• Journal of Korean Society of Forest Science
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• v.97 no.5
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• pp.547-551
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• 2008

The study aimed to develop a cryopreservation method for long-term storage using mature somatic embryo of Japanese larch. In this study, desiccation treatments significantly affected re-induction rates of embryogenic tissue (ET) from dried somatic embryos. In the effect of different dehydration temperature and duration on the re-initiation ET. the highest frequency was shown when somatic embryos were dehydrated at $25^{\circ}C$ for 2 (45.5%) or 1 day (43.3%), respectively. In addition, low temperatures [$4^{\circ}C$, 2 days (44.2%) or 3 days (43.5%)] were marked higher ET initiation. After that, the initiation value was declined with dehydration duration. For comparison of different relative humidity on re-induction frequency of ET, the best re-induction (43.5%) was obtained from somatic embryos pre-dried at $(NH_4)_2SO_4$ (RH 79%). Both $Na_2HPO_4$ (RH 97%) and $Na_2CO_3$ (RH 88%) treatments were showed the similar rate, 34.6, 34.2%, respectively. However the lowest rate (19.6%) was observed in distilled water (RH 100%). In comparison of the various storage temperatures and duration of the dried somatic embryos, the highest frequency (66.9%) of re-initiation was obtained when somatic embryos were cryopreserved for one day. However, the frequency was gradually decreased as the time length of storage increased regardless of types of storage. None of ET re-initiated when stored at $4^{\circ}C$ for 1, 2 and 84 days.

• Proceedings of the Membrane Society of Korea Conference
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• 2008.05a
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• pp.283-284
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• 2008

• Journal of Korean Tunnelling and Underground Space Association
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• v.20 no.1
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• pp.197-209
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• 2018

This paper presents a study on the reduction of concrete lining re-bar according to the tunnel design factors. The design of the concrete lining increases the reinforcing re-bar according to the application of excessive load, and the economical efficiency is reduced. In order to improve the economical efficiency of tunnel construction, rational standards are required for the design factors of concrete lining. Therefore, this research analyzed the characteristics and problems of the design factors applied to the design of concrete lining. Also, the economical review of the concrete lining for design factor application was compared with the amount of reinforcing re-bar calculated from the section design using numerical analysis. The results show that the amount of re-bar is varied according to the design factors. That is, the required amount for re-bar in the tunnel concrete lining could be reduced in the design stage. The results of this study may be useful for economic design of concrete lining in the future.

• YAKHAK HOEJI
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• v.42 no.3
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• pp.296-301
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• 1998

To investigate the effects of ginsenosides from Panax ginseng on mitogenic responses in macrophages and splenocytes from murine, we examined the effects of representative protopanaxadiol and protopanaxatriol ginsenosides ($Rb_1,\;Rb_2,\;Re\;and\;Rg_1$) on tumor necrosis factor-${\alpha}$ (TNF-(${\alpha}$) production in murine macrophage cell line (RAW264.7 cells) stimulated by lipopolysaccharide (LPS) and T cell proliferation in splenocytes stimulated by concanavalin A (Con A). Among the ginsenosides tested, protopanaxadiol ginsenosides ($Rb_1\;and\;Rb_2$) significantly inhibited TNF-${\alpha}$ production in a dose-dependent manner. However, protoppanaxatriol ginsenosides (Re and $Rg_1$) showed little inhibitory activity. The molar concentrations of $Rb_1\;and\;Rb_2$ producing 50% inhibition ($IC_{50}$) of TNF-${\alpha}$ production were $55.8{\mu}g/ml\;(48.0{\mu}M)\;and\;31.8{\mu}g/ml (27.9{\mu}M)$, respectively. As a positive control, prednisolone also exhibited inhibitory activity with an $IC_{50}$ value of $21.7{\mu}M$. In T cell proliferation, $Rg_1$, was not effective but $Rb_1$ and Re or $Rb_2$ significantly increased or inhibited at high concentration, 75 and $100{\mu}g/ml$. In contrast, prednisolone showed potent inhibitory activity with an $IC_{50}$ value of 6.1nM. These results suggest that ginsenosides may take part in the mitogen-induced signaling pathway for TNF-${\alpha}$ production and T cell proliferation from macrophages and splenocytes.

• Korean Journal of Agricultural and Forest Meteorology
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• v.16 no.2
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• pp.137-145
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• 2014

Rice-barley double cropping system is typical in southwestern part of South Korea. However, the information of carbon dioxide ($CO_2$) exchange for barley growing season has still limited in comparison with rice. Using the eddy covariance (EC) technique, seasonal variation of $CO_2$ exchange was analyzed for the barley growing season at a rice-barley double cropping field in Gimje, Korea. The effects of environmental factors and biomass on the $CO_2$ flux also were investigated. Quality control and gap-filling of flux data were conducted before this analysis and investigation. The results indicated that $CO_2$ uptake increased rapidly at tillering stage and maximum net ecosystem exchange of $CO_2$ (NEE) occurred at the early of May, 2012 ($-11.2gCm^{-2}d^{-1}$), when the heading of barley occurred. NEE, gross primary production (GPP), and ecosystem respiration (Re) during the barley growing season were -348.0, 663.3, and $315.2gCm^{-2}$, respectively. In this study, an attempt has been made to measure NEE, GPP, and Re with the help of the EC system for the barley growing season for the first time in Korea, focusing on $CO_2$ exchange between the biosphere and the atmosphere.

• Biomedical Science Letters
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• v.15 no.1
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• pp.81-86
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• 2009

Lasers are necessity in our life related to the fields of medicine and cosmetic surgery. With 808 nm diode laser and $CO_2$ laser, we made some wounds on a dorsum of rat by laser irradiation. All of irradiations shows thermal effects on the whole region of skin tissues. They make wound damage depending on laser power and irradiation time. Because a collagen is plays an important role in tissue repair, we studied collagen accumulation in wound tissue. For wound healing, collagen accumulation was found in the near region of damage in epidermis and dermis layer of the rat skin. In case of the quantitative analysis of collagen in wound tissue, the amount of collagen in wound tissue by $CO_2$ laser irradiation is higher than that of 808 nm diode laser irradiation. And re-epithelialization was significantly faster in wound by $CO_2$ laser irradiation compared with that of 808 nm diode laser irradiation.

• Korean Journal of Agricultural and Forest Meteorology
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• v.23 no.4
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• pp.198-221
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• 2021

After large-scale reforestation in the 1960s and 1970s, forests in Korea have gradually been aging. Net ecosystem CO₂ exchange of old-growth forests is theoretically near zero; however, it can be a CO₂ sink or source depending on the intervention of disturbance or management. In this study, we report the CO₂ budget dynamics of the Gwangneung deciduous old-growth forest (GDK) in Korea and examined the following two questions: (1) is the preserved GDK indeed CO₂ neutral as theoretically known? and (2) can we explain the dynamics of CO₂ budget by the common mechanisms reported in the literature? To answer, we analyzed the 15-year long CO₂ flux data measured by eddy covariance technique along with other biometeorological data at the KoFlux GDK site from 2006 to 2020. The results showed that (1) GDK switched back-and-forth between sink and source of CO₂ but averaged to be a week CO₂ source (and turning to a moderate CO₂ source for the recent five years) and (2) the interannual variability of solar radiation, growing season length, and leaf area index showed a positive correlation with that of gross primary production (GPP) (R²=0.32~0.45); whereas the interannual variability of both air and surface temperature was not significantly correlated with that of ecosystem respiration (RE). Furthermore, the machine learning-based model trained using the dataset of early monitoring period (first 10 years) failed to reproduce the observed interannual variations of GPP and RE for the recent five years. Biomass data analysis suggests that carbon emissions from coarse woody debris may have contributed partly to the conversion to a moderate CO₂ source. To properly understand and interpret the long-term CO₂ budget dynamics of GDK, new framework of analysis and modeling based on complex systems science is needed. Also, it is important to maintain the flux monitoring and data quality along with the monitoring of coarse woody debris and disturbances.

• 한국과학교육학회:학술대회논문집
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• 2009.02a
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• pp.52.2-52.2
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• 2009

• Plant Journal
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• v.14 no.2
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• pp.5-18
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• 2018

• Bulletin of the Korean Chemical Society
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• v.21 no.6
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• pp.638-640
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• 2000