• Journal of the Korea Institute of Information and Communication Engineering
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• v.10 no.10
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• pp.1737-1743
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• 2006

OCR(On channel repeater) provides the high frequency reuse efficiency for allocating frequency bands to repeaters because the frequency of input and output signals of OCRs is the same. However the oscillation probability of OCRs is high due to the same input and output frequency. In order to prevent a repeater from oscillating, we must keep the antenna isolation higher than the gain of the repeater with a some margin. In this paper we simulated the effects of the amplitude, phase and time delay of feedback signals (m the characteristics of non-regeneration OCR. Simulation results show that the highest probability of oscillation is occurred when the gain of a repeater is the same value of the isolation. From the simulation results, we know that the phase of feedback signals can be adjusted to reduce the possibility of oscillation if a non-regeneration repeater has a narrow operation bandwidth or a signal bandwidth is narrow. As the time delay increases, the probability of oscillation and the fluctuation of gain over a certain frequency band increase also. The effects of the amplitude and phase of feedback signals on S/N of 8-VSB signal for generation and non-generation repeater were tested. The measured results show that the set-top can receive 8-VSB signal when the received signal power is $17{\sim}18dB$ higher than the noise power. When the isolation is almost same as the gain of the repeater, then the set-top can not receive 8-VSB signals due to the oscillation of the repeater. And the phase of feedback signals affects S/N at the output of the repeater when the isolation is $11.75{\sim}13.75dB$ larger than the gain of the repeater. In this case the set-top can not receive 8-VSB signal of at $48^{\circ}\;and\;347^{\circ}$ of the phase of feedback signals. However the phase of feedback signals can not affect the S/N of 8-VSB signals of the generation repeater because of the demodulation and modulation process of the generation repenter. The set-top can not receive 8-VSB signals when the amplitude of feedback signals is $12.6{\sim}13.6dB$ larger than the wanted signal power at the input port of the repeater. It's because that the amplitude of feedback signals saturates the front end of the repeater.

• Clinical and Experimental Pediatrics
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• v.46 no.7
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• pp.702-709
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• 2003

Purpose : $IFN{\gamma}$ sentitizes many tumor cells to $TNF{\alpha}$ and FASL-mediated apoptosis by enhancing the expression of TNF or FAS/CD95 receptor and modulating the activation of caspase and Bcl-2 family. It has been reported that $IFN{\gamma}$ and $TNF{\alpha}$ synergistically caused differentiation and growth inhibition of neuroblastoma cells. Even though some neuroblastoma cell express FASR/FASL on the cell surface, they could not induce apoptosis by ligation of the FAS/CD95 receptor. But the treatment of $IFN{\gamma}$ is reported to induce apoptosis in some neuroblastoma cell lines through the CD95/CD95L autocrine circuit. In this study, we examined whether $IFN{\gamma}$ could affect $TNF{\alpha}$ and agonistic FAS/CD95 antibody(CH-11)-induced apoptosis against neuroblastoma cell lines that had shown diverse drug sensitivity and resistance. Methods : CHLA-15, CHLA-90 and LA-N-2 neuroblastoma cells were cultured in IMDM and treated with recombinant $IFN{\gamma}$, $TNF{\alpha}$ and CH-11 antibody. Cell viability was measured by DIMSCAN with a fluorescent calcein-AM. Apoptosis was analyzed through flow cytometry using Annexin V-PE and 7-ADD staining and confirmed by pancaspase and caspase-8 blocking experiments. The expression of TNF RI and FAS/CD95 receptor was evaluated by flow cytometry using the corresponding antibody and PE-conjugated secondary antibody. Results : $IFN{\gamma}$ or $TNF{\alpha}$ alone had no demonstrable cytotoxic effects, whereas both cytokines in combination induced apoptosis synergistically in CHLA-15 and CHLA-90 cells. Although there was no cytotoxicity with the ligation of CH-11 alone in CHLA-90 cells, pretreatment of $IFN{\gamma}$ increased the sensitivity of CH-11-mediated apoptosis. The expression of TNFRI and FAS/CD95R were non-specifically enhanced after treatment of $IFN{\gamma}$ without relation to sensitivity to $TNF{\alpha}$ and CH-11. This finding suggest up-regulation of both receptors may contribute to sensitization of $TNF{\alpha}$ and CH-11-mediated apoptosis by $IFN{\gamma}$ in only sensitive cell lines. Conclusion : $IFN{\gamma}$ induced sensitization of $TNF{\alpha}$ and agonistic FAS/CD95 antibody-mediated apoptosis on some neuroblastoma cells through up-regulation of TNFRI and FAS/CD95 receptor.

• Journal of Plant Biotechnology
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• v.32 no.1
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• pp.37-44
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• 2005

Microspores were isolated from pepper (Capsicum annuum L.) anthers by using a micro-blender and cultured in modified NLN medium at $25^{\circ}C$. The influence of pretreatment period at $32^{\circ}C$, adding the 2-hydroxynicotinic acid to a pretreatment medium, and co-pretreatment anthers with microscopes on the induction of embryo were examined. Globular and torpedo embryos were observed from 3 weeks after culture. Embryo development was not synchronized within culture. After 4 weeks in culture, in addition to globular and torpedo embryos, cotyledonary embryos were observed. Normal cotylodonary embryos developed into plantlets when transferred to a solid hormone free B5 medium containing $2\%$ sucrose. Embryo yields were significantly higher after 1- and 2-day pretreatment at $32^{\circ}C$. However the development of embryo ceased at the globular or heart stage. In contrast, embryo yields were lower after 3- to 6-day pretreatment at $32^{\circ}C$ and embryo developed at the cotyledonary stage. After adding the 2-hydroxynicotinic acid to anther pretreatment solution, embryo yields were slightly increased. However most embryos occurred were at the globular or heart stage. Co-pretreatment of microspores with anthers was deleterious for embryo induction and development. AS far as we know, this is the first report of success in obtaining high frequency of embryogenesis and plantlets formation from isolated microspores of pepper. Although the culture conditions have to be optimized further, this promising microspore culture system can be used for genetic transformation, selection for dominant and recessive traits as well as for the production of homozygous doubled haploid plants.

• Childhood Kidney Diseases
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• v.5 no.2
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• pp.109-116
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• 2001

Purpose Long- term use of steroid, cyclophosphamide and cyclosporin, which are frequently used in the therapy of SDNS, might cause severe side effects. Recently, the immune-modulator levamisole has been tried as a substitute therapy and it has been reported as a method with less side effects and more effectiveness. We started this research in order to observe the effects of levamisole and compare it to other therapy results. Patients and Methods : We chose 16 steroid dependent nephrotic syndrome children, those who had shown frequent relapse during the immunocompromised therapy period. Mean age was $9.1{\pm}1.4$ years in children and the male to female ratio was 15:1. All of subjects were diagonized with MCNS and had received cyclophosphamide or cyclosporin before receiving levamisole. Levamisole at a dose of 2.5mg/kg was used every other day for 1 year and the relapse rate was observed. Results : On average of 14 days after treatment, complete remission was visible in all of the children, and the relapse percentage was $50\%$, which represents 8 children, while remaining 8 children representing $50\%$ of the cases showed no relapse during treatment. During the levamisole therapy period, tile average relapse rate was reduced significantly from $2.18{\pm}0.9/year\;to\;0.77{\pm}0.9/year$(P=0.027). Also the average relapse rate after the therapy was reduced to $1.34{\pm}1.1/year$, which was a significant level compared to the level before treatment(P=0.003). There was no significant difference in terms of duration of remission maintenance. Duration of remission maintenance showed an average of $12.2{\pm}9.1$ months before the use of levamisole, but it was also $10.1{\pm}6.9$ month after therapy. No other side effects such as leukopenia, skin disease and other clinically significant symptoms appeared at all during therapy. Conclusion : The long-term medication of levamisole for the therapy of SDNS children is thought to be able to maintain stable remission by reducing the relapse frequency without causing severe side effects. Further study with a broader range of subjects is required to eluccidate the long-term effects of this treatment. (J. Korean Soc Pediatr Nephrol 2001;5 : 109-16)

• 한국해양학회지
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• v.23 no.1
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• pp.24-40
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• 1988

In the Korea Ocean Nodule Development (KONOD)-1 area between the Clarion and Clipperton fracture zones of the northeastern equatorial Pacific, the pelagic sediment layer can be divided into two or three units on air-gun seismic profile. The acoustic units can be also correlated with those in the DSDP site 163 core. The topmost unit (unit I) is acoustically transparent and consists of zeolitic clay and radiolarian ooze of late Oligocene to middle Eocene age. Unit IIA is well-stratified and transparent in the lower part. consisting of the radiolarian ooze intercalated with chert beds and zeolitic clay of early Eocene to Paleocene age. Unit IIB is stratified with layers of silicified and compacted flinty-cherty nannofossil chalk (late Cretaceous) on top of the acoustic basement. Units I and IIA form the Line Islands Formation that overlies an unnamed formation of unit lIB. The entire layers and the unit I layer propressively thin northward, except near the Line Islands Ridge. The distribution of sediment layer has been controlled by the equatorial Cenozoic CCD and the northward spreading of the Pacific plate. The change of CCD corresponding to the subsidence and migration of the plate has determined the sediment composition of the DSDP 163 core passed across the equator of high sedimentation suite. The late Cretaceous sedimentary layer (unit IIB) in the 163 core was formed above the CCD south of the equator. The unit IIA resulted from rapid subsidence of the Pacific plate below the CCD in the Paleocene. The unit IIA is seen only in the west of 149 W. Both the units IIA and I were probably formed during the Pacific plate passing and after leaving the equatorial region respectively since early Eocene. In the south of the KONOD-l area, the unit I was redistributed by bottom current, a branch of the Antarctic Bottom Water flowing eastward guided by the Clipperton fracture zone. The activities of bottom currents were prolonged for a long geological time. Turbidite layers occur more than 350 km from the Hawaiian Ridge to near the Clarion fracture zone. They originated directly from the Hawaiian Ridge, filling the topographic lows.

• Journal of Sericultural and Entomological Science
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• v.16 no.2
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• pp.99-109
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• 1974

These studies aimed to establishment of controlling measure of the bud blight of mulberry tree when intermediate cutting harvest in autumn. The results obtained as following. 1. Effect of chemicals a) Results of 1972 (1) Of the seventeen chemicals tested. according to in vitro, the mycelial growth of Gibberella lateritium f. sp. mori was highly inhibited by PTAB and Benlate. PTAB and Benlate were also highly effective under the conditions of pathogen inoculated to the piece of mulberry tree and fungicidal action of these chemicals were stronger than the others. (2) Topsin-M. organic fungicide and plant growth regulator were not effective to inhibition of mycelial growth. (3) The effectiveness of fungicides were reduced gradually as the time after treatment increased. PTAB and Benlate retained approximately 50 percent of the original activity even after 15 days. (t) Of the twelve chemicals tested in fold, Benlate combination of PTAB with Apion, Apion and PTAB were the most effective fungicides for the control of bud blight of mulberry tree. (5) There is a sigificant difference between the timing on spraying, but it is not greatly effective for the control of bud blight of mulberry tree. b) Results of 1975 (1) Of the ten chemicals tested, according to in vitro RH 893, combination of Benlate with TMTD and TMTD were the most effective to inhibition of mycelial growth, followed by Benlate and combination of Benlate with Topsin M. (2) Of the eleven chemicals tested, Benlate, combination of Benlate with Kinondu, combination of Benlate with Topsin-M and Topsin M were highly effective under the renditions of pathogen inoculated to the piece of mulberry tree. (3) Of the eleven chemical evaluation tests were conducted in 3 experiment fold of Seoul, Chuncheun and Pusan, Benlate, Topsin-M, Apion, TMTD. combination of Benlate with Topsin-M, combination of Benlate with TMTD, combination of Benlate with Apion were highly effective chemicals for the control of bud blight of mulberry tree. (4) There is no difference between the timing on the chemical spraying after intermediate cutting harvest mulberry tree in autumn. 2. Ecological Control. When the mulberry shoot were cut off one to two buds from the top of intermediate cutting from 15th to 30th on October, bud blight of mulberry tree was greatly reduced in next spring compared with the effective chemical spraying. 3. Economical analysis on the results of chemical and ecological tests. When the expenses of ecological control for bud blight of mulberry tree per one ha was 100. thats of chemical control was from 159 to 254 according to spraying machines.

• Korean Journal of Soil Science and Fertilizer
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• v.43 no.2
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• pp.153-159
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• 2010

Nowadays, Korean farmers rely more on chemical fertilizers than low input sustainable agriculture drawn from the farm itself. In order to improve soil nutritional imbalance for environment friendly agriculture in greenhouse, we have carried out a relationship between fertilizer application level, and soil chemical properties for strawberry cultivation at 56 sites in Chungnam Province. Average amount of nitrogen as basal fertilization was 92.3 Mg $ha^{-1}$ which higher 2.6 times compared to standard amount of basal fertilizer. In case of compost application more than 30 Mg $ha^{-1}$, excessive ratio compared to optimum level was higher 1.8 times for EC value, 3.0 times for available phosphate, 2.6 times for exchangeable potassium, 1.7 times for exchangeable calcium, and 1.6 times for exchangeable magnesium, respectively. Amounts of compost application significantly correlated with available phosphate (r=0.370, $p{\leq}0.01$), exchangeable potassium(r=0.429, $p{\leq}0.01$), exchangeable calcium(r=0.404, $p{\leq}0.01$), exchangeable magnesium(r=0.453, $p{\leq}0.01$), and exchangeable sodium(r=0.369, $p{\leq}0.01$), respectively. Our results suggest that soil nutrients management for sustainable agriculture was optimum fertilization based on soil testing for strawberry cultivation in greenhouse.

• Korean Journal of Animal Reproduction
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• v.24 no.2
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• pp.125-142
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• 2000

13). Analysis of a purified preparation of eCG revealed that its $\beta$ -subunit consists of 149 amino acids, which was confirmed by the molecular cloning of its cDNA. There seem to be at least four to six, or even as many as 11, O-glycosylation sites on the extended C-tenninal region of the eCG $\beta$-subunit. Interestingly, eCG is a unique member of this family, as it appear to be a single molecule that possesses both LH- and FSH-like activities. Using the cDNA prepared from mRNA extracted from equine placental and pituitary tissues, we cloned the cDNA of eCG $\alpha$- and $\beta$ -subunits and eFSH $\beta$ -subunit. The mRNA expression of each subunit seems to be independently regulated, which may account for differences in the quantities of $\alpha$ - and $\beta$ -subunits in the placenta and pituitary. Thus, eCG is a distinct molecule from the view points of its biological function and glycoresidue structures. Recombinant eCGs including the mutants which lack oligosaccharides will be useful tools for analyzing the structure-function relationships of gonadotropins in the horse as well as other species. Similar experiments will also clarify the proposed structure and biological functions for the glycoprotein hormones. These experimental are now possible, and hopefully a resolution of the existing controversy will be forthcoming in the near future.

• Microbiology and Biotechnology Letters
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• v.36 no.1
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• pp.61-66
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• 2008

The proteins in whey are separated and used as food additives. The remains (mainly lactose) are spray-dried to produce sweet whey powder, which is widely used as an additive for animal feed. Sweet whey powder is also used as a carbon source for the production of valuable products such as polysaccharides. Glucose, fructose, galactose, and sucrose as asupplemental carbon source were evaluated for the production of PS-7 from Azotobacter indicus var. myxogenes L3 grown on whey based MSM media. Productions of PS-7 with 2% (w/v) fructose and sucrose were 2.05 and 2.31g/L, respectively. The highest production of PS-7 was 2.82g/L when 2% (w/v) glucose was used as the carbon source. Galactose showed low production of PS-7 among the carbon sources tested. The effects of various carbon sources addition to whey based MSM medium showed that glucose could be the best candidate for the enhancement of PS-7 production using whey based MSM medium. To evaluate the effect of glucose addition to whey based media on PS-7 production, fermentations with whey and glucose mixture (whey 1, 2, 3%; whey 1% + glucose 1%, whey 1% + glucose 2% and glucose 2%, w/v) were carried out. Significant enhancement of PS-7 production with addition of 1% (w/v) and 2% (w/v) glucose in 1% (w/v) whey media was observed. The PS-7 concentration of 2% glucose added whey lactose based medium was higher than that of 1% glucose addition, however, the product yield $Y_{p/s}$ was higher in 1% glucose added whey lactose based MSM medium. Therefore, the optimal condition for the PS-7 production from the Azotobacter indicus var.myxogenes L3, was 1% glucose addition to 1% whey lactose MSM medium.

• Journal of Korean Society of Environmental Engineers
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• v.29 no.1
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• pp.23-30
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• 2007

The ultimate objective of this study is to develop oxygen-enriched combustion techniques applicable to the system of practical industrial boiler. To this end the combustion characteristics of lab-scale LNG combustor were investigated as a first step using the method of numerical simulation by analyzing the flame characteristics and pollutant emission behaviour as a function of oxygen enrichment level. Several useful conclusions could be drawn based on this study. First of all, the increase of oxygen enrichment level instead of air caused long and thin flame called laminar flame feature. This was in good agreement with experimental results appeared in open literature and explained by the effect of the decrease of turbulent mixing due to the decrease of absolute amount of oxidizer flow rate by the absence of the nitrogen species. Further, as expected, oxygen enrichment increased the flame temperatures to a significant level together with concentrations of $CO_2$ and $H_2O$ species because of the elimination of the heat sink and dilution effects by the presence of $N_2$ inert gas. However, the increased flame temperature with $O_2$ enriched air showed the high possibility of the generation of thermal $NO_x$ if nitrogen species were present. In order to remedy the problem caused by the oxygen-enriched combustion, the appropriate amount of recirculation $CO_2$ gas was desirable to enhance the turbulent mixing and thereby flame stability and further optimum determination of operational conditions were necessary. For example, the adjustment of burner with swirl angle of $30\sim45^{\circ}$ increased the combustion efficiency of LNG fuel and simultaneously dropped the $NO_x$ formation.