• Journal of the Mineralogical Society of Korea
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• v.26 no.1
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• pp.19-25
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• 2013

Recent progress in Martian exploration identified hematite as the major candidate for the strong magnetic anomalies observed in Martian lithosphere. In the present study, grain-size dependence of thermoremanent magnetization and low-temperature stability of room-temperature saturation isothermal remanent magnetization (RTSIRM) were monitored using synthetic hematites. For hematite, the antiferromagnetic spin configuration is re-arranged from being perpendicular to the c-axis to be parallel to the c-axis below the Morin transition ($=T_M$). A large fraction of RTSIRM is demagnetized at $T_M$ (= 260 K) during zero-field cooling from 300 K to 10 K. About 37% of the initial RTSIRM is recovered on warming from 10 K to 300 K. Shallow Martian subsurface at 1~2 km depth would experience low-temperature cooling-warming of $T_M$ because average Martian surficial temperature is about 220 K. However in most Martian lithosphere whose temperatures are higher than 260 K, the very stable magnetic memory of hematite could be a contributor to Martian magnetic anomalies.

• Journal of the Korean Society of Food Culture
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• v.20 no.6
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• pp.703-708
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• 2005

This study was carried out to compare the antioxidant activities of the ether, butanol, water extracts from chestnut inner shell(Castanea crenata Sieb. et Zucc.) with those of tocopherol and BHA in soybean oil. All additives were added to soybean oil on the quantities of 0.02%. Comparing the antioxidant activities under autooxidation condition at $45.0{\pm}0.5$ for 42days of the extracts were recorded in the order of butanol>ether>control>BHA>tocopherol depending on the solvent. Under the condition at $60.0{\pm}0.5^{\circ}C$ for 32days, the butanol extracts represented the high antioxidation effect, however, there was no significant differences between the ether extracts and control. Under thermal oxidation condition, the ether extract showed stronger antioxidant activity than those of the butanol extract. In the results of polyphenol compound analysis, ellagic acid, quercetin, morin, naringenin, flavanol were included in the ether extracts and ellagic acid, naringenin, gallic acid, flavanol were included in the butanol extracts, respectively. Among them, ellagic acid in ether extract and gallic acid and naringenin in butanol extracts seed to increase the antioxidant activities in the substrate oil.

• Ecology and Resilient Infrastructure
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• v.8 no.3
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• pp.135-142
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• 2021

Biopolymers have been known as eco-friendly soil strengthening materials and studied to apply levees. However, the effect of biopolymer on vegetation is not fully understood. In this study, we analyzed the root growth of Camelina sativa L. (Camelina) when the xanthan gum was amended to soil in Aluminum (Al) stress conditions. Amendment of 0.05% xanthan gum increased root growth of Camelina under Al stress conditions. Under the Al stress condition, expression of aluminum activate malate transporter 1 (ALMT1) gene of Camelina root was induced but showed a lower level of expression in xanthan gum amended soil than non-amended soil. Additionally, the binding capacity of xanthan gum with Al ions in the solution was confirmed. Using morin staining and ICP-OES analysis, the Al content of the roots in the xanthan gum soil was lower than in the non-xanthan gum soil. These results suggest that xanthan gum amended soils may reduce the detrimental effects of Al on the roots and positively affect the growth of plants. Therefore, xanthan gum is not only an eco-friendly construction material but also can protect the roots in the disadvantageous environment of the plant.

• Archives of Pharmacal Research
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• v.16 no.1
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• pp.25-28
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• 1993

Our previous report demonstrated that certain flavonoid aglycones such as apigenin (flavone), quercetin, morin (flavonols), and biochanin A (isoflavone) showed in vivo antiinflammatory activity via topical and oral routes of adminstation. As a continual study, the various flavonoid glycosides have been evaluated in mouse ear edema assay using archidonic acid or croton-oil as a inflammagen. Flavonoids were orally administered (2 mg/mouse) and ear edema inhibition was measured. Significant antiinflammatory activities were found esepcially in flavone and flavonol glycosides (15-29% inhibition) although the flavonoid derivatives tested showed less antiinflammatory activity than hydrocortisone or indomethacin. Chalcone and flavanone derivatives were not significantly active. And in general, flavonol glycosides of kaempferol-type were found to have a higher oral antiinflammatory activity than that of flavonol glycosides of quercetin-type in mice.

• Journal of Sericultural and Entomological Science
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• v.34 no.2
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• pp.59-66
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• 1992

1-4령 저염인공사료 공동육＋5령 뽕잎육(농가개별육)$\longrightarrow$일주일 양잠에 적합한 광식성 누에품종육성에 필요한 기초지식을 얻기 위해 광식성유전자의 검색, 유전현상, 특성, 광식성계통 작출, 실용광식성 누에 품종육성방법 등에 대하여 소고하였다. 1. 광식성 유전자의 검색은 의잠을 사용하는 것이 가장 성력적이고 편리하며, 또한 섭식성을 정확히 파악할 수 있다. 2. 광식성 누에의 LP-1 사료에 대한 섭식성은 사육온도, 광조건, 발육단계 및 절식에 의하여 크게 영향 받지 않는다. 3. 광식성 유전자는 열성형질이며 1개의 주유전자와 수개의 수식유전자로 구성되어 있는 것으로 추찰된다. 4. LP-1 인공사료에 첨가한 morin 및 n-hexacosanol의 누에 섭식촉진효과는 미소하였으나, 상엽분말 첨가로 인한 누에 섭식촉진효과는 매우 양호하였다. 5. 광식성누에의 섭식성은 어분 및 효모에 의해 영향받지 않았다. 6. 섭식저해물질인 brucin 및 salicine은 정도의 차는 있으나 광식성누에의 섭식성을 저해하였다. 7. 광식성 및 비광광성누에의 LP-1 인공사료에 대한 섭식성의 차이는 누에의 두부에 있는 감각기관의 형태적 차이 때문이 아니라 기능적 차이에 기인하는 것으로 추찰된다. 8. 광식성 육성소재창출은 광식성유전자의 도입육종에 의해 가능하다. 9. 실용 광식성 누에품종육성을 위해 광식성검정에 적합한 인공사료를 사용하고, 실용형질이 우수하면서도 광식성유전자를 가진 계통을 선발, 교잡 또는 계통육성법에 의해 실용형질 및 섭식성을 개량하여 육종 목표를 달성하는 것이 최선책으로 생각된다.

• Archives of Pharmacal Research
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• v.14 no.2
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• pp.147-159
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• 1991

Effects of twenty-one different flavonoids and their related compounds on the phagocytosis of colloidal carbon by macrophages in liver and spleen humoral immune responses against bacterial $\alpha$-amylase and cellular immune responses against oxazolone and dinitrofluorobenzene were studied in vivo and in vitro. It was shown that most of the flavonoids accelerated significantly the phagocytosis, and they suppressed significantly not only humoral and cellular immune responses but also the development of immunological memory after the antigenic stimulation. Especially, malvin was the most active in phagocysis, and disodium cromoglycate and morin were the most active in humoral and cellular immunosuppression, respectively. Daidzuin had the most potent inhibitory activity in the development of memory cells. The structure-activity relationships of the flavonoids in immunosuppression became apparant from these results: 1. The presence of $C_{2-3}$ double bond and $C_4$ Ketone group in C-ring was important for their immunosuppressive activity. 2. Flavonoids with benzene ring at 2 or 3 position in C-ring showed the almost same activities. 3. The opening of C-ring did not affect their immunosuppressive activity. 4. The glycosylated flavonoids at 3 position in C-ring were less less potent than their aglycones. 5. Di-or tri-hydroxylated flavonoids in B-ring were more potent than mono-hydroxylated. 6. Chromanochromanone also had the immunosuppressive activity.

• Archives of Pharmacal Research
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• v.29 no.12
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• pp.1086-1090
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• 2006

The chromatographic separation of the MeOH extract from the twigs of Acer tegmentosum led to the isolation of ten phenolic compounds. The structures of these compounds were determined using spectroscopic methods as 3,7,3',4'-tetramethyl-quercetin (1), 5,3'-dihydroxy-3,7,4'-trimethoxy flavone (2), 2,6-dimethoxy-p-hydroquinone (3), (-)-catechin (4), morin-3-O-${\alpha}$-L-lyxoside (5), p-hydroxy phenylethyl-O-${\beta}$-D-glucopyranoside (6), 3,5-dimethoxy-4-hydroxy phenyl-1-O-${\beta}$-D-glucoside (7), fraxin (8), 3,5-dimethoxy-benzyl alcohol 4-O-${\beta}$-D-glucopyranoside (9) and 4-(2,3-dihydroxy propyl)-2,6-dimethoxy phenyl ${\beta}$-D-glucopyranoside (10). The compounds were examined for their cytotoxic activity against five cancer cell lines. Compound 3 exhibited good cytotoxic activity against five human cancer cell lines with $ED_{50}$ values ranging from $1.32\;to\;3.85\;{\mu}M$.

• Korean Journal of Pharmacognosy
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• v.30 no.1
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• pp.34-39
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• 1999

To search for less toxic antiherpetic agents, the inhibitory effects of twelve kinds of flavonoids including chrysin, quercetin, quercitrin, rutin, fisetin, gossypin, kaempferol, morin, naringenin, naringin, hesperetin and hesperidin on the plaque formation of herpes simplex virus type 1 (HSV-1) and type 2 (HSV-2) in Vero cells were examined by plaque reduction assay in vitro. Some flavonoids tested in this study showed potent antiherpetic activity, reducing intracellular replication of herpes simplex viruses when Vero cell monolayers were infected and subsequently cultured in medium containing flavonoids. Naringenin showed the most potent antiviral activity against HSV-1 with selectivity index (SI) of 19.1 and hesperetin showed the most potent antiviral activity against HSV-2 with SI of 9.8. These results suggest that some flavonoids may be a potential therapeutic agent for the treatment and prevention of herpes simplex virus infections.

• Proceedings of the Korean Society of Applied Pharmacology
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• 1995.04a
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• pp.128-128
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• 1995

To investigate the mechanism of the regulation of cytochrome P450IA1 gene expression, ethoxyresorufin deethylase(EROD) and benzo(a)pyrene hydroxylase in B6 mouse liver, in isolated perfused rat liver system. and in B6 mouse hepatocyte Hepa-I cells were examined. In C57BL/6N mouse, 3-methylcholan- throne( 3MC ) treatment have resulted in the stimulation of EROD activity based on fluorometry by 2.79 fold comparirng with that of control. Measurement of mRNA of cytochrome P450 was carried out by either nothern blot or dot blot analysis. Findings are similar to that of studies with enzymes. Furhtermore, when RTPCR method was applied to detect mRNA in Hepa I cell and liver tissues the results were more clear. Cytochrome P450IA1 upstream DNA containing CAT construct was transfected into Hepa-1 cells. After transfection of CAT construct, 3MC and flavonoids, such as, chrysin, hesperetin, kaempferol, morin, myricetin and aminoyrine were treated. 48 Hours after treatments, cells were harvested and assayed for CAT mRNA by RTPCR. 3MC treatment to hepa I cells transfected with trout P450IA1-CAT construct increased CAT mRNA by 2.81 fold when it was compared with that of control. This increase CAT mRNA was decreased by concomitantly treated flavonoids and aminopyrine. The level of CAT protein was 29.2-58.0% of 3MC stimulated CAT protein. Results of this study suggested that RTPCR seems to be a very good method to study regulation of gene expression in liver tissue or Hepa cells.

• Journal of the korean academy of Pediatric Dentistry
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• v.3 no.1
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• pp.12-17
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• 1976

The study is about the effect of tetracycline-HCl on the amelogenesis and the dentinogenesis of the albino rats by means of histochemistry and fluorescence microscopy. Females in oestrus were mated overnight and examined the next morning for evidence of copulation. The mothers were intraperitonealy injected with a single dose of tetracycline-HCl from the eighth to tenth day of gestation. The heads of new born rats were fixed in Carnoy's solution and 10% formalin solution. The staining methods were alizarin red S stain, PAS reaction, colloidal iron reaction, Morin's stain and hematoxylin-eosin stain, The results were as follows: 1. By the single injection of tetracycline, the matrix formation of enamel and dentin were disturbed, and the shape and arrangement of ameloblast and odontoblast were distorted. 2. It seemed that, with the higher dose of tetracycline, the positive materials of PAS reaction were increased in the disturbed enamel and dentin matrix, but those of alizarin red S stain and colloidal iron reaction were decreased. 3. The fluorescence intensity in the disturbed enamel and dentin matrix were higher than the other areas and appeared to increase gradually with the higher dose of tetracycline.