• Microbiology and Biotechnology Letters
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• v.24 no.6
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• pp.647-651
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• 1996

The development of an enrichment method for the rapid and effective identification of Salmonella spp. in sewage or food was studied. As a growth factor for Salmonella, 10 mM cyclic adenosine monophosphate (cAMP) in trypticase soy broth with 0.6% yeast extract (TSBYE) increased cell number five-folds and 0.6% yeast extract in selenite broth increased cell number ten-folds of control. Bile salts in selenite broth was tested for the selection of S. enteritidis in a mixture with Staphylococcus aureus, Pseudomonas aeruginosa, Lactobacillus plantarum and Escherichia coli. The latter four strains were effectively inhibited at 0.1% bile salt. A two-step culture method was used to enrich Salmonella spp.; a primary-enrichment and secondary- enrichment culture. At a primary-enrichment step, selenite broth with 0.6% yeast extract and 10 mM cAMP was used, and at a secondary-enrichment step, 0.1% bile salt was additionally used. Culture times of a primary- enrichment and a secondary-enrichment step were 8 hr and 6 hr, respectively. In this procedure, cell number increased from 10$^{0.3}$ to 10$^{8.5}$ with inhibition of other strains within 14 hr. In the case of an initial cell concentrarion as low as 10$^{-2}$ cfu/ml, a cell number increased to 10$^{7}$ cfu/ml by using a 10 hr primary-enrichment and 6 hr secondary-enrichment procedure.

• Journal of Physiology & Pathology in Korean Medicine
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• v.23 no.3
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• pp.581-589
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• 2009

The water extract of Dohongsamul-tang(DHSMT) has been traditionally used in treatment of ischemic heart and brain diseases in Oriental Medicine. However, little is known about the mechanism by which DHSMT protects C6 glial cells from glucose deprevation induced damages. Therefore, this study was designed to evaluate the protective effects of DHSMT on 2-deoxy-D-glucose induced autophagy of C6 glial cells. Autophagic phenotype is evaluated by fluorescence microscopy and flow cytometry with specific biological staining dyes, including monodansylcadaverine and acridine orange, as well as Western blot analysis with microtubule-associated protein 1 light chain 3(LC3) and Beclin-1. Treatment with 2-deoxy-D-glucose significantly resulted in a decrease of the viability of C6 glial cells and increase of the extracellular LDH release in a dose and time-dependent manner. However, pretreatment with DHSMT protected C6 glial cells from glucose deprivation with 2-deoxy-D-glucose. The author also observed the fact that autophagy phenotype occurred by 2-deoxy-D-glucose in C6 glial cells. Pretreatment with 3-MA, a pharmacological inhibitior of autophagy, abolished the formation of acidic vesicle organelle in C6 glial cells treated with 2-deoxy-D-glucose. However, pretreatment with DHSMT inhibited the formation of autophagic phenotypes, including formation of acidic vesicle organelle, and increase of the expression of LC-3 II Beclin-1 proteins in C6 glial cells treated with 2-deoxy-D-glucose. Taken together, these data suggest that DHSMT is able to protect C6 glial cells from glucose deprivation with marked inhibition of autophagy formation.

• Journal of Embryo Transfer
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• v.13 no.2
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• pp.159-172
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• 1998

사람 성장호르몬 수용체(hGHR) cDNA는 PCR방법에 의하여 fagment로서 보고되어진 바 있으나, liver cDNA로 부터 전장을 cloning한 보고는 없는 실정으로 본 연구에서는 기능을 가진 약 4.6kbp의 cDNA hGHR을 cloning 하는데 성공하였다. 먼저 cloning하기 위하여 human liver mRNA와 human breast cancer tissue로부터 회수한 mRNA를 RT-PCR방법에 의하여 human cDNA library와 cloning에 필요한 probe를 제작하였다. human library mRNA는 GT-PCR방법에 의하여 증폭하여 증폭되어진 산물은 λZAP Vector를 이용하여 cDNA library를 구축하였고,screeing을 위하여 임 보고 되어진 hGHR fragment native sequence를 기초로 N-terminal부분의 primer를 설계하여 950bp의 probe를 얻는데 성공하였다. 이 probe를 이용하여 준비된 human liver cDNA library로부터 2.5$\times$10 6개의 plaque로부터 6개의 positive clone을 획득하였고, 이들중 poly Asignal인 "AATAAA"를 포함하고 있는 가장 긴 약 3.8kbp의 clone을 sequencing한 결과 open reading frame을 포함하고 있었으나, 5'부분의 결손되어 있었다. 그리하여 이 부분은 human breast cancer tissue로 부터 회수한 mRNA를 RT-PCR에 의하여 증폭하였고, sequencing결과 이미 보고되어진 native hGHR와 비교한 결과 하나의 nucleotide가 silent mutation으로 판명되었다.한편 human liver cDNA library로부터 cloning한 3.8cp의 positive clone의 5'end의 결손된 부분에 silent mutation된 PCR 산물을 연결함으로써 native hGHR와 유사한 cDNA hGHR subcloning에 성공하였다. 이러한 cDNA hGHR의 clone이 function을 가지고 있는지를 검토하기 위하여 eukaryotic 발현 vector인 pCXN2에 의거 ligation한 후 chinese hamster ovary cell[CHO-KI]에 transfect를 실시하였다. Dexamethasone은 첨가하지 않고 hGH만의 존재하에서 이들 cell을 배양시키고 cell menbrane에서 발현 여부를 판정키 위하여 hGHR monocloual antibody를 사용하여 flow cytometery해석을 실시하는 한편 125I-hGH binding assay에 의하여 hGH binding activity를 측정하였다. 최종적으로 GH signal transduction의 target genedf으로 알려져 있는 serine protease inhibitor 2.1(Spi 2.1) gene의 promotor activity를 검토한 결과 hGHR을 transfect한 CHO Cell에 있어서 hGH의 농도에 의존적으로 증가되었다. 따라서 본 실험에서 cloning한 cDNA hGHR는 native hGHR와 같은 기능을 가지는 것으로 판명되었다.것으로 판명되었다.

• Bulletin of the Korean Chemical Society
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• v.31 no.6
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• pp.1577-1582
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• 2010

A 20 wt % Pt/C is fabricated and characterized for use as the cathode catalyst in a polymer electrolyte membrane fuel cell (PEMFC). By using the polyol method, the fabrication process is optimized by modifying the carbon addition sequence and precursor mixing conditions. The crystallographic structure, particle size, dispersion, and activity toward oxygen reduction of the as-prepared catalysts are compared with those of commercial Pt/C catalysts. The most effective catalyst is obtained by ultrasonic treatment of ethylene glycol-carbon mixture and immediate mixing of this mixture with a Pt precursor at the beginning of the synthesis. The catalyst exhibits very uniform particle size distribution without agglomeration. The mass activities of the as-prepared catalyst are 13.4 mA/$mg_{Pt}$ and 51.0 mA/$mg_{Pt}$ at 0.9 V and 0.85 V, respectively, which are about 1.7 times higher than those of commercial catalysts.

• Journal of Veterinary Science
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• v.25 no.3
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• pp.36.1-36.15
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• 2024

Importance: The intravenous administration of adipose tissue-derived mesenchymal stem cells (AdMSCs) in veterinary medicine is an attractive treatment option. On the other hand, it can result in severe complications, including pulmonary thromboembolism (PTE). Objective: The present study assessed the occurrence of PTE after the intravenous infusion of canine AdMSCs (cAdMSCs) into experimental animals. Methods: Five-week-old male BALB/c hairless mice were categorized into groups labeled A to G. In the control group (A), fluorescently stained 2×10⁶ cAdMSCs were diluted in 200 µL of suspension and injected into the tail vein as a single bolus. The remaining groups included the following: group B with 5×10⁶ cells, group C with 3×10⁶ cells, group D with 1×10⁶ cells, group E with 1×10⁶ cells injected twice with a one-day interval, group F with 2×10⁶ cells in 100 µL of suspension, and group G with 2×10⁶ cells in 300 µL of suspension. Results: Group D achieved a 100% survival rate, while none of the subjects in groups B and C survived (p = 0.002). Blood tests revealed a tendency for the D-dimer levels to increase as the cell dose increased (p = 0.006). The platelet count was higher in the low cell concentration groups and lower in the high cell concentration groups (p = 0.028). A histological examination revealed PTE in most deceased subjects (96.30%). Conclusions and Relevance: PTE was verified, and various variables were identified as potential contributing factors, including the cell dose, injection frequency, and suspension volume.

• Journal of Microbiology and Biotechnology
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• v.6 no.2
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• pp.128-131
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• 1996

Lactobacillus acidophilus KFRI 233 (of human origin) exhibited a high tolerance to bile. The maximum cell yield was 6.6${\time}10^9 CFU$ per gram of whey in a 5.0% whey medium. Cell growth was improved with the addition of 0.5% thiotone and 0.25% calcium carbonate. Cell growth reached a maximum level of 5.4${\times}10^8$ CFU/ml at 20 h. Eighty-nine percent of the viable cells in the centrifuged concentrate survived freezing at $-70^{\circ}C$ and this frozen concentrate showed no reduction in the viable cell count after 30 days at $-70^{\circ}C$. Eight percent of the viable cells survived freeze-drying after the addition of 1 g/l sodium carbonate before harvesting by centrifuging and this freeze-dried concentrate showed only a slight reduction in the viable cell count after 30 days at $4^{\circ}C$.

• Journal of Physiology & Pathology in Korean Medicine
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• v.24 no.3
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• pp.401-409
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• 2010

This study was designed to investigate the effects of BojungIkkiTang-Gamybang freeze dried powder (BITG) on proliferauion, protective of cell death induced by chemicals such as paraquat, hydrogen peroxide etc and anti-oxidative effects in C6 glioma cells. In our results, BITC accelerated proliferation rates of C6 cells in vitro. In addition, protective effects on cell death induced by paraquat and hydrogen peroxide. And, BITC did not have effects on SOD and total glutathione activities, but decresed malone dialdehyde activity. In conclusion, these results suggest the possibility of BojungIkkiTang-Gamybang to protect brain cell or neuronal cell from damage induced by oxidative stress. And also suggest that related mechanisms are involved in malone dialdehyde activity.

• Korean Journal of Medicinal Crop Science
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• v.25 no.5
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• pp.315-321
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• 2017

Background: Glycyrrhiza uralensis Radix (GR) is a crude drugs used in Asian countries that has been reported to prevent the progression of neurodegenerative diseases such as Alzheimer's disease. The present study examined whether GR and its active compounds, glycyrrhizic acid (GA) and isoliquiritigenin (IL), exerted protective effects on $H_2O_2$-induced oxidative damage in C6 glial cells. Methods and Results: We exposed C6 glial cells to hydrogen peroxide ($H_2O_2$) for 24 h and investigated the cellular response to GR and its active compounds by evaluating cell viability, reactivie oxygen species (ROS) production, and apoptosis-related protein expression. GR successfully mitigated the reduced cell viability and ROS production induced by $H_2O_2$ in C6 glial cells, IL and GA significantly increased the cell viability and decreased ROS production. In addition, IL and GA down-regulated apoptotic Baxdependent caspase-3 activation, but each compound exerted different mechanisms, i.e., IL dose-dependently decreased ROS production and, GA up-regulated anti-apoptotic Bcl-2 expression. Conclusions: These results demonstrated that GR and its active components, IL and GA, exhibit potential for use as natural neurodegenerative agents for the modulation of apoptosis in C6 glial cells.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.14 no.11
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• pp.922-927
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• 2001

Single-layer green ELs was fabricated with using molecularly-dispersed Bu-PBD into poly-N-vinylcarbazole(PVK) which has low operating voltage and high quantum efficiency. A EL cell structure of glass substrate/indium-tin-oxide/PVK:Bu-PBD:C6(∼ 100nm)/Ca(20nm)/Al(20nm) was employed with variable doping concentration. The keys to obtain high quantum efficiency was excellent film forming capability of molecularly dispersed into PVK and appropriate combination of cathode for avoiding exciplex. We obtained the turn-on voltage of 4.2V and quantum efficiency of 0.52% at 0.lmol% of C6 concentration which has been improved about a factor of 50 in comparison with the undoped cell. The PL peak wavelengths wouldn\`t be turned by changing the concentration of the C6 dopant. Green EL emission peak and FWHM were 520nm and 70nm respectively. PL emission peak was obtained at 495nm.

• Transactions of the Korean hydrogen and new energy society
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• v.30 no.6
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• pp.523-530
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• 2019

For the low-Pt electrodes for polymer electrolyte fuel cells (PEMFCs), the optimization of ionomer content for anode catalyst layers was carried out. A commercial catalyst of 20 wt.% Pt/C was used instead of 50 wt.% Pt/C which is commonly used for PEMFCs. The ionomer content varies from 0.6 to 1.2 based on ionomer to carbon ratio (I/C) and the catalyst layer is formed over the electrolyte by the ultrasonic spray process. Evaluation of the prepared MEA in the unit cell showed that the optimal ionomer content of the air electrode was 0.8 on the I/C basis, while the hydrogen electrode was optimal at the relatively high ionomer content of 1.0. In addition, a large difference in cell performance was observed when the ionomer content of the hydrogen electrode was changed. Increasing the ionomer content from 0.6 to 1.0 by I/C in a hydrogen electrode with 0.05 mg/㎠ platinum loading resulted in more than double cell performance improvements on a 0.6 V. Through the analysis of various electrochemical properties in the single cell, it was assumed that the change in ionomer content of the hydrogen electrode affects the water flow between the hydrogen and air electrodes bounded by the membrane in the cell, which affects the overall performance of the cell. A more specific study will be carried out to understand the water flow mechanism in the future, and this study will show that the optimization process of hydrogen electrode can also be a very important cell design variable for the low-Pt and high-performance MEA.