• Title/Summary/Keyword: cell degradation

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The Variation of Silicon Characteristic with Radiation Damage Effects (Radiation 손상에 기인한 실리콘 특성변화)

  • 장기현
    • Journal of the Korean Institute of Telematics and Electronics
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    • v.15 no.4
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    • pp.26-32
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    • 1978
  • For a long life photovoltaic cell the degradation of the device characteristics with 1 MeV electron radiation must be known so as to be able to predict the life of the cell. Hence, a study was made of radiation damage effects on the bulk properties of the silicon crystal. From the results of the data, it is concluded that there appeared to be a steads rotate damage level reached in f type material.

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Observation of Soft-Rot Wood Degradation Caused by Higher Ascomyceteous fungi

  • Lee, Yang-Soo
    • Mycobiology
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    • v.28 no.1
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    • pp.47-50
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    • 2000
  • The capability of higher ascomyceteous fungi to cause typical soft-rot decay for wood under laboratory conditions is reviewed and discussed. Fungi tested were extremely active in the decomposition of timbers. Scanning electron micrographs illustrated typical soft-rot decay pattern of higher wood decay ascomycetes, with the exception of H. trugodes that caused white-rot decay. Most of the fungi tested could be grouped as soft-rot fungi that showed typical soft-rot type II. Hypha confined primarily to the resin canals in softwoods or vessel elements in hardwoods and spread tracheid to tracheid via pits of cell wall to cell wall with mechanical force.

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Control of asymmetric cell division in early C. elegans embryogenesis: teaming-up translational repression and protein degradation

  • Hwang, Sue-Yun;Rose, Lesilee S.
    • BMB Reports
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    • v.43 no.2
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    • pp.69-78
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    • 2010
  • Asymmetric cell division is a fundamental mechanism for the generation of body axes and cell diversity during early embryogenesis in many organisms. During intrinsically asymmetric divisions, an axis of polarity is established within the cell and the division plane is oriented to ensure the differential segregation of developmental determinants to the daughter cells. Studies in the nematode Caenorhabditis elegans have contributed greatly to our understanding of the regulatory mechanisms underlying cell polarity and asymmetric division. However, much remains to be elucidated about the molecular machinery controlling the spatiotemporal distribution of key components. In this review we discuss recent findings that reveal intricate interactions between translational control and targeted proteolysis. These two mechanisms of regulation serve to carefully modulate protein levels and reinforce asymmetries, or to eliminate proteins from certain cells.

A Study of low cost and high efficiency Solar Cell using SOD(spin on doping) (SOD(Spin On Doping)법을 이용한 저가 고효율 태양전지에 관한 연구)

  • Park, Sung-Hyun;Kim, Kyoung-Hae;Mon, Sang-Il;Kim, Dae-Won;Yi, Jun-Sin
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2002.07b
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    • pp.1054-1056
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    • 2002
  • High temperature Kermal diffusion from $POCl_3$ source usually used for conventional process through put of a cell manufacturing line and potentially reduce cell efficiency through bulk like time degradation. To fabricate high efficiency solar cells with minimal thermal processing, spin-on-doping(SOD) technique can be employed to emitter diffusion of a silicon solar cell. A technique is presented to emitter doping of a mono-crystalline solar cell using spin-on doping (SOD). Moreover it is shown that the sheet resistance variation with RTA temperature and time fer mono-crystalline and multi-crystalline silicon samples. This novel SOD technique was successfully used to produces 11.3% efficiency l04mm by 104mm size mono-crystalline silicon solar cells.

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Production of Brewer's Yeast Extract by Enzymatic Method (효소 분해법에 의한 맥주효모 추출물의 제조)

  • 이시경;박경호;백운화;유주현
    • Microbiology and Biotechnology Letters
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    • v.21 no.3
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    • pp.276-280
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    • 1993
  • Cell lytic enzyme, 5'-phosphodiesterase, and AMP-deaminase were used to produce yeast extract as a natural seasoning from beer yeast cells. Prior to the addition of cell lytic enzyme, heat treatment was performed to increase the cell wall degradation` the optimum condition of the cell lytic enzyme was 50C at pH 7.0. The production yields by the enzymatic method and conventional autolysis method were 42% and 35%, respectively. The total quantity of 5'-nucleotides, GMP and IMP, produced by enzymatic method was increased by 45% than that by the conventional method. Futhermore, the operation time of enzymatic method was only 6.5 hrs, significantly reduced from 24 hrs of the conventional method.

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Changes in the cell structure during maturation and postharvest of persimmon fruits (감과실의 성숙과 추숙중 조직의 변화)

  • Shin, Seung-Ryeul;Song, Jun-Hee;Kim, Soon-Dong;Kim, Kwang-Soo
    • Applied Biological Chemistry
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    • v.34 no.1
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    • pp.32-37
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    • 1991
  • Cell and intercelullar space enlarged during maturation. The cell of soft persimmon was separated from each other. The degradation of middle lamella exhibited in mature persimmon and small vesicle appeared in cytoplasm of turning and mature persimmon. The middle lamella and cell wall were degraded during softening.

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Performance of a Ceramic Fiber Reinforced Polymer Membrane as Electrolyte in Direct Methanol Fuel Cell

  • Nair, Balagopal N.;Yoshikawa, Daishi;Taguchi, Hisatomi
    • Membrane Journal
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    • v.14 no.1
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    • pp.53-56
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    • 2004
  • Direct Methanol Fuel Cell (DMFC) is considered as a candidate technology for applications in stationary, transportation as well as electronic power generation purposes. To develop a high performance direct methanol fuel cell(DMFC), a competent electrolyte membrane is needed. The electrolyte membrane should be durable and methanol crossover must be low. One of the approaches to increase the stability of generally used polymer electrolyte membranes such as Nafion against swelling or thermal degradation is to bond it with an inorganic material physically or chemically. In Noritake Company, we have developed a novel method of reinforcing the polymer electrolyte matrix with inorganic fibers. Methanol crossover values measured were significantly lower than the original polymer electrolyte membranes. These fiber reinforced electrolyte membranes (FREM) were used for DMFC study and stable power output values as high 160 mW/$\textrm{cm}^2$ were measured. The details of the characteristics of the membranes as well as I-V data of fuel cell stacks are detailed in the paper.

Autophagy: a lysosomal degradation process for cellular homeostasis and its relationship with oral squamous cell carcinoma

  • Jung, Junyoung;Kim, Joungmok;Kim, Jeong Hee
    • International Journal of Oral Biology
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    • v.46 no.2
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    • pp.74-80
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    • 2021
  • Autophagy is an evolutionarily well-conserved cellular homeostasis program that responds to various cellular stresses and degrades unnecessary or harmful intracellular materials in lysosomes. Accumulating evidence has shown that autophagy dysfunction often results in various human pathophysiological conditions, including metabolic disorders, cancers, and neurodegenerative diseases. The discovery of an autophagy machinery protein network has revealed underlying molecular mechanisms of autophagy, and advances in the understanding of its regulatory mechanism have provided novel therapeutic targets for treating human diseases. Recently, reports have emerged on the involvement of autophagy in oral squamous cell carcinoma (OSCC). Although the role of autophagy in cancer therapy is controversial, the beneficial use of the induction of autophagic cell death in OSCC has drawn significant attention. In this review, the types of autophagy, mechanism of autophagosome biogenesis, and modulating molecules and therapeutic candidates affecting the induction of autophagic cell death in OSCC are briefly described.

Stability Tests on Anion Exchange Membrane Water Electrolyzer under On-Off Cycling with Continuous Solution Feeding

  • Niaz, Atif Khan;Lim, Hyung-Tae
    • Journal of Electrochemical Science and Technology
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    • v.13 no.3
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    • pp.369-376
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    • 2022
  • In this study, the stability of an anion exchange membrane water electrolyzer (AEMWE) cell was evaluated in an on-off cycling operation with respect to an applied electric bias, i.e., a current density of 500 mA cm-2, and an open circuit. The ohmic and polarization resistances of the system were monitored during operation (~800 h) using electrochemical impedance spectra. Specific consideration was given to the ohmic resistance of the cell, especially that of the membrane under on-off cycling conditions, by consistently feeding the cell with KOH solution. Owing to an excess feed solution, a momentary increase in the polarization resistance was observed immediately after the open-circuit. The excess feed solution was mostly recovered by subjecting the cell to the applied electric bias. Stability tests on the AEMWE cell under on-off cycling with continuous feeding even under an open circuit can guarantee long-term stability by avoiding an irreversible increase in ohmic and polarization resistances.

Electron microscopic observations of the irradiation of ultra-violet ray on cryptococcus neoformans (자외선 조사처리에 의한 cryptococcus neoformans의 전자현미경적 관찰)

  • Hwang, Dong-Hoon;Koh, Choon, Myung;Choi, Tae-Joo;Lew, Joon
    • Korean Journal of Microbiology
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    • v.10 no.1
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    • pp.29-34
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    • 1972
  • The present study is of ultra-fine structure of Cryptococcus neoformans by means of electron microscopy and reveals the following : 1) In constrast to the bacteria, the normal Cryptococcus neofrmans contains nuclear enveloped with nuclear menbrane, mitochondria, endoplasmic reticulum, distinct cell wall and cell membrane, vacuoles and storage granules as observed in the eucaryotic cells. 2) In apparent cell walls and cell membrane with the appearance of electron transparent area (ETA) and changes of cell morphology were observed in the ultra-violet ray irradiated cell. 2) In apparent cell walls and cell membrance with the appreance of electron transparent area (ETA) and changes of cell morphology were observed in the ultra-violet ray irradiated cell. 3) Morphology changes and cytoplasmic element abnormality was increased with irradiated time. 4) Increase of electron transparent area was thought to be associated with degradation of cell.

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