• Journal of the Korean Magnetic Resonance Society
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• v.5 no.1
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• pp.37-45
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• 2001

Synthetic pulmonary surfactants consisting of a mixture of phospholipids with synthetic peptides based on human surfactant-associated protein SP-B were prepared. These surfactants were analyzed f3r their secondary structures by circular dichroism (CD) spectroscopy and NMR spectroscopy. Two synthetic peptides (SP-B(3), SP-B(4)) combined with the phospholipid mixture displayed significant surfactant properties. The CD spectra showed that the u-helical propensities of the peptides in DPC micelles. In the NMR spectroscopy, the tertiary structures of SP-B(3) show that it has $\alpha$-helical structure from Gln5 to Arg13 in DPC micelle and SP-B(4) show that they have $\alpha$-helical structure from Gln5 to Leu12 in DPC micelle. Based on these structures, truncated peptides originated from SP-B protein, can be designed as effective synthetic surfactants for clinical use.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.39A no.9
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• pp.560-562
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• 2014

Broadband power divider operating over the frequency band assigned for all domestic mobile communications is designed and implemented. The implemented power divider with 20Watts power rating has the maximum insertion loss of 3.49dB, input reflection coefficient of below -18.48dB and output reflection coefficient of below -20.2dB, above 24.7dB isolation and -141.2dBc of 3rd PIMD over the operating frequency of 810 ~ 2620MHz.

• BMB Reports
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• v.41 no.12
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• pp.840-845
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• 2008

Nucleophosmin/B23, a major nucleolar phosphoprotein, is overexpressed in actively proliferating cells. In this study, we demonstrate that B23 exclusively localizes in the nucleolus, whereas ATP depletion results in the redistribution of B23 throughout the whole nucleus and destabilizes B23 via caspase-3 mediated cleavage. Interestingly, ATP binding precedes PI(3,4,5)P3 binding at lysine 263 and ATP binding mutants fail to restore the anti-apoptotic functions of B23 in PC12 cells. Thus, the ATP-B23 interaction is required for the stability of the B23 protein and regulates cell survival, confining B23 within the nucleolus in PC12 cells.

• Korean journal of food and cookery science
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• v.21 no.5
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• pp.575-584
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• 2005

The objective of this study was to develop bioactive ginseng yogurt, fermented by B. minimum KK-1 and B. cholerium KK-2, which showed transforming activity of ginseng extract to compound K. Among older people, 3% ginseng yogurt fermented by B. minimum KK-1 and mixed with Bifidobacterium KK-1, KK-2 showed the highest overall acceptability(6.80, 6.80) among 1%(3.87, 3.67), 2%(4.40, 4.53) and 3% ginseng yogurt. The pH of ginseng yogurt was lower than that of plain yogurt. During 9 days of storage, the pH of each yogurt slightly decreased and then increased until 15 days of storage. The 3 8.25 log CFU/g and B. cholerium KK-2; 7.78 log CFU/g). Therefore, ginseng might be used as a growth factor during the fermentation of yogurt. The L value of ginseng yogurt decreased, and the a and b values increased, with increasing ginseng concentration.

• Journal of the Korean Society of Food Science and Nutrition
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• v.28 no.3
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• pp.526-533
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• 1999

Two species of antimicrobial agent producing bacteria and one sensitive strain were isolated from soil. Those were identified as B. subtilis, B. licheniformis, and Curtobacterium sp. by morphological, biochemical, physiological and chemotaxonomic characteristics. These were designated as B. subtilis cx1, B. licheniformis cy2 and Curtobacterium sp. cf3, respectively. Antimicrobial agent produced by B. subtilis cx1 showed high antibacterial activity against gram positive bacteria including of B. subtilis, Curtobacterium sp., L. mesenteroids, Staphy. aureus, S. faecalis and even gram negative bacteria, P. aeruginosa. Antimicrobial agent from B. licheniformis cy2 showed slightly lower antimi crobial activity than that from B. subtilis cx1. These two strains showed maximum production of antimicrobial agents at 30oC for 9~21hr cultivation. Curtobacterium sp. cf3 showed more sensitive activity than a sensitive strain of B. subtilis ATCC 6633 which was same genus or species with the B. subtilis cx1 and B. subtilis cy2, when the antimicrobial agent producing strains, B. subtilis cx1 and B. subtilis cy2, were directly applied onto these sensitive lawns.

• Journal of electromagnetic engineering and science
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• v.4 no.4
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• pp.143-149
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• 2004

This paper describes characteristics of the single-balanced low IF resistive FET mixer for the digital beam forming(DBF) receiver. This DBF receiver based on the direct conversion method is designed with Low IF I and Q channel. A radio frequency(RF), a local oscillator(LO) and an intermediate frequency(IF) considered in this research are 1950 MHz, 1940 MHz and 10 MHz, respectively. Super low noise HJ FET of NE3210S01 is considered in design. The measured results of the proposed mixer are observed IF output power of -22.8 dBm without spurious signal at 10 MHz, conversion loss of -12.8 dB, isolation characteristics of -20 dB below, 1 dB gain compression point(PldB) of -3.9 dBm, input third order intercept point(IIP3) of 20 dBm, output third order intercept point(OIP3) of 4 dBm and dynamic range of 30 dBm. The proposed mixer has 1.0 dB higher IIP3 than previously published single-balanced resistive and GaAs FET mixers, and has 3.0 dB higher IIP3 and 4.3 dB higher PldB than CMOS mixers. This mixer was fabricated on 0.7874 mm thick microstrip $substrate(\varepsilon_r=2.5)$ and the total size is $123.1\;mm\times107.6\;mm$.

• The Proceeding of the Korean Institute of Electromagnetic Engineering and Science
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• v.6 no.2
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• pp.45-53
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• 1995

In mobile communication, the performance of QAM technique is poor under deep fading even though Rayleigh channel characteristics are estimated and compensated. In this paper, we analyze the performance of 3/4 Trellis coded 16QAM in Rayleigh channel where burst errors are randomized by bit reversal block interleaver, and TCM coder is designed by computer search to be adequate for Rayleigh channel. The simulation results show that the interleaver has 2dB gain, the modified Viterbi decoder has 2.5dB, and diversity has 9dB gain at $P_{b}b/=10^{-3}$. This indicates that the 3/4 TC 16QAM is applicable to digital mobile communication with good performance.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2008.10a
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• pp.632-635
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• 2008

In this paper, a diplexer circuit to separate GSM/CDMA band is designed using a LTCC (Low Temperature Cofired Ceramic) multi-layer technology. In order to increase a integration capability of the diplexer, it is designed in 6-layer LTCC sunstrate with a elative dielectric constant of 7.2 using 3-dimensional (3-D) multi-layer inductors and capacitors. The size of the designed diplexer including CB-CPW pads is $3,450{\times}4,000{\times}600{\mu}m^3$. An insertion loss (IL) and return loss of GSM band are less than -0.23dB and -10dB, respectively. In the case of CDMA band, the IL of -0.53dB and RL of below -10dB are archieved.

• Korean Journal of Materials Research
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• v.24 no.5
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• pp.249-254
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• 2014

Due to their unique properties, tungsten borides are good candidates for the industrial applications where certain features such as high hardness, chemical inertness, resistance to high temperatures, thermal shock and corrosion. In this study, conditions were investigated for producing tungsten boride powder from tungsten oxide($WO_3$) by self-propagating high-temperature synthesis (SHS) followed by HCl leaching techniques. In the first stage of the study, the exothermicity of the $WO_3$-Mg reaction was investigated by computer simulation. Based on the simulation experimental study was conducted and the SHS products consisting of borides and other compounds were obtained starting with different initial molar ratios of $WO_3$, Mg and $B_2O_3$. It was found that $WO_3$, Mg and $B_2O_3$ reaction system produced high combustion temperature and radical reaction so that diffusion between W and B was not properly occurred. Addition of NaCl and replacement of $B_2O_3$ with B successfully solved the diffusion problem. From the optimum condition tungsten boride($W_2B$ and WB) powders which has 0.1~0.9 um particle size were synthesized.

• Bulletin of the Korean Chemical Society
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• v.21 no.6
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• pp.613-617
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• 2000

p-(2-Vinyloxyethoxy)benzylidenemalononitrile (4a), methyl p-(2-vinyloxyethoxy)benzylidenecyanoacetate (4b), 3,5-dimethoxy-4-(2'-vinyloxyethoxy)benzylidenemalononitrile (5a), methyl 3,5-dimethoxy-4-(2'-vinyloxy-ethoxy) benzylidenecyanoacetate (5 b), o-(2 -vinyloxyethoxy)benzylidenemalononitrile (6a), methyl o-(2-viny-Ioxyethoxy) benzylidenecyanoacetate (6b), 1,3-di-(2',2'-dicyanovinyl)-5-methyl-2-(2'-vinyloxyetioxy)benzene (7a), l,3-di-(2'-carbomethoxy-2'-cyanovinyl)-5-methyl-2-(2'-vinyloxyethoxy)benzene (7b), 2,3,4-tri-(2'-viny-Ioxyethoxy) benzylidenemalononitrile (8a), methyl 2,3,4-tri-(2'-vinyloxyethoxy)benzylidenecyanoacetate (8b), 2,4,6-tri-(2'-vinyloxyethoxy)benzylidenemalononitrile (9a), and methyl 2,4,6-tri-(2'-vinyloxyethoxy)benzyl-idenecyanoacetate(9b) were prepared by the condensation of the corresponding benzaldehyde 1-3 with malononitrile or methyl cyanoacetate, respectively. Vinyl ether monomers 4, 6, and 8 polymerized readily with radical initiators to yield crosslinked polymers 10, 12, and 14. However, compounds 5, 7, and 9 were inert to radical initiators due to the steric hindrance. The resulting polymers 10, 12, and 14 were not soluble in common solvents showing a thermal stability up to $300^{\circ}C$.