Correlated Thermal Motion in Ferroelectric LiNbO_3 Studied Using Neutron Total Scattering and a Rietveld Analysis

정일경,박성균 한국물리학회 2011 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.59 No.4

We report neutron total scattering and a Rietveld analysis on LiNbO_3 at temperatures from 300 K to 550 K. Using the atomic pair distribution function obtained from the total scattering analysis, we extracted the mean-square relative displacement (MSRD) of the Nb-O atom pair as a function of temperature. At the same time, the thermal parameters for Nb, Li, and O ions were refined using a Rietveld analysis. By combining the results for the MSRD and for the atomic thermal vibrations, we report motional correlation of the nearest-neighbor Nb-O pair, which may play a role in stabilizing the ferroelectric state of LiNbO_3.

Local Structure of Lead-containing Mixed-ion Perovskite Ferroelectrics Studied Using Neutron Total Scattering Analysis

정일경,Dhananjai Pandey 한국물리학회 2012 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.61 No.3

We report the local structures of the lead-containing mixed-ion perovskite Pb(Ni 1 3/2+ Nb 2 3/5+ )O3 (PNN), Pb(Fe 1 2/3+ Nb 1 2/5+ )O3 (PFN), and Pb(Zr 0.6 4+ Ti 0.4 4+ )O3 (PZT) by using a neutron total scattering analysis at low temperatures. Between PNN and PFN, we found that the Pb-O pair distributions were quite similar although they exhibited cubic and monoclinic average structures, respectively. Despite the similarity of the Pb-O pair distributions, the local structures of the B-cations in these compounds were rather different from each other. In the case of PZT, the Pb-O local structure was found to be distinctively different from those of other mixed-valence compounds. These comparisons among Pb-containing mixed-ion perovskites suggest that the valence distribution of the B-cation plays a crucial role in the Pb off-center displacement. Finally, we present the temperature evolution of the Pb-O pair distribution in PNN for temperatures from 300 K to 20 K. Based on this result, we show that a relative displacement of Pb and O against each other is an important feature of the local structure of the Pb ions.

벼의 이상적인 초형에 관여하는 QTL 분석

정일경,김경민 한국자원식물학회 2017 한국자원식물학회지 Vol.30 No.2

Rice is the staple food of at least half of the world's population. Due to global warming, the weather is difficult to forecast nowadays. Therefore, it is necessary to breed various breeding to respond to such changes in the environment. This study was conducted to analyze the QTL about plant form, culm length, ear number and ear length by using 120 lines by anther culture, a cross between the Indica variety Cheongcheong and Japonica variety Nagdong. DNA marker was selected on the QTLs gene, and the following results were obtained. CNDH (Cheongcheong Nagdong Doubled Haploid) lines frequency distribution table curves about culm length, ear number and ear length exhibited showed a continuous variation close to a normal distribution. QTL analysis result, on culm length qPlL1-1 and qPlL1-2 were detected on the chromosome 1 and qPlL5 was detected on the chromosome 5. However, on ear length qPL2, qPL3 and qPL10, were detected on the chromosome 2, 3 and 10, while on ear number qPN1-1 and qPN1-2 were detected on the chromosome 1, qPN9 was detected on the chromosome 9. The QTLs related to culm length was found to chromosomes 5 and LOD scores were 3.81. The QTLs related to ear length was found to chromosomes 2 and 3 LOD scores were 7.13 and 3.20. The QTLs related to ear number was found to chromosome 9 and LOD scores were 4.27. Twenty two (22) Japonica cultivars and 12 Indica cultivars were analyzed polymorphisms, using selected 9 markers from the result about plant form analysis. RM5311, RM555 and RM8111 about the culm length, the ear length and number of ear were selected on the standard of Cheongcheong and Nagdong. Each rate of concordances about the culm length, the ear length and number of ear are 44.11%, 41.17% and 44.11%. 본 실험은 청청과 낙동 조합을 약배양하여 육성한 120 계통을이용하여 이상적인 초형에 관련된 간장, 수장, 개체당 이삭수에대한 QTLs를 분석하고 탐색된 QTLs은 다음과 같은 결과를 얻었다. 모부본인 청청과 낙동의 간장의 평균은 75.3 ± 6.72 ㎝, 수장의 평균은 20.6 ± 2.08 ㎝이었으며 개체당 이삭수의 평균은 16.0 ± 2.37개로 나타났다. 120 계통의 CNDH의 간장의 평균은 71.6 ± 17.38 ㎝였으며, 수장의 평균은 20.3 ± 2.24 ㎝였으며 개체당 이삭수의 평균은 16.1 ± 7.17개로 나타났다. 이에대한 CNDH 계통의 빈도분포표의 곡선은 정규분포에 가까운 연속변이를 나타내었다. 간장, 수장, 개체당 이삭수 QTL 분석결과 간장에서 1번 염색체의 qPlL1-1, qPlL1-2, 5번 염색체의qPlL5, 수장에서 2번 염색체의 qPL2, 3번 염색체의 qPL3, 10번염색체의 qPL10, 개체당 이삭수에서 1번 염색체의 qPN1-1, qPN1-2, 9번 염색체의 qPN9이 탐색되었다. 간장에 대한 QTL에서 5번 염색체의 LOD 값은 3.81, 상가적 값은 5.49였으며, 수장에대한 QTL에서 2번 염색체의 LOD 값은 7.13, 상가적 값은 -2.58 이었으며, 3번 염색체의 LOD 값은 3.20, 상가적 값은 0.88로 나타났다. 개체당 이삭수에 대한 QTL에서 9번 염색체의 LOD 값은 4.27, 상가적 값은 -1.60으로 나타났다. 초형 관련 분석 결과에서 탐색된 9개 마커를 토대로 간장에 대한 RM5311, 수장에 대한 RM555, 개체당 이삭수에 대한 RM8111을 선발하여 모부본인청청, 낙동을 기준으로 자포니카형 22 품종, 인디카형 12 품종에 다형성을 분석하였다. 그림 4와 같이 청청과 낙동과 같은 밴드양상을 나타나거나 다른 크기상태의 밴드양상을 나타내었다. 간장, 수장, 개체당 이삭수의 일치율은 각각 44.11%, 41.17%, 44.11%로 나타났다.

Structural Evolution of Bismuth Sodium Titanate Induced by A-site Non-stoichiometry: Neutron Powder Diffraction Studies

정일경,성연수,송태권,M. H. Kim,A. Llobet 한국물리학회 2015 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.67 No.9

We performed neutron powder diffraction measurements on (Bi0.5Na0.5+x)TiO3 and (Bi0.5+y Na0.5)TiO3 to study the structural evolution induced by the non-stoichiometry. Despite the nonstoichiometry, the local structure (r 3.5 °A) from the pair distribution function analysis is barely affected by a sodium deficit of up to −5 mol%. With increasing pair distance, however, the atomic pair correlations weaken due to the disorder caused by the sodium deficiency. Although the sodium and the bismuth share the same crystallographic site, their non-stoichiometries have rather opposite effects as revealed from distinctive distortions of the Bragg peaks. In addition, a Rietveld refinement demonstrates that the octahedral tilting is continually suppressed for sodium deficits up to −5 mol%. This is contrary to the effect of the bismuth deficiency, which induces little variation in the octahedral tilting.

흰쥐 중뇌 중심회색질에서 Preproenkephalin, Prodynorphin 혹은 Glutamic Acid Decarboxylase mRNA 함유 신경세포의 분포 및 말초염증에 의한 유전자발현의 변화

정일경,강병조,임효덕,김상헌,배준철,김상용,조희중 대한생물치료정신의학회 2002 생물치료정신의학 Vol.8 No.2

아편양 펩타이드와 GABA가 중뇌 중심회색질(PAG)에서 동통조절기능과 관련하여 중요한 역할을 담당함은 잘 알려져 있다. 본 연구에서는 PAG에서 preproenkephalin(pENK), prodynorphin(pDYN) 혹은 glutamic acid decarboxylase (GAD) mRNA함유신경세포의 분포와 또한 말초염증 유발 후 이들 mRNA들이 어떠한 변화를 일으키는지를 in situ hybridization기법에 의하여 관찰하여 다음의 결과를 알 수 있었다.1. pENK mRNA함유신경세포는 대부분 PAG의 모든 수준의 배쪽외측부에서 관찰되었다.2. pDYN mRNA함유신경세포는 주로 하부 PAG의 배쪽외측부에 분포하였다.3. GAD mRNA함유신경세포는 대부분 PAG의 모든 수준의 배쪽외측부에서 관찰되었다.4. 말초염증을 유발시키면 pENK mRNA는 증가, GAD mRNA는 감소를, 그리고 pDYN mRNA는 변화를 나타내지 않았다. 이상의 결과로 pENK, pDYN 및 GAD mRNA함유신경세포는 대부분 PAG에서 동통억제작용과 가장 관련있는 부위, 즉 배쪽외측부에 분포하며 또한 enkephalin과 GABA는 말초염증에 의한 동통유발시 각각 증가 혹은 감소함을 알 수 있었으며 더 나아가 PAG의 enkephalin과 GABA는 말초염증에 의해 유발된 동통조절에 중요한 역할을 할 것으로 사료된다. Objectives : It is well known that opioid peptides and GABA play an important roles in the pain modulation of the periaqueductal gray (PAG). The present study was undertaken to elucidate the distribution of preproenkephalin (pENK), prodynorphin (pDYN) or glutamic acid decarboxylase (GAD) mRNA-containing neurons in the PAG and to know if these mRNAs levels change following peripheral inflammation. Methods : In situ hybridization was performed for the detection of the gene expression in the rat periaqueductal gray following peripheral inflammation produced by an intraplantar injection of Freund's adjuvant into the rat hindpaws. Results : pENK mRNA-containing neurons are found mostly in the ventrolateral portion at all levels of the PAG. pDYN mRNA-containing neurons are concentrated mostly in the ventrolateral portion at the caudal level of the PAG. GAD mRNA-containing neurons are found mostly in the ventrolateral portion at all levels of the PAG. Peripheral inflammation induces an increase of pENK mRNA levels and a decrease of GAD mRNA levels, while pDYN mRNA levels shows no changes. Conclusion : The present results indicate that the pENK, pDYN or GAD mRNA- containing neurons are found mainly in the ventrolateral PAG, the area where analgesia is most easily produced and that syntheses of enkephalin and GABA in the PAG increase and decrease, respectively, following peripheral tissue inflammation. Taken together, they suggest that enkephalin and GABA in the PAG may play an important role in modulating pain induced by peripheral tissue inflammation.

흰쥐 중뇌 중심회색질에서 Preproenkephalin, Prodynorphin 혹은 Glutamic Acid Decarboxylase mRNA함유 신경세포의 분포 및 말초염증에 의한 유전자발현의 변화

정일경,강병조,임효덕,김상헌,배준철,김상용,조희중 대한생물치료정신의학회 2002 생물치료정신의학 Vol.8 No.1

Reverse Monte Carlo Modeling of the Atomic Structure of Relaxor Ferroelectric Pb(Zn1/3Nb2/3)O3

정일경 한국물리학회 2014 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.64 No.9

We performed reverse Monte Carlo (RMC) modeling on neutron total scattering data and obtainedan atomic structure consistent with the local and the average structures of the relaxorferroelectric Pb(Zn1/3Nb2/3)O3. By analyzing the model structure from the RMC analysis, wefound evidence for a significant off-centering of the lead ion that varied in magnitude and direction,leading to a partial ordering of polarizations over a few unit cells. We also estimated the staticlattice distortion of the oxygen lattice from the bond-length distributions of atomic pairs.

Local Structure of Lead-containing Mixed-ion Perovskite Ferroelectrics Studied Using Neutron Total Scattering Analysis

정일경,Dhananjai Pandey 한국물리학회 2012 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.61 No.1

We report the local structures of the lead-containing mixed-ion perovskite Pb(Ni²⁺_1/3Nb⁵⁺_2/3)O₃ (PNN), Pb(Fe³⁺_1/2Nb⁵⁺_1/2)O₃ (PFN), and Pb(Zr⁴⁺_0.6Ti⁴⁺_0.4)O₃ (PZT) by using a neutron total scattering analysis at low temperatures. Between PNN and PFN, we found that the Pb-O pair distributions were quite similar although they exhibited cubic and monoclinic average structures, respectively. Despite the similarity of the Pb-O pair distributions, the local structures of the B-cations in these compounds were rather different from each other. In the case of PZT, the Pb-O local structure was found to be distinctively different from those of other mixed-valence compounds. These comparisons among Pb-containing mixed-ion perovskites suggest that the valence distribution of the B-cation plays a crucial role in the Pb off-center displacement. Finally, we present the temperature evolution of the Pb-O pair distribution in PNN for temperatures from 300 K to 20 K. Based on this result, we show that a relative displacement of Pb and O against each other is an important feature of the local structure of the Pb ions.

高等植物의 自家不和合性의 分子機構

鄭鎰炅 대구효성가톨릭대학교 응용과학연구소 1997 응용과학연구논문집 Vol.5 No.-

Many species of flowering plants possess a self-incompatibility (SI) mechanism that prevents self-pollination and promotes cross-pollination. In many of these species, SI is controlled by a single genetic locus known as S locus, which prevents the fertilization of flowers by pollen from the same plant. SI of this type involves the molecular interaction produced by the S locus in pollen and female tissue (pistil). Until recently, the pistil products of the S locus were known in only two families, Brassicaceae and Solanaceae. In this review, I describes the genetic knowledge and recent research of molecules associated with self-incompatibility in these two families.

미량요소 첨가가 자가불화합성 억제에 미치는 영향

정일경,손태권,김민지 한국자원식물학회 2012 한국자원식물학회지 Vol.25 No.2

Self-incompatibility (SI) system is a genetic barrier that prevents self-fertilization and promotes cross-pollination among different S genotypes. In many of these species, SI is controlled by a single genetic locus known as S locus, which prevents the fertilization by pollen with same locus. S RNases are the products of the S-locus expressed in the stylar tissue of Fuji Apple with gametophytic self-incompatibility system. This study investigated the various types of chemicals in order to select more effective inhibitors and activators. The effect on the inhibition of S RNase of Fuji apples was investigated in vitro. The result showed that the enzyme activity was reduced 24.3% by Iron(Ⅱ) Sulfate, significantly. In vitro studies of pollen growth tube showed that pollen tube growth had a higher germination rate (90%) in 10% Sucrose than in 2% sucrose extension medium. Data on the fruit set of apples treated with inhibitor and activator. Double application of A +(Apple Plus, ISTECH Co. Ltd.,)+Vitamin B6 had the highest central fruit set as 86.1%(Andong). One time application of A ++Vitamin B1 in Yeongju obtained the highest central fruit set (91.9%). 본 연구는 사과의 자가불화합성 현상에 효과적인 저해제와 활력제를 탐색하기 위해 여러 종류의 물질을 조사하였다. 후지 사과의 화주조직에서 분비되는 S RNase에 대한저해효과를 조사하기 위해 In vitro 상에서 효소 저해제를넣어 효소활성을 측정한 결과, Iron(Ⅱ) Sulfate에서 현저하게 활성이 24.3% 감소되어 저해효과가 뛰어난 것으로나타났다. In vitro 상에서 후지 사과의 화분관 신장 억제효과를 분석한 결과, 후지 사과의 화분은 2% Sucrose 신장배지 보다 10% Sucrose 신장배지에서 약 90% 이상의 높은발아율을 나타났다. 또한 저해제와 첨가제 처리에 의한 안동지역과 영주지역의 Field에서 후지 사과 착과율 조사 결과, 안동지역에서는 A++V6 2회 처리가 86.1%로 중심화착과율이 가장 높았으며, 영주지역에서는 A++V1 1회 처리가 91.9%로 중심화 착과율이 가장 높은 것으로 나타났다.