• Title/Summary/Keyword: S/R

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Percentages of the Deuterium Retained After para-Hydroxylation of (R) (+) $4-^2H$$-Phenytoin and (S) (-) $4-^2H$$-Phenytoin in Rat

  • Moustafa, Mohamed A.;El-Emam, Ali A.;Abdelal, Ali M.;Metwally, Mohammed E.S.
    • Archives of Pharmacal Research
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    • v.14 no.1
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    • pp.35-40
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    • 1991
  • (R) (+) and (S) (-) $4-^2H$-phenytoin have been used as substrates for the determination of the percentage of deuterium retention (NIH shift) after para-hydroxylation of the substrates in rat. By using GC-MS analyses, the percentages of deuterium retention were found to be 69% and 70% for the (R) and (S) phenyl rings, respectively. The results add additional evidence for the involvement of arene oxide in the oxidation of the pro (R) and pro (S) phenyls of phenytoin. The oxidation process of each ring could be mediated by independent enzyme systems, a rapid oxidative enzyme for the pro (S) phenyl and a slow oxidative enzyme for the pro (R) phenyl.

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Genetic Characterization based on Partial 28S rRNA Gene Sequence of Korean Two Scallops (한국산 가리비 2종의 28S rRNA 유전자 염기서열에 의한 유전적 특성)

  • Park, Gab-Man
    • The Korean Journal of Malacology
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    • v.13 no.1
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    • pp.1-7
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    • 1997
  • 한국산 가리비, 큰가리비(Patinopecten yessoensis)와 주문진가리비(Chlamys swifti), 2종에 대한 28S ribosomal RNA 유전자의 PCR- 산물을 이용 RFLP 및 염기서열을 밝히고, 이미 보고된 2과 3종의 염기서열과 상동성을 비교 분석하였다. 그 결과 28S rRNA유전자를 이용하여 7가지 제한효소를 처리한 PCR-RFLP의 종간 차이에서 Taq I 제한효소에서만 차이를 볼 수 있었다. 한편 두종간에 28S rRNA유전자의 D1 부위의 염기서열에서 231개 부위 중 14군데에서 변이를 보였다.

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Cerebrosides and Terpene Glycosides from the Root of Aster scaber

  • Kwon, Hak-Cheol;Cho, Ock-Ryun;Lee, Kang-Choon;Lee, Kang-Ro
    • Archives of Pharmacal Research
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    • v.26 no.2
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    • pp.132-137
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    • 2003
  • Three cerebrosides 2, 3, and 5 and two terpene glycosides 1 and 4 have been isolated from the methanol extract of the root of Aster scaber. Their structures were determined as 3-Ο-$\beta$-D-glucuronopyranosyl-oleanolic acid methyl ester (1), (2S, 3S, 4R, 2 R, 8Z, 15 Z)-N-2 -hydroxy-15 -tetracosenoyl-1-Ο-$\beta$-D-glucopyranosyl-4-hydroxy-8-sphingenine (2), (2S, 3S, 4R, 8Z)-N-octadecanoyl-1-Ο-$\beta$-D-glucopyranosyl-4-hydroxy-8-sphingenine (3), 1$\alpha$-hydroxy-6$\beta$-Ο-$\beta$-D-glucosyl-eudesm-3-ene (4), and (2S, 3S, 4R, 2 R, 8Z)-N-2 -hydroxy-hexadecanoyl-1-Ο-$\beta$-D-glucopyranosyl-4-hydroxy-8-sphingenine (5) on the basis of spectroscopic methods.

Studies on the Design and Synthesis of New Monocyclic β-Lactams Containing Substructures of Penicillin G

  • Lee, Sang Hyup
    • Bulletin of the Korean Chemical Society
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    • v.35 no.10
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    • pp.2990-2994
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    • 2014
  • The studies on design and synthesis of new monocyclic ${\beta}$-lactam esters 4(R/S)-(1'-methoxycarbonylpropyl- 2'(R/S)-thio)-3(R)-phenylacetamidoazetidin-2-one (3a) and 4(R/S)-(1'-methoxycarbonyl-2'-methylpropyl-2'- thio)-3(R)-phenylacetamidoazetidin-2-one (3b) were described. Compounds 3a and 3b were specifically designed to retain all penicillin substructures except the bicyclic system, which would be conceived by cleaving the C(3)-N(4) bond of penicillin G. Compounds 3a and 3b are of particular interest in the context of the structural elucidation of monocyclic ${\beta}$-lactams originated from penicillin. Key intermediates, ${\beta}$-mercapto esters 6a and 6b, were synthesized from conjugate acids 4a and 4b using three-step synthetic sequences, respectively, and 4(S)-acetoxy-3(S)-phenylacetamidoazetidin-2-one (7) was obtained from the degradation of penicillin G. Reactions of 6a and 6b with 7, thus obtained, provided the target compounds 3a and 3b, respectively.

Design of Automated Warehousing System for Increased S/R Machine Utilization

  • Hwang, H.;Ko, C.S.
    • Journal of Korean Institute of Industrial Engineers
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    • v.14 no.2
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    • pp.99-114
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    • 1988
  • The objective of this study is mainly related to design aspects of Multi-aisle S/R machine system (MASS) which can substantially reduce high initial investment cost of Automated Storage/Retrieval System. Firstly, the average travel time of the S/R machine is determined under single and dual commands, from which the average performance of S/R machine is evaluated. Secondly, a design model is developed and the system parameters, such as length and height of the system, and the number of S/R machines, traversers and aisles are determined which provide minimum initial investment and operating costs. Also, through experiments, sensitivity analysis is made for the throughput and storage volume.

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Synthesis and Characterization of New Group 13 Complexes of 2-Acetylpyridine-S-methyldithiocarbazate. Single-Crystal Structure of Me₂Ga[$NC_5H_4C$(CH₃)NNC(S)SMe] and Me₂In[$NC_5H_5C$(CH₃)NNC(S)SMe]

  • 백철기;강상욱;이채호;이영행;고재정
    • Bulletin of the Korean Chemical Society
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    • v.18 no.3
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    • pp.311-316
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    • 1997
  • The synthesis and characterization of the mononuclear group 13 heterocyclic carboxaldehyde methyldithiocarbazate complexes Me2M[NC5H4CRNNC(S)SCH3] (M=Al, R=H(1); M=Ga, R=H(2); M=Al, R=CH3(3); M-Ga, R=CH3(4); M=In, R=CH3(5)) are described. Compounds 1-5 were prepared by the reaction of MMe3 (M=Al, Ga, In) with 2-formy or 2-acetylpyridine-S-methyldithiocarbazate in toluene. These compounds 1-5 have been characterized by microanalysis, NMR (1H, 13C) spectroscopy, mass spectra, and single-crystal X-ray diffraction. X-ray single-crystal diffraction analyses reveal that 4-5 are mononuclear metal compounds with coordination number of 5 and N,N,S coordination mode.

Frictional Pressure Drop of a Capillary Tube Flow of Pure HFC Refrigerants and Their Mixtures (HFC 순수냉매 및 혼합냉매의 모세관내에서 마찰에 의한 압력강하)

  • Chang, S.D.;Ro, S.T.
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.7 no.4
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    • pp.589-599
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    • 1995
  • The frictional pressure drop of a capillary tube flow is experimentally investigated for pure refrigerants such as R32, R125, and R134a and refrigerant mixtures such as R32/R134a(30/70 by mass percent), R32/R125(60/40), R125/R134a(30/70), and R32/R125/R134a(23/25/52). The binary interaction parameters for the calculation of viscosities of refrigerant mixtures are found based upon the data in the open literature. Several homogeneous flow models predicting the viscosity of two-phase region are compared to select the best model. Cicchitti's equation is known to be the most adequate for the prediction of the viscosity for refrigerant mixtures, which is used in the analysis of adiabatic capillary flows. A model for the prediction of the frictional pressure drop of single and two-phase flow is developed for refrigerant mixtures in this study. This model may be used to design and analyze the performance of a capillary tube in the refrigerating system.

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Solvent Effect on the Nature of the Metallamacrocycles Formed: Formation of Octanuclear and Dodecanuclear Manganese Metalladiazamacrocycles

  • John, Rohith P.;Lee, Kyung-Jin;Lee, Kyung-Jae;Park, Mi-Ra;Lah, Myoung-Soo
    • Bulletin of the Korean Chemical Society
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    • v.28 no.11
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    • pp.2009-2014
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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.

Properties of a Surface Curvature in Toric Lens (토릭렌즈의 표면 곡률 특성 연구)

  • Park, Sang-An;Kim, Yong-Geun
    • Journal of Korean Ophthalmic Optics Society
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    • v.6 no.2
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    • pp.65-70
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    • 2001
  • We obtained the sum of two curvature ($C_x+C_y$) in toric lens which two toroidal surface is the right angle each other. $$C_x+C_y=\frac{x^2+y^2}{2r_1}+\frac{x^2}{2}(\frac{1}{r_2}-\frac{1}{r_1})$$ and the sum of two curvature ($C_a+C_b$) in toric lens about the cross angle. $$(C_a+C_b)=\frac{x^2cos^2{\alpha}_1}{2r_1}+\frac{x^2cos^2{\alpha}_2}{2r_2}+\frac{y^2sin^2{\alpha}_1}{2r_1}+\frac{y^2sin^2{\alpha}_2}{2r_2}$$ and claculated the parameter S, C, ${\theta}$ of a combination power in toric lens of the cross angle including surface curvature ($C_x$, $C_y$) values. $$S=(n-1)\[\frac{C_x}{x^2}+\frac{C_y}{y^2}\]-\frac{C}{2},\;C=-\frac{2(n-1)}{sin2{\theta}}\[\frac{C_x}{x^2}+\frac{C_y}{y^2}\]$$ $${\theta}=\frac{1}{2}tan^{-1}\[-\frac{{C_xy^2sin2{\theta}_1}+{C_yx^2sin2{\theta}_2}}{{C_xy^2cos2{\theta}_1}+{C_yx^2cos2{\theta}_2}}\]$$.

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Cloning of the Bombyx mori short neuropeptide F receptor (BsNPF-R) cDNA (누에 short neuropeptide F receptor (BsNPF-R)의 cDNA cloning)

  • Shin, Hyojung;Kwon, Kisang;Hong, Sun Mee;Kim, Hong Geun;Park, Kwan-Ho;Choi, Ji-Young;Kim, Seung-Whan;Yu, Kweon;Kwon, O-Yu
    • Journal of Life Science
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    • v.26 no.6
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    • pp.721-726
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    • 2016
  • It has already been reported that short neuropeptide F (sNPF) stimulates feeding behaviors in a wide variety of insect species. In the present study, we cloned cDNA, encoding a sNPF receptor homologue from a silkworm, Bombyx mori, named BsNPF-R. The amino acid sequence of BsNPF-R was compared with those of sNPF-R thus far reported, which is shared with humans (36%), mice (34%), zebrafish (35%), and fruit flies (51%), respectively. A BsNPF-R protein’s mass was theoretically estimated to be 42,731 Da and it is a putative plasma membrane-penetrating protein. The mRNA expression of BsNPF-R was tested; the results showed that a strong expression was detected at the midgut, post-silk gland, Malpighian, and testis; however, a weak expression was at the fat body, hemocyte, and ovary. In addition, the synthesized sNPF of a silkworm regulated the BsNPF-R mRNA expression through the cell-based functional analysis.