• JSTS:Journal of Semiconductor Technology and Science
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• 제7권4호
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• pp.254-259
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• 2007

In this report, several fabrication techniques for the formation of various nanochannels (with $SiO_2$, Si, or Quartz) are introduced. Moreover, simple fabrication technique for generating $SiO_2$ nanochannels without nanolithography is presented. By using different nanochannels, the degree of stretching DNA molecule will be evaluated. Finally, we introduce a nanometer scale fluidic channel with electrodes on the sidewall of it, to detect and analyze single DNA molecule. The cross sectional shape of the nanotrench is V-groove, which was implemented by thermal oxidation. Electrodes were deposited through both sidewalls of nanotrench and the sealing of channel was done by covering thin poly-dimethiysiloxane (PDMS) polymer sheet.

• BMB Reports
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• 제54권3호
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• pp.157-163
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• 2021

The transient interactions between cellular components, particularly on membrane surfaces, are critical in the proper function of many biochemical reactions. For example, many signaling pathways involve dimerization, oligomerization, or other types of clustering of signaling proteins as a key step in the signaling cascade. However, it is often experimentally challenging to directly observe and characterize the molecular mechanisms such interactions-the greatest difficulty lies in the fact that living cells have an unknown number of background processes that may or may not participate in the molecular process of interest, and as a consequence, it is usually impossible to definitively correlate an observation to a well-defined cellular mechanism. One of the experimental methods that can quantitatively capture these interactions is through membrane reconstitution, whereby a lipid bilayer is fabricated to mimic the membrane environment, and the biological components of interest are systematically introduced, without unknown background processes. This configuration allows the extensive use of fluorescence techniques, particularly fluorescence fluctuation spectroscopy and single-molecule fluorescence microscopy. In this review, we describe how the equilibrium diffusion of two proteins, K-Ras4B and the PH domain of Bruton's tyrosine kinase (Btk), on fluid lipid membranes can be used to determine the kinetics of homodimerization reactions.

• Bulletin of the Korean Chemical Society
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• 제12권2호
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• pp.178-181
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• 1991

The crystal structure of dehydrated fully $Cd^{2+}$-exchanged zeolite A evacuated at $2{\times}10^{-6}$ Torr and $450^{\circ}C (a = 12.225(2){\AA})$ and of its ethylene sorption complex (a = 12.219(2) ${\AA}$) have been determined by single crystal X-ray diffraction techniques in the cubic space group Pm3m at $21(1)^{\circ}$. The structures were refined to final error indices, $R_1$ = 0.063 and $R_2$ = 0.065 with 266 reflections and $R_1$ = 0.055 and $R_2$ = 0.062 with 260 reflections, respectively, for which $I{\gg}3{\sigma}(I)$. In both structures, six $Cd^{2+}$ ions lie at two distinguished three-fold axes of unit cell. Dehydrated $Cd_6$-A sorbs 4 ethylene molecules per unit cell at $25^{\circ}C$ (vapor pressure of ethylene is ca. 100 Torr). Each $Cd^{2+}$ ion forms a lateral ${pi}$ complex with an ethylene molecule. Four $Cd^{2+}$ ions exist in a nearly tetrahedral environment, 2.210(7)${\AA}$ apart from three framework oxygen ions (considering ethylene molecule as a monodentate ligand) and $2.67(6){\AA}$ from each carbon atom of ethylene molecule.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2006년도 추계학술대회 논문집 Vol.19
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• pp.255-256
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• 2006

The electrical properties of viologen ($VC_8SH$) were studied in terms of the tunneling current characteristics using self-assembling techniques and ultra high vacuum scanning tunneling microscopy (UHV-STM). We fabricated the Au substrate were deposited by thermal evaporation system($420^{\circ}C$). Self-assembled monolayers (SAMs) were prepared on Au(111), which had been thermally deposited onto freshly cleaved, heated mica. The Au substrate was exposed to a 1 mM/L solution of Octanethiol in ethanol for 24 h to form a monolayer. After through rinsing the sample, it was exposed to a 0.1 mM/L solution of $VC_8SH$ in ethanol for 30 min. We measurement of the morphology on the single viologen molecule. The current-voltage (I-V) properties were measured at arbitary configured points on the surface of the sample by using a STS.

• Tribology and Lubricants
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• 제39권5호
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• pp.216-219
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• 2023

This study employs molecular dynamics simulations to investigate the material behavior of workpieces in waterjet machining processes. To gain fundamental insights into waterjet machining, simulations were conducted using pure water, excluding abrasive particles. The simulation model comprised thousands of water molecules interacting with a single crystal metal workpiece. Water molecule clusters were imparted with various velocities to initiate collisions with the metal workpiece. The material behavior of the metal surface was analyzed with respect to the applied velocity conditions, considering the intricate interplay between water molecules and the workpiece at the atomic scale. The results demonstrated that the machining of the metal workpiece occurred only when water molecules were endowed with velocities above a certain threshold. In cases where energy was insufficient, the metal workpiece exhibited a slight increase in surface roughness due to mild plastic deformation, without undergoing substantial material removal. When machining occurred, the ejection of material revealed a 3-fold symmetric pattern, confirming that material removal in waterjet machining of the metal workpiece is primarily driven by plastic deformation-induced material ejection. This research provides crucial insights into the mechanisms underlying waterjet machining and enhances our understanding of material behavior during the process. The findings can be valuable in optimizing waterjet machining techniques.

• Bulletin of the Korean Chemical Society
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• 제13권1호
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• pp.70-74
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• 1992

Two crystal structures of ethylene (a= 12.272(2) ${\AA}$) and acetylene (a = 12.245(2) ${\AA}$) sorption complexes of dehydrated fully $Ca^{2+}$-exchanged zeolite A have been determined by single crystal X-ray diffraction techniques in the cubic space group, Pm3m at $21(1)^{\circ}C$. Their complexes were prepared by dehydration at $360^{\circ}C$ and $2{\times}10^{-6}$ Torr for 2 days, followed by exposure to 200 Torr of ethylene gas and 120 Torr of acetylene gas both at $24^{\circ}C$, respectively. The structures were refined to final R (weighted) indices of 0.062 with 209 reflections and 0.098 with 171 reflections, respectively, for which I > 3${\sigma}$(I). The structures indicate that all six $Ca^{2+}$ ions in the unit cell are associated with 6-oxygen ring of the aluminosilicate framework. Four of these extend somewhat into the large cavity where each is coordinated to three framework oxide ions and an ethylene molecule and/or an acetylene molecule. The carbon to carbon distance in ethylene sorption structure is 1.48(7) ${\AA}$ and that in acetylene sorption structure 1.25(8) ${\AA}$. The distances between $Ca^{2+}$ ion and carbon atom are 2.87(5) ${\AA}$ in ethylene sorption structure and 2.95(7) ${\AA}$ in acetylene sorption structure. These bonds are relatively weak and probably formed by the electrostatic attractions between the bivalent $Ca^{2+}$ ions and the polarizable ${\pi}$-electron density of the ethylene and/or acetylene molecule.

• The Plant Pathology Journal
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• 제33권4호
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• pp.362-369
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• 2017

White root rot disease, caused by the pathogen Rosellinia necatrix, is one of the world's most devastating plant fungal diseases and affects several commercially important species of fruit trees and crops. Recent global outbreaks of R. necatrix and advances in molecular techniques have both increased interest in this pathogen. However, the lack of information regarding the genomic structure and transcriptome of R. necatrix has been a barrier to the progress of functional genomic research and the control of this harmful pathogen. Here, we identified 10,616 novel full-length transcripts from the filamentous hyphal tissue of R. necatrix (KACC 40445 strain) using PacBio single-molecule sequencing technology. After annotation of the unigene sets, we selected 14 cell cycle-related genes, which are likely either positively or negatively involved in hyphal growth by cell cycle control. The expression of the selected genes was further compared between two strains that displayed different growth rates on nutritional media. Furthermore, we predicted pathogen-related effector genes and cell wall-degrading enzymes from the annotated gene sets. These results provide the most comprehensive transcriptomal resources for R. necatrix, and could facilitate functional genomics and further analyses of this important phytopathogen.

• Rapid Communication in Photoscience
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• 제2권1호
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• pp.34-37
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• 2013

Two novel antenna complexes of $Eu^{III}$ with 1-naphthoic acid (NA) as primary ligand and two aromatic N-donor ligands namely N-hexyl-N-(pyridin-2-yl) pyridin-2-amine (1) and 4-((dipyridin-2-ylamino)methyl)benzoic acid (2) have been synthesized and characterized by various spectroscopic techniques. The room-temperature (298 K) photoluminescence spectrum of $Eu^{III}$ complexes composed of typical line like emissions, assigned to transitions between the first excited state $^5D_0$ to the $^7F_J$ (J = 0-4), resulting in red emission along with the residual emission from the 1-naphthoic acid moiety in the blue region. The determined CIE color coordinate value for the complex 2 is (x = 0.36, y = 0.34), which is in white region.

• Bulletin of the Korean Chemical Society
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• 제20권4호
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• pp.417-421
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• 1999

The complex, K3[La(TTHA)]5H,O, was prepared and its crystal structure was analyzed by single crystal X-ray diffraction method. In the complex, the La(Ⅲ) ion adopts a ten-coordinate geometry with four nitrogen atoms and six carboxyl oxygen atoms from the same TTHA ligand molecule. Its coordination polyhedron can be described as a distorted bicapped square antiprism. Each [La(TTHA)]3- anion is linked by K+ cations via carboxyl groups of TTHA ligand to form a three dimensional crystal structure. The thermal properties were investigated by TG and DTA techniques in argon atmosphere. The materials resulting from thermal treatment were La(OH)3 and K2O which were identified by powder X-ray diffraction technique.

• Bulletin of the Korean Chemical Society
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• 제17권2호
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• pp.201-205
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• 1996

The crystal and molecular structure of thiourea dioxide, (NH2)2CSO2, was determined by x-ray single crystal diffraction techniques. Lattice constants are a=10.669(2), b=10.119(2), and c=3.9151(5) Å with the space group Pnma and Z=4. The thiourea portion of the molecule has a planar conformation. When the two oxygen atoms are included, the sulfur atom is at the apex of a trigonal pyramid formed with the two oxygen atoms and the carbon atom as the base. The crystal structure is stabilized by strong intermolecular hydrogen bonds. Ab initio calculations were performed to investigate the bonding features and reactivity of thiourea dioxide. The calculated bond order of S-C is only 0.481. The hydrogen bond energy was computed to be 22.3 kcal/mol for dimer. MEP analysis reveals that the sites on nucleophilic reactions are S and C atoms.