• 제목/요약/키워드: Sejong formation

Search Result 219, Processing Time 0.034 seconds

Studies on Biochemical Mechanism of DNA Alkylating Agents Tethered to Ligands for Retinoic acid Receptor

  • Yun, Byoung-Gu;Pyun, Sung-Jae;Ji, Sang-Mi;Ham, Won-Hoon;Lee, Young-Joo;Park, Hyun-Ju
    • Proceedings of the PSK Conference
    • /
    • 2003.10b
    • /
    • pp.176.2-176.2
    • /
    • 2003
  • Transcription factors (TF) can bind tightly to specific DNA lesions formed by some anticancer agents. The formation these TF:(drug-modified DNA) complex may disrupt expression of genes critical for cell survival, and it was proved to be one of biochemical mechanisms of anticancer activity. Based on this model, we have designed programmable DNA Alkylating agents that can also attract TF, especially nuclear receptors. As a model compound, we designed drug molecules, RA-mustard and Am580-mustard, that enable to bind both retinoic acid receptor (RAR) and DNA by using molecular modeling techniques, and synthesized them by connecting chlorambucil and ligand for RAR with a linker unit. (omitted)

  • PDF

Analysis of the Formation of Rear Contact for Monocrystalline Silicon Solar Cells (단결정 실리콘 태양전지의 후면 전극형성에 관한 비교분석)

  • Kwon, Hyuk-Yong;Lee, Jae-Doo;Kim, Min-Jeong;Lee, Soo-Hong
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
    • /
    • v.23 no.7
    • /
    • pp.571-574
    • /
    • 2010
  • Surface recombination loss should be reduced for high efficiency of solar cells. To reduce this loss, the BSF (back surface field) is used. The BSF on the back of the p-type wafer forms a p+layer, which prevents the activity of electrons of the p-area for the rear recombination. As a result, the leakage current is reduced and the rear-contact has a good Ohmic contact. Therefore, the open-circuit-voltage (Voc) and fill factor (FF) of solar cells are increased. This paper investigates the formation of the rear contact process by comparing aluminum-paste (Al-paste) with pure aluminum-metal(99.9%). Under the vacuum evaporation process, pure aluminum-metal(99.9%) provides high conductivity and low contact resistance of $4.2\;m{\Omega}cm$, but It is difficult to apply the standard industrial process to it because high vacuum is needed, and it's more expensive than the commercial equipment. On the other hand, using the Al-paste process by screen printing is simple for the formation of metal contact, and it is possible to produce the standard industrial process. However, Al-paste used in screen printing is lower than the conductivity of pure aluminum-metal(99.9) because of its mass glass frit. In this study, contact resistances were measured by a 4-point probe. The contact resistance of pure aluminum-metal was $4.2\;m{\Omega}cm$ and that of Al-paste was $35.69\;m{\Omega}cm$. Then the rear contact was analyzed by scanning electron microscope (SEM).

Primary Cilium by Polyinosinic:Polycytidylic Acid Regulates the Regenerative Migration of Beas-2B Bronchial Epithelial Cells

  • Gweon, Bomi;Jang, Tae-Kyu;Thuy, Pham Xuan;Moon, Eun-Yi
    • Biomolecules & Therapeutics
    • /
    • v.30 no.2
    • /
    • pp.170-178
    • /
    • 2022
  • The airway epithelium is equipped with the ability to resist respiratory disease development and airway damage, including the migration of airway epithelial cells and the activation of TLR3, which recognizes double-stranded (ds) RNA. Primary cilia on airway epithelial cells are involved in the cell cycle and cell differentiation and repair. In this study, we used Beas-2B human bronchial epithelial cells to investigate the effects of the TLR3 agonist polyinosinic:polycytidylic acid [Poly(I:C)] on airway cell migration and primary cilia (PC) formation. PC formation increased in cells incubated under serum deprivation. Migration was faster in Beas-2B cells pretreated with Poly(I:C) than in control cells, as judged by a wound healing assay, single-cell path tracking, and a Transwell migration assay. No changes in cell migration were observed when the cells were incubated in conditioned medium from Poly(I:C)-treated cells. PC formation was enhanced by Poly(I:C) treatment, but was reduced when the cells were exposed to the ciliogenesis inhibitor ciliobrevin A (CilioA). The inhibition of Beas-2B cell migration by CilioA was also assessed and a slight decrease in ciliogenesis was detected in SARS-CoV-2 spike protein (SP)-treated Beas-2B cells overexpressing ACE2 compared to control cells. Cell migration was decreased by SP but restored by Poly(I:C) treatment. Taken together, our results demonstrate that impaired migration by SP-treated cells can be attenuated by Poly(I:C) treatment, thus increasing airway cell migration through the regulation of ciliogenesis.

The Geomorphic Characteristics and Late-Holocene Paleoenvironmental Reconstruction in Sejong-Si Based on the Pollen Analysis of the Right Bank of Geumgang (세종시 금강 우안(右岸)지역의 지형특성과 홀로세 후기 고환경복원)

  • Moon, Youngrong;Yoon, Soon-Ock;Hwang, Sangill
    • Journal of The Geomorphological Association of Korea
    • /
    • v.24 no.4
    • /
    • pp.1-12
    • /
    • 2017
  • This study tried to reconstruct paleovegetation environments during the late Holocene with pollen analysis from archeological trenches at the right bank of Geumgang in Sejong-si. The lower hills was dominantly covered with pine trees, while alder trees and hygrophytes extended on the floodplain since 2,000yr BP. The pollen composition of Alnus dominance in the floodplain during the times is different from the general charateristics of Korean peninsula. Such a phenomenon is thought to be influenced by the fluvial process on the floodplain in the middle reaches of Geumgang around Sejong-si. Mihocheon and some tributaries join to Geumgang around Sejong-si, and the channel of Geumgang becomes narrow around the boundary between Sejong-si and Gongju-si. This narrow channel could attribute to the formation of extensive floodplain around Sejong-si. Moreover, human impacts such as agriculture appear continuously since 1,800yr BP.

Tumor antigen PRAME is a potential therapeutic target of p53 activation in melanoma cells

  • Yong-Kyu Lee;Hyeon Ho Heo;Nackhyoung Kim;Ui-Hyun Park;Hyesook Youn;Eun-Yi Moon;Eun-Joo Kim;Soo-Jong Um
    • BMB Reports
    • /
    • v.57 no.6
    • /
    • pp.299-304
    • /
    • 2024
  • Upregulation of PRAME (preferentially expressed antigen of melanoma) has been implicated in the progression of a variety of cancers, including melanoma. The tumor suppressor p53 is a transcriptional regulator that mediates cell cycle arrest and apoptosis in response to stress signals. Here, we report that PRAME is a novel repressive target of p53. This was supported by analysis of melanoma cell lines carrying wild-type p53 and human melanoma databases. mRNA expression of PRAME was downregulated by p53 overexpression and activation using DNA-damaging agents, but upregulated by p53 depletion. We identified a p53-responsive element (p53RE) in the promoter region of PRAME. Luciferase and ChIP assays showed that p53 represses the transcriptional activity of the PRAME promoter and is recruited to the p53RE together with HDAC1 upon etoposide treatment. The functional significance of p53 activation-mediated PRAME downregulation was demonstrated by measuring colony formation and p27 expression in melanoma cells. These data suggest that p53 activation, which leads to PRAME downregulation, could be a therapeutic strategy in melanoma cells.

Magnetoresistance of Planar Ferromagnetic Junction Defined by Atomic Force Microscopy

  • Yu, D.S.;Jerng, S.K.;Kim, Y.S.;Chun, S.H.
    • Journal of Magnetics
    • /
    • v.14 no.4
    • /
    • pp.172-174
    • /
    • 2009
  • Nanolithography by atomic force microscope local oxidation was applied to the fabrication of planar-type Ni/Ni oxide/Ni junctions from 10 nm-thick Ni films. The junction characteristics were sensitive to the lithography conditions such as the bias voltage. Successful oxidation produced junctions of nonlinear current-voltage characteristics, implying the formation of oxide barriers. Magnetoresistance (MR) at low temperatures resembled that of spin valves.

Investigation of the surface oxide/nitride passivation formation screen printed crystalline silicon solar cells (표면 oxide/nitride passivation 적용된 Screen printed 결정질 태양전지 특성 평가)

  • Lee, Ji-Hun;Cho, Kyeng-Yeon;Lee, Soo-Hong;Lee, Kyu-Sang
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
    • /
    • 2008.06a
    • /
    • pp.223-224
    • /
    • 2008
  • Important element are low cost, high-efficiency crystalline silicon solar cells. in this paper, Will be able to contribute in low cost, high-efficiency silicon solar cells, Applies oxide/nitride passivation, produced screen-printed solar cells. and the Measures efficiency, and evaluated a justice quality oxide/nitride passivation screen-printed solar cells.

  • PDF

Investigation of low cost contact formation for crystalline Si solar cells (저가형 금속 전극이 적용된 양산형 결정질 실리콘 태양전지 특성 평가)

  • Choi, Jun-Young;Kim, Bum-Ho;Lee, Eun-Joo;Lee, Soo-Hong
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
    • /
    • 2007.06a
    • /
    • pp.142-143
    • /
    • 2007
  • 현재 양산용 태앙전지 제조에 가장 널리 쓰이는 전극형성 기술인 Screen printing 기법은 진공 증착법과 무전해 도금에 의한 방법과, 비교할 때 공정장비가 간단하고 자동화에 적합하여 70 년대 이후로 널리 사용되어 왔다. 본 실험에서는 Screen printing기법과 Porous Si을 이용한 양산형 실리콘 태양전지를 제작하여 그 특성을 평가하였으며 13.2%의 변환효율을 나타내었다.

  • PDF

Study of Ni/Cu Front Metal Contact Applying Selective Emitter Silicon Solar Cells (선택도핑을 적용한 Ni/Cu 전면 전극 실리콘 태양전지에 관한 연구)

  • Lee, JaeDoo;Kwon, Hyukyong;Lee, SooHong
    • Korean Journal of Metals and Materials
    • /
    • v.49 no.11
    • /
    • pp.905-909
    • /
    • 2011
  • The formation of front metal contact silicon solar cells is required for low cost, low contact resistance to silicon surfaces. One of the available front metal contacts is Ni/Cu plating, which can be mass produced via asimple and inexpensive process. A selective emitter, meanwhile, involves two different doping levels, with higher doping (${\leq}30{\Omega}/sq$) underneath the grid to achieve good ohmic contact and low doping between the grid in order to minimize the heavy doping effect in the emitter. This study describes the formation of a selective emitter and a nickel silicide seed layer for the front metallization of silicon cells. The contacts were thickened by a plated Ni/Cu two-step metallization process on front contacts. The experimental results showed that the Ni layer via SEM (Scanning Electron Microscopy) and EDX (Energy dispersive X-ray spectroscopy) analyses. Finally, a plated Ni/Cu contact solar cell displayed efficiency of 18.10% on a $2{\times}2cm^2$, Cz wafer.