• KIEE International Transactions on Electrophysics and Applications
• /
• v.5C no.3
• /
• pp.115-118
• /
• 2005

Currently, molecular devices are reported utilizing active self-assembled monolayers (SAMs) containing the nitro group as the active component, which has active redox centers [1]. SAMs are ordered molecular structures formed by the adsorption of an active surfactant on a solid surface. The molecules will be spontaneously oriented toward the substrate surface and form an energetically favorable ordered layer. During this process, the surface-active head group of the molecule chemically reacts with and chemisorbs onto the substrate In this paper, the electrical properties of the 4'4- di(ethynylphenyl)-2'-nitro-1-benzenethiolate was confirmed. This material is well known as a conducting molecule having possible application to molecular level negative differential resistance (NDR) device. To deposit the self-assembly monolayers onto the gold electrode, the prefabricated Au(1 l l) substrates were immersed into 0.5[mM/l] self-assembly molecule in THF solution. Then, the electrical properties and surface morphologies of 4' 4-di(ethynylphenyl)-2' -nitro-1-benzenethiolate were measured by using the ultra-high vacuum scanning tunneling microscopy (UHV-STM).

• Korean Journal of Metals and Materials
• /
• v.47 no.1
• /
• pp.32-37
• /
• 2009

Molecular dynamic simulations on the structural evolution of the Si(001) vicinal surfaces, which are tilted with respect to [100] and [110] directions were performed by using the empirical Tersoff potential. Tersoff potential was implemented at LAMMPS code and confirmed to describe the properties of Si. When the steps are generated along [100] direction, symmetric dimer rows formed with respect to the step edges. On the other hand, when the steps are generated along [110] direction, alternating dimer rows form with respect to the step edges. The configurational differences between the two vicinal surfaces were discussed in terms of the surface diffusion and the possibility of preventing step bunching for the (001) vicinal surface tilted along [100] direction was suggested.

• Journal of Radiopharmaceuticals and Molecular Probes
• /
• v.6 no.2
• /
• pp.171-176
• /
• 2020

Covalent organic frameworks (COFs) are porous crystalline polymers in which organic units are linked by covalent bonds and have a regular arrangement at the atomic level. Recently, the COFs have been much attention in bio-medical area such as bio-imaging, drug delivery, and therapeutics. These 2D nanoparticles are proving their value in nanomedicine due to their large surface area, functionalization through functional groups exposed on the surface, chemical stability due to covalent bonding, and high biocompatibility. The high ω-electron density and crystallinity of COFs makes it a promising candidate for bioimaging probes, and its porosity and large surface area make it possible to be utilized as a drug delivery vehicle. However, the low dispersibility in water, the cytotoxicity problems of COFs are still challenged to be solved in the future. In this regard, several efforts that increase the degree of dispersion through functionalization on the surface of COFs for the application to the biomedical field have been reported. In this review, we would like to describe the advantages and limitations of COFs for bio-imaging and anti-cancer treatment.

• Proceedings of the Korean Vacuum Society Conference
• /
• 1996.06a
• /
• pp.18-18
• /
• 1996

• YAKHAK HOEJI
• /
• v.35 no.6
• /
• pp.461-465
• /
• 1991

Silica-based gel filtration chromatography has been used to characterize molecular weight of proteins. However, the molecular weight measured by this method was distorted by protein-silica interactions like hydrophobic and electrostatic forces. Therefore, we characterized protein-silica interaction using two forms of phytochrome (124 kDa) having different hydrophobicity and surface charge. PH and ionic strength affected the retention time of phytochrome suggesting that electrostatic force is the major interaction between protein and silica surface.

• 대한생식의학회:학술대회논문집
• /
• 2001.11a
• /
• pp.57-62
• /
• 2001

One of recent advances of mammalian fertilization is the understanding of the molecular basis of fertilization. Several proteins localized in sperm nucleus or on sperm surface are necessary for the fertilization process. Protamines, sperm nuclear proteins, are required for normal sperm function that leads to fertilization. Fertilin and cyritestin are sperm surface proteins and essential for sperm-egg binding. Fertilin is also required for sperm transport in the female reproductive tracts. Metalloproteses on sperm plasma membrane are found to play a role in sperm-egg fusion. The functional analysis of these proteins provides a new insight into the molecular mechanisms underlying mammalian fertilization and male fertility.

• Proceedings of the Korean Vacuum Society Conference
• /
• 2001.02a
• /
• pp.82-82
• /
• 2001

• Proceedings of the Polymer Society of Korea Conference
• /
• 2006.10a
• /
• pp.1-2
• /
• 2006

Polymer architecture plays a great role in determining the properties of functional polymers. This lecture will explore the design and the synthesis of polymers with controlled architecture and functionality. Especially featured will be star and dendritic architectures where the functional group placement and the molecular shape can be controlled. This will be followed by examples of applications illustrated with a few model systems of functional polymers designed for use in areas such as organic electronics, catalysis, surface patterning, separation and molecular recognition, and polymer therapeutics.

• Proceedings of the Korean Vacuum Society Conference
• /
• 2004.08a
• /
• pp.201-201
• /
• 2004

• Proceedings of the Korean Vacuum Society Conference
• /
• 2004.08a
• /
• pp.184-184
• /
• 2004