생
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• pp.7-18
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• 1985

Light-regulated translation of chloroplast mRNAs requires nuclear-encoded trans-acting factors that interact with the 5' untranslated region (UTR) of these mRNAs. A set of four proteins (60, 55, 47, and 38 kDa) that bind to the 5'-UTR of the psbA mRNA had been identified in C. reinhardtii. 47 kDa protein (RB47) was found to encode a chloroplast poly (A)-binding protein (cPABP) that specifically binds to the 5'-UTR of the psbA mRNA, and essential for translation of this mRNA, cDNA encoding 60 kDa protein (RB60) was isolated, and the amino acid sequence of the encoded protein was highly homologous to plants and mammalian protein disulfide isomerases (PDI), normally found in the endoplasmic reticulum (ER). Immunoblot analysis of C. reinhardtii proteins showed that anti-PDI recognized a distinct protein of 56 kDa in whole cell extract, whereas anti-rRB60 detected a 60 kDa protein. The ER-PDI was not retained on heparin-agarose resin whereas RB60 was retained. In vitro translation products of the RB60 cDNA can be transported into C. reinhardtii chloroplast in vitro. Immunoblot analysis of isolated pea chloroplasts indicated that higher plant also possess a RB60 homolog. In vitro RNA-binding studies showed that RB60 modulates the binding of cPABP to the 5'-UTR of the psbA mRNA by reversibly changing the redox status of cPABP using redox potential or ADP-dependent phosphorylation. Site-directed mutagenesis of -CGHC- catalytic site in thioredoxin-like domain of RB60 is an unique PDI located in the chloroplast of C. reinhardtii, and suggest that the chloroplast PDI may have evolved to utilize the redox-regulated thioredoxin like domain as a mechanism for regulating the light-activated translation of the psbA mRNA.

• 보존과학연구
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• 통권24호
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• pp.187-213
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• 2003

Sungseonsa Temple site in Chungju city in Chungcheongbuk-doProvince is written in "Goryeosa" as a building for Queen Sinmyeongsunseong, the mother of Gwangjong in AD 954 in Goryeo Dynasty. The museum in Chungcheong University takes charge of the excavation for 3 times from 2000 to 2002 and identified that its construction was carried out till Joseon Dynasty. Among the iron artifacts from the first excavation such as a weeding hoe, a hand knife, a lock, two nails and a plow which had conservation treatments, the sample was collected. Its micro-structure and method of manufacture were investigated. Excavation report for those artifacts has not published yet, therefore, the date of each artifacts is not clearly confirmed. The samples were collected from each part of the objects and then embedded in epoxy resin and etched with nitric acid. The examination of its microstructure is carried out under the microscope and the hardness values were measured by Vickers hardness tester. From the results, some artifacts show different manufacture method sin the each parts. The forming processes of the iron weeding hoe and the iron sickle are similar but the blade of iron weeding hoe was strengthened by carbonization whereas the blade of the iron sickle was done by quenching. The hand knife and the nails were produced through almost same methods and shows similar microstructures. The hand knife seems to be made by repeated beating and folding in low temperature resulting in fine crystallization, but the nail shows large crystallization due to processes in high temperature. Lock is made of white cast iron, that does not show any heat treatment.

• Restorative Dentistry and Endodontics
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• 제37권1호
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• pp.9-15
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• 2012

Objectives: This study evaluated the effect of 2% chlorhexidine digluconate (CHX) with different application times on microtensile bonds strength (MTBS) to dentin in class I cavities and intended to search for ideal application time for a simplified bonding protocol. Materials and Methods: Flat dentinal surfaces with class I cavities ($4mm{\times}4mm{\times}2mm$) in 40 molar teeth were bonded with etch-and-rinse adhesive system, Adper Single Bond 2 (3M ESPE) after: (1) etching only as a control group; (2) etching + CHX 5 sec + rinsing; (3) etching + CHX 15 sec + rinsing; (4) etching + CHX 30 sec + rinsing; and (5) etching + CHX 60 sec + rinsing. Resin composite was builtup with Z-250 (3M ESPE) using a bulk method and polymerized for 40 sec. For each condition, half of the specimens were immediately submitted to MTBS test and the rest of them were assigned to thermocycling of 10,000 cycles between $5^{\circ}C$ and $55^{\circ}C$ before testing. The data were analyzed using two-way ANOVA, at a significance level of 95%. Results: There was no significant difference in bond strength between CHX pretreated group and control group at the immediate testing period. After thermocycling, all groups showed reduced bond strength irrespective of the CHX use. However, groups treated with CHX maintained significantly higher MTBS than control group (p < 0.05). In addition, CHX application time did not have any significant influence on the bond strength among groups treated with CHX. Conclusion: Application of 2% CHX for a short time period (5 sec) after etching with 37% phosphoric acid may be sufficient to preserve dentin bond strength.

• Bulletin of the Korean Chemical Society
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• 제33권11호
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• pp.3665-3670
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• 2012

Metal-p-$NH_2$-Bn-DOTA (paraammionobenzyl-1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid: ABDOTA) complex was synthesized and purified for bio-tagging to quantify biological target materials using laser ablation (LA)-ICP-MS. Since the preparation of a pure and stable tagging complex is the key procedure for quantification, magnetic particles were used to purify the synthesized metal-ABDOTA complex. The magnetic particles immobilized with the complex attracted to a permanent magnet, resulting in fast separation from free un-reacted metal ions in solution. Gd ions formed the metal-complex with a higher yield of 64.3% (${\pm}3.9%$ relative standard deviation (RSD)) than Y ions, 52.3% (${\pm}2.5%$ RSD), in the pH range 4-7. The complex bound to the magnetic particles was released by treatment with a strong base, of which the recovery was 81.7%. As a reference, a solid phase extraction (SPE) column packed with Chelex-100 resin was employed for separation under similar conditions and produced comparable results. The tagging technique complemented polydimethylsiloxane (PDMS) microarray chip sampling in LA-ICP-MS, allowing determination of small sample volumes at high throughputs. For application, immunoglobulin G (IgG) was immobilized on the pillars of PDMS microarray chips and then tagged with the prepared Gd complex. IgG could then be determined through measurement of Gd by LA-ICP-MS. A detection limit of 1.61 ng/mL (${\pm}0.75%$ RSD) for Gd was obtained.

• Journal of Ginseng Research
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• 제36권4호
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• pp.418-424
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• 2012

This study focused on the enzymatic biotransformation of the major ginsenoside Rb1 into Rd for the mass production of minor ginsenosides using a novel recombinant ${\beta}$-glucosidase from Flavobacterium johnsoniae. The gene (bglF3) consisting of 2,235 bp (744 amino acid residues) was cloned and the recombinant enzyme overexpressed in Escherichia coli BL21(DE3) was characterized. This enzyme could transform ginsenoside Rb1 and gypenoside XVII to the ginsenosides Rd and F2, respectively. The glutathione S-transferase (GST) fused BglF3 was purified with GST-bind agarose resin and characterized. The kinetic parameters for ${\beta}$-glucosidase had apparent $K_m$ values of $0.91{\pm}0.02$ and $2.84{\pm}0.05$ mM and $V_{max}$ values of $5.75{\pm}0.12$ and $0.71{\pm}0.01{\mu}mol{\cdot}min^{-1}{\cdot}mg$ of $protein^{-1}$ against p-nitrophenyl-${\beta}$-D-glucopyranoside and Rb1, respectively. At optimal conditions of pH 6.0 and $37^{\circ}C$, BglF3 could only hydrolyze the outer glucose moiety of ginsenoside Rb1 and gypenoside XVII at the C-20 position of aglycon into ginsenosides Rd and F2, respectively. These results indicate that the recombinant BglF3 could be useful for the mass production of ginsenosides Rd and F2 in the pharmaceutical or cosmetic industry.

• Restorative Dentistry and Endodontics
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• 제26권1호
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• pp.23-31
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• 2001

The purpose of this study was to search the optimal silane concentrations for filler- silanization of seven experimental composites. Silica filer was a 25micron crushed type. 0.0%, 0.5%, 1.0%, 1.5%, 2.0%, 2.5%, and 3.0% silane($\gamma$-methacrylooxypropyltrimethoxysilane)were added into silica-filler with weight percentage (wt%). Mixtures(silica filler/silane)were reacted at 6$0^{\circ}C$ for 72hours, and crushed into fine particles those were used as fillers for 7 experimental composites. Monomer was a 3 : 1 mixture of Bis-GMA and TEGDMA containing 0.2% tertiary amine and 0.4% camphoroquinone for light curability. A ratio for mixing the monomer and filler was 75% and 25% respectively. Seven experimental composites was classified with the concentration of silane treated, and the specimen number for each test was 10. Specimens with 6mm diameter and 3mm height dimension for measuring the diametral tensile strength were destroyed with 1mm/min cross-head speed on Instron universal testing machine (No. 4467, USA). Shear bond strength was measured on the specimens bonded to bovine enamel etched with 37% phosphoric acid solution for 1 minute Fractured surfaces were observed by SEM (Hitachi S-3200, Japan) among that of the highest values measured from each groups. Following results were obtained: 1. Experimental composites containing silanized filter showed the significantly higher diametral tensile strength and shear bond strength than the composites containing un-silanized fillers(Group1) (p<0.05). 2. In silanized filler composite resins(Group 2~7), Diametral tensile strength of Group 3 showed the significantly higher than that of Group 2 and Group 6(p<0.05). 3. Shear bond strength was higher in Group 3 than that of Group 7 (p＜0.05)in silanized fillers composite resins. 4. Fracture surface was formed in resin matrixes on the specimens from composites containing the fillers treated with 0.5% 1.0%, and 1.5% silane. These results mean that the optimal silane concentrations are exist for each fillet with its size and surface area, and that 1.0% is a optimal value for concentration to coat the 25$\mu\textrm{m}$ filler with silane.

• 한국전기전자재료학회논문지
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• 제21권9호
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• pp.835-843
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• 2008

We have fabricated the source-drain electrodes for OTFTs by screen printing method and manufactured Ag pastes as conductive paste. To obtain excellent conductivity and screen-printability of Ag pastes, the dispersion characteristics of Ag pastes prepared from two types of acryl resins with different molecular structures and Ag powder treated with caprylic acid, triethanol amine and dodecane thiol as surfactant respectively were investigated. The Ag pastes containing Ag powder treated with dodecane thiol having thiol as anchor group or AA4123 with carboxyl group(COOH) of hydrophilic group as binder resin exhibited excellent dispersity. But, Ag pastes(CA-41, TA-41, DT-41) prepared from AA4123 fabricated the insulating layer since the strong interaction between surface of Ag powder and carboxyl group(COOH) of AA4123 interfered with the formation of conduction path among Ag powders. The viscosity behavior of Ag pastes exhibited shear-thinning flow in the high shear rate range and the pastes with bad dispersion characteristic demonstrated higher shear-thinning index than those with good dispersity due to the weak flocculated network structure. The output curve of OTFT device with a channel length of 107 ${\mu}m$ using screen-printed S-D electrodes from DT-30 showed good saturation behavior and no significant contact resistance. And this device exhibited a saturation mobility of $4.0{\times}10^{-3}$ $cm^2/Vs$, on/off current ratio of about $10^5$ and a threshold voltage of about 0.7 V.

• Restorative Dentistry and Endodontics
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• 제21권2호
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• pp.585-601
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• 1996

The purpose of this study was to elucidate the effect of blood-and saliva-contamination during dentin pretreatment procedure on tensile bond strength, and to investigate the effect of contaminant-removing treatments on the recovery of bond strength of dentin bonding agents. Dentin specimens prepared from freshly extracted bovine mandibular anterior teeth were divided into non-contaminated control and contaminated experimental groups. The specimens of the contaminated group were contaminated with saliva or blood after etching or priming procedure, followed by contaminant-removing treatments. All the specimens were bonded with All Bond$^{(R)}$ 2 dentin bonding agent and Bisfil$^{TM}$ composite resin or Scotchbond$^{TM}$ Multipurpose and Z100. After all the bonded specimens were stored in $37^{\circ}C$ distilled water for 24 hours, tensile bond strengths were measured. The contaminated dentin and fractured dentin surfaces were examined under the scanning electron microscope. The results were as follows : Contaminated specimens showed lower bond strength than non-contaminated ones regardless of the kind of contaminant, contamination time and contaminant-removing treatments, except specimens which were acid-etched following saliva contamination after etching in All Bond$^{(R)}$ 2 groups (p<0.05). Blood contaminant resulted in much bond strength decrease than saliva ones (p<0.01), and contamination after priming resulted in much decrease in bond strength than after etching (p<0.01). Re-etching resulted in increase of bond strength in the specimens contaminated with saliva after etching but not in blood contaminated ones. Re-priming resulted in increase of bond strength in the specimens contaminated after priming regardless of the kind of contaminant.

• Restorative Dentistry and Endodontics
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• 제44권3호
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• pp.27.1-27.12
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• 2019

This case report describes a technique in which endodontic treatment and permanent indirect restoration were completed in the same clinical appointment with the aid of a computer-aided design/computer-aided manufacturing (CAD/CAM) system. Two patients were diagnosed with irreversible pulpitis of the mandibular first molar. After access preparation, root canals were located, irrigation was performed until bleeding ceased, and the coronal tooth structure was prepared for indirect restoration. Then, utilizing an interim 3-mm build-up of the endodontic access cavity, a hemi-arch digital scan was performed with an intraoral scanner. Subsequent to digital scanning, restoration design was performed simultaneously with the endodontic procedure. The root canals were shaped using the Race system under irrigation with 2.5% sodium hypochlorite followed by root canal filling. The pulp chamber was subsequently filled with a 3-mm-thick composite resin restoration mimicking the interim build-up previously utilized to facilitate block milling in the CAD/CAM system. Clinical try-in of the permanent onlay restoration was followed by acid etching, application of a 5th generation adhesive, and cementation of the indirect restoration. Once the restoration was cemented, rubber dam isolation was removed, followed by occlusal adjustment and polishing. After 2 years of follow-up, the restorations were esthetically and functionally satisfactory, without complications.