• Korean Journal of Soil Science and Fertilizer
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• v.22 no.2
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• pp.146-155
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• 1989

A series of the experiments were conducted to evaluate the effects of the water-logging in continuous cropping soils of cucumber. Some of the results obtained from these experiments are summarized as follow: The values of pH in water-logged treatments were from 5.50 to 5.90. Those of EC were less than 0.3 mmhos/cm, were lower than those of control plot. The ratios of Ca/Mg, Ca/K, Mg/K respectively 2.5, 4.8, 2.0, were similar to the standard values. These changes were suitable for cucumber planting. And the number of bacteria among the microflora were determined increased from $10^6$ to $10^7\;cells/g$ dry soil, while that of the Fungi, Fusarium spp, Pythium spp, and Phythophthora spp decreased. In proportion to these changes of microflora, the ratios of B/F in water-logging plot were higher than in the control plot. The contents of Biomass-C were showed 10.47mg/100g soil to 36.12 mg/100g soil, and the contents of that in water-logging were more than in control plots.

• Sleep Medicine and Psychophysiology
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• v.18 no.1
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• pp.35-39
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• 2011

Objective: Diurnal preference is an attribute reflecting whether people are alert and preferring to be active either early or late in the day. It also referred to as chronotype or morningness-eveningness trait. The PER3 genes have been known to influence diurnal preference. In this study, we have investigated the associations between the PER3 gene polymorphisms and diurnal preference in a healthy young population, controlling for the social and environmental confounding factors. Methods: The participants in this experiment included 299 unrelated medical college students (M=191, F=108), with a mean age of 22.9 years. Diurnal preference was measured by a single administration of the 13-item Composite Scale for Morningness (CSM). Genotyping of the PER3 VNTR (rs57875989) was performed using polymerase chain reaction. A two-tailed alpha of 0.05 was chosen. Results: The mean${\pm}$SD score on the CSM scale for all subjects was 31.90${\pm}$6.39. There was no significant difference in total CSM score between gender groups, although females showed a trend towards higher morningness score. Although PER3 5R/5R showed the tendency towards high CSM scores, there were no significant differences on CSM scores among genotypes and allele status of PER3 VNTR (rs57875989). Conclusions: We could not confirm that the PER3 VNTR is associated with diurnal preference in a Korean healthy young population. The future studies need to investigate the association between diurnal preference and other polymorphisms of PER3 gene in larger sample of Korean young healthy population.

• Korean Journal of Materials Research
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• v.3 no.5
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• pp.459-465
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• 1993

By making the inter-metal PECVD $SiO_2$ as a Si rich oxide under the SOG, the hydrogen and water related diffusants could be captured a t SI dangling bonds. This gettering process was known to prevent the device characteristics degradations related to the H, $H_20$. The basic characteristics of Si rich oxide have been studied according to changing high/low frequency power and $SiH_4/N_2O$ gas flow ratio in PECVD. As increase in low frequency power, deposition rate decreased but K.I. and compressive stress increased. Decrease of the water peaks of FTIR spectra at the wave number range of 3300~3800$\textrm{cm}^{-1}$' also indicated that intensty the films were densified. As increase in SiH, gas flow rate, deposition rate, R.I. and etch rate increased while compressive stress decreased. F'TIK spectra showed that peak intensity corresponding to Si-0-Si stretching vibration decreased and shifted to the lower wave numbers. But AES showed that Si dangl~ng bonds were increased as a result of lower Si:O(l: 1.23) ratlo inthe Si rich oxide as compared to Si : O(1 : 1.98) ratio of usual oxide.

• Korean journal of applied entomology
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• v.53 no.1
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• pp.27-34
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• 2014

Entomopathogenic fungi were isolated from Bemisia tabaci in an Oriental melon field, and their growth characteristics, factors related to a natural outbreak, and infectivity against Bemisia tabaci, Tetranychus urticae, and Frankliniella intonsa were investigated. The isolates had erect conidiophores bearing whorls of 4-6 phialides with a swollen base where cylindrical conidia of $3.0-3.4{\mu}m$ were attached. The isolates were identified as Isaria fumosorosea on the basis of morphological characteristics and an ITS sequence with 99% similarity. I. fumosorosea IFs-08 grew well on Sabouraud dextrose agar+yeast extract medium(3.2 mm/day/$24^{\circ}C$); it grew better at $35^{\circ}C$ than at $15^{\circ}C$. The isolates of I. fumosorosea-IFs were highly infective and killed 93.9-96.7% B. tabaci, 84.9-92.0% T. urticae, and 81.5-84.4% F. intonsa in bioassay, whereas three isolates (Isaria tenuipes, Isaria farinosa, and Isaria fumosorosea) from KACC showed a low infectivity of 10-20%. To the best of our knowledge, this is the first report of I. fumosorosea isolated from B. tabaci in Korea.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.30 no.3 s.47
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• pp.409-414
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• 2004

Kojic acid is well known for its anti-pigmentation effect with tyrosinase inhibition activity. However, kojic acid is a unstable compound. In order to improve stability, kojic acid derivative, kojic acid $6-O-2',3',4',6'-tetraacetyl-{\beta}-D-glucopy-ranoside\;(KTGP)$, was synthesized with $O-pentaacetyl-{\beta}-D-glucose$ through the regio- and stereo-selective glycosylation of 6-OH group of kojic acid. High yield $(80\%)$ was obtained by the use of Lewis acid and organic base in nonpolar solvent. Hydrolysis of KTGP with the aid of sodium methoxide in methanol afforded kojic acid $6-O-{\beta}-D-glucopyranoside$ (KGP), which was confirmed by $^1H-NMR\;and\;^{13}C-NMR$ KGP is freely soluble in water and soluble in methanol and ethanol. Inhibition activity of KGP for tyrosinase was investigated by measuring the activity of mushroom tyrosinase compared with those of ascorbic acid, kojic acid, and arbutin. The free radical-scavenger activity was determined by the 1,1-diphenyl- 2-picrylhydrazyl (DPPH) assay. In toxicity assay, KGP was much less toxic than kojic acid and arbutin, Therefore, glycosylation of kojic acid may be useful for the development of stable kojic acid derivatives.

• Food Science and Preservation
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• v.18 no.4
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• pp.597-603
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• 2011

The in-vitro whitening and anti-wrinkle effect of ethanol extracts from apple flesh and peel were investigated. The EtOAc fractions from the ethanol extracts of apple flesh and peel showed in-vitro antioxidant activities in a dose-dependent manner on ABTS radical-scavenging activity and ferric-reducing/antioxidant power, and had the highest total phenolic contents (84.25 and 318.25 mg GAE/g). In addition, the EtOAc fractions generally showed strong UV absorption within the UV-B range. In the cellular system, the melanin synthesis of the B16/F10 melanoma cells was decreased by the EtOAc fractions of apple peel in a concentration-dependent manner. The EtOAc fractions of apple peel also showed a great elastase inhibition of 46.40% at 100 ${\mu}g$/mL, thus showing good in-vitro anti-wrinkle characteristics. These results suggest that the EtOAc fractions from the ethanol extract of apple peel can be used as whitening and anti-wrinkle agents as well as antioxidant resources.

• Korean Journal of Environment and Ecology
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• v.24 no.6
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• pp.735-743
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• 2010

In order to inspect growth responses of Fraxinus rhynchophylla Hance, Koelreuteria paniculata Laxmann, Quercus acutissima Carruther and Ulmus parvifolia Jacquin to NaCl treatment, NaCl solution was treated for four months with 0, 25, 50, 100 and 200 mM concentrations, then survival rate, change of relative growth rate, weight, dry weight and pigment content of leaf were investigated. According to NaCl treatment, pH and EC (electrical conductivity) of soil increased, and growth rates of four tree species fell apparently as treatment time became longer. U. parvifolia had the highest survival rate with 15% in the 200mM treatment, and the other three species withered in the treatment. Relative growth rate, weight and dry weight decreased when NaCl treatment time grew longer. The total chlorophyll declined after it rose to 60 days, and the total chlorophyll and carotenoid of the all species according to NaCl treatment did not change very much. With the result from anlayzing growth responses of four tree species to oxidative stress which occurs during NaCl treatment, U. parvifolia has the highest tolerance, followed by K. paniculata, F. rhynchophylla and Q. acutissima.

• Journal of the Korean Chemical Society
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• v.37 no.6
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• pp.599-603
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• 1993

Crystal structure of bis(1,2-diaminopropane)palladium(II) bis(oxalato)palladate(II) has been determined by X-ray crystallography. Crystal data: $Pd_2C_{10}H_{10}N_{4}O_{8}$, $M_W$ = 573.09, orthorhombic, space group $P_{ccn}$ (No = 56), a = 16.178(5), b = 16.381(6), c = 6.685(2)$\{AA}$, V = 1771.6 $\{AA}^3$, $M_W$W = 573.09, $D_c$ = 2.014 g${\cdot}c\;m^{-3}$, Z = 4, T = 294K, F(000) = 1056.0 and $\mu$ = 20.466 c$m^{-1}$. The intensity data were collected with $Mo-K\alpha$ radiation (${\lambda}$ = 0.7107 $\AA)$ on an automatic four-circle diffractometer with a graphite monochromater. The structure was solved by Patterson method and refined by full matrix least-squares methods using Pivot weights. The final R and S values were R = 0.065, $R_W = 0.059, R_{all}$ = 0.065 and S = 4.315 for 605 observed reflections. Both cation and anion complexes are essentially planar and have dihedral angle of $18(l)^{\circ}$ between thier planes. In the crystal structure, they do not have the Magnus's salt type mixed stacks; instead, the complex anions form regular stacks along the c-axis with the M-M bond length of $3.343(5)\AA$ and their stacks are surrounded by the complex cations through hydrogen bonds with the nitrogen-oxygen distances of 2.94(3) and $3.31(4)\AA.$

• Journal of Life Science
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• v.20 no.5
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• pp.736-744
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• 2010

The root of Playtcodon grandiflorum, called Platycodi radix, has been a favorite edible plant in Asia and contains a large amount of saponins. Melanoma cells (B16F10) were used to investigate the inhibitory effect of aged black Platycodi radix extract (ABPRE) on oxidative stress and matrix metalloproteinases (MMPs). Platycodon radix has been known to have a variety of medicinal effects such as prevention of gastric ulcers, antiallergenic activities, histamine release inhibition, and antioxidant effects. However, the mechanism of its action remains unclear in humans. ABPRE was prepared using ethanol extraction of aged black Platycodi radix. In an antioxidant effect study of ABPRE, it was observed that ABPRE specifically exhibited the scavenging activity of DPPH radical, but did not inhibit the production of malondialdehyde from lipid peroxidation. DNA oxidation was also blocked in the presence of ABPRE. In addition, ABPRE decreased the expression and activation of MMP-2 stimulated by phenazine methosulfate. Furthermore, ABPRE revealed the inhibitory effect on melanin production induced by L-dopa via antioxidant effect and the reduction of tyrosinase expression. Especially, the expression of antioxidant enzymes such as SOD-1 and SOD-2 regulated by Nrf2 was increased in the presence of ABPRE. Therefore, it appears that ABPRE may be a possible chemopreventive agent for the prevention of metastasis related to oxidative stress.

• Membrane Journal
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• v.16 no.1
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• pp.16-24
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• 2006

We report on the preparation and characterization of sulfonated polymer membranes containing perfluorocyclobutane (PFCB) units and fluorene units. The polymers were prepared through three synthetic steps, that is, the synthesis of a trifluorovinylether-terminated monomer, its thermal polymerization, and post-sulfonation using chlorosulfonic acid. A series of sulfonated polymers with different ion exchange capacity (IEC) were prepared by changing the content of chlorosulfonic acid during the post-sulfonation reaction. All the synthesized compounds were characterized by FT-IR, $^{1}H-NMR,\;^{19}F-NMR$, and Mass spectroscopy. As the content of chlorosulfonic acid increased, the SD, IEC, water uptake, and ion conductivity of the sulfonated polymer membranes increased. The sulfonated polymer 4 showed higher values of ion conductivity than the Nafion-$115^{\circledR}$ in a wide range of temperatures ($25{\sim}80^{\circ}C$).