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Sample records for alumina capillaries mcp

  1. Ion guiding in alumina capillaries

    DEFF Research Database (Denmark)

    Juhász, Z.; Sulik, B.; Biri, S.;

    2009-01-01

    Transmission of a few keV impact energy Ne ions through capillaries in anodic alumina membranes has been studied with different ion counting methods using an energy dispersive electrostatic spectrometer, a multichannel plate (MCP) array and sensitive current-measurement. In the present work, we...... focus our attention to the measurements with the MCP array. The alumina capillaries were prepared by electro-chemical oxidation of aluminium foils. For the present experiments guiding of 3-6 keV Ne ions has been studied in two samples with capillary diameter of about 140 nm and 260 nm and with capillary...... length of about 15 μm. At these energies, the ions have been efficiently guided by the capillaries up to few degrees tilt angle. In this work, we compare the results obtained by the energy dispersive spectrometer to those studied by the MCP array. © 2008 Elsevier B.V. All rights reserved....

  2. Capillary condensation in porous alumina observed by positronium lifetime spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Ivanov, Eugeniu [National Institute for Nuclear Physics and Engineering-Horia Hulubei, Atomistilor Street 407, CP MG 06, Magurele, Bucharest (Romania); Center for Advanced Studies in Physics of the Roumanian Academy, Casa Academiei Romane, Calea 13 Septembrie No. 13, Bucharest (Romania); Vata, Ion [National Institute for Nuclear Physics and Engineering-Horia Hulubei, Atomistilor Street 407, CP MG 06, Magurele, Bucharest (Romania)], E-mail: vata@ifin.nipne.ro; Toderian, Stefan; Dudu, Dorin; Rusen, Ion; Stefan, Nitisor [National Institute for Nuclear Physics and Engineering-Horia Hulubei, Atomistilor Street 407, CP MG 06, Magurele, Bucharest (Romania)

    2008-10-31

    The PALS method based on time distribution measurements has been used to study capillary condensation of different gases adsorbed in microporous alumina powder. The isotherms exhibit features which are associated with a shifted gas-liquid transition. The sorption and desorption processes are irreversible presenting a hysteresis effect. Suggestions on some new aspects of the capillary condensation dynamics are made.

  3. Development of hydrophobic clay–alumina based capillary membrane for desalination of brine by membrane distillation

    Directory of Open Access Journals (Sweden)

    Rakhi Das

    2016-09-01

    Full Text Available Clay–alumina compositions of 0, 20, 40 and 55 weight percent (wt% clay and rest alumina were maintained in porous support preparation by extrusion followed by sintering at 1300 °C for 2.5 h to obtain 3 mm/2 mm (outer diameter/inner diameter capillary. 1H,1H,2H,2H-perfluorodecyltriethoxysilane (97% (C8 was used to modify the capillary surface of all compositions without any intermediate membrane layer to impart hydrophobic characteristics and compared in terms of contact angle produced by the capillaries with water and liquid entry pressure (LEPw. FTIR analysis showed that the hydrophilic surface of the capillary membranes was efficiently modified by the proposed grafting method. Capillary with 55 wt% clay produced a pore size of 1.43 micron and was considered as an ideal candidate for grafting with C8 polymer to impart surface hydrophobicity. The contact angle and LEPw value obtained for this modified membrane (C-55-M were 145° and 1 bar, respectively. The modified capillary membrane was applied for desalination of brine by air gap membrane distillation (AGMD at a feed pressure of 0.85 bar. Maximum flux obtained for C-55-M membrane was 98.66 L/m2 day at a temperature difference of 60 °C with salt rejection of 99.96%. Mass transfer coefficient of C-55-M was 16 × 10−3 mm/s at feed temperature of 70 °C.

  4. YSZ-Reinforced Alumina Multi-Channel Capillary Membranes for Micro-Filtration

    Directory of Open Access Journals (Sweden)

    Bo Wang

    2015-12-01

    Full Text Available The combined phase-inversion and sintering method not only produces ceramic hollow fibre membranes with much lower fabrication costs than conventional methods, but these membranes can also be designed to have greatly reduced transport resistances for filtration processes. The bottleneck of this technique is the weak mechanical property of the fibres, due to the small dimensions and the brittle nature of the ceramic materials. In this study, yttrium stabilised zirconia (YSZ reinforced alumina seven-channel capillary microfiltration membranes were prepared with a pore size of ~230 nm and their mechanical property and permeation characteristics were studied. It is found that the addition of YSZ can effectively enhance the mechanical property of the membrane and also increase pure water permeation flux. The Al2O3-YSZ seven-channel capillary membranes could reach a fracture load of 23.4 N and a bending extension of 0.54 mm when being tested with a 6 cm span, to meet the requirements for most industrial microfiltration applications.

  5. YSZ-Reinforced Alumina Multi-Channel Capillary Membranes for Micro-Filtration.

    Science.gov (United States)

    Wang, Bo; Lee, Melanie; Li, Kang

    2015-12-30

    The combined phase-inversion and sintering method not only produces ceramic hollow fibre membranes with much lower fabrication costs than conventional methods, but these membranes can also be designed to have greatly reduced transport resistances for filtration processes. The bottleneck of this technique is the weak mechanical property of the fibres, due to the small dimensions and the brittle nature of the ceramic materials. In this study, yttrium stabilised zirconia (YSZ) reinforced alumina seven-channel capillary microfiltration membranes were prepared with a pore size of ~230 nm and their mechanical property and permeation characteristics were studied. It is found that the addition of YSZ can effectively enhance the mechanical property of the membrane and also increase pure water permeation flux. The Al₂O₃-YSZ seven-channel capillary membranes could reach a fracture load of 23.4 N and a bending extension of 0.54 mm when being tested with a 6 cm span, to meet the requirements for most industrial microfiltration applications.

  6. High yield stress associated with capillary attraction between alumina surfaces in the presence of low molecular weight dicarboxylic acids.

    Science.gov (United States)

    Teh, E-Jen; Leong, Yee-Kwong; Liu, Yinong; Craig, Vincent S J; Walsh, Rick B; Howard, Shaun C

    2010-03-02

    Adsorbed low molecular weight charged molecules are known to give rise to a range of surface forces that affect the rheological behavior of oxide dispersions. The behavior of dicarboxylic acid bolaform compounds in alumina slurry was investigated to determine the influence of the molecular structure on the nanoscale interactions between alumina surfaces and on the macroscopic properties of the slurry. The surface forces in dispersions and between a single particle and a flat surface were characterized by yield stress and atomic force microscopy (AFM) respectively. Absorbed muconic acid increased the yield stress of the alumina system, which indicates an additional attractive interaction between the particles. Adsorbed trans,trans (TT) muconic acid resulted in a much higher yield stress than cis,cis (CC) muconic acid. Force-distance data obtained via AFM displayed features indicating the presence of a capillary force attraction at low pH between the alumina surfaces when TT and CC muconic acids were adsorbed at high surface coverage. This force appeared to explain the high yield stress at low pH (pH 3.6), but the absence of a net attractive force at higher pH (pH 5) did not correlate with the yield stress results. At low pH, the muconic acids become less soluble in the confined space between the interacting surfaces resulting in the formation of an "oily" muconic acid phase located between the interacting surfaces. The nanosized "oil" phase is the source of the capillary force.

  7. Lifetime of MCP-PMTs

    Science.gov (United States)

    Lehmann, A.; Britting, A.; Eyrich, W.; Pfaffinger, M.; Uhlig, F.; Belias, A.; Dzhygadlo, R.; Gerhardt, A.; Götzen, K.; Kalicy, G.; Krebs, M.; Lehmann, D.; Nerling, F.; Patsyuk, M.; Peters, K.; Schepers, G.; Schmitt, L.; Schwarz, C.; Schwiening, J.; Traxler, M.; Zühlsdorf, M.; Düren, M.; Etzelmüller, E.; Föhl, K.; Hayrapetyan, A.; Kröck, B.; Merle, O.; Rieke, J.; Schmidt, M.; Cowie, E.; Keri, T.; Achenbach, P.; Cardinali, M.; Hoek, M.; Lauth, W.; Schlimme, S.; Sfienti, C.; Thiel, M.

    2016-05-01

    The hadron identification in the PANDA experiment at FAIR will be done with DIRC detectors. Because of design and space reasons the sensors of the DIRCs have to be placed inside the strong magnetic field of the solenoid. As the favored photon sensors microchannel-plate photomultipliers (MCP-PMTs) were identified. However, these devices showed serious aging problems until very recently, which manifest themselves by a fast degrading quantum efficiency (QE) of the photo cathode (PC). This is mainly due to feedback ions from the residual gas. In this paper we discuss the recently accomplished huge improvements in the lifetime of MCP-PMTs. With innovative countermeasures applied to the MCP-PMTs in the attempt to reduce the aging effects the manufacturers were able to increase the lifetime of MCP-PMT prototypes by almost two orders of magnitude compared to the former commercially available devices. Our group has studied the aging of MCP-PMTs for more than four years by simultaneously illuminating different types of lifetime-enhanced MCP-PMTs at the same photon rate. Gain, dark count rate, and QE as a function of the wavelength and the PC surface were measured in regular time intervals and studied in dependence of the integrated anode charge. We observe that MCP-PMTs treated with an atomic layer deposition (ALD) technique are by far the best devices available now. A lifetime of up to 10 C/cm2 integrated anode charge was reached with these sensors. This is sufficient for both PANDA DIRCs.

  8. Sinorhizobium meliloti chemoreceptor McpU mediates chemotaxis toward host plant exudates through direct proline sensing.

    Science.gov (United States)

    Webb, Benjamin A; Hildreth, Sherry; Helm, Richard F; Scharf, Birgit E

    2014-06-01

    Bacterial chemotaxis is an important attribute that aids in establishing symbiosis between rhizobia and their legume hosts. Plant roots and seeds exude a spectrum of molecules into the soil to attract their bacterial symbionts. The alfalfa symbiont Sinorhizobium meliloti possesses eight chemoreceptors to sense its environment and mediate chemotaxis toward its host. The methyl accepting chemotaxis protein McpU is one of the more abundant S. meliloti chemoreceptors and an important sensor for the potent attractant proline. We established a dominant role of McpU in sensing molecules exuded by alfalfa seeds. Mass spectrometry analysis determined that a single germinating seed exudes 3.72 nmol of proline, producing a millimolar concentration near the seed surface which can be detected by the chemosensory system of S. meliloti. Complementation analysis of the mcpU deletion strain verified McpU as the key proline sensor. A structure-based homology search identified tandem Cache (calcium channels and chemotaxis receptors) domains in the periplasmic region of McpU. Conserved residues Asp-155 and Asp-182 of the N-terminal Cache domain were determined to be important for proline sensing by evaluating mutant strains in capillary and swim plate assays. Differential scanning fluorimetry revealed interaction of the isolated periplasmic region of McpU (McpU40-284) with proline and the importance of Asp-182 in this interaction. Using isothermal titration calorimetry, we determined that proline binds with a Kd (dissociation constant) of 104 μM to McpU40-284, while binding was abolished when Asp-182 was substituted by Glu. Our results show that McpU is mediating chemotaxis toward host plants by direct proline sensing.

  9. Transport properties of alumina nanofluids

    Energy Technology Data Exchange (ETDEWEB)

    Wong, Kau-Fui Vincent; Kurma, Tarun [Department of Mechanical and Aerospace Engineering, University of Miami, Coral Gables, FL 33124 (United States)], E-mail: kwong@miami.edu

    2008-08-27

    taken at various volumetric concentrations. A 3457.1% increase in the electrical conductivity was measured for a small 1.44% volumetric concentration of alumina nanoparticles in water. The highest value of electrical conductivity, 314 {mu}S cm{sup -1}, was recorded for a volumetric concentration of 8.47%. In the determination of the kinematic viscosity of alumina nanofluid, a standard kinematic viscometer with constant temperature bath was used. Calibrated capillary viscometers were used to measure flow under gravity at precisely controlled temperatures. The capillary viscometers were calibrated with de-ionized water at different temperatures, and the resulting kinematic viscosity values were found to be within 3% of the standard published values. An increase of 35.5% in the kinematic viscosity was observed for an 8.47% volumetric concentration of alumina nanoparticles in water. The maximum kinematic viscosity of alumina nanofluid, 2.901 42 mm{sup 2} s{sup -1}, was obtained at 0 deg. C for an 8.47% volumetric concentration of alumina nanoparticles. The experimental results of the present work will help researchers arrive at better theoretical models.

  10. Transport properties of alumina nanofluids.

    Science.gov (United States)

    Wong, Kau-Fui Vincent; Kurma, Tarun

    2008-08-27

    various volumetric concentrations. A 3457.1% increase in the electrical conductivity was measured for a small 1.44% volumetric concentration of alumina nanoparticles in water. The highest value of electrical conductivity, 314 µS cm(-1), was recorded for a volumetric concentration of 8.47%. In the determination of the kinematic viscosity of alumina nanofluid, a standard kinematic viscometer with constant temperature bath was used. Calibrated capillary viscometers were used to measure flow under gravity at precisely controlled temperatures. The capillary viscometers were calibrated with de-ionized water at different temperatures, and the resulting kinematic viscosity values were found to be within 3% of the standard published values. An increase of 35.5% in the kinematic viscosity was observed for an 8.47% volumetric concentration of alumina nanoparticles in water. The maximum kinematic viscosity of alumina nanofluid, 2.901 42 mm(2) s(-1), was obtained at 0 °C for an 8.47% volumetric concentration of alumina nanoparticles. The experimental results of the present work will help researchers arrive at better theoretical models.

  11. Compact MCP assemblies for mass spectrometers

    Energy Technology Data Exchange (ETDEWEB)

    Matsuura, S. [Hamamatsu Photonics K.K., Shizuoka (Japan). Electron Tube Div.; Umebayashi, S. [Hamamatsu Photonics K.K., Shizuoka (Japan). Electron Tube Div.; Kusuyama, Y. [Hamamatsu Photonics K.K., Shizuoka (Japan). Electron Tube Div.; Natsume, Y. [Hamamatsu Photonics K.K., Shizuoka (Japan). Electron Tube Div.; Oba, K. [Hamamatsu Photonics K.K., Shizuoka (Japan). Electron Tube Div.

    1995-09-01

    We have developed compact microchannel plate (MCP) assemblies which have a high gain, good pulse height resolution and a fast response for MS applications. In this paper, these new assemblies are described referring to their structures, functions and characteristics. (orig.).

  12. Tremendously increased lifetime of MCP-PMTs

    Science.gov (United States)

    Lehmann, A.; Britting, A.; Eyrich, W.; Pfaffinger, M.; Uhlig, F.; Belias, A.; Dzhygadlo, R.; Gerhardt, A.; Götzen, K.; Kalicy, G.; Krebs, M.; Lehmann, D.; Nerling, F.; Patsyuk, M.; Peters, K.; Schepers, G.; Schmitt, L.; Schwarz, C.; Schwiening, J.; Traxler, M.; Zühlsdorf, M.; Düren, M.; Etzelmüller, E.; Föhl, K.; Hayrapetyan, A.; Kröck, B.; Merle, O.; Rieke, J.; Schmidt, M.; Cowie, E.; Keri, T.; Achenbach, P.; Cardinali, M.; Hoek, M.; Lauth, W.; Schlimme, S.; Sfienti, C.; Thiel, M.

    2017-02-01

    Microchannel plate (MCP) PMTs are very attractive photon sensors for low light level applications in strong magnetic fields. However, until recently the main drawback of MCP-PMTs was their aging behavior which manifests itself in a limited lifetime due to a rapidly decreasing quantum efficiency (QE) of the photo cathode (PC) as the integrated anode charge (IAC) increases. In the latest models of PHOTONIS, Hamamatsu, and BINP novel techniques are applied to avoid these aging effects which are supposed to be mainly caused by feedback ion impinging on the PC and damaging it. For more than four years we are running a long-term aging test with new lifetime-enhanced MCP-PMT models by simultaneously illuminating various PMTs with roughly the same photon rate. This allows a fair comparison of the lifetime of all investigated MCP-PMTs and will give some insight into the best techniques to be applied for a lifetime enhancement. In this paper the results of comprehensive aging tests will be discussed. Gain, dark count rate and QE were investigated for their dependence on the IAC. The QE was measured spectrally resolved and as a function of the position across the PC to identify regions where the damage develops first. For the best performing tubes the lifetime improvement compared to former MCP-PMTs is a factor of ∼ 50 based on an IAC of meanwhile > 10 C /cm2. This breakthrough in the lifetime of MCP-PMTs was achieved by coating the MCP pores with an atomic layer deposition (ALD) technique.

  13. MCP-based Photodetectors for Cryogenic Applications

    CERN Document Server

    Dharmapalan, Ranjan; Byrum, Karen; Demarteau, Marcel; Elam, Jeffrey; May, Edward; Wagner, Robert; Walters, Dean; Xia, Lei; Xie, Junqi; Zhao, Huyue; Wang, J

    2016-01-01

    The Argonne MCP-based photo detector is an offshoot of the Large Area Pico-second Photo Detector (LAPPD) project, wherein 6 cm x 6 cm sized detectors are made at Argonne National Laboratory. We have successfully built and tested our first detectors for pico-second timing and few mm spatial resolution. We discuss our efforts to customize these detectors to operate in a cryogenic environment. Initial plans aim to operate in liquid argon. We are also exploring ways to mitigate wave length shifting requirements and also developing bare-MCP photodetectors to operate in a gaseous cryogenic environment.

  14. Capillary sample

    Science.gov (United States)

    ... several times a day using capillary blood sampling. Disadvantages to capillary blood sampling include: Only a limited ... do not constitute endorsements of those other sites. Copyright 1997-2017, A.D.A.M., Inc. Duplication ...

  15. Salmonella chemoreceptors McpB and McpC mediate a repellent response to L-cystine: a potential mechanism to avoid oxidative conditions.

    Science.gov (United States)

    Lazova, Milena D; Butler, Mitchell T; Shimizu, Thomas S; Harshey, Rasika M

    2012-05-01

    Chemoreceptors McpB and McpC in Salmonella enterica have been reported to promote chemotaxis in LB motility-plate assays. Of the chemicals tested as potential effectors of these receptors, the only response was towards L-cysteine and its oxidized form, L-cystine. Although enhanced radial migration in plates suggested positive chemotaxis to both amino acids, capillary assays failed to show an attractant response to either, in cells expressing only these two chemoreceptors. In vivo fluorescence resonance energy transfer (FRET) measurements of kinase activity revealed that in wild-type bacteria, cysteine and cystine are chemoeffectors of opposing sign, the reduced form being a chemoattractant and the oxidized form a repellent. The attractant response to cysteine was mediated primarily by Tsr, as reported earlier for Escherichia coli. The repellent response to cystine was mediated by McpB/C. Adaptive recovery upon cystine exposure required the methyl-transferase/-esterase pair, CheR/CheB, but restoration of kinase activity was never complete (i.e. imperfect adaptation). We provide a plausible explanation for the attractant-like responses to both cystine and cysteine in motility plates, and speculate that the opposing signs of response to this redox pair might afford Salmonella a mechanism to gauge and avoid oxidative environments.

  16. Porous Alumina Films with Width-Controllable Alumina Stripes

    Directory of Open Access Journals (Sweden)

    Huang Shi-Ming

    2010-01-01

    Full Text Available Abstract Porous alumina films had been fabricated by anodizing from aluminum films after an electropolishing procedure. Alumina stripes without pores can be distinguished on the surface of the porous alumina films. The width of the alumina stripes increases proportionally with the anodizing voltage. And the pores tend to be initiated close to the alumina stripes. These phenomena can be ascribed to the electric field distribution in the alumina barrier layer caused by the geometric structure of the aluminum surface.

  17. Porous Alumina Films with Width-Controllable Alumina Stripes.

    Science.gov (United States)

    Huang, Kai; Huang, Shi-Ming; Pu, Lin; Shi, Yi; Wu, Zhi-Ming; Ji, Li; Kang, Jun-Yong

    2010-08-21

    Porous alumina films had been fabricated by anodizing from aluminum films after an electropolishing procedure. Alumina stripes without pores can be distinguished on the surface of the porous alumina films. The width of the alumina stripes increases proportionally with the anodizing voltage. And the pores tend to be initiated close to the alumina stripes. These phenomena can be ascribed to the electric field distribution in the alumina barrier layer caused by the geometric structure of the aluminum surface.

  18. Reuse of activated alumina

    Energy Technology Data Exchange (ETDEWEB)

    Hobensack, J.E. [Martin Marietta Energy Systems, Inc., Piketon, OH (United States)

    1991-12-31

    Activated alumina is used as a trapping media to remove trace quantities of UF{sub 6} from process vent streams. The current uranium recovery method employs concentrated nitric acid which destroys the alumina pellets and forms a sludge which is a storage and disposal problem. A recently developed technique using a distilled water rinse followed by three dilute acid rinses removes on average 97% of the uranium, and leaves the pellets intact with crush strength and surface area values comparable with new material. Trapping tests confirm the effectiveness of the recycled alumina as UF{sub 6} trapping media.

  19. Single ion counting with a MCP (microchannel plate) detector

    Energy Technology Data Exchange (ETDEWEB)

    Tawara, Hiroko; Sasaki, Shinichi; Miyajima, Mitsuhiro [National Lab. for High Energy Physics, Tsukuba, Ibaraki (Japan); Shibamura, Eido

    1996-07-01

    In this study, a single-ion-counting method using alpha-particle-impact ionization of Ar atoms is demonstrated and the preliminary {epsilon}{sub mcp} for Ar ions with incident energies of 3 to 4.7 keV is determined. The single-ion counting by the MCP is aimed to be performed under experimental conditions as follows: (1) A signal from the MCP is reasonably identified as incidence of single Ar-ion. (2) The counting rate of Ar ions is less than 1 s{sup -1}. (3) The incident Ar ions are not focused on a small part of an active area of the MCP, namely, {epsilon}{sub mcp} is determined with respect to the whole active area of the MCP. So far, any absolute detection efficiency has not been reported under these conditions. (J.P.N.)

  20. Capillary origami

    OpenAIRE

    Py, Charlotte; Reverdy, Paul; Doppler, L.; J. Bico; Roman, B.; Baroud, Charles,

    2007-01-01

    International audience; The hairs of a wet dog rushing out from a pond assemble into bundles; this is a common example of the effect of capillary forces on flexible structures. From a practical point of the deformation and adhesion of compliant structures induced by interfacial forces may lead to disastrous effects in mechanical microsystems.

  1. Status of the Timepix MCP-HPD development

    CERN Document Server

    Tick, T; Michel, T; O'Shea, V; Plackett, R; Pospisil, S; Vallerga, J; Visser, J

    2010-01-01

    This paper describes the design of a high-speed, single-photon sensitive, Hybrid Photon Detector (HPD). The detector consists of a vacuum tube, containing a Micro Channel Plate (MCP) and 4 CMOS pixel readout chips, sealed with a transparent optical input window with a photocathode. The design described here utilizes currently available technologies, specifically the Timepix readout chips and the Photonis Planacon MCP-PMT vacuum tubes. The aim of the project is to demonstrate the feasibility of a 4-side buttable square MCP-HPD with high packing fraction sensitive area. Presented here is the mechanical and thermal design of the prototype detector

  2. Dexmedetomidine Attenuates Lipopolysaccharide Induced MCP-1 Expression in Primary Astrocyte

    Science.gov (United States)

    Liu, Huan; Faez Abdelgawad, Amro

    2017-01-01

    Background. Neuroinflammation which presents as a possible mechanism of delirium is associated with MCP-1, an important proinflammatory factor which is expressed on astrocytes. It is known that dexmedetomidine (DEX) possesses potent anti-inflammatory properties. This study aimed to investigate the potential effects of DEX on the production of MCP-1 in lipopolysaccharide-stimulated astrocytes. Materials and Methods. Astrocytes were treated with LPS (10 ng/ml, 50 ng/ml, 100 ng/ml, and 1000 ng/ml), DEX (500 ng/mL), LPS (100 ng/ml), and DEX (10, 100, and 500 ng/mL) for a duration of three hours; expression levels of MCP-1 were measured by real-time PCR. The double immunofluorescence staining protocol was utilized to determine the expression of α2-adrenoceptors (α2AR) and glial fibrillary acidic protein (GFAP) on astrocytes. Results. Expressions of MCP-1 mRNA in astrocytes were induced dose-dependently by LPS. Administration of DEX significantly inhibited the expression of MCP-1 mRNA (P < 0.001). Double immunofluorescence assay showed that α2AR colocalize with GFAP, which indicates the expression of α2-adrenoceptors in astrocytes. Conclusions. DEX is a potent suppressor of MCP-1 in astrocytes induced with lipopolysaccharide through α2A-adrenergic receptors, which potentially explains its beneficial effects in the treatment of delirium by attenuating neuroinflammation. PMID:28286770

  3. Single electron counting using a dual MCP assembly

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Yuzhen [School of Physics, Nanjing University, Nanjing 210093 (China); Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049 (China); State Key Laboratory of Particle Detection and Electronics, Beijing 100049 (China); Liu, Shulin, E-mail: liusl@ihep.ac.cn [Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049 (China); State Key Laboratory of Particle Detection and Electronics, Beijing 100049 (China); Zhao, Tianchi, E-mail: tianchi@u.washington.edu [Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049 (China); State Key Laboratory of Particle Detection and Electronics, Beijing 100049 (China); Department of Physics, University of Washington, Seattle, WA 98195 (United States); Yan, Baojun; Wang, Peiliang [Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049 (China); State Key Laboratory of Particle Detection and Electronics, Beijing 100049 (China); Yu, Yang [Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049 (China); State Key Laboratory of Particle Detection and Electronics, Beijing 100049 (China); School of Science, Xi’an University of Technology, Xi’an 710048 (China); Lei, Xiangcui [Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049 (China); State Key Laboratory of Particle Detection and Electronics, Beijing 100049 (China); Yang, Luping [Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049 (China); State Key Laboratory of Particle Detection and Electronics, Beijing 100049 (China); School of Physics and Electronics, Henan University, Kaifeng 475004 (China); Wen, Kaile [Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049 (China); State Key Laboratory of Particle Detection and Electronics, Beijing 100049 (China); Qi, Ming [School of Physics, Nanjing University, Nanjing 210093 (China); and others

    2016-09-11

    The gain, pulse height resolution and peak-to-valley ratio of single electrons detected by using a Chevron configured Microchannel Plate (MCP) assembly are studied. The two MCPs are separated by a 280 µm gap and are biased by four electrodes. The purpose of the study is to determine the optimum bias voltage arrangements for single electron counting. By comparing the results of various bias voltage combinations, we conclude that good performance for the electron counting can be achieved by operating the MCP assembly in saturation mode. In addition, by applying a small reverse bias voltage across the gap while adjusting the bias voltages of the MCPs, optimum performance of electron counting can be obtained. - Highlights: • Dual MCPs assembly with four electrodes using different voltage combinations has been investigated for single electron counting. • Both the MCP voltages and the gap voltage can affect the gain, pulse height resolution and P/V ratio. • A high gain of the first stage MCP, a saturation mode of the second stage MCP and an appropriately reverse gap voltage can improve the resolution greatly. • The optimum voltage arrangements is significant for the design of MCP detectors in single electron counting applications.

  4. CCL2/MCP-1 modulation of microglial activation and proliferation

    Directory of Open Access Journals (Sweden)

    Garcia-Bueno Borja

    2011-07-01

    Full Text Available Abstract Background Monocyte chemoattractant protein (CCL2/MCP-1 is a chemokine that attracts cells involved in the immune/inflammatory response. As microglia are one of the main cell types sustaining inflammation in brain, we proposed here to analyze the direct effects of MCP-1 on cultured primary microglia. Methods Primary microglia and neuronal cultures were obtained from neonatal and embryonic Wistar rats, respectively. Microglia were incubated with different concentrations of recombinant MCP-1 and LPS. Cell proliferation was quantified by measuring incorporation of bromodeoxyuridine (BrdU. Nitrite accumulation was measured using the Griess assay. The expression and synthesis of different proteins was measured by RT-PCR and ELISA. Cell death was quantified by measuring release of LDH into the culture medium. Results MCP-1 treatment (50 ng/ml, 24 h did not induce morphological changes in microglial cultures. Protein and mRNA levels of different cytokines were measured, showing that MCP-1 was not able to induce proinflammatory cytokines (IL-1β, IL6, MIP-1α, either by itself or in combination with LPS. A similar lack of effect was observed when measuring inducible nitric oxide synthase (NOS2 expression or accumulation of nitrites in the culture media as a different indicator of microglial activation. MCP-1 was also unable to alter the expression of different trophic factors that were reduced by LPS treatment. In order to explore the possible release of other products by microglia and their potential neurotoxicity, neurons were co-cultured with microglia: no death of neurons could be detected when treated with MCP-1. However, the presence of MCP-1 induced proliferation of microglia, an effect opposite to that observed with LPS. Conclusion These data indicate that, while causing migration and proliferation of microglia, MCP-1 does not appear to directly activate an inflammatory response in this cell type, and therefore, other factors may be

  5. Study on MCP-1 related to inflammation induced by biomaterials

    Energy Technology Data Exchange (ETDEWEB)

    Ding Tingting [Ninth People' s Hospital, School of Medicine, Shanghai Jiao Tong University/Shanghai Biomaterials Research and Testing Center, Shanghai 200023 (China); Sun Jiao [Shanghai Key Laboratory of Stomatology, Shanghai 200023 (China); Zhang Ping, E-mail: jiaosun59@yahoo.co [School of Life Science, East China Normal University, Shanghai 200062 (China)

    2009-06-15

    The study of inflammation is important for understanding the reaction between biomaterials and the human body, in particular, the interaction between biomaterials and immune system. In the current study, rat macrophages were induced by multiple biomaterials with different biocompatibilities, including polyvinyl chloride (PVC) containing 8% of organic tin, a positive control material with cellular toxicity. Human umbilical vein endothelial cells (ECV-304), cultured with PRMI-1640, were detached from cells cultured with the supernatant of macrophages containing TNF-alpha and IL-1beta because of stimulation by biomaterials. The cells were then treated with different biomaterials. Then both TNF-alpha and IL-1beta in macrophages were detected by ELISA. Levels of monocyte chemoattractant protein-1 (MCP-1) were measured by RT-PCR. The results suggested that the expression of TNF-alpha and IL-1beta was elevated by polytetrafluoroethylene (PTFE), polylactic-co-glycolic acid (PLGA) and American NPG alloy (p < 0.001). The level of MCP-1 cultured in supernatant of macrophages was higher than in PRMI-1640 with the same biomaterials. And the exposure to PTFE, PLGA and NPG resulted in the high expression of MCP-1 (p < 0.001) following cytokine stimulation. MCP-1 was also significantly expressed in beta-tricalcium phosphate (beta-TCP) and calcium phosphate cement samples (CPC) (p < 0.01). Thus, TNF-alpha, IL-1beta and MCP-1 had played an important role in the immune reaction induced by biomaterials and there was a close relationship between the expression of cytokines and biomcompatibility of biomaterials. Furthermore, these data suggested that MCP-1 was regulated by TNF-alpha and IL-1beta, and activated by both cytokines and biomaterials. The data further suggested that the expression of MCP-1 could be used as a marker to indicate the degree of immune reaction induced by biomaterials.

  6. Calcium aluminate in alumina

    Science.gov (United States)

    Altay, Arzu

    The properties of ceramic materials are determined not only by the composition and structure of the phases present, but also by the distribution of impurities, intergranular films and second phases. The phase distribution and microstructure both depend on the fabrication techniques, the raw materials used, the phase-equilibrium relations, grain growth and sintering processes. In this dissertation research, various approaches have been employed to understand fundamental phenomena such as grain growth, impurity segregation, second-phase formation and crystallization. The materials system chosen was alumina intentionally doped with calcium. Atomic-scale structural analyses of grain boundaries in alumina were carried on the processed samples. It was found that above certain calcium concentrations, CA6 precipitated as a second phase at all sintering temperatures. The results also showed that abnormal grain growth can occur after precipitation and it is not only related to the calcium level, but it is also temperature dependent. In order to understand the formation mechanism of CA6 precipitates in calcium doped alumina samples, several studies have been carried out using either bulk materials or thin films The crystallization of CA2 and CA6 powders has been studied. Chemical processing techniques were used to synthesize the powders. It was observed that CA2 powders crystallized directly, however CA6 powders crystallized through gamma-Al 2O3 solid solution. The results of energy-loss near-edge spectrometry confirmed that gamma-Al2O3 can dissolve calcium. Calcium aluminate/alumina reaction couples have also been investigated. All reaction couples were heat treated following deposition. It was found that gamma-Al2O3 was formed at the interface as a result of the interfacial reaction between the film and the substrate. gamma-Al 2O3 at the interface was stable at much higher temperatures compared to the bulk gamma-Al2O3 formed prior to the CA6 crystallization. In order to

  7. Resolution changes of MCP-PMTs in magnetic fields

    Science.gov (United States)

    Rieke, J.; Belias, A.; Dzhygadlo, R.; Gerhardt, A.; Götzen, K.; Kalicy, G.; Krebs, M.; Lehmann, D.; Nerling, F.; Patsyuk, M.; Peters, K.; Schepers, G.; Schmitt, L.; Schwarz, C.; Schwiening, J.; Traxler, M.; Zühlsdorf, M.; Britting, A.; Eyrich, W.; Lehmann, A.; Pfaffinger, M.; Uhlig, F.; Düren, M.; Etzelmüller, E.; Föhl, K.; Hayrapetyan, A.; Kröck, B.; Merle, O.; Rieke, J.; Schmidt, M.; Cowie, E.; Keri, T.; Achenbach, P.; Cardinali, M.; Hoek, M.; Lauth, W.; Schlimme, S.; Sfienti, C.; Thiel, M.

    2016-05-01

    Micro-channel plate photomultiplier tubes (MCP-PMTs) are chosen in many applications that have to cope with strong magnetic fields. The DIRC detectors of the PANDA experiment plan to employ them as they show excellent timing characteristics, radiation hardness, relatively low dark count rates and sufficient lifetime. This article mainly focuses on the performance of the position reconstruction of detected photons. Two different MCP-PMTs with segmented anode geometries have been tested in magnetic fields of different strengths. The variation of their performance has been studied. The measurements show improved position resolution and image shifts with increasing magnetic field strength.

  8. MCP-based detector some results and perspectives

    CERN Document Server

    Patarakin, O O; Strepetov, A N; Turbin, E V; Sinitsin, V I; Kartamushev, A A

    1997-01-01

    The timing resolution of photomultiplier tubes (PMT) based on shevron-type microchannel plates (MCP) has been studied inmagnetic fields. The same timingresolution with and without a longitudinal magnetic field up to 2.0 kGwas obtained as = 85 ± 2 ps. It is shown that an increase of timing resolution in this magnetic field does not exceed25 ps (upper limit). The timing resolution of = 31 ± 2 pswas obtained for narrow (10resolution) amplitude spectrumfrom Corone discharge. The counting rate of MCP-based detector was studied in function of the direction of the magnetic field.The spatial and timing resolution for the MCP-based PMT were obtained using laser pulses as well. With laser pulses of 0.3 ns a timing resolution of ≅ 450 ps was obtained. Taking into account the amplitude correction narrows to 140 ps. Using 100 fs-laser with the standard constant fractiondiscriminator gives a timing resolution from 20 to 40 ps depending on the read-out MCP region.The perspectives of using...

  9. Leukocytes in capillary flow.

    Science.gov (United States)

    Schmid-Schönbein, G W; Lee, J

    1995-01-01

    During disease, the flow of blood cells through the capillary network is one of the most perilous events in the microcirculation. Capillary distensibility, cytoplasmic activity of endothelial cells, red cells and leukocytes play an important role in capillary perfusion. Occlusion of capillaries is one of the early signs of vascular failure and is encountered in many different conditions and organs. Adhesion of leukocytes to the endothelium via expression of membrane adhesion molecules leads to microvascular entrapment with capillary occlusion.

  10. Optimization of a Water Window Capillary Discharge Radiation Source

    Directory of Open Access Journals (Sweden)

    M. Stefanovič

    2011-01-01

    Full Text Available Computer modeling of a fast electrical discharge in a nitrogen-filled alumina capillary was performed in order to discover discharge system parameters that lead to high radiation intensity in the so-called water window range of wavelengths (2–4 nm. The modeling was performed by means of the two-dimensional RMHD code Z*. The time and spatial distribution of plasma quantities were used for calculating the ion level populations and for estimating the absorption of the 2.88 nm radiation line in the capillary plasma, using the FLYCHK code. Optimum discharge parameters for the capillary discharge water window source are suggested. The heating of the electrodes and the role of capillary channel shielding were analyzed according to the Z* code.

  11. Alumina-magnesia Refractory Castables

    Institute of Scientific and Technical Information of China (English)

    Wang Jing

    2010-01-01

    @@ 1 Scope This standard specifies the classification,technical requirements,test methods,quality appraisal procedures,packing,marking,transportation,storage,and quality certificate of alumina-magnesia refractory castables.

  12. Firmeza de pêssegos 'diamante' tratados com 1-MCP Firmness of peach 'diamante' treated with 1-MCP

    Directory of Open Access Journals (Sweden)

    Fernanda Emanuele da Rocha Oliveira

    2005-12-01

    Full Text Available No Brasil, o consumo de pêssegos in natura vem aumentando a cada ano. No entanto, durante o transporte, o período de armazenamento e a comercialização, as perdas são bastante significativas, havendo a necessidade de desenvolver tecnologias para manter a qualidade pós-colheita e prolongar a vida útil desses frutos. O composto 1-metilciclopropeno (1-MCP vem sendo usado com resultados positivos em diversos tipos de frutos, como goiaba, banana, maçã, entre outras. Neste trabalho, foi avaliado o tratamento com 1-MCP em pêssegos armazenados em condições ambientais para a manutenção da firmeza dos frutos. Os frutos da cv. Diamante foram provenientes do município de Nepomuceno-MG, colhidos no estádio de maturação 'de vez' e selecionados em função do tamanho, estádio de maturação e ausência de injúrias. Os frutos foram submetidos à imersão em hipoclorito de sódio a 1% para desinfecção e parte deles foi tratada com 1-MCP, na concentração aproximada de 625 nL/L, por 12 horas. Em seguida, os frutos foram armazenados por até 10 dias, em temperatura ambiente (22 ± 2°C e 77 ± 2% UR. Foram realizadas análises de firmeza da polpa, solubilização de pectinas e atividades de pectinametilesterase e poligalacturonase a cada 2 dias até o final do período de armazenamento. Os frutos tratados com 1-MCP apresentaram maior firmeza e menor solubilização de pectinas durante o período avaliado e também menor atividade de pectinametilesterase que os frutos-controle até o 6º dia de armazenamento, demonstrando que o 1-MCP foi eficiente em retardar o amaciamento dos frutos no período estudado.In Brazil, the consumption of in natura peaches has been increasing every year. However, during the transport, the storage period and the commercialization, the losses are quite significant, having the need to develop technologies to maintain postharvest quality and to prolong the useful life of those fruits. The compound 1-methylcyclopropene

  13. Ceramic Wick For Capillary-Pumped Heat Pipe

    Science.gov (United States)

    Seidenberg, Benjamin; Swanson, Theodore

    1989-01-01

    Fibrous ceramic wick allows choice of working fluid and high-temperature fabrication and/or operation. Wick material resists degradation at temperatures from -195 to +1,500 degrees C. Liquid refrigerant fills bore of silica/alumina wick. After flowing by capillary action through pores of wick, refrigerant evaporates from finned outer surface of wick and enters heat pipe, flowing toward condenser section.

  14. Monocyte chemoattractant protein 1 (MCP-1) in temporal arteritis and polymyalgia rheumatica

    OpenAIRE

    Ellingsen, T.; Elling, P; Olson, A.; Elling, H; Baandrup, U; Matsushima, K.; Deleuran, B; Stengaard-Pederse..., K

    2000-01-01

    OBJECTIVE—To examine the localisation of monocyte chemoattractant protein 1 (MCP-1) in the inflamed vessel wall in temporal arteritis (TA) and to measure MCP-1 in plasma both in patients with TA and patients with polymyalgia rheumatica (PMR).
METHODS—By immunohistochemical techniques MCP-1 was localised to the vessel wall in patients with TA. In TA, PMR, and healthy controls MCP-1 was quantified by enzyme linked immunosorbent assay (ELISA) in plasma.
RESULTS—MCP-1 was localised to the majorit...

  15. Gelcasting polycrystalline alumina

    Energy Technology Data Exchange (ETDEWEB)

    Janney, M.A. [Oak Ridge National Lab., TN (United States)

    1997-04-01

    This work is being done as part of a CRADA with Osram-Sylvania, Inc. (OSI) OSI is a major U.S. manufacturer of high-intensity lighting. Among its products is the Lumalux{reg_sign} line of high-pressure sodium vapor arc lamps, which are used for industrial, highway, and street lighting. The key to the performance of these lamps is the polycrystalline alumina (PCA) tube that is used to contain the plasma that is formed in the electric arc. That plasma consists of ionized sodium, mercury, and xenon vapors. The key attributes of the PCA tubes are their transparency (95% total transmittance in the visible region), their refractoriness (inner wall temperature can reach 1400{degrees}C), and their chemical resistance (sodium and mercury vapor are extremely corrosive). The current efficiency of the lamps is very high, on the order of several hundred lumens / watt. (Compare - incandescent lamps -13 lumens/watt fluorescent lamps -30 lumens/watt.) Osram-Sylvania would like to explore using gelcasting to form PCA tubes for Lumalux{reg_sign} lamps, and eventually for metal halide lamps (known as quartz-halogen lamps). Osram-Sylvania, Inc. currently manufactures PCA tubes by isostatic pressing. This process works well for the shapes that they presently use. However, there are several types of tubes that are either difficult or impossible to make by isostatic pressing. It is the desire to make these new shapes and sizes of tubes that has prompted Osram-Sylvania`s interest in gelcasting. The purpose of the CRADA is to determine the feasibility of making PCA items having sufficient optical quality that they are useful in lighting applications using gelcasting.

  16. Effects of 1-MCP on Post-Harvest Physiology of Tomato

    Institute of Scientific and Technical Information of China (English)

    SUN Xi-sheng; WANG Zhi-hua; LI Zhi-qiang; ZHANG Zhi-yun; WANG Wen-hui

    2003-01-01

    Tomato (Lycopersicon esculentum cv. 402) was used to investigate the effects of 1-MCP (1-methylcyclopropene) treatment on ethylene production, respiration, vitamin C, chlorophyll, titratable acid,change of fruit color and rot. The results indicated that 1-MCP strongly inhibited ethylene production and respiration of tomato at very low concentration, delayed the incidence of climacteric peak of ethylene production and respiration. 1-MCP also delayed the decrease of vitamin C, chlorophyll and titratable acid during shelf life and storage significantly. Shelf and storage life of fruit treated with 1-MCP were extended at least 10 days at ambient (20 - 22℃ ) and 15 days at storage (9 - 11℃ ) temperature, respectively. Efficacy of 1-MCP on shelf and storage life was improved by increasing its concentration. After treatment of 1-MCP, rots were markedly lower than that of untreated fruit. 1-MCP treatment delayed the fruit color change.

  17. 随机极性MCP-EBPSK传输性能%Transmission performance of MCP-EBPSK with random polar

    Institute of Scientific and Technical Information of China (English)

    靳一; 吴乐南; 冯熳; 邓蕾

    2012-01-01

    为提高随机极性的修正连续相位扩展二元相移键控(MCP-EBPSK)调制信号的传输性能,对比了AWGN信道上自适应门限判决、BP神经网络和支持向量机(SVM)判决3种解调方式的解调性能,并引入了RS码和规则LDPC码来进行改善.根据随机极性MCP-EBPSK调制原理和数字冲击滤波器特殊滤波机理,设计了基于自适应门限判决、BP神经网络和SVM的解调器.同时,在这3种解调方式性能均不佳时,对RS码和规则LDPC编码的随机极性MCP-EBPSK传输性能进行了仿真.仿真结果表明:在AWGN信道上,自适应门限判决、BP神经网络和SVM三种解调方式的解调性能相差不大;当采用自适应门限判决且误码率为10-4时,RS码和规则LDPC码的编码增益分别约为4 dB和7 dB.因此,引入信道编码可显著改善随机极性MCP-EBPSK的传输性能.%In order to improve the transmission performance of random polar and modified extended binary phase shift keying with continuous phase (MCP-EBPSK) modulated signal, the demodulation performance of the adaptive threshold discrimination, BP neural network, and support vector machine (SVM) in additive white Gaussian noise(AWGN) channel is compared, then Reed-Solomon (RS) code and regular low-density parity-check (LDPC) code are introduced. According to the principle of MCP-EBPSK with random polar and the special filtering mechanism of digital impacting filter, the demodulators are designed based on adaptive threshold discrimination, BP neural network, and SVM. Meanwhile, when the demodulation performance of these demodulators is poor, the RS and regular LDPC coded MCP-EBPSK with random polar is also simulated. Simulation results show that in AWGN channel, the demodulation performance of adaptive threshold discrimination, BP neural network and SVM is almost the same; when adaptive threshold discrimination is used and BER is 10-4, the coding gain of RS code and regular LDPC is about 4 dB and 7 dB, respectively

  18. MCP-1 expressed by osteoclasts stimulates osteoclastogenesis in an autocrine/paracrine manner

    Energy Technology Data Exchange (ETDEWEB)

    Miyamoto, Kana [Department of Orthopedic Surgery, Keio University School of Medicine, 35 Shinano-machi, Shinjuku-ku, Tokyo 160-8582 (Japan); Division of Orthopedic Research, Keio University School of Medicine, 35 Shinano-machi, Shinjuku-ku, Tokyo 160-8582 (Japan); Department of Cell Differentiation, The Sakaguchi Laboratory of Developmental Biology, Keio University School of Medicine, 35 Shinano-machi, Shinjuku-ku, Tokyo 160-8582 (Japan); Ninomiya, Ken [Department of Orthopedic Surgery, Keio University School of Medicine, 35 Shinano-machi, Shinjuku-ku, Tokyo 160-8582 (Japan); Department of Cell Differentiation, The Sakaguchi Laboratory of Developmental Biology, Keio University School of Medicine, 35 Shinano-machi, Shinjuku-ku, Tokyo 160-8582 (Japan); Sonoda, Koh-Hei [Department of Ophthalmology, Graduate School of Medical Sciences, Kyushu University, 3-1-1, Maidashi, Higashi-ku, Fukuoka, Fukuoka 812-8582 (Japan); Miyauchi, Yoshiteru; Hoshi, Hiroko [Department of Orthopedic Surgery, Keio University School of Medicine, 35 Shinano-machi, Shinjuku-ku, Tokyo 160-8582 (Japan); Division of Orthopedic Research, Keio University School of Medicine, 35 Shinano-machi, Shinjuku-ku, Tokyo 160-8582 (Japan); Iwasaki, Ryotaro [Division of Orthopedic Research, Keio University School of Medicine, 35 Shinano-machi, Shinjuku-ku, Tokyo 160-8582 (Japan); Department of Cell Differentiation, The Sakaguchi Laboratory of Developmental Biology, Keio University School of Medicine, 35 Shinano-machi, Shinjuku-ku, Tokyo 160-8582 (Japan); Department of Dentistry and Oral Surgery, Keio University School of Medicine, 35 Shinano-machi, Shinjuku-ku, Tokyo 160-8582 (Japan); Miyamoto, Hiroya [Department of Orthopedic Surgery, Keio University School of Medicine, 35 Shinano-machi, Shinjuku-ku, Tokyo 160-8582 (Japan); Division of Orthopedic Research, Keio University School of Medicine, 35 Shinano-machi, Shinjuku-ku, Tokyo 160-8582 (Japan); and others

    2009-06-05

    Monocyte chemoattractant protein-1 (MCP-1) is a chemokine that plays a critical role in the recruitment and activation of leukocytes. Here, we describe that multinuclear osteoclast formation was significantly inhibited in cells derived from MCP-1-deficient mice. MCP-1 has been implicated in the regulation of osteoclast cell-cell fusion; however defects of multinuclear osteoclast formation in the cells from mice deficient in DC-STAMP, a seven transmembrane receptor essential for osteoclast cell-cell fusion, was not rescued by recombinant MCP-1. The lack of MCP-1 in osteoclasts resulted in a down-regulation of DC-STAMP, NFATc1, and cathepsin K, all of which were highly expressed in normal osteoclasts, suggesting that osteoclast differentiation was inhibited in MCP-1-deficient cells. MCP-1 alone did not induce osteoclastogenesis, however, the inhibition of osteoclastogenesis in MCP-1-deficient cells was restored by addition of recombinant MCP-1, indicating that osteoclastogenesis was regulated in an autocrine/paracrine manner by MCP-1 under the stimulation of RANKL in osteoclasts.

  19. Alumina Coating on Carbon Fibers by Sol-Gel Method

    OpenAIRE

    2006-01-01

    Alumina precursor film was coated on carbon fibers by a sol-gel method using aluminum alkoxide solution. The optimum coating condition for the concentration of alumina alkoxide and silane coupling agent was determined to uniformly coat alumina precursor on carbon fibers. Alumina precursor converted to alumina ceramics by heating at 750℃. SEM and EPMA showed that alumina ceramics was uniformly coated on carbon fibers. The thickness of alumina layer increased with increasing coating times. The ...

  20. Transmission characteristics of x-ray in MCP collimator in parallel structure

    Science.gov (United States)

    Qin, Xulei; Li, Ye; Chen, Weijun

    2016-11-01

    In order to improve the imaging quality of X-ray and reduce the effects of X-ray and scatter line on image, the adoption of X-ray collimator is the most effective method. MCP collimator in parallel structure can effectively reduce the ratio of X-ray and scatter line to reach on image plane, and reduce the atomization degree of images, so as to improve the image contrast. Through the establishment first-order radiation transmittance model of MCP collimator, test the performance of MCP collimator, it is prove that the MCP collimator can be used in the imaging system that consists of proximity of X-ray image intensifier, first-order radiation transmittance calculation formula of MCP absorption type collimator in parallel structure is reduced, obtain the transmittance distribution non cosine curve distribution of MCP collimator through calculating.

  1. An introduction to the IAAT ultraviolet MCP detector development

    Science.gov (United States)

    Hermanutz, S.; Barnstedt, J.; Diebold, S.; Elsener, H. R.; Kalkuhl, C.; Kappelmann, N.; Pfeifer, M.; Schanz, T.; Werner, K.

    2014-07-01

    Observations of ultraviolet light is the key to understand high temperature processes in the universe like hot plasma, accretion processes or illuminated protoplanetary discs around UV sources. Furthermore these observation contribute to major cosmological questions, like the distribution of baryonic matter or the formation of the milky way, as pointed out by Gomez de Castro et al.1 Driven by the idea to participate in the Russian World Space Observatory we started to develop a position sensitive micro channel plate detector (MCP) for spectroscopy in the range of 160nm to 300 nm. Although we are not part of this project we still build a MCP detector prototype. In this paper we will present the general design of the detector and mainly focus on the aspect of our photocathode, while the electronics will be explained in more detail in the paper Characterisation of low power readout electronics for a UV microchannel plate detector with cross-strip readout" (Paper number 9144-116) by Marc Pfeifer.

  2. MCP-1 binds to oxidized LDL and is carried by lipoprotein(a) in human plasma

    Science.gov (United States)

    Wiesner, Philipp; Tafelmeier, Maria; Chittka, Dominik; Choi, Soo-Ho; Zhang, Li; Byun, Young Sup; Almazan, Felicidad; Yang, Xiaohong; Iqbal, Navaid; Chowdhury, Punam; Maisel, Alan; Witztum, Joseph L.; Handel, Tracy M.; Tsimikas, Sotirios; Miller, Yury I.

    2013-01-01

    Lipoprotein oxidation plays an important role in pathogenesis of atherosclerosis. Oxidized low density lipoprotein (OxLDL) induces profound inflammatory responses in vascular cells, such as production of monocyte chemoattractant protein-1 (MCP-1) [chemokine (C-C motif) ligand 2], a key chemokine in the initiation and progression of vascular inflammation. Here we demonstrate that OxLDL also binds MCP-1 and that the OxLDL-bound MCP-1 retains its ability to recruit monocytes. A human MCP-1 mutant in which basic amino acids Arg-18 and Lys-19 were replaced with Ala did not bind to OxLDL. The MCP-1 binding to OxLDL was inhibited by the monoclonal antibody E06, which binds oxidized phospholipids (OxPLs) in OxLDL. Because OxPLs are carried by lipoprotein(a) [Lp(a)] in human plasma, we tested to determine whether Lp(a) binds MCP-1. Recombinant wild-type but not mutant MCP-1 added to human plasma bound to Lp(a), and its binding was inhibited by E06. Lp(a) captured from human plasma contained MCP-1 and the Lp(a)-associated endogenous MCP-1 induced monocyte migration. These results demonstrate that OxLDL and Lp(a) bind MCP-1 in vitro and in vivo and that OxPLs are major determinants of the MCP-1 binding. The association of MCP-1 with OxLDL and Lp(a) may play a role in modulating monocyte trafficking during atherogenesis. PMID:23667177

  3. Processing and Performance of Alumina Fiber Reinforced Alumina Composites

    Institute of Scientific and Technical Information of China (English)

    P.Y.Lee; T.Uchijima; T.Yano

    2003-01-01

    Processing of alumina fiber-reinforced alumina matrix composites by hot-pressing was described. The mechanical properties of the composites fabricated by different sintering conditions including temperature and pressure have been investigated. The results indicated that the higher sintering temperature and pressure corresponded to the higher bulk density and higher maximum strength of the composite, whereas the pseudo-ductility of the composite was lower. The preliminary results of the composite with monazite-coated fibers showed that maximum strength could be improved up to 35% compared with the noncoated fiber composite in the same sintering condition. Moreover, the fracture behavior of the composite changed from completely brittle fracture to non-brittle fracture under the suitable sintering conditions. SEM observation of the fracture surface indicated that the coating worked as a protective barrier and avoided sintering of the fibers together even at high temperature and pressure during densification process.

  4. Intramedullary capillary haemangioma.

    LENUS (Irish Health Repository)

    Kelleher, T

    2012-02-03

    Intramedullary capillary haemangioma is extremely rare and only four cases have been previously reported. We describe a further case, outlining the clinical, radiological, surgical and pathological features.

  5. MCP-1 promotes mural cell recruitment during angiogenesis in the aortic ring model.

    Science.gov (United States)

    Aplin, Alfred C; Fogel, Eric; Nicosia, Roberto F

    2010-09-01

    Rings of rat or mouse aorta embedded in collagen gels produce angiogenic outgrowths in response to the injury of the dissection procedure. Aortic outgrowths are composed of branching endothelial tubes and surrounding mural cells. Mural cells emerge following endothelial sprouting and gradually increase during the maturation of the neovessels. Treatment of aortic cultures with angiopoietin-1 (Ang-1), an angiogenic factor implicated in vascular maturation and remodeling, stimulates the mural cell recruitment process. Ang-1 induces expression of many cytokines and chemokines including monocyte chemotactic protein-1 (MCP-1). Inhibition of p38 MAP kinase, a signaling molecule required for mural cell recruitment, blocks Ang1-induced MCP-1 expression. Recombinant MCP-1 dose-dependently increases mural cell number while an anti-MCP-1 blocking antibody reduces it. In addition, antibody mediated neutralization of MCP-1 abrogates the stimulatory effect of Ang-1 on mural cell recruitment. Aortic rings from genetically modified mice deficient in MCP-1 or its receptor CCR2 have fewer mural cells than controls. MCP-1 deficiency also impairs the mural cell recruitment activity of Ang-1. Our studies indicate that spontaneous and Ang1-induced mural cell recruitment in the aortic ring of model of angiogenesis are in part mediated by MCP-1. These results implicate MCP-1 as one of the mediators of mural cell recruitment in the aortic ring model, and suggest that chemokine pathways may contribute to the assembly of the vessel wall during the angiogenesis response to injury.

  6. Sintering behaviour of spinel–alumina composites

    Indian Academy of Sciences (India)

    Soumen Pal; A K Bandyopadhyay; P G Pal; S Mukherjee; B N Samaddar

    2009-04-01

    Study of alumina–magnesia binary phase diagram reveals that around 40–50 wt% alumina dissolves in spinel (MgAl2O4) at 1600°C. Solid solubility of alumina in spinel decreases rapidly with decreasing temperature, which causes exsolution of alumina from spinel phase. Previous work of one of the authors revealed that the exsolution of alumina makes some interlocking structures in between alumina and spinel phases. In the present investigation, refractory grade calcined alumina and spinel powder were used to make different batch compositions. Green pellets, formed at a pressure of 1550 kg cm-2 were fired at different temperatures of 1500°, 1550° and 1600°C for 2 h soaking time. Bulk density, percent apparent porosity, firing shrinkage etc were measured at each temperature. Sintering results were analysed to understand the mechanism of spinel–alumina interactions. SEM study of present samples does not reveal the distinct precipitation of needle shaped -alumina from spinel, but has some effect on densification process of spinel–alumina composites. Microstructural differences between present and previous work suggest an ample scope of further work in spinel–alumina composites.

  7. Wettability of Aluminum on Alumina

    Science.gov (United States)

    Bao, Sarina; Tang, Kai; Kvithyld, Anne; Tangstad, Merete; Engh, Thorvald Abel

    2011-12-01

    The wettability of molten aluminum on solid alumina substrate has been investigated by the sessile drop technique in a 10-8 bar vacuum or under argon atmosphere in the temperature range from 1273 K to 1673 K (1000 °C to 1400 °C). It is shown that the reduction of oxide skin on molten aluminum is slow under normal pressures even with ultralow oxygen potential, but it is enhanced in high vacuum. To describe the wetting behavior of the Al-Al2O3 system at lower temperatures, a semiempirical calculation was employed. The calculated contact angle at 973 K (700 °C) is approximately 97 deg, which indicates that aluminum does not wet alumina at aluminum casting temperatures. Thus, a priming height is required for aluminum to infiltrate a filter. Wetting in the Al-Al2O3 system increases with temperature.

  8. Enforced effect of tk-MCP-1 fusion gene in ovarian cancer

    Directory of Open Access Journals (Sweden)

    Hong Shuhui

    2012-09-01

    Full Text Available Abstract Objective The efficiency of HSV-tk/GCV system is not high because of insufficient gene transfer and incompletely initiative of host antineoplastic potency. The present study was designed to assess the antitumor efficacy of tk-MCP-1 on ovarian cancer in vitro and vivo. Methods A novel bicistronic expression system can help to improve the expression level of a gene in a stable manner. pLXSN/tk-MCP-1 co-expressing tk and MCP-1 genes was constructed using a pLXSN retroviral vector and an internal ribosome entry site sequence by restriction enzyme. Western blot was performed to determine tk and MCP-1 expression in the infected SKOV3. The GCV-sensitively tumoricidal activities of SKOV3/tk-MCP-1 with or without monocytes were compared to those of SKOV3 expressing HSV-tk or MCP-1. We investigated the growth of subcutaneous tumors in SCID mice immuno-reconstituted, and evaluated the antitumor effect of MCP-1 in conjunction with suicide gene. Results The significant GCV-sensitively tumoricidal activity of pLXSN/tk-MCP-1 was observed when compared with those of pLXSN/tk, pLXSN/MCP-1 and pLXSN/neo, especially when monocytes were added. The growth of subcutaneous tumors in SCID mice immuno-reconstituted was markedly suppressed by co-delivery of HSV-tk and MCP-1 genes, and the enhanced antitumor effect was associated with the recruitment of monocytes. Conclusion These results demonstrated pLXSN/tk-MCP-1 presented an enhanced antitumor effects on ovarian cancer by orchestration of immune responses.

  9. Two micron pore size MCP-based image intensifiers

    Science.gov (United States)

    Glesener, John; Estrera, Joseph

    2010-02-01

    Image intensifiers (I2) have many advantages as detectors. They offer single photon sensitivity in an imaging format, they're light in weight and analog I2 systems can operate for hours on a single AA battery. Their light output is such as to exploit the peak in color sensitivity of the human eye. Until recent developments in CMOS sensors, they also were one of the highest resolution sensors available. The closest all solid state solution, the Texas Instruments Impactron chip, comes in a 1 megapixel format. Depending on the level of integration, an Impactron based system can consume 20 to 40 watts in a system configuration. In further investing in I2 technology, L-3 EOS determined that increasing I2 resolution merited a high priority. Increased I2 resolution offers the system user two desirable options: 1) increased detection and identification ranges while maintaining field-of-view (FOV) or 2) increasing FOV while maintaining the original system resolution. One of the areas where an investment in resolution is being made is in the microchannel plate (MCP). Incorporation of a 2 micron MCP into an image tube has the potential of increasing the system resolution of currently fielded systems. Both inverting and non-inverting configurations are being evaluated. Inverting tubes are being characterized in night vision goggle (NVG) and sights. The non-inverting 2 micron tube is being characterized for high resolution I2CMOS camera applications. Preliminary measurements show an increase in the MTF over a standard 5 micron pore size, 6 micron pitch plate. Current results will be presented.

  10. Structural Effects of Lanthanide Dopants on Alumina

    Science.gov (United States)

    Patel, Ketan; Blair, Victoria; Douglas, Justin; Dai, Qilin; Liu, Yaohua; Ren, Shenqiang; Brennan, Raymond

    2017-01-01

    Lanthanide (Ln3+) doping in alumina has shown great promise for stabilizing and promoting desirable phase formation to achieve optimized physical and chemical properties. However, doping alumina with Ln elements is generally accompanied by formation of new phases (i.e. LnAlO3, Ln2O3), and therefore inclusion of Ln-doping mechanisms for phase stabilization of the alumina lattice is indispensable. In this study, Ln-doping (400 ppm) of the alumina lattice crucially delays the onset of phase transformation and enables phase population control, which is achieved without the formation of new phases. The delay in phase transition (θ → α), and alteration of powder morphology, particle dimensions, and composition ratios between α- and θ-alumina phases are studied using a combination of solid state nuclear magnetic resonance, electron microscopy, digital scanning calorimetry, and high resolution X-ray diffraction with refinement fitting. Loading alumina with a sparse concentration of Ln-dopants suggests that the dopants reside in the vacant octahedral locations within the alumina lattice, where complete conversion into the thermodynamically stable α-domain is shown in dysprosium (Dy)- and lutetium (Lu)-doped alumina. This study opens up the potential to control the structure and phase composition of Ln-doped alumina for emerging applications.

  11. Structural Effects of Lanthanide Dopants on Alumina

    Energy Technology Data Exchange (ETDEWEB)

    Patel, Ketan; Blair, Victoria; Douglas, Justin; Dai, Qilin; Liu, Yaohua; Ren, Shenqiang; Brennan, Raymond

    2017-01-06

    Lanthanide (Ln3+) doping in alumina has shown great promise for stabilizing and promoting desirable phase formation to achieve optimized physical and chemical properties. However, doping alumina with Ln elements is generally accompanied by formation of new phases (i.e. LnAlO3, Ln2O3), and therefore inclusion of Ln-doping mechanisms for phase stabilization of the alumina lattice is indispensable. In this study, Ln-doping (400 ppm) of the alumina lattice crucially delays the onset of phase transformation and enables phase population control, which is achieved without the formation of new phases. The delay in phase transition (θ → α), and alteration of powder morphology, particle dimensions, and composition ratios between α- and θ-alumina phases are studied using a combination of solid state nuclear magnetic resonance, electron microscopy, digital scanning calorimetry, and high resolution X-ray diffraction with refinement fitting. Loading alumina with a sparse concentration of Ln-dopants suggests that the dopants reside in the vacant octahedral locations within the alumina lattice, where complete conversion into the thermodynamically stable α-domain is shown in dysprosium (Dy)- and lutetium (Lu)-doped alumina. This study opens up the potential to control the structure and phase composition of Ln-doped alumina for emerging applications.

  12. The R&D of the 20 in. MCP-PMTs for JUNO

    Science.gov (United States)

    Chang, Yaping; Huang, Guorui; Heng, Yuekun; Li, Dong; Liu, Huilin; Liu, Shulin; Li, Weihua; Ning, Zhe; Qi, Ming; Qian, Sen; Sun, Jianning; Si, Shuguang; Tian, Jinshou; Wang, Xingchao; Wang, Xing; Wang, Yifang; Wei, Yonglin; Wang, Wenwen; Xia, Jingkai; Xin, Liwei; Zhao, Tianchi

    2016-07-01

    A new concept of large area photomultiplier based on MCPs was conceived for JUNO by the scientists in IHEP, and with the collaborative work of the MCP-PMT collaboration in China, 8 in. and 20 in. prototypes were produced. Test results show that this type of MCP-PMT can have good SPE performance as the traditional dynode type PMTs.

  13. The MCP-8 gene and its possible association with resistance to Streptococcus agalactiae in tilapia.

    Science.gov (United States)

    Fu, Gui Hong; Wan, Zi Yi; Xia, Jun Hong; Liu, Feng; Liu, Xiao Jun; Yue, Gen Hua

    2014-09-01

    Mast cell proteases play an important role in the regulation of the immune response. We identified the cDNA of the mast cell protease 8 (MCP-8) gene and analyzed its genomic structure in tilapia. The ORF of the MCP-8 was 768 bp, encoding 255 amino acids. Quantitative real-time PCR revealed that the MCP-8 gene was expressed predominantly in spleen, moderately in liver, blood, brain, gill, intestine, skin, and weakly expressed in kidney, muscle and eye. After a challenge with Streptococcus agalactiae, the gene was induced significantly (p 0.05). These results suggest that the MCP-8 gene play an important role in the resistance to S. agalactiae in tilapia. The SNP markers in the MCP-8 gene associated with the resistance to the bacterial pathogen may facilitate selection of tilapia resistant to the bacterial disease.

  14. Electron optics design of an 8-in. spherical MCP-PMT

    Science.gov (United States)

    Chen, Ping; Tian, Jinshou; Qian, Sen; Zhao, Tianchi; Liu, Hulin; Wei, Yonglin; Sai, Xiaofeng; He, Jianping; Wang, Xing; Lu, Yu; Chen, Lin; Guo, Lehui; Pei, Chengquan; Hui, Dandan

    2017-03-01

    This paper discusses the electron optical system of an 8-in. spherical MCP-PMT. The MCP assembly, the supporting pole and the supply voltages are carefully designed to optimize the photoelectron collection efficiency and the transit time spread. Coating the MCP nickel-chromium electrode with an additional high secondary emission material is employed to make a breakthrough on the collection efficiency. With the simulation software CST, the Finite Integration method and the Monte Carlo method are combined to evaluate the collection efficiency, the time properties and the Earth's magnetic field effects. Simulation results show that the photocathode active solid angle is over 3.5 πsr, the average collection efficiency can exceed 95% with the coated MCP and the mean transit time spread is 2.2 ns for a typical electric potential of 500 V applied between the photocathode and the MCP input facet. The prototype and the measured single photoelectron spectrum are also presented.

  15. Influence of Alumina Addition on the Optical Property of Zirconia/Alumina Composite Dental Ceramics

    Institute of Scientific and Technical Information of China (English)

    JIANG Li; LIAO Yunmao; LI Wei; WAN Qianbing; ZHAO Yongqi

    2011-01-01

    The influence of various alumina additions on the optical property of zirconia/alumina composite ceramics was investigated.The relative sintered densities,transmittances,color and the microstructure of the composite ceramics were studied.The experimental results showed that the relative sintered densities and transmittances decreased with alumina addition.The lightness increased obviously but the chroma change was small.Pure zirconia nanopowders sintered densely could obtain the relatively high transmittance,while the transmittance and the lightness of slight addition changed significantly.The zirconia/alumina composite ceramics with alumina addition less than 7.5wt% could achieve the relatively stable and reliable optical properties.

  16. Mechanism and role of MCP-1 upregulation upon chikungunya virus infection in human peripheral blood mononuclear cells

    NARCIS (Netherlands)

    Silva, Mariana Ruiz; van der Ende-Metselaar, Heidi; Mulder, H. Lie; Smit, Jolanda M.; Rodenhuis-Zybert, Izabela A.

    2016-01-01

    Monocyte chemoattractant protein-1 (MCP-1/CCL2)-mediated migration of monocytes is essential for immunological surveillance of tissues. During chikungunya virus (CHIKV) infection however, excessive production of MCP-1 has been linked to disease pathogenesis. High MCP-1 serum levels are detected duri

  17. A role for MCP-1/CCR2 in interstitial lung disease in children

    Directory of Open Access Journals (Sweden)

    Reinhardt Dietrich

    2005-08-01

    Full Text Available Abstract Background Interstitial lung diseases (ILD are chronic inflammatory disorders leading to pulmonary fibrosis. Monocyte chemotactic protein 1 (MCP-1 promotes collagen synthesis and deletion of the MCP-1 receptor CCR2 protects from pulmonary fibrosis in ILD mouse models. We hypothesized that pulmonary MCP-1 and CCR2+ T cells accumulate in pediatric ILD and are related to disease severity. Methods Bronchoalveolar lavage fluid was obtained from 25 children with ILD and 10 healthy children. Levels of pulmonary MCP-1 and Th1/Th2-associated cytokines were quantified at the protein and the mRNA levels. Pulmonary CCR2+, CCR4+, CCR3+, CCR5+ and CXCR3+ T cells were quantified by flow-cytometry. Results CCR2+ T cells and MCP-1 levels were significantly elevated in children with ILD and correlated with forced vital capacity, total lung capacity and ILD disease severity scores. Children with lung fibrosis had significantly higher MCP-1 levels and CCR2+ T cells in bronchoalveolar lavage fluid compared to non-fibrotic children. Conclusion The results indicate that pulmonary CCR2+ T cells and MCP-1 contribute to the pathogenesis of pediatric ILD and might provide a novel target for therapeutic strategies.

  18. NFAT5 Contributes to Osmolality-Induced MCP-1 Expression in Mesothelial Cells

    Directory of Open Access Journals (Sweden)

    Christoph Küper

    2012-01-01

    Full Text Available Increased expression of the C-C chemokine monocyte chemoattractant protein-1 (MCP-1 in mesothelial cells in response to high glucose concentrations and/or high osmolality plays a crucial role in the development of peritoneal fibrosis during continuous ambulatory peritoneal dialysis (CAPD. Recent studies suggest that in kidney cells osmolality-induced MCP-1 upregulation is mediated by the osmosensitive transcription factor, nuclear factor of activated T cells 5 (NFAT5. The present study addressed the question of whether activation of NFAT5 by hyperosmolality, as present in PD fluids, contributes to MCP-1 expression in the mesothelial cell line Met5A. Hyperosmolality, induced by addition of glucose, NaCl, or mannitol to the growth medium, increased NFAT5 activity and stimulated MCP-1 expression in Met5A cells. siRNA-mediated knockdown of NFAT5 attenuated osmolality-induced MCP-1 upregulation substantially. Hyperosmolality also induced activation of nuclear factor-κB (NF-κB. Accordingly, pharmacological inhibition of NF-κB significantly decreased osmolality-induced MCP-1 expression. Taken together, these results indicate that high osmolalities activate the transcription factor NFAT5 in mesothelial cells. NFAT5 in turn upregulates MCP-1, likely in combination with NF-κB, and thus may participate in the development of peritoneal fibrosis during CAPD.

  19. Effect Of 1-MCP Treatment On Storage Potential Of Tomato Fruit

    Directory of Open Access Journals (Sweden)

    Wrzodak Anna

    2015-12-01

    Full Text Available Tomato fruit cv. ’Faustine’ F1 were harvested at mature green and full-red stages and treated with 1 or 2 µl·l−1 of 1-methylcyclopropene (1-MCP at 20 °C and 85-90% RH, for 21 hours to investigate the ability to delay ripening. Treated and control fruit were stored at 12.5 and 20 °C and 85-90% RH. Ethylene production, rate of respiration, weight loss, market value and storage life were determined after 4-week storage. Exposure of tomato fruit to 1-MCP reduced ethylene production and respiration rate of the fruit harvested at mature-green and full-red stages of maturity. Storage life and market value of tomato fruit depended on the treatment with 1-MCP, stage of maturity and storage temperature. Untreated fruits were characterized by the shortest storage life in comparison with the fruit treated with 1-MCP. The lowest market value was observed for tomato fruit harvested as a mature green, untreated with 1-MCP and stored at 20 °C. Treatment of tomato fruit with 1-MCP resulted in the reduction of natural weight loss during storage. These results suggest that 1-MCP treatment can be used in a commercial storage and trading system for tomatoes due to its ability to delay fruit ripening.

  20. MCP-1 expression by rat type II alveolar epithelial cells in primary culture.

    Science.gov (United States)

    Paine, R; Rolfe, M W; Standiford, T J; Burdick, M D; Rollins, B J; Strieter, R M

    1993-05-15

    Recruitment and activation of mononuclear phagocytes are potentially critical regulatory events for control of pulmonary inflammation. Located at the boundary between the alveolar airspace and the interstitium, alveolar epithelial cells are ideally situated to regulate the recruitment and activation of mononuclear phagocytes through the production of cytokines in response to inflammatory stimulation from the alveolar space. To test this hypothesis, we investigated the production of monocyte chemotactic polypeptide-1 (MCP-1), a protein that is chemotactic for and that activates monocytes, by rat type II alveolar epithelial cells in primary culture. Immunocytochemical staining using anti-murine JE, an antibody recognizing rat MCP-1, demonstrated cell-associated MCP-1 Ag throughout the monolayer. The intensity of staining was increased in response to IL-1 beta. When type II epithelial cells formed a tight monolayer on a filter support, there was polar secretion of MCP-1 Ag into the apical compartment by both control and IL-1-stimulated cells as measured by specific MCP-1 ELISA. Northern blot analysis revealed that IL-1 and TNF-alpha stimulated MCP-1 mRNA expression in a dose-dependent manner, whereas dexamethasone blocked MCP-1 expression by cells stimulated with IL-1. In contrast to previous results using transformed epithelial cell lines, MCP-1 mRNA was induced in these primary cultures directly by stimulation with LPS. These data suggest that alveolar epithelial cells may have an important and previously unrecognized role in the initiation and maintenance of inflammatory processes in the lung by recruiting and activating circulating monocytes through the production of MCP-1.

  1. MCP-1 secretion in lung from nonsmoking patients with coal worker`s pneumoconiosis

    Energy Technology Data Exchange (ETDEWEB)

    Boitelle, A.; Gosset, P.; Vanhee, D.; Wallaert, B.; Tonnel, A.B. [Institut Pasteur, INSERM U416, Lille (France); Copin, M.C.; Gosselin, B. [Service d`anatomie et de cytologie pathologique, CHRU, Lille (France); Marquette, C.H. [Hopital A. Calmette, Clinique des maladies respiratoires, Lille (France)

    1997-03-01

    Exposure to coal dust leads to development of coal worker`s pneumoconiosis (CWP), a disease associated with accumulation of macrophages in lower respiratory tract. Mechanisms controlling monocyte recruitment are still poorly understood. Since monocyte chemoattractant protein-1 (MCP-1) is recognized as a potent chemotactic factor for blood monocytes, we tested for presence of MCP-1 in pulmonary compartment of patients with CWP. Bronchoalveolar lavage fluid (BALF) from 16 nonsmoking control subjects and 27 nonsmoking CWP patients (16 with simple pneumoconiosis (SP) and 11 with progressive massive fibrosis (PMF)) was analysed. Alveolar macrophages (AMs) were purified by adherence and BALF was concentrated 10x by lyophilization. MCP-1 was measured in BALF and in 3 h AM supernatants using a sandwich enzyme-linked immunosorbent assay. Localization of MCP-1 in lung tissue was determined by immunohistochemistry on tissue sections from three patients with CWP and two control subjects. MCP-1 levels were higher in concentrated BALF from patients with SP or PMF (median 370 and 555 pg x mL{sup -1}, respectively) than in those form control subjects (median 11 pg x mL{sup -1}) (p<0.001). Released MCP-1 in AM supernatants was enhanced in patients with CWP (median 83 pg x mL{sup -1}) but compared to controls (median 41 pg x mL{sup -1}) this level did not reach significance. Although significantly increased, AM counts in BALF from patients with CWP did not correlate with MCP-1 levels. MCP-1 levels in BALF correlated with MCP-1 levels in AM supernatants ({rho}=0.47; p<0.02). Data demonstrate that: 1) patients with coal worker`s pneumoconiosis have a marked pulmonary overproduction of monocyte chemoattractant protein-1; and 2) in addition to alveolar macrophages, fibroblasts (probably myofibroblasts) and hyperplastic type II pneumocytes may also be responsible for this increased level of monocyte chemoattractant protein-1 in coal worker`s pneumoconiosis. (EG) 29 refs.

  2. A MCP1 fusokine with CCR2-specific tumoricidal activity

    Directory of Open Access Journals (Sweden)

    Yuan Liangping

    2011-09-01

    Full Text Available Abstract Background The CCL2 chemokine is involved in promoting cancer angiogenesis, proliferation and metastasis by malignancies that express CCR2 receptor. Thus the CCL2/CCR2 axis is an attractive molecular target for anticancer drug development. Methods We have generated a novel fusion protein using GMCSF and an N-terminal truncated version of MCP1/CCL2 (6-76 [hereafter GMME1] and investigated its utility as a CCR2-specific tumoricidal agent. Results We found that distinct to full length CCL2 or its N-truncated derivative (CCL2 5-76, GMME1 bound to CCR2 on mouse lymphoma EG7, human multiple myeloma cell line U266, or murine and human medulloblastoma cell lines, and led to their death by apoptosis. We demonstrated that GMME1 specifically blocked CCR2-associated STAT3 phosphorylation and up-regulated pro-apoptotic BAX. Furthermore, GMME1 significantly inhibited EG7 tumor growth in C57BL/6 mice, and induced apoptosis of primary myeloma cells from patients. Conclusion Our data demonstrate that GMME1 is a fusokine with a potent, CCR2 receptor-mediated pro-apoptotic effect on tumor cells and could be exploited as a novel biological therapy for CCR2+ malignancies including lymphoid and central nervous system malignancies.

  3. AB45. URO-MCP-1 mice: a model demonstrating UCPPS hallmark symptoms

    OpenAIRE

    Luo, Yi

    2014-01-01

    Introduction and objective Excessive production of monocyte chemotactic protein-1 (MCP-1) has been observed in various inflammatory, chronic pain, and bladder overactive conditions. We have observed that over half of patients with interstitial cystitis/bladder pain syndrome (IC/BPS) express elevated MCP-1 in the urine. This study was to develop a mouse model that secretes MCP-1 by the urothelium to facilitate the study of IC/BPS in humans. Methods A 4.9 Kb transgene consisting of the uroplaki...

  4. Quantitative analysis of the secretion of the MCP family of chemokines by muscle cells

    DEFF Research Database (Denmark)

    Henningsen, Jeanette; Pedersen, Bente Klarlund; Kratchmarova, Irina

    2011-01-01

    by Amino acids in Cell culture (SILAC) method for quantitative analysis resulted in the identification and generation of quantitative profiles of 59 growth factors and cytokines, including 9 classical chemokines. The members of the CC chemokine family of proteins such as monocyte chemotactic proteins 1, 2......, and 3 (MCP-1/CCL2, MCP-2/CCL8, and MCP-3/CCL7) showed a distinct pattern of secretion during differentiation. Further analysis using combinatorial RNA and protein approaches demonstrated that the MCPs are regulated via both post-transcriptional and post-translational mechanisms. Analyses...

  5. Dissolution Kinetics of Alumina Calcine

    Energy Technology Data Exchange (ETDEWEB)

    Batcheller, Thomas Aquinas

    2001-09-01

    Dissolution kinetics of alumina type non-radioactive calcine was investigated as part of ongoing research that addresses permanent disposal of Idaho High Level Waste (HLW). Calcine waste was produced from the processing of nuclear fuel at the Idaho Nuclear Technology and Engineering Center (INTEC). Acidic radioactive raffinates were solidified at ~500°C in a fluidized bed reactor to form the dry granular calcine material. Several Waste Management alternatives for the calcine are presented in the Idaho High Level Waste Draft EIS. The Separations Alternative addresses the processing of the calcine so that the HLW is ready for removal to a national geological repository by the year 2035. Calcine dissolution is the key front-end unit operation for the separations alternative.

  6. Gas-Filled Capillary Model

    Science.gov (United States)

    Steinhauer, L. C.; Kimura, W. D.

    2006-11-01

    We have developed a 1-D, quasi-steady-state numerical model for a gas-filled capillary discharge that is designed to aid in selecting the optimum capillary radius in order to guide a laser beam with the required intensity through the capillary. The model also includes the option for an external solenoid B-field around the capillary, which increases the depth of the parabolic density channel in the capillary, thereby allowing for propagation of smaller laser beam waists. The model has been used to select the parameters for gas-filled capillaries to be utilized during the Staged Electron Laser Acceleration — Laser Wakefield (STELLA-LW) experiment.

  7. Relationships between serum MCP-1 and subclinical kidney disease: African American-Diabetes Heart Study

    Directory of Open Access Journals (Sweden)

    Murea Mariana

    2012-11-01

    Full Text Available Abstract Background Monocyte chemoattractant protein-1 (MCP-1 plays important roles in kidney disease susceptibility and atherogenesis in experimental models. Relationships between serum MCP-1 concentration and early nephropathy and subclinical cardiovascular disease (CVD were assessed in African Americans (AAs with type 2 diabetes (T2D. Methods Serum MCP-1 concentration, urine albumin:creatinine ratio (ACR, estimated glomerular filtration rate (eGFR, and atherosclerotic calcified plaque (CP in the coronary and carotid arteries and infrarenal aorta were measured in 479 unrelated AAs with T2D. Generalized linear models were fitted to test for associations between MCP-1 and urine ACR, eGFR, and CP. Results Participants were 57% female, with mean ± SD (median age 55.6±9.5 (55.0 years, diabetes duration 10.3±8.2 (8.0 years, urine ACR 149.7±566.7 (14.0 mg/g, CKD-EPI eGFR 92.4±23.3 (92.0 ml/min/1.73m2, MCP-1 262.9±239.1 (224.4 pg/ml, coronary artery CP 280.1±633.8 (13.5, carotid artery CP 47.1±132.9 (0, and aorta CP 1616.0±2864.0 (319.0. Adjusting for age, sex, smoking, HbA1c, BMI, and LDL, serum MCP-1 was positively associated with albuminuria (parameter estimate 0.0021, P=0.04 and negatively associated with eGFR (parameter estimate −0.0003, P=0.001. MCP-1 remained associated with eGFR after adjustment for urine ACR. MCP-1 levels did not correlate with the extent of CP in any vascular bed, HbA1c or diabetes duration, but were positively associated with BMI. No interaction between BMI and MCP-1 was detected on nephropathy outcomes. Conclusions Serum MCP-1 levels are associated with eGFR and albuminuria in AAs with T2D. MCP-1 was not associated with subclinical CVD in this population. Inflammation appears to play important roles in development and/or progression of kidney disease in AAs.

  8. Phyllostachys edulis compounds inhibit palmitic acid-induced monocyte chemoattractant protein 1 (MCP-1 production.

    Directory of Open Access Journals (Sweden)

    Jason K Higa

    Full Text Available BACKGROUND: Phyllostachys edulis Carriere (Poaceae is a bamboo species that is part of the traditional Chinese medicine pharmacopoeia. Compounds and extracts from this species have shown potential applications towards several diseases. One of many complications found in obesity and diabetes is the link between elevated circulatory free fatty acids (FFAs and chronic inflammation. This study aims to present a possible application of P. edulis extract in relieving inflammation caused by FFAs. Monocyte chemoattractant protein 1 (MCP-1/CCL2 is a pro-inflammatory cytokine implicated in chronic inflammation. Nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB and activator protein 1 (AP-1 are transcription factors activated in response to inflammatory stimuli, and upregulate pro-inflammatory cytokines such as MCP-1. This study examines the effect of P. edulis extract on cellular production of MCP-1 and on the NF-κB and AP-1 pathways in response to treatment with palmitic acid (PA, a FFA. METHODOLOGY/PRINCIPAL FINDINGS: MCP-1 protein was measured by cytometric bead assay. NF-κB and AP-1 nuclear localization was detected by colorimetric DNA-binding ELISA. Relative MCP-1 mRNA was measured by real-time quantitative PCR. Murine cells were treated with PA to induce inflammation. PA increased expression of MCP-1 mRNA and protein, and increased nuclear localization of NF-κB and AP-1. Adding bamboo extract (BEX inhibited the effects of PA, reduced MCP-1 production, and inhibited nuclear translocation of NF-κB and AP-1 subunits. Compounds isolated from BEX inhibited MCP-1 secretion with different potencies. CONCLUSIONS/SIGNIFICANCE: PA induced MCP-1 production in murine adipose, muscle, and liver cells. BEX ameliorated PA-induced production of MCP-1 by inhibiting nuclear translocation of NF-κB and AP-1. Two O-methylated flavones were isolated from BEX with functional effects on MCP-1 production. These results may represent a possible

  9. Fracture toughness of advanced alumina ceramics and alumina matrix composites used for cutting tool edges

    Directory of Open Access Journals (Sweden)

    M. Szutkowska

    2012-10-01

    Full Text Available Purpose: Specific characteristics in fracture toughness measurements of advanced alumina ceramics and alumina matrix composites with particular reference to α-Al2O3, Al2O3-ZrO2, Al2O3-ZrO2-TiC and Al2O3-Ti(C,N has been presented.Design/methodology/approach: The present study reports fracture toughness obtained by means of the conventional method and direct measurements of the Vickers crack length (DCM method of selected tool ceramics based on alumina: pure alumina, alumina-zirconia composite with unstabilized and stabilized zirconia, alumina–zirconia composite with addition of TiC and alumina–nitride-carbide titanium composite with 2wt% of zirconia. Specimens were prepared from submicro-scale trade powders. Vicker’s hardness (HV1, fracture toughness (KIC at room temperature, the indentation fracture toughness, Young’s modulus and apparent density were also evaluated. The microstructure was observed by means of scanning electron microscopy (SEM.Findings: The lowest value of KIC is revealed by pure alumina ceramics. The addition of (10 wt% unstabilized zirconia to alumina or a small amount (5 wt% of TiC to alumina–zirconia composite improve fracture toughness of these ceramics in comparison to alumina ceramics. Alumina ceramics and alumina-zirconia ceramics reveal the pronounced character of R-curve because of an increasing dependence on crack growth resistance with crack extension as opposed to the titanium carbide-nitride reinforced composite based on alumina. R-curve has not been observed for this composite.Practical implications: The results show the method of fracture toughness improvement of alumina tool ceramics.Originality/value: Taking into account the values of fracture toughness a rational use of existing ceramic tools should be expected.

  10. Recent Development of High Alumina Refractories in China

    Institute of Scientific and Technical Information of China (English)

    WANGJin-xiang; LIUJie-hua

    1994-01-01

    The paper reviews the achievements which have been attained recently in China in high alumina refractories raw materials and their products,including 1) homogenization ,urification and electric fusion of high alumina raw materials and synthesizing of spinel from natural raw materials;2) processing principle and characteristics and microstructural features of creep-resistance high alu-mina brick ,alumina-magnesia-carbon brick and thermal shock resistanced high alumina brikc and their application in practice.

  11. Neutron Fading Characteristics of Copper Doped Lithium Fluoride (LiF: MCP) Thermoluminescent Dosimeters (TLDs)

    Science.gov (United States)

    2008-05-21

    characteristics for various applications of radiation monitoring including personal, environmental and clinical dosimetry. The characteristics of an "ideal...enables its widespread use in several areas including clinical , personal, and environmental dosimetry. Composition LiF: MCP dosimeters are composed...such as CaF2: Mn (Zeff 16.3) or CaSO . (Zeff 14.3), which is an important attribute for dosimetry. (Miljanic, et al., 2002). LiF: MCP powder has been

  12. Derivatization in Capillary Electrophoresis.

    Science.gov (United States)

    Marina, M Luisa; Castro-Puyana, María

    2016-01-01

    Capillary electrophoresis is a well-established separation technique in analytical research laboratories worldwide. Its interesting advantages make CE an efficient and potent alternative to other chromatographic techniques. However, it is also recognized that its main drawback is the relatively poor sensitivity when using optical detection. One way to overcome this limitation is to perform a derivatization reaction which is intended to provide the analyte more suitable analytical characteristics enabling a high sensitive detection. Based on the analytical step where the CE derivatization takes place, it can be classified as precapillary (before separation), in-capillary (during separation), or postcapillary (after separation). This chapter describes the application of four different derivatization protocols (in-capillary and precapillary modes) to carry out the achiral and chiral analysis of different compounds in food and biological samples with three different detection modes (UV, LIF, and MS).

  13. How Capillary Rafts Sink

    CERN Document Server

    Protiere, S; Aristoff, J; Stone, H

    2010-01-01

    We present a fluid dynamics video showing how capillary rafts sink. Small objects trapped at an interface are very common in Nature (insects walking on water, ant rafts, bubbles or pollen at the water-air interface, membranes...) and are found in many multiphase industrial processes. Thanks to Archimedes principle we can easily predict whether an object sinks or floats. But what happens when several small particles are placed at an interface between two fluids. In this case surface tension also plays an important role. These particles self-assemble by capillarity and thus form what we call a "capillary raft". We show how such capillary rafts sink for varying sizes of particles and define how this parameter affects the sinking process.

  14. Microchannel plate fabrication using glass capillary arrays with Atomic Layer Deposition films for resistance and gain

    Science.gov (United States)

    Popecki, M. A.; Adams, B.; Craven, C. A.; Cremer, T.; Foley, M. R.; Lyashenko, A.; O'Mahony, A.; Minot, M. J.; Aviles, M.; Bond, J. L.; Stochaj, M. E.; Worstell, W.; Elam, J. W.; Mane, A. U.; Siegmund, O. H. W.; Ertley, C.; Kistler, L. M.; Granoff, M. S.

    2016-08-01

    Microchannel plates (MCPs) have been used for many years in space flight instrumentation as fast, lightweight electron multipliers. A new MCP fabrication method combines a glass substrate composed of hollow glass capillary arrays with thin film coatings to provide the resistive and secondary electron emissive properties. Using this technique, the gain, resistance, and glass properties may be chosen independently. Large-area MCPs are available at moderate cost. Secondary emission films of Al2O3 and MgO provide sustained high gain as charge is extracted from the MCP. Long lifetimes are possible, and a total extracted charge of 7 C/cm2 has been demonstrated. Background rates are low because the glass substrate has little radioactive potassium 40. Curved MCPs are easily fabricated with this technique to suit instrument symmetries, simplifying secondary electron steering and smoothing azimuthal efficiency.

  15. Alumina Carbon Refractory Products for Continuous Casting

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    @@ 1 Scope This standard specifies the classification.techni-cal requirements,test methods,inspection rules,packing,marking,transportation,storage and quality certificate of alumina carbon refractory products for continuous casting.

  16. Loss tangent measurements on unirradiated alumina

    Energy Technology Data Exchange (ETDEWEB)

    Zinkle, S.J.; Goulding, R.H. [Oak Ridge National Lab., TN (United States)

    1996-04-01

    Unirradiated room temperature loss tangent for sapphire and several commercial grades of polycrystalline alumina are complied for frequencies between 10{sup 5} and 4x10{sup 11} Hz. Sapphire exhibits significantly lower values for the loss tangent at frequencies up to 10{sup 11} Hz. The loss tangents of 3 different grades of Wesgo alumina (AL300, AL995, AL998) and 2 different grades of Coors alumina (AD94, AD995) have typical values near {approx}10{sup -4} at a frequency of 10{sup 8} Hz. On the other hand, the loss tangent of Vitox alumina exhibits a large loss peak tan d{approx} 5x10{sup -3} at this frequency.

  17. Burned Microporous Alumina-Graphite Brick

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    @@ 1 Scope This standard specifies the definition,classifica-tion,technical requirements,test methods,inspection rules,marking,packing,transportation and quality certificate of burned microporous alumina-graphite brick.

  18. Capillary permeability in adipose tissue

    DEFF Research Database (Denmark)

    Paaske, W P; Nielsen, S L

    1976-01-01

    of about 7 ml/100 g-min. This corresponds to a capillary diffusion capacity of 2.0 ml/100 g-min which is half the value reported for vasodilated skeletal muscle having approximately twice as great capillary surface area. Thus, adipose tissue has about the same capillary permeability during slight metabolic...

  19. Mechanism and role of MCP-1 upregulation upon chikungunya virus infection in human peripheral blood mononuclear cells

    Science.gov (United States)

    Ruiz Silva, Mariana; van der Ende-Metselaar, Heidi; Mulder, H. Lie; Smit, Jolanda M.; Rodenhuis-Zybert, Izabela A.

    2016-01-01

    Monocyte chemoattractant protein-1 (MCP-1/CCL2)-mediated migration of monocytes is essential for immunological surveillance of tissues. During chikungunya virus (CHIKV) infection however, excessive production of MCP-1 has been linked to disease pathogenesis. High MCP-1 serum levels are detected during the viremic phase of CHIKV infection and correlate with the virus titre. In vitro CHIKV infection was also shown to stimulate MCP-1 production in whole blood; yet the role and the mechanism of MCP-1 production upon infection of human peripheral blood mononuclear cells remain unknown. Here we found that active CHIKV infection stimulated production of MCP-1 in monocytes. Importantly however, we found that communication with other leukocytes is crucial to yield MCP-1 by monocytes upon CHIKV infection. Indeed, blocking interferon-α/β receptor or the JAK1/JAK2 signalling downstream of the receptor abolished CHIKV-mediated MCP-1 production. Additionally, we show that despite the apparent correlation between IFN type I, CHIKV replication and MCP-1, modulating the levels of the chemokine did not influence CHIKV infection. In summary, our data disclose the complexity of MCP-1 regulation upon CHIKV infection and point to a crucial role of IFNβ in the chemokine secretion. We propose that balance between these soluble factors is imperative for an appropriate host response to CHIKV infection. PMID:27558873

  20. St. John's Wort protein, p27SJ, regulates the MCP-1 promoter.

    Science.gov (United States)

    Mukerjee, Ruma; Deshmane, Satish L; Darbinian, Nune; Czernik, Marta; Khalili, Kamel; Amini, Shohreh; Sawaya, Bassel E

    2008-09-01

    St. John's Wort is commonly known for its antiviral, antidepressant, and cytotoxic properties, but traditionally St. John's Wort has also been used to treat inflammation. In this study, we sought to characterize the mechanisms used by St. John's Wort to treat inflammation by examining the effect of the recently isolated protein from St. John's Wort, p27SJ on the expression of MCP-1. By employing an adenovirus expression vector, we demonstrate that a low concentration of p27SJ upregulates the MCP-1 promoter through the transcription factor C/EBPbeta. In addition, we found that C/EBPbeta-homologous protein (CHOP) or siRNA-C/EBPbeta significantly reduced the ability of p27SJ to activate MCP-1 gene expression. Results from protein-protein interaction studies illustrate the existence of a physical interaction between p27SJ and C/EBPbeta in microglial cells. The use of chromatin immunoprecipitation assay (ChIP) led to the identification of a new cis-element that is responsive to C/EBPbeta within the MCP-1 promoter. Association of C/EBPbeta with MCP-1 DNA was not affected by the presence of p27SJ. The biological activity of MCP-1 produced by cultures of adenovirus-p27SJ transduced cells was increased relative to controls as measured by the transmigration of human Jurkat cells. Thus, we conclude that at high concentration, p27SJ is a potential agent that may be developed as a modulator of MCP-1 leading to the inhibition of the cytokine-mediated inflammatory responses.

  1. Monocyte chemoattractant protein-1 (MCP-1 regulates macrophage cytotoxicity in abdominal aortic aneurysm.

    Directory of Open Access Journals (Sweden)

    Qiwei Wang

    Full Text Available AIMS: In abdominal aortic aneurysm (AAA, macrophages are detected in the proximity of aortic smooth muscle cells (SMCs. We have previously demonstrated in a murine model of AAA that apoptotic SMCs attract monocytes and other leukocytes by producing MCP-1. Here we tested whether infiltrating macrophages also directly contribute to SMC apoptosis. METHODS AND RESULTS: Using a SMC/RAW264.7 macrophage co-culture system, we demonstrated that MCP-1-primed RAWs caused a significantly higher level of apoptosis in SMCs as compared to control macrophages. Next, we detected an enhanced Fas ligand (FasL mRNA level and membrane FasL protein expression in MCP-1-primed RAWs. Neutralizing FasL blocked SMC apoptosis in the co-culture. In situ proximity ligation assay showed that SMCs exposed to primed macrophages contained higher levels of receptor interacting protein-1 (RIP1/Caspase 8 containing cell death complexes. Silencing RIP1 conferred apoptosis resistance to SMCs. In the mouse elastase injury model of aneurysm, aneurysm induction increased the level of RIP1/Caspase 8 containing complexes in medial SMCs. Moreover, TUNEL-positive SMCs in aneurysmal tissues were frequently surrounded by CD68(+/FasL(+ macrophages. Conversely, elastase-treated arteries from MCP-1 knockout mice display a reduction of both macrophage infiltration and FasL expression, which was accompanied by diminished apoptosis of SMCs. CONCLUSION: Our data suggest that MCP-1-primed macrophages are more cytotoxic. MCP-1 appears to modulate macrophage cytotoxicity by increasing the level of membrane bound FasL. Thus, we showed that MCP-1-primed macrophages kill SMCs through a FasL/Fas-Caspase8-RIP1 mediated mechanism.

  2. Direct foaming porous alumina ceramics

    Energy Technology Data Exchange (ETDEWEB)

    Salvini, V.R.; Sandurkov, B.A.; Klein-Gunnewiek, R.F.; Pandolfelli, V.C. [Federal Univ. of Sao Carlos, Materials Engineering Dept., FIRE Associate Lab., Sao Carlos, SP (Brazil)

    2007-07-01

    This paper presents the work carried out in order to improve the properties of these porous alumina ceramics, concerning their application as thermal insulating. Changes in solid content of ceramic suspension, variations of pore forming agents and other additives were carried out and their effects on the green and the sintered mechanical strength are also shown. According to the literature, several starch types seem to be attractive pore forming agents as well as binders for porous ceramics. Most of them consist of a mixture of two polysaccharide types, amylose (linear) and amylopectin (highly branched). Corn, potato and rice starches were used in the present study because of their difference in size and shape. In order to increase the mechanical strength of the sintered porous ceramics a part of the Al{sub 2}O{sub 3} in the composition was replaced by Al(OH){sub 3}. Due to the changes of the composition and additives, porosities up to 81% and a mechanical strength of 15 MPa were obtained. (orig.)

  3. Die Analyse der Inhibition des Monozyten chemotaktischen Proteins-1 (MCP-1) und der Stimulation durch MCP-1 auf die Koloniebildung und die Zytokinexpression von Plattenepithelkarzinomen der Kopf-Hals-Region im FLAVINO-Assay

    OpenAIRE

    Körner, Carolin

    2015-01-01

    Das Monozyten chemotaktische Protein-1 (MCP-1) ist ein CC-Chemokin, das in seiner Rolle als Chemoattraktor auf Monozyten in der Genese von Malignomen eine wesentliche Rolle spielt. Dabei kann es sowohl zur lokalen Tumorabwehr als auch zur Tumorgenese, Tumor-angiogenese und Metastasierung beitragen. Die vorliegende Arbeit untersucht die MCP-1-Inhibition und die Stimulation durch MCP-1 auf die Koloniebildung und die Zytokinexpression von Plattenepithelkarzinomen der Kopf-Hals-Region (HNSCC) im ...

  4. Preparation of alumina nanoshell coated porous silica spheres for inorganic anions separation.

    Science.gov (United States)

    Song, Zhihua; Wu, Dapeng; Ding, Kun; Guan, Yafeng

    2016-02-12

    It had been reported that alumina nanoshell coating could be obtained on the external surface of various substrates in one-nanometer precision in aqueous solution. In this work, alumina nanoshell coated mesoporous silica microbeads (nanoAl2O3/mesoSiO2) were prepared with the similar method, and were successfully applied to inorganic anions separation. As the mass transfer speed is largely constrained in the mesopore compared with that on the open surface, it was found that a complete alumina nanoshell coating could be obtained within the mesopore until the five-time coating was carried out. After characterization by BET, SEM and FTIR, it was found that the obtained nanoAl2O3/mesoSiO2 particles are smooth and well dispersed, and the mesopores are well reserved. In addition, the full coverage of nanoAl2O3 shell in mesopores was also confirmed by the binding capacity experiments with berberine. Finally, the nanoAl2O3/mesoSiO2 particles were packed in silica capillary for the separation of inorganic anions I(-), SCN(-), Br(-), NO2(-) and NO3(-) with ion chromatography (IC), and a column efficiency of 3.8 × 10(4) plates per meter was obtained for I(-).

  5. Protective effects of MCP-1 inhibitor on a rat model of severe acute pancreatitis

    Institute of Scientific and Technical Information of China (English)

    Guo-Xiong Zhou; Xue-Juan Zhu; Xiao-Ling Ding; Hong Zhang; Jian-Ping Chen; Hui Qiang; Hai-Feng Zhang; Qun Wei

    2010-01-01

    BACKGROUND: Chemokines and their receptors play key roles in the pathogenesis of acute pancreatitis. This study aimed to establish a rat model of severe acute pancreatitis (SAP) for investigating monocyte chemotactic protein-1 (MCP-1) expression in the pathogenesis of the disease. We assessed the effects of the inhibitor of MCP-1, Bindarit, on SAP and explored the mechanisms underlying SAP. METHODS: Seventy-two Sprague-Dawley rats were randomly divided into a saline control group (group S), an SAP group (group P), and a Bindarit group (group T). The SAP model was induced by retrograde infusion of 4% sodium taurocholate into the bilio-pancreatic duct. Based on the SAP model, Bindarit was injected intraperitoneally in group T, and 0.5%methyl cellulose was injected intraperitoneally in groups S and P. In group S, saline was retrogradely infused into the bili-pancreatic duct. Serum amylase levels and the histological changes in the pancreas were assessed at different time-points in each group. Expression of MCP-1 in serum was measured by enzyme-linked immunoadsorbent assay (ELISA). MCP-1 protein and mRNA expression levels were detected by immunohistochemistry, Western blotting, and semi-quantitative reverse transcriptase-polymerase chain reaction (RT-PCR). RESULTS: Serum amylase levels in groups P and T were higher than those in group S. Serum amylase levels were signiifcantly lower in group T than in group P at 6 and 12 hours after operation. The levels of MCP-1 in serum at 6 and 12 hours after operation in group P were signiifcantly higher than in group S, and signiifcantly lower in group T than in group P at 6 and 12 hours after operation. The pathological damage in the pancreas was milder in group T than in group P. MCP-1 protein and mRNA expression levels in the pancreas were higher in groups P and T than in group S. These expression levels were positively correlated with the pathological damage of pancreatic tissues. The activity of MCP-1 in group T was

  6. Exosomes derived from MSCs ameliorate retinal laser injury partially by inhibition of MCP-1

    Science.gov (United States)

    Yu, Bo; Shao, Hui; Su, Chang; Jiang, Yuanfeng; Chen, Xiteng; Bai, Lingling; Zhang, Yan; Li, Qiutang; Zhang, Xiaomin; Li, Xiaorong

    2016-01-01

    Although accumulated evidence supports the notion that mesenchymal stem cells (MSCs) act in a paracrine manner, the mechanisms are still not fully understood. Recently, MSC-derived exosomes (MSC-Exos), a type of microvesicle released from MSCs, were thought to carry functional proteins and RNAs to recipient cells and play therapeutic roles. In the present study, we intravitreally injected MSCs derived from either mouse adipose tissue or human umbilical cord, and their exosomes to observe and compare their functions in a mouse model of laser-induced retinal injury. We found that both MSCs and their exosomes reduced damage, inhibited apoptosis, and suppressed inflammatory responses to obtain better visual function to nearly the same extent in vivo. Obvious down-regulation of monocyte chemotactic protein (MCP)-1 in the retina was found after MSC-Exos injection. In vitro, MSC-Exos also down-regulated MCP-1 mRNA expression in primarily cultured retinal cells after thermal injury. It was further demonstrated that intravitreal injection of an MCP-1-neutralizing antibody promoted the recovery of retinal laser injury, whereas the therapeutic effect of exosomes was abolished when MSC-Exos and MCP-1 were administrated simultaneously. Collectively, these results suggest that MSC-Exos ameliorate laser-induced retinal injury partially through down-regulation of MCP-1. PMID:27686625

  7. Sinorhizobium meliloti chemotaxis to quaternary ammonium compounds is mediated by the chemoreceptor McpX.

    Science.gov (United States)

    Webb, Benjamin A; Karl Compton, K; Castañeda Saldaña, Rafael; Arapov, Timofey D; Keith Ray, W; Helm, Richard F; Scharf, Birgit E

    2017-01-01

    The bacterium Sinorhizobium meliloti is attracted to seed exudates of its host plant alfalfa (Medicago sativa). Since quaternary ammonium compounds (QACs) are exuded by germinating seeds, we assayed chemotaxis of S. meliloti towards betonicine, choline, glycine betaine, stachydrine and trigonelline. The wild type displayed a positive response to all QACs. Using LC-MS, we determined that each germinating alfalfa seed exuded QACs in the nanogram range. Compared to the closely related nonhost species, spotted medic (Medicago arabica), unique profiles were released. Further assessments of single chemoreceptor deletion strains revealed that an mcpX deletion strain displayed little to no response to these compounds. Differential scanning fluorimetry showed interaction of the isolated periplasmic region of McpX (McpX(PR) and McpX34-306 ) with QACs. Isothermal titration calorimetry experiments revealed tight binding to McpX(PR) with dissociation constants (Kd ) in the nanomolar range for choline and glycine betaine, micromolar Kd for stachydrine and trigonelline and a Kd in the millimolar range for betonicine. Our discovery of S. meliloti chemotaxis to plant-derived QACs adds another role to this group of compounds, which are known to serve as nutrient sources, osmoprotectants and cell-to-cell signalling molecules. This is the first report of a chemoreceptor that mediates QACs taxis through direct binding.

  8. Assessment of chemical composition of tomato fruits depending on the cultivar and 1-MCP treatment

    Directory of Open Access Journals (Sweden)

    Anna Wrzodak

    2016-09-01

    Full Text Available The experiments on influence of 1-MCP treatment on the content of some chemical compounds in tomato fruits were performed. For the experiments two greenhouse cultivars of tomato were selected: ‘Faustine F1’ and ‘Habana F1’ (LSL type – long shelf life. Both tomato cultivars were grown on stakes in the field. Tomato fruits were harvested in mature green and full-red stages of maturity. Tomato fruit were treated with 1-MCP at the concentrations of 1.0 or 2.0 μl·l-1 and then stored at the temperature of 12.5°C or 20°C, and 85–90% of relative humidity in ambient atmosphere. Immediately after harvest and after 4 weeks of storage chemical analyses were carried out. The results showed some significant differences in the content of determined compounds depending on 1-MCP treatment, stage of maturity and storage temperature. Fruits of both cultivars showed a higher content of phenolics and dry matter in the case of fruits treated with 1-MCP. The highest content of lycopene was found in tomato fruits of both cultivars harvested in full-red stage, after storage at 20°C. Tomato fruits treated with 1-MCP were characterized by a lower content of lycopene and vitamin C compared to the untreated fruits.

  9. IL-8 and MCP Gene Expression and Production by LPS-Stimulated Human Corneal Stromal Cells

    Directory of Open Access Journals (Sweden)

    Roni M. Shtein

    2012-01-01

    Full Text Available Purpose. To determine time course of effect of lipopolysaccharide (LPS on production of interleukin-8 (IL-8 and monocyte chemotactic protein (MCP by cultured human corneal stromal cells. Methods. Human corneal stromal cells were harvested from donor corneal specimens, and fourth to sixth passaged cells were used. Cell cultures were stimulated with LPS for 2, 4, 8, and 24 hours. Northern blot analysis of IL-8 and MCP gene expression and ELISA for IL-8 and MCP secretion were performed. ELISA results were analyzed for statistical significance using two-tailed Student's t-test. Results. Northern blot analysis demonstrated significantly increased IL-8 and MCP gene expression after 4 and 8 hours of exposure to LPS. ELISA for secreted IL-8 and MCP demonstrated statistically significant increases (P<0.05 after corneal stromal cell stimulation with LPS. Conclusions. This paper suggests that human corneal stromal cells may participate in corneal inflammation by secreting potent leukocyte chemotactic and activating proteins in a time-dependent manner when exposed to LPS.

  10. The production of monocyte chemoattractant protein-1 (MCP-1)/CCL2 in tumor microenvironments.

    Science.gov (United States)

    Yoshimura, Teizo

    2017-02-08

    Infiltration of leukocytes is one of the hallmarks of the inflammatory response. Among the leukocyte populations, neutrophils are the first to infiltrate, followed by monocytes and lymphocytes, suggesting the presence of mediators that specifically recruit these cell types. Cytokine-like chemoattractants with monocyte chemotactic activity, such as lymphocyte-derived chemotactic factor (LDCF) or tumor-derived chemotactic factor (TDCF), were reported as molecules that could play a critical role in the recruitment of monocytes into sites of immune responses or tumors; however, their identities remained unclear. In the 1980s, researchers began to test the hypothesis that leukocyte chemotactic activity is a part of the wider activities exhibited by cytokines, such as interleukin-1 (IL-1). In 1987, we demonstrated, for the first time, the presence of a cytokine like chemoattractant with cell type-specificity (now known as the chemokine interleukin-8 or CXC chemokine ligand 8) that was different from IL-1. This led us to the purification of the second such molecule with monocyte chemotactic activity. This monocyte chemoattractant was found identical to the previously described LDCF or TDCF, and termed monocyte chemoattractant protein-1 (MCP-1). Isolation of MCP-1 created a revolution in not only inflammation but also cancer research that continues today, and MCP-1 has become a molecular target to treat patients with many diseases. In this review, I will first describe a history associated with the discovery of MCP-1 and then discuss complex mechanisms regulating MCP-1 production in tumor microenvironments.

  11. Macrophage Migration Inhibitor Factor Upregulates MCP-1 Expression in an Autocrine Manner in Hepatocytes during Acute Mouse Liver Injury

    OpenAIRE

    Jieshi Xie; Le Yang; Lei Tian; Weiyang Li; Lin Yang; Liying Li

    2016-01-01

    Macrophage migration inhibitor factor (MIF), a multipotent innate immune mediator, is an upstream component of the inflammatory cascade in diseases such as liver disease. Monocyte chemoattractant protein-1 (MCP-1), a highly representative chemokine, is critical in liver disease pathogenesis. We investigated the role of MIF in regulating hepatocytic MCP-1 expression. MIF and MCP-1 expression were characterized by immunochemistry, RT-PCR, ELISA, and immunoblotting in CCl4-treated mouse liver an...

  12. Monitoring Transport Across Modified Nanoporous Alumina Membranes

    Directory of Open Access Journals (Sweden)

    Erich D. Steinle

    2007-11-01

    Full Text Available This paper describes the use of several characterization methods to examinealumina nanotubule membranes that have been modified with specific silanes. The functionof these silanes is to alter the transport properties through the membrane by changing thelocal environment inside the alumina nanotube. The presence of alkyl groups, either long(C18 or short and branched (isopropyl hydrocarbon chains, on these silanes significantlydecreases the rate of transport of permeant molecules through membranes containingalumina nanotubes as monitored via absorbance spectroscopy. The presence of an ionicsurfactant can alter the polarity of these modified nanotubes, which correlates to anincreased transport of ions. Fluorescent spectroscopy is also utilized to enhance thesensitivity of detecting these permeant molecules. Confirmation of the alkylsilaneattachment to the alumina membrane is achieved with traditional infrared spectroscopy,which can also examine the lifetime of the modified membrane. The physical parameters ofthese silane-modified porous alumina membranes are studied via scanning electronmicroscopy. The alumina nanotubes are not physically closed off or capped by the silanesthat are attached to the alumina surfaces.

  13. High contrast laser marking of alumina

    Energy Technology Data Exchange (ETDEWEB)

    Penide, J. [Applied Physics Department, University of Vigo, EEI, Lagoas-Marcosende, 9, Vigo 36310 (Spain); Quintero, F., E-mail: fquintero@uvigo.es [Applied Physics Department, University of Vigo, EEI, Lagoas-Marcosende, 9, Vigo 36310 (Spain); Riveiro, A. [Applied Physics Department, University of Vigo, EEI, Lagoas-Marcosende, 9, Vigo 36310 (Spain); Fernández, A. [Department of Engineering Design, University of Vigo, Escuela de Ingeniería Industrial, Campus Universitario, Vigo E-36310 (Spain); Val, J. del [Applied Physics Department, University of Vigo, EEI, Lagoas-Marcosende, 9, Vigo 36310 (Spain); Comesaña, R. [Materials Engineering, Applied Mechanics and Construction Department, University of Vigo, EEI, Lagoas-Marcosende, Vigo E-36310 (Spain); Lusquiños, F.; Pou, J. [Applied Physics Department, University of Vigo, EEI, Lagoas-Marcosende, 9, Vigo 36310 (Spain)

    2015-05-01

    Highlights: • Laser marking of alumina using near infrared (NIR) lasers was experimentally analyzed. • Color change produced by NIR lasers is due to thermally induced oxygen vacancies. • Laser marking results obtained using NIR lasers and green laser are compared. • High contrast marks on alumina were achieved. - Abstract: Alumina serves as raw material for a broad range of advanced ceramic products. These elements should usually be identified by some characters or symbols printed directly on them. In this sense, laser marking is an efficient, reliable and widely implemented process in industry. However, laser marking of alumina still leads to poor results since the process is not able to produce a dark mark, yielding bad contrast. In this paper, we present an experimental study on the process of marking alumina by three different lasers working in two wavelengths: 1064 nm (Near-infrared) and 532 nm (visible, green radiation). A colorimetric analysis has been carried out in order to compare the resulting marks and its contrast. The most suitable laser operating conditions were also defined and are reported here. Moreover, the physical process of marking by NIR lasers is discussed in detail. Field Emission Scanning Electron Microscopy, High Resolution Transmission Electron Microscopy and X-ray Photoelectron Spectroscopy were also employed to analyze the results. Finally, we propose an explanation for the differences of the coloration induced under different atmospheres and laser parameters. We concluded that the atmosphere is the key parameter, being the inert one the best choice to produce the darkest marks.

  14. Bioactive glass-ceramics coatings on alumina

    Energy Technology Data Exchange (ETDEWEB)

    Vitale Brovarone, C.; Verne, E.; Lupo, F. [Politecnico di Torino (Italy). Materials Science and Chemical Eng. Dept.; Moisescu, C. [Jena Univ. (Germany). Otto-Schott-Inst. fuer Glaschemie; Zanardi, L.; Bosetti, M.; Cannas, M. [Eastern Piemont Univ., Novara (Italy). Medical Science Dept.

    2001-07-01

    In this work, aiming to combine the mechanical performances of alumina with the surface properties of a bioactive material, we coated full density alumina substrates by a bioactive glass-ceramic GC. This latter was specially tailored, in term of costituents and specific quantity to have a thermal expansion coefficient close to that of alumina (8.5-9{sup *}10{sup -6}/ C) which is lower than most of the bioactive glasses and glass-ceramics already in use. In this way, we sought to avoid, as much as possible, the crack formation and propagation due to residual stresses generated by the thermal expansion coefficients mismatch. Furthermore, the high reactivity of alumina toward the glass-ceramic was carefully controlled to avoid deep compositional modification of the GC that will negatively affect its bioactivity. At this purpose, an intermediate layer of an appropriate glass G was coated prior to coat the bioactive glass-ceramic. On the materials obtained, preliminary biological tests have been done to evaluate glass-ceramic biocompatibility respect to alumina. (orig.)

  15. due to Capillary Forces

    Directory of Open Access Journals (Sweden)

    Hassen M. Ouakad

    2009-01-01

    Full Text Available We present modeling and analysis for the static behavior and collapse instabilities of doubly-clamped and cantilever microbeams subjected to capillary forces. These forces can be as a result of a volume of liquid trapped underneath the microbeam during the rinsing and drying process in fabrication. The model considers the microbeam as a continuous medium, the capillary force as a nonlinear function of displacement, and accounts for the mid-plane stretching and geometric nonlinearities. The capillary force is assumed to be distributed over a specific length underneath the microbeam. The Galerkin procedure is used to derive a reduced-order model consisting of a set of nonlinear algebraic and differential equations that describe the microbeams static and dynamic behaviors. We study the collapse instability, which brings the microbeam from its unstuck configuration to touch the substrate and gets stuck in the so-called pinned configuration. We calculate the pull-in length that distinguishes the free from the pinned configurations as a function of the beam thickness and gap width for both microbeams. Comparisons are made with analytical results reported in the literature based on the Ritz method for linear and nonlinear beam models. The instability problem, which brings the microbeam from a pinned to adhered configuration is also investigated. For this case, we use a shooting technique to solve the boundary-value problem governing the deflection of the microbeams. The critical microbeam length for this second instability is also calculated.

  16. Dielectric Performance of a High Purity HTCC Alumina at High Temperatures - a Comparison Study with Other Polycrystalline Alumina

    Science.gov (United States)

    Chen, Liangyu

    2014-01-01

    A very high purity (99.99+%) high temperature co-fired ceramic (HTCC) alumina has recently become commercially available. The raw material of this HTCC alumina is very different from conventional HTCC alumina, and more importantly there is no glass additive in this alumina material for co-firing processing. Previously, selected HTCC and LTCC (low temperature co-fired ceramic) alumina materials were evaluated at high temperatures as dielectric and compared to a regularly sintered 96% polycrystalline alumina (96% Al2O3), where 96% alumina was used as the benchmark. A prototype packaging system based on regular 96% alumina with Au thickfilm metallization successfully facilitated long term testing of high temperature silicon carbide (SiC) electronic devices for over 10,000 hours at 500 C. In order to evaluate this new high purity HTCC alumina for possible high temperature packaging applications, the dielectric properties of this HTCC alumina substrate were measured and compared with those of 96% alumina and a previously tested LTCC alumina from room temperature to 550 C at frequencies of 120 Hz, 1 KHz, 10 KHz, 100 KHz, and 1 MHz. A parallel-plate capacitive device with dielectric of the HTCC alumina and precious metal electrodes were used for measurements of the dielectric constant and dielectric loss of the co-fired alumina material in the temperature and frequency ranges. The capacitance and AC parallel conductance of the capacitive device were directly measured by an AC impedance meter, and the dielectric constant and parallel AC conductivity of the dielectric were calculated from the capacitance and conductance measurement results. The temperature and frequency dependent dielectric constant, AC conductivity, and dissipation factor of the HTCC alumina substrate are presented and compared to those of 96% alumina and a selected LTCC alumina. Other technical advantages of this new co-fired material for possible high packaging applications are also discussed.

  17. [Effect of 1-MCP on senescence and quality in cold-stored edible podded pea].

    Science.gov (United States)

    Wang, Feng; Zheng, Yong-Hua; Zhang, Lan; Feng, Lei; Su, Xin-Guo; Jiang, Yue-Ming

    2004-04-01

    The effects of 1-MCP (1-methylcyclo-propene) at 0.5, 1 and 2 muL/L on senescence and quality attributes in edible podded pea (Pisum sativum L.var.Saccharatum) during cold storage at 1 degrees C were investigated. The results indicated that treatments with 1 and 2 microL/L 1-MCP significantly inhibited respiratory rate, ethylene production and superoxide production, maintained higher levels of SOD, AsA-POD activities and chlorophyll and AsA contents, reduced the increases in MDA and fiber contents and decay index, thereby delayed the senescence process and quality deterioration. Treatment with 0.5 microL/L 1-MCP showed no significant effects on senescence and quality changes in harvested edible podded pea.

  18. The study of the aging behavior on large area MCP-PMT

    CERN Document Server

    Wang, Wen-Wen; Qi, Ming; Xia, Jing-Kai; Cheng, Ya-Ping; Ning, Zhe; Luo, Feng-Jiao; Heng, Yue-Kun; Liu, Shu-Lin; Si, Shu-Guang; Sun, Jian-Ning; Li, Dong; Wang, Xing-Chao; Huang, Guo-Rui; Tian, Jing-Shou; Wei, Yong-Lin; Liu, Hu-Lin; Li, Wei-Hua; Wang, Xing; Xin, Li-Wei

    2015-01-01

    Aging experiments of a novel type of large area MCP-PMT made by JUNO collaboration were conducted.In these aging experiments, the multi-photoelectron spectrum and single photoelectron spectrum were measured daily,as well as the MCP resistance of the second PMT before and after the experiment. Two PMTs were aged successivelyfor cross check. The first PMT was aged for 52 days, while the other one was aged for 84 days. In order to study the mechanism of the aging process, the high voltage on the second PMT was increased to accelerate its aging process when the cumulative output of charge from its anode was about 4 C. From our study, it can be known that large area MCP-PMT aging had a strong relationship with the related MCPs. In accordance with the PMT aging curve,a PMT aging model was setup and a general aging formula was given.

  19. CHANGES IN MECHANICAL PROPERTIES OF MINIMALLY-PROCESSED YELLOW PITAHAYA TREATED WITH 1-MCP

    Directory of Open Access Journals (Sweden)

    LILIANA SERNA COCK

    2012-01-01

    Full Text Available Se evaluaron las propiedades mecánicas de esfuerzo del límite de fluencia (sL, modulo de deformación (Ed, esfuerzo de ruptura (sF, y deformación de Hencky en la ruptura (eHF de muestras de pitahaya amarilla mínimamente procesada y tratadas con 200 μgL-1 de 1-MCP durante el almacenamiento a 10±1 °C y 85% de humedad relativa. Las muestras fueron sometidas a pruebas de compresión uniaxial hasta la ruptura. Los resultados mostraron que las muestras tratadas con 1-MCP presentaron los mayores valores del esfuerzo del límite de fluencia, modulo de elasticidad y esfuerzo de ruptura. Esto indica que la aplicación del 1-MCP proporciona mayor firmeza a la fruta y puede representar una alternativa para disminuir cambios indeseables de textura durante el almacenamiento.

  20. Challenges and Strategies in the Synthesis of Mesoporous Alumina Powders and Hierarchical Alumina Monoliths

    Directory of Open Access Journals (Sweden)

    Anne Galarneau

    2012-02-01

    Full Text Available A new rapid, very simple and one-step sol-gel strategy for the large-scale preparation of highly porous γ-Al2O3 is presented. The resulting mesoporous alumina materials feature high surface areas (400 m2 g−1, large pore volumes (0.8 mL g−1 and the ��-Al2O3 phase is obtained at low temperature (500 °C. The main advantages and drawbacks of different preparations of mesoporous alumina materials exhibiting high specific surface areas and large pore volumes such as surfactant-nanostructured alumina, sol-gel methods and hierarchically macro-/mesoporous alumina monoliths have been analyzed and compared. The most reproducible synthesis of mesoporous alumina are given. Evaporation-Induced Self-Assembly (EISA is the sole method to lead to nanostructured mesoporous alumina by direct templating, but it is a difficult method to scale-up. Alumina featuring macro- and mesoporosity in monolithic shape is a very promising material for in flow applications; an optimized synthesis is described.

  1. Fast plasma discharge capillary design as a high power throughput soft x-ray emission source.

    Science.gov (United States)

    Wyndham, E S; Favre, M; Valdivia, M P; Valenzuela, J C; Chuaqui, H; Bhuyan, H

    2010-09-01

    We present the experimental details and results from a low energy but high repetition rate compact plasma capillary source for extreme ultraviolet and soft x-ray research and applications. Two lengths of capillary are mounted in two versions of a closely related design. The discharge operates in 1.6 and 3.2 mm inner diameter alumina capillaries of lengths 21 and 36 mm. The use of water both as dielectric and as coolant simplifies the compact low inductance design with nanosecond discharge periods. The stored electrical energy of the discharge is approximately 0.5 J and is provided by directly charging the capacitor plates from an inexpensive insulated-gate bipolar transistor in 1 μs or less. We present characteristic argon spectra from plasma between 30 and 300 Å as well as temporally resolved x-ray energy fluence in discrete bands on axis. The spectra also allow the level of ablated wall material to be gauged and associated with useful capillary lifetime according to the chosen configuration and energy storage. The connection between the electron beams associated with the transient hollow cathode mechanism, soft x-ray output, capillary geometry, and capillary lifetime is reported. The role of these e-beams and the plasma as measured on-axis is discussed. The relation of the electron temperature and the ionization stages observed is discussed in the context of some model results of ionization in a non-Maxwellian plasma.

  2. Synthesis and characterization of alumina precursor and alumina to be used as nano composite; Sintese e caracterizacao de precursores de alumina e alumina para uso em nanocompositos

    Energy Technology Data Exchange (ETDEWEB)

    Antunes, M.L.P., E-mail: malu@sorocaba.unesp.b [Universidade Estadual Paulista Julio de Mesquita Filho (UNESP), Sorocaba, SP (Brazil); Santos, H. Souza [Universidade de Sao Paulo (IF/USP), SP (Brazil). Inst. de Fisica; Santos, P. Souza [Universidade de Sao Paulo (EP/USP), SP (Brazil). Escola Politecnica

    2009-07-01

    With the evolution of nanomaterials technology, mainly in the 90s, it was possible to observe produced composites with alumina matrix and nanomaterial as reinforcing materials. It results in a significant improvement of mechanical proprieties of these composites. Thenceforth the study of synthesis and characterization of nanostructured materials has attracted great scientific interest. In this perspective, the aim of this work is to present an experimental procedure to obtain nordstrandite (aluminum hydroxide) with nanometric dimensions. Nordstrandite synthesis, obtained by the reaction of slightly amalgamated aluminum foil with aqueous ethylene glycol, which allows the control of the size of crystal produced. This control could be confirmed by X-Ray Diffraction and Electron Microscopy. Thermal transformation study is also presented. This study allowed the identification of transition aluminas that have potential to produce nanometric aluminas. (author)

  3. Dynamical Mechanical Properties for AD90 Alumina

    Institute of Scientific and Technical Information of China (English)

    REN Hui-lan; NING Jian-guo; LI Ping

    2007-01-01

    The dynamic response of polycrystalline alumina was investigated in the pressure range of 0 -13 GPa by planar impact experiments.Velocity interferometer system for any reflector(VISAR) was used to obtain free surface velocity profile and determine the Hugoniot elastic limit,and manganin gauges were employed to obtain the stress-time histories and determine Hugoniot curve.Both the free surface particle velocity profiles and Hugoniot curves indicate the dispersion of the "plastic" wave for alumina.With the measured stress histories,the complete histories of strain,particle velocity,specific volume and specific internal energy are gained by using path line principle of Lagrange analysis.The dynamic mechanical behaviors for alumina under impact loading are analyzed,such as nonlinear characteristic,strain rate dependence,dispersion and declination of shock wave in the material.

  4. Iron films deposited on porous alumina substrates

    Science.gov (United States)

    Yamada, Yasuhiro; Tanabe, Kenichi; Nishida, Naoki; Kobayashi, Yoshio

    2016-12-01

    Iron films were deposited on porous alumina substrates using an arc plasma gun. The pore sizes (120 - 250 nm) of the substrates were controlled by changing the temperature during the anodic oxidation of aluminum plates. Iron atoms penetrated into pores with diameters of less than 160 nm, and were stabilized by forming γ-Fe, whereas α-Fe was produced as a flat plane covering the pores. For porous alumina substrates with pore sizes larger than 200 nm, the deposited iron films contained many defects and the resulting α-Fe had smaller hyperfine magnetic fields. In addition, only a very small amount of γ-Fe was obtained. It was demonstrated that the composition and structure of an iron film can be affected by the surface morphology of the porous alumina substrate on which the film is grown.

  5. A 30 ps Timing Resolution for Single Photons with Multi-pixel Burle MCP-PMT

    Energy Technology Data Exchange (ETDEWEB)

    Va' vra, J.; Benitez, J.; Coleman, J.; Leith, D.W.G.S.; Mazaheri, G.; Ratcliff, B.; Schwiening, J.; /SLAC

    2006-07-05

    We have achieved {approx}30 psec single-photoelectron and {approx}12ps for multi-photoelectron timing resolution with a new 64 pixel Burle MCP-PMT with 10 micron microchannel holes. We have also demonstrated that this detector works in a magnetic field of 15kG, and achieved a single-photoelectron timing resolution of better than 60 psec. The study is relevant for a new focusing DIRC RICH detector for particle identification at future Colliders such as the super B-factory or ILC, and for future TOF techniques. This study shows that a highly pixilated MCP-PMT can deliver excellent timing resolution.

  6. Effect Of 1-MCP Treatment On Storage Potential Of Tomato Fruit

    OpenAIRE

    Wrzodak Anna; Gajewski Marek

    2015-01-01

    Tomato fruit cv. ’Faustine’ F1 were harvested at mature green and full-red stages and treated with 1 or 2 µl·l−1 of 1-methylcyclopropene (1-MCP) at 20 °C and 85-90% RH, for 21 hours to investigate the ability to delay ripening. Treated and control fruit were stored at 12.5 and 20 °C and 85-90% RH. Ethylene production, rate of respiration, weight loss, market value and storage life were determined after 4-week storage. Exposure of tomato fruit to 1-MCP reduced ethylene production and respirati...

  7. Sensory Quality of ‘Cherry’ Tomatoes in Relation to 1-MCP Treatment and Storage Duration

    OpenAIRE

    Marek GAJEWSKI; Mazur, Katarzyna; Jadwiga RADZANOWSKA; Kowalczyk, Katarzyna; Marcinkowska, Monika; Klaudyna RYL; Karolina KALOTA

    2014-01-01

    1-MCP (1-methylcyclopropene), the ethylene receptors blocker, is used in horticultural practice for prolonging ‘shelf-life’ of several species of fruits and vegetables. The objective of this study was to determine the effect of 1-MCP treatment on sensory characteristics of ‘cherry’ type tomatoes (Solanum lycopersicum L. var. cerasiforme) after 4-week storage. In the experiment the fruits were harvested at pink and light-red fruit stages (3rd and 5th stage, according to USDA classification), a...

  8. Microwave fast sintering of submicrometer alumina

    Directory of Open Access Journals (Sweden)

    Romualdo Rodrigues Menezes

    2010-09-01

    Full Text Available Commercially available alumina powder with high-purity submicrometer particle size and narrow particle size distribution was fully densified by a microwave hybrid fast firing technique. The alumina compacts were surrounded by susceptor material, which helped the heating of the samples, and sintered in a microwave oven at a frequency of 2.45 GHz and a power level of 1.8 kW. The sintered samples reached densities of 99% in sintering cycles of 30 to 40 minutes, a much shorter time than conventional sintering processes. The sintered samples showed uniform microstructures with powder particle size/average grain size rations higher than 1:2.

  9. Nanomechanical humidity detection through porous alumina cantilevers

    Directory of Open Access Journals (Sweden)

    Olga Boytsova

    2015-06-01

    Full Text Available We present here the behavior of the resonance frequency of porous anodic alumina cantilever arrays during water vapor adsorption and emphasize their possible use in the micromechanical sensing of humidity levels at least in the range of 10–22%. The sensitivity of porous anodic aluminium oxide cantilevers (Δf/Δm and the humidity sensitivity equal about 56 Hz/pg and about 100 Hz/%, respectively. The approach presented here for the design of anodic alumina cantilever arrays by the combination of anodic oxidation and photolithography enables easy control over porosity, surface area, geometric and mechanical characteristics of the cantilever arrays for micromechanical sensing.

  10. Tribological properties of nanoscale alumina-zirconia composites

    NARCIS (Netherlands)

    Kerkwijk, B.; Winnubst, A.J.A.; Verweij, H.; Mulder, E.J.; Metselaar, H.S.C.; Schipper, D.J.

    1999-01-01

    The tribological properties of zirconia (Y-TZP), alumina and their composites, alumina dispersed in zirconia (ADZ) and zirconia-toughened alumina (ZTA), were investigated. These ceramics are made by colloidal processing methods such that well-defined, homogeneous microstructures with submicron grain

  11. A Novel Processing Route for Ni-doped Alumina Composites

    Institute of Scientific and Technical Information of China (English)

    JING Mao-xiang; SHEN Xiang-qian; ZHOU Jian-xin; LI Dong-hong; LI Wang-xing

    2006-01-01

    Alumina-based composites containing 0-15wt% Ni metallic phase were produced by hot press-sintering Ni-coated alumina powders. The Ni-coated alumina powders were prepared by the aqueous heterogeneous precipitation of alumina micro-powders and nickel sulfate salt followed by reduction process. The microstructural features and dispersion of Ni phase in Ni-coated alumina powders and the subsequent alumina-Ni cermets were investigated using scanning electron microscope (SEM), X-ray diffractometer (XRD), and transmission electron microscope (TEM). The relative density of the hot press-sintered composites was measured with the Archimedes' method while the fracture strength and the fracture toughness were defined with the three-point bending method and the micro-indentation fracture method. In the formation of alumina-Ni cermets from sintered Ni-coated alumina powders, Ni phase to some extent limits the densification rate and stifles the coarsening and growing process of alumina grains. The Ni phase is found to be located at the interfaces and the triple-joint junctions of alumina grains which results into alteration of the fracture mode of alumina and its increased fracture strength and fracture toughness if compared with monolithic alumina.

  12. Study of the molybdenum retention in alumina; Estudio de la retencion de molibdeno en alumina

    Energy Technology Data Exchange (ETDEWEB)

    Wilkinson, Maria V.; Mondino, Angel V.; Manzini, Alberto [Comision Nacional de Energia Atomica, Buenos Aires (Argentina). Centro Atomico Ezeiza. Radioquimica y Quimica de las Radiaciones

    2002-07-01

    The Argentine National Atomic Energy Commission routinely produces {sup 99} Mo by fission of highly enriched uranium contained in targets irradiated in RA-3 reactor. The current process begins with the dissolution of the irradiated target in a basic media, considering the possibility of changing the targets, it could be convenient to dissolve them in acid media. The use of alumina as a first separation step in acid dissolution processes is already known although it is necessary to determine both the type of alumina to be used and the separation conditions. The study of molybdenum retention in alumina was performed at laboratory scale, using Mo-99 as radiotracer. Different kinds of alumina were tried, varying charge solution acidity. Influence of uranium concentration in the loading solution on molybdenum retention was also studied. (author)

  13. Identification of the mcpA and mcpM Genes, Encoding Methyl-Accepting Proteins Involved in Amino Acid and l-Malate Chemotaxis, and Involvement of McpM-Mediated Chemotaxis in Plant Infection by Ralstonia pseudosolanacearum (Formerly Ralstonia solanacearum Phylotypes I and III)

    Science.gov (United States)

    Hida, Akiko; Oku, Shota; Kawasaki, Takeru; Tajima, Takahisa

    2015-01-01

    Sequence analysis has revealed the presence of 22 putative methyl-accepting chemotaxis protein (mcp) genes in the Ralstonia pseudosolanacearum GMI1000 genome. PCR analysis and DNA sequencing showed that the highly motile R. pseudosolanacearum strain Ps29 possesses homologs of all 22 R. pseudosolanacearum GMI1000 mcp genes. We constructed a complete collection of single mcp gene deletion mutants of R. pseudosolanacearum Ps29 by unmarked gene deletion. Screening of the mutant collection revealed that R. pseudosolanacearum Ps29 mutants of RSp0507 and RSc0606 homologs were defective in chemotaxis to l-malate and amino acids, respectively. RSp0507 and RSc0606 homologs were designated mcpM and mcpA. While wild-type R. pseudosolanacearum strain Ps29 displayed attraction to 16 amino acids, the mcpA mutant showed no response to 12 of these amino acids and decreased responses to 4 amino acids. We constructed mcpA and mcpM deletion mutants of highly virulent R. pseudosolanacearum strain MAFF106611 to investigate the contribution of chemotaxis to l-malate and amino acids to tomato plant infection. Neither single mutant exhibited altered virulence for tomato plants when tested by root dip inoculation assays. In contrast, the mcpM mutant (but not the mcpA mutant) was significantly less infectious than the wild type when tested by a sand soak inoculation assay, which requires bacteria to locate and invade host roots from sand. Thus, McpM-mediated chemotaxis, possibly reflecting chemotaxis to l-malate, facilitates R. pseudosolanacearum motility to tomato roots in sand. PMID:26276117

  14. Optimization of the electron collection efficiency of a large area MCP-PMT for the JUNO experiment

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Lin, E-mail: chenlin@opt.cn [State Key Laboratory of Transient Optics and Photonics, Xi’an Institute of Optics and Precision Mechanics (XIOPM), Chinese Academy of Sciences (CAS), Xi’an 710119 (China); Graduate School of Chinese Academy of Sciences (CAS), Beijing 100049 (China); Xi’an Jiaotong University, Xi’an 710049 (China); Tian, Jinshou [Graduate School of Chinese Academy of Sciences (CAS), Beijing 100049 (China); Liu, Chunliang [Xi’an Jiaotong University, Xi’an 710049 (China); Wang, Yifang; Zhao, Tianchi [Institute of High Energy Physics (IHEP) of CAS, Beijing 100049 (China); Liu, Hulin; Wei, Yonglin; Sai, Xiaofeng [Graduate School of Chinese Academy of Sciences (CAS), Beijing 100049 (China); Chen, Ping [State Key Laboratory of Transient Optics and Photonics, Xi’an Institute of Optics and Precision Mechanics (XIOPM), Chinese Academy of Sciences (CAS), Xi’an 710119 (China); Graduate School of Chinese Academy of Sciences (CAS), Beijing 100049 (China); Wang, Xing; Lu, Yu [Graduate School of Chinese Academy of Sciences (CAS), Beijing 100049 (China); Hui, Dandan; Guo, Lehui [State Key Laboratory of Transient Optics and Photonics, Xi’an Institute of Optics and Precision Mechanics (XIOPM), Chinese Academy of Sciences (CAS), Xi’an 710119 (China); Graduate School of Chinese Academy of Sciences (CAS), Beijing 100049 (China); Liu, Shulin; Qian, Sen; Xia, Jingkai; Yan, Baojun; Zhu, Na [Institute of High Energy Physics (IHEP) of CAS, Beijing 100049 (China); Sun, Jianning; Si, Shuguang [North Night Vision Technology (NNVT) CO., LTD, Nanjing 210110 (China); and others

    2016-08-11

    A novel large-area (20-inch) photomultiplier tube based on microchannel plate (MCP-PMTs) is proposed for the Jiangmen Underground Neutrino Observatory (JUNO) experiment. Its photoelectron collection efficiency C{sub e} is limited by the MCP open area fraction (A{sub open}). This efficiency is studied as a function of the angular (θ), energy (E) distributions of electrons in the input charge cloud and the potential difference (U) between the PMT photocathode and the MCP input surface, considering secondary electron emission from the MCP input electrode. In CST Studio Suite, Finite Integral Technique and Monte Carlo method are combined to investigate the dependence of C{sub e} on θ, E and U. Results predict that C{sub e} can exceed A{sub open}, and are applied to optimize the structure and operational parameters of the 20-inch MCP-PMT prototype. C{sub e} of the optimized MCP-PMT is expected to reach 81.2%. Finally, the reduction of the penetration depth of the MCP input electrode layer and the deposition of a high secondary electron yield material on the MCP are proposed to further optimize C{sub e}.

  15. Thermal Conductivity of Alumina-Toughened Zirconia Composites

    Science.gov (United States)

    Bansal, Narottam P.; Zhu, Dong-Ming

    2003-01-01

    10-mol% yttria-stabilized zirconia (10YSZ)-alumina composites containing 0 to 30 mol% alumina were fabricated by hot pressing at 1500 C in vacuum. Thermal conductivity of the composites, determined at various temperatures using a steady-state laser heat flux technique, increased with increase in alumina content. Composites containing 0, 5, and 10-mol% alumina did not show any change in thermal conductivity with temperature. However, those containing 20 and 30-mol% alumina showed a decrease in thermal conductivity with increase in temperature. The measured values of thermal conductivity were in good agreement with those calculated from simple rule of mixtures.

  16. LOW TEMPERATURE SINTERING OF ALUMINA BIOCERAMIC UNDER NORMAL PRESSURE

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    Superfine alumina powder with high purity (mean particle size is less than 0. 35μm) were used as main starting material for sintering alumina ceramic. A multiple additive MgO-ZrO2 (Y2O3) was homogeneously added into the batch by the chemical coprecipitation method. Sintering of alumina bioceramic at low tempera ture (<1600C) was achieved resulting in a dense and high strength alumina ceramic with the bending strength up to 382 MPa and an improved fracture toughness. Mechanism that the multiple additives promote the sintering of alumina ceramic is discussed on the base of XRD and SEM analysis.

  17. Research of MCP-1 expression in rat's retina injured by ischemia-reperfusion%MCP-1在大鼠视网膜缺血再灌注损伤中的表达及意义研究

    Institute of Scientific and Technical Information of China (English)

    游志鹏; 姜德咏; 李国栋; 赵宏伟

    2003-01-01

    目的了解MCP-1在大鼠视网膜缺血再灌注损伤中的表达及意义.方法建立大鼠视网膜缺北血再灌注模型,以SABC法检测MCP-1在视网膜中的表达,统计学分析.结果MCP-1在视网膜缺血再灌注6 h开始表达,第24小时达到最高峰,48 h开始表达减弱.结论MCP-1在视网膜缺血再灌注损伤中起重要作用.%Objective:The retina ischemia- reperfusion injury is caused by many factors. A lot of cell factors take part in it. Many researches suggest MCP - 1 has special effect on leukocyte and lymphocyte. The research try to study the effect of MCP - 1 in rat's retina ischemia- reperfusion injury. Methods: To employ the rat's retina ischemia- reperfusion model and use SABC method to test the expression of MCP- 1 on retina. Results: There was no MCP - 1 expressed in retina after ischemia- reperfusion injury for one hour. MCP- 1 began to express in retina after ischemia- reperfusion injury for six hours, and expressed at most after ischemia- reperfusion injury for 24 hours. Then it began to decrease in 48 hours after ischemia - repeffusion injury, but it still expressed in retina in seventy- two hours after ischemia- reperfusion injury. Conclusions: MCP- 1 plays an important role in rat's retina ischemia- reperfusion injury.

  18. Selective metallization of alumina by laser

    NARCIS (Netherlands)

    Shrivastva, P.B.; Boose, C.A.; Kolster, B.H.; Harteveld, C.; Meinders, B.

    1991-01-01

    Nickel has been selectively deposited on an alumina substrate without any pretreatment from a flow of a nickel acetate solution using the focused beam of an excimer laser. Nickel spots as well as nickel lines were drawn and subsequently plated with an electroless Ni-B coating. Excellent adhesion of

  19. Stabilization of Self-Assembled Alumina Mesophases

    NARCIS (Netherlands)

    Perez, Lidia Lopez; Perdriau, Sebastien; ten Brink, Gert; Kooi, Bart J.; Heeres, Hero Jan; Melian-Cabrera, Ignacio

    2013-01-01

    An efficient route to stabilize alumina mesophases derived from evaporation-induced self-assembly is reported after investigating various aspects in-depth: influence of the solvent (EtOH, s-BuOH, and t-BuOH) on the textural and structural properties of the mesophases based on aluminum tri-sec-butoxi

  20. Evaluating the potential of IP-10 and MCP-2 as biomarkers for the diagnosis of TB

    DEFF Research Database (Denmark)

    Ruhwald, Morten; Bodmer, T; Maier, C

    2008-01-01

    were obtained from 80 patients with culture and/or PCR proven TB, and 124 unexposed healthy controls; 86 high school students and 38 high school staff. IP-10 and MCP-2 test cut-offs were established based on ROC curve analysis.TB patients produced significantly higher levels of IP-10 (median 2158 pg...

  1. Dielectric Performance of High Purity HTCC Alumina at High Temperatures - A Comparison Study with Other Polycrystalline Alumina

    Science.gov (United States)

    Chen, Liang-Yu

    2012-01-01

    A very high purity (99.99+) high temperature co-fired ceramic (HTCC) alumina has recently become commercially available. The raw material of this HTCC alumina is very different from conventional HTCC alumina, and more importantly there is no glass additive in this co-fired material. Previously, selected HTCC and LTCC (low temperature co-fired ceramic) alumina materials were evaluated at high temperatures as dielectric and compared to a regularly sintered 96 polycrystalline alumina (96 Al2O3), where 96 alumina was used as the benchmark. A prototype packaging system based on regular 96 alumina with Au thick-film metallization successfully facilitated long term testing of high temperature silicon carbide (SiC) electronic devices for over 10,000 hours at 500C. In order to evaluate this new HTCC alumina for possible high temperature packaging applications, the dielectric properties of this HTCC alumina substrate were measured and compared with those of 96 alumina and a LTCC alumina from room temperature to 550C at frequencies of 120 Hz, 1 KHz, 10 KHz, 100 KHz, and 1 MHz. A parallel-plate capacitive device with dielectric of the HTCC alumina and precious metal electrodes were used for measurements of the dielectric constant and dielectric loss of the co-fired alumina material in the temperature and frequency ranges. The capacitance and AC parallel conductance of the capacitive device were directly measured by an AC impedance meter, and the dielectric constant and parallel AC conductivity of the dielectric were calculated from the capacitance and conductance measurement results. The temperature and frequency dependent dielectric constant, AC conductivity, and dissipation factor of the HTCC alumina substrate are presented and compared to those of 96 alumina. Other technical advantages of this new co-fired material for possible high packaging applications are also discussed.

  2. Involvement of spinal monocyte chemoattractant protein-1 (MCP-1) in cancer-induced bone pain in rats.

    Science.gov (United States)

    Hu, Ji-Hua; Zheng, Xiao-Yan; Yang, Jian-Ping; Wang, Li-Na; Ji, Fu-Hai

    2012-05-23

    In this study, we examined the involvement of chemokine monocyte chemoattractant protein-1 (MCP-1) in the spinal cord of a rat model of cancer-induced bone pain (CIBP). In this model, CIBP was established by an intramedullary injection of Walker 256 cells into the tibia of rats. We observed a significant increase in expression levels of MCP-1 and its receptor CCR2 in the spinal cord of CIBP rats. Furthermore, the intrathecal administration of an anti-MCP-1 neutralizing antibody attenuated the mechanical allodynia established in CIBP rats. Likewise, an intrathecal injection of exogenous recombinant MCP-1 induced a striking mechanical allodynia in naïve rats. These results suggest that increases in spinal MCP-1 and CCR2 expression are involved in the development of mechanical allodynia associated with bone cancer rats.

  3. MECHANICAL BEHAVIOUR OF ALUMINA-ZIRCONIA COMPOSITE BY SLURRY METHOD

    Directory of Open Access Journals (Sweden)

    JYOTI PRAKASH

    2011-02-01

    Full Text Available Alumina has got some excellent properties like chemical inertness, thermal and mechanical strength against hazardous environment. Alumina is a good ceramic material which is being used for structuralapplications. To enhance the toughness and strength of the body some Zirconia is also used with it. The use of Zirconia in alumina is known as toughening of alumina. One difficulty arises, when alumina and alumina toughened composite are sintered , because the low sinterability of Alumina-Zirconia forced the compact to give very low density body. To overcome this problem alumina and alumina composites are made from slurry method which gives nearly theoretical density. The combined effect of alumina and Zirconia on the phase transformation and microstructure development of heat-treated Alumina-Zirconia composites has been studied. Slurry is prepared by adding water, dispersant, binder and anti-foaming agent. In the present study, Sintering schedule is optimized and kept constant for all samples. After sintering, mechanical behaviour of the composite has been studied.

  4. Surface modification of alumina nanoparticles with silane coupling agents

    Energy Technology Data Exchange (ETDEWEB)

    Prado, Luis A.S.A.; Sriyai, Montira; Ghislandi, Marcos; Schulte, Karl [Technische Universitaet Hamburg-Harburg, Hamburg (Germany). Inst. fuer Kunststoffe und Verbundwerkstoffe (M-11); Barros-Timmons, Ana [University of Aveiro (Portugal). Dept. of Chemistry. Centro de Investigacao em Materiais Ceramicos e Compositos (CICECO)

    2010-07-01

    In the present paper we describe the surface modification of alumina nanoparticles using epoxy-containing alkoxysilanes (silane coupling agents, SCA). The materials were characterized using infrared spectroscopy and solid-state nuclear magnetic resonance. Whereas, neat alumina nanoparticles could be expectedly modified with the afore mentioned SCA, as evidenced by {sup 13}C CPMAS NMR, the presence of arylsulphonates at the surface of alumina caused the ringopening polymerization of the epoxide. This polymerization reaction facilitated the surface modification of alumina by the SCA. X-ray powder diffraction and {sup 27}Al MAS NMR clearly demonstrated that in spite of the SCA polymerization, there were neither structural changes nor phase transitions in the alumina after the surface modification. The surface modification decreased the thermal stability of alumina, in comparison to pristine alumina nanoparticles. (author)

  5. Tapered capillary optics

    Science.gov (United States)

    Hirsch, Gregory

    1998-01-01

    A metal or glass wire is etched with great precision into a very narrowly tapering cone which has the shape of the desired final capillary-optics bore. By controlling the rate of removal of the wire from an etchant bath, a carefully controlled taper is produced. A sensor measures the diameter of the wire as it leaves the surface of the etchant. This signal is used for feedback control of the withdrawal speed. The etched wire undergoes a treatment to produce an extremely low surface-roughness. The etched and smoothed wire is coated with the material of choice for optimizing the reflectivity of the radiation being focused. This could be a vacuum evaporation, sputtering, CVD or aqueous chemical process. The coated wire is either electroplated, built up with electroless plating, or encapsulated in a polymer cylinder such as epoxy to increase the diameter of the wire for easier handling and greater robustness. During this process, the wire is vertically oriented and tensioned to assure that the wire is absolutely straight. The coated and electroformed wire is bonded to a flat, rigid substrate and is then periodically segmented by cutting or etching a series of narrow slits or grooves into the wire. The wire is vertically oriented and tensioned during the bonding process to assure that it is straight. The original wire material is then chemically etched away through the slits or otherwise withdrawn to leave the hollow internal bore of the final tapered-capillary optical element.

  6. Degradation of alumina and zirconia toughened alumina (ZTA) hip prostheses tested under microseparation conditions in a shock device

    CERN Document Server

    Uribe, Juliana; Gremillard, Laurent; Reynard, Bruno

    2013-01-01

    This paper considers the degradation of alumina and zirconia toughened alumina vs. alumina for hip implants. The materials are as assumed to be load bearing surfaces subjected to shocks in wet conditions. The load is a peak of force; 9 kN was applied over 15 ms at 2 Hz for 800,000 cycles. The volumetric wear and roughness are lower for ZTA than for alumina. The long ZTA ageing did not seem to have a direct influence on the roughness. The ageing increased the wear volumes of ZTA and it was found to have a higher wear resistance compared to alumina.

  7. Evaluation of the reactivity of sera from patients with systemic lupus erythematosus against the human MCP1.

    Science.gov (United States)

    Bronze-da-Rocha, Elsa; Nóvoa, Ana; Teixeira, Natércia; Vasconcelos, Carlos Silva; Cerveira, Conceição; Castro e Melo, João; Carvalho, Manuel Cirne

    2012-08-01

    This study evaluates metaphase chromosome protein 1 (MCP1), a nuclear antigen, as a diagnostic marker for systemic lupus erythematosus (SLE). Reactivity of sera from 114 Portuguese patients with autoimmune rheumatic disease or from healthy blood donors (HBD), against MCP1, produced in bacteria (bact-MCP1) or in its native form (native-MCP1), was determined by immunoblotting. Predictive and discriminative power of MCP1 reactivity for SLE diagnosis in disease-control groups was evaluated by logistic regression, its diagnostic value determined by receiver-operating characteristic analysis and compared with similar analysis of antinuclear antibody and double-stranded DNA (dsDNA). We demonstrated that native-MCP1, in contrast to bact-MCP1, reacts with SLE sera with significant predictive and discriminative power versus other autoimmune diseases (odds ratio [OR] ≤3.537 and ≥3.265; area under the receiver-operating characteristic curve [AUC] ≤0.643 and ≥0.636) or versus HBD (OR = 5.006; AUC = 0.671), showing a good diagnostic power with high specificity (82.1% versus HBD) and low sensitivity for SLE, similar to those of dsDNA. The reactivity of SLE sera with native-MCP1 was shown to be dependent on the presence of phosphorylated residues. Native-MCP1 was shown to have diagnostic value as a specific marker for SLE diagnosis and, therefore, is a suitable substrate for a new antibody test. The widely reported importance of phosphorylated epitopes as targets for autoantibodies in SLE could also be confirmed for native-MCP1.

  8. Sensory Quality of ‘Cherry’ Tomatoes in Relation to 1-MCP Treatment and Storage Duration

    Directory of Open Access Journals (Sweden)

    Marek GAJEWSKI

    2014-06-01

    Full Text Available 1-MCP (1-methylcyclopropene, the ethylene receptors blocker, is used in horticultural practice for prolonging ‘shelf-life’ of several species of fruits and vegetables. The objective of this study was to determine the effect of 1-MCP treatment on sensory characteristics of ‘cherry’ type tomatoes (Solanum lycopersicum L. var. cerasiforme after 4-week storage. In the experiment the fruits were harvested at pink and light-red fruit stages (3rd and 5th stage, according to USDA classification, and stored for 3 and 4 weeks at 12 oC, then moved to 20  sup>oC for 2 days to obtain marketable maturity. 1-MCP was applied after harvest in concentration of 1 ppm, for 12 hours at 18 oC. The plants belonging to the ‘Dasher F1’ cultivar were grown in a greenhouse in rockwool slabs and fruits were harvested in June. Sensory analysis was performed in expert panel with Quantitative Descriptive Analysis (QDA, using 12 sensory descriptors concerning smell, taste, flavour and texture of the fruits. Also semi-consumer test of liking was carried out. As the control freshly harvested red fruits at optimal consumer's maturity were used. The 1-MCP treated fruits harvested in the light-red stage were of better sensory quality than the untreated ones, similar to freshly harvested, but in the case of the pink fruits, the quality was rated lower. It can be concluded that 1-MCP treatment was effective in delaying ripening of the fruits by better keeping their firmness and colour, however in the case of fruits harvested in earlier stage, overall sensory quality and consumer acceptance was scored lower than for the freshly harvested ones, mainly due to more intensive sour taste and lower sweetness.

  9. Capillaries modified by noncovalent anionic polymer adsorption for capillary zone electrophoresis, micellar electrokinetic capillary chromatography and capillary electrophoresis mass spectrometry

    DEFF Research Database (Denmark)

    Bendahl, L; Hansen, S H; Gammelgaard, Bente

    2001-01-01

    A simple coating procedure for generation of a high and pH-independent electroosmotic flow in capillary zone electrophoresis (CZE) and micellar electrokinetic capillary chromatography (MEKC) is described. The bilayer coating was formed by noncovalent adsorption of the ionic polymers Polybrene...

  10. Biomedical applications of capillary electrophoresis

    Science.gov (United States)

    Kartsova, L. A.; Bessonova, E. A.

    2015-08-01

    The review deals with modern analytical approaches used in capillary electrophoresis for solving medical and biological problems: search for biomarkers of various diseases and rapid diagnosis based on characteristic profiles of biologically active compounds by capillary electrophoresis with mass spectrometric detection; monitoring of the residual drugs in biological fluids for evaluating the efficiency of drug therapy; testing of the enantiomeric purity of pharmaceutical products; the use of novel materials as components of stationary and pseudo-stationary phases in capillary electrophoresis and capillary electrochromatography to increase the selectivity of separation of components of complex matrices; and identification of various on-line preconcentration techniques to reduce the detection limits of biologically active analytes. A topical trend in capillary electrophoresis required in clinical practice, viz., the design of microfluidic systems, is discussed. The bibliography includes 173 references.

  11. Graphene coated with alumina and its utilization as a thermal conductivity enhancer for alumina sphere/thermoplastic polyurethane composite

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Ki Tae; Dao, Trung Dung [Department of Chemistry, Energy Harvest-Storage Research Center, University of Ulsan, Ulsan 680-749 (Korea, Republic of); Jeong, Han Mo, E-mail: hmjeong@mail.ulsan.ac.kr [Department of Chemistry, Energy Harvest-Storage Research Center, University of Ulsan, Ulsan 680-749 (Korea, Republic of); Anjanapura, Raghu V. [Center for Emerging Technologies, Jain Global Campus, Jain University, Jakkasandra, Ramanagara 562-112 (India); Aminabhavi, Tejraj M. [Soniya College of Pharmacy, S. R. Nagar, Dharwad 580-002 (India)

    2015-03-01

    Graphene was oxidized with H{sub 2}O{sub 2} to introduce additional anchoring sites for effective alumina coating on graphene by the sol–gel method. The X-ray photoelectron spectroscopy studies showed that the oxygen-containing groups such as hydroxyl group useful for coating were introduced by the oxidation. The transmission electron microscopy images and thermogravimetric analysis data demonstrated that the additional anchoring sites enhanced the efficiency of the alumina coating. A small amount of alumina-coated graphene synergistically improved the thermal conductivity of the alumina sphere/thermoplastic polyurethane (TPU) composite without any increase in the electrical conductivity, because the electrical conductivity of graphene effectively decreased by the alumina coating. Moreover, the synergistic effect of a small amount of graphene was enhanced by the alumina coating, and the stiffening of the alumina sphere/TPU composite due to the added graphene was alleviated by the alumina coating. - Highlights: • Oxidation of graphene with H{sub 2}O{sub 2} introduced anchoring sites for alumina coating. • The anchoring sites improved the efficiency of alumina coating on graphene. • The alumina-coated graphene synergistically enhanced the thermal conductivity.

  12. Rheological Properties of Aqueous Nanometric Alumina Suspensions

    Energy Technology Data Exchange (ETDEWEB)

    Chuanping Li

    2004-12-19

    Colloidal processing is an effective and reliable approach in the fabrication of the advanced ceramic products. Successful colloidal processing of fine ceramic powders requires accurate control of the rheological properties. The accurate control relies on the understanding the influences of various colloidal parameters on the rheological properties. Almost all research done on the rheology paid less attention to the interactions of particle and solvent. However, the interactions of the particles are usually built up through the media in which the particles are suspended. Therefore, interactions of the particle with the media, the adsorbed layers on the particle surface, and chemical and physical properties of media themselves must influence the rheology of the suspension, especially for the dense suspensions containing nanosized particles. Relatively little research work has been reported in this area. This thesis addresses the rheological properties of nanometric alumina aqueous suspensions, and paying more attention to the interactions between particle and solvent, which in turn influence the particle-particle interactions. Dense nanometric alumina aqueous suspensions with low viscosity were achieved by environmentally-benign fructose additives. The rheology of nanometric alumina aqueous suspensions and its variation with the particle volume fraction and concentration of fructose were explored by rheometry. The adsorptions of solute (fructose) and solvent (water) on the nanometric alumina particle surfaces were measured and analyzed by TG/DSC, TOC, and NMR techniques. The mobility of water molecules in the suspensions and its variation with particle volume fractions and fructose additive were determined by the {sup 17}O NMR relaxation method. The interactions between the nanometric alumina particles in water and fructose solutions were investigated by AFM. The results indicated that a large number of water layers were physically bound on the particles

  13. Rheological Properties of Aqueous Nanometric Alumina Suspensions

    Energy Technology Data Exchange (ETDEWEB)

    Li, Chuanping [Iowa State Univ., Ames, IA (United States)

    2004-01-01

    Colloidal processing is an effective and reliable approach in the fabrication of the advanced ceramic products. Successful colloidal processing of fine ceramic powders requires accurate control of the rheological properties. The accurate control relies on the understanding the influences of various colloidal parameters on the rheological properties. Almost all research done on the rheology paid less attention to the interactions of particle and solvent. However, the interactions of the particles are usually built up through the media in which the particles are suspended. Therefore, interactions of the particle with the media, the adsorbed layers on the particle surface, and chemical and physical properties of media themselves must influence the rheology of the suspension, especially for the dense suspensions containing nanosized particles. Relatively little research work has been reported in this area. This thesis addresses the rheological properties of nanometric alumina aqueous suspensions, and paying more attention to the interactions between particle and solvent, which in turn influence the particle-particle interactions. Dense nanometric alumina aqueous suspensions with low viscosity were achieved by environmentally-benign fructose additives. The rheology of nanometric alumina aqueous suspensions and its variation with the particle volume fraction and concentration of fructose were explored by rheometry. The adsorptions of solute (fructose) and solvent (water) on the nanometric alumina particle surfaces were measured and analyzed by TG/DSC, TOC, and NMR techniques. The mobility of water molecules in the suspensions and its variation with particle volume fractions and fructose additive were determined by the 17O NMR relaxation method. The interactions between the nanometric alumina particles in water and fructose solutions were investigated by AFM. The results indicated that a large number of water layers were physically bound on the particles

  14. Application of MCP2515 in TTCAN Level 1 Node%MCP2515在TTCAN协议Level 1节点中应用

    Institute of Scientific and Technical Information of China (English)

    孟庆栋; 张凤登; 刘荣鹏

    2007-01-01

    TCAN是基于CAN的时间触发的高层协议,具有确定性行为,因而适用于安全相关的场合.本文首先从参照时间、基本周期、系统信息阵、网络时间单元和全局时间五个方面对TTCAN协议进行分析,其后讲解了基于MCP2515的一个TTCAN协议Level 1节点的实现方案.

  15. Capillaries for use in a multiplexed capillary electrophoresis system

    Science.gov (United States)

    Yeung, E.S.; Chang, H.T.; Fung, E.N.

    1997-12-09

    The invention provides a side-entry optical excitation geometry for use in a multiplexed capillary electrophoresis system. A charge-injection device is optically coupled to capillaries in the array such that the interior of a capillary is imaged onto only one pixel. In Sanger-type 4-label DNA sequencing reactions, nucleotide identification (``base calling``) is improved by using two long-pass filters to split fluorescence emission into two emission channels. A binary poly(ethyleneoxide) matrix is used in the electrophoretic separations. 19 figs.

  16. Multidimensional capillary electrophoresis.

    Science.gov (United States)

    Grochocki, Wojciech; Markuszewski, Michał J; Quirino, Joselito P

    2015-01-01

    Multidimensional separation where two or more orthogonal displacement mechanisms are combined is a promising approach to increase peak capacity in CE. The combinations allow dramatic improvement of analytical performance since the total peak capacity is given by a product of the peak capacities of all methods. The initial reports were concentrated on the construction of effective connections between capillaries for 2D analysis. Today, 2D and 3D CE systems are now able to separate real complex biological or environmental mixtures with good repeatability, improved resolution with minimal loss of sample. This review will present the developments in the field of multidimensional CE during the last 15 years. The endeavors in this specific field were on the development of interfaces, interface-free techniques including integrated separations, microdevices, and on-line sample concentration techniques to improve detection sensitivity.

  17. Influência do 1-MCP na conservação pós-colheita de rosas cv. Vega Influence of 1-MCP on postharvest conservation of roses cv. Vega

    Directory of Open Access Journals (Sweden)

    Júlia De Pietro

    2010-10-01

    Full Text Available Objetivou-se, neste trabalho, estudar aspectos da fisiologia pós-colheita de rosas cortadas cv. Vega, tratadas com diferentes concentrações de 1-metilcicloropropeno (1-MCP. O experimento foi conduzido em delineamento inteiramente casualizado, em esquema fatorial composto por dois fatores: quatro tratamentos pós-colheita e quatro datas de avaliação (0; 4; 8; 12 dias. As flores foram submetidas aos seguintes tratamentos: 1 Água destilada (controle; 2 1-MCP (100 ppb; 3 1-MCP (250 ppb; 4 1-MCP (500 ppb. Foram realizadas as seguintes avaliações: massa fresca, cor, turgescência, curvatura, taxa respiratória, conteúdo relativo de água, conteúdo de carboidratos solúveis, de redutores e de antocianina. Ao contrário do tratamento controle, todas as concentrações de 1-MCP foram eficientes para retardar a senescência das flores, porém, a concentração de 1-MCP a 500 ppb destacou-se pela melhor manutenção da qualidade, além de prolongar a vida decorativa das hastes até 19 dias.The objective of this work was to study aspects of postharvest physiology of cut roses cv. Vega, treated with different concentrations of 1-metilcloropropene (1-MCP. The experiment was conducted in a complete randomized design composed of two factors: four postharvest treatments and four dates of evaluation (0; 4; 8; 12 days. The following treatments were used: 1 distilled water; 2 1-metilciclopropeno (1-MCP 100 ppb; 3 1-MCP 250 ppb; 4 1-MCP 500 ppb. The following evaluations were made: fresh weight, color, turgor, curvature, respiration rate, relative water content, content of soluble carbohydrates, reducing and anthocyanin. Unlike treatment with distilled water, all concentrations of 1-MCP were effective in delaying the senescence of flowers; however, the concentration of 1-MCP at 500 ppb was highlighted by better maintenance of quality and extended decorate life stem up to 19 days.

  18. Fabrication and Enhanced Thermoelectric Properties of Alumina Nanoparticle-Dispersed Bi0.5Sb1.5Te3 Matrix Composites

    Directory of Open Access Journals (Sweden)

    Kyung Tae Kim

    2013-01-01

    Full Text Available Alumina nanoparticle-dispersed bismuth-antimony-tellurium matrix (Al2O3/BST composite powders were fabricated by using ball milling process of alumina nanoparticle about 10 nm and p-type bismuth telluride nanopowders prepared from the mechanochemical process (MCP. The fabricated Al2O3/BST composite powders were a few hundreds of nanometer in size, with a clear Bi0.5Sb1.5Te3 phase. The composite powders were consolidated into p-type bulk composite by spark plasma sintering process. High-resolution TEM images reveal that alumina nanoparticles were dispersed among the grain boundary or in the matrix grain. The sintered 0.3 vol.% Al2O3/BST composite exhibited significantly improved power factor and reduced thermal conductivity in the temperature ranging from 293 to 473 K compared to those of pure BST. From these results, the highly increased ZT value of 1.5 was obtained from 0.3 vol.% Al2O3/BST composite at 323 K.

  19. Effect of acidosis on IL-8 and MCP-1 during hypoxia and reoxygenation in human NT2-N neurons.

    Science.gov (United States)

    Frøyland, Elisabeth; Pedersen, Elena Didenko; Kvissel, Anne-Katrine; Almaas, Runar; Pharo, Anne; Skålhegg, Bjørn Steen; Mollnes, Tom Eirik; Rootwelt, Terje

    2006-10-03

    Inflammation probably plays a significant role in perinatal brain injury. To study the contribution of locally produced cytokines, the effect on cell death of addition of IL-8 and MCP-1 or antibodies to these, and the impact of acidosis, human postmitotic NT2-N neurons were exposed to 3 h of hypoxia and glucose deprivation and reoxygenated for 21 h. After 3 h of hypoxia with neutral medium, IL-8 was significantly increased compared to controls (150 (100-250)% vs. 100 (85-115)%, p=0.023). After 21 h of neutral reoxygenation, both IL-8 (380 (110-710)% vs. 150 (85-260)%, p=0.041) and monocyte chemoattractant protein-1 (MCP-1) (650 (440-2000)% vs. 310 (230-340)%, p=0.007) were significantly increased compared to controls. After 3 h of hypoxia, both IL-8 (p=0.002) and MCP-1 (p=0.008) were significantly lower in cells with acidotic compared with cells with neutral medium. Acidosis during reoxygenation, however, significantly increased IL-8 release, whereas MCP-1 release was diminished. Similar effects of acidosis were seen in normoxic controls. The cells also secreted RANTES and IP-10, but not 8 other cytokines tested. We found no effect on cell death, measured by MTT assay, of addition of IL-8, MCP-1 or antibodies to these. We conclude that human NT2-N neurons release IL-8 and MCP-1 during 21 h of reoxygenation after 3 h of hypoxia. Acidosis led to a differential effect on IL-8 and MCP-1, with increased IL-8 and decreased MCP-1, both during reoxygenation and in normoxic controls. IL-8 and MCP-1 had no effect on cell death.

  20. Improvement in nanoscale contact resistance of alumina

    Energy Technology Data Exchange (ETDEWEB)

    Bhattacharya, Manjima; Chakraborty, Riya; Mandal, Ashok Kumar [CSIR - Central Glass and Ceramic Research Institute, Kolkata (India); Dey, Arjun [CSIR - Central Glass and Ceramic Research Institute, Kolkata (India); ISRO Satellite Centre, Thermal Systems Group, Bangalore (India); Mukhopadhyay, Anoop Kumar [CSIR - Central Glass and Ceramic Research Institute, Kolkata (India); Central Glass and Ceramic Research Institute, Kolkata 32 (India)

    2012-06-15

    In all contact-related applications such as the wear-resistant inserts, biomedical implants, high strain rate impact-resistant plates, etc., nanohardness, i.e. the intrinsic contact resistance at the nano scale, plays a major role. In spite of the wealth of literature, the studies on nanohardness of dense, coarse-grain alumina ceramics which represent many commercial varieties; have reasonably good hardness at the macro scale and characteristically exhibit R-curve behaviour, are far from significant. Here, to the best of our knowledge, we report for the first time the experimental observations of the increase in intrinsic contact resistance at the nano scale with the loading rate applied to a high-density ({proportional_to}95 % of theoretical) coarse-grain ({proportional_to}20 {mu}m) alumina ceramics. These observations were explained in terms of the initiation of nanoscale plasticity and maximum shear stress generated just underneath the nanoindenter. (orig.)

  1. Nanoparticles in alumina: Microscopy and Theory

    Science.gov (United States)

    Idrobo, Juan C.; Halabica, Andrej; Rashkeev, Sergey; Glazoff, Michael V.; Boatner, Lynn A.; Haglund, Richard F.; Pennycook, Stephen. J.; Pantelides, Sokrates T.

    2007-03-01

    Transition-metal nanoparticles formed by ion implantation in alumina can be used to modify the optical properties of naturally oxidized and anodized aluminum. Here, we report atomic-resolution Z-contrast images using a scanning transmission electron microscope (STEM) of CoFe and other metal nanoparticles in alumina. We also report electron energy loss spectra (EELS) and relate them to visual appearance and optical properties. Finally, we report first-principles density- functional calculations of nucleation mechanisms for these nanoparticles. This research was sponsored by the Office of Basic Energy Sciences, Division of Materials Sciences and Engineering, U.S. Department of Energy, under contract DE-AC05- 00OR22725 with Oak Ridge National Laboratory, managed and operated by UT-Battelle, by NSF grant No. DMR-0513048, and by Alcoa Inc.

  2. Silica containing highly porous alumina ceramic

    Science.gov (United States)

    Svinka, R.; Svinka, V.; Zake, I.

    2011-04-01

    Porous alumina ceramic were produced by slip casting of aqueous alumina slurry with added small amount of metallic aluminium powder. Pores form in result of chemical reaction of aluminum with water by hydrogen gas evolution reaction and solidification of suspension. Porosity of such materials sintered at a temperature of 1600 - 1750°C varies from 60 to 90%. Pore size distribution and mechanical strength of these materials depend largely on the grain size of used raw materials. The major part of pores in the materials produced without additive of silica are larger than 10 ±m, but with 5 - 10 wt.% additive of silica in the raw mix pore size decreases considerably. The sintering shrinkage decreases to 2.5%. Coefficient of thermal expansion equally decreases from 8.9-10-6 K-1 to 7.1 10-6 K-1 and classification temperature increases to 1600°C, while deformation at high temperature decreases considerably.

  3. Impact of AD995 alumina rods

    Energy Technology Data Exchange (ETDEWEB)

    Chhabildas, L.C.; Furnish, M.D.; Reinhart, W.D. [Sandia National Labs., Albuquerque, NM (United States); Grady, D.E. [Applied Research Associates, Inc., Albuquerque, NM (United States)

    1997-10-01

    Gas guns and velocity interferometric techniques have been used to determine the loading behavior of an AD995 alumina rod 19 mm in diameter by 75 mm and 150 mm long, respectively. Graded-density materials were used to impact both bare and sleeved alumina rods while the velocity interferometer was used to monitor the axial-velocity of the free end of the rods. Results of these experiments demonstrate that (1) a time-dependent stress pulse generated during impact allows an efficient transition from the initial uniaxial strain loading to a uniaxial stress state as the stress pulse propagates through the rod, and (2) the intermediate loading rates obtained in this configuration lie between split Hopkinson bar and shock-loading techniques.

  4. Capillary flow solder wettability test

    Energy Technology Data Exchange (ETDEWEB)

    Vianco, P.T.; Rejent, J.A.

    1996-01-01

    A test procedure was developed to assess the capillary flow wettability of solders inside of a confined geometry. The test geometry was comprised of two parallel plates with a controlled gap of constant thickness (0.008 cm, 0.018 cm, 0.025 cm, and 0.038 cm). Capillary flow was assessed by: (1) the meniscus or capillary rise of the solder within the gap, (2) the extent of void formation in the gap, and (3) the time-dependence of the risen solder film. Tests were performed with the lead-free solders.

  5. Ultraviolet photoluminescence of porous anodic alumina films

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    Photoluminescence (PL) properties of porous anodic alumina (PAA) films prepared by using electrochemical anodization technique in a mixed solution of oxalic and sulfuric acid have been investigated. The PAA films have an intensive ultraviolet PL emission around 350 nm, of which a possible PL mechanism has been proposed. It was found that the incorporated oxalic ions, which could transform into PL centers and exist in the PAA films, are responsible for this ultraviolet PL emission.

  6. Tribology of alumina-graphite composites

    Science.gov (United States)

    Yu, Chih-Yuan

    Alumina-graphite composites, which combine high wear resistance and self-lubricity, are a potential and promising candidate for advanced tribological applications. The processing, mechanical properties and tribology of alumina-graphite composites are discussed. Full density is difficult to achieve by a pressureless sintering route. Porosity of the composites increases with graphite content which causes the strength, modulus of elasticity, and hardness of the composites to decrease. The increased porosity does cause the fracture toughness to slightly increases. Tribology of alumina-graphite composites was studied with a pin-on-disk tribometer with emphasis on the following aspects: the graphite content in both pin and disk, the graphite flake size and the orientation of the graphite flakes. Scan electronic microscopy (SEM) and X-ray diffraction are utilized to examine and characterize the wear debris and the worn surface. Results confirmed that it is necessary to optimize the structure and the supply of lubricant to improve the tribological behavior and that the arrangements of sliding couples also affect the tribology of self-lubricated ceramic composites. Continuous measurements of the friction coefficients were collected at high frequency in an attempt to correlate the tribology of alumina-graphite composites to vibrations introduced by friction. While these measurements indicate that the time frequency behavior of tribology is an important area of study, conclusions regarding the frequency response of different sliding couples could not be definitively stated. Finally, a new concept connecting instantaneous wear coefficient and instantaneous contact stress is proposed for prediction of wear behavior of brittle materials.

  7. CAN控制器芯片MCP2510在远程监测系统中的应用

    Institute of Scientific and Technical Information of China (English)

    王继国; 孙新亚

    2004-01-01

    介绍了CAN控制器芯片MCP2510的功能、结构和工作原理,提出了一种利用MCP2510芯片和MSP430单片机组成远程监测系统的方案,并通过硬件电路和软件的实现证明了其可行性和正确性,同时列举了MCP2510在使用中的一些注意事项.

  8. In situ sol-gel preparation of porous alumina monoliths for chromatographic separations of adenosine phosphates.

    Science.gov (United States)

    Zajickova, Zuzana; Rubi, Emir; Svec, Frantisek

    2011-06-03

    A method enabling the in situ preparation of porous alumina monoliths within 100 μm i.d. fused silica capillaries has been developed. These monoliths were prepared using the sol-gel process from a mixture consisting of an inorganic aluminum salt, a porogen, an epoxide, and a solvent. We investigated the effects of varying the preparation conditions on the physical characteristics of the monoliths with respect to their potential application in chromatographic separations. The best columns were obtained from a mixture of aluminum chloride hexahydrate, N,N-dimethylformamide, water, ethanol and propylene oxide. Adenosine phosphates were then separated in the optimized column with retention increasing according to number of phosphate functionalities.

  9. Analysis of Capillary Rise in Asymmetric Branch-Like Capillary

    Science.gov (United States)

    Li, Caoxiong; Shen, Yinghao; Ge, Hongkui; Yang, Zhihui; Su, Shuai; Ren, Kai; Huang, Heyu

    2016-05-01

    Transport in porous media is common in nature, attracting many attentions for a long time. Tree-like network model is often used as a simplification for porous space, expressing the complexity of pore spaces instead of capillary bundle. To investigate spontaneous imbibition characteristics in this network, a dynamic asymmetric branch-like capillary model is used to represent basic network structure, using fractal method to represent tortuosity. This work investigates the influence of parameters on imbibition process in the branch-like capillary model. An analytical equation for the imbibition mass versus time is derived. Parameters from capillary structures to liquid properties are taken into account and analyzed based on the numerical solution of the equation. It is found that the imbibition process in asymmetric branch-like capillary model can be recognized by four sections and brunching tubes are positive for imbibition process. Concomitantly, meniscus arrest event is simulated and discussed. Moreover, the influence of parameters on imbibition process is discussed. These parameters can be classified as static and dynamic. Static parameters mainly change the capillary force, which are related to the ultimate imbibition mass or imbibition ability, while dynamic parameters mainly have influence on resistance of flowing fluid, which are related to the imbibition speed in the imbibition process.

  10. Porous Aluminas: The bio template method for the synthesis of stable high surface area aluminas; Aluminas porosas: El metodo de bio-replica para la sintesis de aluminas estables de alta superficie especifica

    Energy Technology Data Exchange (ETDEWEB)

    Benitez Guerrero, M.; Perez Maqueda, L.; Pena Castro, P.; Pascual Cosp, J.

    2013-07-01

    Development of porous alumina has been the objective of numerous studies in recent decades, due to the intrinsic properties of aluminium oxide, such as high melting point, low thermal conductivity, chemical inertness and corrosion resistance which, in addition to a high surface area and permeability, make aluminas being used for many different industrial and technical applications. The crystallographic and textural stability of alumina acquires significant importance in those processes involving high temperatures; however, most of the synthesis methods yield metastable oxides of little interest in high-temperature processes due to the transformation to alpha phase, with the consequent reduction in surface area. The present article reviews diverse procedures for obtaining porous alumina with high specific surface area, including methods and strategies for preparing high surface alpha-alumina. Within this framework, the paper analyzes the results obtained through bio replica of lignocellulose materials. This technology allows preparing aluminas with the complex structural hierarchy of the lignocellulose templates. (Author)

  11. Synthesis and characterization of single-crystalline alumina nanowires

    Institute of Scientific and Technical Information of China (English)

    ZHAO Qing; XU Xiang-yu; ZHANG Hong-zhou; CHEN Yao-feng; XU Jun; YU Da-peng

    2005-01-01

    Alumina nanowires were synthesized on large-area silicon substrate via simple thermal evaporation method of heating a mixture of aluminum and alumina powders without using any catalyst or template. The phase structure and the surface morphology of the as-grown sample were analyzed by X-ray diffractometry(XRD) and scanning electron microscopy (SEM), respectively. The chemical composition and the microstructure of the as-grown alumina nanowires were characterized using transmission electron microscope(TEM). The nanowires are usually straight and the single crystalline has average diameter of 40 nm and length of 3 - 5 μm. The growth direction is along the [002] direction. Well aligned alumina nanowire arrays were observed on the surface of many large particles. The catalyst-free growth of the alumina nanowires was explained under the framework of a vapor-solid(VS)growth mechanism. This as-synthesized alumina nanowires could find potential applications in the fabrication of nanodevices.

  12. Position sensitive anodes for MCP read-out using induced charge measurement

    CERN Document Server

    Jagutzki, O; Mergel, V; Schmidt-Böcking, H; Spillmann, U; Worth, L B C

    2002-01-01

    We investigate the method of an indirect detection of a MCP charge avalanche projected onto a resistive layer (G. Battistoni, et al., Nucl. Instr. and Meth., 202 (1982) 459). If the sheet resistance is favourable one can detect the charge cloud by the capacitive coupling to an anode structure a few millimetres behind the layer. The anode structure can be, for example, a wedge-and-strip electrode pattern (M. Unverzagt, Diplomarbeit, Universitaet Frankfurt 1992, private communication) as it is used for directly collecting the electron avalanche from a MCP. Detection of the induced charge is beneficial in several respects. Firstly, image distortions produced by secondary electron mediated charge redistribution are eliminated. Secondly, the noise component due to quantized charge collection, commonly referred to as partition noise, is not present. In addition, the dielectric substrate can function both as an element of the vacuum enclosure and HV insulator, making the electrical connections easily accessible and ...

  13. Free-standing alumina nanobottles and nanotubes pre-integrated into nanoporous alumina membranes

    Science.gov (United States)

    Fang, Jinghua; Levchenko, Igor; (Ken Ostrikov, Kostya

    2014-08-01

    A novel interfacial structure consisting of long (up to 5 μm), thin (about 300 nm), highly-ordered, free-standing, highly-reproducible aluminum oxide nanobottles and long tubular nanocapsules attached to a rigid, thin (less than 1 μm) nanoporous anodic alumina membrane is fabricated by simple, fast, catalyst-free, environmentally friendly voltage-pulse anodization. A growth mechanism is proposed based on the formation of straight channels in alumina membrane by anodization, followed by neck formation due to a sophisticated voltage control during the process. This process can be used for the fabrication of alumina nanocontainers with highly controllable geometrical size and volume, vitally important for various applications such as material and energy storage, targeted drug and diagnostic agent delivery, controlled drug and active agent release, gene and biomolecule reservoirs, micro-biologically protected platforms, nano-bioreactors, tissue engineering and hydrogen storage.

  14. Characterisation and testing of a prototype $6 \\times 6$ cm$^2$ Argonne MCP-PMT

    CERN Document Server

    Cowan, Greig A; Needham, Matthew; Gambetta, Silvia; Eisenhardt, Stephan; McBlane, Neil; Malek, Matthew

    2016-01-01

    The Argonne micro-channel plate photomultiplier tube (MCP-PMT) is an offshoot of the Large Area Pico-second Photo Detector (LAPPD) project, wherein \\mbox{6 $\\times$ 6 cm$^2$} sized detectors are made at Argonne National Laboratory. Measurements of the properties of these detectors, including gain, time and spatial resolution, dark count rates, cross-talk and sensitivity to magnetic fields are reported. In addition, possible applications of these devices in future neutrino and collider physics experiments are discussed.

  15. Evaluating the potential of IP-10 and MCP-2 as biomarkers for the diagnosis of TB

    DEFF Research Database (Denmark)

    Ruhwald, Morten; Bodmer, T; Maier, C;

    2008-01-01

    were obtained from 80 patients with culture and/or PCR proven TB, and 124 unexposed healthy controls; 86 high school students and 38 high school staff. IP-10 and MCP-2 test cut-offs were established based on ROC curve analysis.TB patients produced significantly higher levels of IP-10 (median 2158 pg......-gamma may be a simple approach to increase the detection rate of the M.tuberculosis specific in-vitro tests....

  16. State of art report for high temperature wear test of SMART MCP and CEDM bearing material

    Energy Technology Data Exchange (ETDEWEB)

    Cho, Yong Hu; Lee, Jae Seon; Park, Jin Seok; Kim, Ji Ho; Kim, Jong In

    2000-03-01

    Wear resistance properties of machine elements has been more critical in view of its significant effect on life extension, economics and material saving because it has been recognized that nearly 80 percent of damages of mechanical elements in the friction pairs are due to the material loss by wear. And wear properties have direct influence on the life of a machine in a great extend under extremely severe operating condition. Therefore highly improved wear properties of machine elements operating in such circumstances is heavily required. The purpose of this report is to survey current technology for high temperature wear test in order to establish the test plan for the life evaluation of SMART MCP and CEDM bearing materials. Friction and wear test will be done under high pressure (170 MPa) and high temperature (350 degree C) with water as lubricant to simulate the operating condition of the nuclear power reactor. Because pump type for MCP is selected as the caned motor pump which needs no mechanical sealing, the rotating shaft on which bearing is fully submerged by main coolant with high temperature. So MCP bearing operates without additional lubricant. CEDM is adopted as the ball-screw type with fine controllability. So the driving part is designed as the immersed-in type by main coolant. Therefore the anti-wear and reliability of driving parts are much consequent to guarantee the lifetime and the safety of the whole system. Tribometer adapted to high temperature and pressure circumstance is needed to execute bearing material testing. Test parameters are material, sliding speed, sliding distance and applied load. In order to identify the wear mechanism, optical microscope and surface roughness testers are required. The result of this report will provide an elementary data to develop bearing materials and to estimate bearing lifetime for the bearings of MCP and CEDM in SMART. (author)

  17. ELENA MCP detector: absolute efficiency measurement for low energy neutral atoms

    Science.gov (United States)

    Rispoli, R.; De Angelis, E.; Colasanti, L.; Vertolli, N.; Orsini, S.; Scheer, J.; Mura, A.; Milillo, A.; Wurz, P.; Selci, S.; Di Lellis, A. M.; Leoni, R.; D'Alessandro, M.; Mattioli, F.; Cibella, S.

    2012-04-01

    MicroChannel plates (MCP) detectors are frequently used in space instrumentation for detecting a wide range of radiation and particles. In particular, the capability to detect non-thermal low energy neutral species is crucial for the sensor ELENA (Emitted Low-Energy Neutral Atoms), part of the package SERENA (Search for Exospheric Refilling and Emitted Natural Abundances) on board the BepiColombo mission to Mercury to be launched in 2014. ELENA is a TOF sensor, based on a novel concept ultra-sonic oscillating shutter (Start section)which is operated at frequencies up to 50 kHz; a MCP detector is used as a Stop section. It is aimed to detect neutral atoms in the range 10 eV - 5 keV, within 70° FOV, perpendicular to the S/C orbital plane. ELENA will monitor the emission of neutral atoms from the whole surface of Mercury thanks to the spacecraft motion. The major scientific objectives are the interaction between the environment and the planet, the global particle loss-rate and the remote sensing of the surface properties. In particular, surface release processes are investigated by identifying particles release from the surface, via solar wind-induced ion sputtering (100 eV) as well as Hydrogen back-scattered at hundreds eV. MCP absolute detection efficiency for very low energy neutral atoms (EMEFISTO facility of the Physical Institute of University of Bern (CH), measurements on three different type of MCPs coating have been performed providing the behaviors of MCP detection efficiency in the range 10eV-1keV. Outcomes from such measurements are here discussed.

  18. Development and tests of MCP based timing and multiplicity detector for MIPs

    Science.gov (United States)

    Feofilov, G.; Kondratev, V.; Stolyarov, O.; Tulina, T.; Valiev, F.; Vinogradov, L.

    2017-01-01

    We present summary of technological developments and tests of the MCP based large area detector aimed at precise timing and charged particles multiplicity measurements. Results obtained in course of these developments of isochronous (simultaneity) precise signal readout, passive summation of 1 ns signals, fast (1 GHz) front-end electronics, miniature vacuum systems, etc. could be potentially interesting for a number of future applications in different fields.

  19. Study on Fresh-keeping of Strawberry by Using 1-MCP-β-cyclodextrin%1-MCP-β-环糊精对草莓保鲜的应用研究

    Institute of Scientific and Technical Information of China (English)

    何飞

    2011-01-01

    研究了在7 m3密闭体积中用10 mg.L-1 1-MCP-β-环糊精溶液对草莓的保鲜效果。分别测定贮存过程中草莓的感官指标、失重率、总酸含量、可溶性糖含量及维生素C含量含量的变化。结果表面1-MCP-β-环糊精保鲜效果良好。%The effect of 1-MCP-β-cyclodextrin on the preservation of strawberry was studied.The changes in the organoleptic target,weight-loss rate,total acid,content of soluble saccharide and the content of the vitamin C of strawberry were determined during storage.The result indicated that the preservative effect of 1-MCP-β-cyclodextrin was remarkable.

  20. Influence of TAC on Dispersion of Aqueous Nano Alumina Suspension

    Institute of Scientific and Technical Information of China (English)

    ZHAO Wei; YANG De-an; SONG Jian-jing; YANG Zi; LIANG Chong; XU Ming-xia; XU Ting-xian

    2004-01-01

    The stability of aqueous nano alumina powder suspensions with and without dispersant tri-ammonium citrate (TAC) was investigated by measuring zeta potential at different pH values. The isoelectric point (IEP) of alumina powder shifts towards more acidic pH range by adding TAC dispersant. The results illustrate that adsorption of TAC on alumina powder surface existed in the aqueous suspension, which leads to a high stability of the suspension.

  1. Novel self assembly behavior for γ-alumina nanoparticles

    Institute of Scientific and Technical Information of China (English)

    Osama Saber

    2012-01-01

    In this study,self assembly behavior was induced for γ-alumina nanoparticles by adsorption of dimethyl disulfide.Following this trend,we have developed a chemical process to obtain γ-alumina in the nano scale.Scanning electron microscopy images of the prepared γ-alumina showed big and strong agglomeration of the nanoparticles indicating that these nanoparticles have strong surface forces.Transmission electron microscopy images confirmed that the γ-alumina nanoparticles 3-7 nm in size were converted to uniform spherical shape in the size range of 1-2 mm after shaking with dimethyl disulfide in the presence of n-hexane at room temperature.This phenomenon did not appear in the case of alumina in the micro scale.The surface properties of the prepared γ-alumina in the nano scale were characterized and compared with the γ-alumina in the micro scale by using low temperature nitrogen adsorption-desorption system,indicating that the specific surface area of the prepared γ-alumina nanoparticles is larger than that of the γ-alumina in the micro scale.Furthermore,micro-and meso-pores were observed for the γ-alumina nanoparticles while only mesoporous structure was detected for the γ-alumina in the micro scale.These experimental results suggested that the self assembly behavior of the γ-alumina nanoparticles may be due to the selective adsorption of dimethyl disulfide in the micropores of these nanoparticles to act as bridge linking the nanoparticles.

  2. DNA typing by capillary electrophoresis

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, N.

    1997-10-08

    Capillary electrophoresis is becoming more and more important in nucleic acid analysis including DNA sequencing, typing and disease gene measurements. This work summarized the background of DNA typing. The recent development of capillary electrophoresis was also discussed. The second part of the thesis showed the principle of DNA typing based on using the allelic ladder as the absolute standard ladder in capillary electrophoresis system. Future work will be focused on demonstrating DNA typing on multiplex loci and examples of disease diagnosis in the on-line format of PCR-CE. Also capillary array electrophoresis system should allow high throughput, fast speed DNA typing. Only the introduction and conclusions for this report are available here. A reprint was removed for separate processing.

  3. Selectivity in capillary electrokinetic separations

    NARCIS (Netherlands)

    de Zeeuw, R.A; de Jong, G.J.; Ensing, K

    1999-01-01

    This review gives a survey of selectivity modes in capillary electrophoresis separations in pharmaceutical analysis and bioanalysis. Despite the high efficiencies of these separation techniques, good selectivity is required to allow quantitation or identification of a Chemistry and Toxicology, parti

  4. Neutron Imager and Flux Monitor Based on Micro Channel Plates (MCP) in Electrostatic Mirror Configuration

    Science.gov (United States)

    Variale, V.

    In this paper, a new high transparency device based on MCP for the monitoring the flux and spatial profile of a neutron beam will be described. The assembly consists of a carbon foil with a 6Li deposit, placed in the beam, and a MCP equipped with a phosphor screen readout viewed by a CCD camera, placed outside the beam. Secondary emitted electrons (SEE) produced in the carbon foil by the alpha-particles and tritons from the 6Li+n reaction, are deflected to the MCP detector by means of an electrostatic mirror, suitably designed to preserve the spatial resolution. The conductive layer on the phosphor can be used for neutron counting, and to obtain time-of-flight information. A peculiar feature of this device is that the use of an electrostatic mirror minimizes the perturbation of the neutron beam, i.e. absorption and scattering. It can be used at existing time-of-flight (TOF) facilities, in particular at the n_TOF facility at CERN, for monitoring the flux and special profile of the neutron beam in the thermal and epithermal region. In this work, the device principle and design will be presented, together with the main features in terms of resolution and neutron detection efficiency.

  5. Corrosion of Refractory Alumina-Graphite and Alumina-Graphite-Zirconia in Slag Containing Titania

    Institute of Scientific and Technical Information of China (English)

    XU Yuan; LIU Qing-cai; BAI Chen-guang; CHEN Deng-fu; Joseph W Newkirk

    2004-01-01

    The corrosion of refractory alumina-graphite and alumina-graphite-zirconia in the slag containing titania was studied by immersion tests (quasi-static and dynamic tests). Combining direct observation with microscopic investigations, a mechanism for corrosion was proposed based on the oxidation of graphite and the dissolution of refractory components. During the corrosion process, there are some special phenomena and laws that can be explained by the relation between the corrosion rate and the TiO2 mass percent, the rotational refractory velocity and the morphology of the deteriorated layer.

  6. Aqueous combustion synthesis and characterization of zirconia-alumina nanocomposites

    Energy Technology Data Exchange (ETDEWEB)

    Kishan, J.; Mangam, Venu; Reddy, B.S.B.; Das, Siddhartha [Department of Metallurgical and Materials Engineering, Indian Institute of Technology, Kharagpur, West Bengal 721302 (India); Das, Karabi, E-mail: karabi@metal.iitkgp.ernet.i [Department of Metallurgical and Materials Engineering, Indian Institute of Technology, Kharagpur, West Bengal 721302 (India)

    2010-02-04

    The zirconia-alumina nanocomposite powders with 3-48 mol% of alumina are prepared by aqueous combustion synthesis technique using stoichiometric amounts of aluminium nitrate, zirconyl nitrate and glycine. The nanopowders are compacted uniaxially and sintered at 1000 {sup o}C temperature in a muffle furnace. Thermodynamic modeling of the combustion reaction shows that, as the alumina content increases, the amount of gases produced increases with a decrease in the adiabatic flame temperature. The green and sintered densities of cold press composite powders decrease with an increase in the mol% of alumina.

  7. Rheology of Alumina-Based Graphite-Containing Castables

    Institute of Scientific and Technical Information of China (English)

    YE Fangbao; M. Rigaud; LIU Xinhong; ZHONG Xiangchong

    2005-01-01

    In this work, the rheological behavior of ultra-low cement alumina-based castables with addition of flake graphite and extruded graphite pellets has been investigated by using IBB rheometer. Emphasis has been laid on the influence of the type and amount of carbon addition on rheological properties of the alumina-based castables and the results are compared with corresponding alumina castable samples without any carbon addition. It is found that alumina-based castables with extruded graphite pellets have good rheological behavior and flowability with lower water demand ( < 6. 3% )and no segregation during the shearing of castable.

  8. Modelling the initial stage of porous alumina growth during anodization

    Science.gov (United States)

    Aryslanova, E. M.; Alfimov, A. V.; Chivilikhin, S. A.

    2013-05-01

    Artificially on the surface of aluminum there may be build a thick layer of Al2O3, which has a porous structure. In this paper we present a model of growth of porous alumina in the initial stage of anodizing, identifying dependencies anodizing parameters on the rate of growth of the film and the distance between the pores and as a result of the created model equations were found for changes in the disturbance of alumina for the initial stage of anodizing aluminum oxide porous border aluminum-alumina and alumina-electrolyte, with the influence of surface diffusion of aluminum oxide.

  9. Non-myeloid Cells are Major Contributors to Innate Immune Responses via Production of Monocyte Chemoattractant Protein- 1(MCP-1/CCL2

    Directory of Open Access Journals (Sweden)

    Teizo eYoshimura

    2014-01-01

    Full Text Available Monocyte chemoattractant protein-1 (MCP-1/CCL2 is a chemokine regulating the recruitment of monocytes into sites of inflammation and cancer. MCP-1 can be produced by a variety of cell types, such as macrophages, neutrophils, fibroblasts, endothelial cells and epithelial cells. Notably, macrophages produce high levels of MCP-1 in response to proinflammatory stimuli in vitro, leading to the hypothesis that macrophages are the major source of MCP-1 during inflammatory responses in vivo. In stark contrast to the hypothesis, however, there was no significant reduction in MCP-1 protein or the number of infiltrating macrophages in the peritoneal inflammatory exudates of myeloid cell-specific MCP-1-deficient mice in response to i.p injection of thioglycollate or zymosan A. Furthermore, injection of LPS into skin air pouch also had no effect on local MCP-1 production in myeloid-specific MCP-1-deficient mice. Finally, myeloid-specific MCP-1-deficiency did not reduce MCP-1 mRNA expression or macrophage infiltration in LPS-induced lung injury. These results indicate that non-myeloid cells, in response to a variety of stimulants, play a previously unappreciated role in innate immune responses as the primary source of MCP-1.

  10. Pattern recognition of monocyte chemoattractant protein-1 (MCP-1) in whole blood samples using new platforms based on nanostructured materials

    Science.gov (United States)

    Stefan-van Staden, Raluca-Ioana; Gugoasa, Livia Alexandra; Biris, Alexandru Radu

    2015-09-01

    Four stochastic microsensors based on nanostructured materials (graphene, maltodextrin (MD), and diamond) integrated in miniaturized platforms were proposed. Monocyte chemoattractant protein-1 (MCP-1) is a pro-inflammatory cytokine whose main function is to regulate cell trafficking. It is correlated with the incidence of cardiovascular diseases and obesity, and was used as the model analyte in this study. The screening of whole blood samples for MCP-1 can be done for concentrations ranging from 10-12 to 10-8 g mL-1. The method was used for both qualitative and quantitative assessments of MCP-1 in whole blood samples. The lowest quantification limits for the assay of MCP-1 (1 pg mL-1) were reached when the microsensors based on protoporphyrin IX/Graphene-Au-3 and on MD/Graphene were employed in the platform design.

  11. Effect of pharmacological intervention on MIP-1α, MIP-1β and MCP-1 expression in patients with psoriasis vulgaris

    Institute of Scientific and Technical Information of China (English)

    Yong-Jiang Dai; Yu-Yang Li; Hui-Ming Zeng; Xiong-An Liang; Zhi-Jie Xie; Zhi-Ang Zheng; Qin-Hui Pan; Yi-Xiong Xing

    2014-01-01

    Objective:To detect the expression level of macrophage inflammatory protein-1(MIP-1)α, MIP-1β and monocyte chemoattractant protein-1(MCP-1) in with psoriasis vulgaris and explore the role in the pathogenesis of psoriasis vulgaris.Methods:The level ofMIP-1α,MIP-1β andMCP-1 in peripheral blood from50 patients with psoriasis vulgaris and50 normal controls were measured by enzyme linked immunosorbent assay.The correlation with psoriasis area and severity index(PASI) was analyzed.The level ofMIP-1α,MIP-1β andMCP-1 was compared between psoriasis vulgaris patients at active stage and resting stage.And the change inMIP-1α, MIP-1β andMCP-1 before and after therapy was also observed.Results:The content ofMIP-1α, MIP-1β andMCP-1 in patients with psoriasis vulgaris was(1342.78±210.30),(175.28±28.18) and (266.86±32.75) ng/L, respectively, significantly higher than those in control group(P<0.05).The expression level ofMIP-1α,MIP-1β andMCP-1 in peripheral blood of patients with psoriasis vulgaris was positively correlated withPASI(P<0.01).After acitretin therapy, expression level ofMIP-1α,MIP-1β andMCP-1 in peripheral blood of patients with psoriasis vulgaris was significantly decreased.Conclusions:Chemokine factorMIP-1α,MIP-1β andMCP-1 may be involved in the pathogenesis of psoriasis vulgaris.

  12. Two-dimensional capillary electrophoresis using tangentially connected capillaries.

    Science.gov (United States)

    Sahlin, Eskil

    2007-06-22

    A novel type of fused silica capillary system is described where channels with circular cross-sections are tangentially in contact with each other and connected through a small opening at the contact area. Since the channels are not crossing each other in the same plane, the capillaries can easily be filled with different solutions, i.e. different solutions will be in contact with each other at the contact point. The system has been used to perform different types of two-dimensional separations and the complete system is fully automated where a high voltage switch is used to control the location of the high voltage in the system. Using two model compounds it is demonstrated that a type of two-dimensional separation can be performed using capillary zone electrophoresis at two different pH values. It is also shown that a compound with acid/base properties can be concentrated using a dynamic pH junction mechanism when transferred from the first separation to the second separation. In addition, the system has been used to perform a comprehensive two-dimensional capillary electrophoresis separation of tryptic digest of bovine serum albumin using capillary zone electrophoresis followed by micellar electrokinetic chromatography.

  13. 牙龈卟啉单胞菌侵入对人血管内皮细胞分泌MCP-1影响的研究%Expression of MCP-1 in vascular endothelial cells invaded by Porphyromonas gingivalis

    Institute of Scientific and Technical Information of China (English)

    邓辉; 徐静; 余溢; 欧阳玉玲; 吴亚菲

    2012-01-01

    目的 通过研究牙龈卟啉单胞菌(porphyrmonas gingivalis,P.g)侵入对人脐静脉内皮细胞(human umbilical vein endothelial cell,HUVEC)分泌单核细胞趋化蛋白(MCP-1)的影响,了解P.g对其趋化功能的影响.方法 建立P,g侵入HUVEC的体外模型,采用酶联免疫吸附法( ELISA)研究P.g381和P.g33277菌株侵入HUVEC 6、24 h后的培养上清液中MCP -1浓度.结果 ELISA结果显示当P.g381侵入HUVEC 6、24h和P.g33277侵入HUVEC 6 h时,HUVEC分泌的MCP -1水平升高(P<0.01);P,g33277侵入HUVEC 24 h时,HUVEC分泌的MCP -1水平恢复最初水平(P=0.46);P.g381诱导HUVEC表达MCP -1的水平高于P.g33277 (P <0.01).结论 P.g侵入HUVEC后可促进其表达MCP -1,从而上调其趋化功能,在牙周炎与心血管疾病的相关性中可能发挥作用.%Objective To investigate the expression of monocyte chemoattractanl protein-1 (MCP-1) in human umbilical vein endo-thetial cells ( HUVEC) invaded by porphyrroonas gingivalis (P. g). Methods The models of invasion of P. g into HUVEC were established in vitro. HUVEC were infected with either P. g381 or P. g33277 .then the expression of MCP-1 in supernatant was tested by ELISA. Results The expression of MCP-1 was signicantly upregulated in P. g381 -infected HUVEC at 6h and 24h and in P. g33277-infecled HUVEC at 6h{ P<0.01). The upregulalion ability of P.g381 was significantly greater than P. g33277(P<0.01). Conclusions These data demonstrate that the infection of P. g can increase the expression of MCP-1 and chemolactic function of HDVEC, which may play a role in the relationship between periodontitis and cardiovascular diseases.

  14. Nanotube Arrays in Porous Anodic Alumina Membranes

    Institute of Scientific and Technical Information of China (English)

    Liang LI; Naoto KOSHIZAKI; Guanghai LI

    2008-01-01

    This review summarizes the various techniques developed for fabricating nanotube arrays in porous anodic alumina membranes (AAMs). After a brief introduction to the fabrication process of AAMs, taking carbons, metals, semiconductors, organics, biomoleculars, and heterojunctions as typical examples, attention will be focused on the recently established methods to fabricate nanotubes in AAM, including electrochemical deposition, surface sol-gel, modified chemical vapor deposition, atomic layer deposition, and layer-by-layer growth. Every method is demonstrated by one or two reported results. Finally, this review is concluded with some perspectives on the research directions and focuses on the AAM-based nanotubes fields.

  15. Anisotropic shrinkage characteristics of tape cast alumina

    Science.gov (United States)

    Patwardhan, Jaideep Suresh

    Dimensional control during sintering is a major issue in ceramics processing to avoid high post-sintering costs associated with machining of the fired ceramic part to desired tolerances and dimensions. Ceramic forming processes such as tape casting, injection molding, and extrusion involve shear of anisotropic particles resulting in preferential alignment of the particles in the green body. This preferential alignment causes directionality in mechanical, electrical, optical, and magnetic properties and most importantly warpage or distortion during sintering. A large effort has been devoted to synthesizing ceramic green bodies with minimal density gradients and uniform packing and modeling the sintering behavior evolution but little effort has been devoted to characterizing orientation of particles and the effect of preferential alignment on sintering shrinkage anisotropy. A systematic study was initiated to study the effect of processing variables such as shear rate, solids loading, temperature, and binder content on aqueous tape cast alumina. Three different alumina systems: A16-SG, Baikowski RC-UFX DBM and RC-LS DBM were investigated. Aqueous tapes of high solids loading alumina (56 vol. %) were tape cast at various speeds and thicknesses and assuming plane Couette flow a shear rate regime of 21--270 s-1 was investigated. Higher shear rates and high solids loading resulted in higher in-plane anisotropy whereas the anisotropy in the thickness direction was higher for low solids loading systems. The anisotropy was found to be fairly constant above a certain critical shear rate (˜100 s-1) irrespective of the temperature and the solids loading and this correlated with the viscosity-shear rate relationship of the cast slips. The higher shrinkage anisotropy in the thickness direction for the low solids loading systems (35 and 45 vol. %) was attributed to the higher amount of organics in the slip required to sustain the suitable viscosity for tape casting and

  16. NMR Revealed Activated Alumina-Water Interaction

    Institute of Scientific and Technical Information of China (English)

    ZHOU Rui; ZHOU Yan; HU Kai; JI Zhen-ping; CHENG Gong-zhen

    2005-01-01

    Three different spin-lattice relaxation times (T1) of water were obtained in activated alumina-water slurry system, which indicate that there exist three states of water: bound water, pore water and bulk water. The chemical shift (δH) decreases as the amount of water added to the system increases due to the differences in contribution of these three states of water in the samples. The δH value for adsorbed water decreases nearly linearly and T1 increases with elevating temperature, which result from the decrease in the content of bound water by the increase in thermal motion.

  17. Chemical modification/grafting of mesoporous alumina with polydimethylsiloxane (PDMS)

    NARCIS (Netherlands)

    Pinheiro de Melo, A.F.; Nijmeijer, A.; Sripathi, V.G.P.; Winnubst, A.J.A.

    2015-01-01

    A method for polydimethylsiloxane grafting of alumina powders is described which involves chemical modification of the surface of mesoporous (5 nm) γ-alumina flakes with a linker (3-aminopropyltriethoxysilane: APTES), either by a solution phase (SPD) or a vapour phase (VPD) reaction, followed by PDM

  18. Development of Reproducing Alumina-Magnesia-Carbon Bricks

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    The reproducing alumina-magnesia-carbon bricks were prepared with the dumped bricks as starting materials. The bulk density, apparent porosity, crushing strength, modolus of rupture and slag resistance of the specimen were analyzed. The results show that the used refractories can be reused and recycled by the right method. The reproducing alumina-magnesia-carbon bricks with better abilities were prepared.

  19. Textural stability of titania–alumina composite membranes

    NARCIS (Netherlands)

    Kumar, Krishnankutty-Nair P.; Keizer, Klaas; Burggraaf, Anthonie J.

    1993-01-01

    Textural evolution (porosity reduction, pore and crystallite growth) in titania–alumina composite membranes has been studied using thermal analysis, X-ray diffraction, field emission scanning electron microscopy and N2 physisorption techniques. The presence of alumina in the membranes improved the t

  20. 21 CFR 73.1010 - Alumina (dried aluminum hydroxide).

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 1 2010-04-01 2010-04-01 false Alumina (dried aluminum hydroxide). 73.1010 Section 73.1010 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES GENERAL LISTING OF COLOR ADDITIVES EXEMPT FROM CERTIFICATION Drugs § 73.1010 Alumina (dried...

  1. Dynamic compressive and tensile strengths of spark plasma sintered alumina

    Science.gov (United States)

    Girlitsky, I.; Zaretsky, E.; Kalabukhov, S.; Dariel, M. P.; Frage, N.

    2014-06-01

    Fully dense submicron grain size alumina samples were manufactured from alumina nano-powder using Spark Plasma Sintering and tested in two kinds of VISAR-instrumented planar impact tests. In the first kind, samples were loaded by 1-mm tungsten impactors, accelerated to a velocity of about 1 km/s. These tests were aimed at studying the Hugoniot elastic limit (HEL) of Spark Plasma Sintering (SPS)-processed alumina and the decay, with propagation distance, of the elastic precursor wave. In the tests of the second kind, alumina samples of 3-mm thickness were loaded by 1-mm copper impactors accelerated to 100-1000 m/s. These tests were aimed at studying the dynamic tensile (spall) strength of the alumina specimens. The tensile fracture of the un-alloyed alumina shows a monotonic decline of the spall strength with the amplitude of the loading stress pulse. Analysis of the decay of the elastic precursor wave allowed determining the rate of the irreversible (inelastic) strains in the SPS-processed alumina at the initial stages of the shock-induced inelastic deformation and to clarify the mechanisms responsible for the deformation. The 1-% addition of Cr2O3 decreases the HEL of the SPS-processed alumina by 5-% and its spall strength by 50% but barely affects its static properties.

  2. 40 CFR 721.10120 - Siloxane modified alumina nanoparticles (generic).

    Science.gov (United States)

    2010-07-01

    ... nanoparticles (generic). 721.10120 Section 721.10120 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... Specific Chemical Substances § 721.10120 Siloxane modified alumina nanoparticles (generic). (a) Chemical... as siloxane modified alumina nanoparticles (PMN P-05-687) is subject to reporting under this...

  3. Thermal Shock Behaviour of Alumina-Iron Composites

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    Thermal shock behaviour was investigated for two morphologically different composites comprising an alumina matrix and 20 vol. pct Fe particles for a wide range of quenching temperature differences (△T=100~800°C) and compared to a monolithic alumina. The retained strength and critical quenching temperature difference, △Tc, of the two composites were a significant improvement over the values for the respective monolithic alumina. Crack lengths and densities were shown to be greater for the alumina than for the two composites at all quenching temperature differences. The thermal shock resistance parameters for monolithic alumina and the two composites were calculated according to their mechanical and physical properties. The calculated results agree well with the experimental one and indicate possible explanations for the differences in thermal shock behaviour.

  4. Comparison of deep desulfurization methods in alumina production process

    Institute of Scientific and Technical Information of China (English)

    刘战伟; 李旺兴; 马文会; 尹中林; 武国宝

    2015-01-01

    Several methods of deep desulfurization in alumina production process were studied, and the costs of these methods were compared. It is found that most of the S2− in sodium aluminate solution can be removed by adding sodium nitrate or hydrogen peroxide in digestion process, and in this way the effect of S2− on alumina product quality is eliminated. However, the removal efficiency of2-23SOin sodium aluminate solution is very low by this method. Both S2− and2-23SO in sodium aluminate solution can be removed completely by wet oxidation method in digestion process. The cost of desulfurization by wet oxidation is lower than by adding sodium nitrate or hydrogen peroxide. The results of this research reveal that wet oxidation is an economical and feasible method for the removal of sulfur in alumina production process to improve alumina quality, and provide valuable guidelines for alumina production by high-sulfur bauxite.

  5. Morphology and transmittance of porous alumina on glass substrate

    Energy Technology Data Exchange (ETDEWEB)

    Guo Peitao, E-mail: guopeitao@hotmail.com [Wuhan University of Technology. Wuhan (China); Xia Zhilin [Wuhan University of Technology. Wuhan (China); Key Laboratory of Low Dimensional Materials and Application Technology, Xiangtan University, Ministry of Education, Xiangtan (China); Xue Yiyu [Wuhan University of Technology. Wuhan (China); Huang Caihua [China Three Gorges University, Yichang (China); Zhao Lixin [Wuhan University of Technology. Wuhan (China)

    2011-02-01

    The porous optical film has higher threshold of laser-induced damage than densified films, for the study of mechanism of laser-induced damage of porous optical film with ordered pore structure. Porous anodic alumina (PAA) film with high transmittance on glass substrate has been prepared. Aluminum film was deposited on glass substrate by means of resistance and electron beam heat (EBH) evaporation. Porous alumina was prepared in oxalic acid solution under different anodizing conditions. At normal incidence, the optical transmittance spectrum over 300-1000 nm spectra region was obtained by spectrophotometer. SEM was introduced to analysis the morphology of the porous alumina film. The pore aperture increased with the increase of anodizing voltage, which resulted in a rapid decrease of the pore concentration and the optical thickness of porous alumina film. Damage morphology of porous alumina film is found to be typically defects initiated, and the defect is the pore presented on the film.

  6. Thermal Conductivity of Alumina-reinforced Zirconia Composites

    Science.gov (United States)

    Bansal, Narottam P.

    2005-01-01

    10-mol% yttria-stabilized zirconia (10SZ) - alumina composites containing 0-30 mol% alumina were fabricated by hot pressing at 1500 C in vacuum. Thermal conductivity was determined at various temperatures using a steady-state laser heat flux technique. Thermal conductivity of the composites increased with increase in alumina content. Composites containing 0, 5, and 10-mol% alumina did not show any change in thermal conductivity with temperature. However, those containing 20 and 30-mol% alumina showed a decrease in thermal conductivity with increase in temperature. The measured values of thermal conductivity were in good agreement with those calculated from the Maxwell-Eucken model where one phase is uniformly dispersed within a second major continuous phase.

  7. Crosstalk between Tumor Cells and Macrophages in Stroma Renders Tumor Cells as the Primary Source of MCP-1/CCL2 in Lewis Lung Carcinoma

    Directory of Open Access Journals (Sweden)

    Teizo eYoshimura

    2015-06-01

    Full Text Available The chemokine MCP-1/CCL2 is produced by a variety of tumors and plays an important role in cancer progression. We and others previously demonstrated that the primary source of MCP-1 in several mouse tumors, including 4T1 breast cancer, M5076 sarcoma and B16 melanoma, was stromal cells. In the present study, we identified that tumor cells were the primary source of MCP-1 in Lewis lung carcinoma (LLC, because MCP-1 mRNA was highly expressed in tumors grown in both WT and MCP-1-/- mice with elevated serum MCP-1 levels. Since LLC cells isolated from tumors expressed low levels of MCP-1 in vitro, it appeared that the tumor-stromal cell interaction in a tumor microenvironment increased MCP-1 expression in LLC cells. In fact, co-culture of LLC cells with normal mouse peritoneal macrophages or normal lung cells containing macrophages increased MCP-1 expression by LLC cells. Macrophages from TNFα-/- mice failed to activate LLC cells and anti-TNFα neutralizing antibody abolished the effect of WT macrophages on LLC cells. When LLC cells were transplanted into TNFα-/- mice, the levels of MCP-1 mRNA in tumors and serum MCP-1 levels were markedly lower as compared to WT mice, and importantly tumors grew more slowly. Taken together, our results indicate that TNFα released by tumor cell-activated macrophages is critical for increased MCP-1 production by tumors cells. Thus, disruption of tumor-stromal cell interaction may inhibit tumor progression by reducing the production of tumor-promoting proinflammatory mediators, such as MCP-1.

  8. Crosstalk between Tumor Cells and Macrophages in Stroma Renders Tumor Cells as the Primary Source of MCP-1/CCL2 in Lewis Lung Carcinoma.

    Science.gov (United States)

    Yoshimura, Teizo; Liu, Mingyong; Chen, Xin; Li, Liangzhu; Wang, Ji Ming

    2015-01-01

    The chemokine MCP-1/CCL2 is produced by a variety of tumors and plays an important role in cancer progression. We and others previously demonstrated that the primary source of MCP-1 in several mouse tumors, including 4T1 breast cancer, M5076 sarcoma, and B16 melanoma, was stromal cells. In the present study, we identified that tumor cells were the primary source of MCP-1 in Lewis lung carcinoma (LLC), because MCP-1 mRNA was highly expressed in tumors grown in both wild type (WT) and MCP-1(-/-) mice with elevated serum MCP-1 levels. Since LLC cells isolated from tumors expressed low levels of MCP-1 in vitro, it appeared that the tumor-stromal cell interaction in a tumor microenvironment increased MCP-1 expression in LLC cells. In fact, co-culture of LLC cells with normal mouse peritoneal macrophages or normal lung cells containing macrophages increased MCP-1 expression by LLC cells. Macrophages from TNFα(-/-) mice failed to activate LLC cells and anti-TNFα neutralizing antibody abolished the effect of WT macrophages on LLC cells. When LLC cells were transplanted into TNFα(-/-) mice, the levels of MCP-1 mRNA in tumors and serum MCP-1 levels were markedly lower as compared to WT mice, and importantly, tumors grew more slowly. Taken together, our results indicate that TNFα released by tumor cell-activated macrophages is critical for increased MCP-1 production by tumors cells. Thus, disruption of tumor-stromal cell interaction may inhibit tumor progression by reducing the production of tumor-promoting proinflammatory mediators, such as MCP-1.

  9. Impacts on oil recovery from capillary pressure and capillary heterogeneities

    Energy Technology Data Exchange (ETDEWEB)

    Bognoe, Thomas

    2008-07-01

    The main conclusions drawn from this thesis are; 7 scientific papers are published on a broad variety of subjects, and describes in detail the experiments and research treated in this thesis. Scientific research has been performed, investigating the subjects of capillary pressure and capillary heterogeneities from different angles. This thesis discusses the findings in this study and aims to illustrate the benefits of the results obtained for further development of other experiments, and/or even the industrial benefits in field development. The methods for wettability alteration have developed throughout the work. From producing heterogeneous wettability alterations, the methods have improved to giving both radial and lateral uniform wettability alterations, which also remains unaltered throughout the duration of the experimental work. The alteration of wettability is dependent on initial water saturation, flow rate, aging time and crude oil composition. Capillary pressure and relative permeability curves have been measured for core plugs at different wettabilities using conventional centrifuge methods. The trends observed are mostly consistent with theory. The production mechanisms of strongly and moderately water wet chalk has been investigated. At strongly water wet conditions in fractured chalk; the flow is governed by capillary forces, showing strong impact from the fractures. At moderately water wet conditions, the impact of the fractures are absent, and a dispersed water front is observed during the displacement. The oil recovery is about the same, at the two wettabilities. Fracture crossing mechanisms at the same wettability conditions have been mapped. And the observations are consistent with those of the water floods. During strongly water wet displacement, the fracture crossing is occurring once the inlet core has reached endpoint of spontaneous imbibition. At moderately water wet conditions the fracture crossing is less abrupt, and creation of wetting

  10. Non-Aqueous Capillary Electrophoresis

    Science.gov (United States)

    Szumski, Michał; Buszewski, Bogusław

    Non-aqueous capillary electrophoresis and capillary electrochromatography are special variants of these techniques. Here, organic solvents or their mixtures with or without dissolved electrolytes are used as separation buffer or mobile phase, respectively. The most important features of non-aqueous systems are: better solubility of more hydrophobic ionic substances (many natural products) than in water, much less current and Joule heating allows for using highly concentrated buffers and/or larger capillary internal diameters, polar interactions are enhanced in organic solvents which is often highly advantageous in chiral separation systems. This chapter presents most frequently used solvents, their properties, as well as shows pH* scale which is often used in non-aqueous systems.

  11. Capillary imbibition in parallel tubes

    Science.gov (United States)

    McRae, Oliver; Ramakrishnan, T. S.; Bird, James

    2016-11-01

    In modeling porous media two distinct approaches can be employed; the sample can be examined holistically, using global variables such as porosity, or it can be treated as a network of capillaries connected in series to various intermediate reservoirs. In forced imbibition this series-based description is sufficient to characterize the flow, due to the presence of an externally maintained pressure difference. However, in spontaneous imbibition, flow is driven by an internal capillary pressure, making it unclear whether a series-based model is appropriate. In this talk, we show using numerical simulations the dynamics of spontaneous imbibition in concentrically arranged capillary tubes. This geometry allows both tubes access to a semi-infinite reservoir but with inlets in close enough proximity to allow for interference. We compare and contrast the results of our simulations with theory and previous experiments. Schlumberger-Doll Research.

  12. ELENA MCP detector: absolute detection efficiency for low-energy neutral atoms

    Science.gov (United States)

    Rispoli, R.; De Angelis, E.; Colasanti, L.; Vertolli, N.; Orsini, S.; Scheer, J. A.; Mura, A.; Milillo, A.; Wurz, P.; Selci, S.; Di Lellis, A. M.; Leoni, R.; D'Alessandro, M.; Mattioli, F.; Cibella, S.

    2012-09-01

    Microchannel Plates (MCP) detectors are frequently used in space instrumentation for detecting a wide range of radiation and particles. In particular, the capability to detect non-thermal low energy neutral species is crucial for the sensor ELENA (Emitted Low-Energy Neutral Atoms), part of the package SERENA (Search for Exospheric Refilling and Emitted Natural Abundances) on board the BepiColombo mission of ESA to Mercury to be launched in 2015. ELENA is a Time of Flight (TOF) sensor, based on a novel concept using an ultra-sonic oscillating shutter (Start section), which is operated at frequencies up to 50 kHz; a MCP detector is used as a Stop detector. The scientific objective of ELENA is to detect energetic neutral atoms in the range 10 eV - 5 keV, within 76° FOV, perpendicular to the S/C orbital plane. ELENA will monitor the emission of neutral atoms from the whole surface of Mercury thanks to the spacecraft motion. The major scientific objectives are the interaction between the plasma environment and the planet’s surface, the global particle loss-rate and the remote sensing of the surface properties. In particular, surface release processes are investigated by identifying particles released from the surface, via solar wind-induced ion sputtering (MEFISTO facility of the Physical Institute of the University of Bern (CH), measurements on three different types of MCP (with and without coating) have been performed providing the detection efficiencies in the energy range 10eV - 1keV. Outcomes from such measurements are discussed here.

  13. Properties of Transition Metal Doped Alumina

    Science.gov (United States)

    Nykwest, Erik; Limmer, Krista; Brennan, Ray; Blair, Victoria; Ramprasad, Rampi

    Crystallographic texture can have profound effects on the properties of a material. One method of texturing is through the application of an external magnetic field during processing. While this method works with highly magnetic systems, doping is required to couple non-magnetic systems with the external field. Experiments have shown that low concentrations of rare earth (RE) dopants in alumina powders have enabled this kind of texturing. The magnetic properties of RE elements are directly related to their f orbital, which can have as many as 7 unpaired electrons. Since d-block elements can have as many as 5 unpaired electrons the effects of substitutional doping of 3d transition metals (TM) for Al in alpha (stable) and theta (metastable) alumina on the local structure and magnetic properties, in addition to the energetic cost, have been calculated by performing first-principles calculations based on density functional theory. This study has led to the development of general guidelines for the magnetic moment distribution at and around the dopant atom, and the dependence of this distribution on the dopant atom type and its coordination environment. It is anticipated that these findings can aid in the selection of suitable dopants help to guide parallel experimental efforts. This project was supported in part by an internship at the Army Research Laboratory, administered by the Oak Ridge Institute for Science and Education, along with a grant of computer time from the DoD High Performance Computing Modernization Program.

  14. Modified-starch Consolidation of Alumina Ceramics

    Institute of Scientific and Technical Information of China (English)

    JU Chenhui; WANG Yanmin; YE Jiandong; HUANG Yun

    2008-01-01

    The alumina ceramics with the homogeneous microstructure and the higher density were fabricated via the modified-starch consolidation process by 1.0 wt%of a modified starch as a consolidator/binder.The swelling behavior of the modified oxidized tapioca starch was analyzed by optical microscope,and two other corn starches(common corn starch and high amylose COrn starch)were also analyzed for comparison.The modified starch used as a binder for the consolidation swelled at about 55℃.began to gelatinize at 65℃ and then was completely gelatinized at 75℃.But the corn starches could not be completely gelatinized even at 80℃for 1 h.The high-strength green bodies(10.6 MPa)with the complex shapes were produced.The green bodies were sintered without any binder burnout procedure at 1700℃and a relative density of 95.3% was obtained for the sintered bodies,which is similar to that of the sintered sample formed by conventional slip casting.In addition,the effect of temperature on the apparent viscosity of the starch/alumina slurry in the process was investigated,and the corresponding mechanism for the starch consolidation was discussed.

  15. Characterization of endocannabinoid-mediated induction of myeloid-derived suppressor cells involving mast cells and MCP-1.

    Science.gov (United States)

    Jackson, Austin R; Hegde, Venkatesh L; Nagarkatti, Prakash S; Nagarkatti, Mitzi

    2014-04-01

    Endocannabinoids are lipid-signaling molecules found in the nervous system; however, their precise role in the periphery is unclear. In the current study, we observed that a single i.p. administration of AEA caused rapid induction of MDSCs. The MDSCs contained a mixture of granulocytic and monocytic subtypes and expressed Arg-1 and iNOS. The MDSCs suppressed T cell proliferation in vitro and used iNOS to mediate their effect. Moreover, adoptive transfer of MDSCs led to suppression of mBSA-induced DTH. Through the use of pharmacological inhibition, as well as genetic knockout mice, we found that the induction of MDSCs by AEA was CB1-dependent. The induction of MDSCs by AEA was reduced significantly in mast cell-deficient mice, while maintained in LPS-insensitive mice, showing that the induction of MDSCs by AEA was dependent, at least in part, on mast cells and independent of TLR4. Chemokine analysis of AEA- treated WT mice showed an early spike of MCP-1, which was decreased in Kit(W/W-sh) mice, showing a role of mast cells in the secretion of MCP-1 in response to AEA. Also, use of antibodies against MCP-1 or mice deficient in MCP-1 confirmed the role played by MCP-1. Interestingly, MCP-1 played a significant role in the induction of monocytic but not granulocytic MDSCs. Our studies demonstrate for the first time that endocannaboinids activate CB1 on mast cells to induce MCP-1, which facilitates recruitment of monocytic MDSCs.

  16. Myocardial production and release of MCP-1 and SDF-1 following myocardial infarction: differences between mice and man

    Directory of Open Access Journals (Sweden)

    Palasubramaniam Dharshan

    2011-09-01

    Full Text Available Abstract Background Stem cell homing to the heart is mediated by the release of chemo-attractant cytokines. Stromal derived factor -1 alpha (SDF-1a and monocyte chemotactic factor 1(MCP-1 are detectable in peripheral blood after myocardial infarction (MI. It remains unknown if they are produced by, and released from, the heart in order to attract stem cells to repair the damaged myocardium. Methods Murine hearts were studied for expression of MCP-1 and SDF-1a at day 3 and day 28 following myocardial infarction to determine whether production is increased following MI. In addition, we studied the coronary artery and coronary sinus (venous blood from patients with normal coronary arteries, stable coronary artery disease (CAD, unstable angina and MI to determine whether these cytokines are released from the heart into the systemic circulation following MI. Results Both MCP-1 and SDF-1a are constitutively produced and released by the heart. MCP-1 mRNA is upregulated following murine experimental MI, but SDF-1a is suppressed. There is less release of SDF-1a into the systemic circulation in patients with all stages of CAD including MI, mimicking the animal model. However MCP-1 release from the human heart following MI is also suppressed, which is the exact opposite of the animal model. Conclusions SDF-1a and MCP-1 release from the human heart are suppressed following MI. In the case of SDF-1a, the animal model appropriately reflects the human situation. However, for MCP-1 the animal model is the exact opposite of the human condition. Human observational studies like this one are paramount in guiding translation from experimental studies to clinical trials.

  17. Atraso do amadurecimento de banana 'Maçã' pelo 1-MCP, aplicado previamente à refrigeração Ripening delay of 'Apple' banana submitted to 1-MCP, prevoiously applied to refrigeration

    Directory of Open Access Journals (Sweden)

    Gustavo Costa Almeida

    2006-08-01

    Full Text Available O objetivo deste trabalho foi avaliar o efeito de diferentes períodos de exposição da banana 'Maçã' a 50 ppb de 1-MCP (0; 3; 6; 9; 12 e 24 horas sobre sua vida pós-colheita e qualidade. Após exposição ao 1-MCP, os frutos verde-maturos foram armazenados por 30 dias em câmaras com temperatura de 13ºC ± 0,5 e umidade relativa de 95%. Em seguida, as bananas foram armazenadas à temperatura de 20ºC ± 1, até amarelecimento completo da casca. A exposição de banana 'Maçã' a 50 ppb de 1-MCP, por 9 horas, retardou em 7 dias o seu amadurecimento, em comparação a frutos não expostos ao 1-MCP, após 30 dias de armazenamento refrigerado (13ºC, sem prejuízos à sua aparência e composição química. A exposição de banana 'Maçã' a 50 ppb de 1-MCP, por 3 e 6 horas, não estendeu sua vida pós-colheita, tampouco alterou sua composição química. Embora a exposição de banana 'Maçã' a 50 ppb de 1-MCP, por 12 e 24 horas, tenha retardado o seu amadurecimento, promoveu alterações indesejáveis na casca do fruto. Logo, a aplicação de 50 ppb de 1-MCP, por 9 horas, antes da refrigeração, constitui-se numa alternativa viável para prolongar o período de comercialização da banana.The aim of this work was to evaluate 'Apple' banana different periods exposure effect to 50 ppb of 1-MCP (0, 3, 6, 9 and 24 hours on its postharvest life and quality. Mature-green fruits were stored for 30 days in chambers at 13ºC + 0,5 and relative humidity 95%, after exposure to 1-MCP. Then, the bananas were stored at 20ºC + 1 until peel complete yellowing. 'Apple' banana to 50 ppb of 1-MCP exposure during 9 hours delayed in seven days the fruit ripening, comparing to fruit control, after 30 days of cool storage (13ºC, without changing its appearance and chemical composition. The exposure of 'Apple' banana to 50 ppb of 1-MCP for 3 and 6 hours did not extend its postharvest life; neither changed its chemical composition. Although the exposure of

  18. MCP2515在TTCAN协议Level 1节点中应用

    Institute of Scientific and Technical Information of China (English)

    孟庆栋; 张凤登; 刘荣鹏

    2007-01-01

    TCAN是基于CAN的时间触发的高层协议,具有确定性行为,因而适用于安全相关的场合。本文首先从参照时间、基本周期、系统信息阵、网络时间单元和全局时间五个方面对TTCAN协议进行分析,其后讲解了基于MCP2515的一个TTCAN协议Level 1节点的实现方案。

  19. Parsing abnormal grain growth in specialty aluminas

    Science.gov (United States)

    Lawrence, Abigail Kremer

    Grain growth in alumina is strongly affected by the impurities present in the material. Certain impurity elements are known to have characteristic effects on abnormal grain growth in alumina. Specialty alumina powders contain multiple impurity species including MgO, CaO, SiO2, and Na 2O. In this work, sintered samples made from alumina powders containing various amounts of the impurities in question were characterized by their grain size and aspect ratio distributions. Multiple quantitative methods were used to characterize and classify samples with varying microstructures. The grain size distributions were used to partition the grain size population into subpopulations depending on the observed deviation from normal behavior. Using both grain size and aspect ratio a new visual representation for a microstructure was introduced called a morphology frequency map that gives a fingerprint for the material. The number of subpopulations within a sample and the shape of the distribution on the morphology map provided the basis for a classification scheme for different types of microstructures. Also using the two parameters a series of five metrics were calculated that describe the character of the abnormal grains in the sample, these were called abnormal character values. The abnormal character values describe the fraction of grains that are considered abnormal, the average magnitude of abnormality (including both grain size and aspect ratio), the average size, and variance in size. The final metric is the correlation between grain size and aspect ratio for the entire population of grains. The abnormal character values give a sense of how different from "normal" the sample is, given the assumption that a normal sample has a lognormal distribution of grain size and a Gaussian distribution of aspect ratios. In the second part of the work the quantified measures of abnormality were correlated with processing parameters such as composition and heat treatment conditions. A

  20. Capillary interactions in Pickering emulsions

    Science.gov (United States)

    Guzowski, J.; Tasinkevych, M.; Dietrich, S.

    2011-09-01

    The effective capillary interaction potentials for small colloidal particles trapped at the surface of liquid droplets are calculated analytically. Pair potentials between capillary monopoles and dipoles, corresponding to particles floating on a droplet with a fixed center of mass and subjected to external forces and torques, respectively, exhibit a repulsion at large angular separations and an attraction at smaller separations, with the latter resembling the typical behavior for flat interfaces. This change of character is not observed for quadrupoles, corresponding to free particles on a mechanically isolated droplet. The analytical results are compared with the numerical minimization of the surface free energy of the droplet in the presence of spherical or ellipsoidal particles.

  1. Tenderization effect of cold-adapted collagenolytic protease MCP-01 on beef meat at low temperature and its mechanism.

    Science.gov (United States)

    Zhao, Guo-Yan; Zhou, Ming-Yang; Zhao, Hui-Lin; Chen, Xiu-Lan; Xie, Bin-Bin; Zhang, Xi-Ying; He, Hai-Lun; Zhou, Bai-Cheng; Zhang, Yu-Zhong

    2012-10-15

    The enzymes currently used to increase meat tenderness are all mesophilic or thermophilic proteases. This study provides insight into the tenderization effect and the mechanism of a cold-adapted collagenolytic enzyme MCP-01 on beef meat at low temperatures. MCP-01 (10 U of caseinolytic activity) reduced the meat shear force by 23% and increased the relative myofibrillar fragmentation index of the meat by 91.7% at 4 °C, and it also kept the fresh colour and moisture of the meat. Compared to the commercially used tenderizers papain and bromelain, MCP-01 showed a unique tenderization mechanism. MCP-01 had a strong selectivity for degrading collagen at 4 °C, showed a distinct digestion pattern on the myofibrillar proteins, and had a different disruption pattern on the muscle fibres under scanning electron micrograph. These results suggest that the cold-adapted collagenolytic protease MCP-01 may be promising for use as a meat tenderizer at low and moderate temperatures.

  2. Targeting tumor-associated macrophages and inhibition of MCP-1 reduce angiogenesis and tumor growth in a human melanoma xenograft.

    Science.gov (United States)

    Gazzaniga, Silvina; Bravo, Alicia I; Guglielmotti, Angelo; van Rooijen, Nico; Maschi, Fabricio; Vecchi, Annunciata; Mantovani, Alberto; Mordoh, José; Wainstok, Rosa

    2007-08-01

    Chemokines such as monocyte chemoattractant protein (MCP)-1 are key agonists that attract macrophages to tumors. In melanoma, it has been previously shown that variable levels of MCP-1/CCL2 appear to correlate with infiltrating macrophages and tumor fate, with low to intermediate levels of the chemokine contributing to melanoma development. To work under such conditions, a poorly tumorigenic human melanoma cell line was transfected with an expression vector encoding MCP-1. We found that M2 macrophages are associated to MCP-1+ tumors, triggering a profuse vascular network. To target the protumoral macrophages recruitment and reverting tumor growth promotion, clodronate-laden liposomes (Clod-Lip) or bindarit were administered to melanoma-bearing mice. Macrophage depletion after Clod-Lip treatment induced development of smaller tumors than in untreated mice. Immunohistochemical analysis with an anti-CD31 antibody revealed scarce vascular structures mainly characterized by narrow vascular lights. Pharmacological inhibition of MCP-1 with bindarit also reduced tumor growth and macrophage recruitment, rendering necrotic tumor masses. We suggest that bindarit or Clod-Lip abrogates protumoral-associated macrophages in human melanoma xenografts and could be considered as complementary approaches to antiangiogenic therapy.

  3. Fabrication of Alumina Nanowires from Porous Alumina Membranes by Etching in Phosphoric Acid Solution

    Science.gov (United States)

    Wang, Xuehua; Li, Chengyong; Ma, Lianjiao; Cao, Hong; Zhang, Baohua

    Alumina nanowires (ANWs) with high aspect ratios were synthesized by the chemical etching of porous alumina membranes (PAMs) in phosphoric acid solution. The morphology and structure of ANWs were analyzed by SEM and XRD, respectively. The results showed that the typical features of ANWs are around 35 nm in diameter and around 20 μm in length, the crystalline structure of the ANWs was amorphous, which was in accordance with that of the PAMs. Furthermore, the morphology of the PAMs was characterized by AFM and SEM in detail. On the basis of AFM and SEM observations, a possible formation mechanism of ANWs was discussed, and the inhomogeneous of the dissolution between the triple points and the side walls was considered to be the essential factor deciding the formation of ANWs.

  4. Microstructural evolution of alumina-zirconia nanocomposites; Evolucao microestrutural de nanocompositos alumina-zirconia

    Energy Technology Data Exchange (ETDEWEB)

    Ojaimi, C.L.; Chinelatto, A.S.A.; Chinelatto, A.L. [Universidade Estadual de Ponta Grossa (UEPG), PR (Brazil); Pallone, E.M.J.A., E-mail: christianelago@yahoo.com.br [Universidade de Sao Paulo (USP), Pirassununga, Sao Paulo, SP (Brazil). Faculdade de Zootecnia e Engenharia de Alimentos

    2012-07-01

    Ceramic materials have limited use due to their brittleness. The inclusion of nanosized particles in a ceramic matrix, which are called nanocomposites, and ceramic processing control by controlling the grain size and densification can aid in obtaining ceramic products of greater strength and toughness. Studies showed that the zirconia nano inclusions in the matrix of alumina favors an increase in mechanical properties by inhibiting the grain growth of the matrix and not by the mechanism of the transformation toughening phase of zirconia. In this work, the microstructural evolution of alumina nanocomposites containing 15% by volume of nanometric zirconia was studied. From the results it was possible to understand the sintering process of these nanocomposites. (author)

  5. Deformation Behaviour of Coarse Grain Alumina under Shock Loading

    Science.gov (United States)

    Gupta, Satish

    2013-06-01

    To develop better understanding of the shock wave induced deformation behavior of coarse grain alumina ceramics, and for measurement of its Hugoniot Elastic Limit (HEL), in-situ and recovery gas gun experiments have been carried out on coarse grain alumina (grain size ~ 10 μm), prepared in the form of discs (>99.9% TMD) by pressure-less sintering of alpha alumina powder at 1583 K. The HEL value of 1.9 GPa has been determined from the kink in the pressure history recorded using piezoresistance gauge and also from the free surface velocity history of the sample shocked to 9 GPa. The nano-indentation measurements on the alumina samples shocked to 6.5 GPa showed hardness value 15% lower than 21.3 GPa for unshocked alumina, and strong Indentation Size Effect (ISE); the hardness value was still lower and the ISE was stronger for the sample shocked to 12 GPa. The XRD measurements showed reduced particle size and increased microstrains in the shocked alumina fragments. SEM, FESEM and TEM measurements on shock treated samples showed presence of grain localized micro- and nano-scale deformations, micro-cleavages, grain-boundary microcracks, extensive shear induced deformations, and localized micro-fractures, etc. These observations led to the development of a qualitative model for the damage initiation and its subsequent growth mechanisms in shocked alumina. The work performed in collaboration with K.D. Joshi of BARC and A.K. Mukhopadhyay of CGCRI.

  6. Near UV imager with an MCP-based photon counting detector

    Science.gov (United States)

    Ambily, S.; Mathew, Joice; Sarpotdar, Mayuresh; Sreejith, A. G.; Nirmal, K.; Prakash, Ajin; Safonova, Margarita; Murthy, Jayant

    2016-07-01

    We are developing a compact UV Imager using light weight components, that can be own on a small CubeSat or a balloon platform. The system has a lens-based optics that can provide an aberration-free image over a wide field of view. The backend instrument is a photon counting detector with off-the-shelf MCP, CMOS sensor and electronics. We are using a Z-stack MCP with a compact high voltage power supply and a phosphor screen anode, which is read out by a CMOS sensor and the associated electronics. The instrument can be used to observe solar system objects and detect bright transients from the upper atmosphere with the help of CubeSats or high altitude balloons. We have designed the imager to be capable of working in direct frame transfer mode as well in the photon-counting mode for single photon event detection. The identification and centroiding of each photon event are done using an FPGA-based data acquisition and real-time processing system.

  7. Filling of charged cylindrical capillaries

    NARCIS (Netherlands)

    Das, Siddhartha; Chanda, Sourayon; Eijkel, J.C.T.; Tas, N.R.; Chakraborty, Suman; Mitra, Sushanta K.

    2014-01-01

    We provide an analytical model to describe the filling dynamics of horizontal cylindrical capillaries having charged walls. The presence of surface charge leads to two distinct effects: It leads to a retarding electrical force on the liquid column and also causes a reduced viscous drag force because

  8. Capillary thinning of polymeric filaments

    DEFF Research Database (Denmark)

    Kolte, Mette Irene; Szabo, Peter

    1999-01-01

    The capillary thinning of filaments of a Newtonian polybutene fluid and a viscoelastic polyisobutylene solution are analyzed experimentally and by means of numerical simulation. The experimental procedure is as follows. Initially, a liquid sample is placed between two cylindrical plates. Then, th...... and quantified. (C) 1999 The Society of Rheology. [S0148-6055(99)00103-0]....

  9. Pós colheita de bananas-maçã submetidas ao 1-MCP e armazenadas á temperatura ambiente Postharvest of 'apple' banana submetted to 1-MCP and storage in room temperature

    Directory of Open Access Journals (Sweden)

    Ana Carla Marque Pinheiro

    2006-04-01

    Full Text Available Bananas da cultivar Maçã foram adquiridas no estádio dois de coloração da casca (verde maturos e submetidas à ação de 1-MCP. O 1-MCP foi aplicado por 12 horas nas seguintes concentrações: 0 (controle, 50, 100, 150, 200 hL.L-1. Após aplicação, os frutos foram armazenados à temperatura ambiente (temperatura média 20ºC ± 1 e umidade relativa 80% ± 5 e avaliados à medida que atingiam os graus 3, 5 e 7 de coloração da casca. O tratamento com 1-MCP atrasou o início do amadurecimento de bananas-maçã armazenadas sob temperatura ambiente, baseado nas primeiras mudanças de coloração da casca. A aplicação de 1-MCP em bananas-maçã, ditou maiores valores de perda de massa e relação polpa/casca (nos graus 5 e 7 de coloração da casca. O 1-MCP, nas doses 100, 150 e 200 hL.L-1 de 1-MCP promoveu desverdecimento desuniforme e tonalidade avermelhada na casca. O tratamento 50 hL.L-1 de 1-MCP é o mais adequado, por promover a extensão da vida pós-colheita de bananas-maçã da cultivar armazenadas sob temperatura ambiente sem afetar a coloração da casca dos frutos, apresentando qualidade, baseando-se na cor da casca, firmeza, acidez titulável, pH e sólidos solúveis, semelhante ao controle.Mature green 'Apple' bananas were submitted to five concentrations of 1-MCP (0, 50, 100, 150 and 200 hL.L-1 for 12 hours. After treatment, the fruits were stored at room temperature (20ºC ± 1 and 80% ± 5 RH and analyzed at 3,5 and 7 color degree of peel. The treatment with 1-MCP delayed the start of the ripening based in the first changes of peel color. The treatment of 'Apple' bananas with 1-MCP promoted higher values of mass loss and pulp/peel ratio (5 and 7 degrees of color peel. The fruits treated with 100, 150 and 200 nL.L-1 of 1-MCP showed heterogeneous degreening and development of red color on the peel. 1-MCP at 50 nL.L-1 was the most appropriated treatment for promoting the extension of postharvest life of 'Apple' bananas stored

  10. Aplicação de 1-MCP em caqui 'quioto' armazenado sob refrigeração e atmosfera controlada Effect of 1-MCP applied at different times during cold and Ca storage

    Directory of Open Access Journals (Sweden)

    Auri Brackmann

    2003-04-01

    Full Text Available O objetivo deste trabalho foi de avaliar o efeito do 1-MCP aplicado em diferentes épocas durante o armazenamento refrigerado (AR e em atmosfera controlada (AC sobre a qualidade do caqui cv. Quioto. O delineamento experimental utilizado foi o inteiramente casualizado, com quatro repetições de 30 frutos, e os tratamentos foram os seguintes: armazenamento refrigerado (AR; armazenamento refrigerado(AR + 1-MCP (1000ppb no início do armazenamento; armazenamento refrigerado(AR +1-MCP (1000ppb no final do armazenamento; armazenamento em atmosfera controlada (AC com 1kPa de O2 e AC 5kPa de CO2 e AC com 1kPa de O2 e 5kPa de CO2 + 1-MCP no fim do armazenamento, após 2 meses de armazenamento a -0,5ºC mais 5 dias de exposição dos frutos a 10ºC e 3 dias a 20ºC. No armazenamento refrigerado, o 1-MCP, aplicado tanto no início do armazenamento como no final, proporcionou maior firmeza de polpa. Para os parâmetros: sólidos solúveis totais, podridão e escurecimento da película, não houve diferença estatística entre os tratamentos. Conclui-se que a aplicação de 1-MCP, tanto no início como no final do armazenamento mantém elevada a firmeza de polpa.The objective of this work was to evaluate the effect of 1-MCP applied at different period during the cold storage (CS and in controlled atmosphere (CA on the quality of 'Quioto'. Persimmon. The experimental design was completely randomized with four replications of 30 fruits and the tested treatments were: cold storage (CS, cold storage + 1-MCP (1000ppb in the beginning of the storage, cold storage + 1-MCP (1000ppb in the end of the storage period; storage in controlled atmosphere (CA with 1kPa of O2 and 5kPa of CO2 and 1kPa of O2 and 5kPa of CO2 + 1-MCP in the end of the storage, after 2 months of storage at -0.5ºC, plus 5 days at 10ºC and 3 days at 20ºC. In the cooled storage, the 1-MCP, applied as in the beginning of the storage as in the end of the storage, provided greater pulp firmness

  11. DNA Sequencing Using capillary Electrophoresis

    Energy Technology Data Exchange (ETDEWEB)

    Dr. Barry Karger

    2011-05-09

    The overall goal of this program was to develop capillary electrophoresis as the tool to be used to sequence for the first time the Human Genome. Our program was part of the Human Genome Project. In this work, we were highly successful and the replaceable polymer we developed, linear polyacrylamide, was used by the DOE sequencing lab in California to sequence a significant portion of the human genome using the MegaBase multiple capillary array electrophoresis instrument. In this final report, we summarize our efforts and success. We began our work by separating by capillary electrophoresis double strand oligonucleotides using cross-linked polyacrylamide gels in fused silica capillaries. This work showed the potential of the methodology. However, preparation of such cross-linked gel capillaries was difficult with poor reproducibility, and even more important, the columns were not very stable. We improved stability by using non-cross linked linear polyacrylamide. Here, the entangled linear chains could move when osmotic pressure (e.g. sample injection) was imposed on the polymer matrix. This relaxation of the polymer dissipated the stress in the column. Our next advance was to use significantly lower concentrations of the linear polyacrylamide that the polymer could be automatically blown out after each run and replaced with fresh linear polymer solution. In this way, a new column was available for each analytical run. Finally, while testing many linear polymers, we selected linear polyacrylamide as the best matrix as it was the most hydrophilic polymer available. Under our DOE program, we demonstrated initially the success of the linear polyacrylamide to separate double strand DNA. We note that the method is used even today to assay purity of double stranded DNA fragments. Our focus, of course, was on the separation of single stranded DNA for sequencing purposes. In one paper, we demonstrated the success of our approach in sequencing up to 500 bases. Other

  12. Experimental investigation of the radiation shielding of a MCP detector in the radiation environment near Europa

    Science.gov (United States)

    Tulej, Marek; Wurz, Peter; Meyer, Stefan; Lasi, Davide; Lüthi, Matthias; Galli, André; Piazza, Daniele; Desorgher, Laurent; Hajdas, Wojciech; Reggiani, Davide; Karlsson, Stefan; Kalla, Leif

    2016-04-01

    The Neutral Ion Mass spectrometer (NIM) is one of the six instruments in the Particle Environmental Package (PEP) designed for the JUICE mission of ESA to the Jupiter system. NIM will conduct detailed measurements of chemical composition of Jovian moon exospheres and is equipped with a sensitive MCP ion detector. To maintain high sensitivity of the NIM instrument, background signals arising from the presence of a large background of penetrating radiation (mostly high-energy electrons and protons) in Jupiter's magnetosphere have to be minimised. We investigate the performance of a layered-Z radiation shield, an Al-Ta-Al sandwich, as a potential shielding against high-energy electrons. The experimental investigations were performed at the PiM1 beam line of the High Intensity Proton Accelerator Facilities located at the Paul Scherrer Institute (PSI), Villigen, Switzerland. The facility delivers a particle beam containing e,  and  with an adjustable momentum ranging from 17.5 to 345 MeV/c. The measurements of the induced radiation background generated during the interaction of primary particles with Al-Ta-Al sandwich were conducted by beam diagnostic methods and a MCP detector. Diagnostic methods provided for the characterisation of the beam parameters (beam geometry, flux and intensity) and identification of individual particles in the primary beam and in the flux of secondary particles. The MCP detector measurements provided information on the effects of radiation and the results of these measurements define the performance of the shielding material in reducing the background arising from penetrating radiation. In parallel, we performed modelling studies using GEANT 4 and GRASS methods to identify products of the interaction and predict their fluxes and particle rates at the MCP detector. Combination of the experiment and modelling studies yields detailed characterisation of the radiation effects produced by the interaction of the incident e- in the

  13. Ballistic Performance of Alumina and Zirconia-toughened Alumina Against 7.62 Armour Piercing Projectile

    Directory of Open Access Journals (Sweden)

    S G. Savio

    2014-09-01

    Full Text Available A study was carried out to compare the ballistic performance of high purity alumina and zirconia-toughened alumina (ZTA using depth of penetration (DoP test configuration against 7.62 mm armour piercing (AP ammunition. The effect of tile thickness on the differential efficiency factor (DEF was studied for tile thickness in the range of 3 mm to 6 mm for alumina tiles and 3 mm to 5 mm for ZTA tiles. The DEF is found to increase as tile thickness increases. An analysis on the failed shots showed that the residual shot weight does not follow a single linear relationship with ceramic tile thickness unlike the residual DoP for all thicknesses of tiles. Post-ballistic analysis on ceramic powder for particle size distribution was carried out and the results are presented.Defence Science Journal, Vol. 64, No. 5, September 2014, pp.477-483, DOI:http://dx.doi.org/10.14429/dsj.64.6745

  14. Design and fabrication of alumina micro reciprocating engine

    Institute of Scientific and Technical Information of China (English)

    JIN Peng; GAO Yu-long; LIU Nan; JIANG Kylie

    2008-01-01

    Microengines are regarded as the potential replacements for batteries. Aimed at the unsatisfactory thermal property of silicon used in the combustion chambers, ceramics are chosen as the construction material in this paper. The fabrication process where alumina has been chosen as the microengine material is discussed. Vigorous FEA has been carried out, and it is found that the material satisfies the stress and deformation require-ments of the design. Then the alumina fabrication process is described. Soft reusable polydimethylsiloxane (PDMS) moulds are produced from SU-8 resist masters, and alumina microengine parts are produced using the PDMS moulds. Images of the ceramic components show that the fabrication satisfies the design requirements.

  15. Processing of silicon nitride and alumina nanosize powders

    Energy Technology Data Exchange (ETDEWEB)

    Gonzalez, E.J.; Piermarini, G.; Hockey, B.; Malghan, S.G. [National Inst. of Standard and Technology, Gaithersburg, MD (United States)

    1995-08-01

    The effects of pressure on the compaction and subsequent processing of nanosize {gamma} alumina powders were studied. A 3 mm diameter piston/cylinder die was used to compact the nanosize powders to pressures of 1 and 2.5 GPa. The green bodies were sintered at temperatures up to 1600{degrees}C. Results show that green body density can be increased by higher compaction pressures. It appears that as a result of the {gamma}-to-{alpha} transformation in alumina, higher green density does not necessarily produce a higher density sintered alumina body. The microstructures of the sintered bodies are described in terms of porosity and phase content.

  16. Alumina Paste Sublimation Suppression Barrier for Thermoelectric Device

    Science.gov (United States)

    Paik, Jong-Ah (Inventor); Caillat, Thierry (Inventor)

    2014-01-01

    Alumina as a sublimation suppression barrier for a Zintl thermoelectric material in a thermoelectric power generation device operating at high temperature, e.g. at or above 1000K, is disclosed. The Zintl thermoelectric material may comprise Yb.sub.14MnSb.sub.11. The alumina may be applied as an adhesive paste dried and cured on a substantially oxide free surface of the Zintl thermoelectric material and polished to a final thickness. The sublimation suppression barrier may be finalized by baking out the alumina layer on the Zintl thermoelectric material until it becomes substantially clogged with ytterbia.

  17. Special requirements for alumina ceramic of ESG electrode bowl

    Institute of Scientific and Technical Information of China (English)

    ZHANG Jun-an; XUE Kai; ZHANG Jia-tai; ZHANG Qiang

    2004-01-01

    At present ESG (Electrostatic Suspended Gyro) is the most precise inertia element in the world. The electrode bowl, which has direct effect on the precision of ESG, is a key part to ESG. Through the analysis of the function and characteristic of the electrode bowl in hollow rotor ESG and the present situation of new material development in the world, the alumina ceramic is regarded as the best material for the electrode bowl of hollow rotor ESG. By analyzing the present situation of alumina ceramic in the world, main technique requirements have been put forward for the alumina ceramic of ESG electrode bowl which is also fit for solid rotor ESG.

  18. Wenshan’s 800,000-ton Alumina Project Completed

    Institute of Scientific and Technical Information of China (English)

    2012-01-01

    <正>On September 26,2012,the completion ceremony of the 800,000-ton alumina project was held at the alumina factory in Matang Industrial Park, Wenshan city,Yunnan.Wenshan’s 800,000-ton alumina project and its supporting mining construction projects have been listed as one of 20 major industrial construction projects of Yunnan. The project covers an area of approximately 5,500 mu,with an estimated total investment of RMB 4,987 million. It is invested and built

  19. Porous Alumina Based Capacitive MEMS RH Sensor

    CERN Document Server

    Juhasz, L; Timar-Horvath, Veronika; Desmulliez, Marc; Dhariwal, Resh

    2008-01-01

    The aim of a joint research and development project at the BME and HWU is to produce a cheap, reliable, low-power and CMOS-MEMS process compatible capacitive type relative humidity (RH) sensor that can be incorporated into a state-of-the-art, wireless sensor network. In this paper we discuss the preparation of our new capacitive structure based on post-CMOS MEMS processes and the methods which were used to characterize the thin film porous alumina sensing layer. The average sensitivity is approx. 15 pF/RH% which is more than a magnitude higher than the values found in the literature. The sensor is equipped with integrated resistive heating, which can be used for maintenance to reduce drift, or for keeping the sensing layer at elevated temperature, as an alternative method for temperature-dependence cancellation.

  20. Fracture simulation for zirconia toughened alumina microstructure

    CERN Document Server

    Kim, Kyungmok; Forest, Bernard

    2013-01-01

    Purpose - The purpose of this paper is to describe finite element modelling for fracture and fatigue behaviour of zirconia toughened alumina microstructures. Design/methodology/approach - A two-dimensional finite element model is developed with an actual $Al{_2}O{_3}$ - 10 vol% $ZrO{_2}$ microstructure. A bilinear, time-independent cohesive zone law is implemented for describing fracture behaviour of grain boundaries. Simulation conditions are similar to those found at contact between a head and a cup of hip prosthesis. Residual stresses arisen from the mismatch of thermal coefficient between grains are determined. Then, effects of a micro-void and contact stress magnitude are investigated with models containing residual stresses. For the purpose of simulating fatigue behaviour, cyclic loadings are applied to the models. Findings - Results show that crack density is gradually increased with increasing magnitude of contact stress or number of fatigue cycles. It is also identified that a micro-void brings about...

  1. Crystallography of Alumina-YAG-Eutectic

    Science.gov (United States)

    Farmer, Serene C.; Sayir, Ali; Dickerson, Robert M.; Matson, Lawrence E.

    2000-01-01

    Multiple descriptions of the alumina-YAG eutectic crystallography appear in the ceramic literature. The orientation between two phases in a eutectic system has direct impact on residual stress, morphology, microstructural stability, and high temperature mechanical properties. A study to demonstrate that the different crystallographic relationships can be correlated with different growth constraints was undertaken. Fibers produced by Laser-Heated Float Zone (LHFZ) and Edge-defined Film-fed Growth (EFG) were examined. A map of the orientation relationship between Al2O3 and Y3Al5O12 and their relationship to the fiber growth axis as a function of pull rate are presented. Regions in which a single orientation predominates are identified.

  2. Electrochemical modification process of anodic alumina membrane

    Institute of Scientific and Technical Information of China (English)

    YU Mei; LIU Jian-hua; LI Song-mei

    2006-01-01

    The modification procedure of anodic alumina membrane(AAM) was studied. The AAM structure after modification was characterized by nickel nanowires prepared in AAM. Scanning electron microscopy was used to characterize the topography and structure properties of the AAM and nickel nanowires. The transformation of the current during the voltage reduction was studied. The mechanism of current and structure change during modification was discussed. The results show that a root structure produces after the AAM modification. The length of the root structure depends on the velocity of the voltage reduction. Slow voltage reduction leads to a large length of the root structure,otherwise,a short length of the root structure. At the end of the modification,the barrier layer is thin enough to be passed by electrons. Hence,the direct electrodeposition of one-dimensional nanowires can be carried out on the AAM with barrier layer and aluminum matrix successfully without any other treatments.

  3. Aluminum matrix composites reinforced with alumina nanoparticles

    CERN Document Server

    Casati, Riccardo

    2016-01-01

    This book describes the latest efforts to develop aluminum nanocomposites with enhanced damping and mechanical properties and good workability. The nanocomposites exhibited high strength, improved damping behavior and good ductility, making them suitable for use as wires. Since the production of metal matrix nanocomposites by conventional melting processes is considered extremely problematic (because of the poor wettability of the nanoparticles), different powder metallurgy routes were investigated, including high-energy ball milling and unconventional compaction methods. Special attention was paid to the structural characterization at the micro- and nanoscale, as uniform nanoparticle dispersion in metal matrix is of prime importance. The aluminum nanocomposites displayed an ultrafine microstructure reinforced with alumina nanoparticles produced in situ or added ex situ. The physical, mechanical and functional characteristics of the materials produced were evaluated using different mechanical tests and micros...

  4. Armazenamento refrigerado de ameixas 'Laetitia' com uso de 1-MCP e indução de perda de massa fresca Cold storage of 'Laetitia' plums treated with 1-MCP and induced to loss of fresh mass

    Directory of Open Access Journals (Sweden)

    Erlani de Oliveira Alves

    2010-02-01

    Full Text Available O objetivo deste trabalho foi avaliar os efeitos da temperatura de armazenamento, do uso de 1-metilciclopropeno (1-MCP e da indução de perda de massa fresca (IPMF na qualidade de ameixas 'Laetitia'. Os tratamentos utilizados foram: -0,5°C; 0,5°C; 0,5°C em combinação com a indução de perda de massa fresca (IPMF; e 0,5°C após tratamento com aplicação de 1-MCP (1,0µL L-1. Frutos armazenados a 0,5°C e tratados com 1-MCP apresentaram os menores valores da taxa respiratória e da taxa de produção de etileno após quatro dias de exposição em condição ambiente (23°C / 60% de UR. Na saída da câmara fria não houve diferença entre tratamentos. Os frutos armazenados por 30 dias a 0,5°C, em combinação com a IPMF ou 1-MCP, apresentaram na saída da câmara maior firmeza de polpa. Porém, após quatro dias, apenas os frutos armazenados a 0,5°C e tratados com 1-MCP apresentaram maior firmeza de polpa. O índice de cor vermelha, na saída da câmara, foi menor nos frutos armazenados a -0,5°C e a 0,5°C após tratamento com 1-MCP, não sendo observada diferença entre os tratamentos após quatro dias de exposição dos frutos em temperatura ambiente. O armazenamento a -0,5°C proporcionou melhor preservação dos atributos de textura dos frutos do que a 0,5°C, e nesta temperatura o tratamento com 1-MCP proporcionou os melhores resultados. O armazenamento a 0,5°C em relação a -0,5°C causou incremento na incidência de degenerescência da polpa após quatro dias de exposição dos frutos em condição ambiente. A melhor temperatura para o armazenamento refrigerado de ameixas 'Laetitia' é de -0,5°C. O uso do 1-MCP e a IPMF contribuem para a manutenção da qualidade dos frutos durante o armazenamento, e o efeito do 1-MCP persiste após o armazenamento.This research was carried out to study the effects of storage temperature, treatment with 1-methycyclopropene (1-MCP, and induction of fresh mass loss (IFML on quality of 'Laetitia

  5. Characterization of Glasses in One Type of Alumina Rich Fly Ash by Chemical Digestion Methods: Implications for Alumina Extraction

    Directory of Open Access Journals (Sweden)

    Lijun Zhao

    2016-01-01

    Full Text Available In recent years, one type of alumina rich fly ash (ARFA with about 50 wt% of alumina has been extensively investigated for alumina extraction in China. Due to the silica in ARFA, alumina extraction would have to generate a huge amount of solid waste. There is a growing interest in the glasses in ARFA, because they are composed mainly of silica and could be removed prior to alumina extraction. In this work, the glasses in ARFA have been investigated by chemical methods, that is, acid and base digestions. The chemical compositions have been measured by XRF for ARFA from the digestion processes. The K2O standard, XRD, and FTIR spectroscopies were successfully used to define the digestions processes, and size analysis and SEM-EDX provided rich information on particle transformations. As a result, acid and base digestion methods were found to produce very similar results for the glasses in ARFA. The K2O standard was attributed to the formation of glasses by illites, and TiO2 and Fe2O3 were proposed to originate from ilmenite in alumina rich coals (ARC. Some implications of the results were also discussed for the alumina extraction from ARFA.

  6. Insulin resistance is associated with MCP1-mediated macrophage accumulation in skeletal muscle in mice and humans.

    Directory of Open Access Journals (Sweden)

    David Patsouris

    Full Text Available Inflammation is now recognized as a major factor contributing to type 2 diabetes (T2D. However, while the mechanisms and consequences associated with white adipose tissue inflammation are well described, very little is known concerning the situation in skeletal muscle. The aim of this study was to investigate, in vitro and in vivo, how skeletal muscle inflammation develops and how in turn it modulates local and systemic insulin sensitivity in different mice models of T2D and in humans, focusing on the role of the chemokine MCP1. Here, we found that skeletal muscle inflammation and macrophage markers are increased and associated with insulin resistance in mice models and humans. In addition, we demonstrated that intra-muscular TNFα expression is exclusively restricted to the population of intramuscular leukocytes and that the chemokine MCP1 was associated with skeletal muscle inflammatory markers in these models. Furthermore, we demonstrated that exposure of C2C12 myotubes to palmitate elevated the production of the chemokine MCP1 and that the muscle-specific overexpression of MCP1 in transgenic mice induced the local recruitment of macrophages and altered local insulin sensitivity. Overall our study demonstrates that skeletal muscle inflammation is clearly increased in the context of T2D in each one of the models we investigated, which is likely consecutive to the lipotoxic environment generated by peripheral insulin resistance, further increasing MCP1 expression in muscle. Consequently, our results suggest that MCP1-mediated skeletal muscle macrophages recruitment plays a role in the etiology of T2D.

  7. Monocytes infiltrate the pancreas via the MCP-1/CCR2 pathway and differentiate into stellate cells.

    Directory of Open Access Journals (Sweden)

    Kazuko Ino

    Full Text Available Recent studies have shown that monocytes possess pluripotent plasticity. We previously reported that monocytes could differentiate into hepatic stellate cells. Although stellate cells are also present in the pancreas, their origin remains unclear. An accumulation of enhanced green fluorescent protein (EGFP(+CD45(- cells was observed in the pancreases and livers of chimeric mice, which were transplanted with a single hematopoietic stem cell isolated from EGFP-transgenic mice and treated with carbon tetrachloride (CCl4. Because the vast majority of EGFP(+CD45(- cells in the pancreas expressed stellate cell-associated antigens such as vimentin, desmin, glial fibrillary acidic protein, procollagen-I, and α-smooth muscle actin, they were characterized as pancreatic stellate cells (PaSCs. EGFP(+ PaSCs were also observed in CCl4-treated mice adoptively transferred with monocytes but not with other cell lineages isolated from EGFP-transgenic mice. The expression of monocyte chemoattractant protein-1 (MCP-1 and angiotensin II (Ang II increased in the pancreas of CCl4-treated mice and their respective receptors, C-C chemokine receptor 2 (CCR2 and Ang II type 1 receptor (AT1R, were expressed on Ly6C(high monocytes isolated from EGFP-transgenic mice. We examined the effect of an AT1R antagonist, irbesartan, which is also a CCR2 antagonist, on the migration of monocytes into the pancreas. Monocytes migrated toward MCP-1 but not Ang II in vitro. Irbesartan inhibited not only their in vitro chemotaxis but also in vivo migration of adoptively transferred monocytes from peripheral blood into the pancreas. Irbesartan treatment significantly reduced the numbers of EGFP(+F4/80(+CCR2(+ monocytic cells and EGFP(+ PaSCs in the pancreas of CCl4-treated chimeric mice receiving EGFP(+ bone marrow cells. A specific CCR2 antagonist RS504393 inhibited the occurrence of EGFP(+ PaSCs in injured mice. We propose that CCR2(+ monocytes migrate into the pancreas possibly via the

  8. Fused Cast Alumina Refractory Products for Glass Tank Furnace

    Institute of Scientific and Technical Information of China (English)

    SHEN Keyin

    2006-01-01

    @@ 1 Subject and Scope The standard specifies the requirement, testing method, inspection rule and requirements for the labeling, packing, shipping and storing of the fused cast alumina refractory products for glass tanks.

  9. Direct spray pyrolysis of aluminum chloride solution for alumina preparation

    Institute of Scientific and Technical Information of China (English)

    吕国志; 张廷安; 王龙; 马思达; 豆志河; 刘燕

    2014-01-01

    The effects of pyrolysis mode and pyrolysis parameters on Cl content in alumina were investigated, and the alumina products were characterized by XRD, SEM and ASAP. The experimental results indicate that the spray pyrolysis efficiency is higher than that of static pyrolysis process, and the reaction and evaporation process lead to a multi-plot state of the alumina products by spray pyrolysis. Aluminum phase starts to transform intoγ-Al2O3 at spray pyrolysis temperature of 600 °C, which is about 200 °C lower than that of static pyrolysis process. The primary particle size of γ-Al2O3 product is 27.62 nm, and Cl content in alumina products is 0.38%at 800 °C for 20 min.

  10. High Alumina Refractory Bricks for Electric Arc Furnace Roofs

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    @@ 1 Scope This standard specifies the sort, technical requirement, test method, inspection rules, marking, packing, transportation, storage and quality certification of high alumina refractory bricks for electric arc furnace roofs.

  11. Superhydrophobic alumina surface based on stearic acid modification

    Energy Technology Data Exchange (ETDEWEB)

    Feng Libang, E-mail: lepond@hotmail.com [School of Mechatronic Engineering, Lanzhou Jiaotong University, Lanzhou 730070 (China); Zhang Hongxia; Mao Pengzhi; Wang Yanping; Ge Yang [School of Mechatronic Engineering, Lanzhou Jiaotong University, Lanzhou 730070 (China)

    2011-02-15

    A novel superhydrophobic alumina surface is fabricated by grafting stearic acid layer onto the porous and roughened aluminum film. The chemical and phase structure, morphology, and the chemical state of the atoms at the superhydrophobic surface were investigated by techniques as FTIR, XRD, FE-SEM, and XPS, respectively. Results show that a super water-repellent surface with a contact angle of 154.2{sup o} is generated. The superhydrophobic alumina surface takes on an uneven flowerlike structure with many nanometer-scale hollows distribute in the nipple-shaped protrusions, and which is composed of boehmite crystal and {gamma}-Al{sub 2}O{sub 3}. Furthermore, the roughened and porous alumina surface is coated with a layer of hydrophobic alkyl chains which come from stearic acid molecules. Therefore, both the roughened structure and the hydrophobic layer endue the alumina surface with the superhydrophobic behavior.

  12. Aluminum microstructures on anodic alumina for aluminum wiring boards.

    Science.gov (United States)

    Jha, Himendra; Kikuchi, Tatsuya; Sakairi, Masatoshi; Takahashi, Hideaki

    2010-03-01

    The paper demonstrates simple methods for the fabrication of aluminum microstructures on the anodic oxide film of aluminum. The aluminum sheets were first engraved (patterned) either by laser beam or by embossing to form deep grooves on the surface. One side of the sheet was then anodized, blocking the other side by using polymer mask to form the anodic alumina. Because of the lower thickness at the bottom part of the grooves, the part was completely anodized before the complete oxidation of the other parts. Such selectively complete anodizing resulted in the patterns of metallic aluminum on anodic alumina. Using the technique, we fabricated microstructures such as line patterns and a simple wiring circuit-board-like structure on the anodic alumina. The aluminum microstructures fabricated by the techniques were embedded in anodic alumina/aluminum sheet, and this technique is promising for applications in electronic packaging and devices.

  13. High Alumina Refractory Mortars GB/T 2994-2008

    Institute of Scientific and Technical Information of China (English)

    Wang Jing; Chai Junlan

    2009-01-01

    @@ 1 Scope This standard specifies the classification, techni-cal requirements, test methods, quality appraisal pro-cedure, packing, marking, transportation, storage and quality certificate of high alumina refractory mortars.

  14. Electronic Structure of High-Pressure Alumina Polymorphs

    Institute of Scientific and Technical Information of China (English)

    LIU Xiao-Lei; DUAN Wen-Hui; GU Bing-Lin

    2000-01-01

    Electronic properties are investigated for three alumina polymorphs (corundum, Rb2 O3 (Ⅱ) and Pbnm perovskite),which are predicted as the stable structures under different pressure range, by means of the first-principles molecular dynamics method within local density functional framework. The similarity in electronic properties of the polymorphs of alumina is observed. The effect of possible phase transitions on ruby (Cr+3-doped Al2 O3)fluorescences is discussed.

  15. CSL grain boundary distribution in alumina and zirconia ceramics

    OpenAIRE

    Vonlanthen, Pierre; Grobéty, Bernard

    2008-01-01

    The distributions of general and coincidence site lattice (CSL) grain boundaries (GBs) in texture-free alumina and zirconia ceramics sintered at two different temperatures were investigated based on electron backscatter diffraction (EBSD) measurements. Results were compared with the distributions obtained from random 2D spatial models and with calculated random distributions reported in the literature. All alumina samples independent on sintering temperature show the same characteristic devia...

  16. Mixed Capillary Venous Retroperitoneal Hemangioma

    Directory of Open Access Journals (Sweden)

    Mohit Godar

    2013-01-01

    Full Text Available We report a case of mixed capillary venous hemangioma of the retroperitoneum in a 61-year-old man. Abdominal ultrasonography showed a mass to be hypoechoic with increased flow in color Doppler imaging. Dynamic contrast-enhanced computed tomography revealed a centripetal filling-in of the mass, located anterior to the left psoas muscle at the level of sacroiliac joint. On the basis of imaging features, preoperative diagnosis of hemangioma was considered and the mass was excised by laparoscopic method. Immunohistochemical studies were strongly positive for CD31 and CD34, and negative for calretinin, EMA, WT1, HMB45, Ki67, synaptophysin, and lymphatic endothelial cell marker D2–40. Histologically, the neoplasm was diagnosed as mixed capillary venous hemangioma.

  17. Antibacterial activity of zinc oxide-coated nanoporous alumina

    Energy Technology Data Exchange (ETDEWEB)

    Skoog, S.A. [Joint Department of Biomedical Engineering, University of North Carolina and North Carolina State University, Box 7115, Raleigh, NC 27695-7115 (United States); Bayati, M.R. [Department of Materials Science and Engineering, North Carolina State University, Box 7907, Raleigh, NC 27695-7907 (United States); Petrochenko, P.E. [Joint Department of Biomedical Engineering, University of North Carolina and North Carolina State University, Box 7115, Raleigh, NC 27695-7115 (United States); Division of Biology, Office of Science and Engineering Laboratories, Center for Devices and Radiological Health, U.S. Food and Drug Administration, Silver Spring, MD 20993 (United States); Stafslien, S.; Daniels, J.; Cilz, N. [Center for Nanoscale Science and Engineering, North Dakota State University, 1805 Research Park Drive, Fargo, ND 58102 (United States); Comstock, D.J.; Elam, J.W. [Energy Systems Division, Argonne National Laboratory, Argonne, IL 60439 (United States); Narayan, R.J., E-mail: roger_narayan@msn.com [Joint Department of Biomedical Engineering, University of North Carolina and North Carolina State University, Box 7115, Raleigh, NC 27695-7115 (United States); Department of Materials Science and Engineering, North Carolina State University, Box 7907, Raleigh, NC 27695-7907 (United States)

    2012-07-25

    Highlights: Black-Right-Pointing-Pointer Atomic layer deposition was used to deposit ZnO on nanoporous alumina membranes. Black-Right-Pointing-Pointer Scanning electron microscopy showed continuous coatings of zinc oxide nanocrystals. Black-Right-Pointing-Pointer Activity against B. subtilis, E. coli, S. aureus, and S. epidermidis was shown. - Abstract: Nanoporous alumina membranes, also known as anodized aluminum oxide membranes, are being investigated for use in treatment of burn injuries and other skin wounds. In this study, atomic layer deposition was used for coating the surfaces of nanoporous alumina membranes with zinc oxide. Agar diffusion assays were used to show activity of zinc oxide-coated nanoporous alumina membranes against several bacteria found on the skin surface, including Bacillus subtilis, Escherichia coli, Staphylococcus aureus, and Staphylococcus epidermidis. On the other hand, zinc oxide-coated nanoporous alumina membranes did not show activity against Pseudomonas aeruginosa, Enterococcus faecalis, and Candida albicans. These results suggest that zinc oxide-coated nanoporous alumina membranes have activity against some Gram-positive and Gram-negative bacteria that are associated with skin colonization and skin infection.

  18. Porous alumina and zirconia ceramics with tailored thermal conductivity

    Science.gov (United States)

    Gregorová, E.; Pabst, W.; Sofer, Z.; Jankovský, O.; Matějíček, J.

    2012-11-01

    The thermal conductivity of porous ceramics can be tailored by slip casting and uniaxial dry pressing, using either fugitive pore formers (saccharides) or partial sintering. Porous alumina and zirconia ceramics have been prepared using appropriate powder types (ungranulated for casting, granulated for pressing) and identical firing regimes (but different maximum temperatures in the case of partial sintering). Thermal diffusivities have been measured by the laser- and xenon-flash method and transformed into relative thermal conductivities, which enable a temperature-independent comparison between different materials. While the porosity can be controlled in a similar way for both materials when using pore formers, partial sintering exhibits characteristic differences between alumina and zirconia (for alumina porosities below 45 %, full density above 1600 °C, for zirconia porosities below 60 %, full density above 1300 °C). The different compaction behavior of alumina and zirconia (porosity after pressing 0.465 and 0.597, respectively) is reflected in the fact that for alumina the relative conductivity data of partially sintered materials are below the exponential prediction, while for zirconia they coincide with the latter. Notwithstanding these characteristic differences, for both alumina and zirconia it is possible to tailor the thermal conductivity from 100 % down to approx. 15 % of the solid phase value.

  19. Procoagulant behavior and platelet microparticle generation on nanoporous alumina.

    Science.gov (United States)

    Ferraz, Natalia; Hong, Jaan; Karlsson Ott, Marjam

    2010-05-01

    In the present work, we have investigated platelet microparticle (PMP) generation in whole blood after contact with nanoporous alumina. Alumina membranes with pore sizes of 20 and 200 nm in diameter were incubated with whole blood and the number of PMP in the fluid phase was determined by flow cytometry. The role of the complement system in PMP generation was investigated using an analog of the potent complement inhibitor compstatin. Moreover, the procoagulant activity of the two pore size membranes were compared by measuring thrombin formation. Results indicated that PMP were not present in the fluid phase after whole blood contact with either of the alumina membranes. However, scanning electron microscope micrographs clearly showed the presence of PMP clusters on the 200 nm pore size alumina, while PMP were practically absent on the 20 nm membrane. We probed no influence of complement activation in PMP generation and adhesion and we hypothesize that other specific material-related protein-platelet interactions are taking place. A clear difference in procoagulant activity between the membranes could also be seen, 20 nm alumina showed 100% higher procoagulant activity than 200 nm membrane. By combining surface evaluation and flow cytometry analyses of the fluid phase, we are able to conclude that 200 nm pore size alumina promotes PMP generation and adhesion while the 20 nm membrane does not appreciably cause any release or adhesion of PMP, thus indicating a direct connection between PMP generation and nanoporosity.

  20. Dynamic yield and tensile strengths of spark plasma sintered alumina

    Science.gov (United States)

    Girlitsky, I.; Zaretsky, E.; Kalabukhov, S.; Dariel, M.; Frage, N.

    2014-05-01

    Fully dense alumina samples with 0.6 μm grain size were produced from alumina powder using Spark Plasma Sintering and tested in two types of VISAR-instrumented planar impact tests. In the tests of the first type the samples of 0.28 to 6-mm thickness were loaded by 1-mm tungsten impactors accelerated up to a velocity of about 1 km/s. These tests were aimed to study the Hugoniot elastic limit (HEL) of the SPS-processed alumina and the decay of the elastic precursor wave with propagation distance. In the second type of test the samples of ~3-mm thickness were loaded by 1-mm copper impactors accelerated up to velocities 100-1000 m/s. These tests were aimed to study the dynamic tensile (spall) strength of the alumina. The data on tensile fracture of the alumina demonstrate a monotonic decline of the spall strength with the amplitude of the loading stress pulse. The data on the decay of the elastic precursor wave allows for determining the rates of the irreversible (inelastic) strains in the SPS-processed alumina at the initial stages of shock-induced inelastic deformation and, thus, to derive some conclusions concerning the mechanisms responsible of the deformation.

  1. Adsorption of itaconic acid from aqueous solutions onto alumina

    Directory of Open Access Journals (Sweden)

    JELENA J. GULICOVSKI

    2008-08-01

    Full Text Available Itaconic acid, IA (C5H6O4, was investigated as a potential flocculant for the aqueous processing of alumina powders. The adsorption of IA, as a function of its concentration and pH value of the solution, onto the alumina surface was studied by the solution depletion method. The stability of the suspensions in the presence of itaconic acid was evaluated in light of the surface charge of the alumina powder used, the degree of dissociation of IA, as well as the sedimentation behavior and rheology of the suspensions. It was found that the adsorption process is extremely pH dependent; the maximum adsorption of IA onto alumina surface occurring at a pH close to the value of the first IA dissociation constant, pKa1. Also, IA does not influence the value of the point of zero charge of alumina. It was shown that IA represents an efficient flocculant for concentrated acidic alumina suspensions.

  2. Capillary electrophoresis systems and methods

    Science.gov (United States)

    Dorairaj, Rathissh; Keynton, Robert S.; Roussel, Thomas J.; Crain, Mark M.; Jackson, Douglas J.; Walsh, Kevin M.; Naber, John F.; Baldwin, Richard P.; Franco, Danielle B.

    2011-08-02

    An embodiment of the invention is directed to a capillary electrophoresis apparatus comprising a plurality of separation micro-channels. A sample loading channel communicates with each of the plurality of separation channels. A driver circuit comprising a plurality of electrodes is configured to induce an electric field across each of the plurality of separation channels sufficient to cause analytes in the samples to migrate along each of the channels. The system further comprises a plurality of detectors configured to detect the analytes.

  3. Capillary electrophoresis in food authenticity.

    Science.gov (United States)

    Kvasnicka, Frantisek

    2005-06-01

    Food authenticity is a term which simply refers to whether the food purchased by the consumer matches its description. False description can occur in many forms, from the undeclared addition of water or other cheaper materials, or the wrong declaration of the amount of a particular ingredient in the product, to making false statements about the source of ingredients i.e., their geographic, plant, or animal origin. The aim of this review is to summarize applications of capillary electrophoresis in food authentication.

  4. Evaluation of BICRON NE MCP DXT-RAD passive extremity dosemeter

    CERN Document Server

    Yuen, P S; Frketich, G; Rotunda, J

    1999-01-01

    Passive extremity dosemeters currently used in dosimetry communities worldwide have shortcomings. In general, an extremity dosemeter has too thick a detector element, and the dosemeter response is highly energy dependent for beta rays with energies ranging from 200 keV to 2 MeV. It often does not have dosemeter identification, causing problems in the chain of custody. It is often read manually, rendering reading/packing operations very labour intensive. As a result of collaboration between AECL and BICRON NE, a new extremity dosemeter, incorporating a highly sensitive LiF:Mg,Cu,P TLD and tentatively code named MCP DXT-RAD, was developed. It has been evaluated for radiological performance against an ISO draft standard for extremity dosemeters in twelve categories: homogeneity, detection threshold, beta ray energy response, beta angular response, photon energy response, photon angular response, reproducibility, stability under various climatic conditions, linearity, residue, self irradiation, and effect of ligh...

  5. Capillary Electrophoresis - Optical Detection Systems

    Energy Technology Data Exchange (ETDEWEB)

    Sepaniak, M. J.

    2001-08-06

    Molecular recognition systems are developed via molecular modeling and synthesis to enhance separation performance in capillary electrophoresis and optical detection methods for capillary electrophoresis. The underpinning theme of our work is the rational design and development of molecular recognition systems in chemical separations and analysis. There have been, however, some subtle and exciting shifts in our research paradigm during this period. Specifically, we have moved from mostly separations research to a good balance between separations and spectroscopic detection for separations. This shift is based on our perception that the pressing research challenges and needs in capillary electrophoresis and electrokinetic chromatography relate to the persistent detection and flow rate reproducibility limitations of these techniques (see page 1 of the accompanying Renewal Application for further discussion). In most of our work molecular recognition reagents are employed to provide selectivity and enhance performance. Also, an emerging trend is the use of these reagents with specially-prepared nano-scale materials. Although not part of our DOE BES-supported work, the modeling and synthesis of new receptors has indirectly supported the development of novel microcantilevers-based MEMS for the sensing of vapor and liquid phase analytes. This fortuitous overlap is briefly covered in this report. Several of the more significant publications that have resulted from our work are appended. To facilitate brevity we refer to these publications liberally in this progress report. Reference is also made to very recent work in the Background and Preliminary Studies Section of the Renewal Application.

  6. Capillary stretching of elastic fibers

    Science.gov (United States)

    Protiere, Suzie; Stone, Howard A.; Duprat, Camille

    2014-11-01

    Fibrous media consisting of constrained flexible fibers can be found in many engineered systems (membranes in filters, woven textile, matted paper). When such materials interact with a liquid, the presence of liquid/air interfaces induces capillary forces that deform the fibers. To model this interaction we study the behaviour of a finite volume of liquid deposited on two parallel flexible fibers clamped at both ends. A tension along the fibers is imposed and may be varied. We show that the system undergoes various morphological changes as the interfiber distance, the elasticity and the tension of the fibers are varied. For a certain range of parameters, the liquid spreads along the fibers and pulls them together, leading to the ``zipping'' of the fibers. This capillary adhesion can then be enhanced or reduced by changing the tension within the fibers. We will show that balancing stretching and capillary forces allows the prediction of this transition as well as the conditions for which detachment of the fibers occurs. These results may be used to prevent the clogging of fibrous membranes or to optimize the capture of liquids.

  7. Influence of additives on the stability of the phases of alumina; Influencia de aditivos na estabilidade das fases da alumina

    Energy Technology Data Exchange (ETDEWEB)

    Rosario, D.C.C.; Gouvea, D., E-mail: deisedorosario@usp.br [Universidade de Sao Paulo (USP), SP (Brazil). Departamento de Engenharia Metalurgica e de Materiais. Laboratorio de Processos Ceramicos

    2011-07-01

    Problems with the stability of gamma alumina in catalytic reactions have been solved with the inclusion of additives during the synthesis of alumina. These additives stabilize the temperature of phase transition allowing the use of metastable alumina at high temperatures, but the mechanisms of action of additives are not well defined. It is known that each family of additive or additives behaves in different ways for this stabilization. This work aimed to study the performance of MgO and ZrO{sub 2}, respectively at different concentrations in alumina synthesized via Pechini. The samples were analyzed by DSC, X-ray diffraction, measurement of specific surface area by BET analysis, and infrared analysis. The results showed an increase in transition temperature for both additives, and a different changes for specific surface area, showing that MgO and ZrO{sub 2} work on improving the stability but with distinct mechanisms. (author)

  8. Position sensitive anodes for MCP read-out using induced charge measurement

    Science.gov (United States)

    Jagutzki, O.; Lapington, J. S.; Worth, L. B. C.; Spillman, U.; Mergel, V.; Schmidt-Böcking, H.

    2002-01-01

    We investigate the method of an indirect detection of a MCP charge avalanche projected onto a resistive layer (G. Battistoni, et al., Nucl. Instr. and Meth., 202 (1982) 459). If the sheet resistance is favourable one can detect the charge cloud by the capacitive coupling to an anode structure a few millimetres behind the layer. The anode structure can be, for example, a wedge-and-strip electrode pattern (M. Unverzagt, Diplomarbeit, Universität Frankfurt 1992, private communication) as it is used for directly collecting the electron avalanche from a MCP. Detection of the induced charge is beneficial in several respects. Firstly, image distortions produced by secondary electron mediated charge redistribution are eliminated. Secondly, the noise component due to quantized charge collection, commonly referred to as partition noise, is not present. In addition, the dielectric substrate can function both as an element of the vacuum enclosure and HV insulator, making the electrical connections easily accessible and the pattern operable at ground potential, independently of detector operating voltages. This technique can be used to simplify the electronic design requirements where varying high voltages are required at the detector input face such as plasma analysers, etc. It also has application in the manufacture of intensifier tubes (J. Barnstedt, M. Grewing, Nucl. Instr. and Meth., these proceedings) where the inclusion of a readout pattern inside the intensifier body with associated electrical feed-throughs can prove problematic. We will present data on the performance of such detection geometries using several types of charge division anode, and discuss the advantages compared with the "traditional" charge collecting method.

  9. Critical Capillary Number of Interfacial Film Displacement in a Capillary Tube

    CERN Document Server

    Yan, Changfei

    2016-01-01

    The role of surface tension and wettability in the dynamics of air-liquid interfaces during immiscible fluid displacement flows in capillary tube driven by pressure has been investigated. The contact angle and capillary number drive the force wetting processes which is controlled by the balance between the capillary and the viscous lubrication forces. The dynamic wetting condition with the critical capillary number is studied analytically and validated experimentally, which demonstrates that the critical capillary number is associated with the contact angle, slip length and capillary radius.

  10. Progression of Diabetic Capillary Occlusion: A Model.

    Directory of Open Access Journals (Sweden)

    Xiao Fu

    2016-06-01

    Full Text Available An explanatory computational model is developed of the contiguous areas of retinal capillary loss which play a large role in diabetic maculapathy and diabetic retinal neovascularization. Strictly random leukocyte mediated capillary occlusion cannot explain the occurrence of large contiguous areas of retinal ischemia. Therefore occlusion of an individual capillary must increase the probability of occlusion of surrounding capillaries. A retinal perifoveal vascular sector as well as a peripheral retinal capillary network and a deleted hexagonal capillary network are modelled using Compucell3D. The perifoveal modelling produces a pattern of spreading capillary loss with associated macular edema. In the peripheral network, spreading ischemia results from the progressive loss of the ladder capillaries which connect peripheral arterioles and venules. System blood flow was elevated in the macular model before a later reduction in flow in cases with progression of capillary occlusions. Simulations differing only in initial vascular network structures but with identical dynamics for oxygen, growth factors and vascular occlusions, replicate key clinical observations of ischemia and macular edema in the posterior pole and ischemia in the retinal periphery. The simulation results also seem consistent with quantitative data on macular blood flow and qualitative data on venous oxygenation. One computational model applied to distinct capillary networks in different retinal regions yielded results comparable to clinical observations in those regions.

  11. MCP-1 Stimulates MMP-9 Expression via ERK 1/2 and p38 MAPK Signaling Pathways in Human Aortic Smooth Muscle Cells

    Directory of Open Access Journals (Sweden)

    Ci-Qiu Yang

    2014-07-01

    Full Text Available Objective: We investigated the molecular mechanism underlying the role of monocyte chemoattractant protein-1 (MCP-1 in the formation and development of human abdominal aortic aneurysm (AAA. Methods: We examined protein expression profiles using a protein array and found that MCP-1 was the most highly expressed protein in AAA tissues compared with normal aortas. To investigate the potential mechanism of MCP-1 involvement in the pathogenesis of AAA, we treated human aortic smooth muscle cells (HASMCs with human recombinant MCP-1. Results: MCP-1 was the most highly expressed protein in AAA tissues compared with normal aorta; matrix metalloproteinase-9 (MMP-9 expression was also significantly increased. Treatment with MCP-1 significantly increased the expression and activation of MMP-9 and activated the three major mitogen activated protein kinases (MAPKs extracellular signal regulated kinase (ERK, c-Jun amino terminal kinase (JNK1/2 and p38 MAPK. Furthermore, MCP-1-induced secretion of MMP-9 was inhibited by U0126 (inhibitor of the ERK 1/2 pathway and SB203580 (inhibitor of the p38 MAPK pathway, but not SP600125 (inhibitor of the JNK1/2 pathway. Conclusion: These data demonstrate that MCP-1 stimulates secretion of MMP-9 directly through the ERK1/2 and p38 MAPK mediated pathways in HASMCs. Thus, inhibition of this molecular mechanism might be a potential therapeutic target in the non-surgical treatment of AAA.

  12. Effect of alumina composition and surface integrity in alumina/epoxy composites on the ultrasonic attenuation properties.

    Science.gov (United States)

    Cho, Eikhyun; Park, Gwanwoo; Lee, Jae-Wan; Cho, Sung-Min; Kim, Taekyung; Kim, Joongeok; Choi, Wonjoon; Ohm, Won-Suk; Kang, Shinill

    2016-03-01

    We report a method of fabricating backing blocks for ultrasonic imaging transducers, using alumina/epoxy composites. Backing blocks contain scatterers such as alumina particles interspersed in the epoxy matrix for the effective scattering and attenuation of ultrasound. Here, the surface integrity can be an issue, where the composite material may be damaged during machining because of differences in strength, hardness and brittleness of the hard alumina particles and the soft epoxy matrix. Poor surface integrity results in the formation of air cavities between the backing block and the piezoelectric element upon assembly, hence the increased reflection off the backing block and the eventual degradation in image quality. Furthermore, with an issue of poor surface integrity due to machining, it is difficult to increase alumina as scatterers more than a specific mass fraction ratio. In this study, we increased the portion of alumina within epoxy matrix by obtaining an enhanced surface integrity using a net shape fabrication method, and verified that this method could allow us to achieve higher ultrasonic attenuation. Backing blocks were net-shaped with various mass fractions of alumina to characterize the formability and the mechanical properties, including hardness, surface roughness and the internal micro-structure, which were compared with those of machined backing blocks. The ultrasonic attenuation property of the backing blocks was also measured.

  13. 1.5-NM PROJECTION STRUCTURE OF HELA-CELL PROSOME-MCP (PROTEASOME) PROVIDED BY 2-DIMENSIONAL CRYSTALS

    NARCIS (Netherlands)

    PERKINS, GA; BERGSMASCHUTTER, W; KEEGSTRA, W; ARNBERG, AC; COUX, O; SCHERRER, K

    1994-01-01

    We grew two-dimensional crystals of HeLa cell prosomes, also called multicatalytic proteinases (MCP) and proteasomes, for a structure determination by electron microscopy. The molecules were arranged in side views in these crystals. The crystals have p21 plane group symmetry with one particle per un

  14. Effectiveness of 1-Methylcyclopropene (1-MCP Combination with Nisin-EDTA Treatment of Fresh-cut Kiwifruit for Prevention

    Directory of Open Access Journals (Sweden)

    Xiang Li

    2014-02-01

    Full Text Available A comprehensive study was made to determine the effects of 1-MCP (1 &muL L-1 pretreated combined with Nisin-EDTA (0.02 M on fresh-cut kiwifruit slices. Physico-chemical attributes of kiwifruit slices were evaluated every 3 days during storage. The fresh-cut kiwifruits pre-treated with 1-MCP, Nisin-EDTA coating and their combination showed better preservation quality and compared with the control slices during the entire storage period. 1-MCP showed an ability to relieve the pulp softening extent and inhibit total chlorophyll content decrease. Lower Polyphenol Oxidase (PPO and higher ascorbic acid were observed in Nisin-EDTA treated samples which also showed a less total bacteria count compared with the control in the end storage. Moreover, the combination of 1-MCP and Nisin-EDTA was more effective than individual treatment on maintaining the quality of fresh-cut kiwifruit, which suggested that this may be a healthy alternative method for fresh-cut kiwifruit.

  15. Association between new onset diabetic retinopathy and monocyte chemoattractant protein-1 (MCP-1) polymorphism in Japanese type 2 diabetes.

    Science.gov (United States)

    Ninomiya, Hiroyo; Katakami, Naoto; Osonoi, Takeshi; Saitou, Miyoko; Yamamoto, Yuichi; Takahara, Mitsuyoshi; Kawamori, Dan; Matsuoka, Taka-aki; Yamasaki, Yoshimitsu; Shimomura, Iichiro

    2015-06-01

    We longitudinally evaluated the association between monocyte chemoattractant protein-1 (MCP-1) A-2518G polymorphism and new onset of diabetic retinopathy in 758 type 2 diabetic patients. The new onset of retinopathy increased with the increase of the number of G alleles, even after adjustment for age, HbA1c levels, and duration of diabetes.

  16. Experimental investigation of the radiation shielding efficiency of a MCP detector in the radiation environment near Jupiter's moon Europa

    Science.gov (United States)

    Tulej, M.; Meyer, S.; Lüthi, M.; Lasi, D.; Galli, A.; Piazza, D.; Desorgher, L.; Reggiani, D.; Hajdas, W.; Karlsson, S.; Kalla, L.; Wurz, P.

    2016-09-01

    Neutral Ion Mass spectrometer (NIM) is one of the instruments in the Particle Environmental Package (PEP) designed for the JUICE mission of ESA to the Jupiter system. NIM, equipped with a sensitive MCP ion detector, will conduct detailed measurements of the chemical composition of Jovian icy moons exospheres. To achieve high sensitivity of the instrument, radiation effects due to the high radiation background (high-energy electrons and protons) around Jupiter have to be minimised. We investigate the performance of an Al-Ta-Al composite stack as a potential shielding against high-energy electrons. Experiments were performed at the PiM1 beam line of the High Intensity Proton Accelerator Facilities located at the Paul Scherrer Institute, Villigen, Switzerland. The facility delivers a particle beam containing e-, μ- and π- with momentum from 17.5 to 345 MeV/c (Hajdas et al., 2014). The measurements of the radiation environment generated during the interaction of primary particles with the Al-Ta-Al material were conducted with dedicated beam diagnostic methods and with the NIM MCP detector. In parallel, modelling studies using GEANT4 and GRAS suites were performed to identify products of the interaction and predict ultimate fluxes and particle rates at the MCP detector. Combination of experiment and modelling studies yields detailed characterisation of the radiation fields produced by the interaction of the incident e- with the shielding material in the range of the beam momentum from 17.5 to 345 MeV/c. We derived the effective MCP detection efficiency to primary and secondary radiation and effective shielding transmission coefficients to incident high-energy electron beam in the range of applied beam momenta. This study shows that the applied shielding attenuates efficiently high-energy electrons. Nevertheless, owing to nearly linear increase of the bremsstrahlung production rate with incident beam energy, above 130 MeV their detection rates measured by the MCP

  17. Methods of analysis by the U.S. Geological Survey National Water Quality Laboratory; determination of chlorinated pesticides in aquatic tissue by capillary-column gas chromatography with electron-capture detection

    Science.gov (United States)

    Leiker, Thomas J.; Madsen, J.E.; Deacon, J.R.; Foreman, W.T.

    1995-01-01

    A method for the determination of chlorinated organic compounds in aquatic tissue by dual capillary-column gas chromatography with electron-capture detection is described. Whole-body-fish or corbicula tissue is homogenized, Soxhlet extracted, lipid removed by gel permeation chromatography, and fractionated using alumina/silica adsorption chromatography. The extracts are analyzed by dissimilar capillary-column gas chromatography with electron-capture detection. The method reporting limits are 5 micrograms per kilogram (μg/kg) for chlorinated compounds, 50 μg/kg for polychlorinated biphenyls, and 200 μg/kg for toxaphene.

  18. Nanoparticle assisted coagulation of aqueous alumina suspensions

    Directory of Open Access Journals (Sweden)

    Abdullah Fatih Çetinel

    2012-02-01

    Full Text Available Colloidal processing of ceramics offers a high potential to achieve homogeneous microstructures with improved material properties. In this study, a novel forming method is investigated, which was already applied successfully for the fabrication of ceramic matrix composites (CMC, but is also considered to be a suitable direct casting technique for the fabrication of advanced ceramics with tailored microstructure and properties. The so-called nanoparticle assisted coagulation method (NPAC represents a modification of the hydrolysis-assisted solidification (HAS technique. It promises green components with high green strength, uniform density as well as homogeneous and tailored microstructure. Electrostatically stabilized colloidal suspensions with high solid loadings were produced by dispersing various fractions of submicron alumina powder and aluminium hydroxide nano-powder in water without use of any organic binder. Rheology and coagulation kinetics of suspensions and green part properties were studied regarding to modifications of pH value, setting temperature, amount of setting agent, amount of nano-powder, solids loading and process parameters like ultrasound treatment. It could be revealed that the homogeneous core-shell arrangement of submicron and nanoparticles in the colloidal state can be transmitted to the green state, which improves the microstructure and green density of the green parts. For this, the NPAC method is seen as a promising technique for the fabrication of advanced ceramics with tailored microstructure and properties.

  19. Mechanical properties of alumina porcelain during heating

    Science.gov (United States)

    Šín, Peter; Podoba, Rudolf; ŠtubÅa, Igor; Trník, Anton

    2014-11-01

    The mechanical strength and Young's modulus of green alumina porcelain (50 wt. % of kaolin, 25 wt. % of Al2O3, and 25 wt. % of feldspar) were measured during heating up to 900 °C and 1100 °C, respectively. To this end, we used the three point-bending method and modulated force thermomechanical analysis (mf-TMA). The loss liberation - of the physically bound water (20 - 250 °C) strengthens the sample and Young's modulus increases its values significantly. The dehydroxylation that takes place in the range of 400 - 650 °C causes a slight decrease in Young's modulus. On the other hand, the mechanical strength slightly increases in this temperature range, although it has a sudden drop at 420 °C. Beyond the dehydroxylation range, above 650 °C, both Young's modulus and mechanical strength increase. Above 950 °C, a sharp increase of Young's modulus is caused by the solid-state sintering and the new structure created by the high-temperature reactions in metakaolinite.

  20. Capillary pumped loop body heat exchanger

    Science.gov (United States)

    Swanson, Theodore D. (Inventor); Wren, deceased, Paul (Inventor)

    1998-01-01

    A capillary pumped loop for transferring heat from one body part to another body part, the capillary pumped loop comprising a capillary evaporator for vaporizing a liquid refrigerant by absorbing heat from a warm body part, a condenser for turning a vaporized refrigerant into a liquid by transferring heat from the vaporized liquid to a cool body part, a first tube section connecting an output port of the capillary evaporator to an input of the condenser, and a second tube section connecting an output of the condenser to an input port of the capillary evaporator. A wick may be provided within the condenser. A pump may be provided between the second tube section and the input port of the capillary evaporator. Additionally, an esternal heat source or heat sink may be utilized.

  1. Measurement of Liquid Viscosities in Tapered or Parabolic Capillaries.

    Science.gov (United States)

    Ershov; Zorin; Starov

    1999-08-01

    The possibility of using tapered or parabolic capillaries for measurement of liquid viscosities is investigated both experimentally and theoretically. It is demonstrated that even small deviations in capillary radius from a constant value may substantially affect measurement results. Equations are derived which allow correct analysis of the measurement results in tapered or parabolic capillaries. The following cases are analyzed: a water imbibition into a tapered or parabolic capillary and displacement of one liquid by another immiscible liquid in tapered or parabolic capillaries. Two possibilities are considered: (a) the narrow end of the capillary as capillary inlet and (b) the wide end of the capillary as capillary inlet. Copyright 1999 Academic Press.

  2. An adventitial IL-6/MCP1 amplification loop accelerates macrophage-mediated vascular inflammation leading to aortic dissection in mice

    Science.gov (United States)

    Tieu, Brian C.; Lee, Chang; Sun, Hong; LeJeune, Wanda; Recinos, Adrian; Ju, Xiaoxi; Spratt, Heidi; Guo, Dong-Chuan; Milewicz, Dianna; Tilton, Ronald G.; Brasier, Allan R.

    2009-01-01

    Vascular inflammation contributes to cardiovascular diseases such as aortic aneurysm and dissection. However, the precise inflammatory pathways involved have not been clearly defined. We have shown here that subcutaneous infusion of Ang II, a vasopressor known to promote vascular inflammation, into older C57BL/6J mice induced aortic production of the proinflammatory cytokine IL-6 and the monocyte chemoattractant MCP-1. Production of these factors occurred predominantly in the tunica adventitia, along with macrophage recruitment, adventitial expansion, and development of thoracic and suprarenal aortic dissections. In contrast, a reduced incidence of dissections was observed after Ang II infusion into mice lacking either IL-6 or the MCP-1 receptor CCR2. Further analysis revealed that Ang II induced CCR2+CD14hiCD11bhiF4/80– macrophage accumulation selectively in aortic dissections and not in aortas from Il6–/– mice. Adoptive transfer of Ccr2+/+ monocytes into Ccr2–/– mice resulted in selective monocyte uptake into the ascending and suprarenal aorta in regions of enhanced ROS stress, with restoration of IL-6 secretion and increased incidence of dissection. In vitro, coculture of monocytes and aortic adventitial fibroblasts produced MCP-1– and IL-6–enriched conditioned medium that promoted differentiation of monocytes into macrophages, induced CD14 and CD11b upregulation, and induced MCP-1 and MMP-9 expression. These results suggest that leukocyte-fibroblast interactions in the aortic adventitia potentiate IL-6 production, inducing local monocyte recruitment and activation, thereby promoting MCP-1 secretion, vascular inflammation, ECM remodeling, and aortic destabilization. PMID:19920349

  3. MCP-1 -2518 A/G functional polymorphism is associated with increased susceptibility to active pulmonary tuberculosis in Tunisian patients.

    Science.gov (United States)

    Ben-Selma, Walid; Harizi, Hedi; Boukadida, Jalel

    2011-11-01

    Monocyte chemoattractant protein-1 (MCP-1) plays crucial role in protective immunity against Mycobacterium tuberculosis (MT). In this study, we examined whether single nucleotide polymorphism (SNP) -2518 A/G (rs 1024611) of MCP-1 affect the susceptibility to active tuberculosis (TB) in Tunisian populations. Genomic DNA from patients with active TB (168 cases of pulmonary TB and 55 cases of extrapulmonary TB) and ethnically controls (150 cases) was genotyped for the MCP-1 -2518 A/G SNP by polymerase chain reaction fragment length polymorphism (PCR-RFLP). We observed that -2518 G allele and GG genotype (high MCP-1 producer) frequencies were significantly more elevated in active pulmonary TB group in comparison to control group [34 vs. 22%; P = 0.0007; 15 vs. 5%, P corrected for the number of genotypes (Pc) = 0.015; respectively]. Additionally, they were associated with increased risk development of this clinical form of TB [odds ratio (OR) = 1.83, 95% confidence intervals (CI) = 1.26-2.66; OR = 3.1, 95% CI = 1.28-7.76; respectively]. However, wild type allele -2518 A and AA genotype were over-represented in control group (78 and 62%) and seem to be protective factors against TB. Moreover, -2518 AA genotype was more frequent in control group and was associated with resistance against development of active pulmonary TB (OR = 0.56, 95% CI = 0.35-0.89, Pc = 0.03). Our findings confirm the key role of -2518 A/G SNP of MCP-1 and support its association with resistance/susceptibility to the development of active pulmonary TB in the Tunisian population.

  4. Secreted Ectodomain of SIGLEC-9 and MCP-1 Synergistically Improve Acute Liver Failure in Rats by Altering Macrophage Polarity

    Science.gov (United States)

    Ito, Takanori; Ishigami, Masatoshi; Matsushita, Yoshihiro; Hirata, Marina; Matsubara, Kohki; Ishikawa, Tetsuya; Hibi, Hideharu; Ueda, Minoru; Hirooka, Yoshiki; Goto, Hidemi; Yamamoto, Akihito

    2017-01-01

    Effective treatments for acute liver failure (ALF) are still lacking. We recently reported that a single intravenous administration of serum-free conditioned medium from stem cells derived from human exfoliated deciduous teeth (SHED-CM) into the D-galactosamine (D-Gal)-induced rat ALF model improves the liver injury. However, the specific factors in SHED-CM that are responsible for resolving ALF remain unclear. Here we found that depleting SHED-CM of two anti-inflammatory M2 macrophage inducers—monocyte chemoattractant protein-1 (MCP-1) and the secreted ectodomain of sialic acid-binding Ig-like lectin-9 (sSiglec-9)—abolished its ability to resolve rat ALF. Furthermore, treatment with MCP-1/sSiglec-9 alone dramatically improved the survival of ALF rats. This treatment induced anti-inflammatory M2, suppressed hepatocyte apoptosis, and promoted hepatocyte proliferation. Treatment with an M2-depletion reagent (mannosylated clodronate liposomes) suppressed the recovery. In addition, MCP-1 and sSiglec-9 synergistically promoted the M2 differentiation of bone marrow-derived macrophages via CCR2, accompanied by the production of multiple liver-regenerating factors. The conditioned medium from MCP-1/sSiglec-9-activated M2 macrophages, but not from interleukin-4-induced ones, suppressed the D-Gal- and LPS-induced apoptosis of primary hepatocytes and promoted their proliferation in vitro. The unique combination of MCP-1/sSiglec-9 ameliorates rat ALF by inhibiting hepatocellular apoptosis and promoting liver regeneration through the induction of anti-inflammatory/tissue-repairing M2 macrophages. PMID:28272428

  5. Signal pathways underlying homocysteine-induced production of MCP-1 and IL-8 in cultured human whole blood

    Institute of Scientific and Technical Information of China (English)

    Xiao-kun ZENG; You-fei GUAN; Daniel G REMICK; Xian WANG

    2005-01-01

    Aim: To elucidate the mechanisms underlying homocysteine (Hcy)-induced chemokine production. Methods: Human whole blood was pretreated with inhibitors of calmodulin (CaM), protein kinase C (PKC), protein tyrosine kinase(PTK), mitogen-activated protein kinase (MAPK), and NF-κB and activators of PPARγ for 60 min followed by incubation with Hcy 100 μmol/L for 32 h. The levels of mitogen chemokine protein (MCP)-1 and interleukin-8 (IL-8) were determined by enzyme-linked immunosorbant assay (ELISA). Results: Inhibitors of PKC (calphostin C, 50-500 nmol/L and RO-31-8220, 10-100 nmol/L), CaM(W7, 28-280 μmol/L), ERK1/2 MAPK (PD 98059, 2-20 μmol/L), p38 MAPK(SB 203580, 0.6-6 μmol/L), JNK MAPK (curcumin, 2-10 μmol/L), and NF-κB(PDTC, 10-100 nmol/L) markedly reduced Hcy 100 μmol/L-induced production of MCP-1 and IL-8 in human cultured whole blood, but the inhibitors of PTK(genistein, 2.6-26 μmol/L and tyrphostin, 0.5-5 μmol/L) had no obvious effect on MCP-1 and IL-8 production. PPARγ activators (ciglitazone 30 μmol/L and troglitazone 10 μmol/L) depressed the Hcy-induced MCP-1 production but not IL-8 production in the cultured whole blood. Conclusion: Hcy-induced MCP-1 and IL-8 production is mediated by activated signaling pathways such as PKC,CaM, MAPK, and NF-κB. Our results not only provide clues for the signal transduction pathways mediating Hcy-induced chemokine production, but also offer a plausible explanation for a pathogenic role of hyperhomocysteinemia in these diseases.

  6. FGFR3 promotes angiogenesis-dependent metastasis of hepatocellular carcinoma via facilitating MCP-1-mediated vascular formation.

    Science.gov (United States)

    Liu, Xinyu; Jing, Xiaoqian; Cheng, Xi; Ma, Ding; Jin, Zhijian; Yang, Weiping; Qiu, Weihua

    2016-05-01

    The biological role of fibroblast growth factor receptor 3 (FGFR3) in tumor angiogenesis of hepatocellular carcinoma (HCC) has not been discussed before. Our previous work had indicated FGFR3 was overexpressed in HCC, and silencing FGFR3 in Hu7 cells could regulate tumorigenesis via down-regulating the phosphorylation level of key members of classic signaling pathways including ERK and AKT. In the present work, we explored the role of FGFR3 in angiogenesis-dependent metastasis by using SMMC-7721 and QGY-7703 stable cell lines. Our results indicated FGFR3 could regulate in vitro cell migration ability and in vivo lung metastasis ability of HCC, which was in accordance with increased angiogenesis ability in vitro and in vivo. Using the supernatant from SMMC-7721/FGFR3 cells, we conducted a human angiogenesis protein microarray including 43 angiogenesis factors and found that FGFR3 modulated angiogenesis and metastasis of HCC mainly by promoting the protein level of monocyte chemotactic protein 1 (MCP-1). Silencing FGFR3 by short hairpin RNA (shRNA) could reduce MCP-1 level in lysates and supernatant of QGY-7703 cells and SMMC-7721 cells. Silencing MCP-1 in QGY-7703 or SMMC-7721 cells could induce similar phenotypes compared with silencing FGFR3. Our results suggested FGFR3 promoted metastasis potential of HCC, at least partially if not all, via facilitating MCP-1-mediated angiogenesis, in addition to previously found cell growth and metastasis. MCP-1, a key medium between HCC cells and HUVECs, might be a novel anti-vascular target in HCC.

  7. A New Conductivity Detector for Capillary Electrophoresis

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    A new conductivity detector for capillary electrophoresis consisting of an electrochemical cell and a conductive meter was developed. In the cell, the microelectrode and capillary were inserted through the cell wall and fixed by screws and sealing ring, the ends of microelectrode and capillary were located by a guide with two cross holes. LOD for K+ was 1.5×10-5 mol/L.

  8. DNA Sequencing Using capillary Electrophoresis

    Energy Technology Data Exchange (ETDEWEB)

    Dr. Barry Karger

    2011-05-09

    The overall goal of this program was to develop capillary electrophoresis as the tool to be used to sequence for the first time the Human Genome. Our program was part of the Human Genome Project. In this work, we were highly successful and the replaceable polymer we developed, linear polyacrylamide, was used by the DOE sequencing lab in California to sequence a significant portion of the human genome using the MegaBase multiple capillary array electrophoresis instrument. In this final report, we summarize our efforts and success. We began our work by separating by capillary electrophoresis double strand oligonucleotides using cross-linked polyacrylamide gels in fused silica capillaries. This work showed the potential of the methodology. However, preparation of such cross-linked gel capillaries was difficult with poor reproducibility, and even more important, the columns were not very stable. We improved stability by using non-cross linked linear polyacrylamide. Here, the entangled linear chains could move when osmotic pressure (e.g. sample injection) was imposed on the polymer matrix. This relaxation of the polymer dissipated the stress in the column. Our next advance was to use significantly lower concentrations of the linear polyacrylamide that the polymer could be automatically blown out after each run and replaced with fresh linear polymer solution. In this way, a new column was available for each analytical run. Finally, while testing many linear polymers, we selected linear polyacrylamide as the best matrix as it was the most hydrophilic polymer available. Under our DOE program, we demonstrated initially the success of the linear polyacrylamide to separate double strand DNA. We note that the method is used even today to assay purity of double stranded DNA fragments. Our focus, of course, was on the separation of single stranded DNA for sequencing purposes. In one paper, we demonstrated the success of our approach in sequencing up to 500 bases. Other

  9. Slope wavenumber spectrum models of capillary and capillary-gravity waves

    Institute of Scientific and Technical Information of China (English)

    贾永君; 张杰; 王岩峰

    2010-01-01

    Capillary and capillary-gravity waves possess a random character, and the slope wavenumber spectra of them can be used to represent mean distributions of wave energy with respect to spatial scale of variability. But simple and practical models of the slope wavenumber spectra have not been put forward so far. In this article, we address the accurate definition of the slope wavenumber spectra of water surface capillary and capillary-gravity waves. By combining the existing slope wavenumber models and using th...

  10. Alumina-on-alumina total hip replacement for femoral neck fracture in healthy patients

    Directory of Open Access Journals (Sweden)

    Moretti Lorenzo

    2011-02-01

    Full Text Available Abstract Background Total hip replacement is considered the best option for treatment of displaced intracapsular fractures of the femoral neck (FFN. The size of the femoral head is an important factor that influences the outcome of a total hip arthroplasty (THA: implants with a 28 mm femoral head are more prone to dislocate than implants with a 32 mm head. Obviously, a large head coupled to a polyethylene inlay can lead to more wear, osteolysis and failure of the implant. Ceramic induces less friction and minimal wear even with larger heads. Methods A total of 35 THAs were performed for displaced intracapsular FFN, using a 32 mm alumina-alumina coupling. Results At a mean follow-up of 80 months, 33 have been clinically and radiologically reviewed. None of the implants needed revision for any reason, none of the cups were considered to have failed, no dislocations nor breakage of the ceramic components were recorded. One anatomic cementless stem was radiologically loose. Conclusions On the basis of our experience, we suggest that ceramic-on-ceramic coupling offers minimal friction and wear even with large heads.

  11. Capillary electrophoresis theory and practice

    CERN Document Server

    Grossman, Paul D

    1992-01-01

    This book is designed to be a practical guide, used by wide audience, including those new to CE, those more experienced, routine users, those interested in technology development, and those involved with applications research. References have been emphasized to allow the reader to explore the detailed specifics and theoretical foundations.This book draws together the rapidly evolving, diverse, and multidisciplinary subject of capillary electrophoresis (CE). It is designed as a practical guide to be used by a wide audience, including those new to CE as well as more experienced users. T

  12. Electromigration dispersion in Capillary Electrophoresis

    CERN Document Server

    Chen, Zhen; 10.1007/s11538-011-9708-7

    2012-01-01

    In a previous paper (S. Ghosal and Z. Chen Bull. Math. Biol. 2010, vol. 72, pg. 2047) it was shown that the evolution of the solute concentration in capillary electrophoresis is described by a nonlinear wave equation that reduced to Burger's equation if the nonlinearity was weak. It was assumed that only strong electrolytes (fully dissociated) were present. In the present paper it is shown that the same governing equation also describes the situation where the electrolytic buffer consists of a single weak acid (or base). A simple approximate formula is derived for the dimensionless peak variance which is shown to agree well with published experimental data.

  13. Capillary Bridges between Soft Substrates

    Science.gov (United States)

    Wexler, Jason S.; Heard, Tiara M.; Stone, Howard A.

    2014-02-01

    A wetting droplet trapped in the thin gap between two elastic bodies will deflect the bodies towards one another. The deformation increases the total capillary adhesion force by increasing the contact radius and narrowing the gap height. For flat droplets, with a large ratio of radius to gap height, the Laplace pressure causes surface deformations that are orders of magnitude larger than those induced by a sessile droplet of the same radius. We present experiments, scalings, and closed-form solutions that describe the deformation. Using variational techniques, we also show that the problem exhibits a bifurcation, where the gap spontaneously closes due to an incremental increase in drop volume.

  14. The mechanical reliability of alumina scales and coatings

    Energy Technology Data Exchange (ETDEWEB)

    Alexander, K.B.; Pruebner, K.; Tortorelli, P.F. [Oak Ridge National Lab., TN (United States)

    1996-08-01

    The mechanical integrity of oxide scales ultimately determines their ability to protect materials from corrosion and other environmental effects arising from deleterious reactions with gases and condensable products. The microstructure and mechanical behavior of alumina products thermally grown or deposited on Fe-28 at.% Al intermetallic alloys are being characterized in order to develop the knowledge and means to control the mechanical reliability of alumina scales by microstructural manipulation through design and processing. Mechanical characterization involved gravimetric data from cyclic oxidation experiments, in-situ observation of oxidized specimens undergoing flexural loading in a scanning electron microscope, and measurements of hardness, elastic modulus and cracking resistance by nanoindentation. Values of cracking thresholds for Al{sub 2}O{sub 3} scales were consistent with other measurements for surface and bulk alumina. The oxidation behavior of Fe{sub 3}Al alloys coated with a thin (0.5 - 1 {mu}m) alumina film deposited by plasma synthesis has been studied. During exposure in the oxidizing environment, new oxide was formed between the coating and the substrate. The presence of the deposited amorphous oxide inhibited the subsequent thermal oxidation of the metal. Because the thermally grown alumina forms under the deposit, the adherence of the coating is controlled by the strength of the metal/oxide interface that develops during oxidation.

  15. Plasma Processes : Plasma sprayed alumina coatings for radiation detector development

    Indian Academy of Sciences (India)

    Mary Alex; V Balagi; K R Prasad; K P Sreekumar; P V Ananthapadmanabhan

    2000-11-01

    Conventional design of radiation detectors uses sintered ceramic insulating modules. The major drawback of these ceramic components is their inherent brittleness. Ion chambers, in which these ceramic spacers are replaced by metallic components with plasma spray coated alumina, have been developed in our Research Centre. These components act as thin spacers that have good mechanical strength as well as high electrical insulation and replace alumina insulators with the same dimensions. As a result, the design of the beam loss monitor ion chamber for CAT could be simplified by coating the outer surface of the HT electrode with alumina. One of the chambers developed for isotope calibrator for brachytherapy gamma sources has its outer aluminium electrode (60 mm dia × 220 mm long) coated with 250 thick alumina (97%) + titania (3%). In view of potential applications in neutron-sensitive ion chambers used in reactor control instrumentation, studies were carried out on alumina 100 to 500 thick coatings on copper, aluminium and SS components. The electrical insulation varied from 108 ohms to 1012 ohms for coating thicknesses above 200 . The porosity in the coating resulted in some fall in electrical insulation due to moisture absorption. An improvement could be achieved by providing the ceramic surface with moisture-repellent silicone oil coating. Irradiation at Apsara reactor core location showed that the coating on aluminium was found to be unaffected after exposure to 1017 nvt fluence.

  16. Peltier heats in cryolite melts with alumina

    Energy Technology Data Exchange (ETDEWEB)

    Flem, B.E.; Ratkje, S.K.; Sterten, A. [Univ. of Trondheim (Norway)

    1996-10-01

    The Seebeck coefficient was measured for cells with electrolytes of molten mixtures of sodium fluoride and aluminum fluoride saturated with alumina. The electrodes were either a pair of oxygen electrodes or a pair of aluminum electrodes. For the molar ratio NaF/AlF{sub 3} equal to 1.8, 1.2 and 1.0, the authors obtained the Seebeck coefficients {minus}1.80 mV K{sup {minus}1} at 971 C, {minus}1.63 mV K{sup {minus}1} at 813.6 C and {minus}0.583 mV K{sup {minus}1} at 758 C, respectively, for the oxygen electrodes. For the aluminum electrodes, the authors obtained the Seebeck coefficient {minus}1.23 mV K{sup {minus}1} at 962 C, for the molar ratio NaF/AlF{sub 3} equal to 1.8. The results suggest that there is a substantial reversible heat consumption at the anode during aluminum electrolysis and a large reversible heat production at the cathode. The highest temperature in the Hall-Heroult cell is then closer to the cathode than the anode. The transported entropies of Al{sup 3+} and O{sup 2{minus}} were calculated to be 77 J mol{sup {minus}1} K{sup {minus}1} and 10 J mol{sup {minus}1} K{sup {minus}1}, respectively, when the molar ratio NaF/AlF{sub 3} was equal to 1.0.

  17. Atomic Force Controlled Capillary Electrophoresis

    Science.gov (United States)

    Lewis, Aaron; Yeshua, Talia; Palchan, Mila; Lovsky, Yulia; Taha, Hesham

    2010-03-01

    Lithography based on scanning probe microscopic techniques has considerable potential for accurate & localized deposition of material on the nanometer scale. Controlled deposition of metallic features with high purity and spatial accuracy is of great interest for circuit edit applications in the semiconductor industry, for plasmonics & nanophotonics and for basic research in surface enhanced Raman scattering & nanobiophysics. Within the context of metal deposition we will review the development of fountain pen nanochemistry and its most recent emulation Atomic Force Controlled Capillary Electrophoresis (ACCE). Using this latter development we will demonstrate achievement of unprecedented control of nanoparticle deposition using a three-electrode geometry. Three electrodes are attached: one on the outside of a metal coated glass probe, one on the inside of a hollow probe in a solution containing Au nanoparticles in the capillary, and a third on the surface where the writing takes place. The three electrodes provide electrical pulses for accurate control of deposition and retraction of the liquid from the surface overcoming the lack of control seen in both dip pen lithography & fountain pen nanochemistry when the tip contacts the surface. With this development, we demonstrate depositing a single 1.3 nm Au nanoparticle onto surfaces such as semiconductors.

  18. Two-dimensional capillary origami

    Energy Technology Data Exchange (ETDEWEB)

    Brubaker, N.D., E-mail: nbrubaker@math.arizona.edu; Lega, J., E-mail: lega@math.arizona.edu

    2016-01-08

    We describe a global approach to the problem of capillary origami that captures all unfolded equilibrium configurations in the two-dimensional setting where the drop is not required to fully wet the flexible plate. We provide bifurcation diagrams showing the level of encapsulation of each equilibrium configuration as a function of the volume of liquid that it contains, as well as plots representing the energy of each equilibrium branch. These diagrams indicate at what volume level the liquid drop ceases to be attached to the endpoints of the plate, which depends on the value of the contact angle. As in the case of pinned contact points, three different parameter regimes are identified, one of which predicts instantaneous encapsulation for small initial volumes of liquid. - Highlights: • Full solution set of the two-dimensional capillary origami problem. • Fluid does not necessarily wet the entire plate. • Global energy approach provides exact differential equations satisfied by minimizers. • Bifurcation diagrams highlight three different regimes. • Conditions for spontaneous encapsulation are identified.

  19. Sheathless interface for coupling capillary electrophoresis with mass spectrometry

    Science.gov (United States)

    Wang, Chenchen; Tang, Keqi; Smith, Richard D.

    2014-06-17

    A sheathless interface for coupling capillary electrophoresis (CE) with mass spectrometry is disclosed. The sheathless interface includes a separation capillary for performing CE separation and an emitter capillary for electrospray ionization. A portion of the emitter capillary is porous or, alternatively, is coated to form an electrically conductive surface. A section of the emitter capillary is disposed within the separation capillary, forming a joint. A metal tube, containing a conductive liquid, encloses the joint.

  20. Effect of 1-MCP-β-CD on Vase Quality of Cut Carnation Flowers%1-MCP-β-环糊精对香石竹切花保鲜作用的研究

    Institute of Scientific and Technical Information of China (English)

    陈均志; 王瑾; 邵超群

    2009-01-01

    对香石竹切花(Dianthus caryophyllus L.)用不同体积浓度的1-MCP-β-环糊精溶液处理不同的时间,观察其外观形态品质和生理生化指标,得知以50 mg/L的1-MCP-β-环糊精溶液在7 m3的密闭体系中处理8 h效果最佳.能极大提高香石竹切花的观赏价值,减少萎蔫程度,延缓开放,延迟香石竹切花叶片质膜相对透性下降,并对叶片叶绿素含量变化有一定的影响.

  1. Ação do 1-metilciclopropeno (1-MCP na vida de prateleira da banana 'maçã' Action of 1-methylcyclopropene (1-MCP on shelf life of 'apple' banana

    Directory of Open Access Journals (Sweden)

    Ana Carla Marques Pinheiro

    2005-04-01

    Full Text Available Objetivou-se avaliar o efeito do 1-metilciclopropeno (1-MCP, em diferentes concentrações, sobre a vida pós-colheita e sob as variáveis associadas aos atributos de qualidade de banana 'Maçã'. Frutos verde-maturos foram submetidos a cinco concentrações de 1-MCP (0; 50; 100; 150 e 200 etaL.L-1, por 12 horas, e foram analisados durante o amadurecimento sob condição ambiente (20±1ºC e 80±5% UR. O tratamento com 50 etaL.L-1 de 1-MCP atrasou o início do amadurecimento das bananas em aproximadamente 8 dias, baseando-se nas primeiras mudanças de coloração da casca, enquanto os tratamentos 100; 150 e 200 etaL.L-1 atrasaram-no em aproximadamente 10 dias. Observou-se, durante o amadurecimento, o amaciamento dos frutos, associado à conversão de amido em açúcares e ao aumento na solubilização péctica e na atividade da pectinametilesterase (PME e poligalacturonase (PG. A aplicação de 50 etaL.L-1de 1-MCP é a mais adequada por promover a extensão da vida de prateleira de bananas 'Maçã', preservando sua qualidade com base nas análises de açúcares solúveis totais, pectinas total e solúvel, firmeza e aparência externa ao final do armazenamento.The objective of this work was to evaluate the influence of the 1-MCP, at different concentrations, on quality and shelf life of 'Apple' banana. Green mature fruits were submitted to five concentrations of 1-MCP (0, 50, 100, 150 and 200 etaL.L-1, for 12 hours and analyzed during the ripening at room temperature (20ºC ± 1 and 80% ± 5 RH . The 1-MCP at 50 etaL.L-1 delayed, in 8 days, the begining of the ripening, based in the first changes of peel color, whereas 100, 150 and 200 etaL.L-1 treatments delayed the begining of the ripening in 10 days, in comparison to the control. The softening of the fruits, associated to the conversion of starch in sugar and the increasing in the pectic solubilization and activity of pectinmethylsterase and polygalacturonase, was observed during the ripening

  2. Pressureless sintering behavior of injection molded alumina ceramics

    Directory of Open Access Journals (Sweden)

    Liu W.

    2014-01-01

    Full Text Available The pressureless sintering behaviors of two widely used submicron alumina (MgOdoped and undoped with different solid loadings produced by injection molding have been studied systematically. Regardless of the sinterability of different powders depending on their inherent properties, solid loading plays a critical role on the sintering behavior of injection molded alumina, which greatly determines the densification and grain size, and leads to its full densification at low temperatures. As compared to the MgO-doped alumina powder, the undoped specimens exhibit a higher sinterability for its smaller particle size and larger surface area. While full densification could be achieved for MgO-doped powders with only a lower solid loading, due to the fact that MgO addition can reduce the detrimental effect of the large pore space on the pore-boundary separation.

  3. Origin of High-Alumina Basalt, Andesite, and Dacite Magmas.

    Science.gov (United States)

    Hamilton, W

    1964-10-30

    The typical volcanic rocks of most island arcs and eugeosynclines, and of some continental environments, are basalt, andesite, and dacite, of high alumina content. The high-alumina basalt differs from tholeiitic basalt primarily in having a greater content of the components of calcic plagioclase. Laboratory data indicate that in the upper mantle, below the level at which the basaltic component of mantle rock is transformed by pressure to eclogite or pyroxenite, the entire basaltic portion probably is melted within a narrow temperature range, but that above the level of that transformation plagioclase is melted selectively before pyroxene over a wide temperature range. The broad spectrum of high-alumina magmas may represent widely varying degrees of partial melting above the transformation level, whereas narrow-spectrum tholeiite magma may represent more complete melting beneath it.

  4. Fabrication of alumina films with laminated structures by ac anodization

    Directory of Open Access Journals (Sweden)

    Hiroyo Segawa

    2014-01-01

    Full Text Available Anodization techniques by alternating current (ac are introduced in this review. By using ac anodization, laminated alumina films are fabricated. Different types of alumina films consisting of 50–200 nm layers were obtained by varying both the ac power supply and the electrolyte. The total film thickness increased with an increase in the total charge transferred. The thickness of the individual layers increased with the ac voltage; however, the anodization time had little effect on the film thickness. The laminated alumina films resembled the nacre structure of shells, and the different morphologies exhibited by bivalves and spiral shells could be replicated by controlling the rate of increase of the applied potentials.

  5. Alumina Template-Dependant Growth of Cobalt Nanowire Arrays

    Directory of Open Access Journals (Sweden)

    L. Malferrari

    2009-01-01

    Full Text Available Different electrochemical regimes and porous alumina were applied for template synthesis of cobalt nanowire (nw arrays, revealing several peculiar cases. In contrast to quite uniform filling of sulfuric acid alumina templates by alternating current deposition, nonuniform growth of the Co nw tufts and mushrooms was obtained for the case of oxalic acid templates. We showed herein for the first time that such configurations arise from the spontaneous growth of cobalt nw groups evolving from the cobalt balls at the Al/alumina interface. Nevertheless, the uniform growth of densely packed cobalt nw arrays, up to tens of micrometers in length, was obtained via long-term direct current galvanostatic deposition at low current density using oxalic acid templates one-side coated by conducting layer. The unique point of this regime is the formation of hexagonal lattice Co nws with a preferred (100 growth direction.

  6. Porous Alumina as a Promising Biomaterial for Public Health.

    Science.gov (United States)

    Bragazzi, Nicola Luigi; Gasparini, Roberto; Amicizia, Daniela; Panatto, Donatella; Larosa, Claudio

    2015-01-01

    Porous aluminum is a nanostructured material characterized by unique properties, such as chemical stability, regular uniformity, dense hexagonal porous lattice with high aspect ratio nanopores, excellent mechanical strength, and biocompatibility. This overview examines how the structure and properties of porous alumina can be exploited in the field of public health. Porous alumina can be employed for fabricating membranes and filters for bioremediation, water ultrafiltration, and microfiltration/nanofiltration, being a promising technique for having clean and fresh water, which is essential for human health. Porous alumina-based nanobiosensor coated with specific antibodies or peptides seem to be a useful tool to detect and remove pathogens both in food and in water, as well as for environmental monitoring. Further, these applications, being low-energy demanding and cost-effective, are particularly valuable in resource-limited settings and contexts, and can be employed as point of use devices in developing countries, where there is an urgent need of hygiene and safety assurance.

  7. Capillary waveguide optrodes for Medical applications

    Science.gov (United States)

    Kieslinger, Dietmar; Weigl, Bernhard H.; Draxler, Sonja; Lippitsch, Max E.

    1997-01-01

    Glass capillaries with a chemically sensitive coating on the inner surface are used as optical sensors for medical diagnostics. The capillary simultaneously serves as a sample compartment, a sensor element, and an inhomogeneous optical waveguide. Different optical setups have been investigated and compared regarding its waveguiding properties.

  8. Modeling capillary forces for large displacements

    NARCIS (Netherlands)

    Mastrangeli, M.; Arutinov, G.; Smits, E.C.P.; Lambert, P.

    2014-01-01

    Originally applied to the accurate, passive positioning of submillimetric devices, recent works proved capillary self-alignment as effective also for larger components and relatively large initial offsets. In this paper, we describe an analytic quasi-static model of 1D capillary restoring forces tha

  9. Effect of different sources of alumina on the microstructure and mechanical properties of the triaxial porcelain

    OpenAIRE

    Gralik,G.; Chinelattot,A. L.; A. S. A. Chinelatto

    2014-01-01

    Porcelains composed of kaolin-quartz-feldspar are called triaxial porcelains. The use of alumina as a substitute for quartz in porcelains has been developed for some time. The results show a significant improvement in their mechanical properties, but alumina has a high cost. The possibility of using alternative materials as a source of alumina with lower cost was investigated. In this work, alternative raw materials were used as a source of alumina: refractory bauxite, primary aluminum hydrox...

  10. Capillary electrophoresis using core-based hyperbranched polyethyleneimine (CHPEI) static-coated capillaries.

    Science.gov (United States)

    Boonyakong, Cheerapa; Tucker, Sheryl A

    2009-10-01

    With unique 3-D architecture, the application of core-based hyperbranched polyethyleneimine (CHPEI), as a capillary coating in capillary electrophoresis, is demonstrated by manipulation of the electroosmotic mobility (EOF). CHPEI coatings (CHPEI5, M(w) approximately 5000 and CHPEI25, M(w) approximately 25,000) were physically adsorbed onto the inner surface of bare fused-silica capillary (BFS) via electrostatic interaction of the oppositely charged molecules by rinsing the capillaries with different CHPEI aqueous solutions. The EOF values of the coated capillaries were measured over the pH range of 4.0-9.0. At higher pH (pH >6) the coated capillary surface possesses excess negative charges, which causes the reversal of the EOF. The magnitudes of the EOF obtained from the coated capillaries were three-fold lower than that of BFS capillary. Desirable reproducibility of the EOF with % RSD (n = 5) capillaries were successfully utilized to separate phenolic compounds, B vitamins, as well as basic drugs and related compounds with reasonable analysis time (capillary and capillary).

  11. Epstein-Barr virus induces MCP-1 secretion by human monocytes via TLR2.

    Science.gov (United States)

    Gaudreault, Eric; Fiola, Stéphanie; Olivier, Martin; Gosselin, Jean

    2007-08-01

    Epstein-Barr virus (EBV) is a gammaherpesvirus infecting the majority of the human adult population in the world. TLR2, a member of the Toll-like receptor (TLR) family, has been implicated in the immune responses to different viruses including members of the herpesvirus family, such as human cytomegalovirus, herpes simplex virus type 1, and varicella-zoster virus. In this report, we demonstrate that infectious and UV-inactivated EBV virions lead to the activation of NF-kappaB through TLR2 using HEK293 cells cotransfected with TLR2-expressing vector along with NF-kappaB-Luc reporter plasmid. NF-kappaB activation in HEK293-TLR2 cells (HEK293 cells transfected with TLR2) by EBV was not enhanced by the presence of CD14. The effect of EBV was abrogated by pretreating HEK293-TLR2 cells with blocking anti-TLR2 antibodies or by preincubating viral particles with neutralizing anti-EBV antibodies 72A1. In addition, EBV infection of primary human monocytes induced the release of MCP-1 (monocyte chemotactic protein 1), and the use of small interfering RNA targeting TLR2 significantly reduced such a chemokine response to EBV. Taken together, these results indicate that TLR2 may be an important pattern recognition receptor in the immune response directed against EBV infection.

  12. Activated V gamma 9V delta 2 T cells trigger granulocyte functions via MCP-2 release.

    Science.gov (United States)

    Agrati, Chiara; Cimini, Eleonora; Sacchi, Alessandra; Bordoni, Veronica; Gioia, Cristiana; Casetti, Rita; Turchi, Federica; Tripodi, Marco; Martini, Federico

    2009-01-01

    Vgamma9Vdelta2 T cells display a broad antimicrobial activity by directly killing infected cells and by inducing an effective adaptive immune response. The activation of Vgamma9Vdelta2 T cells by aminobisphosphonate drugs such as zoledronic acid (ZOL) results in a massive release of cytokines and chemokines that may induce a bystander activation of other immune cells. The aim of this work was to evaluate the ability of soluble factors released by ZOL-activated Vgamma9Vdelta2 T cells to induce granulocyte activation. We showed that soluble factors released by ZOL-stimulated Vgamma9Vdelta2 T cells activate granulocytes by inducing their chemotaxis, phagocytosis, and alpha-defensins release. Proteomic analysis allowed us to identify a number of cytokines and chemokines specifically released by activated Vgamma9Vdelta2 T cells. Moreover, MCP-2 depletion by neutralizing Ab revealed a critical role of this chemokine in induction of granulocyte alpha-defensins release. Altogether, these data show a Vgamma9Vdelta2-mediated activation of granulocytes through a bystander mechanism, and confirm the wide ability of Vgamma9Vdelta2 T-lymphocytes in orchestrating the immune response. In conclusion, an immune modulating strategy targeting Vgamma9Vdelta2 T cells may represent a key switch to induce an effective and well-coordinated immune response, and can be proposed as a way to strengthen the immune competence during infectious diseases.

  13. An Internal ALD-Based High Voltage Divider and Signal Circuit for MCP-based Photodetectors

    Energy Technology Data Exchange (ETDEWEB)

    Adams, Bernhard W.; Elagin, Andrey; Elam, Jeffrey W.; Frisch, Henry J.; Genat, Jean-Francois; Gregar, Joseph S.; Mane, Anil U.; Minot, Michael J.; Northrup, Richard; Obaid, Razib; Oberla, Eric; Alexander, Vostrikov; Wetstein, Matthew

    2015-04-21

    We describe a pin-less design for the high voltage (HV) resistive divider of the all-glass LAPPD (TM) 8 in,square thin photodetector module. The divider, which distributes high voltage applied to the photocathode to the two micro-channel plates (MCPs) that constitute the amplification stage, is comprised of the two MCPs and three glass mechanical spacers, each of which is coated with a resistive layer using atomic layer deposition (ALD). The three glass grid spacers and the two MCPs form a continuous resistive path between cathode and anode, with the voltages across the MCPs and the spacers determined by the resistance of each. High voltage is applied on an external tab on the top glass window that connects to the photocathode through the metal seal. The DC ground is supplied by microstrips on the bottom glass plate that form the high-bandwidth anode. The microstrips exit the package through the glass-frit seal of the anode base-plate and the package sidewall. The divider is thus completely internal, with no HV pins penetrating the low-profile flat glass package. Measurements of the performance of the divider are presented for the 8 in.-square MCP and spacer package in a custom test fixture and for an assembled externally pumped LAPPD (TM) prototype with an aluminum photocathode. (C) 2015 Elsevier B.V. All rights reserved.

  14. Sector Multipad Prototype of the FMD-MCP Detector for ALICE (1997)

    CERN Document Server

    Antropov, A E; Feofilov, G A; Izrailov, E K; Kasatkin, V A; Klempt, W; Kolojvari, A A; Larin, M P; Lazarev, V A; Novikov, I A; Potapov, S V; Stolyarov, O I; Tsimbal, F A; Tulina, T A; Valiev, F F; Vinogradov, L I

    1997-01-01

    We present results of the technology, manufacturing andfirst tests of a novel MCP-based sector prototypefor the Forward Multiplicity Detector for the ALICE experiment at the LHC. The detector is to provide better than sqrt(M)/Mresolution for high multiplicity events, and about 50 pstiming resolution. Two Sector MCPs are mounted on a 200 ceramics board with the multipad readout integrated with a passive summator. This microelectronics UHF device provides isochronous analogue summation of the fast 1ns signal components from 8 pads, along with the individual readout of charges. The setup is baked under 300C and then sealedinto a singular thin wall (200 ) stainlesssteel vacuum sector chamber with Ti getter keeping a vacuum of 10-5Torr.The separation of the fast and slow componentsallows us to use this detector as the zero level trigger,in pile up and beam-gas interaction diagnostics and for thedetermination of the collision vertex along the beam axis. The results of the first and future lab and in-beam tests are ...

  15. Detection efficiency, spatial and timing resolution of thermal and cold neutron counting MCP detectors

    Science.gov (United States)

    Tremsin, A. S.; McPhate, J. B.; Vallerga, J. V.; Siegmund, O. H. W.; Hull, J. S.; Feller, W. B.; Lehmann, E.

    2009-06-01

    Neutron counting detectors with boron or gadolinium doped microchannel plates (MCPs) have very high detection efficiency, spatial and temporal resolution, and have a very low readout noise. In this paper we present the results of both theoretical predictions and experimental evaluations of detection efficiency and spatial resolution measured at cold and thermal neutron beamlines. The quantum detection efficiency of a detector (not fully optimized) was measured to be 43% and 16% for the cold and thermal beamlines, respectively. The experiments also demonstrate that the spatial resolution can be better than 15 μm—highest achievable with the particular MCP pore dimension used in the experiment, although more electronics development is required in order to increase the counting rate capabilities of those <15 μm resolution devices. The timing accuracy of neutron detection is on the scale of few μs and is limited by the neutron absorption depth in the detector. The good agreement between the predicted and measured performance allows the optimization of the detector parameters in order to achieve the highest spatial resolution and detection efficiency in future devices.

  16. Capacitively coupled pickup in MCP-based photodetectors using a conductive metallic anode

    CERN Document Server

    Angelico, Evan; Adams, Bernhard; Elagin, Andrey; Frisch, Henry; Spieglan, Eric

    2016-01-01

    We have designed and tested a robust 20 $\\times$ 20 cm$^2$ thin metal film internal anode capacitively coupled to an external array of signal pads or micro-strips for use in fast microchannel plate photodetectors. The internal anode, in this case a 10nm-thick NiCr film deposited on a 96% pure Al$_2$O$_3$ 3mm-thick ceramic plate and connected to HV ground, provides the return path for the electron cascade charge. The multi-channel pickup array consists of a printed-circuit card or glass plate with metal signal pickups on one side and the signal ground plane on the other. The pickup can be put in close proximity to the bottom outer surface of the sealed photodetector, with no electrical connections through the photodetector hermetic vacuum package other than a single ground connection to the internal anode. Two pickup patterns were tested using a small commercial MCP-PMT as the signal source: 1) parallel 50$\\Omega$ 25-cm-long micro-strips with an analog bandwidth of 1.5 GHz, and 2) a 20 $\\times$ 20 cm$^2$ array...

  17. MCP detector read out with a bare quad Timepix at kilohertz frame rates

    Science.gov (United States)

    Vallerga, J.; Raffanti, R.; Tremsin, A.; McPhate, J.; Siegmund, O.

    2011-01-01

    The existing Berkeley neutron sensitive MCP/Timepix hybrid detector has been very successful at demonstrating energy resolved spatial imaging with a single Timepix ASIC read out at a ~ 30 Hz frame rate where each neutron's position and time (energy) is determined (X,Y,E). By increasing the detector format using a quad arrangement of Timepix readouts and increasing the frame rate to 1 kHz, we can increase our total event throughput by a factor of 120, thereby taking full advantage of the high fluxes of modern pulsed neutron sources (106 n cm-2 s-1). The key to this conversion is a new design for the ASIC readout, called the Berkeley Quad Timepix detector, consisting of 3 major subsystems. The first is a quad (2 × 2) bare Timepix ASIC board mounted directly behind the neutron sensitive MCPs in a hermetic vacuum enclosure with a sapphire window. The data from the Timepix ASICs flow to the second subsystem called the Interface board whose field programmable gate array (FPGA) rearranges and converts the digital bit stream to LVDS logic levels before sending downstream to the third subsystem, the Roach board. The Roach board is also FPGA based, and takes the data from all the ASICs and analyses the frames to extract information on the input events to pass on to the host PC. This paper describes in detail the hardware and firmware designs to accomplish this task.

  18. Factors contributing to the breakdown of sodium beta-alumina

    Energy Technology Data Exchange (ETDEWEB)

    Buechele, A.C.

    1982-05-01

    Clarification of the breakdown process occurring during charge transfer in sodium beta alumina solid electrolytes was derived from: (1) studying the effects of molten sodium contact at 350/sup 0/C on single crystal sodium beta alumina and polycrystalline sodium beta alumina; (2) determination of critical current density by monitoring acoustic emissions accompanying crack growth in sodium/sodium beta alumina/sodium cells subjected to linear current ramping at 1 mA cm/sup -2/ sec/sup -1/; (3) failure analysis conducted on cycled electrolytes, some from commercial sodium/sulfur cells, which had been subjected to up to 703 Ahr cm/sup -2/ of charge transfer. Gray coloration developing in beta aluminas in contact with molten sodium was found to be a consequence of formation, through reduction by sodium, of oxygen vacancies charge compensated by electrons. Electronic conductivity of the electrolyte increases as a result. No second phase formation was detected. Colored electrolytes from sodium/sulfur cells show evidence of a newly recognized degradation mechanism in which fracture occurs when sodium is reduced and deposited internally under pressure as metal in regions where an electronic conductivity gradient exists. Heating colored beta aluminas in air produces reoxidation and bleaching. Kinetics and other properties of the coloration and bleaching processes were determined. Critical current density was found to bear an inverse relation to average electrolyte grain size. Evidence was found in the cycled electrolytes for a slow crack growth mechanism and a progressive mode of degradation advancing from the sulfur electrode interface. Implications of the findings for the construction and operation of sodium/sulfur battery systems are discussed.

  19. Effect of One-methylcyclopropene (1-MCP) and chlorine dioxide (ClO2) on preservation of green walnut fruit and kernel traits.

    Science.gov (United States)

    Jiang, Liuqing; Feng, Wenyu; Li, Fang; Xu, Jingying; Ma, Yanping; Ma, Huiling

    2015-01-01

    The effect of the ethylene receptor competitor 1-methylcyclopropene (1-MCP) and the legally approved disinfectant chlorine dioxide (ClO2) on preservation of the green walnut fruit during storage was investigated. Green Chinese walnut fruit cv. Xilin No.2 was harvested on commercial maturity and stored at 0-1 °C after the fruit was treated by water (control), 80 mg L(-1)ClO2 (ClO2), 0.5 μL L(-1)1-MCP (1-MCP), or combination treatment of 80 mg L(-1) ClO2 with either 0.1 μL L(-1) 1-MCP (0.1 1-MCP+ ClO2) or 0.5 μL L(-1) 1-MCP (0.5 1-MCP+ ClO2). During storage, respiration, ethylene production, phenolics content, antioxidative activity, weight changes, decay of the fruit and kernel traits of acid value, peroxide value,free fatty were measured. All treatments decreased postharvest respiration intensity in different degrees and inhibited ethylene production peak. ClO2 increased the total phenol and flavonoid content of the green fruit compared with other treatments and the control (P < 0.05), but not did the total antioxidant activity for this treatment. After 42-day storage, ClO2 remained higher fresh weight and lower decay index than control, while 1-MCP increased the fruit decay index. Final acid values of kernel from ClO2, control and 0.1 1-MCP+ ClO2 were not different from their initial values, which from 0.5 1-MCP increased. Final peroxide value for kernel from ClO2 showed no change during storage but increased at least 1.0-fold for other treatments. ClO2 preserved 99.9 % of initial free fatty acid, similar to that for the control (99.8 %), whereas 0.5 1-MCP preserved only 95.7 %. ClO2 is of potential in decay retardation and kernel traits maintenance of green walnut fruit, whereas the 1-MCP has a negative effect for decay control on walnut.

  20. CRACK PROPAGATION BEHAVIOR AND LIFETIME PREDICTION IN ALUMINA AND ZIRCONIA

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    The lifetime prediction of ceramics is discussed on the basis of the relationship between stress intensity factor KI and crack velocity v. The effects of water environment, the cyclic loading and microstructure of material on KI-v characteristics are studied by carrying out the crack growth tests by the double torsion (DT) method under the static and cyclic loading in both environments of air and water for alumina and zirconia. KI-v characteristics determined by the double torsion method are used to predict time-to-failure under the cyclic loading of alumina and zirconia ceramics. The predictions agree qualitatively with the experimental results.

  1. Controllable synthesis and characterization of alumina/MWNT nanocomposites

    Energy Technology Data Exchange (ETDEWEB)

    Nemeth, Zoltan; Hernadi, Klara [Department of Applied and Environmental Chemistry, University of Szeged, Rerrich Bela ter 1, 6720 Szeged (Hungary); Marko, Kata; Erdohelyi, Andras [Department of Physical Chemistry and Material Science, University of Szeged, Aradi ter 2, 6720 Szeged (Hungary); Forro, Laszlo [Laboratory of Physics of Complex Matter, IPMC, EPFL, 1026 Ecublens (Switzerland)

    2011-11-15

    The aim of this work is to develop a controllable synthesis pathway which produces a stable alumina layer on the surface of carbon nanotubes by impregnation method. Precursor compounds such as aluminium isopropoxide and aluminium-acetyl-acetonate were used to cover the surface of multiwalled carbon nanotubes (MWNTs) under different solvent conditions. As-prepared alumina coverages were characterized by TEM, SEM, SEM-EDX, TG and X-ray diffraction techniques. Results revealed that homogeneous coverage can be achieved in a controllable way. (Copyright copyright 2011 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  2. Cylindrical Three-Dimensional Porous Anodic Alumina Networks

    Directory of Open Access Journals (Sweden)

    Pedro M. Resende

    2016-11-01

    Full Text Available The synthesis of a conformal three-dimensional nanostructure based on porous anodic alumina with transversal nanopores on wires is herein presented. The resulting three-dimensional network exhibits the same nanostructure as that obtained on planar geometries, but with a macroscopic cylindrical geometry. The morphological analysis of the nanostructure revealed the effects of the initial defects on the aluminum surface and the mechanical strains on the integrity of the three-dimensional network. The results evidence the feasibility of obtaining 3D porous anodic alumina on non-planar aluminum substrates.

  3. Mechanical properties of tricalcium phosphate-alumina composites

    Science.gov (United States)

    Sakka, S.; Ben Ayed, F.; Bouaziz, J.

    2012-02-01

    Tricalcium phosphate and alumina powder were mixed in order to elaborate biphasic ceramics composites. This study deals to produce bioceramics composites sintered at various temperatures for differents times. The characterization of samples, before and after the sintering process was investigated, using X-Ray diffraction, scanning electronic microscopy, 31P and 27Al nuclear magnetic resonance and differential thermal analysis. Mechanical properties of biphasic composites were studied using Brazilian test. The tricalcium phosphate - 75 wt% alumina composites mechanical resistance increased with sintered temperature. The mechanical resistance reach it's optimum value (8.6 MPa) at 1550°C for two hours.

  4. Effect of Filler Composition on the Brazing of Alumina to Copper Using Ultrasonic Wave

    Institute of Scientific and Technical Information of China (English)

    Khalid M. HAFEZ; Masaaki NAKA

    2003-01-01

    An ultrasonic wave was applied during brazing of alumina to Cu. First alumina was metallized by applying ultrasonicwave in braze bath. Then the metallized alumina was brazed with Cu using the same filler alloy. The filler used wereZn-Al alloys and Zn-Sn A

  5. Development and testing of cost-effective, 6 cm x 6 cm MCP-based photodetectors for fast timing applications

    CERN Document Server

    Wang, Jingbo; Demarteau, Marcel; Elam, Jeffrey; Mane, Anil; May, Edward; Wagner, Robert; Walters, Dean; Xie, Junqi; Xia, Lei; Zhao, Huyue

    2016-01-01

    Micro-channel plate (MCP)-based photodetectors are capable of picosecond level time resolution and sub-mm level position resolution, which makes them a perfect candidate for the next generation large area photodetectors. The large-area picosecond photodetector (LAPPD) collaboration is developing new techniques for making large-area photodetectors based on new MCP fabrication and functionalization methods. A small single tube processing system (SmSTPS) was constructed at Argonne National Laboratory (ANL) for developing scalable, cost-effective, glass-body, 6 cm x 6 cm, picosecond photodetectors based on MCPs functionalized by Atomic Layer Deposition (ALD). Recently, a number of fully processed and hermitically sealed prototypes made of MCPs with 20 micron pores have been fabricated. This is a significant milestone for the LAPPD project. These prototypes were characterized with a pulsed laser test facility. Without optimization, the prototypes have shown excellent results: The time resolution is ~57 ps for sing...

  6. Plasma cytokines eotaxin, MIP-1α, MCP-4, and vascular endothelial growth factor in acute lower respiratory tract infection

    DEFF Research Database (Denmark)

    Relster, Mette Marie; Holm, Anette; Pedersen, Court

    2017-01-01

    Major overlaps of clinical characteristics and the limitations of conventional diagnostic tests render the initial diagnosis and clinical management of pulmonary disorders difficult. In this pilot study, we analyzed the predictive value of eotaxin, macrophage inflammatory protein 1 alpha (MIP-1α...... to predict the etiology and severity. Eotaxin and MCP-4 were significantly lower in patients with C-reactive protein ≥100, and MIP-1α was significantly higher in the patients with CURB-65 > 3, but the predictive power was low. In conclusion, further evaluation, including more patients, is required to assess...... the full potential of eotaxin, MCP-4, MIP-1α, and VEGF as biomarkers for LRTI because of their low predictive power and a high interindividual variation of cytokine levels....

  7. Association of MCP-1-2518A/G polymorphism with susceptibility to autoimmune diseases: a meta-analysis.

    Science.gov (United States)

    Chen, Si; Deng, Chuiwen; Hu, Chaojun; Li, Jing; Wen, Xiaoting; Wu, Ziyan; Li, Yuan; Zhang, Fengchun; Li, Yongzhe

    2016-05-01

    We performed a meta-analysis to estimate whether combined evidence shows the association between the MCP-1-2518A/G polymorphism and susceptibility to autoimmune diseases. Relevant articles dated to July 2014 were acquired from the PubMed, EMBASE, ISI, and CNKI databases. The number of the genotypes and/or alleles for the MCP-1-2518A/G in cases and control subjects was extracted, and statistical analysis was conducted using STATA 11.2 software. Summary odds ratios (ORs) with their 95 % confidence intervals (95 % CIs) were used to calculate the risk of autoimmune diseases with the MCP-1-2518A/G. Significant increased risk of autoimmune diseases could be found for A allele vs. G allele (OR = 1.616, 95 % CI 1.027-2.542, P = 0.038) and AA + AG vs. GG (OR = 1.616, 95 % CI 1.027-2.542, P = 0.038) in Asian patients with rheumatoid arthritis (RA), and for A allele vs. G allele (OR = 1.383, 95 % CI 1.142-1.676, P = 0.022) and AA vs. AG + GG (OR = 1.575, 95 % CI 1.361-1.823, P < 0.001) in European patients with Crohn's disease (CD). In addition, when comparison of European patients with lupus nephritis (LN) and without LN, significant association between patients with LN and without LN also could be found for AA vs. AG + GG (OR = 0.713, 95 % CI 0.545-0.933, P = 0.014). This meta-analysis showed that the MCP-1-2518-A allele confers susceptibility to Asian patients with RA and European patients with CD.

  8. Interaction of vascular smooth muscle cells and monocytes by soluble factors synergistically enhances IL-6 and MCP-1 production.

    Science.gov (United States)

    Chen, Li; Frister, Adrian; Wang, Song; Ludwig, Andreas; Behr, Hagen; Pippig, Susanna; Li, Beibei; Simm, Andreas; Hofmann, Britt; Pilowski, Claudia; Koch, Susanne; Buerke, Michael; Rose-John, Stefan; Werdan, Karl; Loppnow, Harald

    2009-04-01

    Inflammatory mechanisms contribute to atherogenesis. Monocyte chemoattractant protein (MCP)-1 and IL-6 are potent mediators of inflammation. Both contribute to early atherogenesis by luring monocytes and regulating cell functions in the vessel wall. MCP-1 and IL-6 production resulting from the interaction of invading monocytes with local vessel wall cells may accelerate atherosclerosis. We investigated the influence of the interaction of human vascular smooth muscle cells (SMCs) with human mononuclear cells (MNCs) or monocytes on IL-6 and MCP-1 production in a coculture model. Interaction synergistically enhanced IL-6 and MCP-1 production (up to 30- and 10-fold, respectively) compared with separately cultured cells. This enhancement was mediated by CD14-positive monocytes. It was dependent on the SMC-to-MNC/monocyte ratio, and as few as 0.2 monocytes/SMC induced the synergism. Synergistic IL-6 production was observed at the protein, mRNA, and functional level. It was mediated by soluble factors, and simultaneous inhibition of IL-1, TNF-alpha, and IL-6 completely blocked the synergism. IL-1, TNF-alpha, and IL-6 were present in the cultures. Blockade of the synergism by soluble glycoprotein 130Fc/soluble IL-6 receptor, as well as the induction of synergistic IL-6 production by costimulation of SMCs with IL-1, TNF-alpha, and hyper-IL-6, suggested the involvement of IL-6 trans-signaling. The contribution of IL-6 was consistent with enhanced STAT3 phosphorylation. The present data suggest that SMC/monocyte interactions may augment the proinflammatory status in the tissue, contributing to the acceleration of early atherogenesis.

  9. Aumento da expressão do MCP-1 coroidal e escleral em modelo experimental de hipercolesterolemia

    Directory of Open Access Journals (Sweden)

    Rogil José de Almeida Torres

    2012-02-01

    Full Text Available OBJETIVO: O objetivo deste trabalho é demonstrar experimentalmente que a dieta rica em colesterol provoca aumento da expressão da MCP-1 na coroide e esclera. MÉTODO: Coelhos New Zealand foram organizados em dois grupos: GN (grupo dieta normal, composto por 8 coelhos (8 olhos, recebeu ração padrão para coelhos, durante 4 semanas; GH (grupo hipercolesterolêmico, composto por 13 coelhos (13 olhos, recebeu dieta rica em colesterol a 1% por 8 semanas. Foi realizada a dosagem sérica de colesterol total, triglicerídeos, HDL colesterol, glicemia de jejum no início do experimento e no momento da eutanásia. Ao final da 8ª semana para o GH e 4ª semana para o GN foi realizada a eutanásia dos animais e os olhos foram submetidos à análise imuno-histoquímica com o anticorpo anti-MCP-1. RESULTADOS: A dieta provocou significativo aumento do colesterol total e triglicerídeos do GH em relação ao GN (p<0,001. Houve significativo aumento da expressão da MCP-1 na coroide e esclera dos animais do GH em relação ao GN (p<0,001. CONCLUSÃO: Este estudo demonstrou que a dieta hipercolesterolêmica em coelhos induz ao aumento da expressão do MCP-1 na coroide e esclera.

  10. Capillary Discharge XUV Radiation Source

    Directory of Open Access Journals (Sweden)

    M. Nevrkla

    2009-01-01

    Full Text Available A device producing Z-pinching plasma as a source of XUV radiation is described. Here a ceramic capacitor bank pulse-charged up to 100 kV is discharged through a pre-ionized gas-filled ceramic tube 3.2 mm in diameter and 21 cm in length. The discharge current has amplitude of 20 kA and a rise-time of 65 ns. The apparatus will serve as experimental device for studying of capillary discharge plasma, for testing X-ray optics elements and for investigating the interaction of water-window radiation with biological samples. After optimization it will be able to produce 46.9 nm laser radiation with collision pumped Ne-like argon ions active medium. 

  11. Copolymers For Capillary Gel Electrophoresis

    Science.gov (United States)

    Liu, Changsheng; Li, Qingbo

    2005-08-09

    This invention relates to an electrophoresis separation medium having a gel matrix of at least one random, linear copolymer comprising a primary comonomer and at least one secondary comonomer, wherein the comonomers are randomly distributed along the copolymer chain. The primary comonomer is an acrylamide or an acrylamide derivative that provides the primary physical, chemical, and sieving properties of the gel matrix. The at least one secondary comonomer imparts an inherent physical, chemical, or sieving property to the copolymer chain. The primary and secondary comonomers are present in a ratio sufficient to induce desired properties that optimize electrophoresis performance. The invention also relates to a method of separating a mixture of biological molecules using this gel matrix, a method of preparing the novel electrophoresis separation medium, and a capillary tube filled with the electrophoresis separation medium.

  12. Two-dimensional capillary origami

    Science.gov (United States)

    Brubaker, N. D.; Lega, J.

    2016-01-01

    We describe a global approach to the problem of capillary origami that captures all unfolded equilibrium configurations in the two-dimensional setting where the drop is not required to fully wet the flexible plate. We provide bifurcation diagrams showing the level of encapsulation of each equilibrium configuration as a function of the volume of liquid that it contains, as well as plots representing the energy of each equilibrium branch. These diagrams indicate at what volume level the liquid drop ceases to be attached to the endpoints of the plate, which depends on the value of the contact angle. As in the case of pinned contact points, three different parameter regimes are identified, one of which predicts instantaneous encapsulation for small initial volumes of liquid.

  13. Capillary Separation: Micellar Electrokinetic Chromatography

    Science.gov (United States)

    Terabe, Shigeru

    2009-07-01

    Micellar electrokinetic chromatography (MEKC), a separation mode of capillary electrophoresis (CE), has enabled the separation of electrically neutral analytes. MEKC can be performed by adding an ionic micelle to the running solution of CE without modifying the instrument. Its separation principle is based on the differential migration of the ionic micelles and the bulk running buffer under electrophoresis conditions and on the interaction between the analyte and the micelle. Hence, MEKC's separation principle is similar to that of chromatography. MEKC is a useful technique particularly for the separation of small molecules, both neutral and charged, and yields high-efficiency separation in a short time with minimum amounts of sample and reagents. To improve the concentration sensitivity of detection, several on-line sample preconcentration techniques such as sweeping have been developed.

  14. Resposta da aplicação do 1-MCP em frutos de mamoeiro 'Golden' em diferentes estádios de maturação Responses of 1-MCP applications in 'Golden' papaya fruits on differents maturation stages

    Directory of Open Access Journals (Sweden)

    Maximiliano Silva de Souza

    2009-09-01

    Full Text Available O estudo de fatores que influenciam no processo de amadurecimento é fundamental para o planejamento do processo de comercialização, principalmente em frutos com padrão de respiração climatérico e perecível, como é o caso do mamão. Nesse trabalho, avaliou-se o efeito da aplicação do 1-MCP (1-metilciclopropeno sobre o amadurecimento de frutos de mamoeiro nos estádios 0; 1 e 2 de maturação. O 1-MCP diminui a produção de etileno (≈79% e a taxa respiratória (≈45%, principalmente em frutos no estádio 0 de maturação. O uso deste inibidor da ação do etileno retardou a perda de coloração verde da casca dos frutos, principalmente em frutos nos estádios 0 e 1 de maturação. Houve redução na perda de firmeza do fruto e do mesocarpo nos estádios 1 e 2. Entretanto, em frutos no estádio 0 de maturação, a firmeza do mesocarpo manteve-se alta, o que pode comprometer a aceitação destes frutos pelo consumidor. O teor de sólidos solúveis não foi influenciado pela aplicação do 1-MCP. O efeito do 1-MCP na redução da atividade das enzimas PME e PG foi maior em frutos nos estádios 0 e 1 de maturação em comparação a frutos no estádio 2 de maturação. A atividade da PME demonstrou crescente aumento ao longo do período de armazenamento, porém a atividade da PG permaneceu baixa ao longo dos cinco primeiros dias, com aumento posterior. Os resultados mostraram que a PME exerce influência significativa na perda de firmeza da polpa nos primeiros dias, com atuação posterior da PG. O 1-MCP mostrou-se eficiente em retardar o processo de amadurecimento de frutos de mamoeiro, tornando-se mais eficiente quando associado a estádios de maturação iniciais.The study of factors that influence the process of ripening is critical for planning the marketing process, mainly in standard breathing climacteric and perishing fruits, as it is the case of papaya. In this work it was evaluated the effect of the application of 1-MCP (1

  15. The impacting filter bank design for MCP-EBPSK multicarrier demodulation%用于多路MCP-EBPSK信号解调的冲击滤波器组设计

    Institute of Scientific and Technical Information of China (English)

    陈志敏; 吴乐南; 陈贤卿

    2012-01-01

    修正的随机极性连续相位扩展的二元相移键控调制(MCP-EBPSK)通过随机化调制指数的符号,并加入功率谱调节系数,进一步降低了连续相位扩展的二元相移键控(CP-EBPSK)调制信号功率谱中的线谱分量,使得功率谱占用带宽更窄,信息传输更加的高效高速.多载波作为高频谱利用率的复用调制方式,与MCP-EBPSK结合势必会带来更高的系统性能,因此本文对用于解调单路MCP-EBPSK信号的冲击滤波器进行初步改进,通过添加陷波零点来抑制旁路干扰,设计出带陷波的冲击滤波器组.引入量子粒子群优化算法对加入陷波的冲击滤波器组进行优化得到滤波器组系数,仿真显示即使时频混叠的子载波间不满足正交关系,利用各冲击滤波器中心频率处极陡峭的陷波选频特性依然可以实现各子载波的正确解调.因此,设计的冲击滤波器组可以用于子载波无保护间隔的多路MCP-EBPSK信号解调.%The modified pseudo-random extended binary phase shift keying with continous phase ( MCP-EBPSK) could effectively reduce the spectral line compared with the continuous phase extended BPSK( CP-EBPSK) , which could narrow the power spectrum by adding the modified coefficients and randomizing the sign of the modulation index of CP-EBPSK, finally realized the efficient and high data rate transmission. Multiplexing as a high spectral efficiency technique, combined with the MCP-EBPSK would certainly bring better performance. In this paper we improved the impacting filter and designed the filter bank by adding zeros to the impacting filters at the notch frequencies to depress the inter-channel interference (ICI). Use the QPSO (Quantum-behaved Particle Swarm Optimization) algorithm to obtain the filter bank's parameters, the simulation shown that though the subcarriers were time-frequency aliasing and nonorthogonal, the impacting filter bank could separate the composite signal and demodulated properly

  16. Substrate-induced coagulation (SIC) of nano-disperse alumina in non-aqueous media: The dispersibility and stability of alumina in N-methyl-2-pyrrolidinone

    OpenAIRE

    Basch, Angelika; Strnad, Simona

    2011-01-01

    This work investigated colloidal properties such as the zeta-potential, the electrophoretic mobilities and the wetting behaviour of alumina dispersed in non-aqueous media. Non-aqueous dispersions of alumina were prepared in the solvent N-methyl-2-pyrrolidinone (NMP). The wetting behaviour of alumina in NMP was characterized by the powder contact angle method and the Wilhemy plate method. The behaviour of the dispersion should provide information for the development of a substrate-induced coag...

  17. A General Procedure for Surface Modification of Nano-alumina and Its Application to Dendrimers

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    A general procedure for surface modification of nano-alumina using N, N'-dicyclohexyl-carbodiimide (DCC) mediated amidation is reported. Aliphatic and aromatic carboxylic acids reacted smoothly with nano-alumina pretreated with 3-aminopropyltriethoxysilane in the presence of DCC, giving modified aluminas having organic surfaces. The grafted aluminas have been characterized qualitatively by FT-IR or 13C CPMAS NMR spectroscopy, and quantitatively by thermogravimetric analysis and elemental analysis. The procedure was applied to polyether dendrons bearing carboxyl groups at the focal points, giving successful grafting of dendrimers onto nano-alumina.

  18. Effect of La2O3 on Microstructure and Transmittance of Transparent Alumina Ceramics

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    Optically transparent alumina ceramics were fabricated by conventional process and sintered without pressure in H2 atmosphere. The results indicate that relative densities of alumina specimens increase to theoretical densities (T.D.) with increasing content of La2O3. With increasing holding time during sintering, much less pores and larger grains were found in the sintered alumina samples. Higher transmittance was achieved in alumina codoped with MgO and La2O3 as compared with that doped with MgO only. The total-transmittance of alumina sample is up to 86% at a wavelength range of 300~800 nm.

  19. CCL2/MCP-I genotype-phenotype relationship in latent tuberculosis infection.

    Directory of Open Access Journals (Sweden)

    Rabia Hussain

    Full Text Available Among the known biomarkers, chemokines, secreted by activated macrophages and T cells, attract groups of immune cells to the site of infection and may determine the clinical outcome. Association studies of CCL-2/MCP-1 -2518 A/G functional SNP linked to high and low phenotypes with tuberculosis disease susceptibility have shown conflicting results in tuberculosis. Some of these differences could be due the variability of latent infection and recent exposure in the control groups. We have therefore carried out a detailed analysis of CCL-2 genotype SNP -2518 (A/G transition with plasma CCL-2 levels and related these levels to tuberculin skin test positivity in asymptomatic community controls with no known exposure to tuberculosis and in recently exposed household contacts of pulmonary tuberculosis patients. TST positivity was linked to higher concentrations of plasma CCL2 (Mann Whitney U test; p = 0.004 and was more marked when the G allele was present in TST+ asymptomatic controls (A/G; p = 0.01. Recent exposure also had a significant effect on CCL-2 levels and was linked to the G allele (p = 0.007. Therefore association studies for susceptibility or protection from disease should take into consideration the PPD status as well as recent exposure of the controls group used for comparison. Our results also suggest a role for CCL-2 in maintaining the integrity of granuloma in asymptomatic individuals with latent infection in high TB burden settings. Therefore additional studies into the role of CCL-2 in disease reactivation and progression are warranted.

  20. Semiconductor Yield Analysis and Multi-Chip Package (MCP) Die Pairing Optimization using Machine Learning

    Institute of Scientific and Technical Information of China (English)

    Randall Goodwin; Russell Miller; Eugene Tuv; Alexander Borisov

    2006-01-01

    Machine Learning, Artificial Intelligence (AI) and Statistical Learning are related mathematical fields which utilize computer algorithms to create models for the purposes of data description and/or prediction. Some well known examples include biometric identification and authorization systems, speech recognition and user targeted internet advertising. Statistical Learning, which we will use in this paper, also has many applications in semiconductor manufacturing.Some of the challenging characteristics of semiconductor data include high dimensionality, mixtures of categorical and numeric data, non-randomly missing data, non-Gaussian and multimodal distributions, nonlinear complex relationships, noise, outliers and temporal dependencies. These challenges are becoming particularly acute as the quantity of available data increases and the ability to trace lots, wafers, die, and packages throughout the full fab, wafer test, assembly and final test manufacturing flow improves. Statistical-learning techniques are applied to address these challenges. In this paper we discuss the advancement and applications of Tree based classification and regression methods to semiconductor data. We begin the paper with a description of the problem, followed by and overview of the statistical-learning techniques we use in our case studies. We then describe how the challenges presented by semiconductor data were addressed with original extensions to tree-based and kernel-based methods. Next, we review four case studies: home sales price prediction, signal identification/separation, final speed bin classification and die pairing optimization for Multi-Chip Packages (MCP). Results from the case studies demonstrate how statistical-learning addresses the challenges presented by semiconductor manufacturing data and enables improved data discovery and prediction when compared to traditional statistical approaches.

  1. Capacitively coupled pickup in MCP-based photodetectors using a conductive metallic anode

    Science.gov (United States)

    Angelico, E.; Seiss, T.; Adams, B.; Elagin, A.; Frisch, H.; Spieglan, E.

    2017-02-01

    We have designed and tested a robust 20×20 cm2 thin metal film internal anode capacitively coupled to an external array of signal pads or micro-strips for use in fast microchannel plate photodetectors. The internal anode, in this case a 10 nm-thick NiCr film deposited on a 96% pure Al2O3 3 mm-thick ceramic plate and connected to HV ground, provides the return path for the electron cascade charge. The multi-channel pickup array consists of a printed-circuit card or glass plate with metal signal pickups on one side and the signal ground plane on the other. The pickup can be put in close proximity to the bottom outer surface of the sealed photodetector, with no electrical connections through the photodetector hermetic vacuum package other than a single ground connection to the internal anode. Two pickup patterns were tested using a small commercial MCP-PMT as the signal source: 1) parallel 50 Ω 25-cm-long micro-strips with an analog bandwidth of 1.5 GHz, and 2) a 20×20 cm2 array of 2-dimensional square 'pads' with sides of 1.27 cm or 2.54 cm. The rise-time of the fast input pulse is maintained for both pickup patterns. For the pad pattern, we observe 80% of the directly coupled amplitude. For the strip pattern we measure 34% of the directly coupled amplitude on the central strip of a broadened signal. The physical decoupling of the photodetector from the pickup pattern allows easy customization for different applications while maintaining high analog bandwidth.

  2. Gas and surface diffusion in modified γ-alumina systems

    NARCIS (Netherlands)

    Uhlhorn, R.J.R.; Keizer, K.; Burggraaf, A.J.

    1989-01-01

    The transport of pure gases through a microporous membrane is described. The alumina-based membrane (pores 2.5-4 nm) is suitable for Knudsen diffusion separation. To improve the separation factor, interaction with and mobility on the pore wall of one of the gases of a mixture is necessary. To introd

  3. Experiments on individual alumina-supported adatoms and clusters

    Science.gov (United States)

    Nilius, N.; Cörper, A.; Bozdech, G.; Ernst, N.; Freund, H.-J.

    2001-08-01

    To contribute to an understanding of growth conditions and electronic properties of metal clusters on technologically relevant oxides we have examined the mobility of individual, alumina-supported Pt-adatoms and the optical properties of single supported Ag-clusters. Using field-ion microscopy (FIM) we have prepared and imaged an individual Pt-adatom at approximately 40 K, both on the apex plane of a [1 1 0]-oriented NiAl tip and on a thin alumina film, grown on the same NiAl specimen by oxidation. On the alumina film, the onset temperature for Pt surface diffusion approaches 100 K being distinctively lower than the value 165 K measured on NiAl(1 1 0). Employing the tip of a scanning tunneling microscope (STM) as a local electron source, photon emission from individual, alumina-supported Ag-clusters was spectroscopically analyzed. The occurrence of a distinct emission line is explained by the decay of a collective electron oscillation (Mie-plasmon resonance). For decreasing Ag-cluster diameter, the emission lines (i) shift to higher energies and (ii) their widths increase. To explain these observations, we discuss (i) the reduced screening of the plasmon oscillation due to the Ag 4d electrons and (ii) an enhanced electron surface scattering rate in small clusters.

  4. Osseointegration of alumina bioceramic granules: A comparative experimental study

    Science.gov (United States)

    Rerikh, V. V.; Avetisyan, A. R.; Zaydman, A. M.; Anikin, K. A.; Bataev, V. A.; Nikulina, A. A.; Sadovoy, M. A.; Aronov, A. M.; Semantsova, E. S.

    2016-08-01

    To perform a comparative analysis of osseointegration of bioceramic alumina-based granules, hydroxyapatite-based granules, and deproteinized bone granules. The experiment was conducted on 52 adult male Kyoto-Wistar rats weighing 350 to 520 g. The animals were divided into five matched groups that differed only in the type of an implanted material. The granules were implanted in the lumbar vertebral bodies and in the distal right femur of each laboratory animal. Two months after surgery, the animals were euthanized, followed by tissue sampling for morphological studies. An examination of specimens from the groups with implanted alumina granules revealed the newly formed trabecular bone with remodeling signs. The bone tissue filled the intragranular space, tightly adhering to the granule surface. There was no connective tissue capsule on the border between bone tissue and alumina granules. Cylindrical bioceramic alumina-based granules with an open internal channel have a higher strength surpassing than that of analogs and the osseointegration ability close to that of hydroxyapatite and deproteinized bone granules.

  5. Laser-induced prenucleation of alumina for electroless plating

    NARCIS (Netherlands)

    Shrivastva, P.B.; Harteveld, C.; Boose, C.A.; Kolster, B.H.

    1991-01-01

    This paper deals with the deposition of palladium from decomposition of a thin palladium acetate layer on rough and porous alumina ceramic surfaces by irradiating it with a UV excimer laser. The palladium acetate layer was formed from a combination of propyl glycol methyl ether acetate solvent and p

  6. Ionic Segregation on Grain Boundaries in Thermally Grown Alumina Scales

    Energy Technology Data Exchange (ETDEWEB)

    Pint, Bruce A [ORNL; Unocic, Kinga A [ORNL

    2012-01-01

    This study first examined segregation behaviour in the alumina scale formed after 100 h at 1100 C on bare and MCrAlYHfSi-coated single-crystal superalloys with {approx}10 ppma La and Y. For the bare superalloy, Hf and Ti were detected on the grain boundaries of the inner columnar alumina layer. Increasing the oxidation temperature to 1200 C for 2 h did not change the segregation behavior. With the bond coating, both Y and Hf were segregated to the grain boundaries as expected. However, there was evidence of Ti-rich oxide particles near the gas interface suggesting that Ti diffused from the superalloy through the coating. To further understand these segregation observations with multiple dopants, other alumina-forming systems were examined. Alumina scale grain boundary co-segregation of Ti with Y is common for FeCrAl alloys. Co-segregation of Hf and Ti was observed in the scale formed on co-doped NiAl. No La segregation was detected in the scale formed on NiCrAl with only a 19 ppma La addition, however, the scale was adherent.

  7. Structure and surface properties of praseodymium modified alumina

    Energy Technology Data Exchange (ETDEWEB)

    Tankov, I. [Institute of Catalysis, Bulgarian Academy of Sciences, 1113 Sofia (Bulgaria); Pawelec, B. [Instituto de Catalisis y Petroleoquimica, CSIC, Cantoblanco, 28049 Madrid (Spain); Arishtirova, K. [Institute of Catalysis, Bulgarian Academy of Sciences, 1113 Sofia (Bulgaria); Damyanova, S., E-mail: soniad@ic.bas.bg [Institute of Catalysis, Bulgarian Academy of Sciences, 1113 Sofia (Bulgaria)

    2011-10-15

    Mixed PrO{sub 2}-Al{sub 2}O{sub 3} oxides with different PrO{sub 2} content (1-20 wt.%) were prepared by wetness impregnation of {gamma}-alumina with aqueous solution of praseodymium nitrate. The samples were characterized by different techniques, using surface adsorption-desorption of N{sub 2} (S{sub BET}), thermogravimetric analysis (TGA), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), UV-vis diffuse reflectance spectroscopy (DRS), temperature-programmed reduction (TPR) and temperature-programmed desorption of CO{sub 2} (TPD-CO{sub 2}). TGA and XRD showed the presence of small praseodymium oxide species on the alumina surface. XPS and DRS detected electron deficient interaction between deposited praseodymium oxide and alumina. It was observed a lower reduction temperature for supported Pr oxide species compared to that of the bulk Pr{sub 6}O{sub 11}. TPD-CO{sub 2} studies suggested that the deposition of Pr oxide on alumina leaded to increase of the basicity of mixed oxides.

  8. Multifunctional substrates of thin porous alumina for cell biosensors

    KAUST Repository

    Toccafondi, Chiara

    2014-02-27

    We have fabricated anodic porous alumina from thin films (100/500 nm) of aluminium deposited on technological substrates of silicon/glass, and investigated the feasibility of this material as a surface for the development of analytical biosensors aiming to assess the status of living cells. To this goal, porous alumina surfaces with fixed pitch and variable pore size were analyzed for various functionalities. Gold coated (about 25 nm) alumina revealed surface enhanced Raman scattering increasing with the decrease in wall thickness, with factor up to values of approximately 104 with respect to the flat gold surface. Bare porous alumina was employed for micro-patterning and observation via fluorescence images of dye molecules, which demonstrated the surface capability for a drug-loading device. NIH-3T3 fibroblast cells were cultured in vitro and examined after 2 days since seeding, and no significant (P > 0.05) differences in their proliferation were observed on porous and non-porous materials. The effect on cell cultures of pore size in the range of 50–130 nm—with pore pitch of about 250 nm—showed no significant differences in cell viability and similar levels in all cases as on a control substrate. Future work will address combination of all above capabilities into a single device.

  9. Dynamical stability of the alpha and theta phases of alumina

    DEFF Research Database (Denmark)

    Lodziana, Zbigniew; Parlinski, K.

    2003-01-01

    Using density functional calculations the phonon dispersion relations, phonon density of states, and free energy of theta and alpha phases of alumina are investigated. The temperature dependence of the free energy indicates that entropy contributes to the destabilization of the alpha phase at the...

  10. Development of Cast Alumina-Forming Austenitic Stainless Steels

    Science.gov (United States)

    Muralidharan, G.; Yamamoto, Y.; Brady, M. P.; Walker, L. R.; Meyer, H. M., III; Leonard, D. N.

    2016-09-01

    Cast Fe-Ni-Cr chromia-forming austenitic stainless steels with Ni levels up to 45 wt.% are used at high temperatures in a wide range of industrial applications that demand microstructural stability, corrosion resistance, and creep strength. Although alumina scales offer better corrosion protection at these temperatures, designing cast austenitic alloys that form a stable alumina scale and achieve creep strength comparable to existing cast chromia-forming alloys is challenging. This work outlines the development of cast Fe-Ni-Cr-Al austenitic stainless steels containing about 25 wt.% Ni with good creep strength and the ability to form a protective alumina scale for use at temperatures up to 800-850°C in H2O-, S-, and C-containing environments. Creep properties of the best alloy were comparable to that of HK-type cast chromia-forming alloys along with improved oxidation resistance typical of alumina-forming alloys. Challenges in the design of cast alloys and a potential path to increasing the temperature capability are discussed.

  11. Development of Cast Alumina-Forming Austenitic Stainless Steels

    Science.gov (United States)

    Muralidharan, G.; Yamamoto, Y.; Brady, M. P.; Walker, L. R.; Meyer, H. M., III; Leonard, D. N.

    2016-11-01

    Cast Fe-Ni-Cr chromia-forming austenitic stainless steels with Ni levels up to 45 wt.% are used at high temperatures in a wide range of industrial applications that demand microstructural stability, corrosion resistance, and creep strength. Although alumina scales offer better corrosion protection at these temperatures, designing cast austenitic alloys that form a stable alumina scale and achieve creep strength comparable to existing cast chromia-forming alloys is challenging. This work outlines the development of cast Fe-Ni-Cr-Al austenitic stainless steels containing about 25 wt.% Ni with good creep strength and the ability to form a protective alumina scale for use at temperatures up to 800-850°C in H2O-, S-, and C-containing environments. Creep properties of the best alloy were comparable to that of HK-type cast chromia-forming alloys along with improved oxidation resistance typical of alumina-forming alloys. Challenges in the design of cast alloys and a potential path to increasing the temperature capability are discussed.

  12. Joining between alumina and metal by use of plasma sprayed Ni-Al coating on alumina. Alumina ni plasma yoshashita Ni-Al kinzoku himaku wo kaishite no alumina kinzoku tono setsugo

    Energy Technology Data Exchange (ETDEWEB)

    Murakami, N.; Kishitake, K.; Hasebe, M.; Kobayashi, T.; Murashige, K. (Kyushu Institute of Technology, Kitakyushu (Japan). Faculty of Engineering)

    1993-06-30

    A ceramic material is joined and compounded with a metal by spraying another metal on the ceramic material, and then joined with the intended metal because of small adhesion strength in both materials. Adhesion strength of the spraying metal is important even in this case. The present experiment performed plasma spraying of Ni-Al mixed powder on alumina to investigate effects of the heating on the adhesion strength. Solder joining of Ni-Al sprayed alumina with soft steel rod and copper rod was also tested. As a result, the adhesion strength of as-sprayed Ni-Al film on the alumina was about 5 MPa and maximum of 10 MPa. Heating the materials to 1173 K for 10 hours or longer provided an average strength of 20 MPa and a maximum strength of 35 MPa. Improving the adhesion strength requires spinel to be produced through reactions on the interface. It was found that alumina can be joined with metal easily by going through this film. 12 refs., 6 figs.

  13. Thin alumina and silica films by chemical vapor deposition (CVD)

    NARCIS (Netherlands)

    Hofman, R.; Morssinkhof, R.W.J.; Fransen, T.; Westheim, J.G.F.; Gellings, P.J.

    1993-01-01

    Alumina and silica coatings have been deposited by MOCVD (Metal Organic Chemical Vapor Deposition) on alloys to protect them against high temperature corrosion. Aluminium Tri-lsopropoxide (ATI) and DiAcetoxyDitertiaryButoxySilane (DAOBS) have been used as metal organic precursors to prepare these ce

  14. N-doped mesoporous alumina for adsorption of carbon dioxide

    Institute of Scientific and Technical Information of China (English)

    Jayshri A.Thote; Ravikrishna V.Chatti; Kartik S.Iyer; Vivek Kumar; Arti N.Valechha; Nitin K.Labhsetwar; Rajesh B.Biniwale; M.K.N.Yenkie; Sadhana S.Rayalu

    2012-01-01

    N-doped mesoporous alumina has been synthesized using chitosan as the biopolymer template.The adsorbent has been thoroughly investigated for the adsorption of CO2 from a simulated flue gas stream (15% CO2 balanced with N2) and compared with commercially available mesoporous alumina procured from SASOL,Germany.CO2 adsorption was studied under different conditions of pretreatment and adsorption temperature,inlet CO2 concentration and in the presence of oxygen and moisture.The adsorption capacity was determined to be 29.4 mg CO2/g of adsorbent at 55℃.This value was observed to be 4 times higher in comparison to that of commercial mesoporous alumina at a temperature of 55℃.Basicity of alumina surface coupled with the presence of nitrogen in template in synthesized sample is responsible for this enhanced CO2 adsorption.Adsorption capacity for CO2 was retained in the presence of oxygen; however moisture had a deteriorating effect on the adsorption capacity reducing it to nearly half the value.

  15. Pseudogenization of the MCP-2/CCL8 chemokine gene in European rabbit (genus Oryctolagus, but not in species of Cottontail rabbit (Sylvilagus and Hare (Lepus

    Directory of Open Access Journals (Sweden)

    van der Loo Wessel

    2012-08-01

    Full Text Available Abstract Background Recent studies in human have highlighted the importance of the monocyte chemotactic proteins (MCP in leukocyte trafficking and their effects in inflammatory processes, tumor progression, and HIV-1 infection. In European rabbit (Oryctolagus cuniculus one of the prime MCP targets, the chemokine receptor CCR5 underwent a unique structural alteration. Until now, no homologue of MCP-2/CCL8a, MCP-3/CCL7 or MCP-4/CCL13 genes have been reported for this species. This is interesting, because at least the first two genes are expressed in most, if not all, mammals studied, and appear to be implicated in a variety of important chemokine ligand-receptor interactions. By assessing the Rabbit Whole Genome Sequence (WGS data we have searched for orthologs of the mammalian genes of the MCP-Eotaxin cluster. Results We have localized the orthologs of these chemokine genes in the genome of European rabbit and compared them to those of leporid genera which do (i.e. Oryctolagus and Bunolagus or do not share the CCR5 alteration with European rabbit (i.e. Lepus and Sylvilagus. Of the Rabbit orthologs of the CCL8, CCL7, and CCL13 genes only the last two were potentially functional, although showing some structural anomalies at the protein level. The ortholog of MCP-2/CCL8 appeared to be pseudogenized by deleterious nucleotide substitutions affecting exon1 and exon2. By analyzing both genomic and cDNA products, these studies were extended to wild specimens of four genera of the Leporidae family: Oryctolagus, Bunolagus, Lepus, and Sylvilagus. It appeared that the anomalies of the MCP-3/CCL7 and MCP-4/CCL13 proteins are shared among the different species of leporids. In contrast, whereas MCP-2/CCL8 was pseudogenized in every studied specimen of the Oryctolagus - Bunolagus lineage, this gene was intact in species of the Lepus - Sylvilagus lineage, and was, at least in Lepus, correctly transcribed. Conclusion The biological function of a gene was often

  16. Spiral ligament fibrocyte-derived MCP-1/CCL2 contributes to inner ear inflammation secondary to nontypeable H. influenzae-induced otitis media

    Directory of Open Access Journals (Sweden)

    Lim David J

    2010-10-01

    Full Text Available Abstract Background Otitis media (OM, one of the most common pediatric infectious diseases, causes inner ear inflammation resulting in vertigo and sensorineural hearing loss. Previously, we showed that spiral ligament fibrocytes (SLFs recognize OM pathogens and up-regulate chemokines. Here, we aim to determine a key molecule derived from SLFs, contributing to OM-induced inner ear inflammation. Methods Live NTHI was injected into the murine middle ear through the tympanic membrane, and histological analysis was performed after harvesting the temporal bones. Migration assays were conducted using the conditioned medium of NTHI-exposed SLFs with and without inhibition of MCP-1/CCL2 and CCR2. qRT-PCR analysis was performed to demonstrate a compensatory up-regulation of alternative genes induced by the targeting of MCP-1/CCL2 or CCR2. Results Transtympanic inoculation of live NTHI developed serous and purulent labyrinthitis after clearance of OM. THP-1 cells actively migrated and invaded the extracellular matrix in response to the conditioned medium of NTHI-exposed SLFs. This migratory activity was markedly inhibited by the viral CC chemokine inhibitor and the deficiency of MCP-1/CCL2, indicating that MCP-1/CCL2 is a main attractant of THP-1 cells among the SLF-derived molecules. We further demonstrated that CCR2 deficiency inhibits migration of monocyte-like cells in response to NTHI-induced SLF-derived molecules. Immunolabeling showed an increase in MCP-1/CCL2 expression in the cochlear lateral wall of the NTHI-inoculated group. Contrary to the in vitro data, deficiency of MCP-1/CCL2 or CCR2 did not inhibit OM-induced inner ear inflammation in vivo. We demonstrated that targeting MCP-1/CCL2 enhances NTHI-induced up-regulation of MCP-2/CCL8 in SLFs and up-regulates the basal expression of CCR2 in the splenocytes. We also found that targeting CCR2 enhances NTHI-induced up-regulation of MCP-1/CCL2 in SLFs. Conclusions Taken together, we suggest that

  17. Production of recombinant capsid protein of Macrobrachium rosenbergii nodavirus (r-MCP43) of giant freshwater prawn, M. rosenbergii (de Man) for immunological diagnostic methods.

    Science.gov (United States)

    Farook, M A; Madan, N; Taju, G; Majeed, S Abdul; Nambi, K S N; Raj, N Sundar; Vimal, S; Hameed, A S Sahul

    2014-08-01

    White tail disease (WTD) caused by Macrobrachium rosenbergii nodavirus (MrNV) and extra small virus (XSV) is a serious problem in prawn hatcheries. The gene for capsid protein of MrNV (MCP43) was cloned into pRSET B expression vector. The MCP43 protein was expressed as a protein with a 6-histidine tag in Escherichia coli GJ1158 with NaCl induction. This recombinant protein, which was used to raise the antiserum in rabbits, recognized capsid protein in different WTD-infected post-larvae and adult prawn. Various immunological methods such as Western blot, dot blot and ELISA techniques were employed to detect MrNV in infected samples using the antiserum raised against recombinant MCP43 of MrNV. The dot blot assay using anti-rMCP43 was found to be capable of detecting MrNV in WTD-infected post-larvae as early as at 24 h post-infection. The antiserum raised against r-MCP43 could detect the MrNV in the infected samples at the level of 100 pg of total protein. The capsid protein of MrNV estimated by ELISA using anti-rMCP43 and pure r-MCP43 as a standard was found to increase gradually during the course of infection from 24 h p.i. to moribund stage. The results of immunological diagnostic methods employed in this study were compared with that of RT-PCR to test the efficiency of antiserum raised against r-MCP43 for the detection of MrNV. The Western blot, dot blot and ELISA detected all MrNV-positive coded samples as detected by RT-PCR.

  18. Effect of Ethylene and 1-Methylcyclopropene (1-MCP) on color and Firmness of Red and Breaker Stage Tomato Stored at Different Temperatures

    OpenAIRE

    Tadesse, T.N.; Farneti, B.; Woltering, E.J.

    2012-01-01

    The red color of the tomato fruit during ripening is due to the presence lycopene, a compound known for its antioxidant property. This compound is influenced by temperature, ethylene and 1-Methylcyclopropene (1-MCP) treatment. It was believed that ethylene application at chilling temperature could help increase the amount of lycopene content of tomato fruits. In addition, application of 1-MCP was assumed to reduce the action of ethylene on production of lycopene content and decrease loss of f...

  19. Advanced morphological analysis of patterns of thin anodic porous alumina

    Energy Technology Data Exchange (ETDEWEB)

    Toccafondi, C. [Istituto Italiano di Tecnologia, Department of Nanophysics, Via Morego 30, Genova I 16163 (Italy); Istituto Italiano di Tecnologia, Department of Nanostructures, Via Morego 30, Genova I 16163 (Italy); Stępniowski, W.J. [Department of Advanced Materials and Technologies, Faculty of Advanced Technologies and Chemistry, Military University of Technology, 2 Kaliskiego Str., 00-908 Warszawa (Poland); Leoncini, M. [Istituto Italiano di Tecnologia, Department of Nanostructures, Via Morego 30, Genova I 16163 (Italy); Salerno, M., E-mail: marco.salerno@iit.it [Istituto Italiano di Tecnologia, Department of Nanophysics, Via Morego 30, Genova I 16163 (Italy)

    2014-08-15

    Different conditions of fabrication of thin anodic porous alumina on glass substrates have been explored, obtaining two sets of samples with varying pore density and porosity, respectively. The patterns of pores have been imaged by high resolution scanning electron microscopy and analyzed by innovative methods. The regularity ratio has been extracted from radial profiles of the fast Fourier transforms of the images. Additionally, the Minkowski measures have been calculated. It was first observed that the regularity ratio averaged across all directions is properly corrected by the coefficient previously determined in the literature. Furthermore, the angularly averaged regularity ratio for the thin porous alumina made during short single-step anodizations is lower than that of hexagonal patterns of pores as for thick porous alumina from aluminum electropolishing and two-step anodization. Therefore, the regularity ratio represents a reliable measure of pattern order. At the same time, the lower angular spread of the regularity ratio shows that disordered porous alumina is more isotropic. Within each set, when changing either pore density or porosity, both regularity and isotropy remain rather constant, showing consistent fabrication quality of the experimental patterns. Minor deviations are tentatively discussed with the aid of the Minkowski measures, and the slight decrease in both regularity and isotropy for the final data-points of the porosity set is ascribed to excess pore opening and consequent pore merging. - Highlights: • Thin porous alumina is partly self-ordered and pattern analysis is required. • Regularity ratio is often misused: we fix the averaging and consider its spread. • We also apply the mathematical tool of Minkowski measures, new in this field. • Regularity ratio shows pattern isotropy and Minkowski helps in assessment. • General agreement with perfect artificial patterns confirms the good manufacturing.

  20. Synthesis and structural evaluation of freeze-cast porous alumina

    Energy Technology Data Exchange (ETDEWEB)

    Souza, Douglas F., E-mail: souzadf@outlook.com [Department of Metallurgical and Materials Engineering, Federal University of Minas Gerais — UFMG, Avenida Presidente Antônio Carlos, 6627, Campus UFMG, Belo Horizonte, MG CEP: 31270-901, Escola de Engenharia, bloco 2, sala 2230 (Brazil); Nunes, Eduardo H.M., E-mail: eduardohmn@gmail.com [Department of Metallurgical and Materials Engineering, Federal University of Minas Gerais — UFMG, Avenida Presidente Antônio Carlos, 6627, Campus UFMG, Belo Horizonte, MG CEP: 31270-901, Escola de Engenharia, bloco 2, sala 2230 (Brazil); Pimenta, Daiana S.; Vasconcelos, Daniela C.L. [Department of Metallurgical and Materials Engineering, Federal University of Minas Gerais — UFMG, Avenida Presidente Antônio Carlos, 6627, Campus UFMG, Belo Horizonte, MG CEP: 31270-901, Escola de Engenharia, bloco 2, sala 2230 (Brazil); Nascimento, Jailton F.; Grava, Wilson [Petrobras/CENPES, Avenida Horácio Macedo 950, Cidade Universitária, Ilha do Fundão, Rio de Janeiro, RJ CEP:21941-915 (Brazil); Houmard, Manuel [Department of Materials Engineering and Civil Construction, Federal University of Minas Gerais — UFMG, Avenida Presidente Antônio Carlos, 6627, Campus UFMG, Belo Horizonte, MG CEP: 31270-901, Escola de Engenharia, bloco 1, sala 3304 (Brazil); Vasconcelos, Wander L., E-mail: wlv@demet.ufmg.br [Department of Metallurgical and Materials Engineering, Federal University of Minas Gerais — UFMG, Avenida Presidente Antônio Carlos, 6627, Campus UFMG, Belo Horizonte, MG CEP: 31270-901, Escola de Engenharia, bloco 2, sala 2230 (Brazil)

    2014-10-15

    In this work we fabricated alumina samples by the freeze-casting technique using tert-butanol as the solvent. The prepared materials were examined by scanning electron microscopy and X-ray microtomography. Next, they were coated with sol–gel silica films by dip-coating. Permeability tests were carried out in order to assess the permeation behavior of the materials processed in this study. We observed that the sintering time and alumina loading showed a remarkable effect on both the structural properties and flexural strength of the freeze-cast samples. Nitrogen adsorption tests revealed that the silica prepared in this study exhibited a microporous structure. It was observed that the presence of silica coatings on the alumina surface decreased the CO{sub 2} permeance by about one order of magnitude. Because of the similar kinetic diameters of nitrogen and carbon dioxide, the CO{sub 2}/N{sub 2} system showed a separation efficiency that was lower than that observed for the He/CO{sub 2} and He/N{sub 2} systems. We noticed that increasing the feed pressure improved the separation capacity of the obtained materials. - Highlights: • Porous alumina samples obtained by the freeze-casting technique • Microporous silica coating prepared by a simple sol–gel dip-coating methodology • Samples examined by SEM, μ-CT, and nitrogen sorption tests • Mechanical tests were carried out in the freeze-cast samples. • The presence of silica coatings on the alumina surface decreased the CO{sub 2} permeance.

  1. Monte Carlo Simulations of High-speed, Time-gated MCP-based X-ray Detectors: Saturation Effects in DC and Pulsed Modes and Detector Dynamic Range

    Energy Technology Data Exchange (ETDEWEB)

    Craig Kruschwitz, Ming Wu, Ken Moy, Greg Rochau

    2008-10-31

    We present here results of continued efforts to understand the performance of microchannel plate (MCP)–based, high-speed, gated, x-ray detectors. This work involves the continued improvement of a Monte Carlo simulation code to describe MCP performance coupled with experimental efforts to better characterize such detectors. Our goal is a quantitative description of MCP saturation behavior in both static and pulsed modes. We have developed a new model of charge buildup on the walls of the MCP channels and measured its effect on MCP gain. The results are compared to experimental data obtained with a short-pulse, high-intensity ultraviolet laser; these results clearly demonstrate MCP saturation behavior in both DC and pulsed modes. The simulations compare favorably to the experimental results. The dynamic range of the detectors in pulsed operation is of particular interest when fielding an MCP–based camera. By adjusting the laser flux we study the linear range of the camera. These results, too, are compared to our simulations.

  2. Distribution of monocyte chemoattractant protein-1 (MCP-1 A-2518G) and chemokine receptor (CCR2-V64Ι) gene variants in hyperbilirubinemic newborns.

    Science.gov (United States)

    Narter, Fatma; Bireller, Elif Sinem; Engin, Can; Catmakas, Tolga; Narter, Fehmi; Ergen, Arzu; Cakmakoglu, Bedia

    2015-01-01

    Hyperbilirubinemia is one of the most crucial syndromes, which is characterized by high levels of bilirubin, especially when it occurs in newborns. Bilirubin has cytoprotective properties with an antioxidant function and plays several major roles in the inflammation process with its members such as chemokines. The monocyte chemoattractant protein-1 (MCP-1) is a member of the C-C chemokine family and it has been associated with the inflammatory process. There are no data on the chemokine and its receptor genotypes in hyperbilirubinemic newborns to show their distribution. The aim of this study is to investigate the genotypic relationship of MCP-1 and its receptor CCR2-V64Ι with hyperbilirubinemia in Turkish newborns. A total of 85 newborns were included in the study: 20 infants with hyperbilirubinemia (hyperbilirubinemic group) and 65 infants without hyperbilirubinemia (non-hyperbilirubinemic group). Genotyping of MCP-1 A-2518G and CCR2-V64Ι gene polymorphisms were detected by PCR-RFLP, respectively. MCP-1 GG genotype in patients was higher than the controls and this genotype had 2.69 times higher risk for hyperbilirubinemic neonates (P: 0.20). The frequency of MCP-1 A-2518G G+ genotype in patients was higher than the controls (55.0% and 38.5%, respectively). The results of our preliminary study suggest that MCP-1 G+ genotype has the ability to increase the hyperbilirubinemia risk of newborns. These results should be focused on to research on a larger scale to confirm the findings.

  3. Effect of the Cooling System and 1-MCP on the Incidence of Superficial Scald in ‘Granny Smith’ Apples Efecto del Sistema de Enfriamiento y 1-MCP sobre la Incidencia de Escaldado Superficial en Manzanas ‘Granny Smith’

    Directory of Open Access Journals (Sweden)

    Claudia Moggia

    2009-09-01

    Full Text Available A study was carried out to determine the effects of two cooling systems and the application of 1-methylcyclopropene (1-MCP, SmartFreshTM on the incidence of superficial scald in apples (Malus domestica Borkh. cv. Granny Smith. Fruit were collected from a commercial orchard (Colbún, Maule Region, Chile during 2004-2005 season. A completely randomized design was used in a 2 x 2 factorial arrangement, using cooling systems (normal and step-wise cooling and application of 1-MCP (0 and 625 nL L-1 i.a. as the main factors. Fruit from normal cooling were kept at 0 °C throughout the storage period (180 days. Step-wise cooling consisted of storing the fruit at 10 °C for 10 days; 4 °C for the next 20 days and 0 °C for the remaining 150 days. Every month, maturity indices and the chemicals, global antioxidant content (AO, α-farnesene (AF and conjugated trienes (TC, were measured. Incidence of superficial scald was determined after 180 days of storage, plus 10 days at 20 °C . The application of 1-MCP with both cooling systems was capable of maintaining firmness values around 8,2 kg up to the end of the storage period, as well as decreasing the concentration of AF, TC and AO during storage. Incidence of superficial scald on fruit with 1-MCP was 0%, regardless of the type of cooling. Among treatments without 1-MCP, step-wise-cooling was more effective in preventing superficial scald, resulting in 1.3% incidence compared to 75.6% with the normal cooling system. Nevertheless, from the fourth month onwards firmness was lower than that required for export.Se desarrolló un estudio para determinar el efecto de dos sistemas de enfriamiento y la aplicación de 1-metilciclopropeno (1-MCP, SmartFreshTM sobre la incidencia de escaldado superficial en manzanas (Malus domestica Borkh. cv. Granny Smith, colectadas de un huerto comercial (Colbún, Región del Maule, Chile durante la temporada 2004-2005. El ensayo consistió en un diseño completamente al azar con

  4. Nanoparticle-based capillary electroseparation of proteins in polymer capillaries under physiological conditions

    DEFF Research Database (Denmark)

    Nilsson, C.; Harwigsson, I.; Becker, K.

    2010-01-01

    Totally porous lipid-based liquid crystalline nanoparticles were used as pseudostationary phase for capillary electroseparation with LIF detection of proteins at physiological conditions using unmodified cyclic olefin copolymer capillaries (Topas (R), 6.7 cm effective length). In the absence of n...... at protein friendly conditions. The developed capillary-based method facilitates future electrochromatography of proteins on polymer-based microchips under physiological conditions and enables the initial optimization of separation conditions in parallel to the chip development....

  5. EFFECTIVE ELASTIC PROPERTIES OF ALUMINA-ZIRCONIA COMPOSITE CERAMICS - PART 4. TENSILE MODULUS OF POROUS ALUMINA AND ZIRCONIA

    Directory of Open Access Journals (Sweden)

    W. Pabst

    2004-12-01

    Full Text Available In this fourth paper of a series on the effective elastic properties of alumina-zirconia composite ceramics the influence of porosity on the effective tensile modulus of alumina and zirconia ceramics is discussed. The examples investigated are alumina and zirconia ceramics prepared from submicron powders by starch consolidation casting using two different types of starch, potato starch (median size D50 =47.2 µm and corn starch (median size D50 =13.7 µm. The dependence of effective tensile moduli E, on the porosity f, measured for porosities in the ranges of approx. 19-55 vol.% and 10-42 vol.% for alumina and zirconia, respectively, using a resonant frequency technique, was evaluated by fitting with various model relations, including newly developed ones. A detailed comparison of the fitting results suggests the superiority of the new relation E/E0 = (1 - f·(1 - f/fC, developed by the authors (with the tensile modulus of the dense ceramic material E0 and the critical porosity fC, over most other existing fit models. Only for special purposes and well-behaved data sets the recently proposed exponential relation E/E0 = exp [-Bf/(1 - f] and the well-known Phani-Niyogi relation E/E0 = (1 - f/fCN might be preferable.

  6. Porous alumina, zirconia and alumina/zirconia for bone repair: fabrication, mechanical and in vitro biological response.

    Science.gov (United States)

    Hadjicharalambous, Chrystalleni; Buyakov, Ales; Buyakova, Svetlana; Kulkov, Sergey; Chatzinikolaidou, Maria

    2015-04-23

    Zirconia (ZrO2) and alumina (Al2O3) based ceramics are widely used for load-bearing applications in bone repair due to their excellent mechanical properties and biocompatibility. They are often regarded as bioinert since no direct bone-material interface is created unless a porous structure intercedes, leading to better bone bonding. In this regard, investigating interactions between cells and porous ceramics is of great interest. In the present study, we report on the successful fabrication of sintered alumina A-61, zirconia Z-50 and zirconia/alumina composite ZA-60 ceramics with medium porosities of 61, 50 and 60%, respectively, indicating a bimodal pore size distribution and good interconnectivity. They exhibit elastic moduli of 3-10 GPa and compressive strength values of 60-240 MPa, similar to those of human cortical bone.We performed in vitro cell-material investigations comparing the adhesion, proliferation and differentiation of mouse pre-osteoblasts MC3T3-E1 on the three porous materials. While all three ceramics demonstrate a strong cell attachment, better cell spreading is observed on zirconia-containing substrates. Significantly higher cell growth was quantified on the latter ceramics, revealing an increased alkaline phosphatase activity, higher collagen production and increased calcium biomineralization compared to A-61. Hence, these porous zirconia-containing ceramics elicit superior biological responses over porous alumina of similar porosity, promoting enhanced biological interaction, with potential use as non-degradable bone grafts or as implant coatings.

  7. Applicability of chemically modified capillaries in chiral capillary electrophoresis for methamphetamine profiling.

    Science.gov (United States)

    Iwata, Yuko T; Mikuma, Toshiyasu; Kuwayama, Kenji; Tsujikawa, Kenji; Miyaguchi, Hajime; Kanamori, Tatsuyuki; Inoue, Hiroyuki

    2013-03-10

    We examined the applicability of chemically modified capillaries on the chiral capillary electrophoresis of essential compounds for methamphetamine (MA) profiling (MA, amphetamine, ephedrine, pseudoephedrine, norephedrine, and norpseudoephedrine) using highly sulfated γ-cyclodextrin as a chiral selector. Four types of chemically modified capillaries, namely, FunCap-CE/Type D (possessing diol groups), Type A (amino groups), Type C (carboxyl groups), and Type S (sulfate groups), were evaluated. Repeatability, speed, and good chiral resolution sufficient for routine MA profiling were achieved with the Type S capillary.

  8. Cycloaliphatic epoxy resin coating for capillary electrophoresis.

    Science.gov (United States)

    Shah, Roopa S; Wang, Qinggang; Lee, Milton L

    2002-04-05

    Coating the interior surface of a fused-silica capillary with a polymeric material has long been used in capillary electrophoresis (CE) to reduce or eliminate electroosmotic flow and suppress adsorption. A cycloaliphatic epoxide-based resin was bonded to silane treated capillaries and crosslinked with a curing agent. The epoxy resin coating significantly reduced electroosmotic flow over a pH range of 3-10. This coating was sufficiently hydrophilic to suppress protein adsorption. The epoxy resin coated capillary was used to separate several acidic and basic proteins and peptides. Separation efficiencies greater than 400,000 theoretical plates were achieved. The relative standard deviations in migration times for proteins were methods.

  9. Uptake of water droplets by nonwetting capillaries

    CERN Document Server

    Willmott, Geoff R; Hendy, Shaun C

    2010-01-01

    We present direct experimental evidence that water droplets can spontaneously penetrate non-wetting capillaries, driven by the action of Laplace pressure due to high droplet curvature. Using high-speed optical imaging, microcapillaries of radius 50 to 150 micron, and water microdroplets of average radius between 100 and 1900 micron, we demonstrate that there is a critical droplet radius below which water droplets can be taken up by hydrophobised glass and polytetrafluoroethylene (PTFE) capillaries. The rate of capillary uptake is shown to depend strongly on droplet size, with smaller droplets being absorbed more quickly. Droplet size is also shown to influence meniscus motion in a pre-filled non-wetting capillary, and quantitative measurements of this effect result in a derived water-PTFE static contact angle between 96 degrees and 114 degrees. Our measurements confirm recent theoretical predictions and simulations for metal nanodroplets penetrating carbon nanotubes (CNTs). The results are relevant to a wide ...

  10. Capillary detectors for high resolution tracking

    CERN Document Server

    Annis, P

    1997-01-01

    We present a new tracking device based on glass capillary bundles or layers filled with highly purified liquid scintillator and read out at one end by means of image intensifiers and CCD devices. A large-volume prototype consisting of 5 × 105 capillaries with a diameter of 20 μm and a length of 180 cm and read out by a megapixel CCD has been tested with muon and neutrino beams at CERN. With this prototype a two track resolution of 33 μm was achieved with passing through muons. Images of neutrino interactions in a capillary bundle have also been acquired and analysed. Read-out chains based on Electron Bombarded CCD (EBCCD) and image pipeline devices are also investigated. Preliminary results obtained with a capillary bundle read out by an EBCCD are presented.

  11. CAPILLARY ELECTROPHORETIC BEHAVIOR OF SEVEN SULFONYLUREAS

    Science.gov (United States)

    The electrophoretic behavior of bensulfuron Me, sulfometuron Me, nicosulfuron (Accent), chlorimuron Et, thifensulfuron Me (Harmony), metsulfuron Me, and chlorsulfuron was studied under capillary zone electrophoresis (CZE) and micellar electrokinetic chromatography (MEKC) conditio...

  12. Capillary electrochromatography using fibers as stationary phases.

    Science.gov (United States)

    Jinno, K; Watanabe, H; Saito, Y; Takeichi, T

    2001-10-01

    Fiber-packed capillary columns have been evaluated in chromatographic performance in capillary electrochromatography (CEC). The change of electroosmotic flow (EOF) velocity and selectivity using different kinds of fiber materials was examined. Although the EOF velocity among the different fiber packed columns was almost the same, retention of parabens was larger on the Kevlar-packed column than on the Zylon-packed one, and was larger on the as-span-type fiber-packed column than on the high-modulus-type packed one. Using 200 microm ID x 5 cm Kevlar packed column combined with a 100 microm ID x 20 cm precolumn capillary and a 530 microm ID x 45 cm postcolumn capillary, the separation of three parabens within 30 s was achieved. Other compounds were also separated in a few minutes by the fiber-packed CEC method.

  13. Capillary Optics generate stronger X-rays

    Science.gov (United States)

    1996-01-01

    NASA scientist, in the Space Sciences lab at Marshall, works with capillary optics that generate more intense X-rays than conventional sources. This capability is useful in studying the structure of important proteins.

  14. Unusual intraosseous capillary hemangioma of the mandible.

    Science.gov (United States)

    Dereci, Omur; Acikalin, Mustafa Fuat; Ay, Sinan

    2015-01-01

    Intraosseous hemangioma is a benign vascular neoplasm, which is mostly seen in vertebrae, maxillofacial bones, and long bones. Intraosseous hemangioma is rarely seen on jaw bones compared to other skeletal bones and usually occurs in the cavernous form. Capillary intraosseous hemangioma of jaws is an uncommon form of intraosseous hemangioma and has not been thoroughly described so far. In this study, a case of capillary intraosseous hemangioma of the mandible was presented with relevant literature review.

  15. Unusual intraosseous capillary hemangioma of the mandible

    OpenAIRE

    Dereci, Omur; Acikalin, Mustafa Fuat; Ay, Sinan

    2015-01-01

    Intraosseous hemangioma is a benign vascular neoplasm, which is mostly seen in vertebrae, maxillofacial bones, and long bones. Intraosseous hemangioma is rarely seen on jaw bones compared to other skeletal bones and usually occurs in the cavernous form. Capillary intraosseous hemangioma of jaws is an uncommon form of intraosseous hemangioma and has not been thoroughly described so far. In this study, a case of capillary intraosseous hemangioma of the mandible was presented with relevant liter...

  16. Bundled capillary electrophoresis using microstructured fibres.

    Science.gov (United States)

    Rogers, Benjamin; Gibson, Graham T T; Oleschuk, Richard D

    2011-01-01

    Joule heating, arising from the electric current passing through the capillary, causes many undesired effects in CE that ultimately result in band broadening. The use of narrow-bore capillaries helps to solve this problem as smaller cross-sectional area results in decreased Joule heating and the rate of heat dissipation is increased by the larger surface-to-volume ratio. Issues arising from such small capillaries, such as poor detection sensitivity, low loading capacity and high flow-induced backpressure (complicating capillary loading) can be avoided by using a bundle of small capillaries operating simultaneously that share buffer reservoirs. Microstructured fibres, originally designed as waveguides in the telecommunication industry, are essentially a bundle of parallel ∼5 μm id channels that extend the length of a fibre having otherwise similar dimensions to conventional CE capillaries. This work presents the use of microstructured fibres for CZE, taking advantage of their relatively high surface-to-volume ratio and the small individual size of each channel to effect highly efficient separations, particularly for dye-labelled peptides.

  17. Ion guiding in curved glass capillaries

    Energy Technology Data Exchange (ETDEWEB)

    Kojima, Takao M. [Atomic Physics Laboratory, RIKEN, 2-1 Hirosawa, Wako, Saitama 351-0198 (Japan); Ikeda, Tokihiro [Nishina Center for Accelerator-Based Science, RIKEN, 2-1 Hirosawa, Wako, Saitama 351-0198 (Japan); Kanai, Yasuyuki; Yamazaki, Yasunori [Atomic Physics Laboratory, RIKEN, 2-1 Hirosawa, Wako, Saitama 351-0198 (Japan)

    2015-07-01

    Straight and curved glass capillaries were tested for the guiding of 8 keV Ar{sup 8+} ion beams. The straight capillary was about 50 mm long and 0.87 mm/1.1 mm in inner/outer diameter. One of the two curved capillaries was similar, but was curved with a 270 mm radius. The other was 53 mm long, had diameters of 2.34 mm/2.99 mm, and was curved with a 150 mm radius. The corresponding bending angles of the two curved capillaries were 9.6° and 17.5°, respectively. Transmission through the straight capillary disappeared when the tilt angle was larger than 5°. The curved capillaries guided the ion beams into their corresponding bending angles, which were much larger than 5°, with transmission efficiencies of a few tens percent. This demonstrates the possibility of developing a new scheme of simple small beam deflectors and related beam optics.

  18. Cell adhesion during bullet motion in capillaries.

    Science.gov (United States)

    Takeishi, Naoki; Imai, Yohsuke; Ishida, Shunichi; Omori, Toshihiro; Kamm, Roger D; Ishikawa, Takuji

    2016-08-01

    A numerical analysis is presented of cell adhesion in capillaries whose diameter is comparable to or smaller than that of the cell. In contrast to a large number of previous efforts on leukocyte and tumor cell rolling, much is still unknown about cell motion in capillaries. The solid and fluid mechanics of a cell in flow was coupled with a slip bond model of ligand-receptor interactions. When the size of a capillary was reduced, the cell always transitioned to "bullet-like" motion, with a consequent decrease in the velocity of the cell. A state diagram was obtained for various values of capillary diameter and receptor density. We found that bullet motion enables firm adhesion of a cell to the capillary wall even for a weak ligand-receptor binding. We also quantified effects of various parameters, including the dissociation rate constant, the spring constant, and the reactive compliance on the characteristics of cell motion. Our results suggest that even under the interaction between P-selectin glycoprotein ligand-1 (PSGL-1) and P-selectin, which is mainly responsible for leukocyte rolling, a cell is able to show firm adhesion in a small capillary. These findings may help in understanding such phenomena as leukocyte plugging and cancer metastasis.

  19. The Effect of Post-Resistance Exercise Amino Acids on Plasma MCP-1 and CCR2 Expression

    Directory of Open Access Journals (Sweden)

    Adam J. Wells

    2016-07-01

    Full Text Available The recruitment and infiltration of classical monocytes into damaged muscle is critical for optimal tissue remodeling. This study examined the effects of an amino acid supplement on classical monocyte recruitment following an acute bout of lower body resistance exercise. Ten resistance-trained men (24.7 ± 3.4 years; 90.1 ± 11.3 kg; 176.0 ± 4.9 cm ingested supplement (SUPP or placebo (PL immediately post-exercise in a randomized, cross-over design. Blood samples were obtained at baseline (BL, immediately (IP, 30-min (30P, 1-h (1H, 2-h (2H, and 5-h (5H post-exercise to assess plasma concentrations of monocyte chemoattractant protein 1 (MCP-1, myoglobin, cortisol and insulin concentrations; and expressions of C-C chemokine receptor-2 (CCR2, and macrophage-1 antigen (CD11b on classical monocytes. Magnitude-based inferences were used to provide inferences on the true effects of SUPP compared to PL. Changes in myoglobin, cortisol, and insulin concentrations were similar between treatments. Compared to PL, plasma MCP-1 was “very likely greater” (98.1% likelihood effect in SUPP at 2H. CCR2 expression was “likely greater” at IP (84.9% likelihood effect, “likely greater” at 1H (87.7% likelihood effect, “very likely greater” at 2H (97.0% likelihood effect, and “likely greater” at 5H (90.1% likelihood effect in SUPP, compared to PL. Ingestion of SUPP did not influence CD11b expression. Ingestion of an amino acid supplement immediately post-exercise appears to help maintain plasma MCP-1 concentrations and augment CCR2 expression in resistance trained men.

  20. Inhibitory effect of microRNA-27b on interleukin 17 (IL-17)-induced monocyte chemoattractant protein-1 (MCP1) expression.

    Science.gov (United States)

    Huang, K D; Shen, Y; Wei, X; Zhang, F Q; Liu, Y Y; Ma, L

    2016-07-14

    We investigated the effect of microRNA-27b (miR-27b), a gene expression regulatory factor, on the expression of monocyte chemoattractant protein-1 (MCP1) stimulated by interleukin 17 (IL-17). After IL-17 had been added to H9C2 cardiomyocytes, an miR-27b mimic was transfected into the H9C2 cells. The mRNA expression levels of miR-27b and MCP1 in the H9C2 cells were detected by SYBR green I fluorescence quantitative reverse transcription polymerase chain reaction. Enzyme-linked immunosorbent assay was used to measure the expression levels of MCP1 protein in the H9C2 cells. The expression of MCP1 mRNA in the H9C2 cells began to increase 2 h after IL-17 stimulation, reached a peak at 4 h, and then decreased. The MCP1 protein level increased gradually in the 24 h following IL-17 stimulation. After transfection with the miR-27b mimic, the expression of miR-27b in the H9C2 cells significantly increased than that in the miRNA negative control group (P < 0.01). The MCP1 mRNA and protein levels in the miR-27b mimic + IL-17 group were significantly reduced than that in the miRNA negative control + IL-17 group (P < 0.01). miR-27b inhibited IL-17-induced MCP1 expression in the H9C2 cells, which demonstrates that treatment with microRNA could alleviate myocardial injury in viral myocarditis.

  1. Increased Eotaxin and MCP-1 Levels in Serum from Individuals with Periodontitis and in Human Gingival Fibroblasts Exposed to Pro-Inflammatory Cytokines.

    Science.gov (United States)

    Boström, Elisabeth A; Kindstedt, Elin; Sulniute, Rima; Palmqvist, Py; Majster, Mirjam; Holm, Cecilia Koskinen; Zwicker, Stephanie; Clark, Reuben; Önell, Sebastian; Johansson, Ingegerd; Lerner, Ulf H; Lundberg, Pernilla

    2015-01-01

    Periodontitis is a chronic inflammatory disease of tooth supporting tissues resulting in periodontal tissue destruction, which may ultimately lead to tooth loss. The disease is characterized by continuous leukocyte infiltration, likely mediated by local chemokine production but the pathogenic mechanisms are not fully elucidated. There are no reliable serologic biomarkers for the diagnosis of periodontitis, which is today based solely on the degree of local tissue destruction, and there is no available biological treatment tool. Prompted by the increasing interest in periodontitis and systemic inflammatory mediators we mapped serum cytokine and chemokine levels from periodontitis subjects and healthy controls. We used multivariate partial least squares (PLS) modeling and identified monocyte chemoattractant protein-1 (MCP-1) and eotaxin as clearly associated with periodontitis along with C-reactive protein (CRP), years of smoking and age, whereas the number of remaining teeth was associated with being healthy. Moreover, body mass index correlated significantly with serum MCP-1 and CRP, but not with eotaxin. We detected higher MCP-1 protein levels in inflamed gingival connective tissue compared to healthy but the eotaxin levels were undetectable. Primary human gingival fibroblasts displayed strongly increased expression of MCP-1 and eotaxin mRNA and protein when challenged with tumor necrosis factor-α (TNF-α and interleukin-1β (IL-1β), key mediators of periodontal inflammation. We also demonstrated that the upregulated chemokine expression was dependent on the NF-κΒ pathway. In summary, we identify higher levels of CRP, eotaxin and MCP-1 in serum of periodontitis patients. This, together with our finding that both CRP and MCP-1 correlates with BMI points towards an increased systemic inflammatory load in patients with periodontitis and high BMI. Targeting eotaxin and MCP-1 in periodontitis may result in reduced leukocyte infiltration and inflammation in

  2. Aumento da expressão do MCP-1 coroidal e escleral em modelo experimental de hipercolesterolemia

    OpenAIRE

    Rogil José de Almeida Torres; Lucia Noronha; Antonio Marcelo Barbante Casella; Thaís Isabel Lumikoski; Leonardo Brandão Précoma; Caroline Luzia de Almeida Torres; Andréa Luchini; Mario Claudio Soares Sturzeneker; Dalton Bertolim Précoma

    2012-01-01

    OBJETIVO: O objetivo deste trabalho é demonstrar experimentalmente que a dieta rica em colesterol provoca aumento da expressão da MCP-1 na coroide e esclera. MÉTODO: Coelhos New Zealand foram organizados em dois grupos: GN (grupo dieta normal), composto por 8 coelhos (8 olhos), recebeu ração padrão para coelhos, durante 4 semanas; GH (grupo hipercolesterolêmico), composto por 13 coelhos (13 olhos), recebeu dieta rica em colesterol a 1% por 8 semanas. Foi realizada a dosagem sérica de colester...

  3. Capillary electrophoresis in a fused-silica capillary with surface roughness gradient.

    Science.gov (United States)

    Horká, Marie; Šlais, Karel; Karásek, Pavel; Růžička, Filip; Šalplachta, Jiří; Šesták, Jozef; Kahle, Vladislav; Roth, Michal

    2016-10-01

    The electro-osmotic flow, a significant factor in capillary electrophoretic separations, is very sensitive to small changes in structure and surface roughness of the inner surface of fused silica capillary. Besides a number of negative effects, the electro-osmotic flow can also have a positive effect on the separation. An example could be fused silica capillaries with homogenous surface roughness along their entire separation length as produced by etching with supercritical water. Different strains of methicillin-resistant and methicillin-susceptible Staphylococcus aureus were separated on that type of capillaries. In the present study, fused-silica capillaries with a gradient of surface roughness were prepared and their basic behavior was studied in capillary zone electrophoresis with UV-visible detection. First the influence of the electro-osmotic flow on the peak shape of a marker of electro-osmotic flow, thiourea, has been discussed. An antifungal agent, hydrophobic amphotericin B, and a protein marker, albumin, have been used as model analytes. A significant narrowing of the detected zones of the examined analytes was achieved in supercritical-water-treated capillaries as compared to the electrophoretic separation in smooth capillaries. Minimum detectable amounts of 5 ng/mL amphotericin B and 5 μg/mL albumin were reached with this method.

  4. Impaired skin capillary recruitment in essential hypertension is caused by both functional and structural capillary rarefaction

    NARCIS (Netherlands)

    Serne, EH; Gans, ROB; ter Maaten, JC; Tangelder, GJ; Donker, AJM; Stehouwer, CDA

    2001-01-01

    Capillary rarefaction occurs in many tissues in patients with essential hypertension and may contribute to an increased vascular resistance and impaired muscle metabolism. Rarefaction may be caused by a structural (anatomic) absence of capillaries, functional nonperfusion, or both. The aim of this s

  5. Substrate-induced coagulation (SIC) of nano-disperse alumina in non-aqueous media: The dispersibility and stability of alumina in N-methyl-2-pyrrolidinone.

    Science.gov (United States)

    Basch, Angelika; Strnad, Simona

    2011-01-20

    This work investigated colloidal properties such as the zeta-potential, the electrophoretic mobilities and the wetting behaviour of alumina dispersed in non-aqueous media. Non-aqueous dispersions of alumina were prepared in the solvent N-methyl-2-pyrrolidinone (NMP). The wetting behaviour of alumina in NMP was characterized by the powder contact angle method and the Wilhemy plate method. The behaviour of the dispersion should provide information for the development of a substrate-induced coagulation (SIC) coating process of nano-sized alumina in non-aqeous media. SIC is a dip-coating process that coats pretreated but chemically different surfaces with nano-sized particles. It was found that the anionic surfactant dioctyl sulfosuccinate (AOT) had no stabilizing effect on alumina dispersed in NMP.

  6. Study of preparation and surface morphology of self-ordered nanoporous alumina; Estudo da preparacao e da morfologia de superficie de alumina nanoporosa auto-organizada

    Energy Technology Data Exchange (ETDEWEB)

    Rodrigues, Elisa Marchezini; Martins, Maximiliano Delany, E-mail: elisamarch@gmail.com, E-mail: MG.mdm@cdtn.br [Centro de Desenvolvimento da Tecnologia Nuclear (CDTN/CNEN-MG), Belo Horizonte, MG. (Brazil); Silva, Ronald Arreguy, E-mail: arregsilva@yahoo.com.br [Centro Universitario de Belo Horizonte (UniBH), Belo Horizonte, MG (Brazil)

    2013-07-01

    Nanoporous alumina is a typical material that exhibits self-ordered nanochannels spontaneously organized in hexagonal shape. Produced by anodizing of metallic aluminum, it has been used as a template for production of materials at the nanoscale. This work aimed to study the preparation of nanoporous alumina by anodic anodizing of metallic aluminum substrates. The nanoporous alumina was prepared following the methodology proposed by Masuda and Fukuda (1995), a two-step method consisting of anodizing the aluminum sample in the potentiostatic mode, removing the layer of aluminum oxide (alumina) formed and then repeat the anodization process under the same conditions as the first anodization. This method produces nanoporous alumina with narrow pore diameter distribution and well-ordered structure. (author)

  7. Two-dimensional capillary electrophoresis: capillary isoelectric focusing and capillary zone electrophoresis with laser-induced fluorescence detection.

    Science.gov (United States)

    Dickerson, Jane A; Ramsay, Lauren M; Dada, Oluwatosin O; Cermak, Nathan; Dovichi, Norman J

    2010-08-01

    CIEF and CZE are coupled with LIF detection to create an ultrasensitive 2-D separation method for proteins. In this method, two capillaries are joined through a buffer-filled interface. Separate power supplies control the potential at the injection end of the first capillary and at the interface; the detector is held at ground potential. Proteins are labeled with the fluorogenic reagent Chromeo P503, which preserves the isoelectric point of the labeled protein. The labeled proteins were mixed with ampholytes and injected into the first-dimension capillary. A focusing step was performed with the injection end of the capillary at high pH and the interface at low pH. To mobilize components, the interface was filled with a high pH buffer, which was compatible with the second-dimension separation. A fraction was transferred to the second-dimension capillary for separation. The process of fraction transfer and second dimension separation was repeated two dozen times. The separation produced a spot capacity of 125.

  8. Catalyst materials based on plasma-processed alumina nanopowder

    Directory of Open Access Journals (Sweden)

    Dubencovs Konstantins

    2012-01-01

    Full Text Available A platinum catalyst for glycerol oxidation by molecular oxygen has been developed applying the extractive-pyrolytic method and using, as a support, a fine alumina powder with an average particle size of 30-60 nm processed by plasma technology. The extractive-pyrolytic method (EPM allows affixing small amounts of catalytic metals (1-5% with the particle size ranging from several nanometers to several tens of nanometers onto the surface of the support. The prepared material - 4.8 wt. % platinum on nano-sized alumina - can be used as a catalyst for glycerol oxidation by oxygen with conversion up to 84%, in order to produce some organic acids (glyceric and lactic acid with a selectivity of about 60%.

  9. Epitaxial growth of tungsten nanoparticles on alumina and spinel surfaces

    Energy Technology Data Exchange (ETDEWEB)

    Rodriguez-Suarez, T; Lopez-Esteban, S; Pecharroman, C; Esteban-Cubillo, A; Moya, J S [Instituto de Ciencia de Materiales de Madrid (ICMM), Consejo Superior de Investigaciones Cientificas (CSIC), C/ Sor Juana Ines de la Cruz 3, 28049, Cantoblanco, Madrid (Spain); Diaz, L A; Torrecillas, R [Nanomaterials and Nanotechnology Research Center (CINN), Consejo Superior de Investigaciones CientIficas (CSIC), C/ Francisco Pintado Fe 26, 33011, Oviedo, Asturias (Spain); Gremillard, L [Universite de Lyon, INSA-Lyon, MATEIS, UMR CNRS 5510, 20 avenue Albert Einstein, Villeurbanne F-69621 (France)], E-mail: jsmoya@icmm.csic.es

    2008-05-28

    Isolated tungsten nanoparticles ({alpha}-W and {beta}-W phase) were synthesized and epitaxially grown on alumina and spinel particle surfaces with an average tungsten size of {<=}20 nm for a low tungsten content (of {<=}1.5 vol%). Using tungsten (VI) ethoxide alcoholic solutions, tungsten trioxide hydrated precursors were attached to a ceramic grains surface as a nanoparticle coating. High-resolution transmission electron microscopy (HRTEM) micrographs showed epitaxial interfaces between alumina, spinel and metallic tungsten. This epitaxial growth is assumed to be due to the effect of water vapour on the sublimation of ortho-tungstic acid during the reduction process in a hydrogen atmosphere. The planes involved in the epitaxy were found to be (22-bar 0){sub Al2O3} parallel (121){sub W} and (311){sub MgAl2O4} parallel (110){sub W}.

  10. Melt processing of Bi--2212 superconductors using alumina

    Science.gov (United States)

    Holesinger, Terry G.

    1999-01-01

    Superconducting articles and a method of forming them, where the superconducting phase of an article is Bi.sub.2 Sr.sub.2 CaCu.sub.2 O.sub.y (Bi-2212). Alumina is combined with Bi-2212 powder or Bi-2212 precursor powder and, in order to form an intimate mixture, the mixture is melted and rapidly cooled to form a glassy solid. The glassy solid is comminuted and the resulting powder is combined with a carrier. An alternative to melting is to form the mixture of nanophase alumina and material having a particle size of less than about 10 microns. The powder, with the carrier, is melt processed to form a superconducting article.

  11. Preparation of zirconia-alumina powder by co-precipitation

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    A zirconia-alumina powder with a near spherical shape and an average size of 0.1 ~ 0.2μm was prepared byco-precipitation. XRD analysis shows that α-Al2O3 phase may be directly transformed from amorphous in calcining the hydroxide composite. The ZrO2-Al2O3 composite ceramics manufactured from this powder has the maximum fracture toughness of 9 M Pa·m- 1/2 at 15 % ZrO2 and 740 MPa fracture strength at 5 % ZrO2. Zirconia grains about 1 μm in diameter aredispersed uniformly in the alumina ceramic matrix

  12. Measurements of prompt radiation induced conductivity of alumina and sapphire

    Energy Technology Data Exchange (ETDEWEB)

    Hartman, E. Frederick [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Zarick, Thomas Andrew [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Sheridan, Timothy J. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Preston, Eric F. [ITT Coporation, Colorado Springs, CO (United States)

    2011-04-01

    We performed measurements of the prompt radiation induced conductivity in thin samples of Alumina and Sapphire at the Little Mountain Medusa LINAC facility in Ogden, UT. Five mil thick samples were irradiated with pulses of 20 MeV electrons, yielding dose rates of 1E7 to 1E9 rad/s. We applied variable potentials up to 1 kV across the samples and measured the prompt conduction current. Analysis rendered prompt conductivity coefficients between 1E10 and 1E9 mho/m/(rad/s), depending on the dose rate and the pulse width for Alumina and 1E7 to 6E7 mho/m/(rad/s) for Sapphire.

  13. Alumina lightweight ceramics modified with plasma synthesized nanopowders

    Science.gov (United States)

    Zake, I.; Svinka, R.; Svinka, V.; Palcevskis, E.

    2011-12-01

    The aim of this study is to clarify possibilities of using plasma synthesized Al2O3 and SiC nanopowders as additives in alumina lightweight ceramics prepared by slip casting. Each plasma synthesized nanopowder (PSNP) was incorporated in the material by a different method, because of their diverse influence on the properties of slip. Al2O3 PSNP was introduced in the matrix in form of aqueous suspension. SiC nanopowder was added directly to raw materials. Bending strength, bulk density, apparent porosity and thermal shock resistance were determined to evaluate the influence of these additives. The effect of Al2O3 PSNP addition on the properties of material depends on the initial sintering temperature. SiC particles during sintering oxidize into SiO2 and then in the reaction with alumina form mullite. Addition of SiC considerably improves bending strength and thermal shock resistance.

  14. Synthesis of catalysts supported in {gamma}-alumina; Sintese de catalisadores suportados na {gamma}-alumina

    Energy Technology Data Exchange (ETDEWEB)

    Pereira, Luiza Gabriel; Silva, A.J.N.; Santos, I.M.G.; Souza, A.G. [Paraiba Univ, Joao Pessoa, PB (Brazil). Dept. de Quimica. Lab. de Termoquimica e Materiais]. E-mail: luizagaby@yahoo.com.br; Fernandes Junior, V.J.; Araujo, A.S. [Rio Grande do Norte Univ., Natal, RN (Brazil). Dept. de Quimica. Lab. de Combustiveis

    2003-07-01

    Fuels contain a great amount of undesirable pollutants as asphaltenes, metals, sulfides and nitrogen compounds. The content of sulfur in petroleum is around 1%,. When burned, fuels liberate SO{sub x}, the greatest air pollutant . The maximum sulfur quantity in diesel is {approx}350 wppm, but in agreement to European specifications, this content will fall to 50 wppm up to 2005. To remove this sulfur a deep hydrodesulfurization is necessary, requiring high performance catalysts. This way, in this work, the following catalysts were synthesized, using Pechini method: MoO{sub 3} containing Ni and/or Co supported on {gamma}-alumina, with the formulas Co{sub x}Mo{sub 1-x}O{sub 3}/Al{sub 2}O{sub 3}, Ni{sub x}Mo{sub 1-x}O{sub 3}/Al{sub 2}O{sub 3} and Ni{sub x/2}Co{sub x/2}Mo{sub 1-x}O{sub 3}/Al{sub 2}O{sub 3} where x 0,01, 0,02 and 0,03 in mol percentage. This method was proposed, due to its high stoichiometry control, purity, reproducibility and homogeneity. All catalysts were submitted to thermal treatment at 500 deg C to 700 deg C and characterized by thermogravimetry, infrared spectroscopy, X-ray diffraction. Results indicate the stabilization of the requested composition at around 622 deg C. The X-ray diffraction results indicate that secondary phase increases with dopant amount. (author)

  15. A Novel Polybrene/Chondroitin Sulfate C Double Coated Capillary and Its Application in Capillary Electrophoresis

    Institute of Scientific and Technical Information of China (English)

    DU,Ying-Xiang(杜迎翔); HONDA,Susumu; TAGA,Atsushi; LIU,Wen-Ying(刘文英); SUZUKI,Shigeo

    2002-01-01

    A new capillary coated by double polymer, polybrene/chondroitin sulfate C (P/CC), was developed using a simple procedure. The P/CC double coated capillary showed long lifetime,strong chemical stability and good reproducibility. It endured during more than 100 replicated analyses and was also tolerant to HCl (1 mol/L), NaOH (0.01 mol/L), CH3OH and CH3CN. The P/CC double coated capillary can be applied to basic drug analyses. The adsorption of basic drugs to the capillary wall was suppressed and the peak tailing greatly decreased. The use of the P/CC double coated capillary allowed excelent separation of the enantiomers of some basic drugs by using chondroitin sulfate C as the chiral selector, ami the peak symmetry of basic drugs was further improved under these conditions.

  16. Ion irradiation effect of alumina and its luminescence

    Energy Technology Data Exchange (ETDEWEB)

    Aoki, Yasushi; Yamamoto, Shunya; Naramoto, Hiroshi [Japan Atomic Energy Research Inst., Takasaki, Gunma (Japan). Takasaki Radiation Chemistry Research Establishment; My, N.T.

    1997-03-01

    The luminescence spectra of single crystalline alpha-alumina and ruby which has 0.02% of Cr{sub 2}O{sub 3} as a impurity, induced by 200 keV He{sup +} and Ar{sup +} irradiation were measured at room temperature as a function of irradiation dose. The analysis of the measured spectra showed the existence of three main luminescence features in the wavelength region of 250 to 350 nm, namely anionic color centers, F-center at 411 nm and F{sup +}-center at 330 nm and a band observed around 315 nm. As alpha-alumina was irradiated with He{sup +}, F-center and F{sup +}-center luminescence grew and decayed, but the behaviors of those were different from each other. It seems that a concentration quenching occurred on the F-center luminescence in the dose range above 1x10{sup 14} He/cm{sup 2}. Furthermore, F-center luminescence was strongly suppressed in ruby, compared with that in alumina. On the other hand, the luminescence band around 315 nm appeared only in the early stage of irradiation and did not show its growth part. The dose dependent behavior was similar to that of Cr{sup 3+} emission at 695 nm (R-line) in ruby in both cases of He{sup +} and Ar{sup +} irradiation. Based on the experimental results mentioned above, the processes of defect formation and excitation in alumina in the early stage of ion irradiation will be discussed. (author)

  17. Results of recent KROTOS FCI tests. Alumina vs. corium melts

    Energy Technology Data Exchange (ETDEWEB)

    Huhtiniemi, I.; Magallon, D.; Hohmann, H. [Commission of the European Communities, Ispra (Italy). Joint Research Center

    1998-01-01

    Recent results from KROTOS fuel-coolant interaction experiments are discussed. Five tests with alumina were performed under highly subcooled conditions, all of these tests resulted in spontaneous steam explosions. Additionally, four tests were performed at low subcooling to confirm, on one hand, the suppression of spontaneous steam explosions under such conditions and, on the other hand, that such a system is still triggerable using an external initiator. The other test parameters in these alumina tests included the melt superheat and the initial pressure. All the tests in the investigated superheat range (150 K - 750 K) produced a steam explosion and no evidence of the explosion suppression by the elevated initial pressure (in the limited range of 0.1 - 0.375 MPa) was observed in the alumina tests. The corium test series include a test with 3 kg of melt under both subcooled and near saturated conditions at ambient pressure. Two additional tests were performed with subcooled water; one test was performed at an elevated pressure of 0.2 MPa with 2.4 kg of melt and another test with 5.1 kg of melt at ambient pressure. None of these tests with corium produced a propagating energetic steam explosion. However, propagating low energy (about twice the energy of the trigger pulse) events were observed. All corium tests produced significantly higher water level swells during the mixing phase than the corresponding alumina tests. Present experimental evidence suggests that the water depletion in the mixing zone suppresses energetic steam explosions with corium melts at ambient pressure and in the present pour geometry. Processes that could produce such a difference in void generation are discussed. (author)

  18. Friction and Wear of Sintered Alumina at High Temperature

    OpenAIRE

    Senda, Tetsuya; TAKAHASHl, Chiori; UEMATSU, Susumu; Amada, Shigeyasu

    1991-01-01

    The frictional behavior of alumina ceramics was investigated at various temperatures up to 1200℃. The coefficient of friction decreased with increasing temperature and this temperature dependency became more pronounced as higher contact pressures were applied. Wear loss at room temperature could be interpreted as being caused by one of either two different behavior modes. These have a rate difference of a factor of ten. At temperatures higher than 800℃, the wear loss was far less than that at...

  19. MICROWAVE JOINING OF ALUMINA CERAMIC AND HYDROXYLAPATITE BIOCERAMIC

    Institute of Scientific and Technical Information of China (English)

    1999-01-01

    Microwave joining is a rapid developmental new techniqu e in recent years.This paper introduces a new microwave joining equipment which was made by our lab,succeeds in alumina ceramic-hydroxylapatite bioceramic j o in in the equipment, and analyzes the join situation of join boundary by using s canni ng electron microscope(SEM),this paper analyzes the mechanism of microwave joini ng also.

  20. Proton adsorption onto alumina: extension of multisite complexation (MUSIC) theory

    Energy Technology Data Exchange (ETDEWEB)

    Nagashima, K.; Blum, F.D.

    1999-09-01

    The adsorption isotherm of protons onto a commercial {gamma}-alumina sample was determined in aqueous nitric acid with sodium nitrate as a background electrolyte. Three discrete regions could be discerned in the log-log plots of the proton isotherm determined at the solution pH 5 to 2. The multisite complexation (MUSIC) model was modified to analyze the simultaneous adsorption of protons onto various kinds of surface species.

  1. Thin alumina and silica films by chemical vapor deposition (CVD)

    OpenAIRE

    Hofman, R.; Morssinkhof, R.W.J.; Fransen, T.; Westheim, J.G.F.; Gellings, P.J.

    1993-01-01

    Alumina and silica coatings have been deposited by MOCVD (Metal Organic Chemical Vapor Deposition) on alloys to protect them against high temperature corrosion. Aluminium Tri-lsopropoxide (ATI) and DiAcetoxyDitertiaryButoxySilane (DAOBS) have been used as metal organic precursors to prepare these ceramic coatings. The influence of several process steps on the deposition rate and surface morphology is discussed. The deposition of SiO2 at atmospheric pressure is kinetically limited below 833 K ...

  2. Differential gene expression during capillary morphogenesis in a microcarrier-based three-dimensional in vitro model of angiogenesis with focus on chemokines and chemokine receptors

    Institute of Scientific and Technical Information of China (English)

    Xi-Tai Sun; Min-Yue Zhang; Chang Shu; Qiang Li; Xiao-Gui Yan; Ni Cheng; Yu-Dong Qiu; Yi-Tao Ding

    2005-01-01

    AIM: To globally compare the gene expression profiles during the capillary morphogenesis of human microvascular endothelial cells (HMVECs) in an in vitro angiogenesis system with affymetrix oligonucleotide array.METHODS: A microcarrier-based in vitro angiogenesis system was developed, in which ECs migrated into the matrix,proliferated, and formed capillary sprouts. The sprouts elongated, branched and formed networks. The total RNA samples from the HMVECs at the selected time points (0.5,24, and 72 h) during the capillary morphogenesis were used for microarray analyses, and the data were processed with the softwares provided by the manufacturers. The expression patterns of some genes were validated and confirmed by semi-quantitative RT-PCR. The regulated genes were grouped based on their molecular functions and expression patterns, and among them the expression of chemokines and chemokine receptors was specially examined and their functional implications were analyzed.RESULTS: A total of 1 961 genes were up- or downregulated two-folds or above, and among them, 468 genes were up- or down-regulated three-folds or above. The regulated genes could be grouped into categories based on their molecular functions, and were also clustered into six groups based on their patterns of expression. As for chemokines and chemokine receptors, CXCL1/GRO-α,CXCL2/GRO-β, CXCLS/ENA-78, CXCL6/GCP2, IL-8/CXCL8,CXCL12/SDF-1, CXCL9/Mig, CXC11/ITAC, CX3CL1/fractalkine,CCL2/MCP-1, CCL3, CCLS/RANTES, CCL7, CCL15, CCL21,CCL23, CCL28, and CCR1, CCR9, CXCR4 were identified.Moreover, these genes demonstrated different changing patterns during the capillary morphogenesis, which implied that they might have different roles in the sequential process. Among the chemokines identified, CCL2/MCP-1,CCL5/RANTES and CX3CL1 were specially up-regulated at the 24-h time point when the sprouting characterized the morphological change. It was thus suggested that they might exert crucial roles at the early stage

  3. Alumina Based 500 C Electronic Packaging Systems and Future Development

    Science.gov (United States)

    Chen, Liang-Yu

    2012-01-01

    NASA space and aeronautical missions for probing the inner solar planets as well as for in situ monitoring and control of next-generation aeronautical engines require high-temperature environment operable sensors and electronics. A 96% aluminum oxide and Au thick-film metallization based packaging system including chip-level packages, printed circuit board, and edge-connector is in development for high temperature SiC electronics. An electronic packaging system based on this material system was successfully tested and demonstrated with SiC electronics at 500 C for over 10,000 hours in laboratory conditions previously. In addition to the tests in laboratory environments, this packaging system has more recently been tested with a SiC junction field effect transistor (JFET) on low earth orbit through the NASA Materials on the International Space Station Experiment 7 (MISSE7). A SiC JFET with a packaging system composed of a 96% alumina chip-level package and an alumina printed circuit board mounted on a data acquisition circuit board was launched as a part of the MISSE7 suite to International Space Station via a Shuttle mission and tested on the orbit for eighteen months. A summary of results of tests in both laboratory and space environments will be presented. The future development of alumina based high temperature packaging using co-fired material systems for improved performance at high temperature and more feasible mass production will also be discussed.

  4. High strength alumina produced by direct coagulation casting

    Energy Technology Data Exchange (ETDEWEB)

    Baader, F.H.; Will, J.; Tieche, D. [Swiss Federal Institute of Technology, Zuerich (Switzerland)

    1995-09-01

    Direct Coagulation Casting is a new colloidal forming technique. Double layer stabilized, concentrated alumina suspensions are solidified by shifting the suspensions pH from 4 towards the isoelectric point at 9 using the in situ enzyme-catalyzed decomposition of urea. This reaction minimizes the repulsive forces between the suspended particles. The remaining, attractive Van der Waals forces form a stiff particle network. Suspensions with low viscosities (0.3 Pa*s, 59 vol%) were prepared at pH 4. Deagglomeration of the suspensions by ball milling reduced the agglomerate size below 5 pm. The coagulation kinetics could be influenced either by the urease concentration or by the suspension temperature. Process variables were established, providing long idle times, which allowed additional filtration and degassing steps. Coagulation was followed by drying and sintering, whereby densities of more than 3.97 g/cm{sup 3}, a 4-point bending strength of 685 MPa (HIPed) and a high reliablility (m = 40) for high purity alumina were achieved. DCC has the potential to improve the reliability of alumina components of complex shape, as well as to avoid expensive molding.

  5. Zirconia-alumina-nanodiamond composites with gemological properties

    Science.gov (United States)

    Díaz, Luis A.; Montes-Morán, Miguel A.; Peretyagin, Pavel Y.; Vladimirov, Yuriy G.; Okunkova, Anna; Moya, José S.; Torrecillas, Ramón

    2014-02-01

    Nanodiamonds have excellent mechanical and optical properties with a wide range of potential applications as a filler material for nanocomposites. Here, we present a new family of zirconia-alumina-nanodiamond composites using two main processing routes: (1) a colloidal method, and (2) power mixing homogenization. Composites with detonation nanodiamonds quantities ranging within 0.3-5 vol.% followed by a pulsed electrical current sintering at a temperature range from 1,200 to 1,500 °C have been analyzed, and a significant enhancement in mechanical properties, i.e., indentation hardness (16.17 GPa), fracture toughness (15.5 MPa m1/2), and bending strength (1,600 MPa), could be observed. To support these excellent properties, TEM, color, reflectivity, and Raman spectroscopy measurements were also carried out. The microstructure of the composites is very homogeneous with average grain sizes between 200 and 500 nm depending on the processing temperature. Two morphologies are present: (a) intergranular dispersion of alumina grains and nanodiamonds distributed along the grain boundaries of the ZrO2 matrix, and (b) intragranular nano-dispersion of ZrO2 particles with sizes 20-80 nm located inside the alumina grains. In the present article, we show, for the first time in the scientific literature, a continuous palette of gray color gradation of new ceramic materials of metalized colors (white index L* 98-40) for gemological applications.

  6. Nanocarbon-Coated Porous Anodic Alumina for Bionic Devices

    Directory of Open Access Journals (Sweden)

    Morteza Aramesh

    2015-08-01

    Full Text Available A highly-stable and biocompatible nanoporous electrode is demonstrated herein. The electrode is based on a porous anodic alumina which is conformally coated with an ultra-thin layer of diamond-like carbon. The nanocarbon coating plays an essential role for the chemical stability and biocompatibility of the electrodes; thus, the coated electrodes are ideally suited for biomedical applications. The corrosion resistance of the proposed electrodes was tested under extreme chemical conditions, such as in boiling acidic/alkali environments. The nanostructured morphology and the surface chemistry of the electrodes were maintained after wet/dry chemical corrosion tests. The non-cytotoxicity of the electrodes was tested by standard toxicity tests using mouse fibroblasts and cortical neurons. Furthermore, the cell–electrode interaction of cortical neurons with nanocarbon coated nanoporous anodic alumina was studied in vitro. Cortical neurons were found to attach and spread to the nanocarbon coated electrodes without using additional biomolecules, whilst no cell attachment was observed on the surface of the bare anodic alumina. Neurite growth appeared to be sensitive to nanotopographical features of the electrodes. The proposed electrodes show a great promise for practical applications such as retinal prostheses and bionic implants in general.

  7. Mullite/SiAlON/alumina composites by infiltration processing

    Energy Technology Data Exchange (ETDEWEB)

    Albano, M.P.; Scian, A.N. [Centro de Tecnologia de Recursos Minerales y Ceramica, Buenos Aires (Argentina)

    1997-01-01

    The formation of mullite/SiAlON/alumina composites was studied by infiltrating a SiAlON/alumina-base composite with two different solutions, followed by thermal treatment. The base composite was prepared from a mixture of tabular Al{sub 2}O{sub 3} grains, fume SiO{sub 2}, and aluminum powders. The mixture was pressed into test bars and nitrided in a nitrogen-gas (N{sub 2}) atmosphere at 1,480 C. The infiltrants were prehydrolyzed ethyl polysilicate solution and ethyl polysilicate-aluminum nitrate solution. The composites were infiltrated under vacuum, cured at 100 C, and precalcined in air at 700 C. This infiltration process was repeated several times to produce bars that had been subjected to multiple infiltrations, then the bars were calcined in a N{sub 2} atmosphere at 1,480 C to obtain mullite/SiAlON/alumina composites. The infiltration process increased the percentage of nitrogenous crystalline and mullite phases in the matrix; therefore, a decrease of the composite microporosity was observed. The infiltration increased the mechanical strength of the composites. Of the two composites, the one produced using prehydrolyzed ethyl polysilicate as the infiltrant had a higher mechanical strength, before and after being subjected to a severe thermal shock.

  8. Superhydrophobicity of Bionic Alumina Surfaces Fabricated by Hard Anodizing

    Institute of Scientific and Technical Information of China (English)

    Jing Li; Feng Du; Xianli Liu; Zhonghao Jiang; Luquan Ren

    2011-01-01

    Bionic alumina samples were fabricated on convex dome type aluminum alloy substrate using hard anodizing technique.The convex domes on the bionic sample were fabricated by compression molding under a compressive stress of 92.5 MPa.The water contact angles of the as-anodized bionic samples were measured using a contact angle meter (JC2000A) with the 3 μL water drop at room temperature.The measurement of the wetting property showed that the water contact angle of the unmodified as-anodized bionic alumina samples increases from 90° to 137° with the anodizing time.The increase in water contract angle with anodizing time arises from the gradual formation of hierarchical structure or composite structure.The structure is composed of the micro-scaled alumina columns and pores.The height of columns and the depth of pores depend on the anodizing time.The water contact angle increases significantly from 96° to 152° when the samples were modified with self-assembled monolayer of octadecanethiol (ODT),showing a change in the wettability from hydrophobicity to super-hydrophobicity.This improvement in the wetting property is attributed to the decrease in the surface energy caused by the chemical modification.

  9. Intensifying digestion of diaspore and separation of alumina and silica

    Institute of Scientific and Technical Information of China (English)

    李小斌; 彭志宏; 刘桂华; 周秋生

    2003-01-01

    It was found that there lies a linear relationship among the thermodynamic data of complicate inorganic compounds with similar components. A method for estimating the thermodynamic data of complicate compound and a thermodynamic database involving alumina production were developed. It was found that the alumina digestion rate of activated diasporic bauxite by means of heat field increased much due to the structure aberration, i.e, from perfect structure to unstable corundum. The results from thermodynamic calculation and experiments showed that it was feasible for desilication at atmospheric pressure, and the effects on equilibrium concentration of SiO2 included temperature, mole ratio of Na2O/Al2O3 (αk), caustic and Na+ concentration. The technology of desilication of green liquor at atmosphere and separation of alumina and silica in aluminate solution with high concentration were established. The reaction activity of compounds containing silica and the converting law among compounds were studied, and the prototype technology of desilication products by hydrotreatment was also developed.

  10. 1- MCP 处理对鸡蛋果常温贮藏效果的影响%Effects of 1 - MCP Treatment on Qualities of Passion Fruit at Ambient Temperature

    Institute of Scientific and Technical Information of China (English)

    姜翠翠; 李颖; 邱松山; 刘杰凤

    2016-01-01

    为延长鸡蛋果常温贮藏期品质,维持其较好的营养价值,分别采用0.50μL/L 和1.0μL/L 的1-甲基环丙烯(1-MCP)结合 PE 袋对鸡蛋果进行了保鲜处理,分析了鸡蛋果货架期间失重率,感官品质,可溶性固形物、维生素 C 的质量分数,质构特性等指标,并研究了其常温贮藏条件下的果实保鲜效果。结果表明:采用1.0μL/L 的1-MCP 结合 PE 袋处理过的果实在货架末期的失重率为0.39%,感官品质明显优于对照组,样品可溶性固形物质量分数维持在7.00%,维生素 C 的质量分数为28 mg/100 g ,硬度及黏度分别为800 g 和90 g/s ,均显著高于对照组果实。综合比较,1.0μL/L 1-MCP 结合 PE 袋处理能有效延缓果实的后熟衰老,确保货架期鸡蛋果果实品质。%In this paper we explore the effects of 1 - methylcyclopropene (1 -MCP) together with PE film treatment on passion fruit at room temperature ,and analyze the changes of weight loss rate ,soluble solids ,the content of vitamin C and its texture characteristic changes of samples during shelf life .Results show that after the treatment of 1 .0 μL/L 1 -MCP combined with PE film ,the weightlessness rate of sam-ple is 0 .39% ,soluble solids content is 7 .00 % ,the content of Vc is 28 mg/100 g ,the hardness and viscosity are respectively 800 g and 90 g/s ,and the quality of fruits in the end of shelf life is significantly higher than that of control group .Therefore 1 .0 μL/L 1 -MCP together with PE film treatment can effectively inhibit fruit metabolism ,regulate these physiological changes related to the aging process ,and play a better role in preservation .

  11. Formation process of a strong water-repellent alumina surface by the sol-gel method

    Energy Technology Data Exchange (ETDEWEB)

    Feng Libang, E-mail: lepond@hotmail.com [School of Mechatronic Engineering, Lanzhou Jiaotong University, 88 West Anning Road, Lanzhou 730070 (China); Li Hui; Song Yongfeng; Wang Yulong [School of Mechatronic Engineering, Lanzhou Jiaotong University, 88 West Anning Road, Lanzhou 730070 (China)

    2010-03-01

    A novel strong water-repellent alumina thin film is fabricated by chemically adsorbing stearic acid (STA) layer onto the porous and roughened aluminum film coated with polyethyleneimine (PEI). The formation process and the structure of the strong water-repellent alumina film are investigated by means of contact angle measurement and atomic force microscope (AFM). Results show that the water contact angles for the alumina films increase with the increase of the immersion time in the boiling water, and meanwhile, the roughness of the alumina films increases with the dissolution of the boehmite in the boiling water. Finally, the strong water-repellent film with a high water contact angle of 139.1 deg. is obtained when the alumina films have distinct roughened morphology with some papillary peaks and porous structure. Moreover, both the roughened structure and the hydrophobic materials of the STA endow the alumina films with the strong water-repellence.

  12. Formation process of a strong water-repellent alumina surface by the sol-gel method

    Science.gov (United States)

    Feng, Libang; Li, Hui; Song, Yongfeng; Wang, Yulong

    2010-03-01

    A novel strong water-repellent alumina thin film is fabricated by chemically adsorbing stearic acid (STA) layer onto the porous and roughened aluminum film coated with polyethyleneimine (PEI). The formation process and the structure of the strong water-repellent alumina film are investigated by means of contact angle measurement and atomic force microscope (AFM). Results show that the water contact angles for the alumina films increase with the increase of the immersion time in the boiling water, and meanwhile, the roughness of the alumina films increases with the dissolution of the boehmite in the boiling water. Finally, the strong water-repellent film with a high water contact angle of 139.1° is obtained when the alumina films have distinct roughened morphology with some papillary peaks and porous structure. Moreover, both the roughened structure and the hydrophobic materials of the STA endow the alumina films with the strong water-repellence.

  13. A Study on the Effect of Nano Alumina Particles on Fracture Behavior of PMMA

    Directory of Open Access Journals (Sweden)

    Arezou Sezavar

    2015-04-01

    Full Text Available In the current research, the role of nano-sized alumina on deformation and fracture mechanism of Poly Methyl Methacrylate (PMMA was investigated. For this purpose, PMMA matrix nanocomposite reinforced with different wt% of alumina (i.e., 5, 10 and 15 were fabricated using the compression molding technique. Tensile properties of produced nanocomposites were studied using Zwick Z250 apparatus at cross head speed of about 5 mm/min. In order to specify the role of alumina nanoparticles on deformation and fracture mechanism of PMMA, microscopic evaluation was performed using scanning electron microscope (SEM. The achieved results prove that tensile properties of PMMA depend on alumina wt%. For example, addition of 15 wt% alumina to PMMA causes an increase of about 25% modulus of elasticity. Micrographs taken from the fracture surface of PMMA and its nanocomposites show deformation and fracture mechanism of PMMA changes as alumina is added to it.

  14. Muscle glycogen depletion following 75-km of cycling is not linked to increased muscle IL-6, IL-8, and MCP-1 mRNA expression and protein content

    Directory of Open Access Journals (Sweden)

    David Christopher Nieman

    2016-09-01

    Full Text Available The cytokine response to heavy exertion varies widely for unknown reasons, and this study evaluated the relative importance of glycogen depletion, muscle damage, and stress hormone changes on blood and muscle cytokine measures. Cyclists (N=20 participated in a 75-km cycling time trial (168±26.0 min, with blood and vastus lateralis muscle samples collected before and after. Muscle glycogen decreased 77.2±17.4%, muscle IL-6, IL-8, and MCP-1 mRNA increased 18.5±2.8-, 45.3±7.8-, and 8.25±1.75-fold, and muscle IL-6, IL-8, and MCP-1 protein increased 70.5±14.1%, 347±68.1%, and 148±21.3%, respectively (all, P<0.001. Serum myoglobin and cortisol increased 32.1±3.3 to 242±48.3 mg/mL, and 295±27.6 to 784±63.5 nmol/L, respectively (both P<0.001. Plasma IL-6, IL-8, and MCP-1 increased 0.42±0.07 to 18.5±3.8, 4.07±0.37 to 17.0±1.8, and 96.5±3.7 to 240±21.6 pg/mL, respectively (all P<0.001. Increases in muscle IL-6, IL-8, and MCP-1 mRNA were unrelated to any of the outcome measures. Muscle glycogen depletion was related to change in plasma IL-6 (r=0.462, P=0.040, with change in myoglobin related to plasma IL-8 (r=0.582, P=0.007 and plasma MCP-1 (r=0.457, P=0.043, and muscle MCP-1 protein (r=0.588, P=0.017; cortisol was related to plasma IL-8 (r=0.613, P=0.004, muscle IL-8 protein (r=0.681, P=0.004, and plasma MCP-1 (r=0.442, P=0.050. In summary, this study showed that muscle IL-6, IL-8, and MCP-1 mRNA expression after 75-km cycling was unrelated to glycogen depletion and muscle damage, with change in muscle glycogen related to plasma IL-6, and changes in serum myoglobin and cortisol related to the chemotactic cytokines IL-8 and MCP-1.

  15. Micro-injector for capillary electrophoresis.

    Science.gov (United States)

    Sáiz, Jorge; Koenka, Israel Joel; García-Ruiz, Carmen; Müller, Beat; Chwalek, Thomas; Hauser, Peter C

    2015-08-01

    A novel micro-injector for capillary electrophoresis for the handling of samples with volumes down to as little as 300 nL was designed and built in our laboratory for analyses in which the available volume is a limitation. The sample is placed into a small cavity located directly in front of the separation capillary, and the injection is then carried out automatically by controlled pressurization of the chamber with compressed air. The system also allows automated flushing of the injection chamber as well as of the capillary. In a trial with a capillary electrophoresis system with contactless conductivity detector, employing a capillary of 25 μm diameter, the results showed good stability of migration times and peak areas. To illustrate the technique, the fast separation of five inorganic cations (Na(+) , K(+) , NH4 (+) , Ca(2+) , and Mg(2+) ) was set up. This could be achieved in less than 3 min, with good limits of detection (10 μM) and linear ranges (between about 10 and 1000 μM). The system was demonstrated for the determination of the inorganic cations in porewater samples of a lake sediment core.

  16. Restructuring and aging in a capillary suspension.

    Science.gov (United States)

    Koos, Erin; Kannowade, Wolfgang; Willenbacher, Norbert

    2014-12-01

    The rheological properties of capillary suspensions, suspensions with small amounts of an added immiscible fluid, are dramatically altered with the addition of the secondary fluid. We investigate a capillary suspension to determine how the network ages and restructures at rest and under applied external shear deformation. The present work uses calcium carbonate suspended in silicone oil (11 % solids) with added water as a model system. Aging of capillary suspensions and their response to applied oscillatory shear is distinctly different from particulate gels dominated by the van der Waals forces. The suspensions dominated by the capillary force are very sensitive to oscillatory flow, with the linear viscoelastic regime ending at a deformation of only 0.1% and demonstrating power-law aging behavior. This aging persists for long times at low deformations or for shorter times with a sudden decrease in the strength at higher deformations. This aging behavior suggests that the network is able to rearrange and even rupture. This same sensitivity is not demonstrated in shear flow where very high shear rates are required to rupture the agglomerates returning the apparent viscosity of capillary suspensions to the same viscosity as for the pure vdW suspension. A transitional region is also present at intermediate water contents wherein the material response depends very strongly on the type, strength, and duration of the external forcing.

  17. Synthetic Capillaries to Control Microscopic Blood Flow

    Science.gov (United States)

    Sarveswaran, K.; Kurz, V.; Dong, Z.; Tanaka, T.; Penny, S.; Timp, G.

    2016-02-01

    Capillaries pervade human physiology. The mean intercapillary distance is only about 100 μm in human tissue, which indicates the extent of nutrient diffusion. In engineered tissue the lack of capillaries, along with the associated perfusion, is problematic because it leads to hypoxic stress and necrosis. However, a capillary is not easy to engineer due to its complex cytoarchitecture. Here, it is shown that it is possible to create in vitro, in about 30 min, a tubular microenvironment with an elastic modulus and porosity consistent with human tissue that functionally mimicks a bona fide capillary using “live cell lithography”(LCL) to control the type and position of cells on a composite hydrogel scaffold. Furthermore, it is established that these constructs support the forces associated with blood flow, and produce nutrient gradients similar to those measured in vivo. With LCL, capillaries can be constructed with single cell precision—no other method for tissue engineering offers such precision. Since the time required for assembly scales with the number of cells, this method is likely to be adapted first to create minimal functional units of human tissue that constitute organs, consisting of a heterogeneous population of 100–1000 cells, organized hierarchically to express a predictable function.

  18. Comparative study on sintered alumina for ballistic shielding application; Estudo comparativo entre aluminas sinterizadas visando aplicacao em blindagem balistica

    Energy Technology Data Exchange (ETDEWEB)

    Melo, Francisco Cristovao Lourenco de; Goncalves, Diniz Pereira [Centro Tecnico Aeroespacial (CTA), Sao Jose dos Campos, SP (Brazil). Inst. de Aeronautica e Espaco

    1997-12-31

    This work presents a development of the armor made from special ceramic materials and kevlar. An experimental investigation was conducted to study the ballistic penetration resistance on three samples taken from sintered alumina: a commercial one and two formulations A and B made in IAE/CTA. The main differences between the two formulations was the grain size and bend resistance. The knowledge of the mechanisms during the penetration and perforation process allowed to apply a ductile composite laminate made form kevlar under the alumina to delay its rupture. The last ballistic test showed how a Weibull`s modulii and other mechanical properties are able to improve ballistic penetration resistance. (author) 3 refs.

  19. Pyrrolidine dithiocarbamate (PDTC) inhibits the overexpression of MCP-1 and attenuates microglial activation in the hippocampus of a pilocarpine-induced status epilepticus rat model.

    Science.gov (United States)

    Lv, Rilang; Xu, Xiaoyun; Luo, Zheng; Shen, Nan; Wang, Feng; Zhao, Yongbo

    2014-01-01

    The aim of this study was to investigate the effects of pyrrolidine dithiocarbamate (PDTC) on MCP-1 expression and microglial activation in the hippocampus of a rat model of pilocarpine (PILO)-induced status epilepticus (SE). Moreover, seizure susceptibility, frequency and severity as well as brain damage were analyzed and changes in behavior were recorded. Chemokine MCP-1 expression and microglial activation were detected by immunohistochemistry (IHC). Fluoro-Jade C (FJC) and NeuN staining were used for the evaluation of tissue damage. Our results showed that although SE resulted in the upregulation of MCP-1 and microglial activation in the rat hippocampus 24 h after seizure onset, pretreatment with PDTC significantly inhibited the MCP-1 overexpression and attenuated the microglial activation. These effects were accompanied by neurodegenerative amelioration. To the best of our knowledge, these findings indicated for the first time that the activation of the nuclear factor-κB (NF-κB) pathway may contribute to MCP-1 upregulation and microglial activation in the context of epilepsy. PDTC was also shown to exert anticonvulsant activity and to have a neuroprotective effect on the hippocampal CA1 and CA3 regions, potentially through attenuating microglial activation.

  20. Profiling of differentially expressed chemotactic-related genes in MCP-1 treated macrophage cell line using human cDNA arrays

    Institute of Scientific and Technical Information of China (English)

    Guang-Xing Bian; Hong Miao; Lei Qiu; Dong-Mei Cao; Bao-Yu Guo

    2005-01-01

    AIM: To study the global gene expression of chemotactic genes in macrophage line U937 treated with human monocyte chemoattractant protein-1 (MCP-1) through the use of ExpreeChipTMHO2 cDNA array.METHODS: Total RNA was extracted from MCP-1 treated macrophage line U937 and normal U937 cells, reversely transcribed to cDNA, and then screened in parallel with HO2 human cDNA array chip. The scanned result was additionally validated using RT-PCR.RESULTS: The result of cDNA array showed that one chemotactic-related gene was up-regulated more than two-fold (RANTES) and seven chemotactic-related genes were down-regulated more than two-fold (CCR1, CCR5,ccl16, GROβ, GROγ, IL-8 and granulocyte chemotactic protein 2) in MCP-1 treated U937 cells at mRNA level.RT-PCR analysis of four of these differentially expressed genes gave results consistent with cDNA array findings.CONCLUSION: MCP-1 could influence some chemokine and receptor expressions in macrophages in vitro. MCP-1mainly down-regulates the expression of chemotactic genes influencing neutrophilic granulocyte expression (GROβ, GROγ, IL-8 and granulocyte chemotactic protein 2), and the mRNA level of CCR5, which plays a critical role in many disorders and illnesses.

  1. Human monocyte-derived dendritic cells expressing both chemotactic cytokines IL-8, MCP-1, RANTES and their receptors,and their selective migration to these chemokines

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    Objective To characterize the mRNA expression of CXC chemokine IL-8, CC chemokine monocyte chemothractant protein-1 (MCP-1) and regulated on activation,normal T cell expressed and secreted (RANTES), and a newly defined DC chemokine DC- CK1 as well as the expression of IL-8 receptor, MCP-1 receptor and RANTES receptor in human monocyte derived dendritic cells (MoDCs).The migratory responsiveness of MoDC to IL-8, MCP-1 and RANTES was alsso studied. Methods In vitro generated MoDCs were obtained by differentiating monocytes in the presence of GM-CSF and IL-4 for 5 days. The time course of RNA expression was analyzed by RT-PCR and migratoly ability was assessed by a micromultiwell chemotaxis chamber assay. Results IL-8, MCP-1, RANTES and their corres ponding receptors were consistently expressed in MoDCs. DC-CK-1 expression was detectable efter 48 hours of differentiation. MoDC selectively migrated in response to MCP-1 and RANTES but not to IL-8 though transcripts of IL-8 receptor were present. Conclusion Because the capacity of dendritic cells to initiate immune responses depends on their specialized migratory and tissue homing properties, the expression of chemokines and their receptors along with the migratory responsiveness to chemokines of MoDC in our study suggests a potential role of chemokines in the interaction between dendritic cells and T cells and the induction of immune responses.

  2. CD8 T cells are involved in skeletal muscle regeneration through facilitating MCP-1 secretion and Gr1(high) macrophage infiltration.

    Science.gov (United States)

    Zhang, Jing; Xiao, Zhicheng; Qu, Chao; Cui, Wei; Wang, Xiaonan; Du, Jie

    2014-11-15

    Inflammatory microenvironments play a key role in skeletal muscle regeneration. The infiltration of CD8 T cells into injured muscle has been reported. However, the role of CD8 T cells during skeletal muscle regeneration remains unclear. In this study, we used cardiotoxin-induced mouse skeletal muscle injury/regeneration model to investigate the role of CD8 T cells. Muscle regeneration was impaired and matrix deposit was increased in CD8α-deficient mice compared with wild-type (WT) mice whose CD8 T cells were infiltrated into damaged muscle after cardiotoxin injection. Adoptive transfer of CD8 T cells to CD8α-deficient mice improved muscle regeneration and inhibited matrix remodeling. Compared with WT mice, CD8α deficiency limited the recruitment of Gr1(high) macrophages (MPs) into muscle, resulting in the reduction of satellite cell number. The expression of MCP-1 (MCP-1/CCL2), which regulates the migration of Gr1(high) MPs, was reduced in CD8α-deficient mice compared with WT mice. Coculture CD8 T cells with MPs promoted MCP-1 secretion. The i.m. injection of MCP-1 markedly promoted the recruitment of Gr1(high) MPs and improved muscle regeneration in CD8α-deficient mice. We conclude that CD8 T cells are involved in skeletal muscle regeneration by regulating the secretion of MCP-1 to recruit Gr1(high) MPs, which facilitate myoblast proliferation.

  3. Effect of PKC-β Signaling Pathway on Expression of MCP-1 and VCAM-1 in Different Cell Models in Response to Advanced Glycation End Products (AGEs).

    Science.gov (United States)

    Rempel, Lisienny C T; Finco, Alessandra B; Maciel, Rayana A P; Bosquetti, Bruna; Alvarenga, Larissa M; Souza, Wesley M; Pecoits-Filho, Roberto; Stinghen, Andréa E M

    2015-05-14

    Advanced glycation end products (AGEs) are compounds classified as uremic toxins in patients with chronic kidney disease that have several pro-inflammatory effects and are implicated in the development of cardiovascular diseases. To explore the mechanisms of AGEs-endothelium interactions through the receptor for AGEs (RAGE) in the PKC-β pathway, we evaluated the production of MCP-1 and VCAM-1 in human endothelial cells (HUVECs), monocytes, and a coculture of both. AGEs were prepared by albumin glycation and characterized by absorbance and electrophoresis. The effect of AGEs on cell viability was assessed with an MTT assay. The cells were also treated with AGEs with and without a PKC-β inhibitor. MCP-1 and VCAM-1 in the cell supernatants were estimated by ELISA, and RAGE was evaluated by immunocytochemistry. AGEs exposure did not affect cell viability, but AGEs induced RAGE, MCP-1, and VCAM-1 expression in HUVECs. When HUVECs or monocytes were incubated with AGEs and a PKC-β inhibitor, MCP-1 and VCAM-1 expression significantly decreased. However, in the coculture, exposure to AGEs and a PKC-β inhibitor produced no significant effect. This study demonstrates, in vitro, the regulatory mechanisms involved in MCP-1 production in three cellular models and VCAM-1 production in HUVECs, and thus mimics the endothelial dysfunction caused by AGEs in early atherosclerosis. Such mechanisms could serve as therapeutic targets to reduce the harmful effects of AGEs in patients with chronic kidney disease.

  4. Effect of Heat Treatment of the Alumina Powder on the Microstructure and Properties of Coatings

    Directory of Open Access Journals (Sweden)

    Prozorova Mayya

    2015-01-01

    Full Text Available The alumina powder was treated at a high temperature (1000°C. Dense (porosity of less than 2%, solid (1280 ± 30 HV0.3 and wear-resistant coatings based on heat-treated alumina powder were obtained by a multi-chamber detonation sprayer on the steel substrate. The microstructure, microhardness and the wear resistance of the alumina coatings were investigated.

  5. The Effect of Alumina Dispersant Powder on the Workability of Chromia Based Refractory for IGCC Application

    Science.gov (United States)

    Ming, Zhao Jing; Xun, Yang Zheng; Hong, Hwang Kyu; Hwan, Park Sang

    2011-10-01

    The quality of refractory applied on IGCC is a key factor that affects the cost of production. The workability and microstructure of chromia based castable are varied by introducing different type of alumina dispersant powder, such as active alumina powder. In this study, three types of active alumina powder are added to improve the workability. It's proved that the specific surface area and particle size distribution of fine powders in matrix part greatly affect the flow values and microstructures.

  6. PEG-albumin plasma expansion increases expression of MCP-1 evidencing increased circulatory wall shear stress: an experimental study.

    Directory of Open Access Journals (Sweden)

    C Makena Hightower

    Full Text Available Treatment of blood loss with plasma expanders lowers blood viscosity, increasing cardiac output. However, increased flow velocity by conventional plasma expanders does not compensate for decreased viscosity in maintaining vessel wall shear stress (WSS, decreasing endothelial nitric oxide (NO production. A new type of plasma expander using polyethylene glycol conjugate albumin (PEG-Alb causes supra-perfusion when used in extreme hemodilution and is effective in treating hemorrhagic shock, although it is minimally viscogenic. An acute 40% hemodilution/exchange-transfusion protocol was used to compare 4% PEG-Alb to Ringer's lactate, Dextran 70 kDa and 6% Hetastarch (670 kDa in unanesthetized CD-1 mice. Serum cytokine analysis showed that PEG-Alb elevates monocyte chemotactic protein-1 (MCP-1, a member of a small inducible gene family, as well as expression of MIP-1α, and MIP-2. MCP-1 is specific to increased WSS. Given the direct link between increased WSS and production of NO, the beneficial resuscitation effects due to PEG-Alb plasma expansion appear to be due to increased WSS through increased perfusion and blood flow rather than blood viscosity.

  7. Prokaryotic expression and in vitro functional analysis of IL-1β and MCP-1 from guinea pig.

    Science.gov (United States)

    Dirisala, Vijaya R; Jeevan, Amminikutty; Ly, Lan H; McMurray, David N

    2013-06-01

    The Guinea pig (Cavia porcellus) is an excellent animal model for studying human tuberculosis (TB) and also for a number of other infectious and non-infectious diseases. One of the major roadblocks in effective utilization of this animal model is the lack of readily available immunological reagents. In order to address this issue, guinea pig interleukin 1 beta (IL-1β) and monocyte chemoattractant protein-1 (MCP-1) were efficiently cloned and expressed in a prokaryotic expression vector, and the expressed proteins in soluble form from both the genes were confirmed by N-terminal sequencing. The biological activity of recombinant guinea pig IL-1β was demonstrated by its ability to drive proliferation in thymocytes, and the recombinant guinea pig MCP-1 exhibited chemotactic activity for guinea pig resident peritoneal macrophages. These biologically active recombinant guinea pig proteins will facilitate an in-depth understanding of the role they play in the immune responses of the guinea pig to TB and other diseases.

  8. Association of MCP-1-2518A/G polymorphism with uveitis susceptibility: a Meta-analysis%MCP-1基因-2518A/G多态性与葡萄膜炎易感性的Meta分析

    Institute of Scientific and Technical Information of China (English)

    张小玲; 冀垒兵; 高晓唯; 肖云; 章玮; 张燕

    2015-01-01

    Background Monocyte chemoattractant protein-1 (MCP-1) polymorphisms are demonstrated to be significantly associated with the susceptibility to uveitis in recent years,while a consistent conclusion for the association of MCP-1-2518A/G polymorphism and uveitis risk is not reached yet.Objective This study was to comprehensively investigate the correlation between MCP-1-2518A/G polymorphism and uveitis susceptibility.Methods General searches of electronic database including PubMed,Embase,Web of Science,CNKI,VIP,Wanfang database and China biomedical literature database (CBD) were performed to retrieve published case-control studies regarding the association between MCP-1-2518A/G polymorphism and uveitis risk.The data were screened according to the inclusion and exclusion criteria and extracted,and the quality of included studies was evaluated.The pooled odds ratios (OR) with 95% confidence intervals (CI) were calculated.Publication bias and sensitivity analysis were also assessed.All statistical analyses were conducted with RevMan 5.2 and Stata 12.0 software.Results A total of 8 eligible case-control studies involving 1 197 cases and 1 570 controls were included in the Meta-analysis.The results showed no significant association of MCP-1-2518A/G polymorphism with uveitis susceptibility in the G vs.A,GG vs.AA and GG vs.AG+AA models (all at P>0.05).MCP-1-2518A/G polymorphism was found to be significantly associated with uveitis risk in the GG+AG vs.AA model (P =0.01,OR =1.25,95% CI:1.06-1.48),while no significant association was found by the sensitive analysis (GG + AG vs.AA:P =0.19,OR =1.16,95% CI:0.93-1.45).The subgroup analysis by uveitis types revealed that the individuals carrying allele-G or GG genotype harbored a significantly increased risk for anterior uveitis (G vs.A:P=0.01,OR=1.49,95% CI:1.16-1.90;GG vs.AA:P=0.01,OR=2.09,95% CI:1.21-3.61;GG+AG vs.AA:P=0.01,OR=1.58,95% CI:1.12-2.23;GG vs.AG+AA:P=0.01,OR=1.78,95% CI:1.12-2.83).The individuals with

  9. Viscosity of aqueous and cyanate ester suspensions containing alumina nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Lawler, Katherine [Iowa State Univ., Ames, IA (United States)

    2009-01-01

    The viscosities of both aqueous and cyanate ester monomer (BECy) based suspensions of alumina nanoparticle were studied. The applications for these suspensions are different: aqueous suspensions of alumina nanoparticles are used in the production of technical ceramics made by slip casting or tape casting, and the BECy based suspensions are being developed for use in an injection-type composite repair resin. In the case of aqueous suspensions, it is advantageous to achieve a high solids content with low viscosity in order to produce a high quality product. The addition of a dispersant is useful so that higher solids content suspensions can be used with lower viscosities. For BECy suspensions, the addition of nanoparticles to the BECy resin is expected to enhance the mechanical properties of the cured composite. The addition of saccharides to aqueous suspensions leads to viscosity reduction. Through DSC measurements it was found that the saccharide molecules formed a solution with water and this resulted in lowering the melting temperature of the free water according to classic freezing point depression. Saccharides also lowered the melting temperature of the bound water, but this followed a different rule. The shear thinning and melting behaviors of the suspensions were used to develop a model based on fractal-type agglomeration. It is believed that the structure of the particle flocs in these suspensions changes with the addition of saccharides which leads to the resultant viscosity decrease. The viscosity of the BECy suspensions increased with solids content, and the viscosity increase was greater than predicted by the classical Einstein equation for dilute suspensions. Instead, the Mooney equation fits the viscosity behavior well from 0-20 vol% solids. The viscosity reduction achieved at high particle loadings by the addition of benzoic acid was also investigated by NMR. It appears that the benzoic acid interacts with the surface of the alumina particle which may

  10. Electromotive force measurements on cells involving beta-alumina solid electrolyte

    Science.gov (United States)

    Choudhury, N. S.

    1973-01-01

    Open-circuit emf measurements have been made to demonstrate that a two-phase, polycrystalline mixture of beta-alumina and alpha-alumina could be used as a solid electrolyte in galvanic cells with reversible electrodes fixing oxygen or aluminum chemical potentials. These measurements indicate that such a two-phase solid electrolyte may be used to monitor oxygen chemical potentials as low as that corresponding to Al and Al2O3 coexistence (potentials of about 10 to the minus 47th power atm at 1000 K). The activity of Na2O in beta-alumina in coexistence with alpha-alumina was also determined by emf measurements.

  11. The effect of alumina nanofillers size and shape on mechanical behavior of PMMA matrix composite

    Directory of Open Access Journals (Sweden)

    Ben Hasan Somaya Ahmed

    2014-01-01

    Full Text Available Composites with the addition of alumina nanofillers show improvement in mechanical properties. The PMMA polymer was used as a matrix and two different types of nanofillers, having extremely different shapes were added in the matrix to form the composite. Reinforcements were based on alumina nanoparticles having either spherical shape or whiskers having the length to diameter ratio of 100. The influence of alumina fillers size, shape and fillers loading on mechanical properties of prepared composite were studied using the nanoindentation measurements and dynamic mechanical analysis. It was observed that both alumina whiskers and alumina spherical nanoparticles added in the PMMA matrix improved the mechanical properties of the composite but the improvement was significantly higher with alumina whisker reinforcement. The concentration of the reinforcing alumina spherical nanoparticles and alumina whiskers in PMMA matrix varied up to 5 wt. %. The best performance was obtained by the addition of 3 wt. % of alumina whiskers in the PMMA matrix with regard to mechanical properties of the obtained composite.

  12. High field matching effects in superconducting Nb porous arrays catalyzed from anodic alumina templates

    DEFF Research Database (Denmark)

    Vinckx, W.; Vanacken, J.; Moshchalkov, V.V.;

    2007-01-01

    Vortex pinning in a superconducting Nb thin film deposited on an anodically grown alumina template is investigated. Anodic oxidation of aluminium layers permits under specific conditions the formation of highly ordered porous alumina, a membrane-like structure consisting of triangular arrays...... of parallel pores. Its pore diameter and interpore distance are set by careful tuning of the anodization parameters. A superconducting Nb thin film is deposited directly onto the alumina film. The porous alumina acts as a template and it allows Nb to form a periodic pinning array during its growth. Pinning...

  13. On the possibility of producing alumina ceramic with a slight electrical conductivity

    CERN Document Server

    Caspers, Fritz

    1989-01-01

    Antistatic alumina ceramic is desirable for certain particle accelerator applications. In general, highly insulating surface close to a charged particle beam must be avoided in order to prevent the formation of ion pockets and other unwanted electrical effects. For the AA vacuum chamber (UHV), an antistatic ferrite has been produced and successfully installed. The fabrication of antistatic alumina might be possible in a similar way. By using certain metal oxides in the cement, which holds the alumina particles together, a slight conductivity could be obtained after the firing and sintering process, without deteriorating the mechanical and outgassing properties of the alumina compound.

  14. Novel absorption detection techniques for capillary electrophoresis

    Energy Technology Data Exchange (ETDEWEB)

    Xue, Yongjun [Iowa State Univ., Ames, IA (United States)

    1994-07-27

    Capillary electrophoresis (CE) has emerged as one of the most versatile separation methods. However, efficient separation is not sufficient unless coupled to adequate detection. The narrow inner diameter (I.D.) of the capillary column raises a big challenge to detection methods. For UV-vis absorption detection, the concentration sensitivity is only at the μM level. Most commercial CE instruments are equipped with incoherent UV-vis lamps. Low-brightness, instability and inefficient coupling of the light source with the capillary limit the further improvement of UV-vis absorption detection in CE. The goals of this research have been to show the utility of laser-based absorption detection. The approaches involve: on-column double-beam laser absorption detection and its application to the detection of small ions and proteins, and absorption detection with the bubble-shaped flow cell.

  15. Capillary rise of water in hydrophilic nanopores

    CERN Document Server

    Gruener, Simon; Wallacher, Dirk; Kityk, Andriy V; Huber, Patrick; 10.1103/PhysRevE.79.067301

    2009-01-01

    We report on the capillary rise of water in three-dimensional networks of hydrophilic silica pores with 3.5nm and 5nm mean radii, respectively (porous Vycor monoliths). We find classical square root of time Lucas-Washburn laws for the imbibition dynamics over the entire capillary rise times of up to 16h investigated. Provided we assume two preadsorbed strongly bound layers of water molecules resting at the silica walls, which corresponds to a negative velocity slip length of -0.5nm for water flow in silica nanopores, we can describe the filling process by a retained fluidity and capillarity of water in the pore center. This anticipated partitioning in two dynamic components reflects the structural-thermodynamic partitioning in strongly silica bound water layers and capillary condensed water in the pore center which is documented by sorption isotherm measurements.

  16. Photosensitive diazotized poly(ethylene glycol) covalent capillary coatings for analysis of proteins by capillary electrophoresis.

    Science.gov (United States)

    Yu, Bing; Chen, Xin; Cong, Hailin; Shu, Xi; Peng, Qiaohong

    2016-09-01

    A new method for the fabrication of covalently cross-linked capillary coatings of poly(ethylene glycol) (PEG) is described using diazotized PEG (diazo-PEG) as a new photosensitive coating agent. The film of diazo-PEG depends on ionic bonding and was first prepared on the inner surface of capillary by self-assembly, and ionic bonding was converted into covalent bonding after reaction of ultraviolet light with diazo groups through unique photochemical reaction. The covalently bonded coating impedance adsorption of protein on the central surface of capillary and hence the four proteins ribonuclease A, cytochrome c, bovine serum albumin, and lysosome can be baseline separated by using capillary electrophoresis (CE). The covalently cross-linked diazo-PEG capillary column coatings not only improved the CE separation performance for proteins compared to non-covalently cross-linked coatings or bare capillary but also showed a remarkable chemical solidity and repeatability. Because photosensitive diazo-PEG took the place of the highly noxious and silane moisture-sensitive coating reagents in the fabrication of covalent coating, this technique shows the advantage of being environment-friendly and having a high efficiency for CE to make the covalently bonded capillaries.

  17. Mach-like capillary-gravity wakes.

    Science.gov (United States)

    Moisy, Frédéric; Rabaud, Marc

    2014-08-01

    We determine experimentally the angle α of maximum wave amplitude in the far-field wake behind a vertical surface-piercing cylinder translated at constant velocity U for Bond numbers Bo(D)=D/λ(c) ranging between 0.1 and 4.2, where D is the cylinder diameter and λ(c) the capillary length. In all cases the wake angle is found to follow a Mach-like law at large velocity, α∼U(-1), but with different prefactors depending on the value of Bo(D). For small Bo(D) (large capillary effects), the wake angle approximately follows the law α≃c(g,min)/U, where c(g,min) is the minimum group velocity of capillary-gravity waves. For larger Bo(D) (weak capillary effects), we recover a law α∼√[gD]/U similar to that found for ship wakes at large velocity [Rabaud and Moisy, Phys. Rev. Lett. 110, 214503 (2013)]. Using the general property of dispersive waves that the characteristic wavelength of the wave packet emitted by a disturbance is of order of the disturbance size, we propose a simple model that describes the transition between these two Mach-like regimes as the Bond number is varied. We show that the new capillary law α≃c(g,min)/U originates from the presence of a capillary cusp angle (distinct from the usual gravity cusp angle), along which the energy radiated by the disturbance accumulates for Bond numbers of order of unity. This model, complemented by numerical simulations of the surface elevation induced by a moving Gaussian pressure disturbance, is in qualitative agreement with experimental measurements.

  18. Microfluidic chip-capillary electrophoresis devices

    CERN Document Server

    Fung, Ying Sing; Du, Fuying; Guo, Wenpeng; Ma, Tongmei; Nie, Zhou; Sun, Hui; Wu, Ruige; Zhao, Wenfeng

    2015-01-01

    Capillary electrophoresis (CE) and microfluidic chip (MC) devices are relatively mature technologies, but this book demonstrates how they can be integrated into a single, revolutionary device that can provide on-site analysis of samples when laboratory services are unavailable. By introducing the combination of CE and MC technology, Microfluidic Chip-Capillary Electrophoresis Devices broadens the scope of chemical analysis, particularly in the biomedical, food, and environmental sciences.The book gives an overview of the development of MC and CE technology as well as technology that now allows

  19. Capillary origami and superhydrophobic membrane surfaces

    Science.gov (United States)

    Geraldi, N. R.; Ouali, F. F.; Morris, R. H.; McHale, G.; Newton, M. I.

    2013-05-01

    Capillary origami uses surface tension to fold and shape solid films and membranes into three-dimensional structures. It uses the fact that solid surfaces, no matter how hydrophobic, will tend to adhere to and wrap around the surface of a liquid. In this work, we report that a superhydrophobic coating can be created, which can completely suppress wrapping as a contacting water droplet evaporates. We also show that using a wetting azeotropic solution of allyl alcohol, which penetrates the surface features, can enhance liquid adhesion and create more powerful Capillary Origami. These findings create the possibility of selectively shaping membrane substrates.

  20. TESTICULAR CAPILLARY HEMANGIOMA: DESCRIPTION OF A CASE

    Directory of Open Access Journals (Sweden)

    A. S. Markova

    2012-01-01

    Full Text Available The paper describes a clinical case of testicular capillary hemangioma in a 24-year-old man undergone a partial resection of the testis with the intraoperative morphological examination. Testicular capillary hemangioma is a rare benign tumor of a vascular origin, which can be similar to malignant testicular tumors on the clinical presentation, as well as on the imaging methods, in particular to seminoma. The intraoperative histological study can assist in avoiding organ-removing surgical interventions in diagnostically ambiguous cases if a benign testicular tumor is diagnosed.

  1. The relationship of urinary MCP1、 fetuin-A expression and urinary MDA in patients with nephrolithiasis%肾结石患者尿液MCP-1、胎球蛋白-A表达与MDA的关系

    Institute of Scientific and Technical Information of China (English)

    孙春

    2015-01-01

    目的:探讨肾结石患者尿液炎症细胞因子变化以及氧化应激在结石形成中的作用.方法:选择75例草酸钙结石住院患者,随机挑选25例健康人作正常对照组.收集两组人的晨尿,分别运用ELLISA法和TBA法检测尿液中单核细胞趋化蛋白(MCP-1)、胎球蛋白-A (Fetuin-A)及丙二醛(MDA)的含量.结果:MCP-1在结石组含量为212.45 (59.24,673.50)pg/mg cr,在对照组为74.36(22.45,203.57)pg/mg cr,结石组高于对照组(P<0.05);胎球蛋白-A在结石组为320.80(42.28,1819.85)ng/mg cr,在对照组为787.94(187.03,3269.17)ng/mg cr,结石组低于对照组(P<0.05);MDA在结石组高于正常对照组(P<0.05).相关性分析:结石组尿液MCP-1和MDA不相关,r=0.045,P> 0.05;胎球蛋白-A和MDA不相关,r=-0.016,P> 0.05.结论:尿液炎症细胞因子变化和氧化应激损伤可能在肾结石形成中起作用,但是氧化应激损伤可能未参与尿液炎症细胞因子的调节.

  2. Storage of strawberries (Fragaria ananassa L. cv. ‘Oso Grande’, subjected to 1-MCP - doi: 10.4025/actascitechnol.v34i3.8790

    Directory of Open Access Journals (Sweden)

    Polyanna Alves Silva

    2012-05-01

    Full Text Available This study aimed to investigate the influence of 1 - methylcyclopropene (1-MCP on the substances involved in the softening of strawberry, cultivar Oso Grande, stored at room temperature, from the municipality of Itutinga, State of Minas Gerais. The parameters evaluated were: firmness, total pectin, percentage of solubilization, activities of the enzymes pectinmethylesterase (PME (EC 3.1.1.11 and polygalacturonase (PG (EC 3.2.1.15. It was concluded that 1-MCP delayed the softening of the fruits, since the fruits that were treated with 1-MCP after storage, have shown greater firmness, lower activities of PG and PME, and lower contents of total pectin, soluble pectin and percentage of solubilization. 

  3. PENGARUH PERBEDAAN SIFAT PENYANGGA ALUMINA TERHADAP SIFAT KATALIS HYDROTREATING BERBASIS NIKEL-MOLIBDENUM

    Directory of Open Access Journals (Sweden)

    Maria Ulfah

    2012-11-01

    Full Text Available EFFECT OF ALUMINA SUPPORT PROPERTIES ON THE NICKEL-MOLIBDENUM BASE HYDROTREATING CATALYST. Effect of surface characteristics of three species of synthesized γ-alumina (alumina-1, alumina-2 and alumina-3 on characteristics NiMo catalysts has been studied. Those aluminas are derived from boehmite Catapal B by varying rasio mol nitric acid to boehmite. A sol-gel method is used to synthesize γ-Al2O3 support. The Nitrogen adsorption, X-ray diffraction (XRD, Temperature Programmed Reduction (TPR of H2, Temperature Programmed Desorption (TPD of NH3, and mechanical strength are used to characterize the supports and catalysts. The results showed that the surface area alumina affects the formation of crystalline MoO3 in the NiMo catalyst, while γ-Al2O3-3 support which has the highest surface area (about 195 m2/g compared to the other two types of alumina (>195 m2/g does not have a crystalline MoO3. The formation of crystalline MoO3 is not influenced by the acidity alumina. Based on the results of XRD, it is  indicated that the supported alumina-3 NiMo catalyst (having the highest acid strength shows that there is no presence of crystalline MoO3. Pore size distribution of support did not change significantly after the deposition of Ni and Mo oxides. Mechanical strength of support also affects the strength NiMo catalyst. Support alumina-3 which has the highest mechanical strength gives the mechanical strength of the highest NiMo catalyst. Pengaruh sifat penyangga γ-alumina hasil pengembangan (alumina-1, alumina-2 dan alumina-3 pada karakter katalis hydrotreating nikel-molibdenum (NiMo telah dipelajari. Ketiga jenis γ-alumina diturunkan dari boehmite “Catapal B” dengan menvariasikan nisbah mol asam nitrat terhadap boehmite. Pembuatan γ-alumina menggunakan metoda sol-gel. Adsorpsi Nitrogen, X-ray difraksi (XRD, Temperature Programmed Reduction (TPR H2, Temperature Programmed Desorption (TPD NH3, dan kekuatan mekanik digunakan untuk

  4. Involvement of M3 Cholinergic Receptor Signal Transduction Pathway in Regulation of the Expression of Chemokine MOB-1, MCP-1 Genes in Pancreatic Acinar Cells

    Institute of Scientific and Technical Information of China (English)

    郑海; 陈道达; 张景輝; 田原

    2004-01-01

    Whether M3 cholinergic receptor signal transduction pathway is involved in regulation of the activation of NF-κB and the expression of chemokine MOB-1, MCP-1genes in pancreatic acinar cells was investigated. Rat pancreatic acinar cells were isolated, cultured and treated with carbachol, atropine and PDTC in vitro. The MOB-1 and MCP-1 mRNA expression was detected by using RT-PCR. The activation of NF-κB was monitored by using electrophoretic mobility shift assay.The results showed that as compared with control group, M3 cholinergic receptor agonist (103mol/L, 104-4ol/L carbachol) could induce a concentration-dependent and time-dependent increase in the expression of MOB-1, MCP-1 mRNA in pancreatic acinar cells. After treatment with 10 -3mol/L carbachol for 2 h, the expression of MOB-1, MCP-1 mRNA was strongest. The activity of NF-κB in pancreatic acinar cells was significantly increased (P<0.01) after treated with M3 cholinergic receptor agonist (10-3 mol/L carbachol) in vitro for 30 min. Either M3 cholinergic receptor antagonist (10-5 mol/L atropine) or NF-κB inhibitor (10-2 mol/L PDTC) could obviously inhibit the activation of NF-κB and the chemokine MOB-1, MCP-1 mRNA expression induced by carbachol (P <0.05). This inhibitory effect was significantly increased by atropine plus PDTC (P<0.01). The results of these studies indicated that M3 cholinergic receptor signal transduction pathway was likely involved in regulation of the expression of chemokine MOB-1 and MCP-1genes in pancreatic acinar cells in vitro through the activation of NF-κB.

  5. Viscosity of aqueous and cyanate ester suspensions containing alumina nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Lawler, Katherine [Iowa State Univ., Ames, IA (United States)

    2009-01-01

    The viscosities of both aqueous and cyanate ester monomer (BECy) based suspensions of alumina nanoparticle were studied. The applications for these suspensions are different: aqueous suspensions of alumina nanoparticles are used in the production of technical ceramics made by slip casting or tape casting, and the BECy based suspensions are being developed for use in an injection-type composite repair resin. In the case of aqueous suspensions, it is advantageous to achieve a high solids content with low viscosity in order to produce a high quality product. The addition of a dispersant is useful so that higher solids content suspensions can be used with lower viscosities. For BECy suspensions, the addition of nanoparticles to the BECy resin is expected to enhance the mechanical properties of the cured composite. The addition of saccharides to aqueous suspensions leads to viscosity reduction. Through DSC measurements it was found that the saccharide molecules formed a solution with water and this resulted in lowering the melting temperature of the free water according to classic freezing point depression. Saccharides also lowered the melting temperature of the bound water, but this followed a different rule. The shear thinning and melting behaviors of the suspensions were used to develop a model based on fractal-type agglomeration. It is believed that the structure of the particle flocs in these suspensions changes with the addition of saccharides which leads to the resultant viscosity decrease. The viscosity of the BECy suspensions increased with solids content, and the viscosity increase was greater than predicted by the classical Einstein equation for dilute suspensions. Instead, the Mooney equation fits the viscosity behavior well from 0-20 vol% solids. The viscosity reduction achieved at high particle loadings by the addition of benzoic acid was also investigated by NMR. It appears that the benzoic acid interacts with the surface of the alumina particle which may

  6. High-frequency capillary waves excited by oscillating microbubbles

    CERN Document Server

    Pommella, Angelo; Poulichet, Vincent; Garbin, Valeria

    2013-01-01

    This fluid dynamics video shows high-frequency capillary waves excited by the volumetric oscillations of microbubbles near a free surface. The frequency of the capillary waves is controlled by the oscillation frequency of the microbubbles, which are driven by an ultrasound field. Radial capillary waves produced by single bubbles and interference patterns generated by the superposition of capillary waves from multiple bubbles are shown.

  7. Nuclear NF-κB p65 in peripheral blood mononuclear cells correlates with urinary MCP-1, RANTES and the severity of type 2 diabetic nephropathy.

    Directory of Open Access Journals (Sweden)

    Bin Yi

    Full Text Available AIMS: To investigate if nuclear NF-κB p65 expression in ex vivo isolated peripheral blood mononuclear cells correlates with urinary MCP-1 or RANTES and the severity of type 2 diabetic nephropathy. METHODS: According to their urinary albumin-to-creatinine ratio (uACR, 107 patients with type 2 diabetes (eGFR >60 ml/min were divided into normal albuminuria group (DN0 group, 38 cases, microalbuminuria group (DN1 group, 38 cases, and macroalbuminuria group (DN2 group, 31 cases, compared with matched healthy normal control group (NC group, 30 cases. Nuclear NF-κB p65 protein expression levels in peripheral blood mononuclear cells were detected by western blotting. Real-time quantitative polymerase chain reaction was used to detect NF-κB p65 mRNA expression and ELISA assay was used to detect the levels of urinary MCP-1 and RANTES. RESULTS: Nuclear NF-κB p65 protein and NF-κB p65 mRNA expression levels in peripheral blood mononuclear cells, urinary MCP-1/Cr and RANTES/Cr were all significantly higher in all diabetes groups as compared with NC group. In particular, the increase of nuclear NF-κB p65 protein and NF-κB p65 mRNA expressions, urinary MCP-1/Cr and RANTES/Cr all correlated with the severity of type 2 diabetic nephropathy as indicated by the increase in uACR. Pearson correlation analysis indicated that both urinary MCP-1/Cr and RANTES/Cr were positively correlated with nuclear NF-κB p65 protein or NF-κB p65 mRNA levels. Stepwise multiple regression analysis showed that nuclear NF-κB p65 protein or NF-κB p65 mRNA was an independent variable for urinary MCP-1/Cr, and MCP-1/Cr and RANTES/Cr were two independent variables for uACR. CONCLUSION: Our research demonstrates that nuclear NF-κB p65 protein and mRNA expressions in ex vivo isolated peripheral blood mononuclear cells well correlate with urinary MCP-1/Cr, RANTES/Cr and the severity of type 2 diabetic nephropathy.

  8. Association of monocyte chemoattractant protein-1 (MCP-1)-2518A>G polymorphism with susceptibility to coronary artery disease: a meta-analysis.

    Science.gov (United States)

    Bai, Xiao-Yan; Li, Shujing; Wang, Miao; Qu, Xinjian; Hu, Gaolei; Xu, Zhaowei; Chen, Min; He, Guo-Wei; Wu, Huijian

    2015-05-01

    We attempted to systematically elucidate the association between monocyte chemoattractant protein-1 (MCP-1) -2518A>G polymorphism and risk of coronary artery disease (CAD). Eligible studies were identified through PubMed, EBSCO, and Web of Science Databases. The magnitude of MCP-1 polymorphism effect and its possible mode of action on CAD were estimated. The odds ratio (OR) with 95% confidence intervals (CI) were pooled in a specific genetic model to assess the association. A total of 21 studies were involved. There was significant gene effect on CAD risk in the overall population (likelihood ratio test: p G polymorphism may be associated with susceptibility to CAD, especially in Caucasians.

  9. Qualidade de caqui 'Rama forte' após armazenamento refrigerado, influenciada pelos tratamentos 1-MCP e/ou CO2

    Directory of Open Access Journals (Sweden)

    João Peterson Pereira Gardin

    2012-12-01

    Full Text Available Avaliaram-se os efeitos dos tratamentos com CO2 e 1-MCP (1-metilciclopropeno sobre a adstringência (índice de tanino, firmeza da polpa e distúrbios da epiderme em caqui 'Rama Forte'. Frutos foram tratados com 1-MCP por 24 h, logo após a colheita e/ou com alto CO2 (70% por 24 ou 48 h, um dia após a colheita ou após o armazenamento refrigerado (AR. Os caquis foram armazenados sob atmosfera modificada a 0 ºC, por 45 dias, e a seguir mantidos a 23 ºC, por 9 dias. Frutos-controle (não tratados com 1-MCP nem com CO2 amoleceram em três dias e perderam aproximadamente 50% da adstringência em 6 dias após o AR. A exposição ao CO2 acelerou a redução da adstringência. Esse efeito do CO2 foi menor em frutos tratados com 1-MCP, especialmente quando o CO2 foi aplicado após o AR, por apenas 24 h. O tratamento com 1-MCP inibiu o amolecimento e a redução da adstringência, especialmente nos frutos não tratados com CO2. O amolecimento de frutos tratados com 1-MCP foi maior quando a exposição ao CO2 ocorreu antes do AR. A combinação dos tratamentos com 1-MCP e alto CO2 reduziu a incidência de podridões e manchas translúcidas, mas não alterou o desenvolvimento de pintas pretas ('estrias'. Os resultados indicam que é possível induzir perda da adstringência sem excessiva perda da firmeza da polpa de caquis 'Rama Forte' após o AR pela associação dos tratamentos com 1-MCP logo após a colheita e alto CO2 após o AR.

  10. Application Research of MCP23016 in Intelligent Multiplex Control System%MCP23016在智能化多路控制系统中的应用研究

    Institute of Scientific and Technical Information of China (English)

    包敬海; 吕丽珊; 彭丽英

    2016-01-01

    随着物联网的快速发展,智能化系统的应用日益广泛。但是,微控制器的IO端口有限,难以应对日益繁多的外部设备的控制需求。针对此难题,应利用IIC扩展芯片实现多路控制进行解决。以超低功耗MSP430G2253为主控芯片,通过16位IIC芯片MCP23016进行扩展,配合Web Server,使用户能够通过手机随时随地的对1024条线路的通断进行远程控制。实践表明,该系统具有扩展能力强、稳定可靠、响应快速、成本低廉等优点。%With the rapid development of internet of things, the application of intelligent system has become increasingly pop-ular. However, the IO ports of micro-controller is limited and can not cope with the control demand of increasing external equip-ment. Targeting at this problem, this paper proposed to use the IIC chip to realize the intelligent multiplex control, which took the ultra-low power consumption MSP430G2553 as the control core, extended the IO port by MCP23016, coordinated with the Web Server, and finally realized the user’ s remote control 1024 lines on-off whenever and wherever by mobile phone. Practice showed that the system had the advantages of strong extension, great stability and reliability, fast response and low cost.

  11. Cyclodextrin-Functionalized Monolithic Capillary Columns: Preparation and Chiral Applications.

    Science.gov (United States)

    Adly, Frady G; Antwi, Nana Yaa; Ghanem, Ashraf

    2016-02-01

    In this review, the recently reported approaches for the preparation of cyclodextrin-functionalized capillary monolithic columns are highlighted, with few applications in chiral separations using capillary liquid chromatography (CLC) and capillary electrochromatography (CEC). Chirality 28:97-109, 2016. © 2015 Wiley Periodicals, Inc.

  12. In-capillary detection of fast antibody-peptide binding using fluorescence coupled capillary electrophoresis.

    Science.gov (United States)

    Qin, Yuqin; Qiu, Lin; Qin, Haifang; Ding, Shumin; Liu, Li; Teng, Yiwan; Chen, Yao; Wang, Cheli; Li, Jinchen; Wang, Jianhao; Jiang, Pengju

    2016-01-01

    Herein, we report a technique for detecting the fast binding of antibody-peptide inside a capillary. Anti-HA was mixed and interacted with FAM-labeled HA tag (FAM-E4 ) inside the capillary. Fluorescence coupled capillary electrophoresis (CE-FL) was employed to measure and record the binding process. The efficiency of the antibody-peptide binding on in-capillary assays was found to be affected by the molar ratio. Furthermore, the stability of anti-HA-FAM-E4 complex was investigated as well. The results indicated that E4 YPYDVPDYA (E4) or TAMRA-E4 YPYDVPDYA (TAMRA-E4) had the same binding priorities with anti-HA. The addition of excess E4 or TAMRA-E4 could lead to partial dissociation of the complex and take a two-step mechanism including dissociation and association. This method can be applied to detect a wide range of biomolecular interactions.

  13. Preparation approaches of the coated capillaries with liposomes in capillary electrophoresis.

    Science.gov (United States)

    Mei, Jie; Tian, Yan-Ping; He, Wen; Xiao, Yu-Xiu; Wei, Juan; Feng, Yu-Qi

    2010-10-29

    The use of liposomes as coating materials in capillary electrophoresis has recently emerged as an important and popular research area. There are three preparation methods that are commonly used for coating capillaries with liposomes, namely physical adsorption, avidin-biotin binding and covalent coupling. Herein, the three different coating methods were compared, and the liposome-coated capillaries prepared by these methods were evaluated by studying systematically their EOF characterization and performance (repeatability, reproducibility and lifetime). The amount of immobilized phospholipids and the interactions between liposome or phospholipid membrane and neutral compounds for the liposome-coated capillaries prepared by these methods were also investigated in detail. Finally, the merits and disadvantages for each coating method were reviewed.

  14. Numerical simulations of capillary barrier field tests

    Energy Technology Data Exchange (ETDEWEB)

    Morris, C.E. [Univ. of Wollongong (Australia); Stormont, J.C. [Univ. of New Mexico, Albuquerque, NM (United States)

    1997-12-31

    Numerical simulations of two capillary barrier systems tested in the field were conducted to determine if an unsaturated flow model could accurately represent the observed results. The field data was collected from two 7-m long, 1.2-m thick capillary barriers built on a 10% grade that were being tested to investigate their ability to laterally divert water downslope. One system had a homogeneous fine layer, while the fine soil of the second barrier was layered to increase its ability to laterally divert infiltrating moisture. The barriers were subjected first to constant infiltration while minimizing evaporative losses and then were exposed to ambient conditions. The continuous infiltration period of the field tests for the two barrier systems was modelled to determine the ability of an existing code to accurately represent capillary barrier behavior embodied in these two designs. Differences between the field test and the model data were found, but in general the simulations appeared to adequately reproduce the response of the test systems. Accounting for moisture retention hysteresis in the layered system will potentially lead to more accurate modelling results and is likely to be important when developing reasonable predictions of capillary barrier behavior.

  15. Drops: The collapse of capillary jets

    Science.gov (United States)

    Cordoba, Antonio; Cordoba, Diego; Fefferman, Charles; Fontelos, Marco A.

    2002-01-01

    The appearance of fluid filaments during the evolution of a viscous fluid jet is a commonly observed phenomenon. It is shown here that the break-up of such a jet subject to capillary forces is impossible through the collapse of a uniform filament. PMID:12172005

  16. Capillary Electrophoresis Analysis of Conventional Splicing Assays

    DEFF Research Database (Denmark)

    de Garibay, Gorka Ruiz; Acedo, Alberto; García-Casado, Zaida;

    2014-01-01

    of these assays is often challenging. Here, we explore this issue by conducting splicing assays in 31 BRCA2 genetic variants. All variants were assessed by RT-PCR followed by capillary electrophoresis and direct sequencing. If assays did not produce clear-cut outputs (Class-2 or Class-5 according to analytical...

  17. Macroscopic theory for capillary-pressure hysteresis.

    Science.gov (United States)

    Athukorallage, Bhagya; Aulisa, Eugenio; Iyer, Ram; Zhang, Larry

    2015-03-03

    In this article, we present a theory of macroscopic contact angle hysteresis by considering the minimization of the Helmholtz free energy of a solid-liquid-gas system over a convex set, subject to a constant volume constraint. The liquid and solid surfaces in contact are assumed to adhere weakly to each other, causing the interfacial energy to be set-valued. A simple calculus of variations argument for the minimization of the Helmholtz energy leads to the Young-Laplace equation for the drop surface in contact with the gas and a variational inequality that yields contact angle hysteresis for advancing/receding flow. We also show that the Young-Laplace equation with a Dirichlet boundary condition together with the variational inequality yields a basic hysteresis operator that describes the relationship between capillary pressure and volume. We validate the theory using results from the experiment for a sessile macroscopic drop. Although the capillary effect is a complex phenomenon even for a droplet as various points along the contact line might be pinned, the capillary pressure and volume of the drop are scalar variables that encapsulate the global quasistatic energy information for the entire droplet. Studying the capillary pressure versus volume relationship greatly simplifies the understanding and modeling of the phenomenon just as scalar magnetic hysteresis graphs greatly aided the modeling of devices with magnetic materials.

  18. Electroviscous effects in capillary filling of nanochannels

    DEFF Research Database (Denmark)

    Mortensen, Asger; Kristensen, Anders

    2008-01-01

    We theoretically examine the widespread hypothesis of an electroviscous origin of the increase in apparent viscosity observed in recent experiments on capillary filling of nanochannels. Including Debye-layer corrections to the hydraulic resistance, we find that the apparent viscosity reaches a ma...

  19. Elastic deformation due to tangential capillary forces

    NARCIS (Netherlands)

    Das, Siddhartha; Marchand, Antonin; Andreotti, Bruno; Snoeijer, Jacco H.

    2011-01-01

    A sessile liquid drop can deform the substrate on which it rests if the solid is sufficiently “soft.” In this paper we compute the detailed spatial structure of the capillary forces exerted by the drop on the solid substrate using a model based on Density Functional Theory. We show that, in addition

  20. Capillary condensation between disks in two dimensions

    DEFF Research Database (Denmark)

    Gil, Tamir; Ipsen, John Hjorth

    1997-01-01

    Capillary condensation between two two-dimensional wetted circular substrates (disks) is studied by an effective free energy description of the wetting interface. The interfacial free-energy potential is developed on the basis of the theory for the wetting of a single disk, where interfacial capi....... The theory can be applied to the description of flocculations in two-dimensional systems of colloids....

  1. Shift dynamics of capillary self-alignment

    NARCIS (Netherlands)

    Arutinov, G.; Mastrangeli, M.; Smits, E.C.P.; Heck, G.V.; Schoo, H.F.M.; Toonder, J.J.M. den; Dietzel, A.H.

    2014-01-01

    This paper describes the dynamics of capillary self-alignment of components with initial shift offsets from matching receptor sites. The analysis of the full uniaxial self-alignment dynamics of foil-based mesoscopic dies from pre-alignment to final settling evidenced three distinct, sequential regim

  2. Nanoparticles as a tool in capillary electrochromatography

    OpenAIRE

    Ribeiro, Susana

    2009-01-01

    Two different types of molecularly imprinted nanoparticles against (R)-propranolol were used to separate the enantiomers of propranolol in capillary electrochromatography mode, methacrylic acid based nanoparticles and core-shell molecularly imprinted polymer nanoparticles. Partial filling technique was used to avoid interference of molecularly imprinted polymer nanoparticles in UV detection. With methacrylic acid based nanoparticles it was not possible to obtain enantiomer s...

  3. Recent advances of ionic liquids and polymeric ionic liquids in capillary electrophoresis and capillary electrochromatography.

    Science.gov (United States)

    Tang, Sheng; Liu, Shujuan; Guo, Yong; Liu, Xia; Jiang, Shengxiang

    2014-08-29

    Ionic liquids (ILs) and polymeric ionic liquids (PILs) with unique and fascinating properties have drawn considerable interest for their use in separation science, especially in chromatographic techniques. In this article, significant contributions of ILs and PILs in the improvement of capillary electrophoresis and capillary electrochromatography are described, and a specific overview of the most relevant examples of their applications in the last five years is also given. Accordingly, some general conclusions and future perspectives in these areas are discussed.

  4. Macroporous silica–alumina composites with mesoporous walls

    Indian Academy of Sciences (India)

    Gautam Gundiah

    2001-04-01

    Macroporous silica–alumina composites with mesopores have been prepared by employing polymethylmethacrylate beads as templates in the presence of the cationic surfactant, N-cetyl-N,N,N-trimethylammonium bromide. The Si/Al ratio in the composites has been varied between 4.5 and 48 and the occurrence of mesopores has been verified by X-ray diffraction. The surface areas of the samples vary between 676 and 1038 m2g–1, with the highest value in the sample with Si/Al = 48.

  5. Optical properties of porous anodic alumina embedded Cu nanocomposite films

    Science.gov (United States)

    Liu, Huiyuan; Sun, Huiyuan; Liu, Lihu; Hou, Xue; Jia, Xiaoxuan

    2015-06-01

    Porous anodic alumina embedded Cu with iridescent colors were fabricated in copper sulfate electrolyte. The films display highly saturated colors after being synthesized by an ac electrodeposition method. Tunable color in the films is obtained by adjusting anodization time, and can be adjusted across the entire visible range. Theoretical results of the changes in the structural color according to the Bragg-Snell formula are consistent with the experimental results. The films could be used in many areas including decoration, display and multifunctional anti-counterfeiting applications.

  6. Toughening and strengthening mechanism of zirconia-alumina multiphase ceramics

    Energy Technology Data Exchange (ETDEWEB)

    Yu, M.Q.; Fan, S.G. [Research Inst. of Synthetic Crystals, Beijing, BJ (China); Shen, Q.; Zhang, L.M. [Wuhan Univ. of Technology (China)

    2003-07-01

    In the present study, the effect of compositions on the mechanical properties of zirconia-alumina multiphase ceramics was studied. The results showed that with the variety of ZrO{sub 2} content, the change of bending strength and fracture toughness of the multiphase ceramics exhibited a saddle shape which could be divided into three zones: ZTA, ADZ, and Transition zone. The mechanism of toughening and strengthening in each zone was mainly analyzed, and it was found that stress-induced transformation toughening of ZrO{sub 2} and dispersion strengthening of Al{sub 2}O{sub 3} were the two main factors. (orig.)

  7. Development of technology and applications based on porous alumina nanostructures

    OpenAIRE

    Vojkuvka, Lukas

    2009-01-01

    La disertación ha sido organizada de la siguiente manera. En el primer capítulo se presenta el estado del arte, donde se exponen algunos conceptos básicos de las propiedades electroquimicaselectroquímicas del alumino, las fases del crecimiento de los poros y el proceso de auto-ordenación de los mismos. El segundo capítulo de la tesis esta relacionado con la preparación y caracterización morfológica de las muestras de alumina porosa. >En el capítulo 4 se desglosan los resultados obtenidos de l...

  8. Alcohol dehydration: Mechanism of ether formation using an alumina catalyst

    Energy Technology Data Exchange (ETDEWEB)

    Shi, B.; Davis, B.H. [Univ. of Kentucky, Lexington, KY (United States)

    1995-12-01

    Ether formation during the dehydration of secondary alcohols, namely, 2-butanol, 3-pentanol, and 1-cyclopentylethanol, was investigated. Using the proper reaction conditions, the yield of di-2-butyl ether during the dehydration of 2-butanol on alumina can be as high as 40%. That ether is formed by adding an alcohol to the alkene is ruled out by the results from deuterium tracer studies. Results from experiments using S(+)- 2-butanol suggest that the formation of di-2-butyl ether occurs by a S{sub N}2-type mechanism. 33 refs., 5 figs., 3 tabs.

  9. Evaluation of migration behaviour of therapeutic peptide hormones in capillary electrophoresis using polybrene-coated capillaries.

    Science.gov (United States)

    Aptisa, Ghiulendan; Benavente, Fernando; Sanz-Nebot, Victoria; Chirila, Elisabeta; Barbosa, José

    2010-02-01

    Modelling electrophoretic mobility as a function of pH can be simultaneously used for determination of ionization constants and for rapid selection of the optimum pH for separation of mixtures of the modelled compounds. In this work, equations describing the effect of pH on electrophoretic behaviour were used to investigate migration of a series of polyprotic amphoteric peptide hormones between pH 2 and 12 in polybrene-coated capillaries. Polybrene (hexadimethrin bromide) is a polymer composed of quaternary amines that is strongly adsorbed by the fused-silica inner surface, preventing undesired interactions between the peptides and the inner capillary wall. In polybrene-coated capillaries the separation voltage must be reversed, because of the anodic electroosmotic flow promoted by the polycationic polymer attached to the inner capillary wall. The possibility of using polybrene-coated capillaries for determination of accurate ionization constants has been evaluated and the optimum pH for separation of a mixture of the peptide hormones studied has been selected. Advantages and disadvantages of using bare fused-silica and polybrene-coated capillaries for these purposes are discussed.

  10. 2Kx2K resolution element photon counting MCP sensor with >200 kHz event rate capability

    CERN Document Server

    Vallerga, J V

    2000-01-01

    Siegmund Scientific undertook a NASA Small Business Innovative Research (SBIR) contract to develop a versatile, high-performance photon (or particle) counting detector combining recent technical advances in all aspects of Microchannel Plate (MCP) detector development in a low cost, commercially viable package that can support a variety of applications. The detector concept consists of a set of MCPs whose output electron pulses are read out with a crossed delay line (XDL) anode and associated high-speed event encoding electronics. The delay line anode allows high-resolution photon event centroiding at very high event rates and can be scaled to large formats (>40 mm) while maintaining good linearity and high temporal stability. The optimal sensitivity wavelength range is determined by the choice of opaque photocathodes. Specific achievements included: spatial resolution of 200 000 events s sup - sup 1; local rates of >100 events s sup - sup 1 per resolution element; event timing of <1 ns; and low background ...

  11. Development of a New Fast Shower Maximum Detector Based on Microchannel Plates Photomultipliers (MCP-PMT) as an Active Element

    Energy Technology Data Exchange (ETDEWEB)

    Ronzhin, A. [Fermilab; Los, S. [Fermilab; Ramberg, E. [Fermilab; Spiropulu, M. [Caltech; Apresyan, A. [Caltech; Xie, S. [Caltech; Kim, H. [Chicago U.; Zatserklyaniy, A. [UC, Santa Cruz

    2014-09-21

    One possibility to make a fast and radiation resistant shower maximum (SM) detector is to use a secondary emitter as an active element. We present below test beam results, obtained with different types of photodetectors based on microchannel plates (MCPs) as the secondary emitter. We performed the measurements at the Fermilab Test Beam Facility with 120GeV proton beam and 12GeV and 32GeV secondary beams. The goal of the measurement with 120GeV protons was to determine time resolution for minimum ionizing particles (MIPs). The SM time resolution we obtained for this new type of detector is at the level of 20-30ps. We estimate that a significant contribution to the detector response originates from secondary emission of the MCP. This work can be considered as the first step in building a new type of calorimeter based on this principle.

  12. Development of a PDMS-grafted alumina membrane and its evaluation as solvent resistant nanofiltration membrane

    NARCIS (Netherlands)

    Pinheiro de Melo, A.F.; Hoogendoorn, D.; Nijmeijer, A.; Winnubst, A.J.A.

    2014-01-01

    A new solvent resistant nanofiltration (SRNF) membrane is developed by grafting a PDMS polymer into the pores of a 5 nm γ-alumina ceramic membrane. These PDMS-grafted γ-alumina membranes were attained through a two-step synthesis. The linking agent, 3-aminopropyltriethoxysilane (APTES), was first ap

  13. Polyethyleneglycol grafting of γ-alumina membranes for solvent resistant nanofiltration

    NARCIS (Netherlands)

    Tanardi, C.R.; Catana, Romina; Barboiu, Mihai; Ayral, André; Vankelecom, I.F.J.; Nijmeijer, A.; Winnubst, A.J.A.

    2016-01-01

    A method is presented for grafting mesoporous g-alumina (pore size 5 nm), supported on an a-alumina ceramic membrane, with polyethylene glycols (PEG). The grafting performance of g-Al2O3 powders with various PEG grafting agents, having different molecular weights, alkoxy groups, and ureido functiona

  14. Effect of Calcination on the Sintering of Gel-Derived, Zirconia-Toughened Alumina

    NARCIS (Netherlands)

    Exter, den Peter; Winnubst, Louis; Leuwerink, Theo H.P.; Burggraaf, Anthonie J.

    1994-01-01

    The densification behavior of ZrO2 (+ 3 mol% Y2O3)/85 wt% Al2O3 powder compacts, prepared by the hydrolysis of metal chlorides, can be characterized by a transition- and an α-alumina densification stage. The sintering behavior is strongly determined by the densification of the transition alumina agg

  15. Effect of Microstructure of Composite Powders on Microstructure and Properties of Microwave Sintered Alumina Matrix Ceramics

    Institute of Scientific and Technical Information of China (English)

    Hanmin Bian; Yong Yang; You Wang; Wei Tian; Haifu Jiang; Zhijuan Hu; Weimin Yu

    2013-01-01

    Two kinds of different structured alumina-titania composite powders were used to prepare alumina matrix ceramics by microwave sintering.One was powder mixture of alumina and titania at a micron-submicron level,in which fused-and-crushed alumina particles (micrometers) was clad with submicron-sized titania.The other was powder mixture of alumina and titania at nanometer-nanometer level,in which nano-sized alumina and nano-sized titania particles were homogeneously mixed by ball-milling and spray dried to prepare spherical alumina-titania composite powders.The effect of the microstructure of composite powders on microstructure and properties of microwave sintered alumina matrix ceramics were investigated.Nano-sized composite (NC) powder showed enhanced sintering behavior compared with micro-sized composite (MC) powders.The asprepared NC ceramic had much denser,finer and more homogenous microstructure than MC ceramic.The mechanical properties of NC ceramic were significantly higher than that of MC ceramic,e.g.the flexural strength,Vickers hardness and fracture toughness of NC ceramic were 85.3%,130.3% and 25.7% higher than that of MC ceramic,respectively.The improved mechanical properties of NC ceramic compared with that of MC ceramic were attributed to the enhanced densification and the finer and more homogeneous microstruc.ture through the use of the nanostructured composite powders.

  16. Ge Honglin: Expand and Consolidate Chemical Alumina to Create World Top-class Brand

    Institute of Scientific and Technical Information of China (English)

    2015-01-01

    On June 9,Chinalco convened discussion meeting on integrated utilization of chemical alumina and red mud.Ge Honglin,Chairman and Secretary of the Party Leadership Group of Chinalco,emphasized:"It is imperative to unswervingly expand and consolidate chemical alumina,create world top-class brand,continually propel red mud integrated utilization,and improve integrated utilization rate of resources."

  17. A Review of Alumina Feeding and Dissolution Factors in Aluminum Reduction Cells

    Science.gov (United States)

    Lavoie, Pascal; Taylor, Mark P.; Metson, James B.

    2016-08-01

    Modern aluminum reduction cells use point feeding technology to replenish alumina as it is consumed by the electrolytic process. The dissolution of alumina has become increasingly difficult to control as the cell sizes and electrolysis intensity have increased. The mass of alumina added per unit time is now much higher than a decade ago, and must take place within a smaller electrolyte mixing volume. In order to replenish the alumina concentration evenly, the alumina needs to be delivered, dispersed, dissolved, and distributed throughout the reduction cell. The dissolution itself follows a 4-step process that can be limited by a multitude of factors. The status of the research on each of these factors is reviewed in the present paper. Although research in laboratory cells has been conducted many times, and the impact of many factors on dissolution has been measured, published observations of alumina feeding on industrial cells are very sparse, especially regarding the dissolution dynamics in the space-time domain and the impact of the feeder hole condition. The present paper therefore presents a qualitative model of the factors governing alumina dissolution in industrial cells and offers the hypothesis that maintenance of the feeder hole condition is central to ensuring alumina dissolution and prevention of sludging.

  18. Crystallography-Induced Correlations in Pore Ordering of Anodic Alumina Films

    NARCIS (Netherlands)

    Roslyakov, Ilya V.; Koshkodaev, Dmitry S.; Eliseev, Andrei A.; Hermida-Merino, Daniel; Petukhov, Andrei V.; Napolskii, Kirill S.

    2016-01-01

    A crystallographic approach to tailoring the morphology and ordering degree of the porous structure of alumina films obtained by anodization of single-crystalline aluminum is discussed. The examination of porous structure of anodic alumina films formed on low-index and vicinal planes of Al single cr

  19. Modification of alumina matrices through chemical etching and electroless deposition of nano-Au array for amperometric sensing

    Directory of Open Access Journals (Sweden)

    Valinčius Gintaras

    2007-01-01

    Full Text Available AbstractSimple nanoporous alumina matrix modification procedure, in which the electrically highly insulating alumina barrier layer at the bottom of the pores is replaced with the conductive layer of the gold beds, was described. This modification makes possible the direct electron exchange between the underlying aluminum support and the redox species encapsulated in the alumina pores, thus, providing the generic platform for the nanoporous alumina sensors (biosensors with the direct amperometric signal readout fabrication.

  20. Synthesis of alumina-α using chemical and activation energy por microwave; Sintese de alumina-α utilizando ativacao quimica e energia por microondas

    Energy Technology Data Exchange (ETDEWEB)

    Cartaxo, J.M.; Galdino, M.N.; Neves, G.A., E-mail: juliana@dema.ufcg.edu.br [Universidade Federal de Campina Grande (DEMA/UFCG), PB (Brazil). Unidade Academica de Engenharia de Materiais; Campos, L.F.A.; Menezes, R.R. [Universidade Federal da Paraiba (UFPB), PB (Brazil). Dept. de Engenharia de Materiais; Kiminami, R.H.G.A. [Universidade Federal de Sao Carlos (UFSC), SP (Brazil)

    2012-07-01

    With the great technological advances of alumina, this study aimed to synthesize the α-alumina and chemical activation using microwave energy from aluminum nitrate precursor. The synthesized powders were characterized by X-ray diffraction, thermal analysis (DTA and TGA) and surface area by BET. The chemical activation process was conducted by varying the concentration of the acid solution and exposure time of the material solution. The results proved the effectiveness of chemical activation by accelerating the synthesis process. The results of thermal analysis can observe the thermal decomposition temperature and the possible nucleation of new phases of alumina. The results of X-ray diffraction showed that the powders have the structure of α-alumina with specific areas ranging from 3 to 15m{sup 2}/g pore diameters between 190 to 485nm. (author)

  1. Microstructure-mechanical behaviour relationship in alumina-calcium exaluminate composites; Relaciones microestructura-comportamiento mecanico en materiales de alumina-hexaluminato calcico

    Energy Technology Data Exchange (ETDEWEB)

    Sanchez-Herencia, A. J.; Moreno, R.; Baudin, C.

    2001-07-01

    The grain growth behaviour of dense alumina materials has been modified by the addition of calcium hexaluminate particles. Maximum dispersion has been obtained by colloidal processing routes. The influence of sintering temperature (1500-1600 degree centigree) on the size and shape of the alumina grains has been established. The mechanical behaviour of three composite materials with the same composition ({approx}10 vol% CA{sub 6}) and large microstructural differences has been studied in comparison with that of monophasic alumina of the same grain size. The influence of grain size and shape on toughness has been established. R-curve behaviour has been detected during fracture of the material with the alumina grains presenting the largest shape factor. (Author) 18 refs.

  2. A complete soil hydraulic model accounting for capillary and adsorptive water retention, capillary and film conductivity, and hysteresis

    NARCIS (Netherlands)

    Sakai, Masaru; Van Genuchten, Martinus Th; Alazba, A. A.; Setiawan, Budi Indra; Minasny, Budiman

    2015-01-01

    A soil hydraulic model that considers capillary hysteretic and adsorptive water retention as well as capillary and film conductivity covering the complete soil moisture range is presented. The model was obtained by incorporating the capillary hysteresis model of Parker and Lenhard into the hydraulic

  3. Interactions of L-alanine with alumina as studied by vibrational spectroscopy.

    Science.gov (United States)

    Garcia, Ana R; de Barros, Ricardo Brito; Fidalgo, Alexandra; Ilharco, Laura M

    2007-09-25

    The interactions of L-alanine with gamma- and alpha-alumina have been investigated by diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS). L-alanine/alumina samples were dried from aqueous suspensions, at 36.5 degrees C, with two amino acid concentrations (0.4 and 0.8 mmol g-1) and at different pH values (1, 6, and 13). The vibrational spectra proved that the nature of L-alanine interactions with both aluminas is the same (hydrogen bonding), although the groups involved depend on the L-alanine form and on alumina surface groups, both controlled by the pH. For samples prepared at pH 1, cationic L-alanine [CH3CH(NH3+)COOH] displaces physisorbed water from alumina, and strong hydrogen bonds are established between the carbonyl groups of alanine, as electron donors, and the surface Al-OH2+ groups of alumina. This occurs at the expense of alanine dimer dissociation and breaking of intramolecular bonds. When samples are prepared at pH 6, the interacting groups are Al-OH2+ and the carboxylate groups of zwitterionic L-alanine [CH3CH(NH3+)COO-]. The affinity of L-alanine toward alumina decreases, as the strong NH3+...-OOC intermolecular hydrogen bonds prevail over the interactions with alumina. Thus, for a load of 0.8 mmol g-1, phase segregation is observed. On alpha-alumina, crystal deposition is even observed for a load of 0.4 mmol g-1. At pH 13, the carboxylate groups of anionic L-alanine [CH3CH(NH2)COO-] are not affected by alumina. Instead, hydrogen bond interactions occur between NH2 and the Al-OH surface groups of the substrate. Complementary N2 adsorption-desorption isotherms showed that adsorption of L-alanine occurs onto the alumina pore network for samples prepared at pH 1 and 13, whereas at pH 6 the amino acid/alumina interactions are not strong enough to promote adsorption. The mesoporous structure and the high specific surface area of gamma-alumina make it a more efficient substrate for adsorption of L-alanine. For each alumina, however, it is

  4. Mechanical performance of alumina reinforced with NbC, TiC and WC

    Directory of Open Access Journals (Sweden)

    Wilson Acchar

    2012-12-01

    Full Text Available The incorporation of refractory hard particles in Al2O3-based composites may inhibit grain growth of the matrix, which could significantly contribute to mechanical performance of the composite. The present study aimed to investigate the potential use of NbC as alumina reinforcing material, as an alternative to other carbides such as TiC and WC. Alumina was mixed with a fixed carbide concentration of 30 wt.(% in a ball mill and uniaxially hot-pressed at 1650 ºC under a load of 30 MPa in an inert atmosphere. X-ray diffraction revealed no oxidation products were present after the sintering process. Microstructure analyses indicate a homogeneous carbide distribution in the alumina matrix. Results obtained in this study show that alumina reinforced with NbC is a composite material with properties comparable to those of alumina reinforced with WC and TiC, thereby making it good reinforcing material.

  5. Investigation of Mechanical Behavior of Alfa and Gamma Nano- Alumina/ Epoxy Composite Made By Vartm

    Directory of Open Access Journals (Sweden)

    P. Ghabezi

    2016-06-01

    Full Text Available In this paper, the mechanical properties (flexural and tensional modulus and strength are investigated by manufacturing Epoxy/Glass Nano-composite samples with different Nano-particle wt% (Nano-Alumina to find optimum conditions. The alpha and Gamma grade of Nano alumina were added to the epoxy system with the weight percentage of 1, 2, 3, 4, 5 and 6. The experimental results show that the maximum flexural stiffness in Alfa and Gamma Nano-alumina composite is related to 6 wt% and 4 wt% samples, respectively. And the highest tensional stiffness in Alfa and Gamma Nano-alumina composite is related to 4 wt% and 5 wt% samples, respectively. Also the highest toughness for Alfa and Gamma Nano-composites is observed for 4 wt% and 3 wt% samples and in the same way Nano-alumina in grade Alfa with 1 wt% and Gamma with 3 wt% have highest failure strain.

  6. Robust Mechanical Properties of Electrically Insulative Alumina Films by Supersonic Aerosol Deposition

    Science.gov (United States)

    Lee, Jong-Gun; Cha, You-Hong; Kim, Do-Yeon; Lee, Jong-Hyuk; Lee, Tae-Kyu; Kim, Woo-Young; Park, Jieun; Lee, Dongyun; James, Scott C.; Al-Deyab, Salem S.; Yoon, Sam S.

    2015-08-01

    Electrically insulating alumina films were fabricated on steel substrates using supersonic aerosol deposition and their hardness and scratchability were measured. Alumina particles (0.4-μm diameter) were supersonically sprayed inside a low-pressure chamber using between 1 and 20 nozzle passes. These alumina particles were annealed between 300 and 800 K to determine the temperature's effect on film crystal size (37-41 nm). Smoother surface morphology and increased electrical resistance of the thin films were observed as their thicknesses grew by increasing the number of passes. Resistances of up to 10,000 MΩ demonstrate robust electrical insulation. Significant hardness was measured (1232 hv or 13.33 GPa), but the alumina films could be peeled off with normal loads of 36 and 47 N for films deposited on stainless steel and SKD11 substrates, respectively. High insulation and hardness confirm that these alumina films would make excellent electrical insulators.

  7. Processing, nano indentation and scratch testing of alumina-coated YTZP

    Energy Technology Data Exchange (ETDEWEB)

    Valle, J.; Anglada, M.; Ferrari, B.; Baudin, C.

    2015-10-01

    In this work, alumina-coated YTZP materials are proposed as means to combine the mechanical reliability of YTZP with the stiffness and hardness of alumina. Additionally, compressive stresses are developed in the alumina coating when cooling from the sintering temperature due to the thermal expansion mismatch between alumina and YTZP. The proposed processing method involves dipping of pre-sintered YTZP specimens in stable alumina suspensions and co-sintering of the dipped specimens. The influence of the processing parameters on the macro and microstructure of the materials has been established. Berkovich indentation has been performed to determine the Young's modulus of the substrates and coatings. The structural integrity of the coatings has been analysed using scratch tests. The Young's modulus. The optimised specimens present high resistance to scratch up to loads of 150 N. (Author)

  8. Cellulose extraction from Zoysia japonica pretreated by alumina-doped MgO in AMIMCl.

    Science.gov (United States)

    Liu, Le; Ju, Meiting; Li, Weizun; Jiang, Yang

    2014-11-26

    In this study, alumina-doped MgO was produced as a solid alkali for lignocellulose pretreatment. Pretreatment with alumina-doped MgO disrupted the lignocellulose structure and significantly reduced the lignin content of the Z. japonica. After pretreatment, Z. japonica showed significant solubility in 1-allyl-3-methylimidazolium chloride (AMIMCl). The similar high solubility of pretreated Z. japonica samples by original alumina-doped MgO and used alumina-doped MgO also proved that alumina-doped MgO had strong stability, which can be recycled and used repeatedly. The regenerated cellulose was similar to microcrystalline cellulose according to FTIR and NMR analyses. Compared to microcrystalline cellulose, only the crystallinity of the regenerated cellulose decreased.

  9. Micromechanics of deformation in porous liquid phase sintered alumina under hertzian contact

    Energy Technology Data Exchange (ETDEWEB)

    DIGIOVANNI,ANTHONY A.; CHAN,HELEN M.; HARMER,MARTIN P.; NIED,HERMAN F.

    2000-05-15

    A series of fine-grained porous alumina samples, with and without a liquid phase, were fabricated in compositions matched closely to commercially available alumina used as a microelectronic substrates. Hertzian indentation on monolithic specimens of the glass-containing samples produced a greater quasi-ductile stress-strain response compared to that observed in the pure alumina. Maximum residual indentation depths, determined from surface profilometry, correlated with the stress-strain results. Moreover, microstructural observations from bonded interface specimens revealed significantly more damage in the form of microcracking and under extreme loading, pore collapse, in the glass-containing specimens. The absence of the typical twin faulting mechanism observed for larger-grained alumina suggests that the damage mechanism for quasi-ductility in these fine-grained porous alumina derived from the pores acting as a stress concentrator and the grain boundary glass phase providing a weak path for short crack propagation.

  10. Bond strength of a resin cement to high-alumina and zirconia-reinforced ceramics : The effect of surface conditioning

    NARCIS (Netherlands)

    Felipe Valandro, Luiz; Ozcan, Mutlu; Bottino, Marco Cicero; Bottino, Marco Antonio; Scotti, Roberto; Della Bona, Alvaro

    2006-01-01

    Purpose: The aim of this study was to evaluate the effect of two surface conditioning methods on the microtensile bond strength of a resin cement to three high-strength core ceramics: high alumina-based (In-Ceram Alumina, Procera AllCeram) and zirconia-reinforced alumina-based (in-Ceram Zirconia) ce

  11. Bond strength of a resin cement to high-alumina and zirconia-reinforced ceramics: The effect of surface conditioning

    NARCIS (Netherlands)

    Valandro, L.F.; Ozcan, M.; Bottino, M.C.; Bottino, M.A.; Scotti, R.; Della Bona, A.

    2006-01-01

    Purpose: The aim of this study was to evaluate the effect of two surface conditioning methods on the microtensile bond strength of a resin cement to three high-strength core ceramics: high alumina-based (In-Ceram Alumina, Procera AllCeram) and zirconia-reinforced alumina-based (in-Ceram Zirconia) ce

  12. Effects of Roux-en-Y Gastric Bypass on Fasting and Postprandial Levels of the Inflammatory Markers YKL-40 and MCP-1 in Patients with Type 2 Diabetes and Glucose Tolerant Subjects

    DEFF Research Database (Denmark)

    Thomsen, Stine Brinkløv; Rathcke, Camilla Noelle; Jørgensen, Nils Bruun

    2013-01-01

    Background. The inflammatory markers YKL-40 and monocyte chemoattractant protein-1 (MCP-1) are elevated in morbidly obese patients and decline after weight loss. The objective of our study was to investigate the possible changes of YKL-40 and MCP-1, in both the fasting and the postprandial states...

  13. Interfaces fracas em compósitos de matriz cerâmica de alumina/alumina

    OpenAIRE

    Hablitzel,M.P.; Garcia,D.E.; Hotza,D.

    2011-01-01

    O uso de cerâmicas estruturais é limitado por sua fratura frágil. Compósitos de matriz cerâmica (CMCs) são materiais que possuem reforços estruturais que atuam aumentando a energia necessária para que o material se frature. O presente artigo apresenta uma alternativa para a produção de CMCs em que matriz e fibras são constituídas de alumina. Os mecanismos responsáveis pelo aumento da tenacidade ocorrem devido a uma interfase porosa entre matriz e fibras.

  14. Morphology-controlled electrochemical sensing amaranth at nanomolar levels using alumina

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Yuanyuan [School of Chemistry and Chemical Engineering, Huazhong University of Science and Technology, Wuhan 430074 (China); Gan, Tian [College of Chemistry and Chemical Engineering, Xinyang Normal University, Xinyang 464000 (China); Wan, Chidan [School of Chemistry and Chemical Engineering, Huazhong University of Science and Technology, Wuhan 430074 (China); Wu, Kangbing, E-mail: kbwu@hust.edu.cn [School of Chemistry and Chemical Engineering, Huazhong University of Science and Technology, Wuhan 430074 (China)

    2013-02-18

    Highlights: ► A facile way to tune morphology and sensing properties of alumina was developed. ► Oxidation activities of amaranth on alumina surface were morphology-dependent. ► Alumina microfibers were more active and greatly increased the signal of amaranth. ► Sensitive, rapid, selective and accurate method was developed for amaranth detection. -- Abstract: Different-shaped aluminas were readily prepared via hydrothermal reaction. It was found that the morphology and the electrochemical sensing properties of alumina were heavily dependent on the reaction time. When extending the reaction time from 6 h to 24 h, the obtained alumina samples changed from amorphous bumps to regular microfibers in diameter of 200 nm, as confirmed by scanning electron microscopy. Transmission electron microscopy observation revealed that longer reaction time was beneficial for the formation of porous and uniform fiber-like structures. Electrochemical tests proved that alumina microfibers were more active for the oxidation of amaranth and exhibited much higher enhancement effect, compared with alumina bumps. On the surface of alumina microfibers, the oxidation peak currents of amaranth increased remarkably. The influences of pH value, amount of alumina microfibers, and accumulation time on the signal enhancement of amaranth were discussed. As a result, a novel electrochemical method was developed for the detection of amaranth. The linear range was from 1 to 150 nM, and the detection limit was 0.75 nM after 1-min accumulation. The analytical application in drink samples was investigated, and the results consisted with the values that obtained by high-performance liquid chromatography.

  15. 1-methylcyclopropene (1-MCP)-induced alteration in leaf photosynthetic rate, chlorophyll fluorescence, respiration and membrane damage in rice (Oryza sativa L.) under high night temperature

    Science.gov (United States)

    High night temperature (HNT) can induce ethylene-triggered reactive oxygen species production, which can cause premature leaf senescence and membrane damage, thereby affecting production, consumption and transfer of photosynthates, and yield. The 1-methylcyclopropene (1-MCP) can competitively bind w...

  16. Effect of Ethylene and 1-Methylcyclopropene (1-MCP) on color and Firmness of Red and Breaker Stage Tomato Stored at Different Temperatures

    NARCIS (Netherlands)

    Tadesse, T.N.; Farneti, B.; Woltering, E.J.

    2012-01-01

    The red color of the tomato fruit during ripening is due to the presence lycopene, a compound known for its antioxidant property. This compound is influenced by temperature, ethylene and 1-Methylcyclopropene (1-MCP) treatment. It was believed that ethylene application at chilling temperature could h

  17. Concentrações de IL-6, TNF-α e MCP-1 em crianças com excesso de massa corporal

    Directory of Open Access Journals (Sweden)

    Juliano Magalhães Guedes

    2015-08-01

    Full Text Available O objetivo desta revisão sistemática foi verificar a relação das concentrações de IL-6, TNF-α e MCP-1 em crianças com excesso de massa corporal. As bases de dados investigadas PUBMED, SciELO, LILACS e Periódico Capes foram consultadas retrospectivamente para os últimos seis anos (2009 a 2014 utilizando combinações de palavras chaves como inflamação, IL-6, TNF-α, MCP-1 combinadas com crianças e escolares. Foram analisados 21 artigos. Foi encontrado associação entre sobrepeso/obesidade com IL-6, TNF-α e MCP-1 em 73,3% (11/15, 80% (12/15 e 60% (3/5 dos estudos que analisaram tais marcadores, respectivamente. Crianças com excesso de massa corporal possuem concentrações elevadas de IL-6, TNF-α e MCP-1 resultando em inflamação sistêmica crônica e aumentando o risco de desenvolvimento de outras doenças cardiovasculares. 

  18. Capillary Interactions between a Probe Tip and a Nanoparticle

    Institute of Scientific and Technical Information of China (English)

    SUN Li-Ning; WANG Le-Feng; RONG Wei-Bin

    2008-01-01

    To understand capillary interactions between probe tips and nanoparticles under ambient conditions,a theoretical model of capillary forces between them is developed based on the geometric relations. It is found that the contribution of surface tension force to the total capillary force attains to similar order of magnitude as the capillary pressure force in many cases.It is also shown that the tip shape and the radial distance of the meniscus have great influence on the capillary force.The capillary force decreases with the increasing separation distances,and the variance of the contact angles may change the magnitudes of capillary forces several times at large radial distances.The applicability of the symmetric meniscus approximation is discussed.

  19. Gold nanoparticles deposited capillaries for in-capillary microextraction capillary zone electrophoresis of monohydroxy-polycyclic aromatic hydrocarbons.

    Science.gov (United States)

    Wang, Huiyong; Knobel, Gaston; Wilson, Walter B; Calimag-Williams, Korina; Campiglia, Andres D

    2011-03-01

    This article presents the first application of gold nanoparticles deposited capillaries as pre-concentration devices for in-capillary microextraction CZE and their use for the analysis of monohydroxy-polycyclic aromatic hydrocarbons in synthetic urine samples. The successful separation of 1-hydroxypyrene, 9-hydroxyphenanthrene, 3-hydroxybenzo[a]pyrene (3-OHbap), 4-hydroxybenzo[a]pyrene and 5-hydroxybenzo[a]pyrene under a single set of electrophoretic conditions is demonstrated as well as the feasibility to obtain competitive ultraviolet absorption LOD with commercial instrumentation. Enrichment factors ranging from 87 (9-OHphe) to 100 (3-OHbap) made it possible to obtain LOD ranging from 9 ng/mL (9-OHphe and 3-OHbap) to 14 ng/mL (4-hydroxybenzo[a]pyrene).

  20. Synthesis of magnesium aluminate spinel by periclase and alumina chlorination

    Energy Technology Data Exchange (ETDEWEB)

    Orosco, Pablo, E-mail: porosco@unsl.edu.ar [Instituto de Investigaciones en Tecnología Química (INTEQUI), Chacabuco y Pedernera, San Luis (Argentina); Facultad de Química, Bioquímica y Farmacia, Universidad Nacional de San Luis Chacabuco y Pedernera, San Luis (Argentina); Barbosa, Lucía [Instituto de Investigaciones en Tecnología Química (INTEQUI), Chacabuco y Pedernera, San Luis (Argentina); Instituto de Ciencias Básicas (ICB), Universidad Nacional de Cuyo Parque General San Martín, Mendoza (Argentina); Ruiz, María del Carmen [Instituto de Investigaciones en Tecnología Química (INTEQUI), Chacabuco y Pedernera, San Luis (Argentina); Facultad de Química, Bioquímica y Farmacia, Universidad Nacional de San Luis Chacabuco y Pedernera, San Luis (Argentina)

    2014-11-15

    Highlights: • Use of chlorination for the synthesis of magnesium aluminate spinel. • The reagents used were alumina, periclase and chlorine. • Isothermal and non-isothermal assays were performed in air and Cl{sub 2}–N{sub 2} flows. • The chlorination produced magnesium aluminate spinel at 700 °C. • Selectivity of the chlorination reaction to obtain spinel is very high. - Abstract: A pyrometallurgical route for the synthesis of magnesium aluminate spinel by thermal treatment of a mechanical mixture containing 29 wt% MgO (periclase) and 71 wt% Al{sub 2}O{sub 3} (alumina) in chlorine atmosphere was developed and the results were compared with those obtained by calcining the same mixture of oxides in air atmosphere. Isothermal and non-isothermal assays were performed in an experimental piece of equipment adapted to work in corrosive atmospheres. Both reagents and products were analyzed by differential thermal analysis (DTA), X-ray diffraction (XRD) and X-ray fluorescence (XRF). Thermal treatment in Cl{sub 2} atmosphere of the MgO–Al{sub 2}O{sub 3} mixture produces magnesium aluminate spinel at 700 °C, while in air, magnesium spinel is generated at 930 °C. The synthesis reaction of magnesium aluminate spinel was complete at 800 °C.

  1. Alumina ceramics prepared with new pore-forming agents

    Directory of Open Access Journals (Sweden)

    Zuzana Živcová

    2008-06-01

    Full Text Available Porous ceramics have a wide range of applications at all length scales, ranging from fi ltration membranes and catalyst supports to biomaterials (scaffolds for bone ingrowths and thermally or acoustically insulating bulk materials or coating layers. Organic pore-forming agents (PFAs of biological origin can be used to control porosity, pore size and pore shape. This work concerns the characterization and testing of several less common pore-forming agents (lycopodium, coffee, fl our and semolina, poppy seed, which are of potential interest from the viewpoint of size, shape or availability. The performance of these new PFAs is compared to that of starch, which has become a rather popular PFA for ceramics during the last decade. The PFAs investigated in this work are in the size range from 5 μm (rice starch to approximately 1 mm (poppy seed, all with more or less isometric shape. The burnout behavior of PFAs is studied by thermal analysis, i.e. thermogravimetry and differential thermal analysis. For the preparation of porous alumina ceramics from alumina suspensions containing PFAs traditional slip casting (into plaster molds and starch consolidation casting (using metal molds are used in this work. The resulting microstructures are investigated using optical microscopy, combined with image analysis, as well as other methods (Archimedes method of double-weighing in water, mercury intrusion porosimetry.

  2. Thermochemical Analysis of Molybdenum Thin Films on Porous Alumina.

    Science.gov (United States)

    Lee, Kyoungjin; de Lannoy, Charles-François; Liguori, Simona; Wilcox, Jennifer

    2017-01-12

    Molybdenum (Mo) thin films (thickness thin-film composites were stable below 300 °C but had no reactivity toward gases. Mo thin films showed nitrogen incorporation on the surface as well as in the subsurface at 450 °C, as confirmed by X-ray photoelectron spectroscopy. The reactivity toward nitrogen was diminished in the presence of CO2, although no carbon species were detected either on the surface or in the subsurface. The Mo thin films have a very stable native oxide layer, which may further oxidize to higher oxidation states above 500 °C due to the reaction with the porous anodized alumina substrate. The oxidation of Mo thin films was accelerated in the presence of oxidizing gases. At 600 °C in N2, the Mo thin film on anodized alumina was completely oxidized and may also have been volatilized. The results imply that choosing thermally stable and inactive porous supports and operating in nonoxidizing conditions below 500 °C will likely maintain the stability of the Mo composite. This study provides key information about the chemical and structural stability of a Mo thin film on a porous substrate for future membrane applications and offers further insights into the integrity of thin-film composites when exposed to harsh conditions.

  3. Leflunomide对实验性IgA肾病大鼠肾脏TGF -β1、MCP-1表达的影响%Effects of leflunomide on TGF-β1, MCP-1 expression in renal tissue in a rat experimental IgA nephropathy model

    Institute of Scientific and Technical Information of China (English)

    汤颖; 娄探奇; 成彩联; 游宇平; 冯智英

    2007-01-01

    目的:分别从基因和蛋白水平研究leflunomide对实验性IgA肾病(IgAN)大鼠肾组织转化生长因子(TGF-β1)、单核细胞趋化因子(MCP-1)水平的影响,了解其作用机制.方法:建立IgAN大鼠模型,随机分成leflunomide组、强的松组、模型对照组,并同时设立正常对照组.用免疫组化、RT-PCR的方法分别检测和比较各组肾组织TGF-β1、MCP-1蛋白和基因的表达水平.结果:Leflunomide组TGF-β1、MCP-1表达均明显低于模型对照组(P<0.05);leflunomide组与激素组相比,TGF-β1、MCP-1表达无明显差异.结论:Leflunomide可通过下调TGF-β1、MCP-1在肾脏的表达,减少局部炎症反应,延缓肾脏纤维化的进程,从而保护肾脏.

  4. Allelic frequency of the MCP-1 promoter -2518 polymorphism in the Turkish population and in Turkish patients with juvenile rheumatoid arthritis.

    Science.gov (United States)

    Ozyürek, A Ruhi; Gürses, Dolunay; Ulger, Zülal; Levent, Ertürk; Bakiler, A Rahmi; Berdeli, Afig

    2007-04-01

    Although genetic and environmental factors contribute to the pathogenesis of juvenile rheumathoid arthritis (JRA), the etiology and pathogenesis remain controversial. The objective of this study was to investigate genotypic and allelic frequencies of monocyte chemoattractant protein-1 (MCP-1) gene -2518 (G/A) polymorphism in the healthy Turkish population and patients with JRA. Genomic DNA was collected from 66 JRA patients and 150 healthy individuals. To evaluate the association of the -2518 (G/A) MCP-1 gene polymorphism with the outcome of JRA, we analyzed the types of JRA and the score on the childhood health assessment questionnaire (C-HAQ score). In the healthy Turkish population, the frequencies of A and G alleles were 71 and 29%, respectively. No significant difference was observed between the JRA patients and healthy subjects in the distribution allelic and genotypic frequencies of the -2518 (G/A) MCP-1 gene polymorphism (p>0.05). However, the AG genotype was found to be higher and the AA genotype was found to be lower in the patients with systemic type JRA compared to those with the other types of JRA (p=0.019). When the JRA patients were evaluated according to the C-HAQ score, we found that the -2518 (G/A) MCP-1 gene polymorphism did not relate the prognosis (p>0.05). AG genotype was found to be higher in the systemic type of JRA. The results indicate that MCP-1 gene polymorphism might slightly associate with patients with systemic JRA. Further studies are needed to elucidate the role of this polymorphism in the pathogenesis of JRA in various populations because this polymorphism has a functional significance and an ethnic difference.

  5. Co-Treatment of EFF and 1-MCP for Enhancing the Shelf-Life and Aroma Volatile Compounds of Oriental Sweet Melons (Cucumis melo var. makuwa Makino)

    Institute of Scientific and Technical Information of China (English)

    BAI Xiao-hang; TENG Lu-hua; LÜ De-qing; QI Hong-yan

    2014-01-01

    Compared to other melon types, oriental sweet melon (Cucumis melo var. makuwa Makino) is quite a different species with a shorter shelf-life due to its typical climacteric behavior and thin pericarp. The purpose of this experiment is to explore the effects of co-treatment of enhanced freshness formulation (EFF) and 1-methylcyclopropene (1-MCP) on physiological changes and the content of aroma volatile compounds introduced by them of two oriental sweet melon cultivars (Yumeiren and Tianbao) during storage. The melons were stored in incubators with temperature of 15°C and a relative humidity of 85%for 24 d during which fruit quality and related physiological index were measured. Compared to the control, both treatments delayed fruit weight loss rate and kept the fruit ifrmness, water content and soluble solids content. Ascorbate peroxidase (APX) and phenylalanine ammonia lyase (PAL) activities showed lfuctuations in treated melons, while lipoxygenase (LOX) activity (P<0.01) and malondialdehyde (MDA) content (P<0.05) decreased compared to control. During the early stage of storage, alcohols and aldehydes were the main volatile compounds, and esters gradually increased during storage. Of all the esters, acetic esters were the main components, followed by oxalic acid esters and other esters. The total content of aroma volatile compounds, esters, alcohols and aldehydes of co-treated melons were all higher than those of 1-MCP treated and control melons. In addition, the aroma volatile peak of co-treated melons occurred later than that of 1-MCP treated and control melons. In summary, co-treatment of EFF and 1-MCP was more beneifcial than 1-MCP treatment to delay ripening and senescence, maintain fruit quality, enhance shelf-life and improve levels of aroma volatile compounds.

  6. X-ray residual stress measurement of alumina detonation coating. Bakuhatsu yosha alumina himaku no X sen zanryu oryoku sokutei

    Energy Technology Data Exchange (ETDEWEB)

    Tanaka, K.; Mine, N. (Kyoto University, Kyoto (Japan). Faculty of Engineering); Suzuki, K. (Niigata University, Niigata (Japan). Faculty of Engineering); Kawase, R. (Ariake Institute of Technology, Fukuoka (Japan))

    1991-01-15

    Alumina ceramics were coated on mild steel by a detonation gun with different amounts of detonation gas, and residual stresses in coated films were measured by X-ray diffraction from the (844) plane of {gamma}-alumina by Cu-K {alpha} radiation. Cracks and pores were observed on the film surface and cross section. The pore increased and the film bulk density decreased with a decrease in amount of detonation gas, and the mechanical Young {prime} s modulus decreased with an increase in pore. Since strains measured mechanically were those in the film bulk with pores while strains measured by X-ray were average values in only crystalline phases, the X-ray Young {prime} s modulus was larger than the mechanical one. The residual stress in films was a large tensile stress and distributed uniformly in films. The residual tensile stress decreased with an increase in amount of detonation gas, however, it was rather insensitive to the film thickness and surface grinding after coating. 10 refs., 8 figs., 2 tabs.

  7. [Congenital pulmonary capillary hemangiomatosis in a newborn].

    Science.gov (United States)

    Sposito Cavallo, Sandra L; Macias Sobrino, Luciano A; Marenco Altamar, Luifer J; Mejía Alquichire, Andrés F

    2017-02-01

    Pulmonary capillary hemangiomatosis is a rare entity characterized by the proliferation of capillaries into alveolar walls, interlobular septa, pleura and pulmonary interstitium, without malignant characteristics, with almost constant association with pulmonary hypertension. Until now two cases of congenital presentation have been reported in the literature. This is the third case in a newborn; he has not followed the usual pattern associated with pulmonary hypertension as occurs in most patients with this pathology; the highest incidence is among 20-40 years old. We report a preterm newborn patient of 36 weeks of gestation with progressive respiratory distress requiring mechanical ventilation by constant desaturation during his clinical evolution without clinical, radiological or ultrasonographic signs of pulmonary hypertension.

  8. Capillary droplets on Leidenfrost micro-ratchets

    CERN Document Server

    Marin, Alvaro G; Römer, Gertwillem R B E; Pathiraj, B; Veld, Albertus Huis in 't; Lohse, Detlef

    2012-01-01

    Leidenfrost ratchets are structures with the ability of transporting liquid droplets when heated over the critical Leidenfrost temperature. Once this temperature is reached, the droplet levitates over the surface and moves in the direction marked by the slope of the ratchet at terminal velocities around 10 cm/s. Here we provide new experiments with micron-sized ratchets, which have been produced with picosecond pulse laser ablation. In the following work, we use a simple method to measure the thrust driving droplets of capillary size over the micro-ratchets. The mechanism responsible for the force acting on the drop on superheated ratchets has been recently under debate. We extend the recently proposed 'viscous mechanism' proposed by Dupeaux et al. [Europhys. Lett., 96, 58001 (2011)] to capillary droplets and find good agreement with our measurements.

  9. The geometry and wetting of capillary folding

    CERN Document Server

    Péraud, Jean-Philippe

    2014-01-01

    Capillary forces are involved in a variety of natural phenomena, ranging from droplet breakup to the physics of clouds. The forces from surface tension can also be exploited in industrial application provided the length scales involved are small enough. Recent experimental investigations showed how to take advantage of capillarity to fold planar structures into three-dimensional configurations by selectively melting polymeric hinges joining otherwise rigid shapes. In this paper we use theoretical calculations to quantify the role of geometry and fluid wetting on the final folded state. Considering folding in two and three dimensions, studying both hydrophilic and hydrophobic situations with possible contact angle hysteresis, and addressing the shapes to be folded to be successively infinite, finite, curved, kinked, elastic, we are able to derive an overview of the geometrical parameter space available for capillary folding.

  10. Capillary fluid loop developments in Astrium

    Energy Technology Data Exchange (ETDEWEB)

    Figus, C.; Ounougha, L.; Bonzom, P. [Astrium SAS, Toulouse (France); Supper, W. [ESA/ESTEC, Noordwijk (Netherlands); Puillet, C. [CNES, Toulouse (France)

    2003-06-01

    Over the past decade, Astrium has been involved in the development of capillary pumped fluid loops. In the frame of the French technological demonstrator spacecraft called STENTOR, Astrium has gained experience on capillary fluid loop design and manufacturing. After the STENTOR cylindrical evaporator type was successfully tested and qualified, Astrium has developed miniaturised fluid loops for thermal dissipation of electronic devices. For such applications, the use of a flat shape evaporator is very promising, limiting the volume and the mass of the thermal hardware. Both technologies have been submitted to a comprehensive one-g test program and will be flight-tested in the near future. Through a comparative of the reached performances, some main advantages and drawbacks of each design are listed and a definition of what should be the next generation of Astrium fluid loops is given. (author)

  11. Modeling Microscopic Chemical Sensors in Capillaries

    CERN Document Server

    Hogg, Tad

    2008-01-01

    Nanotechnology-based microscopic robots could provide accurate in vivo measurement of chemicals in the bloodstream for detailed biological research and as an aid to medical treatment. Quantitative performance estimates of such devices require models of how chemicals in the blood diffuse to the devices. This paper models microscopic robots and red blood cells (erythrocytes) in capillaries using realistic distorted cell shapes. The models evaluate two sensing scenarios: robots moving with the cells past a chemical source on the vessel wall, and robots attached to the wall for longer-term chemical monitoring. Using axial symmetric geometry with realistic flow speeds and diffusion coefficients, we compare detection performance with a simpler model that does not include the cells. The average chemical absorption is quantitatively similar in both models, indicating the simpler model is an adequate design guide to sensor performance in capillaries. However, determining the variation in forces and absorption as cells...

  12. Space-Time Resolved Capillary Wave Turbulence

    CERN Document Server

    Berhanu, Michael

    2012-01-01

    We report experiments on the full space and time resolved statistics of capillary wave turbulence at the air-water interface. The three-dimensional shape of the free interface is measured as a function of time by using the optical method of Diffusing Light Photography associated with a fast camera. Linear and nonlinear dispersion relations are extracted from the spatio-temporal power spectrum of wave amplitude. When wave turbulence regime is reached, we observe power-law spectra both in frequency and in wave number, whose exponents are found in agreement with the predictions of capillary wave turbulence theory. Finally, the temporal dynamics of the spatial energy spectrum highlights the occurrence of stochastic bursts transferring wave energy through the spatial scales.

  13. Capillary flow through heat-pipe wicks

    Science.gov (United States)

    Eninger, J. E.

    1975-01-01

    Theoretical expressions are obtained for the capillary-pressure limit and permeability of a fibrous wick in terms of the porosity and fiber diameter. Hysteresis in capillary pressure is included through the introduction of an empirical hysteresis constant. A partial-saturation model based on the statistical distribution of local porosity requires an additional empirical constant, the standard deviation. The theory is compared to results of a beta-ray absorption experiment that measured the liquid content of a partially saturated wick and to results of permeability measurements on partially and fully saturated wicks. A simple wick-weighing experiment is described that yields values for the empirical hysteresis constant and the standard deviation. Theoretical results are used to design an optimum wick.

  14. Chemical Power for Microscopic Robots in Capillaries

    CERN Document Server

    Hogg, Tad

    2009-01-01

    The power available to microscopic robots (nanorobots) that oxidize bloodstream glucose while aggregated in circumferential rings on capillary walls is evaluated with a numerical model using axial symmetry and time-averaged release of oxygen from passing red blood cells. Robots about one micron in size can produce up to several tens of picowatts, in steady-state, if they fully use oxygen reaching their surface from the blood plasma. Robots with pumps and tanks for onboard oxygen storage could collect oxygen to support burst power demands two to three orders of magnitude larger. We evaluate effects of oxygen depletion and local heating on surrounding tissue. These results give the power constraints when robots rely entirely on ambient available oxygen and identify aspects of the robot design significantly affecting available power. More generally, our numerical model provides an approach to evaluating robot design choices for nanomedicine treatments in and near capillaries.

  15. Capillary deposition of advected floating particles

    Science.gov (United States)

    Dressaire, Emilie; Debaisieux, Aymeric; Gregori, Federico

    2016-11-01

    The deposition and aggregation of particles flowing through a confined environment can dramatically hinder the transport of suspensions. Yet, the mechanisms responsible for the deposition of particles in shear flow are not fully understood. Here, we use an experimental model system in which floating particles are advected on the surface of a water channel and deposited on fixed obstacles through attractive capillary effects. By varying the flow rate of the liquid, the wetting properties and size of the particles and obstacles, we can tune the magnitude of the capillary and hydrodynamic forces that determine the probability of deposition and the equilibrium position on the substrate. We show that arrays of obstacles can be designed to efficiently capture the floating particles advected by the flow.

  16. Bacterial surface layer proteins as a novel capillary coating material for capillary electrophoretic separations

    Energy Technology Data Exchange (ETDEWEB)

    Moreno-Gordaliza, Estefanía, E-mail: emorenog@ucm.es [Division of Analytical Biosciences, Leiden Academic Centre for Drug Research, Universiteit Leiden, Einsteinweg 55, 2300, RA, Leiden (Netherlands); Department of Analytical Chemistry, Faculty of Chemistry, Universidad Complutense de Madrid, Avda. Complutense s/n, 28040, Madrid (Spain); Stigter, Edwin C.A. [Division of Analytical Biosciences, Leiden Academic Centre for Drug Research, Universiteit Leiden, Einsteinweg 55, 2300, RA, Leiden (Netherlands); Department of Molecular Cancer Research, Universitair Medisch Centrum Utrecht, Wilhelmina Kinder Ziekenhuis, Lundlaan 6, 3584, EA Utrecht (Netherlands); Lindenburg, Petrus W.; Hankemeier, Thomas [Division of Analytical Biosciences, Leiden Academic Centre for Drug Research, Universiteit Leiden, Einsteinweg 55, 2300, RA, Leiden (Netherlands)

    2016-06-07

    A novel concept for stable coating in capillary electrophoresis, based on recrystallization of surface layer proteins on hydrophobized fused silica capillaries, was demonstrated. Surface layer protein A (SlpA) from Lactobacillus acidophilus bacteria was extracted, purified and used for coating pre-silanized glass substrates presenting different surface wettabilities (either hydrophobic or hydrophilic). Contact angle determination on SlpA-coated hydrophobic silica slides showed that the surfaces turned to hydrophilic after coating (53 ± 5°), due to a protein monolayer formation by protein-surface hydrophobic interactions. Visualization by atomic force microscopy demonstrated the presence of a SlpA layer on methylated silica slides displaying a surface roughness of 0.44 ± 0.02 nm. Additionally, a protein layer was visualized by fluorescence microscopy in methylated silica capillaries coated with SlpA and fluorescein isothiocyanate-labeled. The SlpA-coating showed an outstanding stability, even after treatment with 20 mM NaOH (pH 12.3). The electroosmotic flow in coated capillaries showed a partial suppression at pH 7.50 (3.8 ± 0.5 10{sup −9} m{sup 2} V{sup −1} s{sup −1}) when compared with unmodified fused silica (5.9 ± 0.1 10{sup −8} m{sup 2} V{sup −1} s{sup −1}). To demonstrate the potential of this novel coating, the SlpA-coated capillaries were applied for the first time for electrophoretic separation, and proved to be very suitable for the isotachophoretic separation of lipoproteins in human serum. The separations showed a high degree of repeatability (absolute migration times with 1.1–1.8% coefficient-of-variation (CV) within a day) and 2–3% CV inter-capillary reproducibility. The capillaries were stable for more than 100 runs at pH 9.40, and showed to be an exceptional alternative for challenging electrophoretic separations at long-term use. - Highlights: • New coating using recrystallized surface-layer proteins on

  17. Capillary Electrophoresis in the Presence of Fosfomycin

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    Fosfomyein, a sodim salt of cis-(3-methyloxiranyl) phosphonic acid, was used as electrolyte in binary methanol-water media for capillary electrophoresis. The variety of electroosmotic flow with pH*,methanol concentration and ionic strength was investigated. The migration behavior of nine bases was examined under various conditions, and the separation of thymine, cytosine, 5-flurouracil, 4,6-diamino-pyrimidine, purine was accomplished.

  18. Novel cationic polyelectrolyte coatings for capillary electrophoresis.

    Science.gov (United States)

    Duša, Filip; Witos, Joanna; Karjalainen, Erno; Viitala, Tapani; Tenhu, Heikki; Wiedmer, Susanne K

    2016-01-01

    The use of bare fused silica capillary in CE can sometimes be inconvenient due to undesirable effects including adsorption of sample or instability of the EOF. This can often be avoided by coating the inner surface of the capillary. In this work, we present and characterize two novel polyelectrolyte coatings (PECs) poly(2-(methacryloyloxy)ethyl trimethylammonium iodide) (PMOTAI) and poly(3-methyl-1-(4-vinylbenzyl)-imidazolium chloride) (PIL-1) for CE. The coated capillaries were studied using a series of aqueous buffers of varying pH, ionic strength, and composition. Our results show that the investigated polyelectrolytes are usable as semi-permanent (physically adsorbed) coatings with at least five runs stability before a short coating regeneration is necessary. Both PECs showed a considerably decreased stability at pH 11.0. The EOF was higher using Good's buffers than with sodium phosphate buffer at the same pH and ionic strength. The thickness of the PEC layers studied by quartz crystal microbalance was 0.83 and 0.52 nm for PMOTAI and PIL-1, respectively. The hydrophobicity of the PEC layers was determined by analysis of a homologous series of alkyl benzoates and expressed as the distribution constants. Our result demonstrates that both PECs had comparable hydrophobicity, which enabled separation of compounds with log Po/w > 2. The ability to separate cationic drugs was shown with β-blockers, compounds often misused in doping. Both coatings were also able to separate hydrolysis products of the ionic liquid 1,5-diazabicyclo[4.3.0]non-5-ene acetate at highly acidic conditions, where bare fused silica capillaries failed to accomplish the separation.

  19. Capillary condensation for fluids in spherical cavities

    OpenAIRE

    Urrutia, Ignacio; Szybisz, Leszek

    2005-01-01

    The capillary condensation for fluids into spherical nano-cavities is analyzed within the frame of two theoretical approaches. One description is based on a widely used simplified version of the droplet model formulated for studying atomic nuclei. The other, is a more elaborated calculation performed by applying a density functional theory. The agreement between both models is examined and it is shown that a small correction to the simple fluid model improves the predictions. A connection to ...

  20. Capillary floating and the billiard ball problem

    OpenAIRE

    Gutkin, Eugene

    2010-01-01

    We establish a connection between capillary floating in neutral equilibrium and the billiard ball problem. This allows us to reduce the question of floating in neutral equilibrium at any orientation with a prescribed contact angle for infinite homogeneous cylinders to a question about billiard caustics for their orthogonal cross-sections. We solve the billiard problem. As an application, we characterize the possible contact angles and exhibit an infinite family of real analytic non-round cyli...