• Food Science and Biotechnology
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• v.18 no.4
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• pp.1027-1029
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• 2009

The aim of this research was to study the structural and rheological properties of gels formed by ferulated maize bran arabinoxylans (MBAX) at different concentrations. MBAX was cross-linked by a laccase leading to the formation of dimers and trimers of ferulic acid (di-FA, tri-FA) as covalent cross-link. An increase in MBAX gels elasticity (from 11 to 20 Pa) as well as lower mesh size (from 80 to 48 nm) were obtained by augmenting the MBAX concentration from 2.5 to 3.5%(w/v), respectively, but no increase in di-FA and tri-FA content was obtained (0.03 and 0.014 ${\mu}$g/mg MBAX, respectively).

• Bulletin of the Korean Chemical Society
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• v.26 no.4
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• pp.575-578
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• 2005

Electrospray ionization mass spectrometry (ESI MS) was used, along with gas chromatography-mass spectrometry (GC-MS), to monitor Paal-Knorr synthesis of 2,5-dimethyl-1-phenylpyrrole by condensation of aniline with 2,5-hexanedione. In addition to 2,5-dimethyl-1-phenylpyrrole observed as a single spot by TLC, unexpected dimer size compounds were observed by GC-MS. Dimers and trimers were observed by ESI MS. ESI tandem mass spectrometry was used to select plausible structures for the dimer. ESI MS with or without liquid chromatographic separation is useful for observing oligomeric byproducts with low volatility produced in organic reactions.

• Journal of Industrial Technology
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• v.24 no.B
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• pp.59-64
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• 2004

GaAs thin films were grown epitaxially by MOCVD method on (001) GaAs substrate. And as a surfactant, Bi(bismuth) thin films were deposited on GaAs buffer layer by using TMBi(trimethylbismuth) source. In-situ reflectance difference spectroscopy(RDS) was used to monitor the surface reconstruction of GaAs and Bi thin films. As the results, under the exposure of TBAs(tertiarybuthylarsine) and hydrogen atmosphere, the surface reconstruction of GaAs was changed from As-rich c($4{\times}4$) to As-rich ($2{\times}4$), which was due to the adsoption and desorption of As dimers. The first bismuth surface related RDS signal was reported. At the deposition temperature of $450^{\circ}C$, Bi-terminated GaAs surface showed the RDS spectrum similar to that of Sb-terminated GaAs surface, possibly a ($2{\times}4$) surface. And Bi surface layers were rapidly evaporated with increasing the deposition temperature($550^{\circ}C$), finally becoming As-terminated ($2{\times}4$) surface.

• Korean Journal of Crystallography
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• v.15 no.1
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• pp.29-34
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• 2004

The crystal structure of cholesteryl hemisuccinate ($C_{31}H_{50}O_4$) was investigated by X-ray diffraction method. The cholesterol fragment of the title compound were in good agreement with those for related cholesterol derivatives. The unit cell contains four cholesteryl hemisuccinate molecules that are not related by crystal symmetry and have their tetracyclic system almost parellel to each other. There are two pairs of hydrogen-bonded dimer between A and D molecules and B and C molecules. These two hydrogen-bonded dimers are parallel to the c-axis, and are closely packed.

• Journal of Photoscience
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• v.12 no.3
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• pp.163-169
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• 2005

Recent reports suggest that floral organs such as sepals, petals, stamens, and carpels are specified by quaternary MADS protein complexes with different combinations. The formation of quaternary complexes of ABCDE MADS proteins may be the molecular basis of ABCDE model for the floral organ development. The MADS complexes involved in each floral organ development seem to be conserved in at least dicot species although detailed molecular mechanism is slightly different depending on species. Even in monocot, at least rice, MADS complexes similar to those in dicot exist, suggesting that the floral organ specification by MADS protein complexes may be conserved in most of plants. The MADS protein complexes may have more specific recognition of target genes or more transcription activation ability than monomers or dimers, resulting in finely regulated floral organ development.

• Neonatal Medicine
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• v.18 no.1
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• pp.6-13
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• 2011

All newborn infants with clinically significant bleeding should be evaluated for a hemostatic deficit. Medical history should include the following data: familial bleeding disorders, maternal illness and medication, age of bleeding onset, and prophylactic administration of vitamin K. The first essential step for evaluating bleeding neonates is determining whether the baby is sick or well. The physician should also evaluate the extent of the bleeding, features of bleeding lesions, and other abnormal findings from the physical examination. Skeletal anomalies may provide diagnostic clues. Depending on the clinical features and results of screening tests, other tests including coagulation factors may be useful for determining the diagnosis. All laboratory results must be considered in the context of age-related reference values. The platelet function analyzer provides a promising alternative to bleeding time. Fibrin degradation products and D-dimers are used for screening and specially testing fibrinolytic activity, respectively. The Apt test may help to rule out factors derived from maternal blood. Radiologic imaging studies are important because asymptomatic intracranial hemorrhages are common in neonates.

• Proceedings of the Korean Vacuum Society Conference
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• 2011.02a
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• pp.301-301
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• 2011

We present theoretical investigations of the self-assembled growth of one-dimensional (1D) molecular lines directed across the dimer rows on the H-terminated Si(001) surface [1]. Based on density-functional theory calculations, a new growth mechanism of the 1D acetylacetone line is proposed [2], which involves the radical chain reaction initiated at two dangling-bond sites on one side of two adjacent Si dimers. It is also enabled that, if an H-free Si dimer were employed as the initial reaction site, a 1D acetylacetone line can grow along the dimer row. Our findings represent the first insight into the growth of 1D molecular lines not only across but also along the dimer rows on the H-terminated Si(001) surface.

• Proceedings of the Korean Society of Developmental Biology Conference
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• 2001.02a
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• pp.12-13
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• 2001

과학자들 사이에서만 논의되어 왔던 내분비계 장애물질 문제가 일반인들의 관심을 얻게 된 것은 T.Colborn, D.Dumanoski와 J.P.Myers가 과학논문을 근거로 집필한 '도둑맞은 미래(Our Stolen Future)'의 발간이 계기가 되었다 (1996년 1월). 그 후 컵라면 용기에서의 styrene dimers & trimers 검출 논란이 제기되면서 일본 및 우리나라에서도 관심을 갖게 되었는데, 이제 내분비계 장애물질 문제는 단순한 과학적 문제가 아니라 중요한 사회적, 환경적 문제로 인식되고 있으며 지구 온난화, 오존층 파괴와 더불어 지구 3대 환경 문제 중 하나로까지 거론되고 있다. 내분비계 장애물질 문제는 아직까지 명확히 규명되지 않은 상태로 인체에 미치는 영향을 밝히기까지는 장기간의 집중 연구가 필요하다. 여기서는 내분비계 장애작용 검색 및 시험법 확립을 위한 현 시점에서의 국제적 노력에 대하여 미국 EPA 및 OECD를 중심으로 알아보고 OECD 내분비계 장애물질 시험법 확립을 위한 국제협력연구의 일부 실험결과를 발표하고자 한다.

• Applied Chemistry for Engineering
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• v.17 no.5
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• pp.504-508
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• 2006

Molecular weight of polyaniline is controlled in the range of oligomer to low molecular weight by controlling the ratio of aniline dimer (p-aminodiphenylamine) to monomer. Aniline dimers act as nucleation sites in chain growth during the polymerization of aniline. The molecular weights of polyanilines are estimated by GPS and relative viscosity measurement. The physical and chemical properties of polyanilines with various molecular weights are studied by UV-Vis, FT-IR, and electrical conductivity measurements.

• Proceeding of EDISON Challenge
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• 2015.03a
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• pp.163-166
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• 2015

Intramolecular energy migration in a cyclic porphyrin array is spontaneous transfer of energy from one excited site to another. Since the efficiency of energy migration is inversely proportional to distance, the energy migration is occurred on their adjacent sites more often than distant ones. Therefore, the energy migration in the cyclic porphyrin array is largely dependent on their conformational characters. However, evaluation of conformational information by means of experimental tools is ambiguous since their limited resolution. In this work, we calculate the internal angle and distance distributions of cyclic porphyrin arrays using molecular dynamics simulations to obtain conformational information. To evaluate the angle and distance distributions respect to molecular size, we constructed molecules with n porphyrin dimers (n=1,3,7) in implicit solvent environment. Performing molecular dynamics simulations, we modulated alkyl groups to investigate additional conformational effects of the system.