• The Korean Journal of Physiology and Pharmacology
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• v.24 no.1
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• pp.101-110
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• 2020

Transient receptor potential canonical 4 (TRPC4) channel is a nonselective calcium-permeable cation channels. In intestinal smooth muscle cells, TRPC4 currents contribute more than 80% to muscarinic cationic current (mIcat). With its inward-rectifying current-voltage relationship and high calcium permeability, TRPC4 channels permit calcium influx once the channel is opened by muscarinic receptor stimulation. Polyamines are known to inhibit nonselective cation channels that mediate the generation of mIcat. Moreover, it is reported that TRPC4 channels are blocked by the intracellular spermine through electrostatic interaction with glutamate residues (E728, E729). Here, we investigated the correlation between the magnitude of channel inactivation by spermine and the magnitude of channel conductance. We also found additional spermine binding sites in TRPC4. We evaluated channel activity with electrophysiological recordings and revalidated structural significance based on Cryo-EM structure, which was resolved recently. We found that there is no correlation between magnitude of inhibitory action of spermine and magnitude of maximum current of the channel. In intracellular region, TRPC4 attracts spermine at channel periphery by reducing access resistance, and acidic residues contribute to blocking action of intracellular spermine; channel periphery, E649; cytosolic space, D629, D649, and E687.

• Journal of the Korean Geosynthetics Society
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• v.16 no.4
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• pp.129-137
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• 2017

In this study, the prediction of landslide probability was performed to the study area located in ${\bigcirc}{\bigcirc}$ area of Muan-gun, Jeonnam Province around Honam railway using the computer program SHAPP ver 1.0 developed by a decision tree model. The soil samples were collected at total 8 points, and soil tests were performed to measure soil properties. The thematic maps of soil properties such as coefficient of permeability and void ratio were made on the basis of soil test results. The slope angle analysis of topography was performed using a digital map. As the prediction result of landslide probability, 435 cells among total 15,552 cells were predicted to be in the event of landslides. Therefore, the predicted area of occurring landslides may be $43,500m^2$ because the analyzed cell size was $10m{\times}10m$.

• The Journal of Korean Obstetrics and Gynecology
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• v.33 no.3
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• pp.60-79
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• 2020

Objectives: This review plans to assess the efficacy and effectiveness of oriental medicine for the treatment of Ovarian Hyperstimulation Syndrome (OHSS) through literature research and overview. Methods: Database searching was conducted to identify relevant randomized controlled trials (RCTs) on oriental medicine for the treatment of Ovarian Hyperstimulation Syndrome. Studies were searched from Journal of Korean Obstetrics and Gynecology, Korean Medical Database, Korean studies Information Service System, China National Knowledge Infrastructure, Cochrane library, PubMed and EmBase up to 21^st May, 2020. Results: Seventeen studies were finally selected. Fifteen studies intervened with oral Chinese herb medicine, two studies intervened with acupuncture and moxibustion. Nine studies concluded that intervention with oriental medicine significantly relieved OHSS symptoms. Three studies reporting ovary diameter, four studies reporting abdominal circumference and other four studies reporting pelvic effusion showed significant reduction compared to control groups. Six studies showed significantly shorter duration for hospitalization in intervention groups. Only one study showed significantly higher pregnancy rate. Factors related with vascular permeability and blood cell coagulation were significantly lowered in intervention groups in general. Conclusions: From seventeen studies, oriental medicine relieved OHSS symptoms and showed treatment effectiveness. Further strictly designed studies and long-term observed studies are needed to establish evidences.

• Bulletin of the Korean Chemical Society
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• v.27 no.5
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• pp.613-630
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• 2006

Nucleic acids are virtually omnipresent; they exist in every living being. These macromolecules constitute the most important genetic storage material: the genes. Genes are conserved throughout the evolution of all living beings; they are transmitted from the parents to their offspring. Many interdisciplinary research groups are interested in modifying nucleic acids for use in a wider variety of applications. These modified oligonucleotides are used in many diverse fields, including diagnostics, detection, and therapeutics. In this account, we summarize our research efforts related to modified nucleic acid systems. First, we discuss our syntheses of modified oligonucleotides containing fluorescent tags for use as molecular probes (molecular beacons) to detect single-nucleotide polymorphisim (SNP) in nucleic acids and to distinguish between the B and Z forms of DNA. We also describe our research efforts into oligonucleotides functionalized with steroid derivatives to enhance their cell permeability, and the synthesis of several calix[4]arene-oligonucleotide conjugates possessing the ability to form defined triplexes. In addition, we have performed systematic studies to have an understanding about the functional groups necessary for a given nucleoside to behave as an organo or hydrogelator. The aggregation properties of a number of nucleoside-based phospholipids have been examined in different solvents; some of these derivatives are potential candidates for use as nucleoside-based liposomes. Finally, we also describe our research efforts toward the preparation of isoxazole- and isoxazoline-containing nucleoside derivatives and the determination of their antiviral activities.

• Journal of the Korean Electrochemical Society
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• v.20 no.2
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• pp.41-48
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• 2017

Herein, we have fabricated an ultrathin aluminum oxide ($Al_2O_3$) coated PP separator by using a RF sputter deposition process. Approximately 20 nm thickness coating layer on the bare PP separator was formed at the power of 55 W for 2 minutes without thermal damage. Whereas only permeability of the coated separator was degraded slightly, other properties such as thermal stability, uptake amount of liquid electrolyte, and ionic conductivity were improved comparing to the bare PP separator. As a result, an only 20-nm-thick $Al_2O_3$ coating layer could improve the rate capability compared with a bare PP separator under a high current density.

• Journal of Physiology & Pathology in Korean Medicine
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• v.18 no.6
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• pp.1733-1739
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• 2004

The water extract of Hwangryunhaedog-tang(HRHDT} has been traditionally used for treatment of ischemic heart and brain damage in oriental medicine. However, little is known about the mechanism by which the water extract of HRHDT rescues cells from these damages. This study was designed to investigate the protective mechanisms of HRHDT on hypoxia-induced cytotoxicity in H9c2 cardiomyoblast cells. Hypoxia, markedly decreased the viability of H9c2 cells, which was characterized with apparent apoptptic features such as chromatin condensation as well as fragmentation of genomic DNA and nuclei. However, HRHDT significantly reduced hypoxia-induced cell death and apoptotic characteristics. Also, HRHDT prevented the mitochondrial dysfunction including the disruption of mitochondria membrane permeability transition (MPT) and an increase in expression of anti-apoptotic Bcl-2 proteins in hypoxia-H9c2 cells. Taken together, this study suggests that the protective effects of the water extract of HRHDT against hypoxic damages may be mediated by the modulation of Bcl-2 and Bak expression.

• Journal of Physiology & Pathology in Korean Medicine
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• v.18 no.5
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• pp.1418-1425
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• 2004

The water extract of Chongmyung-tang has been traditionally used for treatment of memory-disorder in oriental medicine. This study was designed to investigate the protective mechanisms of Chongmyung-tang on β-amyloid or H₂O₂-induced cytotoxicity in Neuro 2A cells. The water extract of Chongmyung-tang significantly reduced both β-amyloid or H₂O₂-induced cell death and apoptotic characteristics through reduction of intracellular peroxide generation. Also, it inhibited the mitochondrial dysfunction including the disruption of mitochondria membrane permeability transition(MPT) and the modulation in expression of Bcl-2 family proteins in H₂O₂-treated H9c2 cells. Furthermore, pretreatment of quercetin inhibited the activation of caspase-3, in turn, degradation of ICAD/DFF45 were completely abolished in H₂O₂-treated cells. Taken together, that data suggest that the protective effects of the water extract of Chongmyung-tang against β-amyloid induced oxidative injuries may be achieved through modulation of mitochondrial dysfunction.

• International Journal of Vascular Biomedical Engineering
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• v.3 no.2
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• pp.1-9
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• 2005

Flow-induced dilation of blood vessel is the result of a series of bioreaction in vascular endothelial cells(VEC). Shear stress change by blood flow in human artery or vein is sensed by the mechanoreceptor and responsible for such a chain reaction. The inositol(1,4,5)-triphophate($IP_3$) is produced in the first stage to elevate permeability of the intercellular membrane to calcium ions by which the cytosolic calcium concentration is consequently increased. This intracellular calcium transient triggers synthesis of EDRF and prostacyclin. The mathematical model of this VEC calcium dynamics is reproduced from the literature. We then use the Computational Fluid Dynamics(CFD) technique to investigate the blood stream dictating the VEC calcium dynamics. The pulsatile blood flow in a stenosed blood vessel is considered here as a part of study on thrombogenesis. We calculate the pulsating shear stress (thus its temporal change) distributed over the stenosed artery that is implemented to the VEC calcium dynamics model. It has been found that the pulsatile shear stress induces larger intracellular $Ca^{2+}$ transient plus much higher amount of EDRF and prostacyclin release in comparison with the steady shear stress case. It is concluded that pulsatility of the physiological shear stress is important to keep the vasodilation function in the stenosed part of the blood vessel.

• Korean Journal of Microbiology
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• v.37 no.3
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• pp.204-208
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• 2001

A technique for detection of Bacillus in soil and waste water treatment system was developed. Mixed col- tured solutions of 22 Bacillus strains were applied for selection of probe and pretreatment method for FISHAmong the three probes known as useful tool for FISH method,S-G-Bacill-0597-a-A-22 was best for detec-tion of Bacillus. Ninety five percent of DAPl count was observed with FISH method with S-G-Bacill-0597-a-A-22 probe. For increasing the permeability to Bacillus cell walls, pretreatment with lysozyme was betterthan that with lysozyme and SDS/DTT (dithiothreitol). Bacillus spore was not detected with FISH. So, Bacil-lus detection in ecosystem requires FISH with pretreatment of lysozyme and spore staining.

• The Korean Journal of Mycology
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• v.21 no.4
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• pp.285-292
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• 1993

For the enzymatic conversion of 5'-XMP to 5'-GMP, partially purified XMP aminase from Escherichia coli was coupled with the yeast, Saccharomycrs cerevisiae, capable of ATP regeneration through glycolytic pathway. In order to elevate the level of XMP aminase in E. coli, $guaB^{-}(IMP\;dehydrogenase-less)$ mutant were introduced, and the yeast used as ATP supplier was treated by some method to increase its membrane permeability. The optimum conditions for efficient conversion reaction by energy-coupled system were investigated. As the results, a CH 41, $guaB^-$ mutant of E. coli K-12, showed 2.75 fold increase in the level of XMP aminase, compared with its parent cell. And the lyophylized yeast was the most effective at the ATP supplier. The optimum temperature and pH of conversion reaction were $40{\circ]C$ and pH 7.4, and the highest conversion ratio was shown under the reaction condition of 100 mM glucose, 100 mM inorganic phosphate and 6 mM AMP. When 36 units/ml XMP aminase used under the above conditions, the amount of 60 mg/ml yeast was sufficient to be used. Under the optimum condition, 71% of 1.8 mM(65.6 mg/100 ml) 5'-XMP was converted to 5'-GMP within 8 hr.