• 생명과학회지
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• 제13권6호
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• pp.856-864
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• 2003

원핵생물 (Procaryote)의 분류에 16S rRNA유전자가 많이 이용되어 있으나 제한된 해상력과 유전자의 수에 차이가 있는 등의 문제가 있어 이를 보완할 수 있는 새로운 생체분자를 찾고 그 분류 결과를 16S rRNA의 결과와 비교하였다. COG (Clusters of Orthologous of protein) 방법을 이용하여 43종의 미생물중에서 진핵생물을 제외한 42종의 원핵생물 (procaryote)에서만 발견되는 3종류의 COG인 Transcription elongation factor인 COG0195과 bacterial DNA primase인 COG0358 그리고 uridylate kinase인 COG0528를 구하였다. 이중 유사도와 유전자 수를 바탕으로 새로운 분류의 키로 uridylate kinase를 설정하여 분석한 결과, 같은 속 (genus)에 속하는 세균들은 아주 높은bootstrap value를 갖고 분류도에서 같은 위치에 분포하고 고세균 (Archaebacteria) 내부의 응집성이 높은 등의 유사성을 보였다. 한편 alpha와 epsilon 그룹의 Proteobacteria가 분류도에서 다르게 위치하고 진정세균 (Eubacteria)의 Spi-rochaetales에 속하는 Treponema pallidum (Tpa)와 Borrelia burgdorferi (Bbu)가 고세균과 유연관계가 높게 나타나는 등 차이점도 보였다. Uridylate kinase를 이용한 분류는, 아주 높은 보존성에 의해서 생기는 16S rRNA 유전자를 이용한 문제점을 보완하여 원핵생물의 정확한 분류에 기여할 수 있을 것으로 사료되었다.

• Bulletin of the Korean Chemical Society
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• 제14권1호
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• pp.113-117
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• 1993

Good yield synthetic routes for the production of new B-alkyl-dithiaborane clusters are reported. The syntheses of the B-alkyl-dithiaboranes are based on the use of Fischer-type carbene reagents to activate the B-H bonds of dithiaborane for alkyl-addition reactions and are the first examples of transition-mediated reactions of dithiaborane to be reported. Thus, reactions employing arachno-$S_2B_7H_8$- and $(CO)_5M{C(R_1)R_2}$ (M = Cr, W; $R_1 = CH_3,\;C_6H_5;\; R_2 = OCH_3,\;SC_6H_5)$ were found to yield the intermidiate anions I, $[(CO)_5M{C(R_1)R_2S_2B_7H_8}]^-$, which upon protonation gave the corresponding neutral, air-sensitive cluster arachno-4-$RCH_2-6,8-S_2B_7H_8(R=CH_3,\;IIa;\;C_6H_5,\;IIb)$ range from 30 to 35% yield. Complexes IIa and IIb are isoelectronic with arachno-6,8-$S_2B_7H_9$ and, on the basis of the spectroscopic data, are proposed to adopt a similar arachno cage geometry in which an $RCH_2$ units are substituted to 4 position boron atom of the arachno-6,8-$S_2B_7H_9$.

• Journal of Microbiology and Biotechnology
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• 제31권11호
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• pp.1508-1518
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• 2021

Hsa_circ_0001947 is associated with multiple cancers, but its function in non-small cell lung cancer (NSCLC) is ambiguous and needs further research. The targeting relationship among circ_0001947, miR-661, and downstream of tyrosine kinase 7 (DOK7) was predicted by database and further verified by dual-luciferase reporter assay, while their expressions in cancer tissues and cells were detected by quantitative real-time polymerase chain reaction (qRT-PCR). After transfection, cell biological behaviors and expressions of miRNAs, miR-661 and DOK7 were determined by cell function experiments and qRT-PCR, respectively. Circ_0001947 was low-expressed in NSCLC tissues and cells. Circ_0001947 knockdown intensified cell viability and proliferation, induced cell cycle arrest at S phase, suppressed apoptosis and evidently enhanced miR-510, miR-587, miR-661 and miR-942 levels, while circ_0001947 overexpression did the opposite. MiR-661 was a target gene of circ_0001947 that participated in the regulation of circ_0001947 on cell biological behaviors. Furthermore, DOK7, the target gene of miR-661, partly participated in the regulation of miR-661 on cell viability. Hsa_circ_0001947 acts as a sponge of miR-661 to repress NSCLC development by elevating the expression of DOK7.

• The Plant Pathology Journal
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• 제18권2호
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• pp.98-101
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• 2002

Using phytoplasma universal primer pair Pl and P7, a fragment of about 1.8 kb nucleotide sequences of 16S rRNA gene and 16S-23S rRNA intergenic spacer region, and a portion of 23S rRNA gene of jujube witches'broom (JWB) and mulberry dwarf(MD) phytoplasmas were determined. The nucleotide sequences of JWB and MD were 1,850 bp and 1,831 bp long, respectively. The JWB phytoplasma sequence was aligned with the homologous sequence of MD phytoplasma. Twenty-eight base insertions and nine base deletions were found in the JWB phytoplasma sequence compared with that of MD phytoplasma. The similarity of the aligned sequences of JWB and MD was 84.8%. The near-complete 16S rRNA gene DNA sequences of JWB and MD were 1,529 bp and 1,530 bp in length, respectively, and revealed 89.0% homology. The 16S-23S rRNA intergenic spacer region DNA sequences were 263 bp and 243 bp in lengths respectively, while homology was only 70% and the conserved tRNA-lle gene of JWB and MD was located into the intergenic space region between 16S-23S rRNA gene. The nucleotide sequences were 77 bp long in both JWB and MD, and showed 97.4% sequence homology. Based on the phylogenetic analysis of the two phytoplasmas, the JWB phytoplasma belongs to the Elm yellow phytoplasma group (16S rV), whereas, the MD phytoplasma belongs to the Aster yellow group (16S rI).

• Bulletin of the Korean Chemical Society
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• 제28권11호
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• pp.2003-2008
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• 2007

The aminolysis of diphenyl thiophosphinic chloride (2) with substituted anilines in acetonitrile at 55.0 oC is investigated kinetically. Kinetic results yield large Hammett ρX (ρnuc = ?3.97) and Bronsted βX (βnuc = 1.40) values. A concerted mechanism involving a partial frontside nucleophilic attack through a hydrogen-bonded, four-center type transition state is proposed on the basis of the primary normal kinetic isotope effects (kH/kD = 1.0-1.1) with deuterated aniline (XC6H4ND2) nucleophiles. The natural bond order charges on P and the degrees of distortion of 42 compounds: chlorophosphates [(R1O)(R2O)P(=O)Cl], chlorothiophosphates [(R1O)(R2O)P(=S)Cl], phosphonochloridates [(R1O)R2P(=O)Cl], phosphonochlorothioates [(R1O)R2P(=S)Cl], chlorophosphinates [R1R2P(=O)Cl], and chlorothiophosphinates [R1R2P(=S)Cl] are calculated at the B3LYP/ 6-311+G(d,p) level in the gas phase.

• KDI Journal of Economic Policy
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• 제32권3호
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• pp.71-99
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• 2010

Adrian and Brunnermeier(2009)가 제안한 CoVaR는 위기의 파급효과를 측정하는 데 유용한 도구이다. 특히 어떤 금융기관이 금융시스템에 대해 어느 정도의 잠재적 리스크를 갖고 있는지를 측정할 수 있다. 본 연구는 CoVaR를 추정하는데 있어서 Adrian and Brunnermeier(2009)가 사용한 분위수 회귀방식이 아니라 이변량 정규분포 및 $S_U$-정규분포 등 모수적 분포함수를 이용하여 CoVaR를 추정하는 방법을 제안한다. 이들 모형을 이용하여 국내 은행산업을 대상으로 CoVaR를 추정하고, 이를 통해 CoVaR의 현실적 유용성을 점검함과 동시에 각 모형들의 추정 성과를 비교한다. 추정 결과, 은행들이 시스템리스크에 양(+)의 기여를 하고 있는 것으로 나타났다. 모형별로는 $S_U$-정규분포모형에 비해 분위수 회귀와 정규분포모형이 CoVaR를 (절댓값에서) 크게 과소평가하며, 위기수준을 높일수록 그 정도가 심해지는 것으로 나타났다.

• 생명과학회지
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• 제12권4호
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• pp.427-432
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• 2002

잇바디돌김(Porptyra dentata)을 대상으로 핵의 18S ribo-somal RNA를 지령하는 유전자 즉 18S rDNA 유전자를 증폭하고, 염기서열분석을 수행하였다. 전체 18S rDNA의 exon 영역 크기는 1822 bp, intron 영역의 크기는 512 bp였다. 이들 exon과 intron 영역의 G+C함량은 각각 49%와 55%씩 나타내었다. 일본산 잇바디돌김(CenBank accession number: AB013183)의 exon 영역과의 비교에서 상동성이 97.1%에 도달하였다. 568번과 569번 염기사이의 upstream에 위치하는 intron 영 역에서는 AB013183과 52.1%의 상동성을 보였다.

• 호남수학학술지
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• 제26권4호
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• pp.463-469
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• 2004

In this paper we establish some recurrence relations satisfied by quotient moments of upper record values from the exponential distribution. Let $\{X_n,\;n{\geq}1\}$ be a sequence of independent and identically distributed random variables with a common continuous distribution function F(x) and probability density function(pdf) f(x). Let $Y_n=max\{X_1,\;X_2,\;{\cdots},\;X_n\}$ for $n{\geq}1$. We say $X_j$ is an upper record value of $\{X_n,\;n{\geq}1\}$, if $Y_j>Y_{j-1}$, j > 1. The indices at which the upper record values occur are given by the record times {u(n)}, $n{\geq}1$, where u(n)=min\{j{\mid}j>u(n-1),\;X_j>X_{u(n-1)},\;n{\geq}2\} and u(1) = 1. Suppose $X{\in}Exp(1)$. Then $\Large{E\;\left.{\frac{X^r_{u(m)}}{X^{s+1}_{u(n)}}}\right)=\frac{1}{s}E\;\left.{\frac{X^r_{u(m)}}{X^s_{u(n-1)}}}\right)-\frac{1}{s}E\;\left.{\frac{X^r_{u(m)}}{X^s_{u(n)}}}\right)}$ and $\Large{E\;\left.{\frac{X^{r+1}_{u(m)}}{X^s_{u(n)}}}\right)=\frac{1}{(r+2)}E\;\left.{\frac{X^{r+2}_{u(m)}}{X^s_{u(n-1)}}}\right)-\frac{1}{(r+2)}E\;\left.{\frac{X^{r+2}_{u(m-1)}}{X^s_{u(n-1)}}}\right)}$.

• Animal cells and systems
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• 제4권1호
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• pp.77-85
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• 2000

This study has demonstrated the molecular variation of 5S rRNA genes in 15 Allium subgenus Rhizirideum and 1 Allium subg. Allium. For cloning of the 5S rRNA genes, PCR products were obtained from amplification with oligonucleotide primers which were derived from the conserved coding region of 5S rRNA genes. These amplified PCR products were cloned and identified by FISH and sequence analysis. The 5S rRNA loci were primarily located on chromosomes 5 and/or 7 in diploid species and various chromosomes in alloploid species. The size of the coding region of 5S rRNA genes was 120 bp in all the species and the sequences were highly conserved within Allium species. The sizes of nontranscribed spacer (NTS) region were varied from 194 bp (A. dektiude-fustykisum, 2n=16) to 483 bp (A. sativum). Two kinds of NTS regions were observed in A. victorialis var. platyphyllum a diploid, A. wakegi an amphihaploid, A. sacculiferum, A. grayi, A. deltoide-fistulosum and A. wenescens all allotetraploids, while most diploid species showed only one NTS region. The species containing two components of NTS region were grouped with different diploid species in a phylogenetic tree analysis using the sequences of 5S rRNA genes and adjacent non-coding regions.

• 미생물학회지
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• 제37권2호
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• pp.137-144
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• 2001

순천만 갯벌의 세균 군집의 다양성을 조사하기 위해 16S rDNA의 다양성을 조사하였다. 갯벌로부터 전체 핵산을 분리한 후, 세균에 상보적인 universal primer로 증폭된 16S rDNA로부터 클론 라이브러리를 만들었다. 총 111개의 클론으로부터 HaeIII를 이용하여 amplified rDNA restriction analysis (ARDRA)를 수행하고, Gelcompar II 프로그램을 이용하여 pattern을 clustering하였다. 111개의 클론 중 100가지의 서로 다른 RFLP type이 조사되었고, 이들 중 전체 클론 라이브러리를 대표할 수 있는 20개의 클론을 선별하여 부분적인 염기서열을 분석하여 세균 다양성을 분석하였다. 20개의 클론중에는 RDP와 GenBank에서 제공하는 small subunit RNA database와 동일한 클론은 존재하지 않았으며, 이미 알려진 배양 가능한 세균의 16S rRNA 염기서열과 비교 하였을때 77∼96.8%의 유사도를 보였다. 또한 이들 20개의 클론은 alpha-, delta-, gamma-Proteobacteria, low G+C Gram positive bacteria, high G+C Gram positive bacteria, Sphingobacteria (Cytophaga); Cyanobacteria (Chloroplast)등 주요한 7개 lineage에 속했으며, 클론들 중 Proteobacteria가 우점종을 차지하고 있었다.