• Mass Spectrometry Letters
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• v.9 no.2
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• pp.56-60
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• 2018

In this study, matrix-assisted laser desorption/ionization (MALDI) was applied to the TEMPO-assisted FRIPS for the first time. We found that 3-HPA is the optimal matrix for the analysis of p-TEMPO-Bz-Sc-peptides, which gives minimal precursor fragmentations. MALDI-TOF/TOF experiments on p-TEMPO-Bz-Sc-peptides yielded mainly $[a_n+H]^+$, $[z_n+H]^+$, and $[y_n]^+-type$ products, indicating that radical-driven peptide fragmentation occurs in MALDI-TOF/TOF-MS.

• Korean Journal of Medicinal Crop Science
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• v.11 no.4
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• pp.316-320
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• 2003

A protocol is described for rapid multiplication of Zanthoxylum piperitum DC. (Rutaceae), an important aromatic and medicinal plant, through shoot-tip explant cultures. Murashige and Skoog (MS) medium supplemented with various concentrations of N-6-benzyladenine (BA), N-6-benzylaminopurine (BAP) and thidiazuron (TDZ), in single or in combination with ${\alpha}-naphthaleneacetic$ acid (NAA), was used to determine the rate of shoot proliferation. N-6-benzyladenine (BA) used at 0.5mg/l, was the most effective in initiating multiple shoot proliferation at the rate of 23 microshoots per shoot-tip explants after 40 days of culture. Shoot multiplication increased 1.2-fold in each successive subculture. Induction of rooting (98%) was achieved by transferring the shoots to the same basal medium containing 2 mg/l indole-3-butyric acid (IBA). Plantlets went through a hardening phase in a controlled growth chamber, prior to in vivo transfer. These results represented that possible application for the mass production of plantlets through in vitro culture system of Zanthoxylum piperitum DC.

• Journal of the Korean Society of Tobacco Science
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• v.12 no.2
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• pp.77-83
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• 1990

This study was conducted to develop the method of hydrocarbon analysis and investigate hydrocarbon contents in flue-cured and burley tobacco leaves harvested in Korea and U.S.A. Tobacco leaf was extract with hexane in soxhlet apparatus. Hydrocarbon was fractionated from hexane extract by silica gel column chromatography, and then separated and indentified by GC, GC/MS using SE-54 fused silica capillary column. The developed method was feasible to analyze neophytadiene, normal and branched hydrocarbons from Clo to Cn. The result of recovery test was decade 99%, eicosane 100%, triacontane 102%. The major hydrocarbon of tobacco leaves were neophytadiene, nC3l, iC31, nC33, aC33, aC32, aC30 and nC29. The amount of total hydrocarbon in burley and flue-cured tobacco leaves harvested in U.S.A. and Korea were 4591, 2931, 2929 and 3015$\mu\textrm{g}$/g, respectively.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.12 no.3
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• pp.323-328
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• 2001

Multicarrier modulation is a promising technique for mobile communications system, since it has a strong immunity to multipath fading and increasing bandwidth efficiency. In this paper, the performance of MC DS-CDMA/MPSK has been analyzed with that of DS-CDMA/MPSK system using MRC diversity in the same frequency bandwidth. The results show that with no diversity we can see that the BER of about $10^{-5}$ is achieved at $E_b/N_o$ = 25 dB, with diversity is reachable up to 12 dB.

• Korean Journal of Metals and Materials
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• v.48 no.3
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• pp.268-275
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• 2010

A new approach is described for preparing AlN thin films containing various amounts of Co content by using a two-facing targets type sputtering (TFTS) system. The deposited films were annealed isothermally at different temperatures and their microstructure, magnetic properties and resistivity were investigated. A small saturation magnetization ($4{\pi}Ms=0.52{\sim}0.85kG$) was observed irrespective of Co content in the asdeposited films. It was found that annealing conditions can control physical properties as well as the microstructure of the films. A high saturation magnetization (3.7 kG) and resistivity of $2200{\mu}{\Omega}-cm$ was obtained for AlN films containing 25 at.% Co.

• Natural Product Sciences
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• v.5 no.2
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• pp.75-79
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• 1999

Supercritical carbon dioxide was used as a solvent in the extraction of freeze-dried Pandanus odorus leaves. Analysis of the extract with GC-MS showed that Pandanus odorus leaves contain nutritional constituents such as ${\alpha}-tocopherol$ (Vitamin E) and squalene. The contents of ${\alpha}-tocopherol$ and squalene extracted from freeze-dried ground Pandanus odorus leaves at pressures ranging from 80 to $200\;kg\;cm^{-2}$ and temperatures between 40 to $80^{\circ}C$ were $134{\sim}300\;ppm$ and $750{\sim}1,200\;ppm$ respectively. The highest yield was obtained at $200\;kg\;cm^{-2}$ and $40^{\circ}C$. Other major components identified were hexadecanoic acid, 9,12,15-octadecatrien-1-ol, campesterol, stigmasterol and ${\beta}-sitosterol$.

• The Korean Journal of Physiology
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• v.27 no.2
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• pp.175-183
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• 1993

There are many report suggesting that influx and intracellular calcium concentration $([Ca^{2+}]_i)$ are related to cell signalling in various cells. However, it has not been reported that calcium channel activation is affected by the substances involved in signal transduction pathways in the mouse eggs. In this study, the effects of isoprenaline (ISP) and cyclic AMP on calcium influx through calcium channels were investigated to show their relationship with the signal transduction process in unfertilized mouse eggs. Using whole cell voltage clamp techniques, calcium currents, elicited by the depolarizing pulses of 300 ms duration (from -50 mV to 50 mV in 10 mV increments) from a holding potential of -80 mV, were recorded. The current-voltage (I-V) relation of calcium currents was shown to be bell-shaped; the current began to activate at -50 mV and reached its maximum $(-1.33{\pm}0.16\;nA:\;mean{\pm}S.E.,\;n=7)$ at -10 mV, then decayed at around 50 mV. Calcium currents were fully activated within $7\;ms{\sim}20\;ms$ and completely inactivated 200 ms after onset of the step pulse. ISP within the concentration ranges of $10^{-8}\;M{\sim}10^{-4}\;M$ dose-dependently increased the amplitude calcium current. The permeable cyclic AMP analogue,8-bromocyclic AMP, also increased its maximal amplitude by 46ft at $10^{-5}\;M$, while protein kinase inhibitor (PKI), which is known to inhibit 0.02 phosphorylating units of cyclic AMP-dependent protein kinase (PKA) per microgram decreased calcium currents. Currents recorded in the presence of PKI were resistant to increase by the application of $10^{-5}\;M$. Also, PKI inhibited the calcium current increase elicited by ISP treatment. These results suggest that $\beta-adrenergic$ regulation of the calcium channel is mediated by the cAMP-dependent protein kinase. This signal transduction pathway might play a role in regulating $[Ca^{2+}]_i$, level due to the increase of calcium influx in mouse eggs.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.37 no.2B
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• pp.97-109
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• 2012

In this paper, we propose a modulation scheme for a network-coded bi-directional relaying (NBR) system over an asymmetric channel, which means that the qualities of the relay channel (the link between the BS and RS) and access channel (the link between the RS and MS) are not identical. The proposed scheme employs a dual constellation in such a way that the RS broadcasts the network-coded symbols modulated by two different constellations to the MS and BS over two consecutive transmission intervals. We derive an upper bound on the average bit error rate (BER) of the proposed scheme, and compare it with the hybrid constellation-based modulation scheme proposed for the asymmetric bi-directional link. Furthermore, we investigate the channel utilization of the existing bi-directional relaying schemes as well as the NBR system with the proposed dual constellation diversity-based modulation (DCD). From our simulation results, we show that the DCD gives better average BER performance about 3.5~4dB when $E_b/N_0$ is equal to $10^{-2}$, while maintaining the same spectral efficiency as the existing NBR schemes over the asymmetric bi-directional relaying channel.

• Journal of the Korean Chemical Society
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• v.40 no.8
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• pp.557-564
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• 1996

FAB CAD MS/MS(Fast Atom Bombardment Collision Activated Dissociation Mass Spectrometry/Mass Spectrometry) was used to study different degree of bond stability according to the linkage positions of alkali cationized $(Na^+, Li^+, K^+, NH_4^+)$ stereoisomeric and synthetic oligosaccharides. The alkali metal cations were much more stable, requiring over -40 eV of collision energy vs. only -10 eV for the protonated forms. Of the cations, the potassium cationized trisaccharides were more stable than the others. They would not yield fragment ions under the conditions of collision available in triple quadrupole. Other cationized species exhibited decreasing stability in the series $Nap^+>Li^+>NH_4^+$ using 0.8 mTorr argon pressure in the collision cell. Metal cations of the oligosaccharides maintained charge principally on the amino sugar as shown by shift of all the fragment ions containing the amino sugar. The reason for the higher stability of the metal cationized form is the formation of crown ether-like bond around metal cations, N-acetyl group on GlcNAc and oxygens on fucose moiety. Depending on the metal sizes and the conformation of linkage-isomeric region, cationized species gave linkage dependent fragment patterns and exhibited stability in the series 1-6 > 1-4 > 1-3 linkage.

• Korean Journal of Community Nutrition
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• v.20 no.5
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• pp.351-361
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• 2015

Objectives: The purpose of this study was to investigate the relations between diabetic dietary compliance and dietary intake, physical activity and prevalence of metabolic syndrome (MS) in type 2 diabetic patients. Methods: Seventy five subjects diagnosed with type 2 diabetes visiting the D hospital in Dongducheon from May 2014 to Dec 2014 were included in this study. The subjects were divided into two groups according to their diabetic dietary compliance score (median 39); low diabetic dietary compliance (LDDC) group (n=44) and high diabetic dietary compliance (HDDC) group (n=31). Survey data collection was carried out by direct interview method. The nutrient intake, food intake and KDDS (Korean's dietary diversity score), DVS (dietary variety score) and GMVDF (grain, meat, vegetable, dairy and fruit) were analyzed using data from the 24-recall method. Metabolic parameters were obtained from the hospital records. Data was analyzed using Chi-square test and general linear model adjusted for sex. Results: The prevalence of MS was 59.7% in the participating diabetic patients. The prevalence of MS of the HDDC (39.3%) was significantly lower than that of the LDDC (72.7%). The distribution of physical activity showed a significant difference between the groups (p=0.006). The intakes of seeds and nuts of the HDDC were significantly lower than those of the LDDC. Fat and vegetable fat intakes and % fat of energy in the HDDC were significantly lower than those in the LDDC. But, carbohydrate (CHO) and potassium intake and %CHO of energy in the HDDC were significantly higher than those in the LDDC. KDDS and GMVDF showed significant differences between groups (p=0.033; p=0.012). Conclusions: Continuous intervention by specialized nutritionists for long-term self-regulation is needed for diabetic patients, and the high compliance to diabetic diet and increasing physical activity may be effective in the prevention of metabolic syndrome.