• Economic and Environmental Geology
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• 제37권1호
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• pp.1-19
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• 2004

Metallic deposits in Korea have a variety of genetic types such as hydrothermal veins, skarns, hydrothermal replacement and alaskite deposits and so on. Geological, mineralogical and geochemical features including host rock, wall-rock alteration, ore and gangue mineralogy, mineral texture and secondary mineralogy related to weathering process control the environmental signatures of mining areas. The environmental signatures of metallic deposits closed from early 1970s to late 1990s in Korea show complicate geochemistry and mineralogy due to step weathering of primary and secondary minerals such as oxidation-precipitation-remobilization. The potentiality of low pH and high heavy metal Concentration s from acid mine drainage is great in base-metal deposits associated with polymetallic mineralization, breccia-pipe type and Cretaceous hydrothermal Au veins with the amount of pyrite whereas skam, hydrothermal replacement, hydrothermal Cu and Au-Ag vein deposits are in low contamination possibility. The geoenvironmental models reflecting the various geologic features closely relate to disuibution of sulfides and carbonates and their ratios and finally effect on characteristics of environmental signatures such as heavy metal species and their concentrations in acid mine drainage.

• Development and Reproduction
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• 제2권2호
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• pp.149-155
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• 1998

The polysialic acid (polySia) glycotope covalently modifies cell surface glycoconjugates on cells as evolutionarily diverse as microbes and human. The recent chemical identification of polysialylated glycoproteins in the jelly coat and on the cell surface of the sea urchin egg raises important questions about their biosynthesis and possible function. Using CMP-[$^{14}$ C]Neu5Ac as substrate and cell free preparations from eggs and embryos of the sea urchin Stronglylcentrotus nudus, we have identified a membrane associated CMP-Neu5Ac:poly-$\alpha$2, 8 sialosyl sialyltransferase (polyST) that transfers Neu5Ac to an endogenous acceptor. Optimal conditions for the polyST activity were found to be 2$0^{\circ}C$ in 20 mM MOPS buffer (pH 7.0). The polyST activity was increased 2.7 times by the addition of 10 mM $Mg^2$$^{+}$. The membrane-associated polyST also catalyzed the polysialylation of mammalian ganglioside GD3. Given that no structurally similar natural polysialylated gangliosides have been described, nor were observed in the present study, we conclude that a single polyST activity catalyzes sialylation of the endogenous acceptor and the gangliosides. Using an excess of GD3 as an exogenous acceptor, it was established that the expression of the polyST in S. nudus embryos increased rapidly at the mesenchyme blastula stage and reached at maximum at the gastrula stage. The finding that this polyST in the sea urchin embryo is developmentally regulated raises the possibility that it may play a role in the changing cell and tissue interactions that occur during gastrulation and the early stages of spicule formation.n.

• Applied Microscopy
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• 제39권2호
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• pp.125-132
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• 2009

Extracts and fractions of Inonotus obliquus (Chaga in Russia) have been known to have various biological activities, including antimutagenic, anticancer, antioxidative, and immunostimulating effects. This study was performed to confirm anticancer effect of 10% superfine Chaga mushroom processed by nano-mill technology on C57BL/6 mice. Chaga particles belonged in the size of 1 ${\mu}m$ was about 40% after nanomill processing according to the volume distribution. As the result of subcutaneous injection of B16BL6 melanoma cells to the mice, the tumor volume (p<0.001) and tumor weight (p<0.01) was significantly decreased in the experimental (NCh) group as compared with control (C) group and the tumor growth inhibitory rate was 29.2%. On examination of survival rate after intraperitoneal injection of B16BL6 melanoma cells, the mean survival time per a mouse was 17.7 and 26.0 days in C and NCh group respectively. The survival rate of NCh group was 40% when that of C group was 0% at the 35th day. On the result of examination to confirm histological toxicity by Chaga superfine particles, both groups did not show any morphological and pathological changes in the small and large intestine under the light microscope. These results suggest that feeding of superfine Chaga produced by nanomill technique has a tumor growth inhibitory effect in vivo.

• The Korean Journal of Food And Nutrition
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• 제25권4호
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• pp.922-929
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• 2012

This study was performed in order to investigate the quality characteristics of sponge cake made with Laminaria japonia powder. To evaluate the physical and sensory analysis, Laminaria japonia powder was added to wheat flour in various ratio (3, 5, 7, 9%, w/w). The specific gravity and loss rate increased with the addition of Laminaria japonia powder. The crude protein and ash levels in the sponge cakes increased linearly with the addition of 0~9 g of Laminaria japonia powder/100 g of wheat flour. For the crumb color values, lightness (L) and yellowness (b) decreased with the addition of Laminaria japonia powder, whereas redness (a) significantly increased (P<0.05). In the texture analysis, the hardness, gumminess and chewiness were increased; however, the cohesiveness and resilience were reduced by the addition of Laminaria japonia powder. When the sensory characteristics were evaluated, 5% Laminaria japonia sponge cake showed the highest sensory properties, except for color. Therefore, the results suggested that 5% Laminaria japonia sponge cake could be helpful in improving the physical quality as well as the taste.

• Development and Reproduction
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• 제14권2호
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• pp.83-89
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• 2010

Apoptosis is a crucial mechanism for the proper regulation of homeostasis. BCL-2 family proteins are key molecules which control cellular survival and apoptosis. MCL-1 (myeloid cell leukemia-1) is a pro-survival member of BCL-2 family that promotes the survival of cells, and is highly expressed in diverse cancers including ovarian cancer, leukemia, and cervical cancer. Previously we identified IEX-1 (immediate early response gene X-1) as a binding partner of MCL-1. In the present study, we demonstrated that overexpression of IEX-1 induced apoptosis of ovarian cancer cells. Moreover, IEX-1 significantly attenuated the pro-survival function of MCL-1 in these cells. Also, IEX-1-induced cell death activity was able to be modulated by changes in the expression level of MCL-1. Thus, these results suggest that both IEX-1 and MCL-1 modulate each other's function controlling cellular survival and death and the inhibitory activity of IEX-1 toward MCL-1 may be applied for the development of chemotherapeutics.

• Korean Journal of Environmental Biology
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• 제24권2호
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• pp.166-171
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• 2006

To elucidate the effect of phytoestrogens on the prevention of neurodegenerative disease in postmenopausal women, the expression of occludin which build up the blood-brain barrier was examined in hippocampus following oral administration of estrogen (E2), genistein, diadzein or combination of genistein and diadzein in ovariectomized (OVX) female rats. E2 significantly increased occludin mRNA level in OVX rat hippocampus, suggesting that estrogen is a physiological regulator for structural integrity of the blood-brain barrier in hippocampus. Following isoflavone diet for 4 weeks, there was significant increase in occludin mRNA level in hippocampus, suggesting that isoflavone diet may be effective for protection of structural integrity of blood-brain barrier in hippocampus from degenerative changes in estrogen deficiency.

• The Korean Journal of Pharmacology
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• 제32권3호
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• pp.373-380
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• 1996

Recently we reported that GS 386, 1-(4'-methoxybenzyl)-6,7-dimethoxy-3,4-dihydroisoquinoline, inhibited amplitude of the $Ca^{2+}$ current by reducing the probability of $Ca^{2+}$ channel opening without changing channel kinetics in isolated rabbit atrial myocyte. In the present study, further investigation of the mechanism of action of GS 386 was performed using isolated rat trachealis. GS 386 concentration-dependently relaxed rat trachealis contracted by carbachol $(0.3{\mu}M)$ and high $K^+$(65.4 mM) with $IC_{50}$ 5.24 and 5.67 ${\mu}M$, respectively. Verapamil inhibited more effectively the high $K^+-contracted$ tissues than those with carbachol in the rat trachealis muscle. In $Ca^{2+}-free$ media, $Ca^{2+}-induced$ contraction was inhibited by GS 386. Furthermore, high concentration of GS 386 $(100{\mu}M)$ but not verapamil, attenuated a phasic contraction induced not only by carbachol but also caffeine, indicating that GS386 can enter into the cytoplasm where it may exert secondary actions on internal sites of the muscle, such as sarcoplasmic reticulum. Moreover, GS 386 showed verapamil-resistant component of relaxation and increased cAMP levels in rat trachal smooth muscle. These results suggest that the mechanism of action of GS 386 attributes to not only $Ca^{2+}$ antagonistic action but also weak phosphodiesterase inhibitory action.

• Korean Journal of Food Science and Technology
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• 제18권2호
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• pp.130-136
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• 1986

'Shingo' pears were seal-packaged in polyethylene (PE) film with different thickness of 0.04. 0.06, 0.07, and 0.08mm and stored for five months in an experimental storehouse with the temperature varyine 0 to $7^{\circ}C$ and relative humidity varying 86 to 89%. The atmosphere in PE film bags was modified to 5-l4% oxygen with 3-5% carbon dioxide depending on the film thickness and the storage period. Packaging of pears with PE film effectively reduced the weight loss, which resulted in good appearance after 5 months' storage, while non-packaged pears showed a slight wilt. Decay occurrence was not significantly different among the treatments. but role browning occurred a little more in packaged lots than in non-packaged lot. The sensory panel rated the pears front 0.07mm-thick bag highest in flavor, texture, and juiciness, which might be due to the high sugar content and low titratable acidity. The firmness of pear flesh decreased with the stogare time and its change was found to be highly correlated with that of cellulase activity (correlation coefficient= -0.946). Thisresult indicated that cellulase might be one of the enzymes responsible for the softening of pear fruit during storage.

• Journal of Animal Science and Technology
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• 제44권4호
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• pp.483-490
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• 2002

The aim of this study was to determine if a low-molecular weight casein hydrolysate has an anti- hypertensive effect in spontaneously hypertensive rats (SHR). Prior to the in vivo experiment, the casein hydrolysate was confirmed to be resistant to gastrointestinal digestion by confirming the retention of its potency as an inhibitor of angiotensin I-concerting enzyme after incubation with pepsin, trypsin, or chymotrypsin. The in vivo anti-hypertensive effect of the hydrolysate was determined by the tail cuff method. Following an oral administration of the hydrolysate solution, the systolic blood pressure (SBP) decreased by 12.9% (－28.9mmHg; P<0.05) at 3 h after the administration at a dose of 500mg/kg body weight. When the hydrolysate was administered as an emulsion with 30% egg yolk, its anti-hypertensive effect was even more greater at the same dose(－30.8mmHg or －15.9%; P<0.01). In a 50-day long-term trial where the casein hydrolysate was administered once a day, the SBP-lowering effect of the hydrolysate was apparent (P<0.05) from day 35 through the end. Moreover, organ weights and plasma glutamate oxaloacetate transaminase and glutamate pyruvate transaminase activities of the administered SHR were not significantly different from those of controls at the end of the long-term trial.

• Journal of the Korean Ceramic Society
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• 제42권3호
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• pp.211-217
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• 2005

[ $Zn_{1-x}Co_{x}O$ (x=0-0.3) films were grown on Corning 7059 glasses by asymmetrical bipolar pulsed dc magnetron sputtering. The c-axis orientation along (002) plane was enhanced with increasing Co concentration. The $Zn_{1-x}Co_{x}O$ films are grown with fibrous grains of tight dome shape. The transmittance spectra measured from UV-visible showed that sp-d exchange interactions and typical d-d transitions become activated with increasing Co concentration. The electrical resistivity of $Zn_{1-x}Co_{x}O$ films increased with increasing Co concentration, especially it increased greatly at $30at\% Co. X-ray photoelectron spectroscopy and alternating gradient magnetometer analyses indicated that no Co metal cluster is formed and the ferromagnetic properties are exhibited. The low electrical resistivity and room temperature ferromagnetism of $Zn_{1-x}Co_{x}O$ thin films suggested the possibility of the application to Diluted Magnetic Semiconductors (DMSs).