• Bulletin of the Korean Chemical Society
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• 제30권9호
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• pp.1946-1950
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• 2009

Tripod-shaped liquid crystals with $sp^3$ nigrogen at the apex were prepared from triethanolamine. Their physical properties were investigated by using optical microscopy, differential scanning calorimetry, and X-ray diffraction measurements. The XRD study suggests that the tripod-shaped molecules show the 2D-ordered phase of either the frustrated smectic layer structure or discotic columnar phases.

• Molecules and Cells
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• 제21권2호
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• pp.192-196
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• 2006

Salt tolerance was evaluated at the young seedling stage of rice (Oryza sativa L.) using recombinant inbred lines (MG RILs) from a cross between Milyang 23 (japonica/indica) and Gihobyeo (japonica). 22 of 164 MG RILs were classified as tolerant with visual scores of 3.5-5.0 in 0.7% NaCl. Interval mapping of QTLs related to salt tolerance was conducted on the basis of the visual scores at the young seedling stage. Two QTLs, qST1 and qST3, conferring salt tolerance, were detected on chromosome 1 and 3, respectively, and the total phenotypic variance explained by the two QTLs was 36.9% in the MG RIL population. qST1 was the major QTL explaining 27.8% of the total phenotypic variation. qST1 was flanked by Est12~RZ569A, and qST3 was flanked by RG179~RZ596. The detection of new QTLs associated with salt tolerance will provide important information for the functional analysis of rice salt tolerance.

• Molecules and Cells
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• 제42권2호
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• pp.166-174
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• 2019

Bacterial species in the genus Xanthomonas infect virtually all crop plants. Although many genes involved in Xanthomonas virulence have been identified through molecular and cellular studies, the elucidation of virulence-associated regulatory circuits is still far from complete. Functional gene networks have proven useful in generating hypotheses for genetic factors of biological processes in various species. Here, we present a genome-scale co-functional network of Xanthomonas oryze pv. oryzae (Xoo) genes, XooNet (www.inetbio.org/xoonet/), constructed by integrating heterogeneous types of genomics data derived from Xoo and other bacterial species. XooNet contains 106,000 functional links, which cover approximately 83% of the coding genome. XooNet is highly predictive for diverse biological processes in Xoo and can accurately reconstruct cellular pathways regulated by two-component signaling transduction systems (TCS). XooNet will be a useful in silico research platform for genetic dissection of virulence pathways in Xoo.

• Membrane and Water Treatment
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• 제8권3호
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• pp.245-257
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• 2017

The separation of nicotine and tobacco-specific N-nitrosamines is a tough problem in tobacco industry. In this study, separation of nicotine from 4-(methylnitrosamino) -1-(3-pyridyl)-1-butanone (NNK) mixtures was investigated using electrodialysis by taking the principle of the protonation status difference between these two components. The results indicated that the solution pH has a dominant impact on the separation process. In a pH range of 5-7, nicotine molecules are existed as mono- and di-protonated ions and can be separated from the uncharged NNK molecules. The acidic electrolyte is conducive to the separation process from the point of flux and energy consumption; while the alkaline electrolyte has negative impact on the separation process. A current density of $10mA/cm^2$ is an appropriate value for the separation process. The lowest energy consumption of the separation process is 0.58 kWh/kg nicotine with the process cost to be estimated at only $0.208 /kg nicotine. Naturally, electrodialysis is a high-efficiency, cost-effective, and environmentally friendly process to separate and purify nicotine from tobacco juice.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2008년도 추계학술대회 논문집 Vol.21
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• pp.109-110
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• 2008

We have performed a density functional theory study to investigate the reaction of the $HfCl_4$ molecule on $H_2O$ terminated Si (001)-$(2\times1)$ surface. The reaction of the $HfCl_4$ molecule is more favorable on OH-terminated site than H-terminated site. The first $HfCl_4$ molecule is adsorbed on a OH-terminated site with 0.21 eV energy benefit. The second $HfCl_4$ molecule is adsorbed on the most adjacent OH-terminated site of the first molecule and the energy benefit is 0.28 eV. The third and forth molecules have same tendency with the first and second ones. The adsorption energies of the fifth and sixth $HfCl_4$ molecules are 0.01 eV, -0.06 eV respectively. Therefore, we find that the saturation Hf coverage is approximately 5/8 of the available hydroxyl site, which is $2.08\times10^{14}/cm^2$. Our model is well matched with an experimental study by reference.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2011년도 제41회 하계 정기 학술대회 초록집
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• pp.184-184
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• 2011

Using first-principles density-functional calculations, we investigate the chain reaction mechanism of allyl alcohol (ALA) molecules on the H-terminated Si(001)-2${\times}$1 surface. Recently, it was reported [1] that allyl mercaptan (ALM) molecules show a self-directed line growth across the dimer rows through a chain reaction involving several reaction processes: (i) The created radical at the C atom is transferred to the S atom, (ii) the resulting S-centered radical easily abstracts an H atom from the neighboring dimer row, and (iii) the generated S-H group further reacts with the neighboring dimer row to produce the Si-S bond on the neighboring dimer row, accompanying the associative desorption of H2. This H2-desorption process creates a new DB on the neighboring dimer row, setting off the chain reaction across the dimer rows. In the present study, we find that although the structure of ALA with -OH functional is analogous to that of ALM with -SH functional, ALA and ALM lines show a difference in their growth direction. We predict that ALA undergoes the chain reaction to show a line growth along the dimer row, contrasting with the ALM line growth across the Si dimer rows. Our analysis shows that the different growth direction of ALA is due to the strong instability of oxygen radical intermediate, which prevents from growing across the dimer rows. Thus, we demonstrate that the stability of the radical intermediate plays a crucial role in determining the direction of molecular line growth.

• 대한화학회지
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• 제54권4호
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• pp.363-373
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• 2010

마약인 모르핀, 헤로인, 코데인, 펜타조신 그리고, 버프레노파인에 대하여 범밀도함수이론에 근거하여 계산 연구를 수행하였다. 약물특이 분자단과 치환기의 기하학적 파라미터는 B3LYP/6-31+G(d) 레벨로 계산하였고, 전자의 구조는B3LYP/6-311++G(d,p) 레벨로 같은 혼성 범함수를 사용하여 계산하였다. 원자의 전하분포는 Mulliken 개체 수 분석에 의하여 구하였다. 보고된 생물학적 활성, 계산된 분배 계수, 전자 및 기하학적 분석을 토대로 펜타조신과 버프레노파인을 새로 제시된 유사화합물에 대한 모델화합물로 선택하였으며, 이들 유사화합물에 대하여 연구한 뒤, 모델화합물과 비교하였다. 본 연구 결과는 약물특이 분자단의 기하학적 구조와 전자 구조가 다른 치환기의 존재 하에서도 변함없이 유지된다는 것을 보여주었다. 제시된 유사화합물들도 모델 분자의 특성을 갖고 있기 때문에, 이들 유사화합물들도 생물학적 활성을 나타낼 것 같다.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2016년도 제50회 동계 정기학술대회 초록집
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• pp.126-126
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• 2016

Understanding adsorption behavior organic molecules at oxide surfaces is very important for the application of organic-inorganic hybrid materials. Recently, monoethanolamine (MEA) adsorbed on $TiO_2$ surface has received great interests because it can lower the work function of $TiO_2$ in photo-electronic devices such as OLED and solar cells. In this study, we investigated the role of surface defects in adsorption behaviors of MEA at the rutile $TiO_2$ (110) surface by combined study of scanning tunneling microscopy and density functional theory calculations. Our results revealed that oxygen vacancy is the most stable adsorption site for MEA on $TiO_2$ (110) surface at low coverage. As coverage increases, the oxygen vacancies are occupied with the molecules and MEA molecules start to adsorb at Ti rows at higher coverages. Our results show that the defects at oxide surfaces and the intermolecular interactions are important factors for determining stable adsorption structure of MEA at $TiO_2$ (110) surfaces.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2016년도 제50회 동계 정기학술대회 초록집
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• pp.145.1-145.1
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• 2016

Binding and unbinding between molecular oxygen and metallo-porphyrin is a key process for oxygen delivery in respiration. It can be also used to control spin state of magnetic metallo-porphyrin molecules. Controlling and sensing spin states of magnetic molecules in such reactions at the single molecule level is essential for spintronic molecular device applications. Here, we demonstrate that spin states of metallo-porphyrin on surfaces can be controlled over by binding and unbinding of oxygen molecule, and be sensed using scanning tunneling microscopy and spectroscopy. Kondo localized state of metallo-porphyrin showed significant modification by the binding of oxygen molecule, implying that the spin state was changed. Our density functional theory calculation results explain the observations with the hybridization of unpaired spins in d and ${\pi}^*$ orbitals of metallo-porphyrin and oxygen, respectively. Our study opens up ways to control molecular spin state and Kondo effect by means of molecular binding and unbinding reactions on surfaces.

• 한국진공학회지
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• 제15권2호
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• pp.145-151
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• 2006

p-iodo-phenyl octadecyl ether (I-POE)와 p-iodo-phenyl docosyl ether (I-PDE)의 분자의 흑연표면에서의 자기조립과 이 두 분자로 이루어진 혼합물의 자기조립을 주사 터널링 현미경을 이용하여 연구하였다. 각 분자 시스템은 흑연 표면에서 head-to-tail 배향의 안정된 단분자막으로 자기조립한다. 혼합물 시스템에서는 I-POE와 I-PDE 분자들은 표면에서 섞이지 않고, 고립된 단분자막 도메인을 형성한다. 특히 I-POE 분자는 흑연 표면에서 단분자막 구조를 우선적으로 형성하는데 이는 알킬 사슬 길이와 작용기를 가진 헤드 그룹의 효과에 기인한다.