• Journal of the Korea Concrete Institute
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• v.18 no.4 s.94
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• pp.449-458
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• 2006

The discharge of fly ash that is produced by coal-fired electric power plants is rapidly increasing in Korea. The utilization of fly ash in the raw materials would contribute to the elimination of an environmental problem and to the development of new high-performance materials. So it is needed to study the binder obtained by chemically activation of pozzolanic materials by means of a substitute for the cement. Fly ash consists of a glass phase. As it is produced from high temperature, it is a chemically stable material. Fly ash mostly consists of $SiO_2\;and\;Al_2O_3$, and it assumes the form of an oxide in the inside of fly ash. Because this reaction has not broken out by itself, it is need to supply it with additional $OH^-$ through alkali activators. Alkali activators were used for supplying it with additional $OH^-$. This paper concentrated on the strength development according to the kind of chemical activators, the curing temperature, the heat curing time. Also, according to scanning electron microscopy and X-Ray diffraction, the main reaction product in the alkali activated fly ash mortar is Zeolite of $Na_6-(AlO_2)_6-(SiO_2)_{10}-12H_2O$ type.

• The Korean Journal of Physiology and Pharmacology
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• v.1 no.3
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• pp.225-231
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• 1997

As it has been reported that the depolarization-induced norepinephrine (NE) release is modulated by activation of presynaptic $A_1-adenosine$ heteroreceptor and various lines of evidence indicate the involvement of adenylate cyclase system in $A_1-adenosine$ post-receptor mechanism in hippocampus, it was attempted to delineate the role of adenylate cyclase system in the $A_1-receptor-mediated$ control of NE release in this study. Slices from rat hippocampus were equilibrated with $[^3H]-NE$ and the release of the labelled products was evoked by electrical stimulation.(3 Hz, $5Vcm^{-1}$, 2 ms, rectangular pulses). The influence of various agents on the evoked tritium-outflow was investigated. $N^6-Cyclopentyladenosine$ (CPA), a specific $A_1-adenosine$ receptor agonist, in concentrations Tanging from 0.1 to $10{\mu}M$ decreased the $[^3H]-NE$ release in a dose-dependent mauler without any change of basal rate of release. 8-Cyclopentyl-1,3-dipropylxanthine (DPCPX, $2{\mu}M$), a selective $A_1-receptor$ antagonist, inhibited the CPA effect. The responses to N-ethylmaleimide $(3&10{\mu}M)$, a SH-alkylating agent of G-protein, were characterized by increments of the evoked NE-release and the CPA effects were completely abolished by NEM pretreatment. Forskolin, a specific adenylate cyclase activator, in concentrations ranging from 0.1 to $30{\mu}M$ increased the evoked and basal rate of NE release in a dose-dependent manner and the CPA effects were inhibited by forskolin pretreatment. Rolipram $(1&10{\mu}M)$, a phosphodiesterase inhibitor, did not affect the evoked NE release but reduced the CPA effect. And 8-bromo-cAMP $(100&300{\mu}M)$, a membrane permeable cAMP analogue inhibited the CPA effect significantly. These results suggest that the $A_1-adenosine$ heteroreceptor plays an important role in NE-release via nucleotide-binding protein $G_i$ in the rat hippocampus and that the adenylate cyclase system might be participated in this process.

• Journal of Physiology & Pathology in Korean Medicine
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• v.28 no.1
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• pp.29-34
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• 2014

Bone homeostasis is maintained by balance between bone resorbing-osteoclasts and bone forming-osteoblasts. Excessive osteoclastic bone resorption plays a critical role in bone destruction in pathological bone diseases such as osteoporosis, rheumatoid arthritis, and periodontal disease. Many compounds derived from natural products have pharmacological applications and have therapeutic value for treating or preventing several bone diseases characterized by excessive bone resorption. To discover new compounds that can act as anti-resorptive agents, we screened for natural compounds that regulate osteclast differentiation, and found that water extract of Ziziphus Jujuba Mill (WEZJ) has inhibitory effects on osteoclast differentiation. In this study, WEZJ clearly inhibits the osteoclast differentiation in the presence of receptor activator of nuclear factor kB (RANKL), macrophage colony-stimulating factor (M-CSF) without cytoxicity by blocking activation of nuclear factor of activated T cells (NFAT)c1, and c-Fos. In signaling pathway, the phosphorylation of Akt, p38, c-Jun N-terminal kinases (JNK), extracellular signal-regulated kinases (ERK) and the expression of osteoclast-associated receptor (OSCAR), tartrate-resistant acid phosphates (TRAP), Integrin av, Integrin b3, Cathepsin K are suppressed, too. These result suggest that WEZJ may have therapeutic value for treating or preventing several bone diseases characterized by excessive bone destruction.

• Journal of Life Science
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• v.18 no.12
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• pp.1679-1685
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• 2008

Conjugated linoleic acid (CLA) is a naturally occurring compound found in dairy and beef products. It has been shown to suppress cancer cells and to induce apoptosis. Practically, there is emerging evidence that CLA can inhibit chemically induced carcinogenesis in various tissues. However, the molecular mechanisms of CLA on human MCF-7 breast cancer cells have not been clearly explained yet. In this report, we investigated the anti-cancer activity of CLA in MCF-7 cells. It was found that CLA could inhibit the growth of the MCF-7 cells and induce apoptosis, through modulating AMP-activated protein kinase (AMPK) and cyclooxygenase-2 (COX-2). AMPK acts as a cellular fuel gauge and responds to decreased cellular energy status by inhibiting ATP-consuming pathways and increasing ATP-synthesis. CLA treatment with variable concentrations and different time of same-dose CLA on MCF-7 cells resulted in a strong activation of AMPK and an inhibition of COX-2 expression. It supports that CLA induces apoptosis in CLA-treated MCF 7 cells. Therefore, the effects of CLA induced COX-2 expression via activating AMPK can provide new possibility into the understanding the molecular mechanisms of anti-cancer component.

• Korean Journal of Food Science and Technology
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• v.21 no.4
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• pp.480-485
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• 1989

Changes of color intensity and components during browning reaction of water extracts from white tail ginseng were investigated. Temperature dependence was described by the Arrhenius relationship with an activation energy of 16kcal/mole. Temperature sensitivities$(Q_{10}\;value)$ for water extracts of ginseng was 1.90 between $70^{\circ}C\;and\;80^{\circ}C$, 1.57 between $80^{\circ}C\;and\;90^{\circ}C$ and 1.46 between $90^{\circ}C\;and\;100^{\circ}C$. pH value of the solution treated at $90^{\circ}C\;and\;100^{\circ}C$ slightly increased with an increase in reaction time. Among ginseng saponins ginsenoside-Re was most unstable against heat-treatment, white diol group saponins were more stable against heat-treatment. Hydrogen donating activity (reducing activity for ${\alpha},\;{\alpha}'-diphenyl-{\beta}-picrylhydrazyl$) and 3,5-dinitrosalicylic acid(DNS) positive substances of browning reaction products increased in proportion to the length of browning reaction time and temperature, whereas folin positive substances decreased by heat-denaturation of ginseng protein at initial reaction time and then increased thereafter.

• Korean Journal of Food Science and Technology
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• v.52 no.3
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• pp.263-273
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• 2020

In this study, in order to confirm the ameliorative effects of onion (Allium cepa L.) flesh and peel on amyloidbeta (Aβ)-induced cognitive dysfunction, we evaluated their in vitro neuroprotection and in vivo cognitive functions. As the result of in vitro neuroprotection, the protective effect of the ethyl acetate fraction of onion flesh (EOF) on Aβ-induced cytotoxicity was similar to that of the ethyl acetate fraction of onion peel (EOP). In the behavioral tests, the EOF and EOP effectively improved the Aβ-induced learning and memory impairments. For this reason, it could be concluded that the EOF and EOP improved the antioxidant activities (superoxide dismutase, oxidized glutathione/total glutathione, and malondialdehyde) in brain tissue. In addition, the EOF and EOP effectively activated mitochondrial functions by protecting the mitochondrial membrane potential, ATP, mitochondria-mediated protein (BAX and cytochrome c), and caspase 3/7 activities. The EOF and EOP also improved the cholinergic system (acetylcholinesterase and acetylcholine). Therefore, we suggest that onion could be used for management of Aβ-induced cognitive dysfunction.

• Korean Journal of Food Science and Technology
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• v.22 no.7
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• pp.852-857
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• 1990

The rheological properties and food functionality of the novel sugar derivatives, fructo-oligosaccharide, high maltose syrup(HMS), maltitol and sorbitol were examined and compared to those of sucrose. All samples tested showed Newtonian fluid property at the concentration range of 10% to the original concentrated products containing $69{\sim}81%w/w$ solid. HMS showed the highest viscosity. The viscosity increased(r=0.8038) as the average molecular weight of sugar derivatives were increased. The viscosity increased exponentially as the concentration increased, and sugar alcohols had lower value of the exponent compared to HMS and fructo-oligosaccharide. The viscosity of sugar derivatives solutions decreased by the increasing temperature following the Arrhenius equation. The flow activation energies of sorbitol and HMS were higer than that of sucrose. Substitution of sucrose with fructo-oligosaccharide in apple jam processing did not change the textural characteristics, but in redbean jelly(yanggaeng) it reduced the hardness, adhesiveness, springiness and cohesiveness. When sucrose was 100% replaced by HMS, the texture of apple jam and redbean jelly was not changed, but by mixing sucrose and HMS 1 : 1 ratio, the hardness decreased substantially The sugar alcohols reduced the hardness, adhesiveness, springiness of apple jam and redbean jelly significantly. Addition of fructo-oligosaccharide and HMS to sucrose did not influence the solidifying rate of candy, but sorbitol, even at 10% addition, retarded the candy moulding.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.43 no.5
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• pp.415-420
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• 2010

In Korea, oysters are used as an ingredient of Kimchi (Korean pickled cabbage) in early winter. Although viral contamination of oysters, including contamination by norovirus, can provoke gastroenteric illness, little is known of the epidemiological relationship to outbreaks. We postulated that Kimchi ripening can reduce the infectivity of norovirus, in order to test this hypothesis, we carried out a model experiment. Since norovirus is currently regarded as non-culturable, feline calicivirus (FCV) was used as a surrogate to examine the activation of norovirus with Kimchi ripening. In commercial well-prepared Kimchi, the infectivity ($TCID_{50}$) of FCV decreased by 2 log every 12 hours and reached the limit of detection after 48 hours during over-aging at $25^{\circ}C$. During storage at $4^{\circ}C$, the infectivity ($TCID_{50}$) of FCV decreased slowly and reached 5.00 $TCID_{50}$ after 48 hours. The low pH appears to affect the infectivity of FCV directly via organic acids produced by ripening during over-aging and storage. In neutralized lab-prepared Kimchi (pH 7.0), the infectivity ($TCID_{50}$) of FCV also decreased and reached the limit of detection after 72 hours at $4^{\circ}C$. This indicates that there are substances beside organic acids in Kimchi that originate from the raw materials and are produced during ripening. Among the raw materials, salt-fermented anchovies and garlic showed high direct antiviral activity. The main factor decreasing the infectivity of FCV in Kimchi was the high acidity caused by organic acids, regardless of the type, produced by ripening. Furthermore, unknown secondary products of microorganisms associated with Kimchi ripening and antiviral materials originating from raw material might contribute to the decreased infectivity of FCV, the surrogate of norovirus.

• Journal of the Korean Ceramic Society
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• v.40 no.10
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• pp.1005-1014
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• 2003

This paper examines the hydration and physical properties of alkali-blast furnace slag cement activated by Na$_2$SiO$_3$, Na$_2$CO$_3$, NaOH, Na$_2$SO$_4$. Four levels of Na$_2$O content in mixtures, 1, 3, 5, and 7 wt%, were investigated, and a W/S ratio 0.5 was used to prepare paste and mortar specimens. Compressive strength measurement of mortars was carried out adding alkali activated slag 30 wt% to OPC. The main hydration products with alkali activator kinds were C-S-H,C$_4$AH$\_$13/, AFt and Al(OH)$_3$ etc. For using Na$_2$CO$_3$ activated slag, hydration ratio of slag was higher than that of different activators, and Na$_2$SO$_4$ activated slag mortar appeared the highest compressive strength values at 28 days with activator content of 5 and 7 wt%.

• Clinical and Experimental Reproductive Medicine
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• v.25 no.2
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• pp.115-122
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• 1998

The maintenance of a viable pregnancy has long been viewed as an immunological paradox. The deveolping embryo and trophoblast are immunologically foreign to the maternal immune system due to their maternally inherited genes products and tissue-specific differentiation antigens (Hill & Anderson, 1988). Therefore, speculation has arisen that spontaneous abortion may be caused by impaired maternal immune tolerance to the semiallogenic conceptus (Hill, 1990). Loss of recall antigen has been reported in immunosuppressed transplant recipients and is associated with graft survival (Muluk et al., 1991; Schulik et al., 1994). Progesterone $(10^{-5}M)$ has immunosuppressive capabilities (Szekeres-Bartho et al., 1985). Previous study showed that fertile women, but not women with unexplained recurrent abortion (URA), lose their immune response to recall antigens when pregnant (Bermas & Hill, 1997). Therefore, we hypothesized that immunosuppressive doses of progesterone may affect proliferative response of lymphocytes to trophoblast antigen and alloantigen. Proliferative responses using $^3H$-thymidine ($^3H$-TdR) incorporation of peripheral blood mononuclear cells (PBMCs) to the irradiated allogeneic periperal blood mononuclear cells as alloantigen, trophoblast extract and Flu as recall antigen, and PHA as mitogen were serially checked in 9 women who had experienced unexplained recurrent miscarriage. Progesterone vaginal suppositories (100mg b.i.d; Utrogestan, Organon) beginning 3 days after ovulation were given to 9 women with unexplained RSA who had prior evidence of Th1 immunity to trophoblast. We checked proliferation responses to conception cycle before and after progesterone supplementation once a week through the first 7 weeks of pregnancy. All patients of alloantigen and PHA had a positive proliferation response that occmed in the baseline phase. But 4 out of 9 patients (44.4%) of trophoblast antigen and Flu antigen had a positive proliferative response. The suppression of proliferation response to each antigen were started after proliferative phase and during pregnancy cycles. Our data demonstrated that since in vivo progesterone treated PBMCs suppressed more T-lymphocyte activation and $^3H$-TdR incorporation compare to PBMCs, which are not influenced by progesterone. This data suggested that it might be influenced by immunosuppressive effect of progesterone. In conclusion, progesterone may play an important immunological role in regulating local immune response in the fetal-placental unit. Furthermore, in the 9 women given progesterone during a conception cycle, Only two (22%) repeat pregnancy losses occured in these 9 women despite loss of antigen responsiveness (one chemical pregnancy loss and one loss at 8 weeks of growth which was karyotyped as a Trisomy 4). These finding suggested that pregnancy loss due to fetal aneuploidy is not associated with immunological phenomena.