• Title/Summary/Keyword: Chain alignments

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ALMOST SURE LIMITS OF SAMPLE ALIGNMENTS IN PROPORTIONAL HAZARDS MODELS

  • Lim Jo-Han;Kim Seung-Jean
    • Journal of the Korean Statistical Society
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    • v.35 no.3
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    • pp.251-260
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    • 2006
  • The proportional hazards model (PHM) can be associated with a non- homogeneous Markov chain (NHMC) in the sense that sample alignments in the PHM correspond to trajectories of the NHMC. As a result the partial likelihood widely used for the PHM is a probabilistic function of the trajectories of the NHMC. In this paper, we show that, as the total number of subjects involved increases, the trajectories of the NHMC, i.e. sample alignments in the PHM, converges to the solution of an ordinary differential equation which, subsequently, characterizes the almost sure limit of the partial likelihood.

Pretilt Angle Properties of Mixture Nematic Liquid crystal for Mobile Information Device (휴대용 통신단말에 사용되는 혼합액정계에서의 프리틸트각 특성에 관한 연구)

  • Han, Jeongmin;Seo, Daeshik
    • Journal of Satellite, Information and Communications
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    • v.10 no.1
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    • pp.67-70
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    • 2015
  • We studied the state of the dual liquid crystal (LC) alignment which displays both homeotropic and homogeneous alignment on blended polyimide (PI) layer. The research was conducted using rubbing method at different imidizing temperatures and the blended PI was made using homeotropic PI having an alkyl side chain and homogeneous PI without the side chain. The uniform LC alignments were achieved, and have thermal stability. The results of contact angles were similar to that of pretilt angles.

Intrinsic bent DNA colocalizes with the sequence involved in the Nd-sD mutation in the Bombyx mori fibroin light chain gene

  • Barbosa, Joice Felipes;Bravo, Juliana Pereira;Takeda, Karen Izumi;Zanatta, Daniela Bertolini;Silva, Jose Luis Da Conceicao;Balani, Valerio Americo;Fiorini, Adriana;Fernandez, Maria Aparecida
    • BMB Reports
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    • v.41 no.5
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    • pp.394-399
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    • 2008
  • Multiple sequence alignments of the Bombyx mori fibroin light chain gene (fib-L) from hybrids and from Chinese and Japanese strains demonstrated that 51.6% of the fib-L third intron is conserved. One of these conserved segments, 41 bp long, contains the sequence CGTTATTATACATATT, which is duplicated in the B. mori Nd-$s^D$ mutant. In the present work, electrophoretic mobility assays and computational analyses revealed a major peak of intrinsic bent DNA within the segment that undergoes breakage in the previously-described Nd-$s^D$ mutation. This result suggested that this intrinsically-curved region might mediate DNA cleavage and enhance recombination events in the third intron of the Bombyx mori fib-L gene.

The Crystal Structure of L-Leucine Dehydrogenase from Pseudomonas aeruginosa

  • Kim, Seheon;Koh, Seri;Kang, Wonchull;Yang, Jin Kuk
    • Molecules and Cells
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    • v.45 no.7
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    • pp.495-501
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    • 2022
  • Leucine dehydrogenase (LDH, EC 1.4.1.9) catalyzes the reversible deamination of branched-chain L-amino acids to their corresponding keto acids using NAD+ as a cofactor. LDH generally adopts an octameric structure with D4 symmetry, generating a molecular mass of approximately 400 kDa. Here, the crystal structure of the LDH from Pseudomonas aeruginosa (Pa-LDH) was determined at 2.5 Å resolution. Interestingly, the crystal structure shows that the enzyme exists as a dimer with C2 symmetry in a crystal lattice. The dimeric structure was also observed in solution using multiangle light scattering coupled with size-exclusion chromatography. The enzyme assay revealed that the specific activity was maximal at 60℃ and pH 8.5. The kinetic parameters for three different amino acid and the cofactor (NAD+) were determined. The crystal structure represents that the subunit has more compact structure than homologs' structure. In addition, the crystal structure along with sequence alignments indicates a set of non-conserved arginine residues which are important in stability. Subsequent mutation analysis for those residues revealed that the enzyme activity reduced to one third of the wild type. These results provide structural and biochemical insights for its future studies on its application for industrial purposes.

Effects of UV Irradation on the Alignment of Liquid Crystal (러빙배향된 액정셀에 대한 자외선 조사효과)

  • Kim, Young-Sik;Kim, Jae-Hyung
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2001.11b
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    • pp.324-327
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    • 2001
  • Liquid crystal alignments on a rubbed polyimide layer were investigated by using optical transmission method. Using this technique, we also studied the pretilt angle of the polymer molecules near the surface of a side-chain polymer layer as a function of the rubbing strength. In particular, we obtained the optical characteristics of liquid crystal orientations and pretilt angles for LC cell photo-aligned by UV as well after rubbing alignment. High pretilt angle of 3.84 degree was obtained on the weekly rubbed polymide layer duribg UV irradation time of 60min.

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Effects of UV Irradation on the Alignment of Liquid Crystal (러빙배향된 액정셀에 대한 자외선 조사효과)

  • 김영식;김재형
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2001.11a
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    • pp.324-327
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    • 2001
  • Liquid crystal alignments on a rubbed polyimide layer were investigated by using optical transmission method. Using this technique, we also studied the pretilt angle of the polymer molecules near the surface of a side-chain polymer layer as a function of the rubbing strength. In particular, we obtained the optical characteristics of liquid crystal orientations and pretilt angles for LC cell photo-aligned by UV as well after rubbing alignment. High pretilt angle of 3.84 degree was obtained on the weekly rubbed polymide layer during UV irradation time of 60min.

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Isolation and Cloning of Porcine SLC27A2 Gene and Detection of Its Polymorphism Associated with Growth and Carcass Traits

  • Wang, Tao;Liu, Chang;Xiong, Yuan-Zhu;Deng, Chang-Yan;Zuo, Bo;Xie, Hong-Tao;Xu, De-Quan
    • Asian-Australasian Journal of Animal Sciences
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    • v.20 no.8
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    • pp.1169-1173
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    • 2007
  • The protein encoded by SLC27A2 gene is an isozyme of long-chain fatty-acid-coenzyme A ligase family, and it converts free long-chain fatty acids into fatty acyl-CoA esters, and thereby plays a key role in lipid biosynthesis and fatty acid degradation. In the present study, SLC27A2 located on human chromosome 15 was selected as candidate gene and we isolated and cloned partial fragments of mRNA sequence and genomic fragments of porcine SLC27A2 gene. The coding region of the gene as determined by alignments shared 90% and 82% identity with human and mouse cDNAs, respectively. Detection in LargeWhite and Meishan breeds showed that a single nucleotide polymorphism (SNP) ($A{\rightarrow}G$) existed in exon 7, which caused corresponding amino acid changed for encoding. In LargeWhite pigs it encoded for Val while in Meishan pigs it encoded for Ile, so we developed the PCR-RFLP genotype method for detection of this polymorphism. Association study in 135 $F_2$ reference family indicated that significant correlation existed between the polymorphism and growth and carcass traits.

Isolation and characterization of LHT-type plant amino acid transporter gene from Panax ginseng Meyer

  • Zhang, Ru;Zhu, Jie;Cao, Hong-Zhe;Xie, Xiao-Lei;Huang, Jing-Jia;Chen, Xiang-Hui;Luo, Zhi-Yong
    • Journal of Ginseng Research
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    • v.37 no.3
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    • pp.361-370
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    • 2013
  • A lysine histidine transporter (LHT) cDNA was isolated and characterized from the roots of Panax ginseng, designated PgLHT. The cDNA is 1,865 bp with an open reading frame that codes for a protein with 449 amino acids and a calculated molecular mass of 50.6 kDa with a predicted isoelectric point of 8.87. Hydropathy analysis shows that PgLHT is an integral membrane protein with 9 putative membrane-spanning domains. Multiple sequence alignments show that PgLHT shares a high homology with other plant LHTs. The expression profile of the gene was investigated by real-time quantitative polymerase chain reaction during various chemical treatments. PgLHT was up-regulated in the presence of abscisic acid, salicylic acid, methyl jasmonate, NaCl, and amino acids. To further explore the function of PgLHT gene, full-length cDNA of PgLHT was introduced into P. ginseng by Agrobacterium rhizogenes A4. The overexpression of PgLHT in the hairy roots led to an obviously increase of biomass compared to the controls, and after addition of the amino acids, the overexpressed-PgLHT hairy roots grew more rapidly than untreated controls during early stage of the culture cycle. The results suggested that the PgLHT isolated from ginseng might have role in the environmental stresses and growth response.

Unusual Alignment of Liquid Crystals on Rubbed Films of Polyimides with Fluorenyl Side Groups

  • Hahm, Suk-Gyu;Lee, Taek-Joon;Chang, Tai-Hyun;Jung, Jin-Chul;Zin, Wang-Cheol;Ree, Moon-Hor
    • Proceedings of the Polymer Society of Korea Conference
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    • 2006.10a
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    • pp.239-239
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    • 2006
  • In the present study, we synthesized CBDA-FDA and its analogue, poly(4,4' -(9,9-fluorenyl)diphenylene pyromellitimide) (PMDA-FDA), and then investigated quantitatively the orientational distributions of the polymer chain segments in the surfaces of their films by using linearly polarized Fourier transform infrared (FTIR) spectroscopy and optical retardation analysis. We also examined the films' surface topographies using high spatial resolution atomic force microscopy (AFM). Further, rubbed films were used to assemble antiparallel and $90^{\circ}-twisted$ nematic (TN) LC cells, and the alignment behaviors, pretilt angles and anchoring energies of the LC molecules in the cells were determined. The films were found to have very interesting surface morphologies and LC alignment behaviors, which have not previously been reported. The observed LC alignments, pretilt angles and anchoring energies are discussed by taking into account the interactions of the LC molecules with the oriented polymer chain segments and the surface morphologies.

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