• 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.

• Bulletin of the Korean Chemical Society
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• v.24 no.3
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• pp.369-376
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• 2003

Coulson (ZINDO), Mulliken $(MP2/6-31G^*)$ and Natural $(MP2/6-31G^*)$ population analyses of several large molecules were performed by the Fragment Reassociation (FR) method. The agreement between the conventional ZINDO (or conventional MP2) and FR-ZINDO (or FR-MP2) charges of these molecules was excellent. The standard deviations of the FR-ZINDO net atomic charges from the conventional ZINDO net atomic charges were 0.0008 for $C_{10}H_{22}$ (32 atoms), 0.0012 for $NH_2-C_{16}O_2H_{28}-COOH$ (53 atoms), 0.0014 for $NH_3^+-C_{16}O_2H_{28}-COOH$ (54 atoms), 0.0017 for $NH_2-C_{16}O_2H_{28}-COO^-$ (52 atoms), 0.0019 for $NH_3^+-C_{16}O_2H_{28}-COO^-$ (53 atoms), 0.0024 for a conjugated model $(O=CH-(CH=CH)_{15}-C=O-(CH=CH)_{12}-CH=CH_2)$, 118 atoms), 0.0038 for aglycoristocetin $(C_{60}N_7O_{19}H_{52}^+$, 138 atoms), 0.0023 for a polypropylene model complexed with a zirconocene catalyst $(C_{68}H-{121}Zr^+$, 190 atoms) and 0.0013 for magainin $(C_{112}N_{29}O_{28}SH_{177}$, 347 atoms), respectively. The standard deviations of the FR-MP2 Mulliken (or Natural) partial atomic charges from the conventional ones were 0.0016 (or 0.0016) for $C_{10}H_{22}$, 0.0019 (or 0.0018) for $NH_2-C_{16}O_2H_{28}-COOH$ and 0.0033 (or 0.0023) for $NH_3^+-C_{16}O_2H_{28}-COO^-$, respectively. These errors were attributed to the shape of molecules, the choice of fragments and the degree of ionic characters of molecules as well as the choice of methods. The CPU time of aglycoristocetin, conjugated model, polypropylene model complexed with zirconocene and magainin computed by the FR-ZINDO method was respectively 2, 4, 6 and 21 times faster than that by the normal ZINDO method. The CPU time of $NH_2-C_{16}O_2H_{28}-COOH\;and\;NH_3^+-C_{16}O_2H_{28}-COO^-$ computed by the FR-MP2 method was, respectively, 6 and 20 times faster than that by the normal MP2 method. The largest molecule calculated by the FR-ZINDO method was B-DNA (766 atoms). These results will enable us to compute atomic charges of huge molecules near future.

• Journal of Ginseng Research
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• v.47 no.2
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• pp.337-346
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• 2023

Background: Ginsenoside Rb2, a major active component of Panax ginseng, has various physiological activities, including anticancer and anti-inflammatory effects. However, the mechanisms underlying the rejuvenation effect of Rb2 in human skin cells have not been elucidated. Methods: We performed a senescence-associated β-galactosidase staining assay to confirm cellular senescence in human dermal fibroblasts (HDFs). The regulatory effects of Rb2 on autophagy were evaluated by analyzing the expression of autophagy marker proteins, such as microtubule-associated protein 1A/1B-light chain (LC) 3 and p62, using immunoblotting. Autophagosome and autolysosome formation was monitored using transmission electron microscopy. Autophagic flux was analyzed using tandem-labeled GFP-RFP-LC3, and lysosomal function was assessed with Lysotracker. We performed RNA sequencing to identify potential target genes related to HDF rejuvenation mediated by Rb2. To verify the functions of the target genes, we silenced them using shRNAs. Results: Rb2 decreased β-galactosidase activity and altered the expression of cell cycle regulatory proteins in senescent HDFs. Rb2 markedly induced the conversion of LC3-I to LC3-II and LC3 puncta. Moreover, Rb2 increased lysosomal function and red puncta in tandem-labeled GFP-RFP-LC3, which indicate that Rb2 promoted autophagic flux. RNA sequencing data showed that the expression of DNA damage-regulated autophagy modulator 2 (DRAM2) was induced by Rb2. In autophagy signaling, Rb2 activated the AMPK-ULK1 pathway and inactivated mTOR. DRAM2 knockdown inhibited autophagy and Rb2-restored cellular senescence. Conclusion: Rb2 reverses cellular senescence by activating autophagy via the AMPK-mTOR pathway and induction of DRAM2, suggesting that Rb2 might have potential value as an antiaging agent.

• Journal of the Korean Institute of Telematics and Electronics D
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• v.35D no.11
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• pp.70-77
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• 1998

Ni/SiC Schottky diodes have been fabricated using epitaxial 4H-SiC and 6H-SiC wafers. The epitaxial n-type layers were grown on $n^{+}$ substrates, with a doping density of 4.0$\times$10$^{16}$ c $m^{-3}$ and a thickness of 10${\mu}{\textrm}{m}$. Oxide-termination has been adopted in order to obtain high breakdown voltage and low leakage current. The fabricated Ni/4H-SiC and Ni/6H-SiC Schottky barrier diodes show excellent rectifying characteristics up to the measured temperature range of 55$0^{\circ}C$. In case of oxide-terminated Schottky barrier diodes, breakdown voltage of 973V(Ni/4H-SiC) and 920V(Ni/6H-SiC), and a very low leakage current of less than 1nA at -800V has been observed at room temperature. On non-terminated Schottky barrier diodes, breakdown voltages were 430V(Ni/4H-SiC) and 160v(Ni/6H-SiC). At room temperature, SBH(Schottky Barrier Height), ideality factor and specific on-resistance were 1.55eV, 1.3, 3.6$\times$10$^{-2}$ $\Omega$.$\textrm{cm}^2$ for Ni/4H-SiC Schottky barrier diodes, and 1.24eV, 1.2, 2.6$\times$10$^{-2}$$\Omega$.$\textrm{cm}^2$/ for Ni/SH-SiC Schottky barrier diodes, respectively. These results show that both Ni/4H-SiC and Ni/6H-SiC Schottky barrier diodes are very promising for high-temperature and high power applications.s..

• Korean Journal of Plant Tissue Culture
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• v.27 no.2
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• pp.89-94
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• 2000

In order to induce the mutants of Gentiana axillariflora Leveille, nodes were cultured on Schenk and Hilderbrandt (SH) medium containing TDZ 2 mg/L, BAP 2mg/L, GA3 0.5 mg/L and 0.1 mg/L NAA and each mutagen of ethylmethanesulfate (EMS), colchicine, N-methyl-N-nitrosourea (MNU), and sodium azide (NaN$_3$) through filtration. Comparision of morphological characteristics and survival rate in each mutant plants differed depending on mutagen sources and their concentrations. When EMS were treated on nodes, the regenerated plants was thin and albino, regenerated shoots appeared 'erectoides type' and get twisted. The case of colchicine were treated on nodes, the survival rate was from 84% to 97% at ail concentration after 30days but the rate of survival was decreased about 50% at 200 $\mu$M after 60days. The treatment of NaN$_3$200 $\mu$M was not survived. The survival rate was extremely decreased in MNU treatment at 500$\mu$M, according to concentrations two types of leaf characteristic were obtained. Type I of leaf characteristic was modified from oblanceolate to oboid at leaf shape and type II of leaf characteristic was modified from light green to dark violet at leaf color. RAPD analysis was carried out to check the genetic modification of regenerated plants by mutagen treatments. Three polymorphic DNA fragments out of thirty-seven obtained by RAPDs were observed in regenerated plants using 5 decamer primers.

• Journal of Embryo Transfer
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• v.16 no.1
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• pp.7-14
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• 2001

The aims of these study were to diagnose early pregnancy and reproductive disorders by using progesterone concentration and ultrasonography. The measurement of blood progesterone (P$_4$) concentration was conducted to diagnose pregnancy and to detect corpus luteum (CL) or evaluate disorder of CLs. As a result, the incidence rates of reproductive disorders were as follows : SH and EED (41.9%), inacitve ovaries (32.6%), follicullar cyst (9.3%), PCL (7.0%), endometritis (4.7%), pyometra (2.3%) and luteal cyst (2.3%). 61 Cows having P$_4$concentration 1.0 ng/ml(at the insemination) were increased to 1.0 ng/ml $\geq$ 6day after insemination. 50 cows among 61 cows were diagnosed pregnant. 8 cows among 13 HanWoos having P$_4$concentration 1.0 ng/ml at the insemination and 1.0 ng/mnl 6 day after insemination had non-ovulatory estrus and the others had P$_4$concentration 1.0 ng/ml at the insemination and 1.0 ng/ml $\geq$ 6 day after insemination, which was the error of estrus detection. All 13 cows were diagnosed non-pregnant. 47 cows diagnosed pregnant after insemination of P$_4$concentration 3.0 ng/ml were examined by ultrasonography at 30 day post-insemination. As a result, 41 cows were diagnosed pregnant (87.2%) but 14 cows having P$_4$concentration 3.0 ng/ml at 21 day after insemination was diagnosed to non-pregnancy. Calving intervals by surveying 100 cows were as follows 11~12 months (20%), 12~13 months (36%), 13~14 months (19%), 14 months $\geq$ (25%), respectively. In conclusion, hormone and ultrasonography help to detect reproductive disorders exactly and diagnose early pregnancy. This study suggest that diagnosis of early pregnancy and reproductive disorder by blood P$_4$concentration and ultrasonography improve reproduction management of HanWoo.

• Journal of dental hygiene science
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• v.16 no.5
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• pp.370-377
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• 2016

This study is conducted to provide a basis for effective management of bad breath with a poll in 155-scaling patients visiting the dental hygiene department of a university located in Gyeong-gi province after grasping the relevance among halitosis, xerostomia, and stress from them. Analysis was performed using PASW Statistics 18.0. The results of the halitosis measurements based on the general properties showed a significant difference in the hydrogen sulfide ($H_2S$) level depending on the patient's age; the highest level of 355.61 was observed in patients in their twenties followed by 227.85 in the fifties (p<0.001). The level was higher in cases with sinusitis or rhinitis (p=0.034). The $H_2S$ and $(CH_3)_2S$ levels showed are levant (r=0.492, p<0.01) correlation with the components of halitosis. Further, among other factors affecting breath odor, $(CH_3)_2S$ was shown to increase with increased stress. These results indicate that emotional factors, such as stress, should be considered when diagnosing patients with halitosis, and systematic and standardized diagnostic tools should be developed.

• Parasites, Hosts and Diseases
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• v.25 no.1
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• pp.59-68
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• 1987

An epidemiological survey on Metagonimus yokogawai infection was performed in the eastern coast area of Kangwon province. Formalin-ether concentration technique and Stoll's dilution egg counting method were employed to figure out the prevalence and intensity of M. yokogawai infection and eating habits of inhabitants with raw freshwater fish. The results are summarized as follows: 1. The prevalence rate of M. yokogawai infection was 6.6% among a total of 2, 357 examinees; 8.6% (115 out of 1, 345) in male and 4.0% (40 out of 1, 012) in female. 2. The prevalence rates were different by the streams where the examinees were residing: 17.8% along the area of Ohsip-cheon (stream), 11.8% along Maeup-cheon, 1.7% along Hwasang-cheon, 1.3% along Yeongok-cheon, 0.9% along Namdae-cheon, 0.9% along Sa-cheon and 0% in the other streams (Yongchon-cheon, Kangnung Namdae-cheon and Jusoo.cheon) in decreasing order. 3. By social strata, the positive rate was 8.0% (122 out of 1, 521) in general inhabitants and 3.9% (33 out of 836) in school children. 4. By the intensity of infection by means of EPG counts in feces; the light infection (less than 400/EPG) was 74.1%, moderate infection (401-1, 000/EPG) 17.3% and heavy infection (more than 1, 001/EPG) 8.6%. 5. Twelves out of 50 sweetfish (Plecoglossus altivelis) (24%) caught from the streams in eastern coast of Kangwon-Do were infected with metacercariae of M. yokogawai, and the number of larvae detected were 70.7 per 6sh in average. The metacercarial infection rates in fish were also different by the streams; 100% in Ohsip-cheon of Samcheok-Gun, 14.3% in Sa-cheon, 16.7% in Yeongokcheon of Myeongju-Gun and 0% in Namdae-cheon of Yangyang-Gun, respectively. 6. Six hundred ninety live (695) out of 1, 396 inhabitants and school children (49.8%) were experienced in eating raw freshwater fishes (Plecoglossus altivezis, Triboledon hakonensis, Coreoperca sp., Morose sp., Carassius sp. & Cyprinus sp. and Zacco platypus). The data were assayed with the questionnaire collected from the examinees. In summarizing the above results, it is known that the Ohsip-cheon area of Samcheok-Gun is highly infected region, and the other areas of Kangnung Namdae-cheon, Yeongok-cheon and Yangyang Namdae-cheon are very lowly infected or non-infected regions for M yokogawai infection.

• Resources Recycling
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• v.6 no.3
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• pp.15-21
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• 1997

Flyash from a coal-hed power plan1 is produced approximtcly 3 million tons m 1996 and causes the serious environmentalpmblem due to the disposal in the ash pond. Flyash is an accepted additive in concrete where it adds strength, sulfate ateresistanceand reduced cost, provided acccptablc levcls of unbunrned carbon are mmtmed This papzr describes to investigate thc technicalfeasibility of a dry triboelcctrostatlcp roccss to scparate unburned carbon h m f lyash into economically valuable produck Puliclesof unburned carbon and flyash can be impded positivc and negative surface charzes. rcapeclively. with a copper tniochargcr dueto dirferences in the work function values of thc particles and the tnbacharger. and cm he separated by passing thcm throuph anexternal electic field. A laboratory s d e separation system consists of r sacw feeder for ash supply, a tniocharger, verticalcollecling copper plates, power supplies, a flow meter, and a fan. Separation tests taking into account separahian efficiency and ashrecovery showed that flyash recovery was sh-nngly dependent an thc tnbocharger geomzhy, elect"c ficld strength. flyssh s ~ c a,n dash feeding late. Optimal separation conditions were flyash size less than 125 Fm and electric field shcngrh of 200 kV1m. Ovcr 80%of the flyash with 7% lass on ignition was recovered at wrbon contznts less than 3%bon contznts less than 3%

• Journal of Life Science
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• v.20 no.12
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• pp.1882-1888
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• 2010

To develop probiotics, a kind of Lactobacillus sp. was isolated from infant feces. The bacterium was identified as Lactobacillus rhamnosus through 16S rDNA sequence analysis. The strain was a facultative anaerobe which grew better in aerobic conditions. The bacterium lowered the pH of the culture solution down to 2.4 during 48 hr in the MRS medium. The strain inhibited the growth of 6 pathogens - S. aureus, L. monocytogens, S. typhimurium, E. coli O-157, V. parahaemolyticus and P. aeruginosa. When the Lactobacillus were fed to chickens, along with commercial feed, for one month, amounts of $H_2S$ and $NH_3$ in the feces of the chicken decreased to 50% and 70%, respectively, compared to those of control group chickens. Amounts of other bad smells such as $(CH_3)SH$, $(CH_3)_2S$ and $(CH_3)_2S_2$ were not much different in the Lactobacillus-fed chickens compared to the control group. On the other hand, egg weights of the chickens fed Lactobacillus were higher by about $5{\pm}1\;g$ than those in the control group.