• Journal of Ginseng Research
• /
• v.46 no.3
• /
• pp.367-375
• /
• 2022

Background: Short-term hydroponic-cultured ginseng (sHCG), which is 1-year-old ginseng seedlings cultivated for 4 weeks in a hydroponic system, is a functional food item with several biological effects. However, the optimal extraction conditions for sHCG, and the bioactivity of its extracts, have not been evaluated. Methods: Chlorogenic acid (CGA) and ginsenoside contents were evaluated in sHCG, white ginseng (WG), and red ginseng (RG) using high-performance liquid chromatography. Response surface methodology (RSM) was used to optimize the extraction conditions (temperature and ethanol concentration) to maximize the yield of dry matter, CGA, and four ginsenosides (Re, Rg₁, Rb₁, and Rd) from sHCG. The optimal extraction conditions were applied to pilot-scale production of sHCG extracts. The expression levels of tumor necrosis factor (TNF)-α/interferon (IFN)-γ-induced thymic and activation-regulated chemokines (TARC/CCL17) were measured after treatment with sHCG, WG, and RG extracts, and the effects of their bioactive compounds (CGA and four ginsenosides) on human skin keratinocytes (HaCaTs) were evaluated. Results: CGA and four ginsenosides, which are bioactive compounds of sHCG, significantly inhibited TNF-α/IFN-γ-induced TARC/CCL17 expression. The optimal sHCG extraction conditions predicted by the RSM models were 80 ℃ and 60% ethanol (v/v). The sHCG extracts produced at the pilot scale under optimal conditions greatly alleviated TNF-α/IFN-γ-induced TARC/CCL17 production compared with WG and RG extracts. Conclusions: Pesticide-free sHCG extracts, which contain high levels of CGA and the ginsenosides Re, Rg₁, Rb₁, and Rd as bioactive compounds, may have therapeutic potential for atopic diseases.

• Transactions of the Korean hydrogen and new energy society
• /
• v.33 no.6
• /
• pp.733-742
• /
• 2022

Hydrogen fuel cell propulsion ships are emerging to respond to the recently strengthened carbon emission regulations in the international shipping sector. Methanol can be stored in a liquid state at normal pressure and temperature, and has the advantage of lower reforming temperature compared to other fuels. In this study, the optimal operating point of the methanol steam reforming system was derived by changing the Steam Carbon Ratio (SCR) from 0.10 to 3.00. Results showed that In terms of methanol conversion rate and hydrogen yield, the larger the SCR is the better, but in terms of system efficiency, it is most advantageous to operate at SCR 0.70 in Pressure Swing Adsorption (PSA) mode and SCR 0.80 in Pd membrane mode. Through this study, it was found that the optimal SCR in the reformer and the entire system including the reformer may be different, which indicates that the optimum operating point may be different depending on the change of the system configuration.

• KOREAN JOURNAL OF CROP SCIENCE
• /
• v.67 no.1
• /
• pp.17-26
• /
• 2022

Rice is one of the three major grains globally, and has been used as a staple food in Asian countries for a long time. In recent years, with the increase in the use of processed rice, the development and distribution of rice flour varieties have become a research focus. However, rice flour varieties are susceptible to pre-harvest sprouting (PHS). In this study, the optimal transplanting date for rice flour varieties for maximum yield production with PHS avoidance was examined. Four rice flour varieties with different maturity types (early maturing type, Garumi2 and medium-late maturing type, Seolgaeng, Hangaru, and Singil) were selected. The field experiment was conducted in Chuncheon (Central Plain area) and Cheorwon (Northern Plain area), Gangwon Province, Republic of Korea, from 2017 to 2019. The transplanting dates used were May 10, May 20, May 30, June 10, and June 20 in Chuncheon and April 30, May 10, May 20, May 30, and June 10 in Cheorwon. In Chuncheon, late transplantation decreased PHS in Garumi2. In Cheorwon, PHS in Garumi2 decreased with transplantation dates after May 20. The PHS decreased in Seolgaeng, Hangaru, and Singil with late transplantation in Chuncheon and Cheorwon. The optimal transplanting date for maximum yield production while avoiding PHS for Garumi2 was estimated to be June 10 in Chuncheon and May 25 in Cheorwon; for Seolgaeng, the optimal transplanting dates were May 20 in Chuncheon and May 15 in Cheorwon; for Hangaru, it was estimated to be May 30 in Chuncheon and May 15 in Cheorwon; and for Singil, the optimal dates were May 25 in Chuncheon and May 15 in Cheorwon.

• KDI Journal of Economic Policy
• /
• v.13 no.4
• /
• pp.141-153
• /
• 1991

The optimal choice of the tax rate and the inflation rate framework is extended to yield relevant interpretations for the optimal fiscal and monetary policy regime in Korea. To study the relationship between the government budget and monetary growth in different environments of policy coordination, two models assuming different degrees of fiscal dominance are developed. By modelling differing institutional arrangements of the fiscal and the monetary authority from an optimal government finance viewpoint, we find the optimal relationship among some important fiscal and monetary variables. By testing the existence of the relationship empirically, we find the characteristics of the optimal policy-mix regime in Korea. The first model-the strong from of fiscal dominance-studies the optimal collection of seigniorage in a period-by-period optimization with standard assumptions on the income velocity of money, deriving a general testable result: the optimal inflation/tax rate ratio co-vary with the marginal revenue ratio. The second model-the weak form of fiscal dominance-studies an implication of the inflationary bias of discretionary monetary policy in the presence of fiscal side distortions. This model shows that the tax rate and the inflation rate can have a positive correlation. Empirical tests of the theoretical results are done for the Korean economy for 1972-1989 period. The test results show that the macroeconomic policy regime in Korea can be characterized by the strong form of fiscal dominance, implying the importance of the government budget in explaining money growth and inflation.

• The Korean Journal of Mycology
• /
• v.28 no.2
• /
• pp.73-80
• /
• 2000

This study was carried out to investigate the optimal mycelial growth and an artificial cultivation conditions of Pleurotus eryngii. The optimal medium for the mycelial growth and density was MYPA medium. The optimal temperature and pH for the mycelial growth were $25^{\circ}C$ and 6.0, respectively. The modified optimal medium composition were obtained to be soluble starch 3%(w/v), malt extract 0.25%(w/v), yeast extract 0.25%(w/v) and $CaCl_2{\cdot}2H_2O$ 0.05% (w/v). From the results of experiment on the nutritional requirements, the modified optimal medium was higher than MYP medium in mycelial production and growth yield (Yx/s) of Pleurotus eryngii. The optimal sawdust species of solid culture for the mycelial growth and density was Quercus spp. The optimal concentration of additives (rice bran and wheat bran) and moisture content for the mycelial growth were about 30%(v/v) and 70%(v/v), respectively. On the other hand, the optimal concentration of additives for the production of fruiting body was 20%(v/v) of rice bran.

• Plant Biotechnology Reports
• /
• v.5 no.2
• /
• pp.121-126
• /
• 2011

Isoflavonoid production in cell cultures of Pueraria tuberosa as influenced by an angiospermic parasite, Cuscuta reflexa, was studied. During the time course, maximum isoflavonoid content was recorded when Cuscuta elicitor was added on day 15 of culture. Among various concentrations of elicitor tried, $1g\;l^{-1}$ of Cuscuta elicitor was found to be the most effective. The optimized elicitation conditions were used in vessels of varying capacity where maximum yield of ${\sim}91mg\;l^{-1}$ of isoflavonoid was recorded in a 2-l bioreactor which was about 19% higher than the control cultures. In this case, puerarin content increased up to $11mg\;l^{-1}$ which was 580% higher that the value recorded in the control cultures. In the bioreactor, 8 days of elicitation was optimal for the high accumulation of isoflavonoid, giving productivity of ${\sim}4mg\;l^{-1}\;day^{-1}$. The study showed persistent high isoflavonoid yield even during scale-up. Use of a preparation of Cuscuta reflexa as an elicitor is reported for the first time. The increase in isoflavonoid content was elicitor dose-dependent and can be explored to trigger high yields of isoflavonoid/secondary metabolites in production.

• 한국생물공학회:학술대회논문집
• /
• 2001.11a
• /
• pp.378-381
• /
• 2001

In the batch culture experiments, the addition of $MnSO_4$, was examined in flask culture, and then the optimal amounts of $MnSO_4$ was investigated in 2.5- L jar-fermenter. As a results, 0.005% $MnSO_4$ was found to enhance the ARA yield of 1.14- fold. Also the addition of $KH_2PO_4_4$ was investigated in 2.5-L jar-fermenter and the ARA yield was enhanced 1.20-fold. Fed batch culture study shown a relatively high productivity of cell mass (62.1 g/L) and ARA content (12.0 g/L) when 14% ammonia solution were alternatively used to control the pH and nitrogen source in the cultivation period.

• Textile Coloration and Finishing
• /
• v.23 no.3
• /
• pp.155-162
• /
• 2011

para-Aramid has limited dyeability because of its highly crystalline structure and compactness. To improve the dyeability of the para-aramid to reactive dyes of bright color in deep shade, the fabrics were photografted under continuous UV irradiation with dimethylaminopropyl methacrylamide and 4-benzoyl benzoic acid as a monomer and a hydrogen -abstractable photoinitiator respectively. A UV energy of 35J/$cm^2$ and a photoinitiator concentration of ten percent or more with respect to the monomer in the formulation was required for optimal photografting. Grafting yield increased with higher monomer application level. Surface analysis indicated significant alterations in the atomic composition of the photografted fabric surface and the fabric surface was covered with the grafted polymers. While the pristine para-aramid fabrics showed no appreciable dyeability to the ${\alpha}$-bromoacrylamide reactive dyes, the grafted para-aramid fabrics enhanced the dyeability to the reactive dyes substantially. In case of C.I. Reactive Blue 50, a K/S value of 8.7 can be obtained with the grafted para-aramid fabrics with a grafting yield of 2.3 %. Also the color fastness properties of the dyed fabrics was excellent in the conditions of washing, rubbing and light irradiation.

• Journal of Marine Bioscience and Biotechnology
• /
• v.12 no.1
• /
• pp.50-58
• /
• 2020

Sphacelaria is a filamentous brown algal genus that can be epibiotic on macroalgae, marine plants, and sea turtles. Its important role in benthic ecosystems, exposure to different stressors (e.g., grazing), and use as a model organism make Sphacelaria ideal for assessing physiological responses of organisms to environmental inputs. Single-cell RNA sequencing is a powerful new probe for understanding environmental responses of organisms at the molecular (transcriptome) level, capable of delineating gene regulation in different cell types. In the case of plants, this technique requires protoplasts ("naked" plant cells). The existing protoplast isolation protocols for Sphacelaria use non-commercial enzymes and are low-yielding. This study is the first to report the production of protoplasts from Sphacelaria fusca (Hudson) S.F. Gray, using a combination of commercial enzymes, chelation, and osmolarity treatment. A simple combination of commercial enzymes (cellulase Onozuka RS, alginate lyase, and driselase) with chelation pretreatment and an increased osmolarity (2512 mOsm/L H₂O) gave a protoplast yield of 15.08 ± 5.31 × 10⁴ protoplasts/g fresh weight, with all the Sphacelaria cell types represented. Driselase had no crucial effect on the protoplast isolation. However, the increased osmolarity had a highly significant and positive effect on the protoplast isolation, and chelation pretreatment was essential for optimal protoplast yield. The protocol represents a significant step forward for studies on Sphacelaria by efficiently generating protoplasts suitable for cellular studies, including single-cell RNA sequencing and expression profiling.

• Food Science of Animal Resources
• /
• v.33 no.5
• /
• pp.572-580
• /
• 2013

This study was carried out to evaluate the effect on properties of restructured jerky by the addition volume of additives. The treatments were divided into glutinous rice flour, potato starch, soybean and acorn powder. Moisture content, water activity ($a_w$), thiobarbituric acid reactive substances (TBARS), color, yield and sensory evaluation were performed. The moisture contents of four types of restructured jerkies were in the range of 8.92-12.47%, and were lower than that of the control (17.92%). Water activity tended to decreased with increasing addition of all treatments. The restructured jerkies containing glutinous rice flour, potato starch, soybean and acorn powder had lower TBARS than the control. The drying yield tended to increase with increasing amount of additives. In the sensory evaluation results, the highest overall acceptability was found in jerky containing glutinous rice flour, potato starch, and acorn powder when the addition was 9%, while that for soybean powder was determined to be 5%. These results suggest that 9% additions of glutinous rice flour, potato starch or acorn, or 5% soybean powder are optimal addition volumes for the preparation of restructured jerkies.