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Sample records for liquides au cea

  1. Magnetic susceptibilities of liquid Cr-Au, Mn-Au and Fe-Au alloys

    SciTech Connect

    Ohno, S.; Shimakura, H.; Tahara, S.; Okada, T.

    2015-08-17

    The magnetic susceptibility of liquid Cr-Au, Mn-Au, Fe-Au and Cu-Au alloys was investigated as a function of temperature and composition. Liquid Cr{sub 1-c}Au{sub c} with 0.5 ≤ c and Mn{sub 1-c}Au{sub c} with 0.3≤c obeyed the Curie-Weiss law with regard to their dependence of χ on temperature. The magnetic susceptibilities of liquid Fe-Au alloys also exhibited Curie-Weiss behavior with a reasonable value for the effective number of Bohr magneton. On the Au-rich side, the composition dependence of χ for liquid TM-Au (TM=Cr, Mn, Fe) alloys increased rapidly with increasing TM content, respectively. Additionally, the composition dependences of χ for liquid Cr-Au, Mn-Au, and Fe-Au alloys had maxima at compositions of 50 at% Cr, 70 at% Mn, and 85 at% Fe, respectively. We compared the composition dependences of χ{sub 3d} due to 3d electrons for liquid binary TM-M (M=Au, Al, Si, Sb), and investigated the relationship between χ{sub 3d} and E{sub F} in liquid binary TM-M alloys at a composition of 50 at% TM.

  2. Au-ionic liquid functionalized reduced graphene oxide immunosensing platform for simultaneous electrochemical detection of multiple analytes.

    PubMed

    Liu, Na; Ma, Zhanfang

    2014-01-15

    In this work, an Au-ionic liquid functionalized reduced graphene oxide nanocomposite (IL-rGO-Au) was fabricated via the self-assembly of ionic liquid functionalized reduced graphene oxide (IL-rGO) and gold nanoparticles (AuNPs) by electrostatic interaction. The IL-rGO can be synthesized and stabilized by introducing the cations of the amine-terminated ionic liquids (IL-NH2) into the graphene oxide (GO). With the assistance of IL-NH2, AuNPs were uniformly and densely absorbed on the surfaces of the IL-rGO. The proposed IL-rGO-Au nanocomposite can be used as an immunosensing platform because it can not only facilitate the electrons transfer of the electrode surface but also provide a large accessible surface area for the immobilization of abundant antibody. To assess the performance of the IL-rGO-Au nanocomposite, a sandwich-type electrochemical immunosensor was designed for simultaneous multianalyte detection (carcinoembryonic antigen (CEA) and alpha-fetoprotein (AFP) as model analytes). The chitosan (CS) coated prussian blue nanoparticles (PBNPs) or cadmium hexacyanoferrate nanoparticles (CdNPs) and loaded with AuNPs were used as distinguishable signal tags. The resulting immunosensor exhibited high selectivity and sensitivity in simultaneous determination of CEA and AFP in a single run. The linear ranges were from 0.01 to 100 ng mL(-1) for both CEA and AFP. The detection limits reached 0.01 ng mL(-1) for CEA and 0.006 ng mL(-1) for AFP, respectively. No obvious nonspecific adsorption and cross-talk was observed during a series of analyses to detect target analytes. In addition, for the detection of clinical serum samples, it is well consistent with the data determined by the ELISA, indicating that the immunosensor provides a possible application for the simultaneous multianalyte determination of CEA and AFP in clinical diagnostics. PMID:23962704

  3. Ionic liquid functionalized graphene/Au nanocomposites and its application for electrochemical immunosensor.

    PubMed

    Liu, Na; Chen, Xia; Ma, Zhanfang

    2013-10-15

    In this work, a new nanocomposite, which was composed of ionic liquid functionalized graphene sheet (IL-GS) loaded gold nanoparticles (AuNPs), was prepared. The IL-GS was directly synthesized by the electrochemical exfoliation of graphite in ionic liquid (IL). Due to the modification of the IL, IL-GS can not only be dispersed easily in aqueous solution to form a homogeneous colloidal suspension of individual sheet, but also exhibits an improved conductivity. Meanwhile, the loaded AuNPs on the nanocomposites can increase the specific surface area to capture a large amount of antibodies as well as improve the capability of electron transfer. The IL-GS-Au nanocomposites were successfully employed for the fabrication of a facile and sensitive electrochemical immunosensor. Carcinoembryonic antigen (CEA) was used as a model protein. The proposed immunosensor exhibits a wide linear detection range (LDR) from 1 fg mL⁻¹ to 100 ng mL⁻¹, and an ultralow limit of detection (LOD) of 0.1 fg mL⁻¹ (S/N=3). In addition, for the detection of clinical serum samples, it is well consistent with the data determined by the developed immunoassay and ELISA, indicating that the immunosensor provides a possible application for the detection of CEA in clinical diagnostics. PMID:23644143

  4. Decontamination of Nuclear Liquid Wastes Status of CEA and AREVA R and D: Application to Fukushima Waste Waters - 12312

    SciTech Connect

    Fournel, B.; Barre, Y.; Lepeytre, C.; Peycelon, H.; Grandjean, A.; Prevost, T.; Valery, J.F.; Shilova, E.; Viel, P.

    2012-07-01

    Liquid wastes decontamination processes are mainly based on two techniques: Bulk processes and the so called Cartridges processes. The first technique has been developed for the French nuclear fuel reprocessing industry since the 60's in Marcoule and La Hague. It is a proven and mature technology which has been successfully and quickly implemented by AREVA at Fukushima site for the processing of contaminated waters. The second technique, involving cartridges processes, offers new opportunities for the use of innovative adsorbents. The AREVA process developed for Fukushima and some results obtained on site will be presented as well as laboratory scale results obtained in CEA laboratories. Examples of new adsorbents development for liquid wastes decontamination are also given. A chemical process unit based on co-precipitation technique has been successfully and quickly implemented by AREVA at Fukushima site for the processing of contaminated waters. The asset of this technique is its ability to process large volumes in a continuous mode. Several chemical products can be used to address specific radioelements such as: Cs, Sr, Ru. Its drawback is the production of sludge (about 1% in volume of initial liquid volume). CEA developed strategies to model the co-precipitation phenomena in order to firstly minimize the quantity of added chemical reactants and secondly, minimize the size of co-precipitation units. We are on the way to design compact units that could be mobilized very quickly and efficiently in case of an accidental situation. Addressing the problem of sludge conditioning, cementation appears to be a very attractive solution. Fukushima accident has focused attention on optimizations that should be taken into account in future studies: - To better take account for non-typical aqueous matrixes like seawater; - To enlarge the spectrum of radioelements that can be efficiently processed and especially short lives radioelements that are usually less present in

  5. Controlled electrodeposition of Au monolayer film on ionic liquid

    NASA Astrophysics Data System (ADS)

    Ma, Qiang; Pang, Liuqing; Li, Man; Zhang, Yunxia; Ren, Xianpei; Liu, Shengzhong Frank

    2016-05-01

    Gold (Au) nanoparticles have been attractive for centuries for their vibrant appearance enhanced by their interaction with sunlight. Nowadays, there have been tremendous research efforts to develop them for high-tech applications including therapeutic agents, sensors, organic photovoltaics, medical applications, electronics and catalysis. However, there remains to be a challenge to fabricate a monolayer Au coating with complete coverage in controlled fashion. Here we present a facile method to deposit a uniform Au monolayer (ML) film on the [BMIM][PF6] ionic liquid substrate using an electrochemical deposition process. It demonstrates that it is feasible to prepare a solid phase coating on the liquid-based substrate. Moreover, the thickness of the monolayer coating can be controlled to a layer-by-layer accuracy.

  6. Structural and dynamical properties of liquid Al-Au alloys

    NASA Astrophysics Data System (ADS)

    Peng, H. L.; Voigtmann, Th.; Kolland, G.; Kobatake, H.; Brillo, J.

    2015-11-01

    We investigate temperature- and composition-dependent structural and dynamical properties of Al-Au melts. Experiments are performed to obtain accurate density and viscosity data. The system shows a strong negative excess volume, similar to other Al-based binary alloys. We develop a molecular-dynamics (MD) model of the melt based on the embedded-atom method (EAM), gauged against the available experimental liquid-state data. A rescaling of previous EAM potentials for solid-state Au and Al improves the quantitative agreement with experimental data in the melt. In the MD simulation, the admixture of Au to Al can be interpreted as causing a local compression of the less dense Al system, driven by less soft Au-Au interactions. This local compression provides a microscopic mechanism explaining the strong negative excess volume of the melt. We further discuss the concentration dependence of self- and interdiffusion and viscosity in the MD model. Al atoms are more mobile than Au, and their increased mobility is linked to a lower viscosity of the melt.

  7. Metastability of Au-Ge liquid nanocatalysts: Ge vapor-liquid-solid nanowire growth far below the bulk eutectic temperature.

    PubMed

    Adhikari, Hemant; Marshall, Ann F; Goldthorpe, Irene A; Chidsey, Christopher E D; McIntyre, Paul C

    2007-12-01

    The vapor-liquid-solid mechanism of nanowire (NW) growth requires the presence of a liquid at one end of the wire; however, Au-catalyzed Ge nanowire growth by chemical vapor deposition can occur at approximately 100 degrees C below the bulk Au-Ge eutectic. In this paper, we investigate deep sub-eutectic stability of liquid Au-Ge catalysts on Ge NWs quantitatively, both theoretically and experimentally. We construct a binary Au-Ge phase diagram that is valid at the nanoscale and show that equilibrium arguments, based on capillarity, are inconsistent with stabilization of Au-Ge liquid at deep sub-eutectic temperatures, similar to those used in Ge NW growth. Hot-stage electron microscopy and X-ray diffraction are used to test the predictions of nanoscale phase equilibria. In addition to Ge supersaturation of the Au-Ge liquid droplet, which has recently been invoked as an explanation for deep sub-eutectic Ge NW growth, we find evidence of a substantial kinetic barrier to Au solidification during cooling below the nanoscale Au-Ge eutectic temperature. PMID:19206662

  8. Temperature-independent formation of Au nanoparticles in ionic liquids by arc plasma deposition

    NASA Astrophysics Data System (ADS)

    Hatakeyama, Yoshikiyo; Kimura, Satoshi; Kameyama, Tatsuya; Agawa, Yoshiaki; Tanaka, Hiroyuki; Judai, Ken; Torimoto, Tsukasa; Nishikawa, Keiko

    2016-08-01

    An effective preparation method of Au nanoparticles (NPs) is presented, wherein an arc plasma deposition technique is combined with ionic liquids (ILs) used as capture media. This method requires no chemical reaction. By selecting ILs, size-controlled Au NPs are produced easily and on a massive scale.

  9. Evolution of local atomic structure during solidification of Al2Au liquid: An ab initio study

    SciTech Connect

    Xiong, L H; Lou, H B; Wang, X D; Debela, T T; Cao, Q P; Zhang, D X; Wang, S Y; Wang, C Z; Jiang, J Z

    2014-04-01

    The local atomic structure evolution in Al2Au alloy during solidification from 2000 K to 400 K was studied by ab initio molecular dynamics simulations and analyzed using the structure factor, pair correlation functions, bond angle distributions, the Honeycutt-Anderson (HA) index and Voronoi tessellation methods. It was found that the icosahedral-like clusters are negligible in the Al2Au stable liquid and supercooled liquid states, and the most abundant clusters are those having HA indices of 131 and 120 or Voronoi indices of < 0,4,4,0 >, < 0,3, 6,0 > and < 0,4,4,2 > with coordination numbers of 8, 9 and 10, respectively. These clusters are similar to the local atomic structures in the CaF2-type Al2Au crystal, revealing the existence of structure heredity between liquid and crystalline phase in Al2Au alloy. (C) 2014 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

  10. Atomic characterization of Au clusters in vapor-liquid-solid grown silicon nanowires

    SciTech Connect

    Chen, Wanghua; Roca i Cabarrocas, Pere; Pareige, Philippe; Castro, Celia; Xu, Tao; Grandidier, Bruno; Stiévenard, Didier

    2015-09-14

    By correlating atom probe tomography with other conventional microscope techniques (scanning electron microscope, scanning transmission electron microscope, and scanning tunneling microscopy), the distribution and composition of Au clusters in individual vapor-liquid-solid grown Si nanowires is investigated. Taking advantage of the characteristics of atom probe tomography, we have developed a sample preparation method by inclining the sample at certain angle to characterize the nanowire sidewall without using focused ion beam. With three-dimensional atomic scale reconstruction, we provide direct evidence of Au clusters tending to remain on the nanowire sidewall rather than being incorporated into the Si nanowires. Based on the composition measurement of Au clusters (28% ± 1%), we have demonstrated the supersaturation of Si atoms in Au clusters, which supports the hypothesis that Au clusters are formed simultaneously during nanowire growth rather than during the cooling process.

  11. Crystalline monolayer surface of liquid Au-Cu-Si-Ag-Pd: Metallic glass former

    SciTech Connect

    Mechler, S; Yahel, E; Pershan, P S; Meron, M; Lin, B

    2012-02-06

    It is demonstrated by means of x-ray synchrotron reflectivity and diffraction that the surface of the liquid phase of the bulk metallic glass forming alloy Au49Cu26.9Si16.3Ag5.5Pd2.3 consists of a two-dimensional crystalline monolayer phase for temperatures of up to about 50 K above the eutectic temperature. The present alloy as well as glass forming Au82Si18 and Au-Si-Ge alloys containing small amounts of Ge are the only metallic liquids to exhibit surface freezing well above the melting temperature. This suggests that the phenomena of surface freezing in metallic liquids and glass forming ability are related and probably governed by similar physical properties.

  12. Dependence of Morphology of SiOx Nanowires on the Supersaturation of Au-Si Alloy Liquid Droplets Formed on the Au-Coated Si Substrate

    NASA Astrophysics Data System (ADS)

    Zhang, Han; Li, Ji-Xue; Jin, Ai-Zi; Zhang, Ze

    2001-11-01

    A thermodynamic theory about the dependence of morphology of SiOx nanowires on the super-saturation of alloy liquid droplets has been proposed on the basis of the vapour-liquid-solid growth mechanism and has been supported experimentally. By changing the Si concentration in the Au-Si liquid droplets formed on the Au-coated Si substrate, firework-, tulip- and bud-shaped SiOx nanowires were synthesized by a thermal evaporation method and distributed concentrically around some void defects in the Si substrate. Voids were formed underneath the surface of the Si substrate during the thermal evaporation at 850°C and resulted in the Si-concentration deficient thus different saturation of Au-Si droplets. Electron microscopy analysis showed that the nanowires had an amorphous structure and were terminated by Au-Si particles.

  13. Secondary ion mass spectrometry of vapor-liquid-solid grown, Au-catalyzed, Si wires.

    PubMed

    Putnam, Morgan C; Filler, Michael A; Kayes, Brendan M; Kelzenberg, Michael D; Guan, Yunbin; Lewis, Nathan S; Eiler, John M; Atwater, Harry A

    2008-10-01

    Knowledge of the catalyst concentration within vapor-liquid-solid (VLS) grown semiconductor wires is needed in order to assess potential limits to electrical and optical device performance imposed by the VLS growth mechanism. We report herein the use of secondary ion mass spectrometry to characterize the Au catalyst concentration within individual, VLS-grown, Si wires. For Si wires grown by chemical vapor deposition from SiCl 4 at 1000 degrees C, an upper limit on the bulk Au concentration was observed to be 1.7 x 10(16) atoms/cm(3), similar to the thermodynamic equilibrium concentration at the growth temperature. However, a higher concentration of Au was observed on the sidewalls of the wires. PMID:18767881

  14. Synthesis of gold nanoparticles by laser ablation of an Au foil inside and outside ionic liquids

    NASA Astrophysics Data System (ADS)

    Wender, Heberton; Andreazza, Marcos L.; Correia, Ricardo R. B.; Teixeira, Sérgio R.; Dupont, Jairton

    2011-03-01

    Stable gold nanoparticles (AuNPs) were prepared by simple laser ablation of an Au foil placed inside or outside four ionic liquids (ILs), without the addition of any external chemical reagent. Irregular spherical AuNPs with a diameter range of 5 to 20 nm were produced after laser ablation of an Au foil located inside or outside the ILs 1-n-butyl-3-methylimidazolium tetrafluoroborate (BMI.BF4), 1-n-butyl-3-methylimidazolium hexafluorophosphate (BMI.PF6) and 1-(3-cyanopropyl)-3-methylimidazolium bis(trifluoromethylsulfonyl)imide ((BCN)MI.NTf2). Additionally, whereas laser ablation inside the IL 1-n-butyl-3-methylimidazolium dicyanamide BMI.N(CN)2 produced flower-like shaped nanoparticles of about 50 nm in size, ablation outside this IL presented similar results to the others ILs studied, as determined by TEM and UV-Vis. The size and shape of the prepared NPs were related to where NP nucleation and growth occurred, i.e., at the IL surface or within the IL. Indeed, the chemical composition of the IL/air interface and surface ion orientation played important roles in the stabilization of the AuNPs formed by laser ablation outside the ILs.

  15. Surface structure of the liquid Au[subscript 72]Ge[subscript 28] eutectic phase: X-ray reflectivity

    SciTech Connect

    Pershan, P.S.; Stoltz, S.E.; Mechler, S.; Shpyrko, O.G.; Grigoriev, A.Y.; Balagurusamy, V.S. K.; Lin, B.H.; Meron, M.

    2009-12-01

    The surface structure of the liquid phase of the Au{sub 72}Ge{sub 28} eutectic alloy has been measured using resonant and nonresonant x-ray reflectivity and grazing incidence x-ray diffraction. In spite of the significant differences in the surface tension of liquid Ge and Au the Gibbs adsorption enhancement of Ge concentration at the surface is minimal. This is in striking contrast to all the other binary alloys with large differences in the respective surface tensions measured up to date. In addition there is no evidence of the anomalous strong surface layering or in-plane crystalline order that has been reported for the otherwise quite similar liquid Au{sub 82}Si{sub 18} eutectic. Instead, the surface of eutectic Au{sub 72}Ge{sub 28} is liquidlike and the layering can be explained by the distorted crystal model with only slight modifications to the first layer.

  16. Effect of spherical Au nanoparticles on nanofriction and wear reduction in dry and liquid environments

    PubMed Central

    Maharaj, Dave

    2012-01-01

    Summary Nano-object additives are used in tribological applications as well as in various applications in liquids requiring controlled manipulation and targeting. On the macroscale, nanoparticles in solids and liquids have been shown to reduce friction and wear. On the nanoscale, atomic force microscopy (AFM) studies have been performed in single- and multiple-nanoparticle contact, in dry environments, to characterize friction forces and wear. However, limited studies in submerged liquid environments have been performed and further studies are needed. In this paper, spherical Au nanoparticles were studied for their effect on friction and wear under dry conditions and submerged in water. In single-nanoparticle contact, individual nanoparticles, deposited on silicon, were manipulated with a sharp tip and the friction force was determined. Multiple-nanoparticle contact sliding experiments were performed on nanoparticle-coated silicon with a glass sphere. Wear tests were performed on the nanoscale with AFM as well as on the macroscale by using a ball-on-flat tribometer to relate friction and wear reduction on the nanoscale and macroscale. Results indicate that the addition of Au nanoparticles reduces friction and wear. PMID:23213639

  17. 3D motion of DNA-Au nanoconjugates in graphene liquid cell electron microscopy.

    PubMed

    Chen, Qian; Smith, Jessica M; Park, Jungwon; Kim, Kwanpyo; Ho, Davy; Rasool, Haider I; Zettl, Alex; Alivisatos, A Paul

    2013-09-11

    Liquid-phase transmission electron microscopy (TEM) can probe and visualize dynamic events with structural or functional details at the nanoscale in a liquid medium. Earlier efforts have focused on the growth and transformation kinetics of hard material systems, relying on their stability under electron beam. Our recently developed graphene liquid cell technique pushed the spatial resolution of such imaging to the atomic scale but still focused on growth trajectories of metallic nanocrystals. Here, we adopt this technique to imaging three-dimensional (3D) dynamics of soft materials instead, double strand (dsDNA) connecting Au nanocrystals as one example, at nanometer resolution. We demonstrate first that a graphene liquid cell can seal an aqueous sample solution of a lower vapor pressure than previously investigated well against the high vacuum in TEM. Then, from quantitative analysis of real time nanocrystal trajectories, we show that the status and configuration of dsDNA dictate the motions of linked nanocrystals throughout the imaging time of minutes. This sustained connecting ability of dsDNA enables this unprecedented continuous imaging of its dynamics via TEM. Furthermore, the inert graphene surface minimizes sample-substrate interaction and allows the whole nanostructure to rotate freely in the liquid environment; we thus develop and implement the reconstruction of 3D configuration and motions of the nanostructure from the series of 2D projected TEM images captured while it rotates. In addition to further proving the nanoconjugate structural stability, this reconstruction demonstrates 3D dynamic imaging by TEM beyond its conventional use in seeing a flattened and dry sample. Altogether, we foresee the new and exciting use of graphene liquid cell TEM in imaging 3D biomolecular transformations or interaction dynamics at nanometer resolution. PMID:23944844

  18. Formic acid electro-oxidation at PtAu alloyed nanoparticles synthesized by pulsed laser ablation in liquids

    NASA Astrophysics Data System (ADS)

    Oko, Daniel Nii; Zhang, Jianming; Garbarino, Sébastien; Chaker, Mohamed; Ma, Dongling; Tavares, Ana C.; Guay, Daniel

    2014-02-01

    A series of mono dispersed PtxAu100-x alloy nanoparticles (NPs), with x varying from 0 to 100, were prepared by pulsed laser ablation in liquids, using a series of targets that were made by mixing pure Pt and pure Au powders. The structures of PtxAu100-x alloy NPs were assessed by transmission electron microscopy and X-ray diffraction. A face-centered solid solution is obtained over the whole composition range, and the particle size increases from 2.5 to 5.3 nm as x is increased from 0 to 100. The electrocatalytic performances of the PtxAu100-x alloy NPs towards the formic acid oxidation were investigated by cyclic voltammetry and chronoamperometry. On as-prepared PtxAu100-x alloy NPs, oxidation of formic acid occurs through dehydrogenation, while dehydration is the privileged mechanism on as-prepared mixtures of Pt and Au NPs. However, after a series of CV in 0.5 M H2SO4, both types of catalysts are able to oxidize formic acid according to the dehydrogenation pathway. After 600 s of electrolysis, the mass activities of PtxAu100-x alloy NPs is a factor of two larger than that of mixtures of pure Pt and pure Au NPs with the same surface composition, although both types of catalysts display similar activity with respect to the total electrochemically active surface area.

  19. The local orientational orders and structures of liquid and amorphous metals Au and Ni during rapid solidification

    NASA Astrophysics Data System (ADS)

    Luhong, Wang; Haozhe, Liu; Kuiying, Chen; Zhuangqi, Hu

    1997-02-01

    Based on the empirical embedded-atom method, the molecular dynamics studies of the local orientational orders and structures of liquid and amorphous solid of FCC-type metals Au and Ni are performed. During the rapid solidification, the amorphous structures can be obtained and their amorphous transition temperatures are determined. The icosahedral ordering and the short-range ordering are enhanced, and FCC-type as well as HCP-type ordering changes slightly during the quench of Au and Ni. In the mean time, the BCC-type ordering of Au is Ni enhanced, but that of Ni is weakened. The results of the simulation also indicate that the diffusion coefficients in Au and Ni decrease rapidly with decreasing temperature above their glass transition temperatures.

  20. In-situ synthesis of Au nano particles of co-existing morphologies in liquid crystalline matrix

    SciTech Connect

    Dan, Kaustabh Datta, Alokmay

    2015-06-24

    The present study describes the in-situ synthesis of Au nano particles (Au-NP) in the room temperature nematic liquid crystalline (LC) substance MBBA (N-4 methoxybenzylidene 4 butylaniline) without any external reducing or stabilizing agents. UV-Visible absorption and fluorescence spectroscopy clearly show formation of Au-NP within the LC matrix through the plasmon resonance peak for the NPs and EDAX measurements confirm this formation. Transmission electron Microscopy shows co-existence of spherical and prismatic NPs. FTIR spectroscopy shows a considerable shift in the C=N stretch band pointing to the location of the growth centre of the NPs. Polarization microscopy data indicates a definite phase ordering and texture transformation from Nematic to highly ordered smectic mesophase.

  1. In-situ synthesis of Au nano particles of co-existing morphologies in liquid crystalline matrix

    NASA Astrophysics Data System (ADS)

    Dan, Kaustabh; Datta, Alokmay

    2015-06-01

    The present study describes the in-situ synthesis of Au nano particles (Au-NP) in the room temperature nematic liquid crystalline (LC) substance MBBA (N-4 methoxybenzylidene 4 butylaniline) without any external reducing or stabilizing agents. UV-Visible absorption and fluorescence spectroscopy clearly show formation of Au-NP within the LC matrix through the plasmon resonance peak for the NPs and EDAX measurements confirm this formation. Transmission electron Microscopy shows co-existence of spherical and prismatic NPs. FTIR spectroscopy shows a considerable shift in the C=N stretch band pointing to the location of the growth centre of the NPs. Polarization microscopy data indicates a definite phase ordering and texture transformation from Nematic to highly ordered smectic mesophase.

  2. Electrically controllable plasmonic enhanced coherent random lasing from dye-doped nematic liquid crystals containing Au nanoparticles.

    PubMed

    Wang, Lei; Wan, Yuan; Shi, Lijie; Zhong, Haizheng; Deng, Luogen

    2016-08-01

    An electrically controllable plasmonic enhanced coherent random lasing from the dye-doped nematic liquid crystal containing Au nanoparticles is demonstrated. To achieve the optimal control of the RL properties, the polarization of the pump light should be parallel to the rubbing direction of the cells. The lasing output intensity is direction-dependent and the substantial output distributes in an angle range of 0°~30° deviating from the direction of the pump stripe. The coherent feedback associated with the coherent random lasing mainly originates from the cooperative effect of the enhanced localized electric field in the vicinity of Au nanoparticles and the multiple scattering caused by the fluctuations of the liquid crystal director and local dielectric tensor. PMID:27505729

  3. Transfer equation for the description of the dynamics of Au nanoparticle ensemble in liquid under pulsed laser irradiation

    NASA Astrophysics Data System (ADS)

    Kirichenko, N. A.; Shcherbina, M. E.; Serkov, A. A.; Rakov, I. I.

    2016-07-01

    Laser-assisted fragmentation of Au nanoparticles in liquid is examined experimentally by measurement of the size distribution function of particles at various moments of time. Theoretical approach based on the transfer equation is proposed to the description of the phenomena under consideration. Constructed mathematical model is implemented with parameters corresponding to the conditions of the experiment concerned. The results of simulation are in a good agreement with the experiment.

  4. Influence of gold species (AuCl4(-) and AuCl2(-)) on self-assembly of PS-b-P2VP in solutions and morphology of composite thin films fabricated at the air/liquid interfaces.

    PubMed

    Zhao, Xingjuan; Wang, Qian; Zhang, Xiaokai; Lee, Yong-Ill; Liu, Hong-Guo

    2016-01-21

    Composite thin films doped with Au species were fabricated at an air/liquid interface via a series of steps, including the mass transfer of polystyrene-b-poly(2-vinylpyridine) (PS-b-P2VP) across the liquid/liquid interface between a DMF/CHCl3 solution and an aqueous solution containing either AuCl4(-) or AuCl2(-), self-assembly of PS-b-P2VP in a mixed DMF-water solution, and adsorption and further self-organization of the formed aggregates at the air/liquid interface. This is a new approach for fabricating composite polymer films and can be completed within a very short time. AuCl4(-) and AuCl2(-) ions were found to significantly influence the self-assembly behavior of the block copolymer and the morphologies of the composite films, leading to the formation of nanowire arrays and a foam structure at the air/liquid interface, respectively, which originated from rod-like micelles and microcapsules that had formed in the respective solutions. The effect of the metal complex was analyzed based on the packing parameters of the amphiphilic polymer molecules in different microenvironments and the interactions between the pyridine groups and the metal chloride anions. In addition, these composite thin films exhibited stable and durable performance as heterogeneous catalysts for the hydrogenation of nitroaromatics in aqueous solutions. PMID:26688280

  5. Determination of redox reaction rates and orders by in situ liquid cell electron microscopy of Pd and Au solution growth

    SciTech Connect

    Sutter, Eli A.; Sutter, Peter W.

    2014-11-19

    In-situ liquid cell transmission and scanning transmission electron microscopy (TEM/STEM) experiments are important as they provide direct insight into processes in liquids, such as solution growth of nanoparticles among others. In liquid cell TEM/STEM redox reaction experiments the hydrated electrons e⁻aq created by the electron beam are responsible for the reduction of metal-ion complexes. Here we investigate the rate equation of redox reactions involving reduction by e⁻aq generated by the electron beam during in-situ liquid TEM/STEM. Specifically we consider the growth of Pd on Au seeds in aqueous solutions containing Pd-chloro complexes. From the quantification of the rate of Pd deposition at different electron beam currents and as a function of distance from a stationary, nanometer-sized exciting beam, we determine that the reaction is first order with respect to the concentration of hydrated electrons, [e⁻aq]. In addition, by comparing Pd- and Au-deposition, we further demonstrate that measurements of the local deposition rate on nanoparticles in the solution via real-time imaging can be used to measure not only [e⁻aq] but also the rate of reduction of a metal-ion complex to zero-valent metal atoms in solution.

  6. Determination of redox reaction rates and orders by in situ liquid cell electron microscopy of Pd and Au solution growth

    DOE PAGESBeta

    Sutter, Eli A.; Sutter, Peter W.

    2014-11-19

    In-situ liquid cell transmission and scanning transmission electron microscopy (TEM/STEM) experiments are important as they provide direct insight into processes in liquids, such as solution growth of nanoparticles among others. In liquid cell TEM/STEM redox reaction experiments the hydrated electrons e⁻aq created by the electron beam are responsible for the reduction of metal-ion complexes. Here we investigate the rate equation of redox reactions involving reduction by e⁻aq generated by the electron beam during in-situ liquid TEM/STEM. Specifically we consider the growth of Pd on Au seeds in aqueous solutions containing Pd-chloro complexes. From the quantification of the rate of Pdmore » deposition at different electron beam currents and as a function of distance from a stationary, nanometer-sized exciting beam, we determine that the reaction is first order with respect to the concentration of hydrated electrons, [e⁻aq]. In addition, by comparing Pd- and Au-deposition, we further demonstrate that measurements of the local deposition rate on nanoparticles in the solution via real-time imaging can be used to measure not only [e⁻aq] but also the rate of reduction of a metal-ion complex to zero-valent metal atoms in solution.« less

  7. Group V sensitive vapor-liquid-solid growth of Au-catalyzed and self-catalyzed III-V nanowires

    NASA Astrophysics Data System (ADS)

    Dubrovskii, Vladimir G.

    2016-04-01

    We present a new theoretical model that treats the group V sensitive growth rates and structures of Au-catalyzed and self-catalyzed III-V nanowires within a single kinetic picture. It is shown that Au-catalyzed III-V nanowires can grow with a time-independent radius within a wide range of parameters. At high V/III flux ratios, the vapor-liquid-solid growth of Au catalyzed III-V nanowires is controlled by surface diffusion of the group III adatoms, while at low V/III flux ratios it becomes nucleation-limited. Conversely, self-catalyzed III-V nanowires cannot grow with a time-independent droplet size and instead such nanowires may either swell or shrink or converge to a certain stationary radius depending on the V/III flux ratio. Quite importantly, the results are presented in a concise analytical form which is convenient for comparison with experimental data or prior theoretical works. We demonstrate how the model fits the data obtained previously for Au- and Ga-catalyzed GaAs nanowires.

  8. Essential role of catalysts (Mn, Au, and Sn) in the vapor liquid solid growth kinematics of ZnS nanowires

    SciTech Connect

    Rehman, S.; Shehzad, M. A.; Hafeez, M.; Bhatti, A. S.

    2014-01-14

    In this paper, we demonstrate that surface energy of the catalyst is a vital parameter for the growth rate, self doping of the self assembled nanowires synthesized by employing vapor liquid solid growth technique. The synthesis of ZnS nanowires was done by selectively using three different catalysts (Mn, Au, and Sn), where Au, is the most common catalyst, was used as a reference. The distinctive difference in the growth rate was due to the surface energy of the metal alloy droplet and the interface energies, as explained theoretically using thermodynamic approach. We have found that the activation energy of diffusion of (Zn, S) species in the catalyst droplet was low in Sn (0.41 eV for Zn and 0.13 eV for S) and high in Mn (1.79 eV for Zn and 0.61 eV for S) compared to Au (0.62 eV for Zn and 0.21 eV for S) catalyzed ZnS nanostructures. The thermodynamic calculations predicted the growth rates of Sn (7.5 nm/s) catalyzed nanowires was faster than Au (5.1 nm/s) and Mn (4.6 nm/s) catalyzed ZnS nanostructures, which were in agreement with the experimental results. Finally, the location of the catalyst as dopant in the grown nanostructure was predicted and compared with experimental observations.

  9. Formation of a Pt-Decorated Au Nanoparticle Monolayer Floating on an Ionic Liquid by the Ionic Liquid/Metal Sputtering Method and Tunable Electrocatalytic Activities of the Resulting Monolayer.

    PubMed

    Sugioka, Daisuke; Kameyama, Tatsuya; Kuwabata, Susumu; Yamamoto, Takahisa; Torimoto, Tsukasa

    2016-05-01

    A novel strategy to prepare a bimetallic Au-Pt particle film was developed through sequential sputter deposition of Au and Pt on a room temperature ionic liquid (RTIL). Au sputter deposition onto an RTIL containing hydroxyl-functionalized cations produced a monolayer of Au particles 4.2 nm in size on the liquid surface. Subsequent Pt sputtering onto the original Au particle monolayer floating on the RTIL enabled decoration of individual Au particles with Pt metals, resulting in the formation of a bimetallic Au-Pt particle monolayer with a Pt-enriched particle surface. The particle size slightly increased to 4.8 nm with Pt deposition for 120 min. The shell layer of a bimetallic particle was composed of Au-Pt alloy, the composition of which was tunable by controlling the Pt sputter deposition time. The electrochemical surface area (ECSA) was determined by cyclic voltammetry of bimetallic Au-Pt particle monolayers transferred onto HOPG electrodes by a horizontal liftoff method. The Pt surface coverage, determined by ECSAs of Au and Pt, increased from 0 to 56 mol % with elapse of the Pt sputter deposition time up to 120 min. Thus-obtained Au-Pt particle films exhibited electrocatalytic activity for methanol oxidation reaction (MOR) superior to the activities of pure Au or Pt particles. Volcano-type dependence was observed between the MOR activity and Pt surface coverage on the particles. Maximum activity was obtained for Au-Pt particles with a Pt coverage of 49 mol %, being ca. 120 times higher than that of pure Pt particles. This method enables direct decoration of metal particles with different noble metal atoms, providing a novel strategy to develop highly efficient multinary particle catalysts. PMID:27074631

  10. Anion and cation effects on the size control of Au nanoparticles prepared by sputter deposition in imidazolium-based ionic liquids.

    PubMed

    Hatakeyama, Yoshikiyo; Judai, Ken; Onishi, Kei; Takahashi, Satoshi; Kimura, Satoshi; Nishikawa, Keiko

    2016-01-28

    The sputter deposition of metals in an ionic liquid (IL) capture medium is a simple and elegant method for preparing nanoparticles without any chemical reaction. Although there have been some reports on the size determination factors for Au nanoparticles (AuNPs) prepared using this method, the effects with respect to the type of IL used have not been clearly elucidated. This is because there are some complicating factors, some of which have been revealed by our previous systematic studies. In the present study, we prepare AuNPs in nine types of imidazolium-based IL to examine the size determination effects of the type of anion involved, the length of the alkyl chain of the cation, and the preparation temperature for each IL, while keeping other factors constant. For most of the capture media ILs, the sizes of the AuNPs increase with an increase in temperature. The AuNPs prepared in ILs containing different types of anions exhibit distinctly different particle sizes and temperature dependences. Conversely, the alkyl chain is regarded as a secondary stabilizer that works only at higher preparation temperatures. We conclude that the sizes of AuNPs prepared by this method may be determined by the competition between the collision frequency of the ejected Au atoms and the stabilizing capability of the anions that form the first coordination shell around the AuNPs. The AuNP sizes are closely related to the volume of anions. PMID:26344691

  11. CEAS-ASC highlights 2006

    NASA Astrophysics Data System (ADS)

    Caro, Stéphane

    2007-07-01

    The Council of European Aerospace Societies (CEAS) Aeroacoustics Specialists Committee (ASC) supports and promotes the interests of the scientific and industrial aeroacoustics community on a European scale and European aeronautics activities internationally. In this context, "aeroacoustics" encompasses all aerospace acoustics and related areas. Each year the committee highlights some of the research and development projects in Europe. This paper is a report on some highlights of aeroacoustics research in Europe in 2006, compiled from information provided to the ASC of the CEAS. During 2006, numerous research programmes were funded by the European Union. Some of the contributions submitted to the editor summarize selected findings from these programmes, while other articles cover issues supported by national associations. Furthermore, a concise summary of the workshop on "Aeroacoustics of Jet Noise" held in Dublin in September is included in this report. Enquiries concerning all contributions should be addressed to the authors who are given at the end of each subsection.

  12. Real-Time Dynamics of Galvanic Replacement Reactions of Silver Nanocubes and Au Studied by Liquid-Cell Transmission Electron Microscopy.

    PubMed

    Tan, Shu Fen; Lin, Guanhua; Bosman, Michel; Mirsaidov, Utkur; Nijhuis, Christian A

    2016-08-23

    We study the galvanic replacement reaction of silver nanocubes in dilute, aqueous ethylenediaminetetraacetic acid disodium salt (EDTA)-capped gold aurate solutions using in situ liquid-cell electron microscopy. Au/Ag etched nanostructures with concave faces are formed via (1) etching that starts from the faces of the nanocubes, followed by (2) the deposition of an Au layer as a result of galvanic replacement, and (3) Au deposition via particle coalescence and monomer attachment where small nanoparticles are formed during the reaction as a result of radiolysis. Analysis of the Ag removal rate and Au deposition rate provides a quantitative picture of the growth process and shows that the morphology and composition of the final product are dependent on the stoichiometric ratio between Au and Ag. PMID:27389989

  13. Synthesis of alloy AuCu nanoparticles with the L1₀ structure in an ionic liquid using sputter deposition.

    PubMed

    Suzuki, Shushi; Tomita, Yousuke; Kuwabata, Susumu; Torimoto, Tsukasa

    2015-03-01

    Sputter deposition onto ionic liquids (ILs) was applied to synthesize AuCu bimetallic alloy nanoparticles (NPs) dispersed in 1-ethyl-3-methylimidazolium tetrafluoroborate (EMI-BF4). A mixed target of Au and Cu materials was used for simultaneous sputter deposition onto the IL under an Ar pressure of 10 Pa. Two types of heating procedures within the range of 323-573 K were examined for control of the structures of NPs, particularly addressing the phase transition of the alloy NPs from the face centered cubic (fcc) structure to the L1₀ structure. One was heating after the sputter deposition in N2 at atmospheric pressure for 1 h. Another was a combination of heating during the sputter deposition and subsequent heating under an Ar pressure from 0.5 to 0.8 Pa for 1 h. Although both cases exhibited lowering of the phase transition temperatures compared with the temperature for the bulk, the latter procedure at 423 K only provided the NPs (approx. 5 nm) consisting of the L1₀ structure in the dispersed manner. A mechanism for forming the L1₀ structure was proposed for explaining the difference between results obtained using the two procedures. PMID:25623552

  14. Nanophase diagram of binary eutectic Au-Ge nanoalloys for vapor-liquid-solid semiconductor nanowires growth

    PubMed Central

    Lu, Haiming; Meng, Xiangkang

    2015-01-01

    Although the vapor-liquid-solid growth of semiconductor nanowire is a non-equilibrium process, the equilibrium phase diagram of binary alloy provides important guidance on the growth conditions, such as the temperature and the equilibrium composition of the alloy. Given the small dimensions of the alloy seeds and the nanowires, the known phase diagram of bulk binary alloy cannot be expected to accurately predict the behavior of the nanowire growth. Here, we developed a unified model to describe the size- and dimensionality-dependent equilibrium phase diagram of Au-Ge binary eutectic nanoalloys based on the size-dependent cohesive energy model. It is found that the liquidus curves reduce and shift leftward with decreasing size and dimensionality. Moreover, the effects of size and dimensionality on the eutectic composition are small and negligible when both components in binary eutectic alloys have the same dimensionality. However, when two components have different dimensionality (e.g. Au nanoparticle-Ge nanowire usually used in the semiconductor nanowires growth), the eutectic composition reduces with decreasing size. PMID:26053237

  15. Catalyzed oxidative degradation of methyl orange over Au catalyst prepared by ionic liquid-polymer modified silica

    NASA Astrophysics Data System (ADS)

    Wang, Y.; Guo, J. S.

    2015-07-01

    A new type of hybrid material was prepared by grafting an ionic liquid monomer, 1-(p-vinylbenzyl)-3-methylimidazolium chloride, on the surface of the porous silica which was synthesized via sodium silicate hydrolysis. The as-synthesized products were characterized by scanning electron microscope, nitrogen physisorption experiment, thermogravimetric analysis and Fourier transform infrared spectra. A catalyst with Au was prepared using the hybrid material as carrier. The experimental results show that the catalyst exhibits a better catalytic effect of hydrogen peroxide on the degradation of methyl orange. The reason may be that the metal component of the catalyst facilitated the dissociation of hydrogen peroxide to produce abundant highly active free radicals which can rapidly ruin the structure of methyl orange molecules in water. Finally, a probable catalytic degradation mechanism based on diffusion was discussed.

  16. Concurrent growth of InSe wires and In2O3 tulip-like structures in the Au-catalytic vapour-liquid-solid process

    NASA Astrophysics Data System (ADS)

    Taurino, A.; Signore, M. A.

    2015-06-01

    In this work, the concurrent growth of InSe and In2O3 nanostructures, obtained by thermal evaporation of InSe powders on Au-covered Si substrates, has been investigated by scanning and transmission electron microscopy techniques. The vapour-solid and Au catalytic vapour-liquid-solid growth mechanisms, responsible of the simultaneous development of the two different types of nanostructures, i.e. InSe wires and In2O3 tulip-like structures respectively, are discussed in detail. The thermodynamic processes giving rise to the obtained morphologies and materials are explained.

  17. Laser ablative nanostructuring of Au in liquid ambience in continuous wave illumination regime

    NASA Astrophysics Data System (ADS)

    Kucherik, A. O.; Kutrovskaya, S. V.; Arakelyan, S. M.; Ryabchikov, Y. V.; Al-Kattan, A.; Kabashin, A. V.; Itina, T. E.

    2016-03-01

    Gold nanoparticles (Au NPs) attract particular attention because of their unique size-dependent chemical, physicochemical and optical properties and, hence, their potential applications in catalysis, nanoelectronics, photovoltaics and medicine. In particular, laser-produced colloidal nanoparticles are not only biocompatible, but also reveal unique chemical properties. Different laser systems can be used for synthesis of these colloids, varying from continuous wave (CW) to ultra-short femtosecond lasers. The choice of an optimum laser system is still a challenge in application development. To bring more light at this issue, we investigate an influence of laser parameters on nanoparticle formation from a gold target immersed in deionized water. First, an optical diagnostics of laser-induced hydrodynamic processes taking place near the gold surface is performed. Then, gold nanoparticle colloids with average particle sizes smaller than 10 nm and a very narrow dispersion are shown to be formed by CW laser ablation. The obtained results are compared with the ones obtained by using the second harmonics and with previous results obtained by using femtosecond laser systems.

  18. Gold solubility and partitioning between sulfide liquid, monosulfide solid solution and hydrous mantle melts: Implications for the formation of Au-rich magmas and crust-mantle differentiation

    NASA Astrophysics Data System (ADS)

    Li, Yuan; Audétat, Andreas

    2013-10-01

    The solubility of Au in sulfur-free vs. sulfide-saturated melts and its partitioning behavior between sulfide liquid (SL), monosulfide solid solution (MSS) and hydrous basanite melt at variable Au activities was investigated in a fO2 range of FMQ-2 to FMQ+1.6 at 1200 °C/1.5 GPa using piston cylinder apparatus. Gold solubility in sulfur-free (<100 μg/g S) melt is low (0.6-1.6 μg/g) and increases with fO2 in a manner consistent with Au dissolution as AuO1/2, whereas in sulfide-saturated melts it is high (13.6 ± 1.7 μg/g) and independent of fO2. Variations in the chlorine content of sulfide-saturated melts (0.2-1.2 wt% Cl) had no measurable effect on Au solubility. Gold partition coefficients between sulfide liquid and silicate melt (DAuSL/SM) are very high, ∼10,000 ± 3000, which is at the upper end of values reported in previous studies. Gold partition coefficients between MSS and silicate melt (DAuMSS/SM) are much lower, 60 ± 10, which is at the lower end of previous values. Both DAuSL/SM and DAuMSS/SM are independent of fO2. The new Au partition coefficients were used in conjunction with previously published Cu and Ag partition coefficients to investigate the role of MSS versus SL during partial melting in the source region of primitive potassic magmas and during crust-mantle differentiation. The high Au content of ore deposits associated with potassic magmas has commonly been explained by the dissolution of Au-rich sulfide liquid, either during partial melting in the mantle source or during partial re-melting of sulfide-bearing cumulates at the crust-mantle boundary. We argue that MSS is the dominant sulfide phase in the mantle source region of these magmas, and thus that their high Au content is a consequence of low MSS-silicate melt partition coefficients rather than of sulfide exhaustion or partial re-melting of sulfide-bearing cumulates. Continental crust is depleted in Au, Ag and Cu relative to mantle melts, which was thought to be due to removal of

  19. CeO2-modified Au@SBA-15 nanocatalysts for liquid-phase selective oxidation of benzyl alcohol

    NASA Astrophysics Data System (ADS)

    Wang, Tuo; Yuan, Xiang; Li, Shuirong; Zeng, Liang; Gong, Jinlong

    2015-04-01

    Tuning the interfacial perimeter and structure is crucial to understanding the origin of catalytic performance. This paper describes the design, characterization, and application of CeO2 modified Au@SBA-15 (Au-CeO2@SBA-15) catalysts in selective oxidation of benzyl alcohol. The reaction results showed that Au-CeO2@SBA-15 catalysts exhibited higher catalytic activity compared with Au@SBA-15 and Au/CeO2 catalysts under identical conditions along with the high selectivity towards benzaldehyde (>99%). The turnover frequency of benzyl alcohol over the Au-100CeO2@SBA-15 catalyst is about nine-fold and four-fold higher than those of Au@SBA-15 and Au/CeO2 catalysts, respectively. The supported catalysts were characterized by N2 adsorption-desorption, inductively coupled plasma optical emission spectroscopy, X-ray diffraction, transmission electron microscopy, high-angle annular dark-field scanning transmission electron microscopy, scanning transmission electron microscopy-energy dispersive spectrometry, and X-ray photoelectron spectroscopy. It was found that the Au and small CeO2 nanoparticles (~5 nm) were homogeneously mixed in the channels of SBA-15, which led to an increase in the interfacial area between Au and CeO2 and consequently a better catalytic performance of Au-CeO2@SBA-15 catalysts for the selective oxidation of benzyl alcohol to benzaldehyde compared with that of Au/CeO2. The prevention of agglomeration and leaching of Au nanoparticles by restricting them inside the mesopores of SBA-15 was conducive to the stable existence of large quantities of Au-CeO2 interface, which leads to high stability of the Au-CeO2@SBA-15 catalyst.Tuning the interfacial perimeter and structure is crucial to understanding the origin of catalytic performance. This paper describes the design, characterization, and application of CeO2 modified Au@SBA-15 (Au-CeO2@SBA-15) catalysts in selective oxidation of benzyl alcohol. The reaction results showed that Au-CeO2@SBA-15 catalysts

  20. Electrical properties of phosphorus in situ doped Au-catalyst vapor liquid solid silicon nanowires

    NASA Astrophysics Data System (ADS)

    Pichon, L.; Rogel, R.; Jacques, E.

    2015-11-01

    N-type in-situ doped silicon nanowire-based resistors are fabricated following a CMOS process fabrication. Silicon nanowires are prepared by a Vapour Liquid Solid (VLS) method using gold as the catalyst. The doping level is adjusted by varying the phosphine to silane mole ratio during silicon nanowire growth. A macroscopic electrical model is presented to extract the average silicon nanowire electrical resistivity over a large doping level range (varying from undoped to highly doped nanowires). Carrier transport is strongly affected by the trapping effect of gold impurities into silicon nanowires, and silicon nanowire electrical resistivity is three decades higher than for silicon bulk at low doping levels. The technological requirement in terms of doping level control for the fabrication of devices based on a gold catalyst VLS is demonstrated.

  1. Cryogenic turbulence test facilities at CEA/SBT

    NASA Astrophysics Data System (ADS)

    Rousset, B.; Baudet, C.; Bon Mardion, M.; Bourgoin, M.; Braslau, A.; Daviaud, F.; Diribarne, P.; Dubrulle, B.; Gagne, Y.; Gallet, B.; Gibert, M.; Girard, A.; Lehner, T.; Moukharski, I.; Sy, F.

    2015-12-01

    Recently, CEA Grenoble SBT has designed, built and tested three liquid helium facilities dedicated to turbulence studies. All these experiments can operate either in HeI or HeII within the same campaign. The three facilities utilize moving parts inside liquid helium. The SHREK experiment is a von Kármán swirling flow between 0.72 m diameter counterrotating disks equipped with blades. The HeJet facility is used to produce a liquid helium free jet inside a 0.200 m I.D., 0.47 m length stainless steel cylindrical testing chamber. The OGRES experiment consists of an optical cryostat equipped with a particle injection device and an oscillating grid. We detail specific techniques employed to accommodate these stringent specifications. Solutions for operating these facilities without bubbles nor boiling/cavitation are described. Control parameters as well as Reynolds number and temperature ranges are given.

  2. Solid-liquid interdiffusion (SLID) bonding in the Au-In system: experimental study and 1D modelling

    NASA Astrophysics Data System (ADS)

    Deillon, Léa; Hessler-Wyser, Aïcha; Hessler, Thierry; Rappaz, Michel

    2015-12-01

    Au-In bonds with a nominal composition of about 60 at.% In were fabricated for use in wafer-level packaging of MEMS. The microstructure of the bonds was studied by scanning electron microscopy. The bond hermeticity was then assessed using oxidation of Cu thin discs predeposited within the sealed packages. The three intermetallic compounds AuIn2, AuIn and Au7In3 were observed. Their thickness evolution during bonding and after subsequent heat treatment was successfully modelled using a finite difference model of diffusion, thermodynamic data and diffusion coefficients calibrated from isothermal diffusion couples. 17% of the packages were hermetic and, although the origin of the leaks could not be clearly identified, it appeared that hermeticity was correlated with the unevenness of the metallisation and/or wafer and the fact that the bonds shrink due to density differences as the relative fractions of the various phases gradually evolve.

  3. Surface Nanostructures Composed of Thiolated Cyclodextrin/Au and Fe Species: Gas- and Liquid-Phase Preparation.

    PubMed

    Halaszova, Sona; Jerigova, Monika; Lorenc, Dusan; Prochazka, Michal; Velic, Dusan

    2016-08-01

    Supramolecular surface nanostructures have application potential as functional devices. The complex combination of thiolated cyclodextrin, chemisorbed on an Au surface (Au-S-CD), with deposited Fe species is studied by secondary ion mass spectrometry. The Fe species are prepared by pulsed laser ablation in water and thermal effusion in vacuum. Using laser ablation in water, the solution of Fe species is dropped on Au-S-CD, where mass peaks at 1227 m/z, 1243 m/z, and 1260 m/z are observed and assigned to C42 H68 O34 SNa-Fe(+) , C42 H68 O34 SK-Fe(+) together with C42 H68 O34 SNa-FeO(+) , and C42 H68 O34 SK-FeO(+) , respectively. On the other hand, laser ablation directly linked to the Au-S-CD surface results in desorption of CD-S. Thermal effusion, even with a cooled surface, was negative with respect to the complex observation. Laser ablation results in the formation of a supramolecular host-guest complex of the form Au-S-CD-Fe, and in the formation of an adduct of the form Au-S-CD-FeO. PMID:27128204

  4. CEA VARIABLE-THROAT VENTURI SCRUBBER EVALUATION

    EPA Science Inventory

    The report gives detailed results of fractional and overall mass efficiency tests of a Combustion Equipment Associates(CEA) variable-throat venturi scrubber. The tests were performed on a full-scale scrubber used for controlling particles and SOx emissions from a pulverized-coal-...

  5. Effect of Silicon on Activity Coefficients of Siderophile Elements (P, Au, Pd, As, Ge, Sb, and In) in Liquid Fe, with Application to Core Formation

    NASA Technical Reports Server (NTRS)

    Righter, K.; Pando, K.; Danielson, L. R.; Humayun, M.; Righter, M.; Lapen, T.; Boujibar, A.

    2016-01-01

    Earth's core contains approximately 10 percent light elements that are likely a combination of S, C, Si, and O, with Si possibly being the most abundant. Si dissolved into Fe liquids can have a large effect on the magnitude of the activity coefficient of siderophile elements (SE) in Fe liquids, and thus the partitioning behavior of those elements between core and mantle. The effect of Si can be small such as for Ni and Co, or large such as for Mo, Ge, Sb, As. The effect of Si on many siderophile elements is unknown yet could be an important, and as yet unquantified, influence on the core-mantle partitioning of SE. Here we report new experiments designed to quantify the effect of Si on the partitioning of P, Au, Pd, and many other SE between metal and silicate melt. The results will be applied to Earth, for which we have excellent constraints on the mantle siderophile element concentrations.

  6. Ultrasensitive sandwich-type electrochemical immunosensor based on trimetallic nanocomposite signal amplification strategy for the ultrasensitive detection of CEA.

    PubMed

    Tian, Lihui; Liu, Li; Li, Yueyuan; Wei, Qin; Cao, Wei

    2016-01-01

    A novel and ultrasensitive sandwich-type electrochemical immunosensor was designed for the quantitative detection of carcino-embryonic antigen (CEA). This immunosensor was developed by using the trimetallic NiAuPt nanoparticles on graphene nanosheets (NGs) nanosheets (NiAuPt-NGs) as excellent labels and β-cyclodextrin functionalized reduced graphene oxide nanosheets (CD-NGs) as the platform. The CD-NGs with high specific surface area good biocompatibility and the ideal dispersibility was used to capture the primary antibodies (Ab1) efficiently. The trimetallic NiAuPt-NGs nanocomposites were used as the labels for signal amplification, showing better electrocatalytic activity towards the reduction of hydrogen peroxide (H2O2), which is much better than that the monometallic Pt-NGs, bimetallic NiPt-NGs and AuPt-NGs due to the synergetic effect presented in NiAuPt-NGs. The NiAuPt-NGs nanocomposites consist of tightly coupled nanostructures of Au, Ni and Pt, which have neither an alloy nor a core-shell structure. Under the optimal conditions, a linear range from 0.001-100 ng/mL and a low detection limit of 0.27 pg/mL were obtained for CEA. The proposed electrochemical sandwich-type immunosensor may have a promising application in bioassay and it enriches the electrochemical immunoassays. PMID:27488806

  7. Ultrasensitive sandwich-type electrochemical immunosensor based on trimetallic nanocomposite signal amplification strategy for the ultrasensitive detection of CEA

    PubMed Central

    Tian, Lihui; Liu, Li; Li, Yueyuan; Wei, Qin; Cao, Wei

    2016-01-01

    A novel and ultrasensitive sandwich-type electrochemical immunosensor was designed for the quantitative detection of carcino-embryonic antigen (CEA). This immunosensor was developed by using the trimetallic NiAuPt nanoparticles on graphene nanosheets (NGs) nanosheets (NiAuPt-NGs) as excellent labels and β-cyclodextrin functionalized reduced graphene oxide nanosheets (CD-NGs) as the platform. The CD-NGs with high specific surface area good biocompatibility and the ideal dispersibility was used to capture the primary antibodies (Ab1) efficiently. The trimetallic NiAuPt-NGs nanocomposites were used as the labels for signal amplification, showing better electrocatalytic activity towards the reduction of hydrogen peroxide (H2O2), which is much better than that the monometallic Pt-NGs, bimetallic NiPt-NGs and AuPt-NGs due to the synergetic effect presented in NiAuPt-NGs. The NiAuPt-NGs nanocomposites consist of tightly coupled nanostructures of Au, Ni and Pt, which have neither an alloy nor a core-shell structure. Under the optimal conditions, a linear range from 0.001–100 ng/mL and a low detection limit of 0.27 pg/mL were obtained for CEA. The proposed electrochemical sandwich-type immunosensor may have a promising application in bioassay and it enriches the electrochemical immunoassays. PMID:27488806

  8. Interaction of ionic liquids with noble metal surfaces: structure formation and stability of [OMIM][TFSA] and [EMIM][TFSA] on Au(111) and Ag(111).

    PubMed

    Uhl, Benedikt; Huang, Hsinhui; Alwast, Dorothea; Buchner, Florian; Behm, R Jürgen

    2015-10-01

    Aiming at a comprehensive understanding of the interaction of ionic liquids (ILs) with metal surfaces we have investigated the adsorption of two closely related ILs, 1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide [EMIM][TFSA] and 1-methyl-3-octylimidazolium bis(trifluoromethylsulfonyl)imide [OMIM][TFSA], with two noble metal surfaces, Au(111) and Ag(111), under ultrahigh vacuum (UHV) conditions using scanning tunneling microscopy (STM). At room temperature, the ILs form a 2D liquid on either of the two surfaces, while at lower temperatures they condense into two-dimensional (2D) islands which exhibit ordered structures or a short-range ordered 2D glass structure. Comparison of the adlayer structures formed in the different adsorption systems and also with those determined recently for n-butyl-n-methylpyrrolidinium [TFSA](-) adlayers on Ag(111) and Au(111) (B. Uhl et al., Beilstein J. Nanotechnol., 2013, 4, 903) gains detailed insight into the adsorption geometry of the IL ions on the surface. The close similarity of the adlayer structures indicates that (i) the structure formation is dominated by the tendency to optimize the anion adsorption geometry, and that (ii) also in the present systems the cation adsorbs with the alkyl chain pointing up from the surface. PMID:26305417

  9. Reliability study of Au-in solid-liquid interdiffusion bonding for GaN-based vertical LED packaging

    NASA Astrophysics Data System (ADS)

    Sung, Ho-Kun; Wang, Cong; Kim, Nam-Young

    2015-12-01

    An In-rich Au-In bonding system has been developed to transfer vertical light-emitting diodes (VLEDs) from a sapphire to a graphite substrate and enable them to survive under n-ohmic contact treatment at 350 °C. The bonding temperature is 210 °C, and three intermetallic compounds are detected: AuIn, AuIn2, and γ phase. As a result, the remelting temperature increases beyond the theoretical value of 450 °C according to the Au-In binary phase diagram. In fact, reliability testing showed that joints obtained by rapid thermal annealing at 400 °C for 1 min survived whereas those obtained at 500 °C for 1 min failed. Finally, a GaN-based blue VLED was transferred to the graphite substrate by means of the proposed bonding method, and its average light output power was measured to be 386.6 mW (@350 mA) after n-ohmic contact treatment. This wafer-level bonding technique also shows excellent potential for high-temperature packing applications.

  10. CEA TCB: A novel head-to-tail 2:1 T cell bispecific antibody for treatment of CEA-positive solid tumors.

    PubMed

    Bacac, Marina; Klein, Christian; Umana, Pablo

    2016-08-01

    Carcinoembryonic antigen T cell bispecific antibody (CEA TCB) is a bispecific antibody used to recognize CEA and CD3e via a novel molecular format (2:1) that induces T cell-mediated killing of CEA over-expressing tumors while sparing primary cells with low CEA expression. CEA TCB treatment inhibits tumor growth and generates a highly inflamed tumor microenvironment. PMID:27622073

  11. Bidirectional migration of Au colloids and silicon microrods in liquid using asymmetrical alternating current electric field with insulated electrodes

    NASA Astrophysics Data System (ADS)

    Shibata, Akihide; Komiya, Kenji; Watanabe, Keiji; Sato, Takuya; Shiomi, Takeshi; Kotaki, Hiroshi; Schuele, Paul J.; Crowder, Mark A.; Zhan, Changqing; Hartzell, John W.

    2014-02-01

    In this study, we demonstrate the migration of Au colloids and silicon microrods in deionized (DI) water and isopropyl alcohol (IPA) by applying asymmetrical AC bias to two electrodes capped with a thin dielectric film. Both Au colloids and silicon microrods successfully migrate from one electrode to the other when asymmetrical AC bias is applied to the electrodes. Furthermore, the direction of the migration can be easily reversed by inverting the wave form. The insulated electrodes have the potential to prevent contamination and bubbling originating from electrochemical reactions, which makes the adoption of the technique for mass production processes easy and realistic. The bidirectional migration acts similarly to electrophoresis and is effective even in DI water and IPA in which conventional DC electrophoresis with insulated electrodes is ineffective. This technique is widely applicable to the positional control of small objects including nano- and micro-sized devices.

  12. Vapor-liquid-solid growth route to AlN nanowires on Au-coated Si substrate by direct nitridation of Al powder

    NASA Astrophysics Data System (ADS)

    Yu, Leshu; Lv, Yingying; Zhang, Xiaolan; Zhang, Yiyue; Zou, Ruyi; Zhang, Fan

    2011-11-01

    In the past several decades vapor-liquid-solid (VLS) growth mechanism has been used for constructing one dimensional (1D) AlN nanostructures though the clear observation of metallic catalyst particles on top of individual 1D nanostructure is rare. Using Au thin film on Si substrate as metallic catalyst, fine AlN nanowires were grown through the nitridation of Al powder in this study. The systematic characterizations including scanning electron microscopy (SEM), transmission electron microscopy (TEM) and energy dispersive X-ray spectroscopy (EDX) have confirmed the existence of metallic catalyst particles on the top of each AlN nanowire. Therefore the AlN nanowires growth is indeed accomplished via VLS process. The VLS-generated conditions including thickness of Au film and reaction temperature were also explored for the growth of AlN nanowires. Incidentally some other AlN nanostructures such as faceted cross-sectional nanorods, nanobelt and nanocomb were also obtained via vapor-solid growth mechanism on the Si substrate.

  13. Smart Liquid SERS Substrates based on Fe3O4/Au Nanoparticles with Reversibly Tunable Enhancement Factor for Practical Quantitative Detection

    PubMed Central

    Hu, Fei; Lin, Haiyang; Zhang, Zhaoshun; Liao, Fan; Shao, Mingwang; Lifshitz, Yeshayahu; Lee, Shuit-Tong

    2014-01-01

    There is a strong correlation between the surface enhanced Raman scattering (SERS) enhancement factor (EF), the excitation wavelength, and the feature properties (composition, size, geometry, and analytes). The prediction of the EF of specific substrates, crucial to the quantitative SERS detection, is however still very difficult. The present work presents smart liquid SERS substrates consisting of suspensions of Fe3O4/Au nanoparticles, which provide high spot-to-spot uniformity, reproducibility and good reversibility. The EF of these substrates can be reversibly tuned by applying an external magnetic field. The EF magnetic tuning is within 2 orders of magnitude per substrate in the range of 104–107. The ability to reversibly adjust the SERS EF enables to reduce EF variations caused by external effects such as substrate-to-substrate differences and long-term-storage degradation. This improves the quantitative detection of analytes and might be a significant step forward in employing SERS for practical applications. PMID:25428185

  14. Self-Consistent Interpretation of the 2D Structure of the Liquid Au82Si18 Surface: Bending Rigidity and the Debye-Waller Effect

    NASA Astrophysics Data System (ADS)

    Mechler, S.; Pershan, P. S.; Yahel, E.; Stoltz, S. E.; Shpyrko, O. G.; Lin, B.; Meron, M.; Sellner, S.

    2010-10-01

    The structural and mechanical properties of 2D crystalline surface phases that form at the surface of liquid eutectic Au82Si18 are studied using synchrotron x-ray scattering over a large temperature range. In the vicinity of the eutectic temperature the surface consists of a 2D atomic bilayer crystalline phase that transforms into a 2D monolayer crystalline phase during heating. The latter phase eventually melts into a liquidlike surface on further heating. We demonstrate that the short wavelength capillary wave fluctuations are suppressed due to the bending rigidity of 2D crystalline phases. The corresponding reduction in the Debye-Waller factor allows for measured reflectivity to be explained in terms of an electron density profile that is consistent with the 2D surface crystals.

  15. Salient properties of glassforming liquids close to the glass transitionPropriétés spécifiques des liquides au voisinage de la transition vitreuse

    NASA Astrophysics Data System (ADS)

    Alba-Simionesco, C.

    2001-03-01

    This article is focused on the dramatic increase of the viscosity, or on the relaxation time of supercooled molecular liquids, and on the dynamical arrest observed when the temperature is cooled down to the glass transition temperature T g at atmospheric pressure and under pressure. After an introduction of the fragility concept due to Angell, the particular super-Arrhenius behavior of the so-called fragile liquids is shown to be temperature rather than density driven. The non-exponential behavior of structural relaxation as a function of time, and the existence of dynamical heterogeneities are presented, whose emergence is related to the possible manifestation of polyamorphism. Some theories of deeply supercooled liquids are tested.

  16. Simplifying CEA through Excel, VBA, and Subeq

    NASA Technical Reports Server (NTRS)

    Foster, Ryan

    2004-01-01

    Many people use compound equilibrium programs for very different reasons, varying from refrigerators to light bulbs to rockets. A commonly used equilibrium program is CEA. CEA can take various inputs such as pressure, temperature, and volume along with numerous reactants and run them through equilibrium equations to obtain valuable output information, including products formed and their relative amounts. A little over a year ago, Bonnie McBride created the program subeq with the goal to simplify the calling of CEA. Subeq was also designed to be called by other programs, including Excel, through the use of Visual Basic for Applications (VBA). The largest advantage of using Excel is that it allows the user to input the information in a colorful and user-friendly environment while allowing VBA to run subeq, which is in the form of a FORTRAN DLL (Dynamic Link Library). Calling subeq in this form makes it much faster than if it were converted to VBA. Since subeq requires such large lists of reactant and product names, all of which can't be passed in as an array, subeq had to be changed to accept very long strings of reactants and products. To pass this string and adjust the transfer of input and output parameters, the subeq DLL had to be changed. One program that does this is Compaq Visual FORTRAN, which allows DLLs to be edited, debugged, and compiled. Compaq Visual FORTRAN uses FORTRAN 90/95, which has additional features to that of FORTRAN 77. My goals this summer include finishing up the excel spreadsheet of subeq, which I started last summer, and putting it on the Internet so that others can use it without having to download my spreadsheet. To finish up the spreadsheet I will need to work on debugging current options and problems. I will also work on making it as robust as possible, so that all errors that may arise will be clearly communicated to the user. New features will be added old ones will be changed as I receive comments from people using the spreadsheet

  17. CEA TCB: A novel head-to-tail 2:1 T cell bispecific antibody for treatment of CEA-positive solid tumors

    PubMed Central

    Bacac, Marina; Klein, Christian; Umana, Pablo

    2016-01-01

    ABSTRACT Carcinoembryonic antigen T cell bispecific antibody (CEA TCB) is a bispecific antibody used to recognize CEA and CD3e via a novel molecular format (2:1) that induces T cell-mediated killing of CEA over-expressing tumors while sparing primary cells with low CEA expression. CEA TCB treatment inhibits tumor growth and generates a highly inflamed tumor microenvironment. PMID:27622073

  18. Thermal hydraulic characteristics study of prototype NET and CEA cable-in-conduit conductors (CICCs)

    SciTech Connect

    Maekawa, Ryuji

    1995-10-31

    The thermal hydraulic characteristics of low temperature helium in a Cable-in-Conduit Conductor (CICC) significantly affects the overall design and performance of the associated large scale superconducting magnet system. It is essential to understand the transient and steady state behavior of the helium in the conductor. Throughout the development of CICCs, the reduction of flow impedance has been one of the key factors to improving the overall pressure drop. The newly developed CICC for the ITER project has a hybrid cooling scheme: a central channel that is surrounded by bundles, for which the thermal hydraulic characteristics are not well understood. This thesis describes an experimental and analytical investigation of thermal hydraulic characteristics of low temperature helium in conventional and hybrid CICCS. Pressure drop measurements for both NET and CEA conductors have been conducted, using low temperature helium and liquid nitrogen to obtain a range of Reynolds numbers. The results are correlated with classical friction factor and Reynolds number analysis. The flow impedance reduction of the CEA conductor is described by measures of a developed flow model. Thermally induced flow in the CEA conductor has been studied with an inductive heating method. The induced velocity in the central channel is measured by a Pitot tube with steady state Reynolds number up to {approximately}7000. The transient pressure wave propagation has been recorded with pressure transducers placed equally along the conductor. The supercritical helium temperature in the central channel has been measured with the thermometer probe. However, the reduction of the central channel area significantly affects the overall thermal hydraulic characteristics of the conductor. The results suggest the importance of the central channel. A transient heat transfer experiment studied the.transverse heat transfer mechanism in the CEA conductor. The temperatures in the central channel and bundle region

  19. Formation of a 1,8-octanedithiol self-assembled monolayer on Au(111) prepared in a lyotropic liquid-crystalline medium.

    PubMed

    García Raya, Daniel; Madueño, Rafael; Blázquez, Manuel; Pineda, Teresa

    2010-07-20

    A characterization of the 1,8-octanedithiol (ODT) self-assembled monolayer (SAM) formed from a Triton X-100 lyotropic medium has been conducted by electrochemical techniques. It is found that an ODT layer of standing-up molecules is obtained at short modification time without removing oxygen from the medium. The electrochemical study shows that the ODT layer formed after 15 min of modification time has similar electron-transfer blocking properties to the layers formed from organic solvents at much longer modification times. On the basis of XPS data, it is demonstrated that the inability to bind gold nanoparticles (AuNPs) is due to the presence of extra ODT molecules either interdigited or on top of the layer. Treatment consisting of an acid washing step following the formation of the ODT-Au(111) SAM produces a layer that is able to attach AuNPs as demonstrated by electrochemical techniques and atomic force microscopy (AFM) images. PMID:20578682

  20. Complete solid state lighting (SSL) line at CEA LETI

    NASA Astrophysics Data System (ADS)

    Robin, I. C.; Ferret, P.; Dussaigne, A.; Bougerol, C.; Salomon, D.; Chen, X. J.; Charles, M.; Tchoulfian, P.; Gasse, A.; Lagrange, A.; Consonni, M.; Bono, H.; Levy, F.; Desieres, Y.; Aitmani, A.; Makram-Matta, S.; Bialic, E.; Gorrochategui, P.; Mendizabal, L.

    2014-09-01

    With a long experience in optoelectronics, CEA-LETI has focused on Light Emitting Diode (LED) lighting since 2006. Today, all the technical challenges in the implementation of GaN LED based solid state lighting (SSL) are addressed at CEA-LETI who is now an RandD player throughout the entire value chain of LED lighting. The SSL Line at CEA-LETI first deals with the simulation of the active structures and LED devices. Then the growth is addressed in particular 2D growth on 200 mm silicon substrates. Then, technological steps are developed for the fabrication of LED dies with innovative architectures. For instance, Versatile LED Array Devices are currently being developed with a dedicated μLED technology. The objective in this case is to achieve monolithical LED arrays reported and interconnected through a silicon submount. In addition to the required bonding and 3D integration technologies, new solutions for LED chip packaging, thermal management of LED lamps and luminaires are also addressed. LETI is also active in Smart Lighting concepts which offer the possibility of new application fields for SSL technologies. An example is the recent development at CEA LETI of Visible Light Communication Technology also called LiFi. With this technology, we demonstrated a transmission rate up to 10 Mb/s and real time HD-Video transmission.

  1. Ultrasensitive sandwich-type electrochemical immunosensor based on a novel signal amplification strategy using highly loaded toluidine blue/gold nanoparticles decorated KIT-6/carboxymethyl chitosan/ionic liquids as signal labels.

    PubMed

    Wang, Yulan; Li, Xiaojian; Cao, Wei; Li, Yueyun; Li, He; Du, Bin; Wei, Qin

    2014-11-15

    An ultrasensitive sandwich-type electrochemical immunosensor for the quantitative detection of carcinoembryonic antigen (CEA) was designed based on a novel signal amplification strategy. Gold nanoparticles decorated mesoporous silica KIT-6 (Au@KIT-6) with large specific surface area and good adsorption properties was used as a label matrix to immobilize both the secondary antibodies (Ab2) and the electron transfer mediator toluidine blue (TB). Ab2 was loaded on KIT-6 due to the presence of gold nanoparticles (Au NPs) and TB was loaded on KIT-6 by physical adsorption. Ionic liquids (ILs) doped carboxymethyl chitosan (CMC) was used to prevent the leak of TB and facilitate the electron transfer. For the immobilization of primary antibodies (Ab1), gold nanoparticles decorated 3-aminopropyltriethoxysilane functionalized graphene sheets (Au@APTES-GS) were used as transducing materials to modify glassy carbon electrodes (GCE). High sensitivity was achieved for the designed immunosensor based on this novel signal amplification strategy. Under optimal conditions, the immunosensor exhibited an extremely low detection limit of 3.3 fg/mL and wide liner range from 10(-5) ng/mL to 10(2) ng/mL for CEA. Moreover, it exhibited good selectivity, acceptable reproducibility and stability, indicating potential application promising in clinical monitoring of tumor biomarkers. PMID:24967751

  2. Au-F127 strawberry-like nanospheres as an electrochemical interface for sensitive detection of carcinoembryonic antigen in real sample.

    PubMed

    Li, Juan; Xie, Hangqing; Liu, Yuhong; Ren, Hang; Zhao, Wenbo; Huang, Xiaohua

    2015-11-01

    Nanomaterial-based signal-amplification strategies hold a great promise in realizing sensitive biological detection. A simple label-free electrochemical immunosensor for sensitive detection of carcinoembryonic antigen (CEA) was developed by immobilizing anti-CEA antibodies onto the Au-F127 strawberry-like nanospheres modified glassy carbon electrode (Au-F127/GCE). The Au-F127 strawberry-like nanospheres offered a large surface and multifunctional substrate for the effective immobilization of anti-CEA and the existence of Au could accelerate electron transfer and make the electrochemical signal amplified. The Au-F127 nanocomposites and anti-CEA were characterized by transmission electron microscopy (TEM), polycrystalline electron diffraction ring pattern, ultra-violet visible (UV-vis) spectra and attenuated total reflection-Fourier transform infrared (ATR-FTIR) spectra. Electrochemical impedance spectroscopy (EIS) and differential pulse voltammetry (DPV) were employed to verify the stepwise assembly of the immunosensor and evaluated the analytical performance of the fabricated immunosensor, respectively. The immunosensor showed a wide liner response range between 0.01 and 80 ng mL(-1) with a low detection limit of 0.24 pg mL(-1) at a signal-to-noise (S/N) ratio of 3. Additionally, the proposed method was successfully applied to determine CEA in human serum samples with satisfactory results. PMID:26452840

  3. Application of a MABEL Approach for a T-Cell-Bispecific Monoclonal Antibody: CEA TCB.

    PubMed

    Dudal, Sherri; Hinton, Heather; Giusti, Anna M; Bacac, Marina; Muller, Magali; Fauti, Tanja; Colombetti, Sara; Heckel, Tobias; Giroud, Nicolas; Klein, Christian; Umaña, Pablo; Benincosa, Lisa; Bachl, Juergen; Singer, Thomas; Bray-French, Katharine

    2016-09-01

    CEA TCB is a novel T-cell-bispecific (TCB) antibody targeting the carcinoembryonic antigen (CEA) expressed on tumor cells and the CD3 epsilon chain (CD3e) present on T cells, which is currently in Phase 1 clinical trials (NCT02324257) for the treatment of CEA-positive solid tumors. Because the human CEA (hCEA) binder of CEA TCB does not cross-react with cynomolgus monkey and CEA is absent in rodents, alternative nonclinical safety evaluation approaches were considered. These included the development of a cynomolgus monkey cross-reactive homologous (surrogate) antibody (cyCEA TCB) for its evaluation in cynomolgus monkey and the development of double-transgenic mice, expressing hCEA and human CD3e (hCEA/hCD3e Tg), as a potential alternative species for nonclinical safety studies. However, a battery of nonclinical in vitro/ex vivo experiments demonstrated that neither of the previous approaches provided a suitable and pharmacologically relevant model to assess the safety of CEA TCB. Therefore, an alternative approach, a minimum anticipated biological effect level (MABEL), based on an in vitro tumor lysis assay was used to determine the starting dose for the first-in-human study. Using the most conservative approach to the MABEL assessment, a dose of 52 μg was selected as a safe starting dose for clinical study. PMID:27404941

  4. Printing graphene-carbon nanotube-ionic liquid gel on graphene paper: Towards flexible electrodes with efficient loading of PtAu alloy nanoparticles for electrochemical sensing of blood glucose.

    PubMed

    He, Wenshan; Sun, Yimin; Xi, Jiangbo; Abdurhman, Abduraouf Alamer Mohamed; Ren, Jinghua; Duan, Hongwei

    2016-01-15

    The increasing demands for portable, wearable, and implantable sensing devices have stimulated growing interest in innovative electrode materials. In this work, we have demonstrated that printing a conductive ink formulated by blending three-dimensional (3D) porous graphene-carbon nanotube (CNT) assembly with ionic liquid (IL) on two-dimensional (2D) graphene paper (GP), leads to a freestanding GP supported graphene-CNT-IL nanocomposite (graphene-CNT-IL/GP). The incorporation of highly conductive CNTs into graphene assembly effectively increases its surface area and improves its electrical and mechanical properties. The graphene-CNT-IL/GP, as freestanding and flexible substrates, allows for efficient loading of PtAu alloy nanoparticles by means of ultrasonic-electrochemical deposition. Owing to the synergistic effect of PtAu alloy nanoparticles, 3D porous graphene-CNT scaffold, IL binder and 2D flexible GP substrate, the resultant lightweight nanohybrid paper electrode exhibits excellent sensing performances in nonenzymatic electrochemical detection of glucose in terms of sensitivity, selectivity, reproducibility and mechanical properties. PMID:26709299

  5. Surface expression and CEA binding of hnRNP M4 protein in HT29 colon cancer cells.

    PubMed

    Laguinge, Luciana; Bajenova, Olga; Bowden, Emma; Sayyah, Jacqueline; Thomas, Peter; Juhl, Hartmut

    2005-01-01

    Carcinoembryonic antigen (CEA) has been shown to participate in the progression and metastatic growth of colorectal cancer. However, its biological function remains elusive. Recently, we found that CEA protects colon cancer cells from undergoing apoptosis, suggesting a complex role that includes signal transduction activity. Additionally, it was reported that CEA binds to Kupffer cells and macrophages to a membrane-anchored homolog of heterogeneous nuclear protein M4 (hnRNP M4), which subsequently was named CEA-receptor (CEAR). Cytoplasmatic and membranous expression of CEAR in CEA-positive colon cancer tissues prompted us to analyze the CEA-CEAR interaction in HT29 colon cancer cells. Both, CEA and CEAR were found on the cell surface of HT29 cells, as demonstrated by confocal microscopy. Imaging analysis suggested co-localization and, thus, interaction of both molecules. To confirm this observation, immunoprecipitation experiments and Western blot analysis were performed and indicated binding of CEA and CEAR. Immunoprecipitation of CEA resulted in a pull down of CEAR. The pull down of CEAR correlated with the amount of CEA as demonstrated by ribozyme targeting of CEA. Finally, external treatment of HT29 cells with soluble CEA induced tyrosine phosphorylation of CEAR, suggesting a CEA-dependent role of CEAR in signal transduction. Future experiments will elucidate whether the CEA-CEAR interaction is involved in CEA's antiapoptotic role and mediates the prometastatic properties of CEA in colon cancer cells. PMID:15816515

  6. The CEA/CD3-Bispecific Antibody MEDI-565 (MT111) Binds a Nonlinear Epitope in the Full-Length but Not a Short Splice Variant of CEA

    PubMed Central

    Huang, Jiaqi; Brohawn, Philip; Morehouse, Chris; Lekstrom, Kristen; Baeuerle, Patrick A.; Wu, Herren; Yao, Yihong; Coats, Steven R.; Dall’Acqua, William; Damschroder, Melissa; Hammond, Scott A.

    2012-01-01

    MEDI-565 (also known as MT111) is a bispecific T-cell engager (BiTE®) antibody in development for the treatment of patients with cancers expressing carcinoembryonic antigen (CEA). MEDI-565 binds CEA on cancer cells and CD3 on T cells to induce T-cell mediated killing of cancer cells. To understand the molecular basis of human CEA recognition by MEDI-565 and how polymorphisms and spliced forms of CEA may affect MEDI-565 activity, we mapped the epitope of MEDI-565 on CEA using mutagenesis and homology modeling approaches. We found that MEDI-565 recognized a conformational epitope in the A2 domain comprised of amino acids 326–349 and 388–410, with critical residues F326, T328, N333, V388, G389, P390, E392, I408, and N410. Two non-synonymous single-nucleotide polymorphisms (SNPs) (rs10407503, rs7249230) were identified in the epitope region, but they are found at low homozygosity rates. Searching the National Center for Biotechnology Information GenBank® database, we further identified a single, previously uncharacterized mRNA splice variant of CEA that lacks a portion of the N-terminal domain, the A1 and B1 domains, and a large portion of the A2 domain. Real-time quantitative polymerase chain reaction analysis of multiple cancers showed widespread expression of full-length CEA in these tumors, with less frequent but concordant expression of the CEA splice variant. Because the epitope was largely absent from the CEA splice variant, MEDI-565 did not bind or mediate T-cell killing of cells solely expressing this form of CEA. In addition, the splice variant did not interfere with MEDI-565 binding or activity when co-expressed with full-length CEA. Thus MEDI-565 may broadly target CEA-positive tumors without regard for expression of the short splice variant of CEA. Together our data suggest that MEDI-565 activity will neither be impacted by SNPs nor by a splice variant of CEA. PMID:22574157

  7. Baseline carcinoembryonic antigen (CEA) serum levels predict bevacizumab-based treatment response in metastatic colorectal cancer

    PubMed Central

    Prager, Gerald W; Braemswig, Kira H; Martel, Alexandra; Unseld, Matthias; Heinze, Georg; Brodowicz, Thomas; Scheithauer, Werner; Kornek, Gabriela; Zielinski, Christoph C

    2014-01-01

    Carcinoembryonic antigen (CEA) affects tumorigenesis by enhancing tumor cell survival and by inducing tumor angiogenesis. This study aimed to evaluate baseline CEA serum levels to predict bevacizumab-based therapy effect and survival in patients with metastatic colorectal cancer (mCRC). Two hundred and ninety eight mCRC patients receiving chemotherapy plus either bevacizumab or cetuximab were analyzed in a retrospective study. Disease control (DC), progression-free survival (PFS), and overall survival were assessed and related to pretreatment CEA serum levels. Patients with baseline CEA serum levels below the statistical median of 26.8 ng/mL (group I) were compared with patients with higher CEA levels (group II). The cetuximab-based treatment cohort was analyzed for specificity assessment of CEA to predict the anti-vascular endothelial growth factor effect in mCRC. Baseline CEA serum levels inversely correlated with therapeutic response in patients receiving bevacizumab-based treatment (disease control rate, 84% vs 60%), inversely correlated with median PFS leading to a median PFS benefit of 2.1 months for patients in group I when compared with group II, as well as inversely correlated with median overall survival (37.5 months vs 21.4 months). In an independent cohort of 129 patients treated with cetuximab-based therapy, no association of therapeutic response or PFS with CEA serum levels was found. As expected, baseline CEA levels were prognostic for mCRC. These data give first evidence that baseline serum CEA levels might constitute an important predictor for the efficacy of first-line bevacizumab-based therapy in patients with mCRC. Previously, we found that CEA induces angiogenesis independent of VEGF. The data presented here now give first evidence that baseline serum CEA levels in patients might constitute an important predictor for the efficacy of first-line bevacizumab-based therapy for metastatic colorectal cancer. PMID:24850362

  8. Relationship between serum CA19-9 and CEA levels and prognosis of pancreatic cancer

    PubMed Central

    Wu, Lei; Huang, Peijun; Wang, Fang; Li, Daqian; Xie, Erfu; Zhang, Yan

    2015-01-01

    Background To explore the relationship between preoperative serum CA19-9 and CEA levels and prognosis of pancreatic cancer (PC). Methods The clinicopathological data of 128 patients with pancreatic adenocarcinoma who were treated in our center between January 2012 and December 2013 were retrospectively analyzed. The relationships between serum CA19-9 and CEA levels and survival were analyzed using Kaplan-Meier method, log-rank test, and Cox regression analysis. The cut-off values for serum CA19-9 and CEA levels were 39 U/mL and 4.7 ng/mL, respectively. Results Among these 128 patients, the mean age was 62 years, and median survival was 12.2 days. The positive rate of CA19-9 and CEA was 78.1% and 37.5%, respectively. Patients with increased CA19-9 or CEA level suffered a poorer prognosis than those with normal CA19-9 or CEA level (CA19-9: P=0.027; CEA: P=0.036). Cox logistic analysis revealed that lymphatic metastasis, CA19-9 >39 U/mL, and CEA >4.7 ng/mL were independent prognostic factors in patients with pancreatic carcinoma. Conclusions Preoperative serum CA19-9 and CEA level are closely related with survival time in PC patients and therefore may be used for evaluating the prognosis for PC. PMID:26734638

  9. Serum CEA testing in the post-operative surveillance of colorectal carcinoma.

    PubMed Central

    Hine, K. R.; Dykes, P. W.

    1984-01-01

    Six hundred and sixty-three patients were followed with serial serum CEA measurements in addition to routine clinical surveillance after radical resection of colorectal carcinoma. Of 626 available for analysis, 366 (58.4%) remained clinically free of recurrence and had a normal CEA (less than 20 ng ml-1) throughout and 89 (14.2%) had a temporary non-progressive rise in CEA with no evidence of secondary disease. Of 171 patients who developed proven or suggestive recurrence, 114 had a preceding rise in the serum CEA and in further 21 the CEA rose simultaneously with recurrence. In 36 patients secondary disease was detected while the CEA was still within normal limits. CEA was more effective as an early index of distant metastasis, thus in 76% of those patients with a preceding rise in CEA, the secondary disease was disseminated, whereas only 20% had localised recurrence. The pattern of rise in CEA was of no practical value in distinguishing localised from distant recurrence. PMID:6733018

  10. In vivo kinetics of radiolabeled monoclonal anti-CEA antibodies in animal models

    SciTech Connect

    Hagan, P.L.; Halpern, S.E.; Chen, A.; Krishnan, L.; Frincke, J.; Bartholomew, R.M.; David, G.S.; Carlo, D.

    1985-12-01

    Studies were performed to determine the effect of the radiolabel and circulating carcinoembryonic antigen (CEA) on the pharmacodynamics of monoclonal anti-CEA antibodies (MoAbs). The studies were performed in normal BALB/c mice and in nude mice bearing human colon tumors. Three different tumors were used, each of which produced CEA levels characteristic of that particular tumor's secretory rate. The CEJ-326 MoAb labeled with either 111In or 125I was used in all studies. Circulating CEA induced the removal of 125I and 111In MoAbs from the vascular compartment. Liver concentrations of 111In increased and 125I levels decreased as the CEA secretory rate of the tumor rose. This indicates that circulating CEA complexes form in the vascular compartment which, in an animal model, are removed by the liver and spleen. This results in decreased tumor uptake of the labeled MoAb. The iodinated MoAb complexes are dehalogenated while the 111In is retained by the liver. This dehalogenation may account for the relatively low liver activity observed in radioimmunoimaging with intact radioiodinated anti-CEA MoAbs, provided the CEA complexes are similarly removed from the vascular compartment by the human liver.

  11. CEA in policies and plans: UK case studies

    SciTech Connect

    Cooper, Lourdes M.

    2011-09-15

    This paper examines how cumulative effects assessment (CEA) has been considered in Strategic Environmental Assessments (SEA) of regional and local plans in a number of case studies in the UK. Initially, the paper presents the legislative and regulatory requirements for assessing cumulative effects in plans and programmes in the UK. The two approaches for assessing plans in the UK, Sustainability Appraisal (SA) and SEA are discussed and in most cases, a combined SA and SEA process is undertaken by Regional and Local Planning Authorities. The strengths and weaknesses of this approach are explored, as well as their usefulness in decision making. There are problems relating to baseline, establishing trends and predicting cumulative effects at the strategic level. The issues in assessing cumulative effects within this SA/SEA framework are discussed and recommendations for improvements are made.

  12. Partitioning of platinum-group elements and Au between sulfide liquid and basalt and the origins of mantle-crust fractionation of the chalcophile elements

    NASA Astrophysics Data System (ADS)

    Mungall, James E.; Brenan, James M.

    2014-01-01

    The partitioning of platinum-group elements (PGE; Os, Ir, Ru, Rh, Pt, and Pd) and Au between sulfide melt and silicate melt (i.e., DPGEsul) exerts a critical control on the PGE composition of the Earth’s crust and mantle, but previous estimates have been plagued by experimental uncertainties and vary through several orders of magnitude. Here we present direct experimental measurements of DPGEsul, based on in situ microanalysis of the sulfide and silicate melt, with values ranging from ∼4 × 105 (Ru) to ∼2-3 × 106 (Ir, Pt). Our measurements of DPGEsul are >100 times larger than previous results but smaller than anticipated based on comparison of alloy solubilities in sulfide melts and S-free silicate melts. The presence of S in the silicate melt greatly increases alloy solubility. We use our new set of partition coefficients to develop a fully constrained model of PGE behavior during melting which accurately predicts the abundances of PGE in mantle-derived magmas and their restites, including mid-ocean ridge basalts, continental picrites, and the parental magmas of the Bushveld Complex of South Africa. Our model constrains mid-ocean ridge basalt (MORB) to be the products of pooled low and high degree fractional melts. Within-plate picrites are pooled products of larger degrees of fractional melting in columnar melting regimes. A significant control on PGE fractionation in mantle-derived magmas is exerted by residual alloy or platinum group minerals in their source. At low pressures (e.g., MORB genesis) the mantle residual to partial melting retains primitive mantle inter-element ratios and abundances of PGE until sulfide has been completely dissolved but then evolves to extremely high Pt/Pd and low Pd/Ir because Pt and Ir alloys form in the restite. During melting at high pressure to form picrites or komatiites Ir alloy appears as a restite phase but Pt alloy is not stable due to the large effect of pressure on fS2, and of temperature on fO2 along an internal

  13. A chitosan-Au-hyperbranched polyester nanoparticles-based antifouling immunosensor for sensitive detection of carcinoembryonic antigen.

    PubMed

    Sun, Chong; Ma, Lie; Qian, Qiuhui; Parmar, Soniya; Zhao, Wenbo; Zhao, Bo; Shen, Jian

    2014-09-01

    Analysts are always interested in finding new functional nanomaterials and devices with good properties for electrochemical sensor applications. In this paper, hyperbranched polyester nanoparticles with carboxylic acid functional groups (HBPE-CA NPs) were synthesized and combined with chitosan wrapped around Au nanoparticles (CS-Au NPs) to prepare a novel and sensitive electrochemical immunosensor by adsorption of carcinoembryonic antibody (anti-CEA) on the (HBPE-CA)/CS-Au NPs modified glass carbon electrode (GCE). Under the optimized conditions, the proposed immunosensor displayed a good amperometric response to carcinoembryonic antigen (CEA). Moreover, based on the antibiofouling properties, the immunosensor could be used for the direct detection of CEA in whole blood, and exhibited a wide detection range (1-10(7) fg mL(-1)), and a low detection limit of 0.251 fg mL(-1) (signal/noise = 3). Control experiments were also carried out by using ascorbic acid (AA), uric acid (UA), human immunoglobulin G (IgG), BSA and glucose in the absence of CEA. The good stability and repeatability of this immunosensor were also proven. Importantly, the results of the detection of clinical whole blood specimens with the proposed immunosensor showed good consistency with the data determined by enzyme-linked immunosorbent assay (ELISA) in serum samples. Furthermore, the developed immunosensor could provide a promising immunoassay strategy for clinical applications, since the values we measured in whole blood directly are likely closer to the real values. PMID:24957417

  14. The 400W at 1.8K Test Facility at CEA-Grenoble

    NASA Astrophysics Data System (ADS)

    Roussel, P.; Girard, A.; Jager, B.; Rousset, B.; Bonnay, P.; Millet, F.; Gully, P.

    2006-04-01

    A new test facility with a cooling capacity respectively of 400W at 1.8K or 800W at 4.5K, is now under nominal operation in SBT (Low Temperature Department) at CEA Grenoble. It has been recently used for thermohydraulic studies of two phase superfluid helium in autumn 2004. In the near future, this test bench will allow: - to test industrial components at 1.8K (magnets, cavities of accelerators) - to continue the present studies on thermohydraulics of two phase superfluid helium - to develop and simulate new cooling loops for ITER Cryogenics, and other applications such as high Reynolds number flows This new facility consists of a cold box connected to a warm compressor station (one subatmospheric oil ring pump in series with two screw compressors). The cold box, designed by AIR LIQUIDE, comprises two centrifugal cold compressors, a cold turbine, a wet piston expander, counter flow heat exchangers and two phase separators at 4.5K and 1.8K. The new facility uses a Programmable Logic Controller (PLC) connected to a bus for the measurements. The design is modular and will allow the use of saturated fluid flow (two phase flow at 1.8K or 4.5K) or single phase fluid forced flow. Experimental results and cooling capacity in different operation modes are detailed.

  15. A Phase I Study of a Combination of Yttrium-90 labeled Anti-CEA Antibody and Gemcitabine in Patients with CEA Producing Advanced Malignancies

    PubMed Central

    Shibata, Stephen; Raubitschek, Andrew; Leong, Lucille; Koczywas, Marianna; Williams, Lawrence; Zhan, Jiping; Wong, Jeffrey Y.C.

    2011-01-01

    Purpose To determine the maximum tolerated dose of combined therapy using an yttrium-90 labeled anti-CEA antibody with gemcitabine in patients with advanced CEA producing solid tumors. Experimental Design The chimeric human/murine cT84.66 is an anti-CEA intact IgG1, with high affinity and specificity to CEA. This was given at a fixed yttrium-90 labeled dose of 16.6 mCi/m2 to subjects who had and an elevated CEA in serum or in tumor by immunohistochemistry. Also required was a tumor that imaged with an 111In labeled cT84.66 antibody. Patients were treated with escalating doses of gemcitabine given intravenously over 30 minutes on day 1 and 3 after the infusion of the yttrium-90 labeled antibody. Patients were treated in cohorts of 3. The maximum tolerated dose was determined as the highest level at which no more than 1 of 6 patients experienced a dose limiting toxicity. Results A total of 36 patients were enrolled, and all but one had prior systemic therapy. The maximum tolerated dose of gemcitabine in this combination was 150mg/m2. Dose limiting toxicities at a gemcitabine dose of 165mg/m2 included a grade 3 rash and grade 4 neutropenia. One partial response was seen in a patient with colorectal cancer, and 4 patients had a > 50% decrease in baseline CEA levels associated with stable disease. Human antichimeric antibody responses were the primary reason for stopping treatment in 12 patients. Conclusions feasibility of combining gemcitabine with an yttrium-90 labeled anti-CEA antibody is demonstrated with preliminary evidence of clinical response. PMID:19351765

  16. Electrochromic sensing platform based on steric hindrance effects for CEA detection.

    PubMed

    Zhai, Qingfeng; Zhang, Xiaowei; Xia, Yong; Li, Jing; Wang, Erkang

    2016-06-20

    In this work, an electrochromic sensing platform with prussian blue (PB) as the indicator was proposed for signaling carcinoembryonic antigen (CEA) using the bipolar electrode (BPE) system. The CEA aptamer was pre-anchored on the anode pole of the BPE for capturing CEA through strong binding affinity. The presence of CEA induced the increase of steric hindrance and led to lower electrochemical currents. Due to the quantitative relationship between the two reactions occurring at both ends of the BPE, the amount of deposited PB in situ can be used as an indicator for reporting target protein concentration. Using CEA concentration in normal human serum as a reference (5 ng mL(-1)), this electrochromic sensing platform can be used for distinguishing persons with cancer from normal humans easily and quickly, which is very important for subsequent treatment of patients. This novel electrochromic platform has great selectivity for target tumor proteins and provides a fast, visual method for CEA detection. Finally, the proposed biosensor can be applied to detect CEA in human serum, which holds great potential for point-of-care diagnostics combined with the advantage of the closed BPE system. PMID:27160521

  17. Selectively assaying CEA based on a creative strategy of gold nanoparticles enhancing silver nanoclusters' fluorescence.

    PubMed

    Yang, Xiaoming; Zhuo, Yan; Zhu, Shanshan; Luo, Yawen; Feng, Yuanjiao; Xu, Yan

    2015-02-15

    Herein, we have successfully built up connections between nanoparticles and nanoclusters, and further constructed a surface-enhanced fluorescence (SEF) strategy based on the two types of nanomaterials for selectively assaying carcinoembryonic antigen (CEA). Specifically, silver nanoclusters provided the original fluorescence signal, while gold nanoparticles modified with DNA served as the fluorescence enhancer simultaneously. On the basis of this proposed nano-system, the two nanomaterials were linked by CEA-aptamer, thus facilitating SEF occurring. Nevertheless, more competitive interactions between CEA and CEA-aptamer emerged once CEA added, leading to SEF failed and their fluorescence decreased. Significantly, this creative method was further applied to detect CEA, and showed the linear relationship between the fluorescence intensity and CEA concentrations in the range of 0.01-1 ng mL(-1) with a detection limit of 3 pg mL(-1) at a signal-to-noise ratio of 3, demonstrating its sensitivity and promising towards multiple applications. On the whole, this approach we established may broaden potential ways of combining nanoparticles and nanoclusters for detecting trace targets in bioanalytical fields. PMID:25259877

  18. Correlation between serum CEA levels and EGFR mutations in Chinese nonsmokers with lung adenocarcinoma

    PubMed Central

    Jin, Bo; Dong, Yu; Wang, Hui-min; Huang, Jin-su; Han, Bao-hui

    2014-01-01

    Aim: To evaluate the relationship between epidermal growth factor receptor (EGFR) mutations and serum carcinoembryonic antigen (CEA) levels in Chinese nonsmokers with pulmonary adenocarcinoma. Methods: We sequenced exons 18–21 of the EGFR gene in 98 cases. The patients were divided into two groups based on their pre-treatment serum CEA levels (below or above 5 ng/mL) for analyzing the correlations with EGFR mutations. Results: Sixty-seven cases harbored EGFR mutations. The rates of EGFR mutations and exon 19 mutations in the high-CEA group (78.2% and 49.1%, respectively) were significantly higher those in the low-CEA group (55.8% and 20.9%, respectively). Serum CEA levels were found to be the only independent predictor of EGFR mutation (OR 2.837; 95% CI: 1.178–6.829) and exon 19 mutation (OR 3.618; 95% CI: 1.319–9.918). Furthermore, a higher serum CEA level was associated with a higher EGFR mutation rate and a higher exon 19 mutation rate: patients with serum CEA levels <5 ng/mL, ≥5 and <20 ng/mL, ≥20 ng/mL showed the EGFR mutation rate of 55.8%, 74.1%, 82.1%, respectively, and the exon 19 mutation rate of 20.9%, 40.7%, 57.1%, respectively. Patients with EGFR mutations displayed a significantly higher incidence of abnormal serum CEA levels (>5 ng/mL) than patients without EGFR mutations (64.2% vs 38.7%). Conclusion: Elevated serum CEA levels predict the presence of EGFR gene mutations in Chinese nonsmokers with pulmonary adenocarcinoma. PMID:24487967

  19. Imaging of pharyngeal and laryngeal carcinomas with indium-111-labeled monoclonal anti-CEA antibodies

    SciTech Connect

    Kairemo, K.J.; Hopsu, E.V. )

    1990-10-01

    Localization of primary tumors, metastases, or recurrences in 13 consecutive patients with histological verification of squamous cell or adenocarcinoma was made with radioimmunodetection using monoclonal radiolabeled anti-CEA antibody. All surgical specimens stained immunohistochemically, except one, were positive for CEA. Of the known 19 tumor sites 17 were visualized in antibody scans. There were two positive findings that did not prove to be positive during 12 month follow-up. The scintigram findings did not correlate with CEA serum concentrations that, with one exception, were normal in all patients.

  20. Novel electrochemical redox-active species: one-step synthesis of polyaniline derivative-Au/Pd and its application for multiplexed immunoassay

    NASA Astrophysics Data System (ADS)

    Wang, Liyuan; Feng, Feng; Ma, Zhanfang

    2015-11-01

    Electrochemical redox-active species play crucial role in electrochemically multiplexed immunoassays. A one-pot method for synthesizing four kinds of new electrochemical redox-active species was reported using HAuCl4 and Na2PdCl4 as dual oxidating agents and aniline derivatives as monomers. The synthesized polyaniline derivative-Au/Pd composites, namely poly(N-methyl-o-benzenediamine)-Au/Pd, poly(N-phenyl-o-phenylenediamine)-Au/Pd, poly(N-phenyl-p-phenylenediamine)-Au/Pd and poly(3,3’,5,5’-tetramethylbenzidine)-Au/Pd, exhibited electrochemical redox activity at -0.65 V, -0.3 V, 0.12 V, and 0.5 V, respectively. Meanwhile, these composites showed high H2O2 electrocatalytic activity because of the presence of Au/Pd. The as-prepared composites were used as electrochemical immunoprobes in simultaneous detection of four tumor biomarkers (carcinoembryonic antigen (CEA), carbohydrate antigen 19-9 (CA199), carbohydrate antigen 72-4 (CA724), and alpha fetoprotein (AFP)). This immunoassay shed light on potential applications in simultaneous gastric cancer (related biomarkers: CEA, CA199, CA724) and liver cancer diagnosis (related biomarkers: CEA, CA199, AFP). The present strategy to the synthesize redox species could be easily extended to other polymers such as polypyrrole derivatives and polythiophene derivatives. This would be of great significance in the electrochemical detection of more analytes.

  1. Novel electrochemical redox-active species: one-step synthesis of polyaniline derivative-Au/Pd and its application for multiplexed immunoassay

    PubMed Central

    Wang, Liyuan; Feng, Feng; Ma, Zhanfang

    2015-01-01

    Electrochemical redox-active species play crucial role in electrochemically multiplexed immunoassays. A one-pot method for synthesizing four kinds of new electrochemical redox-active species was reported using HAuCl4 and Na2PdCl4 as dual oxidating agents and aniline derivatives as monomers. The synthesized polyaniline derivative-Au/Pd composites, namely poly(N-methyl-o-benzenediamine)-Au/Pd, poly(N-phenyl-o-phenylenediamine)-Au/Pd, poly(N-phenyl-p-phenylenediamine)-Au/Pd and poly(3,3’,5,5’-tetramethylbenzidine)-Au/Pd, exhibited electrochemical redox activity at −0.65 V, −0.3 V, 0.12 V, and 0.5 V, respectively. Meanwhile, these composites showed high H2O2 electrocatalytic activity because of the presence of Au/Pd. The as-prepared composites were used as electrochemical immunoprobes in simultaneous detection of four tumor biomarkers (carcinoembryonic antigen (CEA), carbohydrate antigen 19-9 (CA199), carbohydrate antigen 72-4 (CA724), and alpha fetoprotein (AFP)). This immunoassay shed light on potential applications in simultaneous gastric cancer (related biomarkers: CEA, CA199, CA724) and liver cancer diagnosis (related biomarkers: CEA, CA199, AFP). The present strategy to the synthesize redox species could be easily extended to other polymers such as polypyrrole derivatives and polythiophene derivatives. This would be of great significance in the electrochemical detection of more analytes. PMID:26577799

  2. Au-Sn SLID Bonding: A Reliable HT Interconnect and Die Attach Technology

    NASA Astrophysics Data System (ADS)

    Tollefsen, Torleif André; Larsson, Andreas; Taklo, Maaike Margrete Visser; Neels, Antonia; Maeder, Xavier; Høydalsvik, Kristin; Breiby, Dag W.; Aasmundtveit, Knut

    2013-04-01

    Au-Sn solid-liquid interdiffusion (SLID) bonding is an established reliable high temperature (HT) die attach and interconnect technology. This article presents the life cycle of an optimized HT Au-Sn SLID bond, from fabrication, via thermal treatment, to mechanical rupture. The layered structure of a strong and uniform virgin bond was identified by X-ray diffraction to be Au/ζ (Au0.85Sn0.15)/Au. During HT exposure, it was transformed to Au/β (Au1.8Sn0.2)/Au. After HT exposure, the die shear strength was reduced by 50 pct, from 14 Pa to 70 MPa, which is still remarkably high. Fractographic studies revealed a change in fracture mode; it was changed from a combination of adhesive Au/Ni and cohesive SiC fracture to a cohesive β-phase fracture. Design rules for high quality Au-Sn SLID bonds are given.

  3. Amorphous silicon technology improvement at CEA-LETI

    NASA Astrophysics Data System (ADS)

    Mottin, Eric; Bain, Astrid; Castelein, Pierre; Ouvrier-Buffet, Jean-Louis; Tissot, Jean-Luc; Yon, Jean-Jacques; Chatard, Jean-Pierre

    2002-05-01

    The emergence of uncooled infrared detectors has opened new opportunities for IR imaging both for military and civil applications. Infrared imaging sensors that operate without cryogenic cooling have the potential to provide the military or civilian users with infrared vision capabilities packaged in a camera of extremely small size, weight and power. Uncooled infrared sensor technology has advanced rapidly in the past few years. Higher performance sensors, electronics integration at the sensor, and new concepts for signal processing are generating advanced infrared focal plane arrays. This would significantly reduce the cost and accelerate the implementation of sensors for applications such as surveillance or predictive maintenance. We present the uncooled infrared detector operation principle and the development at CEA/LETI from the 256 x 64 with a pitch of 50 micrometers to the 320 x 240 with a pitch of 35 micrometers . LETI has been involved in Amorphous Silicon uncooled microbolometer development since 1992. This silicon IR detection is now well mastered and matured so that industrial transfer of LETI technology was performed in 2000 towards Sofradir. Industrial production of 320 x 240 microbolometer array with 45micrometers pitch is then started. After a description of the technology and the methodology for reliability enhancement, we present the readout circuit architectures designs and its evolution from the 256 x 64 array to the different version of 320 x 240 arrays. Electro-optical results obtained from these IRCMOS are presented. NEDT close to 30 mK is now obtained with our standard microbolometer amorphous silicon technology.

  4. BDDR, a new CEA technological and operating reactor database

    SciTech Connect

    Soldevilla, M.; Salmons, S.; Espinosa, B.

    2013-07-01

    The new application BDDR (Reactor database) has been developed at CEA in order to manage nuclear reactors technological and operating data. This application is a knowledge management tool which meets several internal needs: -) to facilitate scenario studies for any set of reactors, e.g. non-proliferation assessments; -) to make core physics studies easier, whatever the reactor design (PWR-Pressurized Water Reactor-, BWR-Boiling Water Reactor-, MAGNOX- Magnesium Oxide reactor-, CANDU - CANada Deuterium Uranium-, FBR - Fast Breeder Reactor -, etc.); -) to preserve the technological data of all reactors (past and present, power generating or experimental, naval propulsion,...) in a unique repository. Within the application database are enclosed location data and operating history data as well as a tree-like structure containing numerous technological data. These data address all kinds of reactors features and components. A few neutronics data are also included (neutrons fluxes). The BDDR application is based on open-source technologies and thin client/server architecture. The software architecture has been made flexible enough to allow for any change. (authors)

  5. Comparison of Ablation Predictions for Carbonaceous Materials Using CEA and JANAF-Based Species Thermodynamics

    NASA Technical Reports Server (NTRS)

    Milos, Frank S.

    2011-01-01

    In most previous work at NASA Ames Research Center, ablation predictions for carbonaceous materials were obtained using a species thermodynamics database developed by Aerotherm Corporation. This database is derived mostly from the JANAF thermochemical tables. However, the CEA thermodynamics database, also used by NASA, is considered more up to date. In this work, the FIAT code was modified to use CEA-based curve fits for species thermodynamics, then analyses using both the JANAF and CEA thermodynamics were performed for carbon and carbon phenolic materials over a range of test conditions. The ablation predictions are comparable at lower heat fluxes where the dominant mechanism is carbon oxidation. However, the predictions begin to diverge in the sublimation regime, with the CEA model predicting lower recession. The disagreement is more significant for carbon phenolic than for carbon, and this difference is attributed to hydrocarbon species that may contribute to the ablation rate.

  6. Iodine-131 labeled anti-CEA antibodies uptake by Huerthle cell carcinoma

    SciTech Connect

    Abdel-Nabi, H.; Hinkle, G.H.; Falko, J.M.; Kelly, D.; Olsen, J.O.; Martin, E.W. Jr.

    1985-10-01

    Localization of Huerthle cell cancer deposits in the lung with I-131 labeled anti-carcinoembryonic antigen (CEA) monoclonal antibody is described. This technique may prove useful if conventional scanning with I-131 sodium iodide for distant metastases is negative.

  7. Diagnostic value of mesothelin in pleural fluids: comparison with CYFRA 21-1 and CEA.

    PubMed

    Filiberti, Rosa; Parodi, Stefano; Libener, Roberta; Ivaldi, Giovanni Paolo; Canessa, Pier Aldo; Ugolini, Donatella; Bobbio, Barbara; Marroni, Paola

    2013-06-01

    CYFRA 21-1 and CEA have been applied for the differential diagnosis of malignant pleural mesothelioma (MPM). The soluble mesothelin-related peptide (SMRP) has been proposed as a specific marker for distinguishing MPM from benign diseases and other malignancies in pleural effusions (PEs). In this study, we evaluated the usefulness of SMRP in PEs in the detection of mesotheliomas by comparing it with that of CYFRA 21-1, CEA, and with cytological examination. One hundred and seventy-seven consecutive patients (57 MPM, 64 metastatic tumors, and 56 benign diseases) were evaluated using commercial tests. The performance of the markers was analyzed by standard ROC analysis methods, using the area under a ROC curve (AUC) as a measure of accuracy. CYFRA 21-1 better differentiated malignant from benign effusions. The corresponding area under the receiver operating characteristic curve was 0.87, while it was 0.74 for SMRP and 0.64 for CEA (p < 0.001). Conversely, SMRP differentiated MPM from all other PEs better than both CYFRA 21-1 and CEA (AUC = 0.84, 0.76, and 0.32, respectively, p = 0.003). Low levels of CEA were associated with a MPM diagnosis. The AUC for differentiating MPM from metastases was 0.81 for SMRP, 0.61 for CYFRA 21-1, and 0.20 for CEA (p < 0.001). In cases with negative or suspicious cytology, SMRP and CYFRA 21-1 identified 36/71 and 46/66 malignant PEs (29 and 31 MPM, respectively). Only 1 MPM showed a high CEA concentration. No single marker showed the best performance in any comparison. Results suggest that SMRP could improve CYFRA 21-1 and CEA accuracy in the differential diagnosis of MPM. PMID:23532816

  8. Comparison of the CEAS and Williams-type barley yield models for North Dakota and Minnesota

    NASA Technical Reports Server (NTRS)

    Leduc, S. (Principal Investigator)

    1982-01-01

    The CEAS and Williams type models were compared based on specified selection criteria which includes a ten year bootstrap test (1970-1979). Based on this, the models were quite comparable; however, the CEAS model was slightly better overall. The Williams type model seemed better for the 1974 estimates. Because that year spring wheat yield was particularly low, the Williams type model should not be excluded from further consideration.

  9. Unusual elevation of CEA in a patient with history of colon cancer.

    PubMed

    Hsu, Tzu-Chi

    2006-12-01

    A 35-year-old female received right hemicolectomy for a poorly differentiated adenocarcinoma of the ascending colon with lymph node metastasis (1/28) in February 1997. CEA was 1.68 ng/microl prior to colectomy. Adjuvant chemotherapy with weekly 5-FU and leucovorin intravenously was started following surgery and discontinued after 17 doses in May 1997. She received bilateral salpingo-ophorecctomy for metastatic cancer in August 1999. Intravenous chemotherapy was resumed with weekly 5-FU and leucovorin intravenously in August 1999. CEA was 93.8 ng/microl in November 1999. Intravenous chemotherapy was discontinued after 20 doses and oral chemotherapy with futraful and leucovorin was started in January 2000. CEA was found to be 240.3 ng/microl in December 1999 and then elevated to 1521.3 ng/microl in June 2001, which was 10 months after resection of metastatic ovarian cancer. No metastatic lesions could be detected, however, with image studies. The CEA decreased to 396.6 ng/microl three months later. Futraful was switched to uracil-tegafur (UFUR) in September 2001. The CEA for the patient ranged from 68.5 to 298.9 ng/microl for the following 5 years without aggressive chemotherapy. No evidence of recurrence could be demonstrated by imaging studies. The patient is not a smoker and denied exposure to a smoking environment. She was also not known to have persistent infections, inflammatory bowel disease, pancreatitis, cirrhosis of the liver, or any benign tumors. The current case suggested that: (i) elevation of CEA is not necessarily well correlated with presence of metastatic colon cancer; (ii) some patients may live with elevated CEA for years without evidence of recurrence or metastasis; (iii) aggressive chemotherapy may not be necessary in patients with only elevated CEA. PMID:17060406

  10. Ultra-relativistic Au+Au and d+Au collisions:

    NASA Astrophysics Data System (ADS)

    Back, B. B.; Baker, M. D.; Ballintijn, M.; Barton, D. S.; Betts, R. R.; Bickley, A. A.; Bindel, R.; Budzanowski, A.; Busza, W.; Carroll, A.; Chai, Z.; Decowski, M. P.; García, E.; Gburek, T.; George, N.; Gulbrandsen, K.; Gushue, S.; Halliwell, C.; Hamblen, J.; Hauer, M.; Heintzelman, G. A.; Henderson, C.; Hofman, D. J.; Hollis, R. S.; Hołyński, R.; Holzman, B.; Iordanova, A.; Johnson, E.; Kane, J. L.; Katzy, J.; Khan, N.; Kucewicz, W.; Kulinich, P.; Kuo, C. M.; Lin, W. T.; Manly, S.; McLeod, D.; Mignerey, A. C.; Nouicer, R.; Olszewski, A.; Pak, R.; Park, I. C.; Pernegger, H.; Reed, C.; Remsberg, L. P.; Reuter, M.; Roland, C.; Roland, G.; Rosenberg, L.; Sagerer, J.; Sarin, P.; Sawicki, P.; Seals, H.; Sedykh, I.; Skulski, W.; Smith, C. E.; Stankiewicz, M. A.; Steinberg, P.; Stephans, G. S. F.; Sukhanov, A.; Tang, J.-L.; Tonjes, M. B.; Trzupek, A.; Vale, C.; van Nieuwenhuizen, G. J.; Vaurynovich, S. S.; Verdier, R.; Veres, G. I.; Wenger, E.; Wolfs, F. L. H.; Wosiek, B.; Woźniak, K.; Wuosmaa, A. H.; Wysłouch, B.

    In this talk I will review PHOBOS data on charged particle multiplicities, obtained in Au+Au and d+Au collisions at RHIC. The general features of the Au+Au pseudorapidity distributions results will be discussed and compared to those of /line{p}p collisions. The total charged particle multiplicity, scaled by the number of participant pairs, is observed to be about 40% higher in Au+Au collisions than in /line{p}p and d+Au systems, but, surprisingly at the same level of e+e- collisions. Limiting fragmentation scaling is seen to be obeyed in Au+Au collisions.

  11. Expression of CEA, CA19-9, CA125, and EpCAM in pseudomyxoma peritonei.

    PubMed

    Nummela, Pirjo; Leinonen, Hannele; Järvinen, Petrus; Thiel, Alexandra; Järvinen, Heikki; Lepistö, Anna; Ristimäki, Ari

    2016-08-01

    Pseudomyxoma peritonei is a fatal clinical syndrome with mucinous tumor cells disseminated into peritoneal cavity and secreting abundant mucinous ascites. The serum tumor markers CEA, CA19-9, and CA125 are used to monitor pseudomyxoma peritonei remission, but their expression at tissue level has not been well characterized. Herein, we analyzed expression of these proteins and the adenocarcinoma marker EpCAM in 92 appendix-derived pseudomyxoma peritonei tumors by immunohistochemistry. All tumors were found to ubiquitously express CEA and EpCAM. In the majority of the tumors (94.6%), CEA showed polarized immunostaining, but in 5 aggressive high-grade tumors containing numerous signet ring cells, a nonpolarized staining was detected. We found preoperative CEA serum values to correlate with peritoneal cancer index. However, the serum values of the advanced cases with nonpolarized staining pattern were normal, and the patients died within 5 years after diagnosis. Thus, serum CEA measurements did not reflect aggressiveness of these tumors. CA19-9 showed strong immunopositivity in most of the tumors (91.3%), and mutated enzyme FUT3 was demonstrated from the cases showing negative or weak staining. CA125 was infrequently expressed by tumor cells (focal staining in 6.5% of the cases), but in most of the cases (79.3%), adjacent nonneoplastic mesothelial cells showed immunopositivity. As a conclusion, CEA and EpCAM are invariably expressed by pseudomyxoma peritonei tumor cells and could be exploited to targeted therapies against this malignancy. PMID:27038681

  12. Reduced graphene oxide supported Au nanoparticles as an efficient catalyst for aerobic oxidation of benzyl alcohol

    NASA Astrophysics Data System (ADS)

    Yu, Xianqin; Huo, Yujia; Yang, Jing; Chang, Sujie; Ma, Yunsheng; Huang, Weixin

    2013-09-01

    Various Au/C catalysts were prepared by Au nanoparticels supported on different carbonaceous supports including reduced graphene oxide (RGO), activated carbon (AC) and graphite (GC) using sol-immobilization method. Au/RGO shows a much higher activity than Au/AC and Au/GC in the liquid phase aerobic oxidation of benzyl alcohol. The superior catalytic performance of Au/RGO may be related to the presence of surface O-containing functional groups and moderate graphite character of RGO supports.

  13. Relativity, gold, closed-shell interactions, and CsAu.NH3.

    PubMed

    Pyykkö, Pekka

    2002-10-01

    The chemical properties of gold are strongly influenced by relativistic effects. One example is the large electronegativity of Au, which qualitatively explains the stability of (solid or liquid) cesium auride, Cs(+)Au(-), and other systems with Au(-) ions. An especially impressive compound is CsAu.NH(3), the structure and bonding of which are discussed. Future possibilities for finding further aurides are outlined. PMID:12370896

  14. Melanoma cell surface-expressed phosphatidylserine as a therapeutic target for cationic anticancer peptide, temporin-1CEa.

    PubMed

    Wang, Che; Chen, Yin-Wang; Zhang, Liang; Gong, Xian-Ge; Zhou, Yang; Shang, De-Jing

    2016-07-01

    We have previously reported that temporin-1CEa, a cationic antimicrobial peptide, exerts preferential cytotoxicity toward cancer cells. However, the exact molecular mechanism for this cancer-selectivity is still largely unknown. Here, we found that the negatively charged phosphatidylserine (PS) expressed on cancer cell surface serves as a target for temporin-1CEa. Our results indicate that human A375 melanoma cells express 50-fold more PS than non-cancerous HaCaT cells. The expression of cell surface PS in various cancer cell lines closely correlated with their ability to be recognized, bound and killed by temporin-1CEa. Additionally, the cytotoxicity of temporin-1CEa against A375 cells can be ameliorated by annexin V, which binds to cell surface PS with high affinity. Moreover, the data of isothermal titration calorimetry assay further confirmed a direct binding of temporin-1CEa to PS, at a ratio of 1:5 (temporin-1CEa:PS). Interestingly, the circular dichroism spectra analysis using artificial biomembrane revealed that PS not only provides electrostatic attractive sites for temporin-1CEa but also confers the membrane-bound temporin-1CEa to form α-helical structure, therefore, enhances the affinity and membrane disrupting ability of temporin-1CEa. In summary, these findings suggested that the melanoma cells expressed PS may serve as a promising target for temporin-1CEa or other cationic anticancer peptides. PMID:26596643

  15. Collective flow in Au + Au collisions

    SciTech Connect

    Ritter, H.G.; EOS Collaboration

    1994-05-01

    Based on a preliminary sample of Au + Au collisions in the EOS time projection chamber at the Bevalac, we study sideward flow as a function of bombarding energy between 0.25A GeV and 1.2A GeV. We focus on the increase in in-plane transverse momentum per nucleon with fragment mass. We also find event shapes to be close to spherical in the most central collisions, independent of bombarding energy and fragment mass up to {sup 4}He.

  16. The value of KRAS mutation testing with CEA for the diagnosis of pancreatic mucinous cysts

    PubMed Central

    Kadayifci, Abdurrahman; Al-Haddad, Mohammad; Atar, Mustafa; Dewitt, John M.; Forcione, David G.; Sherman, Stuart; Casey, Brenna W.; Fernandez-del Castillo, Carlos; Schmidt, C. Max; Pitman, Martha B.; Brugge, William R.

    2016-01-01

    Background and aims: Pancreatic cyst fluid (PCF) CEA has been shown to be the most accurate preoperative test for detection of cystic mucinous neoplasms (CMNs). This study aimed to assess the added value of PCF KRAS mutational analysis to CEA for diagnosis of CMNs. Patients and methods: This is a retrospective study of prospectively collected endoscopic ultrasonography (EUS) fine-needle aspiration (FNA) data. KRAS mutation was determined by direct sequencing or equivalent methods. Cysts were classified histologically (surgical cohort) or by clinical (EUS or FNA) findings (clinical cohort). Performance characteristics of KRAS, CEA and their combination for detection of a cystic mucinous neoplasm (CMN) and malignancy were calculated. Results: The study cohort consisted of 943 patients: 147 in the surgical cohort and 796 in the clinical cohort. Overall, KRAS and CEA each had high specificity (100 % and 93.2 %), but low sensitivity (48.3 % and 56.3 %) for the diagnosis of a CMN. The positivity of KRAS or CEA increased the diagnostic accuracy (80.8 %) and AUC (0.84) significantly compared to KRAS (65.3 % and 0.74) or CEA (65.8 % and 0.74) alone, but only in the clinical cohort (P < 0.0001 for both). KRAS mutation was significantly more frequent in malignant CMNs compared to histologically confirmed non-malignant CMNs (73 % vs. 37 %, P = 0.001). The negative predictive value of KRAS mutation was 77.6 % in differentiating non-malignant cysts. Conclusions: The detection of a KRAS mutation in PCF is a highly specific test for mucinous cysts. It outperforms CEA for sensitivity in mucinous cyst diagnosis, but the data does not support its routine use. PMID:27092317

  17. Casimir force between liquid metals

    NASA Astrophysics Data System (ADS)

    Esquivel-Sirvent, R.; Escobar, J. V.

    2014-08-01

    We present a theoretical calculation of the Casimir force between liquid metals at room temperature using as case studies mercury (Hg) and eutectic indium gallium (EInGa). The surface tension of the liquids creates surfaces of zero roughness that are truly equipotential, an ideal characteristic for Casimir force experiments. As we show the dielectric properties of Au, EInGa and Hg are very similar and the difference on the Casimir force between Au and EInGa and Au and Hg is less than 4%. Based on these results, a modification of the IUPUI experiment for detecting deviations of Newtonian gravity is proposed.

  18. Au transport in catalyst coarsening and Si nanowire formation.

    PubMed

    Kim, B J; Tersoff, J; Kodambaka, S; Jang, Ja-Soon; Stach, E A; Ross, F M

    2014-08-13

    The motion of Au between AuSi liquid eutectic droplets, both before and during vapor-liquid-solid growth, is important in controlling tapering and diameter uniformity in Si nanowires. We measure the kinetics of coarsening of AuSi droplets on Si(001) and Si(111), quantifying the size evolution of droplets during annealing in ultrahigh vacuum using in situ transmission electron microscopy. For individual droplets, we show that coarsening kinetics are modified when disilane or oxygen is added: coarsening rates increase in the presence of disilane but decrease in oxygen. Matching droplet size measurements on Si(001) with coarsening models confirms that Au transport is driven by capillary forces and that the kinetic coefficients depend on the gas environment present. We suggest that the gas effects are qualitatively similar whether transport is attachment limited or diffusion limited. These results provide insight into manipulating nanowire morphologies for advanced device fabrication. PMID:25040757

  19. Structure of SiAu16: can a silicon atom be stabilized in a gold cage?

    PubMed

    Sun, Qiang; Wang, Qian; Chen, Gang; Jena, Puru

    2007-12-01

    Nanostructures of Au and Si as well as Au-Si hybrid structures are topics of great current interest from both scientific and technological points of view. Recent discovery of Au clusters having fullerene-like geometries and the possibility of endohedral complexes with Si atoms inside the Au cage opens new possibilities for designing Au-Si nanostructures. Using ab initio simulated annealing method we have examined the stability of Si-Au16 endohedral complex. Contrary to what we believed, we find that the endohedral configuration is metastable and the structure where Si atom binds to the exterior surface of the Au16 cage is the lowest energy structure. The bonding of Si to Au cluster mimics its behavior of that in bulk and liquid phase of Au. In addition, doping of Si in high concentration would cause fracture and embrittlement in gold nanostructures just as it does in the bulk phase. Covalent bonding between Au-Au and Au-Si is found to be a dominant feature in the stability of the Au-Si nanostructures. Our study provides insight that may be useful in fabricating hybrid Au-Si nanostructures for applications microelectronics, catalysis, biomedicine, and jewelry industry. PMID:18067374

  20. Uropathogenic E. coli Exploit CEA to Promote Colonization of the Urogenital Tract Mucosa.

    PubMed

    Muenzner, Petra; Kengmo Tchoupa, Arnaud; Klauser, Benedikt; Brunner, Thomas; Putze, Johannes; Dobrindt, Ulrich; Hauck, Christof R

    2016-05-01

    Attachment to the host mucosa is a key step in bacterial pathogenesis. On the apical surface of epithelial cells, members of the human carcinoembryonic antigen (CEA) family are abundant glycoproteins involved in cell-cell adhesion and modulation of cell signaling. Interestingly, several gram-negative bacterial pathogens target these receptors by specialized adhesins. The prototype of a CEACAM-binding pathogen, Neisseria gonorrhoeae, utilizes colony opacity associated (Opa) proteins to engage CEA, as well as the CEA-related cell adhesion molecules CEACAM1 and CEACAM6 on human epithelial cells. By heterologous expression of neisserial Opa proteins in non-pathogenic E. coli we find that the Opa protein-CEA interaction is sufficient to alter gene expression, to increase integrin activity and to promote matrix adhesion of infected cervical carcinoma cells and immortalized vaginal epithelial cells in vitro. These CEA-triggered events translate in suppression of exfoliation and improved colonization of the urogenital tract by Opa protein-expressing E. coli in CEA-transgenic compared to wildtype mice. Interestingly, uropathogenic E. coli expressing an unrelated CEACAM-binding protein of the Afa/Dr adhesin family recapitulate the in vitro and in vivo phenotype. In contrast, an isogenic strain lacking the CEACAM-binding adhesin shows reduced colonization and does not suppress epithelial exfoliation. These results demonstrate that engagement of human CEACAMs by distinct bacterial adhesins is sufficient to blunt exfoliation and to promote host infection. Our findings provide novel insight into mucosal colonization by a common UPEC pathotype and help to explain why human CEACAMs are a preferred epithelial target structure for diverse gram-negative bacteria to establish a foothold on the human mucosa. PMID:27171273

  1. Uropathogenic E. coli Exploit CEA to Promote Colonization of the Urogenital Tract Mucosa

    PubMed Central

    Muenzner, Petra; Kengmo Tchoupa, Arnaud; Klauser, Benedikt; Brunner, Thomas; Putze, Johannes; Dobrindt, Ulrich; Hauck, Christof R.

    2016-01-01

    Attachment to the host mucosa is a key step in bacterial pathogenesis. On the apical surface of epithelial cells, members of the human carcinoembryonic antigen (CEA) family are abundant glycoproteins involved in cell-cell adhesion and modulation of cell signaling. Interestingly, several gram-negative bacterial pathogens target these receptors by specialized adhesins. The prototype of a CEACAM-binding pathogen, Neisseria gonorrhoeae, utilizes colony opacity associated (Opa) proteins to engage CEA, as well as the CEA-related cell adhesion molecules CEACAM1 and CEACAM6 on human epithelial cells. By heterologous expression of neisserial Opa proteins in non-pathogenic E. coli we find that the Opa protein-CEA interaction is sufficient to alter gene expression, to increase integrin activity and to promote matrix adhesion of infected cervical carcinoma cells and immortalized vaginal epithelial cells in vitro. These CEA-triggered events translate in suppression of exfoliation and improved colonization of the urogenital tract by Opa protein-expressing E. coli in CEA-transgenic compared to wildtype mice. Interestingly, uropathogenic E. coli expressing an unrelated CEACAM-binding protein of the Afa/Dr adhesin family recapitulate the in vitro and in vivo phenotype. In contrast, an isogenic strain lacking the CEACAM-binding adhesin shows reduced colonization and does not suppress epithelial exfoliation. These results demonstrate that engagement of human CEACAMs by distinct bacterial adhesins is sufficient to blunt exfoliation and to promote host infection. Our findings provide novel insight into mucosal colonization by a common UPEC pathotype and help to explain why human CEACAMs are a preferred epithelial target structure for diverse gram-negative bacteria to establish a foothold on the human mucosa. PMID:27171273

  2. Elevated Level of Serum Carcinoembryonic Antigen (CEA) and Search for a Malignancy: A Case Report

    PubMed Central

    Saif, Muhammad W

    2016-01-01

    Carcinoembryonic antigen (CEA) has been shown to be associated with tumor burden in patients with colorectal cancer. However, it is also elevated to a significant degree in a number of other malignant and non-malignant conditions. We report a case of reversible CEA elevation in a patient using lithium for bipolar disorder. A 58-year-old female with a longstanding smoking history and a past medical history of chronic obstructive pulmonary disease (COPD), bipolar illness, hypothyroidism, and obesity was found to have an elevated CEA level of 11.2 ng/ml (normal level <5 ng/ml) in the workup for postmenopausal bleeding. Her history was not positive for malignancy of colorectum, ovaries, thyroid, or breast.  She underwent a large number of imaging and endoscopic studies to evaluate for colorectal, breast, ovarian, and lung cancer; however, it did not reveal any evidence of malignancy. Upon review of her medications, she reported that she had recently started lithium for her bipolar illness. We followed up her CEA level while her dose of lithium was reduced from 450 to 300 mg per day. Her CEA level decreased from 25 mg/dl to 6.1 mg/dl and remained stable over the course of the next eight months. Our case is the first case report that identifies lithium as a potential cause of reversible CEA elevation. The underlying mechanism is yet to be elucidated, but it underscores the importance of investigating the medications as part of the workup. PMID:27446768

  3. An Information Building on Radioactivity and Nuclear Energy for the French CEA Cadarache Research Center - 13492

    SciTech Connect

    Brunel, Guy; Denis, Dominique; Boulet, Alain

    2013-07-01

    The CEA Cadarache research center is one of the 10 research centers of the French Alternative Energies and Atomic Energy Commission (CEA). Distributed throughout various research platforms, it focuses on nuclear fission, nuclear fusion, new energy technologies (hydrogen, solar, biomass) and fundamental research in the field of vegetal biology. It is the most important technological research and development centers for energy in Europe. Considering the sensitive nature of nuclear activities, the questions surrounding the issue of radioactive waste, the nuclear energy and the social, economic and environmental concerns for present and future generations, the French Government asked nuclear actors to open communication and to give all the information asked by the Local Information Commission (CLI) and the public [1]. In this context, the CEA Cadarache has decided to better show and explain its expertise and experience in the area of nuclear energy and nuclear power plant design, and to make it available to stakeholders and to the public. CEA Cadarache receives each year more than 9000 visitors. To complete technical visits of the research facilities and laboratories, a scientific cultural center has been built in 2011 to inform the public on CEA Cadarache research activities and to facilitate the acceptance of nuclear energy in a way suited to the level of knowledge of the visitors. A modern interactive exhibition of 150 m{sup 2} allows visitors to find out more about energy, CEA Cadarache research programs, radioactive waste management and radiological impact on the research center activities. It also offers an auditorium for group discussions and for school groups to discover science through enjoyment. This communication center has received several thousand visitors since its opening on October 2011; the initial results of this experience are now available. It's possible to explain the design of this exhibition, to give some statistics on the number of the visitors

  4. Elevated Level of Serum Carcinoembryonic Antigen (CEA) and Search for a Malignancy: A Case Report.

    PubMed

    Asad-Ur-Rahman, Fnu; Saif, Muhammad W

    2016-01-01

    Carcinoembryonic antigen (CEA) has been shown to be associated with tumor burden in patients with colorectal cancer. However, it is also elevated to a significant degree in a number of other malignant and non-malignant conditions. We report a case of reversible CEA elevation in a patient using lithium for bipolar disorder. A 58-year-old female with a longstanding smoking history and a past medical history of chronic obstructive pulmonary disease (COPD), bipolar illness, hypothyroidism, and obesity was found to have an elevated CEA level of 11.2 ng/ml (normal level <5 ng/ml) in the workup for postmenopausal bleeding. Her history was not positive for malignancy of colorectum, ovaries, thyroid, or breast.  She underwent a large number of imaging and endoscopic studies to evaluate for colorectal, breast, ovarian, and lung cancer; however, it did not reveal any evidence of malignancy. Upon review of her medications, she reported that she had recently started lithium for her bipolar illness. We followed up her CEA level while her dose of lithium was reduced from 450 to 300 mg per day. Her CEA level decreased from 25 mg/dl to 6.1 mg/dl and remained stable over the course of the next eight months. Our case is the first case report that identifies lithium as a potential cause of reversible CEA elevation. The underlying mechanism is yet to be elucidated, but it underscores the importance of investigating the medications as part of the workup. PMID:27446768

  5. Latest pixel size reduction of uncooled IR-FPA at CEA, LETI

    NASA Astrophysics Data System (ADS)

    Becker, Sebastien; Imperinetti, Pierre; Yon, Jean-Jacques; Ouvrier-Buffet, Jean-Louis; Goudon, Valérie; Hamelin, Antoine; Vialle, Claire; Arnaud, Agnès.

    2012-10-01

    Recent developments at the Infrared Lab (LIR) of CEA, LETI have been concentrated on the pixel size reduction of uncooled infrared detectors. With the support from French company ULIS, we have successfully demonstrated the technological integration of 12μm pixels on a commercial TV-format read-out circuit (VGA-ROIC) supplied by ULIS. The 12μm pixel has been designed, processed and characterized in CEA, LETI and first results showed exceptional performances. This paper presents the characterization and associated imagery results.

  6. Diagnostic value of CEA and CYFRA 21-1 tumor markers in primary lung cancer.

    PubMed

    Okamura, Kyoko; Takayama, Koichi; Izumi, Miiru; Harada, Taishi; Furuyama, Kazuto; Nakanishi, Yoichi

    2013-04-01

    Lung cancer is sometimes difficult to differentiate from benign lung diseases expressing nodular shadow in imaging study. We assessed the diagnostic value of two commonly used tumor markers in distinguishing primary lung cancer from benign lung disease. The serum levels of carcinoembryonic antigen (CEA) and cytokeratin 19 fragments (CYFRA 21-1) were retrospectively analyzed in 655 lung cancer patients and 237 patients with benign lung disease. The standard cut-off levels of 3.2 ng/mL CEA and 3.5 ng/mL CYFRA 21-1 and twice these respective levels (6.4 ng/mL and 7.0 ng/mL) were used. CEA and CYFRA 21-1 levels were elevated in 32% and 11% of benign lung disease patients, respectively. CEA sensitivity and specificity for lung cancer diagnosis was 69% and 68% respectively, while that for CYFRA 21-1 was 43% and 89%, respectively. Thus, the combined value for the specificity of the two tumor markers was greater than either alone. Patients were grouped depending on their hospital status, and prevalence rates were determined. The prevalence rate of lung cancer in admitted patients was 51%, the prevalence rate of lung cancer in outpatients was 12%, and the prevalence rate of lung cancer identified during health check-ups was 0.1%. Positive predictive values (PPVs) were calculated using Bayes' theorem, and varied with the serum tumor marker and prevalence rate: PPVs of CEA [prevalence rate] were 69.2% [51%], 22.7% [12%], and 0.22% [0.1%], while PPVs of CYFRA 21-1 were 80.3% [51%], 34.8% [12%], and 0.39% [0.1%]. However, PPVs for lung cancer diagnosis at a prevalence rate of 51% were 87.3% or higher when the patient exhibited positive CEA and CYFRA 21-1, or CEA or CYFRA 21-1 levels twice the standard cut-off. Our results indicate that CEA and CYFRA 21-1 are reliable serum tumor markers for the diagnosis of lung cancer in addition to CT scans when combined or used individually at twice the standard cut-off level in high prevalence rate groups. The prevalence rate should

  7. AuRu/AC as an effective catalyst for hydrogenation reactions

    DOE PAGESBeta

    Villa, Alberto; Chan-Thaw, Carine E.; Campisi, Sebastiano; Bianchi, Claudia L.; Wang, Di; Kotula, Paul G.; Kübel, Christian; Prati, Laura

    2015-03-23

    AuRu bimetallic catalysts have been prepared by sequential deposition of Au on Ru or vice versa obtaining different nanostructures: when Ru has been deposited on Au, a Aucore–Rushell has been observed, whereas the deposition of Au on Ru leads to a bimetallic phase with Ru enrichment on the surface. In the latter case, the unexpected Ru enrichment could be attributed to the weak adhesion of Ru on the carbon support, thus allowing Ru particles to diffuse on Au particles. Both structures result very active in catalysing the liquid phase hydrogenolysis of glycerol and levulinic acid but the activity, the selectivitymore » and the stability depend on the structure of the bimetallic nanoparticles. Ru@Au/AC core–shell structure mostly behaved as the monometallic Ru, whereas the presence of bimetallic AuRu phase in Au@Ru/AC provides a great beneficial effect on both activity and stability.« less

  8. Quantitative real-time detection of carcinoembryonic antigen (CEA) from pancreatic cyst fluid using 3-D surface molecular imprinting.

    PubMed

    Yu, Yingjie; Zhang, Qi; Buscaglia, Jonathan; Chang, Chung-Chueh; Liu, Ying; Yang, Zhenhua; Guo, Yichen; Wang, Yantian; Levon, Kalle; Rafailovich, Miriam

    2016-07-21

    In this study, a sensitive, yet robust, biosensing system with real-time electrochemical readout was developed. The biosensor system was applied to the detection of carcinoembryonic antigen (CEA), which is a common marker for many cancers such as pancreatic, breast, and colon cancer. Real time detection of CEA during a medical procedure can be used to make critical decisions regarding further surgical intervention. CEA was templated on gold surface (RMS roughness ∼3-4 nm) coated with a hydrophilic self-assembled monolayer (SAM) on the working electrode of an open circuit potentiometric network. The subsequent removal of template CEA makes the biosensor capable of CEA detection based on its specific structure and conformation. The molecular imprinting (MI) biosensor was further calibrated using the potentiometric responses in solutions with known CEA concentrations and a detection limit of 0.5 ng ml(-1) was achieved. Potentiometric sensing was then applied to pancreatic cyst fluid samples obtained from 18 patients when the cyst fluid was also evaluated using ELISA in a certified pathology laboratory. Excellent agreement was obtained between the quantitation of CEA obtained by both the ELISA and MI biosensor detection for CEA. A 3-D MI model, using the natural rms roughness of PVD gold layers, is presented to explain the high degree of sensitivity and linearity observed in those experiments. PMID:27193921

  9. Assembly and analysis of cosmid contigs in the CEA-gene family region of human chromosome 19.

    PubMed Central

    Tynan, K; Olsen, A; Trask, B; de Jong, P; Thompson, J; Zimmermann, W; Carrano, A; Mohrenweiser, H

    1992-01-01

    The carcinoembryonic antigen (CEA)-like genes are members of a large gene family which is part of the immunoglobulin superfamily. The CEA family is divided into two major subgroups, the CEA-subgroup and the pregnancy-specific glycoprotein (PSG)-subgroup. In the course of an effort to develop a set of overlapping cosmids spanning human chromosome 19, we identified 245 cosmids in a human chromosome 19 cosmid library (6-7X redundant) by hybridization with an IgC-like domain fragment of the CEA gene. A fluorescence-based restriction enzyme digest fingerprinting strategy was used to assemble 212 probe-positive cosmids, along with 115 additional cosmids from a collection of approximately 8,000 randomly selected cosmids, into five contigs. Two of the contigs contain CEA-subgroup genes while the remaining three contigs contain PSG-subgroup genes. These five contigs range in size from 100 kb to over 300 kb and span an estimated 1 Mb. The CEA-like gene family was determined by fluorescence in situ hybridization to map in the q13.1-q13.2 region of human chromosome 19. Analysis of the two CEA-subgroup contigs provided verification of the contig assembly strategy and insight into the organization of 9 CEA-subgroup genes. PMID:1579453

  10. Qualification sous irradiation du crayon cea: de la conception des composants a l'irradiation d'assemblages en reacteur de puissance

    NASA Astrophysics Data System (ADS)

    Marin, Jean-François; Pillet, Claude; François, Bernard; Morize, Pierre; Petitgrand, Sylvie; Atabek, Rose-Marie; Houdaille, Brigitte

    1982-04-01

    Cet article résume les principaux résultats obtenus au CEA au cours des dix dernières années dans la conception, la qualification et la fabrication des différents éléments originaux constitutifs d'un assemblage de réacteur à eau pressurisée, notamment: l'oxyde UO 2 obtenu par le procédé du Double Cycle Inverse, la gaine en zircaloy 4 recris talllsée, la grille à ressort papillon, la structure à grilles coulissantes. Les etudes et essais hors-pile de comportement thermomécanique du crayon et thermohydraulique des composants de l'assemblage, les irradiations paramétriques de crayons jusqu'à une combustion massique élevée, la validation à partir d'examens aprés irradiation des principaux modèles introduits dans les calculs de conception, enfin l'introduction en réacteur prototype, puis en réacteur de puissance d'assemblages comportant ces différents éléments, constituent les principales étapes de ce développement.

  11. Network nanostructured polypyrrole hydrogel/Au composites as enhanced electrochemical biosensing platform

    NASA Astrophysics Data System (ADS)

    Rong, Qinfeng; Han, Hongliang; Feng, Feng; Ma, Zhanfang

    2015-06-01

    In this work, a new network nanocomposite composed of polypyrrole hydrogel (PPy hydrogel) loaded gold nanoparticles (AuNPs) was prepared. The PPy hydrogel was directly synthesized by mixing the pyrrole monomer and phytic acid, and the mixed solution can be gelated to form hydrogel at once. The three-dimensional network nanostructured PPy hydrogel not only provided a greater effective surface area for increasing the quantity of immobilized biomolecules and facilitated the transport of electrons and ions, but also exhibited an improved conductivity. Meanwhile, the electrodeposited AuNPs on the PPy hydrogel can further increase the specific surface area to capture a large amount of antibodies as well as improve the capability of electron transfer. The network PPy hydrogel/Au nanocomposites were successfully employed for the fabrication of a sensitive label-free amperometric immunosensor. Carcinoembryonic antigen (CEA) was used as a model protein. The proposed immunosensor exhibited a wide linear detection range from 1 fg mL-1 to 200 ng mL-1, and an ultralow limit of detection of 0.16 fg mL-1 (S/N = 3), and it also possessed good selectivity. Moreover, the detection of CEA in ten human serums showed satisfactory accuracy compared with the data determined by ELISA, indicating that the immunosensor provided potential application for clinical diagnosis.

  12. Network nanostructured polypyrrole hydrogel/Au composites as enhanced electrochemical biosensing platform.

    PubMed

    Rong, Qinfeng; Han, Hongliang; Feng, Feng; Ma, Zhanfang

    2015-01-01

    In this work, a new network nanocomposite composed of polypyrrole hydrogel (PPy hydrogel) loaded gold nanoparticles (AuNPs) was prepared. The PPy hydrogel was directly synthesized by mixing the pyrrole monomer and phytic acid, and the mixed solution can be gelated to form hydrogel at once. The three-dimensional network nanostructured PPy hydrogel not only provided a greater effective surface area for increasing the quantity of immobilized biomolecules and facilitated the transport of electrons and ions, but also exhibited an improved conductivity. Meanwhile, the electrodeposited AuNPs on the PPy hydrogel can further increase the specific surface area to capture a large amount of antibodies as well as improve the capability of electron transfer. The network PPy hydrogel/Au nanocomposites were successfully employed for the fabrication of a sensitive label-free amperometric immunosensor. Carcinoembryonic antigen (CEA) was used as a model protein. The proposed immunosensor exhibited a wide linear detection range from 1 fg mL(-1) to 200 ng mL(-1), and an ultralow limit of detection of 0.16 g mL(-1) (S/N = 3), and it also possessed good selectivity. Moreover, the detection of CEA in ten human serums showed satisfactory accuracy compared with the data determined by ELISA, indicating that the immunosensor provided potential application for clinical diagnosis. PMID:26074185

  13. Network nanostructured polypyrrole hydrogel/Au composites as enhanced electrochemical biosensing platform

    PubMed Central

    Rong, Qinfeng; Han, Hongliang; Feng, Feng; Ma, Zhanfang

    2015-01-01

    In this work, a new network nanocomposite composed of polypyrrole hydrogel (PPy hydrogel) loaded gold nanoparticles (AuNPs) was prepared. The PPy hydrogel was directly synthesized by mixing the pyrrole monomer and phytic acid, and the mixed solution can be gelated to form hydrogel at once. The three-dimensional network nanostructured PPy hydrogel not only provided a greater effective surface area for increasing the quantity of immobilized biomolecules and facilitated the transport of electrons and ions, but also exhibited an improved conductivity. Meanwhile, the electrodeposited AuNPs on the PPy hydrogel can further increase the specific surface area to capture a large amount of antibodies as well as improve the capability of electron transfer. The network PPy hydrogel/Au nanocomposites were successfully employed for the fabrication of a sensitive label-free amperometric immunosensor. Carcinoembryonic antigen (CEA) was used as a model protein. The proposed immunosensor exhibited a wide linear detection range from 1 fg mL−1 to 200 ng mL−1, and an ultralow limit of detection of 0.16 fg mL−1 (S/N = 3), and it also possessed good selectivity. Moreover, the detection of CEA in ten human serums showed satisfactory accuracy compared with the data determined by ELISA, indicating that the immunosensor provided potential application for clinical diagnosis. PMID:26074185

  14. Mutational Profiles Reveal an Aberrant TGF-β-CEA Regulated Pathway in Colon Adenomas.

    PubMed

    Chen, Jian; Raju, Gottumukkala S; Jogunoori, Wilma; Menon, Vipin; Majumdar, Avijit; Chen, Jiun-Sheng; Gi, Young Jin; Jeong, Yun Seong; Phan, Liem; Belkin, Mitchell; Gu, Shoujun; Kundra, Suchin; Mistry, Nipun A; Zhang, Jianping; Su, Xiaoping; Li, Shulin; Lin, Sue-Hwa; Javle, Milind; McMurray, John S; Rahlfs, Thomas F; Mishra, Bibhuti; White, Jon; Rashid, Asif; Beauchemin, Nicole; Weston, Brian R; Shafi, Mehnaz A; Stroehlein, John R; Davila, Marta; Akbani, Rehan; Weinstein, John N; Wu, Xifeng; Mishra, Lopa

    2016-01-01

    Mutational processes and signatures that drive early tumorigenesis are centrally important for early cancer prevention. Yet, to date, biomarkers and risk factors for polyps (adenomas) that inordinately and rapidly develop into colon cancer remain poorly defined. Here, we describe surprisingly high mutational profiles through whole-genome sequence (WGS) analysis in 2 of 4 pairs of benign colorectal adenoma tissue samples. Unsupervised hierarchical clustered transcriptomic analysis of a further 7 pairs of adenomas reveals distinct mutational signatures regardless of adenoma size. Transitional single nucleotide substitutions of C:G>T:A predominate in the adenoma mutational spectrum. Strikingly, we observe mutations in the TGF-β pathway and CEA-associated genes in 4 out of 11 adenomas, overlapping with the Wnt pathway. Immunohistochemical labeling reveals a nearly 5-fold increase in CEA levels in 23% of adenoma samples with a concomitant loss of TGF-β signaling. We also define a functional role by which the CEA B3 domain interacts with TGFBR1, potentially inactivating the tumor suppressor function of TGF-β signaling. Our study uncovers diverse mutational processes underlying the transition from early adenoma to cancer. This has broad implications for biomarker-driven targeting of CEA/TGF-β in high-risk adenomas and may lead to early detection of aggressive adenoma to CRC progression. PMID:27100181

  15. Serum CA 242 in pancreatic cancer. Comparison with CA 19-9 and CEA.

    PubMed

    Pezzilli, R; Billi, P; Plate, L; Laudadio, M A; Sprovieri, G

    1995-01-01

    Serum CA 242, CA 19-9 and CEA concentrations were determined in 94 subjects divided into 5 groups: Group 1 consisted of 22 healthy subjects; Group 2 consisted of 40 patients with pancreatic adenocarcinoma; according to Cubilla and Fitzgerald's classification, 11 tumours were Stage I, 4 were Stage II, and 25 were Stage III. Group 3 consisted of 10 chronic pancreatitis patients, group 4 of 10 acute pancreatitis patients, group 5 of 12 patients with nonpancreatic digestive carcinomas. Ten of these 12 patients had distant metastases. The sensitivity of CA 19-9 in the diagnosis of pancreatic cancer was higher than that of CEA and CA 242 (p < 0.05 and p < 0.005, respectively). In Stage I cancer patients the sensitivity of the markers studied was less than 50% (45% for CA 19-9, 18% for CEA, and 9% for CA 242) whereas most of the 25 patients with metastatic tumours of the pancreas had elevated serum levels of all 3 markers. The various combinations of the three markers did not significantly improve the sensitivity in diagnosing pancreatic cancer. No relationship was found between the localization of the tumour and the serum levels of the 3 markers studied. Similarly, no differences were found between patients with cholestasis and those without. The specificity of the 3 markers, evaluated in patients with benign pancreatic diseases, was 100% for CA 242, 90% for CA 199 and 70% for CEA.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:8562994

  16. 77 FR 74283 - Clearing Requirement Determination Under Section 2(h) of the CEA

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-12-13

    ...\\ Clearing Requirement Determination Under Section 2(h) of the CEA; Proposed Rule, 77 FR 47170 (Aug. 7, 2012... to Trade Under Section 2(h)(8) of the Commodity Exchange Act, 76 FR 77728 (Dec. 14, 2011). Clearing... FR 44464 (July 26, 2011); 17 CFR 39.5. The determinations and rules adopted in this release...

  17. 15 CFR 950.7 - Center for Environmental Assessment Services (CEAS).

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... experiment design, data analysis, and data management support to project managers and produces merged... key role in the Global Atmospheric Research Program (GARP) experiments). (7) CEAS provides special... global oceanographic data base from observations taken during the First GARP Global Experiment (FGGE)....

  18. 15 CFR 950.7 - Center for Environmental Assessment Services (CEAS).

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... experiment design, data analysis, and data management support to project managers and produces merged... key role in the Global Atmospheric Research Program (GARP) experiments). (7) CEAS provides special... global oceanographic data base from observations taken during the First GARP Global Experiment (FGGE)....

  19. 15 CFR 950.7 - Center for Environmental Assessment Services (CEAS).

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... experiment design, data analysis, and data management support to project managers and produces merged... key role in the Global Atmospheric Research Program (GARP) experiments). (7) CEAS provides special... global oceanographic data base from observations taken during the First GARP Global Experiment (FGGE)....

  20. 15 CFR 950.7 - Center for Environmental Assessment Services (CEAS).

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... experiment design, data analysis, and data management support to project managers and produces merged... key role in the Global Atmospheric Research Program (GARP) experiments). (7) CEAS provides special... global oceanographic data base from observations taken during the First GARP Global Experiment (FGGE)....

  1. 15 CFR 950.7 - Center for Environmental Assessment Services (CEAS).

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... experiment design, data analysis, and data management support to project managers and produces merged... key role in the Global Atmospheric Research Program (GARP) experiments). (7) CEAS provides special... global oceanographic data base from observations taken during the First GARP Global Experiment (FGGE)....

  2. Spanish Pre-University Students' Use of English: CEA Results from the University Entrance Examination

    ERIC Educational Resources Information Center

    Diez-Bedmar, Maria Belen

    2011-01-01

    In this paper an updated overview of the main errors that Spanish students make when writing the English exam in the University Entrance Examination is provided. To do so, a Computer-aided Error Analysis (CEA) (Dagneaux, Denness & Granger, 1998) was conducted on a representative sample of the students who took the exam in June 2008 in Jaen, and…

  3. 77 FR 47169 - Clearing Requirement Determination Under Section 2(h) of the CEA

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-08-07

    ... Commodity Exchange Act, 76 FR 77728 (Dec. 14, 2011). Clearing is at the heart of the Dodd-Frank financial...; and (4) the staying of a clearing requirement. \\19\\ See 76 FR 44464 (July 26, 2011); 17 CFR 39.5. This... under Section 2(h) of the CEA, 76 FR 58186 (Sept. 20, 2011). This comment letter is available on...

  4. Environmental Profiles of Paper vs. Electronic UC-CEAS Annual Reports

    EPA Science Inventory

    In 2010, the University of Cincinnati College of Engineering and Applied Sciences (UC-CEAS) created a new electronic format for the Annual Report that could be distributed through the college’s website to replace the prior print version. In order to determine the environmental co...

  5. Mutational Profiles Reveal an Aberrant TGF-β-CEA Regulated Pathway in Colon Adenomas

    PubMed Central

    Jogunoori, Wilma; Menon, Vipin; Majumdar, Avijit; Chen, Jiun-Sheng; Gi, Young Jin; Jeong, Yun Seong; Phan, Liem; Belkin, Mitchell; Gu, Shoujun; Kundra, Suchin; Mistry, Nipun A.; Zhang, Jianping; Su, Xiaoping; Li, Shulin; Lin, Sue-Hwa; Javle, Milind; McMurray, John S.; Rahlfs, Thomas F.; Mishra, Bibhuti; White, Jon; Rashid, Asif; Beauchemin, Nicole; Weston, Brian R.; Shafi, Mehnaz A.; Stroehlein, John R.; Davila, Marta; Akbani, Rehan; Weinstein, John N.; Wu, Xifeng; Mishra, Lopa

    2016-01-01

    Mutational processes and signatures that drive early tumorigenesis are centrally important for early cancer prevention. Yet, to date, biomarkers and risk factors for polyps (adenomas) that inordinately and rapidly develop into colon cancer remain poorly defined. Here, we describe surprisingly high mutational profiles through whole-genome sequence (WGS) analysis in 2 of 4 pairs of benign colorectal adenoma tissue samples. Unsupervised hierarchical clustered transcriptomic analysis of a further 7 pairs of adenomas reveals distinct mutational signatures regardless of adenoma size. Transitional single nucleotide substitutions of C:G>T:A predominate in the adenoma mutational spectrum. Strikingly, we observe mutations in the TGF-β pathway and CEA-associated genes in 4 out of 11 adenomas, overlapping with the Wnt pathway. Immunohistochemical labeling reveals a nearly 5-fold increase in CEA levels in 23% of adenoma samples with a concomitant loss of TGF-β signaling. We also define a functional role by which the CEA B3 domain interacts with TGFBR1, potentially inactivating the tumor suppressor function of TGF-β signaling. Our study uncovers diverse mutational processes underlying the transition from early adenoma to cancer. This has broad implications for biomarker-driven targeting of CEA/TGF-β in high-risk adenomas and may lead to early detection of aggressive adenoma to CRC progression. PMID:27100181

  6. MC32 tumor cells acquire Ag-specific CTL resistance through the loss of CEA in a colon cancer model

    PubMed Central

    Lee, Sang-Yeul; Sin, Jeong-Im

    2015-01-01

    We previously reported that MC32 cells resist carcinoembryonic antigen (CEA) DNA vaccination by losing their antigen presentation to Ag-specific CTLs in the context of MHC class I antigens in a colon cancer therapeutic model. In this study, we selected 2 tumor cells, MC32-S2–2 and MC32-S4–2, which have the ability to form tumors in CEA DNA vaccine-immunized mice. Wild type MC32 cells grew significantly less in CEA-immunized mice (with Ag-specific CTL lytic activity) than in control mice (with no Ag-specific CTL lytic activity). However, MC32-S2–2 and MC32-S4–2 cells grew at a similar rate in both control and CEA-immunized mice, confirming their resistant status against CEA DNA vaccination. MC32-S2–2 and MC32-S4–2 cells were not susceptible to lysis by CEA-specific CD8+ T cells. Moreover, when MC32-S2–2 and MC32-S4–2 cells were used as stimulating agents of CEA-specific immune cells for IFN-γ production, these cells failed to stimulate the induction of Ag-specific IFN-γ, suggesting a loss of tumor cell recognition by Ag-specific immune cells. However, MC32-S2–2 and MC32-S4–2 cells expressed MHC class I antigens in a manner similar to that of wild type MC32 cells. Finally, Western blot assay confirmed that in MC32-S2–2 and MC32-S4–2 cells, CEA expression remained absent but mouse CEA was expressed. Taken together, these data show that MC32 cells may also be able to achieve resistance to CEA-specific CTLs by antigen loss in this model. PMID:25902414

  7. Dispersion of Radionuclides and Exposure Assessment in Urban Environments: A Joint CEA and LLNL Report

    SciTech Connect

    Glascoe, Lee; Gowardhan, Akshay; Lennox, Kristin; Simpson, Matthew; Yu, Kristen; Armand, Patrick; Duchenne, Christophe; Mariotte, Frederic; Pectorin, Xavier

    2014-12-19

    In the interest of promoting the international exchange of technical expertise, the US Department of Energy’s Office of Emergency Operations (NA-40) and the French Commissariat à l'Energie Atomique et aux énergies alternatives (CEA) requested that the National Atmospheric Release Advisory Center (NARAC) of Lawrence Livermore National Laboratory (LLNL) in Livermore, California host a joint table top exercise with experts in emergency management and atmospheric transport modeling. In this table top exercise, LLNL and CEA compared each other’s flow and dispersion models. The goal of the comparison is to facilitate the exchange of knowledge, capabilities, and practices, and to demonstrate the utility of modeling dispersal at different levels of computational fidelity. Two modeling approaches were examined, a regional scale modeling approach, appropriate for simple terrain and/or very large releases, and an urban scale modeling approach, appropriate for small releases in a city environment. This report is a summary of LLNL and CEA modeling efforts from this exercise. Two different types of LLNL and CEA models were employed in the analysis: urban-scale models (Aeolus CFD at LLNL/NARAC and Parallel- Micro-SWIFT-SPRAY, PMSS, at CEA) for analysis of a 5,000 Ci radiological release and Lagrangian Particle Dispersion Models (LODI at LLNL/NARAC and PSPRAY at CEA) for analysis of a much larger (500,000 Ci) regional radiological release. Two densely-populated urban locations were chosen: Chicago with its high-rise skyline and gridded street network and Paris with its more consistent, lower building height and complex unaligned street network. Each location was considered under early summer daytime and nighttime conditions. Different levels of fidelity were chosen for each scale: (1) lower fidelity mass-consistent diagnostic, intermediate fidelity Navier-Stokes RANS models, and higher fidelity Navier-Stokes LES for urban-scale analysis, and (2) lower-fidelity single

  8. Variation of uptake of anti-CEA monoclonal antibody with tumor type and mass

    SciTech Connect

    Williams, L.E.; Philben, V.J.; Jakowatz, J.G.; Beatty, B.G.; Vlahos, W.G.; Paxton, R.J.; Shively, J.E.; Beatty, J.D.

    1985-05-01

    A nude mouse model xenografted with 3 human tumor (T) was studied with an anti-carcinoembryonic (..cap alpha..-CEA) monoclonal antibody (MoAb). The MoAb was labeled with In-111 using a bi-functional chelation technique. In vitro cross-reactivity with human blood (B) and liver (L) cells was minimal. Human colon tumors were WIDR, SW403 an LS174T. The murine carcinoma EMT6 was used as a control. In all cases only 62.5 ngm of ..cap alpha..-CEA charged at 10 ..mu..Ci/..mu..gm was given to each animal. The corresponding value in humans, 200 ..mu..gm, is probably subimmunogenic. Organ distribution in percent injected dose/gm (% ID/gm) and images were obtained at 48 h post-injection of the MoAb. CEA levels (mgm/gm of T) were measured for each tumor using the same MoAb (T 84.66). Variation of % ID/gm with LS174T mass (m) was also determined. Uptake by EMT6 was 2.4 +- 0.2 % ID/gm. LS174T uptake varied approximately as the inverse of tumor mass. The authors conclude that tumor accumulation of ..cap alpha..-CEA MoAb is not directly correlated with the amount of CEA in the lesion. The best uptake, T/B and T/L values occurred with LS174T; this was also borne out by the 48 h images. Because of the smaller average SW403 mass, this result cannot readily be explained as a tumor size effect.

  9. Label-Free Electrochemiluminescent Immunosensor for Detection of Carcinoembryonic Antigen Based on Nanocomposites of GO/MWCNTs-COOH/Au@CeO₂.

    PubMed

    Pang, Xuehui; Li, Jianxiu; Zhao, Yongbei; Wu, Dan; Zhang, Yong; Du, Bin; Ma, Hongmin; Wei, Qin

    2015-09-01

    A high-sensitivity electrochemiluminescence (ECL) sensor was conducted to detect carcinoembryonic antigen (CEA). Nanocomposites of graphene oxide/carboxylated multiwall carbon nanotubes/gold/cerium oxide nanoparticles (GO/MWCNTs-COOH/Au@CeO2) were used as antibody carriers and sensing platforms to modify on glassy carbon electrodes (GCE). CeO2 nanoparticles were first exploited as an ECL luminescent material and the possible ECL mechanism was proposed in this work. GO/MWCNTs-COOH was used as a loading matrix for CeO2 nanoparticles because of the superior conductivity and large specific surface area. Au nanoparticles were further deposited on this matrix to attach anti-CEA and enhance the sensitivity of immunosensor. The proposed sensing platform showed excellent cathodic ECL performance and sensitive response to CEA. The effects of experimental conditions on the ECL performance were investigated. The proposed immunosensor showed the broad linear range (0.05-100 ng/mL) and the low detection limit (LOD, 0.02 ng/mL, signal-to-noise ratio = 3) according to the selected experimental conditions. The excellent analysis performance for determination of CEA in the human serum samples simplied this immunosensor displayed high sensitivity and excellent repeatability. More importantly, this conducted immunosensor broadens the use scope of CeO2 nanoparticles. PMID:26271682

  10. Hookah smoking and cancer: carcinoembryonic antigen (CEA) levels in exclusive/ever hookah smokers

    PubMed Central

    Sajid, Khan Mohammad; Chaouachi, Kamal; Mahmood, Rubaida

    2008-01-01

    Background We have recently published some work on CEA levels in hookah (also called narghile, shisha elsewhere) and cigarette smokers. Hookah smokers had higher levels of CEA than non-smokers although mean levels were low compared to cigarette smokers. However some of them were also users of other tobacco products (cigarettes, bidis, etc.). Objectives To find serum CEA levels in ever/exclusive hookah smokers, i.e. those who smoked only hookah (no cigarettes, bidis, etc.), prepared between 1 and 4 times a day with a quantity of up to 120 g of a tobacco-molasses mixture each (i.e. the tobacco weight equivalent of up to 60 cigarettes of 1 g each) and consumed in 1 to 8 sessions. Methods Enhanced chemiluminescent immunometric technique was applied to measure CEA levels in serum samples from 59 exclusive male smokers with age ranging from 20–80 years (mean = 58.8 ± 14.7 years) and 8–65 years of smoking (mean = 37.7 ± 16.8). 36 non-smokers served as controls. Subjects were divided into 3 groups according to the number of preparations; the number of sessions and the total daily smoking time: Light (1; 1; ≤ 20 minutes); Medium (1–3; 1–3; >20 min to ≤ 2 hrs) and Heavy smokers (2–4; 3–8; >2 hrs to ≤ 6 hrs). Because of the nature of distribution of CEA levels among our individuals, Wilcoxon's rank sum two-sample test was applied to compare the variables. Results The overall CEA levels in exclusive hookah smokers (mean: 3.58 ± 2.61 ng/ml; n = 59) were not significantly different (p ≤ 0.0937) from the levels in non-smokers (2.35 ± 0.71 ng/ml). Mean levels in light, medium and heavy smokers were: 1.06 ± 0.492 ng/ml (n = 5); 2.52 ± 1.15 ng/ml (n = 28) and 5.11 ± 3.08 ng/ml (n = 26) respectively. The levels in medium smokers and non-smokers were also not significantly different (p ≤ 0.9138). In heavy smokers, the CEA levels were significantly higher than in non-smokers (p ≤ 0.0001567). Conclusion Overall CEA levels in exclusive hookah smokers were

  11. Value of human chorionic gonadotropin compared to CEA in discriminating benign from malignant effusions.

    PubMed

    Lamerz, R; Stoetzer, O J; Mezger, J; Brandt, A; Darsow, M; Wilmanns, W

    1999-01-01

    Human chorionic gonadotropin (HCG) is expressed in germ cell tumors and urothelial, breast, lung and colon cancers. The aim of the study was to investigate if the determination of HCG in comparison with CEA is able to discriminate between malignant and benign effusions. Effusion and partially serum samples of 61 patients with benign (g.i., heart/kidney isnuff.) and 116 patients with malignant diseases (g.i., gynec., lung, misc., CUP) were investigated. HCG was specifically determined by an IRMA using 2 monoclonal antibodies, CEA by a conventional double Ab RIA. Cytological staining was preformed using the Pappenheim-method on cytospin preparations. Significant differences (p < 0.001) were found for HCG between benign and malignant ascitic effusions with the best discrimination at 5 IU/l (ROC) and an overall sensitivity of 31.3% (spec. vs benign eff. 93.4%) increasing in subgroups from hematol. (5.8%) < misc. (31.3%) < gynec. (32.1%) < g.i. (36%) < lung (38.1%) to CUP (50%). CEA also showed significant differences between benign and malignant total and ascitic effusions, and weaker for the pleural subgroup (cutoff 9 ng/ml) with a total sensitivity of 44.6% (sp = 100%) increasing from misc. (30.8%) < lung (47.1%) < CUP (50%) < gynec. (60%) < g.i. (60.9%). Comparative cytology and TM determinations increased the positiverate of cytology (45.2%) to 58.3% for either cytology or HCG positive cases, or to 61.6% for either cytology or CEA positive cases. For the combined determination of cytologoy and HCG and CEA, the overall TM positive rate for 33 cytology-pos. cases was 78.8%, but in 40 cytology-negative cases 37.5% for TM positive cases. In conclusion HCG is useful in ascitic > pleural effusions with high specificity (90% at 5 IU/l) but low sensitivity of 31% increasing in g.i., lung and gynecologic cases, CEA a more general TM with higher sensitivity of 45% increasing in g.i., gynecologic and lung cases (sp. 100% at 9 ng/ml) both adding significantly to cytology

  12. Effect of Au Content on Thermal Stability and Mechanical Properties of Au-Cu-Ag-Si Bulk Metallic Glasses

    NASA Astrophysics Data System (ADS)

    Guo, H.; Zhang, W.; Chen, M. W.; Saotome, Y.; Fukuhara, M.; Inoue, A.

    2011-06-01

    The thermal stability, glass-forming ability (GFA), and mechanical and electrical properties of Au-based Au x Si17Cu75.5- x Ag7.5 ( x = 40 to 75.5 at. pct) metallic glasses were investigated. The glass transition temperature ( T g ) and crystallization temperature ( T x ) decreased with increasing Au content. The ultralow T g values below 373 K (100 °C) were obtained for alloys with x = 55 to 75.5. The alloys with x = 45 to 70 exhibited a high stabilization of supercooled liquid and a high GFA, and the supercooled liquid region and critical sample diameter for glass formation were in the range of 31 K to 50 K and 2 to 5 mm, respectively. The compressive fracture strength ( σ c,f ), Young's modulus ( E), and Vicker's hardness ( H v ) of the bulk metallic glasses (BMGs) decreased with increasing Au content. A linear correlation between Au concentration and the characteristic temperature, i.e., T g and T x , and mechanical properties, i.e., σ c,f , E, and H v , as well as electrical resistivity can be found in the BMGs, which will be helpful for the composition design of the desirable Au-based BMGs with tunable physical properties.

  13. CEA serum level as early predictive marker of outcome during EGFR-TKI therapy in advanced NSCLC patients.

    PubMed

    Facchinetti, Francesco; Aldigeri, Raffaella; Aloe, Rosalia; Bortesi, Beatrice; Ardizzoni, Andrea; Tiseo, Marcello

    2015-08-01

    Considering the role of carcinoembryonic antigen (CEA) serum levels as potential useful predictive marker during chemotherapy treatment, we studied its applicability in advanced non-small cell lung cancer (NSCLC) patients treated with epidermal growth factor receptor (EGFR) tyrosine-kinase inhibitors (TKIs). Our retrospective cohort consists of 79 patients (33 EGFR mutated and 46 EGFR wild type or unknown) affected by advanced NSCLC, for whom CEA serum values at the beginning of TKI therapy and after the first month of treatment were available, regardless of treatment line. Baseline CEA value, percentage of CEA reduction after 1 month, and percentage of patients with ≥20 % CEA decrease after 1 month (CEA response) were correlated with disease control rate (DCR), progression-free (PFS), and overall (OS) survival, according to EGFR mutational status. Median baseline CEA levels were significantly higher in EGFR mutated (40.9 ng/ml; interquartile range (IQR) 8.9-197.6) than in wild-type cases (6.2 ng/ml; IQR 2.8-12.8; p = 0.003). Both percentage reduction in CEA levels (-10.7 vs. +13.4 %) and percentage of cases with CEA response (42 vs. 20 %) were significantly higher in mutated vs. wild-type/unknown patients (p = 0.007 and p = 0.027, respectively). In wild-type/unknown patients, CEA response was significantly correlated with DCR (p = 0.001) and resulted as a significant predictor of PFS both in univariate (p = 0.002) and in multivariate analyses (hazard ratio (HR) 0.27; 95 % confidence interval (CI) 0.11-0.66; p = 0.004); only a trend was found for OS prediction (p = 0.082). In EGFR-mutated group, CEA reduction did not show any correlation either with PFS or OS. CEA response after 1 month of EGFR-TKI therapy could be a useful marker, worthy to further studies, as early predictor of treatment outcome in EGFR wild-type/unknown unselected NSCLC cases for which no molecular predictor is yet available. PMID:25731731

  14. Laser generated Ag and Ag-Au composite nanoparticles for refractive index sensor

    NASA Astrophysics Data System (ADS)

    Navas, M. P.; Soni, R. K.

    2014-09-01

    Localized surface plasmon resonance (LSPR) wavelength of metal nanoparticles (NPs) is highly sensitive to size, shape and the surrounding medium. Metal targets were laser ablated in liquid for preparation of spherical Ag and Ag@Au core-shell NP colloidal solution for refractive index sensing. The LSPR peak wavelength and broadening of the NPs were monitored in different refractive index liquid. Quasi-static Mie theory simulation results show that refractive index sensitivity of Ag, Ag-Au alloy and Ag@Au core-shell NPs increases nearly linearly with size and shell thickness. However, the increased broadening of the LSPR peak with size, alloy concentration and Au shell thickness restricts the sensing resolution of these NPs. Figure-of-merit (FOM) was calculated to optimize the size of Ag NPs, concentration of Ag-Au alloy NPs and Au shell thickness of Ag@Au core-shell NPs. The refractive index sensitivity (RIS) and FOM were optimum in the size range 20-40 nm for Ag NPs. Laser generated Ag@Au NPs of Au shell thickness in the range of 1-2 nm showed optimum FOM, where thin layer of Au coating can improve the stability of Ag NPs.

  15. C.-E.A. Winslow Day: Proceedings of the June 3, 1977 Centenary Celebration

    PubMed Central

    Viseltear, Arthur J.

    1977-01-01

    Sponsored by Yale University, the City of New Haven, and the John B. Pierce Foundation, the C.-E.A. Winslow Day program consisted of speeches by Mr. Leonard Woodcock, President Emeritus, U.A.W., the Honorable Kenneth Gibson, Mayor of Newark, and Dr. Hector Acuña, Director, Pan American Health Organization; reminiscences of Ira Hiscock, Anna M.R. Lauder Professor Emeritus of Public Health, Mary Elizabeth Tennant, Associate Professor Emeritus of Nursing (Public Health), A. Pharo Gagge, Emeritus Fellow, John B. Pierce Foundation, and Mrs. Harriet Welch, Former President of the VNA of New Haven. The proceedings also included the presentation of gifts and the official C.-E.A. Winslow Day Proclamation. PMID:345631

  16. Electrochemistry of Au(II) and Au(III) pincer complexes: determination of the Au(II)-Au(II) bond energy.

    PubMed

    Dann, Thomas; Roşca, Dragoş-Adrian; Wright, Joseph A; Wildgoose, Gregory G; Bochmann, Manfred

    2013-10-01

    The bond energy of the unsupported Au-Au bond in the Au(ii) dimer [(C(∧)N(∧)C)Au]2 and the difference between Au(III)-OH and Au(III)-H bond enthalpies have been determined experimentally by electrochemical methods, with Au-OH and Au-H complexes showing unexpected differences in their reduction pathways, supported by DFT modelling. PMID:24051607

  17. Decommissioning of the nuclear licensed facilities at the Fontenay aux Roses CEA center

    SciTech Connect

    Jeanjacques, Michel; Piketty, Laurence; Letuhaire, Nathalie; Mandard, Lionel; Meden, Igor; Estivie, David; Boissonneau, Jean Francois; Fouquereau, Alain; Pichereau, Eric; Binet, Cedric

    2007-07-01

    Available in abstract form only. Full text of publication follows: The French Atomic Energy Commission (CEA) center at Fontenay aux Roses (CEN-FAR) is the Commission's oldest center is located in the southern suburbs of Paris. It was opened on 26 March 1946 to host the first French nuclear reactor ZOE that went critical on 12 December 1946. The first laboratories were installed in existing buildings on the site. (authors)

  18. Aeroacoustics research in Europe: The CEAS-ASC report on 2013 highlights

    NASA Astrophysics Data System (ADS)

    Bennett, G. J.; Kennedy, J.; Meskell, C.; Carley, M.; Jordan, P.; Rice, H.

    2015-03-01

    The Council of European Aerospace Societies (CEAS) Aeroacoustics Specialists Committee (ASC) supports and promotes the interests of the scientific and industrial aeroacoustics community on an European scale and European aeronautics activities internationally. In this context, "aeroacoustics" encompasses all aerospace acoustics and related areas. Each year the committee highlights some of the research and development projects in Europe. This paper is a report on highlights of aeroacoustics research in Europe in 2013, compiled from information provided to the ASC of the CEAS. During 2013, a number of research programmes involving aeroacoustics were funded by the European Commission. Some of the highlights from these programmes are summarised in this paper, as well as highlights from other programmes funded by national programmes or by industry. Furthermore, a concise summary of the CEAS-ASC workshop "Atmospheric and Ground Effects on Aircraft Noise" held in Seville, Spain in September 2013 is included in this report. Enquiries concerning all contributions should be addressed to the authors who are given at the end of each subsection. This issue of the "highlights" paper is dedicated to the memory of Prof. John A. Fitzpatrick, Professor of Mechanical Engineering, Trinity College Dublin, and a valued member of the Aeroacoustics Specialists Committee. John passed away in September 2012 and is fondly missed across the globe by the friends he made in the Aeroacoustics Community. This paper is edited by PhD graduates and colleagues of John's who conduct research in aeroacoustics, inspired by his thirst for knowledge.

  19. Colorectal tumors: scintigraphy with In-111 anti-CEA monoclonal antibody and correlation with surgical, histopathologic, and immunohistochemical findings

    SciTech Connect

    Abdel-Nabi, H.H.; Schwartz, A.N.; Goldfogel, G.; Ortman-Nabi, J.A.; Matsuoka, D.M.; Unger, M.W.; Wechter, D.G.

    1988-03-01

    A prospective clinical study of 17 patients with a histologic diagnosis of colorectal carcinoma proved at colonoscopy and surgery was performed with indium-111 anticarcinoembryonic-antigen (CEA) monoclonal antibody (MoAb), ZCE-025. MoAb scanning depicted nine of 16 primary colorectal carcinomas on planar scintigrams (true-positive findings = 56%) and ten of 16 lesions on single-photon emission computed tomography (SPECT) scans (true-positive findings = 62%). Liver metastases were detected in three of three patients, and lymph node metastases were detected in one of four patients. Immunohistochemical examination for CEA in resected colorectal cancer tissues demonstrated a positive correlation between MoAb imaging of primary lesions and cytoplasmic-stromal intracellular CEA distribution. There was no correlation between CEA serum levels and lesion detectability with MoAb scanning.

  20. Synthesis and biological investigations of a ZnPc-antiCEA bioconjugate for imaging of colorectal cancer

    PubMed Central

    Sehgal, Inder; Li, Hairong; Ongarora, Benson; Devillier, Daniel; Vicente, M. Graça H.

    2014-01-01

    Two zinc(II) phthalocyanines (ZnPcs) were conjugated with a monoclonal antibody (MAb) directed against carcinoembryonic antigen (CEA), using an in situ activated carboxylic acid on the ZnPcs. The bioconjugate with the highest ZnPc/MAb ratio of 3 was investigated in vitro for its ability to target and fluorescently label human colorectal HT-29 cells. The ZnPc-CEA MAb 2 was observed to efficiently target HT-29 cells, about 37 times more than unconjugated ZnPc. Furthermore, in the presence of a 4-fold excess of unlabelled anti-CEA antibody, the fluorescence signal of 2 was reduced by ~90% showing that the targeting is CEA-mediated. These studies further confirm the high specificity of Pc-antibody conjugates for antigens over-expressed on tumor cells and warrant further investigations of these immunoconjugates and their derivatives for imaging of colorectal cancer. PMID:25328375

  1. Magnetoresistance of Au films

    DOE PAGESBeta

    Zhang, D. L.; Song, X. H.; Zhang, X.; Zhang, Xiaoguang

    2014-12-10

    Measurement of the magnetoresistance (MR) of Au films as a function of temperature and film thickness reveals a strong dependence on grain size distribution and clear violation of the Kohler s rule. Using a model of random resistor network, we show that this result can be explained if the MR arises entirely from inhomogeneity due to grain boundary scattering and thermal activation of grain boundary atoms.

  2. Magnetoresistance of Au films

    SciTech Connect

    Zhang, D. L.; Song, X. H.; Zhang, X; Zhang, Xiaoguang

    2014-01-01

    Measurement of the magnetoresistance (MR) of Au films as a function of temperature and film thickness reveals a strong dependence on grain size distribution and clear violation of the Kohler s rule. Using a model of random resistor network, we show that this result can be explained if the MR arises entirely from inhomogeneity due to grain boundary scattering and thermal activation of grain boundary atoms.

  3. Real-Time Imaging of the Formation of Au-Ag Core-Shell Nanoparticles.

    PubMed

    Tan, Shu Fen; Chee, See Wee; Lin, Guanhua; Bosman, Michel; Lin, Ming; Mirsaidov, Utkur; Nijhuis, Christian A

    2016-04-27

    We study the overgrowth process of silver-on-gold nanocubes in dilute, aqueous silver nitrate solution in the presence of a reducing agent, ascorbic acid, using in situ liquid-cell electron microscopy. Au-Ag core-shell nanostructures were formed via two mechanistic pathways: (1) nuclei coalescence, where the Ag nanoparticles absorbed onto the Au nanocubes, and (2) monomer attachment, where the Ag atoms epitaxially deposited onto the Au nanocubes. Both pathways lead to the same Au-Ag core-shell nanostructures. Analysis of the Ag deposition rate reveals the growth modes of this process and shows that this reaction is chemically mediated by the reducing agent. PMID:27043921

  4. Covalent disulfide-linked anti-CEA diabody allows site-specific conjugation and radiolabeling for tumor targeting applications

    PubMed Central

    Olafsen, Tove; Cheung, Chia-wei; Yazaki, Paul J.; Li, Lin; Sundaresan, Gobalakrishnan; Gambhir, Sanjiv S.; Sherman, Mark A.; Williams, Lawrence E.; Shively, John E.; Raubitschek, Andrew A.; Wu, Anna M.

    2014-01-01

    An engineered anti-carcinoembryonic antigen (CEA) diabody (scFv dimer, 55 kDa) was previously constructed from the murine anti-CEA T84.66 antibody. Tumor targeting, imaging and biodistribution studies in nude mice bearing LS174T xenografts with radiolabeled anti-CEA diabody demonstrated rapid tumor uptake and fast blood clearance, which are favorable properties for an imaging agent. Current radiolabeling approaches result in random modification of the protein surface, which may impair immunoreactivity especially for smaller antibody fragments. Site-specific conjugation approaches can direct modifications to reactive groups located away from the binding site. Here, cysteine residues were introduced into the anti-CEA diabody at three different locations, to provide specific thiol groups for chemical modification. One version (with a C-terminal Gly-Gly-Cys) existed exclusively as a disulfide-bonded dimer. This cysteine-modified diabody (Cys-diabody) retained high binding to CEA and demonstrated tumor targeting and biodistribution properties identical to the non-covalent diabody. Furthermore, following reduction of the disulfide bond, the Cys-diabody could be chemically modified using a thiol-specific bifunctional chelating agent, for radiometal labeling. Thus, the Cys-diabody provides a covalently linked alternative to conventional diabodies, which can be reduced and modified site-specifically. This format will provide a versatile platform for targeting a variety of agents to CEA-positive tumors. PMID:14985534

  5. Electrochemical Insight into the Brust-Schiffrin Synthesis of Au Nanoparticles.

    PubMed

    Uehara, Akihiro; Booth, Samuel G; Chang, Sin Yuen; Schroeder, Sven L M; Imai, Takahito; Hashimoto, Teruo; Mosselmans, J Frederick W; Dryfe, Robert A W

    2015-12-01

    The mechanism of the Brust-Schiffrin gold nanoparticle synthesis has been investigated through the use of ion transfer voltammetry at the water/1,2-dichloroethane (DCE) solution interface, combined with X-ray absorption fine structure (XAFS) of the reaction between [AuCl4](-) and thiol (RSH) in homogeneous toluene (TL) solution. Ion transfer calculations indicate the formation of [AuCl2](-) at RSH/Au ratios from 0.2-2 with a time-dependent variation observed over several days. At RSH/Au ratios above 2 and after time periods greater than 24 h, the formation of Au(I)SR is also observed. The relative concentrations of reaction products observed at the liquid/liquid interface are in excellent agreement with those observed by XAFS for the corresponding reaction in a single homogeneous phase. BH4(-) ion transfer reactions between water and DCE indicate that the reduction of [AuCl4](-) or [AuCl2](-) to Au nanoparticles by BH4(-) proceeds in the bulk organic phase. On the other hand, BH4(-) was unable to reduce the insoluble [Au(I)SR]n species to Au nanoparticles. The number and size of the nanoparticles formed was dependent on the concentration ratio of RSH/Au, as well as the experimental duration because of the competing formation of the [Au(I)SR]n precipitate. Higher concentrations of nanoparticles, with diameters of 1.0-1.5 nm, were formed at RSH/Au ratios from 1 to 2. PMID:26559785

  6. Determination of Size Effects during the Phase Transition of a Nanoscale Au-Si Eutectic

    NASA Astrophysics Data System (ADS)

    Kim, B. J.; Tersoff, J.; Wen, C.-Y.; Reuter, M. C.; Stach, E. A.; Ross, F. M.

    2009-10-01

    The phase diagram of a nanoscale system can be substantially different than in the bulk, but quantitative measurements have proven elusive. Here we use in situ microscopy to observe a phase transition in a nanoscale system, together with a simple quantitative model to extract the size effects from these measurements. We expose a Au particle to disilane gas, and observe the transition from a two-phase Au+AuSi system to single-phase AuSi. Size effects are evident in the nonlinear disappearance of the solid Au. Our analysis shows a substantial shift in the liquidus line, and a discontinuous change in the liquid composition at the transition. It also lets us estimate the liquid-solid interfacial free energy.

  7. Determination of size effects during the phase transition of a nanoscale Au-Si eutectic.

    PubMed

    Kim, B J; Tersoff, J; Wen, C-Y; Reuter, M C; Stach, E A; Ross, F M

    2009-10-01

    The phase diagram of a nanoscale system can be substantially different than in the bulk, but quantitative measurements have proven elusive. Here we use in situ microscopy to observe a phase transition in a nanoscale system, together with a simple quantitative model to extract the size effects from these measurements. We expose a Au particle to disilane gas, and observe the transition from a two-phase Au + AuSi system to single-phase AuSi. Size effects are evident in the nonlinear disappearance of the solid Au. Our analysis shows a substantial shift in the liquidus line, and a discontinuous change in the liquid composition at the transition. It also lets us estimate the liquid-solid interfacial free energy. PMID:19905650

  8. Formation and Stabilization of Single-Crystalline Metastable AuGe Phases in Ge Nanowires

    SciTech Connect

    Sutter, E.; Sutter, P.

    2011-07-22

    We use in situ observations by variable temperature transmission electron microscopy on AuGe alloy drops at the tips of Ge nanowires (NWs) with systematically varying composition to demonstrate the controlled formation of metastable solid phases integrated in NWs. The process, which operates in the regime of vapor-liquid-solid growth, involves a size-dependent depression of the alloy liquidus at the nanoscale that leads to extremely Ge-rich AuGe melts at low temperatures. During slow cooling, these liquid AuGe alloy drops show pronounced departures from equilibrium, i.e., a frustrated phase separation of Ge into the adjacent solid NW, and ultimately crystallize as single-crystalline segments of metastable {gamma}-AuGe. Our findings demonstrate a general avenue for synthesizing NW heterostructures containing stable and metastable solid phases, applicable to a wide range of materials of which NWs form by the vapor-liquid-solid method.

  9. Templated Control of Au nanospheres in Silica Nanowires

    SciTech Connect

    Tringe, J W; Vanamu, G; Zaidi, S H

    2007-03-15

    The formation of regularly-spaced metal nanostructures in selectively-placed insulating nanowires is an important step toward realization of a wide range of nano-scale electronic and opto-electronic devices. Here we report templated synthesis of Au nanospheres embedded in silica nanowires, with nanospheres consistently spaced with a period equal to three times their diameter. Under appropriate conditions, nanowires form exclusively on Si nanostructures because of enhanced local oxidation and reduced melting temperatures relative to templates with larger dimensions. We explain the spacing of the nanospheres with a general model based on a vapor-liquid-solid mechanism, in which an Au/Si alloy dendrite remains liquid in the nanotube until a critical Si concentration is achieved locally by silicon oxide-generated nanowire growth. Additional Si oxidation then locally reduces the surface energy of the Au-rich alloy by creating a new surface with minimum area inside of the nanotube. The isolated liquid domain subsequently evolves to become an Au nanosphere, and the process is repeated.

  10. Antibacterial Au nanostructured surfaces

    NASA Astrophysics Data System (ADS)

    Wu, Songmei; Zuber, Flavia; Brugger, Juergen; Maniura-Weber, Katharina; Ren, Qun

    2016-01-01

    We present here a technological platform for engineering Au nanotopographies by templated electrodeposition on antibacterial surfaces. Three different types of nanostructures were fabricated: nanopillars, nanorings and nanonuggets. The nanopillars are the basic structures and are 50 nm in diameter and 100 nm in height. Particular arrangement of the nanopillars in various geometries formed nanorings and nanonuggets. Flat surfaces, rough substrate surfaces, and various nanostructured surfaces were compared for their abilities to attach and kill bacterial cells. Methicillin-resistant Staphylococcus aureus, a Gram-positive bacterial strain responsible for many infections in health care system, was used as the model bacterial strain. It was found that all the Au nanostructures, regardless their shapes, exhibited similar excellent antibacterial properties. A comparison of live cells attached to nanotopographic surfaces showed that the number of live S. aureus cells was <1% of that from flat and rough reference surfaces. Our micro/nanofabrication process is a scalable approach based on cost-efficient self-organization and provides potential for further developing functional surfaces to study the behavior of microbes on nanoscale topographies.We present here a technological platform for engineering Au nanotopographies by templated electrodeposition on antibacterial surfaces. Three different types of nanostructures were fabricated: nanopillars, nanorings and nanonuggets. The nanopillars are the basic structures and are 50 nm in diameter and 100 nm in height. Particular arrangement of the nanopillars in various geometries formed nanorings and nanonuggets. Flat surfaces, rough substrate surfaces, and various nanostructured surfaces were compared for their abilities to attach and kill bacterial cells. Methicillin-resistant Staphylococcus aureus, a Gram-positive bacterial strain responsible for many infections in health care system, was used as the model bacterial strain. It

  11. Pt@AuNPs integrated quantitative capillary-based biosensors for point-of-care testing application.

    PubMed

    Wu, Ze; Fu, Qiangqiang; Yu, Shiting; Sheng, Liangrong; Xu, Meng; Yao, Cuize; Xiao, Wei; Li, Xiuqing; Tang, Yong

    2016-11-15

    Current diagnostic technologies primarily rely on bulky and costly analytical instruments. Therefore, cost-effective and portable diagnosis tools that can be used for point-of-care tests (POCT) are highly desirable. In this study, we report a cost-effective, portable capillary-based biosensor for quantitative detection of biomarkers by the naked eye. This capillary-based biosensor was tested by measuring the distance of blue ink movement, which was directly correlated with the oxygen (O2) produced by efficient core-shell Pt@Au nanoparticles (Pt@AuNPs) catalysts decomposed hydrogen peroxide (H2O2). By linking the Pt@AuNPs with antibodies, capillary-based biosensor sandwich immunoassays were constructed. The concentrations of the target proteins were positively correlated with the distances of ink movement. To demonstrate their performance, the biosensors were used to detect the cancer biomarker sprostate-specific antigen (PSA) and carcinoembryonic antigen (CEA). The linear detection range (LDR) of the capillary-based biosensor for detecting PSA was from 0.02 to 2.5ng/mL, and the limit of detection (LOD) was 0.017ng/mL. LDR of the biosensor for detecting CEA was from 0.063 to 16ng/mL, and the LOD was 0.044ng/mL. For detection of PSA and CEA in clinical serum samples, the detection results of the capillary-based biosensor were well correlate with the results from of chemiluminescence immunoassays (CLIAs). Thus, the capillary-based biosensor may potentially be a useful strategy for point-of-care testing, in addition to being portable and cost effective. PMID:27240013

  12. AIRIX: an induction accelerator facility developed at CEA for flash radiography in detonics

    NASA Astrophysics Data System (ADS)

    Cavailler, Claude

    1999-06-01

    AIRIX is an induction linear accelerator which will be used for flash radiography in CEA/DAM. Designed to produce an X-ray dose of more than 500 Rads at 1 meter with an X-ray focal spot size diameter of less than 2 mm (LANL-CEA DAM definition), this facility consists in a 4 MeV/3.5 kA pulsed electron injector and 16 MeV induction accelerator powered by 32 high voltage generators. A prototype of this accelerator, called PIVAIR, has been studied and realized in CEA CESTA near Bordeaux. PIVAIR is a validation step for AIRIX at 8 MeV. It includes an injector (4 MeV, 3.5 kA, 60 ns) and 16 inductor cells supplied by 8 high voltage generators (250 kV, 70 ns). Two different technologies of induction cells have been tested (rexolite insulator or ferrite under vacuum). We have chosen ferrite under vacuum cells technology after comparison of results on beam transport and reliability tests. A focusing experiment at 7.2 MeV of the electron beam as been achieved during summer 1997. We have begun to produce X-rays in October 1997. A dose level of 50 Rad at 1 meter has been achieved with an X-ray spot size diameter of 3.5 to 4 mm (LANL-CEA DAM definition). Static flash radiography of very dense object have been achieved from November 97 until February 98. We have been able to test in situ new kinds of very high sensitive X- ray detectors and to check they had reached our very ambitious goals: (1) quantum efficiency at 5 MeV greater than 50% instead of 1% for luminous screens and film; (2) sensitivity less than 10 (mu) Rad (100 time more sensitive than radiographic luminous screens and films); (3) dynamic range greater than 100; (4) resolution less than 2 mm. We will present in this communication brand new kinds of detection systems, called high stopping power detectors, such as: (1) (gamma) camera with segmented thick crystal of BGO and MCP image intensifier; (2) multistep parallel plate avalanche chamber; (3) pixellized CdTe MeV photoconductor matrix. AIRIX accelerator is being

  13. Elecsys CEA, PSA and AFP. Clinical results of a multicentre evaluation.

    PubMed

    Uhl, W; Chan, D W; Jones, K; Kelley, C; Assmann, G; von Eckardstein, A; Sägers, A; Yvert, J P; Schneider, A M; Torralba, A; Fuentes-Arderiu, X; Gonzalez de la Presa, B; Vives, M; Greiling, H; Eberle, A; Niederau, C M; Cremer, P; Reiter, W; Vogeser, M; Neumeier, D; Luppa, P; Huber, U

    1998-01-01

    Three tumormarker assays, Elecsys CEA, PSA and AFP, have been evaluated in an international multicentre study to characterize their clinical performance and to verify the comparability with the corresponding tests of the Enzymun-Test product line and other methods. For each of the markers results were obtained from four laboratories. On the basis of 314 and 199 specimens respectively, (preliminary) reference ranges could be established for CEA and PSA. For the prostate marker, the age dependence of the antigen level could be clearly confirmed. Mean concentrations range between 0.51 ng/ml (< 40 years) and 3.57 ng/ml (> 70 years). Referring to CEA, 95th percentiles of 4.31 ng/ml and 2.69 ng/ml were elaborated for smokers and nonsmokers. In general, good to excellent correlations (r > 0.98) were found between the Elecsys and Enzymun-Tests. Regarding the systematic comparability of both systems, most of the slopes derived from the individual method comparison studies are within the +/- 10% range of the respective standardization results. The specific distribution pattern of the individual tumormarker values elaborated with sample material of known clinical background, reflects the well established categorization of different benign and malignant diseases according to their characteristic marker levels. Of utmost importance, however, is the excellent comparability of the Elecsys assays with the corresponding Enzymun-Tests and the FDA approved AIA 1200 tests from TOSOH in follow-up studies. Almost superimposable concentration curves guarantee that identical diagnostic information is derived from all three methods. Especially for PSA, a series of measurements on sera of prostatectomized patients proved the usability and clinical value of the test also for this particular indication. For either one of the Elecsys tests, the feasibility of using plasma as sample material was verified. PMID:9677672

  14. R and D Programs and Policy within the CEA-AREVA Joint Vitrification Lab (LCV) - 13592

    SciTech Connect

    Piroux, Jean Christophe; Paradis, Luc; Ladirat, Christian; Brueziere, Jerome; Chauvin, Eric

    2013-07-01

    Waste management is a key issue for the reprocessing industry; furthermore, vitrification is considered as the reference for nuclear waste management. In order to further improve and strengthen their historical cooperation in high temperature waste management, the CEA, R and D organization, and AREVA, Industrial Operator, decided, in September 2010, to create a Joint Vitrification Laboratory within the framework of a strategic partnership. The main objectives of the CEA-AREVA Joint Vitrification Laboratory (LCV) are (i) support AREVA's activities, notably in its La Hague plants and for new projects, (ii) strengthen the CEA's lead as a reference laboratory in the field of waste conditioning. The LCV is mandated to provide strong, innovative solutions through the performance of R and D on processes and materials for vitrification, fusion and incineration, for high, intermediate and low level waste. The activities carried out in the LCV include academic research on containment matrices (formulation, long-term behaviour), and the improvement of current technologies/development of new ones in lab-scale to full-scale pilot facilities, in non-radioactive and radioactive conditions, including modelling and experimental tools. This paper focuses on the programs and policy managed within the LCV, as well as the means employed by the CEA and AREVA to meet common short-,mid- and long-term challenges, from a scientific and industrial point of view. Among other things, we discuss the technical support provided for the La Hague vitrification facilities on hot melter and CCIM technologies, the start-up of new processes (decommissioning effluents, UMo FP) with CCIM, the preparation of future processes by means of an assessment of new technologies and containment matrices (improved glasses, ceramics, etc.), as well as incineration/vitrification for organic and metallic mixed waste or metallic fusion. The close relationship between the R and D teams and industrial operators enables

  15. Development of recycled plastic composites for structural applications from CEA plastics

    NASA Astrophysics Data System (ADS)

    Bhalla, Agrim

    Plastic waste from consumer electronic appliances (CEAs) such as computer and printer parts including Polystyrene (PS), Acrylonitrile Butadiene Styrene (ABS), Polystyrene (PS) and PC/ABS were collected using handheld FTIR Spectrophotometer. The blends of these plastics with High Density Polyethylene (HDPE) are manufactured under special processing conditions in a single screw compounding injection molding machine. The blends are thermoplastics have high stiffness and strength, which may enhance the mechanical properties of HDPE like tensile modulus, ultimate tensile strength, tensile break and tensile yield. These composites have a potential to be used for the future application of recycled plastic lumber, thus replacing the traditional wood lumber.

  16. Charting a course through the CEAs: diagnosis and management of medullary thyroid cancer.

    PubMed

    Rowe, Christopher W; Bendinelli, Cino; McGrath, Shaun

    2016-09-01

    Medullary thyroid cancer (MTC) is an uncommon thyroid cancer that requires a high index of suspicion to facilitate diagnosis of early-stage disease amenable to surgical cure. The challenges of diagnosis, as well as management in the setting of persistent disease, are explored in the context of a case presenting with the incidental finding of elevated carcinoembryonic antigen (CEA) and an (18) F-fluorodeoxyglucose positron emission tomography ((18) F-FDG-PET)-positive thyroid incidentaloma detected following treatment of colorectal cancer. Strategies to individualize prognosis, and emerging PET-based imaging modalities, particularly the potential role of (18) F-DOPA-PET in staging, are reviewed. PMID:27230389

  17. Surface morphology and optical properties of porphyrin/Au and Au/porphyrin/Au systems

    NASA Astrophysics Data System (ADS)

    Kalachyova, Yevgeniya; Lyutakov, Oleksiy; Solovyev, Andrey; Slepička, Petr; Švorčík, Vaclav

    2013-12-01

    Porphyrin/Au and Au/porphyrin/Au systems were prepared by vacuum evaporation and vacuum sputtering onto glass substrate. The surface morphology of as-prepared systems and those subjected to annealing at 160°C was studied by optical microscopy, atomic force microscopy, and scanning electron microscopy techniques. Absorption and luminescence spectra of as-prepared and annealed samples were measured. Annealing leads to disintegration of the initially continuous gold layer and formation of gold nanoclusters. An amplification of Soret band magnitude was observed on the Au/meso-tetraphenyl porphyrin (TPP) system in comparison with mere TPP. Additional enhancement of luminescence was observed after the sample annealing. In the case of sandwich Au/porphyrin/Au structure, suppression of one of the two porphyrins' luminescence maxima and sufficient enhancement of the second one were observed.

  18. Antibacterial Au nanostructured surfaces.

    PubMed

    Wu, Songmei; Zuber, Flavia; Brugger, Juergen; Maniura-Weber, Katharina; Ren, Qun

    2016-02-01

    We present here a technological platform for engineering Au nanotopographies by templated electrodeposition on antibacterial surfaces. Three different types of nanostructures were fabricated: nanopillars, nanorings and nanonuggets. The nanopillars are the basic structures and are 50 nm in diameter and 100 nm in height. Particular arrangement of the nanopillars in various geometries formed nanorings and nanonuggets. Flat surfaces, rough substrate surfaces, and various nanostructured surfaces were compared for their abilities to attach and kill bacterial cells. Methicillin-resistant Staphylococcus aureus, a Gram-positive bacterial strain responsible for many infections in health care system, was used as the model bacterial strain. It was found that all the Au nanostructures, regardless their shapes, exhibited similar excellent antibacterial properties. A comparison of live cells attached to nanotopographic surfaces showed that the number of live S. aureus cells was <1% of that from flat and rough reference surfaces. Our micro/nanofabrication process is a scalable approach based on cost-efficient self-organization and provides potential for further developing functional surfaces to study the behavior of microbes on nanoscale topographies. PMID:26648134

  19. Miscibility and alignment effects of mixed monolayer cyanobiphenyl liquid-crystal-capped gold nanoparticles in nematic cyanobiphenyl liquid crystal hosts.

    PubMed

    Qi, Hao; Kinkead, Brandy; Marx, Vanessa M; Zhang, Huai R; Hegmann, Torsten

    2009-06-01

    Against the rule: Liquid crystal hosts (5CB and 8CB) are doped with different thiol decorated gold nanoparticles (see figure). The "simple" hexanethiol and dodecanethiol capped nanoparticles (Au1 and Au2) are more compatible to the nematic cyanobiphenyl liquid crystals than nanoparticles capped simultaneously with alkylthiols and a nematic cyanobiphenyl thiol (Au3 and Au4).This study focuses on the miscibility of liquid crystal (LC) decorated gold nanoparticles (NPs) in nematic LCs. To explore if LC functional groups on the gold NP corona improve the compatibility (miscibility) with structurally related LC hosts, we examined mixtures of two LC hosts, 5CB and 8CB, doped at 5 wt % with different types of gold NPs. Four alkanethiol-capped NPs were synthesized; two homogeneously coated with alkanethiols (Au1 with C(6)H(13)SH and Au2 with C(12)H(25)SH), and two that were additionally capped at a different ratio with a mesogenic cyanobiphenyl end-functionalized alkanethiol HS10OCB (C(6)H(13)SH + HS10OCB for Au3 and C(12)H(25)SH + HS10OCB for Au4). Investigating these mixtures in the bulk for settling of the NPs, and in thin films using polarized optical microscopy (POM) between untreated glass slides as well as POM studies and electro-optic tests in planar ITO/polyimide test cells, reveal that the alkanethiol capped NPs Au1 and Au2 are more compatible with the two polar cyanobiphenyl hosts in comparison to the NPs decorated with the cyanobiphenyl moieties. All NPs induce homeotropic alignment in 5CB and 8CB between untreated glass slides, with Au1 and Au2 showing characteristic birefringent stripes, and Au3 and A4 exhibiting clear signs of aggregation. In rubbed polyimide cells, however, Au3 and Au4 fail to induce homeotropic alignment and show clear signs of macroscopic aggregation. PMID:19334026

  20. 40 YEARS OF EXPERIENCE WITH LIQUID-LIQUID EXTRACTION EQUIPMENT IN THE NUCLEAR INDUSTRY

    SciTech Connect

    Drain, F.; Vinoche, R.; Duhamet, J.

    2003-02-27

    Three types of liquid-liquid extraction equipment are used in industrial reprocessing plants. Each is described below, with a special focus on pulsed columns and centrifugal extractors, which have been the subject of an extensive R&D program by the French Atomic Energy Commission (CEA). Various models have been developed to simulate equipment behavior and flowsheets. The excellent results obtained during industrial operation of the UP3 and UP2-800 plants in La Hague have confirmed the validity of the choices made during the design phases and pave the way for future improvement of the reprocessing process, from a technical and a financial standpoint.

  1. Metanephrine neuroendocrine tumor marker detection by SERS using Au nanoparticle/Au film sandwich architecture.

    PubMed

    Boca, Sanda; Farcau, Cosmin; Baia, Monica; Astilean, Simion

    2016-02-01

    Neuroendocrine tumors, such as pheochromocytoma or paraganglioma, are dangerous tumors that constitute a potential threat for a large number of patients. Currently, the biochemical diagnosis of neuroendocrine tumors is based on measurement of the direct secretory products of the adrenomedullary-sympathetic system or of their metabolites, such as catecholamines or their metanephrine derivatives, from plasma or urine. The techniques used for analysis of plasma free metanephrines, i.e. high-performance liquid chromatography or high-performance liquid chromatography coupled with mass-spectrometry are technically-demanding and time consuming, which limit their availability. Here we demonstrate a simple, fast and low-cost method for detecting metanephrine by Surface Enhanced Raman Scattering (SERS). The protocol consists in using evaporation-induced self-assembly of gold (Au) nanoparticles incubated with the analyte, on planar gold films. The assembly process produces regions with a dense distribution of both inter-particle gaps and particle-film gaps. Finite-difference time-domain simulations confirm that both kinds of gaps are locations of enhanced electromagnetic fields resulting from inter-particle and particle-film plasmonic coupling, useful for SERS amplification. Metanephrine vibrational bands assignment was performed according to density functional theory calculations. Metanephrine metabolite was detected in liquid at concentration levels lower than previously reported for other similar metabolites. The obtained results demonstrate that the Au nanoparticle/Au film exhibits noticeable SERS amplification of the adsorbed metabolite and can be used in the design of efficient, stable SERS-active substrates for the detection and identification of specific tumor markers. PMID:26820563

  2. Aeroacoustics research in Europe: The CEAS-ASC report on 2010 highlights

    NASA Astrophysics Data System (ADS)

    Balázs Nagy, Attila

    2011-10-01

    The Council of European Aerospace Societies (CEAS) Aeroacoustics Specialists Committee (ASC) supports and promotes the interests of the scientific and industrial aeroacoustics community on an European scale and European aeronautics activities internationally. In this context, "aeroacoustics" encompasses all aerospace acoustics and related areas. Each year the committee highlights some of the research and development projects in Europe. This paper is a report on highlights of aeroacoustics research in Europe in 2010, compiled from information provided to the ASC of the CEAS. At the end of 2010, project X-NOISE EV of the Seventh Framework Programme of the European Commission has been launched as a continuation of the X-Noise series, with objectives of reducing aircraft noise and reaching the goal set by the ACARE 2020 Vision. Some contributions submitted to the editor summarizes selected findings from European projects launched before or concluded in 2010, while other articles cover issues supported by national associations or by industries. Furthermore, a concise summary of the workshop on "Aeroacoustics of High-Speed Aircraft Propellers and Open Rotors" held in Warsaw in October is included in this report. Enquiries concerning all contributions should be addressed to the authors who are given at the end of each subsection.

  3. High intensity ECR ion source (H+, D+, H-) developments at CEA/Saclay

    NASA Astrophysics Data System (ADS)

    Gobin, R.; Beauvais, P.-Y.; Bogard, D.; Charruau, G.; Delferrière, O.; Menezes, D. De; France, A.; Ferdinand, R.; Gauthier, Y.; Harrault, F.; Jannin, J.-L.; Lagniel, J.-M.; Leroy, P.-A.; Mattéi, P.; Sherman, J.; Sinanna, A.; Ausset, P.; Bousson, S.; Pottin, B.

    2002-02-01

    Source of light ions with high intensities The (SILHI) source has been producing proton beams since 1996. The first aim is to produce up to 100 mA cw beams at 95 keV for the injector of protons for high intensity demonstrator. This prototype is developed by a CEA/DSM-CNRS/IN2P3 collaboration for applications such as accelerator driven systems for nuclear waste transmutation, production of radioactive ion beams, or secondary particles. To measure installation reliability, continuous 5 day long runs have been performed. In October 1999, a 99.96% availability was achieved with a single short beam off and a 103 H uninterrupted beam. A new extraction system leads to lower beam losses and higher LEBT transparency. SILHI now produces a 95 keV-130 mA total beam with a proton fraction higher than 80%. Up to a 157 mA (247 mA/cm2) total cw beam has been extracted. The new EPICS control system, electromagnetic interference hardened devices and automatic control procedures now allow us to do longer runs. To analyze the reliability of these upgrades, a 4 week test was planned. In the framework of the International Fusion Material Irradiation Facility project CEA participation, 135 mA-95 kV deuteron pulsed beams were produced. Extraction simulations and recent SILHI results are also presented. In addition, a new test bench has been recently developed to analyze H- beam production.

  4. Aeroacoustics research in Europe: The CEAS-ASC report on 2014 highlights

    NASA Astrophysics Data System (ADS)

    Detandt, Yves

    2015-11-01

    The Council of European Aerospace Societies (CEAS) Aeroacoustics Specialists Committee (ASC) supports and promotes the interests of the scientific and industrial aeroacoustics community on an European scale and European aeronautics activities internationally. Each year the committee highlights some of the research and development projects in Europe. This paper is the 2014 issue of this collection of Aeroacoustic Highlights, compiled from informations submitted to the CEAS-ASC. The contributions are classified in different topics; the first categories being related to specific aeroacoustic challenges (airframe noise, fan and jet noise, helicopter noise, aircraft interior noise) and two last sections are respectively devoted to recent improvements and emerging techniques and to general advances in aeroacoustics. For each section, the present paper focus on accomplished projects, providing the state of the art in each research category in 2014. A number of research programmes involving aeroacoustics were funded by the European Commission. Some of the highlights from these programmes are summarised in this paper, as well as highlights funded by national programmes or by industry.

  5. Treatment of actinide exposures: a review of Ca-DTPA injections inside CEA-COGEMA plants.

    PubMed

    Grappin, Louise; Berard, Philippe; Menetrier, Florence; Carbone, Lise; Courtay, Catherine; Castagnet, Xavier; Le Goff, Jean-Pierre; Neron, Marie-Odile; Piechowski, Jean

    2007-01-01

    Calcium diethylenetriamine pentacetate (Ca-DTPA) has been used for medical treatment of plutonium and americium contaminations in the CEA and COGEMA plants from 1970 to 2003. This paper is a survey of the injections Ca-DTPA administered as a chelating molecule and it will be a part of the authorisation process for Ca-DTPA by intravenous administration. Out of 1158 injections administered to 469 persons, 548 events of possible or confirmed contamination were reported. These employees were followed by occupational physicians according to the current French regulations. These incidents took place at work, were most often minor, not requiring follow-up treatment. The authors present (1) a synthesis of the most recent findings. Due to its short biological half-time and its limited action in the blood, Ca-DTPA does not chelate with plutonium and americium as soon as these elements are deposited in the target organs. It justifies an early treatment, even in cases of suspected contamination followed by additional injections if necessary (2) data concerning these 1158 injections (route of contamination, dosage, adverse effects, etc.) The authors also investigated a study on the efficacy of the product on a group of persons having received five or more injections. These results were compared with the efficacy estimated theoretically. Dosages and therapeutic schemes were proposed based on these observations. This synthesis is the result of a collective work having mobilised the occupational medicine departments, the medical laboratories inside a working group CEA-COGEMA-SPRA. PMID:17940101

  6. Structural and phonon transmission study of Ge-Au-Ge eutectically bonded interfaces

    SciTech Connect

    Knowlton, W.B. |

    1995-07-01

    This thesis presents a structural analysis and phonon transparency investigation of the Ge-Au-Ge eutectic bond interface. Interface development was intended to maximize the interfacial ballistic phonon transparency to enhance the detection of the dark matter candidate WIMPs. The process which was developed provides an interface which produces minimal stress, low amounts of impurities, and insures Ge lattice continuity through the interface. For initial Au thicknesses of greater than 1,000 {angstrom} Au per substrate side, eutectic epitaxial growth resulted in a Au dendritic structure with 95% cross sectional and 90% planar Au interfacial area coverages. In sections in which Ge bridged the interface, lattice continuity across the interface was apparent. Epitaxial solidification of the eutectic interface with initial Au thicknesses < 500 A per substrate side produced Au agglomerations thereby reducing the Au planar interfacial area coverage to as little as 30%. The mechanism for Au coalescence was attributed to lateral diffusion of Ge and Au in the liquid phase during solidification. Phonon transmission studies were performed on eutectic interfaces with initial Au thicknesses of 1,000 {angstrom}, 500 {angstrom}, and 300 {angstrom} per substrate side. Phonon imaging of eutectically bonded samples with initial Au thicknesses of 300 {angstrom}/side revealed reproducible interfacial percent phonon transmissions from 60% to 70%. Line scan phonon imaging verified the results. Phonon propagation TOF spectra distinctly showed the predominant phonon propagation mode was ballistic. This was substantiated by phonon focusing effects apparent in the phonon imaging data. The degree of interface transparency to phonons and resulting phonon propagation modes correlate with the structure of the interface following eutectic solidification. Structural studies of samples with initial Au thickness of 1,000 {angstrom}/side appear to correspond with the phonon transmission study.

  7. Radioimmunoimaging of metastatic medullary carcinoma of the thyroid gland using an indium-111-labeled monoclonal antibody to CEA

    SciTech Connect

    Edington, H.D.; Watson, C.G.; Levine, G.; Tauxe, W.N.; Yousem, S.A.; Unger, M.; Kowal, C.D.

    1988-12-01

    Elevated levels of carcinoembryonic antigen (CEA) or calcitonin after surgical therapy for medullary carcinoma of the thyroid gland (MCT) indicate the presence of residual or metastatic disease. CEA elevations appear to be prognostically more reliable in patients with metastatic disease and suggest a more virulent tumor. Attempts to stage the disease with use of conventional imaging techniques are usually inadequate, as is the therapy for disseminated or recurrent MCT. An indium-111-labeled anti-CEA monoclonal antibody (ZCE-025) was used to image metastases in a patient with MCT. Potential applications of monoclonal antibody technology in the management of MCT would include (1) preoperative differentiation of unicentric from multicentric thyroid gland involvement, (2) detection of regional or distant metastases or both, (3) measurement of response to systemic therapy, and (4) the facilitation of radionuclide immunoconjugate therapy.

  8. Different Levels of CEA, CA153 and CA125 in Milk and Benign and Malignant Nipple Discharge

    PubMed Central

    Zhao, Song; Mei, Yu; Wang, Jianli; Zhang, Kai; Ma, Rong

    2016-01-01

    Background The aim of this study was to assess the diagnostic values of three breast tumor markers (i.e., CEA, CA153 and CA125) in milk and nipple discharge in the prediction of different breast diseases diagnoses. Methods Three hundred thirty-six patients (96 breast cancer and 240 benign disease patients) with nipple discharge and a control group of 56 healthy parturient participants were enrolled in the present study. Nipple discharge samples were preoperatively collected from the patients, and milk was collected from the colostrum of the parturient participants. The samples were assayed for the CEA, CA153 and CA125 levels. Cutoff values were determined for the detection of breast diseases using ROC curves. Results The levels of CEA, CA153 and CA125 were significantly different between the nipple discharge and the milk (all ps < 0.001). In the nipple discharge, the CEA and CA153 levels in the breast cancer group were significantly greater than those in the benign group (all ps < 0.001), and cutoff values of 263.3 ng/mL and 1235.3 U/mL, respectively, were established. However, the expression of CA125 did not differ significantly between the breast cancer and benign groups. Conclusion Differences in the apparent expression levels of CEA, CA153 and CA125 in patients with nipple discharge and healthy persons were validated. The present data suggest that CEA and CA153 might potentially be useful in the differential diagnoses of benign tumors and breast cancer. CA125 did not seem to be useful for breast cancer detection. PMID:27327081

  9. HIQA's CEA of Breast Screening: Pragmatic Policy Recommendations are Welcome, but ACERs Reported as ICERs are Not.

    PubMed

    O'Mahony, James F; Normand, Charles

    2015-12-01

    The Health Information and Quality Authority (HIQA) is Ireland's statutory cost-effectiveness analysis (CEA) agency. It recently published a CEA of screening strategies for women at elevated risk of breast cancer. Although the strategies recommended by HIQA exceed Ireland's cost-effectiveness threshold, they can reasonably be welcomed as a pragmatic response to constraints on disinvestment and are expected to improve screening cost-effectiveness. What is not welcome, however, is HIQA's reporting of average cost-effectiveness ratios (ACERs) as incremental cost-effectiveness ratios (ICERs). The distinction between ACERs and ICERs is well understood in CEA, as is the fact that ICERs not ACERs are the appropriate metric to determine cost-effectiveness. This article critiques HIQA's reporting, considering the implications for the particular case of breast cancer screening and the broader context of consistency of and confidence in CEA as a guide to resource allocation in Ireland. The reporting of ACERs as ICERs is unlikely to be of any great significance in the particular case of screening women at elevated risk of breast cancer, given likely constraints on disinvestment. Despite this, ICERs still need to be reported correctly. If thresholds are exceeded in certain cases, then it is important that decision makers appreciate by how much. More generally, using ACERs in some cases and ICERs in others raises concerns that methods are being applied inconsistently, which risks compromising confidence in CEA in Ireland. As Ireland's statutory CEA authority, HIQA has a special onus of responsibility to ensure established methods are applied correctly. PMID:26686777

  10. Comparison of Serum CA72-4 and CEA Levels in Patient with Endoscopically Suspected Gastric Carcinoma.

    PubMed

    Rehena, Z; Ghosh, C K; Afroz, F; Alam, M B; Ferdousi, S; Mahmuduzzaman, M; Sultana, T; Ahmed, A N

    2015-07-01

    Several serum tumour markers have been described for gastric cancer. Preoperative level of tumor marker helps to predict the diagnosis of gastric carcinoma. CA72-4 as a serum tumour marker for gastric cancer is evaluated, and compared its utility in this regard with that of carcinoembryonic antigen (CEA). Analysis of gastric carcinoma by serum levels of CEA and CA72-4 and their correlation with histopathology help the clinician to develop his management strategies for gastric carcinoma. A prospective observational study was carried out in the Department of Clinical Pathology, Bangabandhu Sheikh Mujib Medical University (BSMMU) in collaboration with Department of Surgery BSMMU, DMCH, Delta Hospital Limited, Dhaka, during the period of October 2010 to September 2011. Serum CA72-4 and CEA were analyzed in 71 endoscopically suspected patients for gastric carcinoma. Among them 58 cases were diagnosed as malignant gastric disease and 13 cases were nonmalignant gastric disease. Sensitivity of CA 72-4 and CEA were 48.3% and 31% respectively and specificity were 92.3% and 76.9% respectively. In poorly differentiated carcinoma, positivity for CA72-4 and CEA were 55.6% and 36.1% respectively. Because of the high positivity of CA72-4 in poorly differentiated carcinoma, CA72-4 is reliable tumour marker in advanced cases. As the sensitivity of CA72-4 was more than that of CEA in diagnosis of gastric cancer, CA72-4 can be used in conjunction with other diagnostic tests like endoscopy that would be more helpful for the patients. PMID:26329953

  11. Clinical significance of joint detection of serum CEA, SCCA, and bFGF in the diagnosis of lung cancer

    PubMed Central

    Zhao, Wei; Yu, Haixiang; Han, Zhifeng; Gao, Nan; Xue, Jinru; Wang, Yan

    2015-01-01

    Lung cancer is a type of malignant tumor with highest morbidity and mortality. This study tested three tumor marker levels including CEA, SCCA, and bFGF to explore their value in lung cancer diagnosis and pathological type judgment. Venous blood was extracted from lung cancer patients, lung benign lesion patients and healthy control. Electrochemiluminescence immunoassay was applied to detect serum CEA and SCCA content. ELISA was used to test serum bFGF level. Serum CEA, SCCA, and bFGF levels and positive rates were significantly higher in lung cancer group than that of lung benign disease group and health control (P < 0.05). bFGF showed higher detection sensitivity than CEA in lung cancer (P < 0.05). Three joint detection sensitivity was higher than single test (P < 0.05), while its specificity was lower (P < 0.05), and the accuracy presented no significant difference. Serum CEA and SCCA levels and positive rates were obviously higher in non-small cell lung cancer patients when compared with small cell lung cancer patients (P < 0.05), while bFGF level was similar between small cell lung cancer and non-small cell lung cancer. bFGF showed higher detection rate than SCCA in small cell lung cancer (P < 0.05). Three joint detection exhibited higher positive rate in small cell lung cancer and non-small lung cancer than single test. Serum CEA, SCCA and bFGF joint detection improved detection sensitivity in lung cancer and had important reference value for pathological type deduction. PMID:26464712

  12. AuRu/AC as an effective catalyst for hydrogenation reactions

    SciTech Connect

    Villa, Alberto; Chan-Thaw, Carine E.; Campisi, Sebastiano; Bianchi, Claudia L.; Wang, Di; Kotula, Paul G.; Kübel, Christian; Prati, Laura

    2015-03-23

    AuRu bimetallic catalysts have been prepared by sequential deposition of Au on Ru or vice versa obtaining different nanostructures: when Ru has been deposited on Au, a Aucore–Rushell has been observed, whereas the deposition of Au on Ru leads to a bimetallic phase with Ru enrichment on the surface. In the latter case, the unexpected Ru enrichment could be attributed to the weak adhesion of Ru on the carbon support, thus allowing Ru particles to diffuse on Au particles. Both structures result very active in catalysing the liquid phase hydrogenolysis of glycerol and levulinic acid but the activity, the selectivity and the stability depend on the structure of the bimetallic nanoparticles. Ru@Au/AC core–shell structure mostly behaved as the monometallic Ru, whereas the presence of bimetallic AuRu phase in Au@Ru/AC provides a great beneficial effect on both activity and stability.

  13. Synthesis of selenolate-protected Au18(SeC6H5)14 nanoclusters

    NASA Astrophysics Data System (ADS)

    Xu, Qian; Wang, Shuxin; Liu, Zhao; Xu, Guoyong; Meng, Xiangming; Zhu, Manzhou

    2013-01-01

    This work reports the first synthesis of selenophenolate-protected Au18(SePh)14 nanoclusters. This cluster exhibits distinct differences from its thiolate analogue in terms of optical absorption properties. The Au18(SePh)14 nanoclusters were obtained via a controlled reaction of Au25(SCH2CH2Ph)18 with selenophenol. Electrospray ionization time-of-flight mass spectrometry (ESI-TOF-MS) revealed the crude product to contain predominantly Au18(SePh)14 nanoclusters, and side products include Au15(SePh)13, Au19(SePh)15 and Au20(SePh)16. High-performance liquid chromatography (HPLC) was employed to isolate Au18(SePh)14 nanoclusters. The results of thermogravimetric analysis (TGA), elemental analysis (EA), and 1H/13C NMR spectroscopy confirmed the cluster composition. To the best of our knowledge, this is the first report of selenolate-protected Au18 nanoclusters. Future theoretical and X-ray crystallographic work will reveal the geometric structure and the nature of selenolate-gold bonding in the nanocluster.

  14. CEAS/AIAA/ICASE/NASA Langley International Forum on Aeroelasticity and Structural Dynamics 1999. Pt. 2

    NASA Technical Reports Server (NTRS)

    Whitlow, Jr., Woodrow (Editor); Todd, Emily N. (Editor)

    1999-01-01

    The proceedings of a workshop sponsored by the Confederation of European Aerospace Societies (CEAS), the American Institute of Aeronautics and Astronautics (AIAA), the National Aeronautics and Space Administration (NASA), Washington, D.C., and the Institute for Computer Applications in Science and Engineering (ICASE), Hampton, Virginia, and held in Williamsburg, Virginia June 22-25, 1999 represent a collection of the latest advances in aeroelasticity and structural dynamics from the world community. Research in the areas of unsteady aerodynamics and aeroelasticity, structural modeling and optimization, active control and adaptive structures, landing dynamics, certification and qualification, and validation testing are highlighted in the collection of papers. The wide range of results will lead to advances in the prediction and control of the structural response of aircraft and spacecraft.

  15. Science and Technology Research and Development in Support to ITER and the Broader Approach at CEA

    SciTech Connect

    Becoulet, A.; Hoang, G T; Abiteboul, J.; Achard, J.; Alarcon, T.; Klepper, C Christopher

    2013-01-01

    In parallel to the direct contribution to the procurement phase of ITER and Broader Approach, CEA has initiated research & development programmes, accompanied by experiments together with a significant modelling effort, aimed at ensuring robust operation, plasma performance, as well as mitigating the risks of the procurement phase. This overview reports the latest progress in both fusion science and technology including many areas, namely the mitigation of superconducting magnet quenches, disruption-generated runaway electrons, edge-localized modes (ELMs), the development of imaging surveillance, and heating and current drive systems for steady-state operation. The WEST (W Environment for Steady-state Tokamaks) project, turning Tore Supra into an actively cooled W-divertor platform open to the ITER partners and industries, is presented.

  16. TRIPOLI-4®, CEA, EDF and AREVA Reference Monte Carlo Code

    NASA Astrophysics Data System (ADS)

    2014-06-01

    This paper presents an overview of TRIPOLI-4®, the fourth generation of the 3D continuous-energy Monte Carlo code developed by the Service d'Etudes des Réacteurs et de Mathématiques Appliquées (SERMA) at CEA Saclay. The paper surveys the generic features: programming language, parallel operation, tracked particles, nuclear data, geometry, simulation modes, standard variance reduction techniques, sources, tracking and collision algorithms, tallies, sensitivity studies. Moreover, specific and recent features are also detailed: Doppler broadening of the elastic scattering kernel, neutron and photon material irradiation, advanced variance reduction techniques, Green's functions, cycle correlation correction, nuclear data management and depletion capabilities. The productivity tools (T4G, SALOME TRIPOLI, T4RootTools), the Verification & Validation process and the distribution and licensing policy are finally presented.

  17. Evaluation of the CEAS model for barley yields in North Dakota and Minnesota

    NASA Technical Reports Server (NTRS)

    Barnett, T. L. (Principal Investigator)

    1981-01-01

    The CEAS yield model is based upon multiple regression analysis at the CRD and state levels. For the historical time series, yield is regressed on a set of variables derived from monthly mean temperature and monthly precipitation. Technological trend is represented by piecewise linear and/or quadriatic functions of year. Indicators of yield reliability obtained from a ten-year bootstrap test (1970-79) demonstrated that biases are small and performance as indicated by the root mean square errors are acceptable for intended application, however, model response for individual years particularly unusual years, is not very reliable and shows some large errors. The model is objective, adequate, timely, simple and not costly. It considers scientific knowledge on a broad scale but not in detail, and does not provide a good current measure of modeled yield reliability.

  18. Validation of the 4C code against data from the HELIOS loop at CEA Grenoble

    NASA Astrophysics Data System (ADS)

    Zanino, R.; Bonifetto, R.; Casella, F.; Savoldi Richard, L.

    2013-01-01

    We complete the first validation campaign of the Cryogenic Circuit Conductor and Coil (4C) code, focusing on the cryogenic circuit module of 4C, which is based on the component models from the recently developed "Cryogenics" Modelica library. Measured data from the HELIOS facility (HElium Loop for hIgh LOads Smoothing) at CEA Grenoble, France, are used as reference. HELIOS includes a supercritical He loop (cold circulator, pipes equipped with resistive heaters, control and bypass valves, heat exchangers) and a saturated He bath. A repetitive heat pulse test is simulated with 4C. The computed evolution of temperature, pressure and mass flow rate at different circuit locations, both in the loop and in the bath, shows a very good agreement with the measurements.

  19. Recent progress on minor-actinide-bearing oxide fuel fabrication at CEA Marcoule

    NASA Astrophysics Data System (ADS)

    Lebreton, Florent; Prieur, Damien; Horlait, Denis; Delahaye, Thibaud; Jankowiak, Aurélien; Léorier, Caroline; Jorion, Frédéric; Gavilan, Elisabeth; Desmoulière, François

    2013-07-01

    Partitioning and transmutation (P&T) of minor actinides (MA: americium, neptunium and curium) in fast neutron reactors or accelerator-driven systems is a route envisaged to reduce nuclear waste inventory. Over the years, several modes of P&T were proposed, each being based on the use of dedicated fuels such as inert-matrix fuels, MA-bearing MOX or MA-bearing blankets. In this context, progress on the manufacturing of such fuels is a key-challenge in order to render P&T viable at the industrial scale. Here, MA-bearing oxide fuel fabrication and characterization conducted in the CEA Marcoule Atalante facility is reviewed. A particular attention is also given to the research conducted on uranium-americium mixed-oxides fuels, which are now considered the reference fuels for MA transmutation in France.

  20. GEDEON: A joint venture between research (CEA and CNRS) and industry (EDF and FRAMATOME)

    NASA Astrophysics Data System (ADS)

    Schapira, J. P.

    1999-07-01

    Nuclear waste partitionning and transmutation (P & T) are considered in France as an official line of research, in accordance with the Law of December 30, 1991 concerning research in the field of long lived and highly active nuclear waste. A research group called GEDEON ( GEstion des DEchets par des Options Nouvelles) has been set up between CEA, CNRS, EDF and FRAMATOME with the aim to carry out basic research related to the use of accelerator driven subcritical systems (ADS) and of thorium as an option to reduce the waste long term impacts. In the partners agreement of GEDEON, the following subjects have been identified: spallation physics, nuclear data, subcritical neutronic studies, materials, thorium, system and scenario studies. The organization as well as the scientific program and activities of GEDEON are presented.

  1. Science and technology research and development in support to ITER and the Broader Approach at CEA

    NASA Astrophysics Data System (ADS)

    Bécoulet, A.; Hoang, G. T.; Abiteboul, J.; Achard, J.; Alarcon, T.; Alba-Duran, J.; Allegretti, L.; Allfrey, S.; Amiel, S.; Ané, J. M.; Aniel, T.; Antar, G.; Argouarch, A.; Armitano, A.; Arnaud, J.; Arranger, D.; Artaud, J. F.; Audisio, D.; Aumeunier, M.; Autissier, E.; Azcona, L.; Back, A.; Bahat, A.; Bai, X.; Baiocchi, B.; Balaguer, D.; Balme, S.; Balorin, C.; Barana, O.; Barbier, D.; Barbuti, A.; Basiuk, V.; Baulaigue, O.; Bayetti, P.; Baylard, C.; Beaufils, S.; Beaute, A.; Bécoulet, M.; Bej, Z.; Benkadda, S.; Benoit, F.; Berger-By, G.; Bernard, J. M.; Berne, A.; Bertrand, B.; Bertrand, E.; Beyer, P.; Bigand, A.; Bonhomme, G.; Borel, G.; Boron, A.; Bottereau, C.; Bottollier-Curtet, H.; Bouchand, C.; Bouquey, F.; Bourdelle, C.; Bourg, J.; Bourmaud, S.; Brémond, S.; Bribiesca Argomedo, F.; Brieu, M.; Brun, C.; Bruno, V.; Bucalossi, J.; Bufferand, H.; Buravand, Y.; Cai, L.; Cantone, V.; Cantone, B.; Caprin, E.; Cartier-Michaud, T.; Castagliolo, A.; Belo, J.; Catherine-Dumont, V.; Caulier, G.; Chaix, J.; Chantant, M.; Chatelier, M.; Chauvin, D.; Chenevois, J.; Chouli, B.; Christin, L.; Ciazynski, D.; Ciraolo, G.; Clairet, F.; Clapier, R.; Cloez, H.; Coatanea-Gouachet, M.; Colas, L.; Colledani, G.; Commin, L.; Coquillat, P.; Corbel, E.; Corre, Y.; Cottet, J.; Cottier, P.; Courtois, X.; Crest, I.; Dachicourt, R.; Dapena Febrer, M.; Daumas, C.; de Esch, H. P. L.; De Gentile, B.; Dechelle, C.; Decker, J.; Decool, P.; Deghaye, V.; Delaplanche, J.; Delchambre-Demoncheaux, E.; Delpech, L.; Desgranges, C.; Devynck, P.; Dias Pereira Bernardo, J.; Dif-Pradalier, G.; Doceul, L.; Dong, Y.; Douai, D.; Dougnac, H.; Dubuit, N.; Duchateau, J.-L.; Ducobu, L.; Dugue, B.; Dumas, N.; Dumont, R.; Durocher, A.; Durocher, A.; Duthoit, F.; Ekedahl, A.; Elbeze, D.; Escarguel, A.; Escop, J.; Faïsse, F.; Falchetto, G.; Farjon, J.; Faury, M.; Fedorzack, N.; Féjoz, P.; Fenzi, C.; Ferlay, F.; Fiet, P.; Firdaouss, M.; Francisquez, M.; Franel, B.; Frauche, J.; Frauel, Y.; Futtersack, R.; Garbet, X.; Garcia, J.; Gardarein, J.; Gargiulo, L.; Garibaldi, P.; Garin, P.; Garnier, D.; Gauthier, E.; Gaye, O.; Geraud, A.; Gerome, M.; Gervaise, V.; Geynet, M.; Ghendrih, P.; Giacalone, I.; Gibert, S.; Gil, C.; Ginoux, S.; Giovannangelo, L.; Girard, S.; Giruzzi, G.; Goletto, C.; Goncalves, R.; Gonde, R.; Goniche, M.; Goswami, R.; Grand, C.; Grandgirard, V.; Gravil, B.; Grisolia, C.; Gros, G.; Grosman, A.; Guigue, J.; Guilhem, D.; Guillemaut, C.; Guillerminet, B.; Guimaraes Filho, Z.; Guirlet, R.; Gunn, J. P.; Gurcan, O.; Guzman, F.; Hacquin, S.; Hariri, F.; Hasenbeck, F.; Hatchressian, J. C.; Hennequin, P.; Hernandez, C.; Hertout, P.; Heuraux, S.; Hillairet, J.; Honore, C.; Hornung, G.; Houry, M.; Hunstad, I.; Hutter, T.; Huynh, P.; Icard, V.; Imbeaux, F.; Irishkin, M.; Isoardi, L.; Jacquinot, J.; Jacquot, J.; Jiolat, G.; Joanny, M.; Joffrin, E.; Johner, J.; Joubert, P.; Jourd'Heuil, L.; Jouve, M.; Junique, C.; Keller, D.; Klepper, C.; Kogut, D.; Kubič, M.; Labassé, F.; Lacroix, B.; Lallier, Y.; Lamaison, V.; Lambert, R.; Larroque, S.; Latu, G.; Lausenaz, Y.; Laviron, C.; Le, R.; Le Luyer, A.; Le Niliot, C.; Le Tonqueze, Y.; Lebourg, P.; Lefevre, T.; Leroux, F.; Letellier, L.; Li, Y.; Lipa, M.; Lister, J.; Litaudon, X.; Liu, F.; Loarer, T.; Lombard, G.; Lotte, P.; Lozano, M.; Lucas, J.; Lütjens, H.; Magaud, P.; Maget, P.; Magne, R.; Mahieu, J.-F.; Maini, P.; Malard, P.; Manenc, L.; Marandet, Y.; Marbach, G.; Marechal, J.-L.; Marfisi, L.; Marle, M.; Martin, C.; Martin, V.; Martin, G.; Martinez, A.; Martino, P.; Masset, R.; Mazon, D.; Mellet, N.; Mercadier, L.; Merle, A.; Meshcheriakov, D.; Messina, P.; Meyer, O.; Millon, L.; Missirlian, M.; Moerel, J.; Molina, D.; Mollard, P.; Moncada, V.; Monier-Garbet, P.; Moreau, D.; Moreau, M.; Moreau, P.; Morel, P.; Moriyama, T.; Motassim, Y.; Mougeolle, G.; Moulton, D.; Moureau, G.; Mouyon, D.; Naim Habib, M.; Nardon, E.; Négrier, V.; Nemeth, J.; Nguyen, C.; Nguyen, M.; Nicolas, L.; Nicolas, T.; Nicollet, S.; Nilsson, E.; N'Konga, B.; Noel, F.; Nooman, A.; Norscini, C.; Nouailletas, R.; Oddon, P.; Ohsako, T.; Orain, F.; Ottaviani, M.; Pagano, M.; Palermo, F.; Panayotis, S.; Parrat, H.; Pascal, J.-Y.; Passeron, C.; Pastor, P.; Patterlini, J.; Pavy, K.; Pecquet, A.-L.; Pégourié, B.; Peinturier, C.; Pelletier, T.; Peluso, B.; Petrzilka, V.; Peysson, Y.; Pignoly, E.; Pirola, R.; Pocheau, C.; Poitevin, E.; Poli, V.; Poli, S.; Pompon, F.; Porchy, I.; Portafaix, C.; Preynas, M.; Prochet, P.; Prou, M.; Ratnani, A.; Raulin, D.; Ravenel, N.; Renard, S.; Ricaud, B.; Richou, M.; Ritz, G.; Roche, H.; Roubin, P.; Roux, C.; Ruiz, K.; Sabathier, F.; Sabot, R.; Saille, A.; Saint-Laurent, F.; Sakamoto, R.; Salasca, S.; Salmon, T.; Salmon, T.; Samaille, F.; Sanchez, S.; Santagiustina, A.; Saoutic, B.; Sarazin, Y.; Sardain, P.; Schlosser, J.; Schneider, M.; Schwob, J.; Segui, J.; Seguin, N.; Selig, G.; Serret, D.; Signoret, J.; Signoret, J.; Simonin, A.; Soldaini, M.; Soler, B.; Soltane, C.; Song, S.; Sourbier, F.; Sparagna, J.; Spitz, P.; Spuig, P.; Storelli, A.; Strugarek, A.; Tamain, P.; Tena, M.; Theis, J.; Thomine, O.; Thouvenin, D.; Torre, A.; Toulouse, L.; Travère, J.; Tsitrone, E.; Turck, B.; Urban, J.; Vallet, J.-C.; Vallory, J.; Valognes, A.; Van Helvoirt, J.; Vartanian, S.; Verger, J.-M.; Vermare, L.; Vermare, C.; Vezinet, D.; Vicente, K.; Vidal, J.; Vignal, N.; Vigne, T.; Villecroze, F.; Villedieu, E.; Vincent, B.; Volpe, B.; Volpe, D.; Volpe, R.; Wagrez, J.; Wang, H.; Wauters, T.; Wintersdorff, O.; Wittebol, E.; Zago, B.; Zani, L.; Zarzoso, D.; Zhang, Y.; Zhong, W.; Zou, X. L.

    2013-10-01

    In parallel to the direct contribution to the procurement phase of ITER and Broader Approach, CEA has initiated research & development programmes, accompanied by experiments together with a significant modelling effort, aimed at ensuring robust operation, plasma performance, as well as mitigating the risks of the procurement phase. This overview reports the latest progress in both fusion science and technology including many areas, namely the mitigation of superconducting magnet quenches, disruption-generated runaway electrons, edge-localized modes (ELMs), the development of imaging surveillance, and heating and current drive systems for steady-state operation. The WEST (W Environment for Steady-state Tokamaks) project, turning Tore Supra into an actively cooled W-divertor platform open to the ITER partners and industries, is presented. Commissariat à l'Energie Atomique et aux énergies alternatives.

  2. Au20: A Tetrahedral Cluster

    SciTech Connect

    Li, Jun; Li, Xi; Zhai, Hua Jin; Wang, Lai S.

    2003-02-07

    Photoelectron spectroscopy revealed that a 20 atom gold cluster has an extremely large energy gap, which is even greater than that of C60, and an electron affinity comparable with that of C60. This observation suggests that the Au20 cluster must be extremely stable and chemically inert. Using relativistic density functional calculations, we found that Au20 possesses a remarkable tetrahedral structure, which is a fragment of the bulk face-centered cubic lattice of gold with a small structural relaxation. Au20 is thus a true cluster molecule, while at the same time it is exactly part of the bulk, but with very different properties. The tetrahedral Au20 may possess interesting catalytic properties and may be synthesized in bulk quantity or assembled on non-interacting surfaces.

  3. Levels of CEA, CA153, CA199, CA724 and AFP in nipple discharge of breast cancer patients

    PubMed Central

    Zhao, Song; Mei, Yu; Wang, Yongmei; Zhu, Jiang; Zheng, Guixi; Ma, Rong

    2015-01-01

    The distinction between breast cancer and benign breast diseases with nipple discharge remains an important diagnostic challenge. The purpose of this study was to predict the potential usefulness of tumor markers in nipple discharge and to investigate the relationship of tumor markers and clinical characteristics with breast cancer.One hundred and eleven patients with nipple discharge received breast surgery from November 2013 to December 2014 were included in the study. We evaluated levels of five tumor markers (CEA, CA153, CA199, CA724 and AFP) prior to treatment. Patients were divided into two groups according to postoperative pathological results: 30 cases in breast cancer group and 81 cases in benign group. The relationships of clinical characteristics with breast cancer were investigated by multivariate analysis with a logistic regression model.It showed significant differences in levels of nipple discharge CEA (P < 0.001) and CA153 (P = 0.014), but not CA199 (P = 0.856), CA724 (P = 0.171), AFP (P = 0.834) among two groups. Logistic regression analysis demonstrated complaint, age, menopause, abnormal palpable mass, CEA and CA153 were associated with breast cancer. In summary, measurements of CA199, CA724 and AFP in nipple discharge are not of great clinical value. Detecting CEA and CA153 in nipple dischargecould potentially be used for the early detection of breast cancer with in high-risk populations. PMID:26885008

  4. "C.-E.A. Winslow and the early years of public health at Yale, 1915-1925".

    PubMed Central

    Viseltear, A. J.

    1982-01-01

    C.-E.A. Winslow was the first chairman of the Department of Public Health at the Yale University School of Medicine. This paper considers the development and changing agenda of his department, the structure of Yale University, and the maturation of public health as a discipline. Winslow's successes and failures are discussed as they relate to Yale and external societal influences. PMID:6753362

  5. P21 and CEA expression and AgNOR counts in dimethylhydrazine-induced colon carcinoma in rats

    PubMed Central

    Zhang, Zhi-Gang; Wu, Jing-Ying; Fu, Xiang-Dong; Gu, Da-Kun; Fang, Fang

    1997-01-01

    AIM: To study P21 and carcinoembryonic antigen (CEA) expression and to measure argyrophilic nucleolar organizer region (AgNOR) counts in various lesions of colonic mucosa and the mechanism of carcinogenesis. METHODS: Thirty-eight male Wistar rats were injected with dimethylhydrazine (DMH) once a week for 25 wk. P21 and CEA expression was detected by immunohistochemical methods, and AgNOR was counted by silver staining paraffin sections from various colonic lesions. RESULTS: The incidence of colonic carcinoma in DMH-treated rats was 71.05% (27/38), and lymph node metastasis occurred in six rats. Immunohistochemical studies showed that P21 was primarily expressed in dysplasia and carcinomas, while CEA was expressed in carcinomas and metastatic tumors. AgNOR counts were higher in dysplasia and carcinomas. There were significant differences in P21 and CEA expression between benign and malignant lesions (P < 0.05). The difference in AgNOR counts was also significant between normal and dysplastic tissues, and between dysplasia and malignant lesions (P < 0.05). CONCLUSION: Dysplasia is a premalignant change of colonic carcinoma. The detection of P21 via immunohistochemistry and AgNOR counting may be an important clinical screening technique for colon carcinoma and premalignant lesions.

  6. Prognostic value of serum CYFRA21-1 and CEA for non-small-cell lung cancer.

    PubMed

    Zhang, Zhi-Hui; Han, Yun-Wei; Liang, Hui; Wang, Le-Min

    2015-11-01

    The aim of the study was to assess the clinical prognostic value of serum cytokeratin 19 fragment (CYFRA21-1) and carcinoembryonic antigen (CEA) for non-small-cell lung cancer (NSCLC) patients. Literatures related to effects of serum CYFRA21-1 and CEA on the prognosis of lung cancer patients were retrieved from databases such as PubMed, Springer Link, Embase, Wanfang, and CNKI. Meta-analysis was carried out using RevMan 5.1 software. Ten literatures involving 1990 NSCLC patients were selected in this study. Total survive estimation merging hazard ratio (HR) in all NSCLC patients with high-level serum CYFRA21-1 was 1.64 (95% CI 1.46-1.84, P < 0.001) and that in all NSCLC patients with high level serum CEA was 1.46 (95% CI 1.28-1.65, P < 0.001). Serum CYFRA21-1 and CEA can be used as prognostic factors of NSCLC patients. Combinative detection of the two indices will be more reliable. PMID:26333429

  7. Prognostic value of serum CYFRA21-1 and CEA for non-small-cell lung cancer

    PubMed Central

    Zhang, Zhi-Hui; Han, Yun-Wei; Liang, Hui; Wang, Le-Min

    2015-01-01

    The aim of the study was to assess the clinical prognostic value of serum cytokeratin 19 fragment (CYFRA21-1) and carcinoembryonic antigen (CEA) for non-small-cell lung cancer (NSCLC) patients. Literatures related to effects of serum CYFRA21-1 and CEA on the prognosis of lung cancer patients were retrieved from databases such as PubMed, Springer Link, Embase, Wanfang, and CNKI. Meta-analysis was carried out using RevMan 5.1 software. Ten literatures involving 1990 NSCLC patients were selected in this study. Total survive estimation merging hazard ratio (HR) in all NSCLC patients with high-level serum CYFRA21-1 was 1.64 (95% CI 1.46–1.84, P < 0.001) and that in all NSCLC patients with high level serum CEA was 1.46 (95% CI 1.28–1.65, P < 0.001). Serum CYFRA21-1 and CEA can be used as prognostic factors of NSCLC patients. Combinative detection of the two indices will be more reliable. PMID:26333429

  8. Synergistic catalysis of metal-organic framework-immobilized Au-Pd nanoparticles in dehydrogenation of formic acid for chemical hydrogen storage.

    PubMed

    Gu, Xiaojun; Lu, Zhang-Hui; Jiang, Hai-Long; Akita, Tomoki; Xu, Qiang

    2011-08-10

    Bimetallic Au-Pd nanoparticles (NPs) were successfully immobilized in the metal-organic frameworks (MOFs) MIL-101 and ethylenediamine (ED)-grafted MIL-101 (ED-MIL-101) using a simple liquid impregnation method. The resulting composites, Au-Pd/MIL-101 and Au-Pd/ED-MIL-101, represent the first highly active MOF-immobilized metal catalysts for the complete conversion of formic acid to high-quality hydrogen at a convenient temperature for chemical hydrogen storage. Au-Pd NPs with strong bimetallic synergistic effects have a much higher catalytic activity and a higher tolerance with respect to CO poisoning than monometallic Au and Pd counterparts. PMID:21761819

  9. Interfacial nanodroplets guided construction of hierarchical Au, Au-Pt, and Au-Pd particles as excellent catalysts

    PubMed Central

    Ma, Aijing; Xu, Jie; Zhang, Xuehua; Zhang, Bin; Wang, Dayang; Xu, Haolan

    2014-01-01

    Interfacial nanodroplets were grafted to the surfaces of self-sacrificed template particles in a galvanic reaction system to assist the construction of 3D Au porous structures. The interfacial nanodroplets were formed via direct adsorption of surfactant-free emulsions onto the particle surfaces. The interfacial nanodroplets discretely distributed at the template particle surfaces and served as soft templates to guide the formation of porous Au structures. The self-variation of footprint sizes of interfacial nanodroplets during Au growth gave rise to a hierarchical pore size distribution of the obtained Au porous particles. This strategy could be easily extended to synthesize bimetal porous particles such as Au-Pt and Au-Pd. The obtained porous Au, Au-Pt, and Au-Pd particles showed excellent catalytic activity in catalytic reduction of 4-nitrophenol. PMID:24797697

  10. Interfacial nanodroplets guided construction of hierarchical Au, Au-Pt, and Au-Pd particles as excellent catalysts.

    PubMed

    Ma, Aijing; Xu, Jie; Zhang, Xuehua; Zhang, Bin; Wang, Dayang; Xu, Haolan

    2014-01-01

    Interfacial nanodroplets were grafted to the surfaces of self-sacrificed template particles in a galvanic reaction system to assist the construction of 3D Au porous structures. The interfacial nanodroplets were formed via direct adsorption of surfactant-free emulsions onto the particle surfaces. The interfacial nanodroplets discretely distributed at the template particle surfaces and served as soft templates to guide the formation of porous Au structures. The self-variation of footprint sizes of interfacial nanodroplets during Au growth gave rise to a hierarchical pore size distribution of the obtained Au porous particles. This strategy could be easily extended to synthesize bimetal porous particles such as Au-Pt and Au-Pd. The obtained porous Au, Au-Pt, and Au-Pd particles showed excellent catalytic activity in catalytic reduction of 4-nitrophenol. PMID:24797697

  11. Symmetry energy from elliptic flow in 197Au + 197Au

    NASA Astrophysics Data System (ADS)

    Russotto, P.; Wu, P. Z.; Zoric, M.; Chartier, M.; Leifels, Y.; Lemmon, R. C.; Li, Q.; Łukasik, J.; Pagano, A.; Pawłowski, P.; Trautmann, W.

    2011-03-01

    The elliptic-flow ratio of neutrons with respect to protons or light complex particles in reactions of neutron-rich systems at relativistic energies is proposed as an observable sensitive to the strength of the symmetry term in the equation of state at supra-normal densities. The results obtained from the existing FOPI/LAND data for 197Au + 197Au collisions at 400 MeV/nucleon in comparison with the UrQMD model favor a moderately soft symmetry term with a density dependence of the potential term proportional to (ρ /ρ0) γ with γ = 0.9 ± 0.4.

  12. Flow in Au+Au collisions at RHIC

    NASA Astrophysics Data System (ADS)

    Belt Tonjes, Marguerite; PHOBOS Collaboration; Back, B. B.; Baker, M. D.; Ballintijn, M.; Barton, D. S.; Betts, R. R.; Bickley, A. A.; Bindel, R.; Budzanowski, A.; Busza, W.; Carroll, A.; Decowski, M. P.; García, E.; George, N.; Gulbrandsen, K.; Gushue, S.; Halliwell, C.; Hamblen, J.; Heintzelman, G. A.; Henderson, C.; Hofman, D. J.; Hollis, R. S.; Holynski, R.; Holzman, B.; Iordanova, A.; Johnson, E.; Kane, J. L.; Katzy, J.; Khan, N.; Kucewicz, W.; Kulinich, P.; Kuo, C. M.; Lin, W. T.; Manly, S.; McLeod, D.; Mignerey, A. C.; Nouicer, R.; Olszewski, A.; Pak, R.; Park, I. C.; Pernegger, H.; Reed, C.; Remsberg, L. P.; Reuter, M.; Roland, C.; Roland, G.; Rosenberg, L.; Sagerer, J.; Sarin, P.; Sawicki, P.; Skulski, W.; Steinberg, P.; Stephans, G. S. F.; Sukhanov, A.; Tang, J.-L.; Trzupek, A.; Vale, C.; van Nieuwenhuizen, G. J.; Verdier, R.; Wolfs, F. L. H.; Wosiek, B.; Wozniak, K.; Wuosmaa, A. H.; Wyslouch, B.

    2004-08-01

    The study of flow can provide information on the initial state dynamics and the degree of equilibration attained in heavy-ion collisions. This contribution presents results for both elliptic and directed flow as determined from data recorded by the PHOBOS experiment in Au+Au runs at RHIC at \\sqrt{s_{{\\rm NN}}} = 19.6, 130 and 200 GeV. The PHOBOS detector provides a unique coverage in pseudorapidity for measuring flow at RHIC. The systematic dependence of flow on pseudorapidity, transverse momentum, centrality and energy is discussed.

  13. Binding of insecticidal lectin Colocasia esculenta tuber agglutinin (CEA) to midgut receptors of Bemisia tabaci and Lipaphis erysimi provides clues to its insecticidal potential.

    PubMed

    Roy, Amit; Gupta, Sumanti; Hess, Daniel; Das, Kali Pada; Das, Sampa

    2014-07-01

    The insecticidal potential of Galanthus nivalis agglutinin-related lectins against hemipterans has been experimentally proven. However, the basis behind the toxicity of these lectins against hemipterans remains elusive. The present study elucidates the molecular basis behind insecticidal efficacy of Colocasia esculenta tuber agglutinin (CEA) against Bemisia tabaci and Lipaphis erysimi. Confocal microscopic analyses highlighted the binding of 25 kDa stable homodimeric lectin to insect midgut. Ligand blots followed by LC MS/MS analyses identified binding partners of CEA as vacuolar ATP synthase and sarcoplasmic endoplasmic reticulum type Ca(2+) ATPase from B. tabaci, and ATP synthase, heat shock protein 70 and clathrin heavy chain assembly protein from L. erysimi. Internalization of CEA into hemolymph was confirmed by Western blotting. Glycoprotein nature of the receptors was identified through glycospecific staining. Deglycosylation assay indicated the interaction of CEA with its receptors to be probably glycan mediated. Surface plasmon resonance analysis revealed the interaction kinetics between ATP synthase of B. tabaci with CEA. Pathway prediction study based on Drosophila homologs suggested the interaction of CEA with insect receptors that probably led to disruption of cellular processes causing growth retardation and loss of fecundity of target insects. Thus, the present findings strengthen our current understanding of the entomotoxic potentiality of CEA, which will facilitate its future biotechnological applications. PMID:24753494

  14. [Clinical evaluation of the tumor marker CA 19-9 in comparison with carcinoembryonic antigen (CEA) in surgical pre- and postoperative diagnosis].

    PubMed

    Lorenz, M; Happ, J; Hottenrott, C; Maul, F D; Baum, R P; Hör, G; Encke, A

    1986-02-01

    A new tumor marker (CA 19-9) was investigated. CA 19-9 is a tumor-associated antigen which is detected by a monoclonal antibody. CA 19-9 (CIS-Centocor) was compared simultaneously with CEA (carcinoembryonic antigen) in 347 patients. 123 patients with gastrointestinal tumors showed a sensitivity of 31% for CA 19-9 (CEA 49%), combination increased sensitivity to 58%. The highest sensitivity was found in pancreas carcinoma (CA 19-9 75%, CEA 66%, combination 92%); it was lower in gastric, colon, and oesophagus carcinomas. In relapsed colorectal carcinomas sensitivity was 53% (CEA 78%, combination 85%). In cases of relapse, tumor markers may become positive even if they were not detectable before resection of the primary tumor. Specificity for CA 19-9 was 100% (CEA 84%) compared to a group of non-malignant diseases including patients with inflammations and patients with nicotin abuse (n = 102). Because of its high specificity and superior sensitivity to CEA in pancreas carcinomas CA 19-9 should be determined in primary and relapse diagnosis in combination with CEA. PMID:3459133

  15. Laser irradiation-induced Au-ZnO nanospheres with enhanced sensitivity and stability for ethanol sensing.

    PubMed

    Zhang, Hao; Wu, Shouliang; Liu, Jun; Cai, Yunyu; Liang, Changhao

    2016-08-10

    Incorporating noble metal nanoparticles on the surface or the inner side of semiconductors to form a hybrid nanostructure is an effective route for improving the gas sensing performance of the semiconductors. In this study, we present novel Au-decorated ZnO nanospheres (Au-ZnO NSs) obtained by the laser irradiation of liquids. Structural characterization indicated that the Au-ZnO NSs consisted of single crystalline ZnO NSs with a few Au nanoparticles decorated on their surfaces and abundant encapsulated Au nanoparticles with relatively small sizes. Laser irradiation-induced heating-melting-evaporating processes are responsible for the formation of unique Au-ZnO NSs. The gas sensing properties of the Au-ZnO NSs, as gas sensing materials, were investigated and compared with those of pure ZnO NSs. The former showed a lower working temperature, higher sensitivity, better selectivity, and good reproducibility. The response values of the Au-ZnO NS and pure ZnO NS sensors to ethanol of 100 ppm were 252 and 75 at a working temperature of 320 °C and 360 °C, respectively. Significant enhancements in gas sensing performance should be attributed to the electronic sensitization induced by the depleted layers between the encapsulated Au nanoparticles and ZnO and chemical sensitization originating from the catalytic effects of Au nanoparticles decorated on the surfaces that dissociated molecular oxygen. PMID:27465699

  16. Electrochemical synthesis of mesoporous Pt-Au binary alloys with tunable compositions for enhancement of electrochemical performance.

    PubMed

    Yamauchi, Yusuke; Tonegawa, Akihisa; Komatsu, Masaki; Wang, Hongjing; Wang, Liang; Nemoto, Yoshihiro; Suzuki, Norihiro; Kuroda, Kazuyuki

    2012-03-21

    Mesoporous Pt-Au binary alloys were electrochemically synthesized from lyotropic liquid crystals (LLCs) containing corresponding metal species. Two-dimensional exagonally ordered LLC templates were prepared on conductive substrates from diluted surfactant solutions including water, a nonionic surfactant, ethanol, and metal species by drop-coating. Electrochemical synthesis using such LLC templates enabled the preparation of ordered mesoporous Pt-Au binary alloys without phase segregation. The framework composition in the mesoporous Pt-Au alloy was controlled simply by changing the compositional ratios in the precursor solution. Mesoporous Pt-Au alloys with low Au content exhibited well-ordered 2D hexagonal mesostructures, reflecting those of the original templates. With increasing Au content, however, the mesostructural order gradually decreased, thereby reducing the electrochemically active surface area. Wide-angle X-ray diffraction profiles, X-ray photoelectron spectra, and elemental mapping showed that both Pt and Au were atomically distributed in the frameworks. The electrochemical stability of mesoporous Pt-Au alloys toward methanol oxidation was highly improved relative to that of nonporous Pt and mesoporous Pt films, suggesting that mesoporous Pt-Au alloy films are potentially applicable as electrocatalysts for direct methanol fuel cells. Also, mesoporous Pt-Au alloy electrodes showed a highly sensitive amperometric response for glucose molecules, which will be useful in next-generation enzyme-free glucose sensors. PMID:22352760

  17. Magnetomotive room temperature dicationic ionic liquid: a new concept toward centrifuge-less dispersive liquid-liquid microextraction.

    PubMed

    Beiraghi, Asadollah; Shokri, Masood; Seidi, Shahram; Godajdar, Bijan Mombani

    2015-01-01

    A new centrifuge-less dispersive liquid-liquid microextraction technique based on application of magnetomotive room temperature dicationic ionic liquid followed by electrothermal atomic absorption spectrometry (ETAAS) was developed for preconcentration and determination of trace amount of gold and silver in water and ore samples, for the first time. Magnetic ionic liquids not only have the excellent properties of ionic liquids but also exhibit strong response to an external magnetic field. These properties provide more advantages and potential application prospects for magnetic ionic liquids than conventional ones in the fields of extraction processes. In this work, thio-Michler's ketone (TMK) was used as chelating agent to form Ag/Au-TMK complexes. Several important factors affecting extraction efficiency including extraction time, rate of vortex agitator, pH of sample solution, concentration of the chelating agent, volume of ionic liquid as well as effects of interfering species were investigated and optimized. Under the optimal conditions, the limits of detection (LOD) were 3.2 and 7.3ngL(-1) with the preconcentration factors of 245 and 240 for Au and Ag, respectively. The precision values (RSD%, n=7) were 5.3% and 5.8% at the concentration level of 0.05μgL(-1) for Au and Ag, respectively. The relative recoveries for the spiked samples were in the acceptable range of 96-104.5%. The results demonstrated that except Hg(2+), no remarkable interferences are created by other various ions in the determination of Au and Ag, so that the tolerance limits (WIon/WAu or Ag) of major cations and anions were in the range of 250-1000. The validated method was successfully applied for the analysis of Au and Ag in some water and ore samples. PMID:25528072

  18. Solubility of Au in Cl- and S-bearing hydrous silicate melts

    NASA Astrophysics Data System (ADS)

    Botcharnikov, R. E.; Linnen, R. L.; Holtz, F.

    2010-04-01

    The solubility of Au in Cl- and S-bearing hydrous rhyodacitic and andesitic melts has been experimentally investigated at 1050 °C, 200 MPa and log fO 2 close to the Ni/NiO solid oxygen buffer (NNO). The concentrations of Au in the experimental glasses have been determined using Laser Ablation ICP-MS (LA) with special efforts to avoid incorporation of Au micronuggets in the analysis. It is concluded that metal micronuggets are an experimental artefact and produced by Au partitioning into the fluids during heating with consequent precipitation on fluid dissolution in the melting glass powder. Hence, the micronuggets do not represent quench phases and must be excluded from the analysis. The micro-analytical data obtained by LA show that Au concentrations vary from ˜0.2 to ˜2.5 ppm by weight, generally consistent with the literature data for other melt compositions. The measured Au concentrations increase with increasing amounts of Cl and S dissolved in the silicate melt and show a correlation with the apparent activities of Cl and S in the system. The apparent activities of Cl and S are defined by the simplified linear relationship between volatile concentrations in the melt and activity of volatiles. The maximum activity ( a∗ = 1) is assumed to be reached at the saturation of the systems in respect of Cl-rich brine or FeS liquid for Cl and S, respectively. The dependence of Au solubility on the concentrations/activities of Cl and S at the fixed redox conditions shows that Au may form not only oxide- but also Cl- and S-bearing complexes in silicate melts. Furthermore, it indicates that exsolution of S and Cl from the melt by degassing/segregation/crystallization processes may lead to mobilization and extraction of Au into the fluid, liquid and/or mineral phase(s).

  19. Comprehensive Bio-Imaging with Fluorinated Nanoparticles Using Breathable Liquids

    PubMed Central

    Kurczy, Michael E.; Zhu, Zheng Jiang; Ivanisevic, Julijana; Schuyler, Adam M.; Lalwani, Kush; Santidrian, Antonio F.; David, John W.; Giddabasappa, Anand; Roberts, Amanda; Olivos, Hernando J.; O'Brien, Peter J.; Franco, Lauren; Fields, Matthew W.; Paris, Liliana P.; Friedlander, Martin; Johnson, Caroline H.; Epstein, Adrian; Gendleman, Howard E.; Wood, Malcolm; Felding-Habermann, Brunhilde; Patti, Gary J.; Spilker, Mary E.; Siuzdak, Gary

    2015-01-01

    Fluorocarbons are lipophobic and non-polar molecules that exhibit remarkable bio-compatibility, with applications in liquid ventilation and synthetic blood. The unique properties of these compounds have also enabled mass spectrometry imaging of tissues where the fluorocarbons act as a Teflon-like coating for nanostructured surfaces to assist in desorption/ionization. Here we report fluorinated gold nanoparticles (f-AuNPs) designed to facilitate nanostructure imaging mass spectrometry. Irradiation of f-AuNPs results in the release of the fluorocarbon ligands providing a driving force for analyte desorption. The f-AuNPs allow for the mass spectrometry analysis of both lipophilic and polar (central carbon) metabolites. An important property of AuNPs is that they also act as contrast agents for X-ray microtomography and electron microscopy, a feature we have exploited by infusing f-AuNPs into tissue via fluorocarbon liquids to facilitate multi-modal (molecular and anatomical) imaging. PMID:25601659

  20. Comprehensive bioimaging with fluorinated nanoparticles using breathable liquids

    NASA Astrophysics Data System (ADS)

    Kurczy, Michael E.; Zhu, Zheng-Jiang; Ivanisevic, Julijana; Schuyler, Adam M.; Lalwani, Kush; Santidrian, Antonio F.; David, John M.; Giddabasappa, Anand; Roberts, Amanda J.; Olivos, Hernando J.; O'Brien, Peter J.; Franco, Lauren; Fields, Matthew W.; Paris, Liliana P.; Friedlander, Martin; Johnson, Caroline H.; Epstein, Adrian A.; Gendelman, Howard E.; Wood, Malcolm R.; Felding, Brunhilde H.; Patti, Gary J.; Spilker, Mary E.; Siuzdak, Gary

    2015-01-01

    Fluorocarbons are lipophobic and non-polar molecules that exhibit remarkable biocompatibility, with applications in liquid ventilation and synthetic blood. The unique properties of these compounds have also enabled mass spectrometry imaging of tissues where the fluorocarbons act as a Teflon-like coating for nanostructured surfaces to assist in desorption/ionization. Here we report fluorinated gold nanoparticles (f-AuNPs) designed to facilitate nanostructure imaging mass spectrometry. Irradiation of f-AuNPs results in the release of the fluorocarbon ligands providing a driving force for analyte desorption. The f-AuNPs allow for the mass spectrometry analysis of both lipophilic and polar (central carbon) metabolites. An important property of AuNPs is that they also act as contrast agents for X-ray microtomography and electron microscopy, a feature we have exploited by infusing f-AuNPs into tissue via fluorocarbon liquids to facilitate multimodal (molecular and anatomical) imaging.

  1. Comprehensive bioimaging with fluorinated nanoparticles using breathable liquids.

    PubMed

    Kurczy, Michael E; Zhu, Zheng-Jiang; Ivanisevic, Julijana; Schuyler, Adam M; Lalwani, Kush; Santidrian, Antonio F; David, John M; Giddabasappa, Anand; Roberts, Amanda J; Olivos, Hernando J; O'Brien, Peter J; Franco, Lauren; Fields, Matthew W; Paris, Liliana P; Friedlander, Martin; Johnson, Caroline H; Epstein, Adrian A; Gendelman, Howard E; Wood, Malcolm R; Felding, Brunhilde H; Patti, Gary J; Spilker, Mary E; Siuzdak, Gary

    2015-01-01

    Fluorocarbons are lipophobic and non-polar molecules that exhibit remarkable biocompatibility, with applications in liquid ventilation and synthetic blood. The unique properties of these compounds have also enabled mass spectrometry imaging of tissues where the fluorocarbons act as a Teflon-like coating for nanostructured surfaces to assist in desorption/ionization. Here we report fluorinated gold nanoparticles (f-AuNPs) designed to facilitate nanostructure imaging mass spectrometry. Irradiation of f-AuNPs results in the release of the fluorocarbon ligands providing a driving force for analyte desorption. The f-AuNPs allow for the mass spectrometry analysis of both lipophilic and polar (central carbon) metabolites. An important property of AuNPs is that they also act as contrast agents for X-ray microtomography and electron microscopy, a feature we have exploited by infusing f-AuNPs into tissue via fluorocarbon liquids to facilitate multimodal (molecular and anatomical) imaging. PMID:25601659

  2. X-ray detector calibration at CEA/Bruyères-le-Châtel

    NASA Astrophysics Data System (ADS)

    Beck, L.; Stemmler, P.; Ban, G.; Villette, B.; Frotté, V.; Bizeuil, C.; Boutin, J.-Y.; Nazet, C.

    1996-02-01

    At CEA/Bruyères-le-Châtel (Service CEM), there are facilities to calibrate X-ray detectors from 200 eV to 100 keV, with an accuracy of 4% at high energies ( E > 3 keV). The source is the direct radiation from the X-ray tubes [C Kα (277 eV) to Ti KαKβ (4.51/4.93 keV)] or fluorescence emission from secondary targets [Mg Kα (1.25 keV) to U Kα (98 keV)]. In addition, calibrations are carried out with the synchrotron radiation of the Super-ACO storage ring (LURE-Orsay), by selecting the monoenergetic beams with a double crystal monochromator which is tunable between 0.8 and 8 keV. The resolution is better than 1 eV. This last tool is very useful in the study of the absorption edges of the detector compounds (for example, Si K-edge and Ar K-edge). Some examples are presented of results obtained between 1 and 50 keV, with special reference to high flux detectors such as gold photocathodes and silicon avalanche photodiodes. Thick silicon photodiodes (for the high energy range) were also calibrated.

  3. A Review of 25 Years of Corrosion Studies on HLW Container Materials at the CEA

    SciTech Connect

    Helie, Max

    2007-07-01

    The Commissariat a l'Energie Atomique (CEA, French Atomic Energy Commission) has been involved in researches on nuclear waste management for more than 25 years. One of the key issues is the prediction of the long term behavior and aging of the High Level Waste (HLW) containers in order to develop concepts that will ensure the confinement of the activity over extremely long periods of time. Preliminary studies were carried out on two concepts, one of a thin 'corrosion resistant' container made of titanium or nickel base alloy, and the other on a thick 'corrosion allowance' container made or carbon steel. The results of these experiments showed that the 'corrosion resistant' concept led to a high uncertainty on the development and propagation rate of localized forms of corrosion, and the concept of geological disposal in an argillaceous host formation of thick waste containers made of carbon steel was chosen as the reference for further studies. This eventually led to the voting of a law relative to nuclear waste management on June 28 2006, which endorses the geological disposal of corrosion allowance containers as the reference solution, while stating than an effort must be kept on the research on actinides transmutation to reduce the time during which a geological disposal facility has to be proven capable to ensure the confinement of the radioactive waste. Studies are still in progress to better assess the corrosion mechanisms relevant to this situation in order to provide reliable models for the long term prediction of the containers corrosion behavior. (author)

  4. Training and Certification Program for Certified Energy Auditors (CEA) and Certified Building Commissioning Professionals (CBCP)

    SciTech Connect

    Kent, Bill

    2012-08-24

    The Association of Energy Engineers (AEE) has offered energy efficiency training and certification programs for over 30 years. During that time AEE has certified more than 22,000 professionals. All of our certification programs are the result of extensive industry research and program development and oversight by certification boards. For this project award, AEE proposed to work with the Department of Energy to utilize and extend existing industry recognized Certified Energy Auditor (CEA) and Certified Building Commissioning Professional (CBCP) programs under this Training Program Development Announcement. These expanded training programs will have significant impact in training professionals for building commissioning and energy auditing to achieve the goal of bringing existing buildings up to their optimal energy performance potential and ensuring that new buildings maintain their expected optimal level of performance. The goals and objectives of the training development project were achieved with the development of new training programs that are now being offered as self-sustaining commercial training and certification programs. These new programs are training and certifying professionals who are accomplishing the goal of increasing building energy performance in both existing and new buildings.

  5. Treatment of G1 Baskets at the CEA Marcoule Site - 12027

    SciTech Connect

    Fourquet, Line; Boya, Didier

    2012-07-01

    In the dismantling program for the first-generation French reactors in accordance with the nonproliferation treaty, the CEA is in charge of cleanup and dismantling operations for the facilities at Marcoule, including the decladding units. The G1 decladding was built between 1955 and 1957 in order to de-clad spent fuel elements from the G1 plutonium-producing reactor and prepare them for dissolution. The facility was also used for interim storage of G1, G2 and G3 fuel dissolution baskets, which had been used during plant operation for transfer (from the decladding facility to the UP1 plant) and/or dissolution of spent fuel elements. One of the cleanup projects involves recovery of the baskets, which will be cut up, sorted, and conditioned in metal bins. The bins will be immobilized with cement grout, then transferred to the onsite solid waste conditioning facility (CDS) and to the repository operated by the French National Radioactive Waste Management Agency (ANDRA). The project is now in progress, after special safety permits were issued and measurement stations and dedicated tools were developed to handle all types of baskets (which differed according to their origin and use). The disposal of all the baskets is scheduled to last 2 years and will produce 55 metal waste bins. (authors)

  6. Status of the light ion source developments at CEA/Saclay

    NASA Astrophysics Data System (ADS)

    Gobin, R.; Beauvais, P.-Y.; Bogard, D.; Charruau, G.; Delferrière, O.; De Menezes, D.; France, A.; Ferdinand, R.; Gauthier, Y.; Harrault, F.; Mattéi, P.; Benmeziane, K.; Leherissier, P.; Paquet, J.-Y.; Ausset, P.; Bousson, S.; Gardes, D.; Olivier, A.; Celona, L.; Sherman, J.

    2004-05-01

    SILHI (High Intensity Light Ion Source) is an ECR ion source producing high intensity proton or deuteron beams at 95 keV. It is now installed in the IPHI site building, at the CEA/Saclay center. IPHI is a front end demonstrator of high power accelerator. The source regularly delivers more than 130 mA protons in cw mode and already produced more than 170 mA deuterons in pulsed mode at nominal energy. The last beam characterizations, including emittance measurements, space charge compensation analysis, and diagnostic improvements, will be reported. Taking into account the SILHI experience, new developments are in progress to build and test a 5 mA deuteron source working in cw mode. This new source will also operate at 2.45 GHz and permanent magnets will provide the magnetic configuration. This source, of which the design will be discussed, will have to fit in with the SPIRAL 2 accelerator developed at GANIL to produce radioactive ion beams. The H- test stand status is briefly presented here and detailed in companion papers.

  7. Application of boronated anti-CEA immunoliposome to tumour cell growth inhibition in in vitro boron neutron capture therapy model.

    PubMed Central

    Yanagië, H.; Tomita, T.; Kobayashi, H.; Fujii, Y.; Takahashi, T.; Hasumi, K.; Nariuchi, H.; Sekiguchi, M.

    1991-01-01

    An immunoliposome containing a 10B-compound has been examined as a selective drug delivery system in boron neutron-capture therapy. Liposomes, conjugated with monoclonal antibodies specific for carcinoembryonic antigen (CEA) were shown to bind selectively to cells bearing CEA on their surface. The immunoliposomes attached to tumour cells suppressed growth in vitro upon thermal neutron irradiation and suppression was dependent upon the concentration of the 10B-compound in the liposomes and on the density of antibody conjugated to the liposomes. The results suggest that immunoliposomes containing the 10B-compound could act as a selective and efficient carrier of 10B atoms to target tumour cells in boron neutron-capture therapy. Images Figure 1 PMID:2021537

  8. Enhanced antitumor effect of combining TRAIL and MnSOD mediated by CEA-controlled oncolytic adenovirus in lung cancer.

    PubMed

    Zhang, R; Zhang, X; Ma, B; Xiao, B; Huang, F; Huang, P; Ying, C; Liu, T; Wang, Y

    2016-06-01

    Lung cancer, especially adenocarcinoma, is one of the leading causes of death in the world. Carcinoembryonic antigen (CEA), a superb non-small-cell lung cancer marker candidate, showed a beneficial effect in cancer therapy with oncolytic adenovirus in recent studies. Cancer-targeting dual gene-virotherapy delivers two therapeutic genes, linked by a connexon, in the replication-deficient vector instead of one gene so that they can work in common. In this study, we constructed a tumor-specific oncolytic adenovirus, CD55-TRAIL-IETD-MnSOD. The virus has the fusion protein complementary DNAs for tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) and for manganese superoxide dismutase (MnSOD) complementary DNA linked through a 4-amino acid caspase-8 cleavage site (IETD), and uses a CEA promoter to control virus E1A express. This is the first work to use a CEA promoter-regulated oncolytic adenovirus carrying two therapeutic genes for cancer research. Its targeting and anticancer capacity was evaluated by in vitro and in vivo experiments. The results indicated that CD55-TRAIL-IETD-MnSOD caused more cell apoptosis than CD55-TRAIL or CD55-MnSOD alone, or their combination in vitro, with low cytotoxicity of normal cells. In the A549 tumor xenograft model in nude mice, data showed that CD55-TRAIL-IETD-MnSOD could effectively suppress tumor growth than single gene groups, with no histological damage in liver, spleen or kidney tissues. Thus, the CEA-regulated dual-gene oncolytic virus CD55-TRAIL-IETD-MnSOD may be a novel potential therapy for lung cancer. PMID:27080225

  9. Comparison of CEAS and Williams-type models for spring wheat yields in North Dakota and Minnesota

    NASA Technical Reports Server (NTRS)

    Barnett, T. L. (Principal Investigator)

    1982-01-01

    The CEAS and Williams-type yield models are both based on multiple regression analysis of historical time series data at CRD level. The CEAS model develops a separate relation for each CRD; the Williams-type model pools CRD data to regional level (groups of similar CRDs). Basic variables considered in the analyses are USDA yield, monthly mean temperature, monthly precipitation, and variables derived from these. The Williams-type model also used soil texture and topographic information. Technological trend is represented in both by piecewise linear functions of year. Indicators of yield reliability obtained from a ten-year bootstrap test of each model (1970-1979) demonstrate that the models are very similar in performance in all respects. Both models are about equally objective, adequate, timely, simple, and inexpensive. Both consider scientific knowledge on a broad scale but not in detail. Neither provides a good current measure of modeled yield reliability. The CEAS model is considered very slightly preferable for AgRISTARS applications.

  10. Intermetallic compounds, copper and palladium alloys in Au-Pd ore of the Skaergaard pluton, Greenland

    NASA Astrophysics Data System (ADS)

    Rudashevsky, N. S.; Rudashevsky, V. N.; Nielsen, T. F. D.

    2015-12-01

    Copper-palladium intermetallic compounds and alloys (2314 grains) from the Au-Pd ore of the Skaergaard layered gabbroic pluton have been studied. Skaergaardite PdCu, nielsenite PdCu3, (Cu,Pd)β, (Cu,Pd)α, (Pd,Cu,Au,Pt) alloys, and native palladium have been identified as a result of 1680 microprobe analyses. The average compositions and various chemical varieties of these minerals are characterized, as well as vertical and lateral zoning in distribution of noble metals. The primary Pd-Cu alloys were formed within a wide temperature interval broadly synchronously with cooling and crystallization of host gabbro and in close association with separation of Fe-Cu sulfide liquid. In the course of crystallization of residual gabbroic melt enriched in iron, noble and heavy metals and saturated with the supercritical aqueous fluid, PGE and Au are selectively concentrated in the Fe-Cu sulfide phase as Pd-Cu and Cu-Au alloys.

  11. High-density, uniform gallium nitride nanorods grown on Au-coated silicon substrate

    NASA Astrophysics Data System (ADS)

    Cao, Chuanbao; Xiang, Xu; Zhu, Hesun

    2005-01-01

    High-density GaN nanorods with uniform diameters and lengths were successfully grown on Au-coated silicon substrate. The diameters were in the range of 50-80 nm, and the lengths ranged from 1 to 2 μm. A significant feature is that each nanorod was attached with nanoparticle at its very end, which is consistent with the vapor-liquid-solid (VLS) growth mechanism. It was also found that the as-grown final product is strongly dependent on the thickness of the Au thin film coated on the silicon substrate. According to the experimental results, we proposed that the catalytic activity of gold is determined by the size of Au particles, and just very small Au clusters exhibit effective reactivity in the growth of GaN one-dimensional nanostructures.

  12. Observation of dynamic water microadsorption on Au surface

    SciTech Connect

    Huang, Xiaokang Gupta, Gaurav; Gao, Weixiang; Tran, Van; Nguyen, Bang; McCormick, Eric; Cui, Yongjie; Yang, Yinbao; Hall, Craig; Isom, Harold

    2014-05-15

    Experimental and theoretical research on water wettability, adsorption, and condensation on solid surfaces has been ongoing for many decades because of the availability of new materials, new detection and measurement techniques, novel applications, and different scales of dimensions. Au is a metal of special interest because it is chemically inert, has a high surface energy, is highly conductive, and has a relatively high melting point. It has wide applications in semiconductor integrated circuitry, microelectromechanical systems, microfluidics, biochips, jewelry, coinage, and even dental restoration. Therefore, its surface condition, wettability, wear resistance, lubrication, and friction attract a lot of attention from both scientists and engineers. In this paper, the authors experimentally investigated Au{sub 2}O{sub 3} growth, wettability, roughness, and adsorption utilizing atomic force microscopy, scanning electron microscopy, reflectance spectrometry, and contact angle measurement. Samples were made using a GaAs substrate. Utilizing a super-hydrophilic Au surface and the proper surface conditions of the surrounding GaAs, dynamic microadsorption of water on the Au surface was observed in a clean room environment. The Au surface area can be as small as 12 μm{sup 2}. The adsorbed water was collected by the GaAs groove structure and then redistributed around the structure. A model was developed to qualitatively describe the dynamic microadsorption process. The effective adsorption rate was estimated by modeling and experimental data. Devices for moisture collection and a liquid channel can be made by properly arranging the wettabilities or contact angles of different materials. These novel devices will be very useful in microfluid applications or biochips.

  13. Formation of alternating interfacial layers in Au-12Ge/Ni joints

    PubMed Central

    Lin, Shih-kang; Tsai, Ming-yueh; Tsai, Ping-chun; Hsu, Bo-hsun

    2014-01-01

    Au-Ge alloys are promising materials for high-power and high-frequency packaging, and Ni is frequently used as diffusion barriers. This study investigates interfacial reactions in Au-12Ge/Ni joints at 300°C and 400°C. For the reactions at 300°C, typical interfacial morphology was observed and the diffusion path was (Au) + (Ge)/NiGe/Ni5Ge3/Ni. However, an interesting phenomenon – the formation of (Au,Ni,Ge)/NiGe alternating layers – was observed for the reactions at 400°C. The diffusion path across the interface was liquid/(Au,Ni,Ge)/NiGe/···/(Au,Ni,Ge)/NiGe/Ni2Ge/Ni. The periodic thermodynamic instability at the NiGe/Ni2Ge interface caused the subsequent nucleation of new (Au,Ni,Ge)/NiGe pairs. The thermodynamic foundation and mechanism of formation of the alternating layers are elaborated in this paper. PMID:24690992

  14. Strain-Mediated Interfacial Dynamics during Au-PbS Core-Shell Nanostructure Formation.

    PubMed

    Niu, Kai-Yang; Liu, Miao; Persson, Kristin A; Han, Yu; Zheng, Haimei

    2016-06-28

    An understanding of the hierarchical nanostructure formation is of significant importance for the design of advanced functional materials. Here, we report the in situ study of lead sulfide (PbS) growth on gold (Au) nanorod seeds using liquid cell transmission electron microscopy (TEM). By tracking the formation dynamics of Au-PbS core-shell nanoparticles, we found the preferential heterogeneous nucleation of PbS on the ends of a Au nanorod prior to the development of a complete PdS shell. During PbS shell growth, drastic sulfidation of Au nanorod was observed, leading to large volume shrinkage (up to 50%) of the initial Au nanorod seed. We also captured intriguing wavy interfacial behavior, which can be explained by our DFT calculation results that the local strain gradient at the core-shell interface facilitates the mass transport and mediates reversible phase transitions of AuAu2S during the PbS shell growth. PMID:27214625

  15. Field-temperature phase diagram and entropy landscape of CeAuSb2

    NASA Astrophysics Data System (ADS)

    Zhao, Lishan; Yelland, Edward A.; Bruin, Jan A. N.; Sheikin, Ilya; Canfield, Paul C.; Fritsch, Veronika; Sakai, Hideaki; Mackenzie, Andrew P.; Hicks, Clifford W.

    2016-05-01

    We report a field-temperature phase diagram and an entropy map for the heavy-fermion compound CeAuSb2. CeAuSb2 orders antiferromagnetically below TN=6.6 K and has two metamagnetic transitions, at 2.8 and 5.6 T. The locations of the critical end points of the metamagnetic transitions, which may play a strong role in the putative quantum criticality of CeAuSb2 and related compounds, are identified. The entropy map reveals an apparent entropy balance with Fermi-liquid behavior, implying that above the Néel transition the Ce moments are incorporated into the Fermi liquid. High-field data showing that the magnetic behavior is remarkably anisotropic are also reported.

  16. Microfluidic paper-based analytical device for photoelectrochemical immunoassay with multiplex signal amplification using multibranched hybridization chain reaction and PdAu enzyme mimetics.

    PubMed

    Lan, Feifei; Sun, Guoqiang; Liang, Linlin; Ge, Shenguang; Yan, Mei; Yu, Jinghua

    2016-05-15

    Combining multibranched hybridization chain reaction (mHCR), the photoelectrochemical (PEC) immunosensor was fabricated with a microfluidic paper-based analytical devices using different sizes of CdTe quantum dots (QDs) sensitized flower-like 3D ZnO superstructures as photoactive materials. Firstly, 4-aminothiophenol (PATP) functioned ZnO was anchored on gold-paper working electrode. With the aid of PATP, large-sized CdTe-COOH QDs (QDs1) were conjugated onto the ZnO surface because of the formation of a strong bond (Zn-S) between the thiol of PATP molecule and the ZnO, and the remaining amino group formed an amide bond with carboxylic acid group capping CdTe. Then the small-sized CdTe-NH2 QDs (QDs2) were modified on the QDs1 by forming amide bond, which leaded to a very strong photocurrent response because of the formation of cosensitized structure. The designed mHCR produced long products with multiple branched arms, which could attached multiple PdAu nanoparticles and catalyze the oxidation of hydroquinone (HQ) using H2O2 as anoxidant. Double strands DNA with multiple branched arms (mdsDNA) was formed by mHCR. In the presence of carcinoembryonic antigen (CEA), PdAu-mdsDNA conjugates-labeled CEA antibody was captured. The concentrations of CEA were measured through the decrease in photocurrent intensity resulting from the increase in steric hindrance of the immunocomplex and the polymeric oxidation product of HQ. In addition, the oxidation product of HQ deposited on the as-obtained electrode, which could efficiently inhibit the photoinduced electron transfer. Under optimal conditions, the PEC immunosensor exhibited excellent analytical performance: the detection range of CEA was from 0.001 to 90 ng mL(-1) with low detection limit of 0.33 pg mL(-1). The as-obtained immunosensor exhibited excellent precision, prominent specificity, acceptable stability and reproducibility, and could be used for the detection of CEA in real samples. The proposed assay opens a

  17. Global polarization measurement in Au+Au collisions

    SciTech Connect

    Abelev, B.I.; Adams, J.; Aggarwal, M.M.; Ahammed, Z.; Amonett,J.; Anderson, B.D.; Anderson, M.; Arkhipkin, D.; Averichev, G.S.; Bai,Y.; Balewski, J.; Barannikova, O.; Barnby, L.S.; Baudot, J.; Bekele, S.; Belaga, V.V.; Bellingeri-Laurikainen, A.; Bellwied, R.; Benedosso, F.; Bhardwaj, S.; Bhasin, A.; Bhati, A.K.; Bichsel, H.; Bielcik, J.; Bielcikova, J.; Bland, L.C.; Blyth, S.-L.; Bonner, B.E.; Botje, M.; Bouchet, J.; Brandin, A.V.; Bravar, A.; Bystersky, M.; Cadman, R.V.; Cai,X.Z.; Caines, H.; Calderon de la Barca Sanchez, M.; Castillo, J.; Catu,O.; Cebra, D.; Chajecki, Z.; Chaloupka, P.; Chattopadhyay, S.; Chen,H.F.; Chen, J.H.; Cheng, J.; Cherney, M.; Chikanian, A.; Christie, W.; Coffin, J.P.; Cormier, T.M.; Cosentino, M.R.; Cramer, J.G.; Crawford,H.J.; Das, D.; Das, S.; Daugherity, M.; de Moura, M.M.; Dedovich, T.G.; DePhillips, M.; Derevschikov, A.A.; Didenko, L.; Dietel, T.; Djawotho,P.; Dogra, S.M.; Dong, W.J.; Dong, X.; Draper, J.E.; Du, F.; Dunin, V.B.; Dunlop, J.C.; Dutta Mazumdar, M.R.; Eckardt, V.; Edwards, W.R.; Efimov,L.G.; Emelianov, V.; Engelage, J.; Eppley, G.; Erazmus, B.; Estienne, M.; Fachini, P.; Fatemi, R.; Fedorisin, J.; Filimonov, K.; Filip, P.; Finch,E.; Fine, V.; Fisyak, Y.; Fu, J.; Gagliardi, C.A.; Gaillard, L.; Ganti,M.S.; Ghazikhanian, V.; Ghosh, P.; Gonzalez, J.S.; Gorbunov, Y.G.; Gos,H.; Grebenyuk, O.; Grosnick, D.; Guertin, S.M.; Guimaraes, K.S.F.F.; Guo,Y.; Gupta, N.; Gutierrez, T.D.; Haag, B.; Hallman, T.J.; Hamed, A.; Harris, J.W.; He, W.; Heinz, M.; Henry, T.W.; Hepplemann, S.; Hippolyte,B.; Hirsch, A.; Hjort, E.; Hoffman, A.M.; Hoffmann, G.W.; Horner, M.J.; Huang, H.Z.; Huang, S.L.; Hughes, E.W.; Humanic, T.J.; Igo, G.; Jacobs,P.; Jacobs, W.W.; Jakl, P.; Jia, F.; Jiang, H.; Jones, P.G.; Judd, E.G.; Kabana, S.; Kang, K.; Kapitan, J.; Kaplan, M.; Keane, D.; Kechechyan, A.; Khodyrev,V.Yu.; Kim, B.C.; Kiryluk, J.; Kisiel, A.; Kislov, E.M.; Klein,S.R.; Kocoloski, A.; Koetke, D.D.; et al.

    2007-08-02

    The system created in non-central relativisticnucleus-nucleus collisions possesses large orbital angular momentum. Dueto spin-orbit coupling, particles produced in such a system could becomeglobally polarized along the direction of the system angular momentum. Wepresent the results of Lambda and anti-Lambda hyperon global polarizationmeasurements in Au+Au collisions at sqrt sNN=62.4 GeV and 200 GeVperformed with the STAR detector at RHIC. The observed globalpolarization of Lambda and anti-Lambda hyperons in the STAR acceptance isconsistent with zero within the precision of the measurements. Theobtained upper limit, lbar P Lambda, anti-Lambda rbar<= 0.02, iscompared to the theoretical values discussed recently in theliterature.

  18. Universality in fragment inclusive yields from Au+Au collisions

    NASA Astrophysics Data System (ADS)

    Insolia, A.; Tuvè, C.; Albergo, S.; Bieser, F.; Brady, F. P.; Caccia, Z.; Cebra, D.; Chacon, A. D.; Chance, J. L.; Choi, Y.; Costa, S.; Elliott, J. B.; Gilkes, M.; Hauger, J. A.; Hirsch, A. S.; Hjort, E. L.; Justice, M.; Keane, D.; Kintner, J.; Lisa, M.; Matis, H. S.; McMahan, M.; McParland, C.; Olson, D. L.; Partlan, M. D.; Porile, N. T.; Potenza, R.; Rai, G.; Rasmussen, J.; Ritter, H. G.; Romero, J. L.; Russo, G. V.; Scharenberg, R.; Scott, A.; Shao, Y.; Srivastava, B. K.; Symons, T. J. M.; Tincknell, M. L.; Wang, S.; Warren, P. G.; Wieman, H. H.; Wolf, K. L.

    2001-11-01

    The inclusive light fragment (Z⩽7) yield data in Au+Au reactions, measured by the EOS Collaboration at the LBNL Bevalac, are presented and discussed. For peripheral collisions the measured charge distributions develop progressively according to a power law which can be fitted by a single τ exponent independently of the bombarding energy in the range 250-1200 A MeV. In addition to this universal feature, we observe that the location of the maximum in the individual yields of different charged fragments shift towards lower multiplicity as the fragment charge increases from Z=3 to Z=7. This trend is common to all six measured beam energies. Moments of charge distributions and correlations among different moments are reported. Finally, the THe,DT thermometer has been constructed for central and peripheral collisions using the double yield ratios of He and D, T projectile fragments. The measured nuclear temperatures are in agreement with experimental findings in other fragmentation reactions.

  19. Nuclear Modification of Jet Fragmentation in Au+Au Collisions

    NASA Astrophysics Data System (ADS)

    Rowan, Zachary; Phenix Collaboration

    2015-10-01

    The characterization of energy in the quark gluon plasma is facilitated by measurements of modifications to the observed jet fragmentation. A favorable channel of study relies on direct photons created in the initial parton interactions of heavy ion collisions. Such a photon traverses the created medium unscathed and grants us a proxy for the transverse momentum of an away side jet. PHENIX Au+Au data recorded at √{sNN} = 200 GeV during RHIC run 14 benefit from the background rejection capability of the silicon vertex detector, enabling the extraction of a higher purity hadron signal. This advantage, combined with a larger integrated luminosity, allows previous PHENIX measurements of fragmentation functions to be extended to greater jet energies. In this talk, the status of the analysis of direct photon hadron correlations with the new data set will be discussed.

  20. Global polarization measurement in Au+Au collisions

    NASA Astrophysics Data System (ADS)

    Abelev, B. I.; Aggarwal, M. M.; Ahammed, Z.; Anderson, B. D.; Arkhipkin, D.; Averichev, G. S.; Bai, Y.; Balewski, J.; Barannikova, O.; Barnby, L. S.; Baudot, J.; Baumgart, S.; Belaga, V. V.; Bellingeri-Laurikainen, A.; Bellwied, R.; Benedosso, F.; Betts, R. R.; Bhardwaj, S.; Bhasin, A.; Bhati, A. K.; Bichsel, H.; Bielcik, J.; Bielcikova, J.; Bland, L. C.; Blyth, S.-L.; Bombara, M.; Bonner, B. E.; Botje, M.; Bouchet, J.; Brandin, A. V.; Burton, T. P.; Bystersky, M.; Cai, X. Z.; Caines, H.; Sánchez, M. Calderón De La Barca; Callner, J.; Catu, O.; Cebra, D.; Cervantes, M. C.; Chajecki, Z.; Chaloupka, P.; Chattopadhyay, S.; Chen, H. F.; Chen, J. H.; Chen, J. Y.; Cheng, J.; Cherney, M.; Chikanian, A.; Christie, W.; Chung, S. U.; Clarke, R. F.; Codrington, M. J. M.; Coffin, J. P.; Cormier, T. M.; Cosentino, M. R.; Cramer, J. G.; Crawford, H. J.; Das, D.; Dash, S.; Daugherity, M.; Moura, M. M. De; Dedovich, T. G.; Dephillips, M.; Derevschikov, A. A.; Didenko, L.; Dietel, T.; Djawotho, P.; Dogra, S. M.; Dong, X.; Drachenberg, J. L.; Draper, J. E.; Du, F.; Dunin, V. B.; Dunlop, J. C.; Mazumdar, M. R. Dutta; Edwards, W. R.; Efimov, L. G.; Emelianov, V.; Engelage, J.; Eppley, G.; Erazmus, B.; Estienne, M.; Fachini, P.; Fatemi, R.; Fedorisin, J.; Feng, A.; Filip, P.; Finch, E.; Fine, V.; Fisyak, Y.; Fu, J.; Gagliardi, C. A.; Gaillard, L.; Ganti, M. S.; Garcia-Solis, E.; Ghazikhanian, V.; Ghosh, P.; Gorbunov, Y. N.; Gos, H.; Grebenyuk, O.; Grosnick, D.; Grube, B.; Guertin, S. M.; Guimaraes, K. S. F. F.; Gupta, A.; Gupta, N.; Haag, B.; Hallman, T. J.; Hamed, A.; Harris, J. W.; He, W.; Heinz, M.; Henry, T. W.; Heppelmann, S.; Hippolyte, B.; Hirsch, A.; Hjort, E.; Hoffman, A. M.; Hoffmann, G. W.; Hofman, D. J.; Hollis, R. S.; Horner, M. J.; Huang, H. Z.; Hughes, E. W.; Humanic, T. J.; Igo, G.; Iordanova, A.; Jacobs, P.; Jacobs, W. W.; Jakl, P.; Jones, P. G.; Judd, E. G.; Kabana, S.; Kang, K.; Kapitan, J.; Kaplan, M.; Keane, D.; Kechechyan, A.; Kettler, D.; Khodyrev, V. Yu.; Kiryluk, J.; Kisiel, A.; Kislov, E. M.; Klein, S. R.; Knospe, A. G.; Kocoloski, A.; Koetke, D. D.; Kollegger, T.; Kopytine, M.; Kotchenda, L.; Kouchpil, V.; Kowalik, K. L.; Kravtsov, P.; Kravtsov, V. I.; Krueger, K.; Kuhn, C.; Kulikov, A. I.; Kumar, A.; Kurnadi, P.; Kuznetsov, A. A.; Lamont, M. A. C.; Landgraf, J. M.; Lange, S.; Lapointe, S.; Laue, F.; Lauret, J.; Lebedev, A.; Lednicky, R.; Lee, C.-H.; Lehocka, S.; Levine, M. J.; Li, C.; Li, Q.; Li, Y.; Lin, G.; Lin, X.; Lindenbaum, S. J.; Lisa, M. A.; Liu, F.; Liu, H.; Liu, J.; Liu, L.; Ljubicic, T.; Llope, W. J.; Longacre, R. S.; Love, W. A.; Lu, Y.; Ludlam, T.; Lynn, D.; Ma, G. L.; Ma, J. G.; Ma, Y. G.; Mahapatra, D. P.; Majka, R.; Mangotra, L. K.; Manweiler, R.; Margetis, S.; Markert, C.; Martin, L.; Matis, H. S.; Matulenko, Yu. A.; McShane, T. S.; Meschanin, A.; Millane, J.; Miller, M. L.; Minaev, N. G.; Mioduszewski, S.; Mischke, A.; Mitchell, J.; Mohanty, B.; Morozov, D. A.; Munhoz, M. G.; Nandi, B. K.; Nattrass, C.; Nayak, T. K.; Nelson, J. M.; Nepali, C.; Netrakanti, P. K.; Nogach, L. V.; Nurushev, S. B.; Odyniec, G.; Ogawa, A.; Okorokov, V.; Olson, D.; Pachr, M.; Pal, S. K.; Panebratsev, Y.; Pavlinov, A. I.; Pawlak, T.; Peitzmann, T.; Perevoztchikov, V.; Perkins, C.; Peryt, W.; Phatak, S. C.; Planinic, M.; Pluta, J.; Poljak, N.; Porile, N.; Poskanzer, A. M.; Potekhin, M.; Potrebenikova, E.; Potukuchi, B. V. K. S.; Prindle, D.; Pruneau, C.; Pruthi, N. K.; Putschke, J.; Qattan, I. A.; Raniwala, R.; Raniwala, S.; Ray, R. L.; Relyea, D.; Ridiger, A.; Ritter, H. G.; Roberts, J. B.; Rogachevskiy, O. V.; Romero, J. L.; Rose, A.; Roy, C.; Ruan, L.; Russcher, M. J.; Sahoo, R.; Sakrejda, I.; Sakuma, T.; Salur, S.; Sandweiss, J.; Sarsour, M.; Sazhin, P. S.; Schambach, J.; Scharenberg, R. P.; Schmitz, N.; Seger, J.; Selyuzhenkov, I.; Seyboth, P.; Shabetai, A.; Shahaliev, E.; Shao, M.; Sharma, M.; Shen, W. Q.; Shimanskiy, S. S.; Sichtermann, E. P.; Simon, F.; Singaraju, R. N.; Smirnov, N.; Snellings, R.; Sorensen, P.; Sowinski, J.; Speltz, J.; Spinka, H. M.; Srivastava, B.; Stadnik, A.; Stanislaus, T. D. S.; Staszak, D.; Stock, R.; Strikhanov, M.; Stringfellow, B.; Suaide, A. A. P.; Suarez, M. C.; Subba, N. L.; Sumbera, M.; Sun, X. M.; Sun, Z.; Surrow, B.; Symons, T. J. M.; Toledo, A. Szanto De; Takahashi, J.; Tang, A. H.; Tarnowsky, T.; Thomas, J. H.; Timmins, A. R.; Timoshenko, S.; Tokarev, M.; Trainor, T. A.; Trentalange, S.; Tribble, R. E.; Tsai, O. D.; Ulery, J.; Ullrich, T.; Underwood, D. G.; Buren, G. Van; Kolk, N. Van Der; Leeuwen, M. Van; Molen, A. M. Vander; Varma, R.; Vasilevski, I. M.; Vasiliev, A. N.; Vernet, R.; Vigdor, S. E.; Viyogi, Y. P.; Vokal, S.; Voloshin, S. A.; Wada, M.; Waggoner, W. T.; Wang, F.; Wang, G.; Wang, J. S.; Wang, X. L.; Wang, Y.; Webb, J. C.; Westfall, G. D.; , C. Whitten, Jr.; Wieman, H.; Wissink, S. W.; Witt, R.; Wu, J.; Wu, Y.; Xu, N.; Xu, Q. H.; Xu, Z.; Yepes, P.; Yoo, I.-K.; Yue, Q.; Yurevich, V. I.; Zawisza, M.; Zhan, W.; Zhang, H.; Zhang, W. M.; Zhang, Y.; Zhang, Z. P.; Zhao, Y.; Zhong, C.; Zhou, J.; Zoulkarneev, R.; Zoulkarneeva, Y.; Zubarev, A. N.; Zuo, J. X.

    2007-08-01

    The system created in noncentral relativistic nucleus-nucleus collisions possesses large orbital angular momentum. Because of spin-orbit coupling, particles produced in such a system could become globally polarized along the direction of the system angular momentum. We present the results of Λ and Λ¯ hyperon global polarization measurements in Au+Au collisions at sNN=62.4 and 200 GeV performed with the STAR detector at the BNL Relativistic Heavy Ion Collider (RHIC). The observed global polarization of Λ and Λ¯ hyperons in the STAR acceptance is consistent with zero within the precision of the measurements. The obtained upper limit, |PΛ,Λ¯|⩽0.02, is compared with the theoretical values discussed recently in the literature.

  1. Nomograms for Predicting the Prognostic Value of Pre-Therapeutic CA15-3 and CEA Serum Levels in TNBC Patients

    PubMed Central

    Wang, Bin; Zhao, Zhiping; Xie, Xiaoming; Wei, Weidong

    2016-01-01

    Previous studies have indicated that carcinoembryonic antigen (CEA) and cancer antigen 15–3 (CA15-3) levels are both independent prognostic factors in breast cancer. However, the utility of CEA and CA15-3 levels as conventional cancer biomarkers in patients with triple-negative breast cancer (TNBC) remains controversial. The current study was performed to explore the predictive value of pre-therapeutic serum CEA and CA15-3 levels, and nomograms were developed including these serum cancer biomarkers to improve the prognostic evaluation of TNBC patients. Pre-therapeutic CA15-3 and CEA concentrations were measured in 247 patients with stage I–IV TNBC. Kaplan-Meier analysis showed that TNBC patients with high levels of both CEA and CA15-3 had shorter overall survival (OS) and disease-free survival (DFS) rates than those in the low-level groups (p<0.05). Multivariate analysis suggested that pre-therapeutic CA15-3 and CEA levels are independent predictive elements for OS (p = 0.022 and p = 0.040, respectively) and DFS (p = 0.023 and p = 0.028, respectively). In addition, novel nomograms were established and validated to provide personal forecasts of OS and DFS for patients with TNBC. These novel nomograms may help physicians to select the optimal treatment plans to ensure the best outcomes for TNBC patients. PMID:27561099

  2. Nomograms for Predicting the Prognostic Value of Pre-Therapeutic CA15-3 and CEA Serum Levels in TNBC Patients.

    PubMed

    Dai, Danian; Chen, Bo; Tang, Hailin; Wang, Bin; Zhao, Zhiping; Xie, Xiaoming; Wei, Weidong

    2016-01-01

    Previous studies have indicated that carcinoembryonic antigen (CEA) and cancer antigen 15-3 (CA15-3) levels are both independent prognostic factors in breast cancer. However, the utility of CEA and CA15-3 levels as conventional cancer biomarkers in patients with triple-negative breast cancer (TNBC) remains controversial. The current study was performed to explore the predictive value of pre-therapeutic serum CEA and CA15-3 levels, and nomograms were developed including these serum cancer biomarkers to improve the prognostic evaluation of TNBC patients. Pre-therapeutic CA15-3 and CEA concentrations were measured in 247 patients with stage I-IV TNBC. Kaplan-Meier analysis showed that TNBC patients with high levels of both CEA and CA15-3 had shorter overall survival (OS) and disease-free survival (DFS) rates than those in the low-level groups (p<0.05). Multivariate analysis suggested that pre-therapeutic CA15-3 and CEA levels are independent predictive elements for OS (p = 0.022 and p = 0.040, respectively) and DFS (p = 0.023 and p = 0.028, respectively). In addition, novel nomograms were established and validated to provide personal forecasts of OS and DFS for patients with TNBC. These novel nomograms may help physicians to select the optimal treatment plans to ensure the best outcomes for TNBC patients. PMID:27561099

  3. d + Au hadron correlation measurements at PHENIX

    SciTech Connect

    Anne M. Sickles

    2014-05-13

    In these proceedings, we discuss recent results from d + Au collisions in PHENIX ridge related measurements and their possible hydrodynamic origin. We present the v2 at midrapidity and measurements of the pseudorapidity dependence of the ridge, distinguishing between the d-going and Au-going directions. We investigate the possible geometrical origin by comparing v2 in d + Au to that in p + Pb, Au + Au and Pb + Pb collisions. Future plans to clarify the role of geometry in small collision systems at RHIC are discussed.

  4. Ionic liquid of a gold nanocluster: a versatile matrix for electrochemical biosensors.

    PubMed

    Kwak, Kyuju; Kumar, S Senthil; Pyo, Kyunglim; Lee, Dongil

    2014-01-28

    Ionic liquids are room-temperature molten salts that are increasingly used in electrochemical devices, such as batteries, fuel cells, and sensors, where their intrinsic ionic conductivity is exploited. Here we demonstrate that combining anionic, redox-active Au25 clusters with imidazolium cations leads to a stable ionic liquid possessing both ionic and electronic conductivity. The Au25 ionic liquid was found to act as a versatile matrix for amperometric enzyme biosensors toward the detection of glucose. Enzyme electrodes prepared by incorporating glucose oxidase in the Au25 ionic liquid show high electrocatalytic activity and substrate affinity. Au25 clusters in the electrode were found to act as effective redox mediators as well as electronic conductors determining the detection sensitivity. With the unique electrochemical properties and almost unlimited structural tunability, the ionic liquids of quantum-sized gold clusters may serve as versatile matrices for a variety of electrochemical biosensors. PMID:24350837

  5. Low temperature fabrication and doping concentration analysis of Au/Sb ohmic contacts to n-type Si

    NASA Astrophysics Data System (ADS)

    Liu, J. Q.; Wang, C.; Zhu, T.; Wu, W. J.; Fan, J.; Tu, L. C.

    2015-11-01

    This paper investigates low temperature ohmic contact formation of Au/Sb to n-type Si substrates through AuSb/NiCr/Au metal stacks. Liquid epitaxy growth is utilized to incorporate Sb dopants into Si substrate in AuSi melt. The best specific contact resistivity achieved is 0.003 Ω ṡ cm2 at 425 oC. Scanning electron microscopy (SEM) reveals inverted pyramidal crater regions at the metal/semiconductor interface, indicating that AuSi alloying efficiently occurs at such sites. Secondary ion mass spectroscopy (SIMS) shows that Sb atoms are successfully incorporated into Si as doping impurities during the anneal process, and the Sb doping concentration at the contact interface is found to be higher than the solid solubility limit in a Si crystal. This ohmic contacts formation method is suitable for semiconductor fabrication processes with limited thermal budget, such as post CMOS integration of MEMS.

  6. Low temperature fabrication and doping concentration analysis of Au/Sb ohmic contacts to n-type Si

    SciTech Connect

    Liu, J. Q.; Wang, C.; Zhu, T.; Wu, W. J.; Fan, J.; Tu, L. C.

    2015-11-15

    This paper investigates low temperature ohmic contact formation of Au/Sb to n-type Si substrates through AuSb/NiCr/Au metal stacks. Liquid epitaxy growth is utilized to incorporate Sb dopants into Si substrate in AuSi melt. The best specific contact resistivity achieved is 0.003 Ω ⋅ cm{sup 2} at 425 {sup o}C. Scanning electron microscopy (SEM) reveals inverted pyramidal crater regions at the metal/semiconductor interface, indicating that AuSi alloying efficiently occurs at such sites. Secondary ion mass spectroscopy (SIMS) shows that Sb atoms are successfully incorporated into Si as doping impurities during the anneal process, and the Sb doping concentration at the contact interface is found to be higher than the solid solubility limit in a Si crystal. This ohmic contacts formation method is suitable for semiconductor fabrication processes with limited thermal budget, such as post CMOS integration of MEMS.

  7. Cometary Activity Beyond 4 AU

    NASA Astrophysics Data System (ADS)

    Womack, M.

    2000-10-01

    Recent observations of the distantly active comets 29 P/Schwassmann-Wachmann 1, 2060 Chiron, and C/1995 O1 (Hale-Bopp) are consistent with models that predict that the activity beyond 4 AU is dominated by outgassing of CO and CO2 molecules trapped in an amorphous water ice surface undergoing crystallization. The nominal CO production rates in Hale-Bopp, SW 1 and Chiron over the range of r = 4 to 9 AU are consistent with Q(CO) = (2.9+/-0.5)x1030r{(-2.5 +/- 0.1)}, with sporadic outbursts superimposed. The data indicate that the gas production rates in distant comets are primarily determined by the composition, and not the size, of the nucleus. The dust production rates, however, are very different among these comets and are not well-correlated with heliocentric distance. Thus, the gas and dust mixtures may not be uniform amongst these comets, nor in an individual comet. Development and sublimation of an icy grain coma at ~ 5 AU appears to be a common feature in distantly active comets. Sublimation of such icy grains is probably the main source of emission of OH, CH3OH, HCN, and H2S in comets beyond 4 AU. Studying the energetics of these phenomena provides an excellent opportunity to learn more about the composition and physical behavior of comet nuclei, as well as other icy bodies in the outer solar system, such as moons and Kuiper Belt Objects. This work was funded by the NSF CAREER Program.

  8. Fabrication of crystalline Ge thin films by co-deposition of Au and Ge at low substrate temperatures (<200 °C) without post annealing

    NASA Astrophysics Data System (ADS)

    Sugiyama, Takatoshi; Mishiba, Naoya; Kamiko, Masao; Kyuno, Kentaro

    2016-09-01

    Crystalline Ge thin films with (111) orientation are obtained by co-depositing Au and Ge on a substrate heated to ∼170 °C, with Au segregating at the film surface, which is desirable for selective etching. Although in the conventional metal-induced crystallization method using Au as a catalyst, a bilayer of Au and amorphous Ge layers have to be annealed for Ge to crystallize, the film in this study is already crystalline in the as-deposited state. The effective crystallization process implies the existence of a supercooled liquid alloy layer at the growth front.

  9. Lead-free solder alloys: Thermodynamic properties of the (Au + Sb + Sn) and the (Au + Sb) system

    PubMed Central

    Hindler, Michael; Guo, Zhongnan; Mikula, Adolf

    2012-01-01

    The thermodynamic properties of liquid (Au–Sb–Sn) alloys were studied with an electromotive force (EMF) method using the eutectic mixture of KCl/LiCl with addition of SnCl2 as a liquid electrolyte. Activities of Sn in the liquid alloys were measured at three cross-sections with constant molar ratios of Au:Sb = 2:1, 1:1, and 1:2 with tin in the concentration range between 5 at.% and 90 at.% from the liquidus of the samples up to 1073 K. The integral Gibbs excess energies and the integral enthalpies at 873 K were calculated by Gibbs–Duhem integration. Additionally liquid Au–Sb alloys have been measured at 913 K with the EMF method as no reliable data for the Gibbs excess energies have been found in literature. The eutectic mixture of KCl/LiCl with addition of SbCl3 has been used as an electrolyte for the measurements. The Gibbs excess energies from the (Au + Sb) system were necessary for the integration of the thermodynamic properties of the ternary (Au + Sb + Sn) system. PMID:24926101

  10. Synthesis and optical property characterization of elongated AuPt and Pt@Au metal nanoframes

    NASA Astrophysics Data System (ADS)

    Lee, Sangji; Jang, Hee-Jeong; Jang, Ho Young; Hong, Soonchang; Moh, Sang Hyun; Park, Sungho

    2016-02-01

    We report a facile method to synthesize elongated nanoframes consisting of Pt and Au in solution. Pentagonal Au nanorods served as templates and successfully led to an elongated AuPt nanoframe after etching the core Au. Subsequently, the coating of Au around Pt ridges resulted in Pt@Au metal nanoframes. The resulting elongated nanostructure exhibited 5 well-defined ridges continuously connected along the long axis. During the shape evolution from pure Au nanorods to elongated Pt@Au metal nanoframes, their corresponding localized surface plasmon resonance bands were monitored. Especially, unique surface plasmon features were observed for elongated Pt@Au nanoframes where the short-axis oscillation of surface free electrons is strongly coupled but the long-axis oscillation is not coupled among the ridges.We report a facile method to synthesize elongated nanoframes consisting of Pt and Au in solution. Pentagonal Au nanorods served as templates and successfully led to an elongated AuPt nanoframe after etching the core Au. Subsequently, the coating of Au around Pt ridges resulted in Pt@Au metal nanoframes. The resulting elongated nanostructure exhibited 5 well-defined ridges continuously connected along the long axis. During the shape evolution from pure Au nanorods to elongated Pt@Au metal nanoframes, their corresponding localized surface plasmon resonance bands were monitored. Especially, unique surface plasmon features were observed for elongated Pt@Au nanoframes where the short-axis oscillation of surface free electrons is strongly coupled but the long-axis oscillation is not coupled among the ridges. Electronic supplementary information (ESI) available. See DOI: 10.1039/c5nr08200e

  11. Evaluation of serum CEA, CYFRA21-1 and CA125 for the early detection of colorectal cancer using longitudinal preclinical samples

    PubMed Central

    Thomas, D S; Fourkala, E-O; Apostolidou, S; Gunu, R; Ryan, A; Jacobs, I; Menon, U; Alderton, W; Gentry-Maharaj, A; Timms, J F

    2015-01-01

    Background: Blood-borne biomarkers for early detection of colorectal cancer (CRC) could markedly increase screening uptake. The aim of this study was to evaluate serum carcinoembryonic antigen (CEA), CYFRA21-1 and CA125 for the early detection of CRC in an asymptomatic cohort. Methods: This nested case–control study within UKCTOCS used 381 serial serum samples from 40 women subsequently diagnosed with CRC, 20 women subsequently diagnosed with benign disease and 40 matched non-cancer controls with three to four samples per subject taken annually up to 4 years before diagnosis. CEA, CYFRA21-1 and CA125 were measured using validated assays and performance of markers evaluated for different pre-diagnosis time groups. Results: CEA levels increased towards diagnosis in a third of all cases (half of late-stage cases), whereas longitudinal profiles were static in both benign and non-cancer controls. At a threshold of >5 ng ml−1 the sensitivities for detecting CRC up to 1 and 4 years before clinical presentation were 25% and 13%, respectively, at 95% specificity. At a threshold of >2.5 ng ml−1, sensitivities were 57.5% and 38.4%, respectively, with specificities of 81% and 83.5%. CYFRA21-1 and CA125 had no utility as screening markers and did not enhance CEA performance when used in combination. CEA gave average lead times of 17–24 months for test-positive cases. Conclusions: CEA is elevated in a significant proportion of individuals with preclinical CRC, but would not be useful alone as a screening tool. This work sets a baseline from which to develop panels of biomarkers which combine CEA for improved early detection of CRC. PMID:26035703

  12. Phase I Hepatic Immunotherapy for Metastases study of intra-arterial chimeric antigen receptor modified T cell therapy for CEA+ liver metastases

    PubMed Central

    Katz, Steven C.; Burga, Rachel A.; McCormack, Elise; Wang, Li Juan; Mooring, Wesley; Point, Gary; Khare, Pranay D.; Thorn, Mitchell; Ma, Qiangzhong; Stainken, Brian F.; Assanah, Earle O.; Davies, Robin; Espat, N. Joseph; Junghans, Richard P.

    2015-01-01

    Purpose Chimeric antigen receptor modified T cells (CAR-T) have demonstrated encouraging results in early-phase clinical trials. Successful adaptation of CAR-T technology for CEA-expressing adenocarcinoma liver metastases (LM), a major cause of death in patients with gastrointestinal cancers, has yet to be achieved. We sought to test intrahepatic delivery of anti-CEA CAR-T through percutaneous hepatic artery infusions (HAI). Experimental Design We conducted a phase I trial to test HAI of CAR-T in patients with CEA+ LM. Six patients completed the protocol, and 3 received anti-CEA CAR-T HAIs alone in dose-escalation fashion (108, 109, and 1010 cells). We treated an additional 3 patients with the maximum planned CAR-T HAI dose (1010 cells X 3) along with systemic IL2 support. Results Four patients had more than 10 LM and patients received a mean of 2.5 lines of conventional systemic therapy prior to enrollment. No patient suffered a grade 3 or 4 adverse event related to the CAR-T HAIs. One patient remains alive with stable disease at 23 months following CAR-T HAI and 5 patients died of progressive disease. Among the patients in the cohort that received systemic IL2 support, CEA levels decreased 37% (range 19–48%) from baseline. Biopsies demonstrated an increase in LM necrosis or fibrosis in 4 of 6 patients. Elevated serum IFNγ levels correlated with IL2 administration and CEA decreases. Conclusions We have demonstrated the safety of anti-CEA CAR-T HAIs with encouraging signals of clinical activity in a heavily pre-treated population with large tumor burdens. Further clinical testing of CAR-T HAIs for LM is warranted. PMID:25850950

  13. Major Upgrade of the Reactor Dosimetry Interpretation Methodology Used at the CEA General Principle

    NASA Astrophysics Data System (ADS)

    Destouches, C.; Gregoire, G.; Beretz, D.; Bourganel, S.; Chiron, M.

    2009-08-01

    One of the main objectives of reactor dosimetry is the determination of the physical parameters characterizing the neutron field in which test samples are irradiated. These characteristics, from neutron spectrum to reaction rates characterization are used in experimental reactors to carry out the follow-up of the irradiation and to qualify the neutron calculation used to model the experiment. In power reactors these characteristics are used for the follow-up of the predicted damages to vessel and interns. Neutron parameters are derived from the dosimeter's activities which have suitable reactions (response functions and radioactive emissions). Then, the activities are analyzed using nuclear data, neutron computation results and data characterizing the conditions of irradiation (temporal and technological data, changes of location, etc.). The current CEA interpretation process applied for industrial power reactor interpretation process presents limitations coming mainly from the calculational tools and the nuclear data knowledge available at the time this method was developed in the mid 90's. However nowadays due to, first the improvement of the neutron calculational tools, for example, a full 3D Monte Carlo reactor modeling providing reaction in a point wise format is now possible in a reasonable time, and second, recent releases of the updated international nuclear data libraries, JEFF3.1, ENDF/B-VII for transport calculation and IRDF2002 and EAF2007 for dosimetry libraries, we have been engaged in a deep renewal of the reactor dosimetry interpretation process. The mains goals of this works are to improve the modeling of the experiment and the neutron parameters calculation for each phase of interest. In addition, uncertainties associated to the derived metrics are quantified in a rigorous way using simulation methods designed to cope with the high non-linearity of the process. After a detailed presentation of the current interpretation process and its limitations

  14. Research at the CEA in the field of safety in 2nd and 3rd generation light water reactors

    NASA Astrophysics Data System (ADS)

    Billot, Philippe

    2012-05-01

    The research programs at the CEA in the field of safety in nuclear reactors are carried out in a framework of international partnerships. Their purpose is to develop studies on: The methods allowing for the determination of earthquake hazards and their consequences; The behaviour of fuel in an accident situation; The comprehension of deflagration and detonation phenomena of hydrogen and the search for effective prevention methods involving an explosion risk; The cooling of corium in order to stop its progression in and outside the vessel thereby reducing the risk of perforating the basemat; The behaviour of the different fission product families according to their volatility for the UO2 and MOX fuels.

  15. Nuclear data uncertainty propagation for neutronic key parameters of CEA's SFR V2B and CFV sodium fast reactor designs

    SciTech Connect

    Archier, P.; Buiron, L.; De Saint Jean, C.; Dos Santos, N.

    2012-07-01

    This paper presents a nuclear data uncertainty propagation analysis for two CEA's Sodium-cooled Fast Reactor designs: the SFR V2B and CFV cores. The nuclear data covariance matrices are provided by the DER/SPRC/LEPh's nuclear data team (see companion paper) for several major isotopes. From the current status of this analysis, improvements on certain nuclear data reactions are highlighted as well as the need for new specific integral experiments in order to meet the technological breakthroughs proposed by the CFV core. (authors)

  16. Sandia National Laboratories results for the 2010 criticality accident dosimetry exercise, at the CALIBAN reactor, CEA Valduc France.

    SciTech Connect

    Ward, Dann C.

    2011-09-01

    This document describes the personal nuclear accident dosimeter (PNAD) used by Sandia National Laboratories (SNL) and presents PNAD dosimetry results obtained during the Nuclear Accident Dosimeter Intercomparison Study held 20-23 September, 2010, at CEA Valduc, France. SNL PNADs were exposed in two separate irradiations from the CALIBAN reactor. Biases for reported neutron doses ranged from -15% to +0.4% with an average bias of -7.7%. PNADs were also exposed on the back side of phantoms to assess orientation effects.

  17. Controlled synthesis and synergistic effects of graphene-supported PdAu bimetallic nanoparticles with tunable catalytic properties

    NASA Astrophysics Data System (ADS)

    Liu, Chang-Hai; Liu, Rui-Hua; Sun, Qi-Jun; Chang, Jian-Bing; Gao, Xu; Liu, Yang; Lee, Shuit-Tong; Kang, Zhen-Hui; Wang, Sui-Dong

    2015-03-01

    Graphene-supported bimetallic nanoparticles are promising nanocatalysts, which can show strong and tunable catalytic activity and selectivity. Herein room-temperature-ionic-liquid-assisted metal sputtering is utilized to synthesize PdAu bimetallic nanoparticles on graphene with bare surface, small size, high surface density and controlled Pd-to-Au ratio. This controllable synthetic approach is green-chemistry compatible and totally free of additives and byproducts. The supported PdAu nanoparticles show excellent catalytic capabilities for both oxidation and reduction reactions, strongly dependent on the Pd-to-Au ratio. A strong correlation among catalytic performance, bimetallic composition and charge redistribution in the PdAu nanoparticles has been demonstrated. The results suggest that sufficient Au d-holes appear to be significant to the catalysis of oxidation reaction, and a metallic Pd surface is critical to the catalysis of reduction reaction. By the present method, the bimetallic combination can be tailored for distinct types of catalytic reactions.Graphene-supported bimetallic nanoparticles are promising nanocatalysts, which can show strong and tunable catalytic activity and selectivity. Herein room-temperature-ionic-liquid-assisted metal sputtering is utilized to synthesize PdAu bimetallic nanoparticles on graphene with bare surface, small size, high surface density and controlled Pd-to-Au ratio. This controllable synthetic approach is green-chemistry compatible and totally free of additives and byproducts. The supported PdAu nanoparticles show excellent catalytic capabilities for both oxidation and reduction reactions, strongly dependent on the Pd-to-Au ratio. A strong correlation among catalytic performance, bimetallic composition and charge redistribution in the PdAu nanoparticles has been demonstrated. The results suggest that sufficient Au d-holes appear to be significant to the catalysis of oxidation reaction, and a metallic Pd surface is critical

  18. Photoelectrochemical sensing of 4-chlorophenol based on Au/BiOCl nanocomposites.

    PubMed

    Yan, Pengcheng; Xu, Li; Xia, Jiexiang; Huang, Yan; Qiu, Jingxia; Xu, Qian; Zhang, Qi; Li, Huaming

    2016-08-15

    The Au/BiOCl composites have been prepared by a facile one-pot ethylene glycol (EG) assisted solvothermal reaction in the presence of ionic liquid 1-hexadecyl-3-methylimidazolium chloride ([C16mim]Cl). During the synthesis procedure, the [C16mim]Cl has been used as Cl source, solvent of this system, and dispersing agent to effectively disperse Au on the surface of BiOCl. The as-prepared samples have been systematically characterized by multiple instruments to investigate the structure, morphology, and photoelectrochemical properties. According to the photoelectrochemical data, the Au/BiOCl composites exhibit better photoelectrochemical performance toward the detection of 4-chlorophenol than that of the pure BiOCl. The photocurrent response of Au/BiOCl modified electrode is high and stable under light irradiation. The proposed Au/BiOCl modified electrode shows a wide linear response ranging from 0.16 to 20mgL(-1) with detection limit of 0.05mgL(-1). It indicates a dramatically promising application of bismuth oxyhalides in photoelectrochemical detection. It will be expected that the present study may be lightly extended to the monitor of other organic pollutants by photoelectrochemical detection of the Au/BiOCl composites. PMID:27260461

  19. Self-assembly of alkanols on Au(111) surfaces.

    PubMed

    Zhang, Hai-Ming; Yan, Jia-Wei; Xie, Zhao-Xiong; Mao, Bing-Wei; Xu, Xin

    2006-05-15

    Self-assembled monolayers (SAMs) of alkanols (1-C(N)H(2N+1)OH) with varying carbon-chain lengths (N = 10-30) have been systematically studied by means of scanning tunneling microscopy (STM) at the interfaces between alkanol solutions (or liquids) and Au(111) surfaces. The carbon skeletons were found to lie flat on the surfaces. This orientation is consistent with SAMs of alkanols on highly oriented pyrolytic graphite (HOPG) and MoS2 surfaces, and also with alkanes on reconstructed Au(111) surfaces. This result differs from a prior report, which claimed that 1-decanol molecules (N = 10) stood on their ends with the OH polar groups facing the gold substrate. Compared to alkanes, the replacement of one terminal CH3 group with an OH group introduces new bonding features for alkanols owing to the feasibility of forming hydrogen bonds. While SAMs of long-chain alkanols (N > 18) resemble those of alkanes, in which the aliphatic chains make a greater contribution, hydrogen bonding plays a more important role in the formation of SAMs of short-chain alkanols. Thus, in addition to the titled lamellar structure, a herringbone-like structure, seldom seen in SAMs of alkanes, is dominant in alkanol SAMs for values of N < 18. The odd-even effect present in alkane SAMs is also present in alkanol SAMs. Thus, the odd N alkanols (alkanols with an odd number of carbon atoms) adopt perpendicular lamellar structures owing to the favorable interactions of the CH3 terminal groups, similar to the result observed for odd alkanes. In contrast to alkanes on Au(111) surfaces, for which no SAMs on an unreconstructed gold substrate were observed, alkanols are capable of forming SAMs on either the reconstructed or the unreconstructed gold surfaces. Structural models for the packing of alkanol molecules on Au(111) surfaces have been proposed, which successfully explain these experimental observations. PMID:16534826

  20. Wetting and energetics of solid Au and Au-Ge/SiC interfaces

    SciTech Connect

    Wang, Z.; Wynblatt, P.

    1998-09-01

    A solid state wetting technique has been used to investigate the effects of alloying Au with Ge on the wetting and energetics of Au/SiC interfaces at 1123 K. Germanium was found to segregate to the Au/SiC interface, thereby lowering the contact angle of Au on SiC from 133 to 110, and doubling the work of adhesion of Au on SiC. Calculations based on a monolayer model predict a segregation of 0.89 monolayers of Ge at the Au/SiC interface for Au containing 2.3 at.% Ge. This agrees reasonably well with a coverage of 0.6 monolayers Ge at the Au/SiC interface obtained by direct measurements based on the crater edge profiling technique. The work also demonstrates that simple models of interfacial composition can be combined with the Gibbs adsorption isotherm to provide reliable estimates of interfacial composition at complex four-component interfaces.

  1. Pt{sub 3}Au and PtAu clusters: Electronic states and potential energy surfaces

    SciTech Connect

    Dai, D.; Balasubramanian, K.

    1994-03-15

    We carried out complete active space multiconfiguration self-consistent-field calculations followed by multireference singles+doubles configuration interaction with the Davidson correction which included up to 3.55 million configurations employing relativistic effective core potentials on Pt{sub 3}+Au and PtAu clusters. Four low-lying electronic states were identified for Pt{sub 3}+Au. The {sup 2}{ital A}{sub 2} electronic state ({ital C}{sub 3{ital v}}) was found to be the ground state of Pt{sub 3}Au. Spin--orbit effects were found to be significant. We also computed six low-lying electronic states of PtAu and four low-lying electronic states of PtAu{sup +}. The 5/2 ({sup 2}{Delta}) and 0{sup +}({sup 1}{Sigma}{sup +}) states were found to be the ground states of PtAu and PtAu{sup +}, respectively.

  2. Gold nanowired: a linear (Au25)(n) polymer from Au25 molecular clusters.

    PubMed

    De Nardi, Marco; Antonello, Sabrina; Jiang, De-en; Pan, Fangfang; Rissanen, Kari; Ruzzi, Marco; Venzo, Alfonso; Zoleo, Alfonso; Maran, Flavio

    2014-08-26

    Au25(SR)18 has provided fundamental insights into the properties of clusters protected by monolayers of thiolated ligands (SR). Because of its ultrasmall core, 1 nm, Au25(SR)18 displays molecular behavior. We prepared a Au25 cluster capped by n-butanethiolates (SBu), obtained its structure by single-crystal X-ray crystallography, and studied its properties both experimentally and theoretically. Whereas in solution Au25(SBu)18(0) is a paramagnetic molecule, in the crystal it becomes a linear polymer of Au25 clusters connected via single Au-Au bonds and stabilized by proper orientation of clusters and interdigitation of ligands. At low temperature, [Au25(SBu)18(0)]n has a nonmagnetic ground state and can be described as a one-dimensional antiferromagnetic system. These findings provide a breakthrough into the properties and possible solid-state applications of molecular gold nanowires. PMID:25088331

  3. Interplanetary dust between 1 and 5 AU

    NASA Technical Reports Server (NTRS)

    Stanley, J. E.; Singer, S. F.; Alvarez, J. M.

    1979-01-01

    Analyses of data from the Meteoroid Detection Experiment (MDE) and the Imaging Photopolarimeter (IPP) aboard Pioneer 10 and 11 have led to contradictory conclusions. While the MDE indicates a significant particle environment in the outer solar system (out to at least 5 AU), the IPP sees no zodiacal light (therefore implying no small particles) past 3.3 AU. These two results are reconciled by noting that the spectral index p (relating particle radius and particle concentration) is not a constant in the solar system but changes from less than 2 near 1 AU to more than 2.5 at 5 AU for particles in the range of 10 microns.

  4. Neutron Activation and Thermoluminescent Detector Responses to a Bare Pulse of the CEA Valduc SILENE Critical Assembly

    SciTech Connect

    Miller, Thomas Martin; Celik, Cihangir; McMahan, Kimberly L.; Lee, Yi-kang; Gagnier, Emmanuel; Authier, Nicolas; Piot, Jerome; Jacquet, Xavier; Rousseau, Guillaume; Reynolds, Kevin H.

    2015-09-01

    This benchmark experiment was conducted as a joint venture between the US Department of Energy (DOE) and the French Commissariat à l'Energie Atomique (CEA). Staff at the Oak Ridge National Laboratory (ORNL) in the US and the Centre de Valduc in France planned this experiment. The experiment was conducted on October 11, 2010 in the SILENE critical assembly facility at Valduc. Several other organizations contributed to this experiment and the subsequent evaluation, including CEA Saclay, Lawrence Livermore National Laboratory (LLNL), the Y-12 National Security Complex (NSC), Babcock International Group in the United Kingdom, and Los Alamos National Laboratory (LANL). The goal of this experiment was to measure neutron activation and thermoluminescent dosimeter (TLD) doses from a source similar to a fissile solution critical excursion. The resulting benchmark can be used for validation of computer codes and nuclear data libraries as required when performing analysis of criticality accident alarm systems (CAASs). A secondary goal of this experiment was to qualitatively test performance of two CAAS detectors similar to those currently and formerly in use in some US DOE facilities. The detectors tested were the CIDAS MkX and the Rocky Flats NCD-91. These detectors were being evaluated to determine whether they would alarm, so they were not expected to generate benchmark quality data.

  5. Diagnostic value of CYFRA 21-1 and CEA for predicting lymph node metastasis in operable lung cancer.

    PubMed

    Chen, Feng; Yan, Cui-E; Li, Jia; Han, Xiao-Hong; Wang, Hai; Qi, Jun

    2015-01-01

    Tumour markers are used extensively for the management of lung cancer, including diagnosis, evaluating effectiveness of treatments, monitoring recurrence after therapy and for predicting prognosis. However, there exists a knowledge gap regarding potential quantitative correlations between tumour marker levels and the extents of lymph node involvement in primary lung cancer. The current study is comprised of 139 lung cancer patients scheduled to undergo surgical operation. Of the 139 patients, 107 were subsequently diagnosed with lung cancer without lymph node involvement and 32 were diagnosed with malignant disease with lymph node involvement by histological examination. Preoperative tumour marker levels were quantified in each patient. The median tumour marker levels were statistically higher in lung cancer patients with malignant lymph nodes than in those who suffered either benign lung disease or carcinoma in situ (Kruskal-Wallistest; P = 0.001). Tumour marker levels were significantly correlated with clinical stage (ANOVA; P = 0.009). When examined as a dichotomous variable (CYFRA 21-1 ≤ 5.0 and CEA ≤ 5.0 group and CYFRA 21-1 > 5.0 or CEA > 5.0 group), elevated tumour marker levels correlated strongly with the presence of positive lymph nodes (χ(2) test; P = 0.000). This correlation suggests that the tumour marker levels are clinical predictors for the malignant involvement of lymph nodes in operable lung cancer patients. PMID:26309663

  6. Bright, NIR-emitting Au23 from Au25: characterization and applications including biolabeling.

    PubMed

    Muhammed, Madathumpady Abubaker Habeeb; Verma, Pramod Kumar; Pal, Samir Kumar; Kumar, R C Arun; Paul, Soumya; Omkumar, Ramakrishnapillai Vyomakesannair; Pradeep, Thalappil

    2009-10-01

    A novel interfacial route has been developed for the synthesis of a bright-red-emitting new subnanocluster, Au(23), by the core etching of a widely explored and more stable cluster, Au(25)SG(18) (in which SG is glutathione thiolate). A slight modification of this procedure results in the formation of two other known subnanoclusters, Au(22) and Au(33). Whereas Au(22) and Au(23) are water soluble and brightly fluorescent with quantum yields of 2.5 and 1.3 %, respectively, Au(33) is organic soluble and less fluorescent, with a quantum yield of 0.1 %. Au(23) exhibits quenching of fluorescence selectively in the presence of Cu(2+) ions and it can therefore be used as a metal-ion sensor. Aqueous- to organic-phase transfer of Au(23) has been carried out with fluorescence enhancement. Solvent dependency on the fluorescence of Au(23) before and after phase transfer has been studied extensively and the quantum yield of the cluster varies with the solvent used. The temperature response of Au(23) emission has been demonstrated. The inherent fluorescence of Au(23) was used for imaging human hepatoma cells by employing the avidin-biotin interaction. PMID:19711391

  7. The Electronic Properties and L3 XANES of Au and Nano-Au

    SciTech Connect

    Yiu, Y.M.; Zhang, P.; Sham, T.K.

    2004-04-20

    The electronic properties of Au crystal and nano Au have been investigated by theory and experiment. Molecularly capped nano-Au was synthesized using the two-phase method. Au nano-particles have been characterized by X-Ray Diffraction (XRD) and Transmission Electron Microscopy (TEM). They retain the fcc crystal structure. Their sizes have been determined to be in a range from 5.5 nm to 1.7 nm. The L3 X-ray Absorption Near Edge Structure (XANES) of nano-Au and Au foil have been recorded using synchrotron radiation, and examined by theoretical calculation based on the first principles. Both theory and experiment show that the nano-Au particles have essentially all the Au L3 XANES features of bulk Au in the near edge region with less pronounced resonance peaks. It is also shown that nano Au exhibits lower 4f binding energy than bulk Au in good agreement with quantum confined Au systems reported previously.

  8. Efficient double-quenching of electrochemiluminescence from CdS:Eu QDs by hemin-graphene-Au nanorods ternary composite for ultrasensitive immunoassay

    PubMed Central

    Liu, Jing; Cui, Meirong; Zhou, Hong; Zhang, Shusheng

    2016-01-01

    A novel ternary composite of hemin-graphene-Au nanorods (H-RGO-Au NRs) with high electrocatalytic activity was synthesized by a simple method. And this ternary composite was firstly used in construction of electrochemiluminescence (ECL) immunosensor due to its double-quenching effect of quantum dots (QDs). Based on the high electrocatalytic activity of ternary complexes for the reduction of H2O2 which acted as the coreactant of QDs-based ECL, as a result, the ECL intensity of QDs decreased. Besides, due to the ECL resonance energy transfer (ECL-RET) strategy between the large amount of Au nanorods (Au NRs) on the ternary composite surface and the CdS:Eu QDs, the ECL intensity of QDs was further quenched. Based on the double-quenching effect, a novel ultrasensitive ECL immunoassay method for detection of carcinoembryonic antigen (CEA) which is used as a model biomarker analyte was proposed. The designed immunoassay method showed a linear range from 0.01 pg mL−1 to 1.0 ng mL−1 with a detection limit of 0.01 pg mL−1. The method showing low detection limit, good stability and acceptable fabrication reproducibility, provided a new approach for ECL immunoassay sensing and significant prospect for practical application. PMID:27460868

  9. Design and Testing of a Liquid Nitrous Oxide and Ethanol Fueled Rocket Engine

    SciTech Connect

    Youngblood, Stewart

    2015-08-01

    A small-scale, bi-propellant, liquid fueled rocket engine and supporting test infrastructure were designed and constructed at the Energetic Materials Research and Testing Center (EMRTC). This facility was used to evaluate liquid nitrous oxide and ethanol as potential rocket propellants. Thrust and pressure measurements along with high-speed digital imaging of the rocket exhaust plume were made. This experimental data was used for validation of a computational model developed of the rocket engine tested. The developed computational model was utilized to analyze rocket engine performance across a range of operating pressures, fuel-oxidizer mixture ratios, and outlet nozzle configurations. A comparative study of the modeling of a liquid rocket engine was performed using NASA CEA and Cantera, an opensource equilibrium code capable of being interfaced with MATLAB. One goal of this modeling was to demonstrate the ability of Cantera to accurately model the basic chemical equilibrium, thermodynamics, and transport properties for varied fuel and oxidizer operating conditions. Once validated for basic equilibrium, an expanded MATLAB code, referencing Cantera, was advanced beyond CEAs capabilities to predict rocket engine performance as a function of supplied propellant flow rate and rocket engine nozzle dimensions. Cantera was found to comparable favorably to CEA for making equilibrium calculations, supporting its use as an alternative to CEA. The developed rocket engine performs as predicted, demonstrating the developedMATLAB rocket engine model was successful in predicting real world rocket engine performance. Finally, nitrous oxide and ethanol were shown to perform well as rocket propellants, with specific impulses experimentally recorded in the range of 250 to 260 seconds.

  10. Au nanorod helical superstructures with designed chirality.

    PubMed

    Lan, Xiang; Lu, Xuxing; Shen, Chenqi; Ke, Yonggang; Ni, Weihai; Wang, Qiangbin

    2015-01-14

    A great challenge for nanotechnology is to controllably organize anisotropic nanomaterials into well-defined three-dimensional superstructures with customized properties. Here we successfully constructed anisotropic Au nanorod (AuNR) helical superstructures (helices) with tailored chirality in a programmable manner. By designing the 'X' pattern of the arrangement of DNA capturing strands (15nt) on both sides of a two-dimensional DNA origami template, AuNRs functionalized with the complementary DNA sequences were positioned on the origami and were assembled into AuNR helices with the origami intercalated between neighboring AuNRs. Left-handed (LH) and right-handed (RH) AuNR helices were conveniently accomplished by solely tuning the mirrored-symmetric 'X' patterns of capturing strands on the origami. The inter-rod distance was precisely defined as 14 nm and inter-rod angle as 45°, thus a full helix contains 9 AuNRs with its length up to about 220 nm. By changing the AuNR/origami molar ratio in the assembly system, the average number of AuNR in the helices was tuned from 2 to 4 and 9. Intense chiroptical activities arose from the longest AuNR helices with a maximum anisotropy factor of ∼0.02, which is highly comparable to the reported macroscopic AuNR assemblies. We expect that our strategy of origami templated assembly of anisotropic chiral superstructures would inspire the bottom-up fabrication of optically active nanostructures and shed light on a variety of applications, such as chiral fluids, chiral signal amplification, and fluorescence combined chiral spectroscopy. PMID:25516475