• Bulletin of the Korean Chemical Society
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• v.28 no.5
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• pp.783-790
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• 2007

The immobilization of proteins and their molecular interactions on various polymer-modified glass substrates [i.e. 3-aminopropyltriethoxysilane (APTS), 3-glycidoxypropyltrimethoxysilane (GPTS), poly (ethylene glycol) diacrylate (PEG-DA), chitosan (CHI), glutaraldehyde (GA), 3-(trichlorosilyl)propyl methacrylate (TPM), 3'-mercaptopropyltrimethoxysilane (MPTMS), glycidyl methacrylate (GMA) and poly-l-lysine (PL).] for potential applications in a nanoarray protein chip at the single-molecule level was evaluated using prismtype dual-color total internal reflection fluorescence microscopy (dual-color TIRFM). A dual-color TIRF microscope, which contained two individual laser beams and a single high-sensitivity camera, was used for the rapid and simultaneous dual-color detection of the interactions and colocalization of different proteins labeled with different fluorescent dyes such as Alexa Fluor® 488, Qdot® 525 and Alexa Fluor® 633. Most of the polymer-modified glass substrates showed good stability and a relative high signal-to-noise (S/N) ratio over a 40-day period after making the substrates. The GPTS/CHI/GA-modified glass substrate showed a 13.5-56.3% higher relative S/N ratio than the other substrates. 1% Top-Block in 10 mM phosphate buffered saline (pH 7.4) showed a 99.2% increase in the blocking effect of non-specific adsorption. These results show that dual-color TIRFM is a powerful methodology for detecting proteins at the single-molecule level with potential applications in nanoarray chips or nano-biosensors.

• Journal of Biomedical Engineering Research
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• v.40 no.5
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• pp.165-170
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• 2019

Cancer cells are different from normal cells in terms of life cycle, behavior, and growth patterns. Cancer cells can migrate freely in the body through blood vessels and lymph nodes. The cancer cells easily interact with various substrates including extracellular matrix and vessels and they can differentiate in the new environment. However, it is not well known about the adhesion preference of cancer cells on the substrate and the mechanism of their interaction. In this study, we prepared the nano-, micro-patterned substrates using E-beam lithography techniques. MCF-7 cells were tested on the substrates to find out their adhesion preference. The substrates were made by polydimethylsiloxane (PDMS) with specific patterns including pillars with a diameter of 500 nm, 700 nm, $3{\mu}m$ and $5{\mu}m$. MCF-7 cells were seeded on the substrates and incubated for 24 hours. As a result, this study clearly demonstrated that the MCF-7 cells preferred 700 nm patterning.

• Journal of Environmental Science International
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• v.27 no.11
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• pp.937-946
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• 2018

This study investigated the applicability of horticultural media with recycled coir substrates the growth of Chinese cabbage (Brassica campestris L. ssp. Pekinensis) and lettuce (Lactuca sativa L.) crop. The six different types of coir based substrates were A, Coir 45: Perlite 35: Vermiculite 12: Zeolite 8 (%), B, Coir 55: Perlite 25: Vermiculite 12: Zeolite 8 (%), C, Coir 65: Perlite 15: Vermiculite 12: Zeolite 8 (%), D, Coir 75: Perlite 5: Vermiculite 12: Zeolite 8 (%), E, Coir 85: Perlite 5: Vermiculite 5: Zeolite 5 (%) and F, nursery media (control). The pH and Electric conductivity of the horticultural nursery media were 6.06-7.00 and $0.45-1.10dS/m^{-1}$, respectively. The nursery media containing coir substrates had higher level of Total N, Ca, K, Mg and P than those without coir. Additionally, it was observed that the growth of Chinese cabbage was the best on D (containing 75% coir) while that of lettuce was the best on E (containing 85% coir). In general, when substrates containg a higher percentage of coir were used, the growth of Chinese cabbage and lettuce was ideal. Additionally, the P, Ca, and Mg content in both plants was not significantly altered by the amount of coir present in the media. However, with an increase in the amount of coir substrate, the chlorophyll, N, and K content was increased. After harvesting, there was no significant difference in the chemical properties of the horticultural nursery media of both plants. Thus, it can be suggested that, coir substrate after a single use could be recycled as horticulture nursery media.

• Korean Journal of Metals and Materials
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• v.49 no.4
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• pp.313-320
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• 2011

100 nm-thick hydrogenated amorphous silicon $({\alpha}-Si:H)$ films were deposited on a glass and glass/30 nm Ni substrates by inductively-coupled plasma chemical vapor deposition (ICP-CVD) at temperatures ranging from 100 to $550^{\circ}C$. The sheet resistance, microstructure, phase transformation and surface roughness of the films were characterized using a four-point probe, AFM (atomic force microscope), TEM (transmission electron microscope), AES (Auger electron spectroscopy), HR-XRD(high resolution X-ray diffraction), and micro-Raman spectroscopy. A nano-thick NiSi phase was formed at substrate temperatures >$400^{\circ}C$. AFM confirmed that the surface roughness did not change as the substrate temperature increased, but it increased abruptly to 6.6 nm above $400^{\circ}C$ on the glass/30 nm Ni substrates. HR-XRD and micro-Raman spectroscopy showed that all the Si samples were amorphous on the glass substrates, whereas crystalline silicon appeared at $550^{\circ}C$ on the glass/30 nm Ni substrates. These results show that crystalline NiSi and Si can be prepared simultaneously on Ni-inserted substrates.

• Korean Journal of Metals and Materials
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• v.46 no.2
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• pp.88-96
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• 2008

Thermal evaporated 10 nm-$Ni_{50}Co_{50}$/(70 nm-poly)Si films were deposited to examine the energy saving properties of silicides formed by rapid thermal annealing at temperature ranging from 500 to $1,100^{\circ}C$ for 40 seconds. Thermal evaporated 10 nm-Ni/(70 nm-poly)Si films were also deposited as a reference using the same method for depositing the 10 nm-$Ni_{50}Co_{50}$/(70 nm-poly)Si films. A four-point probe was used to examine the sheet resistance. Transmission electron microscopy (TEM) and X-ray diffraction XRD were used to determine cross sectional microstructure and phase changes, respectively. UV-VIS-NIR and FT-IR (Fourier transform infrared spectroscopy) were used to examine the near-infrared (NIR) and middle-infrared (MIR) absorbance. TEM analysis confirmed that the uniform nickel-cobalt composite silicide layers approximately 21 to 55 nm in thickness had formed on the single and polycrystalline silicon substrates as well as on the 25 to 100 nm thick nickel silicide layers. In particular, nickel-cobalt composite silicides showed a low sheet resistance, even after rapid annealing at $1,100^{\circ}C$. Nickel-cobalt composite silicide and nickel silicide films on the single silicon substrates showed similar absorbance in the near-IR region, while those on the polycrystalline silicon substrates showed excellent absorbance until the 1,750 nm region. Silicides on polycrystalline substrates showed high absorbance in the middle IR region. Nickel-cobalt composite silicides on the poly-Si substrates annealed at $1,000^{\circ}C$ superior IR absorption on both NIR and MIR region. These results suggest that the newly proposed $Ni_{50}Co_{50}$ composite silicides may be suitable for applications of IR absorption coatings.

• Journal of Dairy Science and Biotechnology
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• v.39 no.1
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• pp.9-19
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• 2021

Enterobacter sakazakii (Cronobacter spp.) causes meningitis, necrotizing enterocolitis, sepsis, and bacteremia in neonates and children and has a high mortality rate. For rapid E. sakazakii detection, various differential and selective media containing α-glucosidase substrates, such as 5-bromo-4-chloro-3-indolyl-α-D-glucopyranoside (BCIG) or 4-methylumbelliferyl-α-D-glucoside (α-MUG), have been developed as only E. sakazakii exhibits α-glucosidase activity in the genus Enterobacter. However, Escherichia vulneris (family: Enterobacteriaceae) can also utilize α-glucosidase substrates, thereby resulting in false positives. Various iron sources are known to promote the growth of gram-negative bacteria. This study aimed to develop a selective medium containing α-glucosidase substrates for E. sakazakii detection that would eliminate false positives, such as those of E. vulneris, and to determine the role of iron source in the medium. Three previously developed (TPD) media, i.e., Oxoid, OK, and VRBG, and the medium developed in this study, i.e., NGTE, were evaluated using 58 E. sakazakii and 5 non-E. sakazakii strains. Fifty-four E. sakazakii strains appeared as fluorescent or chromogenic colonies on all four media that were assessed. Two strains showed colonies on NGTE medium and not on TPD media. In contrast, the remaining two strains showed colonies on TPD media and not on NGTE medium. None of the non-E. sakazakii strains showed fluorescent or chromogenic colonies on any of the evaluated media except E. vulneris, which showed colonies on TPD media and not on NGTE medium. This study demonstrated that the newly developed NGTE medium was not only equally efficient in promoting the growth of bacterial colonies when compared with the currently available media but also eliminated false positives, such as E. vulneris.

• Composites Research
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• v.36 no.5
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• pp.377-382
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• 2023

To enhance the performance of graphene-based devices, it is of great importance to better understand the interfacial interaction of graphene with its underlying substrates. In this study, the adhesion energy of monolayer graphene placed on dielectric substrates was characterized using mode I fracture tests. Large-area monolayer graphene was synthesized on copper foil using chemical vapor deposition (CVD) with methane and hydrogen. The synthesized graphene was placed on target dielectric substrates using polymer-assisted wet transfer technique. The monolayer graphene placed on a substrate was mechanically delaminated from the dielectric substrate by mode I fracture tests using double cantilever beam configuration. The obtained force-displacement curves were analyzed to estimate the adhesion energies, showing 1.13 ± 0.12 J/m² for silicon dioxide and 2.90 ± 0.08 J/m² for silicon nitride. This work provides the quantitative measurement of the interfacial interactions of CVD-grown graphene with dielectric substrates.

• The Transactions of the Korean Institute of Electrical Engineers C
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• v.49 no.12
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• pp.649-653
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• 2000

We have grown carbon nanotubes by thermal chemical vapor deposition of $C_{2}H_{2}$ on catalytic metal deposited on silicon oxide substrates. Highly purified carbon nanotubes are uniformly grown on a large area of the silicon oxide substrates. It is observed that surface modification of catalytic metals deposited on substrates by either etching with dipping in a HF solution and/or $NH_{3}$ pretreatment is a crucial step for the nanotube growth prior to the reaction of $C_{2}H_{2}$ gas. The diameters of carbon naotubes could be controlled by applying the different catalytic metals.

• Journal of Ecology and Environment
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• v.37 no.3
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• pp.139-145
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• 2014

Denitrification permanently removes nitrate from aquatic ecosystems, so construction of denitrification walls to enhance denitrification activity is often suggested to reduce the nitrate levels from tributary ecosystems. However, little information is available to guide the choice of appropriate organic materials for increasing denitrification rates in the walls. This study investigated how differences in organic substrates originating from litter and organic materials affected denitrification and carbon mineralization rates in riparian sediments. Potential denitrification rates were highest in riparian sediments that contained large quantities of extractable organic carbon (Ext. Org C) and that had high anaerobic carbon mineralization rates, but they were negatively correlated with C:N ratios. Therefore, this research suggested that the both carbon quantity and quality should be considered when assessing the efficiency of organic substrates to remove nitrate from tributary ecosystems.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.26 no.12
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• pp.894-898
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• 2013

Zinc oxide(ZnO) was sputtered on various glass and flexible substrates such as polyethylene terephthalate(PET) and polycarbonate(PC). A Q-switched $Nd:YVO_4$ laser with a wavelength of 1,064 nm was used for the direct etching of ZnO films. It was possible to obtain laser etched line patterns on the ZnO films on PC substrate at some specific laser beam conditions. In the flexible substrates, more thermal energy of laser beam is expected to be spreaded for the etching process.