• Asian-Australasian Journal of Animal Sciences
• /
• v.22 no.1
• /
• pp.26-34
• /
• 2009

Porcine embryonic stem (ES) cells have a great potential as tools for transgenic animal production and studies of regulation of differentiation genes. Although several studies showed successful derivation of porcine ES-like cells, these cells were not maintained long-term in culture. Therefore, this study was conducted to establish porcine pluripotent ES-like cells using in vivo fertilized embryos and to maintain these cells in long term culture. Porcine ES-like cells from in vivo embryos obtained by immunosurgery or whole explant culture were successfully cultured for over 56 passages. Morphology of porcine ES-like cells was flat-shaped with a monolayer type colony. These cells stained for alkaline phosphatase throughout the culture. Furthermore, porcine ES-like cells reacted with antibodies against Oct-4, SSEA-1, SSEA-4, Tra-1-60, and Tra-1-81, which are typical markers of undifferentiated stem cells. To characterize the ability of porcine ES-like cells to differentiate into three germ layers, embryoid body formation was induced. After plating of these cells, porcine ES-like cells were spontaneously differentiated into various cell types of all three germ layers. In addition, porcine ES-like cells were successfully derived from IVF blastocysts in media containing human recombinant basic fibroblast growth factor.

• The korean journal of orthodontics
• /
• v.24 no.3 s.46
• /
• pp.673-693
• /
• 1994

Most adults, unlike growing children, have some periodontal problems which can influence the outcome of the orthodontic treatment. In cases where periodontal disease progression resulted in marked reduction of periodontium, orthodontic treatment could result in the worsening of the periodontal conditions, and therefore orthodontic treatment planning in such adult patients requires special considerations for the periodontal problems. This study investigates the effects of horizontal orthodontic tooth movement on the changes in the mesial, distal and furcation areas of the disease affected periodontium of adult dogs with advanced bone loss. Six adult dogs with healthy periodontium were selected, and mandibular 2nd premolars were extracted. In the mandibular 3rd premolars, angular bony defects in the mesial and distal sides, and horizontal bony defects in the furcation areas were created. Those that received the flap operation and plaque control were designated as the control, those that had horizontal tooth movement without plaque control after the flap operation as Experimental group I, those that had horizontal tooth movement under plaque control without the flap operation as Experimental group II, and those that had horizontal tooth movement under plaque control after the flap operation as Experimental group III. The control group was sacrificed 2 months postoperatively, and the experimental groups were sacrificed 5 months after the initiation of tooth movement. Specimens were histologically analyzed under light microscope. The results were as follows; 1. After the horizontal tooth movements, Experimental group I and II showed angular bony defects in the mesial sides of the roots and the distal side of the furcation areas, which correspond to the pressure sides. 2. After the horizontal tooth movements, Experimental group I and II showed decreased level of alveolar bone crest in the distal sides of the roots, which correspond to the tension sides. 3. Long junctional epithelium in the control group has not been replaced by periodontal connective tissue after the horizontal tooth movements. 4. Limited formation of new bone was observed in the angular bony defects in the mesial and distal aspects of the roots in the control group. 5. Inflammatory cell infiltration in the connective tissue was most severe in the Experimental group I, followed by Experimental group II, III, and the control group in that order. These results seem to indicate that plaque control was the most influencing factor in the alteration of the periodontal tissue after the horizontal tooth movements in the periodontal tissue with alveolar bone defects.

• Journal of the Korean Chemical Society
• /
• v.40 no.8
• /
• pp.557-564
• /
• 1996

FAB CAD MS/MS(Fast Atom Bombardment Collision Activated Dissociation Mass Spectrometry/Mass Spectrometry) was used to study different degree of bond stability according to the linkage positions of alkali cationized $(Na^+, Li^+, K^+, NH_4^+)$ stereoisomeric and synthetic oligosaccharides. The alkali metal cations were much more stable, requiring over -40 eV of collision energy vs. only -10 eV for the protonated forms. Of the cations, the potassium cationized trisaccharides were more stable than the others. They would not yield fragment ions under the conditions of collision available in triple quadrupole. Other cationized species exhibited decreasing stability in the series $Nap^+>Li^+>NH_4^+$ using 0.8 mTorr argon pressure in the collision cell. Metal cations of the oligosaccharides maintained charge principally on the amino sugar as shown by shift of all the fragment ions containing the amino sugar. The reason for the higher stability of the metal cationized form is the formation of crown ether-like bond around metal cations, N-acetyl group on GlcNAc and oxygens on fucose moiety. Depending on the metal sizes and the conformation of linkage-isomeric region, cationized species gave linkage dependent fragment patterns and exhibited stability in the series 1-6 > 1-4 > 1-3 linkage.

• Korean Journal of Agricultural Science
• /
• v.15 no.1
• /
• pp.15-22
• /
• 1988

Factors affecting the regeneration, reversion of protoplasts from mycelium of F. velutipes were investigated and the selection of auxotrophic mutants from protoplasts of F. velutipes was performed. PDP medium stabilized with 0.6M sucrose was suitable for the regeneration of protoplasts, and regeneration frequency was 0.47-1.32. The regeneration frequency of protoplasts was increased when nutrients were added to the regeneration medium. Especially, yeast extract was the most effective to regeneration of protoplasts. Regeneration pattern of protoplasts was formation of germ tubes from bud-like cells. 13-18% of monokaryotic strains was appeared from reverted protoplasts. Five of auxotrophic mutants were isolated from strains showed survival frequency of 1.9-16.

• Journal of the Korean Chemical Society
• /
• v.61 no.4
• /
• pp.179-184
• /
• 2017

In this paper, a $ZnO/SiO_2$ nano-composite was prepared by a simple chemical method at room temperature. For the synthesis of ZnO nanoparticles (NPs), a sonochemical method was used, and $SiO_2$ NPs were prepared by precipitation method. The formation of $ZnO/SiO_2$ NCs was characterized by X-ray diffractometer (XRD) and confirmed by field-emission scanning electron microscopy (FE-SEM) and Fourier transform infra-red spectroscopy(FT-IR). The photocatalytic properties of $ZnO/SiO_2$ NCs formed at different concentrations of $SiO_2$ were evaluated by rhodamine-B dye. It was confirmed that increasing $SiO_2$ concentration resulted in an increase in the photocatalytic property. In addition, the antibacterial activity of $ZnO/SiO_2$ NCs was conducted against Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus). As a result, the antibacterial activities of E.coli and S. aureus were increased in the presence of thick SiO NPs layer.

• Journal of Life Science
• /
• v.28 no.2
• /
• pp.257-264
• /
• 2018

The YrdC superfamily is a group of proteins that are highly conserved in almost all organisms sequenced so far. YrdC in Escherichia coli was suggested to be involved in ribosome biogenesis, translation termination, cold adaptation, and threonylcarbamoyl adenosine formation in tRNA. In this study, to unambiguously demonstrate that yrdC is essential in E. coli, we constructed two yrdC mutant strains of E. coli and examined their phenotypes. In the temperature-sensitive yrdC mutant strain, cell growth stopped almost immediately under nonpermissive conditions and it appeared to accumulate 16S ribosomal RNA precursors without significant accumulation of 30S ribosomal subunits. We also cloned yeast and human homologs and demonstrated that they complement the E. coli yrdC-deletion strain. By mutational study, we demonstrated that the concave surface in the middle of the YrdC protein plays an important role in E. coli, yeast, and human versions. By comparison of two yrdC-deletion strains, we also unambiguously demonstrated that yrdC is essential for viability in E. coli and that the functions of its yeast and human homologs overlap with that of E. coli YrdC.

• Proceedings of the Korean Vacuum Society Conference
• /
• 2016.02a
• /
• pp.251-251
• /
• 2016

For several decades, industrial processes consume a huge amount of raw water for various objects that consequently results in the generation of large amounts of wastewater. Wastewaters are consisting of complex mixture of different inorganic and organic compounds and some of them can be toxic, hazardous and hard to degrade. These effluents are mainly treated by conventional technologies such are aerobic and anaerobic treatment and chemical coagulation. But, these processes are not suitable for eliminating all hazardous chemical compounds form wastewater and generate a large amount of toxic sludge. Therefore, other processes have been studied and applied together with these techniques to enhance purification results. These include photocatalysis, absorption, advanced oxidation processes, and ozonation, but also have their own drawbacks. In recent years, electrochemical techniques have received attention as wastewater treatment process that could be show higher purification results. Among them, boron doped diamond (BDD) attract attention as electrochemical electrode due to good chemical and electrochemical stability, long lifetime and wide potential window that necessary properties for anode electrode. So, there are many researches about high quality BDD on Nb, Ta, W and Si substrates, but, their application in effluents treatment is not suitable due to high cost of metal and low conductivity of Si. To solve these problems, Ti has been candidate as substrate in consideration of cost and property. But there are adhesion issues that must be overcome to apply Ti as BDD substrate. Al, Cu, Ti and Nb thin films were deposited on Ti substrate to improve adhesion between substrate and BDD thin film. In this paper, BDD films were deposited by hot filament chemical vapor deposition (HF-CVD) method. Prior to deposition, cleaning processes were conducted in acetone, ethanol, and isopropyl alcohol (IPA) using sonification machine for 7 min, respectively. And metal layer with the thickness of 200 nm were deposited by DC magnetron sputtering (DCMS). To analyze microstructure X-ray diffraction (XRD, Bruker gads) and field emission scanning electron microscopy (FE-SEM, Hitachi) were used. It is confirmed that metal layer was effective to adhesion property and improved electrode property. Electrochemical measurements were carried out in a three electrode electrochemical cell containing a 0.5 % H2SO4 in deionized water. As a result, it is confirmed that metal inter layer heavily effect on BDD property by improving adhesion property due to suppressing formation of titanium carbide.

• Journal of the Society of Cosmetic Scientists of Korea
• /
• v.42 no.4
• /
• pp.343-349
• /
• 2016

Many minerals and nutrient salts are abundant in Jeju lava sea water. The objective of this study was to evaluate the skin hydration effects of Jeju lava sea water. The skin barrier serves as a protective barrier that prevents the loss of moisture. The water holding capacity and water transport of the epidermis have been proposed to be important determinants of skin hydration. Jeju lava sea water increased the mRNA expression of filaggrin and caspase-14 which is related to natural moisturizing factor (NMF) formation. Aquaporins 3 (AQP3) are proteins that facilitate the transport of water across cell membranes. Jeju lava sea water increased the mRNA expression and protein expression of AQP3. We employed a skin equivalent model to assess the efficacy of Jeju lava sea water. In a skin equivalent model, Jeju lava sea water increased the CD44 (hyaluronic acid receptor) which is related to skin hydration. From these results, we found out Jeju lava sea water maybe help to skin hydration.

• BMB Reports
• /
• v.48 no.1
• /
• pp.54-59
• /
• 2015

IL-10-producing B (Breg) cells regulate various immune responses. However, their phenotype remains unclear. CD40 expression was significantly increased in B cells by LPS, and the Breg cells were also enriched in $CD40^{hi}CD5^+$ B cells. Furthermore, CD40 expression on Breg cells was increased by IL-10, CD40 ligand, and B cell-activating factor, suggesting that $CD40^{hi}$ is a common phenotype of Breg cells. LPS-induced CD40 expression was largely suppressed by an anti-IL-10 receptor antibody and in IL-$10^{-/-}CD5^+CD19^+$ B cells. The autocrine effect of IL-10 on the CD40 expression was largely suppressed by an inhibitor of JAK/STAT3. In vivo, the LPS treatment increased the population of $CD40^{hi}CD5^+$ Breg cells in mice. However, the population of $CD40^{hi}CD5^+$ B cells was minimal in IL-$10^{-/-}$ mice by LPS. Altogether, our findings show that Breg cells are largely enriched in $CD40^{hi}CD5^+$ B cells and the autocrine effect of IL-10 is critical to the formation of $CD40^{hi}CD5^+$ Breg cells.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.23 no.3
• /
• pp.402-408
• /
• 1994

Human plasma low density lipoprotein (LDL) is the major factor of coronary heart disease.But recent studies suggest the normal LDL can be realdily oxidized by oxygen free radicals and not interact with LDL receptors.Lipoprotei particles consist of lipid and protein, and fatty acids are prone to oxidatioin.The fatty acid compositions of LDL from Koreans was compared with that of Westerners.From the results, the raio of unsaturated fatty acids of korean and Westerner approximately 30 and 70%, respectively.which means Westerners are more labile in the lipid oxidation of LDL than Koreams.Normal LDL was incubated with $CuSO_4$ in PBS to lead for the peroxidation of LDL, and it was tested by the detection of TBARS and free radicals.Then, ascorbate, ${\alpha}-tocopherol$ and hyaluronic acid were found to have effects of antioxidants on LDL oxidation.The amount of free radical increased as the extent of oxidation increased.The time course of free radical formation was similar to TBARS.Therefore, determination of free radical by Luminometer was much more convenient than that of TBARS.