• Journal of Technologic Dentistry
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• v.43 no.2
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• pp.35-41
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• 2021

Purpose: This study aimed to investigate the flexural strength and surface microstructure of the zirconia crown according to the number of glazing zirconia prostheses. Methods: The specimens were made as follows. A specimen without glazing: 1ea, first glazed specimens (group B): 10ea, second glazed specimens (group C): 10ea, third glazed specimens (group D): 10ea. Three-point measuring strength equipment and electron microscopes were used for strength measurement and microstructure observation. As for statistical analysis, one-way ANOVA and t-test (level of significance level=5%) were used to determine the difference in the change in flexural strength according to the number of glazing zirconia prostheses. Results: ANOVA analysis of groups B (1st glazing), C (2nd glazing), and D (3rd glazing) revealed that the change in strength between the groups is statistically significant (p=0.023). The Mann-Whitney test for each group revealed that the difference in flexural strength between groups B and C was not statistically significant (z=-0.302, p=0.762) while that between groups C and D was statistically significant (z=-0.257, p=0.01). Microstructure observation revealed 3 changes in the microstructure of the surface of the glaze powder were observed. Conclusion: According to the number of glazing zirconia prostheses, it was found that the difference in strength between groups was statistically significant, and changes in the microstructure were observed.

• Journal of Korean Society of Forest Science
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• v.73 no.1
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• pp.21-32
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• 1986

This study was done to classify 15 species in the genus Acer through tracking of the changing shape of the vascular branch from the base part to the terminal part of petiole by the anatomical method. The basic vascular branches were 3 ea, except A. mandshuricum 3-4 ea. The vascular bundle was separated, moved and connected from the base part to the terminal part of petiol, the number of separated vascular branch was 11-32 ea., the number of connected vascular branch was 0-17 ea., and the ratio of the separated vascular branch to the connected was 0.00-8.00. The maximum number of vascular branch in No, 39 of cross section part was observed in 12 species; A. ginnala and A. buergerianum were No. 11, A. truncatum and A. platanoides were No. 13, A. saccharium was No. 26. The number of the connected vascular branches with the main vascular branch were 0-6, while the number of the separated vascular branch were 0-7. On the ratio of separation to connection of the base vascular branch; "A", "B" and "C", the symmetrical shapes on the basis of "B" were A>BC, AB>C shape. The classical groups by the development of main vascular branch formation were obtained 7 groups of "a" through "g" shape. Especially, A. negundo and A. saccharinum were shown to have central vascular branches with unique changing patterns.

• Journal of Acupuncture Research
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• v.23 no.3
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• pp.77-90
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• 2006

Objectives : To evaluate the analgesic effect of electroacupuncture on Choksamni (ST36) in the collagen-induced arthritis rats and investigate the role played by serotonergic receptor subtypes $(5-HT_{1A},\;5-HT_{1B},\;5-HT_4)$ in the antinociceptive effect of electroacupuncture in the thermal hyperalgesia test. Methods : Immunization of male Sprague-Dawley rats with bovine type II collagen emulsified in incomplete Freund's adjuvant, followed by booster injection 14 days later induced collagen-induced arthritis (CIA). The thermal hyperalgesia was evaluated weekly with tail flick latency (TFL). In the fourth week after first immunization. EA stimulation (2Hz, 0.07mA, 0.3ms) was delivered into Choksamni for 20 minutes. We measured the analgesic effect of EA with TFL afer intraperitoneal injection of normal saline, WAYl00635, SB216641 and GR125487. Results : TFLs were gradually decreased in CIA as time elapsed after the immunization of arthrogenic collagen and the maximum value was reached from third to fifth week. EA stimulation on ST36 inhibited chronic inflammatory pain induced by CIA. The analgesic effect of EA was inhibited by pretreatment of $5-HT_{1A}$. antagonist (WAYl00635), $5-HT_{1B}$ antagonist (SB216641) and $5-HT_4$ antagonist (GR125487). Conclusion : Electroacupuncture has the analgesic effect on chronic inflammatory pain and its mechanism was mediated by $5-HT_{1A}$, $5-HT_{1B}$ and $5-HT_4$.

• Korean Journal of Pharmacognosy
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• v.45 no.3
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• pp.220-226
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• 2014

Diospyros lotus has been cultivated for its edible fruits and leaves which are considered for its medicinal importance. The aim of this study was to evaluate the anti-melanogenesis of ethyl acetate (EA) fractions from D. lotus leaves in B16 cells. The order of the total polyphenol content with regard to the different solvent fractions from D. lotus leaves was EA>butanol>metahanol>chloroform>n-hexane. The major compounds of EA fraction from D. lotus leaves by HPLC analysis were myricitrin and myricetin. Cellular TYR activity and melanin content in response to treatment with 100 mg/mL of EA fraction was inhibited more strongly than group treated with arbutin. Further, EA fraction exhibited significant anti-melanogenesis effects by reducing the levels of microphthalima-associated transcription factor (MITE), inhibiting the synthesis of TYR, tyrosinase-related protein-1 (TRP-1) and TRP-2. Therefore, EA fractions from D. lotus leaves may be a good source of skin-whitening agents in the future development of medicine-based trouble skin therapy.

• Journal of The Korean Association For Science Education
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• v.1 no.1
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• pp.1-14
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• 1978

The aims of this research are two-folds; tomake an outline of 15 experiments conducted by J.Piaget and to make an analysis of Piagetian understandiug level on child's conception of Movement and Speed. The finding of this study are as follows; 1) The outline reveals that all of the experiments(15EA.) were constructed logically under the bases of Cognitive Development i.e. Succession order or placing (2EA.), Change of location (4EA.) Qualitative Speed(6EA.), and Quantification of Speed (3EA.) etc. 2) The analysis indicates that the concept on Movement and Speed which children develop go through generally from the stage (1B) of late preoperation to the stage(3A) oarly formal operation.

• Archives of Pharmacal Research
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• v.18 no.6
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• pp.415-422
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• 1995

Twenty-four flavones were synthesized with various hydroxyl and/or methoxyl groups on A and B rings. Their antimutagenic properties were evaluated against ben:w(a)pyrene (BaP) and a pool of mutagenic urine concentrate (U) using a modified liquid incubation method of Ames test. The tester strain was Salmonella typhimurium TA98+S9 Mix. The antimutagenic activities were calculated by non linear regression analysis and the doses of flavones (in nmoles) required for a 50% reduction of induced revertants with BaP and U were defined as the inhibition doses (TEX>$ID_{508}{\;}and{\;}ID_{508}$ respectively). Seventeen flavones possessed significant antimutagenic activity against BaP. $ID_{508}$ ranged from 15.1 nmoles (F22) to 1000.6 nmoles (F13). Eighteen f1avones showed significant antimutagenic activity against U. $ID_{50U}$ ranged from 23.5 nmoles (F22) to 354.6 nmoles (F3). The 2',3',4'-trihydroxyflavone (F22, $ID_{508}=15.1$ nmoles, $ID_{50U}=23.5$ nmoles) and the 2',3',4',7-tetrahydroxyflavone (F20, $ID_{508}=37.8$ nmoles; $ID_{50U}=62.3$ nmoles) had antimutagenic activities similar to those of chlorophyllin ($ID_{508}=19.6$ nmoles and $ID_{50U}=44.2$ nmoles) and were evaluated against B(alP 7,8-dihydrodiol-9,10-epoxide. Against this last mutagen, the flavones which included three OH in B ring showed the highest activity and this property seemed independent of the substituent groups on A ring.

• Journal of the Korean Institute of Landscape Architecture
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• v.42 no.4
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• pp.1-9
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• 2014

This research aims to analyze changes in anion according to locations through changes in the measuring point centering on a single tree. The subject tree was the Zelkova serrata which is most widely used as a landscape tree, and the measurement was conducted for a total of 3 days with summer solstice as the basic date. In consideration of the solar altitude and the location of the Zelkova serrata, a total of 4 measurement points - $T_a$ at the opposite direction of the shadow, $T_b$ in the center of the tree $T_c$ in the center of the shadow, and $T_d$ at the end of the shadow - were established. The mean temperature of the measurement days was the highest at $T_a$ with $28.4^{\circ}C$ and was the lowest at $T_c$, in the center of the shadow with $27.9^{\circ}C$. The relative humidity was the lowest with 42.5% at $T_a$ where the temperature was the highest. The amount of insolation was the highest at $T_a$ with $1,024.6W/m^2$, followed by $T_d(701.48W/m^2$), $T_c$($215.63W/m^2$), and $T_b(227.75W/m^2)$, and the anion was the highest at $T_a$ with $654ea/cm^3$, followed by $T_d$, $T_c$, and $T_b$, with $639.4ea/cm^3$, $615.3ea/cm^3$, $612.3ea/cm^3$, respectively. The results of the correlation analysis proved that anion correlated with the temperature, the amount of insolation, and the relative humidity on the significant level. Of these, the temperature and the amount of insolation had the positive correlation with the correlation coefficients of .687 and .332, respectively, and the significance probability of .000, and .037, respectively. The relative humidity was found to have negative correlation. Its correlation coefficient and the significance probability were -.557, and .000, respectively.

• Korean Journal of Soil Science and Fertilizer
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• v.8 no.2
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• pp.69-80
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• 1975

Relationships between yield and various nitrogen efficiencies, between efficiencies and between efficiency and nitrogen uptake amount of rice plant were proposed and tested using data from N.P.K simple trials about 30 to 50 locations, for three years. Established relationships are well in accordance with experimental results by showing highly significant correlations between them. The overall indications are that high yielding capacity of fields with fertilizer application, depends primarily on high fertilizer nitrogen uptake by increasing fertilizer use efficiency (Eu), secondly the efficiency (Ef) of absorbed fertilizer nitrogen (Nf) and fertilization efficiency (Fe) and also depends much on nitrogen efficiency for grain yield (E) to great extend and that the efficiency (Es) of soil nitrogen (Ns) contributes to E more than Ef does. All nitrogen efficiencies are negatively correlated with the uptake amount of corresponding nitrogen and counterpart efficiency. Es and Ef could be determined firstly by difference method and secondly E versus Cs (Cs=Ns/Ns+Nf) plotting and thirdly E-Cs plotting with labelled fertilizermethod using the equation E=Es Cs+B where B=Ef Cf but a constant under the given condition and at last Y-Ns plotting with labelled fertilizer using Eq Y=$Es{\cdot}Ns+B$ where B=$Ef{\cdot}Nf$. Es which seems not much variable from field to field is mostly greater (about 80% of tested fields) than Ef which is much variable and depends much on fertilizer form. The relationships tested and well agreed are as follows: 1. Y=$Es{\cdot}Ns+Ef{\cdot}Nf$ (Y is yield) 2. E=$Es{\cdot}Cs+Ef{\cdot}Cf$ where Cf=Nf/Nf+Ns 3. E=b-aN where E=E, Es or Ef and N=N, Ns or Nf respectively, (E=Y/N, N=Nf+Ns), b is theoretical maximum under the given system and a is tangent at N=O of the curve, Y=EN. 4. Fe=Ef Eu and Se=$Es{\cdot}Eu$ where Se is efficiency of soil available nitrogen. 5. E=$(Se{\cdot}Cs+Fe{\cdot}Cf)/Eu$ 6. Y=$Es{\cdot}Eu{\cdot}Sf+Ef{\cdot}Eu{\cdot}Fn$or Y=$Es{\cdot}Eu{\cdot}Ea{\cdot}Sn+Ef{\cdot}Eu{\cdot}Fn $where Sf=$Ea{\cdot}Sn$, Ea is soil available nitrogen equivalent to fertilizer(Sf) divided by total soil nitrogen (Sn).

• Journal of the East Asian Society of Dietary Life
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• v.27 no.2
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• pp.235-242
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• 2017

In this study, we evaluated the polyphenol content, flavonoid content, antioxidant and biological of 70% EtOH extract and its fractions (dichloromethane, ethyl acetate and water) of the plant Chrysanthemum indicum L. (CI) belonging to family chrysanthemum. antioxidant activity was determined 1,1-diphenyl-2-picrylhydrazyl (DPPH), 2,2'-azino-bis-3-ethylbenzthiazoline-6-sulphonic acid (ABTS), and superoxide scavenging activity. The biological activity tests included measurement of ${\alpha}$-glucosidase and PTP1B. The results show that content of polyphenol and flavonoid in 70% EtOH of CI 30.20 mg and 31.58 mg, respectively. Among the different samples, ethyl acetate (EA) fraction showed the highest level of polyphenol (87.87 mg) and flavonoid (65.12 mg). The DPPH, ABTS and superoxide dismutase(SOD) antioxidant assay of EA fraction showed 93.84%, 93.38% and 84.68% inhibition respectively. The EA fraction also showed the highest antioxidant activity compared to 70% EtOH extract and other fractions. EA fraction ($20{\mu}g/mL$) showed the highest 30.29% and 99.24%, respectively compared to other samples. The results of this study show that the EA fraction contained more antioxidant and antidiabetic components than 70% EtOH extract and other fractions. In conclusion, we believe that CI may be useful natural antioxidant and functional material.

• Microbiology and Biotechnology Letters
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• v.47 no.2
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• pp.195-200
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• 2019

The purpose of this study was to investigate the melanogenesis inhibiting activity of the ethanol extract from Polygonum amphibium L. Firstly, the n-hexane (Hx), chloroform ($CHCl_3$), ethyl acetate (EA), n-butanol (BuOH), and water (Water) fractions were isolated from the P. amphibium L. ethanol extract. The efficacy of melanogenesis was found to significantly decrease via the EA and BuOH fractions when compared to the control in B16F10 cells. EA particularly showed the lowest melanin content in B16F10 cells when compared to all the other extracts. Concentration-dependent inhibition of melanin synthesis was also observed in the EA fraction at concentrations below $50{\mu}g/ml$, which did not exhibit cytotoxicity in B16F10 cells. Notably, the expression of three key proteins (tyrosinase, tyrosinase-related protein-1 (TRP-1), and TRP-2), which are involved in melanogenesis, were significantly decreased via the EA fraction. EA also inhibited body pigmentation in vivo in a zebrafish model. Overall, we demonstrated melanogenesis suppression using the EA fraction from P. amphibium L., which could be a potential candidate for an antimelanogenesis agent.