• 제목/요약/키워드: Rearrangements

검색결과 118건 처리시간 0.031초

Synthesis of Some Pyrimido[4,5-b]quinoline Derivatives

  • Marjani, Ahmad Poursattar;Khalafy, Jabbar;Ebrahimlo, Ali Reza Molla;Prager, Rolf.H.
    • Bulletin of the Korean Chemical Society
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    • 제32권7호
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    • pp.2183-2186
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    • 2011
  • A series of pyrimidoquinoline derivatives was synthesized in good yield and short reaction times by reaction of 3-arylaminoisoxazol-5(2H)-ones with derivatives of 2-chloro-3-formylquinoline in toluene under reflux conditions.

Wide phenotypic variations in Charcot-Marie-Tooth 1A neuropathy with rare copy number variations on 17p12

  • Kanwal, Sumaira;Choi, Byung-Ok;Kim, Sang-Beom;Koo, Hea-Soo;Kim, Jee-Young;Hyun, Young-Se;Lee, Hye-Jin;Chung, Ki-Wha
    • Animal cells and systems
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    • 제15권4호
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    • pp.301-309
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    • 2011
  • Charcot-Marie-Tooth disease (CMT) is clinically heterogeneous hereditary motor and sensory neuropathies with genetic heterogeneity, age-dependent penetrance, and variable expressivity. Rare copy number variations by nonrecurrent rearrangements have recently been suggested to be associated with Charcot-Marie-Tooth 1A (CMT1A) neuropathy. In our previous study, we found three Korean CMT1A families with rare copy number variations (CNVs) on 17p12 by nonrecurrent rearrangement. Careful clinical examinations were performed in all the affected individuals with rare CNVs (n=19), which may be the first full study of a subject from a large CMT1A family with nonrecurrent rearrangement. The clinical phenotype showed no significant difference compared with common CMT1A patients, but with variable phenotypes. In particular, a broad intrafamilial phenotypic spectrum was observed within the same family, which may suggest the existence of a genetic modifier. This study may broaden the understanding of the role of CNVs in the pathogenesis of CMT.

분자궤도론에 의한 반응성 결정 (제34보). 수소 시그마 결합 자리옮김 반응에 대한 MINDO/3 이론연구 (1) : 중앙탄소원자를 가진 계 (Determination of Reactivity by MO Theory (XXXIV). MINDO/3 Theoretical Studies on Sigmatropic Hydrogen Rearrangements (1) : Systems with Central Carbon Atom)

  • 조정기;이익춘;오혁근;조인호
    • 대한화학회지
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    • 제28권4호
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    • pp.217-230
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    • 1984
  • 중앙 탄소 원자를 가진 계에서의 1,2-와 1,3-그리고 1,5-수소 시그마 결합 자리 옮김반응에 관하여 전이상태와 활성화 에너지 장벽을 결정하기 위하여 MINDO/3 방법을 이용하였다. 전이상태의 안정성을 설명하는 데에는 궤도의 대칭성 외에 입체효과와 방향성 그리고 궤도간의 상호작용 또한 기여됨을 알았다. 헤테로 원자를 가진 계의 경우, 고립 전자쌍의 궤도가 수소의 자리 옮김반응에 관여하므로 전이상태에서 요구되는 궤도의 비틀림을 줄이게 되며, 그에 따라 활성화 에너지 장벽이 낮게 나타났다. 더욱 정확한 ab initio 계산에 의하여 얻어진 결과와 비교했을 때, 본 연구에서의 MINDO/3방법으로 얻은 상대적인 에너지 장벽의 크기 순서는 일치하는 경향성을 보였다.

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Reanalysis of Ohno's hypothesis on conservation of the size of the X chromosome in mammals

  • Kim, Hyeongmin;Lee, Taeheon;Sung, Samsun;Lee, Changkyu;Kim, Heebal
    • Animal cells and systems
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    • 제16권6호
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    • pp.438-446
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    • 2012
  • In 1964, Susumu Ohno, an evolutionary biologist, hypothesized that the size of X chromosome was conserved in mammalian evolution, and that this was based on chromosomal length. Today, unlike Ohno's method which was based on estimated lengths, we know the exact lengths of some mammalian sequences. The aim of this study was to reanalyze Ohno's hypothesis. In mammalian species, variation in the length of the X chromosome is greater than in the autosomes; however, this variation is not statistically significant. This means that differences in chromosomal length occur equally in the X chromosome and in the autosomes. Interspersed nuclear elements and genetic rearrangements were analyzed to maintain the same variance between the length of the X chromosome and the autosomes. The X chromosome contained fewer short interspersed elements (SINEs) (0.90 on average); however, it did contain more long interspersed elements (LINEs) than did autosomes (1.56 on average). An overall correlation of LINEs and SINEs with genetic rearrangements was observed; however, synteny breaks were more closely associated with LINEs in the autosomes, and with SINEs in the X chromosome. These results suggest that the chromosome-specific activities of LINEs and SINEs result in the same variance between the lengths of the X chromosome and the autosomes. This is based on the function of interspersed nuclear elements, such as LINEs, which can inactivate the X chromosome and the reliance of non-autonomous SINEs on LINEs for transposition.

Comparison of polymerase chain reaction for antigen receptor gene rearrangement and flow cytometric analysis for the diagnosis of canine lymphoma

  • Song, Ru-Hui;Yu, Do-Hyeon;Kim, Jun-Hwan;Lee, Hyun-Seok;Lee, Da-Mi;Park, Chul;Yu, Il-Jung;Park, Jin-Ho
    • 한국동물위생학회지
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    • 제34권3호
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    • pp.265-271
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    • 2011
  • Lymphoma is the most common hematopoietic malignancy in dogs. Diagnosis of lymphoma is classically performed by morphological assessment and immunohistochemistry. But some cases in the early stage are difficult to distinguish and need more objective and accurate methods. So, Polymerase chain reaction (PCR) for antigen receptor rearrangements (PARR) and flow cytometric immunophenotype of lymphoma have been developed continuously. In this study, we performed these two methods to classify lymphoma type in 3 cases. According to PARR analysis, B cell origin lymphoma was diagnosed in two of three cases by testing PBMC and lymph node. All fine needle aspiration (FNA) samples of lymph nodes had high expression of CD21 on >88% of total cell population and PBMC samples also showed high expression of CD21 on >30% of total lymphocytes in those two cases, while the expression of CD3, CD4 and CD8 was absent. These results suggest that concurrent use of PARR and flow cytometric immunophenotype is more effective and valuable tool for the diagnosis and monitoring of canine lymphoma patients.

FISH(Fluorescence in situ hybridization)를 이용하여 분석한 방사선에 의해 유발된 림프구의 염색체 이상 (Radiation induced Chromosome aberration in human Iymphocyte detected by Fluorescence in sifu hybridization)

  • 정해원;손은희;기혜성;하성환
    • 한국환경성돌연변이발암원학회지
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    • 제16권2호
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    • pp.88-96
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    • 1996
  • Fluorescence in situ hybridization (FISH) with the DNA probe for human chromosome 4 was used to analyse in vitro radiation induced chromosome rearrangement in peripheral lymphocyte. Translocations, dicentrics, acentrics and color junctions involving the painted chromosome were scored according to the Protocol for Aberration Identification and Nomenclature Terminology (PAINT) system. The frequency of chromosome rearrangements including reciprocal translocation, dicentric, acentric fragment and color junction increased with radiation dose. The frequency of dicentric chromosome reduced by the fixation time following irradiation, whereas that of translocation was relatively persistent. The applicability of FISH for scoring stable translocation for biological dosimetry was demonstrated.

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Formation and Physical Properties of Yogurt

  • Lee, W.J.;Lucey, J.A.
    • Asian-Australasian Journal of Animal Sciences
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    • 제23권9호
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    • pp.1127-1136
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    • 2010
  • Yogurt gels are a type of soft solid, and these networks are relatively dynamic systems that are prone to structural rearrangements. The physical properties of yogurt gels can be qualitatively explained using a model for casein interactions that emphasizes a balance between attractive (e.g., hydrophobic attractions, casein cross-links contributed by calcium phosphate nanoclusters and covalent disulfide cross-links between caseins and denatured whey proteins) and repulsive (e.g., electrostatic or charge repulsions, mostly negative at the start of fermentation) forces. Various methods are discussed to investigate the physical and structural attributes of yogurts. Various processing variables are discussed which influence the textural properties of yogurts, such as total solids content, heat treatment, and incubation temperatures. A better understanding of factors contributing to the physical and structural attributes may allow manufacturers to improve the quality of yogurt.

Structure and Dynamics of Perfluoroalkanes and Their ${\beta}$-Cyclodextrin Inclusion Compounds Investigated by Solid-state $^{19}F$ MAS NMR

  • Tatsuno, Hiroto;Ando, Shinji
    • 한국고분자학회:학술대회논문집
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    • 한국고분자학회 2006년도 IUPAC International Symposium on Advanced Polymers for Emerging Technologies
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    • pp.305-305
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    • 2006
  • The molecular structure and dynamics of inclusion compounds (ICs) consisting of n-perfluoroalkane (PFA) guests and ${\Box}-cyclodextrin$ (${\Box}-CD$) host were investigated using $^{19}F$ magic angle spinning (MAS) and $^{1}H{\to}^{19}F$ cross polarization (CP) / MAS NMR spectroscopy with the aid of thermal analyses, FT-IR spectroscopy, X-ray diffraction, and $^{1}H{\to}^{19}F$ CP/MAS technique revealed that $C_{9}F_{20}$ molecules included in ${\Box}-CD$ undergo vigorous molecular motion and partly come out of the ${\Box}-CD$ channel above $80^{\circ}C$. In case of $C_{20}F_{42}/{\Box}-CD$, an exothermic peak is observed by differential scanning calorimetry (DSC) at ca. $40^{\circ}C$ which suggests that ${\Box}-CD$ molecules become mobile and commence rearrangements that form more ordered structures at higher temperatures.

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Efficient Bimodal Ring-opening Polymerization of ε-Caprolactone Catalyzed by Titanium Complexes with N-Alkoxy-β-ketoiminate Ligands

  • Cho, Min-Ho;Yoon, Jin-San;Lee, Ik-Mo
    • Bulletin of the Korean Chemical Society
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    • 제28권12호
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    • pp.2471-2476
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    • 2007
  • A series of titanium complexes containing terdentate β-ketoiminate ligands were found to be efficient for the ring-opening polymerization of ε-caprolactone (ε-CL), producing poly(ε-caprolactone) (PCL) with bimodal distribution. Steric factors imposed by methyl substituents on the back bone of the alkoxy group affected significantly the polymerization rate and physical properties of the resulting PCL. Intra- and intermolecular transesterifications rather than disproportional rearrangements were responsible for the bimodal behavior and for the change in the molecular weight (Mw). Dilution with toluene reduced yield, and lowered polydispersity (PDI) and Mw of PCL, while the catalytic activities of the dimeric complex, [Ti(Oi-Pr)2(N-alkoxy-β- ketoiminate)]2 and Ti(Oi-Pr)4 were not sensitive to the added solvent. The dimeric complex showed living character, while other catalysts suffered from chain termination reactions.