• Asian-Australasian Journal of Animal Sciences
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• 제17권12호
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• pp.1635-1640
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• 2004

Two experiments were conducted to evaluate developmental gene expression of antimicrobial peptide PR-39 and effect of zinc oxide on gene regulation of PR-39 in piglets using semi-quantitative RT-PCR analysis. In experiment 1, fifteen female Tai-Hu pigs (a local breed in China) in five groups, each of three pigs at 1, 14, 28, 42 and 56 days of age were used to determine effect of age and weaning on mRNA expression of PR-39. In experiment 2, nine groups of pigs (total seventy-two female 36 days-age weanling Tai-Hu piglets) were assigned to three treatments (${ZnO}_0$, ${ZnO}_{100}$ and ${ZnO}_{3000}$). The feeding experimental period lasted 15 days. After feeding experiment, nine pigs with three animals in each treatment were chosen to determine the effect of ZnO on PR-39 mRNA expression of pigs. The results showed that PR-39 mRNA levels increased steadily in postnatal day 1-28 (preweaning), and weaning significantly decreased PR-39 mRNA expression of piglets (p<0.05). ${ZnO}_{3000}$ (3,000 mg zinc/kg diet) significantly increased PR-39 mRNA expression (p<0.05) when piglets were feed ${ZnO}_{3000}$ diet for 15 days. ${ZnO}_{100}$ (100 mg zinc/kg diet) also increased PR-39 gene expression, but the result was not statistically significant (p>0.05). The result was in accordance with the effect of ${ZnO}_{3000}$ and ${ZnO}_{100}$ on weight gain of piglets and prevention of diarrhea.

• 한국세라믹학회지
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• 제39권11호
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• pp.1023-1027
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• 2002

본 연구에서는 초임계 mixing을 이용하여 $SrTiO_3:\;Pr^{3+}$ 형광체 분말을 제조하였으며, 일반적 제조 방법인 고상법으로 제조된 분말과 발광특성을 비교하였다. 초임계 mixing에 의해 제조된 $SrTiO_3:\;Pr^{3+}$ 형광체 분말은 단상의 perovskite 구조를 갖으며, 형상은 구형인 좁은 입도분포를 보인다. 발광특성의 증대를 sensitizer인 $Al^{3+}$과 $Ga^{3+}$을 첨가하여 형광체의 발광특성을 관찰하였다.

• Journal of Ginseng Research
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• 제39권4호
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• pp.406-413
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• 2015

Background: Pathogenesis-related 10 (PR-10) proteins are small, cytosolic proteins with a similar three-dimensional structure. Crystal structures for several PR-10 homologs have similar overall folding patterns, with an unusually large internal cavity that is a binding site for biologically important molecules. Although structural information on PR-10 proteins is substantial, understanding of their biological function remains limited. Here, we showed that one of the PgPR-10 homologs, PgPR-10.3, shares binding properties with flavonoids, kinetin, emodin, deoxycholic acid, and ginsenoside Re (1 of the steroid glycosides). Methods: Gene expression patterns of PgPR-10.3 were analyzed by quantitative real-time PCR. The three-dimensional structure of PgPR-10 proteins was visualized by homology modeling, and docking to retrieve biologically active molecules was performed using AutoDock4 program. Results: Transcript levels of PgPR-10.3 expressed in leaves, stems, and roots of 3-wk-old ginseng plantlets were on average 86-fold lower than those of PgPR-10.2. In mature 2-yr-old ginseng plants, the mRNA of PgPR-10.3 is restricted to leaves. Ginsenoside Re production is especially prominent in leaves of Panax ginseng Meyer, and the binding property of PgPR-10.3 with ginsenoside Re suggests that this protein has an important role in the control of secondary metabolism. Conclusion: Although ginseng PR-10.3 gene is expressed in all organs of 3-wk-old plantlets, its expression is restricted to leaves in mature 2-yr-old ginseng plants. The putative binding property of PgPR-10.3 with Re is intriguing. Further verification of binding affinity with other biologically important molecules in the large hydrophobic cavity of PgPR-10.3 may provide an insight into the biological features of PR-10 proteins.

• 대한한방내과학회지
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• 제39권4호
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• pp.676-685
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• 2018

Objectives: The aim of this study was to estimate the single oral toxicity of Peucedani Radix (PR) ethanol extracts. PR is one of the important herbs for removal of phlegm, the viscous turbid pathological product that can accumulate in the body and cause a variety of diseases. However, research on the pharmacologic toxicity of PR is lacking. Methods: In this study, PR was orally administered to 5-week-old male ICR mice at an oral dose of 2,000, 3,000, or 5,000 mg/kg. After a single-dose administration, the mortality and behavioral changes were observed daily and body weights were measured every two days. After 14 days, the organ weight, organ index, macroscopy, hematological analysis, and serum biochemistry analysis were determined. Results: No mortality, body weight changes, abnormal behavioral changes, or anatomical signs of toxicity were found. The organ weight, organ index, hematological analysis, and serum biochemistry analysis were also within the normal ranges. Conclusions: These results suggest that the 50% lethal dose of PR is more than 5,000 mg/kg. This could indicate that PR is a safe drug without acute toxicity and side effects.

• Asian-Australasian Journal of Animal Sciences
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• 제21권7호
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• pp.936-940
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• 2008

The PCR-amplified prion protein (PrP) gene was sequenced to determine the frequency of scrapie-associated as well as novel PrP genotypes in 72 healthy goats representing five breeds. A total of six genotypes were detected, resulting from the three reported 143 (H/R), 154 (R/H) and 240 (S/P) and the two novel 39 (S/R) and 185 (I/F) amino acid polymorphisms. Of the four silent mutations 42 (a$\rightarrow$g), 138 (c$\rightarrow$t), 231 (c$\rightarrow$a) and 237 (g$\rightarrow$c) detected in this study, 237 (g$\rightarrow$c) is novel. A genotype (SIP/RFP) harboring three amino acid polymorphisms 39 (S/R), 185 (I/F) and 240 (S/P) was found in few goats. Although both scrapie-associated genotypes with 143 (H/R) and 154 (R/H) polymorphisms and others with 39 (S/R), 185 (I/F) and 240 (S/P) polymorphisms were present in the studied Pakistani goats, their frequency was lower than that of the wild-type genotype SHRIS/SHRIS (34.7%). These results emphasize the need for further sequencing of the PrP gene in a large number of goats representing the five studied breeds, so that overall PrP variability can be assessed in these breeds in research addressing future concerns about scrapie.

• 반도체디스플레이기술학회지
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• 제5권2호
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• pp.37-39
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• 2006

We employed in-situ spectroscopic ellipsometry(SE) and imaging ellipsometry(IE) to study the interaction of water and photoresist(PR) in 193 immersion lithography. Real time measurement of SE showed thickness increase when PR was immerged in water indicating swelling effect. From the temporal evolution we could observe its reaction-limited behavior. Meanwhile, IE could identify the modification of PR surface by contact of water even for a short period of a second.

• Toxicological Research
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• 제27권2호
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• pp.119-123
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• 2011

In this research, the genotoxic effect of Picrorrhiza Rhizoma (PR) aqueous extract was evaluated using the mouse micronucleus test. PR extract was administered once a day for 2 continuous days by oral gavage to male ICR mice at doses of 2000, 1000 and 500 mg/kg. Cyclophosphamide was used as a known genotoxic agent in a positive control. The appearance of a micronucleus (MN) in polychromatic erythrocyte (PCE) is used as an index for genotoxic potential, and PCE ratio is used as an index of cytotoxicity. Although significant (p < 0.01) increase of the number of PCE with one or more nuclei (MNPCE) was detected in cyclophosphamide treated groups, no significant increases of MNPCE numbers were observed in all three different dosages of PR extracts treated mice with over 0.39 of the individual polychromatic erythrocyte ratio in all mice used in this study. The results obtained indicated that PR extract shows no genotoxicity effects up to 2000 mg/kg dosing levels.

• Journal of Plant Biotechnology
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• 제39권3호
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• pp.169-174
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• 2012

Quantitative trait loci (QTLs), which were related to the ability of callus induction and plant regeneration in seed culture of rice, were analyzed using a mapping population from a cross between the rice cultivars 'Samgang' (tongil type) and 'Nagdong' (japonica). A tongil type rice cultivar, 'Samgang' showed lower frequency (20%) of plant regeneration than that (35%) of japonica rice, 'Nagdong'. Transgressive segregations were observed for the ability of callus induction and plant regeneration from the seed-derived calli of 58 doubled haploid (DH) lines. The ability of plant regeneration of 58 doubled haploid lines showed a continuous distribution with comparatively wide range (10.0 to 66.7%) of variation. Composite interval mapping analysis was used to identify the QTLs controlling callus induction and plant regeneration ability. Four significant QTLs, qCWS6, qCWS8, qCWS9 and qCWS11, associated with callus weight per seed were detected on chromosomes 6, 8, 9, and 11 with LOD values of 3.30, 2.60, 2.70 and 2.43, explaining 36% of the total phenotypic variation. Three significant QTLs, qPR1, qPR6, and qPR11, for the ability of plant regeneration were located on chromosome 1, 6, and 11 at LOD score of 2.25, 2.15 and 2.55, accounting for 24 % of the total phenotypic variation. The present study should be useful for improving the efficiency of plant regeneration in tissue culture of indica rice by means of marker-assisted selection.

• 천문학회보
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• 제39권2호
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• pp.74.2-74.2
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• 2014

Magnetohydrodynamics(MHD) dynamo depends on many factors such as viscosity ${\gamma}$, magnetic diffusivity ${\eta}$, magnetic Reynolds number $Re_M$, external driving source, or magnetic Prandtl number $Pr_M$. $Pr_M$, the ratio of ${\gamma}$ to ${\eta}$ (for example, galaxy ${\sim}10^{14}$), plays an important role in small scale dynamo. With the high PrM, conductivity effect becomes very important in small scale regime between the viscous scale ($k_{\gamma}{\sim}Re^{3/4}k_fk_f$:forcing scale) and resistivity scale ($k_{\eta}{\sim}PrM^{1/2}k_{\gamma}$). Since ${\eta}$ is very small, the balance of local energy transport due to the advection term and nonlocal energy transfer decides the magnetic energy spectra. Beyond the viscous scale, the stretched magnetic field (magnetic tension in Lorentz force) transfers the magnetic energy, which is originally from the kinetic energy, back to the kinetic eddies leading to the extension of the viscous scale. This repeated process eventually decides the energy spectrum of the coupled momentum and magnetic induction equation. However, the evolving profile does not follow Kolmogorov's -3/5 law. The spectra of EV (${\sim}k^{-4}$) and EM (${\sim}k^0$ or $k^{-1}$) in high $Pr_M$ have been reported, but our recent simulation results show a little different scaling law ($E_V{\sim}k^{-3}-k^{-4}$, $EM{\sim}k^{-1/2}-k^{-1}$). We show the results and explain the reason.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2001년도 추계학술대회 논문집 Vol.14 No.1
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• pp.467-471
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• 2001

DC accelerated aging characteristics of $Pr_{6}O_{11}$-based ZnO varistors, which are composed of $ZnO+Pr_{6}O_{11}+CoO+Cr_{2}O_{3}+Dy_{2}O_{3}$ ceramics were investigated with CoO content in the range of 0.5 - 5.0 mol%. The varistors doped with 1.0 mol% revealing maximum value(66.61) in the nonlinear exponent exhibited excellent stability, in which the variation rates of the varistor voltage, the nonlinear exponent and leakage current are -1.93%, -10.48%, and +288.79%, respectively, under DC accelerated aging stress, such as $(0.85V_{lmA}/115^{\circ}C/24h)+(0.90V_{lmA}120^{\circ}C/24h)+(0.95V_{lmA}/125^{\circ}C/24h)+(0.95V_{lmA}/150^{\circ}C/24h)$. Next the varistors doped with 2.0 mol% exhibiting the nonlinear exponent of 47.39 showed high stability.