• Corrosion Science and Technology
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• v.4 no.1
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• pp.33-38
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• 2005

Some feasibility studies are conducted to produce an advanced ceramic coating, which reveals superior chemical and mechanical strength, on metal base structure used in chemical plant. This advanced coating on metallic frame can replace ceramic delivery pipe and reaction chamber used in chemical plant, which are operated in hi-temperature and corrosive/erosive environment. An dual spraying is adopted to reduce the residual stress in order to increase the coating thickness and the residual stress is estimated by in-situ manner. Then new methodology is tried to form special coating of yttrium aluminum garnet(YAG), which reveals hi-strength and low-creep rates at hi-temperature, superior anti-corrosion property, hi-stability against Alkali-Vapor corrosion, and so on, on iron base structure. To verify the formation of YAG during thermal spraying, XRD(X ray diffraction) technique was used.

• BMB Reports
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• v.54 no.5
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• pp.233-245
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• 2021

In eukaryotes, the genome is hierarchically packed inside the nucleus, which facilitates physical contact between cis-regulatory elements (CREs), such as enhancers and promoters. Accumulating evidence highlights the critical role of higher-order chromatin structure in precise regulation of spatiotemporal gene expression under diverse biological contexts including lineage commitment and cell activation by external stimulus. Genomics and imaging-based technologies, such as Hi-C and DNA fluorescence in situ hybridization (FISH), have revealed the key principles of genome folding, while newly developed tools focus on improvement in resolution, throughput and modality at single-cell and population levels, and challenge the knowledge obtained through conventional approaches. In this review, we discuss recent advances in our understanding of principles of higher-order chromosome conformation and technologies to investigate 4D chromatin interactions.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.32 no.1
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• pp.64-69
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• 2019

Methylammonium lead triiodide ($MAPbI_3$)-based perovskite solar cells potentially have potential advantages such as high efficiency and low-cost manufacturing procedures. However, $MAPbI_3$ is structurally unstable and has low phase-change temperatures ($30^{\circ}C$ and $130^{\circ}C$); it is necessary to solve these problems. We investigated the crystal structure and phase separation using real-time temperature-change X-ray diffraction, transmission electron microscopy, and electron energy loss spectroscopy. $MAPbI_3$ has a tetragonal structure, and at about $35^{\circ}C$ the c-axis contracts, transforming $MAPbI_3$ into the related cubic crystal structure. In addition, at $130^{\circ}C$, phase separation occurs in which $CH_3NH_2$ and HI at the center of the unit cell of the perovskite structure are extracted by gas, leavingand only $PbI_2$ of the three-component structure, is produced as the final solid product.

• Genomics & Informatics
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• v.21 no.2
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• pp.19.1-19.13
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• 2023

Liver cancer, particularly hepatocellular carcinoma (HCC), poses a significant global threat to human lives. To advance the development of innovative diagnostic and treatment approaches, it is essential to examine the hidden features of HCC, particularly its 3D genome architecture, which is not well understood. In this study, we investigated the 3D genome organization of four HCC cell lines-Hep3B, Huh1, Huh7, and SNU449-using in situ Hi-C and assay for transposase-accessible chromatin sequencing. Our findings revealed that HCC cell lines had more long-range interactions, both intra-and interchromosomal, compared to human mammary epithelial cells (HMECs). Unexpectedly, HCC cell lines displayed cell line-specific compartmental modifications at the megabase (Mb) scale, which could potentially be leveraged in determining HCC subtypes. At the sub-Mb scale, we observed decreases in intra-TAD (topologically associated domain) interactions and chromatin loops in HCC cell lines compared to HMECs. Lastly, we discovered a correlation between gene expression and the 3D chromatin architecture of SLC8A1, which encodes a sodium-calcium antiporter whose modulation is known to induce apoptosis by comparison between HCC cell lines and HMECs. Our findings suggest that HCC cell lines have a distinct 3D genome organization that is different from those of normal and other cancer cells based on the analysis of compartments, TADs, and chromatin loops. Overall, we take this as evidence that genome organization plays a crucial role in cancer phenotype determination. Further exploration of epigenetics in HCC will help us to better understand specific gene regulation mechanisms and uncover novel targets for cancer treatment.

• Korean Journal of Veterinary Research
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• v.41 no.1
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• pp.1-6
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• 2001

Pituitary adenyl ate cyclase activating polypeptide (PACAP) was originally isolated from the ovine hypothalamus and stimulated cAMP production in anterior pituitary cells. It is known that PACAP stimulates cAMP accumulation and contributes to the spermatogenesis and steroidogenesis in rat testis. The principal aim of this study is to determinate the distribution of PACAP mRNA and protein in adult rat testis. For this study, we used in situ hybridization and immunohistochemistry techniques in adult rat testis. PACAP mRNA was stage specifically expressed in seminiferous tubules. Positive signals of PACAP mRNA were detected in the developing germ cells at stages HI-VII of the epithelial cycle. The strongest signals of PACAP mRNA and protein were detected in round spermatids at stages V to early VII of the cycle. These results demonstrate that PACAP which is synthesised in the developing germ cells contributes to the spermatogenesis in rat testis. Thus, we suggest that PACAP plays a critical role in the function of testis.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.30 no.1C
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• pp.45-51
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• 2010

In urban area, design and construction of civil engineering structures such as subway tunnel, underground space and deep excavation is impeded by unreliable site investigation. Variety of embedded objects, electric noises and traffic vibrations degrades the quality of site investigation, whatever the site-investigation technique would be. In this research, a preliminary research was performed to develop a dedicated site investigation technique for urban geotechnical sites, which can overcome the limitations of urban sites. HiRAS (Hybrid Integration of Surface Waves and Resistivity) technique which is the first outcome of the preliminary research was proposed in this paper. The technique combines surface wave as well as electrical resistivity. CapSASW method for surface-wave technique and PDC-R technique for electrical resistivity survey were incorporated to develop HiRAS technique. CapSASW method is a good method for evaluating material stiffness and PDC-R technique is a reliable method for determination of underground stratification even in a site with electrical noise. For the inversion analysis of HiRAS techniuqe, a site-specific relationship between stress-wave velocity and resistivity was employed. As for outgrowth of this research, the 2-D distribution of Poisson's ratio could be also determined.

• BMB Reports
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• v.54 no.10
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• pp.489-496
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• 2021

Chromatin has highly organized structures in the nucleus, and these higher-order structures are proposed to regulate gene activities and cellular processes. Sequencing-based techniques, such as Hi-C, and fluorescent in situ hybridization (FISH) have revealed a spatial segregation of active and inactive compartments of chromatin, as well as the non-random positioning of chromosomes in the nucleus, respectively. However, regardless of their efficiency in capturing target genomic sites, these techniques are limited to fixed cells. Since chromatin has dynamic structures, live cell imaging techniques are highlighted for their ability to detect conformational changes in chromatin at a specific time point, or to track various arrangements of chromatin through long-term imaging. Given that the imaging approaches to study live cells are dramatically advanced, we recapitulate methods that are widely used to visualize the dynamics of higher-order chromatin structures.

• Transactions on Electrical and Electronic Materials
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• v.18 no.5
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• pp.253-256
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• 2017

A thin Te interlayer was applied to a Ni/n-InGaAs contact to reduce the contact resistance between Ni-InGaAs and n-InGaAs. A 5-nm-thick Te layer was first deposited on a Si-doped n-type $In_{0.53}Ga_{0.47}As$ layer, followed by in situ deposition of a 30-nm-thick Ni film. After the formation of the Ni-InGaAs alloy by rapid thermal annealing at $300^{\circ}C$ for 30 s, the extracted specific contact resistivity (${\rho}_c$) reduced by more than one order of magnitude from $2.86{\times}10^{-4}{\Omega}{\cdot}cm^2$ to $8.98{\times}10^{-6}{\Omega}{\cdot}cm^2$ than that of the reference sample. A thinner Ni-InGaAs alloy layer with a better morphology was obtained by the introduction of the Te layer. The improved interface morphology and the graded Ni-InGaAs layer formed at the interface were believed to be responsible for ${\rho}_c$ reduction.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.31 no.3
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• pp.141-145
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• 2018

Ni-InGaAs shows promise as a self-aligned S/D (source/drain) alloy for n-InGaAs MOSFETs (metal-oxide-semiconductor field-effect transistors). However, limited thermal stability and instability of the microstructural morphology of Ni-InGaAs could limit the device performance. The in situ deposition of a Pd interlayer beneath the Ni layer was proposed as a strategy to improve the thermal stability of Ni-InGaAs. The Ni-InGaAs alloy layer prepared with the Pd interlayer showed better surface roughness and thermal stability after furnace annealing at $570^{\circ}C$ for 30 min, while the Ni-InGaAs without the Pd interlayer showed degradation above $500^{\circ}C$. The Pd/Ni/TiN structure offers a promising route to thermally immune Ni-InGaAs with applications in future n-InGaAs MOSFET technologies.

• Tuberculosis and Respiratory Diseases
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• v.45 no.4
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• pp.823-834
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• 1998

Background: Chronic inhalation of silica induces the lung fiborsis. The alveolar macrophages ingest the inhaled silica; they liberate the pro-inflammatory cytokines such as IL-1$\beta$, IL-6, TNF-$\alpha$ and fibrogenic cytokines, TGF-$\beta$ and PDGF. Cytokines liberated from macrophage have pivotal role in pulmonary fibrosis. There is a complex cytokine network toward fibrosis. However, the exact roles and the interaction among the proinflammatory cytokines and TGF-$\beta$, a fibrogenic cytokine, have not been defined, yet. In this study, we investigated silica induced IL-1$\beta$, IL-6, TNF-$\alpha$ and TGF-$\beta$ production and the effect of IL-1$\beta$, IL-6, TNF-$\alpha$ on the production of TGF-$\beta$ from lung macrophages of Balb/C mice. Method: We extracted the lung of Balb/C mice and purified monocytes by Percoll gradient method. Macrphages were stimulated by silica ($SiO_2$) in the various concentration for 2, 4, 8, 12, and 24 hours. The supernatants were used for the measurement of protein levels by bioassay, and cells for the levels of mRNA by in situ hybridization. Results: The production of IL-6 was not observed till 4 hours, and reached the peak levels at 8 hours after stimulation of silica. The production of TNF-$\alpha$ increased from 2 hours and reached the peak levels at 4 hours after stimulation of silica. The spontaneous TGF-$\beta$ production reached the peak levels at 24 hours. TNF-$\alpha$ upregulated the silica induced TGF-$\beta$ production. Silica induced TGF-$\beta$ production was blocked by pretreated anti-TNF-$\alpha$ antibody. In situ hybridization revealed the increased positive signals at 4 hours in IL-6, at 4 hours TNF-$\alpha$ and 12 hours in TGF-$\beta$. Conclusion: The results above suggest that silica induced the sequential production of IL-6, 1NF-$\alpha$ and TGF-$\beta$ from macrophages and TNF-$\alpha$ upregultaes the production of TGF-$\beta$ from silica-induced macrophages.