• Elastomers and Composites
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• v.50 no.4
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• pp.279-285
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• 2015

This study examined the mechanical properties and the flame retardant properties of CR rubber containing inorganic flame retardant with various contents of aluminium trihydroxide (ATH, $Al(OH)_3$). The content of aluminium trihydroxide was added in 0, 30, 50, 70 and 100 phr for T1~T5 samples. It was found that increasing the amount of addition over 30 phr resulted in decreasing the mechanical properties. On the other hand in oxygen index measurements T1 sample showed a value of 38.6%, indicating the improvement of flame retardant properties showed a value of 49.7~64.2%. In case of burn test, it was confirmed that CR rubber containing over ATH 50phr content showed performance corresponding to that of first grade fire-resistance.

• Toxicological Research
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• v.11 no.2
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• pp.229-234
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• 1995

This study was carried out to evaluate the cytotoxicity of cadmium on 3T3 fibroblast and to develop the antidote on 3T3 fibroblast which was injuried by $IC_{50}$ of cadmium. The groups for repaired effects were divided into 7 groups such as medium alone treated group. Cadmium treated $IC_{50}$ groups and 5 experimental groups $(IC_{50}$ cadmium plus $10^{-4}$ concentration of each methanol fraction). After incubation for 48 hrs in the same conditions, MTT (tetrazolium MTT), NR (neutral red) and SRB (sulforhodamine B protein) assay were measured. Light microscopic observations were also investigated. The ethyl acetate fraction of Perilla frutescens showed significantly repaired effect against cadmium cytotoxiclty and this fraction inhibited critical cell regeneration in light microscopy.

• Korean journal of applied entomology
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• v.44 no.1 s.138
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• pp.43-50
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• 2005

Parasitism of the egg parasitoid, Trichogramma evanescens, to its main host insect, the Asian corn borer, Ostrinia furnacalis in Korea was compared with that of T. ostriniae that is the dominant species in China on the same host insect. Parasitoid adults of both species emerged more than 50 percent within 4 hours after lights-on in 16L/8D photo period regime and showed a circadian rhythm of emergence. The developmental period from oviposition to emergence in both parasitoids was ca. 11 days and there were no significant differences between the two species and between female and male of each species, either. Both species also showed superparasitism even when the parasitic rates in one egg mass were below 100 percent. Both species oviposited by 5 days after emergence, and maximum longevities of each female adult of both species were 8 day for T. evanescens and 6 day for T. ostriniae. The total number of eggs parasitized by T. evanescens was ca. 38 eggs and ca. 31 eggs by T. ostriniae. Newly emerged female parasitoid laid eggs on about $50\%$ of the host insect egg mass, and the parasitism decreased with the adult age of egg parasitoids in both species. The sex ratio of two species was female-biased about $80\%$.

• Journal of The Korean Society of Grassland and Forage Science
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• v.28 no.4
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• pp.295-300
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• 2008

This experiment was conducted to compare forage production and feed value of winter forage crops at the experimental field of Livestock Division, National Institute of Animal Science from 2003 to 2004 in Jeju. The experiment was arranged in slit plot design with three replications. Main plots consisted of two cutting times, one time cutting and two times cutting. Sub plots consisted of 5 different seed combinations, T1 (Italian ryegrass), T2 (Oat), T3 (Italian ryegrass 25+Oat 75%), T4 (Italian ryegrass 50+Oat 50%), T5 (Italian ryegrass 75+Oat 25%). One time cutting showed the highest dry matter (DM) yield by 18,680 kg/ha. Tow times cutting showed the highest crude protein (CP) content by 11.97%. The all treatments have narrow range of total digestible nutrient (TDN) from 60.6% to 70.4%.

• Radiation Oncology Journal
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• v.14 no.3
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• pp.229-236
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• 1996

Purpose : To evaluate the changes of differential counts and lymphocyte subsets in cancer patients' leukocyte before and after radiotherapy. Materials and Methods : From Dec. 1994 to Mar 1995, the changes of leukocyte and its subsets in 16 patients who received radiotherapy in the Dept. of Radiation Oncology of Dong-A University Hospital were investigated. Radiation was delivered from 2700 cGy to 6660 cGy with median dose of 5400 cGy. The results of pre- and Post-radiotherapy were analyzed by paired T-test. The results of patients Who received < 50 Gy and $\geq$ 50 Gy were analyzed by Wilcoxon test. Results : Before and after radiotherapy, there was not any significant differences in the counts of leukocyte, granulocyte and monocyte. A remarkable decrease was noted in lymphocyte counts after radiotherapy(p=0.015). T cells, B cells and natural killer cells were also decreased in number after radiotherapy but it was not significant statistically. 1 helper cells and T suppressor cells were also decreased in number(p>0.05). The ratio of T helper/suppressor cell was decreased from 1.52 to 1, 11 and it was significant statistically(p=0.016). The portion of T suppressor cell among all T cells was increased after radiotherapy (p=0.0195). No significant difference was observed in the analysis of leukocyte and its subsets between patients who received < 50 Gy and $\geq$ 50 Gy, Conclusion : Radiotherapy caused remarkable decrease in lymphocyte count and its subsets. Among all lymphocyte subsets, T helper cell might be the most vulnerable to radiation, considering decreased ratio of T helper/suppressor cell count after radiotherapy.

• Asian Journal of Turfgrass Science
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• v.8 no.1
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• pp.1-11
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• 1994

Studies were conducted to evaluate the effect of priming and preimbibition on gerraination of unscarified and KOH-scarified zoysiagrass (Zoysia japonica Steud.) seeds, respectively. Germi-nation percentages at 35˚C of seeds primed in $KNO_3$ and Ca($NO_3$)$_2$ were significantly higher than that of untreated seeds. The optimum conditions for priming unscarified seeds were in aerated $KNO_3$ solution at O4 M for 4 days at 20˚C. No additional benefit of $GA_3$ on increasing germination was not found in seed priming with solution of $KNO_3$ + $GA_3$ or in seeds preimbibed with $GA_3$ after priming. Scarified seeds preimbibed with distilled water(DW) for 4 days at 20˚C germinated higher and with fewer days to 50% of total germination(T 50) than untreated seeds. Preimbibition with $GA_3$ solution at 50 ppm for 4 days at 5, 10, 15 and 20˚C enabled up to 97% of seeds to germinate and reduced days to T 50 about 1.1 to 1.2 days at 35˚C Especially, seeds preimbibed with $GA^2$˚$_3_2_1$$\times$ had greatly higher germination and lower T 50 than untreated or DW-preimbibibed seeds at 30˚C, which is inadequate to germination in general. Preimbibed seed performance was unchanged after storage at room temperature for 50 days. Seeds preimbibed with GA $_3$ had higher rate of seedling emergence and faster growth of shoot than untreated seeds after sowing at 30˚C in growing medium in growth chamber.

• Korean Journal of Microbiology
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• v.52 no.3
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• pp.344-351
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• 2016

A marine bacterium, designated as strain 50C-3, was isolated from a seawater sample collected from the East Sea of South Korea. The strain is a Gram-negative, aerobic, yellow colored polar-flagellated bacterium that grows at $20-50^{\circ}C$ and pH 5.5-8.5. Optimal growth occurred at $40-50^{\circ}C$, at pH 6.5-7.5, and in the presence of 2% (w/v) NaCl. Based on 16S rRNA gene sequence similarity, the isolate was considered to represent a member of the genus Ruegeria. The result of this analysis showed that strain 50C-3 shared 99.4% and 96.98% sequence similarity with Ruegeria intermedia CC-GIMAT-$2^T$ and Ruegeria lacuscaerulensis ITI-$1157^T$, respectively. Furthermore, strain 50C-3 showed clear differences from related strains in terms of several characteristics such as motility, carbon utilization, enzyme production, etc. The DNA G+C content was 66.7 mol%. Chemotaxonomic analysis indicated ubiquinone-10 (Q-10) as the predominant respiratory quinone. Based on phenotypic, chemotaxonomic, and phylogenetic characteristics, the isolate represents a novel variant of the Ruegeria intermedia CC-GIMAT-$2^T$, for which we named Ruegeria sp. 50C-3 (KCTC23890=DSM25519). Strain 50C-3 did not produce cellulase and agarase, but produced alkaline phosphatase, ${\alpha}$-galactosidase, and ${\beta}$-galactosidase. The three enzymes showed stable activities even at $50^{\circ}C$ and thus regarded as thermostable enzymes. Especially, the ${\beta}$-galactosidase activity enhanced by 1.9 times at $50^{\circ}C$ than that at $37^{\circ}C$, which may be very useful for industrial application.

• Biomolecules & Therapeutics
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• v.13 no.3
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• pp.138-142
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• 2005

Adenosine and GABA are known to be major inhitory neurotransmitters in the central nervous system and its receptors mediate various neurophamacological effects including cardiovascular modulatory effects. Inhibitory cardiovascular effects induced by intrathecal (i.t.) administration of adenosine $A_1$ receptor agonist and its modulation by cyclic AMP was suggested by our previous report. In this experiment, we examined the modulation of cardiovascular effects of adenosine $A_1$ receptor and adenosine $A_2$ receptor by $GABA_B$ receptors antagonist in the spinal cord. I.t. administration of 10 nmol of $N^6$-cyclohexyladenosine (CHA, an adenosine $A_1$ receptor agonist), I.t. administration of 2 nmol of 5'-(N-cyclopropyl)-carboxamidoadenosine (CPCA, an adenosine $A_2$ receptor agonist), pretreatment with 5-aminovaleric acid (a $GABA_B$ receptor antagonist, 50 nmol, i.t.) prior to administration of CHA and pretreatment with 5-aminovaleric acid (a $GABA_B$ receptor antagonist, 50 nmol, i.t.) prior to administration of CPCA were performed in anesthetized, artificially ventilated Sprague-Dawley rats. I.t. administration of 50 nmol of 5-aminovaleric acid significantly attenuated the inhibitory cardiovascular effects of CHA but did not attenuated the inhibitory cardiovascular effects of CPCA. It is suggested that cardiovascular responses of adenosine $A_1$ receptor is modulated by $GABA_B$ receptor and adenosine $A_2$ receptor is not modulated by $GABA_B$ receptor in the spinal cord.

• Journal of the Korean Institute of Telematics and Electronics
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• v.5 no.2
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• pp.8-14
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• 1968

A linear current-pulse discriminator consisting: of a transistor monostable multivibrator and a Si tunnel diode is described. The input currant pulse range is about 50$\mu$A~5.23mA. The measured maximum linearity deviation is $\pm$0.75% in the input current pulse range mentioned above. The pulse resolving ability of the discriminator measured depends upon the bias current through the T, D. ; and, under the reverse bias current of 3mA, the resolving time is 2rs if allow the excess pulse amplitude of 5%. The threshold stability of the discriminator depends mainly upon the stability of the peak current Ip of the T. D. ; and, under the ambient temperature variation from $0^{\circ}C$ to 5$0^{\circ}C$, no bigger threshold variation than the maximum linearity deviation, i. e. $\pm$ 0.75%, was observed.

• The Korean Journal of Zoology
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• v.6 no.2
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• pp.11-15
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• 1963

A total of 220 adult male mice (18-20g) of the S.M. strain were divided into ten experimental and control groups. The total-body X-ray irradiation doses used were 50 r, 100r, 200r, 400r, 600r, 800r, 1,000r, 1,200r, 1,400r, and1,600r. The respiratory arrest (mortality) caused by each irradiation doses were observed for 30 days. Relationships between irradiation doses and survival time and percentage of response were examined. From this experiment, a formula was obtained to express the relationship among three factors, which may be presented as follows : {{{{{{{{P= { 10} over { SQRT { 2 pi } } INT _{ - INF }^{ p'} e-{(p'-50)^2 } over {200 }dp···(a) p'=100 LEFT { t^0.3- LEFT ( { { 16.9965} over {D-60 } } RIGHT ) ^{ { 1} over {2.5 } } } / LEFT { LEFT ( { 26372.43} over {D-81.86 } RIGHT ) ^{ { 1} over {2.5 } } -( { { 16.9965} over {D-60 } } RIGHT ) ^{ { 1} over {2.5 } } ···(b) p= { (D-60) t^0.75-16.9965} over {0.2186 t^0.75 +263.55434 }····(c) }} {{{{P= { 10} over { SQRT { 2 pi } } INT _{ - INF }^{ p'} e-{(p'-50)^2 } over {200 }dp···(a) p'=100 LEFT { t^0.3- LEFT ( { { 16.9965} over {D-60 } } RIGHT ) ^{ { 1} over {2.5 } } } / LEFT { LEFT ( { 26372.43} over {D-81.86 } RIGHT ) ^{ { 1} over {2.5 } } -( { { 16.9965} over {D-60 } } RIGHT ) ^{ { 1} over {2.5 } } ···(b) p= { (D-60) t^0.75-16.9965} over {0.2186 t^0.75 +263.55434 }····(c)