• Journal of the Korea Institute of Information and Communication Engineering
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• v.7 no.3
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• pp.454-460
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• 2003

The modulated frequency dependence on the pyroelectric properties of LiTaO$_3$ single crystal was investigated by the dynamic method. The pyroelectric coefficient of LiTaO$_3$ single crystal was 2.1${\times}$$10^{-8}$/$\textrm{cm}^2$ㆍK. and figure of merits for the responsivity and the detectivity were 1.31${\times}$$10^{-10}$Cㆍcm/J and 1.47${\times}$$10^{-8}$C\ulcornercm/J. respectively. The voltage responsivity corresponded with the pyroelectric voltage exhibited the highest value as about 165V /W at 4Hz and then was in inverse proportion to the frequency over 20Hz. The noise equivalent power and the detectivity at 4Hz were 8.4${\times}$$10^{-9}$ W/Hz$^{1}$2/ and 2.2${\times}$$10^{7}$ cmㆍHz$^{1}$2//W, respectively. Therefore, we could found that LiTaO$_3$ single crystal shows a excellent pyroelectric properties in low frequency region for the human body detection.tection.

• Biomolecules & Therapeutics
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• v.17 no.4
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• pp.446-454
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• 2009

1-Furan-2-yl-3-pyridin-2-yl-propenone (FPP-3) has recently been synthesized and characterized to have an anti-inflammatory activity through the inhibition of the production of nitric oxide and tumor necrosis factor-$\alpha$. In the present study, adverse effects of FPP-3 on immune functions were determined in female BALB/c mice. When mice were administered orally with FPP-3 at 125, 250 or 500 mg/kg for 7 consecutive days, FPP-3 suppressed the number of antibody-forming cells and reduced thymus weight at 500 mg/kg. In addition, FPP-3 administered mice exhibited reduced splenic cellularity and numbers of splenocyte subsets, such as $CD3^+$ cells, $CD3^+CD4^+$ cells, $CD3^+CD8^+$ cells and macrophages. IL-4 mRNA expression was significantly suppressed by FPP-3 treatment. Moreover, the number of $CD4^+IL-4^+$ cells was reduced following the treatment of mice with 500 mg/kg of FPP-3. These results suggested that FPP-3 at 500 mg/kg might be immunotoxic, and that FPP-3-induced immunotoxicity might be mediated, at least in part, through the inhibition of cytokine production, such as IL-4.

• The Bulletin of The Korean Astronomical Society
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• v.40 no.1
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• pp.54.1-54.1
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• 2015

We report results of investigation of amplitude calibration for very long baseline interferometry (VLBI) observations with Korean VLBI Network (KVN). Amplitude correction factors are estimated based on comparison of KVN observations at 22 GHz correlated by Daejeon hardware correlator and DiFX software correlator in Korea Astronomy and Space Science Institue (KASI) with Very Long Baseline Array (VLBA) observations at 22 GHz by DiFX software correlator in National Radio Astronomy Observatory (NRAO). We used the observations for compact radio sources, 3C 454.3 and NRAO 512 which are almost unresolved for baselines in a range of 350-477 km. VLBA visibility data of the sources observed with similar baselines as KVN are selected, fringe-fitted, calibrated, and compared in their amplitudes. We found that visibility amplitudes of KVN observations should be corrected by factors of 1.14 and 1.40 when correlated by DiFX and Daejeon correlators, respectively. These correction factors are attributed to the combination of two steps of 2-bit quantization in KVN observing systems and characteristics of Daejeon correlator.

• ALGAE
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• v.26 no.3
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• pp.229-235
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• 2011

Spliced leader (SL) trans-splicing is a mRNA processing mechanism in dinoflagellate nuclear genes. Although studies have identified a short, conserved dinoflagellate SL (dinoSL) sequence (22-nt) in their nuclear-encoded transcripts, whether the majority of nuclear-coded transcripts in dinoflagellates have the dinoSL sequence remains doubtful. In this study, we investigated dinoSL-containing gene transcripts using 454 pyrosequencing data (Cochlodinium polykrikoides, 93 K sequence reads, 31 Mb; Prorocentrum minimum, 773 K sequence reads, 291 Mb). After making comparisons and performing local BLAST searches, we identified dinoSL for one C. polykrikoides gene transcript and eight P. minimum gene transcripts. This showed transcripts containing the dinoSL sequence were markedly fewer in number than the total expressed sequence tag (EST) transcripts. In addition, we found no direct evidence to prove that most dinoflagellate nuclear-coded transcripts have this dinoSL sequence.

• Archives of Pharmacal Research
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• v.18 no.6
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• pp.454-457
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• 1995

To improve the yield of genuine aglycones from glycosides, the conditions of alkaline hydrolysis were investigated, and a modified method was established. The modified method empolyed pyridine as an aprotic solvent. To complete the hydrolysis and obtain 20(S)-protopanaxadiol (1) and 20(S)-protopanaxatriol(2), which are the genuine aglycones of ginsenosides, total ginsenosides were refluxed with sodium methoxide in pyridine. Addition of methanol, a protic polar solvent to the reaction miuxture, led partial hydrolysis yielding a mixture of the genuine prosapogenols. Of the prosapogenols compound 3 and 6 characteristically possessed D-glucopyranosyl moiety attached at the sterically hindered C-20 hydroxyl group. 3 and 6 were not obtaijned by other hydrolysisw methods except by the soil bacterial hydrolysis.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.55 no.3
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• pp.259-267
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• 2010

This study was performed at Rice and Winter Cereal Crops Department of NICS during 2007 and 2008 to investigate the characteristics of rice leaf emergence and to obtain basic data which can be used for rice growth simulation model by which we can forecast rice growth stage and heading date accurately under different cultivars, transplanting date, and climatic conditions. To confirm leaf emergence rate according to rice maturing ecotype, we surveyed the leaf emergence rate and heading date of Unkwangbyeo, Hwayoungbyeo and Nampyeongbyeo which are early maturing, medium maturing and medium-late maturing cultivars, respectively, according to seedling raising duration and transplanting time. When seedling duration was 15 days, the growth duration between transplanting time and completion of flag leaf emergence on main culm were 51.5~78.3 days in Unkwangbyeo, 55.3~87.9 days in Hwayoungbyeo and 58.4~98.4 days in Nampyeongbyeo, respectively. When seedling duration was 30 days, they were 50.1~75.5 days in Unkwangbyeo, 52.4~84.7 days in Hwayoungbyeo and 56.4~93.8 days in Nampyeongbyeo, respectively. As transplanting time delayed, the emerged leaf number after transplanting decreased in all rice cultivars. The cumulative temperature between transplanting time to completion of flag leaf elongation on main culm were $1,281^{\circ}C{\sim}1,650^{\circ}C$ in Unkwangbyeo, $1,344^{\circ}C{\sim}1,891^{\circ}C$ in Hwayoungbyeo and $1,454^{\circ}C{\sim}2,173^{\circ}C$ in Nampyeongbyeo, respectively. Leaf emergence rate on main culm were precisely represented by equation, y = $y_0$ + a / [1 + exp( - (x - $x_0$) / b)]^c, when we used daily mean temperature as variable.

• YAKHAK HOEJI
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• v.38 no.4
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• pp.451-454
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• 1994

In accordance with reported references, 8-methyl-8,14-cycloberbine was derived from berberinephenolbetaine. On acidic treatment the 8-methyl-8,14-cycloberbines were converted easily to the compounds $1{\sim}7$ in good yields. We developed a novel method for a synthesis of the C8-N bond adduct compounds 8 and 9 from 8-methyl-8,14-cycloberbine by treatment with oxalyl chloride, and 1,3-dichloroaceton.

• The Transactions of the Korean Institute of Electrical Engineers C
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• v.53 no.8
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• pp.448-454
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• 2004

In this paper, circular polarized antennas of Tx 30GHz and Rx 20GHz are implemented in LTCC process. Tx antenna has a circular patch structure and Rx antenna has a ring patch structure. The feeding line of Tx antenna is placed in the center hole of Rx ring patch antenna which is printed under Tx circular patch antenna layer. It makes antenna size smaller. Tx antenna's return loss in under -l0dB level from 30GHz to 31GHz and Rx antenna is under -10 dB from 20GHz to 21GHz. The isolation between two antennas is less than -20dB. Axial ratio is less than 3dB thoughout each band.

• Journal of the Korean Ceramic Society
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• v.38 no.5
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• pp.454-460
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• 2001

장석, 석영, 점토와 17 wt% $Al_2$O$_3$를 함유한 알루미나질 자기 애자를 제조하였다. 분말을 ball milling으로 6시간 분쇄하였으며 성형체를 압출법으로 제조한 후 터널가마에서 130$0^{\circ}C$, 50분 동안 소결하였다. 터널가마에서 소결한 시편의 소결밀도는 이론밀도의 97%에 도달하였고, 3점 꺾임강도는 1658kgf/$ extrm{cm}^2$ 이었으며 ICL(indentation crack length) 방법으로 측정한 파괴인성은 2.3 MPa.m$^{1}$2/이었다. 기계적 성질을 향상시키기 위하여 ZrO$_2$를 첨가하여 15 wt% $Al_2$O$_3$-2 wt% ZrO$_2$와 12 wt% $Al_2$O$_3$-5 wt% ZrO$_2$를 복합체를 제조하였다. ZrO$_2$를 첨가한 시편의 꺾임강도는 1740kgf/$\textrm{cm}^2$이고 파괴인성은 2.4 MPa.m$^{1}$2/로 약 10% 기계적 성질이 향상되었다.

• Proceedings of the Korean Society of Developmental Biology Conference
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• 2003.10a
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• pp.94-94
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• 2003

Rotavirus는 유아나 어린아이들에게 가장 일반적으로 나타나는 심한 위장염의 원인자이며 설사로 인한 심한 탈수 증세를 일으켜 급속히 성장하는 유아의 균형적인 영양 공급을 방해함으로써 유아들의 발육과 성장 그리고 심하면 생명에 커다란 영향을 미치게 된다. 한편 모유로 키운 유아들은 설사병의 낮은 발병율과 연관이 있었다. 특히 모유의 뮤신 복합체는 rotavirus에 특이적으로 결합하여 항 바이러스활동을 보여주는 것으로 나타났다. 이러한 배경에서 본 연구는 human breast tissue로부터 lactadherin의 cloning 및 sequence 분석을 통하여 유전자의 다양성을 조사하기로 하였다. 한국 여성 9명의 유두 근처 조직에서 lactadherin을 cloning하여 그 sequence를 보고 된 서양여성의 염기서열과 비교 분석결과 여러 곳에서 single nucleotide variation이 발견되었고 본 연구에서 클론한 lactadherin(31bp-1518bp)의 염기서열과 보고된 서양여성 lactadherin gene의 SNP와 비교하였을 때 8개의 SNP중 3부분만이 일치한다는 것을 확인하였다. 또한 같은 조직중 정상 조직과 암 조직 부분에서 각각 lactadherin을 클론하여 염기서열을 비교 분석하였는데 정상 조직에서 2곳의 silent mutation있었고 암조직에서 2곳의 mutation과 1곳의 silent mutation을 발견하였으며 전체 적으로 정상조직과 암 조직 부분에서 lactadherin을 clone하여 염기서열을 분석해본 결과 암조직일수록 유전자의 변이 비율이 높다는 것을 알 수 있었다. 그리고 동일한 염기서열 상에서 많은 변이가 일어났는데 286dp(A->C), 1418dp(G->C)은 mutation이었고 327dp (A->G), 454(C->T)은 silent mutation이었다. 그 외 DNA상에서 여러 부근에 변이가 존재하였는데 이 결과로 보아 coding region에 위치한 cSNP 중 amino acid 변화를 일으켜 protein structure 또는 function에 영향을 줄 수 있는 non-synonymous cSNP 일 것으로 예상되어지며 natural selection의 영향을 받고 있음을 암시하고 있다. 본 연구에서 관찰되어진 각각의 염기 서열의 변이는 한국 사람이 가지는 lactadherin gene의 cSNP의 일부라고 판단하였다.