• Title/Summary/Keyword: Biological mechanism

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A Review of Chlorine Evolution Mechanism on Dimensionally Stable Anode (DSA®) (DSA 전극에서 염소 발생 메커니즘)

  • Kim, Jiye;Kim, Choonsoo;Kim, Seonghwan;Yoon, Jeyong
    • Korean Chemical Engineering Research
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    • v.53 no.5
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    • pp.531-539
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    • 2015
  • Chlor-alkali industry is one of the largest electrochemical processes which annually producing 70 million tons of sodium hydroxide and chlorine from sodium chloride solution. $DSA^{(R)}$ (Dimensionally Stable Anodes) electrodes such as $RuO_2$ and $IrO_2$, which is popular in chlor-alkali process, have been investigated to improve the chlorine generation efficiency. Although DSA electrode has been developed with various researches, understanding of the chlorine evolution mechanism is essential to the development of highly efficient DSA electrode. In this review paper, chlorine generation mechanisms are summarized and that of key factors are identified to systematically understand the chlorine generation mechanism. Rate determining step, effect of pH, reaction intermediate, and electrode crystal structure were intensively overviewed as key factors of the chlorine mechanism.

Design and Control of a New Micro End-effector for Biological Cell Manipulation

  • Shim, Jae-Hong;Cho, Sung-Yong;Cho, Young-Im;Kim, Deok-Ho;Kim, Byung-Kyu
    • 제어로봇시스템학회:학술대회논문집
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    • 2003.10a
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    • pp.2445-2450
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    • 2003
  • Recently, biological technology industry shows great development. Instruments and systems related biological technology have been developed actively. In this paper, we developed a new micro end-effector for biological cell manipulation. The existing micro end-effector for biological cell manipulation has not any force sensing mechanism. Usually, excessive contact force occurring when the end-effector and a cell collide might make a damage on the cell. However, unfortunately, user can not notice the condition in case of using the existing end-effector. In order to overcome we proposed the improved micro end-effector having a force sensing mechanism. This paper presents the design concepts of the new micro end-effector. We carried out calibration of the force sensor and tested the performance of the proposed micro end-effector. Through a series of experiments the new micro end-effector shows the possibility of application for precision biological cell manipulation such as DNA operation

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Role of Diazotrophic Bacteria in Biological Nitrogen Fixation and Plant Growth Improvement

  • Shin, Wansik;Islam, Rashedul;Benson, Abitha;Joe, Manoharan Melvin;Kim, Kiyoon;Gopal, Selvakumar;Samaddar, Sandipan;Banerjee, Somak;Sa, Tongmin
    • Korean Journal of Soil Science and Fertilizer
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    • v.49 no.1
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    • pp.17-29
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    • 2016
  • Though there is an abundant supply of nitrogen in the atmosphere, it cannot be used directly by the biological systems since it has to be combined with the element hydrogen before their incorporation. This process of nitrogen fixation ($N_2$-fixation) may be accomplished either chemically or biologically. Between the two elements, biological nitrogen fixation (BNF) is a microbiological process that converts atmospheric di-nitrogen ($N_2$) into plant-usable form. In this review, the genetics and mechanism of nitrogen fixation including genes responsible for it, their types and role in BNF are discussed in detail. Nitrogen fixation in the different agricultural systems using different methods is discussed to understand the actual rather than the potential $N_2$-fixation procedure. The mechanism by which the diazotrophic bacteria improve plant growth apart from nitrogen fixation such as inhibition of plant ethylene synthesis, improvement of nutrient uptake, stress tolerance enhancement, solubilization of inorganic phosphate and mineralization of organic phosphate is also discussed. Role of diazotrophic bacteria in the enhancement of nitrogen fixation is also dealt with suitable examples. This mini review attempts to address the importance of diazotrophic bacteria in nitrogen fixation and plant growth improvement.

Mxi1 influences cyst formation in three-dimensional cell culture

  • Yook, Yeon-Joo;Yoo, Kyung-Hyun;Song, Seon-Ah;Seo, Min-Ji;Ko, Je-Yeong;Kim, Bo-Hye;Lee, Eun-Ji;Chang, Eun-Sun;Woo, Yu-Mi;Park, Jong-Hoon
    • BMB Reports
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    • v.45 no.3
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    • pp.189-193
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    • 2012
  • Cyst formation is a major characteristic of ADPKD and is caused by the abnormal proliferation of epithelial cells. Renal cyst formation disrupts renal function and induces diverse complications. The mechanism of cyst formation is unclear. mIMCD-3 cells were established to develop simple epithelial cell cysts in 3-D culture. We confirmed previously that Mxi1 plays a role in cyst formation in Mxi1-deficient mice. Cysts in Mxi1 transfectanted cells were showed by collagen or mebiol gels in 3-D cell culture system. Causative genes of ADPKD were measured by q RT-PCR. Herein, Mxi1 transfectants rarely formed a simple epithelial cyst and induced cell death. Overexpression of Mxi1 resulted in a decrease in the PKD1, PKD2 and c-myc mRNA relating to the pathway of cyst formation. These data indicate that Mxi1 influences cyst formation of mIMCD-3 cells in 3-D culture and that Mxi1 may control the mechanism of renal cyst formation.

Molecular Mechanism of Adipocyte Differentiation and It′s Impact on Obesity

  • Seo, Jong-Bae;Lee, Yun-Suk;Cho, Hye-Jin;Kim, Jae-Bum
    • Proceedings of the Korean Society of Applied Pharmacology
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    • 2003.11a
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    • pp.11-14
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    • 2003
  • Adipocyte development has an impact on human health issues mainly through the association of obesity with Type II diabetes, hyperlipidemia, hypertension and cardiovascular disorders. Obesity results from excessive food intake and reduced energy expenditure, and such surplus energy is stored in adipose tissue.

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Antimicrobial Activity and Mechanism of Silver (은(Ag)의 미생물 불활성화 특성 및 기작)

  • Kim, Jee Yeon;Kim, Taeyoung;Yoon, Jeyong
    • Applied Chemistry for Engineering
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    • v.20 no.3
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    • pp.251-257
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    • 2009
  • Recently, there is much interest in the antimicrobial activity of silver since silver has known to be safe and effective as a disinfectant or an antimicrobial agent against a broad spectrum of microorganisms. Although silver has been applied to various kinds of products due to the effective antimicrobial activity, the quantitative antimicrobial activity or detailed mechanism of silver is not clearly investigated yet, causing the controversy and confusion. In this review paper, we summarized the characteristics, antimicrobial activities and mechanisms, synergistic effects with other antimicrobials, and applicability of silver.