• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.21 no.2
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• pp.157-166
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• 1985

The Purpose of this study are to investigate the characteristics of the flame behavior of gasoline-methanol blended fuels in spark ignition engine. Ionization probe were installed at the cylinder head and piston in order to measure flame speed. Other parameter such as engine performance, fuel consumption rate and exhaust gas were measured. The results were as follows. 1. In the case of increase methanol contents in blend fuel, flame propagation speed were increased, and thermal efficiency of the engine were increased due to decrease of energy consumption rate. 2. In the case of fixed equivalance ratio, NO sub(X) in exhaust gas were increased in accordance with increase of spark advance, and mean effective pressure were decreased in accordance with increase of methanol contents. 3. CO and HC concentration were decreased in accordance with increase of methanol contents.

• Korean Journal of Medicinal Crop Science
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• v.18 no.1
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• pp.22-27
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• 2010

This study was carried out to investigate the physicochemical characteristics of 3-year-old ginseng (for Samgyetang product) cultured by various seeding density in direct-sowing culture. Ginsengs were cultured by the seeding density, 275, 300, 330 352 and 396 seeds per Kan, $180{\times}90cm$ area. Survived rate (82.1%) were the highest in plot of 352 seeds sowed, length and leaf width were high in plot of 300 and 352 seeds. Root yield grain was increased with increase of the seeding density in direct-sowing culture except 352 seeds sowed. Average root weight and diameter were the highest in plot of 352 seeds sowed, 31.6 g and 18.4 mm, respectively. Crude saponin and each ginsenosides content were the highest in plot of 275 seeds sowed. Rg1 content was decreased, Rc and Rb2 content were increased with increase of the seeding density. Total soluble sugar content was the highest in plot of 330 seeds sowed and the lowest in plot of 396 seeds sowed, and oligo- and disaccaride content were high in plot of 330 and 352 seeds sowed. Reological characteristics of ginsengs cultivated according to various seeding density, hardness and springness were high and maximum fracture force was low with decrease of the seeding quantity.

• Bulletin of the Korean Space Science Society
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• 2009.10a
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• pp.32.4-32.4
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• 2009

한국천문연구원은 미국 텍사스대학교와 공동으로 근적외선 광대역 고분산 분광기 IGRINS (Immersion Grating Infrared Spectrograph)를 개발하고 있다. IGRINS는 R=40,000의 높은 분광분해능으로 H-밴드 ($1.49\sim1.80{\mu}m$)와 K-밴드 ($1.96\sim2.46{\mu}m$) 전체 분광스펙트럼을 한 번에 관측할 수 있다. IGRINS를 구성하는 핵심 부품은 실리콘 담금격자 (Silicon Immersion Grating)와 VPH (Volume Phased Holographic) 격자, 그리고 HAWAII2RG 적외선 센서이다. 실리콘 담금격자를 사용함으로써 적외선 분광기의 크기를 일반적인 격자를 사용한 것보다 2-3배정도 줄일 수 있게 되었다. IGRINS는 개발 후 미국 맥도날드 천문대에 3년간 장착하여 관측연구에 활용될 예정이다. 이후 IGRINS는 4미터급 이상의 망원경에 장착될 예정이다. 한국천문연구원은 IGRINS 국제공동 개발을 위하여 2009년 8월 텍사스 대학과 양해각서(MOU)를 교환하였으며 현재 개념 설계를 끝내고 기본 설계를 진행하고 있다. 기본설계검토 회의 (Preliminary Design Review)은 12월에 실시할 예정이다. 또한 과학연구 활용 극대화를 위하여 사용자 그룹을 조직하였으며, 여름학교를 열어 적외선 분광 연구에 대한 교육을 실시하였다. 이 발표에서는 IGRINS의 개발 현황을 보고하고, IGRINS의 설계와 활용 분야에 대하여 소개한다.

• Journal of Ginseng Research
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• v.40 no.1
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• pp.47-54
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• 2016

Background: The roots of Panax ginseng contain noble tetracyclic triterpenoid saponins derived from dammarenediol-II. Dammarene-type ginsenosides are classified into the protopanaxadiol (PPD) and protopanaxatriol (PPT) groups based on their triterpene aglycone structures. Two cytochrome P450 (CYP) genes (CYP716A47 and CYP716A53v2) are critical for the production of PPD and PPT aglycones, respectively. CYP716A53v2 is a protopanaxadiol 6-hydroxylase that catalyzes PPT production from PPD in P. ginseng. Methods: We constructed transgenic P. ginseng lines overexpressing or silencing (via RNA interference) the CYP716A53v2 gene and analyzed changes in their ginsenoside profiles. Result: Overexpression of CYP716A53v2 led to increased accumulation of CYP716A53v2 mRNA in all transgenic roots compared to nontransgenic roots. Conversely, silencing of CYP716A53v2 mRNA in RNAi transgenic roots resulted in reduced CYP716A53v2 transcription. HPLC analysis revealed that transgenic roots overexpressing CYP716A53v2 contained higher levels of PPT-group ginsenosides ($Rg_1$, Re, and Rf) but lower levels of PPD-group ginsenosides (Rb1, Rc, $Rb_2$, and Rd). By contrast, RNAi transgenic roots contained lower levels of PPT-group compounds and higher levels of PPD-group compounds. Conclusion: The production of PPD- and PPT-group ginsenosides can be altered by changing the expression of CYP716A53v2 in transgenic P. ginseng. The biological activities of PPD-group ginsenosides are known to differ from those of the PPT group. Thus, increasing or decreasing the levels of PPT-group ginsenosides in transgenic P. ginseng may yield new medicinal uses for transgenic P. ginseng.

• Journal of Ginseng Research
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• v.24 no.4
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• pp.202-205
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• 2000

KJHST (Kejihongsarntang) is a modified oriental prescription that consists of five herbs such as Ginseng Radix rubra Koreana, Atractylodis Rhizoma, Zingiberis Rhiaoma, Cinnamomi Ramulus and Glycyrrhizae Radix. For the evaluation of antioxidant and staminal activities of KJHST (Kejihongsarntang), the study was done in comparison of Ginseng Radix rubra (GR). For the antioxidant study, KJHST inhibited hemolysis of erythrocyte and decolored the DPPH(2,2-diphenyl-1-picrylhydrazyl) free radical in a dose depenrlent manner more effectively than GR alone in vitro. KJHST and GR significantly suppressed the time course (1 hr∼6 hr)-level of MDA (malondialdehyde) following AAPH (2,2'-azo-bis-(2-amidino-propane) dihydrochloride) treatment in vivo as compared with control data with no statistical difference. From the evaluation of stamina by swimming test GR and KJHST significantly increased the swimming time in a time and dose dependent manner as compared with control data, while GR was more effective than KJHST in 2 weeks after treatment, though KJHST was more effective than GR at low dose (25 m/kg) 4 weeks after treatment. From the results it can be concluded GR and KJHST had antioxidant and staminal activities.

• Korean Journal of Pharmacognosy
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• v.43 no.1
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• pp.10-15
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• 2012

An accurate and sensitive analysis method was established for simultaneous determination of three bioactive compounds (glycyrrhizin, 6-gingerol and ginsenoside Rg3) in the Ejung Tang with high-performance liquid chromatography (HPLC)-photodiode array detection (DAD)-electrospray ionization (ESI)-Mass spectrometry (MS). The optimizing chromatographic separations a were acquired by an $C_{18}$ column ($5{\mu}m$, $4.6I.D{\times}250mm$, SHISHEDO) using gradient elution with water comprising 0.1% TFA(trifluoroacetic acid) and acetonitrile at a performing temperature of $35^{\circ}C$. Flow rate was 1.0 ml/min. A detection UV wavelength set at 205 nm and 250 nm. The three compounds were identified by electrospray ionization mass spectrometry. All calibration curves indicated great linear regression within test ranges ($R^2>0.9997$). The established method provided acceptable precision and accuracy. The relative standard deviations (RSDs) of intra-day and inter-day were less than 2.00% and 3.00%, respectively. The recoveries were found to range from 94.49 to 101.10% for the three compounds analyzed. These results showed that this method was effective and reliable for quality control of Eiung-Tang.

• Korean Journal of Medicinal Crop Science
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• v.25 no.4
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• pp.217-223
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• 2017

Background: In Korea, 6-year-old ginseng root is economically more important than 4 or 5-year-old roots. In general, the root age is determined by counting the number of stem vestiges. However, this method does not accurately estimate ginseng root age. Methods and Results: In this study, the stem vestige counting method was used to survey a total of 18,395 fresh ginsengs cultured in 2014, and 2015, to determine the accuracy of this method. The proportion of 6-year-old roots, with more than four stem vestiges, was 46.1% in 2014. For the cultivar Chunpoong cultivated in Eumseong and Goesan countries in 2015, the proportion of more than four stem vestiges was 55.9%, and 43.5%, respectively. The proportion of more than four stem vestiges for the Gumpoong cultivated in Eumseong and Yangpyeong countries was 67.0%, and 35.1%, respectively, whereas that for the cultivar Yunpoong was 36.0% and 61.0%, respectively. Moreover, it was confirmed that differences in the levels of Rg1 will enable root age determination. Conclusions: Root age determination by the stem vestige test was found to differ depending on the environmental and cultivation conditions. To determine the age of ginseng roots, a comprehensive method, such as counting stem vestiges and evaluating differences in ginsenoside levels, should be applied.

• Journal of Ginseng Research
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• v.26 no.2
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• pp.74-78
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• 2002

To develop a new traditional ginseng liquor by using rice and ginseng, the physicochemical properties and overall acceptability of ginseng liquors made by addition of different concentration (1-8%) of ginseng in some kinds of rice mash were investigated and compared. The Ilpum-4 traditional ginseng liquor which was prepared by adding 4% ginseng into Ilpum rice mash showed the best acceptability in the sensory evaluation test and high ethanol content (15.6%), and its angiotensin-converting enzyme inhibitory activity and electron-donating ability were better than those of the other ginseng liquors. The Ilpum-4 traditional ginseng liquor contained 0.53% (w/v) of crude saponin and it was mainly composed of ginsenoside Rg$_1$.

• Proceedings of the Korean Society of Sericultural Science Conference
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• 1997.06a
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• pp.23-49
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• 1997

This is a progress report of rice biotechnology including development of gene transformation system, gene cloning and molecular mapping in rice. The scope of the research was focused on the connection between conventional breeding and biotech-researches. Plant transformation via Agrobacterium or particle bombardment was developed to introduce one or several genes to recommended rice cultivars. Two chimeric genes containing a maize ribosome inactivating protein gene (RIP) and a gerbicide resistant gene (bar) were introduced to Nipponbare, a Japonica cultivar, and transmitted to Korean cultivars. The homozygous progenies of herbicide resistant transgenic plant showed good fertility and agronomic characters. To explore the genetic resourses in rice, over 8,000 cDNA clones from immature rice seed have been isolated and sequenced. About 13% of clones were identified as enzymes related to metabolic pathway. Among them, twenty clones have high homology with genes encoding enzymes in the photorespiratory carbon cycle reaction. Up to now about 100 clones were fully sequenced and registered at EMBL and GenBank. For the mapping of quantitative tarits loci (QTL) and eternal recombinant inbred population with 164 F13 lines (MGRI) was developed from a cross between Milyang 23 and Gihobyeo, Korean rice cultivars. After construction of fully saturated RFLP and AFLP map, quantitative traits using MGRI population were analyzed and integrated into the molecular map. Eighty seven loci were determined with 27 QTL characters including yield and yield components on rice chromosomes. Map based cloning was also tried to isolate semi-dwarf (sd-1) gene in rice. A DNA probe, RG 109, the most tightly linked to sd-1 gene was used to screen from bacterial artifical chromosome (BAC) libraries and five over lapping clones presumably containing sd-1 gene were isolated. Rice genetic database including results of biotech reasearch and classical genetics is provided at Korea Rice Genome Server which is accessible with world wide web (www) browser. The server provides rice cDNA sequences and map informations linked with phenotypic images.

• Journal of Applied Biological Chemistry
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• v.62 no.1
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• pp.93-100
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• 2019

The root of Panax ginseng is used in ethnomedicine throughout eastern Asia and various recent studies have proved that Panax ginseng has inhibitory effects on cardiovascular disease. Each factor causing cardiovascular disease is known to have a very complex process which is achieved by a diverse number of mechanisms. Among these factors, platelets are the most important because they directly participate in thrombogenesis. Therefore, inhibiting the activity of platelets is an essential element for prevention of cardiovascular diseases. Our previous study showed the antiplatelet effects of Korean red ginseng extract and two of its components, ginsenoside Rg3 and ginsenoside Ro. However, the inhibitory mechanism of other ginsenosides remains unclear. Therefore, we investigated the inhibitory mechanism of ginsenoside F4 (G-F4) from Korean red ginseng on the regulation of signaling molecules involved in human platelet aggregation. With the use of G-F4, collagen-induced human platelet aggregation was inhibited in a dose-dependent manner, and it suppressed collagen-induced elevation of $[Ca^{2+}]_i$ mobilization through elevated phosphorylation of inositol 1, 4, 5-triphosphate receptor I ($Ser^{1756}$). In addition, G-F4 inhibited fibrinogen binding to ${\alpha}IIb/{\beta}_3$ during collagen-induced human platelet aggregation. Thus, in the present study, G-F4 showed an inhibitory effect on human platelet activation, suggesting its potential use as a new natural medicine for preventing platelet-mediated cardiovascular diseases.