• Journal of Life Science
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• v.13 no.4
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• pp.473-480
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• 2003

We analyzed the patterns of mineral ions and growth responses among symbiotic nitrogen fixing legumes by external nitrogen applications under salt gradients. Glycine max, Phaseolus angularis and Albizzia julibrissin showed remarkable growth inhibition above 40 mM NaCl treatments, but Cassia tora did not exhibit any visible injury symptom up to 100 mM NaCl treatments. As to ionic pattern, the $Na^+$ and $Cl^-$contents in leaves of G. max, P. angularis and A. julibrissin progressively increased with higher contents of external salinity. Compared to other plants, C. tora excluded $Na^+$more efficiently and maintained rather constant ionic contents in spite of high salt levels. With a few exception, these 4 legume plants exhibited better growth by the external nitrogen supply rather than the contribution of symbiotic nitrogen fixation only under saline condition.

• Journal of Korean Neurosurgical Society
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• v.29 no.4
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• pp.461-470
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• 2000

Objective : Many investigators have demonstrated the protective effects of hypothermia following traumatic brain injury(TBI) in both animals and humans. It has long been recognized that mild to moderate hypothermia improves neurologic outcomes as well as reduces histologic and biochemical sequelae after TBI. In this study, two immunohistochemical staining using terminal deoxynucleotidyl-transferase-mediated biotin dUTP nick end labeling(TUNEL), staining of apoptosis, and ${\beta}$-amyloid precursor protein(${\beta}$-APP), a marker of axonal injury, were done and the authors evaluated the protective effects of hypothermia on axonal and neuronal injury after TBI in rats. Material and Method : The animals were prepared for the delivery of impact-acceleration brain injury as described by Marmarou and colleagues. TBI is achieved by allowing of a weight drop of 450gm, 1 m height to fall onto a metallic disc fixed on the intact skull of the rats. Fourty Sprague-Dawley rats weighing 400 to 450g were subjected to experimental TBI induced by an impact-acceleration device. Twenty rats were subjected to hypothermia after injury, with their rectal temperatures maintained at $32^{\circ}C$ for 1 hour. After this 1-hour period of hypothermia, rewarming to normothermic levels was accomplished over 30-minute period. Following 12 hours, 24 hours, 1 week and 2 weeks later the animals were killed and semiserial sagittal sections of the brain were reacted for visualization of the apoptosis and ${\beta}$-APP. Results : The density of ${\beta}$-APP marked damaged axons within the corticospinal tract at the pontomedullary junction and apoptotic cells at the contused cerebral cortex were calculated for each animal. In comparison with the untreated controls, a significant reduction in ${\beta}$-APP marked damaged axonal density and apoptotic cells were found in all hypothermic animals(p<0.05). Conclusion : This study shows that the posttraumatic hypothermia result in substantial protection in TBI, at least in terms of the injured axons and neurons.

• Journal of Ginseng Research
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• v.43 no.1
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• pp.125-134
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• 2019

Background: Excessive stress causes varied physiological and psychological disorders including male reproductive problems. Here, we attempted to investigate the protective effects of Korean Red Ginseng (Panax ginseng Meyer; KRG) against sub-acute immobilization stress-induced testicular damage in experimental rats. Methods: Male rats (age, 4 wk; weight, 60-70 g) were divided into four groups (n = 8 in each group): normal control group, immobilization control group, immobilization group treated with 100 mg/kg of KRG daily, and immobilization group treated with 200 mg/kg of KRG daily. Normal control and immobilization control groups received vehicle only. KRG (100 mg/kg and 200 mg/kg) was mixed in the standard diet powder and fed daily for 6 mo. Parameters such as organ weight, blood chemistry, sperm kinematic values, and expression levels of testicular-related molecules were measured using commercially available kits, Western blotting, and reverse transcription polymerase chain reaction. Results: Data revealed that KRG restored the altered testis and epididymis weight in immobilization stress-induced rats significantly (p < 0.05). Further, KRG ameliorated the altered blood chemistry and sperm kinematic values when compared with the immobilization control group and attenuated the altered expression levels of spermatogenesis-related proteins (nectin-2, cAMP responsive element binding protein 1, and inhibin-${\alpha}$), sex hormone receptors (androgen receptor, luteinizing hormone receptor, and follicle-stimulating hormone receptor), and antioxidant-related enzymes (glutathione S-transferase m5, peroxiredoxin-4, and glutathione peroxidase 4) significantly in the testes of immobilization stress-induced rats. Conclusion: KRG protected immobilization stress-induced testicular damage and fertility factors in rats, thereby indicating its potential in the treatment of stress-related male sterility.

• Korean journal of applied entomology
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• v.60 no.1
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• pp.79-90
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• 2021

Landscape composition and structure are important factors determining biological diversity including pests and natural enemires in agricultural ecosystem. This study was conducted to indentify effect of landscape composition on occurrence of lepidopteran pest population in Geochang, Gyoungdnam. For this, orchard characteristics and management practices were surveyed in 80 conventional apple orchards in Geochang, Korea, along with the monitoring of pest population densities. The landscape features of each surveyed orchard also obtained by extracting information from the public-service map. Grapholita molesta was the most dominat and damaging pest followed by Phyllonorycter ringoniella and Carposina sasakii in trap catches. Adoxophyes paraorana occurrences were low. Farmers spray insecticides and fungicides ap. 12.4 times per year respectively while acaricides were sprayed 2.4 times. Major landscape features such as surrounding apple orchard or paddy field did not influence the pest populations but presence of plum, peach, wild peach, graph, and even abandoned orchards significantly resulted in higher pest population mostly on G. molesta. C. sasakii population was higher in orchards with grape, peach, and P. ringoniella with peach, grape, abandoned orchards and jujube. Results highlight the need of landscape management not only for the rural amenity but also for increasing functional diversity of agroecosystem as well as reducing pest population.

• Korean Journal of Metals and Materials
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• v.47 no.2
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• pp.129-137
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• 2009

Corrosion behaviors of TiN coated dental casting alloys have been researched by using various electrochemical methods. Three casting alloys (Alloy 1: 63Co-27Cr-5.5Mo, Alloy 2: 63Ni-16Cr-5Mo, Alloy 3: 63Co-30Cr-5Mo) were prepared for fabricating partial denture frameworks with various casting methods; centrifugal casting(CF), high frequency induction casting(HFI) and vacuum pressure casting(VP). The specimens were coated with TiN film by RF-magnetron sputtering method. The corrosion behaviors were investigated using potentiostat (EG&G Co, 263A. USA) in 0.9% NaCl solution at $36.5{\pm}1^{\circ}C$. The corrosion morphologies were analyzed using FE-SEM and EDX. Alloy 1 and Alloy 2 showed the ${\alpha}-Co$ and ${\varepsilon}-Co$ phase on the matrix, and it was disappeared in case of TiN coated Alloy 1 and 2. In the Alloy 3, $Ni_2Cr$ second phases were appeared at matrix. Corrosion potentials of TiN coated alloy were higher than that of non-coated alloy, but current density at passive region of TiN coated alloy was lower than that of non-coated alloy. Pitting corrosion resistances were increased in the order of centrifugal casting, high frequency induction casting and vacuum pressure casting method from cyclic potentiodynamic polarization test.

• The Korean Journal of Food And Nutrition
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• v.36 no.1
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• pp.6-16
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• 2023

To investigate the anti-inflammatory activity of submerged culture using Cordyceps militaris mycelium, culture-including mycelia was extracted and lyophilized into postbiotics (hot-water extract; CM-HW). HW was fractionated into crude polysaccharide (CM-CP) by ethanol precipitation, and CM-CP was further dialyzed into CM-DCP by dialysis with running water using 12~14 kDa dialysis tube. When the cytotoxicity of subfractions against cells was assessed, no subfraction had a cytotoxic impact that was substantially different from the control groups. In an inflammatory model using LPS-stimulated RAW 264.7 cells, CM-DCP significantly decreased IL-6 and MCP-1 production levels compared to the LPS-control group. CM-DCP also inhibited IL-6 and IL-8 secretion in HaCaT keratinocytes stimulated with TNF-α and IFN-γ. In the meanwhile, the neutral sugar content and mannose ratio of anti-inflammatory CM-DCP were higher than the other fractions, and CM-DCP contained β-1,3/1,6-glucan of 216.1 mg/g. High pressure size exclusion chromatography revealed that CM-DCP contained molecules with a molecular weight range of 5.6 to 144.0 kDa. In conclusion, postbiotics of C. militaris mycelium significantly promoted anti-inflammatory activity, suggesting that neutral polysaccharides including Glc and Man contribute to the anti-inflammation in RAW 264.7 or HaCaT cells.

• Nuclear Engineering and Technology
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• v.54 no.11
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• pp.4102-4110
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• 2022

Aiming at high-power and long-pulse operation up to 1000 s, some improvements have been made for both 2.45 GHz and 4.6 GHz lower hybrid (LH) systems during the recent 5 years. At first, the guard limiters of the LH antennas with graphite tiles were upgraded to tungsten, the most promising material for plasma facing components in nuclear fusion devices. These new guard limiters can operate at a peak power density of 12.9 MW/m². Strong hot spots were usually observed on the old graphite limiters when 4.6 GHz system operated with power >2.0 MW [B. N. Wan et al., Nucl. Fusion 57 (2017) 102019], leading to a reduction of the maximum power capability. With the new limiters, 4.6 GHz LH system, the main current drive (CD) and electron heating tool for EAST, can be operated with power >2.5 MW routinely. Long-pulse operation up to 100 s with 4.6 GHz LH power of 2.4 MW was achieved in 2021 and the maximal temperature on the guard limiters measured by an infrared (IR) camera was about 540 ℃, much below the permissible value of tungsten material (~1200 ℃). A discharge with a duration of 1056 s was achieved and the 4.6 GHz LH energy injected into the plasma was up to 1.05 GJ. Secondly, the fully-active-multijunction (FAM) launcher of 2.45 GHz system was upgraded to a passive-active-multijunction (PAM), for which the density of optimum coupling was relatively low (below the cut-off value). Good coupling with reflection coefficient ~3% has been achieved with plasma-antenna distance up to 11 cm for the new PAM. Finally, in order to eliminate the effect of ion cyclotron range of frequencies (ICRF) wave on 4.6 GHz LH wave coupling, the location of the ICRF launcher was changed to a port that is located 157.5° toroidally from the 4.6 GHz LH system and is not magnetically connected.

• Journal of Korea Technology Innovation Society
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• v.10 no.1
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• pp.73-97
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• 2007

R&D into future technologies should be conducted in conjunction with technological innovation strategies that are linked to corporate survival within a framework of information and knowledge-based competitiveness. As such, future technology strategies should be ensured through open R&D organizations. The development of future technologies should not be conducted simply on the basis of future forecasts, but should take into account customer needs in advance and reflect them in the development of the future technologies or services. This research aims to select as segmentation variables the customers' attitude towards accepting future telecommunication technologies and their value orientation in their everyday life, as these factors wilt have the greatest effect on the demand for future telecommunication services and thus segment the future telecom service market. Likewise, such research seeks to segment the market from the stage of technology R&D activities and employ the results to formulate technology development strategies. Based on the customer attitude towards accepting new technologies, two groups were induced, and a hierarchical customer segmentation model was provided to conduct secondary segmentation of the two groups on the basis of their respective customer value orientation. A survey was conducted in June 2006 on 800 consumers aged 15 to 69, residing in Seoul and five other major South Korean cities, through one-on-one interviews. The samples were divided into two sub-groups according to their level of acceptance of new technology; a sub-group demonstrating a high level of technology acceptance (39.4%) and another sub-group with a comparatively lower level of technology acceptance (60.6%). These two sub-groups were further divided each into 5 smaller sub-groups (10 total smaller sub-groups) through two rounds of segmentation. The ten sub-groups were then analyzed in their detailed characteristics, including general demographic characteristics, usage patterns in existing telecom services such as mobile service, broadband internet and wireless internet and the status of ownership of a computing or information device and the desire or intention to purchase one. Through these steps, we were able to statistically prove that each of these 10 sub-groups responded to telecom services as independent markets. We found that each segmented group responds as an independent individual market. Through correspondence analysis, the target segmentation groups were positioned in such a way as to facilitate the entry of future telecommunication services into the market, as well as their diffusion and transferability.

• Journal of The Korean Society of Grassland and Forage Science
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• v.22 no.4
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• pp.259-264
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• 2002

DK 754S, a forage corn hybrid is bred by Dekalb plant Genetics Co.. Garst 8255 by Garst Seeds Co., and GW 737 by Crosbyton Co. in US, respectively. These have been tested in Suwon and Chonan for 3 years to test their regional yield trial. In result, we were able to confirm the excellence of above cultivars and these were selected as new recommended cultivars April of 2002 by NACF. The characteristics of these cultivars are as follows ; 1. DK 7545 a. This cultivar is mid-late maturing, high quality, high yielding forage corn hybrid. Its mean tasseling date is the 11th of July. It takes 78 days from emergence to tasseling date, which is almost same with Kwanganok. The culm length and the ear height are 231 cm and 127 cm. It is relatively strong to lodging. b. The color of ear is yellow, the number of ear row is nineteen. DK 7545 shows strength to H maydis and MBSDV has occurred between 0% and 4.1% in Chonan test area but it still does not affect yielding at all. It is relatively resistant to corn borer and its stay green is almost same level comparing to a check hybrid, Kwanganok. c. Dry matter yield of this cultivar is 19.6 tons, TDN is 13.4 tons per a ha, therefore these hybrids are increased by from 6 to 9% comparing to Kwanganok. The percent ear among total dry matters yield is 43.7%. 2. Garst 8255 a. This hybrid is mid-late maturing, high quality, high yielding forage corn like as Kwanganok. Its the mean tasseling date and the period from emergence to tasseling date are almost same with a check hybrid, Kwanganok. The Culm length and the ear height are 259 cm, and 146 cm which are tall. It resists to lodging and shows excellence of stay green. b. Garst 8285 resists to H maydis, and MBSDV, and corn borer as much as Kwanganok has. c. Dry matter yield of this cultivar is 21,735 kg. TDN is 14,627 kg per a ha, therefore this is increased by 21%, 16%, respectively, comparing to a check hybrid, Kwanganok. The percent ear among total dry matters yield is 44.2%. 3. GW 737 a. This hybrid is mid-late maturing, high quality, high yielding forage com hybrid like as Kwanganok. Its mean tasseling date is 13th of July which is 2 days late comparing with a check hybrid, Kwanganok and the period from emergence to tasseling date is 80 days. b. The culm length and the ear height are 274 cm and 150 cm, which are tall. It resists to lodging moderately and shows excellence of stay green. c. GW 737 resists to H maydis and MBSDV very well, corn borer moderately resistance. d. Dry matter yield of this cultivar is 18,025kg, TDN 15,164kg per a ha, therefore this hybrid remarkably increased by 26%, 20%, respectively, comparing to a check hybrid, Kwanganok.

• Parasites, Hosts and Diseases
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• v.27 no.4
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• pp.231-248
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• 1989

The growth and development of the metacercariae of F. seoulensis cultivated in vitro or on the chick chorioallantois were assessed by comparison with the optimum process of maturation in albino rats and new born chickens. The process of maturation was divided for convenience into six stages: Stage 1 ; cell multiplication, Stage 2; body shaping, Stage 3; separation of genital anlagen, Stage :1 organogeny, Stage 5; gametogony, and Stage 6: oviposition. In Hank's and Tyrode's .solutions, the metacercariae were alive up to 200 days or more at $4^{\circ}C$ without any development. The in vivo maturation process in rats or chicks was as follows: stage 1 from 6 hours; stage 2 from 24 hours; stage 3 from 48 to 72 hours; stage 4 from 3 to 4 days; stage 5 from 4 to 5 days; and stage 6 from 5 to 8 days. Despite unsuccessful infection of the metacercariae to 12 day old chicks, fully mature worms of stage 5 or 6 were recovered from new born chicks (1 to 2 days old), The metacercariae of F. seoulensis grown in vitro were up to stage 3 and no further maturation was observed. Of various media employed, the medium NCTC 109 (Gibco) or NCTC 135(Gibco) supplemented with 20% egg yolk or 20% whole egg macerate or 0.5% yeast was basically required for the earlier development of the fluke. It took 16.1 days(in average) to reach the stage 3 after cultivation. The metacercariae cultivated on the chorioallantoic membranes of 6∼13 day old chick embryo at 37∼38℃ showed their full development up to stage 5 or 6. However, the worms were in general remarkably retarded, compared with those grown in rats or chickens. In the experiments of worm transplant, although the transfer was failed from in vitro culture to in vivo of rats(Per os), the transplants from in vitro culture to the chorioallantois and from the choriollantois to in vivo of rat host were successful with or without development of the transferred worms. In the present study, it was observed that the metacercariae of F, seoulensis can be maintained in vitro media with poor development as well as fully matured in 1 to 2 day-old chicks or on the chorioallantois at a very low rate.