• Title/Summary/Keyword: Aggregation Function

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Bacterial Overexpression and Denaturing Purification of VPS34-Binding Domain of Beclin 1

  • Baek, Jong-Hyuk;Jung, Juneyoung;Seo, Jeongbin;Kim, Jeong Hee;Kim, Joungmok
    • Journal of Microbiology and Biotechnology
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    • v.26 no.10
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    • pp.1808-1816
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    • 2016
  • As a scaffolding subunit of the PIK3C3/VPS34 complex, Beclin 1 recruits a variety of proteins to class III phosphatidylinositol-3-kinase (VPS34), resulting in the formation of a distinct PIK3C3/VPS34 complex with a specific function. Therefore, the investigation of a number of Beclin 1 domains required for the protein-protein interactions will provide important clues to understand the PIK3C3/VPS34 complex, of which Beclin1-VPS34 interaction is the core unit. In the present study, we have designed a bacterial overexpression system for the Beclin 1 domain corresponding to VPS34 binding (Vps34-BD) and set up the denaturing purification protocol due to the massive aggregation of Vps34-BD in Escherichia coli. The expression and purification conditions determined in this study successfully provided soluble and functional Vps34-BD.

A Study of Mechanical Properties and Microstructure of ZrO2-Ag Depending on the Composite Route (ZrO2-Ag의 복합화 공정에 따른 기계적 특성 및 미세조직 평가)

  • Yeo, In-Chul;Han, Jae-Kil;Kang, In-Cheol
    • Journal of Powder Materials
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    • v.19 no.6
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    • pp.416-423
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    • 2012
  • This paper introduces an effect of a preparing $ZrO_2$-Ag composite on its mechanical properties and microstructure. In present study, $ZrO_2$-Ag was prepared by reduction-deposition route and wetting dispersive milling method, respectively. Two type of Ag powders (nano Ag and micron Ag size, respectively) were dispersed into $ZrO_2$ powder during wetting dispersive milling in D.I. water. Each sample was sintered at $1450^{\circ}C$ for 2hr in atmosphere, and then several mechanical tests and analysis of microstructure were carried out by bending test, hardness, fracture toughness and fracture surface microstructure. As for microstructure, the Ag coated $ZrO_2$ showed homogeneously dispersed Ag in $ZrO_2$ in where pore defect did not appear. However, $ZrO_2$-nano Ag and $ZrO_2$-micro Ag composite appeared Ag aggregation and its pore defect, which carried out low mechanical property and wide error function value.

Preparation and Characteristics of Unsaturated PE Immunoliposome Incorporated with Ganglioside $G_{M1}$ (Ganglioside $G_{M1}$을 함유한 불포화 PE Immunoliposome의 제조와 특성)

  • Kim, Chang-Soo;Lee, Eun-Ok;Kim, Jong-Duk
    • Journal of Pharmaceutical Investigation
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    • v.21 no.3
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    • pp.161-170
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    • 1991
  • The storage stabilities of immunoliposomes incorporated with variable amounts of ganglioside $G_{M1}$ were investigated as a function of time. temperature. and composition by observing absorbance of visible light and calcein release. In the column chromatographe, the layer of unsaturated PE(dioleoylphosphatidylethanolamine : DOPE). unable to form stable liposomes at physiological temperature and pH, were formed when palmitoyl-immunoglobulin G(IgG) $(2.5{\times}10^{-4}\;mol/DOPE\;mol)$ added. The incorporation of ganglioside $G_{M1}$ into immunoliposome. enhanced the stabilities of bilayers during the extended period of storage. The turbidities of immunoliposomes coated with ganglioside $G_{M1}$ exhibited the maximum near 20 mol% $G_{M1}/DOPE$ mol. probably because of the disturbance of the bilayer characteristics, i.e., layer transition or reorientation of interaction sites. At low temperature. the higher stability was achieved than at elevated temperatures. After one week of storage. the redispersed liposomal solutions at lower temperatures maintained the original elution patterns in chromatography but broader distribution at elevated temperatures. During the storage, it is suggested the aggregation is the more dominant phenomena for liposomes kept at $5^{\circ}C$ than the fusion. while he fusion is at elevated temperatures.

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Structural Characterization of Growth-Related Translationally Controlled Tumor Protein P23

  • Lee, Bong-Jin;Hong, Yoon-Hun;Park, Sang-Ho;Lee, Kyunglim
    • Journal of the Korean Magnetic Resonance Society
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    • v.5 no.1
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    • pp.46-55
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    • 2001
  • P23, a translationally controlled turner protein is involved in the interleukin-4 secretion from human basophils and is also known to be an IgE-dependent histamine-releasing factor. However, the precise physiological function and structure of P23 have not been elucidated. In the current study, we constructed the optimal expression and purification protocol of P23 and investigated the secondary structure and structural stability in various conditions. Circular dichroism (CD) investigation showed that the secondary structure of P23 adopts mainly a P-sheet conformation. CD spectroscopy and differential scanning calorimetry revealed that P23 is fairly stable in the pH range of neutral and mild-basic conditions and in the temperature range of 10 - 50$\^{C}$. Since the thermal stability and the P-sheet content of P23 were decreased by the addition of Ca$\^$2+/ ion, it could be suggested that Ca$\^$2+/ion induces structural change by partially destabilizing the structure of P23. In addition various H experiments were monitored to solve the aggregation of P23. Den results will provide the preliminary structural information about P23.

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Real-Time Monitoring Agent for Ubiquitous System (유비쿼터스 시스템을 위한 실시간 모니터링 에이전트)

  • Kwon, Sung-Hyun;Lee, Byoung-Hoon;Kim, Jai-Hoon;Cho, We-Duke
    • Journal of KIISE:Computing Practices and Letters
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    • v.14 no.8
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    • pp.803-807
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    • 2008
  • The ubiquitous middleware configurated an aggregation of the various services. The services are made in different languages and the various services that are dynamically changing environment are carried out in collaboration service. The ubiquitous system that services in the these environment is required appropriate response to real-time system and reliability. In this paper, we suggest the monitoring agent that a monitoring system added or removed the services in real-time is made continuous monitoring in run-time environment and guaranteed performance and reliability of a application by maximally reducing overhead that combined with applications is occurred. The suggested scheme shows the demonstration to fit the scenario situation and verifies function and performance of monitoring about the service applications through the experiment.

Potential Applications of Low Altitude Remote Sensing for Monitoring Jellyfish

  • Jo, Young-Heon;Bi, Hongsheng;Lee, Jongsuk
    • Korean Journal of Remote Sensing
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    • v.33 no.1
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    • pp.15-24
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    • 2017
  • Jellyfish (cnidarian) are conspicuous in many marine ecosystems when in bloom. Despite their importance for the ecosystem structure and function, very few sampling programs are dedicated to sample jellyfish because they are patchily distributed and easily clogged plankton net. Although satellite remote sensing is an excellent observing tool for many phenomena in the ocean, their uses for monitoring jellyfish are not possible due to the coarse spatial resolutions. Hence, we developed the low altitude remote sensing platform to detect jellyfish in high resolutions, which allow us to monitor not only horizontal, but also vertical migration of them. Using low altitude remote sensing platform,we measured the jellyfish from the pier at the Chesapeake Biological Laboratory in Chesapeake Bay. The patterns observed included discrete patches, in rows that were aligned with waves that propagated from deeper regions, and aggregation around physical objects. The corresponding areas of exposed jellyfish on the sea surface were $0.1{\times}10^4pixel^2$, $0.3{\times}10^4pixel^2$, and $2.75{\times}10^4pixel^2$, respectively. Thus, the research result suggested that the migration of the jellyfish was related to the physical forcing in the sea surface.

Chromatic Characteristics of Copper Glaze as a Function of Copper Oxide Addition and Sintering Atmosphere

  • No, Hyunggoo;Kim, Soomin;Kim, Ungsoo;Cho, Wooseok
    • Journal of the Korean Ceramic Society
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    • v.54 no.1
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    • pp.61-65
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    • 2017
  • Examined in this study were the effects of copper oxide (II) addition and sintering conditions on the chromatic characteristics of copper glaze. Oxidatively sintered samples exhibited the negative increase of $CIEa^*$ and the positive increase of $CIEb^*$ with the increase of CuO concentration, leading to Green and Green-Yellow coloration. On the other hand, $CIEa^*$ and $CIEb^*$ of reductively sintered samples were positively increased in direct proportion. The green color of oxidatively sintered samples was originated from the $Cu^{2+}$ ions formed by the dissolution of CuO. The reductively sintered samples resulted in dull tone red color with low chroma. Such behavior seems to be influenced by the interplay of metal Cu aggregation, metal Cu globule, and $Cu_2O$ formed in the glaze layer through the redox interaction of CuO during the sintering process.

A Study on Tensile Properties of Multi-Welled Carbon Nanotube/Epoxy Composites (다중벽 탄소나노튜브/에폭시 복합재료의 인장 물성에 관한 연구)

  • Lee Sang-Eui;Lee Won-Jun;Kim Chun-Gon
    • Composites Research
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    • v.17 no.6
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    • pp.1-7
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    • 2004
  • The studies of particulate reinforced composites have been conducted for many years. The nanocomposites to be studied vigorously in recent years are one of them. We fabricated and studied multi-walled carbon nanotube(MWNT)/epoxy composites which may be useful as matrix for continuous fiber-reinforced composites. We investigated tensile properties of MWNT/epoxy composites as a function of MWNT concentration, which were prepared by the fabrication method established in this study. Tensile stiffness and strength increased 19% at 0.5 wt% and 12% at 0.2 wt%, respectively. We observed the reaggregation phenomenon of MWNTS during curing, which should be controlled to obtain higher tensile properties.

Nano-particles of Mechanochemical Synthesis

  • Urakaev, Farit Kh.
    • Journal of the Speleological Society of Korea
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    • no.71
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    • pp.5-11
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    • 2006
  • A theoretical investigation of the solid phase mechanochemical synthesis of nano sized target product on the basis of dilution of the initial powdered reagent mixture by another product of an exchange reaction is presented. On the basis of the proposed 3 mode particle size distribution in mechanically activated mixture, optimal molar ratios of the components in mixture are calculated, providing the occurrence of impact friction contacts of reagent particles and excluding aggregation of the nanosized particles of the target reaction product. Derivation of kinetic equations for mechanochemical synthesis of nanoscale particles by the final product dilution method in the systems of exchange reactions is submitted. On the basis of obtained equations the necessary times of mechanical activation for complete course of mechanochemical reactions are designed. Kinetics of solid phase mechanosynthesis of nano TlCl by dilution of initial (2NaCl+$Tl_2SO_4$) mixture with the exchange reaction product (diluent,$zNa_2SO_4$, z=z*=11.25) was studied experimentally. Some peculiar features of the reaction mechanism were found. Parameters of the kinetic curve of nano TlCl obtained experimentally were compared with those for the model reaction KBr+TlCl+zKCl=(z+1) KCl+TlBr (z=z1*=13.5), and for the first time the value of mass transfer coefficient in a mechanochemical reactor with mobile milling balls was evaluated. Dynamics of the size change was followed for nanoparticle reaction product as a function of mechanical activation time.

MORPHOLOGICAL CHARACTERISTICS OF NONLINEAR OPTICAL MOLECULES AT THE AIR/WATER INTERFACE

  • Lim, Sung-Taek;Park, Mi-Kyung;Shin, Dong-Myung;Kwon, Ohoak
    • Journal of Photoscience
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    • v.5 no.1
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    • pp.11-15
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    • 1998
  • The texture change of non-linear optical molecules at the air/water interface was investigated as a function of surface pressure with Brewster angle microscopy. The texture change resulted from the aggregation of dye molecules is important to understand the film uniformity and grain formation process. The 4-Octadecylhydroxy-4'-nitrostilbene (OHNS) generated the small spots of size around 1$\mu$m. The spots exhibit high contrast with other film area and do not show angle dependent reflectivity change. It is interesting to observe that the size of the domain stays the same as the film pressure increases. At high surface pressure, the contrast ratio of domains becomes high, which means dense packing of OHNS. And, the size of domain grows. In the middle of domain, highly contrasted domains are formed. The first and the second order transitions of OHNS observed from surface pressure-area isotherm result from the two types of grains. The N,N-Dihexadecylcyanoaniline (DHCA) formed highly contrasted gains over entire region, and the grains are the double layers. The difference in Langmuir film of OHNS and DHCA at the air/water interface is consistent with the small tilt angle from the surface normal for OHNS and the large tilt angle for DHCA in the Langmuir-Blodgett films.

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