• Korean Journal of Plant Tissue Culture
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• v.25 no.4
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• pp.257-261
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• 1998

The repeated subcultures of in vitro plant materials in wasabi became highly vitrified and the capacity for multiple shoot formation from the vitrified plant materials was very low. In order to improve the quality of in vitro propagated planting materials, the experiments were carried out using culture vessels capped with membrane filter(MF). When vitrified shoots were cultured on MS medium with 0.2mg/L BA in the vessels with MF or without MF for 60 days, the shoots in the vessels with MF did not vitrified. In contrast, the shoots grown in the vessels without MF vitrified at 65%. The stomates of vitrified leaves were circular and inflated, whereas those of normal leaves acclimatizated in the vessels with MF were ovate in shape. The hardened shoots were also cultured on MS media without sucrose containing 0.01mg/L IBA in vessels with(photoautotrophic culture) or without(control) MF. Sucrose was necessary for survival of the in vitro plantlets in the vessels without MF. After 20 days of culture, the shoots in the vessels without MF on the sucrose-free media turned yellow and died. But the shoots in the vessels with MF in the sucrose-free media produced a lot of roots. When shoots were cultured on MS medium with 2% sucrose containing 0.01mg/L IBA in the vessels with(photomixotrophic culture) or without(heterotrophic culture) MF, best growth occured in photomixotrophic culture.

• Journal of Physiology & Pathology in Korean Medicine
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• v.18 no.3
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• pp.868-873
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• 2004

Renal dysfunction could be developed as the secondary disease of liver cirrhosis. Delayed or suppresed lipid peroxidation by the treatment with physiological active substances could be explained as the antioxidative and protective effect in tissue damage. In this study, we investigated an antioxidative effect and renal function improvement of Hovenia dulcis in liver fibrosis(cirrhosis) induced rats. The female Sprague-Dawley rats (180∼210 g) were divided into 3 groups (Normal, AC: CCl₄ mixture treated group, AC-HV: CCl₄ mixture+ Hovenia dulcis treated group) and renal damage was developed by CCl₄ mixture administration in 4 weeks (0.8 ㎖/rat). The tissue of kidney and liver and sera were used for quantitative measurement of enzyme activity, MDA and Hyp. The histological change and gene expression of collagen α1(III) mRNA and a1(IV) mRNA were observed by Masson's trichrome staining and RT-PCR. As a result, the clinical biochemical parameters of liver function (AST and ALT) in sera of AC-HV group showed significantly 46.4% and 104.8% lower (p<0.005), and the level of ALP and BUN as the parameter of protein urine and azotemia showed 17.8 % and 25.8 % lower than in AC group. In AC-HV group, the concentration of MDA in kidney and liver was decreased significantly 15.8% and 21.3% when compared with AC group (p<0.01 -0.005). The content of Hyp in kidney of AC-HV group is merely higher than in AC group, in contrast to liver tissue. The expression of collagen α1(III) mRNA and collagen α1(IV) mRNA was decreased in AC, but both of collagen mRNA in normal and AC-HV group expressed fast similar. More massive lipid droplets, thicker collagen fiber bundles in portal triads and more formation of portal central septum were observed in the liver of AC group than in AC-HV group. In conclusion, CCl₄ mixture intoxication could be developed not only liver fibrosis(cirrhosis) but also renal dysfunction by the massive lipid peroxidation and suppression of interstitial collagen and basement membrane collagen synthesis. And the water extract of Hovenia dulcis may be possessed the antioxidative and protective effect and improvement of kidney function in renal dysfunction induced rats.

• The Journal of Korean Medicine
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• v.34 no.1
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• pp.116-135
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• 2013

Objectives: This study was intended to clarify how Jakyakkamchobuja-tang (hereinafter referred to JKBT) affects mice of C57BL/10 whose osteoarthritis was induced by papain. Methods: Osteoarthritis was induced in mice by injecting papain in the knee joint. Mice were divided into 4 groups (n=6). The normal group were not treated at all whereas the control group (OAC-control) were induced for osteoarthritis by papain and oral medicated with 200 ul of physiological saline per day. The positive comparison group (OAC-$Joins^{(R)}$) were injected with papain and after 7 days, 100 mg/kg of $Joins^{(R)}$ were medicated with 200 ul of physiological saline mixed. The experimental group (OAC-JKBT) were injected with papain and after 7 days were medicated with 400 mg/kg of JKBT mixed with 200 ul of physiological saline. OAC-$Joins^{(R)}$ and OAC-JKBT were oral medicated for each substance for a total of 4 weeks, once per day. After experiments (from 1 week after injection of papain to 4 weeks elapsed), the function of liver and kidney, inflammation cytokine values within serum, degree of revelation for inflammation cytokine genes, immune cells within blood, metabolism of arachidonic acid and amount of cartilage were measured and histopathological variations for knee joint structures were observed. Results: Functions of liver and kidney were not affected. IL-$1{\beta}$ (interleukin-$1{\beta}$), MCP-1 (monocyte chemoattractant protein-1) and TNF-${\alpha}$ (tumor necrosis factor-${\alpha}$) were significantly reduced and IL-6 (interleukin-6) was also reduced but not significantly. After analyzing inflammation cytokine in joints with mRNA (messenger ribonucleic acid), revelation of IL-6, TNF-${\alpha}$, COX-2 (cyclooxygenase-2) and iNOS-II (inducible nitric oxide synthase-II) were all significantly reduced. Revelation of IL-$1{\beta}$ gene was also reduced but not significantly. Neutrophil for WBC (white blood cell) within serum was significantly reduced; monocyte was also reduced but not significantly. PGE2 (prostaglandin E2), TXB2 (thromboxane B2) were significantly reduced and LTB4 (leukotriene B4) was also reduced but not significantly. Destruction of cartilage on micro CT (computed tomography)-arthrography was reduced but had no significant differences. In terms of histopathology, infiltration of inflammation, proliferation of synovial membrane, subsidence of cartilage and bone due to penetration of excessive formation of synovial cell and destruction of cartilage were small (H&E (hematoxylin and eosin), safranine O staining). Conclusions: Based on these results, Jakyakkamchobuja-tang (JKBT) is believed to be useful for suppressing the progress of osteoarthritis and its treatments because of its anti-inflammatory effects and alleviation of pain with histopathological effective efficacy.

• Journal of the Korea Concrete Institute
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• v.18 no.1 s.91
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• pp.125-132
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• 2006

Recently, surface finishing and protection materials were developed to restore performance of the deteriorated concrete and inhibiting corrosion of the reinforcing-bar. For this purpose, surface protection agent as well as coatings are used. Coatings have the advantage of low Permeability of $CO_2,\;SO_2$ and water. However, for coatings such as epoxy, urethane and acryl, long-term adhesive strength is reduced and the formed membrane of those is blistered by various causes. Also when organic coatings are applied to the wet surface of concrete, those have a problem with adhesion. On the other hand, surface protection agent penetrates into pore structure in concrete through capillary and cm make a dense micro structure in concrete as a result of filling effect. Furthermore, the chemical reaction between silicate from surface protection agent and cement hydrates can also make a additional hydration product which is ideally compatible with concrete body. The aim of this study is to examine the effect of penetrative surface protection agent(SPA) by evaluating several concrete durability characteristics. The results show that the concrete penetrated surface protection agent exhibited higher durability characteristics for instance, carbonation velocity coefficient, resistance to chemical attack and chloride ion penetration than the plain concrete. These results due to formation of a discontinuous macro-pore system which inhibits deterioration factors of concrete by changed the pore structure(porosity and pore size distributions) of the concrete penetrated surface protection agent.

• The korean journal of orthodontics
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• v.35 no.4 s.111
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• pp.262-274
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• 2005

Tooth movement is a result of mutual physiologic responses between the periodontal ligament and alveolar bone stimulated by mechanical strain. The PDL cell and osteoblast are known to have an influence on bone formation by controlling collagen synthesis and alkaline phosphatase activation. Moreover. recent studies have shown that the PDL cell and osteoblast release osteoprotegerin (OPG) and the receptor activator of nuclear factor ぉ ligand (RANKL) to control the level of osteoclast differentiation and activation which in turn influences bone resorption. In this study. progressively increased, continuous tensional force was applied to PDL cells. The objective was to find out which kind of biochemical reactions occur after tensional force application and to illuminate the alveolar bone resorption and apposition mechanism. Continuous and progressively increased tensile force was applied to PDL cells cultured on a petriperm dish with a flexible membrane The amount of $PGE_2$ and ALP synthesis were measured after 1, 3, 0 and 12 hours of force application. Secondly RT-PCR analysis was carried out for OPG and RANKL which control osteoclast differentiation and MMP-1 -8, -9, -13 aud TIMP-1 which regulate the resolution of collagen and resorption of the osteoid layer According to the results. we concluded that progressively increased, concluded force application to human PDL cells reduces $PGE_2$ synthesis, and increases OPG mRNA expression.

• Applied Microscopy
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• v.24 no.3
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• pp.23-33
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• 1994

It is well known that dichlorvos (DDVP), an organophosphate insecticide in common use, is so easily and rapidly hydrolyzed and excreted that it has usually little toxic effect on human body. In these days, however, it is widely used as an industrial and domestic insecticide and as an anthelmintic agent for animals, so that the accident of chemical poisoning occurs frequently. DDVP acts as a powerful inhibitor of carboxylic esterase, which can cause accumulation of acetylcholine at the synapses so paralysis of muscle and the transmission failure in cholinergic synapses dueing to desensitization of acetylcholin receptor may occure. Moreover accumulation of the acetylcholine brings about the elevation of the cyclic-AMP, which alters the cellular metabolisms of nucleic acid, carbohydrate, protein and lipid. Present study has undertaken to investigate the cardiotoxic effect of DDVP by electron microscopic study. A total of 30 Sprague-Dawley strain rats, weighing about 250gm were used as experimental animals. 2mg/kg/day of DDVP is intraperitonealy injected 3 times with intervals of every other day. On 1 day, 3 days, 5 days, 7 days and 14 days after drug administration, the animals were sacrified by cervical dislocation. Left ventricular cardiac muscles were resected and sliced into $1mm^3$. The specimens were embedded with Epon 812 and prepared by routine methods for electron microscopical observation. All preparations were stained with lead citrate and uranyl acetate and then observed with Hitachi-600 transmission electron microscope. The results were as follows: 1. In the cardiac muscle of DDVP treated rats, mitochondria with disorganized double membrane and mitochondrial crista, and vacuole formation in mitochondrial matrix were observed. But structures of mitochondria were recovered to normal in 14 days group. 2. In the cardiac muscle of DDVP treated rats, cisternae of sarcoplasmic reticulum were dilated and sacculated. But these changes were recovered to normal in 14 days group. 3. In the cardiac muscle of DDVP treated rats, glycogen particles around damaged myofibrils were decreased. But amount of glycogen particles were restored in 14 days group. 4. In the cardiac muscle of DDVP treated rats, disruption and discontinuation of myofilaments and disorganization of Z-disc were observed. But the structures of myofibrils were recovered to normal in 14 days group. It is consequently suggested that DDVP would induce the reversible degenerative changes on the ultrastructures in cardiac muscle of rat.

• Korean Journal of Animal Reproduction
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• v.26 no.3
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• pp.205-214
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• 2002

There are many methods to introduce exogenous DNA into embryo to produce transgenic animals. Exogenous gene can be integrated into oocyte by sperm vector. In this study, sperm was used as a vector for a transgene, which is encoding enhanced green fluorescent protein (EGFP). The objective of this study was to investigate the expression of exogenous gene in bovine embryos after injection of spermatozoa cocultured with EGFP DNA fragment. Spermatozoa were plunged into liquid nitrogen and thawed several times or shook in 0.2% Triton X-100 to remove sperm membrane followed by DTT treatment. The injected oocytes were co-cultured with vero cells in CR1aa, and expression of EGFP gene was observed under fluorescent microscope. Blastocyst formation rates of oocytes injected with sperm treated with DTT, DTT-freezing or DTT-Triton X-100 were 34.7, 39.4 and 31.9%, respectively. The rates of EGFP expression in oocytes injected with 54 ng DNA after DTT-treated, DTT-freezing and DTT-Triton X-100-treated sperm were 0, 19.1 and 13.9%. On the other hands, expression rate of oocytes injected with sperm cocultured with 13.5, 27 and 63.5 ng of EFGP DNA were 6.7, 9.0 and 5.1%, respectively. When intact sperm was mixed with 63.5 ng/${mu}ell$ EGFP DNA fragment, and then electroporated before injection, the expression rate of injected oocyte was 2%. Unexpectedly, electro-poration could not increase the expression rate. These results suggest that sperm can be used as a transgene vector, even if the efficiency was low (19.1%).

• Journal of Periodontal and Implant Science
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• v.29 no.2
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• pp.415-433
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• 1999

Implant stability is the key to long-term successful outcome for osseointegrated implants. To evaluate the initial healing response of bone around HA-coated implants without primary bone contact. 21 HA-coated thread type implants(STERI-OSS?) were placed in the femurs of 5 mongrel dogs, about 1-year old. Implants, 8 mm in length and 3.8mm(experimental 1group), 5.0mm(experimental 2group) and 6.0mm(control group) in diameter, were inserted after 3 holes of 6.0mm in diameter and 10mm in depth were prepared in the surgical sites each dog. Implants were supported by only nonresorbable membrane($Teflon^{(R)}$), in order to prevent the ingrowth of upper soft tissue into the gap between bone and implant, and to maintain each implant to be positioned in the center of the drilled hole. 9 implants with different diameters were inserted in 3 dogs for histologic observation, and 12 implants were inserted in 2 dogs for mobility test and removal torque test. Fluorescent dyes were injected for the observation of new bone formation in order of $Terramycin^{(R)}$, Arizarin $Red^{(R)}$, and $Calcein^{(R)}$ at an interval of 2 weeks. 3 dogs were sacrificed for histologic observation at 4, 8, and 12-week after placement. Light microscopy and confocal laser scanning microscopy were used to qualitatively characterize the bone around HA-coated implant. 2 dogs were sacrificed for mobility test($Periotest^{(R)}$, Simens AG, Bensheim, Germany) and removal torque test($Autograph^{(R)}$ AGS-1000D series, Japan) at 8 and 12-week after placement The results were as follows: 1. Histologic observation showed that osseointegration occurred to both control and experimental groups as time lapse, but delayed bone healing was revealed in 3.8mm group (experimental 1group), compared to contrtol group and 5.0mm group (experimental 2group). 2. The mobility test showed that the experimental groups had no distinguishable movement during experimental periods of 8 and 12-week, and there was no difference in mobility depending on the gap between bone and implant, and time lapse. 3. The removal torque forces were increased depended on the gaps decreasing between bone and implant, and time lapse. The results suggest that HA-coated implant without primary bone contact, based on guided bone regeneration could obtain its stability in all experimental groups as time lapse, but bone healing was delayed in experimental group of 3.8mm. And the results suggested that studies on correlationship between mobility test and removal torque test for implant stability would be necessary.

• Journal of the Korean Electrochemical Society
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• v.20 no.2
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• pp.27-33
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• 2017

Conventional lithium ion batteries suffer from notorious safety issues caused by inevitable lithium dendrite formation and proliferation during over/fast charging processes. The lithium dendrites or mechanical damage on the separator induce internal short circuit in LiB that generates extensive amount of heat within contacted electrode surfaces through the separator. During this heat generation, conventional polyolefin separators shrinks dramatically, and increasing short circuit pathway, that causes the battery to explode. To overcome this serious issue, ceramic coated separators are developed in commercial LiB to enhance thermal and mechanical stability. In this paper, various size(IL = 488.5 nm, I = 538.7 nm, S = 810.3 nm, D = 1533.3 nm) of $Al_2O_3$ particles are coated using styrene-butadiene rubber(SBR) / carboxymethyl cellulose(CMC) binder on PE separator to investigate its thermal stability and electrochemical effect on LiB coin cell with NCM cathode and Li metal anode.

• Transactions of the Korean hydrogen and new energy society
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• v.24 no.3
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• pp.223-229
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• 2013

Polymer Electrolyte Membrane Fuel Cell (PEMFC) is a power generation system to convert chemical energy of fuels and oxidants to electricity directly by electrochemical reactions. As a catalyst support for PEMFCs, carbon black has been generally used due to its large surface area and high electrical conductivity. However, under certain circumstances (start up/shut down, fuel starvation, ice formation etc.), carbon supports are subjected to serve corrosion in the presence of water. Therefore, it would be desirable to switch carbon supports to corrosion-resistive support materials such as metal oxide. $TiO_2$ has been attractive as a support with its stability in fuel cell operation atmosphere, low cost, commercial availability, and the ease to control size and structure. However, low electrical conductivity of $TiO_2$ still inhibits its application to catalyst support for PEMFCs. In this paper, to explore feasibility of $TiO_2$ as a catalyst support for PEMFCs, $TiO_2$ nanofibers were synthesized by electrospinning and calcinated at 600, 700, 800 and $900^{\circ}C$. Effects of calcination temperature on crystal structure and electrical conductivity of electrospun $TiO_2$ nanofibers were examined. Electrical conductivity of $TiO_2$ nanofibers increased significantly with increasing calcination temperature from $600^{\circ}C$ to $700^{\circ}C$ and then increased gradually with increasing the calcination temperature from $700^{\circ}C$ to $900^{\circ}C$. It was revealed that the remarkable increase in electrical conductivity could be attributed to phase transition of $TiO_2$ nanofibers from anatase to rutile at the temperature range from $600^{\circ}C$ to $700^{\circ}C$.