• Title/Summary/Keyword: Selective use

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Lead-selective PVC Membrane Electordes Based on Bis(Crown ether)s

  • 오금철;강은철;정규성;팽기정
    • Bulletin of the Korean Chemical Society
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    • v.20 no.5
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    • pp.556-558
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    • 1999
  • Lead-selective PVC membrane electrodes based on newly synthesized bis(crown ether)s containing 18-crown-6 moiety was prepared using standard PVC membrane composition. In order to monitor lead in environmental samples by lead sensor, especially good selectivity over alkali and alkaline earth metals has to be obtained. Thus, responses of the PVC membrane prepared with new bis(crown ether)s and Fluka ionophore V (crown ether) base to various cations include lead, alkali and alkaline earth metal ions were investigated for their use as a lead sensor. The polymeric liquid membrane based on trans-1 8-crown-6 ether exhibits the best overall potentiometric performances as a lead-selective electrode in terms of a wide linear dynamic range (between 10-6 and 10-2 M, Pb2+), excellent detection limit (less than 10-6 M) and good durability within limited error. The preferences of lead over other cations, such as Ag+, Hg2+, Na+, Ca2+ and even K+ in the aforementioned electrode are much better than the Fluka ionophore V system.

Protein and RNA Quality Control by Autophagy in Plant Cells

  • Yoon, Seok Ho;Chung, Taijoon
    • Molecules and Cells
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    • v.42 no.4
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    • pp.285-291
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    • 2019
  • Eukaryotic cells use conserved quality control mechanisms to repair or degrade defective proteins, which are synthesized at a high rate during proteotoxic stress. Quality control mechanisms include molecular chaperones, the ubiquitin-proteasome system, and autophagic machinery. Recent research reveals that during autophagy, membrane-bound organelles are selectively sequestered and degraded. Selective autophagy is also critical for the clearance of excess or damaged protein complexes (e.g., proteasomes and ribosomes) and membrane-less compartments (e.g., protein aggregates and ribonucleoprotein granules). As sessile organisms, plants rely on quality control mechanisms for their adaptation to fluctuating environments. In this mini-review, we highlight recent work elucidating the roles of selective autophagy in the quality control of proteins and RNA in plant cells. Emphasis will be placed on selective degradation of membrane-less compartments and protein complexes in the cytoplasm. We also propose possible mechanisms by which defective proteins are selectively recognized by autophagic machinery.

Localized Induction-Heating Method by the Use of Selective Mold Material (재료의 선택적 사용에 의한 금형의 국부적 유도가열기법)

  • Park, Keun;Do, Bum-Suk;Park, Jung-Min;Lee, Sang-Ik
    • Proceedings of the Korean Society for Technology of Plasticity Conference
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    • 2009.05a
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    • pp.168-171
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    • 2009
  • High-frequency induction is an efficient way to heat mold surface by electromagnetic induction in a non-contact procedure. Though the induction heating has an advantage in terms of its rapid-heating capacity on the mold surface, it still has a restriction on mold temperature control due to geometric restriction of an induction coil according to the mold shape. It has been recently applied to the injection molding of thin-walled parts or micro/nano structures. For localized induction heating, an injection mold composed of ferromagnetic material and paramagnetic material is used. The electromagnetic induction concentrates on the ferromagnetic material, from which we can selectively heat for the local mold elements. The present study proposed a localized induction heating method by means of selective use of mold material. The feasibility of the proposed heating method is investigated through the comparison of experimental observations according to the mold material.

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Investigation of Research Trends in the Selective Functional Movement Assessment (SFMA) (선택적 기능 동작 평가의 연구 동향 분석)

  • Kim, Jae-Eun;Do, Kwang-Sun
    • Journal of The Korean Society of Integrative Medicine
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    • v.9 no.2
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    • pp.63-73
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    • 2021
  • Purpose : Selective functional movement assessment(SFMA) is a movement-based assessment tool designed for clinicians to diagnose and treat pain and functional physical problems. This concept is used for assistance in occupations related to movement, including clinical medical personnel, such as physical therapists, physical education instructors, and athlete coaches. Although this concept is widely used by clinicians, research and scientific proofs are relatively insufficient. This study aimed to review the literature on the understanding, reliability and effectiveness of SFMA, and to consider its role in the future of rehabilitation. Methods : In this review, a total of nine articles were selected according to the eligibility criteria of three major thesis topics. The main topics covered in the literature are reliability and effectiveness of clinical use of SFMA. To gather research articles, we searched official term 'Selective Functional Movement Assessment'. Among the searched 60 studies, nine were mentioned in this study that contained overlapping information and matched our desired topic. We reviewed four reliability analyses, four case reports, and one experimental study. Results : Reliability has an intermediate degree between high raters and within raters. The validity of the SFMA system is influenced by a combination of experience and logic; hence, further improvement is needed. Therefore, if the intervention was effective based on the diagnosis result, then biomechanical evidence is necessary to further support the claim. Conclusion : In future research, to use SFMA as a diagnostic tool with high accuracy, it is necessary to improve the reliability of the main problem through breakout, support for guidelines and validity and efficiency.

Study on Planar Orientation and Selective Reflection of Cholesteric Liquid Crystals (콜레스테릭 액정의 Planar 배열과 선택 반사 특성에 관한 연구)

  • Jung, Gap-Ha;Seo, In-Seon;Lee, Mong-Ryong;Choi, Suk-Won;Song, Ki-Gook
    • Polymer(Korea)
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    • v.34 no.3
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    • pp.242-246
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    • 2010
  • FTIR spectroscopy has been employed in order to quantitatively investigate the relationship between planar arrangements and selective reflectance of cholesteric liquid crystals. It was found that the selective reflection was enhanced as the amount of planar arrangements in cholesteric liquid crystals increased. Although the planar arrangements of cholesteric liquid crystals can be induced only by the shear force effect, it was more effective to use the alignment layer to obtain the perfect planar arrangements.

Status of Research on Selective Laser Sintering of Nanomaterials for Flexible Electronics Fabrication (나노물질의 선택적 레이저소결을 이용한 유연전기소자 구현 연구현황)

  • Ko, Seung-Hwan
    • Transactions of the Korean Society of Mechanical Engineers B
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    • v.35 no.5
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    • pp.533-538
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    • 2011
  • A plastic-compatible low-temperature metal deposition and patterning process is essential for the fabrication of flexible electronics because they are usually built on a heat-sensitive flexible substrate, for example plastic, fabric, paper, or metal foil. There is considerable interest in solution-processible metal nanoparticle ink deposition and patterning by selective laser sintering. It provides flexible electronics fabrication without the use of conventional photolithography or vacuum deposition techniques. We summarize our recent progress on the selective laser sintering of metals and metal oxide nanoparticles on a polymer substrate to realize flexible electronics such as flexible displays and flexible solar cells. Future research directions are also discussed.

Spatially Selective Immobilization of Functional Materials onto Silicon Surfaces Using Electrochemical Method (전기화학을 이용한 실리콘 표면상으로 기능성 물질의 공간 선택적 고정화 연구)

  • Park, Soo-Hyoun;Ah, Chil-Seong;Kim, Kyu-Won
    • Journal of the Korean Electrochemical Society
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    • v.12 no.1
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    • pp.40-46
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    • 2009
  • We present a method for spatially selective immobilization of functional materials, such as proteins and nanoparticles, onto pre-activated silicon surfaces by electrochemical reaction. Carboxymethylbenzendiazonium (CMBD) cations, being adsorbable on silicon surfaces through electrochemically reductive deposition, is used as an anchor molecule to prepare the pre-activated silicon surfaces. It is demonstrated that the use of BD reaction is very efficient for the selective immobilization because the functional materials are immobilized exclusively onto the pre-adsorbed CMBD region. The method is applied to immobilize gold nanoparticles on the selected nanowire of the nanowire array.

A Study on Selective Laser Melting Process Considering Phase Transformation for Ti-6Al-4V (Ti-6Al-4V 합금에서 상 변화를 고려한 Selective Laser Melting 프로세스 연구)

  • Song, Seong-Il;Park, Joo-Heon;Jin, Byeong-Ju;Lee, Kyoung-Don
    • Journal of Korea Foundry Society
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    • v.39 no.6
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    • pp.110-115
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    • 2019
  • Recently, various studies have been conducted on additive manufacturing technology developed using metal materials. In this study, a numerical analysis was introduced to analyze the effects of the thermal deformation and residual stress which arise during the SLM (selective laser melting) manufacturing process. A phase-transformation mechanism is implemented with the use of the Ti-6Al-4V material, in which a solid-state phase transformation (SSPT) can be induced during a numerical analysis. In this case, the phase of the Ti-6Al-4V material changes from a powder to a solid state and then to the Martensite phase in sequence during heating and cooling steps. The numerical analysis during the SLM process was verified by comparing the results of tensile tests with those from the numerical analysis based on the SSPT material properties.

Selective Si Epitaxial Growth by Control of Hydrogen Atmosphere During Heating-up (승온중 수소 분위기 제어에 의한 선택적 Si 에피텍시 성장)

  • Son, Yong-Hun;Park, Seong-Gye;Kim, Sang-Hun;Nam, Seung-Ui;Kim, Hyeong-Jun
    • Korean Journal of Materials Research
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    • v.12 no.5
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    • pp.363-368
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    • 2002
  • we proposed the use of $Si_2H_ 6/H_2$ chemistry for selective silicon epitaxy growth by low-pressure chemical vapor deposition(LPCVD) in the temperature range $600~710^{\circ}C$ under an ultraclean environment. As a result of ultraclean processing, an incubation period of Si deposition only on $SiO_2$ was found, and low temperature epitaxy selective deposition on Si was achieved without addition of HCI. Total gas flow rate and deposition pressure were 16.6sccm and 3.5mtorr, respectively. In this condition, we selectively obtained high-quality epitaxial Si layers of the 350~1050$\AA$ thickness. In older to extend the selectivity, we kept high pressure $H_2$ environment without $Si_2H_6$ gas for few minutes after first incubation period and then we conformed the existence of second incubation period.