• Progress in Superconductivity and Cryogenics
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• v.15 no.3
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• pp.40-48
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• 2013

Cryoablation device is a surgical instrument to produce the cooling effect to destroy detrimental biological tissue by utilizing low temperature around 110 K. Usually, this device has the concentrated cooling region, so that it is suitable for concentrated and thick target. Accordingly, it is hard to apply this device for the target which is distributed and thin target. In this study, the design procedure of a closed-loop cryoablation device with multiple J-T expansion part is developed for the treatment of incompetent of great saphenous vein. The developed cyoablation device is designed with the analysis of 1-dimensional (1-D) bio-heat equation. The energy balance is considered to determine the minimum mass flow rate of refrigerant for consecutive flow boiling to develop the uniform cooling temperature. Azeotropic mixed refrigerant R410A and zeotropic mixed refrigerant (MR) of R22 ($CHClF_2$) and R23 ($CHF_3$) are utilized as operating fluids of the developed cryoablation device to form the sufficient temperature and to verify the quality of the inside of cryoablation probe. The experimental results of R410A and the zeotropic MR show the temperature non-uniformity over the range are $244.8K{\pm}2.7K$ and $239.8K{\pm}4.7K$ respectively. The experimental results demonstrate that the probe experiences the consecutive flow boiling over the target range of 200 mm.

• Bulletin of the Korean Chemical Society
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• v.35 no.12
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• pp.3459-3464
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• 2014

Synthesis and structural characterization of mercury(II) halides and perchlorate complexes (1-4) of bis-$OS_2$-macrocycle (L) are reported. L reacts with mercury(II) chloride and bromide to yield an isostructural 2D coordination polymers with type $[Hg(L)X_2]_n$ (1: X = Cl and 2: X = Br). In 1, each Hg atom which lies outside the cavity is six-coordinate with a distorted octahedral geometry, being bound to four adjacent ligands via monodentate Hg-S bonds and two remaining sites are occupied by two terminal chlorido ligands to form a fishnet-like 2D structure. When reacting with mercury(II) iodide, L afforded a 1D coordination polymer $\{[Hg_2(L)I_4]{\cdot}CHCl_3\}_n$ (3) in which each exocyclic Hg atom is four-coordinate, being bound to two sulfur donors from different ligands doubly bridging the ligand molecules in a head-to-tail mode. The coordination sphere in 3 is completed by two iodo terminal ligands, adopting a distorted tetrahedral geometry. On reacting with mercury(II) perchlorate, L forms solvent-coordinated 1D coordination polymer $\{[Hg_2(L)(DMF)_6](ClO_4)_4{\cdot}2DMF\}_n$ (4) instead of the anion-coordination. In 4, the Hg atom is five-coordinate, being bound to two sulfur donors from two different ligands doubly bridging the ligand molecules in a side-by-side mode to form a ribbon-like 1D structure. The three remaining coordination sites in 4 are completed by three DMF molecules in a monodentate manner. Consequently, the different structures and connectivity patterns for the observed exocyclic coordination polymers depending on the anions used are influenced not only by the coordination ability of the anions but also by anion sizes.

• YAKHAK HOEJI
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• v.41 no.2
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• pp.161-173
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• 1997

Tuber of Aconitum chiisanense(Ranunculaceae) a specific medicinal plant in Korea, which is known to have the activity to recover reduced metabolism of feeble patients and has been used to symptoms such as pain, paralysis, atonia and coldness of extremities, etc. were studied. The powdered tubers of the plant were extracted with 10% EtOH 3 times and the combined extract was dissolved in 1N HCl solution and washed with ethyl acetate. The aqueous layer was basified with solid $Na_2CO_3$ and extracted with $CHCl_3$ to obtain an alkaloidal fraction. The alkaloidal fraction was subjected to column chromatography using silica gel, alumina and Sephdex LH 20, etc. From the alkaloidal fraction, five diterpene alkaloids, mesaconitine, aconitine, hypaconitine, 8-O-ethyl 14-benzoylmesaconine and talatizamine, were isolated and identified on the basis of their physico-chemical properties and spectroscopic evidences($^1H$-, $^{13}C$-NMR, EI-MS, IR, 2D-NMR) respectively. Especially the Compound IV, 8-O-ethyl 14-benzoylmesaconine, was assumed to be an artifact resulting from mesaconitine during extraction procedures. The contents of mesaconitine, aconitine and hypaconitine in the mother tuber of this plant were 0.300%, 0.024%, and 0.068%. And that of the attached tuber(new one) of this plant were 0.336%, 0.034% and 0.240% respectively.

• Biomolecules & Therapeutics
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• v.4 no.4
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• pp.437-442
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• 1996

Hypoglycemic effect of Tabebuia avellandae was investigated in the streptozotocin(STZ)-induced diabetic rats. Diabetes was induced in male Sprague-Dawley rats by injections of STZ (45 mg/kg, i.v.). Rats weighing 200-250 g were divided into 6 groups: normal, STZ-control, hexane fr., CHCl$_3$fr., BuOH fr. and $H_2O$ fr. group. Normal and STZ-control rats received 3% Tween 80 only. Four groups of diabetic rats were administered orally at doses of 100, 400, 300 and 400 mg/kg/day of hexane, CHC1$_3$, BuOH and $H_2O$ fr. respectively. Fractions were administered orally to the rats for 7 days after STZ injection. All rats were anesthetized with ether, blood samples were taken by cardiac puncture for clinical chemistry and the rats were killed by exsanguination. Liver, kidney, heart and spleen were removed, weighed and analyzed. We measured glucose, protein, cholesterol and triglyceride levels in the plasma and glycogen, cholesterol and triglyceride levels in liver. The extent of blood glucose decrement in rats administered $H_2O$ fraction was greater than that in the STZ-control rats. The serum cholesterol and triglyceride levels were significantly lowered by administration of $H_2O$ fraction compared with those of STZ-control group. Treatment of rats with Tabebuia avellandae fractions caused decreases in STZ-induced elevation of cholesterol and triglyceride. Liver triglyceride level was significantly lowered hexane and BuOH fraction group compared with STZ-control group. These results suggest that $H_2O$ fraction of Tabebuia avellandae has the hypoglycemic action against STZ-induced diabetic rats.

• Natural Product Sciences
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• v.17 no.2
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• pp.117-122
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• 2011

We investigated the effect of Orostachys japonicus extracts on serum lipids, leptin and insulin level in hyperlipidemic rats. Also, diacylglycerol acyltransferase (DGAT) activity and thiobarbituric acid reactive substance (TBARS) were assessed. Inhibitory effect of DGAT related to triglyceride synthesis emerged approximately 96% in EtOAc fraction and showed 90% and 67%, respectively, in CHCl3 and BuOH fractions. Furthermore, the EtOAc and BuOH fractions inhibited 81% and 77%, respectively, in glycerol-3-phosphate acyl transferase (GPAT). Hyperlipidemia and obesity marker, contents of leptin and insulin on serum of hyperlipidemic rats, decreased 50% and 25%, respectively, compared with control group in treated EtOAc fraction. The oxidative stress marker, a concentration of TBARS, showed decrease of approximately 30% in treated EtOAc fraction. Moreover, high density lipoprotein (HDL)-cholesterol contents on serum of rats fed a hyperlipidemic diet were increased 10% and low density lipoprotein (LDL)-cholesterol decreased 50% as well as triglyceride amount of feces multiplied approximately two times more than control group in treated EtOAc fraction. The data suggest that the fractions of O. japonicus may be a potent biomaterial for treatment of hyperlipidemia or obesity.

• Applied Biological Chemistry
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• v.47 no.2
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• pp.274-278
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• 2004

Four anthraquinone derivatives were isolated from the root of Rumex japonicus Houtt. These compounds were identified as physcion, emodin, chrysophanol-10,10'-bianthrone and $physcion-10,10'-bianthrone^(a)$, respectively. The last compound (a), especially, showed strong activity against A549, PC-3, UO-31 and HCT-15 human cancer cell lines with $IC_{50}$ values, ranging from 0.45 to $1.33\;{\mu}g/ml^{-1})$.

• Korean Journal of Soil Science and Fertilizer
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• v.31 no.4
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• pp.392-399
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• 1998

Nitrogen fertilizers such as urea are readily hydrolyzed in soils to produce ammonium ions which pass through nitrification and denitrification processes. These serial processes have drawn attention due to nitrogen losses, eutrophication, blue baby syndrome, and ozone depletion problems. The purpose of this study was to test the inhibitory effects of hot-water extract and organic solvent fractions of Artemisia asiatica leaves on soil urea hydrolysis and nitrification. In addition, the effects of organic solvent fractions on urease activity and ureolytic bacterial population were also investigated. First, hot-water extract of Artemisia asiatica leaves inhibited soil nitrification substantially with a marginal stimulatory effect on soil urea hydrolysis. Soils treated with hot-water extract of Artemisia asiatica leaves showed significant decreases in the accumulation of soil $NO_3-N$ (~68% decrease) compared with the control soil without the treatment of hot-water extract. In contrast, $CHCl_3$/MeOH fraction and basic aqueous layer of Artemisia asiatica leaves inhibited soil urea hydrolysis very strongly, causing 5.8 and 4.3-fold higher accumulation in amounts of remaining urea-N compared with the non-treated soil. Meanwhile, non of the organic solvent fractions showed any significant effects on soil nitrification inhibition. The inhibition of ureolytic bacterial activity by $CHCl_3$/MeOH fraction and aqueous basic layer of Artemisia asiatica leaves without any effects on urease activity itself led us to conclude that the inhibitions of soil urea hydrolysis were caused by the antagonistic effects on ureolytic bacterial activity.

• Bulletin of the Korean Chemical Society
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• v.33 no.2
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• pp.443-448
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• 2012

Ferrocenyl chalcones (Fc-C(O)CH=CH-Ar: Fc-Ar) with mono- and di-1-naphthalenyl moieties (Fc-1Naph and Fc-d1Naph) were prepared and spectroscopically characterized. The enone bridge was in the s-cis conformation and the $\pi$-electrons on the C=C bond were further delocalized on the bridge. The naphthalenyl moiety deviates greatly from the enone-Cp plane by $26.9(1)^{\circ}$. Cyclic voltammetry measurements for Fc-1Naph exhibit one reversible cycle for the redox of the ferrocenyl moiety at a lower potential, and one irreversible oxidation peak at the higher potential region. For Fc-d1Naph, the cyclic voltammogram is more featureless. Fluorescence properties for both compounds are active in polar solvents with $\lambda_{em}$ = 500 nm (EtOH) and $\lambda_{em}$ = 512 nm (MeOH) for Fc-1Naph and $\lambda_{em}$ = 496 nm (EtOH) and $\lambda_{em}$ = 508 nm (MeOH) for Fc-d1Naph. The intensity of Fc-d1Naph is more than twice than that of Fc-1Naph. The fluorescence properties for both compounds are inactive in the less polar solvents such as $CH_3CN$, $CH_2Cl_2$ and $CHCl_3$.

• Korean Journal of Agricultural Science
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• v.45 no.3
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• pp.509-519
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• 2018

This study was investigated the anti-oxidant property and neuro-protective effect of Cirsium japonicum var. maackii (CJM) against oxidative stress in hydrogen peroxide ($H_2O_2$)-induced C6 glial cells. We measured the 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical, hydroxyl radical (${\cdot}OH$), and superoxide ($O_2{^-}$) radical scavenging activities of an ethanol extract and four fractions [n-Butanol, ethyl acetate (EtOAc), $CHCl_3$, and n-Hexane] from CJM. The results of this study show that the extract and all fractions from CJM had a dose-dependent DPPH radical scavenging activity. In particular, the EtOAc fraction exhibited the strongest scavenging effect with 88.23% at a concentration of $500{\mu}g/mL$. In addition, the EtOAc fraction from CJM also effectively scavenged ${\cdot}OH$ radicals and $O_2{^-}$ radicals, compared to other extract and fractions. In C6 glial cells, $H_2O_2$ markedly decreased the cell viability as well as increased lactate dehydrogenase (LDH) release and reactive oxygen species (ROS) production. However, the EtOAc fraction of CJM attenuated the cellular damage from the oxidative stress by elevating the cell viability and inhibiting the LDH release and ROS over-production compared with the $H_2O_2$-treated control group. Our findings indicate that the EtOAc fraction from CJM has antioxidant effect and neuro-protective effect against oxidative stress, suggesting that it can be used as a natural antioxidant and therapeutic agent for the prevention of neurodegenerative disorders.

• The Korean Journal of Mycology
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• v.45 no.3
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• pp.175-187
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• 2017

Laetiporus sulphrueus var. miniatus is widely distributed worldwide, and has commonly been used as a medicinal mushroom. In the present study, we investigated the effects of water extract and solvent fractions from the Laetiporus miniatus as possible antioxidant, anti-thrombin and anti-invasive agents against phorbol 12-myristate 13-acetate (PMA)- or thrombin-induced matrix metalloproteinase-2 (MMP-2) and MMP-9 activities. Samples were fractionated into n-hexane, $CHCl_3$, ethyl acetate, n-butanol, and water fractions, and individually analysed. The water fraction had the highest extraction yield at 34.90% (w/w), while the n-butanol fraction demonstrated the highest anti-oxidative activity at 81.44%. In the thrombin inhibitory activity test, the water fraction exhibited the highest activity at 94.64%. Even at the concentration of $40{\mu}g/mL$, evaluation of anti-proliferating activity in YD-10B cells did not reveal any cytotoxic effects. Although MMP-9 expression in YD-10B cells increased after the addition of PMA and thrombin, MMP-2 did not. Additionally, MMP-2/-9 levels in PMA-treated YD-10B cells (i.e., both mRNA expression and protein activation) were highly inhibited in the hexane and chloroform fractions. Compared with MMP-2 levels, MMP-9 mRNA expression and proteolytic activity were inhibited to a greater extent by the hexane and chloroform fractions in thrombin-treated YD-10B cells. Taken together, these results support that thrombin induces tumor invasion through MMP-2/9 and suggest that the L. miniatus may act as an effective functional food, conferring anti-oxidative, anti-thrombotic and anti-cancer activities.