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Sample records for franco-estoniennes au moyen

  1. Faible taux de succès du sevrage tabagique à court et moyen termes au décours d'un infarctus aigu du myocarde dans un service de cardiologie de Dakar au Sénégal

    PubMed Central

    Mbaye, Alassane; Diop, Adja Mariétou; Dioum, Momar; Bodian, Malick; Ndiaye, Mouhamadou Bamba; Kane, Adama; Yaméogo, Nobila Valentin; Diao, Maboury; Ba, Oumar; Kane, Abdoul

    2011-01-01

    Introduction Le tabagisme est un puissant facteur de risque cardio-vasculaire. Son sevrage semble moins bien pris en compte chez les coronariens. Les objectifs de ce travail étaient d’évaluer la prévalence du tabagisme et le sevrage tabagique au décours d'un infarctus du myocarde dans un service de cardiologie au Sénégal. Méthodes Il s'agit d'une étude transversale et descriptive réalisée entre janvier 2008 et juin 2010. Nous avons recruté les patients hospitalisés pour infarctus du myocarde puis les fumeurs actifs ont été inclus dans notre enquête. Les malades étaient sensibilisés pour l'arrêt du tabac puis suivis à 3 mois, 6 mois et 12 mois pour évaluer le sevrage tabagique. Résultats Nous avons recensé 82 patients hospitalisés pour un infarctus du myocarde, parmi eux 26 sujets (25 hommes) étaient fumeurs (31,7%). L’âge moyen des sujets fumeurs était de 56±11,5 ans. La consommation moyenne de tabac était de 32±14 paquets-année et le score moyen de Fagerström de 8. Tous les patients ont arrêté le tabac pendant l'hospitalisation. Après un suivi de 3 mois, 45% des patients ont repris le tabac, 65% à 6 mois et 85% à 12 mois. Conclusion Le tabagisme est assez fréquent chez les patients sénégalais présentant un infarctus du myocarde. Le taux de sevrage tabagique à court et moyen termes est faible. Le sevrage tabagique devrait alors constituer un objectif privilégié dans la prévention des maladies cardio-vasculaires. PMID:22187601

  2. Enhanced Aircraft Platform Availability Through Advanced Maintenance Concepts and Technologies (Amelioration de la disponibilite des plateformes d’aeronefs au moyen de concepts de maintenance et de technologies evolues)

    DTIC Science & Technology

    2011-06-01

    Les sessions ont été organisées de la manière suivante : • Perspectives nationales sur l’évolution des concepts de ...concernent certains Panels, vous pouvez demander d’être inclus soit à titre personnel, soit au nom de votre organisation, sur la liste d’envoi. Les ...concepts de maintenance et de technologies évolués (RTO-MP-AVT-144) Synthèse D’immenses modifications dans la maintenance et le soutien des

  3. Prise en charge d'une menace d'accouchement prématuré sur béance cervico-utérine au moyen d'un pessaire-cerclage obstétrical

    PubMed Central

    Nohuz, Erdogan; Albaut, Maël; Brunel, Angélique; Champel, Nadine; Pellizzaro, Julie; Gallot, Denis; Lemery, Didier; Vendittelli, Françoise

    2015-01-01

    Nous rapportons le recours efficace à un pessaire dans la prise en charge d'une menace d'accouchement prématuré. Une patiente de 28 ans, G2P1, ayant présenté une fausse-couche tardive à 20 semaines d'aménorrhée (SA) un an auparavant, bénéficiait d'un cerclage cervical à 15 SA. L’échographie endovaginale réalisée à 24 SA (sensation de pesanteur pelvienne) révélait un funnelling majeur et une longueur cervicale à 7 mm. Un pessaire obstétrical permettait la poursuite de la grossesse jusqu'au terme de 36 SA. Ce dispositif semble intéressant chez des patientes présentant une béance cervico-isthmique et chez qui un cerclage cervical s'est révélé inefficace. PMID:26161207

  4. Précipitation sélective de cations métalliques au moyen d'acide azélaïque issu de l'oxydation de l'acide oléique

    NASA Astrophysics Data System (ADS)

    Zimmermann, F.; Meux, E.; Oget, N.; Lecuire, J. M.; Mieloszynski, J. L.

    2004-12-01

    Actuellement, les métaux présents dans les effluents liquides industriels sont précipités sous forme d'hydroxydes métalliques par ajout de lait de chaux. Les boues obtenues sont dirigées vers des centres de stockage de déchets ultimes sans possibilité de valorisation. Cette étude propose comme alternative au traitement actuel, une précipitation sélective par des réactifs qui peuvent être préparés à partir d'acides carboxyliques résultant de l'oxydation de l'acide oléique présent dans les huiles végétales. Cette publication présente dans un premier temps l'oxydation de l'acide oléique par le système oxydant NaIO4/RuO4 pour l'obtention de deux acides carboxyliques. Le rendement de l'oxydation de l'acide oléique est de 100% avec production des acides pélargonïque et azélaïque qui sont facilement purifiés par recristallisation dans l’eau. Dans un deuxième temps, cette étude présente la caractérisation de différents azélates métalliques. La détermination de leur stœchiométrie conduit à des composés de type MAz pour les cations divalents et M2Az3 pour les trivalents. Des mesures de solubilités ont été réalisées pour les azélates de Fe(III), Pb(II), Zn(II), Cu(II), Ni(II) et Ca(II). La gamme de solubilité s'étend de 1,17.10-2 M pour CaAz à 1,58.10-6 M pour Fe2Az3.

  5. Liposarcome myxoïde primitif du médiastin moyen

    PubMed Central

    Marouf, Rachid; Alloubi, Ihssan

    2014-01-01

    Les liposarcomes “LPS” myxoïdes sont des tumeurs rares, notamment dans leur localisation médiastinale. Nous rapportons un cas d'un liposarcome myxoïde du médiastin moyen, chez un patient de 69 ans, sans passé pathologique particulier et sans signes d'appels respiratoires. Une radiographie thoracique faite lors d'un bilan préopératoire montre un élargissement médiastinal dont le scanner thoracique le rattache à une tumeur hétéro dense, siège de quelques zones de densité graisseuse au niveau du médiastin moyen. Malgré son volume, cette masse parait de contours nets, sans envahissement ni compression des structures adjacentes. La ponction biopsie transpariétale scanno-guidée est compatible avec un liposarcome myxoïde; Une exérèse chirurgicale complète est réalisée. Après 24 mois de surveillance, le patient ne présente pas de signe de récidive. Le LPS myxoïde du médiastin est une entité rarissime et quelques cas sporadiques ont été reportés dans la littérature. La chirurgie parait être le traitement de choix. La radiothérapie et la chimiothérapie gardent leur place dans des indications bien particulières. PMID:25709724

  6. Détermination de la solubilité du tétrahydrothiophène (THT) liquide dans les principaux constituants du gaz naturel (CH4, CO2 et N2) au moyen d'un dispositif dynamique avec analyse chromatographique en ligne de la phase vapeur

    NASA Astrophysics Data System (ADS)

    Ghanem, G.; Tagand, G.; Loiseleur, H.; Ingrain, D.; Jose, J.

    1998-05-01

    Some odorous products as tetrahydrothiophene (THT) whose odour is perceived at low concentration, are injected in natural gas in order to odorize it. This artificial odorization allows to detect immediately any gas leak in atmosphere. The authors have measured the equilibrium compositions of gaseous phases for binaires THT-CH4, THT-N2 and THT-CO2 in the transport and distribution conditions of natural gas [ {1 < P (bar) < 60} and {-30 < t(^circ C) < 50}] . For this purpose an experimental device based on a principle of dynamic saturation coupled with an on-line gas chromatographic analysis was assembled and adjusted. Additional thermodynamic properties are required to know the molar composition of vapour phase. The authors have measured the THT vapour pressure and estimated the second virial coefficients. For the estimations it was necessary to know the critical values and the acentric factor that have been calculated with various correlations. Certains produits comme le tétrahydrothiophène (THT), dont l'odeur est perçue à faible teneur, sont injectés dans le gaz naturel en vue de son odorisation. Cette odorisation artificielle rend toute fuite éventuelle de gaz dans l'atmosphère immédiatement détectable. Les auteurs ont mesuré les compositions à l'équilibre des phases gaseuses des binaires THT-CH4, THT-N02 et THT-CO2 dans les conditions de transport et de distribution du gaz [ {1 < P (bar) < 60} and {-30 < t(^circ C) < 50}] . Dans ce but, un dispositif expérimental original basé sur un principe de saturation dynamique avec analyse chromatographique en ligne de la phase vapeur a été réalisé et mis au point. Des grandeurs thermodynamiques supplémentaires sont nécessaires pour atteindre les compositions molaires de la phase vapeur. Les auteurs ont mesuré les pressions de vapeur du THT et estimé les seconds coefficients du viriel. Ces estimations font intervenir les grandeurs critiques et facteurs acentriques qui ont été calculés par diverses

  7. L'engelure causée par le butane commercial au cours d’un accident industriel

    PubMed Central

    Assi-Dje Bi Dje, V.; Abhe, C.M.; Sie-Essoh, J.B.; Kouamé, K.; Vilasco, B.

    2014-01-01

    Summary Les engelures sont encore exceptionnelles en Afrique sub-saharienne, mais l’essor des industries pétrochimiques en rapport avec la promotion d’une large utilisation du gaz domestique (butane commercial) expose au risque de survenue de ce type de brûlures abusivement dites gelures. Nous rapportons un cas de brûlures au froid par gaz de pétrole liquéfié (GPL) en milieu professionnel dont le diagnostic de gravité et la prise en charge tardifs ont défavorisé l’évolution locale. Le respect des mesures de sécurité au sein des usines reste néanmoins le principal moyen de prévention de ce type de brûlures méconnues. PMID:26170791

  8. @AuAg nanostructures

    NASA Astrophysics Data System (ADS)

    Singh, Rina; Soni, R. K.

    2014-09-01

    Bimetallic and trimetallic nanoparticles have attracted significant attention in recent times due to their enhanced electrochemical and catalytic properties compared to monometallic nanoparticles. The numerical calculations using Mie theory has been carried out for three-layered metal nanoshell dielectric-metal-metal (DMM) system consisting of a particle with a dielectric core (Al@Al2O3), a middle metal Ag (Au) layer and an outer metal Au (Ag) shell. The results have been interpreted using plasmon hybridization theory. We have also prepared Al@Al2O3@Ag@Au and Al@Al2O3@AgAu triple-layered core-shell or alloy nanostructure by two-step laser ablation method and compared with calculated results. The synthesis involves temporal separations of Al, Ag, and Au deposition for step-by-step formation of triple-layered core-shell structure. To form Al@Ag nanoparticles, we ablated silver for 40 min in aluminium nanoparticle colloidal solution. As aluminium oxidizes easily in water to form alumina, the resulting structure is core-shell Al@Al2O3. The Al@Al2O3 particle acts as a seed for the incoming energetic silver particles for multilayered Al@Al2O3@Ag nanoparticles is formed. The silver target was then replaced by gold target and ablation was carried out for different ablation time using different laser energy for generation of Al@Al2O3@Ag@Au core-shell or Al@Al2O3@AgAu alloy. The formation of core-shell and alloy nanostructure was confirmed by UV-visible spectroscopy. The absorption spectra show shift in plasmon resonance peak of silver to gold in the range 400-520 nm with increasing ablation time suggesting formation of Ag-Au alloy in the presence of alumina particles in the solution.

  9. Les Lesions Oculaires Par Jeu de Feu au Cours de Achoura

    PubMed Central

    El Ketani, A.; Amir, F.; Ali, T.B.; Hamdani, M.; Zaghloul, K.

    2006-01-01

    Summary Les enfants célèbrent la fête de Achoura au Maroc par des jeux de feu, ce qui occasionne des blessures oculaires plus au moins graves. Nous rapportons 15 observations de malades traités au Service d'Ophtalmologie Pédiatrique de l'Hôpital 20 Août 1953 de Casablanca. L'âge moyen des patients était de 12 ans et demi, avec des extrêmes de 3 et 25 ans. Les pétards, la première cause des accidents (50%), ont occasionné des contusions oculaires avec parfois un oedème de Berlin (deux cas). L'atteinte oculaire par fusée a occasionné un éclatement de globe et une plaie de paupière. Les bombes de carbone ont été responsables de brûlures de deuxième degré palpébrales et conjonctivo-cornéennes avec de multiples corps étrangers cornéens profonds. Les «étoiles» et la limaille de fer ont provoqué des brûlures cornéennes moins graves avec des corps étrangers superficiels. Les pistolets à bille ont été responsables de contusions oculaires. La réglementation de vente des jeux de feu et la sensibilisation du grand public par les moyens audiovisuels permettraient de prévenir ces blessures oculaires. PMID:21991053

  10. Discordance gradient-surface dans le rétrécissement mitral: le gradient moyen transmitral est-il un critère de sévérité ou un indice de tolérance du rétrécissement mitral serré?

    PubMed Central

    Najih, Hayat; Arous, Salim; Laarje, Aziza; Baghdadi, Dalila; Benouna, Mohamed Ghali; Azzouzi, Leila; Habbal, Rachida

    2016-01-01

    Le rétrécissement mitral (RM) rhumatismal demeure une valvulopathie fréquente dans les pays en voie de développement. Cependant, les pays industrialisés ont vu l'émergence ces dernières années de nouvelles étiologies de RM; notamment l'origine médicamenteuse et/ou toxique responsable de valvulopathies restrictives aussi bien sténosantes que régurgitantes. Pour cette raison, l'évaluation échocardiographique du RM et surtout, la définition de critères objectifs pour conclure au caractère serré du RM reste toujours d'actualité. Les objectifs du travail sont: évaluer l'existence ou non d'une corrélation directe entre le gradient moyen transmitral (GMT) et la sévérité du RM chez les patients porteurs d'un RM serré ou très serré (critère primaire) et analyser les différents paramètres qui conditionnent le gradient moyen transmitral (GMT) (Critère secondaire). Il s'agit d'une étude transversale monocentrique incluant tous les patients admis au service de Cardiologie du CHU Ibn Rochd de Casablanca pour un RM serré ou très serré, sur une période d'une année (Janvier 2014 à Décembre 2014). Nous avons analysés séparément deux groupes de patients : ceux avec un gradient moyen transmitral<10 mmHg (groupe 1) et ceux avec un gradient>10mmHg (groupe2). 50 patients porteurs d'un RM serré ou très serré ont été inclus. L'âge moyen de nos patients est de 41,7 ans avec prédominance féminine (sex ratio: 0,25). 64% de nos patients avaient un RM serré et 36% avaient un RM très serré. 52% (26 patients) avaient un GMT <10mmHg et 48% (24 patients) avaient un gradient moyen >10mmHg, ce qui suggère l'absence de corrélation directe entre la sévérité du RM et le GMT (coefficient de Pearson R: -0,137). Pour la dyspnée, 80% des patients du groupe 1 étaient dyspnéiques stade II de la NYHA et 70% des patients du groupe 2 étaient dyspnéiques stade III (41%) ou IV (29%) de la NYHA, ce qui signifie l'existence d'une corr

  11. Actinomycose pelvienne pseudo tumorale associée au dispositif intra-utérin: à propos de trois cas

    PubMed Central

    El Hassani, Moulay Elmehdi; Babahabib, Abdellah; Kouach, Jaouad; Kassidi, Farid; El Houari, Younes; Moussaoui, Driss; Dehayni, Mohamed

    2014-01-01

    L'actinomycose est une maladie chronique suppurative granulomateuse d'origine infectieuse responsable d'un syndrome tumoral. La localisation pelvienne est rare et souvent associée, chez la femme, au port au long court du dispositif intra-utérin (DIU). Le diagnostic préopératoire n'est possible que dans 17% des cas. Nous rapportons trois observations, d'actinomycose pelvienne pseudo tumorale compliquées chez des femmes porteuses de DIU, qui illustrent le rôle de ce moyen de contraception dans la genèse de cette pathologie ainsi que les difficultés de prise en charge. PMID:25722760

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

    SciTech Connect

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

    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 liquidmore » 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.« less

  13. Strategy for managing water in the Middle East and North Africa; Strategie pour la gestion de l`eau au moyen-orient et en afrique du nord

    SciTech Connect

    NONE

    1995-07-01

    Water has always been of central concern to life in the Middle East and North Africa (MENA). Burgeoning populations are placing unprecendented pressures on the resource, calling urgently for new approaches to water planning and management if escalating conflicts are to be avoided and if environmental degradation is to be reversed. The booklet sets out the implications of the new Bank policy for the MENA region, calling for a concerted effort by government and Bank staff to address water resources in a coordinated and sustainable manner. It proposes a practical, step-by-step approach to achieving this objective that could lead tomore » new Bank-supported operations to address the water sector as a whole.« less

  14. Nouvelles approches en theorie du champ moyen dynamique: le cas du pouvoir thermoelectrique et celui de l'effet orbital d'un champ magnetique

    NASA Astrophysics Data System (ADS)

    Arsenault, Louis-Francois

    Les applications reliees a la generation d'energie motivent la recherche de materiaux ayant un fort pouvoir thermoelectrique (S). De plus, S nous renseigne sur certaines proprietes fondamentales des materiaux, comme, par exemple, la transition entre l'etat coherent et incoherent des quasi-particules lorsque la temperature augmente. Empiriquement, la presence de fortes interactions electron-electron peut mener a un pouvoir thermoelectrique geant. Nous avons donc etudie le modele le plus simple qui tient compte de ces fortes interactions, le modele de Hubbard. La theorie du champ moyen dynamique (DMFT) est tout indiquee dans ce cas. Nous nous sommes concentres sur un systeme tridimensionnel (3d) cubique a face centree (fcc), et ce, pour plusieurs raisons. A) Ce type de cristal est tres commun dans la nature. B) La DMFT donne de tres bons resultats en 3d et donc ce choix sert aussi de preuve de principe de la methode. C) Finalement, a cause de la frustration electronique intrinseque au fcc, celui-ci ne presente pas de symetrie particule-trou, ce qui est tres favorable a l'apparition d'une grande valeur de S. Ce travail demontre que lorsque le materiau est un isolant a demi-remplissage a cause des fortes interactions (isolant de Mott), il est possible d'obtenir de grands pouvoirs thermoelectriques en le dopant legerement. C'est un resultat pratique important. Du point de vue methodologique, nous avons montre comment la limite de frequence infinie de S et l'approche dite de Kelvin, qui considere la limite de frequence nulle avant la limite thermodynamique pour S, donnent des estimations fiables de la vraie limite continue (DC) dans les domaines de temperature appropriee. Ces deux approches facilitent grandement les calculs en court-circuit ant la necessite de recourir a de problematiques prolongements analytiques. Nous avons trouve que la methode de calcul a frequence infinie fonctionne bien lorsque les echelles d'energie sont relativement faibles. En d'autres termes

  15. 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

  16. Antibacterial Au nanostructured surfaces.

    PubMed

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

    2016-02-07

    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.

  17. Facteurs liés au diagnostic tardif du cancer du sein: expérience du CHU Mohammed VI Marrakech

    PubMed Central

    Aloulou, Sofia; El Mahfoudi, Amal; El Omrani, Abdelhamid; Khouchani, Mouna

    2015-01-01

    Le cancer du sein est le premier cancer féminin en termes d'incidence et de mortalité. Au Maroc, il vient au premier rang des cancers de la femme avant celui du col utérin Il constitue un problème de santé publique. Son pronostic est étroitement lié au stade auquel le diagnostic est posé. Il s'agit d'une pathologie dont les moyens diagnostiques sont de nos jours développés, allant de la détection précoce à la mise en évidence de lésions infra-cliniques, ce qui a nettement amélioré le pronostic dans les pays développés. Ce travail que nous présentons a pour objectif d'identifier dans notre pratique quotidienne, les facteurs qui amènent les patientes à consulter à des stades tardifs. Une étude rétrospective a été menée de janvier 2012 à janvier 2013 portant sur 130 patientes porteuses d'un cancer du sein au sein du service d'onco-radiotherapie CHU Mohammed VI Marrakech. Un questionnaire a été élaboré et dument renseigné en ayant recours aux dossiers des malades. Ainsi 63,07% des patientes consultaient au-delà de six mois avec un délai moyen de consultation de 8,47 mois avec comme motif de consultation des lésions classées T4 dans 27,69%, et des tumeurs d'emblée métastatiques dans 13,84%. Les facteurs retrouvés à l'interrogatoire étaient le manque de moyens financiers 40%, l’éloignement des structures sanitaires dans 23%, les habitudes socioculturelles avec les traitements traditionnels en première intention 20%, et l'insuffisance de prise en charge thérapeutique 7%. Cependant, pris individuellement, aucune concordance significative n’était retrouvée entre ces facteurs et le long délai diagnostique. Dans notre pratique, c'est la conjonction de la triade ignorance, indigence et habitudes socioculturelles qui constituent le facteur essentiel du diagnostic tardif des cancers du sein. PMID:26327999

  18. Intense fluorescence of Au20.

    PubMed

    Yu, Chongqi; Harbich, Wolfgang; Sementa, Luca; Ghiringhelli, Luca; Aprá, Edoardo; Stener, Mauro; Fortunelli, Alessandro; Brune, Harald

    2017-08-21

    Ligand-protected Au clusters are non-bleaching fluorescence markers in bio- and medical applications. Here we show that their fluorescence can be an intrinsic property of the Au cluster itself. We find a very intense and sharp fluorescence peak located at λ=739.2 nm (1.68 eV) for Au 20 clusters in a Ne matrix held at 6 K. The fluorescence reflects the Highest Occupied Molecular Orbital-Lowest Unoccupied Molecular Orbital (HOMO-LUMO) diabatic bandgap of the cluster. Au 20 shows a very rich absorption fine structure reminiscent of well defined molecule-like quantum levels. These levels are resolved since Au 20 has only one stable isomer (tetrahedral); therefore our sample is mono-disperse in cluster size and conformation. Density-functional theory (DFT) and time-dependent DFT calculations clarify the nature of optical absorption and predict both main absorption peaks and intrinsic fluorescence in fair agreement with experiment.

  19. La survie en hémodialyse chronique au Cameroun

    PubMed Central

    Fouda, Hermine; Ashuntantang, Gloria; Kaze, François; Halle, Marie-Patrice

    2017-01-01

    Introduction L'hémodialyse est le seul traitement de substitution rénale disponible au Cameroun; elle est subventionnée à 95% par l'Etat depuis 2002 et le nombre de centre de dialyse va croissant. Cependant, depuis l'ouverture du premier centre en 1990, aucune donnée n'existe sur la survie des hémodialysés chroniques. Méthodes Nous avons conduit une étude de cohorte prospective multicentrique de 15 mois dans le but d'évaluer la mortalité et les facteurs qui influencent la survie des hémodialysés chroniques camerounais. Résultats Nous avons suivi 197 patients dont 109 incidents. L'âge moyen était de 47,97± 13,19 ans et 55% étaient de sexe masculin. La durée moyenne en dialyse des patients prévalent était de 12,5 mois. Le taux de mortalité était de 57,58% dont 50% pendant les 3 premiers mois et le taux d'abandon était de 8,6%. L'urémie et les sepsis sur cathéter étaient les principales causes de décès. La survie globale à 15 mois était de 30,77%, avec une durée moyenne de vie de 8 mois. Les patients prévalent, la résidence dans la ville du centre de dialyse, la prise en charge non familiale, le suivi pré dialyse > 3 mois, la cholestérolémie à l'entrée en dialyse> 1,5g/l, un score mental > 25 étaient associés à une meilleure survie. Conclusion La mortalité en hémodialyse au Cameroun est élevée, avec une survie moyenne de 8 mois et la plupart des patients décèdent au cours des 3 premiers mois. PMID:28491228

  20. Port-au-Prince, Haiti

    NASA Image and Video Library

    2010-01-14

    This image, produced from instrument data aboard NASA Space Shuttle Endeavour, is a perspective view of the topography of Port-au-Prince, Haiti where a magnitude 7.0 earthquake occurred on January 12, 2010.

  1. Intense fluorescence of Au 20

    SciTech Connect

    Yu, Chongqi; Harbich, Wolfgang; Sementa, Luca

    2017-08-21

    Ligand-protected Au clusters are non-bleaching fluorescence markers in bio- and medical applications. We show that their fluorescence is an intrinsic property of the Au cluster itself. We find a very intense and sharp fluorescence peak located at λ =739.2 nm (1.68 eV) for Au20 clusters in a Ne matrix held at 6 K. The fluorescence reflects the HOMO-LUMO diabatic bandgap of the cluster. The cluster shows a very rich absorption fine structure reminiscent of well defined molecule-like quantum levels. These levels are resolved since Au20 has only one stable isomer (tetrahedral), therefore our sample is mono-disperse in cluster size andmore » conformation. Density-functional theory (DFT) and time-dependent DFT calculations clarify the nature of optical absorptionand predict both main absorption peaks and intrinsic fluorescence in good agreement with experiment.« less

  2. Impact du traitement antirétroviral sur le profil biologique des enfants VIH positifs suivis au Centre Hospitalier et Universitaire de Yaoundé au Cameroun

    PubMed Central

    Kalla, Ginette Claude Mireille; Assoumou, Marie-Claire Okomo; Kamgaing, Nelly; Monebenimp, Francisca; Mbopi-Keou, Francois-Xavier

    2015-01-01

    Introduction L'objectif de ce travail était d’évaluer l'impact du traitement antirétroviral sur le profil biologique des enfants VIH positifs suivis au Centre Hospitalier et Universitaire de Yaoundé au Cameroun. Méthodes Il s'agissait d'une étude rétrospective réalisée de Mai 2003 à Décembre 2012 au CHU de Yaoundé au Cameroun. Pour cette étude, nous avons obtenu une clairance éthique. Résultats L’âge moyen était de 54.02±46.34 mois. The sexe ratio était de 0.96 en faveur des garçons. Le diagnostic s’était fait tardivement (74.2%) ainsi que la mise sous traitement (83.3%). Seuls 36 des 116 enfants (31%) avait pu avoir un bilan biologique à l'initiation du traitement antirétroviral et six mois après l'initiation du traitement antirétroviral. Après six mois de traitement, nous avons enregistrés une augmentation significative des paramètres biologiques suivants: taux de glycémie de 0.09g/L (0.75-0.84; p= 0.007), pourcentage de CD4 chez les enfants de moins de 5 ans de 4.62% (20.12-24.75; p = 0.022), valeur absolue de CD4 chez les enfants de plus de 5 ans de 294 cellules/mm3 (151.18-445.18; p = 0.011), le rapport CD4/CD8 de 0.35 (0.55-0.90; p = 0.000). Enfin, après six mois de traitement, on enregistrait une baisse significative de la charge virale du VIH de 3.90 log (5.85-1.95; p = 0.006). Conclusion Il ressort de cette étude que la restauration immunitaire et la suppression virologique peuvent être obtenus après six mois de traitement antirétroviral. Cependant, des efforts doivent encore être faits en ce qui concerne la prise en charge du suivi biologique, gage d'un bon suivi thérapeutique au Cameroun. PMID:26113902

  3. Classical polymorphisms in Berbers from Moyen Atlas (Morocco): genetics, geography, and historical evidence in the Mediterranean peoples.

    PubMed

    Harich, N; Esteban, E; Chafik, A; López-Alomar, A; Vona, G; Moral, P

    2002-01-01

    Mediterranean population relationships have recently been reviewed through the analysis of classical and DNA markers. The differentiation between Berbers and Arabic-speakers to the south, and the genetic impact of the seven centuries of Muslim domination in the Iberian Peninsula have been among the most interesting questions posed in these studies. The present study seeks to assess the degree of genetic affinity between the two main population groups of Morocco: Berbers and Arabic-speakers. Data from the Berber study population were also compared with published information on 20 circum-Mediterranean groups. A Berber sample of 140 individuals from Moyen Atlas (Morocco) has been characterized using 15 classical markers (ABO, Duffy, MNSs, Rh, ACPl, AKl, ESD, GLOI, 6-PGD, PGMl, GC, HP, PI, PLG and TF). Allele frequencies in the Berbers fit well into the general southern Mediterranean ranges, albeit with some peculiarities, such as the high FY*A, ACPl*C, and PI*S values. The general pattern of relationships among Mediterranean peoples tested by genetic variance analysis was compatible with a north-south geographical differentiation. Spatial auto-correlation analysis in the different geographical regions of the Mediterranean reveals that the highest degree of association between allele frequencies and geographical distances corresponds to the western (41% of significant correlograms) and northern Mediterranean populations (33%). When only southern Mediterranean groups were considered, the degree of geographical structure considerably decreases (11% of significant correlograms). The different loci studied revealed close similarity between the Berbers and other north African groups, mainly with Moroccan Arabic-speakers, which is in accord with the hypothesis that the current Moroccan population has a strong Berber background. Differences in the spatial pattern of allele frequencies also are compatible with specific population histories in distinct Mediterranean areas

  4. Studies of Au/SAMs/PEDOT-PSS/Au tunnel junctions

    NASA Astrophysics Data System (ADS)

    Sun, Nan; Lieberman, Marya; Ruggiero, Steven

    2008-03-01

    We report on tunneling through thin organic films. Junctions of the form: Au/SAMs/Polymer/Au were prepared on electronic-grade Si substrates with Self-Assembled Monolayers (SAMs) including octanedithiol (HS-C8H16-SH) and mercaptohexadecanoic (HS-C15H30-COOH). A transitional conducting polymer film PEDOT-PSS was spun on to the SAMs layer, and junctions were completed with a gold film. X-ray photoelectron spectroscopy (XPS) was employed to monitor the quality of the SAMs films. The electron tunneling properties including dI/dV and d^2I/dV^2 versus bias for the SAMs are discussed.

  5. Suppression of Υ production in d + Au + and Au + Au collisions at √ sNN =200 GeV

    DOE PAGES

    None

    2014-07-01

    We report measurements of Upsilon meson production in p + p, d +Au, and Au+Au collisions using the STAR detector at RHIC. We compare the Upsilon yield to the measured cross section in p + p collisions in order to quantify any modifications of the yield in cold nuclear matter using d +Au data and in hot nuclear matter using Au+Au data separated into three centrality classes. Our p +p measurement is based on three times the statistics of our previous result. We obtain a nuclear modification factor for Upsilon (1S + 2S + 3S) in the rapidity range |y|more » < 1 in d + Au collisions of R dAu = 0.79 ± 0.24(stat.) ± 0.03(syst.) ± 0.10(p + p syst.). A comparison with models including shadowing and initial state part on energy loss indicates the presence of additional cold-nuclear matter suppression. Similarly, in the top 10% most-central Au + Au collisions, we measure a nuclear modification factor of R AA = 0.49 ±0.1(stat.) ±0.02(syst.) ±0.06(p + p syst.), which is a larger suppression factor than that seen in cold nuclear matter. Our results are consistent with complete suppression of excited-state Upsilon mesons in Au + Au collisions. The additional suppression in Au + Au is consistent with the level expected in model calculations that include the presence of a hot, deconfined Quark–Gluon Plasma. However, understanding the suppression seen in d + Au is still needed before any definitive statements about the nature of the suppression in Au + Au can be made.« less

  6. Au Exchange or Au Deposition: Dual Reaction Pathways in Au-CsPbBr3 Heterostructure Nanoparticles.

    PubMed

    Roman, Benjamin J; Otto, Joseph; Galik, Christopher; Downing, Rachel; Sheldon, Matthew

    2017-09-13

    We have designed a facile synthetic strategy for the selective deposition of Au metal on all-inorganic CsPbBr 3 perovskite nanocrystals that includes the addition of PbBr 2 salt along with AuBr 3 salt. PbBr 2 is necessary because the addition of Au 3+ to solutions of CsPbBr 3 nanocrystals otherwise results in the exchange of Au 3+ ions from solution with Pb 2+ cations within the nanocrystal lattice to produce Cs 2 Au I Au III Br 6 nanocrystals with a tetragonal crystal structure and a band gap of about 1.6 eV, in addition to Au metal deposition. Including excess Pb 2+ ions in solution prevents the exchange reaction. Au metal deposits on the surface of the nanocrystals to produce the Au-CsPbBr 3 heterostructure nanoparticles with an Au particle diameter determined by the Au 3+ ion concentration. Fluorescence quenching caused by Au deposition monotonically increases with deposition size, but the fluorescence quantum yield (QY) is significantly greater than if any cation exchange has occurred. An optimized synthesis can produce Au-CsPbBr 3 nanoparticles with 70% QY and no evidence of cation exchange.

  7. Chiral magnetic effect search in p+Au, d+Au and Au+Au collisions at RHIC

    NASA Astrophysics Data System (ADS)

    Zhao, Jie

    2018-01-01

    Metastable domains of fluctuating topological charges can change the chirality of quarks and induce local parity violation in quantum chromodynamics. This can lead to observable charge separation along the direction of the strong magnetic field produced by spectator protons in relativistic heavy-ion collisions, a phenomenon called the chiral magnetic effect (CME). A major background source for CME measurements using the charge-dependent azimuthal correlator (Δϒ) is the intrinsic particle correlations (such as resonance decays) coupled with the azimuthal elliptical anisotropy (v2). In heavy-ion collisions, the magnetic field direction and event plane angle are correlated, thus the CME and the v2-induced background are entangled. In this report, we present two studies from STAR to shed further lights on the background issue. (1) The Δϒ should be all background in small system p+Au and d+Au collisions, because the event plane angles are dominated by geometry fluctuations uncorrelated to the magnetic field direction. However, significant Δϒ is observed, comparable to the peripheral Au+Au data, suggesting a background dominance in the latter, and likely also in the mid-central Au+Au collisions where the multiplicity and v2 scaled correlator is similar. (2) A new approach is devised to study Δϒ as a function of the particle pair invariant mass (minv) to identify the resonance backgrounds and hence to extract the possible CME signal. Signal is consistent with zero within uncertainties at high minv. Signal at low minv, extracted from a two-component model assuming smooth mass dependence, is consistent with zero within uncertainties.

  8. Le recours aux modeles dans l'enseignement de la biologie au secondaire : Conceptions d'enseignantes et d'enseignants et modes d'utilisation

    NASA Astrophysics Data System (ADS)

    Varlet, Madeleine

    Le recours aux modeles et a la modelisation est mentionne dans la documentation scientifique comme un moyen de favoriser la mise en oeuvre de pratiques d'enseignement-apprentissage constructivistes pour pallier les difficultes d'apprentissage en sciences. L'etude prealable du rapport des enseignantes et des enseignants aux modeles et a la modelisation est alors pertinente pour comprendre leurs pratiques d'enseignement et identifier des elements dont la prise en compte dans les formations initiale et disciplinaire peut contribuer au developpement d'un enseignement constructiviste des sciences. Plusieurs recherches ont porte sur ces conceptions sans faire de distinction selon les matieres enseignees, telles la physique, la chimie ou la biologie, alors que les modeles ne sont pas forcement utilises ou compris de la meme maniere dans ces differentes disciplines. Notre recherche s'est interessee aux conceptions d'enseignantes et d'enseignants de biologie au secondaire au sujet des modeles scientifiques, de quelques formes de representations de ces modeles ainsi que de leurs modes d'utilisation en classe. Les resultats, que nous avons obtenus au moyen d'une serie d'entrevues semi-dirigees, indiquent que globalement leurs conceptions au sujet des modeles sont compatibles avec celle scientifiquement admise, mais varient quant aux formes de representations des modeles. L'examen de ces conceptions temoigne d'une connaissance limitee des modeles et variable selon la matiere enseignee. Le niveau d'etudes, la formation prealable, l'experience en enseignement et un possible cloisonnement des matieres pourraient expliquer les differentes conceptions identifiees. En outre, des difficultes temporelles, conceptuelles et techniques peuvent freiner leurs tentatives de modelisation avec les eleves. Toutefois, nos resultats accreditent l'hypothese que les conceptions des enseignantes et des enseignants eux-memes au sujet des modeles, de leurs formes de representation et de leur approche

  9. L’explosion intravésicale au cours des procédures de résection endoscopique: Un incident dangereux qui peut être évité

    PubMed Central

    Anzaoui, Jihad El; Abakka, Najib; El harrech, Younes; Ghoundale, Omar; Touiti, Driss; Lahkim, Mohammed; Fihri, Jawad Fassi; Bakzaza, Walid; Mejdane, Abdelhadi

    2013-01-01

    Résumé Les explosions survenant au cours des manœuvres endoscopiques urologiques sont rares et dangereuses. Elles sont dues à une production d’hydrogène par hydrolyse de l’eau lors des procédés de coagulation et de section. L’hydrogène devient très combustible une fois mélangé avec l’oxygène ambiant. Nous rapportons un cas d’explosion intravésicale au cours d’une résection transurethrale d’une tumeur de la vessie et nous exposons, par une revue de littérature, les différentes théories physiopathologiques et les moyens de prévention. PMID:23914274

  10. Au36(SPh)23 nanomolecules.

    PubMed

    Nimmala, Praneeth Reddy; Dass, Amala

    2011-06-22

    A new core size protected completely by an aromatic thiol, Au(36)(SPh)(23), is synthesized and characterized by MALDI-TOF mass spectrometry and UV-visible spectroscopy. The synthesis involving core size changes is studied by MS, and the complete ligand coverage by aromatic thiol group is shown by NMR.

  11. Evolution of Excited-State Dynamics in Periodic Au 28, Au 36, Au 44, and Au 52 Nanoclusters

    DOE PAGES

    Zhou, Meng; Zeng, Chenjie; Sfeir, Matthew Y.; ...

    2017-08-10

    An understanding of the correlation between the atomic structure and optical properties of gold nanoclusters is essential for exploration of their functionalities and applications involving light harvesting and electron transfer. We report the femto-nanosecond excited state dynamics of a periodic series of face-centered cubic (FCC) gold nanoclusters (including Au 28, Au 36, Au 44, and Au 52), which exhibit a set of unique features compared with other similar sized clusters. Molecular-like ultrafast S n → S 1 internal conversions (i.e., radiationless electronic transitions) are observed in the relaxation dynamics of FCC periodic series. Excited-state dynamics with near-HOMO–LUMO gap excitation lacksmore » ultrafast decay component, and only the structural relaxation dominates in the dynamical process, which proves the absence of core–shell relaxation. Interestingly, both the relaxation of the hot carriers and the band-edge carrier recombination become slower as the size increases. The evolution in excited-state properties of this FCC series offers new insight into the structure-dependent properties of metal nanoclusters, which will benefit their optical energy harvesting and photocatalytic applications.« less

  12. How Does Amino Acid Ligand Modulate Au Core Structure and Characteristics in Peptide Coated Au Nanocluster?

    PubMed

    Li, Nan; Li, Xu; Zhao, Hongkang; Zhao, Lina

    2018-03-01

    The atomic structures and the corresponding physicochemical properties of peptide coated Au nanoclusters determine their distinctive biological targeting applications. To learn the modulation of amino acid ligand on the atomic structure and electronic characteristics of coated Au core is the fundamental knowledge for peptide coated Au nanocluster design and construction. Based on our recent coated Au nanocluster configuration study (Nanoscale, 2016, 8, 11454), we built the typically simplified Au13(Cys-Au-Cys) system to more clearly learn the basic modulation information of amino acid ligand on Au core by the density functional theory (DFT) calculations. There are two isomers as ligand adjacent bonding (Iso1) and diagonal bonding (Iso2) to Au13 cores. The geometry optimizations indicate the adjacent bonding Iso1 is more stable than Iso2. More important, the Au13 core of Iso1 distorts much more significantly than that of Iso2 by Cys-Au-Cys bonding through the root-mean-square deviation (RMSD) analysis, which modulate their electronic characteristics in different ways. In addition, the frontier molecular orbital results of Au13(Cys-Au-Cys) isomers confirm that the Au cores mainly determine the blue shifts of Au13(Cys-Au-Cys) systems versus the original Au13 core in their UV-visible absorption spectrum studies. The configuration of Au13 core performs deformation under Cys-Au-Cys ligand modulation to reach new stability with distinct atomic structure and electronic properties, which could be the theory basis for peptide coated AuNCs design and construction.

  13. Cancer du sein au Maroc: profil phénotypique des tumeurs

    PubMed Central

    Khalil, Ahmadaye Ibrahim; Bendahhou, Karima; Mestaghanmi, Houriya; Saile, Rachid; Benider, Abdellatif

    2016-01-01

    Le cancer du sein est le plus fréquent chez la femme et figure parmi les principales causes de mortalité liées au cancer. La curabilité de ce type tumoral est en augmentation, grâce aux programmes de dépistage et aux progrès thérapeutiques, qui ont certes augmenté la survie des patients. Mais des défis restent à relever en rapport avec l’instabilité phénotypique des cellules cancéreuses. L’objectif de ce travail est d’étudier le profil phénotypique du cancer du sein chez les patients pris en charge au Centre Mohammed VI pour le traitement des Cancers, durant les années 2013-2014. Il s’agit d’une étude transversale sur deux années, incluant les cas du cancer du sein pris en charge au Centre. Le recueil des données était fait à partir des dossiers des patients et analysés par le logiciel Epi Info. 1277 patients ont été pris en charge au sein de notre centre. 99,5% des cas de sexe féminin, l’âge moyen était 50,20 ± 11,34 ans. Le type histologique le plus fréquent était le carcinome canalaire infiltrant (80,7% des cas). Le stade diagnostic était précoce (56,9%). Le phénotype moléculaire le plus fréquent était le luminal A (41,4% des cas). Le luminal B, le HER2 et les triples négatifs étaient dans respectivement 10,4%, 6,3%, 11,2% des cas. L’étude du phénotype tumoral des patients atteints du cancer du sein permet l’orientation du clinicien dans le choix du traitement, et des décideurs dans la planification de programmes de lutte contre cette pathologie. PMID:28292037

  14. Transport characteristics in Au/pentacene/Au diodes

    NASA Astrophysics Data System (ADS)

    Hayashi, Toshiaki; Naka, Akiyoshi; Hiroki, Masanobu; Yokota, Tomoyuki; Someya, Takao; Fujiwara, Akira

    2018-03-01

    We have used scanning and transmission electron microscopes (SEM and TEM) to study the structure of a pentacene thin film grown on a Au layer with and shown that it consists of randomly oriented amorphous pentacene clusters. We have also investigated the transport properties of amorphous pentacene in a metal-semiconductor-metal (MSM) diode structure and shown that the current is logarithmically proportional to the square root of the applied voltage, which indicates that transport occurs as the result of hopping between localized sites randomly distributed in space and energy.

  15. Analyse des facteurs histo-pronostiques du cancer du rectum non métastatique dans une série ouest Algérienne de 58 cas au CHU-Tlemcen

    PubMed Central

    Mesli, Smain Nabil; Regagba, Derbali; Tidjane, Anisse; Benkalfat, Mokhtar; Abi-Ayad, Chakib

    2016-01-01

    Introduction L'objectif de notre travail est d'analyser les facteurs histo-pronostiques des cancers du rectum non métastatique opérés au service de chirurgie «A» de Tlemcen à ouest Algérien durant une période de six ans. Méthodes Etude rétrospective de 58 patients qui avait un adénocarcinome rectal. Le critère de jugement était la survie. Les paramètres étudiés, le sexe, l’âge, stade tumoral, et les récidives tumorales. Résultats L’âge moyen était de 58 ans. Avec 52% d'hommes contre 48% femmes avec sex-ratio (1,08). Le siège tumoral était: moyen rectum avec 41,37%, 34,48% au bas rectum et dans 24,13% au haut rectum. La classification TNM avec 17,65% au stade I, 18,61% au stade II, 53, 44% au stade III et 7,84% au stade IV. La survie médiane globale était de 40 mois ±2,937 mois. La survie en fonction du stade tumoral, le stade III et IV avait un faible taux de survie (19%) a 3 ans contre le stade I, II avait un taux de survie de (75%) (P = 0,000) (IC 95%). Les patients avec récidives tumorales avaient un taux de survie faible à 3 ans par rapport à ceux n'ayant pas eu de récidive (30,85% Vs 64,30% P = 0,043). Conclusion Dans cette série, l’étude uni varié des différents facteurs pronostiques conditionnant la survie n'a permis de retenir que trois facteurs influençant la survie, à savoir la taille tumorale, le stade, et les récidives tumorales. En analyse multi variée en utilisant le modèle Cox un seul facteur été retenu la récidive tumorale. PMID:27583069

  16. Evaluation des Connaissances-Attitudes-Pratiques des populations des districts sanitaires de Benoye, Laoukassy, Moundou et N’Djaména Sud sur la rage canine au Tchad

    PubMed Central

    Mindekem, Rolande; Lechenne, Monique; Alfaroukh, Idriss Oumar; Moto, Daugla Doumagoum; Zinsstag, Jakob; Ouedraogo, Laurent Tinoaga; Salifou, Sahidou

    2017-01-01

    Introduction La rage canine demeure une préoccupation en Afrique comme au Tchad. La présente étude vise à évaluer les Connaissances-Attitudes-Pratiques des populations pour la prise en charge appropriée des personnes exposées et une lutte efficace. Méthodes C’était une étude transversale descriptive réalisée en juillet et septembre dans quatre districts sanitaires au Tchad en 2015. Les données ont été collectées à l’aide d’un questionnaire auprès des ménages recrutés suivant un sondage aléatoire à 3 degrés. Résultats C’était 2428 personnes enquêtées avec un niveau maximum primaire (54,12%). L’âge moyen était de 36 ± 13,50 ans. Ils étaient cultivateurs (35,17%), commerçants (18,04%), ménagères (12,81%). La rage était définie comme une maladie transmise du chien à l’homme (41,43%), une altération du cerveau (41,27%), une sous-alimentation (10,26%). Le chat était faiblement connu réservoir (13,84%) et vecteur (19,77%) ainsi que la griffure comme moyen de transmission (4,61%) et la vaccination du chat comme mesure préventive (0,49%). Les premiers soins en cas de morsure à domicile étaient les pratiques traditionnelles (47,69%), le lavage des plaies (19,48%) ou aucune action entreprise (20,43%). Les ménages consultaient la santé humaine (78,50%), la santé animale (5,35%) et les guérisseurs traditionnels (27%). Conclusion La communication en rapport avec des premiers soins à la maison en cas de morsure, la connaissance du chat comme réservoir et vecteur, celle de la griffure comme moyen de transmission et la promotion de la consultation des services vétérinaires en cas de morsure sont nécessaires. PMID:28761600

  17. Au38(SPh)24: Au38 Protected with Aromatic Thiolate Ligands.

    PubMed

    Rambukwella, Milan; Burrage, Shayna; Neubrander, Marie; Baseggio, Oscar; Aprà, Edoardo; Stener, Mauro; Fortunelli, Alessandro; Dass, Amala

    2017-04-06

    Au 38 (SR) 24 is one of the most extensively investigated gold nanomolecules along with Au 25 (SR) 18 and Au 144 (SR) 60 . However, so far it has only been prepared using aliphatic-like ligands, where R = -SC 6 H 13 , -SC 12 H 25 and -SCH 2 CH 2 Ph. Au 38 (SCH 2 CH 2 Ph) 24 when reacted with HSPh undergoes core-size conversion to Au 36 (SPh) 24 , and existing literature suggests that Au 38 (SPh) 24 cannot be synthesized. Here, contrary to prevailing knowledge, we demonstrate that Au 38 (SPh) 24 can be prepared if the ligand exchanged conditions are optimized, under delicate conditions, without any formation of Au 36 (SPh) 24 . Conclusive evidence is presented in the form of matrix-assisted laser desorption/ionization mass spectrometry (MALDI-MS), electrospray ionization mass spectra (ESI-MS) characterization, and optical spectra of Au 38 (SPh) 24 in a solid glass form showing distinct differences from that of Au 38 (S-aliphatic) 24 . Theoretical analysis confirms experimental assignment of the optical spectrum and shows that the stability of Au 38 (SPh) 24 is not negligible with respect to that of its aliphatic analogous, and contains a significant component of ligand-ligand attractive interactions. Thus, while Au 38 (SPh) 24 is stable at RT, it converts to Au 36 (SPh) 24 either on prolonged etching (longer than 2 hours) at RT or when etched at 80 °C.

  18. Pathologies cutanées vues au laboratoire d'anatomie pathologique à Lomé, Togo

    PubMed Central

    Darre, Tchin; Mouhari-Toure, Abas; Saka, Bayaki; Amouzou, Efoé-ga Yawod Olivier; Dare, Sassil; Landoh, Dadja Essoya; Amegbor, Koffi; Pitché, Palokinam; Napo-Koura, Gado

    2015-01-01

    Introduction Les affections cutanées restent encore un problème de santé publique dans la majorité des pays en développement. Notre étude s'est fixée comme objectif de déterminer les aspects épidémiologiques et histologiques des dermatoses au Togo. Méthodes Il s'agissait d'une étude descriptive et transversale portant sur les cas de dermatoses diagnostiquées de 2002 à 2013 (10 ans) au laboratoire d'anatomie pathologique (LAP) du CHU- Sylvanus Olympio. Tous les cas d'examen portant sur un prélèvement de peau (biopsie, exérèse, pièces opératoires) ont été colligés de 2002 à 2013 à partir des données des registres dudit laboratoire. Résultats Au cours de la période d’étude, 1119 (7,6%) des 14720 prélèvements reçus au LAP étaient des prélèvements de peau, ce qui correspond à une fréquence annuelle de 111,9 prélèvements. L’âge moyen des patients dont les prélèvements de peau appartenaient était de 35,4 ans et le sex-ratio (H/F) de 1,39. Au plan histologique, les lésions cutanées étaient reparties en dermatoses non tumorales (390 cas, 34,8%), dermatoses tumorales et pseudo tumorales (607 cas, 54,2%) et des dermatoses de diagnostic incertain (122 cas, 10,9%). La lèpre (95 cas, 8,5%) et le carcinome épidermoïde (134 cas, 11,9%) étaient les types histologiques les plus fréquents. Conclusion Les dermatoses tumorales et pseudo tumorales font plus l'objet de demande d'examen anatomopathologique au Togo, ce qui s'explique par la hantise de tumeurs malignes devant toute dermatose tumorale. L'amélioration du plateau technique du LAP (immunohistochimie, immunofluorescence directe) permettra d'accroitre ses capacités diagnostiques. PMID:26405477

  19. Tunable VO2/Au Hyperbolic Metamaterial

    DTIC Science & Technology

    2016-02-12

    United States Government.   Tunable VO2/Au hyperbolic metamaterial S. Prayakarao1, B. Mendoza2,3, A. Devine2,3, C. Kyaw2, R. B. Van Dover2, V...can be used as a tunable component of an active metamaterial . The lamellar metamaterial studied in this work is composed of subwavelength VO2 and Au...Au lamellar metamaterial stacks have been fabricated and studied in the electrical conductivity and optical (transmission and reflection

  20. Les calculs urinaires de l'enfant au Burkina Faso: à propos de 67 cas

    PubMed Central

    Ouédraogo, Isso; Napon, Aïcha Madina; Bandré, Emile; Ouédraogo, Francis Somkieta; Tapsoba, Wendlamita Toussaint; Wandaogo, Albert

    2015-01-01

    L'objectif de cette étude est de déterminer la fréquence, de décrire les circonstances de découverte, les signes cliniques et paracliniques, la composition chimique des calculs prélevés et les difficultés rencontrées dans le traitement des lithiases urinaires. Notre étude a été rétrospective sur une période de six ans (janvier 2005 à décembre 2010) et a eu pour cadre le CHUP-CDG et a concerné 67 patients âgés de moins de 15 ans opérés pour lithiases urinaires. Les calculs de la dernière année au nombre de douze ont fait l'objet d'une analyse spectrophotométrique. La lithiase urinaire figure parmi les dix premières pathologies du service de chirurgie et représente 1,32% des hospitalisations. L’âge moyen de nos patients est de deux ans et varie de 6 mois à 14 ans. La symptomatologie de la lithiase urinaire est polymorphe. Le diagnostic des lithiases urinaires a été essentiellement radiologique (ASP) dans 87, 50 des cas. Les localisations les plus fréquentes sont: vésicales (49,25%) et pyéliques (46,26%). L'ECBU a révélé une infection urinaire chez 9 patients. Les germes le plus fréquemment rencontrés sont: Klebsiella pneumoniae pneumoniae (22,22%) et staphyloccocus aureus (22,22%). Les difficultés du traitement sont dues à la modicité de nos moyens diagnostiques et à la nature chimique des calculs et le traitement a été dans tous les cas chirurgical. La composition chimique est dominée par les sels calciques notamment les oxalates, les phosphates et les carbonates. PMID:26175840

  1. Comparative Study of the Adsorption of Thiols and Selenols on Au(111) and Au(100).

    PubMed

    Arisnabarreta, Nicolás; Ruano, Gustavo D; Lingenfelder, Magalí; Patrito, E Martín; Cometto, Fernando P

    2017-12-05

    The effect of the Au crystalline plane on the adsorption of different thiols and selenols is studied via reductive desorption (RD) and X-ray photoelectron spectroscopy (XPS) measurements. Self-assembled monolayers (SAMs) using aliphatic (ATs) and aromatic thiols (ArTs) on both Au(111) and Au(100) were prepared. The electrochemical stability of these SAMs on both surfaces is evaluated by comparing the position of the RD peaks. The longer the AT chain the more stable the SAM on Au(100) when compared to Au(111). By means of XPS measurements, we determine that the binding energy (BE) of the S 2p signal corresponding to the S atoms at the thiol/Au interface, commonly assigned at 162.0 eV, shifts 0.2 eV from Au(111) to Au(100) for SAMs prepared using thiols with the C* (C atom bonded to S) in sp 3 hybridization, such as ATs. However, when the thiol presents the C* with an sp 2 hybridization, such as in the case of ArTs, the BE remains at 162.0 eV regardless of the surface plane. Selenol-based SAMs were characterized comparatively on both Au(100) and Au(111). Our results show that selenol SAMs become even more electrochemically stable on Au(100) with respect to Au(111) than the analogue sulfur-based SAM. According to our results, we suggest that the electronic distribution around the Au-S/Se bond could be responsible for the different structural arrangements reported in the literature (gold adatoms, etc.), which should be dependent on the crystalline face (Au(hkl)-S) and the chemical nature of the environment of the adsorbates (sp 3 -C* vs sp 2 -C* and Au-SR vs Au-SeR).

  2. Cout direct hospitalier des accidents vasculaires cérébraux à Parakou au nord du Benin

    PubMed Central

    Adoukonou, Thierry; Kouna-Ndouongo, Philomène; Codjia, Jean-Mannix; Covi, Richmine; Tognon-Tchegnonsi, Francis; Preux, Pierre-Marie; Houinato, Dismand

    2013-01-01

    Introduction Les accidents vasculaires cérébraux constituent un véritable problème de santé publique en Afrique avec une charge importante. Les données fiables sur sa réelle charge économique sont rares en Afrique. L'objectif de cette étude était d’évaluer le coût direct hospitalier des AVC à Parakou au Bénin. Méthodes Il s'agissait d'une étude transversale économique ayant inclus des patients hospitalisés pour un AVC à l'hôpital de Parakou entre le 1er Juin 2010 au 31Mai 2011. Les données concernant les différents postes de consommation ont été collectées selon la méthode dite bottom-up. Le coût était envisagé du point de vue de la société et du patient. L'unité du coût était le franc CFA (valeur en 2011). Une régression linéaire multiple était utilisée pour déterminer les meilleurs prédicteurs du coût. Résultats Ils étaient 78 patients dont 52 hommes, âgés en moyenne de 57 ans ± 10.9. Le NIHSS moyen était de 14,4. Le taux de mortalité était de 20,5%. Le coût direct moyen était de 316.810,3 (±230.774,8) F CFA (environ 704 ± 512 Euros). Les grands postes de consommation étaient les explorations paracliniques (34.3%) les soins et médicaments (28.4%) et les frais d'hospitalisation (17.9%). Les meilleurs prédicteurs du coût élevé étaient un AVC hémorragique, un NIHSS élevé à l'admission et une longue durée d'hospitalisation. Conclusion Cette étude suggère un coût élevé de la prise en charge actuelle des AVC à Parakou. PMID:24839529

  3. Prévalence de l'hépatite B chez les personnes infectées par le VIH à Parakou au Bénin

    PubMed Central

    Dovonou, Comlan Albert; Amidou, Salimanou Ariyoh; Kpangon, Amadohoué Arsène; Traoré, Yacoubou Adam; Godjedo, Togbemabou Primous Martial; Satondji, Assongba Joseph; Wachinou, Ablo Prudence; Issa-Djibril, Fatioulaye Mahamadi; Fourn, Léonard; Zannou, Djimon Marcel; Gandaho, Prosper

    2015-01-01

    Introduction La co-infection avec l'hépatite B est l'un des défis majeurs de la prise en charge du VIH depuis l'amélioration de l'accès aux antirétroviraux en Afrique. La présente étude visait à estimer la prévalence de l'hépatite B chez les personnes séropositives au VIH à Parakou et décrire les facteurs associés. Méthodes Il s'agit d'une étude transversale menée de Mai 2011 à Juin 2012 dans le service de Médecine du CHU de Parakou. Ont été inclus tous les adultes séropositifs au VIH vus en consultation ou hospitalisés. Les données ont été collectées par interviews et dépouillement de dossiers médicaux. L'antigène HBs a été recherché par un test rapide et l'ALAT a été dosé. L'analyse des données a été faite avec le logiciel EpiInfo 3.5.1. Les proportions ont été comparées grâce au test de Chi-deux ou au test de Fisher au seuil de significativité de 5%. Un modèle de régression logistique multivariable a permis d'expliquer la prévalence de l'hépatite B. Résultats Sur les 744 sujets inclus on a dénombré 555 femmes. L’âge moyen était de 35,5 + 10,1 ans. La prévalence de l'hépatite B a été estimée à 16,9% (IC95: 14,3%-19,9%). Cette prévalence était plus élevée chez les sujets originaires du Borgou/Alibori et ceux au stade 4 de l'OMS. Conclusion La prévalence de la co-infection VIH/VHB au CHU Parakou est élevée. Le dispositif national de prise en charge et de prévention de l'hépatite B chez les personnes séropositives au VIH doit être renforcé. PMID:26097629

  4. Au 38 (SPh) 24 : Au 38 Protected with Aromatic Thiolate Ligands

    SciTech Connect

    Rambukwella, Milan; Burrage, Shayna; Neubrander, Marie

    2017-03-21

    Au38(SR)24 is one of the most extensively investigated gold nanomolecules along with Au25(SR)18 and Au144(SR)60. However, so far it has only been prepared using aliphatic-like ligands, where R = –SC6H13, -SC12H25 and –SCH2CH2Ph. Au38(SCH2CH2Ph)24 when reacted with HSPh undergoes core-size conversion to Au36(SPh)24, and existing literature suggest that Au38(SPh)24 cannot be synthesized. Here, contrary to prevailing knowledge, we demonstrate that Au38(SPh)24 can be prepared if the ligand exchanged conditions are optimized, without any formation of Au36(SPh)24. Conclusive evidence is presented in the form of MALDI-MS, ESI-MS characterization, and optical spectra of Au38(SPh)24 in a solid glass form showing distinct differencesmore » from that of Au38(S-aliphatic)24. Theoretical analysis confirms experimental assignment of the optical spectrum and shows that the stability of Au38(SPh)24 is comparable to that of its aliphatic analogues, but results from different physical origins, with a significant component of ligand-ligand attractive interactions.« less

  5. Strengthening of Au-Au bonds in small gold clusters by adsorbing noble gases

    NASA Astrophysics Data System (ADS)

    Ghiringhelli, Luca M.; Levchenko, Sergey; Scheffler, Matthias

    2012-02-01

    In state-of-the-art experiments for the vibrational spectra of metal clusters in the gas phase, photodissociation spectroscopy is performed on clusters complexed with noble gas (RG) atoms, where a RG atom is usually expected to form a weak van der Waals bond. By employing DFT (PBE functional with selected comparisons to PBE0, and to MP2 and CCSD(T) calculations), we surprisingly find a partially covalent bond of neutral dimers with RG. For RG = Ar, Kr, Xe one or two RG atoms can bind in a linear molecule with Au2. While both Hirschfeld and Mulliken analyses show a small electron transfer from the RG to Au2, the Au-Au bond shortens and the Au-Au stretch frequency increases. This is inconsistent with the expected effect of electron transfer to the antibonding orbital of the dimer. Electron-density (n) differences between the bonded systems and the isolated fragments show an accumulation of n between RG and the neighboring Au atom, and between the gold atoms. The analysis of the projected density of states reveals that, although only non-bonding orbital interactions and no charge transfer occurs between RG and Au2, the d-electrons of Au2 are redistributed due to the interaction with RG in such a way that the Au-Au σs bond is strengthened.

  6. Comment on “the ground-state structures of Au10-, Au8Ni and Au9Ni clusters”

    NASA Astrophysics Data System (ADS)

    Zheng, Ben-Xia; Die, Dong; Li, Qian-Qian; Dai, Ming-Liang; Li, Zhi-Qin; Yang, Ji-Xian

    2017-09-01

    The lowest energy structures of Aun+1- and AunNi (n = 2-9) clusters have been researched using the CALYPSO structure searching method in conjunction with the density functional theory. It is found that the most stable structures of Au10-, Au8Ni and Au9Ni clusters reported by Tang et al. [C. M. Tang, X. X. Chen and X. D. Yang, Int. J. Mod. Phys. B 28, 1450138 (2014)] are low-lying isomers. The correct ground states and vibrational spectra are given in this paper.

  7. Controlled Synthesis of Au@AgAu Yolk-Shell Cuboctahedra with Well-Defined Facets.

    PubMed

    Londono-Calderon, Alejandra; Bahena, Daniel; Yacaman, Miguel J

    2016-08-02

    The synthesis of Au@AgAu yolk-shell cuboctahedra nanoparticles formed by galvanic replacement in a seed-mediated method is described. Initially, single-crystal Au seeds are used for the formation of Au@Ag core-shell nanocubes, which serve as the template material for the deposition of an external Au layer. The well-controlled synthesis yields the formation of cuboctahedra nanoparticles with smooth inner and outer Au/Ag surfaces. The deposition/oxidation process is described to understand the formation of cuboctahedra and octahedra nanoparticles. The Au core maintains the initial morphology of the seed and remains static at the center of the yolk-shell because of residual Ag. Structural analysis of the shell indicates intrinsic stacking faults (SFs) near the surface. Energy dispersive X-ray spectroscopy (EDS) and X-ray photoelectron spectroscopy (XPS) compositional analysis show an Au-Ag nonordered alloy forming the shell. The three-dimensional structure of the nanoparticles presented open facets on the [111] as observed by electron tomography SIRT reconstruction over a stack of high-angle annular dark-field scanning transmission electron microscopy (HAADF-STEM) images. The geometrical model was validated by analyzing the direction of streaks in coherent nanobeam diffraction (NBD). The catalytic activity was evaluated using a model reaction based on the reduction of 4-nitrophenol (4-NTP) by NaBH4 in the presence of Au@AgAu yolk-shell nanoparticles.

  8. Approaching the theoretical strength in nanoporous Au

    NASA Astrophysics Data System (ADS)

    Volkert, C. A.; Lilleodden, E. T.; Kramer, D.; Weissmüller, J.

    2006-08-01

    The mechanical properties of nanoporous Au have been investigated by uniaxial compression. Micron-sized columns were machined in the surface of nanoporous Au using a focused Ga+ beam and compressed with a flat punch in a nanoindenter. Using scaling laws for foams, the yield strength of the 15nm diameter ligaments is estimated to be 1.5GPa, close to the theoretical strength of Au. This value agrees well with extrapolations of the yield strength of submicron, fully dense gold columns and shows that in addition to foam density and structure, the absolute size of ligaments and cell walls can be used to tailor foam properties.

  9. Joint Command Support Through Workspace Analysis, Design and Optimization (Soutien du Commandement Interarmees au Moyen de L’Analyse, de la Conception et de L’Optimisation de L’Espace de Travail)

    DTIC Science & Technology

    2009-10-01

    2009-100 October 2009 Defence Research and Development Canada Recherche et développement pour la défense Canada DEFENCE DÉFENSE & Joint...the Minister of National Defence, 2009 © Sa Majesté la Reine (en droit du Canada), telle que représentée par le ministre de la Défense nationale...practises, and discusses future research and development (R&D) efforts that are needed to further advance DRDC’s capability in this area. Résumé …..... La

  10. Macro- et microdosage de traces de cobalt III. Dosage par spectrophotométrie au moyen du nitroso-sel R. (nitroso-1-naphtol-2-disulfonate-3,6 de sodium) (in German)

    SciTech Connect

    Haerdi, W.; Vogel, J.; Monnier, D.

    1959-01-01

    A complete study was made of the determination of traces (up to 10⁻⁹ g) of Co by spectrophotometry using Nitroso-salt R. The errors were determined, and two new cuvettes are described. With the proposed technique 3 x 10⁻⁹g of Co in a volume of 0.3 ml can be determined. (tr-auth)

  11. Lutte contre la mortalité maternelle en milieu rural: décentralisation de l’offre des soins obstétricaux d’urgence au Burkina Faso

    PubMed Central

    Kaboré, Souleymane; Méda, Clément Ziemlé; Sombié, Issiaka; Savadogo, Léon Blaise; Karama, Robert; Bakouan, Koabié; Ouédraogo, Djénéba Sanon; Coulibaly, Norbert; Kargougou, Robert Lucien; Lankoandé, Emanuel; Sawadogo, Ramatou windsouri; Gosch, Karen

    2017-01-01

    Introduction Pour combler la pénurie en sages-femmes (SF) dans le district sanitaire de Tougan au Burkina Faso, il a été conçu une stratégie de décentralisation de l'offre des soins obstétricaux d'urgence basée sur des interventions ponctuelles de prise en charge des complications obstétricales au niveau des centres de santé (CS) en milieu rural par des SF. La présente étude a eu pour objectif de décrire cette expérience et d'analyser ses résultats. Méthodes Il s'agit d'une étude intervention de type transversal analytique basée sur une revue des données routinières de l'ensemble des parturientes prises en charge de 2013 à 2015. La collecte des données s'est déroulée du 5 au 20 janvier 2016. Un test Chi2, des rapports de cotes (OR) et leurs intervalles de confiance à 95% ont été calculés. Résultats Au total 416 parturientes présentant des complications obstétricales ont été prises en charge par les SF de zone. L'âge moyen des parturientes était de 26.4 ans. La distance médiane parcourue pour prendre en charge les parturientes était de quinze km pour un délai moyen d'intervention de 21.1 minutes (déviation standard = 7.13 minutes). Les dystocies représentaient la moitié (50.7%, IC95% = 45.8-55.6) des complications prises en charge suivies des hémorragies (26.4%, IC95% = 22.3%-31.0%). Plus de 77% des interventions avaient abouti à la résolution locale des complications obstétricales. Enfin, le résultat de l'intervention était fonction de la pathologie prise en charge (OR = 5.88; p < 0.001). Conclusion Cette stratégie a permis d'apporter une réplique à l'absence de SF dans les CS périphériques du district sanitaire de Tougan. Dans ce contexte particulier, cette intervention pourrait apporter une solution alternative au manque de ressources humaines en santé en milieu rural. PMID:28979638

  12. La cardiothyréose au centre hospitalier universitaire de Bobo-Dioulasso, Burkina Faso

    PubMed Central

    Yaméogo, Aimé Arsène; Yaméogo, Nobila Valentin; Compaoré, Yves Daniel; Ouédraogo, Tinoago Laurent; Zabsonré, Patrice

    2012-01-01

    Introduction La cardiothyréose est une affection fréquente et grave à l’ouest du Burkina Faso. Notre objectif était d’étudier les caractéristiques épidémiologiques, cliniques, thérapeutiques et évolutives des cardiothyréoses au centre hospitalier universitaire de Bobo-Dioulasso. Méthodes Etude prospective de 12 mois pourtant sur des cas de cardiothyréose colligés dans les services de cardiologie et de médecine interne. Résultats Quatorze (14) cas de cardiothyréose ont été colligés soit 33,3% des patients hospitalisés pour hyperthyroïdies. L’âge moyen des patients était de 53,57 ans ± 9,97. Les femmes au foyer (71,40%) aux conditions socio-économiques défavorables étaient les plus touchées. Parmi nos cas 21,42% des patients avaient déjà un antécédent d’hyperthyroïdie et l’HTA était le facteur de risque cardiovasculaire majeur (64,28%). Tous les patients présentaient une insuffisance cardiaque associée à un trouble du rythme (57,14%), essentiellement à type de fibrillation auriculaire (42,9%), une insuffisance coronarienne (7,14%) et un trouble de la conduction (7,14%). Le goitre multi-nodulaire a été l’entité étiopathogénique la plus fréquente (57,10%). Les antithyroïdiens de synthèse, les mesures hygiéno-diététiques et un traitement spécifique de l’insuffisance cardiaque ont été constamment utilisés pendant une durée d’hospitalisation moyenne de 23,57 jours ± 7,54. Si l’évolution immédiate peut être satisfaisante avec une euthyroïdie à 28,5% à moyen terme, les ruptures thérapeutiques peuvent être mortelles (un patient soit 7,14%) chez des patients généralement âgés majoritairement de sexe féminin avec un niveau socio-économique bas. Conclusion Le traitement de la cardiothyréose est efficace d’où l’intérêt d’une politique sanitaire pour une prise en charge adéquate. PMID:22593774

  13. Contrôle du marché informel à l’heure de la mondialisation des échanges. Le cas des antirétroviraux au Chili

    PubMed Central

    Brousselle, Astrid; Morales, Cristián

    2013-01-01

    Résumé Les nouveaux médicaments pour le VIH/sida ont créé des besoins d’accessibilité aux traitements que les gouvernements n’ont pas toujours réussi à couvrir. Il en résulte l’émergence d’un marché informel des ARV. Par l’analyse de la situation au Chili, nous traitons des différents créneaux d’approvisionnement, des conséquences de l’existence d’un tel marché, ainsi que des moyens envisageables pour réduire les effets indésirables. Les aspects tant microéconomiques que macroéconomiques concernant le marché et l’accessibilité aux médicaments sont abordés. PMID:23997580

  14. Diphosphine-protected ultrasmall gold nanoclusters: opened icosahedral Au 13 and heart-shaped Au 8 clusters

    DOE PAGES

    Zhang, Shan-Shan; Feng, Lei; Senanayake, Ravithree D.; ...

    2018-01-01

    Two ultrasmall gold clusters, Au 13 and Au 8 , were identified as a distorted I h icosahedral Au 13 and edge-shared “core + 4 exo ” structure Au 8 S 2 cores, respectively. They showed interesting luminescence and electrochemical properties.

  15. Suppression of ϒ production in d +Au and Au+Au collisions at √{sNN}=200 GeV

    NASA Astrophysics Data System (ADS)

    Adamczyk, L.; Adkins, J. K.; Agakishiev, G.; Aggarwal, M. M.; Ahammed, Z.; Alekseev, I.; Alford, J.; Anson, C. D.; Aparin, A.; Arkhipkin, D.; Aschenauer, E. C.; Averichev, G. S.; Balewski, J.; Banerjee, A.; Barnovska, Z.; Beavis, D. R.; Bellwied, R.; Bhasin, A.; Bhati, A. K.; Bhattarai, P.; Bichsel, H.; Bielcik, J.; Bielcikova, J.; Bland, L. C.; Bordyuzhin, I. G.; Borowski, W.; Bouchet, J.; Brandin, A. V.; Brovko, S. G.; Bültmann, S.; Bunzarov, I.; Burton, T. P.; Butterworth, J.; Caines, H.; Calderón de la Barca Sánchez, M.; Cebra, D.; Cendejas, R.; Cervantes, M. C.; Chaloupka, P.; Chang, Z.; Chattopadhyay, S.; Chen, H. F.; Chen, J. H.; Chen, L.; Cheng, J.; Cherney, M.; Chikanian, A.; Christie, W.; Chwastowski, J.; Codrington, M. J. M.; Corliss, R.; Cramer, J. G.; Crawford, H. J.; Cui, X.; Das, S.; Davila Leyva, A.; De Silva, L. C.; Debbe, R. R.; Dedovich, T. G.; Deng, J.; Derevschikov, A. A.; Derradi de Souza, R.; Dhamija, S.; di Ruzza, B.; Didenko, L.; Dilks, C.; Ding, F.; Djawotho, P.; Dong, X.; Drachenberg, J. L.; Draper, J. E.; Du, C. M.; Dunkelberger, L. E.; Dunlop, J. C.; Efimov, L. G.; Engelage, J.; Engle, K. S.; Eppley, G.; Eun, L.; Evdokimov, O.; Fatemi, R.; Fazio, S.; Fedorisin, J.; Filip, P.; Finch, E.; Fisyak, Y.; Flores, C. E.; Gagliardi, C. A.; Gangadharan, D. R.; Garand, D.; Geurts, F.; Gibson, A.; Girard, M.; Gliske, S.; Grosnick, D.; Guo, Y.; Gupta, A.; Gupta, S.; Guryn, W.; Haag, B.; Hajkova, O.; Hamed, A.; Han, L.-X.; Haque, R.; Harris, J. W.; Hays-Wehle, J. P.; Heppelmann, S.; Hill, K.; Hirsch, A.; Hoffmann, G. W.; Hofman, D. J.; Horvat, S.; Huang, B.; Huang, H. Z.; Huck, P.; Humanic, T. J.; Igo, G.; Jacobs, W. W.; Jang, H.; Judd, E. G.; Kabana, S.; Kalinkin, D.; Kang, K.; Kauder, K.; Ke, H. W.; Keane, D.; Kechechyan, A.; Kesich, A.; Khan, Z. H.; Kikola, D. P.; Kisel, I.; Kisiel, A.; Koetke, D. D.; Kollegger, T.; Konzer, J.; Koralt, I.; Korsch, W.; Kotchenda, L.; Kravtsov, P.; Krueger, K.; Kulakov, I.; Kumar, L.; Kycia, R. A.; Lamont, M. A. C.; Landgraf, J. M.; Landry, K. D.; Lauret, J.; Lebedev, A.; Lednicky, R.; Lee, J. H.; Leight, W.; LeVine, M. J.; Li, C.; Li, W.; Li, X.; Li, X.; Li, Y.; Li, Z. M.; Lima, L. M.; Lisa, M. A.; Liu, F.; Ljubicic, T.; Llope, W. J.; Longacre, R. S.; Luo, X.; Ma, G. L.; Ma, Y. G.; Madagodagettige Don, D. M. M. D.; Mahapatra, D. P.; Majka, R.; Margetis, S.; Markert, C.; Masui, H.; Matis, H. S.; McDonald, D.; McShane, T. S.; Minaev, N. G.; Mioduszewski, S.; Mohanty, B.; Mondal, M. M.; Morozov, D. A.; Munhoz, M. G.; Mustafa, M. K.; Nandi, B. K.; Nasim, Md.; Nayak, T. K.; Nelson, J. M.; Nogach, L. V.; Noh, S. Y.; Novak, J.; Nurushev, S. B.; Odyniec, G.; Ogawa, A.; Oh, K.; Ohlson, A.; Okorokov, V.; Oldag, E. W.; Oliveira, R. A. N.; Pachr, M.; Page, B. S.; Pal, S. K.; Pan, Y. X.; Pandit, Y.; Panebratsev, Y.; Pawlak, T.; Pawlik, B.; Pei, H.; Perkins, C.; Peryt, W.; Peterson, A.; Pile, P.; Planinic, M.; Pluta, J.; Plyku, D.; Poljak, N.; Porter, J.; Poskanzer, A. M.; Pruthi, N. K.; Przybycien, M.; Pujahari, P. R.; Qiu, H.; Quintero, A.; Ramachandran, S.; Raniwala, R.; Raniwala, S.; Ray, R. L.; Riley, C. K.; Ritter, H. G.; Roberts, J. B.; Rogachevskiy, O. V.; Romero, J. L.; Ross, J. F.; Roy, A.; Ruan, L.; Rusnak, J.; Sahoo, N. R.; Sahu, P. K.; Sakrejda, I.; Salur, S.; Sandacz, A.; Sandweiss, J.; Sangaline, E.; Sarkar, A.; Schambach, J.; Scharenberg, R. P.; Schmah, A. M.; Schmidke, W. B.; Schmitz, N.; Seger, J.; Seyboth, P.; Shah, N.; Shahaliev, E.; Shanmuganathan, P. V.; Shao, M.; Sharma, B.; Shen, W. Q.; Shi, S. S.; Shou, Q. Y.; Sichtermann, E. P.; Singaraju, R. N.; Skoby, M. J.; Smirnov, D.; Smirnov, N.; Solanki, D.; Sorensen, P.; deSouza, U. G.; Spinka, H. M.; Srivastava, B.; Stanislaus, T. D. S.; Stevens, J. R.; Stock, R.; Strikhanov, M.; Stringfellow, B.; Suaide, A. A. P.; Sumbera, M.; Sun, X.; Sun, X. M.; Sun, Y.; Sun, Z.; Surrow, B.; Svirida, D. N.; Symons, T. J. M.; Szanto de Toledo, A.; Takahashi, J.; Tang, A. H.; Tang, Z.; Tarnowsky, T.; Thomas, J. H.; Timmins, A. R.; Tlusty, D.; Tokarev, M.; Trentalange, S.; Tribble, R. E.; Tribedy, P.; Trzeciak, B. A.; Tsai, O. D.; Turnau, J.; Ullrich, T.; Underwood, D. G.; Van Buren, G.; van Nieuwenhuizen, G.; Vanfossen, J. A.; Varma, R.; Vasconcelos, G. M. S.; Vasiliev, A. N.; Vertesi, R.; Videbæk, F.; Viyogi, Y. P.; Vokal, S.; Vossen, A.; Wada, M.; Walker, M.; Wang, F.; Wang, G.; Wang, H.; Wang, J. S.; Wang, X. L.; Wang, Y.; Wang, Y.; Webb, G.; Webb, J. C.; Westfall, G. D.; Wieman, H.; Wimsatt, G.; Wissink, S. W.; Witt, R.; Wu, Y. F.; Xiao, Z.; Xie, W.; Xin, K.; Xu, H.; Xu, N.; Xu, Q. H.; Xu, Y.; Xu, Z.; Yan, W.; Yang, C.; Yang, Y.; Yang, Y.; Ye, Z.; Yepes, P.; Yi, L.; Yip, K.; Yoo, I.-K.; Zawisza, Y.; Zbroszczyk, H.; Zha, W.; Zhang, J. B.; Zhang, J. L.; Zhang, S.; Zhang, X. P.; Zhang, Y.; Zhang, Z. P.; Zhao, F.; Zhao, J.; Zhong, C.; Zhu, X.; Zhu, Y. H.; Zoulkarneeva, Y.; Zyzak, M.

    2014-07-01

    We report measurements of ϒ meson production in p + p, d +Au, and Au +Au collisions using the STAR detector at RHIC. We compare the ϒ yield to the measured cross section in p + p collisions in order to quantify any modifications of the yield in cold nuclear matter using d +Au data and in hot nuclear matter using Au +Au data separated into three centrality classes. Our p + p measurement is based on three times the statistics of our previous result. We obtain a nuclear modification factor for ϒ (1 S + 2 S + 3 S) in the rapidity range | y | < 1 in d +Au collisions of RdAu = 0.79 ± 0.24 (stat.) ± 0.03 (syst.) ± 0.10 (p + p syst.). A comparison with models including shadowing and initial state parton energy loss indicates the presence of additional cold-nuclear matter suppression. Similarly, in the top 10% most-central Au +Au collisions, we measure a nuclear modification factor of RAA = 0.49 ± 0.1 (stat.) ± 0.02 (syst.) ± 0.06 (p + psyst.), which is a larger suppression factor than that seen in cold nuclear matter. Our results are consistent with complete suppression of excited-state ϒ mesons in Au +Au collisions. The additional suppression in Au +Au is consistent with the level expected in model calculations that include the presence of a hot, deconfined Quark-Gluon Plasma. However, understanding the suppression seen in d +Au is still needed before any definitive statements about the nature of the suppression in Au +Au can be made.

  16. Toward hybrid Au nanorods @ M (Au, Ag, Pd and Pt) core-shell heterostructures for ultrasensitive SERS probes

    NASA Astrophysics Data System (ADS)

    Xie, Xiaobin; Gao, Guanhui; Kang, Shendong; Lei, Yanhua; Pan, Zhengyin; Shibayama, Tamaki; Cai, Lintao

    2017-06-01

    Being able to precisely control the morphologies of noble metallic nanostructures is of essential significance for promoting the surface-enhanced Raman scattering (SERS) effect. Herein, we demonstrate an overgrowth strategy for synthesizing Au @ M (M = Au, Ag, Pd, Pt) core-shell heterogeneous nanocrystals with an orientated structural evolution and highly improved properties by using Au nanorods as seeds. With the same reaction condition system applied, we obtain four well-designed heterostructures with diverse shapes, including Au concave nanocuboids (Au CNs), Au @ Ag crystalizing face central cube nanopeanuts, Au @ Pd porous nanocuboids and Au @ Pt nanotrepangs. Subsequently, the exact overgrowth mechanism of the above heterostructural building blocks is further analysed via the systematic optimiziation of a series of fabrications. Remarkably, the well-defined Au CNs and Au @ Ag nanopeanuts both exhibit highly promoted SERS activity. We expect to be able to supply a facile strategy for the fabrication of multimetallic heterogeneous nanostructures, exploring the high SERS effect and catalytic activities.

  17. Isomorphism and solid solutions among Ag- and Au-selenides

    SciTech Connect

    Palyanova, Galina A.; Seryotkin, Yurii V.; Novosibirsk State University

    2016-09-15

    Au-Ag selenides were synthesized by heating stoichiometric mixtures of elementary substances of initial compositions Ag{sub 2−x}Au{sub x}Se with a step of x=0.25 (0≤x≤2) to 1050 °C and annealing at 500 °C. Scanning electron microscopy, optical microscopy, electron microprobe analysis and X-ray powder diffraction methods have been applied to study synthesized samples. Results of studies of synthesized products revealed the existence of three solid solutions with limited isomorphism Ag↔Au: naumannite Ag{sub 2}Se – Ag{sub 1.94}Au{sub 0.06}Se, fischesserite Ag{sub 3}AuSe{sub 2} - Ag{sub 3.2}Au{sub 0.8}Se{sub 2} and gold selenide AuSe - Au{sub 0.94}Ag{sub 0.06}Se. Solid solutions and AgAuSe phases were added tomore » the phase diagram of Ag-Au-Se system. Crystal-chemical interpretation of Ag-Au isomorphism in selenides was made on the basis of structural features of fischesserite, naumannite, and AuSe. - Highlights: • Au-Ag selenides were synthesized. • Limited Ag-Au isomorphism in the selenides is affected by structural features. • Some new phases were introduced to the phase diagram Ag-Au-Se.« less

  18. Spectra and ratios of identified particles in Au+Au and d+Au collisions at sNN=200 GeV

    NASA Astrophysics Data System (ADS)

    Adare, A.; Afanasiev, S.; Aidala, C.; Ajitanand, N. N.; Akiba, Y.; Al-Bataineh, H.; Alexander, J.; Angerami, A.; Aoki, K.; Apadula, N.; Aramaki, Y.; Atomssa, E. T.; Averbeck, R.; Awes, T. C.; Azmoun, B.; Babintsev, V.; Bai, M.; Baksay, G.; Baksay, L.; Barish, K. N.; Bassalleck, B.; Basye, A. T.; Bathe, S.; Baublis, V.; Baumann, C.; Bazilevsky, A.; Belikov, S.; Belmont, R.; Bennett, R.; Berdnikov, A.; Berdnikov, Y.; Bhom, J. H.; Bickley, A. A.; Blau, D. S.; Bok, J. S.; Boyle, K.; Brooks, M. L.; Buesching, H.; Bumazhnov, V.; Bunce, G.; Butsyk, S.; Camacho, C. M.; Campbell, S.; Caringi, A.; Chen, C.-H.; Chi, C. Y.; Chiu, M.; Choi, I. J.; Choi, J. B.; Choudhury, R. K.; Christiansen, P.; Chujo, T.; Chung, P.; Chvala, O.; Cianciolo, V.; Citron, Z.; Cole, B. A.; Conesa del Valle, Z.; Connors, M.; Constantin, P.; Csanád, M.; Csörgő, T.; Dahms, T.; Dairaku, S.; Danchev, I.; Das, K.; Datta, A.; David, G.; Dayananda, M. K.; Denisov, A.; Deshpande, A.; Desmond, E. J.; Dharmawardane, K. V.; Dietzsch, O.; Dion, A.; Donadelli, M.; Drapier, O.; Drees, A.; Drees, K. A.; Durham, J. M.; Durum, A.; Dutta, D.; D'Orazio, L.; Edwards, S.; Efremenko, Y. V.; Ellinghaus, F.; Engelmore, T.; Enokizono, A.; En'yo, H.; Esumi, S.; Fadem, B.; Fields, D. E.; Finger, M.; Finger, M., Jr.; Fleuret, F.; Fokin, S. L.; Fraenkel, Z.; Frantz, J. E.; Franz, A.; Frawley, A. D.; Fujiwara, K.; Fukao, Y.; Fusayasu, T.; Garishvili, I.; Glenn, A.; Gong, H.; Gonin, M.; Goto, Y.; Granier de Cassagnac, R.; Grau, N.; Greene, S. V.; Grim, G.; Grosse Perdekamp, M.; Gunji, T.; Gustafsson, H.-Å.; Haggerty, J. S.; Hahn, K. I.; Hamagaki, H.; Hamblen, J.; Han, R.; Hanks, J.; Hartouni, E. P.; Haslum, E.; Hayano, R.; He, X.; Heffner, M.; Hemmick, T. K.; Hester, T.; Hill, J. C.; Hohlmann, M.; Holzmann, W.; Homma, K.; Hong, B.; Horaguchi, T.; Hornback, D.; Huang, S.; Ichihara, T.; Ichimiya, R.; Ide, J.; Ikeda, Y.; Imai, K.; Inaba, M.; Isenhower, D.; Ishihara, M.; Isobe, T.; Issah, M.; Isupov, A.; Ivanischev, D.; Iwanaga, Y.; Jacak, B. V.; Jia, J.; Jiang, X.; Jin, J.; Johnson, B. M.; Jones, T.; Joo, K. S.; Jouan, D.; Jumper, D. S.; Kajihara, F.; Kametani, S.; Kamihara, N.; Kamin, J.; Kang, J. H.; Kapustinsky, J.; Karatsu, K.; Kasai, M.; Kawall, D.; Kawashima, M.; Kazantsev, A. V.; Kempel, T.; Khanzadeev, A.; Kijima, K. M.; Kikuchi, J.; Kim, A.; Kim, B. I.; Kim, D. H.; Kim, D. J.; Kim, E.; Kim, E.-J.; Kim, S. H.; Kim, Y.-J.; Kinney, E.; Kiriluk, K.; Kiss, Á.; Kistenev, E.; Kleinjan, D.; Kochenda, L.; Komkov, B.; Konno, M.; Koster, J.; Kotchetkov, D.; Kozlov, A.; Král, A.; Kravitz, A.; Kunde, G. J.; Kurita, K.; Kurosawa, M.; Kwon, Y.; Kyle, G. S.; Lacey, R.; Lai, Y. S.; Lajoie, J. G.; Lebedev, A.; Lee, D. M.; Lee, J.; Lee, K.; Lee, K. B.; Lee, K. S.; Leitch, M. J.; Leite, M. A. L.; Leitner, E.; Lenzi, B.; Li, X.; Lichtenwalner, P.; Liebing, P.; Linden Levy, L. A.; Liška, T.; Litvinenko, A.; Liu, H.; Liu, M. X.; Love, B.; Luechtenborg, R.; Lynch, D.; Maguire, C. F.; Makdisi, Y. I.; Malakhov, A.; Malik, M. D.; Manko, V. I.; Mannel, E.; Mao, Y.; Masui, H.; Matathias, F.; McCumber, M.; McGaughey, P. L.; McGlinchey, D.; Means, N.; Meredith, B.; Miake, Y.; Mibe, T.; Mignerey, A. C.; Mikeš, P.; Miki, K.; Milov, A.; Mishra, M.; Mitchell, J. T.; Mohanty, A. K.; Moon, H. J.; Morino, Y.; Morreale, A.; Morrison, D. P.; Moukhanova, T. V.; Murakami, T.; Murata, J.; Nagamiya, S.; Nagle, J. L.; Naglis, M.; Nagy, M. I.; Nakagawa, I.; Nakamiya, Y.; Nakamura, K. R.; Nakamura, T.; Nakano, K.; Nam, S.; Newby, J.; Nguyen, M.; Nihashi, M.; Nouicer, R.; Nyanin, A. S.; Oakley, C.; O'Brien, E.; Oda, S. X.; Ogilvie, C. A.; Oka, M.; Okada, K.; Onuki, Y.; Oskarsson, A.; Ouchida, M.; Ozawa, K.; Pak, R.; Pantuev, V.; Papavassiliou, V.; Park, I. H.; Park, J.; Park, S. K.; Park, W. J.; Pate, S. F.; Pei, H.; Peng, J.-C.; Pereira, H.; Peresedov, V.; Peressounko, D. Yu.; Petti, R.; Pinkenburg, C.; Pisani, R. P.; Proissl, M.; Purschke, M. L.; Purwar, A. K.; Qu, H.; Rak, J.; Rakotozafindrabe, A.; Ravinovich, I.; Read, K. F.; Rembeczki, S.; Reygers, K.; Riabov, V.; Riabov, Y.; Richardson, E.; Roach, D.; Roche, G.; Rolnick, S. D.; Rosati, M.; Rosen, C. A.; Rosendahl, S. S. E.; Rosnet, P.; Rukoyatkin, P.; Ružička, P.; Sahlmueller, B.; Saito, N.; Sakaguchi, T.; Sakashita, K.; Samsonov, V.; Sano, S.; Sato, T.; Sawada, S.; Sedgwick, K.; Seele, J.; Seidl, R.; Semenov, A. Yu.; Seto, R.; Sharma, D.; Shein, I.; Shibata, T.-A.; Shigaki, K.; Shimomura, M.; Shoji, K.; Shukla, P.; Sickles, A.; Silva, C. L.; Silvermyr, D.; Silvestre, C.; Sim, K. S.; Singh, B. K.; Singh, C. P.; Singh, V.; Slunečka, M.; Soltz, R. A.; Sondheim, W. E.; Sorensen, S. P.; Sourikova, I. V.; Sparks, N. A.; Stankus, P. W.; Stenlund, E.; Stoll, S. P.; Sugitate, T.; Sukhanov, A.; Sziklai, J.; Takagui, E. M.; Taketani, A.; Tanabe, R.; Tanaka, Y.; Taneja, S.; Tanida, K.; Tannenbaum, M. J.; Tarafdar, S.; Taranenko, A.; Tarján, P.; Themann, H.; Thomas, D.; Thomas, T. L.; Togawa, M.; Toia, A.; Tomášek, L.; Torii, H.; Towell, R. S.; Tserruya, I.; Tsuchimoto, Y.; Vale, C.; Valle, H.; van Hecke, H. W.; Vazquez-Zambrano, E.; Veicht, A.; Velkovska, J.; Vértesi, R.; Vinogradov, A. A.; Virius, M.; Vrba, V.; Vznuzdaev, E.; Wang, X. R.; Watanabe, D.; Watanabe, K.; Watanabe, Y.; Wei, F.; Wei, R.; Wessels, J.; White, S. N.; Winter, D.; Wood, J. P.; Woody, C. L.; Wright, R. M.; Wysocki, M.; Xie, W.; Yamaguchi, Y. L.; Yamaura, K.; Yang, R.; Yanovich, A.; Ying, J.; Yokkaichi, S.; You, Z.; Young, G. R.; Younus, I.; Yushmanov, I. E.; Zajc, W. A.; Zhang, C.; Zhou, S.; Zolin, L.

    2013-08-01

    The transverse momentum (pT) spectra and ratios of identified charged hadrons (π±, K±, p, p¯) produced in sNN=200 GeV Au+Au and d+Au collisions are reported in five different centrality classes for each collision species. The measurements of pions and protons are reported up to pT=6 GeV/c (5 GeV/c), and the measurements of kaons are reported up to pT=4 GeV/c (3.5 GeV/c) in Au+Au (d+Au) collisions. In the intermediate pT region, between 2 and 5 GeV/c, a significant enhancement of baryon-to-meson ratios compared to those measured in p+p collisions is observed. This enhancement is present in both Au+Au and d+Au collisions and increases as the collisions become more central. We compare a class of peripheral Au+Au collisions with a class of central d+Au collisions which have a comparable number of participating nucleons and binary nucleon-nucleon collisions. The pT-dependent particle ratios for these classes display a remarkable similarity, which is then discussed.

  19. Au nanoparticles films used in biological sensing

    NASA Astrophysics Data System (ADS)

    Rosales Pérez, M.; Delgado Macuil, R.; Rojas López, M.; Gayou, V. L.; Sánchez Ramírez, J. F.

    2009-05-01

    Lactobacillus para paracasei are used commonly as functional food and probiotic substances. In this work Au nanoparticles self-assembled films were used for Lactobacillus para paracasei determination at five different concentrations. Functionalized substrates were immersed in a colloidal solution for one and a half hour at room temperature and dried at room temperature during four hours. After that, drops of Lactobacillus para paracasei in aqueous solution were put into the Au nanoparticles film and let dry at room temperature for another two hours. Infrared spectroscopy in attenuated total reflectance sampling mode was used to observe generation peaks due to substrate silanization, enhancement of Si-O band intensity due to the Au colloids added to silanized substrate and also to observe the enhancement of Lactobacillus para paracasei infrared intensity of the characteristic frequencies at 1650, 1534 and 1450 cm-1 due to surface enhancement infrared absorption.

  20. Resistive switching characteristics of Au/P-doped NiO/Au segmented nanowires synthesized by electrochemical deposition

    NASA Astrophysics Data System (ADS)

    Lee, Saeeun; Kim, Donguk; Eom, Hyeonjin; Kim, Woo-byoung; Yoo, Bongyoung

    2014-02-01

    In this paper, we detail the synthesis and characteristics of Au/NiO/Au segmented nanowire-based resistive switching memory devices. The fabrication of the memory devices involves the step-by-step electrodeposition of Au-Ni-Au into an anodic aluminum oxide template followed by the thermal oxidation process to make NiO. The unipolar resistive change is observed in Au/NiO/Au nanowires exhibiting a set voltage of 0.6 V and a reset voltage of 1 V with a current compliance of 10 mA. Au diffused Au into NiO during the thermal oxidation lowers the resistance of NiO and the forming voltage. The change in the switching behavior from unipolar to bipolar is achieved by doping approximately 3 at. % phosphorous in the interface of NiO and a Au electrode.

  1. Local structure and X-ray magnetic circular dichroism of Au in Au-Co nanoalloys

    NASA Astrophysics Data System (ADS)

    Maurizio, C.; Michieli, N.; Kalinic, B.; Mattarello, V.; Bello, V.; Wilhelm, F.; Ollefs, K.; Mattei, G.

    2018-03-01

    Coupling a plasmonic metal with a magnetic one in thin films and nanostructures is very interesting for the emerging field of magnetoplasmonics. In particular, coupling through alloying is a promising strategy to induce a magnetic moment on the plasmonic metal atoms, in a way that is intimately related to the local structure of the (metastable) alloy material. In this framework, Au:Co bimetallic films have been produced via magnetron co-sputtering deposition. X-ray absorption spectroscopy (XAS) at both Au- and Co-edges clearly indicates the formation of a full-metallic layer composed for the major part of a binary AuxCo1-x alloy, with x = 0.7-0.8. XAS and transmission electron microscopy analyses suggest the presence of a minor fraction of segregated metals. X-ray magnetic circular dichroism (XMCD) analysis at Au L2,3 edges detected a net magnetic moment of Au atoms (μ = 0.06 μB), significantly larger (≈3.5 times) that the one for Au-capped Co nanoclusters and comparable to the one for a Co-rich Au/Co multilayer, despite the 4 times larger concentration of Co with respect to the present case. This Au-Co magnetic coupling is favored by a high degree of mixing of the two metals in the alloy.

  2. Fabrication of segmented Au/Co/Au nanowires: insights in the quality of Co/Au junctions.

    PubMed

    Jang, Bumjin; Pellicer, Eva; Guerrero, Miguel; Chen, Xiangzhong; Choi, Hongsoo; Nelson, Bradley J; Sort, Jordi; Pané, Salvador

    2014-08-27

    Electrodeposition is a versatile method, which enables the fabrication of a variety of wire-like nanoarchitectures such as nanowires, nanorods, and nanotubes. By means of template-assisted electrodeposition, segmented Au/Co/Au nanowires are grown in anodic aluminum oxide templates from two different electrolytes. To tailor the properties of the cobalt segments, several electrochemical conditions are studied as a function of current density, pulse deposition, and pH. The morphology, crystal structure, and magnetic properties are accordingly investigated. Changes in the deposition conditions affect the cobalt electrocrystallization process directly. Cobalt tends to crystallize mainly in the hexagonal close-packed structure, which is the reason cobalt might not accommodate satisfactorily on the face-centered cubic Au surface or vice versa. We demonstrate that by modifying the electrolyte and the applied current densities, changes in the texture and the crystalline structure of cobalt lead to a good quality connection between dissimilar segments. In particular, lowering the bath pH, or using pulse plating at a high overpotential, produces polycrystalline fcc Co and thus well-connected Co/Au bimetallic junctions with smooth interface. These are crucial factors to be carefully considered taking into account that nanowires are potential building blocks in micro- and nanoelectromechanical systems.

  3. Production of ω mesons in p + p, d + Au, Cu + Cu, and Au + Au collisions at sNN=200 GeV

    NASA Astrophysics Data System (ADS)

    Adare, A.; Afanasiev, S.; Aidala, C.; Ajitanand, N. N.; Akiba, Y.; Al-Bataineh, H.; Al-Jamel, A.; Alexander, J.; Angerami, A.; Aoki, K.; Apadula, N.; Aphecetche, L.; Aramaki, Y.; Armendariz, R.; Aronson, S. H.; Asai, J.; Atomssa, E. T.; Averbeck, R.; Awes, T. C.; Azmoun, B.; Babintsev, V.; Bai, M.; Baksay, G.; Baksay, L.; Baldisseri, A.; Barish, K. N.; Barnes, P. D.; Bassalleck, B.; Basye, A. T.; Bathe, S.; Batsouli, S.; Baublis, V.; Bauer, F.; Baumann, C.; Bazilevsky, A.; Belikov, S.; Belmont, R.; Bennett, R.; Berdnikov, A.; Berdnikov, Y.; Bhom, J. H.; Bickley, A. A.; Bjorndal, M. T.; Blau, D. S.; Boissevain, J. G.; Bok, J. S.; Borel, H.; Boyle, K.; Brooks, M. L.; Brown, D. S.; Bucher, D.; Buesching, H.; Bumazhnov, V.; Bunce, G.; Burward-Hoy, J. M.; Butsyk, S.; Camacho, C. M.; Campbell, S.; Caringi, A.; Chai, J.-S.; Chang, B. S.; Charvet, J.-L.; Chen, C.-H.; Chernichenko, S.; Chi, C. Y.; Chiba, J.; Chiu, M.; Choi, I. J.; Choi, J. B.; Choudhury, R. K.; Christiansen, P.; Chujo, T.; Chung, P.; Churyn, A.; Chvala, O.; Cianciolo, V.; Citron, Z.; Cleven, C. R.; Cobigo, Y.; Cole, B. A.; Comets, M. P.; Conesa Del Valle, Z.; Connors, M.; Constantin, P.; Csanád, M.; Csörgő, T.; Dahms, T.; Dairaku, S.; Danchev, I.; Das, K.; Datta, A.; David, G.; Dayananda, M. K.; Deaton, M. B.; Dehmelt, K.; Delagrange, H.; Denisov, A.; D'Enterria, D.; Deshpande, A.; Desmond, E. J.; Dharmawardane, K. V.; Dietzsch, O.; Dion, A.; Donadelli, M.; Drachenberg, J. L.; Drapier, O.; Drees, A.; Drees, K. A.; Dubey, A. K.; Durham, J. M.; Durum, A.; Dutta, D.; Dzhordzhadze, V.; D'Orazio, L.; Edwards, S.; Efremenko, Y. V.; Egdemir, J.; Ellinghaus, F.; Emam, W. S.; Engelmore, T.; Enokizono, A.; En'yo, H.; Espagnon, B.; Esumi, S.; Eyser, K. O.; Fadem, B.; Fields, D. E.; Finger, M.; Finger, M., Jr.; Fleuret, F.; Fokin, S. L.; Forestier, B.; Fraenkel, Z.; Frantz, J. E.; Franz, A.; Frawley, A. D.; Fujiwara, K.; Fukao, Y.; Fung, S.-Y.; Fusayasu, T.; Gadrat, S.; Garishvili, I.; Gastineau, F.; Germain, M.; Glenn, A.; Gong, H.; Gonin, M.; Gosset, J.; Goto, Y.; Granier de Cassagnac, R.; Grau, N.; Greene, S. V.; Grim, G.; Grosse Perdekamp, M.; Gunji, T.; Gustafsson, H.-Å.; Hachiya, T.; Hadj Henni, A.; Haegemann, C.; Haggerty, J. S.; Hagiwara, M. N.; Hahn, K. I.; Hamagaki, H.; Hamblen, J.; Han, R.; Hanks, J.; Harada, H.; Hartouni, E. P.; Haruna, K.; Harvey, M.; Haslum, E.; Hasuko, K.; Hayano, R.; He, X.; Heffner, M.; Hemmick, T. K.; Hester, T.; Heuser, J. M.; Hiejima, H.; Hill, J. C.; Hobbs, R.; Hohlmann, M.; Holmes, M.; Holzmann, W.; Homma, K.; Hong, B.; Horaguchi, T.; Hornback, D.; Huang, S.; Hur, M. G.; Ichihara, T.; Ichimiya, R.; Ide, J.; Iinuma, H.; Ikeda, Y.; Imai, K.; Inaba, M.; Inoue, Y.; Isenhower, D.; Isenhower, L.; Ishihara, M.; Isobe, T.; Issah, M.; Isupov, A.; Ivanischev, D.; Iwanaga, Y.; Jacak, B. V.; Jia, J.; Jiang, X.; Jin, J.; Jinnouchi, O.; Johnson, B. M.; Jones, T.; Joo, K. S.; Jouan, D.; Jumper, D. S.; Kajihara, F.; Kametani, S.; Kamihara, N.; Kamin, J.; Kaneta, M.; Kang, J. H.; Kanou, H.; Kapustinsky, J.; Karatsu, K.; Kasai, M.; Kawagishi, T.; Kawall, D.; Kawashima, M.; Kazantsev, A. V.; Kelly, S.; Kempel, T.; Khanzadeev, A.; Kijima, K. M.; Kikuchi, J.; Kim, A.; Kim, B. I.; Kim, D. H.; Kim, D. J.; Kim, E.; Kim, E. J.; Kim, S. H.; Kim, Y.-J.; Kim, Y.-S.; Kim, Y. J.; Kinney, E.; Kiriluk, K.; Kiss, Á.; Kistenev, E.; Kiyomichi, A.; Klay, J.; Klein-Boesing, C.; Kochenda, L.; Kochetkov, V.; Komkov, B.; Konno, M.; Koster, J.; Kotchetkov, D.; Kozlov, A.; Král, A.; Kravitz, A.; Kroon, P. J.; Kubart, J.; Kunde, G. J.; Kurihara, N.; Kurita, K.; Kurosawa, M.; Kweon, M. J.; Kwon, Y.; Kyle, G. S.; Lacey, R.; Lai, Y. S.; Lajoie, J. G.; Lebedev, A.; Le Bornec, Y.; Leckey, S.; Lee, D. M.; Lee, J.; Lee, K.; Lee, K. B.; Lee, K. S.; Lee, M. K.; Lee, T.; Leitch, M. J.; Leite, M. A. L.; Leitner, E.; Lenzi, B.; Li, X.; Li, X. H.; Lichtenwalner, P.; Liebing, P.; Lim, H.; Linden Levy, L. A.; Liška, T.; Litvinenko, A.; Liu, H.; Liu, M. X.; Love, B.; Luechtenborg, R.; Lynch, D.; Maguire, C. F.; Makdisi, Y. I.; Malakhov, A.; Malik, M. D.; Manko, V. I.; Mannel, E.; Mao, Y.; Mašek, L.; Masui, H.; Matathias, F.; McCain, M. C.; McCumber, M.; McGaughey, P. L.; Means, N.; Meredith, B.; Miake, Y.; Mibe, T.; Mignerey, A. C.; Mikeš, P.; Miki, K.; Miller, T. E.; Milov, A.; Mioduszewski, S.; Mishra, G. C.; Mishra, M.; Mitchell, J. T.; Mitrovski, M.; Mohanty, A. K.; Moon, H. J.; Morino, Y.; Morreale, A.; Morrison, D. P.; Moss, J. M.; Moukhanova, T. V.; Mukhopadhyay, D.; Murakami, T.; Murata, J.; Nagamiya, S.; Nagata, Y.; Nagle, J. L.; Naglis, M.; Nagy, M. I.; Nakagawa, I.; Nakamiya, Y.; Nakamura, K. R.; Nakamura, T.; Nakano, K.; Nam, S.; Newby, J.; Nguyen, M.; Nihashi, M.; Norman, B. E.; Nouicer, R.; Nyanin, A. S.; Nystrand, J.; Oakley, C.; O'Brien, E.; Oda, S. X.; Ogilvie, C. A.; Ohnishi, H.; Ojha, I. D.; Oka, M.; Okada, K.; Omiwade, O. O.; Onuki, Y.; Oskarsson, A.; Otterlund, I.; Ouchida, M.; Ozawa, K.; Pak, R.; Pal, D.; Palounek, A. P. T.; Pantuev, V.; Papavassiliou, V.; Park, I. H.; Park, J.; Park, S. K.; Park, W. J.; Pate, S. F.; Pei, H.; Peng, J.-C.; Pereira, H.; Peresedov, V.; Peressounko, D. Yu.; Petti, R.; Pinkenburg, C.; Pisani, R. P.; Proissl, M.; Purschke, M. L.; Purwar, A. K.; Qu, H.; Rak, J.; Rakotozafindrabe, A.; Ravinovich, I.; Read, K. F.; Rembeczki, S.; Reuter, M.; Reygers, K.; Riabov, V.; Riabov, Y.; Richardson, E.; Roach, D.; Roche, G.; Rolnick, S. D.; Romana, A.; Rosati, M.; Rosen, C. A.; Rosendahl, S. S. E.; Rosnet, P.; Rukoyatkin, P.; Ružička, P.; Rykov, V. L.; Ryu, S. S.; Sahlmueller, B.; Saito, N.; Sakaguchi, T.; Sakai, S.; Sakashita, K.; Sakata, H.; Samsonov, V.; Sano, S.; Sato, H. D.; Sato, S.; Sato, T.; Sawada, S.; Sedgwick, K.; Seele, J.; Seidl, R.; Semenov, A. Yu.; Semenov, V.; Seto, R.; Sharma, D.; Shea, T. K.; Shein, I.; Shevel, A.; Shibata, T.-A.; Shigaki, K.; Shimomura, M.; Shohjoh, T.; Shoji, K.; Shukla, P.; Sickles, A.; Silva, C. L.; Silvermyr, D.; Silvestre, C.; Sim, K. S.; Singh, B. K.; Singh, C. P.; Singh, V.; Skutnik, S.; Slunečka, M.; Smith, W. C.; Soldatov, A.; Soltz, R. A.; Sondheim, W. E.; Sorensen, S. P.; Sourikova, I. V.; Sparks, N. A.; Staley, F.; Stankus, P. W.; Stenlund, E.; Stepanov, M.; Ster, A.; Stoll, S. P.; Sugitate, T.; Suire, C.; Sukhanov, A.; Sullivan, J. P.; Sziklai, J.; Tabaru, T.; Takagi, S.; Takagui, E. M.; Taketani, A.; Tanabe, R.; Tanaka, K. H.; Tanaka, Y.; Taneja, S.; Tanida, K.; Tannenbaum, M. J.; Tarafdar, S.; Taranenko, A.; Tarján, P.; Themann, H.; Thomas, D.; Thomas, T. L.; Togawa, M.; Toia, A.; Tojo, J.; Tomášek, L.; Torii, H.; Towell, R. S.; Tram, V.-N.; Tserruya, I.; Tsuchimoto, Y.; Tuli, S. K.; Tydesjö, H.; Tyurin, N.; Vale, C.; Valle, H.; van Hecke, H. W.; Vazquez-Zambrano, E.; Veicht, A.; Velkovska, J.; Vértesi, R.; Vinogradov, A. A.; Virius, M.; Vrba, V.; Vznuzdaev, E.; Wagner, M.; Walker, D.; Wang, X. R.; Watanabe, D.; Watanabe, K.; Watanabe, Y.; Wei, F.; Wei, R.; Wessels, J.; White, S. N.; Willis, N.; Winter, D.; Wood, J. P.; Woody, C. L.; Wright, R. M.; Wysocki, M.; Xie, W.; Yamaguchi, Y. L.; Yamaura, K.; Yang, R.; Yanovich, A.; Yasin, Z.; Ying, J.; Yokkaichi, S.; You, Z.; Young, G. R.; Younus, I.; Yushmanov, I. E.; Zajc, W. A.; Zaudtke, O.; Zhang, C.; Zhou, S.; Zimányi, J.; Zolin, L.

    2011-10-01

    The PHENIX experiment at the Relativistic Heavy Ion Collider has measured ω meson production via leptonic and hadronic decay channels in p+p, d+Au, Cu+Cu, and Au+Au collisions at sNN = 200 GeV. The invariant transverse momentum spectra measured in different decay modes give consistent results. Measurements in the hadronic decay channel in Cu+Cu and Au+Au collisions show that ω production has a suppression pattern at high transverse momentum, similar to that of π0 and η in central collisions, but no suppression is observed in peripheral collisions. The nuclear modification factors, RAA, are consistent in Cu+Cu and Au+Au collisions at similar numbers of participant nucleons.

  4. RHIC Au beam in Run 2014

    SciTech Connect

    Zhang, S. Y.

    2014-09-15

    Au beam at the RHIC ramp in run 2014 is reviewed together with the run 2011 and run 2012. Observed bunch length and longitudinal emittance are compared with the IBS simulations. The IBS growth rate of the longitudinal emittance in run 2014 is similar to run 2011, and both are larger than run 2012. This is explained by the large transverse emittance at high intensity observed in run 2012, but not in run 2014. The big improvement of the AGS ramping in run 2014 might be related to this change. The importance of the injector intensity improvement in run 2014more » is emphasized, which gives rise to the initial luminosity improvement of 50% in run 2014, compared with the previous Au-Au run 2011. In addition, a modified IBS model, which is calibrated using the RHIC Au runs from 9.8 GeV/n to 100 GeV/n, is presented and used in the study.« less

  5. 22 CFR 62.31 - Au pairs.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... pair participant with child development and child safety instruction, as follows: (1) Prior to... development instruction of which no less than 4 shall be devoted to specific training for children under the... and participate directly in the home life of the host family. All au pair participants provide child...

  6. 22 CFR 62.31 - Au pairs.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... at a weekly rate based upon 45 hours of child care services per week and paid in conformance with the... Labor. EduCare participants shall be compensated at a weekly rate that is 75% of the weekly rate paid to... contain the following information: (1) Au pair's name, SEVIS identification number, date of birth, the...

  7. 22 CFR 62.31 - Au pairs.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... at a weekly rate based upon 45 hours of child care services per week and paid in conformance with the... Labor. EduCare participants shall be compensated at a weekly rate that is 75% of the weekly rate paid to... contain the following information: (1) Au pair's name, SEVIS identification number, date of birth, the...

  8. 22 CFR 62.31 - Au pairs.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... at a weekly rate based upon 45 hours of child care services per week and paid in conformance with the... Labor. EduCare participants shall be compensated at a weekly rate that is 75% of the weekly rate paid to... contain the following information: (1) Au pair's name, SEVIS identification number, date of birth, the...

  9. 22 CFR 62.31 - Au pairs.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... at a weekly rate based upon 45 hours of child care services per week and paid in conformance with the... Labor. EduCare participants shall be compensated at a weekly rate that is 75% of the weekly rate paid to... contain the following information: (1) Au pair's name, SEVIS identification number, date of birth, the...

  10. Cancer du sein au Cameroun, profil histo-épidémiologique: à propos de 3044 cas

    PubMed Central

    Engbang, Jean Paul Ndamba; Essome, Henri; Koh, Valère Mve; Simo, Godefroy; Essam, Jean Daniel Sime; Mouelle, Albert Sone; Essame, Jean Louis Oyono

    2015-01-01

    Décrire les caractéristiques épidémiologiques et histo-pathologiques des tumeurs malignes du sein au Cameroun. Il s'agissait d'une étude rétrospective descriptive portant sur les tumeurs malignes du sein, colligées, dans les registres des différents laboratoires d'Anatomie Pathologique publiques et privés repartis dans cinq régions (centre, littoral, Ouest, Nord-ouest, Sud-ouest), pendant une période de 10 ans (2004-2013). Les paramètres étudiés étaient la fréquence, l’âge, le sexe, la localisation, le type et le grade histologique, et les récepteurs hormonaux. Un total de 3044 cas de cancers du sein a été recensé, soit une fréquence annuelle de 304,4 cas en moyenne. Le sexe féminin était le plus représenté avec 2971 cas (97,60%) et les hommes avec 73 cas (2,40%), soit un sexe ratio (H/F) de 0,02. L’âge moyen des patients était de 46±15,87 ans, avec des extrêmes de 13 et 95 ans. Selon la localisation, le sein gauche était atteint dans 1244 cas (52%) et le sein droit dans 1115 cas (47%). Au plan histologique, on retrouvait essentiellement des carcinomes avec 96,50% des cas, des sarcomes 1,39%, des lymphomes 1,07% et la maladie de Paget du mamelon, 1,03%. Les tumeurs épithéliales étaient infiltrantes dans 2049 cas (84,46%), avec une prédominance du carcinome canalaire infiltrant (1870 cas) et non infiltrantes dans 377 cas (15,54%). Le grade histo-pronostic de SBR avait révélé une prédominance du grade II dans 66% des cas. Les cancers du sein restent une pathologie fréquente au Cameroun et atteignent principalement la population féminine en âge de procréer. Ils sont caractérisés par la prédominance du carcinome canalaire infiltrant. PMID:26523182

  11. The effect of Au amount on size uniformity of self-assembled Au nanoparticles

    NASA Astrophysics Data System (ADS)

    Chen, S.-H.; Wang, D.-C.; Chen, G.-Y.; Chen, K.-Y.

    2008-03-01

    The self-assembled fabrication of nanostructure, a dreaming approach in the area of fabrication engineering, is the ultimate goal of this research. A finding was proved through previous research that the size of the self-assembled gold nanoparticles could be controlled with the mole ratio between AuCl4- and thiol. In this study, the moles of Au were fixed, only the moles of thiol were adjusted. Five different mole ratios of Au/S with their effect on size uniformity were investigated. The mole ratios were 1:1/16, 1:1/8, 1:1, 1:8, 1:16, respectively. The size distributions of the gold nanoparticles were analyzed by Mac-View analysis software. HR-TEM was used to derive images of self-assembled gold nanoparticles. The result reached was also the higher the mole ratio between AuCl4- and thiol the bigger the self-assembled gold nanoparticles. Under the condition of moles of Au fixed, the most homogeneous nanoparticles in size distribution derived with the mole ratio of 1:1/8 between AuCl4- and thiol. The obtained nanoparticles could be used, for example, in uniform surface nanofabrication, leading to the fabrication of ordered array of quantum dots.

  12. Sharp Transition from Nonmetallic Au246 to Metallic Au279 with Nascent Surface Plasmon Resonance.

    PubMed

    Higaki, Tatsuya; Zhou, Meng; Lambright, Kelly J; Kirschbaum, Kristin; Sfeir, Matthew Y; Jin, Rongchao

    2018-05-02

    The optical properties of metal nanoparticles have attracted wide interest. Recent progress in controlling nanoparticles with atomic precision (often called nanoclusters) provide new opportunities for investigating many fundamental questions, such as the transition from excitonic to plasmonic state, which is a central question in metal nanoparticle research because it provides insights into the origin of surface plasmon resonance (SPR) as well as the formation of metallic bond. However, this question still remains elusive because of the extreme difficulty in preparing atomically precise nanoparticles larger than 2 nm. Here we report the synthesis and optical properties of an atomically precise Au 279 (SR) 84 nanocluster. Femtosecond transient absorption spectroscopic analysis reveals that the Au 279 nanocluster shows a laser power dependence in its excited state lifetime, indicating metallic state of the particle, in contrast with the nonmetallic electronic structure of the Au 246 (SR) 80 nanocluster. Steady-state absorption spectra reveal that the nascent plasmon band of Au 279 at 506 nm shows no peak shift even down to 60 K, consistent with plasmon behavior. The sharp transition from nonmetallic Au 246 to metallic Au 279 is surprising and will stimulate future theoretical work on the transition and many other relevant issues.

  13. Experimental and Theoretical Studies on Oxidation of Cu-Au Alloy Surfaces: Effect of Bulk Au Concentration

    PubMed Central

    Okada, Michio; Tsuda, Yasutaka; Oka, Kohei; Kojima, Kazuki; Diño, Wilson Agerico; Yoshigoe, Akitaka; Kasai, Hideaki

    2016-01-01

    We report results of our experimental and theoretical studies on the oxidation of Cu-Au alloy surfaces, viz., Cu3Au(111), CuAu(111), and Au3Cu(111), using hyperthermal O2 molecular beam (HOMB). We observed strong Au segregation to the top layer of the corresponding clean (111) surfaces. This forms a protective layer that hinders further oxidation into the bulk. The higher the concentration of Au in the protective layer formed, the higher the protective efficacy. As a result, of the three Cu-Au surfaces studied, Au3Cu(111) is the most stable against dissociative adsorption of O2, even with HOMB. We also found that this protective property breaks down for oxidations occurring at temperatures above 300 K. PMID:27516137

  14. Experimental and Theoretical Studies on Oxidation of Cu-Au Alloy Surfaces: Effect of Bulk Au Concentration.

    PubMed

    Okada, Michio; Tsuda, Yasutaka; Oka, Kohei; Kojima, Kazuki; Diño, Wilson Agerico; Yoshigoe, Akitaka; Kasai, Hideaki

    2016-08-12

    We report results of our experimental and theoretical studies on the oxidation of Cu-Au alloy surfaces, viz., Cu3Au(111), CuAu(111), and Au3Cu(111), using hyperthermal O2 molecular beam (HOMB). We observed strong Au segregation to the top layer of the corresponding clean (111) surfaces. This forms a protective layer that hinders further oxidation into the bulk. The higher the concentration of Au in the protective layer formed, the higher the protective efficacy. As a result, of the three Cu-Au surfaces studied, Au3Cu(111) is the most stable against dissociative adsorption of O2, even with HOMB. We also found that this protective property breaks down for oxidations occurring at temperatures above 300 K.

  15. Jet-Hadron Correlations in √sNN =200 GeV p +p and Central Au +Au Collisions

    NASA Astrophysics Data System (ADS)

    Adamczyk, L.; Adkins, J. K.; Agakishiev, G.; Aggarwal, M. M.; Ahammed, Z.; Alekseev, I.; Alford, J.; Anson, C. D.; Aparin, A.; Arkhipkin, D.; Aschenauer, E. C.; Averichev, G. S.; Banerjee, A.; Beavis, D. R.; Bellwied, R.; Bhasin, A.; Bhati, A. K.; Bhattarai, P.; Bichsel, H.; Bielcik, J.; Bielcikova, J.; Bland, L. C.; Bordyuzhin, I. G.; Borowski, W.; Bouchet, J.; Brandin, A. V.; Brovko, S. G.; Bültmann, S.; Bunzarov, I.; Burton, T. P.; Butterworth, J.; Caines, H.; Calderón de la Barca Sánchez, M.; Cebra, D.; Cendejas, R.; Cervantes, M. C.; Chaloupka, P.; Chang, Z.; Chattopadhyay, S.; Chen, H. F.; Chen, J. H.; Chen, L.; Cheng, J.; Cherney, M.; Chikanian, A.; Christie, W.; Chwastowski, J.; Codrington, M. J. M.; Contin, G.; Cramer, J. G.; Crawford, H. J.; Cui, X.; Das, S.; Davila Leyva, A.; De Silva, L. C.; Debbe, R. R.; Dedovich, T. G.; Deng, J.; Derevschikov, A. A.; Derradi de Souza, R.; Dhamija, S.; di Ruzza, B.; Didenko, L.; Dilks, C.; Ding, F.; Djawotho, P.; Dong, X.; Drachenberg, J. L.; Draper, J. E.; Du, C. M.; Dunkelberger, L. E.; Dunlop, J. C.; Efimov, L. G.; Engelage, J.; Engle, K. S.; Eppley, G.; Eun, L.; Evdokimov, O.; Eyser, O.; Fatemi, R.; Fazio, S.; Fedorisin, J.; Filip, P.; Finch, E.; Fisyak, Y.; Flores, C. E.; Gagliardi, C. A.; Gangadharan, D. R.; Garand, D.; Geurts, F.; Gibson, A.; Girard, M.; Gliske, S.; Greiner, L.; Grosnick, D.; Gunarathne, D. S.; Guo, Y.; Gupta, A.; Gupta, S.; Guryn, W.; Haag, B.; Hamed, A.; Han, L.-X.; Haque, R.; Harris, J. W.; Heppelmann, S.; Hirsch, A.; Hoffmann, G. W.; Hofman, D. J.; Horvat, S.; Huang, B.; Huang, H. Z.; Huang, X.; Huck, P.; Humanic, T. J.; Igo, G.; Jacobs, W. W.; Jang, H.; Judd, E. G.; Kabana, S.; Kalinkin, D.; Kang, K.; Kauder, K.; Ke, H. W.; Keane, D.; Kechechyan, A.; Kesich, A.; Khan, Z. H.; Kikola, D. P.; Kisel, I.; Kisiel, A.; Koetke, D. D.; Kollegger, T.; Konzer, J.; Koralt, I.; Kotchenda, L.; Kraishan, A. F.; Kravtsov, P.; Krueger, K.; Kulakov, I.; Kumar, L.; Kycia, R. A.; Lamont, M. A. C.; Landgraf, J. M.; Landry, K. D.; Lauret, J.; Lebedev, A.; Lednicky, R.; Lee, J. H.; LeVine, M. J.; Li, C.; Li, W.; Li, X.; Li, X.; Li, Y.; Li, Z. M.; Lisa, M. A.; Liu, F.; Ljubicic, T.; Llope, W. J.; Lomnitz, M.; Longacre, R. S.; Luo, X.; Ma, G. L.; Ma, Y. G.; Madagodagettige Don, D. M. M. D.; Mahapatra, D. P.; Majka, R.; Margetis, S.; Markert, C.; Masui, H.; Matis, H. S.; McDonald, D.; McShane, T. S.; Minaev, N. G.; Mioduszewski, S.; Mohanty, B.; Mondal, M. M.; Morozov, D. A.; Mustafa, M. K.; Nandi, B. K.; Nasim, Md.; Nayak, T. K.; Nelson, J. M.; Nigmatkulov, G.; Nogach, L. V.; Noh, S. Y.; Novak, J.; Nurushev, S. B.; Odyniec, G.; Ogawa, A.; Oh, K.; Ohlson, A.; Okorokov, V.; Oldag, E. W.; Olvitt, D. L., Jr.; Pachr, M.; Page, B. S.; Pal, S. K.; Pan, Y. X.; Pandit, Y.; Panebratsev, Y.; Pawlak, T.; Pawlik, B.; Pei, H.; Perkins, C.; Peryt, W.; Pile, P.; Planinic, M.; Pluta, J.; Poljak, N.; Porter, J.; Poskanzer, A. M.; Pruthi, N. K.; Przybycien, M.; Pujahari, P. R.; Putschke, J.; Qiu, H.; Quintero, A.; Ramachandran, S.; Raniwala, R.; Raniwala, S.; Ray, R. L.; Riley, C. K.; Ritter, H. G.; Roberts, J. B.; Rogachevskiy, O. V.; Romero, J. L.; Ross, J. F.; Roy, A.; Ruan, L.; Rusnak, J.; Rusnakova, O.; Sahoo, N. R.; Sahu, P. K.; Sakrejda, I.; Salur, S.; Sandweiss, J.; Sangaline, E.; Sarkar, A.; Schambach, J.; Scharenberg, R. P.; Schmah, A. M.; Schmidke, W. B.; Schmitz, N.; Seger, J.; Seyboth, P.; Shah, N.; Shahaliev, E.; Shanmuganathan, P. V.; Shao, M.; Sharma, B.; Shen, W. Q.; Shi, S. S.; Shou, Q. Y.; Sichtermann, E. P.; Singaraju, R. N.; Skoby, M. J.; Smirnov, D.; Smirnov, N.; Solanki, D.; Sorensen, P.; Spinka, H. M.; Srivastava, B.; Stanislaus, T. D. S.; Stevens, J. R.; Stock, R.; Strikhanov, M.; Stringfellow, B.; Sumbera, M.; Sun, X.; Sun, X. M.; Sun, Y.; Sun, Z.; Surrow, B.; Svirida, D. N.; Symons, T. J. M.; Szelezniak, M. A.; Takahashi, J.; Tang, A. H.; Tang, Z.; Tarnowsky, T.; Thomas, J. H.; Timmins, A. R.; Tlusty, D.; Tokarev, M.; Trentalange, S.; Tribble, R. E.; Tribedy, P.; Trzeciak, B. A.; Tsai, O. D.; Turnau, J.; Ullrich, T.; Underwood, D. G.; Van Buren, G.; van Nieuwenhuizen, G.; Vandenbroucke, M.; Vanfossen, J. A.; Varma, R.; Vasconcelos, G. M. S.; Vasiliev, A. N.; Vertesi, R.; Videbæk, F.; Viyogi, Y. P.; Vokal, S.; Vossen, A.; Wada, M.; Wang, F.; Wang, G.; Wang, H.; Wang, J. S.; Wang, X. L.; Wang, Y.; Wang, Y.; Webb, G.; Webb, J. C.; Westfall, G. D.; Wieman, H.; Wissink, S. W.; Witt, R.; Wu, Y. F.; Xiao, Z.; Xie, W.; Xin, K.; Xu, H.; Xu, J.; Xu, N.; Xu, Q. H.; Xu, Y.; Xu, Z.; Yan, W.; Yang, C.; Yang, Y.; Yang, Y.; Ye, Z.; Yepes, P.; Yi, L.; Yip, K.; Yoo, I.-K.; Yu, N.; Zawisza, Y.; Zbroszczyk, H.; Zha, W.; Zhang, J. B.; Zhang, J. L.; Zhang, S.; Zhang, X. P.; Zhang, Y.; Zhang, Z. P.; Zhao, F.; Zhao, J.; Zhong, C.; Zhu, X.; Zhu, Y. H.; Zoulkarneeva, Y.; Zyzak, M.; STAR Collaboration

    2014-03-01

    Azimuthal angular correlations of charged hadrons with respect to the axis of a reconstructed (trigger) jet in Au +Au and p +p collisions at √sNN =200 GeV in STAR are presented. The trigger jet population in Au +Au collisions is biased toward jets that have not interacted with the medium, allowing easier matching of jet energies between Au +Au and p +p collisions while enhancing medium effects on the recoil jet. The associated hadron yield of the recoil jet is significantly suppressed at high transverse momentum (pTassoc) and enhanced at low pTassoc in 0%-20% central Au +Au collisions compared to p +p collisions, which is indicative of medium-induced parton energy loss in ultrarelativistic heavy-ion collisions.

  16. Bonding, Luminescence, Metallophilicity in Linear Au3 and Au2Ag Chains Stabilized by Rigid Diphosphanyl NHC Ligands.

    PubMed

    Ai, Pengfei; Mauro, Matteo; Gourlaouen, Christophe; Carrara, Serena; De Cola, Luisa; Tobon, Yeny; Giovanella, Umberto; Botta, Chiara; Danopoulos, Andreas A; Braunstein, Pierre

    2016-09-06

    The heterofunctional and rigid ligand N,N'-diphosphanyl-imidazol-2-ylidene (PCNHCP; P = P(t-Bu)2), through its phosphorus and two N-heterocyclic carbene (NHC) donors, stabilizes trinuclear chain complexes, with either Au3 or AgAu2 cores, and dinuclear Au2 complexes. The two oppositely situated PCNHCP (L) ligands that "sandwich" the metal chain can support linear and rigid structures, as found in the known tricationic Au(I) complex [Au3(μ3-PCNHCP,κP,κCNHC,κP)2](OTf)3 (OTf = CF3SO3; [Au3L2](OTf)3; Chem. Commun. 2014, 50, 103-105) now also obtained by transmetalation from [Ag3(μ3-PCNHCP,κP,κCNHC,κP)2](OTf)3 ([Ag3L2](OTf)3), or in the mixed-metal tricationic [Au2Ag(μ3-PCNHCP,κP,κCNHC,κP)2](OTf)3 ([Au2AgL2](OTf)3). The latter was obtained stepwise by the addition of AgOTf to the digold(I) complex [Au2(μ2-PCNHCP,κP,κCNHC)2](OTf)2 ([Au2L2](OTf)2). The latter contains two dangling P donors and displays fluxional behavior in solution, and the Au···Au separation of 2.8320(6) Å in the solid state is consistent with metallophilic interactions. In the solvento complex [Au3Cl2(tht)(μ3-PCNHCP,κP,κCNHC,κP)](OTf)·MeCN ([Au3Cl2(tht)L](OTf)·MeCN), which contains only one L and one tht ligand (tht = tetrahydrothiophene), the metal chain is bent (148.94(2)°), and the longer Au···Au separation (2.9710(4) Å) is in line with relaxation of the rigidity due to a more "open" structure. Similar features were observed in [Au3Cl2(SMe2)L](OTf)·2MeCN. A detailed study of the emission properties of [Au3L2](OTf)3, [Au3Cl2(tht)L](OTf)·MeCN, [Au2L2](OTf)2, and [Au2AgL2](OTf)3 was performed by means of steady state and time-resolved photophysical techniques. The complex [Au3L2](OTf)3 displays a bright (photoluminescence quantum yield = 80%) and narrow emission band centered at 446 nm with a relatively small Stokes' shift and long-lived excited-state lifetime on the microsecond timescale, both in solution and in the solid state. In line with the very narrow emission

  17. AU-FREDI - AUTONOMOUS FREQUENCY DOMAIN IDENTIFICATION

    NASA Technical Reports Server (NTRS)

    Yam, Y.

    1994-01-01

    The Autonomous Frequency Domain Identification program, AU-FREDI, is a system of methods, algorithms and software that was developed for the identification of structural dynamic parameters and system transfer function characterization for control of large space platforms and flexible spacecraft. It was validated in the CALTECH/Jet Propulsion Laboratory's Large Spacecraft Control Laboratory. Due to the unique characteristics of this laboratory environment, and the environment-specific nature of many of the software's routines, AU-FREDI should be considered to be a collection of routines which can be modified and reassembled to suit system identification and control experiments on large flexible structures. The AU-FREDI software was originally designed to command plant excitation and handle subsequent input/output data transfer, and to conduct system identification based on the I/O data. Key features of the AU-FREDI methodology are as follows: 1. AU-FREDI has on-line digital filter design to support on-orbit optimal input design and data composition. 2. Data composition of experimental data in overlapping frequency bands overcomes finite actuator power constraints. 3. Recursive least squares sine-dwell estimation accurately handles digitized sinusoids and low frequency modes. 4. The system also includes automated estimation of model order using a product moment matrix. 5. A sample-data transfer function parametrization supports digital control design. 6. Minimum variance estimation is assured with a curve fitting algorithm with iterative reweighting. 7. Robust root solvers accurately factorize high order polynomials to determine frequency and damping estimates. 8. Output error characterization of model additive uncertainty supports robustness analysis. The research objectives associated with AU-FREDI were particularly useful in focusing the identification methodology for realistic on-orbit testing conditions. Rather than estimating the entire structure, as is

  18. Influence of Au and TiO2 structures on hydrogen dissociation over TiO2/Au(100)

    NASA Astrophysics Data System (ADS)

    Nakamura, I.; Mantoku, H.; Furukawa, T.; Takahashi, A.; Fujitani, T.

    2012-11-01

    We performed H2-D2 exchange reactions over TiOx/Au(100) and compared the observed reaction kinetics with those reported for TiOx/Au(111) in order to clarify the influence of the Au and TiO2 structures on dissociation of H2 molecules. Low energy electron diffraction observations showed that the TiO2 produced on Au(100) was disordered, in contrast to the comparatively ordered TiO2 structure formed on Au(111). The activation energies and the turnover frequencies for HD formation over TiO2/Au(100) agreed well with those for TiO2/Au(111), clearly indicating that the hydrogen dissociation sites created over TiO2/Au(100) were the perimeter interface between stoichiometric TiO2 and Au, as was previously concluded for TiO2/Au(111). We concluded that the creation of active sites for hydrogen dissociation was independent of the Au and TiO2 structures consisting perimeter interface, and that local bonds that formed between Au and O atoms of stoichiometric TiO2 were essential for the creation of active sites.

  19. Di-hadron correlations with identified leading hadrons in 200 GeV Au + Au and d + Au collisions at STAR

    NASA Astrophysics Data System (ADS)

    Adamczyk, L.; Adkins, J. K.; Agakishiev, G.; Aggarwal, M. M.; Ahammed, Z.; Alekseev, I.; Aparin, A.; Arkhipkin, D.; Aschenauer, E. C.; Averichev, G. S.; Bai, X.; Bairathi, V.; Banerjee, A.; Bellwied, R.; Bhasin, A.; Bhati, A. K.; Bhattarai, P.; Bielcik, J.; Bielcikova, J.; Bland, L. C.; Bordyuzhin, I. G.; Bouchet, J.; Brandenburg, D.; Brandin, A. V.; Bunzarov, I.; Butterworth, J.; Caines, H.; Calderón de la Barca Sánchez, M.; Campbell, J. M.; Cebra, D.; Cervantes, M. C.; Chakaberia, I.; Chaloupka, P.; Chang, Z.; Chattopadhyay, S.; Chen, X.; Chen, J. H.; Cheng, J.; Cherney, M.; Christie, W.; Contin, G.; Crawford, H. J.; Das, S.; De Silva, L. C.; Debbe, R. R.; Dedovich, T. G.; Deng, J.; Derevschikov, A. A.; di Ruzza, B.; Didenko, L.; Dilks, C.; Dong, X.; Drachenberg, J. L.; Draper, J. E.; Du, C. M.; Dunkelberger, L. E.; Dunlop, J. C.; Efimov, L. G.; Engelage, J.; Eppley, G.; Esha, R.; Evdokimov, O.; Eyser, O.; Fatemi, R.; Fazio, S.; Federic, P.; Fedorisin, J.; Feng, Z.; Filip, P.; Fisyak, Y.; Flores, C. E.; Fulek, L.; Gagliardi, C. A.; Garand, D.; Geurts, F.; Gibson, A.; Girard, M.; Greiner, L.; Grosnick, D.; Gunarathne, D. S.; Guo, Y.; Gupta, S.; Gupta, A.; Guryn, W.; Hamad, A.; Hamed, A.; Haque, R.; Harris, J. W.; He, L.; Heppelmann, S.; Heppelmann, S.; Hirsch, A.; Hoffmann, G. W.; Hofman, D. J.; Horvat, S.; Huang, T.; Huang, B.; Huang, H. Z.; Huang, X.; Huck, P.; Humanic, T. J.; Igo, G.; Jacobs, W. W.; Jang, H.; Jia, J.; Jiang, K.; Judd, E. G.; Kabana, S.; Kalinkin, D.; Kang, K.; Kauder, K.; Ke, H. W.; Keane, D.; Kechechyan, A.; Khan, Z. H.; Kikoła, D. P.; Kisiel, A.; Kochenda, L.; Koetke, D. D.; Kosarzewski, L. K.; Kraishan, A. F.; Kravtsov, P.; Krueger, K.; Kumar, L.; Lamont, M. A. C.; Landgraf, J. M.; Landry, K. D.; Lauret, J.; Lebedev, A.; Lednicky, R.; Lee, J. H.; Li, X.; Li, W.; Li, Z. M.; Li, Y.; Li, C.; Li, X.; Lisa, M. A.; Liu, F.; Ljubicic, T.; Llope, W. J.; Lomnitz, M.; Longacre, R. S.; Luo, X.; Ma, G. L.; Ma, Y. G.; Ma, R.; Ma, L.; Magdy, N.; Majka, R.; Manion, A.; Margetis, S.; Markert, C.; Masui, H.; Matis, H. S.; McDonald, D.; Meehan, K.; Mei, J. C.; Minaev, N. G.; Mioduszewski, S.; Mishra, D.; Mohanty, B.; Mondal, M. M.; Morozov, D. A.; Mustafa, M. K.; Nandi, B. K.; Nasim, Md.; Nayak, T. K.; Nigmatkulov, G.; Niida, T.; Nogach, L. V.; Noh, S. Y.; Novak, J.; Nurushev, S. B.; Odyniec, G.; Ogawa, A.; Oh, K.; Okorokov, V.; Olvitt, D.; Page, B. S.; Pak, R.; Pan, Y. X.; Pandit, Y.; Panebratsev, Y.; Pawlik, B.; Pei, H.; Perkins, C.; Peterson, A.; Pile, P.; Pluta, J.; Poniatowska, K.; Porter, J.; Posik, M.; Poskanzer, A. M.; Pruthi, N. K.; Putschke, J.; Qiu, H.; Quintero, A.; Ramachandran, S.; Raniwala, R.; Raniwala, S.; Ray, R. L.; Ritter, H. G.; Roberts, J. B.; Rogachevskiy, O. V.; Romero, J. L.; Roy, A.; Ruan, L.; Rusnak, J.; Rusnakova, O.; Sahoo, N. R.; Sahu, P. K.; Sakrejda, I.; Salur, S.; Sandweiss, J.; Sarkar, A.; Schambach, J.; Scharenberg, R. P.; Schmah, A. M.; Schmidke, W. B.; Schmitz, N.; Seger, J.; Seyboth, P.; Shah, N.; Shahaliev, E.; Shanmuganathan, P. V.; Shao, M.; Sharma, B.; Sharma, M. K.; Shen, W. Q.; Shi, S. S.; Shou, Q. Y.; Sichtermann, E. P.; Sikora, R.; Simko, M.; Singha, S.; Skoby, M. J.; Smirnov, N.; Smirnov, D.; Song, L.; Sorensen, P.; Spinka, H. M.; Srivastava, B.; Stanislaus, T. D. S.; Stepanov, M.; Strikhanov, M.; Stringfellow, B.; Sumbera, M.; Summa, B.; Sun, Y.; Sun, Z.; Sun, X. M.; Sun, X.; Surrow, B.; Svirida, D. N.; Szelezniak, M. A.; Tang, A. H.; Tang, Z.; Tarnowsky, T.; Tawfik, A.; Thomas, J. H.; Timmins, A. R.; Tlusty, D.; Todoroki, T.; Tokarev, M.; Trentalange, S.; Tribble, R. E.; Tribedy, P.; Tripathy, S. K.; Tsai, O. D.; Ullrich, T.; Underwood, D. G.; Upsal, I.; Van Buren, G.; van Nieuwenhuizen, G.; Vandenbroucke, M.; Varma, R.; Vasiliev, A. N.; Vertesi, R.; Videbæk, F.; Viyogi, Y. P.; Vokal, S.; Voloshin, S. A.; Vossen, A.; Wang, J. S.; Wang, F.; Wang, H.; Wang, G.; Wang, Y.; Wang, Y.; Webb, G.; Webb, J. C.; Wen, L.; Westfall, G. D.; Wieman, H.; Wissink, S. W.; Witt, R.; Wu, Y. F.; Wu; Xiao, Z. G.; Xie, W.; Xin, K.; Xu, H.; Xu, Z.; Xu, Q. H.; Xu, Y. F.; Xu, N.; Yang, S.; Yang, Y.; Yang, Q.; Yang, Y.; Yang, C.; Yang, Y.; Ye, Z.; Ye, Z.; Yepes, P.; Yi, L.; Yip, K.; Yoo, I.-K.; Yu, N.; Zbroszczyk, H.; Zha, W.; Zhang, Y.; Zhang, Z.; Zhang, J. B.; Zhang, J.; Zhang, X. P.; Zhang, S.; Zhang, J.; Zhao, J.; Zhong, C.; Zhou, L.; Zhu, X.; Zoulkarneeva, Y.

    2015-12-01

    The STAR Collaboration presents for the first time two-dimensional di-hadron correlations with identified leading hadrons in 200 GeV central Au + Au and minimum-bias d + Au collisions to explore hadronization mechanisms in the quark gluon plasma. The enhancement of the jet-like yield for leading pions in Au + Au data with respect to the d + Au reference and the absence of such an enhancement for leading non-pions (protons and kaons) are discussed within the context of a quark recombination scenario. The correlated yield at large angles, specifically in the ridge region, is found to be significantly higher for leading non-pions than pions. The consistencies of the constituent quark scaling, azimuthal harmonic model and a mini-jet modification model description of the data are tested, providing further constraints on hadronization.

  20. Di-hadron correlations with identified leading hadrons in 200 GeV Au + Au and d + Au collisions at STAR

    SciTech Connect

    Adamczyk, L.; Adkins, J. K.; Agakishiev, G.

    2015-10-23

    The STAR Collaboration presents for the first time two-dimensional di-hadron correlations with identified leading hadrons in 200 GeV central Au + Au and minimum-bias d + Au collisions to explore hadronization mechanisms in the quark gluon plasma. The enhancement of the jet-like yield for leading pions in Au + Au data with respect to the d + Au reference and the absence of such an enhancement for leading non-pions (protons and kaons) are discussed within the context of a quark recombination scenario. The correlated yield at large angles, specifically in the ridge region, is found to be significantly higher formore » leading non-pions than pions. The consistencies of the constituent quark scaling, azimuthal harmonic model and a mini-jet modification model description of the data are tested, providing further constraints on hadronization.« less

  1. From the ternary Eu(Au/In) 2 and EuAu 4(Au/In) 2 with remarkable Au/In distributions to a new structure type: The gold-rich Eu 5Au 16(Au/In) 6 structure

    DOE PAGES

    Steinberg, Simon; Card, Nathan; Mudring, Anja -Verena

    2015-08-13

    The ternary Eu(Au/In) 2 (EuAu 0.46In 1.54 (2)) (I), EuAu 4(Au/In) 2 (EuAu 4+xIn 2–x with x = 0.75(2) (II), 0.93(2), and 1.03(2)), and Eu 5Au 16(Au/In) 6 (Eu 5Au 17.29In 4.71(3)) (III) have been synthesized, and their structures were characterized by single-crystal X-ray diffraction. I and II crystallize with the CeCu 2-type (Pearson Symbol oI12; Imma; Z = 4; a = 4.9018(4) Å; b = 7.8237(5) Å; c = 8.4457(5) Å) and the YbAl 4Mo 2-type (tI14; I4/ mmm; Z = 2; a = 7.1612(7) Å; c = 5.5268(7) Å) and exhibit significant Au/In disorder. I is composed ofmore » an Au/In-mixed diamond-related host lattice encapsulating Eu atoms, while the structure of II features ribbons of distorted, squared Au 8 prisms enclosing Eu, Au, and In atoms. Combination of these structural motifs leads to a new structure type as observed for Eu 5Au 16(Au/In) 6 (Eu 5Au 17.29In 4.71(3)) (oS108; Cmcm; Z = 4; a = 7.2283(4) Å; b = 9.0499(6) Å; c = 34.619(2) Å), which formally represents a one-dimensional intergrowth of the series EuAu 2–“EuAu 4In 2”. The site preferences of the disordered Au/In positions in II were investigated for different hypothetical “EuAu 4(Au/In) 2” models using the projector-augmented wave method and indicate that these structures attempt to optimize the frequencies of the heteroatomic Au–In contacts. Furthermore, a chemical bonding analysis on two “EuAu 5In” and “EuAu 4In 2” models employed the TB-LMTO-ASA method and reveals that the subtle interplay between the local atomic environments and the bond energies determines the structural and site preferences for these systems.« less

  2. Fe impurities weaken the ferromagnetic behavior in Au nanoparticles.

    PubMed

    Crespo, P; García, M A; Fernández Pinel, E; Multigner, M; Alcántara, D; de la Fuente, J M; Penadés, S; Hernando, A

    2006-10-27

    In this Letter, we report on a crucial experiment showing that magnetic impurities reduce the ferromagnetic order temperature in thiol-capped Au glyconanoparticles (GNPs). The spontaneous magnetization of AuFe GNPs exhibits a fast decrease with temperature that contrasts with the almost constant value of the magnetization observed in Au NPs. Moreover, hysteresis disappears below 300 K. Both features indicate that Fe impurities reduce the high local anisotropy field responsible for the ferromagnetic behavior in Au GNPs. As a consequence, the amazing ferromagnetism in Au NPs should not be associated with the presence of magnetic impurities.

  3. Positron annihilation study of cavities in black Au films

    NASA Astrophysics Data System (ADS)

    Melikhova, O.; Čížek, J.; Hruška, P.; Vlček, M.; Procházka, I.; Anwand, W.; Novotný, M.; Bulíř, J.

    2017-01-01

    Defects in a black Au film were studied using variable energy positron annihilation spectroscopy. Black Au films exhibit porous morphology similar to cauliflower. This type of structure enhances the optical absorption due to a multiple reflections in the micro-cavities. A nanostructured black Au film was compared with conventional smooth Au films with high reflectivity. The black Au film exhibited a remarkably enhanced S-parameter in sub-surface region. This is caused by a narrow para-Positronium contribution to the annihilation peak.

  4. (AuAg)144(SR)60 alloy nanomolecules

    NASA Astrophysics Data System (ADS)

    Kumara, Chanaka; Dass, Amala

    2011-08-01

    (Au-Ag)144(SR)60 alloy nanomolecules were synthesized and characterized by ESI mass spectrometry to atomic precision. The number of Ag atoms can be varied by changing the incoming metal ratio and plateaus at ~60. UV-vis data demonstrates that the electronic structure of the nanomolecules can be tuned by incorporation of silver atoms. Based on the proposed 3-shell structure of Au144(SR)60, we hypothesize that the Ag atoms are selectively incorporated in to the symmetry equivalent 60-atom shell--having Au12, Au42, Ag60 concentric shells with 30 -SR-Au-SR- protecting units.

  5. Aspects épidémiologiques, diagnostiques et thérapeutiques des ostéosarcomes de l'enfant au CHU Aristide le Dantec de Dakar: à propos de 16 cas

    PubMed Central

    Ndour, Oumar; Alumeti, Desire Munyali; Fall, Mbaye; Fall, Aimée Faye; Diouf, Cheikh; Ndoye, Ndeye Aby; Ngom, Gabriel; Ndoye, Mamadou

    2013-01-01

    Le but de cette étude était de décrire les aspects épidémiologiques, diagnostiques et thérapeutiques des ostéosarcomes de l'enfant. Il s'agissait d'une étude rétrospective sur dix ans qui a colligé 16 dossiers d'ostéosarcome pris en charge au service de Chirurgie Pédiatrique de l'hôpital Aristide Le Dantec de Dakar. Les paramètres étudiés étaient le niveau d'instruction et le niveau socioprofessionnel des parents, l'origine géographique, l’âge, le sexe, les antécédents particuliers, le délai de consultation, les motifs de consultation, les signes physiques, les signes radiologiques, la biologie, les modalités thérapeutiques et l’évolution. Tous les patients avaient bénéficié d'un examen anatomopathologique qui a confirmé le diagnostic d'ostéosarcome. Pour la majeure partie de nos patients (58% des cas) les parents avaient un niveau d'instruction bas. L’âge moyen était de 11ans. Une prédominance masculine était retrouvée avec un sex-ratio de 3,25:1. Le délai de consultation moyen était de 16 mois. Le principal motif de consultation était la tuméfaction (10 cas). Huit patients avaient bénéficié d'un traitement traditionnel. La taille de la tumeur était supérieure à 10cm dans 14 cas. La localisation la plus fréquente était le genou (14 cas). La radiographie standard retrouvait dans 15 cas des images d'ostéolyse. Le bilan d'extension n'avait pas retrouvé de métastases. Les options thérapeutiques étaient dominées par l'amputation seule (43,75% des cas). La survie à 2 ans était de 17%. L'ostéosarcome atteint le plus souvent le garçon après l’âge de 10 ans. Sa prise en charge au Sénégal se heurte à d’énormes difficultés liées au retard diagnostique. La solution repose essentiellement sur une collaboration pluridisciplinaire. PMID:23720705

  6. Les péricardites tuberculeuses au centre hospitalier universitaire de Bobo-Dioulasso, Burkina Faso

    PubMed Central

    Yaméogo, Aimé Arsène; Kyelem, Carole Gilberte; Nikiéma, Zakari; Birba, Emile; Yaméogo, Téné Marceline; Zabsonré, Patrice

    2012-01-01

    Introduction La tuberculose constitue toujours un problème de santé publique. Sa localisation péricardique reste fréquente. L’objectif de cette étude rétrospective descriptive était de décrire les caractéristiques cliniques et évolutives des cas de péricardites tuberculeuses dans le service de cardiologie du centre hospitalier universitaire de Bobo-Dioulasso. Méthodes Nous avons mené une étude rétrospective descriptive des cas de péricardite tuberculeuse colligés en deux ans à partir des dossiers et registres dans le service de cardiologie du CHU de Bobo-Dioulasso de janvier 2009 à décembre 2010. Résultats De janvier 2009 à décembre 2010, parmi 945 hospitalisations dans le service de cardiologie, une péricardite tuberculeuse a été diagnostiquée chez dix patients âgés de 18 à 82 ans. L’âge moyen était de 46,8±25 ans avec un sexe ratio de un. Soixante pour cent des patients avaient moins de 40 ans. Tous les patients avaient un niveau socio-économique bas. Une notion de contage tuberculeux a été retrouvée chez six patients. Trois patients présentaient une tuberculose pulmonaire à microscopie positive. L’insuffisance cardiaque était constante chez tous les patients avec deux cas de tamponnade à l’admission ayant nécessité une ponction péricardique d’urgence. Tous les patients avaient une sérologie VIH négative. L’échocardiographie a été importante pour le diagnostic positif et dans la prise en charge. L’évolution sous traitement antituberculeux et de l’IC a été bonne chez neuf patients à la fin de la première phase du traitement antituberculeux. Un cas de décès a cependant été enregistré chez un patient avec une HTA déjà compliquée d’accident vasculaire cérébrale ischémique. Conclusion Les péricardiques tuberculeuses sont fréquentes au Burkina Faso. Elles touchent surtout les sujets jeunes et un intérêt particulier devrait être accordé au dépistage et au traitement précoce des

  7. Nuclear modification factors of ϕ mesons in d+Au, Cu+Cu, and Au+Au collisions at sNN=200GeV

    NASA Astrophysics Data System (ADS)

    Adare, A.; Afanasiev, S.; Aidala, C.; Ajitanand, N. N.; Akiba, Y.; Al-Bataineh, H.; Alexander, J.; Al-Jamel, A.; Angerami, A.; Aoki, K.; Apadula, N.; Aphecetche, L.; Aramaki, Y.; Armendariz, R.; Aronson, S. H.; Asai, J.; Atomssa, E. T.; Averbeck, R.; Awes, T. C.; Azmoun, B.; Babintsev, V.; Bai, M.; Baksay, G.; Baksay, L.; Baldisseri, A.; Barish, K. N.; Barnes, P. D.; Bassalleck, B.; Basye, A. T.; Bathe, S.; Batsouli, S.; Baublis, V.; Bauer, F.; Baumann, C.; Bazilevsky, A.; Belikov, S.; Belmont, R.; Bennett, R.; Berdnikov, A.; Berdnikov, Y.; Bhom, J. H.; Bickley, A. A.; Bjorndal, M. T.; Blau, D. S.; Boissevain, J. G.; Bok, J. S.; Borel, H.; Borggren, N.; Boyle, K.; Brooks, M. L.; Brown, D. S.; Bucher, D.; Buesching, H.; Bumazhnov, V.; Bunce, G.; Burward-Hoy, J. M.; Butsyk, S.; Campbell, S.; Caringi, A.; Chai, J.-S.; Chang, B. S.; Charvet, J. L.; Chen, C. H.; Chernichenko, S.; Chiba, J.; Chi, C. Y.; Chiu, M.; Choi, I. J.; Choi, J. B.; Choudhury, R. K.; Christiansen, P.; Chujo, T.; Chung, P.; Churyn, A.; Chvala, O.; Cianciolo, V.; Citron, Z.; Cleven, C. R.; Cobigo, Y.; Cole, B. A.; Comets, M. P.; Conesa Del Valle, Z.; Connors, M.; Constantin, P.; Csanád, M.; Csörgő, T.; Dahms, T.; Dairaku, S.; Danchev, I.; Das, K.; Datta, A.; David, G.; Dayananda, M. K.; Deaton, M. B.; Dehmelt, K.; Delagrange, H.; Denisov, A.; D'Enterria, D.; Deshpande, A.; Desmond, E. J.; Dharmawardane, K. V.; Dietzsch, O.; Dion, A.; Donadelli, M.; D'Orazio, L.; Drachenberg, J. L.; Drapier, O.; Drees, A.; Drees, K. A.; Dubey, A. K.; Durham, J. M.; Durum, A.; Dutta, D.; Dzhordzhadze, V.; Edwards, S.; Efremenko, Y. V.; Egdemir, J.; Ellinghaus, F.; Emam, W. S.; Engelmore, T.; Enokizono, A.; En'Yo, H.; Espagnon, B.; Esumi, S.; Eyser, K. O.; Fadem, B.; Fields, D. E.; Finger, M., Jr.; Finger, M.; Fleuret, F.; Fokin, S. L.; Forestier, B.; Fraenkel, Z.; Frantz, J. E.; Franz, A.; Frawley, A. D.; Fujiwara, K.; Fukao, Y.; Fung, S. Y.; Fusayasu, T.; Gadrat, S.; Garishvili, I.; Gastineau, F.; Germain, M.; Glenn, A.; Gong, H.; Gonin, M.; Gosset, J.; Goto, Y.; Granier de Cassagnac, R.; Grau, N.; Greene, S. V.; Grim, G.; Grosse Perdekamp, M.; Gunji, T.; Gustafsson, H.-Å.; Hachiya, T.; Hadj Henni, A.; Haegemann, C.; Haggerty, J. S.; Hagiwara, M. N.; Hahn, K. I.; Hamagaki, H.; Hamblen, J.; Hanks, J.; Han, R.; Harada, H.; Hartouni, E. P.; Haruna, K.; Harvey, M.; Haslum, E.; Hasuko, K.; Hayano, R.; Heffner, M.; Hemmick, T. K.; Hester, T.; Heuser, J. M.; He, X.; Hiejima, H.; Hill, J. C.; Hobbs, R.; Hohlmann, M.; Holmes, M.; Holzmann, W.; Homma, K.; Hong, B.; Horaguchi, T.; Hornback, D.; Huang, S.; Hur, M. G.; Ichihara, T.; Ichimiya, R.; Iinuma, H.; Ikeda, Y.; Imai, K.; Inaba, M.; Inoue, Y.; Isenhower, D.; Isenhower, L.; Ishihara, M.; Isobe, T.; Issah, M.; Isupov, A.; Ivanischev, D.; Iwanaga, Y.; Jacak, B. V.; Jia, J.; Jiang, X.; Jin, J.; Jinnouchi, O.; Johnson, B. M.; Jones, T.; Joo, K. S.; Jouan, D.; Jumper, D. S.; Kajihara, F.; Kametani, S.; Kamihara, N.; Kamin, J.; Kaneta, M.; Kang, J. H.; Kanou, H.; Kapustinsky, J.; Karatsu, K.; Kasai, M.; Kawagishi, T.; Kawall, D.; Kawashima, M.; Kazantsev, A. V.; Kelly, S.; Kempel, T.; Khanzadeev, A.; Kijima, K. M.; Kikuchi, J.; Kim, A.; Kim, B. I.; Kim, D. H.; Kim, D. J.; Kim, E. J.; Kim, E.; Kim, Y.-J.; Kim, Y.-S.; Kinney, E.; Kiss, Á.; Kistenev, E.; Kiyomichi, A.; Klay, J.; Klein-Boesing, C.; Kochenda, L.; Kochetkov, V.; Komkov, B.; Konno, M.; Koster, J.; Kotchetkov, D.; Kotov, D.; Kozlov, A.; Král, A.; Kravitz, A.; Kroon, P. J.; Kubart, J.; Kunde, G. J.; Kurihara, N.; Kurita, K.; Kurosawa, M.; Kweon, M. J.; Kwon, Y.; Kyle, G. S.; Lacey, R.; Lai, Y. S.; Lajoie, J. G.; Lebedev, A.; Le Bornec, Y.; Leckey, S.; Lee, D. M.; Lee, J.; Lee, K. B.; Lee, K. S.; Lee, M. K.; Lee, T.; Leitch, M. J.; Leite, M. A. L.; Lenzi, B.; Lichtenwalner, P.; Liebing, P.; Lim, H.; Linden Levy, L. A.; Liška, T.; Litvinenko, A.; Liu, H.; Liu, M. X.; Li, X.; Li, X. H.; Love, B.; Lynch, D.; Maguire, C. F.; Makdisi, Y. I.; Malakhov, A.; Malik, M. D.; Manko, V. I.; Mannel, E.; Mao, Y.; Mašek, L.; Masui, H.; Matathias, F.; McCain, M. C.; McCumber, M.; McGaughey, P. L.; Means, N.; Meredith, B.; Miake, Y.; Mibe, T.; Mignerey, A. C.; Mikeš, P.; Miki, K.; Miller, T. E.; Milov, A.; Mioduszewski, S.; Mishra, G. C.; Mishra, M.; Mitchell, J. T.; Mitrovski, M.; Mohanty, A. K.; Moon, H. J.; Morino, Y.; Morreale, A.; Morrison, D. P.; Moss, J. M.; Moukhanova, T. V.; Mukhopadhyay, D.; Murakami, T.; Murata, J.; Nagamiya, S.; Nagata, Y.; Nagle, J. L.; Naglis, M.; Nagy, M. I.; Nakagawa, I.; Nakamiya, Y.; Nakamura, K. R.; Nakamura, T.; Nakano, K.; Nam, S.; Newby, J.; Nguyen, M.; Nihashi, M.; Norman, B. E.; Nouicer, R.; Nyanin, A. S.; Nystrand, J.; Oakley, C.; O'Brien, E.; Oda, S. X.; Ogilvie, C. A.; Ohnishi, H.; Ojha, I. D.; Okada, K.; Oka, M.; Omiwade, O. O.; Onuki, Y.; Oskarsson, A.; Otterlund, I.; Ouchida, M.; Ozawa, K.; Pak, R.; Pal, D.; Palounek, A. P. T.; Pantuev, V.; Papavassiliou, V.; Park, I. H.; Park, J.; Park, S. K.; Park, W. J.; Pate, S. F.; Pei, H.; Peng, J.-C.; Pereira, H.; Peresedov, V.; Peressounko, D. Yu.; Petti, R.; Pinkenburg, C.; Pisani, R. P.; Proissl, M.; Purschke, M. L.; Purwar, A. K.; Qu, H.; Rak, J.; Rakotozafindrabe, A.; Ravinovich, I.; Read, K. F.; Rembeczki, S.; Reuter, M.; Reygers, K.; Riabov, V.; Riabov, Y.; Richardson, E.; Roach, D.; Roche, G.; Rolnick, S. D.; Romana, A.; Rosati, M.; Rosen, C. A.; Rosendahl, S. S. E.; Rosnet, P.; Rukoyatkin, P.; Ružička, P.; Rykov, V. L.; Ryu, S. S.; Sahlmueller, B.; Saito, N.; Sakaguchi, T.; Sakai, S.; Sakashita, K.; Sakata, H.; Samsonov, V.; Sano, S.; Sato, H. D.; Sato, S.; Sato, T.; Sawada, S.; Sedgwick, K.; Seele, J.; Seidl, R.; Semenov, V.; Seto, R.; Sharma, D.; Shea, T. K.; Shein, I.; Shevel, A.; Shibata, T.-A.; Shigaki, K.; Shimomura, M.; Shohjoh, T.; Shoji, K.; Shukla, P.; Sickles, A.; Silva, C. L.; Silvermyr, D.; Silvestre, C.; Sim, K. S.; Singh, B. K.; Singh, C. P.; Singh, V.; Skutnik, S.; Slunečka, M.; Smith, W. C.; Soldatov, A.; Soltz, R. A.; Sondheim, W. E.; Sorensen, S. P.; Sourikova, I. V.; Staley, F.; Stankus, P. W.; Stenlund, E.; Stepanov, M.; Ster, A.; Stoll, S. P.; Sugitate, T.; Suire, C.; Sukhanov, A.; Sullivan, J. P.; Sziklai, J.; Tabaru, T.; Takagi, S.; Takagui, E. M.; Taketani, A.; Tanabe, R.; Tanaka, K. H.; Tanaka, Y.; Taneja, S.; Tanida, K.; Tannenbaum, M. J.; Tarafdar, S.; Taranenko, A.; Tarján, P.; Themann, H.; Thomas, D.; Thomas, T. L.; Togawa, M.; Toia, A.; Tojo, J.; Tomášek, L.; Torii, H.; Towell, R. S.; Tram, V.-N.; Tserruya, I.; Tsuchimoto, Y.; Tuli, S. K.; Tydesjö, H.; Tyurin, N.; Vale, C.; Valle, H.; van Hecke, H. W.; Vazquez-Zambrano, E.; Veicht, A.; Velkovska, J.; Vértesi, R.; Vinogradov, A. A.; Virius, M.; Vrba, V.; Vznuzdaev, E.; Wagner, M.; Walker, D.; Wang, X. R.; Watanabe, D.; Watanabe, K.; Watanabe, Y.; Wei, F.; Wessels, J.; White, S. N.; Willis, N.; Winter, D.; Woody, C. L.; Wright, R. M.; Wysocki, M.; Xie, W.; Yamaguchi, Y. L.; Yamaura, K.; Yang, R.; Yanovich, A.; Yasin, Z.; Ying, J.; Yokkaichi, S.; Young, G. R.; Younus, I.; You, Z.; Yushmanov, I. E.; Zajc, W. A.; Zaudtke, O.; Zhang, C.; Zhou, S.; Zimányi, J.; Zolin, L.

    2011-02-01

    The PHENIX experiment at the Relativistic Heavy Ion Collider has performed systematic measurements of ϕ meson production in the K+K- decay channel at midrapidity in p+p, d+Au, Cu+Cu, and Au+Au collisions at sNN=200GeV. Results are presented on the ϕ invariant yield and the nuclear modification factor RAA for Au+Au and Cu+Cu, and RdA for d+Au collisions, studied as a function of transverse momentum (1Au+Au collisions, the RAA of ϕ exhibits a suppression relative to expectations from binary scaled p+p results. The amount of suppression is smaller than that of the π0 and the η in the intermediate pT range (2-5GeV/c), whereas, at higher pT, the ϕ, π0, and η show similar suppression. The baryon (proton and antiproton) excess observed in central Au+Au collisions at intermediate pT is not observed for the ϕ meson despite the similar masses of the proton and the ϕ. This suggests that the excess is linked to the number of valence quarks in the hadron rather than its mass. The difference gradually disappears with decreasing centrality, and, for peripheral collisions, the RAA values for both particle species are consistent with binary scaling. Cu+Cu collisions show the same yield and suppression as Au+Au collisions for the same number of Npart. The RdA of ϕ shows no evidence for cold nuclear effects within uncertainties.

  8. [Hyp-Au-Sn9(Hyp)3-Au-Sn9(Hyp)3-Au-Hyp]-: the longest intermetalloid chain compound of tin.

    PubMed

    Binder, Mareike; Schrenk, Claudio; Block, Theresa; Pöttgen, Rainer; Schnepf, Andreas

    2017-10-12

    The reaction of the metalloid tin cluster [Sn 10 (Hyp) 4 ] 2- with (Ph 3 P)Au-SHyp (Hyp = Si(SiMe 3 ) 3 ) gave an intermetalloid cluster [Au 3 Sn 18 (Hyp) 8 ] - 1, which is the longest intermetalloid chain compound of tin to date. 1 shows a structural resemblance to binary AuSn phases, which is expected for intermetalloid clusters.

  9. Au Based Nanocomposites Towards Plasmonic Applications

    NASA Astrophysics Data System (ADS)

    Panniello, A.; Curri, M. L.; Placido, T.; Reboud, V.; Kehagias, N.; Sotomayor Torres, C. M.; Mecerreyes, D.; Agostiano, A.; Striccoli, M.

    2010-06-01

    Incorporation of nano-sized metals in polymers can transfer their unique features to the host matrix, providing nanocomposite materials with improved optical, electric, magnetic and mechanical properties. In this work, colloidal Au nanorods have been incorporated into PMMA based random co-polymer, properly functionalized with amino groups and the optical and morphological properties of the resulting nanocomposite have been investigated by spectroscopic and AFM measurements. Au nanorods have demonstrated to preserve the plasmon absorption and to retain morphological features upon the incorporation, thus making the final metal modified polymer composite exploitable for the fabrication of plasmonic devices. The prepared nanocomposites have been then patterned by Nano Imprint Lithography technique in order to demonstrate the viability of the materials towards optical applications.

  10. Collision-spike sputtering of Au nanoparticles

    SciTech Connect

    Sandoval, Luis; Urbassek, Herbert M.

    2015-08-06

    Ion irradiation of nanoparticles leads to enhanced sputter yields if the nanoparticle size is of the order of the ion penetration depth. While this feature is reasonably well understood for collision-cascade sputtering, we explore it in the regime of collision-spike sputtering using molecular-dynamics simulation. For the particular case of 200-keV Xe bombardment of Au particles, we show that collision spikes lead to abundant sputtering with an average yield of 397 ± 121 atoms compared to only 116 ± 48 atoms for a bulk Au target. Only around 31 % of the impact energy remains in the nanoparticles after impact; themore » remainder is transported away by the transmitted projectile and the ejecta. As a result, the sputter yield of supported nanoparticles is estimated to be around 80 % of that of free nanoparticles due to the suppression of forward sputtering.« less

  11. [Gold antirheumatic drug: desired and adverse effects of Au(I) and Au(III) [corrected] on the immune system.

    PubMed

    Griem, P; Gleichmann, E

    1996-01-01

    Three new findings are reviewed that help to understand the mechanisms of action of anti-rheumatic gold drugs, such as disodium aurothiomalate (Na2Au(I)TM): i) We found that Na2Au(I)TM selectively inhibits T-cell receptor-mediated antigen recognition by murine CD4+ T-cell hybridomas specific for antigenic peptides containing at least two cysteine residues. Presumably, Au(I) acts as a chelating agent forming linear complexes (Cys-Au(I)-Cys) which prevents correct antigen-processing and/or peptide recognition by the T-cell receptor, ii) We were able to show that Au(I) is oxidized to Au(III) in mononuclear phagocytes, such as macrophages. Because Au(III) rapidly oxidizes protein and itself is re-reduced to Au(I), this may introduce an Au(I)/Au(III) redox system into phagocytes which scavenges reactive oxygen species, such as hypochlorous acid (HOCl) and inactivates lysosomal enzymes, iii) Pretreatment with Au(III) of a model protein antigen, bovine ribonuclease A (RNase A), induced novel antigenic determinants recognized by CD4+ T lymphocytes. Analysis of the fine specificity of these "Au(III)-specific" T-cells revealed that they react to RNase peptides that are not presented to T-cells when the native protein, i.e., not treated with Au(III), is used as antigen. The T-cell recognition of these cryptic peptides did not require the presence of gold. This finding has important implications for understanding the pathogenesis of allergic and autoimmune responses induced by gold drugs. Taken together, our findings indicate that Au(I) and Au(III) each exert specific effects on several distinct functions of macrophages and the activation of T-cells. These effects may explain both the desired anti-inflammatory and the adverse effects of antirheumatic gold drugs.

  12. Interstellar Pickup Ion Observations to 38 au

    NASA Astrophysics Data System (ADS)

    McComas, D. J.; Zirnstein, E. J.; Bzowski, M.; Elliott, H. A.; Randol, B.; Schwadron, N. A.; Sokół, J. M.; Szalay, J. R.; Olkin, C.; Spencer, J.; Stern, A.; Weaver, H.

    2017-11-01

    We provide the first direct observations of interstellar H+ and He+ pickup ions in the solar wind from 22 to 38 au. We use the Vasyliunas and Siscoe model functional form to quantify the pickup ion distributions, and while the fit parameters generally lie outside their physically expected ranges, this form allows fits that quantify variations in the pickup H+ properties with distance. By ˜20 au, the pickup ions already provide the dominant internal pressure in the solar wind. We determine the radial trends and extrapolate them to the termination shock at ˜90 au, where the pickup H+ to core solar wind density reaches ˜0.14. The pickup H+ temperature and thermal pressure increase from 22 to 38 au, indicating additional heating of the pickup ions. This produces very large extrapolated ratios of pickup H+ to solar wind temperature and pressure, and an extrapolated ratio of the pickup ion pressure to the solar wind dynamic pressure at the termination shock of ˜0.16. Such a large ratio has profound implications for moderating the termination shock and the overall outer heliospheric interaction. We also identify suprathermal tails in the H+ spectra and complex features in the He+ spectra, likely indicating variations in the pickup ion history and processing. Finally, we discover enhancements in both H+ and He+ populations just below their cutoff energies, which may be associated with enhanced local pickup. This study serves to document the release and serves as a citable reference of these pickup ion data for broad community use and analysis.

  13. Synthesis of Pd-Au bimetallic nanocrystals via controlled overgrowth.

    PubMed

    Lim, Byungkwon; Kobayashi, Hirokazu; Yu, Taekyung; Wang, Jinguo; Kim, Moon J; Li, Zhi-Yuan; Rycenga, Matthew; Xia, Younan

    2010-03-03

    This paper describes the synthesis of Pd-Au bimetallic nanocrystals with controlled morphologies via a one-step seeded-growth method. Two different reducing agents, namely, L-ascorbic acid and citric acid, were utilized for the reduction of HAuCl(4) in an aqueous solution to control the overgrowth of Au on cubic Pd seeds. When L-ascorbic acid was used as the reducing agent, conformal overgrowth of Au on the Pd nanocubes led to the formation of Pd-Au nanocrystals with a core-shell structure. On the contrary, localized overgrowth of Au was observed when citric acid was used as the reducing agent, producing Pd-Au bimetallic dimers. Through this morphological control, we were able to tune the localized surface plasmon resonance peaks of Pd-Au bimetallic nanostructures in the visible region.

  14. Mammalian sensitivity to elemental gold (Au?)

    USGS Publications Warehouse

    Eisler, R.

    2004-01-01

    There is increasing documentation of allergic contact dermatitis and other effects from gold jewelry, gold dental restorations, and gold implants. These effects were especially pronounced among females wearing body-piercing gold objects. One estimate of the prevalence of gold allergy worldwide is 13%, as judged by patch tests with monovalent organogold salts. Eczema of the head and neck was the most common response of individuals hypersensitive to gold, and sensitivity can last for at least several years. Ingestion of beverages containing flake gold can result in allergic-type reactions similar to those seen in gold-allergic individuals exposed to gold through dermal contact and other routes. Studies with small laboratory mammals and injected doses of colloidal gold showed increased body temperatures, accumulations in reticular cells, and dose enhancement in tumor therapy; gold implants were associated with tissue injuries. It is proposed that Au? toxicity to mammals is associated, in part, with formation of the more reactive Au+ and Au3+ species.

  15. Functionalized Au@Ag-Au nanoparticles as an optical and SERS dual probe for lateral flow sensing.

    PubMed

    Bai, Tingting; Wang, Meng; Cao, Min; Zhang, Juan; Zhang, Kangzhen; Zhou, Ping; Liu, Zhengxia; Liu, Ying; Guo, Zhirui; Lu, Xiang

    2018-03-01

    Lateral flow assay strips (LFASs) with Au nanoparticles (NPs) have been widely used as a probe for biomarkers in point-of-care testing; however, there still remain challenges in detection sensitivity and quantitative analysis. In this study, we developed a surface-enhanced Raman scattering (SERS)-based LFAS for quantitative analysis of a biomarker in the low concentration range. Moreover, apart from conventional Au NPs, three other types of citrate-capped Au-Ag bimetallic NPs: Au core with Ag shell NPs (Au@Ag NPs), rattle-like Au core in Ag-Au shell NPs (Au@Ag-Au NPs) and Ag-Au NPs were prepared and functionalized, and their solution-based SERS activities were comprehensively studied by experimental measurement and theoretical analysis. The results clearly indicated that the citrate-capped Au@Ag-Au NPs exhibited the highest SERS activity among the probes tested. Au@Ag-Au NPs were used as both optical and SERS probes in a SERS-based LFAS. In the presence of the analyte at high concentrations, a purple color appeared in the test zone. Highly sensitive and quantitative analysis was realized by measurement of SERS signals from the test lines. One of the most specific markers for cardiac injury, cardiac troponin I (cTnI), was chosen as the detection model. The detection limit of the SERS-based LFAS for cardiac troponin I was 0.09 ng/mL, lowered by nearly 50 times compared with visual results, and could be further lowered by optimization. These results demonstrated that the SERS-based LFAS using citrate-capped Au@Ag-Au NPs as probes can be a powerful tool for highly sensitive and quantitative detection of biomarkers. Graphical abstract A surface-enhanced Raman scattering (SERS)-based lateral flow assay strip using rattle-like Au core in Ag-Au shell (Au@Ag-Au) nanoparticles as probes was developed for quantitative analysis of a biomarker, with a detection limit nearly 50 times lower than that of visual assessment. C control line, T test line.

  16. Electron beam induced evolution in Au, Ag, and interfaced heterogeneous Au/Ag nanoparticles

    SciTech Connect

    Liu, Yuzi; Sun, Yugang

    2015-01-01

    Sintering and sublimation process of nanoparticles made of Ag, Au, and interfaced Ag/Au heterodimers has been investigated by in-situ transmission electron microscopy at room temperature. Such process is driven by the illumination of high-energy electron beam accelerated at 200kV that promotes atom diffusion in the physically contacted nanoparticles. Upon electron illumination, adjacent Au nanoparticles gradually merge together to form a larger particle along with the reduction of surface area despite that orientated attachment is not observed. The nanoparticle fusion process is significantly different from the well-established thermal diffusion mechanism. In addition to the similar fusion process, Ag nanoparticles undergo apparentmore » sublimation because the transferred energy from electron beam to nanoparticles is higher than the surface binding energy of Ag atoms when the electron scattering angle is larger than 112°. The electron beam illumination can transform the interfaced Au/Ag dimers to Au@Ag core-shell particles followed by a slow sublimation of the Ag shells. Both diffusion and sublimation of Ag atoms are dependent on the intensity of electron beam, i.e., higher beam intensity is favorable to accelerate both process.« less

  17. Suppression of high transverse momentum π0 spectra in Au + Au collisions at RHIC

    NASA Astrophysics Data System (ADS)

    Kahana, D. E.; Kahana, S. H.

    2008-02-01

    Au + Au, s1/2 = 200 GeV measurements at RHIC, obtained with the PHENIX, STAR, PHOBOS and BRAHMS detectors, have all indicated a suppression of high p⊥ particle production, relative to an appropriately normalized NN level. For central collisions and vanishing pseudo-rapidity these experiments exhibit suppression in charged meson production, especially at medium-to-large transverse momenta. In the PHENIX experiment similar behaviour has been reported for π0 spectra. In a recent work [1] on the simpler D + Au interaction, to be considered perhaps as a tune-up for Au + Au, we reported on a pre-hadronic cascade mechanism which can explain the mixed observation of moderately reduced p⊥ suppression at higher pseudo-rapidity as well as the Cronin enhancement at mid-rapidity. Here, we present the extension of this work to the more massive ion-ion collisions. Our major thesis is that much of the suppression is generated in a late stage cascade of colourless pre-hadrons produced after an initial short-lived coloured phase. We present a pQCD argument to justify this approach and to estimate the time duration τp of this initial phase. Of essential importance is the brevity in time of the coloured phase existence relative to that of the strongly interacting pre-hadron phase, the latter essentially an interactive cascade. These distinctions in phase are of course not strict, but adequate for treating the suppression of moderate and high p⊥ mesons.

  18. Doppler transcranien au cours de la drépanocytose chez l'enfant Malagasy

    PubMed Central

    Herinirina, Nicolas Fanantenana; Rajaonarison, Lova Hasina Ny Ony Narindra; Herijoelison, Andry Roussel; Rakoto, Olivat Aimée Alson; Ahmad, Ahmad

    2016-01-01

    Introduction Le doppler transcrânien est un outil efficace permettant de dépister les enfants drépanocytaires à risque d'AVC. Méthodes Nous avons réalisé une étude descriptive transversale sur des enfants Malagasy âgés entre 24 mois et 15 ans (groupe 1: 57 drépanocytaires, groupe 2: 43 témoins) afin d’évaluer le profil vélocimétrique des artères cérébrales chez les drépanocytaires. Un examen Doppler transcrânien a été réalisé avec étude des flux sanguins cérébraux chez les enfants des deux groupes. Résultats Pour les sujets drépanocytaires, la vitesse moyenne (VM) de l'artère cérébrale moyenne était de 100,9 ± 26,8 cm/s, l'indice de pulsatilité (IP) de 0,73 ± 0,20, la différence entre les artères cérébrales moyennes droite et gauche (ACMr) de 19,8 ± 21,5 cm/s, le rapport des vitesses de l'artère cérébrale antérieure/artère cérébrale moyenne (ACA/ACM) de 0,7 ± 0,2. Pour les enfants non drépanocytaires, VM: 80,6 ± 19,3 cm/s, IP: 0,79 ± 0,14, ACMr: 17 ± 20,1 cm/s, ACA/ACM: 0,8 ± 0,2. La vélocité des enfants drépanocytaires était supérieure au groupe contrôle. Les vitesses ont été corrélées avec le taux d'hémoglobine et l’âge et non pas avec le sexe et le volume globulaire moyen. Conclusion Les vitesses circulatoires cérébrales sont élevées chez les drépanocytaires que les enfants non drépanocytaires et sont influencées par le taux d'hémoglobine et l’âge. PMID:27516829

  19. L'asthme allergique au centre tunisien

    PubMed Central

    Joobeur, Samah; Mhamed, Saousen Cheikh; Saad, Ahmed Ben; Mribah, Hathami; Dekhil, Asma; Rouatbi, Naceur; El Kamel, Ali

    2015-01-01

    L'asthme allergique pose un réel problème de santé publique vu sa prévalence et son coût de prise en charge élevés. Etudier le profil clinique, fonctionnel respiratoire, allergologique, thérapeutique et évolutif de l'asthme allergique dans une région du centre tunisien. Etude rétrospective portant sur 1132 dossiers de patients porteurs d'asthme allergique suivis dans le service de pneumologie et d'allergologie à l'hôpital de Monastir (Tunisie). L’âge moyen est de 27 ± 12,5 ans. 61,1% des patients sont âgés entre 16 et 39 ans. Une prédominance féminine est notée (56,7%). L'identification de l'allergène en cause s'est basée essentiellement sur les tests cutanés allergologiques (99,4%). Les principaux pneumallergènes identifiés sont les acariens (91,2%), suivis par les pollens (22,8%) et les phanères des animaux (12%). La classification selon la sévérité a conclu à un asthme intermittent à persistant léger chez 87.1% de nos patients. Le traitement s'est basé essentiellement sur la corticothérapie inhalée (67,6%). L'asthme dans notre étude a été jugé contrôlé dans 68,3% des cas, partiellement contrôlé dans 24,8% et non contrôlé dans 6,9% des cas. L'asthme allergique est une affection répandue qui touche essentiellement le sujet jeune en pleine activité. Une prise en charge adéquate permet de contrôler la maladie et de réduire ses répercussions sur le patient et la collectivité. PMID:26097637

  20. Au99(SPh)42 nanomolecules: aromatic thiolate ligand induced conversion of Au144(SCH2CH2Ph)60.

    PubMed

    Nimmala, Praneeth Reddy; Dass, Amala

    2014-12-10

    A new aromatic thiolate protected gold nanomolecule Au99(SPh)42 has been synthesized by reacting the highly stable Au144(SCH2CH2Ph)60 with thiophenol, HSPh. The ubiquitous Au144(SR)60 is known for its high stability even at elevated temperature and in the presence of excess thiol. This report demonstrates for the first time the reactivity of the Au144(SCH2CH2Ph)60 with thiophenol to form a different 99-Au atom species. The resulting Au99(SPh)42 compound, however, is unreactive and highly stable in the presence of excess aromatic thiol. The molecular formula of the title compound is determined by high resolution electrospray mass spectrometry (ESI-MS) and confirmed by the preparation of the 99-atom nanomolecule using two ligands, namely, Au99(SPh)42 and Au99(SPh-OMe)42. This mass spectrometry study is an unprecedented advance in nanoparticle reaction monitoring, in studying the 144-atom to 99-atom size evolution at such high m/z (∼12k) and resolution. The optical and electrochemical properties of Au99(SPh)42 are reported. Other substituents on the phenyl group, HS-Ph-X, where X = -F, -CH3, -OCH3, also show the Au144 to Au99 core size conversion, suggesting minimal electronic effects for these substituents. Control experiments were conducted by reacting Au144(SCH2CH2Ph)60 with HS-(CH2)n-Ph (where n = 1 and 2), bulky ligands like adamantanethiol and cyclohexanethiol. It was observed that conversion of Au144 to Au99 occurs only when the phenyl group is directly attached to the thiol, suggesting that the formation of a 99-atom species is largely influenced by aromaticity of the ligand and less so on the bulkiness of the ligand.

  1. Facteurs de risque de l'infection par le VIH dans le district de santé de Meyomessala au Cameroun

    PubMed Central

    Mbopi-Keou, Francois-Xavier; Nguefack-Tsague, Georges; Kalla, Ginette Claude Mireille; Abessolo, Stéphanie Abo'o; Angwafo, Fru; Muna, Walinjom

    2014-01-01

    Introduction L'objectif de ce travail était de déterminer les facteurs de risque de l'infection par le VIH dans le district de santé de Meyomessala (Région du Sud) au Cameroun. Méthodes Il s'agissait d'une étude transversale, descriptive et analytique qui s'est déroulée de Février à Mai 2011. Pour cette étude, nous avons obtenu une clairance éthique. Résultats L’échantillon était constitué de 315 participants dont 181 (57,46%) hommes et 134 (42,54%) femmes. L’âge moyen était de 24,5±8ans (extrême: 15-45ans). Quarante personnes (40) étaient séropositifs, soit une prévalence de l'infection par le VIH de 12,7%. Cette prévalence augmentait significativement (p = 0) avec le nombre de partenaires occasionnels au cours des douze derniers mois, allant de 2,7% chez ceux n'ayant eu aucun partenaire occasionnel à 21,25% chez ceux ayant plus de trois partenaires occasionnels (RC = 9,72; IC = 1,27-74,14; P = 0,03). le fait d’être âgé entre 20 et 24 ans (RC = 4,88; IC = 1,74-13,67; p = 0), avoir plus de trois partenaires sexuels au cours des douze derniers mois (RC = 9,72; IC = 1,27-74,14; p = 0,03), avoir les rapports sexuels avec les prostitués (RC = 2,86; IC = 1,42-5,76; p = 0), avoir eu le chlamydia (RC = 3,00; IC = 1,07-8,39; p = 0,04), avoir eu la syphilis (RC = 3,35; IC = 1,57-7,14; p = 0), avoir des avantages sociaux lors du premier rapport sexuel (RC = 2,57; IC = 1,03-6,43; p = 0,04) constituaient des potentiels facteurs de risque du VIH. Conclusion Il apparait urgent d'intensifier les campagnes de sensibilisation au risque d'infection par le VIH et les maladies sexuellement transmissibles dans le district de santé de Meyomessala PMID:25419299

  2. Cancer du sein bilatéral synchrone au Maroc: caractéristiques épidémiologiques et cliniques

    PubMed Central

    Boufettal, Houssine; Samouh, Naïma

    2015-01-01

    Préciser la fréquence, les facteurs de risque et le pronostic du cancer du sein bilatéral, à partir d'une étude rétrospective de 22 cas de cancer du sein bilatéral synchrone dans un pays du Maghreb. De 2002 à 2010, 625 patientes étaient prises en charge pour cancer du sein au service de Gynécologie-Obstétrique «C» du centre hospitalier universitaire de Casablanca. 22 cas de cancer bilatéral synchrone étaient diagnostiqués. Nos résultats sont comparés avec ceux de la littérature. La fréquence de la bilatéralité du cancer du sein synchrone était de 3,52% (22/625). L'intervalle de temps moyen entre les deux cancers est de 4 mois (0 à 6 mois). Les patientes âgées de moins de 40 ans lors du premier cancer avaient six fois plus de risque de développer un cancer au niveau du sein controlatéral que les femmes âgées de plus de 40 ans. Les patientes atteintes d'une tumeur T3 ou T4 avaient un risque neuf fois plus élevé que les autres. 90,9% (2/22) des cas des premiers cancers sont des adénocarcinomes infiltrants. Les types histologiques du premier et du douzième cancer étaient identiques dans 86,4% (19/22) des cas. Quant au pronostic, il dépend à la fois du stade du premier et du deuxième cancer et le traitement de ce dernier doit obéir aux mêmes règles du traitement du premier cancer. L'incidence du cancer bilatéral synchrone du sein est de 3,52% dans notre série. Le cancer du sein unilatéral constitue un facteur de risque de développement d'un cancer du sein controlatéral. Une surveillance à vie est nécessaire au cours d'un cancer du sein pour détecter un cancer controlatéral. PMID:26090066

  3. Steering epitaxial alignment of Au, Pd, and AuPd nanowire arrays by atom flux change.

    PubMed

    Yoo, Youngdong; Seo, Kwanyong; Han, Sol; Varadwaj, Kumar S K; Kim, Hyun You; Ryu, Ji Hoon; Lee, Hyuck Mo; Ahn, Jae Pyoung; Ihee, Hyotcherl; Kim, Bongsoo

    2010-02-10

    We have synthesized epitaxial Au, Pd, and AuPd nanowire arrays in vertical or horizontal alignment on a c-cut sapphire substrate. We show that the vertical and horizontal nanowire arrays grow from half-octahedral seeds by the correlations of the geometry and orientation of seed crystals with those of as-grown nanowires. The alignment of nanowires can be steered by changing the atom flux. At low atom deposition flux vertical nanowires grow, while at high atom flux horizontal nanowires grow. Similar vertical/horizontal epitaxial growth is also demonstrated on SrTiO(3) substrates. This orientation-steering mechanism is visualized by molecular dynamics simulations.

  4. Relativistic multireference many-body perturbation theory calculations on Au64+ - Au69+ ions

    SciTech Connect

    Vilkas, M J; Ishikawa, Y; Trabert, E

    2006-03-31

    Many-body perturbation theory (MBPT) calculations are an adequate tool for the description of the structure of highly charged multi-electron ions and for the analysis of their spectra. They demonstrate this by way of a re-investigation of n=3, {Delta}n=0 transitions in the EUV spectra of Na-, Mg-, Al-like, and Si-like ions of Au that have been obtained previously by heavy-ion accelerator based beam-foil spectroscopy. They discuss the evidence and propose several revisions on the basis of the multi-reference many-body perturbation theory calculations of Ne- through P-like ions of Au.

  5. Au-Rh and Au-Pd nanocatalysts supported on rutile titania nanorods: structure and chemical stability.

    PubMed

    Konuspayeva, Zere; Afanasiev, Pavel; Nguyen, Thanh-Son; Di Felice, Luca; Morfin, Franck; Nguyen, Nhat-Tai; Nelayah, Jaysen; Ricolleau, Christian; Li, Z Y; Yuan, Jun; Berhault, Gilles; Piccolo, Laurent

    2015-11-14

    Au, Rh, Pd, Au-Rh and Au-Pd nanoparticles (NPs) were synthesized by colloidal chemical reduction and immobilized on hydrothermally-prepared rutile titania nanorods. The catalysts were characterized by aberration-corrected TEM/STEM, XPS, and FTIR, and were evaluated in the hydrogenation of tetralin in the presence of H2S. Oxidizing and reducing thermal treatments were employed to remove the polyvinyl alcohol (PVA) surfactant. Reduction in H2 at 350 °C was found efficient for removing the PVA while preserving the size (ca. 3 nm), shape and bimetallic nature of the NPs. While Au-Pd NPs are alloyed at the atomic scale, Au-Rh NPs contain randomly distributed single-phase domains. Calcination-reduction of Au-Rh NPs mostly leads to separated Au and Rh NPs, while pre-reduction generates a well-defined segregated structure with Rh located at the interface between Au and TiO2 and possibly present around the NPs as a thin overlayer. Both the titania support and gold increase the resistance of Rh and Pd to oxidation. Furthermore, although detrimental to tetralin hydrogenation initial activity, gold stabilizes the NPs against surface sulfidation in the presence of 50 ppm H2S, leading to increased catalytic performances of the Au-Rh and Au-Pd systems as compared to their Rh and Pd counterparts.

  6. Atomic and molecular adsorption on Au(111)

    DOE PAGES

    Santiago-Rodriguez, Yohaselly; Herron, Jeffrey A.; Curet-Arana, Maria C.; ...

    2014-05-02

    Periodic self-consistent density functional theory (DFT-GGA) calculations were used to study the adsorption of several atomic species, molecular species and molecular fragments on the Au(111) surface with a coverage of 1/4 monolayer (ML). Binding geometries, binding energies, and diffusion barriers were calculated for 27 species. Furthermore, we calculated the surface deformation energy associated with the binding events. The binding strength for all the analyzed species can be ordered as follows: NH 3 < NO < CO < CH 3 < HCO < NH 2 < COOH < OH < HCOO < CNH 2 < H < N < NH Au(111); the desorption of NH 3, NO and CO are more favorable than their decomposition; the oxidation of CO and hydrogenation of CO and NO on Au(111) to form HCO and HNO, respectively, are also thermodynamically favorable.« less

  7. Aspects épidemiocliniques et évolutifs chez 157 cas de leishmaniose cutanée au Maroc

    PubMed Central

    Hjira, Naoufal; Frikh, Rachid; Marcil, Tarik; Lamsyah, Hanane; Oumakhir, Siham; Baba, Noureddine; Boui, Mohammed

    2014-01-01

    Connue au Maroc depuis la fin du XIX siècle, la leishmaniose cutanée (LC) constitue un problème de santé publique dans notre pays. Le but de notre travail est de décrire le profil épidémioclinique et l’évolution post thérapeutique chez les patients ayant une leishmaniose cutanée dans notre contexte. Nous avons effectué une étude rétrospective, basée sur l'exploitation des dossiers de malades ayant présenté une leishmaniose cutanée confirmée entre janvier 2003 et décembre 2012. Nous avons colligés 157 cas de leishmaniose cutanée. L’âge moyen des patients était de 34.5 ans avec des extrêmes de 6 ans à 63 ans. Le sex-ratio était de 2.34 H/F. La durée d’évolution moyenne des lésions était de 3,6 mois avec des extrêmes de 2 semaines à 10 mois. Les lésions étaient uniques dans 29.5% des cas. Les lésions siégeaient sur membres dans 63%. La forme ulcèro- croûteuse touchait plus de 48%. Le Glucantime était utilisé dans 29.3% des cas, l'azote liquide était utilisé chez 111 autres. L’évolution post-thérapeutique était favorable avec disparition quasi-complète des lésions dans un délai variant de 6 à 10 semaines, au prix de cicatrices inesthétiques chez 14 patients. La leishmaniose cutanée continue à poser un vrai problème de santé publique dans notre pays. L’émergence de formes sévères et résistantes à travers le monde doit inciter à multiplier et renforcer les mesures prophylactiques. PMID:25309671

  8. Aspects descriptifs du VIH/SIDA chez les sujets âgés de 50 ans et plus suivis au Centre de Traitement Agréé de Bafoussam - Cameroun

    PubMed Central

    Mbopi-Kéou, François-Xavier; Djomassi, Lucienne Dempouo; Monebenimp, Francisca

    2012-01-01

    Introduction La littérature scientifique dispose de très peu de données relatives à l’épidémiologie du VIH chez les sujets âgés en Afrique subsaharienne. Au Cameroun, les caractéristiques épidémiologiques de l'infection par le VIH chez les sujets âgés de 50 ans et plus ne sont pas documentées. Méthodes Dans une étude de cohorte rétrospective et une enquête transversale, nous avons comparé les caractéristiques clinico-biologiques et la survie post thérapeutique des patients âgés de 50 ans et plus, sous traitement antirétroviral au Centre de Traitement Agrée de Bafoussam - Cameroun, aux adultes plus jeunes. Résultats L’âge moyen était de 39 ans, les extrêmes étant 17 et 88 ans. Les sujets âgés de 50 ans et plus représentaient 14,1% des cas. Les plus âgés étaient moins bien informés sur les modes de transmission du virus (p = 0,04). Leur séropositivité au VIH était le plus souvent découverte au décours d'une infection opportuniste (p = 0,02). La fréquence de comorbidité était significativement plus élevée chez les personnes âgées de 50 ans et plus (p < 10-5). Nous n'avons pas retrouvé une association statistiquement significative entre l'observance thérapeutique et l’âge (p = 0,83). La survie post-thérapeutique n’était pas significativement liée à l’âge (p = 0,81). Conclusion Les sujets âgés ne sont pas à l'abri du VIH. La promotion du dépistage et les programmes d’éducation sanitaire relatifs au VIH/SIDA devraient être renforcés au sein de cette communauté déjà affaiblie par le poids de l’âge, afin de réduire l'incidence du SIDA et de leur assurer prise en charge précoce. PMID:23133707

  9. Conductive Au nanowires regulated by silk fibroin nanofibers

    NASA Astrophysics Data System (ADS)

    Dong, Bo-Ju; Lu, Qiang

    2014-03-01

    Conductive Au-biopolymer composites have promising applications in tissue engineering such as nerve tissue regeneration. In this study, silk fibroin nanofibers were formed in aqueous solution by regulating silk self-assembly process and then used as template for Au nanowire fabrication. We performed the synthesis of Au seeds by repeating the seeding cycles for several times in order to increase the density of Au seeds on the nanofibers. After electroless plating, densely decorated Au seeds grew into irregularly shaped particles following silk nanofiber to fill the gaps between particles and finally form uniform continuous nanowires. The conductive property of the Au-silk fibroin nanowires was studied with current-voltage ( I-V) measurement. A typical ohmic behavior was observed, which highlighted their potential applications in nerve tissue regeneration.

  10. Forming Super-Puffs Beyond 1 AU

    NASA Astrophysics Data System (ADS)

    Lee, Eve J.; Chiang, Eugene

    2017-06-01

    Super-puffs are an uncommon class of short-period planets seemingly too voluminous for their small masses (4-10 Rearth, 2-6 Mearth). Super-puffs most easily acquire their thick atmospheres as dust-free, rapidly cooling worlds outside ˜1AU where nebular gas is colder, less dense, and therefore less opaque. These puffy planets probably migrated in to their current orbits; they are expected to form the outer links of mean-motion resonant chains, and to exhibit atmospheric characteristics consistent with formation at large distances. I will also discuss, in general, how densities of planets can be used to infer their formation locations.

  11. Reconfigurable c-Si/Au hybrid nanoantenna

    NASA Astrophysics Data System (ADS)

    Chebykin, A. V.; Zalogina, A. S.; Zuev, D. A.; Makarov, S. V.

    2017-09-01

    We have performed numerical optimization of hybrid c-Si/Au nanoantenna's geometry to improve efficiency of NV-centers radiation. We have shown that Purcell factor at the wavelength 635 nm can be as much as 4550 for point light emitter placed in the gap between gold spherical nanoparticle and truncated silicon nanocone. We have demonstrated that electric field enhancement can reach a value of 12.9 at the wavelength of NV-center pumping, 532 nm. Our results can be useful for the development of more efficient sources of single photons based on NV-centers in nanodiamonds.

  12. Photosynthetic electron transport system promotes synthesis of Au-nanoparticles.

    PubMed

    Shabnam, Nisha; Pardha-Saradhi, P

    2013-01-01

    In this communication, a novel, green, efficient and economically viable light mediated protocol for generation of Au-nanoparticles using most vital organelle, chloroplasts, of the plant system is portrayed. Thylakoids/chloroplasts isolated from Potamogeton nodosus (an aquatic plant) and Spinacia oleracea (a terrestrial plant) turned Au³⁺ solutions purple in presence of light of 600 µmol m⁻² s⁻¹ photon flux density (PFD) and the purple coloration intensified with time. UV-Vis spectra of these purple colored solutions showed absorption peak at ∼545 nm which is known to arise due to surface plasmon oscillations specific to Au-nanoparticles. However, thylakoids/chloroplasts did not alter color of Au³⁺ solutions in dark. These results clearly demonstrated that photosynthetic electron transport can reduce Au³⁺ to Au⁰ which nucleate to form Au-nanoparticles in presence of light. Transmission electron microscopic studies revealed that Au-nanoparticles generated by light driven photosynthetic electron transport system of thylakoids/chloroplasts were in range of 5-20 nm. Selected area electron diffraction and powder X-ray diffraction indicated crystalline nature of these nanoparticles. Energy dispersive X-ray confirmed that these nanoparticles were composed of Au. To confirm the potential of light driven photosynthetic electron transport in generation of Au-nanoparticles, thylakoids/chloroplasts were tested for their efficacy to generate Au-nanoparticles in presence of light of PFD ranging from 60 to 600 µmol m⁻² s⁻¹. The capacity of thylakoids/chloroplasts to generate Au-nanoparticles increased remarkably with increase in PFD, which further clearly demonstrated potential of light driven photosynthetic electron transport in reduction of Au³⁺ to Au⁰ to form nanoparticles. The light driven donation of electrons to metal ions by thylakoids/chloroplasts can be exploited for large scale production of nanoparticles.

  13. Nucleon shadowing effects in Cu + Cu and Au + Au collisions at RHIC within the HIJING code

    NASA Astrophysics Data System (ADS)

    Abdel-Waged, Khaled; Felemban, Nuha

    2018-02-01

    The centrality dependence of pseudorapidity density of charged particles ({{{d}}{N}}{{ch}}/{{d}}η ) in Cu + Cu (Au + Au) collisions at Relativistic Heavy Ion Collider energy of \\sqrt{{s}{{NN}}}=22.4, 62.4 and 200 (19.6, 62.4 and 200) GeV, is investigated within an improved HIJING code. The standard HIJING model is enhanced by a prescription for collective nucleon-nucleon (NN) interactions and more modern parton distribution functions. The collective NN-interactions are used to induce both cascade and nucleon shadowing effects. We find collective cascade broadens the pseudorapidity distributions in the tails (at | η | > {y}{beam}) above 25%-30% collision centrality to be consistent with the {{{d}}{N}}{{ch}}/{{d}}η data at \\sqrt{{s}{{NN}}} =19.6,22.4,62.4 {GeV}. The overall contribution of nucleon shadowing is shown to depress the whole shape of {{{d}}{N}}{{ch}}/{{d}}η in the primary interaction region (at | η | < {y}{beam}) for semiperipheral (20%-25%) and peripheral (≥slant 35 % {--}40 % ) Cu + Cu (Au + Au) interactions at \\sqrt{{s}{{NN}}}=200 {GeV}, in accordance with the PHOBOS data.

  14. Control of density and LSPR of Au nanoparticles on graphene.

    PubMed

    Lee, Seungwoo; Lee, Min hyung; Shin, Hyeon-jin; Choi, Dukyun

    2013-07-12

    In this study, we introduce the tunable density and localized surface plasmon resonance (LSPR) of plasmonic gold (Au) nanoparticles which were formed on monolayer graphene at room temperature, based on the difference of the reduction potential between graphene and the Au(3+) precursor. The size of the Au nanoparticles was ~40 nm, which is very desirable to provide an optical enhancement effect by LSPR in the full visible range. It is demonstrated that the density of the Au nanoparticles was modulated by the surface energy of the graphene on the substrate as well as the concentration of the Au(3+) precursor. Furthermore, the cycle number of the reduction process strongly affected the distribution of the nanoparticle size and their optical properties. The LSPR of the plasmonic Au nanoparticles was red-shifted from 560 to 620 nm and its full width at half maximum broadened as the Au(3+) precursor concentration was increased and the cyclic reduction process progressed. Based on the optical enhancement of the plasmonic Au nanoparticles and the extraordinary physical characteristics of graphene, the Au/graphene assembly may offer a promising optoelectronic platform for next-generation flexible optical electronics or biosensors.

  15. Structure sensitive adsorption of DMSO on Au surfaces

    SciTech Connect

    Ikemiya, N.; Gewirth, A.A.

    2000-02-10

    Using a variable temperature STM, the authors have observed the absorption of DMSO on Au(100) and Au(111) surfaces at temperatures below 215 K. For DMSO on Au(100), the molecules are trapped on the terraces at high points on the hex reconstruction giving rise to an ordered low coverage phase. Consistent with data from previous temperature programmed desorption (TPD) measurements, this phase coexists with a higher coverage striped phase formed when the DMSO molecules associate with each other. On Au(111), the DMSO molecules nucleate, order, and grow only from step edges; the steps are the only appropriately electropositive sites on thismore » surface.« less

  16. Observation of D0 Meson Nuclear Modifications in Au +Au Collisions at √sNN =200 GeV

    NASA Astrophysics Data System (ADS)

    Adamczyk, L.; Adkins, J. K.; Agakishiev, G.; Aggarwal, M. M.; Ahammed, Z.; Alekseev, I.; Alford, J.; Anson, C. D.; Aparin, A.; Arkhipkin, D.; Aschenauer, E. C.; Averichev, G. S.; Banerjee, A.; Beavis, D. R.; Bellwied, R.; Bhasin, A.; Bhati, A. K.; Bhattarai, P.; Bichsel, H.; Bielcik, J.; Bielcikova, J.; Bland, L. C.; Bordyuzhin, I. G.; Borowski, W.; Bouchet, J.; Brandin, A. V.; Brovko, S. G.; Bültmann, S.; Bunzarov, I.; Burton, T. P.; Butterworth, J.; Caines, H.; Calderón de la Barca Sánchez, M.; Cebra, D.; Cendejas, R.; Cervantes, M. C.; Chaloupka, P.; Chang, Z.; Chattopadhyay, S.; Chen, H. F.; Chen, J. H.; Chen, L.; Cheng, J.; Cherney, M.; Chikanian, A.; Christie, W.; Chwastowski, J.; Codrington, M. J. M.; Contin, G.; Cramer, J. G.; Crawford, H. J.; Cui, X.; Das, S.; Davila Leyva, A.; De Silva, L. C.; Debbe, R. R.; Dedovich, T. G.; Deng, J.; Derevschikov, A. A.; Derradi de Souza, R.; Dhamija, S.; di Ruzza, B.; Didenko, L.; Dilks, C.; Ding, F.; Djawotho, P.; Dong, X.; Drachenberg, J. L.; Draper, J. E.; Du, C. M.; Dunkelberger, L. E.; Dunlop, J. C.; Efimov, L. G.; Engelage, J.; Engle, K. S.; Eppley, G.; Eun, L.; Evdokimov, O.; Eyser, O.; Fatemi, R.; Fazio, S.; Fedorisin, J.; Filip, P.; Finch, E.; Fisyak, Y.; Flores, C. E.; Gagliardi, C. A.; Gangadharan, D. R.; Garand, D.; Geurts, F.; Gibson, A.; Girard, M.; Gliske, S.; Greiner, L.; Grosnick, D.; Gunarathne, D. S.; Guo, Y.; Gupta, A.; Gupta, S.; Guryn, W.; Haag, B.; Hamed, A.; Han, L.-X.; Haque, R.; Harris, J. W.; Heppelmann, S.; Hirsch, A.; Hoffmann, G. W.; Hofman, D. J.; Horvat, S.; Huang, B.; Huang, H. Z.; Huang, X.; Huck, P.; Humanic, T. J.; Igo, G.; Jacobs, W. W.; Jang, H.; Judd, E. G.; Kabana, S.; Kalinkin, D.; Kang, K.; Kauder, K.; Ke, H. W.; Keane, D.; Kechechyan, A.; Kesich, A.; Khan, Z. H.; Kikola, D. P.; Kisel, I.; Kisiel, A.; Koetke, D. D.; Kollegger, T.; Konzer, J.; Koralt, I.; Kotchenda, L.; Kraishan, A. F.; Kravtsov, P.; Krueger, K.; Kulakov, I.; Kumar, L.; Kycia, R. A.; Lamont, M. A. C.; Landgraf, J. M.; Landry, K. D.; Lauret, J.; Lebedev, A.; Lednicky, R.; Lee, J. H.; LeVine, M. J.; Li, C.; Li, W.; Li, X.; Li, X.; Li, Y.; Li, Z. M.; Lisa, M. A.; Liu, F.; Ljubicic, T.; Llope, W. J.; Lomnitz, M.; Longacre, R. S.; Luo, X.; Ma, G. L.; Ma, Y. G.; Madagodagettige Don, D. M. M. D.; Mahapatra, D. P.; Majka, R.; Margetis, S.; Markert, C.; Masui, H.; Matis, H. S.; McDonald, D.; McShane, T. S.; Minaev, N. G.; Mioduszewski, S.; Mohanty, B.; Mondal, M. M.; Morozov, D. A.; Mustafa, M. K.; Nandi, B. K.; Nasim, Md.; Nayak, T. K.; Nelson, J. M.; Nigmatkulov, G.; Nogach, L. V.; Noh, S. Y.; Novak, J.; Nurushev, S. B.; Odyniec, G.; Ogawa, A.; Oh, K.; Ohlson, A.; Okorokov, V.; Oldag, E. W.; Olvitt, D. L.; Pachr, M.; Page, B. S.; Pal, S. K.; Pan, Y. X.; Pandit, Y.; Panebratsev, Y.; Pawlak, T.; Pawlik, B.; Pei, H.; Perkins, C.; Peryt, W.; Pile, P.; Planinic, M.; Pluta, J.; Poljak, N.; Porter, J.; Poskanzer, A. M.; Pruthi, N. K.; Przybycien, M.; Pujahari, P. R.; Putschke, J.; Qiu, H.; Quintero, A.; Ramachandran, S.; Raniwala, R.; Raniwala, S.; Ray, R. L.; Riley, C. K.; Ritter, H. G.; Roberts, J. B.; Rogachevskiy, O. V.; Romero, J. L.; Ross, J. F.; Roy, A.; Ruan, L.; Rusnak, J.; Rusnakova, O.; Sahoo, N. R.; Sahu, P. K.; Sakrejda, I.; Salur, S.; Sandweiss, J.; Sangaline, E.; Sarkar, A.; Schambach, J.; Scharenberg, R. P.; Schmah, A. M.; Schmidke, W. B.; Schmitz, N.; Seger, J.; Seyboth, P.; Shah, N.; Shahaliev, E.; Shanmuganathan, P. V.; Shao, M.; Sharma, B.; Shen, W. Q.; Shi, S. S.; Shou, Q. Y.; Sichtermann, E. P.; Singaraju, R. N.; Skoby, M. J.; Smirnov, D.; Smirnov, N.; Solanki, D.; Sorensen, P.; Spinka, H. M.; Srivastava, B.; Stanislaus, T. D. S.; Stevens, J. R.; Stock, R.; Strikhanov, M.; Stringfellow, B.; Sumbera, M.; Sun, X.; Sun, X. M.; Sun, Y.; Sun, Z.; Surrow, B.; Svirida, D. N.; Symons, T. J. M.; Szelezniak, M. A.; Takahashi, J.; Tang, A. H.; Tang, Z.; Tarnowsky, T.; Thomas, J. H.; Timmins, A. R.; Tlusty, D.; Tokarev, M.; Trentalange, S.; Tribble, R. E.; Tribedy, P.; Trzeciak, B. A.; Tsai, O. D.; Turnau, J.; Ullrich, T.; Underwood, D. G.; Van Buren, G.; van Nieuwenhuizen, G.; Vandenbroucke, M.; Vanfossen, J. A.; Varma, R.; Vasconcelos, G. M. S.; Vasiliev, A. N.; Vertesi, R.; Videbæk, F.; Viyogi, Y. P.; Vokal, S.; Vossen, A.; Wada, M.; Wang, F.; Wang, G.; Wang, H.; Wang, J. S.; Wang, X. L.; Wang, Y.; Wang, Y.; Webb, G.; Webb, J. C.; Westfall, G. D.; Wieman, H.; Wissink, S. W.; Witt, R.; Wu, Y. F.; Xiao, Z.; Xie, W.; Xin, K.; Xu, H.; Xu, J.; Xu, N.; Xu, Q. H.; Xu, Y.; Xu, Z.; Yan, W.; Yang, C.; Yang, Y.; Yang, Y.; Ye, Z.; Yepes, P.; Yi, L.; Yip, K.; Yoo, I.-K.; Yu, N.; Zawisza, Y.; Zbroszczyk, H.; Zha, W.; Zhang, J. B.; Zhang, J. L.; Zhang, S.; Zhang, X. P.; Zhang, Y.; Zhang, Z. P.; Zhao, F.; Zhao, J.; Zhong, C.; Zhu, X.; Zhu, Y. H.; Zoulkarneeva, Y.; Zyzak, M.; STAR Collaboration

    2014-10-01

    We report the first measurement of charmed-hadron (D0) production via the hadronic decay channel (D0→K-+π+) in Au +Au collisions at √sNN =200 GeV with the STAR experiment. The charm production cross section per nucleon-nucleon collision at midrapidity scales with the number of binary collisions, Nbin, from p +p to central Au +Au collisions. The D0 meson yields in central Au +Au collisions are strongly suppressed compared to those in p+p scaled by Nbin, for transverse momenta pT>3 GeV /c, demonstrating significant energy loss of charm quarks in the hot and dense medium. An enhancement at intermediate pT is also observed. Model calculations including strong charm-medium interactions and coalescence hadronization describe our measurements.

  17. IMAGING PROMINENCE ERUPTIONS OUT TO 1 AU

    SciTech Connect

    Wood, Brian E.; Howard, Russell A.; Linton, Mark G., E-mail: brian.wood@nrl.navy.mil

    2016-01-10

    Views of two bright prominence eruptions trackable all the way to 1 AU are here presented, using the heliospheric imagers on the Solar TErrestrial RElations Observatory (STEREO) spacecraft. The two events first erupted from the Sun on 2011 June 7 and 2012 August 31, respectively. Only these two examples of clear prominence eruptions observable this far from the Sun could be found in the STEREO image database, emphasizing the rarity of prominence eruptions this persistently bright. For the 2011 June event, a time-dependent 3D reconstruction of the prominence structure is made using point-by-point triangulation. This is not possible for the August event due to amore » poor viewing geometry. Unlike the coronal mass ejection (CME) that accompanies it, the 2011 June prominence exhibits little deceleration from the Sun to 1 AU, as a consequence moving upwards within the CME. This demonstrates that prominences are not necessarily tied to the CME's magnetic structure far from the Sun. A mathematical framework is developed for describing the degree of self-similarity for the prominence's expansion away from the Sun. This analysis suggests only modest deviations from self-similar expansion, but close to the Sun the prominence expands radially somewhat more rapidly than self-similarity would predict.« less

  18. Measurements of charmonium production in p+p, p+Au, and Au+Au collisions at s NN = 200  GeV with the STAR experiment

    DOE PAGES

    Todoroki, Takahito

    2017-09-25

    Here, we present the first results from the STAR MTD of mid-rapidity charmonium measurements via the di-muon decay channel in p+p, p+Au, and Au+Au collisions at √S NN = 200 GeV at RHIC. The inclusive J/Ψ production cross section in p+p collisions can be described by the Non-Relativistic QCD (NRQCD) formalism coupled with the color glass condensate e ective theory (CGC) at low transverse momentum (p T) and next-to-leading order NRQCD at high p T. The nuclear modification factor in p+Au collisions for inclusive J/Ψ is below unity at low p T and consistent with unity at high p T,more » which can be described by calculations including both nuclear PDF and nuclear absorption e ects. The double ratio of inclusive J/Ψ and Ψ(2S) production rates for 0 < p T < 10 GeV/c at mid-rapidity between p+p and p+Au collisions is measured to be 1.37 0.42 0.19. The nuclear modification factor in Au+Au collisions for inclusive J/Ψ shows significant J/Ψ suppression at high p T in central collisions and can be qualitatively described by transport models including dissociation and regeneration contributions.« less

  19. Ordered arrays of Au catalysts by FIB assisted heterogeneous dewetting

    NASA Astrophysics Data System (ADS)

    Benkouider, A.; Ronda, A.; David, T.; Favre, L.; Abbarchi, M.; Naffouti, M.; Osmond, J.; Delobbe, A.; Sudraud, P.; Berbezier, I.

    2015-12-01

    Synthesizing Au0.8Si0.2 nanocatalysts that are homogeneous in size and have controlled position is becoming a challenging and crucial prequisite for the fabrication of ordered semiconductor nanowires. In this study, Au0.8Si0.2 nanocatalysts are synthesized via dewetting of Au layers on Si(111) during thermal annealing in an ultra-high vacuum. In the first part of the paper, the mechanism of homogeneous dewetting is analyzed as a function of the Au-deposited thickness (h Au). We distinguish three different dewetting regimes: (I) for a low thickness ({h}{{Au}}≤slant 0.4 {nm}), a submonolyer coverage of Au is stabilized and there is no dewetting. (II) For an intermediate thickness (0.4 {nm}\\lt {h}{Au}≤slant 5 {nm}), there is both dewetting and Au0.8Si0.2 phase formation. The size and density of the Au0.8Si0.2 clusters are directly related to h Au. When cooling down to room temperature, the clusters decompose and reject the Si at the Au/Si substrate interface. (III) For a large thickness ({h}{{Au}}\\gt 5 {nm}), only dewetting takes place, without forming AuSi clusters. In this regime, the dewetting is kinetically controlled by the self-diffusion of Au (activation energy ∼0.43 eV) without evidence of an Si-alloying effect. As a practical consequence, when relying solely on the homogeneous dewetting of Au/Si(111) to form the Au0.8Si0.2 catalysts (without a supply of Si atoms from vapor), regime II should be used to obtain good size and density control. In the second part of the paper, a process for ordering the catalysts using focused ion beam-(FIB) assisted dewetting (heterogeneous dewetting) is developed. We show that no matter what the FIB milling conditions and the Au nominal thickness are, dewetting is promoted by ion beam irradiation and is accompanied by the formation of Au0.8Si0.2 droplets. The droplets preferentially form on the patterned areas, while in similar annealing conditions, they do not form on the unpatterned areas. This behavior is attributed

  20. Gold Apes Hydrogen. The Structure and Bonding in the Planar B7Au2- and B7Au2 Clusters

    SciTech Connect

    Zhai, Hua JIN.; Wang, Lai S.; Zubarev, Dmitry Y.

    2006-02-09

    We produced the B7Au2- mixed cluster and studied its electronic structure and chemical bonding using photoelectron spectroscopy and ab initio calculations. The photoelectron spectra of B7Au2- were observed to be relatively simple with vibrational resolution, in contrast to the complicated spectra observed for pure B7-, which had contributions from three isomers (Alexandrova et al., J. Phys. Chem. A, 2004, 108, 3509). Theoretical calculations show that B7Au2- possesses an extremely stable planar structure, identical to that of B7H2-, demonstrating that Au mimics H in its bonding to boron, analogous to the Au-Si bonding. The ground state structure of B7Au2- (B7H2-) canmore » be viewed as adding two Au (H) atoms to the terminal B atoms of a higher-lying planar isomer of B7-. The bonding and stability in the planar B7Au2- (B7H2-) clusters are elucidated on the basis of the strong covalent B-Au (H) bonding and the concepts of aromaticity/antiaromaticity in these systems.« less

  1. Controlled synthesis of PbS-Au nanostar-nanoparticle heterodimers and cap-like Au nanoparticles

    NASA Astrophysics Data System (ADS)

    Zhao, Nana; Li, Lianshan; Huang, Teng; Qi, Limin

    2010-11-01

    Uniform PbS-Au nanostar-nanoparticle heterodimers consisting of one Au nanoparticle grown on one horn of a well-defined six-horn PbS nanostar were prepared using the PbS nanostars as growth substrates for the selective deposition of Au nanoparticles. The size of the Au nanoparticles on the horns of the PbS nanostars could be readily adjusted by changing the PbS concentration for the deposition of Au nanoparticles. An optimum cetyltrimethylammonium bromide concentration and temperature were essential for the selective deposition of uniform Au nanoparticles on single horns of the PbS nanostars. Unusual PbS-Au nanoframe-nanoparticle heterodimers were obtained by etching the PbS-Au nanostar-nanoparticle heterodimers with oxalic acid while novel cap-like Au nanoparticles were obtained by etching with hydrochloric acid. The obtained heterodimeric nanostructures and cap-like nanoparticles are promising candidates for anisotropic nanoscale building blocks for the controllable assembly of useful, complex architectures.

  2. Controlled synthesis of PbS-Au nanostar-nanoparticle heterodimers and cap-like Au nanoparticles.

    PubMed

    Zhao, Nana; Li, Lianshan; Huang, Teng; Qi, Limin

    2010-11-01

    Uniform PbS-Au nanostar-nanoparticle heterodimers consisting of one Au nanoparticle grown on one horn of a well-defined six-horn PbS nanostar were prepared using the PbS nanostars as growth substrates for the selective deposition of Au nanoparticles. The size of the Au nanoparticles on the horns of the PbS nanostars could be readily adjusted by changing the PbS concentration for the deposition of Au nanoparticles. An optimum cetyltrimethylammonium bromide concentration and temperature were essential for the selective deposition of uniform Au nanoparticles on single horns of the PbS nanostars. Unusual PbS-Au nanoframe-nanoparticle heterodimers were obtained by etching the PbS-Au nanostar-nanoparticle heterodimers with oxalic acid while novel cap-like Au nanoparticles were obtained by etching with hydrochloric acid. The obtained heterodimeric nanostructures and cap-like nanoparticles are promising candidates for anisotropic nanoscale building blocks for the controllable assembly of useful, complex architectures.

  3. Incidence des accidents vasculaires cérébraux chez les patients VIH positifs sous traitement antirétroviral au long court

    PubMed Central

    Mapoure, Yacouba Njankouo; Nkongni, Ines Nepetsoun; Luma, Henry Namme; Ngahane, Bertrand Hugo Mbtachou; Barla, Esther; Ngwane, Samuel; Mouelle, Albert Soné; Njamnshi, Alfred Kongnyu

    2016-01-01

    Introduction Avec l'introduction de la trithérapie dans les années 1996, la morbidité et la mortalité liées à l'infection par le VIH a nettement diminué. Concomitamment avec ce succès clinique, plusieurs changements métaboliques incluant diabète, hypertension artérielle, dyslipidémie et lipodystrophie ont été observés, ceux-ci étant des pourvoyeurs d'accidents vasculaires cérébraux. L'objectif de ce travail était de déterminer l'incidence des accidents vasculaires cérébraux chez les patients VIH positifs sous traitement antirétroviral au long court. Méthodes Il s'agissait d'une étude de cohorte rétrospective, menée dans le Centre de Traitement Agrée de l'Hôpital Général de Douala (HGD), avec un recueil des données sur 10 ans allant de Mai 2001 à avril 2010, portant sur les patients VIH positifs adultes sous traitement antirétroviral depuis au moins 6 mois. Les patients étaient suivis selon le protocole national de prise en charge du Cameroun. La survenue d'un AVC a été déterminée par la méthode Kaplan-Meyer tandis que les facteurs associés à la survenue d'un AVC ont été recherché par le test de Khi-2. Le seuil de signification statistique était fixé à 0,05. Résultats 307 patients étaient inclus dont 62,4% de sexe féminin, et l’âge moyen était de 40,1 ± 9,9 ans. L'incidence des AVC était de 1,7% sur 72 mois de suivi sans différence significative entre les femmes et les hommes (P= 0,76). Le taux d'incidence calculé était de 0,3 pour 100 personnes années. Dans 85,7% des cas il s'agissait d'un AVC ischémique. Le délai moyen de survenue d'un AVC était de 33,4 mois. Les facteurs associés à la survenue d'un AVC étaient: les patients ayant initié leur traitement au stade III et IV de l'OMS et le taux de CD4 > 100/mm3 à l'initiation du traitement antirétroviral. Conclusion L'incidence des AVC chez les patients VIH positifs sous traitement antirétroviral est similaire à celle rapportée ant

  4. The growth and enhanced catalytic performance of Au@Pd core-shell nanodendrites.

    PubMed

    Wang, Haihua; Sun, Zhenhua; Yang, Yi; Su, Dangsheng

    2013-01-07

    Au@Pd core-shell nanodendrites were synthesized by reducing H(2)PdCl(4) with ascorbic acid onto the surface of Au polyhedra at room temperature. The Au@Pd core-shell nanodendrites consisting of a Au core and nanoporous Pd shell, exhibited plasmonic properties and higher catalytic activity in comparison with Au@Pd core-shell nanocubes.

  5. Registration of ‘AU-1101’ peanut

    USDA-ARS?s Scientific Manuscript database

    AU-1101’ (Reg. No. CV-xxx, PI 661498) is a large-seeded virginia-type peanut (Arachis hypogaea L. subsp. hypogaea var. hypogaea) with high yield and medium maturity, uniform pod size and shape, high grade, superior shelling characters, low oil content, normal oleic acid content, and good flavor. AU-...

  6. CO oxidation on Alsbnd Au nano-composite systems

    NASA Astrophysics Data System (ADS)

    Rajesh, C.; Majumder, C.

    2018-03-01

    Using first principles method we report the CO oxidation behaviour of Alsbnd Au nano-composites in three different size ranges: Al6Au8, Al13Au42 and a periodic slab of Alsbnd Au(1 1 1) surface. The clusters prefer enclosed structures with alternating arrangement of Al and Au atoms, maximising Auδ-sbnd Alδ+ bonds. Charge distribution analysis suggests the charge transfer from Al to Au atoms, corroborated by the red shift in the density of states spectrum. Further, CO oxidation on these nano-composite systems was investigated through both Eley - Rideal and Langmuir Hinshelwood mechanism. While, these clusters interact with O2 non-dissociatively with an elongation of the Osbnd O bond, further interaction with CO led to formation of CO2 spontaneously. On contrary, the CO2 evolution by co-adsorption of O2 and CO molecules has a transition state barrier. On the basis of the results it is inferred that nano-composite material of Alsbnd Au shows significant promise toward effective oxidative catalysis.

  7. Synthesis and crystal structure of a new Cu3Au-type ternary phase in the Au-In-Pd system: distribution of atoms over crystallographic positions.

    PubMed

    Ptashkina, Evgeniya A; Kabanova, Elizaveta G; Tursina, Anna I; Yatsenko, Alexandr V; Kuznetsov, Victor N

    2018-03-01

    A new Cu 3 Au-type ternary phase (τ phase) is found in the AuPd-rich part of the Au-In-Pd system. It has a broad homogeneity range based on extensive (Pd,Au) and (In,Au) replacement, with the composition varying between Au 17.7 In 25.3 Pd 57.0 and Au 50.8 In 16.2 Pd 33.0 . The occupancies of the crystallographic positions were studied by single-crystal X-ray diffraction for three samples of different composition. The sites with m-3m symmetry are occupied by atoms with a smaller scattering power than the atoms located on 4/mmm sites. Two extreme structure models were refined. Within the first, the occupation type changes from (Au,In,Pd) 3 (Pd,In) to (Au,Pd) 3 (In,Pd,Au) with an increase in the Au gross content. For the second model, the occupation type (Au,In,Pd) 3 (Pd,Au) remains essentially unchanged for all Au concentrations. Although the diffraction data do not allow the choice of one of these models, the latter model, where Au substitutes In on 4/mmm sites, seems to be preferable, since it agrees with the fact that the homogeneity range of the τ phase is inclined to the Au corner and provides the same occupation type for all the studied samples of different compositions.

  8. Largely enhanced photocatalytic activity of Au/XS2/Au (X = Re, Mo) antenna-reactor hybrids: charge and energy transfer.

    PubMed

    Chen, Kai; Ding, Si-Jing; Luo, Zhi-Jun; Pan, Gui-Ming; Wang, Jia-Hong; Liu, Jia; Zhou, Li; Wang, Qu-Quan

    2018-02-22

    An antenna-reactor hybrid coupling plasmonic antenna with catalytic nanoparticles is a new strategy to optimize photocatalytic activity. Herein, we have rationally proposed a Au/XS 2 /Au (X = Re, Mo) antenna reactor, which has a large Au core as the antenna and small satellite Au nanoparticles as the reactor separated by an ultrathin two-dimensional transition-metal dichalcogenide XS 2 shell (∼2.6 nm). Due to efficient charge transfer across the XS 2 shell as well as energy transfer via coupling of the Au antenna and Au reactor, the photocatalytic activity has been largely enhanced: Au/ReS 2 /Au exhibits a 3.59-fold enhancement, whereas Au/MoS 2 /Au exhibits a 2.66-fold enhancement as compared to that of the sum of the three individual components. The different enhancement in the Au/ReS 2 /Au and Au/MoS 2 /Au antenna-reactor hybrid is related to the competition and cooperation of charge and energy transfer. These results indicate the great potential of the Au/XS 2 /Au antenna-reactor hybrid for the development of highly efficient plasmonic photocatalysts.

  9. Identification of Au–S complexes on Au(100)

    DOE PAGES

    Walen, Holly; Liu, Da -Jiang; Oh, Junepyo; ...

    2016-01-25

    In this study, using a combination of scanning tunneling microscopy and density functional theory (DFT) calculations, we have identified a set of related Au–S complexes that form on Au(100), when sulfur adsorbs and lifts the hexagonal surface reconstruction. The predominant complex is diamond-shaped with stoichiometry Au 4S 5. All of the complexes can be regarded as combinations of S–Au–S subunits. The complexes exist within, or at the edges of, p(2 × 2) sulfur islands that cover the unreconstructed Au regions, and are observed throughout the range of S coverage examined in this study, 0.009 to 0.12 monolayers. A qualitative modelmore » is developed which incorporates competitive formation of complexes, Au rafts, and p(2 × 2) sulfur islands, as Au atoms are released by the surface structure transformation.« less

  10. MODELING THE ACCRETION STRUCTURE OF AU Mon

    SciTech Connect

    Atwood-Stone, Corwin; Miller, Brendan P.; Richards, Mercedes T.

    2012-12-01

    AU Mon is a long-period (11.113 days) Algol-type binary system with a persistent accretion disk that is apparent as double-peaked H{alpha} emission. We present previously unpublished optical spectra of AU Mon which were obtained over 20 years from 1991-2011 with dense orbital phase coverage. We utilize these data, along with archival UV spectra, to model the temperature and structure of the accretion disk and the gas stream. Synthetic spectral profiles for lines including H{alpha}, H{beta}, and the Al III and Si IV doublets were computed with the Shellspec program. The best match between the model spectra and the observations ismore » obtained for an accretion disk of inner/outer radius 5.1/23 R {sub Sun }, thickness of 5.2 R {sub Sun }, density of 1.0 Multiplication-Sign 10{sup -13} g cm{sup -3}, and maximum temperature of 14,000 K, along with a gas stream at a temperature of {approx}8000 K transferring {approx}2.4 Multiplication-Sign 10{sup -9} M {sub Sun} yr{sup -1}. We show H{alpha} Doppler tomograms of the velocity structure of the gas, constructed from difference profiles calculated through sequentially subtracting contributions from the stars and accretion structures. The tomograms provide independent support for the Shellspec modeling, while also illustrating that residual emission at sub-Keplerian velocities persists even after subtracting the disk and stream emission. Spectral variability in the H{alpha} profile beyond that expected from either the orbital or the long-period cycle is present on both multi-week and multi-year timescales, and may reflect quasi-random changes in the mass transfer rate or the disk structure. Finally, a transient UV spectral absorption feature may be modeled as an occasional outflow launched from the vicinity of the disk-stream interaction region.« less

  11. Proton-antiproton suppression in 200A GeV Au-Au collisions

    NASA Astrophysics Data System (ADS)

    Renk, Thorsten; Eskola, Kari J.

    2007-08-01

    We discuss the measured nuclear suppression of p+p¯ production in 200A GeV Au-Au collisions at the Relativistic Heavy Ion Collider (RHIC) within radiative energy loss. For the Albino-Kniehl-Kramer (AKK) set of fragmentation functions, proton production is dominated by gluons, giving rise to the expectation that the nuclear suppression for p+p¯ should be stronger than for pions due to the stronger coupling of gluons to the quenching medium. Using a hydrodynamical description for the soft matter evolution, we show that this is indeed seen in the calculation. However, the expected suppression factors for pions and protons are sufficiently similar that a discrimination with present data is not possible. In the high pT region above 6 GeV where the contributions of hydrodynamics and recombination to hadron production are negligible, the model calculation is in good agreement with the data on p+p¯ suppression.

  12. Charge-Asymmetry Dependence of Proton Elliptic Flow in 200 GeV Au +Au Collisions

    NASA Astrophysics Data System (ADS)

    Smith, Rachel; STAR Collaboration

    2016-09-01

    The chiral magnetic wave (CMW) is predicted to manifest a finite electric quadrupole moment in the quark-gluon plasma produced in high-energy heavy-ion collisions. This quadrupole moment generates a divergence in the azimuthal anisotropy (v2) of positively and negatively charged particles such that v2(+) < v2(-). This effect is proportional to the apparent charge asymmetry (Ach) of particles in the same rapidity window. The Ach dependence of v 2 has already been observed in the cases of charged pions and kaons. We present preliminary STAR measurements of v 2 for protons and anti-protons as a function of Ach from √sNN = 200 GeV Au +Au collisions for different centrality classes. The results are then compared with the previously reported results of pions and kaons. For the STAR Collaboration.

  13. Azimuthal Anisotropy in U +U and Au +Au Collisions at RHIC

    NASA Astrophysics Data System (ADS)

    Adamczyk, L.; Adkins, J. K.; Agakishiev, G.; Aggarwal, M. M.; Ahammed, Z.; Alekseev, I.; Alford, J.; Aparin, A.; Arkhipkin, D.; Aschenauer, E. C.; Averichev, G. S.; Banerjee, A.; Bellwied, R.; Bhasin, A.; Bhati, A. K.; Bhattarai, P.; Bielcik, J.; Bielcikova, J.; Bland, L. C.; Bordyuzhin, I. G.; Bouchet, J.; Brandin, A. V.; Bunzarov, I.; Burton, T. P.; Butterworth, J.; Caines, H.; Calderón de la Barca Sánchez, M.; Campbell, J. M.; Cebra, D.; Cervantes, M. C.; Chakaberia, I.; Chaloupka, P.; Chang, Z.; Chattopadhyay, S.; Chen, J. H.; Chen, X.; Cheng, J.; Cherney, M.; Christie, W.; Contin, G.; Crawford, H. J.; Das, S.; De Silva, L. C.; Debbe, R. R.; Dedovich, T. G.; Deng, J.; Derevschikov, A. A.; di Ruzza, B.; Didenko, L.; Dilks, C.; Dong, X.; Drachenberg, J. L.; Draper, J. E.; Du, C. M.; Dunkelberger, L. E.; Dunlop, J. C.; Efimov, L. G.; Engelage, J.; Eppley, G.; Esha, R.; Evdokimov, O.; Eyser, O.; Fatemi, R.; Fazio, S.; Federic, P.; Fedorisin, J.; Feng, Z.; Filip, P.; Fisyak, Y.; Flores, C. E.; Fulek, L.; Gagliardi, C. A.; Garand, D.; Geurts, F.; Gibson, A.; Girard, M.; Greiner, L.; Grosnick, D.; Gunarathne, D. S.; Guo, Y.; Gupta, S.; Gupta, A.; Guryn, W.; Hamad, A.; Hamed, A.; Haque, R.; Harris, J. W.; He, L.; Heppelmann, S.; Heppelmann, S.; Hirsch, A.; Hoffmann, G. W.; Hofman, D. J.; Horvat, S.; Huang, H. Z.; Huang, B.; Huang, X.; Huck, P.; Humanic, T. J.; Igo, G.; Jacobs, W. W.; Jang, H.; Jiang, K.; Judd, E. G.; Kabana, S.; Kalinkin, D.; Kang, K.; Kauder, K.; Ke, H. W.; Keane, D.; Kechechyan, A.; Khan, Z. H.; Kikola, D. P.; Kisel, I.; Kisiel, A.; Koetke, D. D.; Kollegger, T.; Kosarzewski, L. K.; Kotchenda, L.; Kraishan, A. F.; Kravtsov, P.; Krueger, K.; Kulakov, I.; Kumar, L.; Kycia, R. A.; Lamont, M. A. C.; Landgraf, J. M.; Landry, K. D.; Lauret, J.; Lebedev, A.; Lednicky, R.; Lee, J. H.; Li, W.; Li, Y.; Li, C.; Li, Z. M.; Li, X.; Li, X.; Lisa, M. A.; Liu, F.; Ljubicic, T.; Llope, W. J.; Lomnitz, M.; Longacre, R. S.; Luo, X.; Ma, L.; Ma, R.; Ma, Y. G.; Ma, G. L.; Magdy, N.; Majka, R.; Manion, A.; Margetis, S.; Markert, C.; Masui, H.; Matis, H. S.; McDonald, D.; Meehan, K.; Minaev, N. G.; Mioduszewski, S.; Mohanty, B.; Mondal, M. M.; Morozov, D. A.; Mustafa, M. K.; Nandi, B. K.; Nasim, Md.; Nayak, T. K.; Nigmatkulov, G.; Nogach, L. V.; Noh, S. Y.; Novak, J.; Nurushev, S. B.; Odyniec, G.; Ogawa, A.; Oh, K.; Okorokov, V.; Olvitt, D. L.; Page, B. S.; Pak, R.; Pan, Y. X.; Pandit, Y.; Panebratsev, Y.; Pawlik, B.; Pei, H.; Perkins, C.; Peterson, A.; Pile, P.; Planinic, M.; Pluta, J.; Poljak, N.; Poniatowska, K.; Porter, J.; Posik, M.; Poskanzer, A. M.; Pruthi, N. K.; Putschke, J.; Qiu, H.; Quintero, A.; Ramachandran, S.; Raniwala, S.; Raniwala, R.; Ray, R. L.; Ritter, H. G.; Roberts, J. B.; Rogachevskiy, O. V.; Romero, J. L.; Roy, A.; Ruan, L.; Rusnak, J.; Rusnakova, O.; Sahoo, N. R.; Sahu, P. K.; Sakrejda, I.; Salur, S.; Sandweiss, J.; Sarkar, A.; Schambach, J.; Scharenberg, R. P.; Schmah, A. M.; Schmidke, W. B.; Schmitz, N.; Seger, J.; Seyboth, P.; Shah, N.; Shahaliev, E.; Shanmuganathan, P. V.; Shao, M.; Sharma, B.; Sharma, M. K.; Shen, W. Q.; Shi, S. S.; Shou, Q. Y.; Sichtermann, E. P.; Sikora, R.; Simko, M.; Skoby, M. J.; Smirnov, D.; Smirnov, N.; Song, L.; Sorensen, P.; Spinka, H. M.; Srivastava, B.; Stanislaus, T. D. S.; Stepanov, M.; Stock, R.; Strikhanov, M.; Stringfellow, B.; Sumbera, M.; Summa, B. J.; Sun, X.; Sun, X. M.; Sun, Z.; Sun, Y.; Surrow, B.; Svirida, D. N.; Szelezniak, M. A.; Tang, Z.; Tang, A. H.; Tarnowsky, T.; Tawfik, A. N.; Thomas, J. H.; Timmins, A. R.; Tlusty, D.; Tokarev, M.; Trentalange, S.; Tribble, R. E.; Tribedy, P.; Tripathy, S. K.; Trzeciak, B. A.; Tsai, O. D.; Ullrich, T.; Underwood, D. G.; Upsal, I.; Van Buren, G.; van Nieuwenhuizen, G.; Vandenbroucke, M.; Varma, R.; Vasiliev, A. N.; Vertesi, R.; Videbaek, F.; Viyogi, Y. P.; Vokal, S.; Voloshin, S. A.; Vossen, A.; Wang, F.; Wang, Y.; Wang, H.; Wang, J. S.; Wang, Y.; Wang, G.; Webb, G.; Webb, J. C.; Wen, L.; Westfall, G. D.; Wieman, H.; Wissink, S. W.; Witt, R.; Wu, Y. F.; Xiao, Z.; Xie, W.; Xin, K.; Xu, Y. F.; Xu, N.; Xu, Z.; Xu, Q. H.; Xu, H.; Yang, Y.; Yang, Y.; Yang, C.; Yang, S.; Yang, Q.; Ye, Z.; Yepes, P.; Yi, L.; Yip, K.; Yoo, I.-K.; Yu, N.; Zbroszczyk, H.; Zha, W.; Zhang, X. P.; Zhang, J. B.; Zhang, J.; Zhang, Z.; Zhang, S.; Zhang, Y.; Zhang, J. L.; Zhao, F.; Zhao, J.; Zhong, C.; Zhou, L.; Zhu, X.; Zoulkarneeva, Y.; Zyzak, M.; STAR Collaboration

    2015-11-01

    Collisions between prolate uranium nuclei are used to study how particle production and azimuthal anisotropies depend on initial geometry in heavy-ion collisions. We report the two- and four-particle cumulants, v2{2 } and v2{4 }, for charged hadrons from U +U collisions at √{sNN }=193 GeV and Au +Au collisions at √{sNN}=200 GeV . Nearly fully overlapping collisions are selected based on the energy deposited by spectators in zero degree calorimeters (ZDCs). Within this sample, the observed dependence of v2{2 } on multiplicity demonstrates that ZDC information combined with multiplicity can preferentially select different overlap configurations in U +U collisions. We also show that v2 vs multiplicity can be better described by models, such as gluon saturation or quark participant models, that eliminate the dependence of the multiplicity on the number of binary nucleon-nucleon collisions.

  14. Interpretation of the first data on central Au+Au collisions at

    SciTech Connect

    Jeon, Sangyong; Kapusta, Joseph

    2001-01-01

    We compare three semimicroscopic theories to the first data on particle production in central Au+Au collisions taken at RHIC by the PHOBOS Collaboration as well as to existing data on central Pb+Pb collisions taken at the SPS by the NA49 Collaboration. The Linear Extrapolation of Ultrarelativistic nucleon-nucleon Scattering to nucleus-nucleus collisions (LEXUS) represents the SPS data quite well but predicts too many particles at RHIC. The wounded nucleon model predicts too few particles at both the SPS and RHIC; the collective tube model predicts fewer particles still. This suggests a transition in the dynamics of particle production between s=17 andmore » 56A GeV as one goes from the SPS to RHIC.« less

  15. Deep sub-threshold ϕ production in Au+Au collisions

    NASA Astrophysics Data System (ADS)

    Adamczewski-Musch, J.; Arnold, O.; Behnke, C.; Belounnas, A.; Belyaev, A.; Berger-Chen, J. C.; Biernat, J.; Blanco, A.; Blume, C.; Böhmer, M.; Bordalo, P.; Chernenko, S.; Chlad, L.; Deveaux, C.; Dreyer, J.; Dybczak, A.; Epple, E.; Fabbietti, L.; Fateev, O.; Filip, P.; Fonte, P.; Franco, C.; Friese, J.; Fröhlich, I.; Galatyuk, T.; Garzón, J. A.; Gernhäuser, R.; Golubeva, M.; Greifenhagen, R.; Guber, F.; Gumberidze, M.; Harabasz, S.; Heinz, T.; Hennino, T.; Hlavac, S.; Höhne, C.; Holzmann, R.; Ierusalimov, A.; Ivashkin, A.; Kämpfer, B.; Karavicheva, T.; Kardan, B.; Koenig, I.; Koenig, W.; Kolb, B. W.; Korcyl, G.; Kornakov, G.; Kotte, R.; Kühn, W.; Kugler, A.; Kunz, T.; Kurepin, A.; Kurilkin, A.; Kurilkin, P.; Ladygin, V.; Lalik, R.; Lapidus, K.; Lebedev, A.; Lopes, L.; Lorenz, M.; Mahmoud, T.; Maier, L.; Mangiarotti, A.; Markert, J.; Maurus, S.; Metag, V.; Michel, J.; Mihaylov, D. M.; Morozov, S.; Müntz, C.; Münzer, R.; Naumann, L.; Nowakowski, K. N.; Palka, M.; Parpottas, Y.; Pechenov, V.; Pechenova, O.; Petukhov, O.; Pietraszko, J.; Przygoda, W.; Ramos, S.; Ramstein, B.; Reshetin, A.; Rodriguez-Ramos, P.; Rosier, P.; Rost, A.; Sadovsky, A.; Salabura, P.; Scheib, T.; Schuldes, H.; Schwab, E.; Scozzi, F.; Seck, F.; Sellheim, P.; Siebenson, J.; Silva, L.; Sobolev, Yu. G.; Spataro, S.; Ströbele, H.; Stroth, J.; Strzempek, P.; Sturm, C.; Svoboda, O.; Szala, M.; Tlusty, P.; Traxler, M.; Tsertos, H.; Usenko, E.; Wagner, V.; Wendisch, C.; Wiebusch, M. G.; Wirth, J.; Zanevsky, Y.; Zumbruch, P.; Hades Collaboration

    2018-03-01

    We present data on charged kaons (K±) and ϕ mesons in Au(1.23A GeV)+Au collisions. It is the first simultaneous measurement of K- and ϕ mesons in central heavy-ion collisions below a kinetic beam energy of 10A GeV. The ϕ /K- multiplicity ratio is found to be surprisingly high with a value of 0.52 ± 0.16 and shows no dependence on the centrality of the collision. Consequently, the different slopes of the K+ and K- transverse-mass spectra can be explained solely by feed-down, which substantially softens the spectra of K- mesons. Hence, in contrast to the commonly adapted argumentation in literature, the different slopes do not necessarily imply diverging freeze-out temperatures of K+ and K- mesons caused by different couplings to baryons.

  16. Biosynthesis of Au, Ag and Au-Ag nanoparticles using edible mushroom extract

    NASA Astrophysics Data System (ADS)

    Philip, Daizy

    2009-07-01

    Integration of green chemistry principles to nanotechnology is one of the key issues in nanoscience research. There is growing need to develop environmentally benign metal nanoparticle synthesis process that do not use toxic chemicals in the synthesis protocols to avoid adverse effects in medical applications. Here, it is a report on extracellular synthesis method for the preparation of Au, Ag and Au-Ag nanoparticles in water, using the extract of Volvariella volvacea, a naturally occurring edible mushroom, as reducing and protecting agents. Gold nanoparticles of different sizes (20-150 nm) and shapes from triangular nanoprisms to nearly spherical and hexagonal are obtained by this novel method. The size and shape of gold nanoparticles are also found to depend on temperature of the extract. The silver nanoparticles are spherical with size ˜15 nm. There is increased productivity of nanoparticles as shown by sharp and intense surface plasmon resonance bands for the nanoparticles prepared using an excess of the extract. The Au-Ag nanoparticles prepared by co-reduction has only one plasmon band due to alloying of the constituents. All the synthesized nanoparticles are found to be photoluminescent and are highly crystalline as shown by SAED and XRD patterns with fcc phase oriented along the (1 1 1) plane. FTIR measurements were carried out to identify the possible biomolecules responsible for capping and efficient stabilization of the nanoparticles. It is found that Au nanoparticles are bound to proteins through free amino groups and silver nanoparticles through the carboxylate group of the amino acid residues. The position and intensity of the emission band is found to depend on composition of the nanoparticles indicating the possible use in therapeutic applications.

  17. Aspects cliniques, électrocardiographiques et échocardiographiques de l’hypertendu âgé au Sénégal

    PubMed Central

    Sarr, Simon Antoine; Babaka, Kana; Mboup, Mouhamadou Cherif; Fall, Pape Diadie; Dia, Khadidiatou; Bodian, Malick; Ndiaye, Mouhamadou Bamba; Kane, Adama; Diao, Maboury; Ba, Serigne Abdou

    2016-01-01

    Introduction L’hypertension artérielle (HTA) du sujet âgé est un facteur indépendant de maladie cardio-vasculaire. Nos objectifs étaient de décrire les aspects cliniques, électrocardiographique et échocardiographiques de l’HTA du sujet âgé. Méthodes Nous avons mené une étude descriptive et transversale de Janvier à Septembre 2013. Etaient inclus les sujets hypertendus âgés d’au moins 60 ans suivis en ambulatoire au service de cardiologie de l’Hôpital Principal de Dakar. Les données statistiques étaient analysées par le logiciel Epi Info 7 et une valeur de p < 0,05 était retenue comme significative. Résultats Au total, 208 patients étaient inclus. L’âge moyen était de 69,9 ans avec une prédominance féminine (sex-ratio de 0,85). La pression artérielle moyenne était de 162/90mmHg. L’HTA était contrôlée dans 13% des cas. A l’électrocardiogramme, on notait un trouble du rythme (17,78%), une hypertrophie auriculaire gauche (45,19%), une hypertrophie ventriculaire gauche (28,85%) et 2 cas de bloc auriculo-ventriculaire complet. Le Holter ECG révélait 4 cas de tachycardie ventriculaire non soutenue (IVb de Lown), 6 cas de fibrillation atriale paroxystique et 1 cas de flutter atrial paroxystique. L’échocardiographie réalisée chez 140 patients retrouvait une HVG à prédominance concentrique chez 25 patients, plus fréquente chez les hommes (p=0,04) et une dilatation de l’oreillette gauche dans 56,42% des cas, plus fréquente chez les patients plus âgés (p= 0,01). Conclusion Les aspects électrocardiographiques et échocardiographiques dans la population hypertendue âgée sont caractérisés par l’hypertrophie ventriculaire gauche notamment concentrique, la fréquence des arythmies révélées quelques fois par l’enregistrement électrocardiographique de longue durée. PMID:28292040

  18. Stream dynamics between 1 AU and 2 AU: A detailed comparison of observations and theory

    NASA Technical Reports Server (NTRS)

    Burlaga, L. F.; Pizzo, V.; Lazarus, A.; Gazis, P. R.

    1984-01-01

    A radial alignment of three solar wind stream structures observed by IMP-7 and -8 (at 1.0 AU) and Voyager 1 and 2 (in the range 1.4 to 1.8 AU) in late 1977 is presented. It is demonstrated that several important aspects of the observed dynamical evolution can be both qualitatively and quantitatively described with a single-fluid 2-D MHD numerical model of quasi-steady corotating flow, including accurate prediction of: (1) the formation of a corotating shock pair at 1.75 AU in the case of a simple, quasi-steady stream; (2) the coalescence of the thermodynamic and magnetic structures associated with the compression regions of two neighboring, interacting, corotating streams; and (3) the dynamical destruction of a small (i.e., low velocity-amplitude, short spatial-scale) stream by its overtaking of a slower moving, high-density region associated with a preceding transient flow. The evolution of these flow systems is discussed in terms of the concepts of filtering and entrainment.

  19. Cationic AuIII versus AuI : Catalyst-Controlled Divergent Reactivity of Alkyne-Tethered Lactams.

    PubMed

    Alcaide, Benito; Almendros, Pedro; Cembellín, Sara; Fernández, Israel; Martínez Del Campo, Teresa

    2017-03-02

    Switchable reactivity through cationic gold-based catalyst control built on the oxidation state, namely cationic Au III versus Au I , has been achieved in the direct functionalization of 2-azetidinone-tethered alkynyl indoles. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  20. Observation of D 0 meson nuclear modifications in Au + Au collisions at s NN = 200 GeV

    DOE PAGES

    Adamczyk, L.; Adkins, J. K.; Agakishiev, G.; ...

    2014-09-30

    We report the first measurement of charmed-hadron (D 0) production via the hadronic decay channel (D 0→K -+π +) in Au+Au collisions at √ sNN=200 GeV with the STAR experiment. The charm production cross section per nucleon-nucleon collision at midrapidity scales with the number of binary collisions, N bin, from p+p to central Au+Au collisions. The D 0 meson yields in central Au+Aucollisions are strongly suppressed compared to those in p+p scaled by N bin, for transverse momenta p T>3 GeV/c, demonstrating significant energy loss of charm quarks in the hot and dense medium. An enhancement at intermediate p Tmore » is also observed. Model calculations including strong charm-medium interactions and coalescence hadronization describe our measurements.« less

  1. High-temperature stability of Au/Pd/Cu and Au/Pd(P)/Cu surface finishes

    NASA Astrophysics Data System (ADS)

    Ho, C. E.; Hsieh, W. Z.; Lee, P. T.; Huang, Y. H.; Kuo, T. T.

    2018-03-01

    Thermal reliability of Au/Pd/Cu and Au/Pd(4-6 wt.% P)/Cu trilayers in the isothermal annealing at 180 °C were investigated by X-ray photoelectron spectroscopy (XPS), time-of-flight secondary ion mass spectrometry (TOF-SIMS), and transmission electron microscopy (TEM). The pure Pd film possessed a nanocrystalline structure with numerous grain boundaries, thereby facilitating the interdiffusion between Au and Cu. Out-diffusion of Cu through Pd and Au grain boundaries yielded a significant amount of Cu oxides (CuO and Cu2O) over the Au surface and gave rise to void formation in the Cu film. By contrast, the Pd(P) film was amorphous and served as a good diffusion barrier against Cu diffusion. The results of this study indicated that amorphous Pd(P) possessed better oxidation resistance and thermal reliability than crystalline Pd.

  2. Wafer-level Au-Au bonding in the 350-450 °C temperature range

    NASA Astrophysics Data System (ADS)

    Tofteberg, Hannah R.; Schjølberg-Henriksen, Kari; Fasting, Eivind J.; Moen, Alexander S.; Taklo, Maaike M. V.; Poppe, Erik U.; Simensen, Christian J.

    2014-08-01

    Metal thermocompression bonding is a hermetic wafer-level packaging technology that facilitates vertical integration and shrinks the area used for device sealing. In this paper, Au-Au bonding at 350, 400 and 450 °C has been investigated, bonding wafers with 1 µm Au on top of 200 nm TiW. Test Si laminates with device sealing frames of 100, 200, and 400 µm in width were realized. Bond strengths measured by pull tests ranged from 8 to 102 MPa and showed that the bond strength increased with higher bonding temperatures and decreased with increasing frame width. Effects of eutectic reactions, grain growth in the Au film and stress relaxation causing buckles in the TiW film were most pronounced at 450 °C and negligible at 350 °C. Bond temperature below the Au-Si eutectic temperature 363 °C is recommended.

  3. Electronic and geometric structures of Au30 clusters: a network of 2e-superatom Au cores protected by tridentate protecting motifs with u3-S

    NASA Astrophysics Data System (ADS)

    Tian, Zhimei; Cheng, Longjiu

    2015-12-01

    Density functional theory calculations have been performed to study the experimentally synthesized Au30S(SR)18 and two related Au30(SR)18 and Au30S2(SR)18 clusters. The patterns of thiolate ligands on the gold cores for the three thiolate-protected Au30 nanoclusters are on the basis of the ``divide and protect'' concept. A novel extended protecting motif with u3-S, S(Au2(SR)2)2AuSR, is discovered, which is termed the tridentate protecting motif. The Au cores of Au30S(SR)18, Au30(SR)18 and Au30S2(SR)18 clusters are Au17, Au20 and Au14, respectively. The superatom-network (SAN) model and the superatom complex (SAC) model are used to explain the chemical bonding patterns, which are verified by chemical bonding analysis based on the adaptive natural density partitioning (AdNDP) method and aromatic analysis on the basis of the nucleus-independent chemical shift (NICS) method. The Au17 core of the Au30S(SR)18 cluster can be viewed as a SAN of one Au6 superatom and four Au4 superatoms. The shape of the Au6 core is identical to that revealed in the recently synthesized Au18(SR)14 cluster. The Au20 core of the Au30(SR)18 cluster can be viewed as a SAN of two Au6 superatoms and four Au4 superatoms. The Au14 core of Au30S2(SR)18 can be regarded as a SAN of two pairs of two vertex-sharing Au4 superatoms. Meanwhile, the Au14 core is an 8e-superatom with 1S21P6 configuration. Our work may aid understanding and give new insights into the chemical synthesis of thiolate-protected Au clusters.Density functional theory calculations have been performed to study the experimentally synthesized Au30S(SR)18 and two related Au30(SR)18 and Au30S2(SR)18 clusters. The patterns of thiolate ligands on the gold cores for the three thiolate-protected Au30 nanoclusters are on the basis of the ``divide and protect'' concept. A novel extended protecting motif with u3-S, S(Au2(SR)2)2AuSR, is discovered, which is termed the tridentate protecting motif. The Au cores of Au30S(SR)18, Au30(SR)18 and Au30S

  4. Theoretical studies of acrolein hydrogenation on Au20 nanoparticle

    NASA Astrophysics Data System (ADS)

    Li, Zhe; Chen, Zhao-Xu; He, Xiang; Kang, Guo-Jun

    2010-05-01

    Gold nanoparticles play a key role in catalytic processes. We investigated the kinetics of stepwise hydrogenation of acrolein on Au20 cluster model and compared with that on Au(110) surface. The rate-limiting step barrier of CC reduction is about 0.5 eV higher than that of CO hydrogenation on Au(110) surface. On Au20 nanoparticle, however, the energy barrier of the rate-determining step for CC hydrogenation turns out to be slightly lower than the value for the CO reduction. The selectivity difference on the two substrate models are attributed to different adsorption modes of acrolein: via the CC on Au20, compared to through both CC and CO on Au(110). The preference switch implies that the predicted selectivity of competitive hydrogenation depends on substrate model sensitively, and particles with more low-coordinated Au atoms than flat surfaces are favorable for CC hydrogenation, which is in agreement with experimental result.

  5. Investigation of the thermal annealing effect on electrical properties of Ni/Au, Ni/Mo/Au and Mo/Au Schottky barriers on AlGaN/GaN heterostructures

    NASA Astrophysics Data System (ADS)

    Sleptsov, E. V.; Chernykh, A. V.; Chernykh, S. V.; Dorofeev, A. A.; Gladysheva, N. B.; Kondakov, M. N.; Sleptsova, A. A.; Panichkin, A. V.; Konovalov, M. P.; Didenko, S. I.

    2017-03-01

    Investigation of the thermal annealing effect on Schottky barrier parameters and the leakage current of Ni/Au, Ni/Mo/Au and Mo/Au Schottky barriers on AlGaN/GaN heterostructures has been performed. Improvement of Schottky barrier parameters after annealing of the investigated metallization schemes was observed. Ni/Au and Mo/Au contacts drastically degrade after annealing at the temperatures higher than 400 °C, whereas the Ni/Mo/Au contact exhibits excellent parameters after 500 °C annealing (qϕb = 1.00 eV, n = 1.13 и Ileak = 5 μA).

  6. Sensitized mass change detection using Au nanoporous electrode for biosensing

    NASA Astrophysics Data System (ADS)

    Asai, Naoto; Terasawa, Hideaki; Shimizu, Tomohiro; Shingubara, Shoso; Ito, Takeshi

    2017-06-01

    Nanostructured Au was obtained on an electrode of a quartz crystal microbalance (QCM) chip by anodization in an oxalic acid solution. The effective surface area was expanded by these nanostructures and evaluated by electrochemical measurement, scanning electron microscopy (SEM), and atomic force microscopy (AFM). Several morphologies, such as a nanosphere and a spongy structure, were observed under various anodic conditions. We demonstrated that a QCM chip with an anodized Au electrode was effective in biosensing because of its large surface area. The frequency shift corresponding to an antigen-antibody reaction improved on a Au nanosphere electrode compared with a flat surface electrode and spongy structure.

  7. AuScope VLBI Project and Hobart 26-m Antenna

    NASA Technical Reports Server (NTRS)

    Lovell, Jim; Dickey, John; Reid, Brett; McCallum, Jamie; Shabala, Stas; Watson, Christopher; Ellingsen, Simon; Memin, Anthony

    2013-01-01

    This is a report on the activities carried out at the three AuScope VLBI observatories and the Hobart 26-m antenna. In 2012 the three AuScope 12-m antennas at Hobart (Hb), Katherine (Ke), and Yarragadee (Yg) completed their first full year of operations as an array. The Hobart 26-m antenna (Ho) continued to make a contribution to IVS, providing overlap with the Hb time series. In total the AuScope antennas and the Hobart 26 m observed for 146 antenna days in 2012. In this report we also briefly highlight our research activities during 2012 and our plans for 2013.

  8. FT-ICR/MS and ab initio study of polynuclear Au and Au-Cu clusters in aqueous fluids

    NASA Astrophysics Data System (ADS)

    Lemke, K.; Tse, K.; Sadjadi, A.

    2011-12-01

    The geochemistry and transport of aqueous transition metals such as copper and gold in the Earth's crust is still poorly known. FT-ICR mass spectrometry and ab initio calculations can provide fundamental insight on a molecular-scale level into the structure, stability and abundance of relevant Cu and Au species. We have measured high temperature ion cluster mass spectra of aqueous gold and copper chloride solutions using a custom-modified FT-ICR mass spectrometer equipped with an electrospray ionization source. In pure dilute aqueous AuCl3 solutions (1-25mM), Au(III) is present as an ion complex [AuCl2]+ and is hydrated with up to four water molecules, with the trihydrate [AuCl2]+(H2O)3 being the most stable species. In addition, several polynuclear ion clusters were observed, e.g. the dinuclear ion [Au2Cl5]+, including the hydrated forms [Au2Cl5]+(H2O) and [Au2Cl5]+(H2O)2. In more concentrated AuCl3 solutions (100mM, pH=2.3) the protonated Zundel cation [H5O2]+, [H7O3]+ and Eigen cation [H9O4]+ were detected, suggesting that protonated water clusters are equally relevant species in crustal fluids. We also measured mass spectra of binary solutions of aqueous transition metals, i.e. CuCl2/AuCl3 (5mM) and detected mixed Au(III)/Cu(II)-chloro clusters up to the tetranuclear [AuCu3Cl8]+ ion and their hydrated forms. The ab initio component of this study was designed to deliver additional insight into the structure of individual transition metal clusters as well as to the relative stability of each species, both unhydrated and in the presence of water molecules. Ab initio calculations were first conducted using MP2 theory and results thereof were then applied as starting points for subsequent couple-cluster CCSD(T) theory calculations. For the dinuclear ion [Au2Cl5]+, for example, the MP2 global minimum is a planar structure (see Figure; A) with an Au-Au bond distance of 3.435Å, while the second isomer (see Figure; B) has an Au-Au bond distance of 3.588Å and is around

  9. Au plasmonics in a WS{sub 2}-Au-CuInS{sub 2} photocatalyst for significantly enhanced hydrogen generation

    SciTech Connect

    Cheng, Zhongzhou; School of Materials Science and Engineering, University of Science and Technology Beijing, Beijing 100083; Wang, Zhenxing, E-mail: wangzx@nanoctr.cn, E-mail: hej@nanoctr.cn

    2015-11-30

    Promoting the activities of photocatalysts is still the critical challenge in H{sub 2} generation area. Here, a Au plasmon enhanced photocatalyst of WS{sub 2}-Au-CuInS{sub 2} is developed by inserting Au nanoparticles between WS{sub 2} nanotubes and CuInS{sub 2} (CIS) nanoparticles. Due to the localized surface plasmonic resonance properties from Au nanoparticles, WS{sub 2}-Au-CIS shows the best performance as compared to Au-CIS, CIS, WS{sub 2}-CIS, CIS-Au, WS{sub 2}-Au, and WS{sub 2}-CIS-Au. The surface plasmonic resonance effects dramatically intensify the absorption of visible light and help to inject hot electrons into the semiconductors. Our findings open up an efficient method to optimizemore » the type-II structures for photocatalytic water splitting.« less

  10. Abnormal behaviors in galvanically displaced Au nanostructure on silicon below and above percolation threshold a coverage of Au nanostructure.

    NASA Astrophysics Data System (ADS)

    Lee, Seung-Hoon; Hwang, Seongpil; Jeong, Jung Hyun; Jang, Jae-Won

    Temperature dependent resistivity of galvanically displaced Au nanostructure (NS) on p-type Silicon (p-Si) was investigated by tuning a coverage of Au NS below and above a percolation threshold (pc) in temperature range of 10-300K. Below pc [Au nanoparticles are deposited on p-Si], the temperature coefficient of resistivity (TCR) and cryogenic sensitivity (Sv) of p-Si in the low-temperature region (10-30 K) are remarkably improved upto 35% of TCR and 5785% of Sv in Au coverage of 21.9% compared to p-Si. Above pc [Au nanofeatures (NFs) are deposited on p-Si], the resistivity of the Au NFs on p-Si show metal to semiconductor transition (MST) as the temperature increases and the temperature of the MST is tuned from 145 to 232 K as Au% is changed from 82.7 to 54.3%. Our investigation can propose a new optoelectronic application by galvanic displacement method and can provide the better understanding for effect of metal NS on doped semiconductor in the galvanic displacement method. This research was supported by Basic Science Research Program through the National Research Foundation of Korea (NRF) funded by the Ministry of Education, Science and Technology (NRF-2015R1A1A1A05027681 and NRF-2016K1A3A1A32913212).

  11. The growth and enhanced catalytic performance of Au@Pd core-shell nanodendrites

    NASA Astrophysics Data System (ADS)

    Wang, Haihua; Sun, Zhenhua; Yang, Yi; Su, Dangsheng

    2012-12-01

    Au@Pd core-shell nanodendrites were synthesized by reducing H2PdCl4 with ascorbic acid onto the surface of Au polyhedra at room temperature. The Au@Pd core-shell nanodendrites consisting of a Au core and nanoporous Pd shell, exhibited plasmonic properties and higher catalytic activity in comparison with Au@Pd core-shell nanocubes.Au@Pd core-shell nanodendrites were synthesized by reducing H2PdCl4 with ascorbic acid onto the surface of Au polyhedra at room temperature. The Au@Pd core-shell nanodendrites consisting of a Au core and nanoporous Pd shell, exhibited plasmonic properties and higher catalytic activity in comparison with Au@Pd core-shell nanocubes. Electronic supplementary information (ESI) available: Experimental details, characterization and catalytic performance measurement of Au nanopolyhedra and Au@Pd core-shell nanostructures, TEM image of Au nanopolyhedra and Au@Pd core-shell nanodendrites after four cycles of the Suzuki coupling reaction, TEM and high-resolution images of a single Au@Pd core-shell nanodendrite, and XRD pattern of Au@Pd core-shell nanodendrites, UV-vis spectrum of Au@Pd nanodendrites in the range 200-400 nm, references. See DOI: 10.1039/c2nr32849f

  12. Corrigendum to “Suppression of Υ production in d+Au and Au+Au collisions at √ SNN = 200 GeV" [Phys. Lett. B 735 (2014) 127-137

    DOE PAGES

    Adamczyk, L.

    2015-04-01

    We report measurements of Υ meson production in p + p, d + Au, and Au+Au collisions using the STAR detector at RHIC. We compare the Υ yield to the measured cross section in p + p collisions in order to quantify any modifications of the yield in cold nuclear matter using d + Au data and in hot nuclear matter using Au+Au data separated into three centrality classes. Our p + p measurement is based on three times the statistics of our previous result. We obtain a nuclear modification factor for Upsilon (1S + 2S + 3S) in themore » rapidity range |y| < 1 in d + Au collisions of R dAu = 0.79 ± 0.24(stat.) ± 0.03(syst.) ± 0.10(p + p syst.). A comparison with models including shadowing and initial state parton energy loss indicates the presence of additional cold-nuclear matter suppression. Similarly, in the top 10% most-central Au + Au collisions, we measure a nuclear modification factor of R AA = 0.49 ±0.1(stat.) ±0.02(syst.) ±0.06(p + p syst.), which is a larger suppression factor than that seen in cold nuclear matter. Our results are consistent with complete suppression of excited-state Upsilon mesons in Au + Au collisions. The additional suppression in Au + Au is consistent with the level expected in model calculations that include the presence of a hot, deconfined Quark–Gluon Plasma. However, understanding the suppression seen in d + Au is still needed before any definitive statements about the nature of the suppression in Au + Au can be made.« less

  13. Transverse-energy distributions at midrapidity in p +p, d +Au, and Au +Au collisions at √sNN =62.4-200 GeV and implications for particle-production models

    NASA Astrophysics Data System (ADS)

    Adler, S. S.; Afanasiev, S.; Aidala, C.; Ajitanand, N. N.; Akiba, Y.; Al-Jamel, A.; Alexander, J.; Aoki, K.; Aphecetche, L.; Armendariz, R.; Aronson, S. H.; Averbeck, R.; Awes, T. C.; Azmoun, B.; Babintsev, V.; Baldisseri, A.; Barish, K. N.; Barnes, P. D.; Bassalleck, B.; Bathe, S.; Batsouli, S.; Baublis, V.; Bauer, F.; Bazilevsky, A.; Belikov, S.; Bennett, R.; Berdnikov, Y.; Bjorndal, M. T.; Boissevain, J. G.; Borel, H.; Boyle, K.; Brooks, M. L.; Brown, D. S.; Bruner, N.; Bucher, D.; Buesching, H.; Bumazhnov, V.; Bunce, G.; Burward-Hoy, J. M.; Butsyk, S.; Camard, X.; Campbell, S.; Chai, J.-S.; Chand, P.; Chang, W. C.; Chernichenko, S.; Chi, C. Y.; Chiba, J.; Chiu, M.; Choi, I. J.; Choudhury, R. K.; Chujo, T.; Cianciolo, V.; Cleven, C. R.; Cobigo, Y.; Cole, B. A.; Comets, M. P.; Constantin, P.; Csanád, M.; Csörgő, T.; Cussonneau, J. P.; Dahms, T.; Das, K.; David, G.; Deák, F.; Delagrange, H.; Denisov, A.; D'Enterria, D.; Deshpande, A.; Desmond, E. J.; Devismes, A.; Dietzsch, O.; Dion, A.; Drachenberg, J. L.; Drapier, O.; Drees, A.; Dubey, A. K.; Durum, A.; Dutta, D.; Dzhordzhadze, V.; Efremenko, Y. V.; Egdemir, J.; Enokizono, A.; En'yo, H.; Espagnon, B.; Esumi, S.; Fields, D. E.; Finck, C.; Fleuret, F.; Fokin, S. L.; Forestier, B.; Fox, B. D.; Fraenkel, Z.; Frantz, J. E.; Franz, A.; Frawley, A. D.; Fukao, Y.; Fung, S.-Y.; Gadrat, S.; Gastineau, F.; Germain, M.; Glenn, A.; Gonin, M.; Gosset, J.; Goto, Y.; Granier de Cassagnac, R.; Grau, N.; Greene, S. V.; Grosse Perdekamp, M.; Gunji, T.; Gustafsson, H.-Å.; Hachiya, T.; Hadj Henni, A.; Haggerty, J. S.; Hagiwara, M. N.; Hamagaki, H.; Hansen, A. G.; Harada, H.; Hartouni, E. P.; Haruna, K.; Harvey, M.; Haslum, E.; Hasuko, K.; Hayano, R.; He, X.; Heffner, M.; Hemmick, T. K.; Heuser, J. M.; Hidas, P.; Hiejima, H.; Hill, J. C.; Hobbs, R.; Holmes, M.; Holzmann, W.; Homma, K.; Hong, B.; Hoover, A.; Horaguchi, T.; Hur, M. G.; Ichihara, T.; Iinuma, H.; Ikonnikov, V. V.; Imai, K.; Inaba, M.; Inuzuka, M.; Isenhower, D.; Isenhower, L.; Ishihara, M.; Isobe, T.; Issah, M.; Isupov, A.; Jacak, B. V.; Jia, J.; Jin, J.; Jinnouchi, O.; Johnson, B. M.; Johnson, S. C.; Joo, K. S.; Jouan, D.; Kajihara, F.; Kametani, S.; Kamihara, N.; Kaneta, M.; Kang, J. H.; Katou, K.; Kawabata, T.; Kawagishi, T.; Kazantsev, A. V.; Kelly, S.; Khachaturov, B.; Khanzadeev, A.; Kikuchi, J.; Kim, D. J.; Kim, E.; Kim, E. J.; Kim, G.-B.; Kim, H. J.; Kim, Y.-S.; Kinney, E.; Kiss, Á.; Kistenev, E.; Kiyomichi, A.; Klein-Boesing, C.; Kobayashi, H.; Kochenda, L.; Kochetkov, V.; Kohara, R.; Komkov, B.; Konno, M.; Kotchetkov, D.; Kozlov, A.; Kroon, P. J.; Kuberg, C. H.; Kunde, G. J.; Kurihara, N.; Kurita, K.; Kweon, M. J.; Kwon, Y.; Kyle, G. S.; Lacey, R.; Lajoie, J. G.; Lebedev, A.; Leâ Bornec, Y.; Leckey, S.; Lee, D. M.; Lee, M. K.; Leitch, M. J.; Leite, M. A. L.; Li, X. H.; Lim, H.; Litvinenko, A.; Liu, M. X.; Maguire, C. F.; Makdisi, Y. I.; Malakhov, A.; Malik, M. D.; Manko, V. I.; Mao, Y.; Martinez, G.; Masui, H.; Matathias, F.; Matsumoto, T.; McCain, M. C.; McGaughey, P. L.; Miake, Y.; Miller, T. E.; Milov, A.; Mioduszewski, S.; Mishra, G. C.; Mitchell, J. T.; Mohanty, A. K.; Morrison, D. P.; Moss, J. M.; Moukhanova, T. V.; Mukhopadhyay, D.; Muniruzzaman, M.; Murata, J.; Nagamiya, S.; Nagata, Y.; Nagle, J. L.; Naglis, M.; Nakamura, T.; Newby, J.; Nguyen, M.; Norman, B. E.; Nyanin, A. S.; Nystrand, J.; O'Brien, E.; Ogilvie, C. A.; Ohnishi, H.; Ojha, I. D.; Okada, K.; Omiwade, O. O.; Oskarsson, A.; Otterlund, I.; Oyama, K.; Ozawa, K.; Pal, D.; Palounek, A. P. T.; Pantuev, V.; Papavassiliou, V.; Park, J.; Park, W. J.; Pate, S. F.; Pei, H.; Penev, V.; Peng, J.-C.; Pereira, H.; Peresedov, V.; Peressounko, D. Yu.; Pierson, A.; Pinkenburg, C.; Pisani, R. P.; Purschke, M. L.; Purwar, A. K.; Qu, H.; Qualls, J. M.; Rak, J.; Ravinovich, I.; Read, K. F.; Reuter, M.; Reygers, K.; Riabov, V.; Riabov, Y.; Roche, G.; Romana, A.; Rosati, M.; Rosendahl, S. S. E.; Rosnet, P.; Rukoyatkin, P.; Rykov, V. L.; Ryu, S. S.; Sahlmueller, B.; Saito, N.; Sakaguchi, T.; Sakai, S.; Samsonov, V.; Sanfratello, L.; Santo, R.; Sarsour, M.; Sato, H. D.; Sato, S.; Sawada, S.; Schutz, Y.; Semenov, V.; Seto, R.; Sharma, D.; Shea, T. K.; Shein, I.; Shibata, T.-A.; Shigaki, K.; Shimomura, M.; Shohjoh, T.; Shoji, K.; Sickles, A.; Silva, C. L.; Silvermyr, D.; Sim, K. S.; Singh, C. P.; Singh, V.; Skutnik, S.; Smith, W. C.; Soldatov, A.; Soltz, R. A.; Sondheim, W. E.; Sorensen, S. P.; Sourikova, I. V.; Staley, F.; Stankus, P. W.; Stenlund, E.; Stepanov, M.; Ster, A.; Stoll, S. P.; Sugitate, T.; Suire, C.; Sullivan, J. P.; Sziklai, J.; Tabaru, T.; Takagi, S.; Takagui, E. M.; Taketani, A.; Tanaka, K. H.; Tanaka, Y.; Tanida, K.; Tannenbaum, M. J.; Taranenko, A.; Tarján, P.; Thomas, T. L.; Togawa, M.; Tojo, J.; Torii, H.; Towell, R. S.; Tram, V.-N.; Tserruya, I.; Tsuchimoto, Y.; Tuli, S. K.; Tydesjö, H.; Tyurin, N.; Uam, T. J.; Vale, C.; Valle, H.; van Hecke, H. W.; Velkovska, J.; Velkovsky, M.; Vértesi, R.; Veszprémi, V.; Vinogradov, A. A.; Volkov, M. A.; Vznuzdaev, E.; Wagner, M.; Wang, X. R.; Watanabe, Y.; Wessels, J.; White, S. N.; Willis, N.; Winter, D.; Wohn, F. K.; Woody, C. L.; Wysocki, M.; Xie, W.; Yanovich, A.; Yokkaichi, S.; Young, G. R.; Younus, I.; Yushmanov, I. E.; Zajc, W. A.; Zaudtke, O.; Zhang, C.; Zhou, S.; Zimányi, J.; Zolin, L.; Zong, X.; Phenix Collaboration

    2014-04-01

    Measurements of the midrapidity transverse-energy distribution, dET/dη, are presented for p +p, d +Au, and Au +Au collisions at √sNN =200 GeV and additionally for Au +Au collisions at √sNN =62.4 and 130 GeV. The dET/dη distributions are first compared with the number of nucleon participants Npart, number of binary collisions Ncoll, and number of constituent-quark participants Nqp calculated from a Glauber model based on the nuclear geometry. For Au +Au, /Npart increases with Npart, while /Nqp is approximately constant for all three energies. This indicates that the two-component ansatz, dET/dη ∝(1-x)Npart/2+xNcoll, which was used to represent ET distributions, is simply a proxy for Nqp, and that the Ncoll term does not represent a hard-scattering component in ET distributions. The dET/dη distributions of Au +Au and d +Au are then calculated from the measured p +p ET distribution using two models that both reproduce the Au +Au data. However, while the number-of-constituent-quark-participant model agrees well with the d +Au data, the additive-quark model does not.

  14. Predicting ICME properties at 1AU

    NASA Astrophysics Data System (ADS)

    Lago, A.; Braga, C. R.; Mesquita, A. L.; De Mendonça, R. R. S.

    2017-12-01

    Coronal mass ejections (CMEs) are among the main origins of geomagnetic disturbances. They change the properties of the near-earth interplanetary medium, enhancing some key parameters, such as the southward interplanetary magnetic field and the solar wind speed. Both quantities are known to be related to the energy transfer from the solar wind to the Earth's magnetosphere via the magnetic reconnection process. Many attempts have been made to predict the magnetic filed and the solar wind speed from coronagraph observations. However, we still have much to learn about the dynamic evolution of ICMEs as they propagate through the interplanetary space. Increased observation capability is probably needed. Among the several attempts to establish correlations between CME and ICME properties, it was found that the average CME propagation speed to 1AU is highly correlated to the ICME peak speed (Dal Lago et al, 2004). In this work, we present an extended study of such correlation, which confirms the results found in our previous study. Some suggestions on how to use this kind of results for space weather estimates are explored.

  15. Evaluation of the Olympus AU-510 analyser.

    PubMed

    Farré, C; Velasco, J; Ramón, F

    1991-01-01

    The selective multitest Olympus AU-510 analyser was evaluated according to the recommendations of the Comision de Instrumentacion de la Sociedad Española de Quimica Clinica and the European Committee for Clinical Laboratory Standards. The evaluation was carried out in two stages: an examination of the analytical units and then an evaluation in routine work conditions. The operational characteristics of the system were also studied.THE FIRST STAGE INCLUDED A PHOTOMETRIC STUDY: dependent on the absorbance, the inaccuracy varies between +0.5% to -0.6% at 405 nm and from -5.6% to 10.6% at 340 nm; the imprecision ranges between -0.22% and 0.56% at 405 nm and between 0.09% and 2.74% at 340 nm. Linearity was acceptable, apart from a very low absorbance for NADH at 340 nm; and the imprecision of the serum sample pipetter was satisfactory.TWELVE SERUM ANALYTES WERE STUDIED UNDER ROUTINE CONDITIONS: glucose, urea urate, cholesterol, triglycerides, total bilirubin, creatinine, phosphate, iron, aspartate aminotransferase, alanine aminotransferase and gamma-glutamyl transferase.The within-run imprecision (CV%) ranged from 0.67% for phosphate to 2.89% for iron and the between-run imprecision from 0.97% for total bilirubin to 7.06% for iron. There was no carryover in a study of the serum sample pipetter. Carry-over studies with the reagent and sample pipetters shows some cross contamination in the iron assay.

  16. BaAu2S2: A Au-Based Intrinsic Photocatalyst for High-Performance Visible-Light Photocatalysis.

    PubMed

    Zhou, Molin; Jiang, Xin; Jiang, Xingxing; Xiao, Ke; Guo, Yangwu; Huang, Hongwei; Lin, Zheshuai; Yao, Jiyong; Tung, Chen-Ho; Wu, Li-Zhu; Wu, Yicheng

    2017-05-01

    A new Au-based sulfide BaAu 2 S 2 was obtained through solid-state reaction. It crystallizes in the tetragonal space group I4 1 /amd with unit cell parameters of a = 6.389 72(2) Å, b = 6.389 72(2) Å, c = 12.7872(1) Å, and Z = 4. Its structure features [AuS 2/2 ] ∞ zigzag chains composed of corner-sharing AuS 2 linear units. With a direct band gap of 2.49 eV, BaAu 2 S 2 is suitable for the visible-light harvesting. Moreover, it exhibits excellent visible-light photocatalytic activity, which is 1.3 times that of graphitic carbon nitride (g-C 3 N 4 ) and also demonstrates excellent circulating stability. On the basis of the crystal and electronic structure analysis, the electrons are highly delocalized along the [AuS 2/2 ] chains, and the electron effective mass of BaAu 2 S 2 is only approximately one-fifth of that of g-C 3 N 4 , which may help the separation of the electron/hole pairs during the photocatalytic process. Additionally, the absorption coefficient of BaAu 2 S 2 is extremely high, exceeding 1 × 10 4 cm -1 over the entire absorbable visible spectrum (hν > E g ), which is significantly higher than that of g-C 3 N 4 . Such factors may contribute to its outstanding photocatalytic performances. According to our best knowledge, BaAu 2 S 2 is the first noble metal-based chalcogenide photocatalyst reported as intrinsic light-harvesting and electron/hole-generating centers. This study may provide valuable insights for further research on photocatalytic materials.

  17. 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.

  18. Heterostructured Au/Pd-M (M = Au, Pd, Pt) nanoparticles with compartmentalized composition, morphology, and electrocatalytic activity

    NASA Astrophysics Data System (ADS)

    Lutz, Patrick S.; Bae, In-Tae; Maye, Mathew M.

    2015-09-01

    The synthesis, processing, and galvanic exchange of three heterostructured nanoparticle systems is described. The surface accessibility and redox potential of a Au/Pd-Ag dumbbell nanoparticle, where a Au/Pd core/shell region, and a silver region make up the domains, was used to prepare the new nanostructures with controlled composition, morphology, and microstructure. Results indicate that the silver domain was particularly susceptible to galvanic displacement, and was exchanged to Au/Pd-M (M = Au, Pd, Pt). Interestingly, the dumbbell morphology remained after exchange, and the silver region was transformed to hollow, parachute, or concentric domains respectively. The morphology and microstructure change was visualized via TEM and HRTEM, and the composition changes were probed via STEM-EDS imaging and XPS. The electrocatalytic activity of the Au/Pd-M towards methanol oxidation was studied, with results indicating that the Au/Pd-Pt nanoparticles had high activity attributed to the porous nature of the platinum domains.The synthesis, processing, and galvanic exchange of three heterostructured nanoparticle systems is described. The surface accessibility and redox potential of a Au/Pd-Ag dumbbell nanoparticle, where a Au/Pd core/shell region, and a silver region make up the domains, was used to prepare the new nanostructures with controlled composition, morphology, and microstructure. Results indicate that the silver domain was particularly susceptible to galvanic displacement, and was exchanged to Au/Pd-M (M = Au, Pd, Pt). Interestingly, the dumbbell morphology remained after exchange, and the silver region was transformed to hollow, parachute, or concentric domains respectively. The morphology and microstructure change was visualized via TEM and HRTEM, and the composition changes were probed via STEM-EDS imaging and XPS. The electrocatalytic activity of the Au/Pd-M towards methanol oxidation was studied, with results indicating that the Au/Pd-Pt nanoparticles had

  19. Assembling Bare Au Nanoparticles at Positively Charged Templates

    SciTech Connect

    Wang, Wenjie; Zhang, Honghu; Kuzmenko, Ivan

    2016-05-26

    In-situ X-ray reflectivity (XRR) and grazing incidence X-ray small-angle scattering (GISAXS) reveal that unfunctionalized (bare) gold nanoparticles (AuNP) spontaneously adsorb to a cationic lipid template formed by a Langmuir monolayer of DPTAP (1,2-dihexadecanoyl-3-trimethylammonium-propane) at vapor/aqueous interfaces. Analysis of the XRR yields the electron density profile across the chargedinterfaces along the surface normal showing the AuNPs assemble with vertical thickness comparable to the particle size. The GISAXS analysis indicates that the adsorbed mono-particle layer exhibits shortrange in-plane correlations. By contrast, single-stranded DNA-functionalized AuNPs, while attracted to the positively charged surface (more efficiently with the addition of salt to the solution), displaymore » less in-plane regular packing compared to bare AuNPs.« less

  20. Assembling Bare Au Nanoparticles at Positively Charged Templates

    SciTech Connect

    Wang, Wenjie; Zhang, Honghu; Kuzmenko, Ivan

    2016-05-26

    In-situ X-ray reflectivity (XRR) and grazing incidence X-ray small-angle scattering (GISAXS) reveal that unfunctionalized (bare) gold nanoparticles (AuNP) spontaneously adsorb to a cationic lipid template formed by a Langmuir monolayer of DPTAP (1,2-dihexadecanoyl-3-trimethylammonium-propane) at vapor/aqueous interfaces. Analysis of the XRR yields the electron density profile across the charged-interfaces along the surface normal showing the AuNPs assemble with vertical thickness comparable to the particle size. The GISAXS analysis indicates that the adsorbed mono-particle layer exhibits short-range in-plane correlations. By contrast, single-stranded DNA-functionalized AuNPs, while attracted to the positively charged surface (more efficiently with the addition of salt to the solution), displaymore » less in-plane regular packing compared to bare AuNPs.« less

  1. Diastereoselective Au-Catalyzed Allene Cycloisomerizations to Highly Substituted Cyclopentenes.

    PubMed

    Reeves, Ryan D; Phelps, Alicia M; Raimbach, William A T; Schomaker, Jennifer M

    2017-07-07

    Site- and regiocontrolled Au-catalyzed allene carbocyclizations furnish highly substituted cyclopentenes in >1:1 dr. Significant substitution on the substrate is tolerated, with potential to install five contiguous stereocenters after alkene functionalization. Major challenges include identifying a Au/Cu catalyst that controls both the relative rates of allene epimerization/cyclization and the facial selectivity in addition of a metal enolate to the allene. Experiments to achieve stereodivergent cyclizations and transform key cyclopentenes into useful synthetic building blocks are described.

  2. ϒ measurements in p+p, p+Au and Au+Au collisions at √{sNN} = 200GeV with the STAR experiment

    NASA Astrophysics Data System (ADS)

    Ye, Zaochen; STAR Collaboration

    2017-11-01

    In these proceedings, we present the latest ϒ measurements with the STAR experiment. The production cross-section in p+p and the nuclear modification factor RpA in p+Au collisions at √{sNN} = 200GeV are obtained via the dielectron channel. These measurements provide a p+p reference with significantly improved precision and quantification of the cold nuclear matter effects for ϒ measurements in heavy-ion collisions at RHIC. The nuclear modification factor RAA in Au+Au collisions at √{sNN} = 200GeV is obtained via both the dimuon and dielectron channels. The centrality and transverse momentum dependences of ϒ (1 S) and ϒ (2 S + 3 S) RAA are reported and compared to those at the LHC and theoretical calculations.

  3. Surpoids et obésité dans la population au-dessus de 20 ans en milieu urbain bamakois (Mali)

    PubMed Central

    Oumar Bâ, Hamidou; Menta, Ichaka; Camara, Youssouf; Sangaré, Ibrahima; Sidibé, Noumou; Doumbia, Seydou; Diarra, Mamadou Bocary

    2014-01-01

    Introduction Il est question dans notre travail d’étudier le SP et l'OB et les facteurs associés dans la population âgée de 20 ans ou plus. Méthodes Notre échantillon a été obtenu à partir d'une enquête sur les pathologies cardiovasculaires dans le District de Bamako et impliquant 2199 sujets de 5-104 ans, en sélectionnant tous les sujets âgés d'au moins 20 ans (1162). Pour chaque sujet, l'IMC, rapport taille / hanche et le tour de taille ont été déterminées. Les données ont été analysées avec SPSS 12. Résultats L’âge moyen était de 36,86 années, 61,4% étaient des femmes, 49,7% dans le secteur informel et 38,0% avaient réalisé l'enseignement primaire. Facteurs de risque cardiovasculaires étaient l'inactivité physique (72,4%), le tabagisme (12,2%) et hypertension (26,7%). La prévalence de l'obésité était de 8,8 et 14,7% respectivement sur la base de l'indice de masse et le tour de taille. Conclusion Le SP et l'OB sont à prendre en compte dans les mesures de politique sanitaire que dans la pratique quotidienne des professionnels de santé, il est peut-être plus utile d'utiliser plusieurs paramètres pour être à même de bien stratifier nos patients par rapport à leur risque. PMID:25932065

  4. Synthesis of Au38(SCH2CH2Ph)24, Au36(SPh-tBu)24, and Au30(S-tBu)18 Nanomolecules from a Common Precursor Mixture.

    PubMed

    Rambukwella, Milan; Dass, Amala

    2017-10-17

    Phenylethanethiol protected nanomolecules such as Au 25 , Au 38 , and Au 144 are widely studied by a broad range of scientists in the community, owing primarily to the availability of simple synthetic protocols. However, synthetic methods are not available for other ligands, such as aromatic thiol and bulky ligands, impeding progress. Here we report the facile synthesis of three distinct nanomolecules, Au 38 (SCH 2 CH 2 Ph) 24 , Au 36 (SPh-tBu) 24 , and Au 30 (S-tBu) 18 , exclusively, starting from a common Au n (glutathione) m (where n and m are number of gold atoms and glutathiolate ligands) starting material upon reaction with HSCH 2 CH 2 Ph, HSPh-tBu, and HStBu, respectively. The systematic synthetic approach involves two steps: (i) synthesis of kinetically controlled Au n (glutathione) m crude nanocluster mixture with 1:4 gold to thiol molar ratio and (ii) thermochemical treatment of the purified nanocluster mixture with excess thiols to obtain thermodynamically stable nanomolecules. Thermochemical reactions with physicochemically different ligands formed highly monodispersed, exclusively three different core-size nanomolecules, suggesting a ligand induced core-size conversion and structural transformation. The purpose of this work is to make available a facile and simple synthetic method for the preparation of Au 38 (SCH 2 CH 2 Ph) 24 , Au 36 (SPh-tBu) 24 , and Au 30 (S-tBu) 18 , to nonspecialists and the broader scientific community. The central idea of simple synthetic method was demonstrated with other ligand systems such as cyclopentanethiol (HSC 5 H 9 ), cyclohexanethiol(HSC 6 H 11 ), para-methylbenzenethiol(pMBT), 1-pentanethiol(HSC 5 H 11 ), 1-hexanethiol(HSC 6 H 13 ), where Au 36 (SC 5 H 9 ) 24 , Au 36 (SC 6 H 11 ) 24 , Au 36 (pMBT) 24 , Au 38 (SC 5 H 11 ) 24 , and Au 38 (SC 6 H 13 ) 24 were obtained, respectively.

  5. Au70S20(PPh3)12: an intermediate sized metalloid gold cluster stabilized by the Au4S4 ring motif and Au-PPh3 groups.

    PubMed

    Kenzler, Sebastian; Schrenk, Claudio; Frojd, Andrew R; Häkkinen, Hannu; Clayborne, Andre Z; Schnepf, Andreas

    2018-01-02

    Reducing (Ph 3 P)AuSC(SiMe 3 ) 3 with l-Selectride® gives the medium-sized metalloid gold cluster Au 70 S 20 (PPh 3 ) 12 . Computational studies show that the phosphine bound Au-atoms not only stabilize the electronic structure of Au 70 S 20 (PPh 3 ) 12 , but also behave as electron acceptors leading to auride-like gold atoms on the exterior.

  6. Hohlraum Te Inferred from Au L-Shell Emission

    NASA Astrophysics Data System (ADS)

    Regan, S. P.; Epstein, R.; Meyerhofer, D. D.; Sangster, T. C.; May, M. J.; Schneider, M. B.; Barrios, M. A.; Moody, J. D.; Baker, K. L.; Berzak Hopkins, L.; Brown, G. V.; Callahan, D.; Doeppner, T.; Fournier, K. B.; Hinkel, D. E.; Jones, O. S.; Kauffman, R.; Khan, S.; Kilkenny, J. D.; Landen, O. L.; Liedahl, D. A.; Nagel, S. R.; Ross, J. S.; Smalyuk, V. A.

    2014-10-01

    Laser-ablation plasmas created at the inner wall of the hohlraum (Au bubble) and at the laser entrance hole (LEH) radiate L-shell emission from Ne-like to Co-like charge states of Au. A 1-D spatially resolved and time-integrated spectrum in the 6- to 16-keV range with E/d E = 100 to 300 is recorded along the axis of the hohlraum. The Au L-shell spectral line shapes of the 2p3 / 2 - 3 s , 2p3 / 2 - 3d5 / 2 , and 2p1 / 2 - 3d3 / 2 transitions are analyzed using an atomic physics code to infer the Te of the radiating plasma. Preliminary results indicate the Au LEH plasma of a near-vacuum hohlraum has an inferred Te of 5 to 6 keV, while a gas-filled hohlraum has a significantly lower Te. A comparison of the Au L-shell spectra and the Te sensitivity will be presented, along with the plan to measure the L-shell emission from the Au bubble. This material is based upon work supported by the Department Of Energy National Nuclear Security Administration under Award Number DE-NA0001944. Part of this work was performed under the auspices of the U.S. Department of Energy by LLNL under Contract DE-AC52-07NA27344.

  7. Biosupported Bimetallic Pd Au Nanocatalysts for Dechlorination of Environmental Contaminants

    SciTech Connect

    De Corte, S.; Fitts, J.; Hennebel, T.

    2011-08-30

    Biologically produced monometallic palladium nanoparticles (bio-Pd) have been shown to catalyze the dehalogenation of environmental contaminants, but fail to efficiently catalyze the degradation of other important recalcitrant halogenated compounds. This study represents the first report of biologically produced bimetallic Pd/Au nanoparticle catalysts. The obtained catalysts were tested for the dechlorination of diclofenac and trichloroethylene. When aqueous bivalent Pd(II) and trivalent Au(III) ions were both added to concentrations of 50 mg L{sup -1} and reduced simultaneously by Shewanella oneidensis in the presence of H{sub 2}, the resulting cell-associated bimetallic nanoparticles (bio-Pd/Au) were able to dehalogenate 78% of the initially added diclofenacmore » after 24 h; in comparison, no dehalogenation was observed using monometallic bio-Pd or bio-Au. Other catalyst-synthesis strategies did not show improved dehalogenation of TCE and diclofenac compared with bio-Pd. Synchrotron-based X-ray diffraction, (scanning) transmission electron microscopy and energy dispersive X-ray spectroscopy indicated that the simultaneous reduction of Pd and Au supported on cells of S. oneidensis resulted in the formation of a unique bimetallic crystalline structure. This study demonstrates that the catalytic activity and functionality of possibly environmentally more benign biosupported Pd-catalysts can be improved by coprecipitation with Au.« less

  8. Molecular chains and carpets of sexithiophenes on Au(111)

    NASA Astrophysics Data System (ADS)

    Glowatzki, H.; Duhm, S.; Braun, K.-F.; Rabe, J. P.; Koch, N.

    2007-09-01

    The two organic molecular materials α -sexithiophene (6T) and α,ω -dihexylsexithiophene (DH6T) adsorbed on Au(111) in the (sub)monolayer range were investigated by scanning tunneling microscopy (STM) in order to explore the effect of alkyl substitution on the self-assembly at surfaces. Metal substrate step edges are identified as preferred nucleation sites for 6T, while stable nucleus formation for DH6T occurs at kinks of the Au(111) herringbone reconstruction. At low coverage, 6T forms continuous chains of single-molecular width along Au step edges, involving molecular conformation changes by rotations around C-C bonds of neighboring thiophene units. In contrast, DH6T exhibits no ordered structures in the submonolayer range. At monolayer coverage, substantially different structures were observed for the two molecules. 6T forms rows of molecules with parallel long molecular axes, whereas DH6T forms lines along these axes, where the conjugated cores are embedded in a matrix of hexyl chains. Because of different preferred nucleation sites, 6T forms a continuous molecular carpet on extended Au(111) terraces, whereas DH6T resembles a patchworklike carpet as domain boundaries are induced by the Au(111) herringbone surface structure, leading to reduced domain sizes. Alkylation of 6T thus drastically changes the adsorption behavior and the resulting layer structure on the Au surface. These results should be valuable for developing new directed self-assembly schemes on prepatterned surfaces.

  9. On the stability of AuFe alloy nanoparticles.

    PubMed

    Velasco, V; Pohl, D; Surrey, A; Bonatto-Minella, A; Hernando, A; Crespo, P; Rellinghaus, B

    2014-05-30

    AuFe nanoparticles with mean diameters d p  = 13.2 nm have been prepared by inert-gas condensation. Conventional and high-resolution transmission electron microscopy and energy-dispersive x-ray spectroscopy investigations show that the particles are mostly icosahedra. Scanning transmission electron microscopy-energy-dispersive x-ray spectroscopy and scanning transmission electron microscopy-electron energy-loss spectroscopy show that the as-grown particles exhibit a core-shell structure. The shell is mainly composed of an amorphous FeO layer. Although Fe and Au are immiscible in the bulk, the particle cores are found to be homogeneously mixed at the atomic level with a local composition of around Au84Fe16 (at.%). AuFe nanoparticles exhibit a complex magnetic structure in which the core behaves as a spin glass with a freezing temperature of 35 K, whereas the amorphous FeO shell behaves as a ferro-ferrimagnetic system. On annealing above 300 °C, the AuFe icosahedra phases separate into their elemental constituents. Hence the as-grown AuFe icosahedra are metastable, thereby implying that the bulk phase diagram also applies for nanoscopic materials.

  10. Au-Pt-Au nanoraspberry structures used for mercury ion detection

    NASA Astrophysics Data System (ADS)

    Huang, Jiang-Hao; Huang, Shuai; Wen, Xiaoyan; Li, Min; Lu, Haifei

    2017-12-01

    Detection of Hg2+ with high sensitivity is of great significance in the biochemical sensing field. Quantitative of Hg2+ was realized based on the influence of Hg2+ on the UV-vis absorption performance of Au-Pt-Au core-shell nanoraspberry (APA)-rhodamine-6G (R6G) structure. First, APA sol was added into R6G indicator solution and the UV-vis absorption signal intensity of R6G was evidently promoted. The signal intensity monotonously increased as more APA sol was added. However, when HgCl2 solution was introduced, the signal intensity declined. A linear relationship between Hg2+ concentration and signal intensity at 527 nm was revealed, based on which quantitative determination of Hg2+ could be realized. Hg2+ detection sensitivity was measured to be 0.031 a.u./M with a limit of detection of 10-7 M and the response time was 20 s. A high Hg2+ detection selectivity over Cu2+, Na+, Li+, and K+ was demonstrated. Due to its simplicity and high sensitivity, the proposed method could find an extensive application prospect in the Hg2+ detection field.

  11. QUELS FUTURS TRAITEMENTS POUR LA DEPENDANCE AU TABAC ET AU CANNABIS?

    PubMed Central

    LE FOLL, Bernard; JUSTINOVA, Zuzana; TANDA, Gianlugi; GOLDBERG, Steven R.

    2009-01-01

    RESUME Plus de trois millions de morts sont attribués au tabagisme dans le monde par an, et l’usage de tabac est en progression dans les pays en voie de développement. L’usage de tabac est donc une des rares causes de mortalité qui augmente, avec une prévision de plus de 10 millions de morts par an dans 30–40 ans. Le cannabis ou marijuana est la drogue illicite la plus consommée dans le monde et il n’y a actuellement pas de traitement disponible. Bien que les systèmes dopaminergiques jouent un rôle central dans les effets renforçants des drogues, d’autres systèmes sont impliqués. Nous présentons ici des résultats récents obtenus avec des antagonistes des récepteurs cannabinoides CB1, des récepteurs D3 de la dopamine et des récepteurs opioïdes. Ces antagonistes qui modulent de façon directe ou indirecte la transmission dopaminergique cérébrale représentent des approches prometteuses pour le traitement du tabagisme ou de la dépendance au cannabis. Ces approches sont à valider dans des essais cliniques. PMID:18663981

  12. Adsorption and desorption of thermally generated hydrogen atoms on Au(111) and Ag/Au(111)

    NASA Astrophysics Data System (ADS)

    Luh, Dah-An; Li, Kun-Rong; Huang, Ren-Yu; Chen, Ching-Hung; Cheng, Cheng-Maw; Tsuei, Ku-Ding; Wang, Chia-Hsin; Yang, Yaw-Wen

    2015-05-01

    To explore the possibility of employing thermally generated H atoms to determine the chemical composition of a metallic surface, we investigated the adsorption and desorption of H atoms generated with a thermal cracker on surfaces Au(111) and Ag/Au(111). Angle-resolved photoemission spectra showed that the noble-metallic surfaces deteriorated upon exposure to a flux of H atoms at ~ 100 K. Upon subsequent annealing, the order of the surfaces was mostly recovered when H atoms on the surfaces desorbed, but the recovery was incomplete even with annealing at a temperature much higher than that at which H atoms desorb. X-ray photoemission spectra showed that O-containing contaminants existed on the surfaces after the H dosing. The evolution of O 1s during annealing indicated that the O-containing contaminants were H2O and its moieties generated during thermal cracking; the disturbances of the surfaces remaining above the desorption temperature of H atoms were likely caused by chemisorbed O. Our results show that it is possible to employ thermally generated H atoms to determine the chemical composition of a metallic surface, but a small proportion of H2O in a H2 gas line might be unavoidable; precautions against possible O contamination are required when a thermal cracker is employed.

  13. Beam energy dependence of d and d ‾ production in Au+Au collisions at RHIC

    NASA Astrophysics Data System (ADS)

    Yu, Ning; STAR Collaboration

    2017-11-01

    The binding energy of light nuclei is small compared to the temperature of the system created in heavy-ion collisions. Consequently, the yields of light nuclei can be used to probe the freeze-out properties, such as correlation volume and local baryon density of the medium created in high-energy nuclear collisions. In this paper, we report the results of deuteron and anti-deuteron production in Au+Au collision at √{sNN} = 7.7, 11.5, 14.5, 19.6, 27, 39, 62.4, and 200 GeV, measured by STAR at RHIC. The collision energy, centrality and transverse momentum dependence of the coalescence parameter B2 for deuteron and anti-deuteron production are discussed. We find the values of B2 for anti-deuterons are systematically lower than those for deuterons indicating the correlation volume of anti-baryon are larger than that of baryon. In addition, the values of B2 are found to vary with collision energy and show a broad minimum around √{sNN} = 20GeV, implying a change of the equation of state of the medium in these collisions.

  14. Phospholipid Encapsulated AuNR@Ag/Au Nanosphere SERS Tags with Environmental Stimulus Responsive Signal Property.

    PubMed

    Su, Xueming; Wang, Yunqing; Wang, Wenhai; Sun, Kaoxiang; Chen, Lingxin

    2016-04-27

    Surface-enhanced Raman scattering (SERS) tags draw much attention due to the ultrasensitivity and multiplex labeling capability. Recently, a new kind of SERS tags was rationally designed by encapsulating metal nanoparticles with phospholipid bilayers, showing great potential in theranostics. The lipid bilayer coating confers biocompatibility and versatility to changing surface chemistry of the tag; however, its "soft" feature may influence SERS signal stability, which is rarely investigated. Herein, we prepared phospholipid-coated AuNR@Ag/Au nanosphere SERS tags by using three different kinds of Raman reporters, i.e., thio-containing 4-nitrothiophenol (NT), nitrogen-containing hydrophobic chromophore cyanine 7 monoacid (Cy7), and alkyl chain-chromophore conjugate 1,1'-dioctadecyl-3,3,3',3'-tetramethylindodicarbocyanine (DiD). It was found that signal responses were different upon additional stimulation which the tags may encounter in theranostic applications including the presence of detergent Triton X-100, lipid membrane, and photothermal treatment. Living-cell imaging also showed signal changing distinction. The different SERS signal performances were attributed to the different Raman reporter releasing behaviors from the tags. This work revealed that Raman reporter structure determined signal stability of lipid-coated SERS tags, providing guidance for the design of stimulus responsive tags. Moreover, it also implied the potential of SERS technique for real time drug release study of lipid based nanomedicine.

  15. Azimuthal Anisotropy in U+U and Au+Au Collisions at RHIC.

    PubMed

    Adamczyk, L; Adkins, J K; Agakishiev, G; Aggarwal, M M; Ahammed, Z; Alekseev, I; Alford, J; Aparin, A; Arkhipkin, D; Aschenauer, E C; Averichev, G S; Banerjee, A; Bellwied, R; Bhasin, A; Bhati, A K; Bhattarai, P; Bielcik, J; Bielcikova, J; Bland, L C; Bordyuzhin, I G; Bouchet, J; Brandin, A V; Bunzarov, I; Burton, T P; Butterworth, J; Caines, H; Calderón de la Barca Sánchez, M; Campbell, J M; Cebra, D; Cervantes, M C; Chakaberia, I; Chaloupka, P; Chang, Z; Chattopadhyay, S; Chen, J H; Chen, X; Cheng, J; Cherney, M; Christie, W; Contin, G; Crawford, H J; Das, S; De Silva, L C; Debbe, R R; Dedovich, T G; Deng, J; Derevschikov, A A; di Ruzza, B; Didenko, L; Dilks, C; Dong, X; Drachenberg, J L; Draper, J E; Du, C M; Dunkelberger, L E; Dunlop, J C; Efimov, L G; Engelage, J; Eppley, G; Esha, R; Evdokimov, O; Eyser, O; Fatemi, R; Fazio, S; Federic, P; Fedorisin, J; Feng, Z; Filip, P; Fisyak, Y; Flores, C E; Fulek, L; Gagliardi, C A; Garand, D; Geurts, F; Gibson, A; Girard, M; Greiner, L; Grosnick, D; Gunarathne, D S; Guo, Y; Gupta, S; Gupta, A; Guryn, W; Hamad, A; Hamed, A; Haque, R; Harris, J W; He, L; Heppelmann, S; Heppelmann, S; Hirsch, A; Hoffmann, G W; Hofman, D J; Horvat, S; Huang, H Z; Huang, B; Huang, X; Huck, P; Humanic, T J; Igo, G; Jacobs, W W; Jang, H; Jiang, K; Judd, E G; Kabana, S; Kalinkin, D; Kang, K; Kauder, K; Ke, H W; Keane, D; Kechechyan, A; Khan, Z H; Kikola, D P; Kisel, I; Kisiel, A; Koetke, D D; Kollegger, T; Kosarzewski, L K; Kotchenda, L; Kraishan, A F; Kravtsov, P; Krueger, K; Kulakov, I; Kumar, L; Kycia, R A; Lamont, M A C; Landgraf, J M; Landry, K D; Lauret, J; Lebedev, A; Lednicky, R; Lee, J H; Li, W; Li, Y; Li, C; Li, Z M; Li, X; Li, X; Lisa, M A; Liu, F; Ljubicic, T; Llope, W J; Lomnitz, M; Longacre, R S; Luo, X; Ma, L; Ma, R; Ma, Y G; Ma, G L; Magdy, N; Majka, R; Manion, A; Margetis, S; Markert, C; Masui, H; Matis, H S; McDonald, D; Meehan, K; Minaev, N G; Mioduszewski, S; Mohanty, B; Mondal, M M; Morozov, D A; Mustafa, M K; Nandi, B K; Nasim, Md; Nayak, T K; Nigmatkulov, G; Nogach, L V; Noh, S Y; Novak, J; Nurushev, S B; Odyniec, G; Ogawa, A; Oh, K; Okorokov, V; Olvitt, D L; Page, B S; Pak, R; Pan, Y X; Pandit, Y; Panebratsev, Y; Pawlik, B; Pei, H; Perkins, C; Peterson, A; Pile, P; Planinic, M; Pluta, J; Poljak, N; Poniatowska, K; Porter, J; Posik, M; Poskanzer, A M; Pruthi, N K; Putschke, J; Qiu, H; Quintero, A; Ramachandran, S; Raniwala, S; Raniwala, R; Ray, R L; Ritter, H G; Roberts, J B; Rogachevskiy, O V; Romero, J L; Roy, A; Ruan, L; Rusnak, J; Rusnakova, O; Sahoo, N R; Sahu, P K; Sakrejda, I; Salur, S; Sandweiss, J; Sarkar, A; Schambach, J; Scharenberg, R P; Schmah, A M; Schmidke, W B; Schmitz, N; Seger, J; Seyboth, P; Shah, N; Shahaliev, E; Shanmuganathan, P V; Shao, M; Sharma, B; Sharma, M K; Shen, W Q; Shi, S S; Shou, Q Y; Sichtermann, E P; Sikora, R; Simko, M; Skoby, M J; Smirnov, D; Smirnov, N; Song, L; Sorensen, P; Spinka, H M; Srivastava, B; Stanislaus, T D S; Stepanov, M; Stock, R; Strikhanov, M; Stringfellow, B; Sumbera, M; Summa, B J; Sun, X; Sun, X M; Sun, Z; Sun, Y; Surrow, B; Svirida, D N; Szelezniak, M A; Tang, Z; Tang, A H; Tarnowsky, T; Tawfik, A N; Thomas, J H; Timmins, A R; Tlusty, D; Tokarev, M; Trentalange, S; Tribble, R E; Tribedy, P; Tripathy, S K; Trzeciak, B A; Tsai, O D; Ullrich, T; Underwood, D G; Upsal, I; Van Buren, G; van Nieuwenhuizen, G; Vandenbroucke, M; Varma, R; Vasiliev, A N; Vertesi, R; Videbaek, F; Viyogi, Y P; Vokal, S; Voloshin, S A; Vossen, A; Wang, F; Wang, Y; Wang, H; Wang, J S; Wang, Y; Wang, G; Webb, G; Webb, J C; Wen, L; Westfall, G D; Wieman, H; Wissink, S W; Witt, R; Wu, Y F; Xiao, Z; Xie, W; Xin, K; Xu, Y F; Xu, N; Xu, Z; Xu, Q H; Xu, H; Yang, Y; Yang, Y; Yang, C; Yang, S; Yang, Q; Ye, Z; Yepes, P; Yi, L; Yip, K; Yoo, I-K; Yu, N; Zbroszczyk, H; Zha, W; Zhang, X P; Zhang, J B; Zhang, J; Zhang, Z; Zhang, S; Zhang, Y; Zhang, J L; Zhao, F; Zhao, J; Zhong, C; Zhou, L; Zhu, X; Zoulkarneeva, Y; Zyzak, M

    2015-11-27

    Collisions between prolate uranium nuclei are used to study how particle production and azimuthal anisotropies depend on initial geometry in heavy-ion collisions. We report the two- and four-particle cumulants, v_{2}{2} and v_{2}{4}, for charged hadrons from U+U collisions at sqrt[s_{NN}]=193  GeV and Au+Au collisions at sqrt[s_{NN}]=200  GeV. Nearly fully overlapping collisions are selected based on the energy deposited by spectators in zero degree calorimeters (ZDCs). Within this sample, the observed dependence of v_{2}{2} on multiplicity demonstrates that ZDC information combined with multiplicity can preferentially select different overlap configurations in U+U collisions. We also show that v_{2} vs multiplicity can be better described by models, such as gluon saturation or quark participant models, that eliminate the dependence of the multiplicity on the number of binary nucleon-nucleon collisions.

  16. Beam Energy Dependence of the Third Harmonic of Azimuthal Correlations in Au +Au Collisions at RHIC

    NASA Astrophysics Data System (ADS)

    Adamczyk, L.; Adkins, J. K.; Agakishiev, G.; Aggarwal, M. M.; Ahammed, Z.; Alekseev, I.; Aparin, A.; Arkhipkin, D.; Aschenauer, E. C.; Attri, A.; Averichev, G. S.; Bai, X.; Bairathi, V.; Bellwied, R.; Bhasin, A.; Bhati, A. K.; Bhattarai, P.; Bielcik, J.; Bielcikova, J.; Bland, L. C.; Bordyuzhin, I. G.; Bouchet, J.; Brandenburg, J. D.; Brandin, A. V.; Bunzarov, I.; Butterworth, J.; Caines, H.; Calderón de la Barca Sánchez, M.; Campbell, J. M.; Cebra, D.; Chakaberia, I.; Chaloupka, P.; Chang, Z.; Chatterjee, A.; Chattopadhyay, S.; Chen, J. H.; Chen, X.; Cheng, J.; Cherney, M.; Christie, W.; Contin, G.; Crawford, H. J.; Das, S.; De Silva, L. C.; Debbe, R. R.; Dedovich, T. G.; Deng, J.; Derevschikov, A. A.; di Ruzza, B.; Didenko, L.; Dilks, C.; Dong, X.; Drachenberg, J. L.; Draper, J. E.; Du, C. M.; Dunkelberger, L. E.; Dunlop, J. C.; Efimov, L. G.; Engelage, J.; Eppley, G.; Esha, R.; Evdokimov, O.; Eyser, O.; Fatemi, R.; Fazio, S.; Federic, P.; Fedorisin, J.; Feng, Z.; Filip, P.; Fisyak, Y.; Flores, C. E.; Fulek, L.; Gagliardi, C. A.; Garand, D.; Geurts, F.; Gibson, A.; Girard, M.; Greiner, L.; Grosnick, D.; Gunarathne, D. S.; Guo, Y.; Gupta, S.; Gupta, A.; Guryn, W.; Hamad, A. I.; Hamed, A.; Haque, R.; Harris, J. W.; He, L.; Heppelmann, S.; Heppelmann, S.; Hirsch, A.; Hoffmann, G. W.; Horvat, S.; Huang, T.; Huang, X.; Huang, B.; Huang, H. Z.; Huck, P.; Humanic, T. J.; Igo, G.; Jacobs, W. W.; Jang, H.; Jentsch, A.; Jia, J.; Jiang, K.; Judd, E. G.; Kabana, S.; Kalinkin, D.; Kang, K.; Kauder, K.; Ke, H. W.; Keane, D.; Kechechyan, A.; Khan, Z. H.; Kikoła, D. P.; Kisel, I.; Kisiel, A.; Kochenda, L.; Koetke, D. D.; Kosarzewski, L. K.; Kraishan, A. F.; Kravtsov, P.; Krueger, K.; Kumar, L.; Lamont, M. A. C.; Landgraf, J. M.; Landry, K. D.; Lauret, J.; Lebedev, A.; Lednicky, R.; Lee, J. H.; Li, X.; Li, C.; Li, X.; Li, Y.; Li, W.; Lin, T.; Lisa, M. A.; Liu, F.; Ljubicic, T.; Llope, W. J.; Lomnitz, M.; Longacre, R. S.; Luo, X.; Ma, R.; Ma, G. L.; Ma, Y. G.; Ma, L.; Magdy, N.; Majka, R.; Manion, A.; Margetis, S.; Markert, C.; Matis, H. S.; McDonald, D.; McKinzie, S.; Meehan, K.; Mei, J. C.; Minaev, N. G.; Mioduszewski, S.; Mishra, D.; Mohanty, B.; Mondal, M. M.; Morozov, D. A.; Mustafa, M. K.; Nandi, B. K.; Nasim, Md.; Nayak, T. K.; Nigmatkulov, G.; Niida, T.; Nogach, L. V.; Noh, S. Y.; Novak, J.; Nurushev, S. B.; Odyniec, G.; Ogawa, A.; Oh, K.; Okorokov, V. A.; Olvitt, D.; Page, B. S.; Pak, R.; Pan, Y. X.; Pandit, Y.; Panebratsev, Y.; Pawlik, B.; Pei, H.; Perkins, C.; Pile, P.; Pluta, J.; Poniatowska, K.; Porter, J.; Posik, M.; Poskanzer, A. M.; Pruthi, N. K.; Putschke, J.; Qiu, H.; Quintero, A.; Ramachandran, S.; Raniwala, S.; Raniwala, R.; Ray, R. L.; Ritter, H. G.; Roberts, J. B.; Rogachevskiy, O. V.; Romero, J. L.; Ruan, L.; Rusnak, J.; Rusnakova, O.; Sahoo, N. R.; Sahu, P. K.; Sakrejda, I.; Salur, S.; Sandweiss, J.; Sarkar, A.; Schambach, J.; Scharenberg, R. P.; Schmah, A. M.; Schmidke, W. B.; Schmitz, N.; Seger, J.; Seyboth, P.; Shah, N.; Shahaliev, E.; Shanmuganathan, P. V.; Shao, M.; Sharma, A.; Sharma, B.; Sharma, M. K.; Shen, W. Q.; Shi, Z.; Shi, S. S.; Shou, Q. Y.; Sichtermann, E. P.; Sikora, R.; Simko, M.; Singha, S.; Skoby, M. J.; Smirnov, N.; Smirnov, D.; Solyst, W.; Song, L.; Sorensen, P.; Spinka, H. M.; Srivastava, B.; Stanislaus, T. D. S.; Stepanov, M.; Stock, R.; Strikhanov, M.; Stringfellow, B.; Sumbera, M.; Summa, B.; Sun, Z.; Sun, X. M.; Sun, Y.; Surrow, B.; Svirida, D. N.; Tang, Z.; Tang, A. H.; Tarnowsky, T.; Tawfik, A.; Thäder, J.; Thomas, J. H.; Timmins, A. R.; Tlusty, D.; Todoroki, T.; Tokarev, M.; Trentalange, S.; Tribble, R. E.; Tribedy, P.; Tripathy, S. K.; Tsai, O. D.; Ullrich, T.; Underwood, D. G.; Upsal, I.; Van Buren, G.; van Nieuwenhuizen, G.; Vandenbroucke, M.; Varma, R.; Vasiliev, A. N.; Vertesi, R.; Videbæk, F.; Vokal, S.; Voloshin, S. A.; Vossen, A.; Wang, F.; Wang, G.; Wang, J. S.; Wang, H.; Wang, Y.; Wang, Y.; Webb, G.; Webb, J. C.; Wen, L.; Westfall, G. D.; Wieman, H.; Wissink, S. W.; Witt, R.; Wu, Y.; Xiao, Z. G.; Xie, W.; Xie, G.; Xin, K.; Xu, Y. F.; Xu, Q. H.; Xu, N.; Xu, H.; Xu, Z.; Xu, J.; Yang, S.; Yang, Y.; Yang, Y.; Yang, C.; Yang, Y.; Yang, Q.; Ye, Z.; Ye, Z.; Yepes, P.; Yi, L.; Yip, K.; Yoo, I.-K.; Yu, N.; Zbroszczyk, H.; Zha, W.; Zhang, X. P.; Zhang, Y.; Zhang, J.; Zhang, J.; Zhang, S.; Zhang, S.; Zhang, Z.; Zhang, J. B.; Zhao, J.; Zhong, C.; Zhou, L.; Zhu, X.; Zoulkarneeva, Y.; Zyzak, M.; STAR Collaboration

    2016-03-01

    We present results from a harmonic decomposition of two-particle azimuthal correlations measured with the STAR detector in Au +Au collisions for energies ranging from √{sN N }=7.7 to 200 GeV. The third harmonic v32{2 }=⟨cos 3 (ϕ1-ϕ2)⟩ , where ϕ1-ϕ2 is the angular difference in azimuth, is studied as a function of the pseudorapidity difference between particle pairs Δ η =η1-η2 . Nonzero v32{2 } is directly related to the previously observed large-Δ η narrow-Δ ϕ ridge correlations and has been shown in models to be sensitive to the existence of a low viscosity quark gluon plasma phase. For sufficiently central collisions, v32{2 } persist down to an energy of 7.7 GeV, suggesting that quark gluon plasma may be created even in these low energy collisions. In peripheral collisions at these low energies, however, v32{2 } is consistent with zero. When scaled by the pseudorapidity density of charged-particle multiplicity per participating nucleon pair, v32{2 } for central collisions shows a minimum near √{sN N }=20 GeV .

  17. Beam Energy Dependence of the Third Harmonic of Azimuthal Correlations in Au + Au Collisions at RHIC

    DOE PAGES

    Adamczyk, L.; Adkins, J. K.; Agakishiev, G.; ...

    2016-03-18

    In this paper, we present results from a harmonic decomposition of two-particle azimuthal correlations measured with the STAR detector in Au + Au collisions for energies ranging from √sNN = 7.7 to 200 GeV. The third harmonic vmore » $$2\\atop{3}$${ 2 } = , where Φ1 - Φ2 is the angular difference in azimuth, is studied as a function of the pseudorapidity difference between particle pairs Δη = η1-η2 . Nonzero v$$2\\atop{3}$${ 2 } is directly related to the previously observed large- Δη narrow- ΔΦ ridge correlations and has been shown in models to be sensitive to the existence of a low viscosity quark gluon plasma phase. For sufficiently central collisions, v$$2\\atop{3}$${ 2 } persist down to an energy of 7.7 GeV, suggesting that quark gluon plasma may be created even in these low energy collisions. In peripheral collisions at these low energies, however, v$$2\\atop{3}$${ 2 } is consistent with zero. Finally, when scaled by the pseudorapidity density of charged-particle multiplicity per participating nucleon pair, v$$2\\atop{3}$${ 2 } for central collisions shows a minimum near √sNN = 20 GeV .« less

  18. Azimuthal anisotophy in U + U and Au + Au collisions at RHIC

    DOE PAGES

    Adamczyk, L.

    2015-11-24

    Collisions between prolate uranium nuclei are used to study how particle production and azimuthal anisotropies depend on initial geometry in heavy-ion collisions. We report the two- and four-particle cumulants, v 2{2} and v 2{4}, for charged hadrons from U+U collisions at √ SNN = 193 GeV and Au+Au collisions at √ SNN = 200 GeV. Nearly fully overlapping collisions are selected based on the energy deposited by spectators in zero degree calorimeters (ZDCs). Within this sample, the observed dependence of v 2{2} on multiplicity demonstrates that ZDC information combined with multiplicity can preferentially select different overlap configurations in U+U collisions.more » As a result, we also show that v 2 vs multiplicity can be better described by models, such as gluon saturation or quark participant models, that eliminate the dependence of the multiplicity on the number of binary nucleon-nucleon collisions.« less

  19. Probing Au nanoparticle uptake by enzyme following the digestion of a starch-Au-nanoparticle composite.

    PubMed

    Deka, Jashmini; Paul, Anumita; Ramesh, A; Chattopadhyay, Arun

    2008-09-16

    In this letter, we report on the digestion of starch, when present as a composite with Au nanoparticles (NPs), by alpha-amylase. It has been observed that the rate of digestion of free starch and that in the composite were identical. Also, the well-established iodine test could be carried out to investigate the kinetics in the presence of Au NPs. The investigations revealed that following the digestion of starch in the composite the NPs were released and subsequently attached to the enzyme only and not to the degraded products of starch. Also, the enzyme attached to NPs, following digestion, retained its catalytic activity. The particle sizes of the NPs were not affected in the process because no agglomeration was observed. Experimental observations indicated the possibility of oriented attachment of alpha-amylase to the NPs in comparison to amyloglucosidase, another digestive enzyme. Finally, we observed a change in the surface plasmon resonance (SPR) of the NPs following the digestion of starch in the composite, and thus we could demonstrate that the SPR of the NPs could be used as a direct probe for monitoring the digestion of the composite by the enzyme.

  20. The Antirheumatic Drug Gold, a Coin With Two Faces: AU(I) and AU(III). Desired and Undesired Effects on the Immune System

    PubMed Central

    Takahashi, Kazuo; Griem, Peter; Goebel, Carsten; Gonzalez, Jose; Gleichmann, Ernst

    1994-01-01

    Three new findings are reviewed that help to understand the mechanisms of action of antirheumatic Au(I) drugs, such as disodium aurothiomalate (Na2Au(I)TM): (i) We found that Na2Au(I)TM selectively inhibits T cell receptor (TCR)-mediated antigen recognition by murine CD4+ T cell hybridomas specific for antigenic peptides containing at least two cysteine residues. Presumably, Au(I) acts as a chelating agent forming linear complexes (Cys-Au(I)-Cys) which prevent correct antigen-processing and/or peptide recognition by the TCR. (ii) We were able to show that Au(I) is oxidized to Au(III) in phagocytic cells, such as macrophages. Because Au(III) is re-reduced to Au(I) this may introduce an Au(I)/Au(III) redox system into phagocytes which scavenges reactive oxygen species, such as OCl- and inactivates lysosomal enzymes. (iii) Pretreatment with Au(III) of a model protein antigen, bovine ribonuclease A (RNase A), induced novel antigenic determinants recognized by CD4+ T lymphocytes. Analysis of the fine specificity of these ‘Au(III)-specific’ T cells revealed that they react to RNase peptides that are not presented to T cells when the native protein, i.e., not treated with Au(III), is used as antigen. The T cell recognition of these cryptic peptides did not require the presence of gold. This finding has important implications for understanding the pathogenesis of allergic and autoimmune responses induced by Au(I) drugs. Taken together, our findings indicate that Au(I) and Au(III) each exert specific effects on several distinct components of macrophages and the subsequent activation of T cells; these effects may explain both the desired anti-inflammatory and the adverse effects of antirheumatic gold drugs. PMID:18476265

  1. Centrality and collision system dependence of antiproton production from p+A to Au+Au collisions at AGS energies

    NASA Technical Reports Server (NTRS)

    Sako, H.; Ahle, L.; Akiba, Y.; Ashktorab, K.; Baker, M. D.; Beavis, D.; Britt, H. C.; Chang, J.; Chasman, C.; Chen, Z.; hide

    1997-01-01

    Antiproton production in heavy ion collisions reflects subtle interplay between initial production and absorption by nucleons. Because the AGS energies (10--20 A(center-dot)GeV/c) are close to the antiproton production threshold, antiproton may be sensitive to cooperative processes such as QGP and hadronic multi-step processes. On the other hand, antiproton has been proposed as a probe of baryon density due to large N(anti N) annihilation cross sections. Cascade models predict the maximum baryon density reaches about 10 times the normal nucleus density in central Au+Au collisions, where the strong antiproton absorption is expected. In this paper, the authors show systematic studies of antiproton production from p+A to Au+Au collisions.

  2. Collective flow measurements with HADES in Au+Au collisions at 1.23A GeV

    NASA Astrophysics Data System (ADS)

    Kardan, Behruz; Hades Collaboration

    2017-11-01

    HADES has a large acceptance combined with a good mass-resolution and therefore allows the study of dielectron and hadron production in heavy-ion collisions with unprecedented precision. With the statistics of seven billion Au-Au collisions at 1.23A GeV recorded in 2012, the investigation of higher-order flow harmonics is possible. At the BEVALAC and SIS18 directed and elliptic flow has been measured for pions, charged kaons, protons, neutrons and fragments, but higher-order harmonics have not yet been studied. They provide additional important information on the properties of the dense hadronic medium produced in heavy-ion collisions. We present here a high-statistics, multidifferential measurement of v1 and v2 for protons in Au+Au collisions at 1.23A GeV.

  3. Wetting - Dewetting Transitions of Au/Ni Bilayer Films

    NASA Astrophysics Data System (ADS)

    Cen, Xi

    Thin films deposited at low temperatures are often kinetically constrained and will dewet the underlying substrate when annealed. Solid state dewetting is driven by the minimization of the total free energy of thin film-substrate interface and free surface, and mostly occurs through surface diffusion. Dewetting is a serious concern in microelectronics reliability. However, it can also be utilized for the self-assembly of nanostructures with potentials in storage, catalysis, or transistors. Therefore, a fundamental understanding of the dewetting behavior of thin metal films is critical for improving the thermal stability of microelectronics and controlling the order of self-assembled nanostructures. Mechanisms for dewetting of single layer films have been studied extensively. However little work has been reported on multilayer or alloyed thin films. In the thesis, the solid state dewetting of Au/Ni bilayer films deposited on SiO2/Si substrates was investigated by scanning electron microscopy (SEM), transmission electron microscopy (TEM) and aberration corrected scanning TEM (STEM). Ex-situ SEM and TEM studies were performed with in-situ TEM heating characterization to identify the mechanisms during the dewetting process of Au/Ni bilayer films. The solid state dewetting of Au/Ni bilayer films from SiO2/Si substrates exhibits both homogeneous and localized dewetting of Ni and long-edge retraction for Au under isothermal annealing condition. The top Au layer retracts up to 1 mm from the edge of the substrate wafer to reduce the energetically unfavored Au/Ni interface. In contrast, Ni dewets and agglomerates locally due to its limited diffusivity compared to Au. Film morphology and local chemical composition varies significantly across hundreds of microns along the direction normal to the retracting edge. Besides long range edge receding, localized dewetting shows significant changes in film morphology and chemical distribution. Both Au and Ni shows texturing. Despite

  4. Effect of Au thickness on AuAg bimetallic growth on reconstructed Si(5 5 12) surfaces

    NASA Astrophysics Data System (ADS)

    Bhukta, Anjan; Ghosh, Arnab; Guha, Puspendu; Maiti, Paramita; Satpati, Biswarup; Satyam, Parlapalli Venkata

    2017-03-01

    Large, stable and single domain unit cell with row-like structures makes reconstructed Si(5 5 12) surface an important one-dimensional growth template of nanostructures. We report on the morphological aspects of the growth of AuAg bimetallic nanostructures on a reconstructed Si(5 5 12) surface that has been deposited with a 0.5 monolayer (ML) Ag and various Au thicknesses (0.5 to 5.0 ML) to determine the optimum gold thickness for a growth of high aspect ratio of AuAg nanostructures. The mean aspect ratio of AuAg nanostructures increases up to Au thickness of 3.0 ML and for larger thickness the mean aspect ratio decreases. The prior growth of 0.5 ML Ag on reconstructed surface result in the formation of one-dimensional Ag strips which are helping for preferential nucleation sites along Si< 1bar{1}0 rangle to form AuAg bimetallic long aspect ratio structures. Followed by these early processes of growth, for Au thickness >3.0 ML, excess Au ad-atoms begin to accumulate along Si< 66bar{5} rangle and consequences reduction of mean aspect ratio of bimetallic nanostructures. Nanostructures are grown using molecular beam epitaxy method under ultra-high vacuum conditions and in situ scanning tunneling microscopy has been used to investigate the morphological variations. Determination of structural aspects and compositional analysis has been carried out using Rutherford backscattering spectrometry and high-resolution (scanning) transmission electron microscopy methods.

  5. Coincidence studies of He ionized by C{sup 6+}, Au{sup 24+}, and Au{sup 53+}

    SciTech Connect

    McGovern, M.; Walters, H. R. J.; Assafrao, D.

    2010-04-15

    A recently developed [Phys. Rev. A 79, 042707 (2009)] impact parameter coupled pseudostate approximation (CP) is applied to calculate triple differential cross sections for single ionization of He by C{sup 6+}, Au{sup 24+}, and Au{sup 53+} projectiles at impact energies of 100 and 2 MeV/amu for C{sup 6+} and 3.6 MeV/amu for Au{sup 24+} and Au{sup 53+}. For C{sup 6+}, satisfactory, but not perfect, agreement is found with experimental measurements in coplanar geometry, but there is substantial disagreement with data taken in a perpendicular plane geometry. The CP calculations firmly contradict a projectile-nucleus interaction model which has been used tomore » support the perpendicular plane measurements. For Au{sup 24+} and Au{sup 53+}, there is a complete lack of accord with the available experiments. However, for Au{sup 24+} the theoretical position appears to be quite firm with clear indications of convergence in the CP approximation and very good agreement between CP and the completely different three-distorted-waves eikonal-initial-state (3DW-EIS) approximation. The situation for Au{sup 53+} is different. At the momentum transfers at which the measurements were made, there are doubts about the convergence of the CP approximation and a factor of 2 difference between the CP and 3DW-EIS predictions. The discord between theory and experiment is even greater with the experiment giving cross sections a factor of 10 larger than the theory. A study of the convergence of the CP approximation shows that it improves rapidly with reducing momentum transfer. As a consequence, lower-order cross sections than the triple are quite well converged and present an opportunity for a more reliable test of the experiment.« less

  6. Λ Λ Correlation Function in Au +Au Collisions at √{sN N }=200 GeV

    NASA Astrophysics Data System (ADS)

    Adamczyk, L.; Adkins, J. K.; Agakishiev, G.; Aggarwal, M. M.; Ahammed, Z.; Alekseev, I.; Alford, J.; Anson, C. D.; Aparin, A.; Arkhipkin, D.; Aschenauer, E. C.; Averichev, G. S.; Banerjee, A.; Beavis, D. R.; Bellwied, R.; Bhasin, A.; Bhati, A. K.; Bhattarai, P.; Bichsel, H.; Bielcik, J.; Bielcikova, J.; Bland, L. C.; Bordyuzhin, I. G.; Borowski, W.; Bouchet, J.; Brandin, A. V.; Brovko, S. G.; Bültmann, S.; Bunzarov, I.; Burton, T. P.; Butterworth, J.; Caines, H.; Calderón de la Barca Sánchez, M.; Campbell, J. M.; Cebra, D.; Cendejas, R.; Cervantes, M. C.; Chaloupka, P.; Chang, Z.; Chattopadhyay, S.; Chen, H. F.; Chen, J. H.; Chen, L.; Cheng, J.; Cherney, M.; Chikanian, A.; Christie, W.; Chwastowski, J.; Codrington, M. J. M.; Contin, G.; Cramer, J. G.; Crawford, H. J.; Cui, X.; Das, S.; Davila Leyva, A.; De Silva, L. C.; Debbe, R. R.; Dedovich, T. G.; Deng, J.; Derevschikov, A. A.; Derradi de Souza, R.; di Ruzza, B.; Didenko, L.; Dilks, C.; Ding, F.; Djawotho, P.; Dong, X.; Drachenberg, J. L.; Draper, J. E.; Du, C. M.; Dunkelberger, L. E.; Dunlop, J. C.; Efimov, L. G.; Engelage, J.; Engle, K. S.; Eppley, G.; Eun, L.; Evdokimov, O.; Eyser, O.; Fatemi, R.; Fazio, S.; Fedorisin, J.; Filip, P.; Fisyak, Y.; Flores, C. E.; Gagliardi, C. A.; Gangadharan, D. R.; Garand, D.; Geurts, F.; Gibson, A.; Girard, M.; Gliske, S.; Greiner, L.; Grosnick, D.; Gunarathne, D. S.; Guo, Y.; Gupta, A.; Gupta, S.; Guryn, W.; Haag, B.; Hamed, A.; Han, L.-X.; Haque, R.; Harris, J. W.; Heppelmann, S.; Hirsch, A.; Hoffmann, G. W.; Hofman, D. J.; Horvat, S.; Huang, B.; Huang, H. Z.; Huang, X.; Huck, P.; Humanic, T. J.; Igo, G.; Jacobs, W. W.; Jang, H.; Judd, E. G.; Kabana, S.; Kalinkin, D.; Kang, K.; Kauder, K.; Ke, H. W.; Keane, D.; Kechechyan, A.; Kesich, A.; Khan, Z. H.; Kikola, D. P.; Kisel, I.; Kisiel, A.; Koetke, D. D.; Kollegger, T.; Konzer, J.; Koralt, I.; Kosarzewski, L. K.; Kotchenda, L.; Kraishan, A. F.; Kravtsov, P.; Krueger, K.; Kulakov, I.; Kumar, L.; Kycia, R. A.; Lamont, M. A. C.; Landgraf, J. M.; Landry, K. D.; Lauret, J.; Lebedev, A.; Lednicky, R.; Lee, J. H.; Li, C.; Li, W.; Li, X.; Li, X.; Li, Y.; Li, Z. M.; Lisa, M. A.; Liu, F.; Ljubicic, T.; Llope, W. J.; Lomnitz, M.; Longacre, R. S.; Luo, X.; Ma, G. L.; Ma, Y. G.; Mahapatra, D. P.; Majka, R.; Margetis, S.; Markert, C.; Masui, H.; Matis, H. S.; McDonald, D.; McShane, T. S.; Minaev, N. G.; Mioduszewski, S.; Mohanty, B.; Mondal, M. M.; Morozov, D. A.; Mustafa, M. K.; Nandi, B. K.; Nasim, Md.; Nayak, T. K.; Nelson, J. M.; Nigmatkulov, G.; Nogach, L. V.; Noh, S. Y.; Novak, J.; Nurushev, S. B.; Odyniec, G.; Ogawa, A.; Oh, K.; Ohlson, A.; Okorokov, V.; Oldag, E. W.; Olvitt, D. L.; Page, B. S.; Pan, Y. X.; Pandit, Y.; Panebratsev, Y.; Pawlak, T.; Pawlik, B.; Pei, H.; Perkins, C.; Pile, P.; Planinic, M.; Pluta, J.; Poljak, N.; Poniatowska, K.; Porter, J.; Poskanzer, A. M.; Pruthi, N. K.; Przybycien, M.; Putschke, J.; Qiu, H.; Quintero, A.; Ramachandran, S.; Raniwala, R.; Raniwala, S.; Ray, R. L.; Riley, C. K.; Ritter, H. G.; Roberts, J. B.; Rogachevskiy, O. V.; Romero, J. L.; Ross, J. F.; Roy, A.; Ruan, L.; Rusnak, J.; Rusnakova, O.; Sahoo, N. R.; Sahu, P. K.; Sakrejda, I.; Salur, S.; Sandweiss, J.; Sangaline, E.; Sarkar, A.; Schambach, J.; Scharenberg, R. P.; Schmah, A. M.; Schmidke, W. B.; Schmitz, N.; Seger, J.; Seyboth, P.; Shah, N.; Shahaliev, E.; Shanmuganathan, P. V.; Shao, M.; Sharma, B.; Shen, W. Q.; Shi, S. S.; Shou, Q. Y.; Sichtermann, E. P.; Simko, M.; Skoby, M. J.; Smirnov, D.; Smirnov, N.; Solanki, D.; Sorensen, P.; Spinka, H. M.; Srivastava, B.; Stanislaus, T. D. S.; Stevens, J. R.; Stock, R.; Strikhanov, M.; Stringfellow, B.; Sumbera, M.; Sun, X.; Sun, X. M.; Sun, Y.; Sun, Z.; Surrow, B.; Svirida, D. N.; Symons, T. J. M.; Szelezniak, M. A.; Takahashi, J.; Tang, A. H.; Tang, Z.; Tarnowsky, T.; Thomas, J. H.; Timmins, A. R.; Tlusty, D.; Tokarev, M.; Trentalange, S.; Tribble, R. E.; Tribedy, P.; Trzeciak, B. A.; Tsai, O. D.; Turnau, J.; Ullrich, T.; Underwood, D. G.; Van Buren, G.; van Nieuwenhuizen, G.; Vandenbroucke, M.; Vanfossen, J. A.; Varma, R.; Vasconcelos, G. M. S.; Vasiliev, A. N.; Vertesi, R.; Videbæk, F.; Viyogi, Y. P.; Vokal, S.; Vossen, A.; Wada, M.; Wang, F.; Wang, G.; Wang, H.; Wang, J. S.; Wang, X. L.; Wang, Y.; Wang, Y.; Webb, G.; Webb, J. C.; Westfall, G. D.; Wieman, H.; Wissink, S. W.; Witt, R.; Wu, Y. F.; Xiao, Z.; Xie, W.; Xin, K.; Xu, H.; Xu, J.; Xu, N.; Xu, Q. H.; Xu, Y.; Xu, Z.; Yan, W.; Yang, C.; Yang, Y.; Yang, Y.; Ye, Z.; Yepes, P.; Yi, L.; Yip, K.; Yoo, I.-K.; Yu, N.; Zbroszczyk, H.; Zha, W.; Zhang, J. B.; Zhang, J. L.; Zhang, S.; Zhang, X. P.; Zhang, Y.; Zhang, Z. P.; Zhao, F.; Zhao, J.; Zhong, C.; Zhu, X.; Zhu, Y. H.; Zoulkarneeva, Y.; Zyzak, M.; STAR Collaboration

    2015-01-01

    We present Λ Λ correlation measurements in heavy-ion collisions for Au +Au collisions at √{sN N }=200 GeV using the STAR experiment at the Relativistic Heavy-Ion Collider. The Lednický-Lyuboshitz analytical model has been used to fit the data to obtain a source size, a scattering length and an effective range. Implications of the measurement of the Λ Λ correlation function and interaction parameters for dihyperon searches are discussed.

  7. Measuring the source size at mid-rapidity using HBT for very central Au-Au collisions at AGS energies

    SciTech Connect

    Baker, M.D.

    1995-10-01

    Hanbury-Brown Twiss correlations are used to measure the source size for charged pions in fixed target Au-Au collision at roughly 11A {center_dot} GeV/c using the E866 spectrometer. The measured source size parameter is studied as a function of energy deposited in a zero-degree calorimeter, focusing especially on the region of very lot energy deposition which corresponds to the most central collisions.

  8. In vitro corrosion of dental Au-based casting alloys in polyvinylpyrrolidone-iodine solution.

    PubMed

    Takasusuki, Norio; Ida, Yusuke; Hirose, Yukito; Ochi, Morio; Endo, Kazuhiko

    2013-01-01

    The corrosion and tarnish behaviors of two Au-based casting alloys (ISO type 1 and type 4 Au alloys) and their constituent pure metals, Au, Ag, Cu, Pt, and Pd in a polyvinylpyrrolidone-iodine solution were examined. The two Au alloys actively corroded, and the main anodic reaction for both was dissolution of Au as AuI₂(-). The amount of Au released from the ISO type 1 Au alloy was significantly larger than that from the ISO type 4 Au alloy (P<0.05). Visible light spectrophotometry revealed that the type 1 alloy exhibited higher susceptibility to tarnishing than the type 4 alloy. The corrosion forms of the two Au alloys were found to be completely different, i.e., the type 1 alloy exhibited the corrosion attack over the entire exposed surface with a little irregularity whereas the type 4 alloy exhibited typical intergranular corrosion, which was caused by local cells produced by segregation of Pd and Pt.

  9. Facile Synthesis of Au Nanocube-CdS Core-Shell Nanocomposites with Enhanced Photocatalytic Activity

    NASA Astrophysics Data System (ADS)

    Liu, Xiao-Li; Liang, Shan; Li, Min; Yu, Xue-Feng; Zhou, Li; Wang, Qu-Qua

    2014-06-01

    Au nanocube-CdS core-shell nanocomposites are prepared by using a one-pot method in aqueous phase with cetyltrimethylammonium bromide as the surfactant. The extinction properties and photocatalytic activity of Au-CdS nanocomposites are investigated. Compared with the pure Au nanocubes, the Au-CdS nanocomposites exhibit enhanced extinction intensity. Compared with CdS nanoparticles, the Au-CdS nanocomposites exhibit improved photocatalytic activity. Furthermore, the photocatalytic efficiency is even better with the increase in the core size of the Au-CdS nanocomposites. Typically, the photocatalytic efficiency of the Au-CdS with 62 nm sized Au nanocubes is about two times higher than that of the pure CdS. It is believed that the Au-CdS nanocomposites may find potential applications in environmental fields, and this synthesis method can be extended to prepare a wide variety of functional composites with Au cores.

  10. Homoepitaxial electrodeposition on reconstructed and unreconstructed Au(100): An in-situ STM study

    NASA Astrophysics Data System (ADS)

    Al-Shakran, Mohammad; Kibler, Ludwig A.; Jacob, Timo

    2015-01-01

    A study of homoepitaxial electrodeposition on reconstructed and unreconstructed Au(100) surfaces is presented. The growth behavior has been investigated by in-situ scanning tunneling microscopy for Au(100) in contact with 0.1 M H2SO4 + 5 μM K[AuCl4]. It is shown that the initial surface structure is decisive for the emerging Au structures, giving rise to clearly different surface morphologies for electro-crystallization of Au on the unreconstructed and on the reconstructed Au(100) surface. A layer-by-layer growth is observed at more positive potentials for unreconstructed Au(100). The electrodeposition proceeds initially by the formation of Au islands followed by island coalescence due to the high mobility of surface atoms. Monatomic recessed stripes are formed as a result of the coalescence of deposited Au islands. At more negative potentials, the growth of Au proceeds strongly anisotropic on the reconstructed surface by the formation of reconstructed elongated islands.

  11. Au(n)Hg(m) clusters: mercury aurides, gold amalgams, or van der Waals aggregates?

    PubMed

    Zaleski-Ejgierd, Patryk; Pyykkö, Pekka

    2009-11-12

    The class of bimetallic clusters, Au(n)M(m) (M = Zn, Cd, Hg), is calculated at the ab initio level using the DFT, RI-MP2, and CCSD(T) methods. For the triatomic Au2M (M = Zn, Cd), the auride-type linear Au-M-Au structures are preferred; for Au2Hg, the linear Au-Au-Hg "amalgam" is preferred. The mixed cation [HgAuHg]+, an analog of the known solid-state species Hg32+, is predicted. For larger Au(n)Hg(m) clusters, the results are similar to the isoelectronic Au(n)M- anions. Several local minima and transition states are identified. All are found to be planar.

  12. Les conjonctivites néonatales dans le canton de Glidji au Sud du Togo: une étude transversale à propos de 159 nouveau-nés

    PubMed Central

    Kokou, Vonor; Nidain, Maneh; Kassoula, Nononsaa Batomguela; Kwassi, Fiaty- Amenouvor; Meba, Banla; Patrice, Balo Komi

    2016-01-01

    Introduction Le but de l’étude était décrire les aspects épidémiologiques des conjonctivites néonatales dans le canton de Glidji au Sud du Togo. Methodes Nous avons mené une étude transversale dans les 4 Unités Sanitaires Périphériques du canton de Glidji du 19 Mars au 13 Mai 2009 soit 8 semaines. Tous les nouveau-nés ont été inclus et la conjonctivite néonatale était définie par la présence chez un nouveau-né d'au moins deux des signes suivants: hyperhémie conjonctivale, œdème palpébral, chémosis, sécrétions purulentes, larmoiement. Les paramètres étudiés étaient l’âge, le sexe, les facteurs de risque, les antécédents, la présence ou non de conjonctivite, les germes en causes et l’évolution sous traitement. Resultats Sur la période, 159 nouveau-nés ont été examinés. L’âge moyen était de 10,9 jours avec des extrêmes de 0 à 28 jours. Il y avait 80 garçons pour 79 filles soit un sex-ratio de 1,01. Sur les 159 nouveau-nés, 7 cas de conjonctivite ont été diagnostiqués soit une prévalence de 4,4%. Les facteurs de risque identifiés étaient l'accouchement par voie basse et la présence d'IST chez la mère pendant la grossesse. Sur les 7 cas de conjonctivite, l'examen cytobactériologique a permis d'isoler le staphylococcus aureus dans 2 cas. L’évolution des cas de conjonctivite sous traitement était favorable avec régression des signes dès le 3è jour. Conclusion Les conjonctivites néonatales avaient une prévalence de 4,4% dans le canton de Glidji au sud du Togo et le staphylocoque doré était le germe en cause. Leur prévention passe par un bon suivi lors de la consultation prénatale et l'instillation de collyre antibiotique à la naissance PMID:27642383

  13. Measurement of D 0 Azimuthal Anisotropy at Midrapidity in Au + Au Collisions at s N N = 200 GeV

    SciTech Connect

    Adamczyk, L.; Adkins, J. K.; Agakishiev, G.

    2017-05-26

    In this paper, we report the first measurement of the elliptic anisotropy (v2) of the charm meson D 0 at midrapidity (|y| < 1) in Au + Au collisions atmore » $$\\sqrt{s}$$$_ {NN}$$ = 200 GeV. The measurement was conducted by the STAR experiment at RHIC utilizing a new high-resolution silicon tracker. The measured D 0 v 2 in 0%–80% centrality Au + Au collisions can be described by a viscous hydrodynamic calculation for a transverse momentum (p T) of less than 4 GeV/c . The D 0 v 2 as a function of transverse kinetic energy (m T - m 0 , where m T = $$\\sqrt{p}$$$2\\atop{T}$$ + m$$2\\atop{0}$$) is consistent with that of light mesons in 10%–40% centrality Au + Au collisions. These results suggest that charm quarks have achieved local thermal equilibrium with the medium created in such collisions. In conclusion, several theoretical models, with the temperature-dependent, dimensionless charm spatial diffusion coefficient (2πTD s) in the range of ~2–12 , are able to simultaneously reproduce our D 0 v 2 result and our previously published results for the D 0 nuclear modification factor.« less

  14. Versatile and efficient catalysts for energy and environmental processes: Mesoporous silica containing Au, Pd and Au-Pd

    NASA Astrophysics Data System (ADS)

    da Silva, Anderson G. M.; Fajardo, Humberto V.; Balzer, Rosana; Probst, Luiz F. D.; Lovón, Adriana S. P.; Lovón-Quintana, Juan J.; Valença, Gustavo P.; Schreine, Wido H.; Robles-Dutenhefner, Patrícia A.

    2015-07-01

    We described a versatile approach for the synthesis of Au/MCM-41, Pd/MCM-41 and Au-Pd/MCM-41 by the direct incorporation of the noble metals into the MCM-41 framework. The structural, textural and chemical properties were characterized by X-ray diffraction (XRD), temperature-programmed reduction (TPR), N2-adsorption (BET and BJH methods), H2-chemisorption, small angle X-ray scattering (SAXS), transmission electron microscope (TEM) and X-ray photoelectron spectroscopy (XPS). The nanomaterials, being comprised of Au, Pd and Au-Pd nanoparticles and possessing high surface areas were applied as versatile and efficient catalysts in benzene, toluene and o-xylene (BTX) oxidation and in the steam reforming of ethanol for hydrogen production. The results revealed that the catalytic behavior in both processes was influenced by the experimental conditions and the nature of the catalyst employed. The Au-Pd/MCM-41 catalyst was the most active in the BTX total oxidation. On the basis of characterization data, it was proposed that the close contact between Pd and Au and the higher dispersion of Pd may be responsible for the enhanced activity of the bimetallic catalyst. However, the strong interaction between the noble metals did not improve the performance of the bimetallic catalyst in ethanol steam reforming, the Pd/MCM-41 catalyst being the most active and selective for hydrogen production.

  15. Au crystal growth on natural occurring Au-Ag aggregate elucidated by means of precession electron diffraction (PED)

    NASA Astrophysics Data System (ADS)

    Roqué Rosell, Josep; Portillo Serra, Joaquim; Aiglsperger, Thomas; Plana-Ruiz, Sergi; Trifonov, Trifon; Proenza, Joaquín A.

    2018-02-01

    In the present work, a lamella from an Au-Ag aggregate found in Ni-laterites has been examined using Transmission Electron Microscope to produce a series of Precision Electron Diffraction (PED) patterns. The analysis of the structural data obtained, coupled with Energy Dispersive X-ray microanalysis, made it possible to determine the orientation of twinned native gold growing on the Au-Ag aggregate. The native Au crystal domains are found to have grown at the outermost part of the aggregate whereas the inner core of the aggregate is an Au-Ag alloy (∼4 wt% Ag). The submicron structural study of the natural occurring Au aggregate points to the mobilization and precipitation of gold in laterites and provides insights on Au aggregates development at supergene conditions. This manuscript demonstrates the great potential of electron crystallographic analysis, and in particular, PED to study submicron structural features of micron sized mineral aggregates by using the example of a gold grain found in a Ni-laterite deposits.

  16. Rationalization of Au concentration and distribution in AuNi@Pt core-shell nanoparticles for oxygen reduction reaction

    DOE PAGES

    An, Wei; Liu, Ping

    2015-09-18

    Improving the activity and stability of Pt-based core–shell nanocatalysts for proton exchange membrane fuel cells while lowering Pt loading has been one of the big challenges in electrocatalysis. Here, using density functional theory, we report the effect of adding Au as the third element to enhance the durability and activity of Ni@Pt core–shell nanoparticles (NPs) during the oxygen reduction reaction (ORR). Our results show that the durability and activity of a Ni@Pt NP can be finely tuned by controlling Au concentration and distribution. For a NiAu@Pt NP, the durability can be greatly promoted by thermodynamically favorable segregation of Au tomore » replace the Pt atoms at vertex, edge, and (100) facets on the shell, while still keeping the ORR activity on the active Pt(111) shell as high as that of Ni@Pt nanoparticles. Such behavior strongly depends on a direct interaction with the Ni interlayer. The results not only highlight the importance of interplay between surface strain on the shell and the interlayer–shell interaction in determining the durability and activity but also provide guidance on how to maximize the usage of Au to optimize the performance of core–shell (Pt) nanoparticles. As a result, such understanding has allowed us to discover a novel NiAu@Pt nanocatalyst for the ORR.« less

  17. Heterojunction metal-oxide-metal Au-Fe{sub 3}O{sub 4}-Au single nanowire device for spintronics

    SciTech Connect

    Reddy, K. M., E-mail: mrkongara@boisestate.edu; Punnoose, Alex; Hanna, Charles

    2015-05-07

    In this report, we present the synthesis of heterojunction magnetite nanowires in alumina template and describe magnetic and electrical properties from a single nanowire device for spintronics applications. Heterojunction Au-Fe-Au nanowire arrays were electrodeposited in porous aluminum oxide templates, and an extensive and controlled heat treatment process converted Fe segment to nanocrystalline cubic magnetite phase with well-defined Au-Fe{sub 3}O{sub 4} interfaces as confirmed by the transmission electron microscopy. Magnetic measurements revealed Verwey transition shoulder around 120 K and a room temperature coercive field of 90 Oe. Current–voltage (I-V) characteristics of a single Au-Fe{sub 3}O{sub 4}-Au nanowire have exhibited Ohmic behavior. Anomalous positivemore » magnetoresistance of about 0.5% is observed on a single nanowire, which is attributed to the high spin polarization in nanowire device with pure Fe{sub 3}O{sub 4} phase and nanocontact barrier. This work demonstrates the ability to preserve the pristine Fe{sub 3}O{sub 4} and well defined electrode contact metal (Au)–magnetite interface, which helps in attaining high spin polarized current.« less

  18. Amperometric Immunosensor for Carbofuran Detection Based on MWCNTs/GS-PEI-Au and AuNPs-Antibody Conjugate

    PubMed Central

    Zhu, Ying; Cao, Yaoyao; Sun, Xia; Wang, Xiangyou

    2013-01-01

    In this paper, an amperometric immunosensor for the detection of carbofuran was developed. Firstly, multiwall carbon nanotubes (MWCNTs) and graphene sheets-ethyleneimine polymer-Au (GS-PEI-Au) nanocomposites were modified onto the surface of a glass carbon electrode (GCE) via self-assembly. The nanocomposites can increase the surface area of the GCE to capture a large amount of antibody, as well as produce a synergistic effect in the electrochemical performance. Then the modified electrode was coated with gold nanoparticles-antibody conjugate (AuNPs-Ab) and blocked with BSA. The monoclonal antibody against carbofuran was covalently immobilized on the AuNPs with glutathione as a spacer arm. The morphologies of the GS-PEI-Au nanocomposites and the fabrication process of the immunosensor were characterized by X-ray diffraction (XRD), ultraviolet and visible absorption spectroscopy (UV-vis) and scanning electron microscopy (SEM), respectively. Under optimal conditions, the immunosensor showed a wide linear range, from 0.5 to 500 ng/mL, with a detection limit of 0.03 ng/mL (S/N = 3). The as-constructed immunosensor exhibited notable performance features such as high specificity, good reproducibility, acceptable stability and regeneration performance. The results are mainly due to the excellent properties of MWCNTs, GS-PEI-Au nanocomposites and the covalent immobilization of Ab with free hapten binding sites for further immunoreaction. It provides a new avenue for amperometric immunosensor fabrication. PMID:23604029

  19. Effect of Au nano-particle aggregation on the deactivation of the AuCl3/AC catalyst for acetylene hydrochlorination

    PubMed Central

    Dai, Bin; Wang, Qinqin; Yu, Feng; Zhu, Mingyuan

    2015-01-01

    A detailed study of the valence state and distribution of the AuCl3/AC catalyst during the acetylene hydrochlorination deactivation process is described and discussed. Temperature-programmed reduction and X-ray photoelectron spectral analysis indicate that the active Au3+ reduction to metallic Au0 is one reason for the deactivation of AuCl3/AC catalyst. Transmission electron microscopy characterization demonstrated that the particle size of Au nano-particles increases with increasing reaction time. The results indicated that metallic Au0 exhibits considerable catalytic activity and that Au nano-particle aggregation may be another reason for the AuCl3/AC catalytic activity in acetylene hydrochlorination. PMID:25994222

  20. Core/shell Au/MnO nanoparticles prepared through controlled oxidation of AuMn as an electrocatalyst for sensitive H2O2 detection.

    PubMed

    Zhu, Huiyuan; Sigdel, Aruna; Zhang, Sen; Su, Dong; Xi, Zheng; Li, Qing; Sun, Shouheng

    2014-11-10

    Monodisperse 5 nm AuMn nanoparticles were synthesized by hydride reduction of manganese acetylacetonate in the presence of Au nanoparticles. The alloy was formed through fast Mn diffusion into the Au structure. The AuMn nanoparticles were converted to Au-MnO composite particles through air annealing at 170 °C. These Au-MnO particles, especially the core/shell Au/MnO nanoparticles, were active for the electrochemical reduction of H2 O2 , with a detection limit reaching 8 nM. This highly sensitive electrochemical sensor based on the Au/MnO nanoparticles was used to monitor H2 O2 concentrations released from living cells, from which tumorigenic cells were discovered to release higher levels of H2 O2 than the non-tumorigenic cells. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  1. Jet-hadron correlations in √[s(NN)]=200  GeV p+p and central Au+Au collisions.

    PubMed

    Adamczyk, L; Adkins, J K; Agakishiev, G; Aggarwal, M M; Ahammed, Z; Alekseev, I; Alford, J; Anson, C D; Aparin, A; Arkhipkin, D; Aschenauer, E C; Averichev, G S; Banerjee, A; Beavis, D R; Bellwied, R; Bhasin, A; Bhati, A K; Bhattarai, P; Bichsel, H; Bielcik, J; Bielcikova, J; Bland, L C; Bordyuzhin, I G; Borowski, W; Bouchet, J; Brandin, A V; Brovko, S G; Bültmann, S; Bunzarov, I; Burton, T P; Butterworth, J; Caines, H; Calderón de la Barca Sánchez, M; Cebra, D; Cendejas, R; Cervantes, M C; Chaloupka, P; Chang, Z; Chattopadhyay, S; Chen, H F; Chen, J H; Chen, L; Cheng, J; Cherney, M; Chikanian, A; Christie, W; Chwastowski, J; Codrington, M J M; Contin, G; Cramer, J G; Crawford, H J; Cui, X; Das, S; Davila Leyva, A; De Silva, L C; Debbe, R R; Dedovich, T G; Deng, J; Derevschikov, A A; Derradi de Souza, R; Dhamija, S; di Ruzza, B; Didenko, L; Dilks, C; Ding, F; Djawotho, P; Dong, X; Drachenberg, J L; Draper, J E; Du, C M; Dunkelberger, L E; Dunlop, J C; Efimov, L G; Engelage, J; Engle, K S; Eppley, G; Eun, L; Evdokimov, O; Eyser, O; Fatemi, R; Fazio, S; Fedorisin, J; Filip, P; Finch, E; Fisyak, Y; Flores, C E; Gagliardi, C A; Gangadharan, D R; Garand, D; Geurts, F; Gibson, A; Girard, M; Gliske, S; Greiner, L; Grosnick, D; Gunarathne, D S; Guo, Y; Gupta, A; Gupta, S; Guryn, W; Haag, B; Hamed, A; Han, L-X; Haque, R; Harris, J W; Heppelmann, S; Hirsch, A; Hoffmann, G W; Hofman, D J; Horvat, S; Huang, B; Huang, H Z; Huang, X; Huck, P; Humanic, T J; Igo, G; Jacobs, W W; Jang, H; Judd, E G; Kabana, S; Kalinkin, D; Kang, K; Kauder, K; Ke, H W; Keane, D; Kechechyan, A; Kesich, A; Khan, Z H; Kikola, D P; Kisel, I; Kisiel, A; Koetke, D D; Kollegger, T; Konzer, J; Koralt, I; Kotchenda, L; Kraishan, A F; Kravtsov, P; Krueger, K; Kulakov, I; Kumar, L; Kycia, R A; Lamont, M A C; Landgraf, J M; Landry, K D; Lauret, J; Lebedev, A; Lednicky, R; Lee, J H; LeVine, M J; Li, C; Li, W; Li, X; Li, X; Li, Y; Li, Z M; Lisa, M A; Liu, F; Ljubicic, T; Llope, W J; Lomnitz, M; Longacre, R S; Luo, X; Ma, G L; Ma, Y G; Madagodagettige Don, D M M D; Mahapatra, D P; Majka, R; Margetis, S; Markert, C; Masui, H; Matis, H S; McDonald, D; McShane, T S; Minaev, N G; Mioduszewski, S; Mohanty, B; Mondal, M M; Morozov, D A; Mustafa, M K; Nandi, B K; Nasim, Md; Nayak, T K; Nelson, J M; Nigmatkulov, G; Nogach, L V; Noh, S Y; Novak, J; Nurushev, S B; Odyniec, G; Ogawa, A; Oh, K; Ohlson, A; Okorokov, V; Oldag, E W; Olvitt, D L; Pachr, M; Page, B S; Pal, S K; Pan, Y X; Pandit, Y; Panebratsev, Y; Pawlak, T; Pawlik, B; Pei, H; Perkins, C; Peryt, W; Pile, P; Planinic, M; Pluta, J; Poljak, N; Porter, J; Poskanzer, A M; Pruthi, N K; Przybycien, M; Pujahari, P R; Putschke, J; Qiu, H; Quintero, A; Ramachandran, S; Raniwala, R; Raniwala, S; Ray, R L; Riley, C K; Ritter, H G; Roberts, J B; Rogachevskiy, O V; Romero, J L; Ross, J F; Roy, A; Ruan, L; Rusnak, J; Rusnakova, O; Sahoo, N R; Sahu, P K; Sakrejda, I; Salur, S; Sandweiss, J; Sangaline, E; Sarkar, A; Schambach, J; Scharenberg, R P; Schmah, A M; Schmidke, W B; Schmitz, N; Seger, J; Seyboth, P; Shah, N; Shahaliev, E; Shanmuganathan, P V; Shao, M; Sharma, B; Shen, W Q; Shi, S S; Shou, Q Y; Sichtermann, E P; Singaraju, R N; Skoby, M J; Smirnov, D; Smirnov, N; Solanki, D; Sorensen, P; Spinka, H M; Srivastava, B; Stanislaus, T D S; Stevens, J R; Stock, R; Strikhanov, M; Stringfellow, B; Sumbera, M; Sun, X; Sun, X M; Sun, Y; Sun, Z; Surrow, B; Svirida, D N; Symons, T J M; Szelezniak, M A; Takahashi, J; Tang, A H; Tang, Z; Tarnowsky, T; Thomas, J H; Timmins, A R; Tlusty, D; Tokarev, M; Trentalange, S; Tribble, R E; Tribedy, P; Trzeciak, B A; Tsai, O D; Turnau, J; Ullrich, T; Underwood, D G; Van Buren, G; van Nieuwenhuizen, G; Vandenbroucke, M; Vanfossen, J A; Varma, R; Vasconcelos, G M S; Vasiliev, A N; Vertesi, R; Videbæk, F; Viyogi, Y P; Vokal, S; Vossen, A; Wada, M; Wang, F; Wang, G; Wang, H; Wang, J S; Wang, X L; Wang, Y; Wang, Y; Webb, G; Webb, J C; Westfall, G D; Wieman, H; Wissink, S W; Witt, R; Wu, Y F; Xiao, Z; Xie, W; Xin, K; Xu, H; Xu, J; Xu, N; Xu, Q H; Xu, Y; Xu, Z; Yan, W; Yang, C; Yang, Y; Yang, Y; Ye, Z; Yepes, P; Yi, L; Yip, K; Yoo, I-K; Yu, N; Zawisza, Y; Zbroszczyk, H; Zha, W; Zhang, J B; Zhang, J L; Zhang, S; Zhang, X P; Zhang, Y; Zhang, Z P; Zhao, F; Zhao, J; Zhong, C; Zhu, X; Zhu, Y H; Zoulkarneeva, Y; Zyzak, M

    2014-03-28

    Azimuthal angular correlations of charged hadrons with respect to the axis of a reconstructed (trigger) jet in Au+Au and p+p collisions at √[s(NN)]=200  GeV in STAR are presented. The trigger jet population in Au+Au collisions is biased toward jets that have not interacted with the medium, allowing easier matching of jet energies between Au+Au and p+p collisions while enhancing medium effects on the recoil jet. The associated hadron yield of the recoil jet is significantly suppressed at high transverse momentum (pTassoc) and enhanced at low pTassoc in 0%-20% central Au+Au collisions compared to p+p collisions, which is indicative of medium-induced parton energy loss in ultrarelativistic heavy-ion collisions.

  2. Structural features of Ag[AuF{sub 4}] and Ag[AuF{sub 6}] and the structural relationship of Ag[AgF{sub 4}]{sub 2} and Au[AuF{sub 4}]{sub 2} to Ag[AuF{sub 4}]{sub 2}

    SciTech Connect

    Graudejus, O.; Wilkinson, A.P.; Bartlett, N.

    2000-04-03

    Synchrotron radiation X-ray powder diffraction data (SPDD) have been obtained for Ag[AgF{sub 4}]{sub 2}, Au[AuF{sub 4}]{sub 2}, Ag[AuF{sub 4}], and Ag[AuF{sub 6}]. Ag[AgF{sub 4}]{sub 2} and Au[AuF{sub 4}]{sub 2} are isostructural with Ag[AuF{sub 4}]{sub 2}. The structure of Ag[AgF{sub 4}]{sub 2} was refined successfully (SPDD) applying the Rietveld method, yielding interatomic distances ({angstrom}), other AA{prime}F{sub 4} salts (A = Na-Rb; A{prime} = Ag, Au), crystallizes in the KBrF{sub 4} structure type. SPDD gave (in {angstrom}) four Au{sup III}-F = 1.89(1) and eight Ag{sup 1}-F = 2.577(7). SPDD for AgAuF{sub 6} confirmed that it has the LiSbF{sub 6} structure.

  3. Spin-Orbit Splittings and Low-Lying Electronic States of AuSi and AuGe: Anion Photoelectron Spectroscopy and ab Initio Calculations.

    PubMed

    Tran, Quoc Tri; Lu, Sheng-Jie; Zhao, Li-Juan; Xu, Xi-Ling; Xu, Hong-Guang; Tran, Van Tan; Li, Jun; Zheng, Wei-Jun

    2018-04-05

    We measured the photoelectron spectra of diatomic AuSi - and AuGe - and conducted calculations on the structures and electronic properties of AuSi -/0 and AuGe -/0 . The calculations at the CASSCF/CASPT2 level confirmed that experimentally observed spectra features of AuSi - and AuGe - can be attributed to the transitions from the 3 Σ - anionic ground state to the 2 Π ( 2 Π 1/2 and 2 Π 3/2 ), 4 Σ - , 3 2 Σ + , and 4 2 Σ + electronic states of their neutral counterparts. The electron affinities (EAs) of AuSi and AuGe are determined by the experiments to be 1.54 ± 0.05 and 1.51 ± 0.05 eV, respectively. The spin-orbit splittings ( 2 Π 1/2 - 2 Π 3/2 ) of AuSi and AuGe measured in this work are in agreement with the literature values. The energy difference between the 4 Σ - (A) and 2 Π 1/2 states of AuSi obtained in this work is in reasonable agreement with the literature value, while that of AuGe obtained in this work by anion photoelectron spectroscopy is slightly larger than the literature value by neutral emission spectroscopy. The term energies of the 3 2 Σ + (B) and 4 2 Σ + (C) states of AuSi and AuGe were also determined based on the photoelectron spectra. Because of the different bond lengths between the anionic and neutral states, the electronic state terms energies of AuSi and AuGe estimated from the anion photoelectron spectra might be slightly different from those obtained from the neutral emission spectra.

  4. Formation, Migration, and Reactivity of Au CO Complexes on Gold Surfaces

    DOE PAGES

    Wang, Jun; McEntee, Monica; Tang, Wenjie; ...

    2016-01-12

    Here, we report experimental as well as theoretical evidence that suggests Au CO complex formation upon the exposure of CO to active sites (step edges and threading dislocations) on a Au(111) surface. Room-temperature scanning tunneling microscopy (STM), X-ray photoelectron spectroscopy, transmission infrared spectroscopy, and density functional theory calculations point to Au CO complex formation and migration. Room-temperature STM of the Au(111) surface at CO pressures in the range from 10^ 8 to 10^ 4 Torr (dosage up to 10^6 langmuir) indicates Au atom extraction from dislocation sites of the herringbone reconstruction, mobile Au CO complex formation and diffusion, and Aumore » adatom cluster formation on both elbows and step edges on the Au surface. The formation and mobility of the Au CO complex result from the reduced Au Au bonding at elbows and step edges leading to stronger Au CO bonding and to the formation of a more positively charged CO (CO +) on Au. These studies indicate that the mobile Au CO complex is involved in the Au nanoparticle formation and reactivity, and that the positive charge on CO increases due to the stronger adsorption of CO at Au sites with lower coordination numbers.« less

  5. Profil diagnostique et évolutif du myélome multiple au Sénégal: étude monocentrique de 2005 à 2016

    PubMed Central

    Fall, Seynabou; Dieng, Fatma; Diouf, Coumba; Djiba, Boundia; Ndao, Awa Cheikh; Ndiaye, Fatou Samba Diago

    2017-01-01

    Introduction Les thérapeutiques innovantes du myélome multiple sont peu accessibles en Afrique subsaharienne. Le but de cette étude est de décrire les particularités diagnostiques et évolutives observées dans notre pratique de prise en charge des myélomateux. Méthodes Une étude rétrospective (2005 - 2016) descriptive à visée analytique, mené à l’hôpital Le Dantec (Sénégal) a concerné les myélomateux inclus selon les critères de l’International Myeloma Working Group (2003, 2014). Résultats Ont été colligés 136 dossiers (69 hommes, 67 femmes) de patients d’âge moyen 59 ans ± 10,1 ans et qui ont un âge inférieur à 65 ans dans 69,1% des cas. Les signes révélateurs ont été des douleurs osseuses (96,3%), une insuffisance rénale (36,8%), une infection (23,5%), une fracture pathologique (17,6%), une compression médullaire (16,9%), et une hypercalcémie maligne (16,2%). L’isotype a été IgG dans 61,3% des cas et Kappa dans 65% des cas. Les malades ont été classés stade III (59,4%) et I-II (40,6%) de l’index staging system. Sous traitement conventionnel (Méphalan-Prédnisone: 67,6%, innovant: 5,9%), la survie médiane a été de 20 mois (1-78 mois). La survie est meilleure, en l’absence de complications neurologiques, infectieuses et au score I-II de l’Index Staging System. Conclusion Dans notre étude, le myélome multiple est fréquemment diagnostiqué avant 65 ans, au stade de forte masse tumorale. La survie globale peut être améliorée par un dépistage précoce et un accès aux thérapeutiques adéquates. PMID:29187931

  6. L’embolie pulmonaire au centre hospitalier universitaire Campus de Lomé (Togo): étude rétrospective à propos de 51 cas

    PubMed Central

    Pessinaba, Soulemane; Atti, Yaovi Dodzi Molba; Baragou, Soodougoua; Pio, Machihude; Afassinou, Yaovi; Kpélafia, Mohamed; Goeh-Akué, Edem; Damorou, Findibé

    2017-01-01

    Introduction L’objectif était d’étudier les aspects épidémiologiques, cliniques et évolutifs de l’embolie pulmonaire au CHU Campus de Lomé. Méthodes C’est une étude rétrospective, analytique et descriptive sur une période de 39 mois (1erNovembre 2011- 31 Janvier 2015). Etaient inclus, tous les dossiers des patients hospitalisés dans le service de cardiologie du CHU Campus pour une EP. Résultats La prévalence de l’EP était de 3,1%. Le sex ratio femme/homme était de 2,2. L’âge moyen des patients était de 52,7 ± 14,4 ans. Les facteurs de risque de MTEV étaient dominés par: l’obésité (54,9%), l’alitement (25,5%) et le long voyage (17,6%). Les principaux symptômes étaient: dyspnée (98,0%), douleur thoracique (78,4%) et toux (60,8%). Le score de Wells était élevé dans 29,4%. L’ECG notait: tachycardie (78,4%), HVD (49,0%), aspect S1Q3T3 (47,1%) et bloc droit (39,2%). L’échodoppler cardiaque transthoracique montrait une dilatation cavitaire droite et thrombus intra ventriculaire droit dans 5,6%. L’angioscanner thoracique était normal dans 9,8% et objectivait un embole dans 82,4%. Le traitement était fait d’HBPM à dose curative avec relais par un AVK. Une thrombolyse était effectuée chez 8 malades. L’évolution était favorable dans 86,3%. Le taux de létalité était de 13,7%. Conclusion La prévalence de l’EP est relativement faible chez nous mais probablement sous estimée. L’EP pose un problème thérapeutique au Togo à cause du coût élevé des examens complémentaires et de la thrombolyse. La prévention reste donc l’arme efficace. PMID:28904659

  7. Aspects cliniques et thérapeutiques du priapisme au CHU Gabriel Touré: étude de 36 cas

    PubMed Central

    Kassogué, Amadou; Coulibaly, Mamadou; Ouattara, Zanafon; Diarra, Alkadri; Tembely, Aly; El Fassi, Mohamed Jamal; Farih, Moulay Hassan; Ouattara, Kalilou

    2014-01-01

    Le priapisme est une érection prolongée douloureuse et irréductible survenant en dehors de toute stimulation sexuelle et n'aboutissant pas à une éjaculation. C'est une urgence urologique. Au Mali, la drépanocytose, une pathologie endémique joue un rôle de premier plan parmi les étiologies. L'objectif de cette étude est d'analyser les aspects cliniques et thérapeutiques du priapisme. Nous avons réalisé une étude rétrospective de type descriptive portant sur 36 cas de priapisme colligés au service d'urologie du CHU Gabriel Touré sur une période de 6 ans et 4 mois. L’âge moyen de nos patients était de 17 ans. Les tranches d’âge les plus représentées étaient comprises entre (11-20 ans) et (21-30 ans) soit 58%. 11 patients soit 31 % avaient eu un antécédent d’érection prolongée; le délai de consultation à partir du premier signe du priapisme était retardé, 31 % des patients étaient venus dans les 24-72h. Sur les 34 patients qui avaient fait l’électrophorèse de l'hémoglobine, 31 patients soit 91 % étaient porteurs d'hémoglobine anormale S et ou C. 32 patients soit 89% de nos patients avaient eu une ponction des corps caverneux. La détumescence a été obtenue le même jour chez 61 % des patients. Chez 11 patients soit 31 %, l’érection était bonne. Le priapisme est une urgence urologique, dont la fréquence est élevée dans la population drépanocytaire. La drépanocytose était la principale cause dans notre pays, tout praticien doit systématiquement y penser avant toute autre étiologie. PMID:25317234

  8. La baisse de la densité osseuse au cours des maladies inflammatoires chroniques de l'intestin: prévalence et facteurs de risqué

    PubMed Central

    Trabelsi, Aida Ben Slama; Abdellaoui, Faouzi; Ksiaa, Mehdi; Souguir, Ahlem; Zeglaoui, Hela; Rejeb, Mohamed Ben; Brahem, Ahlem; Ajmi, Salem; Jmaa, Ali

    2013-01-01

    Introduction La baisse de la densité minérale osseuse représente la principale manifestation osseuse décrite au cours des maladies inflammatoires chroniques de l'intestin. En Tunisie, très peu d’études ont rapportés sa prévalence et ses facteurs de risque. Le but de ce travail était de déterminer la prévalence de la perte osseuse au cours des maladies inflammatoires chroniques de l'intestin, et rechercher ses facteurs de risque. Méthodes Patients et méthodes: étude ouverte transversale, réalisée de 2007 jusqu’à 2012. Résultats 146 cas étaient colligés, dont 105 avaient une maladie de Crohn (71,9%) et 41 avaient une rectocolite hémorragique (28,1%). Il s'agissait de 62 hommes et 84 femmes. L’âge moyen était de 33,18 ans. La perte osseuse était trouvée chez 85 patients (58,2%). Il s'agissait d'une ostéopénie dans 57 cas et d'ostéoporose dans 28 cas. Les facteurs de risque de perte osseuse étaient une activité physique limitée (p=0,013), un indice de masse corporel ‘20 kg/m2 (p=0,015), une maladie active (p=0,035), l’étendue de l'atteinte intestinale (p=0,006) et une dose cumulée de corticothérapie dépassant 4,5g de Prednisone (p=0,003). Conclusion La déminéralisation osseuse est une complication fréquente mais non constante. Ceci justifie un dépistage précoce chez les patients à risque, qui pourront ainsi bénéficier d'un traitement substitutif. PMID:24198872

  9. Hydrothermal Cation Exchange Enabled Gradual Evolution of Au@ZnS-AgAuS Yolk-Shell Nanocrystals and Their Visible Light Photocatalytic Applications.

    PubMed

    Feng, Jingwen; Liu, Jia; Cheng, Xiaoyan; Liu, Jiajia; Xu, Meng; Zhang, Jiatao

    2018-01-01

    Yolk-shell hybrid nanoparticles with noble metal core and programmed semiconductor shell composition may exhibit synergistic effects and tunable catalytic properties. In this work, the hydrothermal cation exchange synthesis of Au@ZnS-AgAuS yolk-shell nanocrystals (Y-S NCs) with well-fabricated void size, grain-boundary-architectured ZnS-AgAuS shell and in situ generated Au cocatalyst are demonstrated. Starting from the novel cavity-free Au@AgAuS core-shell NCs, via aqueous cation exchange reaction with Zn 2+ , the gradual evolution with produced Au@ZnS-AgAuS Y-S NCs can be achieved successfully. This unprecedented evolution can be reasonably explained by cation exchange initialized chemical etching of Au core, followed by the diffusion through the shell to be AgAuS and then ZnS. By hydrothermal treatment provided optimal redox environment, Au ions in shell were partially reduced to be Au NCs on the surface. The UV-vis absorption spectra evolution and visible light photocatalytic performances, including improved photodegradation behavior and photocatalytic hydrogen evolution activity, have demonstrated their potential applications. This new one-pot way to get diverse heterointerfaces for better photoinduced electron/hole separation synergistically can be anticipated for more kinds of photocatalytic organic synthesis.

  10. Thiol ligand-induced transformation of Au38(SC2H4Ph)24 to Au36(SPh-t-Bu)24.

    PubMed

    Zeng, Chenjie; Liu, Chunyan; Pei, Yong; Jin, Rongchao

    2013-07-23

    We report a disproportionation mechanism identified in the transformation of rod-like biicosahedral Au38(SCH2CH2Ph)24 to tetrahedral Au36(TBBT)24 nanoclusters. Time-dependent mass spectrometry and optical spectroscopy analyses unambiguously map out the detailed size-conversion pathway. The ligand exchange of Au38(SCH2CH2Ph)24 with bulkier 4-tert-butylbenzenethiol (TBBT) until a certain extent starts to trigger structural distortion of the initial biicosahedral Au38(SCH2CH2Ph)24 structure, leading to the release of two Au atoms and eventually the Au36(TBBT)24 nanocluster with a tetrahedral structure, in which process the number of ligands is interestingly preserved. The other product of the disproportionation process, i.e., Au40(TBBT)m+2(SCH2CH2Ph)24-m, was concurrently observed as an intermediate, which was the result of addition of two Au atoms and two TBBT ligands to Au38(TBBT)m(SCH2CH2Ph)24-m. The reaction kinetics on the Au38(SCH2CH2Ph)24 to Au36(TBBT)24 conversion process was also performed, and the activation energies of the structural distortion and disproportionation steps were estimated to be 76 and 94 kJ/mol, respectively. The optical absorption features of Au36(TBBT)24 are interpreted on the basis of density functional theory simulations.

  11. Hydrothermal Cation Exchange Enabled Gradual Evolution of Au@ZnS–AgAuS Yolk–Shell Nanocrystals and Their Visible Light Photocatalytic Applications

    PubMed Central

    Feng, Jingwen; Liu, Jia; Cheng, Xiaoyan; Liu, Jiajia; Xu, Meng

    2017-01-01

    Abstract Yolk–shell hybrid nanoparticles with noble metal core and programmed semiconductor shell composition may exhibit synergistic effects and tunable catalytic properties. In this work, the hydrothermal cation exchange synthesis of Au@ZnS–AgAuS yolk–shell nanocrystals (Y–S NCs) with well‐fabricated void size, grain‐boundary‐architectured ZnS–AgAuS shell and in situ generated Au cocatalyst are demonstrated. Starting from the novel cavity‐free Au@AgAuS core‐shell NCs, via aqueous cation exchange reaction with Zn2+, the gradual evolution with produced Au@ZnS–AgAuS Y–S NCs can be achieved successfully. This unprecedented evolution can be reasonably explained by cation exchange initialized chemical etching of Au core, followed by the diffusion through the shell to be AgAuS and then ZnS. By hydrothermal treatment provided optimal redox environment, Au ions in shell were partially reduced to be Au NCs on the surface. The UV–vis absorption spectra evolution and visible light photocatalytic performances, including improved photodegradation behavior and photocatalytic hydrogen evolution activity, have demonstrated their potential applications. This new one‐pot way to get diverse heterointerfaces for better photoinduced electron/hole separation synergistically can be anticipated for more kinds of photocatalytic organic synthesis. PMID:29375968

  12. Transverse energy (ET) distributions at mid-rapidity in p + p, d + Au and Au + Au collisions at √{sNN} = 200 GeV and implications for particle production models

    NASA Astrophysics Data System (ADS)

    Tannenbaum, M. J.; Phenix Collaboration

    2014-11-01

    Measurements of the mid-rapidity transverse energy distribution dET / dη are presented for p + p, d + Au , and Au+Au collisions at √{sNN} = 62.4- 200 GeV. The ET distributions are compared with the number of participants, Npart, the number of constituent-quark participants, Nqp, and the number of color-strings (Additive Quark Model - AQM) calculated from a Glauber model. For Au+Au, 〈 dET / dη 〉 / (0.5Npart) increases with Npart, while 〈 dET / dη 〉 /Nqp is approximately constant vs. centrality for √{sNN} ≥ 62.4 GeV. This indicates that the two component ansatz, dETAA / dη = (dETpp / dη) [ (1 - x)Npart / 2 + xNcoll ], which has been used to represent ET distributions, is simply a proxy for Nqp, and that the Ncoll term does not represent a hard-scattering component in ET distributions. The dET / dη distributions of d + Au , and Au+Au are calculated from the measured p + pET distribution using two models (AQM and Nqp) that both reproduce the Au+Au data. For the asymmetric d + Au system, the Nqp model reproduces the data while the AQM does not.

  13. Drowned reefs and antecedent karst topography, Au'au channel, S.E. Hawaiian Islands

    USGS Publications Warehouse

    Grigg, R.W.; Grossman, E.E.; Earle, S.A.; Gittings, S.R.; Lott, D.; McDonough, J.

    2002-01-01

    During the last glacial maximum (LGM), about 21,000 years ago, the Hawaiian Islands of Maui, Lanai, and Molokai were interconnected by limestone bridges, creating a super-island known as Maui-Nui. Approximately 120 m of sea-level rise during the Holocene Transgression flooded, and then drowned, these bridges separating the islands by inter-island channels. A new multibeam high-resolution bathymetric survey of the channels between the islands, coupled with observations and video-transects utilizing DeepWorker-2000 submersibles, has revealed the existence of numerous drowned reef features including concentric solution basins, solution ridges (rims), sand and sediment plains, and conical-shaped reef pinnacles. The concentric basins contain flat lagoon-like bottoms that are rimmed by steep-sided limestone walls. Undercut notches rim the basins at several depths, marking either sea-level still stands or paleo-lake levels. All of the solution basins shallower than 120 m were subaerial at the LGM, and at one stage or another may have been shallow shoreline lakes. Today, about 70 drowned reef pinnacles are scattered across the Maui-Lanai underwater bridge and all are situated in wave-sheltered positions. Most drowned during the interval between 14,000 and 10,000 years ago when sea-level rise averaged 15 mm/year. Virtually all of the surficial topography in the Au'au Channel today is a product of karst processes accentuated by marginal reef growth during the Holocene. Both the submerged basins and the drowned reefs represent an archive of sea-level and climate history in Hawaii during the late Quaternary.

  14. Dielectron production in Au + Au collisions at √{sN N}=200 GeV

    NASA Astrophysics Data System (ADS)

    Adare, A.; Aidala, C.; Ajitanand, N. N.; Akiba, Y.; Akimoto, R.; Alexander, J.; Alfred, M.; Al-Ta'Ani, H.; Angerami, A.; Aoki, K.; Apadula, N.; Aramaki, Y.; Asano, H.; Aschenauer, E. C.; Atomssa, E. T.; Averbeck, R.; Awes, T. C.; Azmoun, B.; Babintsev, V.; Bai, M.; Bandara, N. S.; Bannier, B.; Barish, K. N.; Bassalleck, B.; Bathe, S.; Baublis, V.; Baumgart, S.; Bazilevsky, A.; Beaumier, M.; Beckman, S.; Belmont, R.; Berdnikov, A.; Berdnikov, Y.; Blau, D. S.; Bok, J. S.; Boyle, K.; Brooks, M. L.; Bryslawskyj, J.; Buesching, H.; Bumazhnov, V.; Butsyk, S.; Campbell, S.; Castera, P.; Chen, C.-H.; Chi, C. Y.; Chiu, M.; Choi, I. J.; Choi, J. B.; Choi, S.; Choudhury, R. K.; Christiansen, P.; Chujo, T.; Chvala, O.; Cianciolo, V.; Citron, Z.; Cole, B. A.; Connors, M.; Csanád, M.; Csörgő, T.; Dairaku, S.; Danley, T. W.; Datta, A.; Daugherity, M. S.; David, G.; Deblasio, K.; Dehmelt, K.; Denisov, A.; Deshpande, A.; Desmond, E. J.; Dharmawardane, K. V.; Dietzsch, O.; Ding, L.; Dion, A.; Diss, P. B.; Do, J. H.; Donadelli, M.; D'Orazio, L.; Drapier, O.; Drees, A.; Drees, K. A.; Durham, J. M.; Durum, A.; Edwards, S.; Efremenko, Y. V.; Engelmore, T.; Enokizono, A.; Esumi, S.; Eyser, K. O.; Fadem, B.; Feege, N.; Fields, D. E.; Finger, M.; Finger, M.; Fleuret, F.; Fokin, S. L.; Frantz, J. E.; Franz, A.; Frawley, A. D.; Fukao, Y.; Fusayasu, T.; Gainey, K.; Gal, C.; Gallus, P.; Garg, P.; Garishvili, A.; Garishvili, I.; Ge, H.; Giordano, F.; Glenn, A.; Gong, X.; Gonin, M.; Goto, Y.; Granier de Cassagnac, R.; Grau, N.; Greene, S. V.; Grosse Perdekamp, M.; Gunji, T.; Guo, L.; Gustafsson, H.-Å.; Hachiya, T.; Haggerty, J. S.; Hahn, K. I.; Hamagaki, H.; Hamilton, H. F.; Han, S. Y.; Hanks, J.; Hasegawa, S.; Haseler, T. O. S.; Hashimoto, K.; Haslum, E.; Hayano, R.; He, X.; Hemmick, T. K.; Hester, T.; Hill, J. C.; Hollis, R. S.; Homma, K.; Hong, B.; Horaguchi, T.; Hori, Y.; Hoshino, T.; Hotvedt, N.; Huang, J.; Huang, S.; Ichihara, T.; Iinuma, H.; Ikeda, Y.; Imai, K.; Imrek, J.; Inaba, M.; Iordanova, A.; Isenhower, D.; Issah, M.; Ivanishchev, D.; Jacak, B. V.; Javani, M.; Jezghani, M.; Jia, J.; Jiang, X.; Johnson, B. M.; Joo, K. S.; Jouan, D.; Jumper, D. S.; Kamin, J.; Kanda, S.; Kaneti, S.; Kang, B. H.; Kang, J. H.; Kang, J. S.; Kapustinsky, J.; Karatsu, K.; Kasai, M.; Kawall, D.; Kazantsev, A. V.; Kempel, T.; Key, J. A.; Khachatryan, V.; Khanzadeev, A.; Kijima, K. M.; Kim, B. I.; Kim, C.; Kim, D. J.; Kim, E.-J.; Kim, G. W.; Kim, H. J.; Kim, K.-B.; Kim, M.; Kim, Y.-J.; Kim, Y. K.; Kimelman, B.; Kinney, E.; Kiss, Á.; Kistenev, E.; Kitamura, R.; Klatsky, J.; Kleinjan, D.; Kline, P.; Koblesky, T.; Komatsu, Y.; Komkov, B.; Koster, J.; Kotchetkov, D.; Kotov, D.; Král, A.; Krizek, F.; Kunde, G. J.; Kurita, K.; Kurosawa, M.; Kwon, Y.; Kyle, G. S.; Lacey, R.; Lai, Y. S.; Lajoie, J. G.; Lebedev, A.; Lee, B.; Lee, D. M.; Lee, J.; Lee, K. B.; Lee, K. S.; Lee, S.; Lee, S. H.; Lee, S. R.; Leitch, M. J.; Leite, M. A. L.; Leitgab, M.; Lewis, B.; Li, X.; Lim, S. H.; Linden Levy, L. A.; Liu, M. X.; Love, B.; Lynch, D.; Maguire, C. F.; Makdisi, Y. I.; Makek, M.; Manion, A.; Manko, V. I.; Mannel, E.; Masumoto, S.; McCumber, M.; McGaughey, P. L.; McGlinchey, D.; McKinney, C.; Meles, A.; Mendoza, M.; Meredith, B.; Miake, Y.; Mibe, T.; Mignerey, A. C.; Milov, A.; Mishra, D. K.; Mitchell, J. T.; Miyachi, Y.; Miyasaka, S.; Mizuno, S.; Mohanty, A. K.; Mohapatra, S.; Montuenga, P.; Moon, H. J.; Moon, T.; Morrison, D. P.; Motschwiller, S.; Moukhanova, T. V.; Murakami, T.; Murata, J.; Mwai, A.; Nagae, T.; Nagamiya, S.; Nagashima, K.; Nagle, J. L.; Nagy, M. I.; Nakagawa, I.; Nakagomi, H.; Nakamiya, Y.; Nakamura, K. R.; Nakamura, T.; Nakano, K.; Nattrass, C.; Nederlof, A.; Netrakanti, P. K.; Nihashi, M.; Niida, T.; Nishimura, S.; Nouicer, R.; Novák, T.; Novitzky, N.; Nyanin, A. S.; O'Brien, E.; Ogilvie, C. A.; Okada, K.; Orjuela Koop, J. D.; Osborn, J. D.; Oskarsson, A.; Ouchida, M.; Ozawa, K.; Pak, R.; Pantuev, V.; Papavassiliou, V.; Park, B. H.; Park, I. H.; Park, J. S.; Park, S.; Park, S. K.; Pate, S. F.; Patel, L.; Patel, M.; Pei, H.; Peng, J.-C.; Pereira, H.; Perepelitsa, D. V.; Perera, G. D. N.; Peressounko, D. Yu.; Perry, J.; Petti, R.; Pinkenburg, C.; Pinson, R.; Pisani, R. P.; Proissl, M.; Purschke, M. L.; Qu, H.; Rak, J.; Ramson, B. J.; Ravinovich, I.; Read, K. F.; Reynolds, D.; Riabov, V.; Riabov, Y.; Richardson, E.; Rinn, T.; Roach, D.; Roche, G.; Rolnick, S. D.; Rosati, M.; Rowan, Z.; Rubin, J. G.; Sahlmueller, B.; Saito, N.; Sakaguchi, T.; Sako, H.; Samsonov, V.; Sano, M.; Sarsour, M.; Sato, S.; Sawada, S.; Schaefer, B.; Schmoll, B. K.; Sedgwick, K.; Seidl, R.; Sen, A.; Seto, R.; Sett, P.; Sexton, A.; Sharma, D.; Shein, I.; Shibata, T.-A.; Shigaki, K.; Shimomura, M.; Shoji, K.; Shukla, P.; Sickles, A.; Silva, C. L.; Silvermyr, D.; Sim, K. S.; Singh, B. K.; Singh, C. P.; Singh, V.; Slunečka, M.; Snowball, M.; Soltz, R. A.; Sondheim, W. E.; Sorensen, S. P.; Sourikova, I. V.; Stankus, P. W.; Stenlund, E.; Stepanov, M.; Ster, A.; Stoll, S. P.; Sugitate, T.; Sukhanov, A.; Sumita, T.; Sun, J.; Sziklai, J.; Takagui, E. M.; Takahara, A.; Taketani, A.; Tanaka, Y.; Taneja, S.; Tanida, K.; Tannenbaum, M. J.; Tarafdar, S.; Taranenko, A.; Tennant, E.; Themann, H.; Tieulent, R.; Timilsina, A.; Todoroki, T.; Tomášek, L.; Tomášek, M.; Torii, H.; Towell, C. L.; Towell, R.; Towell, R. S.; Tserruya, I.; Tsuchimoto, Y.; Tsuji, T.; Vale, C.; van Hecke, H. W.; Vargyas, M.; Vazquez-Zambrano, E.; Veicht, A.; Velkovska, J.; Vértesi, R.; Virius, M.; Vossen, A.; Vrba, V.; Vznuzdaev, E.; Wang, X. R.; Watanabe, D.; Watanabe, K.; Watanabe, Y.; Watanabe, Y. S.; Wei, F.; Wei, R.; White, A. S.; White, S. N.; Winter, D.; Wolin, S.; Woody, C. L.; Wysocki, M.; Xia, B.; Xue, L.; Yalcin, S.; Yamaguchi, Y. L.; Yang, R.; Yanovich, A.; Ying, J.; Yokkaichi, S.; Yoo, J. H.; Yoon, I.; You, Z.; Younus, I.; Yu, H.; Yushmanov, I. E.; Zajc, W. A.; Zelenski, A.; Zhou, S.; Zou, L.; Phenix Collaboration

    2016-01-01

    We present measurements of e+e- production at midrapidity in Au +Au collisions at √{sNN}=200 GeV. The invariant yield is studied within the PHENIX detector acceptance over a wide range of mass (me e<5 GeV /c2) and pair transverse momentum (pT<5 GeV /c ) for minimum bias and for five centrality classes. The e+e- yield is compared to the expectations from known sources. In the low-mass region (me e=0.30 - 0.76 GeV /c2 ) there is an enhancement that increases with centrality and is distributed over the entire pair pT range measured. It is significantly smaller than previously reported by the PHENIX experiment and amounts to 2.3 ±0.4 (stat )±0.4 (syst )±0.2 (model ) or to 1.7 ±0.3 (stat )±0.3 (syst )±0.2 (model ) for minimum bias collisions when the open heavy-flavor contribution is calculated with pythia or mc@nlo, respectively. The inclusive mass and pT distributions, as well as the centrality dependence, are well reproduced by model calculations where the enhancement mainly originates from the melting of the ρ meson resonance as the system approaches chiral symmetry restoration. In the intermediate-mass region (me e=1.2 - 2.8 GeV /c2 ), the data hint at a significant contribution in addition to the yield from the semileptonic decays of heavy-flavor mesons.

  15. Simulation of Au particle interaction on graphene sheets

    NASA Astrophysics Data System (ADS)

    Mcleod, A.; Vernon, K. C.; Rider, A. E.; Ostrikov, K.

    2013-09-01

    The interaction of Au particles with few layer graphene is of interest for the formation of the next generation of sensing devices 1. In this paper we investigate the coupling of single gold nanoparticles to a graphene sheet, and multiple gold nanoparticles with a graphene sheet using COMSOL Multiphysics. By using these simulations we are able to determine the electric field strength and associated hot-spots for various gold nanoparticle-graphene systems. The Au nanoparticles were modelled as 8 nm diameter spheres on 1.5 nm thick (5 layers) graphene, with properties of graphene obtained from the refractive index data of Weber 2 and the Au refractive index data from Palik 3. The field was incident along the plane of the sheet with polarisation tested for both s and p. The study showed strong localised interaction between the Au and graphene with limited spread; however the double particle case where the graphene sheet separated two Au nanoparticles showed distinct interaction between the particles and graphene. An offset was introduced (up to 4 nm) resulting in much reduced coupling between the opposed particles as the distance apart increased. Findings currently suggest that the graphene layer has limited interaction with incident fields with a single particle present whilst reducing the coupling region to a very fine area when opposing particles are involved. It is hoped that the results of this research will provide insight into graphene-plasmon interactions and spur the development of the next generation of sensing devices.

  16. Radiotherapy of bile duct carcinoma using intracatheter 198Au grains.

    PubMed

    Hiratsuka, J; Imajo, Y; Numaguchi, K; Ohumi, T; Shirabe, T

    1991-01-01

    Eight patients with bile duct carcinoma were treated with radiotherapy using intracatheter 198Au grains. The intracatheter 198Au grains in an inner tube were inserted into a percutaneous transhepatic catheter. A plastic tip was placed between these grains to improve spatial and temporal dose allocation. This method and 192Ir wire irradiation resemble each other closely in dose distribution, but the former has the following advantages over the latter. 1) The number of 198Au grains used can be changed quite easily in accordance with the length of the stenosis. 2) The half-life of 198Au is about 2.7 days, and a dose of 25-40 Gy at 1.0 cm from the source is delivered over this period. The medical staff can protect themselves from radioactivity when the sources are withdrawn after brachytherapy. 3) 192Ir wire is not used very frequently in spite of its long half-life (74 days) because bile duct carcinoma is uncommon. 4) In Japan, 198Au grains can be purchased on a weekly basis, so treatment plans can be easily made. The eight patients also received external irradiation and the median survival after onset of radiotherapy was 7.9 months. There have been few systemic or local complications.

  17. Chirality-Controlled Syntheses of Double-Helical Au Nanowires.

    PubMed

    Nakagawa, Makoto; Kawai, Takeshi

    2018-04-18

    The selective large-scale syntheses of noble metal nanocrystals with complex shapes using wet-chemical approaches remain exciting challenges. Here we report the chirality-controllable syntheses of double-helical Au nanowires (NWs) using chiral soft-templates composed of two organogelators with their own active functions; one organogelator serves to introduce helicity into the template and the other acts as a capping agent to control the Au shape. One-dimensional twisted-nanoribbon templates are prepared simply by mixing the two organogelators in water containing a small amount of toluene, followed by the addition of LiCl; template chirality is controlled through the selection of the handedness of the helicity-inducing organogelator. Double-helical Au NWs synthesized on these chiral templates have the same helical structure as the template because the Au NWs grow along both edges of the twisted nanoribbons with right- or left-handed helicities. Dispersions of the right- and left-handed double-helical Au NWs exhibit opposite CD signals.

  18. Multiple Nonstoichiometric Phases with Discrete Composition Ranges in the CaAu5−CaAu4Bi−BiAu2 System. A Case Study of the Chemistry of Spinodal Decomposition

    SciTech Connect

    Lin, Qisheng; Corbett, John D.

    2010-04-01

    Synthetic explorations in the CaAu{sub 5}-CaAu{sub 4}Bi-BiAu{sub 2} system at 400 C reveal five separate solid solution regions that show three distinct substitution patterns in the CaAu{sub 5} parent: (I) CaAu{sub 4}(Au{sub 1-m}Bi{sub m}) with 0 {le} m {le} 0.15(1), (II) 0.33(1) {le} m {le} 0.64(1), (III) 0.85(4) {le} m {le} 0.90(2); (IV) (Ca{sub 1-r}Au{sub r})Au{sub 4}(Bi{sub 1-s}Au{sub s}) with 0 {le} r {le} 0.39(1) and 0 {le} s {le} 0.12(2); (V) (Ca{sub 1-p-q}Au{sub p}Bi{sub q})Au{sub 4}Bi with 0.09(2) {le} p {le} 0.13(1) and 0.31(2) {le} q {le} 0.72(4). Single crystal X-ray studies establish that all of these phase regionsmore » have common cubic symmetry F{sub 4}3m and that their structures (MgCu{sub 4}Sn-type, an ordered derivative of MgCu{sub 2}) all feature three-dimensional networks of Au{sub 4} tetrahedra, in which the truncated tetrahedra are centered and capped by Ca/Au, Au/Bi, or Ca/Au/Bi mixtures to give 16-atom Friauf polyhedra. TB-LMTO-ASA and -COHP calculations also reveal that direct interactions between Ca-Au and Ca-Bi pairs of atoms are relatively weak and that the Bi-Au interactions in the unstable ideal CaAu{sub 4}Bi are antibonding in character at E{sub F} but that their bonding is optimized at {+-}1 e. Compositions between the five nonstoichiometric phases appear to undergo spinodal decompositions. The last phenomenon has been confirmed by HRTEM, STEM-HAADF, EPMA, and XRD studies of the nominal composition CaAu{sub 4.25}Bi{sub 0.75}. Its DTA analyses suggest that the phases resulting from spinodal decomposition have nearly the same melting point ({approx}807 C), as expected, and that they are interconvertible through peritectic reactions at {approx}717 C.« less

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

    DOE PAGES

    Villa, Alberto; Chan-Thaw, Carine E.; Campisi, Sebastiano; ...

    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 Au core–Ru shell 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,more » 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.« less

  20. Structure of SiAu16: Can a silicon atom be stabilized in a gold cage?

    NASA Astrophysics Data System (ADS)

    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 fullerenelike 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, biomedine, and jewelry industry.

  1. Reduced Solar Wind Speeds at New Horizons Beyond 30 AU

    NASA Astrophysics Data System (ADS)

    Elliott, H. A.; McComas, D. J.; Zirnstein, E.; Delamere, P. A.; Bagenal, F.; Stern, A.; Weaver, H. A., Jr.; Young, L. A.; Ennico Smith, K.; Olkin, C.

    2017-12-01

    Prior comparisons between Voyager 2 and IMP 8 observations found the solar wind had clearly decrease by 8% at a distance of 25 AU. Since mid-2016 solar rotation averaged speeds at New Horizons have been elevated relative to speeds observed in 2014 and 2015. However, we find a clear decrease in the New Horizons speeds beyond 30 AU when compared to those of ACE near Earth. At distances between 30-38.5 AU the relative speed reduction is in the 8-11% range. We will further this work by also comparing with available STEREO observations. By including STEREO, we can assess how sensitive the speed comparisons are to longitude separations and determine the appropriate time scale to average over.

  2. Facile synthesis of Ag nanocubes and Au nanocages.

    PubMed

    Skrabalak, Sara E; Au, Leslie; Li, Xingde; Xia, Younan

    2007-01-01

    This protocol describes a method for the synthesis of Ag nanocubes and their subsequent conversion into Au nanocages via the galvanic replacement reaction. The Ag nanocubes are prepared by a rapid (reaction time < 15 min), sulfide-mediated polyol method in which Ag(I) is reduced to Ag(0) by ethylene glycol in the presence of poly(vinyl pyrrolidone) (PVP) and a trace amount of Na(2)S. When the concentration of Ag atoms reaches supersaturation, they agglomerate to form seeds that then grow into Ag nanostructures. The presence of both PVP and Na(2)S facilitate the formation of nanocubes. With this method, Ag nanocubes can be prepared and isolated for use within approximately 3 h. The Ag nanocubes can then serve as sacrificial templates for the preparation of Au nanocages, with a method for their preparation also described herein. The procedure for Au nanocage preparation and isolation requires approximately 5 h.

  3. Surfactant assisted Au nanoparticle layering in titanium oxide thin films

    NASA Astrophysics Data System (ADS)

    Mukherjee, Smita; Das, Pradip Shekhar; Choudhuri, Madhumita; Datta, Alokmay; Ghosh, Jiten; Mukhopadhyay, Anoop Kr.

    2017-05-01

    Au Nanoparticle (NP) decorated TiO2 thin films, prepared by a unique surfactant assisted 2D self-assembling technique with molecular level control, showed significant decrease in optical band gap as well as enhanced crystallinity compared to its sol-gel prepared pristine counterpart. Spin coated Au NP overlayers on titania in absence of surfactant, on the other hand, had no appreciable effect on either band gap or crystal structure compared to undoped TiO2 films. Apart from exhibiting band gap tuning of TiO2, this cheap, scalable technique of surfactant aided deposition of 2D layers of Au NPs on semiconducting oxides, may be used for development of multilayered structures with promising light harvesting and unidirectional energy transfer (LUET) applications.

  4. The Cu 3Au(001) surface: a He diffraction study

    NASA Astrophysics Data System (ADS)

    Mannori, C.; Scimia, T.; Cantini, P.; Terreni, S.; Canepa, M.; Mattera, L.

    1999-08-01

    We present the results of a helium diffraction study of the morphology of a Cu 3Au(001) surface at 140 K. Biatomic steps only are not able to describe the terrace morphology, and monoatomic steps must be included. The step height (1.855±0.015 Å) is closely comparable to the bulk interlayer spacing of Cu 3Au along the <001> direction (1.865 Å). Two kinds of terraces have been identified. The first class (A-terraces) are the majority. They are large terraces that display the well-known c(2×2) ordering of the Au-Cu termination. The second type (B-terraces) consists of much smaller terraces of uncertain composition. B-terraces are separated from A-terraces by a monoatomic step. Monoatomic steps are probably bunched into pairs.

  5. Magneto-optical microcavity with Au plasmonic layer

    NASA Astrophysics Data System (ADS)

    Mikhailova, T. V.; Lyashko, S. D.; Tomilin, S. V.; Karavainikov, A. V.; Prokopov, A. R.; Shaposhnikov, A. N.; Berzhansky, V. N.

    2017-11-01

    Optical and Faraday rotation spectra of magneto-optical microcavity coated with Au plasmonic layer of gradient thickness were investigated theoretically and experimentally. It was shown that the Tamm plasmon-polaritons mode forms near the long-wavelength edge of photonic band gap. The presence of Au coating of thickness of 90.4 nm increase the Faraday rotation at Tamm plasmon-polaritons and cavity resonances in 1.3 and 7 times, respectively. By transfer matrix method it were found that the incorporation of SiO2 buffer layer with a thickness in the range from 155 to 180 nm between microcavity and Au coating leads to the strong coupling between cavity mode and Tamm plasmon-polaritons. In this case, one or two resonances arise in the vicinity of the cavity mode depending on the thickness of plasmonic layer. The Faraday rotation for coupled mode in twice less than the value of rotation for single cavity mode.

  6. Enhancing the reactivity of gold: Nanostructured Au(111) adsorbs CO

    DOE PAGES

    Hoffmann, F. M.; Hrbek, J.; Ma, S.; ...

    2015-12-02

    Low-coordinated sites are surface defects whose presence can transform a surface of inert or noble metal such as Au into an active catalyst. We prepared gold surfaces modified by pits, starting with a well-ordered Au(111) surface; we then used microscopy (STM) for their structural characterization and CO spectroscopy (IRAS and NEXAFS) for probing reactivity of surface defects. In contrast to the Au(111) surface CO adsorbs readily on the pitted surfaces bonding to low-coordinated sites identified as step atoms forming {111} and {100} microfacets. Finally, pitted nanostructured surfaces can serve as interesting and easily prepared models of catalytic surfaces with definedmore » defects that offer an attractive alternative to vicinal surfaces or nanoparticles commonly employed in catalysis science.« less

  7. Tri-metallic PtPdAu mesoporous nanoelectrocatalysts.

    PubMed

    Li, Chunjie; Wang, Hongjing; Li, Yinghao; Yu, Hongjie; Yin, Shuli; Xue, Hairong; Li, Xiaonian; Xu, You; Wang, Liang

    2018-06-22

    The design of mesoporous materials with multi-metallic compositions is highly important for various electrocatalytic applications. In this paper, we demonstrate an efficient method to directly fabricate tri-metallic PtPdAu mesoporous nanoparticles (PtPdAu MNs) in a high yield, which is simply performed by heating treatment of the reaction mixture aqueous solution at 40 °C for 4 h. Profiting from its mesoporous structure and multi-metallic components, the as-prepared PtPdAu MNs exhibit enhanced electrocatalytic activities toward both methanol oxidation reaction and oxygen reduction reaction in comparison with bi-metallic PtPd MNs and commercial Pt/C catalyst.

  8. Au-Ag hollow nanostructures with tunable SERS properties

    NASA Astrophysics Data System (ADS)

    Jiji, S. G.; Gopchandran, K. G.

    2017-01-01

    Fabrication of hollow Au-Ag nanoparticles is done by the sequential action of galvanic replacement and Kirkendall effect. Polyol synthesized silver nanoparticles were used as templates and the size of cavities is controlled by the systematic addition of the HAuCl4. Au-Ag nanoparticles carved in different depths were tested for application as substrates for surface enhanced Raman scattering. Two medically important Raman active analytes-Nile blue chloride and Crystal violet were used in the surface enhanced Raman scattering (SERS) performance analysis. A systematic study has been made on the Raman enhancement of hollow nanoparticles fabricated with different cavity dimensions and compared with that of the silver templates used. The enhancement observed for these hollow substrates with cavities is of interest since Au protected hollow nanostructures are vital and an active area of interest in drug delivery systems.

  9. 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.

  10. Surface plasmon aided high sensitive non-enzymatic glucose sensor using Au/NiAu multilayered nanowire arrays.

    PubMed

    Wang, Lanfang; Zhu, Weiqi; Lu, Wenbo; Qin, Xiufang; Xu, Xiaohong

    2018-07-15

    A novel plasmon aided non-enzymatic glucose sensor was first constructed based on the unique half-rough Au/NiAu multilayered nanowire arrays. These multilayered and half-rough nanowires provide high chemical activity and large surface area for glucose oxidation in an alkaline solution. Under visible light irradiation, the surface plasmons originated from Au part enhance the electron transfer in the vertically aligned nanowires, leading to high sensitivity and wide detection range. The resulting sensor exhibits a wide glucose detection concentration range, low detection limit, and high sensitivity for plasmon aided non-enzymatic glucose sensor. Moreover, the detection sensitivity is enhanced by almost 2 folds compared to that in the dark, which significantly enhanced the performance of Au/NiAu multilayered nanowire arrays sensor. An excellent selectivity and acceptable stability were also achieved. These results indicate that surface plasmon aided nanostructures are promising new platforms for the construction of non-enzymatic glucose sensors. Copyright © 2018 Elsevier B.V. All rights reserved.

  11. A redox-switchable Au8-cluster sensor.

    PubMed

    Wu, Te-Haw; Hsu, Yu-Yen; Lin, Shu-Yi

    2012-07-09

    The proof of concept of a simple sensing platform based on the fluorescence of a gold cluster consisting of eight atoms, which is easily manipulated by reduction and oxidation of a specific molecule in the absence of chemical linkers, is demonstrated. Without using any coupling reagents to arrange the distance of the donor-acceptor pair, the fluorescence of the Au(8) -cluster is immediately switched off in the presence of 2-pyridinethiol (2-PyT) quencher. Through an upward-curving Stern-Volmer plot, the system shows complex fluorescence quenching with a combination of static and dynamic quenching processes. To analyze the static quenching constant (V) by a "sphere of action" model, the collisional encounter between the Au(8) -cluster and 2-PyT presents a quenching radius (r) ≈5.8 nm, which is larger than the sum of the radii of the Au(8) -cluster and 2-PyT. This implies that fluorescence quenching can occur even though the Au(8) -cluster and 2-PyT are not very close to each other. The quenching pathway may be derived from a photoinduced electron-transfer process of the encounter pair between the Au(8) -cluster (as an electron donor) and 2-PyT (as an electron acceptor) to allow efficient fluorescence quenching in the absence of coupling reagents. Interestingly, the fluorescence is restored by oxidation of 2-PyT to form the corresponding disulfide compound and then quenched again after the reduction of the disulfide. This redox-switchable fluorescent Au(8) -cluster platform is a novel discovery, and its utility as a promising sensor for detecting H(2) O(2) -generating enzymatic transformations is demonstrated. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  12. L’évaluation du syndrome du Burnout chez les médecins en formation au CHU Ibn Rochd de Casablanca

    PubMed Central

    El Kettani, Assiya; Serhier, Zineb; Othmani, Mohammed Bennani; Agoub, Mohamed; Battas, Omar

    2017-01-01

    Introduction Le Burnout est très répandu en milieu hospitalier et sa gravité est encore plus accrue chez les jeunes médecins. L'objectif est de déterminer la prévalence du burnout parmi les médecins en formation (internes et résidents) au CHU Ibn Rochd de Casablanca et chercher les facteurs associés. Méthodes Étude transversale descriptive menée en 2013- 2014 auprès d'un échantillon de 300 médecins à l'aide d'un questionnaire auto-administré; le burnout était évalué par la version française du Maslash Burnout Inventory (MBI). Résultats Un total de191 médecins a participé à l'étude (taux de réponse à 63,7%) avec une prédominance féminine à 79,1% et une moyenne d'âge de 26,7ans (ET = 3). Les scores moyens des sous-dimensions du MBI: l'épuisement émotionnel, la dépersonnalisation et l'accomplissement personnel étaient respectivement de (33,7 ± 10,7), (12,2 ± 6,5) et (30,6 ± 8,3). Le burnout sévère touchait 31,8% des participants. Il était associé aux problèmes de communication au sein de l'équipe soignante (p < 0,01), l'accompagnement insuffisant (p < 0,05), l'insatisfaction des séniors (p = 0,01), la crainte de faire des erreurs médicales (p < 0,05), le recours à un psychothérapeute (p < 0,001), la consommation de psychotropes (p = 0,001), les troubles anxieux (p < 0,01), la dépression (p < 0,01) et les idées suicidaires (p < 0,05). Les facteurs protecteurs étaient représentés par: le sentiment d'équité au sein de l'équipe soignante (p < 0,01) et la pratique de loisirs (p < 0,05). Le changement d'orientation de carrière était associé au burnout sévère (p < 0,05). Conclusion Ces résultats rejoignent ceux des études précédentes et justifient l'intérêt d'un programme de prévention à différents niveaux. Introduction Burnout is very widespread in the hospital setting and it becomes much more severe in young physicians. The objective of this study aims to evaluate the prevalence of burnout among doctors

  13. Nuclear Shadowing and Select d+Au Observables

    NASA Astrophysics Data System (ADS)

    Adeluyi, Adeola; Fai, George

    2007-04-01

    Much of the complexity of the description of d+Au collisions in the framework of perturbative Quantum Chromodynamics (pQCD) derives from effects of the nuclear environment. Here we investigate the effects of the most recent available nuclear shadowing parametrization, the Hirai-Kumano-Nagai (HKN) nuclear parton distribution functions (nPDFs) and the updated Albino-Kniehl-Kramer (AKK) fragmentation functions on three select d+Au collision observables. We compare our results to available experimental data from the STAR and BRAHMS collaborations.

  14. Nanoscale Pattern Formation during Electrodeposition: Ru on Reconstructed Au(111)

    NASA Astrophysics Data System (ADS)

    Strbac, S.; Magnussen, O. M.; Behm, R. J.

    1999-10-01

    Scanning tunneling microscopy results on Ru electrodeposition on reconstructed Au(111) are presented, which show a novel type of site-selective nucleation on this surface. At potentials around 0.0 V vs the Ag/AgCl reference electrode, nucleation of Ru monolayer islands proceeds almost exclusively in the fcc regions of the reconstructed surface rather than at the elbow sites as commonly found for metal/Au(111) systems. These results provide a link between nucleation on two-dimensional and uniaxial dislocation networks. The nucleation behavior allows the formation of well-defined nm-scale admetal structures which replicate the reconstruction pattern.

  15. Nondestructive analysis of Au-Cr layers in aged microcircuits

    SciTech Connect

    Antolak, A.; Morse, D.; Wilson, K.

    1997-11-01

    Particle-induced x-ray emission (PIXE), Rutherford backscattering spectroscopy (RBS), and nuclear reaction analysis (NRA) are being used to investigated compositional changes in MK4 radar unit microelectronics resulting from possible age-related chromium diffusion in gold. Since the analysis is nondestructive, changes in the mechanical properties of the system can be more readily correlated to measured compositional changes at the buried interface. Measurements are conducted to investigate trace levels of chromium at the external Au surface, determine the actual gold layer thickness of the test sample, and measure compositional changes occurring at the Au-Cr interface.

  16. Atomic Structure of Au 329(SR) 84 Faradaurate Plasmonic Nanomolecules

    DOE PAGES

    Kumara, Chanaka; Zuo, Xiaobing; Ilavsky, Jan; ...

    2015-04-03

    To design novel nanomaterials, it is important to precisely control the composition, determine the atomic structure, and manipulate the structure to tune the materials property. Here we present a comprehensive characterization of the material whose composition is Au 329(SR) 84 precisely, therefore referred to as a nanomolecule. The size homogeneity was shown by electron microscopy, solution X-ray scattering, and mass spectrometry. We proposed its atomic structure to contain the Au 260 core using experiments and modeling of a total-scattering-based atomic-pair distribution functional analysis. HAADF-STEM images shows fcc-like 2.0 ± 0.1 nm diameter nanomolecules.

  17. Thermodynamic Properties of Liquid Ag-Au-Sn Alloys

    NASA Astrophysics Data System (ADS)

    Hindler, M.; Knott, S.; Mikula, A.

    2010-10-01

    The thermodynamic properties of liquid Ag-Au-Sn alloys were studied with an electromotive force (EMF) method using the eutectic mixture of KCl/LiCl as a liquid electrolyte. Activities of Sn in the liquid alloys were measured at three cross-sections with constant molar ratios of Ag:Au = 2:1, 1:1, and 1:2 with tin in the concentration range between 20 at.% and 90 at.% from the liquidus of the samples up to 1030 K. The integral Gibbs energies at 973 K and the integral enthalpies were calculated by Gibbs-Duhem integration.

  18. Magnetic clouds between 2-4 AU: Voyager observations

    NASA Technical Reports Server (NTRS)

    Burlaga, L. F.; Behannon, K. W.

    1981-01-01

    Magnetic clouds were observed in the solar wind between 2-4 AU. It was shown that they are stable enough to persist without major changes out to such distances. It is estimated that the clouds expand at a speed of the order of 45 km/s. The average Alfven speed at the front and rear boundaries is 104 km/s, the expansion speed is estimated to be nearly half of the Alfven speed, which is consistent with an earlier estimate of the expansion speed of clouds between the Sun and 1 AU. The magnetic field configuration is highly ordered and consistent with the passage of some kind of loop.

  19. Beyond 3 AU from the Sun: "Hypervolatiles" in Distant Comets

    NASA Astrophysics Data System (ADS)

    Bonev, Boncho P.; Villanueva, Geronimo Luis; Mumma, Michael J.; DiSanti, Michael A.; Paganini, Lucas; Boehnhardt, Hermann; Lippi, Manuela; Gibb, Erika L.; Bockelee-Morvan, Dominique; de Val-Borro, Miguel; Kawakita, Hideyo; Altwegg, Kathrin

    2016-10-01

    Our understanding of inner coma composition in comets has long been biased towards heliocentric distances (Rh) smaller than 2-3 AU. However, observations far from the Sun are also of high value for better understanding the nucleus structure and outgassing of volatiles. Substantial and very important evidence for the activity of distant comets has been accumulated from photometry and analyses of light curves, but direct detections of primary (parent) volatiles are still rare. For example, comet C/2006 W3 (Christensen) remained outside 3.1 AU throughout its apparition, yet it presented the best opportunity since Hale-Bopp (1997) for detailed spectroscopic studies in a distant comet. C/2006 W3 was observed from several space- and ground-based facilities using both infrared and radio techniques. CO, CH4, and C2H6 were measured via infrared spectroscopy at ESO-VLT at Rh = 3.25 AU. Production rates were found to exceed those measured for each of these species in most other comets, despite those comets being observed much closer to the Sun. With its relatively high CO/CO2 ratio, C/2006 W3 also appears as an outlier in the AKARI comet survey of 18 comets. The detections of H2O (Herschel Space Observatory) and CO (ESO-VLT) allow for constraining the coma abundance ratio H2O/CO at Rh = 5 AU.We will compare the C2H6/CH4/CO ratios in C/2006 W3 with those in other comets spanning a large range in Rh: from D/2012 S1 ISON (~0.7 AU) to 29P/Schwassmann-Wachmann 1 (~ 6.3 AU). Notably in situ measurements by the Rosetta mission were performed in the coma of 67P/Churyumov-Gerasimenko, at a very similar heliocentric distance to C/2006 W3 (3.15 AU). While comparisons of column-integrated remote sensing measurements and abundances from in-situ mass spectrometry (as performed by the ROSINA instrument) are not straightforward, both types of measurement are of high value for constraining models of nucleus outgassing beyond 3 AU from the Sun, where the inferred nucleus structure and

  20. Hexagonal-diamond-like gold lattices, Ba and (Au,T)3 interstitials, and delocalized bonding in a family of intermetallic phases Ba2Au6(Au,T)3 (T = Zn, Cd, Ga, In, or Sn).

    PubMed

    Lin, Qisheng; Mishra, Trinath; Corbett, John D

    2013-07-31

    Au-rich polar intermetallics exhibit a wide variety of structural motifs, and this hexagonal-diamond-like gold host is unprecedented. The series Ba2Au6(Au,T)3 (T = Zn, Cd, Ga, In, or Sn), synthesized through fusion of the elements at 700-800 °C followed by annealing at 400-500 °C, occur in space group R3[overline]c (a ≈ 8.6-8.9 Å, c ≈ 21.9-22.6 Å, and Z = 6). Their remarkable structure, generated by just three independent atoms, features a hexagonal-diamond-like gold superstructure in which tunnels along the 3-fold axes are systematically filled by interstitial Ba atoms (blue) and triangles of disordered (Au,T)3 atoms (green) in 2:1 proportions. The Au/Zn mixing in the latter spans ~34 to 87% Zn, whereas the Au/Sn result is virtually invariant compositionally. Complementary bonding between the gold lattice and the disordered (Au,T)3 units is substantial and very regular. Bonding and charge density analyses indicate delocalized bonding within the gold host and the (Au,T)3 triangular units, and moderately polarized bonding between Ba and the electronegative framework. The new structure can also be viewed empirically as the result of an atom-by-triad [i.e., Ba by (Au,T)3 triangle] topological substitution in a BaAu2 (AlB2-type) superstructure.

  1. The coupled geochemistry of Au and As in pyrite from hydrothermal ore deposits

    NASA Astrophysics Data System (ADS)

    Deditius, Artur P.; Reich, Martin; Kesler, Stephen E.; Utsunomiya, Satoshi; Chryssoulis, Stephen L.; Walshe, John; Ewing, Rodney C.

    2014-09-01

    The ubiquity of Au-bearing arsenian pyrite in hydrothermal ore deposits suggests that the coupled geochemical behaviour of Au and As in this sulfide occurs under a wide range of physico-chemical conditions. Despite significant advances in the last 20 years, fundamental factors controlling Au and As ratios in pyrite from ore deposits remain poorly known. Here we explore these constraints using new and previously published EMPA, LA-ICP-MS, SIMS, and μ-PIXE analyses of As and Au in pyrite from Carlin-type Au, epithermal Au, porphyry Cu, Cu-Au, and orogenic Au deposits, volcanogenic massive sulfide (VHMS), Witwatersrand Au, iron oxide copper gold (IOCG), and coal deposits. Pyrite included in the data compilation formed under temperatures from ∼30 to ∼600 °C and in a wide variety of geological environments. The pyrite Au-As data form a wedge-shaped zone in compositional space, and the fact that most data points plot below the solid solubility limit defined by Reich et al. (2005) indicate that Au1+ is the dominant form of Au in arsenian pyrite and that Au-bearing ore fluids that deposit this sulfide are mostly undersaturated with respect to native Au. The analytical data also show that the solid solubility limit of Au in arsenian pyrite defined by an Au/As ratio of 0.02 is independent of the geochemical environment of pyrite formation and rather depends on the crystal-chemical properties of pyrite and post-depositional alteration. Compilation of Au-As concentrations and formation temperatures for pyrite indicates that Au and As solubility in pyrite is retrograde; Au and As contents decrease as a function of increasing temperature from ∼200 to ∼500 °C. Based on these results, two major Au-As trends for Au-bearing arsenian pyrite from ore deposits are defined. One trend is formed by pyrites from Carlin-type and orogenic Au deposits where compositions are largely controlled by fluid-rock interactions and/or can be highly perturbed by changes in temperature and

  2. Structures and magnetic properties of Fe and Ni monoatomic chains encapsulated by an Au nanotube

    NASA Astrophysics Data System (ADS)

    Han, Zhi-Dong; Li, Xiu-Yan; Yang, Zhi; Liu, Rui-Ping; Liu, Shao-Ding; Zhang, Ying

    2012-11-01

    Structures and magnetic properties of transition metal (TM) Fe or Ni monoatomic chains (MACs) encapsulated by a Au (5, 5) nanotube (Fe@Au and Ni@Au) are investigated using the density functional theory (DFT). The calculated results show that both Fe@Au and Ni@Au prefer to adopt ferromagnetic (FM) orders as ground states. In particular, the Fe@Au keeps the magnetic properties of free-standing Fe MAC, indicating that this system may be viewed as a new candidate in electromagnetic devices.

  3. La grossesse extra-utérine dans une région semi-rurale en Afrique: Aspects épidémiologiques, cliniques et thérapeutiques à propos d'une série de 74 cas traités à l'Hôpital de District de Sangmelima au Sud-Cameroun

    PubMed Central

    Kenfack, Bruno; Noubom, Michel; Bongoe, Adamo; Tsatedem, Faustin Atemkeng; Ngono, Modeste; Tsague, Georges Nguefack; Mboudou, Emile

    2012-01-01

    La grossesse extra-utérine (GEU) constitue une cause fréquente de morbidité et parfois de mortalité chez les femmes en âge de procréation. Son étiologie n'est pas clairement précisée. Son tableau clinique est polymorphe et ses méthodes thérapeutiques très diversifiées. C'est dans le but d’étudier les aspects épidémiologiques cliniques et thérapeutiques dans une zone rurale à ressources limitées d'Afrique que ce travail a été réalisé. Il s'agit d'une étude descriptive transversale sur une durée de trois ans, portant sur 74 cas de GEU traités à l'Hôpital de District de Sangmelima. Le matériel utilisé était constitué d'une fiche anonyme de collecte des données, des dossiers du malade, et du registre opératoire. Au cours de la période d’étude, 2142 naissances vivantes ont été enregistrées, soit un taux de GEU de 3,45%. Les femmes non mariées et celles ayant les antécédents d'IST étaient les plus atteintes. Le délai moyen entre le début des symptômes et l'admission était de132h. L’âge gestationnel moyen au moment du diagnostic était de 8,14 semaines. Le diagnostic était clinique dans 61% des cas. L'annexe controlatérale était cliniquement normale dans 53% des cas. Le traitement était chirurgical d'emblée chez 97% des cas. Aucun décès n'a été observé. La GEU est fréquente dans cette zone rurale, les malades consultent à un stade tardif, le diagnostic est surtout clinique, et le traitement chirurgical par laparotomie. PMID:23396682

  4. Gold chloride clusters with Au(III) and Au(I) probed by FT-ICR mass spectrometry and MP2 theory.

    PubMed

    Lemke, Kono H

    2014-05-07

    Microsolvated clusters of gold chloride are probed by electrospray ionization mass spectrometry (ESI-MS) and scalar relativistic electronic structure calculations. Electrospray ionization of aqueous AuCl3 leads to mononuclear clusters of types [AuCl2](+)(H2O)n (n = 0-4), [AuOHCl](+)(H2O)n (n = 0-1) and [AuCl2](+)(HCl)2(H2O)n (n = 0-4). In addition, strong ion signals due to dinuclear [Au2Cl5-xOHx](+)(H2O)n (x = 0-1) are present in ESI mass spectra of aqueous AuCl3, with the abundance of individual dinuclear species controlled by the concentration-dependent variation of the precursor complexes [AuCl2-xOHx](+)(H2O)n and AuCl3. Equilibrium structures, energies and thermodynamic properties of mono- and dinuclear gold clusters have been predicted using MP2 and CCSD(T) theory, and these data have been applied to examine the influence of microsolvation on cluster stability. Specifically, results from CCSD(T) calculations indicate that non-covalently bound ion-neutral complexes Au(+)(Cl2)(H2O)n, with formal Au(I), are the dominant forms of mononuclear gold with n = 0-2, while higher hydrates (n > 2) are covalently bound [AuCl2](+)(H2O)n complexes in which gold exists as Au(III). MP2 calculations show that the lowest energy structure of dinuclear gold is an ion-molecule cluster [Au2Cl(Cl2)2](+) consisting of a single-bridged digold-chloronium ion bound end-on to two dichlorine ligands, with two higher energy isomers, single-bridged [Au2Cl3(Cl2)](+) and double-bridged [Au2Cl5](+) clusters. Finally, AuAu interactions in the singly-bridged clusters [Au2Cl(Cl2)2](+)(H2O)n and [Au2Cl3(Cl2)](+)(H2O)n are examined employing a wide range of computational tools, including natural bond order (NBO) analysis and localized orbital locator (LOL) profiles.

  5. Au@CdO core/shell nanoparticles synthesized by pulsed laser ablation in Au precursor solution

    NASA Astrophysics Data System (ADS)

    Mostafa, Ayman M.; Yousef, Samir A.; Eisa, Wael H.; Ewaida, Mahmoud A.; Al-Ashkar, Emad A.

    2017-12-01

    Au@CdO core/shell nanocomposite was prepared using Pulsed Laser Ablation in Liquids (PLAL) via one step-process. A nanosecond pulsed laser (Nd:YAG, λ = 1064 nm) was used to ablate Cd sheet immersed in HAuCl4 solution. The surface plasmon resonance (SPR) using UV-vis absorption spectroscopy was employed to monitor the fast changes occurring in the NP colloidal solutions upon interaction between Cd sheets and Au precursor. The structure of the as-prepared samples was confirmed by high resolution transmission electron microscope (HRTEM) analysis and energy dispersion X-Ray spectroscopy (EDX) analysis. A mechanism for the growth of Au@CdO core/shell nanocomposite was given.

  6. Redox Chemistry and [Au(CN)2-] in the Formation of Gold Metabolites

    PubMed Central

    Shaw III, G. Frank; Schraa, Sabine; Gleichmann, Ernst; Grover, Yash Paul; Dunemann, Lothar; Jagarlamudi, Annapurna

    1994-01-01

    The role of hypochlorite ion, which can be generated by the enzyme myleoperoxidase, in the biochemistry of gold(I) anti-arthritic drugs was investigated. Sodium hypochlorite (OCl−) directly and rapidly oxidizes AuSTm, Au(CN)2-, AuSTg (gold thioglucose) and auranofin (Et3PAuSATg). The resulting gold(III) species were detected by an Ion Chromotography Ion-Pairing technique that was developed to distinguish gold(I) and gold(III). Formation of Au(III) was also demonstrated spectrophotometrically after the conversion to AuCl4−. The reactions of AuSTm, AuSTg, and auranofin are complex and gold(III) appears only after the initial oxidation of the thiolate (and phosphine) ligands. The enzymatic reaction, using MPO with H2O2 and Cl− as substrates, leads to slow oxidation of Au(CN)2-, AuSTm or AuSTg. The extent and rate of reaction depend on the concentrations of MPO, H2O2, and Au(I). The continued presence of Au(I) during the initial stages of reaction (oxidation of the thiolates in AuSTm and AuSTg) and the conversion to Au(III) in the latter stages of the reaction were demonstrated. Au(CN)2-, a gold metabolite, binds tightly to serum albumin. Unlike other gold(I) complexes, aurocyanide reacts almost negligibly at Cys-34 via ligand exchange. Instead, there is a strong association (K1 = 5.5 × 104 and K2 = 7.0 × 103; n1 = 0.8 and n2 = 3) of intact Au(CN)2-. The full extent of binding is revealed only by equilibrium methods such as NMR or ultrafiltration; the bound gold dissociates extensively on conventional gel-exclusion columns and partially on Penefesky spun columns. The immunological and pharmacological significance of these results are discussed. PMID:18476255

  7. Low frequency noise in the unstable contact region of Au-to-Au microcontact for microelectromechanical system switches

    NASA Astrophysics Data System (ADS)

    Qiu, Haodong; Wang, Hong; Ke, Feixiang

    2014-06-01

    The noise behavior of Au-to-Au microcontact for microelectromechanical system switches has been experimentally studied in the unstable contact region. The results suggest that the electrical conduction remains nonmetallic at the initial stage during contact formation due to the existence of alien films, and traps in the alien layer located at the contact interface could play an important role in determining the conduction noise. The conduction fluctuation induced by electron trapping-detrapping associated with the hydrocarbon layer is found to be an intrinsic noise source contributing to the low frequency noise in the unstable contact region.

  8. Low frequency noise in the unstable contact region of Au-to-Au microcontact for microelectromechanical system switches

    SciTech Connect

    Qiu, Haodong; Wang, Hong, E-mail: ewanghong@ntu.edu.sg; Ke, Feixiang

    2014-06-23

    The noise behavior of Au-to-Au microcontact for microelectromechanical system switches has been experimentally studied in the unstable contact region. The results suggest that the electrical conduction remains nonmetallic at the initial stage during contact formation due to the existence of alien films, and traps in the alien layer located at the contact interface could play an important role in determining the conduction noise. The conduction fluctuation induced by electron trapping-detrapping associated with the hydrocarbon layer is found to be an intrinsic noise source contributing to the low frequency noise in the unstable contact region.

  9. Dijet imbalance measurements in Au + Au and p p collisions at s N N = 200 GeV at STAR

    DOE PAGES

    Adamczyk, L.; Adkins, J. K.; Agakishiev, G.; ...

    2017-08-10

    In this paper, we report the first dijet transverse momentum asymmetry measurements from Au + Au and pp collisions at RHIC. The two highest-energy back-to-back jets reconstructed from fragments with transverse momenta above 2 GeV/c display a significantly higher momentum imbalance in heavy-ion collisions than in the pp reference. Finally, when reexamined with correlated soft particles included, we observe that these dijets then exhibit a unique new feature—momentum balance is restored to that observed in pp for a jet resolution parameter of R = 0.4, while rebalancing is not attained with a smaller value of R = 0.2.

  10. Elliptic flow in Au+Au collisions at square root(S)NN = 130 GeV.

    PubMed

    Ackermann, K H; Adams, N; Adler, C; Ahammed, Z; Ahmad, S; Allgower, C; Amsbaugh, J; Anderson, M; Anderssen, E; Arnesen, H; Arnold, L; Averichev, G S; Baldwin, A; Balewski, J; Barannikova, O; Barnby, L S; Baudot, J; Beddo, M; Bekele, S; Belaga, V V; Bellwied, R; Bennett, S; Bercovitz, J; Berger, J; Betts, W; Bichsel, H; Bieser, F; Bland, L C; Bloomer, M; Blyth, C O; Boehm, J; Bonner, B E; Bonnet, D; Bossingham, R; Botlo, M; Boucham, A; Bouillo, N; Bouvier, S; Bradley, K; Brady, F P; Braithwaite, E S; Braithwaite, W; Brandin, A; Brown, R L; Brugalette, G; Byrd, C; Caines, H; Calderón de la Barca Sánchez, M; Cardenas, A; Carr, L; Carroll, J; Castillo, J; Caylor, B; Cebra, D; Chatopadhyay, S; Chen, M L; Chen, W; Chen, Y; Chernenko, S P; Cherney, M; Chikanian, A; Choi, B; Chrin, J; Christie, W; Coffin, J P; Conin, L; Consiglio, C; Cormier, T M; Cramer, J G; Crawford, H J; Danilov, V I; Dayton, D; DeMello, M; Deng, W S; Derevschikov, A A; Dialinas, M; Diaz, H; DeYoung, P A; Didenko, L; Dimassimo, D; Dioguardi, J; Dominik, W; Drancourt, C; Draper, J E; Dunin, V B; Dunlop, J C; Eckardt, V; Edwards, W R; Efimov, L G; Eggert, T; Emelianov, V; Engelage, J; Eppley, G; Erazmus, B; Etkin, A; Fachini, P; Feliciano, C; Ferenc, D; Ferguson, M I; Fessler, H; Finch, E; Fine, V; Fisyak, Y; Flierl, D; Flores, I; Foley, K J; Fritz, D; Gagunashvili, N; Gans, J; Gazdzicki, M; Germain, M; Geurts, F; Ghazikhanian, V; Gojak, C; Grabski, J; Grachov, O; Grau, M; Greiner, D; Greiner, L; Grigoriev, V; Grosnick, D; Gross, J; Guilloux, G; Gushin, E; Hall, J; Hallman, T J; Hardtke, D; Harper, G; Harris, J W; He, P; Heffner, M; Heppelmann, S; Herston, T; Hill, D; Hippolyte, B; Hirsch, A; Hjort, E; Hoffmann, G W; Horsley, M; Howe, M; Huang, H Z; Humanic, T J; Hümmler, H; Hunt, W; Hunter, J; Igo, G J; Ishihara, A; Ivanshin, Y I; Jacobs, P; Jacobs, W W; Jacobson, S; Jared, R; Jensen, P; Johnson, I; Jones, P G; Judd, E; Kaneta, M; Kaplan, M; Keane, D; Kenney, V P; Khodinov, A; Klay, J; Klein, S R; Klyachko, A; Koehler, G; Konstantinov, A S; Kormilitsyne, V; Kotchenda, L; Kotov, I; Kovalenko, A D; Kramer, M; Kravtsov, P; Krueger, K; Krupien, T; Kuczewski, P; Kuhn, C; Kunde, G J; Kunz, C L; Kutuev, R K; Kuznetsov, A A; Lakehal-Ayat, L; Lamas-Valverde, J; Lamont, M A; Landgraf, J M; Lange, S; Lansdell, C P; Lasiuk, B; Laue, F; Lebedev, A; LeCompte, T; Leonhardt, W J; Leontiev, V M; Leszczynski, P; LeVine, M J; Li, Q; Li, Q; Li, Z; Liaw, C J; Lin, J; Lindenbaum, S J; Lindenstruth, V; Lindstrom, P J; Lisa, M A; Liu, H; Ljubicic, T; Llope, W J; LoCurto, G; Long, H; Longacre, R S; Lopez-Noriega, M; Lopiano, D; Love, W A; Lutz, J R; Lynn, D; Madansky, L; Maier, R; Majka, R; Maliszewski, A; Margetis, S; Marks, K; Marstaller, R; Martin, L; Marx, J; Matis, H S; Matulenko, Y A; Matyushevski, E A; McParland, C; McShane, T S; Meier, J; Melnick, Y; Meschanin, A; Middlekamp, P; Mikhalin, N; Miller, B; Milosevich, Z; Minaev, N G; Minor, B; Mitchell, J; Mogavero, E; Moiseenko, V A; Moltz, D; Moore, C F; Morozov, V; Morse, R; de Moura, M M; Munhoz, M G; Mutchler, G S; Nelson, J M; Nevski, P; Ngo, T; Nguyen, M; Nguyen, T; Nikitin, V A; Nogach, L V; Noggle, T; Norman, B; Nurushev, S B; Nussbaum, T; Nystrand, J; Odyniec, G; Ogawa, A; Ogilvie, C A; Olchanski, K; Oldenburg, M; Olson, D; Ososkov, G A; Ott, G; Padrazo, D; Paic, G; Pandey, S U; Panebratsev, Y; Panitkin, S Y; Pavlinov, A I; Pawlak, T; Pentia, M; Perevotchikov, V; Peryt, W; Petrov, V A; Pinganaud, W; Pirogov, S; Platner, E; Pluta, J; Polk, I; Porile, N; Porter, J; Poskanzer, A M; Potrebenikova, E; Prindle, D; Pruneau, C; Puskar-Pasewicz, J; Rai, G; Rasson, J; Ravel, O; Ray, R L; Razin, S V; Reichhold, D; Reid, J; Renfordt, R E; Retiere, F; Ridiger, A; Riso, J; Ritter, H G; Roberts, J B; Roehrich, D; Rogachevski, O V; Romero, J L; Roy, C; Russ, D; Rykov, V; Sakrejda, I; Sanchez, R; Sandler, Z; Sandweiss, J; Sappenfield, P; Saulys, A C; Savin, I; Schambach, J; Scharenberg, R P; Scheblien, J; Scheetz, R; Schlueter, R; Schmitz, N; Schroeder, L S; Schulz, M; Schüttauf, A; Sedlmeir, J; Seger, J; Seliverstov, D; Seyboth, J; Seyboth, P; Seymour, R; Shakaliev, E I; Shestermanov, K E; Shi, Y; Shimanskii, S S; Shuman, D; Shvetcov, V S; Skoro, G; Smirnov, N; Smykov, L P; Snellings, R; Solberg, K; Sowinski, J; Spinka, H M; Srivastava, B; Stephenson, E J; Stock, R; Stolpovsky, A; Stone, N; Stone, R; Strikhanov, M; Stringfellow, B; Stroebele, H; Struck, C; Suaide, A A; Sugarbaker, E; Suire, C; Symons, T J; Takahashi, J; Tang, A H; Tarchini, A; Tarzian, J; Thomas, J H; Tikhomirov, V; Szanto De Toledo, A; Tonse, S; Trainor, T; Trentalange, S; Tokarev, M; Tonjes, M B; Trofimov, V; Tsai, O; Turner, K; Ullrich, T; Underwood, D G; Vakula, I; Van Buren, G; VanderMolen, A M; Vanyashin, A; Vasilevski, I M; Vasiliev, A N; Vigdor, S E; Visser, G; Voloshin, S A; Vu, C; Wang, F; Ward, H; Weerasundara, D; Weidenbach, R; Wells, R; Wells, R; Wenaus, T; Westfall, G D; Whitfield, J P; Whitten, C; Wieman, H; Willson, R; Wilson, K; Wirth, J; Wisdom, J; Wissink, S W; Witt, R; Wolf, J; Wood, L; Xu, N; Xu, Z; Yakutin, A E; Yamamoto, E; Yang, J; Yepes, P; Yokosawa, A; Yurevich, V I; Zanevski, Y V; Zhang, J; Zhang, W M; Zhu, J; Zimmerman, D; Zoulkarneev, R; Zubarev, A N

    2001-01-15

    Elliptic flow from nuclear collisions is a hadronic observable sensitive to the early stages of system evolution. We report first results on elliptic flow of charged particles at midrapidity in Au+Au collisions at square root(S)NN = 130 GeV using the STAR Time Projection Chamber at the Relativistic Heavy Ion Collider. The elliptic flow signal, v2, averaged over transverse momentum, reaches values of about 6% for relatively peripheral collisions and decreases for the more central collisions. This can be interpreted as the observation of a higher degree of thermalization than at lower collision energies. Pseudorapidity and transverse momentum dependence of elliptic flow are also presented.

  11. Proton and pion production relative to the reaction plane in Au + Au collisions at 11A GeV/c

    SciTech Connect

    David, G.; Herrmann, N.; Drigert, M.

    1997-12-01

    Results are presented of an analysis of proton and charged pion azimuthal distributions measured with respect to the reaction plane in Au + Au collisions at a beam momentum of about 11A GeV/c. The azimuthal anisotropy is studied as a function of particle rapidity and transverse momentum for different centralities of the collisions. The triple differential (in rapidity, transverse momentum, and azimuthal angle) distributions are reconstructed. A comparison of the results with a previous analysis of charged-particle and transverse energy flow as well as with model predictions are presented. {copyright} {ital 1997} {ital The American Physical Society}

  12. True nature of an archetypal self-assembly system: mobile Au-thiolate species on Au(111).

    PubMed

    Yu, Miao; Bovet, N; Satterley, Christopher J; Bengió, S; Lovelock, Kevin R J; Milligan, P K; Jones, Robert G; Woodruff, D P; Dhanak, V

    2006-10-20

    Alkanethiol self-assembled monolayer (SAM) phases on Au(111) have been assumed to involve direct S head group bonding to the substrate. Using x-ray standing wave experiments, we show the thiolate actually bonds to gold adatoms; self-organization in these archetypal SAM systems must therefore be governed by the movement of these Au-S-R moieties on the surface between two distinct local hollow sites on the surface. The results of recent ab initio total energy calculations provide strong support for this description, and a rationale for the implied significant molecular mobility in these systems.

  13. Synthesis of magnetic Al/Au nanoparticles by co-reduction of Au3+ and Al3+ metal salts.

    PubMed

    Gilaki, M

    2010-08-15

    In current study, it reported the synthesis of water soluble; monos disperse Al/Au bimetallic nanoparticles with a middling length of 7 nm. Synthesis engages concurrent reduction of Al3+ and Au3+ in water to give way bimetallic nanoparticles. The elemental content of Al is 1.5%. Nanoparticles display ferromagnetic performance as deliberate by SQUID. These particles can be effortlessly conjugated to thiolated DNA, as confirmation by mobility shifts in agarose gel electrophoresis. Nanoparticles heat in solution to temperatures above 40 degrees C, representative appropriateness for hyperthermia.

  14. Depth limit for reef building corals in the Au'au Channel, S.E. Hawaii

    NASA Astrophysics Data System (ADS)

    Grigg, Richard W.

    2006-03-01

    In this paper, the relationship between reef building (accretion) and depth in an optimal inter-island channel environment in Hawaii is analyzed. For accretion, the growth rate of Porites lobata is used as a proxy for the reef community, because it is the most abundant and dominant species of reef building coral in Hawaii. Optimal growth of P. lobata occurs at a depth of 6 m, below which both growth rate and abundance decrease with increasing depth. A lower depth limit for this species is found at about 80-100 m, yet reef accretion ceases at ~50 m depth. Below 50 m, rates of bio-erosion of colony holdfasts equal or exceed the growth of basal attachments, causing colonies to detach from the bottom. Continued bio-erosion further erodes and dislodges colonies leading to their breakdown and ultimately to the formation of coralline rubble and sand. Thus, within this channel environment in Hawaii, a threshold for reef building exists at ~ 50 m depth, where coral accretion is interrupted by bio-erosion. Conceptually viewed, this depth horizon is analogous to a vertical Darwin Point, although quite narrow in space and time. More importantly, it explains the history of reef morphology in the Au’au Channel where a chronological hiatus exists at a depth near 50 m. This hiatus separates shallower modern growth (about 100 years or less) from the deeper reef which is all due to accretion during the early Holocene or Pleistocene epochs.

  15. Selective Hydrogenation of Acetylene over Pd, Au, and PdAu Supported Nanoparticles

    NASA Astrophysics Data System (ADS)

    Walker, Michael P.

    The removal of trace amounts of acetylene in ethylene streams is a high-volume industrial process that must possess high selectivity of alkyne hydrogenation over hydrogenation of alkenes. Current technology uses metallic nanoparticles, typically palladium or platinum, for acetylene removal. However, problems arise due to the deactivation of the catalysts at high temperatures as well as low selectivities at high conversions. Pore expanded MCM-41 is synthesized via a two-step strategy in which MCM-41 was prepared via cetyltrimethylammonium bromide (CTMABr) followed by the hydrothermal treatment with N,N-dimethyldecylamine (DMDA). This material was washed with ethanol to remove DMDA, or calcined to remove both surfactants. PE-MCM-41 based materials were impregnated with palladium, gold, and palladium-gold nanoparticles. The removal of DMDA had an effect on both the conversion and selectivity, in which they were found to drop significantly. However, by using the bimetallic PdAu catalysts, higher selectivity could be achieved due to increased electron density.

  16. Global transverse energy distributions in Si+Al,Au at 14.6 A GeV/c and Au+Au at 11.6A GeV/c.

    SciTech Connect

    Ahle, L.; Akiba, Y.; Beavis, D.

    1994-01-01

    Measurements of the global transverse energy distributions d{sigma}/dE{sub T} and dE{sub T}/d{eta} using the new AGS beam of 197Au at 11.6A GeV/c on a Au target, as well as a beam of 28Si at 14.6A GeV/c on Al and Au targets, are presented for a leadglass detector with acceptance 1.3 {le} {eta} {le} 2.4 and 0 {le} {phi} < 2{pi}. The d{rho}/dET spectra are observed to have different shapes for the different systems and simple energy rescaling does not account for the projectile dependence. The Au+Au d{sigma}/dE{sub T} spectrum is satisfactorily constructed from the upper edge of Si+Au by themore » geometric Wounded Projectile Nucleon Model after applying a correction for the beam energy.« less

  17. Fibres Optiques En Therapie Laser Au Contact Du Tissu

    NASA Astrophysics Data System (ADS)

    Lenz, P.; Sabben, G.; Lambert, R.; Berger, F.

    1984-03-01

    Les fibres en quartz, non protegees par un courant de gaz et placees au contact du tissu, peuvent etre utilisees pratiquement indefiniment grace a un "autonettoyage" et une "regenera-tion". Elles provoquent des lesions tissulaires semblables a celles obtenues avec les fibres conventionnelles.

  18. Charge-dependent anisotropic flow in Cu + Au collisions

    NASA Astrophysics Data System (ADS)

    Niida, Takafumi

    2016-12-01

    We present the first measurements of charge-dependent directed flow in Cu+Au collisions at √{sNN} = 200 GeV. The directed flow has been measured as functions of the transverse momentum and pseudorapidity with the STAR detector. The results show a small but finite difference between positively and negatively charged particles. The difference is qualitatively explained by the patron-hadron-string-dynamics (PHSD) model including the effect of the electric field, but much smaller than the model calculation, which indicates only a small fraction of all final state quarks are created within the lifetime of the initial electric field. Higher-order azimuthal anisotropic flow is also presented up to the fourth-order for unidentified charged particles and up to the third-order for identified charged particles (π, K, and p). For unidentified particles, the results are reasonably described by the event-by-event viscous hydrodynamic model with η / s = 0.08 - 0.16. The trends observed for identified particles in Cu+Au collisions are similar to those observed in symmetric (Au+Au) collisions.

  19. PHENIX results on flow observables in asymmetric Cu + Au collisions

    NASA Astrophysics Data System (ADS)

    Schaefer, B.

    2016-12-01

    Measurements of anisotropic flow from Cu+Au √{sNN} = 200 GeV collisions in PHENIX at RHIC in 2012 are presented for inclusive charged particles and identified hadrons π±, K±, p, and p ‾ at midrapidity. Fourier coefficients characterizing the azimuthal distribution of produced particles with respect to the event plane measured at forward rapidity are examined over a broad range of pT and collision centrality. Directed, elliptic, and triangular moments (v1, v2, v3 as functions of pT) all exhibit mass ordering. Comparisons are made to Cu+Cu and Au+Au systems as well as to hydrodynamical and transport model calculations [A. Adare, et al., "Measurements of directed, elliptic, and triangular flow in Cu+Au collisions at √{sNN} = 200 GeV", arXiv:1509.07784.]. Unlike v2 and v3, v1 decreases with centrality, mass ordering is seen for all three, and v2 and v3 with respect to transverse momentum feature common scaling with 1 / (εnNpart1/3).

  20. Nitrogen mineralization from 'AU Golden' sunn hemp residue

    USDA-ARS?s Scientific Manuscript database

    The tropical legume sunn hemp (Crotalaria juncea) cultivar ‘AU Golden’ has the potential to provide substantial amounts of nitrogen (N) to subsequent crops that could reduce recommended application rates of synthetic N fertilizers. Nitrogen fertilization problems via legumes are often due to asynch...

  1. New ideally absorbing Au plasmonic nanostructures for biomedical applications

    NASA Astrophysics Data System (ADS)

    Zakomirnyi, Vadim I.; Rasskazov, Ilia L.; Karpov, Sergey V.; Polyutov, Sergey P.

    2017-01-01

    In this paper a new set of plasmonic nanostructures operating at the conditions of an ideal absorption (Grigoriev et al., 2015 [1]) was proposed for novel biomedical applications. We consider spherical x/Au nanoshells and Au/x/Au nanomatryoshkas, where 'x' changes from conventional Si and SiO2 to alternative plasmonic materials (Naik and Shalaev, 2013 [2]), such as zinc oxide doped with aluminum, gallium and indium tin oxide. The absorption peak of proposed nanostructures lies within 700-1100 nm wavelength region and corresponds to the maximal optical transparency of hemoglobin and melanin as well as to the radiation frequency of available pulsed medical lasers. It was shown that the ideal absorption takes place in a given wavelength region for Au coatings with thickness less than 12 nm. In this case finite quantum size effects for metallic nanoshells play a significant role. The mathematical model for the search of the ideal absorption conditions was modified by taking into account the finite quantum size effects.

  2. Glucose-mediated catalysis of Au nanoparticles in microgels.

    PubMed

    Wu, Qingshi; Cheng, Han; Chang, Aiping; Xu, Wenting; Lu, Fan; Wu, Weitai

    2015-11-18

    The catalytic activity of Au nanoparticles in phenylboronic acid-containing polymer microgels can be tuned through the swelling-deswelling transition of the microgels in response to changes in glucose concentration. Upon adding glucose, the model catalytic reduction of hydrophilic 4-nitrophenol is accelerated, while the reduction of relatively more hydrophobic nitrobenzene slows down.

  3. Epitaxial growth of thermally stable cobalt films on Au(111)

    NASA Astrophysics Data System (ADS)

    Haag, N.; Laux, M.; Stöckl, J.; Kollamana, J.; Seidel, J.; Großmann, N.; Fetzer, R.; Kelly, L. L.; Wei, Z.; Stadtmüller, B.; Cinchetti, M.; Aeschlimann, M.

    2016-10-01

    Ferromagnetic thin films play a fundamental role in spintronic applications as a source for spin polarized carriers and in fundamental studies as ferromagnetic substrates. However, it is challenging to produce such metallic films with high structural quality and chemical purity on single crystalline substrates since the diffusion barrier across the metal-metal interface is usually smaller than the thermal activation energy necessary for smooth surface morphologies. Here, we introduce epitaxial thin Co films grown on an Au(111) single crystal surface as a thermally stable ferromagnetic thin film. Our structural investigations reveal an identical growth of thin Co/Au(111) films compared to Co bulk single crystals with large monoatomic Co terraces with an average width of 500 Å, formed after thermal annealing at 575 K. Combining our results from photoemission and Auger electron spectroscopy, we provide evidence that no significant diffusion of Au into the near surface region of the Co film takes place for this temperature and that no Au capping layer is formed on top of Co films. Furthermore, we show that the electronic valence band is dominated by a strong spectral contribution from a Co 3d band and a Co derived surface resonance in the minority band. Both states lead to an overall negative spin polarization at the Fermi energy.

  4. Using Dawn to Observe SEP Events Past 2 AU

    NASA Astrophysics Data System (ADS)

    Villarreal, M. N.; Russell, C. T.; Prettyman, T. H.

    2017-12-01

    The launch of the STEREO spacecraft provided much insight into the longitudinal and radial distribution of solar energetic particles (SEPs) relative to their origin site. However, almost all of the observations of SEP events have been made exclusively near 1 AU. The Dawn mission, which orbited around Vesta before arriving at Ceres, provides an opportunity to analyze these events at much further distances. Although Dawn's Gamma Ray and Neutron Detector (GRaND) is not optimized for SEP characterization, it is sensitive to protons greater than 4 MeV, making it capable of detecting a solar energetic particle event in its vicinity. Solar energetic particles in this area of the solar system are important as they are believed to cause sputtering at bodies such as Ceres and comets (Villarreal et al., 2017; Wurz et al., 2015). In this study, we use Dawn's GRaND data from 2011-2015 when Dawn was at distances between 2-3 AU. We compare the SEP events seen by Dawn with particle measurements at 1 AU using STEREO, Wind, and ACE to understand how the SEP events evolved past 1 AU.References: Villarreal, M. N., et al. (2017), The dependence of the Cerean exosphere on solar energetic particle events, Astrophys. J. Lett., 838, L8.Wurz, P. et al. (2015), Solar wind sputtering of dust on the surface of 67P/Churyumov-Gerasimenko, A&A, 583, A22.

  5. Using Dawn to Observe SEP Events Past 2 AU

    NASA Astrophysics Data System (ADS)

    Villarreal, Michaela; Russell, Christopher T.; Prettyman, Thomas H.

    2017-10-01

    The launch of the STEREO spacecraft provided much insight into the longitudinal and radial distribution of solar energetic particles (SEPs) relative to their origin site. However, almost all of the observations of SEP events have been made exclusively near 1 AU. The Dawn mission, which orbited around Vesta before arriving at Ceres, provides an opportunity to analyze these events at much further distances. Although Dawn's Gamma Ray and Neutron Detector (GRaND) is not optimized for SEP characterization, it is sensitive to protons greater than 4 MeV, making it capable of detecting a solar energetic particle event in its vicinity. Solar energetic particles in this area of the solar system are important as they are believed to cause sputtering at bodies such as Ceres and comets (Villarreal et al., 2017; Wurz et al., 2015). In this study, we use Dawn’s GRaND data from 2011-2015 when Dawn was at distances between 2-3 AU. We compare the SEP events seen by Dawn with particle measurements at 1 AU using STEREO, Wind, and ACE to understand how the SEP events evolved past 1 AU.References: Villarreal, M. N., et al. (2017), The dependence of the Cerean exosphere on solar energetic particle events, Astrophys. J. Lett., 838, L8.Wurz, P. et al. (2015), Solar wind sputtering of dust on the surface of 67P/Churyumov-Gerasimenko, A&A, 583, A22.

  6. Syn-deformational features of Carlin-type Au deposits

    USGS Publications Warehouse

    Peters, S.G.

    2004-01-01

    Syn-deformational ore deposition played an important role in some Carlin-type Au deposits according to field and laboratory evidence, which indicates that flow of Au-bearing fluids was synchronous with regional-scale deformation events. Gold-related deformation events linked to ore genesis were distinct from high-level, brittle deformation that is typical of many epithermal deposits. Carlin-type Au deposits, with brittle-ductile features, most likely formed during tectonic events that were accompanied by significant fluid flow. Interactive deformation-fluid processes involved brittle-ductile folding, faulting, shearing, and gouge development that were focused along illite-clay and dissolution zones caused by hydrothermal alteration. Alteration along these deformation zones resulted in increased porosity and enhancement of fluid flow, which resulted in decarbonated, significant dissolution, collapse, and volume and mass reduction. Carlin-type Au deposits commonly are hosted in Paleozoic and Mesozoic sedimentary rocks (limestone, siltstone, argillite, shale, and quartzite) on the margins of cratons. The sedimentary basins containing the host rocks underwent tectonic events that influenced the development of stratabound, structurally controlled orebodies. Published by Elsevier Ltd.

  7. Formation of Au and tetrapyridyl porphyrin complexes in superfluid helium.

    PubMed

    Feng, Cheng; Latimer, Elspeth; Spence, Daniel; Al Hindawi, Aula M A A; Bullen, Shem; Boatwright, Adrian; Ellis, Andrew M; Yang, Shengfu

    2015-07-14

    Binary clusters containing a large organic molecule and metal atoms have been formed by the co-addition of 5,10,15,20-tetra(4-pyridyl)porphyrin (H2TPyP) molecules and gold atoms to superfluid helium nanodroplets, and the resulting complexes were then investigated by electron impact mass spectrometry. In addition to the parent ion H2TPyP yields fragments mainly from pyrrole, pyridine and methylpyridine ions because of the stability of their ring structures. When Au is co-added to the droplets the mass spectra are dominated by H2TPyP fragment ions with one or more Au atoms attached. We also show that by switching the order in which Au and H2TPyP are added to the helium droplets, different types of H2TPyP-Au complexes are clearly evident from the mass spectra. This study suggests a new route for the control over the growth of metal-organic compounds inside superfluid helium nanodroplets.

  8. Understanding the effect of ultrathin AuPd alloy shells of irregularly shaped Au@AuPd nanoparticles with high-index facets on enhanced performance of ethanol oxidation

    NASA Astrophysics Data System (ADS)

    Bi, Cuixia; Feng, Cong; Miao, Tingting; Song, Yahui; Wang, Dayang; Xia, Haibing

    2015-11-01

    In this study, irregularly shaped, concave cuboidal Au@AuPd nanoparticles (ISCC-Au@AuPd NPs) with high-index facets were synthesized via Pd overgrowth on pre-formed ISCC-Au NPs with a concentration of Pd precursors as low as 2%. The AuPd alloy nature of the resulting shells was confirmed by X-ray photoelectron spectroscopy, cyclic voltammogram analysis, and energy dispersive X-ray spectroscopy. Among the irregularly shaped NPs obtained, the ISCC-Au97.5@Au0.5Pd2.0 NPs display the largest electrochemically active surface area (up to 92.11 m2 g-1), as their closed-packed agglomeration was prevented, and the best long-term stability with respect to ethanol oxidation (0.50 M) in alkaline media (0.30 KOH) by efficiently removing intermediates. Their mass- and ECSA-normalized current densities (4.15 A mgPd-1 and 4.51 mA cm-2) are about 20.7 times and 6.9 times higher than those of commercial Pd/C catalysts (0.20 A mgPd-1 and 0.65 mA cm-2), respectively.In this study, irregularly shaped, concave cuboidal Au@AuPd nanoparticles (ISCC-Au@AuPd NPs) with high-index facets were synthesized via Pd overgrowth on pre-formed ISCC-Au NPs with a concentration of Pd precursors as low as 2%. The AuPd alloy nature of the resulting shells was confirmed by X-ray photoelectron spectroscopy, cyclic voltammogram analysis, and energy dispersive X-ray spectroscopy. Among the irregularly shaped NPs obtained, the ISCC-Au97.5@Au0.5Pd2.0 NPs display the largest electrochemically active surface area (up to 92.11 m2 g-1), as their closed-packed agglomeration was prevented, and the best long-term stability with respect to ethanol oxidation (0.50 M) in alkaline media (0.30 KOH) by efficiently removing intermediates. Their mass- and ECSA-normalized current densities (4.15 A mgPd-1 and 4.51 mA cm-2) are about 20.7 times and 6.9 times higher than those of commercial Pd/C catalysts (0.20 A mgPd-1 and 0.65 mA cm-2), respectively. Electronic supplementary information (ESI) available: High magnification TEM

  9. Les méningiomes intracrâniens opérés au CHU Sylvanus Olympio de Lomé: aspects anesthésiologiques et complications à propos de 21 cas

    PubMed Central

    Egbohou, Pilakimwé; Mouzou, Tabana; Beketi, Kadanga; Kpelao, Essossinam; Moumouni, Abdel Kader; Sama, Hamza Doles; Assénouwé, Sarakawabalo; Akala-Yoba, Gnimdou; Tomta, Kadjika

    2017-01-01

    L’objectif était de relever les aspects anesthésiologiques et les complications périopératoires des méningiomes intracrâniens opérés au CHU Sylvanus Olympio de Lomé (CHU SO). Il s’agissait d’une étude rétrospective sur dossiers de patients opérés de méningiomes intracrâniens durant la période de Décembre 2010 à décembre 2015 (5 ans) au CHU SO. 21 (45,6%) méningiomes recensés sur 46 tumeurs cérébrales opérées. Age moyen: 49 ± 20 ans; prédominance masculine (52,4%), ratio M/F: 1,1. Classification ASA: ASA II: 16 patients, ASA III: 4 patients, et ASA IV: 1 patient. L’anesthésie a été intraveineuse totale avec du Propofol (100%) comme hypnotique et du fentanyl (76,2%) comme morphinique le plus disponible. Complications peropératoires: saignement, pertes sanguines moyennes: 1750 ± 584 ml; hypotension avec Pression artérielle moyenne (PAM) < 60 mmHg: 10 (47,6%) patients; choc hémorragique 2 (9,5%) patients, arrêt cardiocirculatoire: 01(4,7%) patient réanimé avec succès. Complications postopératoires: convulsions 5 (23,8%) cas, hyperthermie 4 (19%) cas, choc hémorragique 2(9,5%) cas, décès: 2 (9,5%) cas. La morbidité et la mortalité périopératoire de la chirurgie du méningiome intracrânien au CHU SO de Lomé reste élevée. L’amélioration du plateau technique et une consultation précoce permettrait de réduire ces complications. PMID:29158865

  10. Gestion de l’anémie des patients hémodialysés chroniques: cas du Service de Néphrologie et d’hémodialyse du CHU du Point G au Mali

    PubMed Central

    Tounkara, Alhadji Ahmadou; Coulibaly, Abdoul Mahama Sériba; Coulibaly, Nouhoun; Traoré, Békaye; Maïga, Mahamane Kalil

    2017-01-01

    Introduction L'anémie est une complication fréquente de l'IRC couramment retrouvée chez les patients hémodialysés chroniques. Chez ces derniers, la prise en charge est principalement basée sur l'administration d'érythropoïétine et la supplémentation en fer. Le but de ce travail était d'évaluer la prise en charge de l'anémie des hémodialysés chroniques dans le service de Néphrologie du CHU du Point G. Méthodes Il s'agissait d'une étude transversale réalisée dans ledit service du 1er au 31 Août 2016. Résultats Au total, 63 patients sur 174 participants avaient été retenus, 34 hommes et 29 femmes avec un sex-ratio à 1,17 en faveur des hommes. L'âge moyen des patients était de 48,79 ans ± 11,59, la durée moyenne en hémodialyse était de 3,77ans ± 2,6. La fréquence hospitalière de l'anémie chez nos dialysés était de 84,12%. La transfusion sanguine était retrouvée chez 92,1%, avec une moyenne annuelle de 5,81poches ± 5,91. La supplémentation martiale était notée dans 87,3% des cas. Les moyennes respectives de ferritine et de CST étaient de 1245 ng/ml ± 629,52 et 46,16%±19,12. L'administration occasionnelle d'EPO à des doses n'excédant pas les 4000UI était rapportée par 79,4% des patients. La principale difficulté pour l'utilisation de l' EPO était le coût (74,6%). L'infection au VHC touchait 60,1% des patients ayant réalisé le dit bilan. Conclusion La gestion de l'anémie des dialysés chroniques doit être intégrée dans un cadre politique nationale de la santé. PMID:28674560

  11. Résultat de la radio chimiothérapie concomitante du cancer du col utérin au service oncologie-radiothérapie à l'hôpital universitaire Joseph Ravoahangy Andrianavalona de 2007 à 2009

    PubMed Central

    Randriamanovontsoa, Ezra Niaina; Ratsimandresy, Dera Andraina; Rakotonarivo, Jean Marc; Rakototiana, Auberlin Felantsoa; Rantomalala, Harinirina Yoël Honora; Rafaramino, Florine

    2014-01-01

    La radiochimiothérapie devient un standard pour le traitement du cancer du col utérin à partir de IB de mauvais pronostic. L'objectif de ce travail est de rapporter les résultats de cette modalité thérapeutique. Il s'agissait d'une étude rétrospective descriptive des dossiers des patientes atteintes d'un cancer du col utérin du Janvier 2007 au Décembre 2009 traitées par une radiochimiothérapie concomitante. Les patientes ayant reçu une dose inférieure à 45Gy étaient éliminées dans cette étude. Les critères de l'OMS ont été utilisés pour évaluer la réponse tumorale. Au total 46patientes étaient retenues avec un âge moyen de 47ans. Le carcinome épidermoide représentait 89,13%, diagnostiqués au stade localement avancé dans 82,60%. Seulement 26,08% de nos patients ont bénéficié d'une tomodensitométrie abdominale et pelvienne. La dose reçue variait de 45 à 75 Gy. Les résultats thérapeutiques à un mois de la fin du traitement montraient: 45,63% de rémission complète et 30,42% de rémission partielle supérieure à 50%. La toxicité précoce était dominée par la neutropénie chiffrée à 30,55%. A travers de cette étude, la radiochimiothérapie concomitante a amélioré les résultats thérapeutiques à court terme. PMID:25883726

  12. Inverse Catalysts for CO Oxidation: Enhanced Oxide–Metal Interactions in MgO/Au(111), CeO 2/Au(111), and TiO 2/Au(111)

    DOE PAGES

    Palomino, Robert M.; Gutiérrez, Ramón A.; Liu, Zongyuan; ...

    2017-09-26

    Au(111) does not bind CO and O 2 well. The deposition of small nanoparticles of MgO, CeO 2, and TiO 2 on Au(111) produces excellent catalysts for CO oxidation at room temperature. In an inverse oxide/metal configuration there is a strong enhancement of the oxide–metal interactions, and the inverse catalysts are more active than conventional Au/MgO(001), Au/CeO 2(111), and Au/TiO 2(110) catalysts. An identical trend was seen after comparing the CO oxidation activity of TiO2/Au and Au/TiO 2 powder catalysts. In the model systems, the activity increased following the sequence: MgO/Au(111) < CeO 2/Au(111) < TiO 2/Au(111). Ambient pressure X-raymore » photoelectron spectroscopy (AP-XPS) was used to elucidate the role of the titania–gold interface in inverse TiO 2/Au(111) model catalysts during CO oxidation. Stable surface intermediates such as CO(ads), CO 3 2–(ads), and OH(ads) were identified under reaction conditions. CO 3 2–(ads) and OH(ads) behaved as spectators. The concentration of CO(ad) initially increased and then decreased with increasing TiO 2 coverage, demonstrating a clear role of the Ti–Au interface and the size of the TiO 2 nanostructures in the catalytic process. Overall, our results show an enhancement in the strength of the oxide–metal interactions when working with inverse oxide/metal configurations, a phenomenon that can be utilized for the design of efficient catalysts useful for green and sustainable chemistry.« less

  13. Core-shell Au@Pd nanoparticles with enhanced catalytic activity for oxygen reduction reaction via core-shell Au@Ag/Pd constructions

    PubMed Central

    Chen, Dong; Li, Chengyin; Liu, Hui; Ye, Feng; Yang, Jun

    2015-01-01

    Core-shell nanoparticles often exhibit improved catalytic properties due to the lattice strain created in these core-shell particles. Herein, we demonstrate the synthesis of core-shell Au@Pd nanoparticles from their core-shell Au@Ag/Pd parents. This strategy begins with the preparation of core-shell Au@Ag nanoparticles in an organic solvent. Then, the pure Ag shells are converted into the shells made of Ag/Pd alloy by galvanic replacement reaction between the Ag shells and Pd2+ precursors. Subsequently, the Ag component is removed from the alloy shell using saturated NaCl solution to form core-shell Au@Pd nanoparticles with an Au core and a Pd shell. In comparison with the core-shell Au@Pd nanoparticles upon directly depositing Pd shell on the Au seeds and commercial Pd/C catalysts, the core-shell Au@Pd nanoparticles via their core-shell Au@Ag/Pd templates display superior activity and durability in catalyzing oxygen reduction reaction, mainly due to the larger lattice tensile effect in Pd shell induced by the Au core and Ag removal. PMID:26144550

  14. [Preparation of OMC-Au/L-Lysine/Au modified glassy carbon electrode and the study on its detection response to hydroquinone and catechol].

    PubMed

    Zhou, Yao-Yu; Tang, Lin; Li, Zhen; Liu, Yuan-Yuan; Yang, Gui-De; Wu, Meng-Shi; Lei, Xiao-Xia; Zheng, Guang-Ming

    2013-03-01

    Ordered mesoporous carbon-Au nanoparticles (OMC-Au) nanocomposites were synthesized by a one-step chemical reduction route, and an OMC-Au/L-Lysine/Au composite film-modified glassy carbon electrode (GCE) was constructed. The microstructure of OMC and OMC-Au/L-Lysine/Au composite films were characterized by SEM, and the preparation process of OMC-Au/L-Lysine/Au modified glassy carbon electrode was investigated using cyclic voltammetry and electrochemical impedance spectroscopy. The electrocatalytic oxidation of hydroquinone and catechol on the modified electrode was discussed by differential pulse voltammetry in this study, and a sensor for separate determination of hydroquinone and catechol based on OMC-Au/L-Lysine/Au modified glassy carbon electrode was developed. Under the optimal conditions, the cathodic peak current was linearly related to hydroquinone concentration over ranges from 1.0 x 10(-6) mol x L(-1) to 8.0 x 10(-4) mol x L(-1) with a detection limit of 3.0 x 10(-7) mol x L(-1), and linearly related to catechol concentration from 1.0 x 10(-7) mol x L(-1) to 8.0 x 10(-5) mol x L(-1) with a detection limit of 8.0 x 10(-7) mol x L(-1).

  15. Synthesis of Au@Pt bimetallic nanoparticles with concave Au nanocuboids as seeds and their enhanced electrocatalytic properties in the ethanol oxidation reaction

    NASA Astrophysics Data System (ADS)

    Tan, Lingyu; Li, Lidong; Peng, Yi; Guo, Lin

    2015-12-01

    Herein, a new type of uniform and well-structured Au@Pt bimetallic nanoparticles (BNPs) with highly active concave Au nanocuboids (NCs) as seeds was successfully synthesized by using the classic seed-mediated method. Electrochemical measurements were conducted to demonstrate their greatly enhanced catalytic performance in the ethanol oxidation reaction (EOR). It was found that the electrochemical performance for Au@Pt BNPs with the concave Au NCs as seeds, which were enclosed by {611} high-index facets, could be seven times higher than that of the Au@Pt bimetallic nanoparticles with regular spherical Au NPs as seeds. Furthermore, our findings show that the morphology and electrocatalytic activity of the Au@Pt BNPs can be tuned simply by changing the compositional ratios of the growth solution. The lower the amount of H2PtCl6 used in the growth solution, the thinner the Pt shell grew, and the more high-index facets of concave Au NCs seeds were exposed in Au@Pt BNPs, leading to higher electrochemical activity. These as-prepared concave Au@Pt BNPs will open up new strategies for improving catalytic efficiency and reducing the use of the expensive and scarce resource of platinum in the ethanol oxidation reaction, and are potentially applicable as electrochemical catalysts for direct ethanol fuel cells.

  16. Reduction of HAuCl 4 by Na 2S revisited: The case for Au nanoparticle aggregates and against Au 2S/Au core/shell particles

    DOE PAGES

    Schwartzberg, A. M.; Grant, C. D.; van Buuren, Tony; ...

    2007-03-10

    The reaction of sodium sulfide with chloroauric acid has been surrounded by a controversy over the structure of the resulting product. The original report proposed a Au 2S/Au core/shell structure based on strong near-IR resonance and limited transmission electron microscopy. Subsequent reports used the same model without further attempts to determine the structure of the products. With a significant body of experimental work compiled over a period of several years, we have shown that the major product of this reaction is aggregated spherical nanoparticles of gold with a minority component consisting of triangular and rod-like structures. This is in contradictionmore » to the core/shell structures as originally proposed. Recently, there have been additional reports that again suggest a Au 2S/Au core/shell structure or irregularly shaped Au nanoparticles as an explanation for the near-IR resonance. To help resolve this issue, we have carried out further experiments to determine how the reaction products may depend on experimental conditions such as concentration and aging of the reactants, particularly Na 2S. It has been determined that sodium thiosulfate is the likely product from Na 2S aging. In addition, persistent spectral hole burning experiments have been conducted on gold nanoparticle aggregate (GNA) samples at excitation intensities that are lower than that required to melt the nanostructures. We have observed a decrease in optical absorption on resonance with the excitation laser wavelength, with simultaneous increases in absorption to the blue and red of this wavelength region. However, in the presence of the stabilizer poly(vinyl pyrrolidone) (PVP), no increase in absorbance was observed but rather a blue shifting and decrease in intensity of the near-IR plasmon resonance. These results imply that the non-stabilized GNAs are able to break apart and reform into off resonant aggregate structures. In contrast, this behavior is suppressed in PVP stabilized

  17. XANES and EXAFS study of Au-substituted YBa2Cu3O(7-delta)

    NASA Technical Reports Server (NTRS)

    Ruckman, Mark W.; Hepp, Aloysius F.

    1990-01-01

    The near-edge structure (XANES) of the Au L3 and Cu K edges of YBa2Au(0.3)Cu(2.7)O(7-delta) was studied. X ray diffraction suggests that Au goes on the Cu(1) site and XANES shows that this has little effect on the oxidation state of the remaining copper. The gold L3 edge develops a white line feature whose position lies between that of trivalent gold oxide (Au2O3) and monovalent potassium gold cyanide (KAu(CN)2) and whose intensity relative to the edge step is smaller than in the two reference compounds. The L3 EXAFS for Au in the superconductor resembles that of Au2O3. However, differences in the envelope of the Fourier filtered component for the first shell suggest that the local structure of the Au in the superconductor is not equivalent to Au2O3.

  18. Optical and electrical properties of colloidal (spherical Au)-(spinel ferrite nanorod) heterostructures.

    PubMed

    George, Chandramohan; Genovese, Alessandro; Qiao, Fen; Korobchevskaya, Kseniya; Comin, Alberto; Falqui, Andrea; Marras, Sergio; Roig, Anna; Zhang, Yang; Krahne, Roman; Manna, Liberato

    2011-11-01

    We report here a simple synthetic route to Au-Fe(x)O(y) heterostructures in which spinel ferrite (Fe(x)O(y)) grows as a nanorod on a spherical gold (Au) seed. The large red shift in the plasmon resonance in the heterostructures could be explained by a dielectric effect (although we could not entirely exclude a contribution due to electron transfer from Au to defect states at the Au-Fe(x)O(y) interface), while the magnetic properties of the Au-Fe(x)O(y) heterostructures were basically the same as those of the corresponding nanocrystals after Au leaching. In films of Au-Fe(x)O(y) heterostructures the electrical conductivity appeared to be mediated by the Au domains.

  19. Surface-enhanced Raman spectroscopy with Au-nanoparticle substrate fabricated by using femtosecond pulse

    NASA Astrophysics Data System (ADS)

    Zhang, Wending; Li, Cheng; Gao, Kun; Lu, Fanfan; Liu, Min; Li, Xin; Zhang, Lu; Mao, Dong; Gao, Feng; Huang, Ligang; Mei, Ting; Zhao, Jianlin

    2018-05-01

    Au-nanoparticle (Au-NP) substrates for surface-enhanced Raman spectroscopy (SERS) were fabricated by grid-like scanning a Au-film using a femtosecond pulse. The Au-NPs were directly deposited on the Au-film surface due to the scanning process. The experimentally obtained Au-NPs presented local surface plasmon resonance effect in the visible spectral range, as verified by finite difference time domain simulations and measured reflection spectrum. The SERS experiment using the Au-NP substrates exhibited high activity and excellent substrate reproducibility and stability, and a clearly present Raman spectra of target analytes, e.g. Rhodamine-6G, Rhodamine-B and Malachite green, with concentrations down to 10‑9 M. This work presents an effective approach to producing Au-NP SERS substrates with advantages in activity, reproducibility and stability, which could be used in a wide variety of practical applications for trace amount detection.

  20. Asymmetric photoelectric property of transparent TiO2 nanotube films loaded with Au nanoparticles

    NASA Astrophysics Data System (ADS)

    Wang, Hui; Liang, Wei; Liu, Yiming; Zhang, Wanggang; Zhou, Diaoyu; Wen, Jing

    2016-11-01

    Semitransparent composite films of Au loaded TiO2 nanotubes (TNT-Au) were prepared by sputtering Au nanoparticles on highly transparent TiO2 nanotubes films, which were fabricated directly on FTO glasses by anodizing the Ti film sputtered on the FTO glasses. Compared with pure TNT films, the prepared TNT-Au films possessed excellent absorption ability and high photocurrent response and improved photocatalytic activity under visible-light irradiation. It could be concluded that Au nanoparticles played important roles in improving the photoelectrochemical performance of TNT-Au films. Moreover, in this work, both sides of TNT-Au films were researched and compared owing to theirs semitransparency. It was firstly found that the photoelectric activity of TNT-Au composite films with back-side illumination was obviously superior to front-side illumination.

  1. Fabrication of Au 25(SG) 18–ZIF-8 Nanocomposites: A Facile Strategy to Position Au 25(SG) 18 Nanoclusters Inside and Outside ZIF-8

    DOE PAGES

    Luo, Yucheng; Fan, Shiyan; Yu, Wenqian; ...

    2017-12-22

    Multifunctional composite materials are currently highly desired for sustainable energy applications. A general strategy to integrate atomically precise Au 25(SG) 18 with ZIF-8 (Zn(MeIm) 2, MeIm = 2-methylimidazole), is developed in this paper via the typical Zn-carboxylate type of linkage. Au 25(SG) 18 are uniformly encapsulated into a ZIF-8 framework (Au 25(SG) 18@ZIF-8) by coordination-assisted self-assembly. In contrast, Au 25(SG) 18 integrated by simple impregnation is oriented along the outer surface of ZIF-8 (Au 25(SG) 18/ZIF-8). The porous structure and thermal stability of these nanocomposites are characterized by N 2 adsorption–desorption isothermal analysis and thermal gravimetric analysis. The distribution ofmore » Au 25(SG) 18 in the two nanocomposites is confirmed by electron microscopy, and the accessibility of Au 25(SG) 18 is evaluated by the 4-nitrophenol reduction reaction. The as-prepared nanocomposites retain the high porosity and thermal stability of the ZIF-8 matrix, while also exhibiting the desired catalytic and optical properties derived from the integrated Au 25(SG) 18 nanoclusters (NCs). Au 25(SG) 18@ZIF-8 with isolated Au 25 sites is a promising heterogenous catalyst with size selectivity imparted by the ZIF-8 matrix. Finally, the structural distinction between Au 25(SG) 18@ZIF-8 and Au 25(SG) 18/ZIF-8 determines their different emission features, and provides a new strategy to adjust the optical behavior of Au 25(SG) 18 for applications in bioimaging and biotherapy.« less

  2. A Hierarchically Modified Graphite Cathode with Au Nanoislands, Cysteamine, and Au Nanocolloids for Increased Electricity-Assisted Production of Isobutanol by Engineered Shewanella oneidensis MR-1.

    PubMed

    La, Ju A; Jeon, Jong-Min; Sang, Byoung-In; Yang, Yung-Hun; Cho, Eun Chul

    2017-12-20

    It is necessary to understand the surface structural effects of electrodes on the bioalcohol productivity of Shewanella oneidensis MR-1, but this research area has not been deeply explored. Here, we report that the electricity-assisted isobutanol productivity of Shewanella oneidensis MR-1::pJL23 can be enhanced by sequentially modifying a graphite felt (GF) surface with Au nanoislands (Au), cysteamine (NH 2 ), and Au nanoparticles (Au NPs). After bacteria were incubated for 50 h with the unmodified GF under various electrode potentials (vs Ag/AgCl), the bacterial isobutanol concentrations increased from 2.9 ± 1 mg/L under no electricity supply to a maximum of 5.9 ± 1 mg/L at -0.6 V. At this optimum electrode potential, the concentrations continued increasing to 9.1 ± 1, 14 ± 2, and 27 ± 2 mg/L when the GF electrodes were modified with Au, NH 2 -Au, and Au NP-NH 2 -Au, respectively. We further studied how each surface structure affected the bacterial adsorptions, current profiles, and biofilms' electrochemical performances. In particular, these modifications induced the adsorption of elongated bacteria, with the amount dependent on the electrode structure. In the presence of electric supply, the amount of elongated bacteria further increased. We also found that the NH 2 -Au-GF and Au NP-NH 2 -Au-GF electrodes themselves could increase the concentrations to 11 ± 0.3 and 12 ± 2 mg/L, respectively, upon the bacterial incubation without electricity. Among the electrodes tested, the contribution of electricity to the bacterial isobutanol production was the greatest with the Au NP-NH 2 -Au-GF electrode. After 96 h of incubation, the concentration increased to 72 ± 2 mg/L, which was 4.7 and 3.7 times the previously reported values obtained without and with electricity, respectively.

  3. Crystal structure and bonding in BaAu5Ga2 and AeAu4+xGa3-x (Ae = Ba and Eu): hexagonal diamond-type Au frameworks and remarkable cation/anion partitioning in the Ae-Au-Ga systems.

    PubMed

    Smetana, Volodymyr; Steinberg, Simon; Card, Nathan; Mudring, Anja-Verena; Miller, Gordon J

    2015-02-02

    Five new polar intermetallic compounds in the Ae-Ga-Au system (Ae = Ba, Eu), BaAu(5)Ga(2) (I), BaAu(4.3)Ga(2.7) (II), Ba(1.0)Au(4.5)Ga(2.4 )(III), EuAu(4.8)Ga(2.2) (IV), and Eu(1.1)Au(4.4)Ga(2.2) (V), have been synthesized and their crystal structures determined by single-crystal X-ray diffraction. I crystallizes in the orthorhombic crystal system with a large unit cell [Pearson symbol oP64; Pnma, Z = 8, a = 8.8350(5) Å, b = 7.1888(3)Å, c = 20.3880(7) Å], whereas all other compounds are hexagonal [hP24; P6̅2m, Z = 3, a = 8.54-8.77(1) Å, c = 7.19-7.24(1) Å]. Both structures contain mutually orthogonal layers of Au(6) hexagons in chair and boat conformations, resulting in a hexagonal diamond-like network. Ae atoms and additional (Au/Ga)(3) groups are formally encapsulated by (Au(6))(2) distorted hexagonal prisms formed of three edge-sharing hexagons in the boat conformation or, alternatively, lie between two Au(6) hexagons in the chair conformation. The (Au/Ga)(3) groups can be substituted by Ae atoms in some of the hexagonal structures with no change to the structural symmetry. Tight-binding electronic structure calculations using linear-muffin-tin-orbital methods on idealized models "BaAu(5)Ga(2)" and "BaAu(4)Ga(3)" show both compounds to be metallic with evident pseudogaps near the corresponding Fermi levels. The integrated crystal orbital Hamilton populations are dominated by Au-Au and Au-Ga orbital interactions, although Ba-Au and Ba-Ga contributions are significant. Furthermore, Au-Au interactions vary considerably along different directions in the unit cells, with the largest values for the hexagons in the boat conformation and the lowest values for those in the chair conformation. II revealed that partial substitution of Au atoms in the hexagonal diamond net by a post-transition element (Ga) may occur in this family, whereas the sizes of the (Au/Ga)(3) groups and strong Ba-Au covalent interactions allow for their mutual replacement in the voids.

  4. Observation of dynamic water microadsorption on Au surface

    SciTech Connect

    Huang, Xiaokang, E-mail: xiaokang.huang@tqs.com; Gupta, Gaurav; Gao, Weixiang

    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 bothmore » 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.« less

  5. Evaluation d’un enseignement par les étudiants appliquée au module « aide à la rédaction de thèse»: destiné aux internes des hôpitaux des Armées au Centre d’épidémiologie et de Santé Publique des Armées, Marseille

    PubMed Central

    Kasouati, Jalal; Velut, Guillaume; Deparis, Xavier; Touloune, Farida

    2016-01-01

    Introduction En éducation, l'évaluation concerne les institutions de formation, les programmes, les enseignants ou les étudiants. Elle peut être prédictive, sommative ou formative. L'Evaluation d'un Enseignement par les Etudiants (EEE) est l'un des outils de ce dernier type. Objectif Évaluer l'enseignement de la première partie de la formation « aide à la rédaction de thèse ». Méthodes C'est une étude transversale classée dans le cadre « EEE » qui a porté sur le module « aide à la rédaction de thèse » dispensée au CESPA au profit de 27 participants préparant leur projet de fin d'étude. Résultats Le taux de réponse des participants présents était de 100%. D'un sexe ratio F/M de 2 et de une moyenne d'âge de 25,5 ans +/- 2,7 ans, les questionnés étaient majoritairement des internes de médecine générale. Plus de 85% affirmait n'avoir bénéficié d'aucune formation au préalable dans les domaines traités. Les participants avaient des attentes qui rejoignaient sommairement les objectifs de la formation. A part le rythme jugé non adapté par plus de la moitié, 80% des participants ont été satisfaits des autres aspects évalués et 95,8% parmi eux prévoyaient d'assister à la deuxième partie de la formation Pour tout les participants, la formation a permis d'amélioré de façon significative leur connaissance et aurais certainement un impact positif sur leurs travaux de recherche. Conclusion Notre travail était un moyen d'installer une certaine complicité entre les étudiants et les enseignants pour atteindre un objectif commun: « AMELIORER LA FORMATION ». PMID:27800091

  6. Highly active Pt@Au nanoparticles encapsulated in perfluorosulfonic acid for the reduction of oxygen.

    PubMed

    Cheng, Niancai; Li, Huaiguang; Li, Guoqiang; Lv, Haifeng; Mu, Shichun; Sun, Xueliang; Pan, Mu

    2011-12-28

    The Pt@Au catalysts demonstrate remarkably high oxygen reduction reaction (ORR) activity compared with Pt/C catalysts. The ORR of Pt(2)@Au(1)/C and Pt(1)@Au(2)/C is 9.5 and 6.6 times that of Pt/C, respectively. This improvement is attributed to the electronic structure effect of the Au core on the Pt shell and introduction of PFSA. This journal is © The Royal Society of Chemistry 2011

  7. Weak aurophilic interactions in a series of Au(III) double salts.

    PubMed

    Chernyshev, Alexander N; Chernysheva, Maria V; Hirva, Pipsa; Kukushkin, Vadim Yu; Haukka, Matti

    2015-08-28

    In this work, several new examples of rare Au(III)Au(III) aurophilic contacts are reported. A series of gold(iii) double salts and complexes, viz. [AuX2(L)][AuX4] (L = 2,2'-bipyridyl, X = Cl , Br ; L = 2,2'-bipyrimidine, X = Cl , Br ; L = 2,2'-dipyridylamine, X = Cl , Br ), [AuX3(biq)] (biq = 2,2'-biquinoline, X = Cl , Br ), [LH][AuX4] (L = 2,2'-bipyridyl, X = Cl ; L = 2,2'-bipyrimidine, X = Cl ; L = 2,2'-dipyridylamine, X = Cl , Br ; L = 2,2'-biquinoline, X = Cl , Br ), [AuBr2(bpy)]2[AuBr4][AuBr2] , [AuCl2(bpm)][AuCl2] , (bpmH)2[AuBr4][AuBr2] , and (dpaH)[AuBr2] (, , and were reported earlier) was synthesized by coordination of a particular ligand to the Au(III) center and subsequent reduction of the formed product with acetone. Inspection of the X-ray structural data for , , and indicates that the Au(III) metal centers approach each other closer than the sum of their van der Waals radii, thus forming the aurophilic contacts, which were confirmed by topological charge density analysis according to the Quantum Theory of Atoms in Molecules (QTAIM). In , , and , such contacts are located only between the metal centers of the ion pair, whereas in , the aurophilic interactions form the cation-anion-anion array, and in , the aurophilicity exists between the gold atoms of the cations. It was also demonstrated that the interatomic distance alone is not a reliable measure of the aurophilic interactions, at least at the weakest limit of the interaction strength, and it needs to be complemented with structural analysis of the whole molecule and computational results.

  8. Development of Pt-Au-Graphene-Carbon Nanotube Composite for Fuel Cells and Biosensors Applications

    DTIC Science & Technology

    2011-02-11

    1 Project Title:- Development of Pt-Au-Graphene- Carbon nanotube composites for fuel cells and biosensors applications Objectives:- This...project addresses the architectures needed for the processing of Pt-Au-graphene- carbon nanotube (Pt-Au/f-G/f-CNT) nanocomposites and aims at the...05-2010 4. TITLE AND SUBTITLE Development of Pt-Au-Graphene- Carbon nanotube composite for fuel cells and biosensors applications 5a. CONTRACT

  9. Stability, structural and electronic properties of benzene molecule adsorbed on free standing Au layer

    SciTech Connect

    Katoch, Neha, E-mail: nehakatoch2@gmail.com; Kapoor, Pooja; Sharma, Munish

    2016-05-23

    We report stability and electronic properties of benzene molecule adsorbed on the Au atomic layer within the framework of density function theory (DFT). Horizontal configuration of benzene on the top site of Au monolayer prefers energetically over other studied configurations. On the adsorption of benzene, the ballistic conductance of Au monolayer is found to decrease from 4G{sub 0} to 2G{sub 0} suggesting its applications for the fabrications of organic sensor devices based on the Au atomic layers.

  10. Délais de prise en charge des syndromes coronariens aigus avec sus-décalage du segment ST à Ouagadougou et facteurs associés à un allongement de ces délais: étude transversale à propos de 43 cas colligés au CHU-Yalgado Ouédraogo

    PubMed Central

    Yameogo, Nobila Valentin; Samadoulougou, André; Millogo, Georges; Kologo, Koudougou Jonas; Kombassere, Karim; Toguyeni, Boubacar Jean Yves; Zabsonre, Patrice

    2012-01-01

    La prise en charge de l'infarctus du myocarde est une course contre la montre et les trois premières heures constituent les « golden hours ». Les objectifs de ce travail étaient de déterminer le délai de prise en charge des infarctus du myocarde du myocarde au Burkina Faso, les facteurs liés à un allongement du délai et le pronostic des patients. Il s'agit d'une étude transversale descriptive menée de Septembre 2010 à Août 2011. Le critère d'inclusion était l'infarctus du myocarde dont le diagnostic était basé sur des critères clinique (douleur angineuse), électrocardiographique (sus-décalage persistant du segment ST dans au moins deux dérivations contiguës du même territoire coronaire, onde Q de nécrose) et biologique (élévation de la troponine). Les informations relatives au délai de prise en charge ont été recueillies: début du premier symptôme, contact avec le premier agent de santé et le cardiologue, nombre de centre de santé consulté avant le transfert en cardiologie, situation géographique des patients, moyen de transport utilisé. Les données ont été analysées grâce au logiciel SPSS version 17. Durant la période d’étude, 43 patients d’âge moyen de 56,51 ± 12,91 ans ont été admis pour infarctus du myocarde. Plus de la moitié des patients (72,0%) habitait Ouagadougou et sa banlieue. Le délai moyen entre le début de la douleur et la consultation dans la première structure sanitaire était de 48 ± 20,8 heures; celui entre le début de la douleur et la réalisation du premier ECG était en moyenne de 8,6 ±4,5 jours. Le délai entre la réalisation de l'ECG et l'admission dans le service de cardiologie était de 4,35 ±4,0 jours [00 heure et 13 jours]. Le délai entre l'admission dans le service de cardiologie et la thrombolyse était de 34 minutes. Enfin le délai entre le début de la douleur et le contact avec le cardiologue était de 9,6±3,5 jours. Il n'y avait pas de différence statiquement

  11. Measurement of the Shared Momentum Fraction zg using Jet Reconstruction in p + p and Au + Au Collisions with STAR

    NASA Astrophysics Data System (ADS)

    Kauder, K.; STAR Collaboration

    2017-11-01

    One key difference in current energy loss models lies in the treatment of the Altarelli-Parisi, AP, splitting functions. It has been shown that the shared momentum fraction, henceforth called Jet Splitting Functionzg as determined by the SoftDrop grooming process can be made a Sudakov-safe measurement of the symmetrized AP functions in p+p collisions. The STAR collaboration presents the first zg measurements at √{sNN} = 200 GeV in p+p and Au+Au collisions, where in Au+Au we use a set of di-jets with hard cores reconstructed with a 2 GeV/c constituent cut. For a jet resolution parameter of R = 0.4, these di-jet pairs were found to be significantly imbalanced with respect to p+p, yet regained balance when all soft constituents were included. We find that within uncertainties there are no signs of a modified Jet Splitting Function on trigger or recoil sides of this di-jet selection.

  12. Nanoporous Au-based chronocoulometric aptasensor for amplified detection of Pb(2+) using DNAzyme modified with Au nanoparticles.

    PubMed

    Zhang, Chen; Lai, Cui; Zeng, Guangming; Huang, Danlian; Tang, Lin; Yang, Chunping; Zhou, Yaoyu; Qin, Lei; Cheng, Min

    2016-07-15

    The authors herein described an amplified detection strategy employing nanoporous Au (NPG) and gold nanoparticles (AuNPs) to detect Pb(2+) ions in aqueous solution. The thiol modified Pb(2+)-specific DNAzyme was self-assembled onto the surface of the NPG modified electrode for hybridizing with the AuNPs labeled oligonucleotide and for forming the DNA double helix structure. Electrochemical signal, redox charge of hexaammineruthenium(III) chloride (RuHex), was measured by chronocoulometry. Taking advantage of amplification effects of the NPG electrode for increasing the reaction sites of capture probe and DNA-AuNPs complexes for bringing about the adsorption of large numbers of RuHex molecules, this electrochemical sensor could detect Pb(2+) quantitatively, in the range of 0.05-100nM, with a limit of detection as low as 0.012nM. Selectivity measurements revealed that the sensor was specific for Pb(2+) even with interference by high concentrations of other metal ions. This sensor was also used to detect Pb(2+) ions from samples of tap water, river water, and landfill leachate samples spiked with Pb(2+) ions, and the results showed good agreement with the found values determined by an atomic fluorescence spectrometer. This simple aptasensor represented a promising potential for on-site detecting Pb(2+) in drinking water. Copyright © 2016 Elsevier B.V. All rights reserved.

  13. Tuning the Kondo effect in thin Au films by depositing a thin layer of Au on molecular spin-dopants

    NASA Astrophysics Data System (ADS)

    Ataç, D.; Gang, T.; Yilmaz, M. D.; Bose, S. K.; Lenferink, A. T. M.; Otto, C.; de Jong, M. P.; Huskens, J.; van der Wiel, W. G.

    2013-09-01

    We report on the tuning of the Kondo effect in thin Au films containing a monolayer of cobalt(II) terpyridine complexes by altering the ligand structure around the Co2+ ions by depositing a thin Au capping layer on top of the monolayer on Au by magnetron sputtering (more energetic) and e-beam evaporation (softer). We show that the Kondo effect is slightly enhanced with respect to that of the uncapped film when the cap is deposited by evaporation, and significantly enhanced when magnetron sputtering is used. The Kondo temperature (TK) increases from 3 to 4.2/6.2 K for the evaporated/sputtered caps. X-ray absorption spectroscopy and surface-enhanced Raman spectroscopy investigation showed that the organic ligands remain intact upon Au e-beam evaporation; however, sputtering inflicts significant change in the Co2+ electronic environment. The location of the monolayer—on the surface or embedded in the film—has a small effect. However, the damage of Co-N bonds induced by sputtering has a drastic effect on the increase of the impurity-electron interaction. This opens up the way for tuning of the magnetic impurity states, e.g. spin quantum number, binding energy with respect to the host Fermi energy, and overlap via the ligand structure around the ions.

  14. Numerical simulations of high-speed solar wind streams within 1 AU and their signatures at 1 AU

    NASA Technical Reports Server (NTRS)

    Smith, Z.; Dryer, M.

    1991-01-01

    A parametric study of the evolution within, and signatures at, 1 AU of high-speed streams is performed with the use of a MHD two-and-a-half-dimensional time-dependent model. This study is an extension of an earlier one by Smith and Dryer (1990) who examined the ecliptic plane consequences of relatively short-duration, energetic solar disturbances. The present study examines both the erupting and corotating parts of long-duration, high-speed streams characteristic of coronal hole flows. By examining the variation of the simulated plasma velocity, density, temperature, and magnetic field at 1 AU, as well as the location of the solar coronal hole sources relative to the observer at 1 AU, it was possible to provide some insight into the identification of the solar sources of interplanetary disturbances. Two definitions for angle locating the solar source of interplanetary disturbances at 1 AU are presented and discussed. The results are applied to the suggestion by Hewish (1988) that low-latitude coronal holes are suitably positioned to be the sources of major geomagnetic storms when the holes are in the eastern half of the solar hemisphere at the time of the commencement of the storm. The results indicate that, for these cases, the streams emanating from within the hole must be very fast, greater than 1000 km/s, or very wide, greater than 60 deg, at the inner boundary of 18 solar radii.

  15. Au-rich filamentary behavior and associated subband gap optical absorption in hyperdoped Si

    NASA Astrophysics Data System (ADS)

    Yang, W.; Akey, A. J.; Smillie, L. A.; Mailoa, J. P.; Johnson, B. C.; McCallum, J. C.; Macdonald, D.; Buonassisi, T.; Aziz, M. J.; Williams, J. S.

    2017-12-01

    Au-hyperdoped Si, synthesized by ion implantation and pulsed laser melting, is known to exhibit a strong sub-band gap photoresponse that scales monotonically with the Au concentration. However, there is thought to be a limit to this behavior since ultrahigh Au concentrations (>1 ×1020c m-3 ) are expected to induce cellular breakdown during the rapid resolidification of Si, a process that is associated with significant lateral impurity precipitation. This work shows that the cellular morphology observed in Au-hyperdoped Si differs from that in conventional, steady-state cellular breakdown. In particular, Rutherford backscattering spectrometry combined with channeling and transmission electron microscopy revealed an inhomogeneous Au distribution and a subsurface network of Au-rich filaments, within which the Au impurities largely reside on substitutional positions in the crystalline Si lattice, at concentrations as high as ˜3 at. %. The measured substitutional Au dose, regardless of the presence of Au-rich filaments, correlates strongly with the sub-band gap optical absorptance. Upon subsequent thermal treatment, the supersaturated Au forms precipitates, while the Au substitutionality and the sub-band gap optical absorption both decrease. These results offer insight into a metastable filamentary regime in Au-hyperdoped Si that has important implications for Si-based infrared optoelectronics.

  16. Au13(8e): A secondary block for describing a special group of liganded gold clusters containing icosahedral Au13 motifs

    NASA Astrophysics Data System (ADS)

    Xu, Wen Wu; Zeng, Xiao Cheng; Gao, Yi

    2017-05-01

    A grand unified model (GUM) has been proposed recently to understand structure anatomy and evolution of liganded gold clusters. In this work, besides the two types of elementary blocks (triangular Au3(2e) and tetrahedral Au4(2e)), we introduce a secondary block, namely, the icosahedral Au13 with 8e valence electrons, noted as Au13(8e). Using this secondary block, structural anatomy and evolution of a special group of liganded gold nanoclusters containing icosahedral Au13 motifs can be conveniently analyzed. In addition, a new ligand-protected cluster Au49(PR3)10(SR)15Cl2 is predicted to exhibit high chemical and thermal stability, suggesting likelihood of its synthesis in the laboratory.

  17. Application of Turkevich Method for Gold Nanoparticles Synthesis to Fabrication of SiO2@Au and TiO2@Au Core-Shell Nanostructures

    PubMed Central

    Dobrowolska, Paulina; Krajewska, Aleksandra; Gajda-Rączka, Magdalena; Bartosewicz, Bartosz; Nyga, Piotr; Jankiewicz, Bartłomiej J.

    2015-01-01

    The Turkevich synthesis method of Au nanoparticles (AuNPs) was adopted for direct fabrication of SiO2@Au and TiO2@Au core-shell nanostructures. In this method, chloroauric acid was reduced with trisodium citrate in the presence of amine-functionalized silica or titania submicroparticles. Core-shells obtained in this way were compared to structures fabricated by mixing of Turkevich AuNPs with amine-functionalized silica or titania submicroparticles. It was found that by modification of reaction conditions of the first method, such as temperature and concentration of reagents, control over gold coverage on silicon dioxide particles has been achieved. Described method under certain conditions allows fabrication of semicontinuous gold films on the surface of silicon dioxide particles. To the best of our knowledge, this is the first report describing use of Turkevich method to direct fabrication of TiO2@Au core-shell nanostructures.

  18. Observation of D0 meson nuclear modifications in Au+Au collisions at sqrt[s(NN)] = 200 GeV.

    PubMed

    Adamczyk, L; Adkins, J K; Agakishiev, G; Aggarwal, M M; Ahammed, Z; Alekseev, I; Alford, J; Anson, C D; Aparin, A; Arkhipkin, D; Aschenauer, E C; Averichev, G S; Banerjee, A; Beavis, D R; Bellwied, R; Bhasin, A; Bhati, A K; Bhattarai, P; Bichsel, H; Bielcik, J; Bielcikova, J; Bland, L C; Bordyuzhin, I G; Borowski, W; Bouchet, J; Brandin, A V; Brovko, S G; Bültmann, S; Bunzarov, I; Burton, T P; Butterworth, J; Caines, H; Calderón de la Barca Sánchez, M; Cebra, D; Cendejas, R; Cervantes, M C; Chaloupka, P; Chang, Z; Chattopadhyay, S; Chen, H F; Chen, J H; Chen, L; Cheng, J; Cherney, M; Chikanian, A; Christie, W; Chwastowski, J; Codrington, M J M; Contin, G; Cramer, J G; Crawford, H J; Cui, X; Das, S; Davila Leyva, A; De Silva, L C; Debbe, R R; Dedovich, T G; Deng, J; Derevschikov, A A; Derradi de Souza, R; Dhamija, S; di Ruzza, B; Didenko, L; Dilks, C; Ding, F; Djawotho, P; Dong, X; Drachenberg, J L; Draper, J E; Du, C M; Dunkelberger, L E; Dunlop, J C; Efimov, L G; Engelage, J; Engle, K S; Eppley, G; Eun, L; Evdokimov, O; Eyser, O; Fatemi, R; Fazio, S; Fedorisin, J; Filip, P; Finch, E; Fisyak, Y; Flores, C E; Gagliardi, C A; Gangadharan, D R; Garand, D; Geurts, F; Gibson, A; Girard, M; Gliske, S; Greiner, L; Grosnick, D; Gunarathne, D S; Guo, Y; Gupta, A; Gupta, S; Guryn, W; Haag, B; Hamed, A; Han, L-X; Haque, R; Harris, J W; Heppelmann, S; Hirsch, A; Hoffmann, G W; Hofman, D J; Horvat, S; Huang, B; Huang, H Z; Huang, X; Huck, P; Humanic, T J; Igo, G; Jacobs, W W; Jang, H; Judd, E G; Kabana, S; Kalinkin, D; Kang, K; Kauder, K; Ke, H W; Keane, D; Kechechyan, A; Kesich, A; Khan, Z H; Kikola, D P; Kisel, I; Kisiel, A; Koetke, D D; Kollegger, T; Konzer, J; Koralt, I; Kotchenda, L; Kraishan, A F; Kravtsov, P; Krueger, K; Kulakov, I; Kumar, L; Kycia, R A; Lamont, M A C; Landgraf, J M; Landry, K D; Lauret, J; Lebedev, A; Lednicky, R; Lee, J H; LeVine, M J; Li, C; Li, W; Li, X; Li, X; Li, Y; Li, Z M; Lisa, M A; Liu, F; Ljubicic, T; Llope, W J; Lomnitz, M; Longacre, R S; Luo, X; Ma, G L; Ma, Y G; Madagodagettige Don, D M M D; Mahapatra, D P; Majka, R; Margetis, S; Markert, C; Masui, H; Matis, H S; McDonald, D; McShane, T S; Minaev, N G; Mioduszewski, S; Mohanty, B; Mondal, M M; Morozov, D A; Mustafa, M K; Nandi, B K; Nasim, Md; Nayak, T K; Nelson, J M; Nigmatkulov, G; Nogach, L V; Noh, S Y; Novak, J; Nurushev, S B; Odyniec, G; Ogawa, A; Oh, K; Ohlson, A; Okorokov, V; Oldag, E W; Olvitt, D L; Pachr, M; Page, B S; Pal, S K; Pan, Y X; Pandit, Y; Panebratsev, Y; Pawlak, T; Pawlik, B; Pei, H; Perkins, C; Peryt, W; Pile, P; Planinic, M; Pluta, J; Poljak, N; Porter, J; Poskanzer, A M; Pruthi, N K; Przybycien, M; Pujahari, P R; Putschke, J; Qiu, H; Quintero, A; Ramachandran, S; Raniwala, R; Raniwala, S; Ray, R L; Riley, C K; Ritter, H G; Roberts, J B; Rogachevskiy, O V; Romero, J L; Ross, J F; Roy, A; Ruan, L; Rusnak, J; Rusnakova, O; Sahoo, N R; Sahu, P K; Sakrejda, I; Salur, S; Sandweiss, J; Sangaline, E; Sarkar, A; Schambach, J; Scharenberg, R P; Schmah, A M; Schmidke, W B; Schmitz, N; Seger, J; Seyboth, P; Shah, N; Shahaliev, E; Shanmuganathan, P V; Shao, M; Sharma, B; Shen, W Q; Shi, S S; Shou, Q Y; Sichtermann, E P; Singaraju, R N; Skoby, M J; Smirnov, D; Smirnov, N; Solanki, D; Sorensen, P; Spinka, H M; Srivastava, B; Stanislaus, T D S; Stevens, J R; Stock, R; Strikhanov, M; Stringfellow, B; Sumbera, M; Sun, X; Sun, X M; Sun, Y; Sun, Z; Surrow, B; Svirida, D N; Symons, T J M; Szelezniak, M A; Takahashi, J; Tang, A H; Tang, Z; Tarnowsky, T; Thomas, J H; Timmins, A R; Tlusty, D; Tokarev, M; Trentalange, S; Tribble, R E; Tribedy, P; Trzeciak, B A; Tsai, O D; Turnau, J; Ullrich, T; Underwood, D G; Van Buren, G; van Nieuwenhuizen, G; Vandenbroucke, M; Vanfossen, J A; Varma, R; Vasconcelos, G M S; Vasiliev, A N; Vertesi, R; Videbæk, F; Viyogi, Y P; Vokal, S; Vossen, A; Wada, M; Wang, F; Wang, G; Wang, H; Wang, J S; Wang, X L; Wang, Y; Wang, Y; Webb, G; Webb, J C; Westfall, G D; Wieman, H; Wissink, S W; Witt, R; Wu, Y F; Xiao, Z; Xie, W; Xin, K; Xu, H; Xu, J; Xu, N; Xu, Q H; Xu, Y; Xu, Z; Yan, W; Yang, C; Yang, Y; Yang, Y; Ye, Z; Yepes, P; Yi, L; Yip, K; Yoo, I-K; Yu, N; Zawisza, Y; Zbroszczyk, H; Zha, W; Zhang, J B; Zhang, J L; Zhang, S; Zhang, X P; Zhang, Y; Zhang, Z P; Zhao, F; Zhao, J; Zhong, C; Zhu, X; Zhu, Y H; Zoulkarneeva, Y; Zyzak, M

    2014-10-03

    We report the first measurement of charmed-hadron (D(0)) production via the hadronic decay channel (D(0) → K(-) + π(+)) in Au+Au collisions at sqrt[s(NN)] = 200 GeV with the STAR experiment. The charm production cross section per nucleon-nucleon collision at midrapidity scales with the number of binary collisions, N(bin), from p+p to central Au+Au collisions. The D(0) meson yields in central Au + Au collisions are strongly suppressed compared to those in p+p scaled by N(bin), for transverse momenta p(T) > 3 GeV/c, demonstrating significant energy loss of charm quarks in the hot and dense medium. An enhancement at intermediate p(T) is also observed. Model calculations including strong charm-medium interactions and coalescence hadronization describe our measurements.

  19. Tuning SPT-3G Transition-Edge-Sensor Electrical Properties with a Four-Layer Ti-Au-Ti-Au Thin-Film Stack

    NASA Astrophysics Data System (ADS)

    Carter, F. W.; Ade, P. A. R.; Ahmed, Z.; Anderson, A. J.; Austermann, J. E.; Avva, J. S.; Thakur, R. Basu; Bender, A. N.; Benson, B. A.; Carlstrom, J. E.; Cecil, T.; Chang, C. L.; Cliche, J. F.; Cukierman, A.; Denison, E. V.; de Haan, T.; Ding, J.; Divan, R.; Dobbs, M. A.; Dutcher, D.; Everett, W.; Foster, A.; Gannon, R. N.; Gilbert, A.; Groh, J. C.; Halverson, N. W.; Harke-Hosemann, A. H.; Harrington, N. L.; Henning, J. W.; Hilton, G. C.; Holzapfel, W. L.; Huang, N.; Irwin, K. D.; Jeong, O. B.; Jonas, M.; Khaire, T.; Kofman, A. M.; Korman, M.; Kubik, D.; Kuhlmann, S.; Kuo, C. L.; Kutepova, V.; Lee, A. T.; Lowitz, A. E.; Meyer, S. S.; Michalik, D.; Miller, C. S.; Montgomery, J.; Nadolski, A.; Natoli, T.; Nguyen, H.; Noble, G. I.; Novosad, V.; Padin, S.; Pan, Z.; Pearson, J.; Posada, C. M.; Rahlin, A.; Ruhl, J. E.; Saunders, L. J.; Sayre, J. T.; Shirley, I.; Shirokoff, E.; Smecher, G.; Sobrin, J. A.; Stan, L.; Stark, A. A.; Story, K. T.; Suzuki, A.; Tang, Q. Y.; Thompson, K. L.; Tucker, C.; Vale, L. R.; Vanderlinde, K.; Vieira, J. D.; Wang, G.; Whitehorn, N.; Yefremenko, V.; Yoon, K. W.; Young, M. R.

    2018-04-01

    We have developed superconducting Ti transition-edge sensors with Au protection layers on the top and bottom for the South Pole Telescope's third-generation receiver (a cosmic microwave background polarimeter, due to be upgraded this austral summer of 2017/2018). The base Au layer (deposited on a thin Ti glue layer) isolates the Ti from any substrate effects; the top Au layer protects the Ti from oxidation during processing and subsequent use of the sensors. We control the transition temperature and normal resistance of the sensors by varying the sensor width and the relative thicknesses of the Ti and Au layers. The transition temperature is roughly six times more sensitive to the thickness of the base Au layer than to that of the top Au layer. The normal resistance is inversely proportional to sensor width for any given film configuration. For widths greater than five micrometers, the critical temperature is independent of width.

  20. J /ψ production at low pT in Au + Au and Cu + Cu collisions at √sNN =200 GeV with the STAR detector

    NASA Astrophysics Data System (ADS)

    Adamczyk, L.; Adkins, J. K.; Agakishiev, G.; Aggarwal, M. M.; Ahammed, Z.; Alekseev, I.; Alford, J.; Anson, C. D.; Aparin, A.; Arkhipkin, D.; Aschenauer, E. C.; Averichev, G. S.; Banerjee, A.; Beavis, D. R.; Bellwied, R.; Bhasin, A.; Bhati, A. K.; Bhattarai, P.; Bichsel, H.; Bielcik, J.; Bielcikova, J.; Bland, L. C.; Bordyuzhin, I. G.; Borowski, W.; Bouchet, J.; Brandin, A. V.; Brovko, S. G.; Bültmann, S.; Bunzarov, I.; Burton, T. P.; Butterworth, J.; Caines, H.; Calderón de la Barca Sánchez, M.; Campbell, J. M.; Cebra, D.; Cendejas, R.; Cervantes, M. C.; Chaloupka, P.; Chang, Z.; Chattopadhyay, S.; Chen, H. F.; Chen, J. H.; Chen, L.; Cheng, J.; Cherney, M.; Chikanian, A.; Christie, W.; Chwastowski, J.; Codrington, M. J. M.; Contin, G.; Cramer, J. G.; Crawford, H. J.; Cui, X.; Das, S.; Davila Leyva, A.; De Silva, L. C.; Debbe, R. R.; Dedovich, T. G.; Deng, J.; Derevschikov, A. A.; Derradi de Souza, R.; di Ruzza, B.; Didenko, L.; Dilks, C.; Ding, F.; Djawotho, P.; Dong, X.; Drachenberg, J. L.; Draper, J. E.; Du, C. M.; Dunkelberger, L. E.; Dunlop, J. C.; Efimov, L. G.; Engelage, J.; Engle, K. S.; Eppley, G.; Eun, L.; Evdokimov, O.; Eyser, O.; Fatemi, R.; Fazio, S.; Fedorisin, J.; Filip, P.; Fisyak, Y.; Flores, C. E.; Gagliardi, C. A.; Gangadharan, D. R.; Garand, D.; Geurts, F.; Gibson, A.; Girard, M.; Gliske, S.; Greiner, L.; Grosnick, D.; Gunarathne, D. S.; Guo, Y.; Gupta, A.; Gupta, S.; Guryn, W.; Haag, B.; Hamed, A.; Han, L.-X.; Haque, R.; Harris, J. W.; Heppelmann, S.; Hirsch, A.; Hoffmann, G. W.; Hofman, D. J.; Horvat, S.; Huang, B.; Huang, H. Z.; Huang, X.; Huck, P.; Humanic, T. J.; Igo, G.; Jacobs, W. W.; Jang, H.; Judd, E. G.; Kabana, S.; Kalinkin, D.; Kang, K.; Kauder, K.; Ke, H. W.; Keane, D.; Kechechyan, A.; Kesich, A.; Khan, Z. H.; Kikola, D. P.; Kisel, I.; Kisiel, A.; Koetke, D. D.; Kollegger, T.; Konzer, J.; Koralt, I.; Kosarzewski, L. K.; Kotchenda, L.; Kraishan, A. F.; Kravtsov, P.; Krueger, K.; Kulakov, I.; Kumar, L.; Kycia, R. A.; Lamont, M. A. C.; Landgraf, J. M.; Landry, K. D.; Lauret, J.; Lebedev, A.; Lednicky, R.; Lee, J. H.; Li, C.; Li, W.; Li, X.; Li, X.; Li, Y.; Li, Z. M.; Lisa, M. A.; Liu, F.; Ljubicic, T.; Llope, W. J.; Lomnitz, M.; Longacre, R. S.; Luo, X.; Ma, G. L.; Ma, Y. G.; Mahapatra, D. P.; Majka, R.; Margetis, S.; Markert, C.; Masui, H.; Matis, H. S.; McDonald, D.; McShane, T. S.; Minaev, N. G.; Mioduszewski, S.; Mohanty, B.; Mondal, M. M.; Morozov, D. A.; Mustafa, M. K.; Nandi, B. K.; Nasim, Md.; Nayak, T. K.; Nelson, J. M.; Nigmatkulov, G.; Nogach, L. V.; Noh, S. Y.; Novak, J.; Nurushev, S. B.; Odyniec, G.; Ogawa, A.; Oh, K.; Ohlson, A.; Okorokov, V.; Oldag, E. W.; Olvitt, D. L.; Page, B. S.; Pan, Y. X.; Pandit, Y.; Panebratsev, Y.; Pawlak, T.; Pawlik, B.; Pei, H.; Perkins, C.; Pile, P.; Planinic, M.; Pluta, J.; Poljak, N.; Poniatowska, K.; Porter, J.; Poskanzer, A. M.; Powell, C. B.; Pruthi, N. K.; Przybycien, M.; Putschke, J.; Qiu, H.; Quintero, A.; Ramachandran, S.; Raniwala, R.; Raniwala, S.; Ray, R. L.; Riley, C. K.; Ritter, H. G.; Roberts, J. B.; Rogachevskiy, O. V.; Romero, J. L.; Ross, J. F.; Roy, A.; Ruan, L.; Rusnak, J.; Rusnakova, O.; Sahoo, N. R.; Sahu, P. K.; Sakrejda, I.; Salur, S.; Sandweiss, J.; Sangaline, E.; Sarkar, A.; Schambach, J.; Scharenberg, R. P.; Schmah, A. M.; Schmidke, W. B.; Schmitz, N.; Seger, J.; Seyboth, P.; Shah, N.; Shahaliev, E.; Shanmuganathan, P. V.; Shao, M.; Sharma, B.; Shen, W. Q.; Shi, S. S.; Shou, Q. Y.; Sichtermann, E. P.; Simko, M.; Skoby, M. J.; Smirnov, D.; Smirnov, N.; Solanki, D.; Sorensen, P.; Spinka, H. M.; Srivastava, B.; Stanislaus, T. D. S.; Stevens, J. R.; Stock, R.; Strikhanov, M.; Stringfellow, B.; Sumbera, M.; Sun, X.; Sun, X. M.; Sun, Y.; Sun, Z.; Surrow, B.; Svirida, D. N.; Symons, T. J. M.; Szelezniak, M. A.; Takahashi, J.; Tang, A. H.; Tang, Z.; Tarnowsky, T.; Thomas, J. H.; Timmins, A. R.; Tlusty, D.; Tokarev, M.; Trentalange, S.; Tribble, R. E.; Tribedy, P.; Trzeciak, B. A.; Tsai, O. D.; Turnau, J.; Ullrich, T.; Underwood, D. G.; Van Buren, G.; van Nieuwenhuizen, G.; Vandenbroucke, M.; Vanfossen, J. A.; Varma, R.; Vasconcelos, G. M. S.; Vasiliev, A. N.; Vertesi, R.; Videbæk, F.; Viyogi, Y. P.; Vokal, S.; Vossen, A.; Wada, M.; Wang, F.; Wang, G.; Wang, H.; Wang, J. S.; Wang, X. L.; Wang, Y.; Wang, Y.; Webb, G.; Webb, J. C.; Westfall, G. D.; Wieman, H.; Wissink, S. W.; Witt, R.; Wu, Y. F.; Xiao, Z.; Xie, W.; Xin, K.; Xu, H.; Xu, J.; Xu, N.; Xu, Q. H.; Xu, Y.; Xu, Z.; Yan, W.; Yang, C.; Yang, Y.; Yang, Y.; Ye, Z.; Yepes, P.; Yi, L.; Yip, K.; Yoo, I.-K.; Yu, N.; Zbroszczyk, H.; Zha, W.; Zhang, J. B.; Zhang, J. L.; Zhang, S.; Zhang, X. P.; Zhang, Y.; Zhang, Z. P.; Zhao, F.; Zhao, J.; Zhong, C.; Zhu, X.; Zhu, Y. H.; Zoulkarneeva, Y.; Zyzak, M.; STAR Collaboration

    2014-08-01

    The J /ψ pT spectrum and nuclear modification factor (RAA) are reported for pT<5GeV /c and |y|<1 from 0% to 60% central Au +Au and Cu +Cu collisions at √sNN =200GeV at STAR. A significant suppression of pT-integrated J /ψ production is observed in central Au +Au events. The Cu +Cu data are consistent with no suppression, although the precision is limited by the available statistics. RAA in Au +Au collisions exhibits a strong suppression at low transverse momentum and gradually increases with pT. The data are compared to high-pT STAR results and previously published BNL Relativistic Heavy Ion Collider results. Comparing with model calculations, it is found that the invariant yields at low pT are significantly above hydrodynamic flow predictions but are consistent with models that include color screening and regeneration.

  1. J/ψ suppression at forward rapidity in Au + Au collisions at sNN=39 and 62.4 GeV

    NASA Astrophysics Data System (ADS)

    Adare, A.; Aidala, C.; Ajitanand, N. N.; Akiba, Y.; Akimoto, R.; Al-Ta'ani, H.; Alexander, J.; Angerami, A.; Aoki, K.; Apadula, N.; Aramaki, Y.; Asano, H.; Aschenauer, E. C.; Atomssa, E. T.; Awes, T. C.; Azmoun, B.; Babintsev, V.; Bai, M.; Bannier, B.; Barish, K. N.; Bassalleck, B.; Bathe, S.; Baublis, V.; Baumgart, S.; Bazilevsky, A.; Belmont, R.; Berdnikov, A.; Berdnikov, Y.; Bing, X.; Blau, D. S.; Boyle, K.; Brooks, M. L.; Buesching, H.; Bumazhnov, V.; Butsyk, S.; Campbell, S.; Castera, P.; Chen, C.-H.; Chi, C. Y.; Chiu, M.; Choi, I. J.; Choi, J. B.; Choi, S.; Choudhury, R. K.; Christiansen, P.; Chujo, T.; Chvala, O.; Cianciolo, V.; Citron, Z.; Cole, B. A.; Connors, M.; Csanád, M.; Csörgő, T.; Dairaku, S.; Datta, A.; Daugherity, M. S.; David, G.; Denisov, A.; Deshpande, A.; Desmond, E. J.; Dharmawardane, K. V.; Dietzsch, O.; Ding, L.; Dion, A.; Donadelli, M.; Drapier, O.; Drees, A.; Drees, K. A.; Durham, J. M.; Durum, A.; D'Orazio, L.; Edwards, S.; Efremenko, Y. V.; Engelmore, T.; Enokizono, A.; Esumi, S.; Eyser, K. O.; Fadem, B.; Fields, D. E.; Finger, M.; Finger, M., Jr.; Fleuret, F.; Fokin, S. L.; Frantz, J. E.; Franz, A.; Frawley, A. D.; Fukao, Y.; Fusayasu, T.; Gainey, K.; Gal, C.; Garishvili, A.; Garishvili, I.; Glenn, A.; Gong, X.; Gonin, M.; Goto, Y.; Granier de Cassagnac, R.; Grau, N.; Greene, S. V.; Grosse Perdekamp, M.; Gunji, T.; Guo, L.; Gustafsson, H.-Å.; Hachiya, T.; Haggerty, J. S.; Hahn, K. I.; Hamagaki, H.; Hanks, J.; Hashimoto, K.; Haslum, E.; Hayano, R.; He, X.; Hemmick, T. K.; Hester, T.; Hill, J. C.; Hollis, R. S.; Homma, K.; Hong, B.; Horaguchi, T.; Hori, Y.; Huang, S.; Ichihara, T.; Iinuma, H.; Ikeda, Y.; Imrek, J.; Inaba, M.; Iordanova, A.; Isenhower, D.; Issah, M.; Ivanischev, D.; Jacak, B. V.; Javani, M.; Jia, J.; Jiang, X.; Johnson, B. M.; Joo, K. S.; Jouan, D.; Kamin, J.; Kaneti, S.; Kang, B. H.; Kang, J. H.; Kang, J. S.; Kapustinsky, J.; Karatsu, K.; Kasai, M.; Kawall, D.; Kazantsev, A. V.; Kempel, T.; Khanzadeev, A.; Kijima, K. M.; Kim, B. I.; Kim, C.; Kim, D. J.; Kim, E.-J.; Kim, H. J.; Kim, K.-B.; Kim, Y.-J.; Kim, Y. K.; Kinney, E.; Kiss, Á.; Kistenev, E.; Klatsky, J.; Kleinjan, D.; Kline, P.; Komatsu, Y.; Komkov, B.; Koster, J.; Kotchetkov, D.; Kotov, D.; Král, A.; Krizek, F.; Kunde, G. J.; Kurita, K.; Kurosawa, M.; Kwon, Y.; Kyle, G. S.; Lacey, R.; Lai, Y. S.; Lajoie, J. G.; Lebedev, A.; Lee, B.; Lee, D. M.; Lee, J.; Lee, K. B.; Lee, K. S.; Lee, S. H.; Lee, S. R.; Leitch, M. J.; Leite, M. A. L.; Leitgab, M.; Lewis, B.; Lim, S. H.; Linden Levy, L. A.; Liu, M. X.; Love, B.; Maguire, C. F.; Makdisi, Y. I.; Makek, M.; Manion, A.; Manko, V. I.; Mannel, E.; Masumoto, S.; McCumber, M.; McGaughey, P. L.; McGlinchey, D.; McKinney, C.; Mendoza, M.; Meredith, B.; Miake, Y.; Mibe, T.; Mignerey, A. C.; Milov, A.; Mishra, D. K.; Mitchell, J. T.; Miyachi, Y.; Miyasaka, S.; Mohanty, A. K.; Moon, H. J.; Morrison, D. P.; Motschwiller, S.; Moukhanova, T. V.; Murakami, T.; Murata, J.; Nagae, T.; Nagamiya, S.; Nagle, J. L.; Nagy, M. I.; Nakagawa, I.; Nakamiya, Y.; Nakamura, K. R.; Nakamura, T.; Nakano, K.; Nattrass, C.; Nederlof, A.; Nihashi, M.; Nouicer, R.; Novitzky, N.; Nyanin, A. S.; O'Brien, E.; Ogilvie, C. A.; Okada, K.; Oskarsson, A.; Ouchida, M.; Ozawa, K.; Pak, R.; Pantuev, V.; Papavassiliou, V.; Park, B. H.; Park, I. H.; Park, S. K.; Pate, S. F.; Patel, L.; Pei, H.; Peng, J.-C.; Pereira, H.; Peressounko, D. Yu.; Petti, R.; Pinkenburg, C.; Pisani, R. P.; Proissl, M.; Purschke, M. L.; Qu, H.; Rak, J.; Ravinovich, I.; Read, K. F.; Reynolds, R.; Riabov, V.; Riabov, Y.; Richardson, E.; Roach, D.; Roche, G.; Rolnick, S. D.; Rosati, M.; Sahlmueller, B.; Saito, N.; Sakaguchi, T.; Samsonov, V.; Sano, M.; Sarsour, M.; Sawada, S.; Sedgwick, K.; Seidl, R.; Sen, A.; Seto, R.; Sharma, D.; Shein, I.; Shibata, T.-A.; Shigaki, K.; Shimomura, M.; Shoji, K.; Shukla, P.; Sickles, A.; Silva, C. L.; Silvermyr, D.; Sim, K. S.; Singh, B. K.; Singh, C. P.; Singh, V.; Slunečka, M.; Soltz, R. A.; Sondheim, W. E.; Sorensen, S. P.; Soumya, M.; Sourikova, I. V.; Stankus, P. W.; Stenlund, E.; Stepanov, M.; Ster, A.; Stoll, S. P.; Sugitate, T.; Sukhanov, A.; Sun, J.; Sziklai, J.; Takagui, E. M.; Takahara, A.; Taketani, A.; Tanaka, Y.; Taneja, S.; Tanida, K.; Tannenbaum, M. J.; Tarafdar, S.; Taranenko, A.; Tennant, E.; Themann, H.; Todoroki, T.; Tomášek, L.; Tomášek, M.; Torii, H.; Towell, R. S.; Tserruya, I.; Tsuchimoto, Y.; Tsuji, T.; Vale, C.; van Hecke, H. W.; Vargyas, M.; Vazquez-Zambrano, E.; Veicht, A.; Velkovska, J.; Vértesi, R.; Virius, M.; Vossen, A.; Vrba, V.; Vznuzdaev, E.; Wang, X. R.; Watanabe, D.; Watanabe, K.; Watanabe, Y.; Watanabe, Y. S.; Wei, F.; Wei, R.; White, S. N.; Winter, D.; Wolin, S.; Woody, C. L.; Wysocki, M.; Yamaguchi, Y. L.; Yang, R.; Yanovich, A.; Ying, J.; Yokkaichi, S.; You, Z.; Younus, I.; Yushmanov, I. E.; Zajc, W. A.; Zelenski, A.

    2012-12-01

    We present measurements of the J/ψ invariant yields in sNN=39 and 62.4 GeV Au + Au collisions at forward rapidity (1.2<|y|<2.2). Invariant yields are presented as a function of both collision centrality and transverse momentum. Nuclear modifications are obtained for central relative to peripheral Au + Au collisions (RCP) and for various centrality selections in Au + Au relative to scaled p + p cross sections obtained from other measurements (RAA). The observed suppression patterns at 39 and 62.4 GeV are quite similar to those previously measured at 200 GeV. This similar suppression presents a challenge to theoretical models that contain various competing mechanisms with different energy dependencies, some of which cause suppression and others enhancement.

  2. Glucose-functionalized Au nanoprisms for optoacoustic imaging and near-infrared photothermal therapy

    NASA Astrophysics Data System (ADS)

    Han, Jishu; Zhang, Jingjing; Yang, Meng; Cui, Daxiang; de La Fuente, Jesus M.

    2015-12-01

    Targeted imaging and tumor therapy using nanomaterials has stimulated research interest recently, but the high cytotoxicity and low cellular uptake of nanomaterials limit their bioapplication. In this paper, glucose (Glc) was chosen to functionalize Au nanoprisms (NPrs) for improving the cytotoxicity and cellular uptake of Au@PEG-Glc NPrs into cancer cells. Glucose is a primary source of energy at the cellular level and at cellular membranes for cell recognition. A coating of glucose facilitates the accumulation of Au@PEG-Glc NPrs in a tumor region much more than Au@PEG NPrs. Due to the high accumulation and excellent photoabsorbing property of Au@PEG-Glc NPrs, enhanced optoacoustic imaging of a tumor in vivo was achieved, and visualization of the tumor further guided cancer treatment. Based on the optical-thermal conversion performance of Au@PEG-Glc NPrs, the tumor in vivo was effectively cured through photothermal therapy. The current work demonstrates the great potential of Au@PEG-Glc NPrs in optoacoustic imaging and photothermal cancer therapy in future.Targeted imaging and tumor therapy using nanomaterials has stimulated research interest recently, but the high cytotoxicity and low cellular uptake of nanomaterials limit their bioapplication. In this paper, glucose (Glc) was chosen to functionalize Au nanoprisms (NPrs) for improving the cytotoxicity and cellular uptake of Au@PEG-Glc NPrs into cancer cells. Glucose is a primary source of energy at the cellular level and at cellular membranes for cell recognition. A coating of glucose facilitates the accumulation of Au@PEG-Glc NPrs in a tumor region much more than Au@PEG NPrs. Due to the high accumulation and excellent photoabsorbing property of Au@PEG-Glc NPrs, enhanced optoacoustic imaging of a tumor in vivo was achieved, and visualization of the tumor further guided cancer treatment. Based on the optical-thermal conversion performance of Au@PEG-Glc NPrs, the tumor in vivo was effectively cured through

  3. Annealing of Au, Ag and Au-Ag alloy nanoparticle arrays on GaAs (100) and (111)B.

    PubMed

    Whiticar, Alexander M; Mårtensson, Erik K; Nygård, Jesper; Dick, Kimberly A; Bolinsson, Jessica

    2017-05-19

    Metal nanoparticles (NPs), in particular gold NPs, are often used in the fabrication process of semiconductor nanowires. Besides being able to induce the 1D crystallization of new material, it is highly beneficial if the NPs can be used to dictate the position and diameter of the final nanowire structure. To achieve well-defined NP arrays of varying diameter and pitch distances for nanowire growth, it is necessary to understand and control the effect that a pre-growth annealing process may have on the pre-defined NP arrays. Recently, it has been demonstrated that silver (Ag) may be an alternative to using gold (Au) NPs as seed for particle-seeded nanowire fabrication. This work brings light onto the effect of annealing of Au, Ag and Au-Ag alloy metal NP arrays in two commonly used epitaxial systems, the molecular beam epitaxy (MBE) and the metalorganic vapor phase epitaxy (MOVPE). The metal NP arrays are fabricated with the aid of electron beam lithography on GaAs 100 and 111B wafers and the evolution of the NPs with respect to shape, size and position on the surfaces is studied after annealing using scanning electron microscopy. We find that while the Au NP arrays are found to be stable when annealed up to 600 °C in a MOVPE system, a diameter and pitch dependent splitting of the particles is seen for annealing in a MBE system. The Ag NP arrays are found to be less stable, with smaller diameters (≤50 nm) dissolving during the annealing process in both epitaxial systems. In general, the mobility of the NPs is observed to differ between the two the GaAs 100 and 111B surfaces. Finally, our observations on the effect of annealing on Au-Ag alloy NP arrays suggest that these NP can withstand necessary annealing conditions for a complete de-oxidation of GaAs surfaces in both MOVPE and MBE.

  4. Annealing of Au, Ag and Au-Ag alloy nanoparticle arrays on GaAs (100) and (111)B

    NASA Astrophysics Data System (ADS)

    Whiticar, Alexander M.; Mårtensson, Erik K.; Nygård, Jesper; Dick, Kimberly A.; Bolinsson, Jessica

    2017-05-01

    Metal nanoparticles (NPs), in particular gold NPs, are often used in the fabrication process of semiconductor nanowires. Besides being able to induce the 1D crystallization of new material, it is highly beneficial if the NPs can be used to dictate the position and diameter of the final nanowire structure. To achieve well-defined NP arrays of varying diameter and pitch distances for nanowire growth, it is necessary to understand and control the effect that a pre-growth annealing process may have on the pre-defined NP arrays. Recently, it has been demonstrated that silver (Ag) may be an alternative to using gold (Au) NPs as seed for particle-seeded nanowire fabrication. This work brings light onto the effect of annealing of Au, Ag and Au-Ag alloy metal NP arrays in two commonly used epitaxial systems, the molecular beam epitaxy (MBE) and the metalorganic vapor phase epitaxy (MOVPE). The metal NP arrays are fabricated with the aid of electron beam lithography on GaAs 100 and 111B wafers and the evolution of the NPs with respect to shape, size and position on the surfaces is studied after annealing using scanning electron microscopy. We find that while the Au NP arrays are found to be stable when annealed up to 600 °C in a MOVPE system, a diameter and pitch dependent splitting of the particles is seen for annealing in a MBE system. The Ag NP arrays are found to be less stable, with smaller diameters (≤50 nm) dissolving during the annealing process in both epitaxial systems. In general, the mobility of the NPs is observed to differ between the two the GaAs 100 and 111B surfaces. Finally, our observations on the effect of annealing on Au-Ag alloy NP arrays suggest that these NP can withstand necessary annealing conditions for a complete de-oxidation of GaAs surfaces in both MOVPE and MBE.

  5. The Influence of Interstitial Ga and Interfacial Au (sub 2)P (sub 3) on the Electrical and Metallurgical Behavior of Au-Contacted III-V Semiconductors

    NASA Technical Reports Server (NTRS)

    Weizer, Victor G.; Fatemi, Navid S.

    1991-01-01

    The introduction of a very small amount of Ga into Au contact metallization on InP is shown to have a significant effect on both the metallurgical and electrical behavior of that contact system. Ga atoms in the interstices of the Au lattice are shown to be effective in preventing the solid state reactions that normally take place between Au and InP during contact sintering. In addition to suppressing the metallurgical interaction, the presence of small amounts of Ga is shown to cause an order of magnitude reduction in the specific contact resistivity. Evidence is presented that the reactions of GaP and GaAs with Au contacts are also drastically affected by the presence of Ga. The sintering behavior of the Au-GaP and the Au-GaAs systems (as contrasted with that of the Au-InP system) is explained as due to the presence of interstitial Ga in the contact metallization. Finally the large, two-to-three order of magnitude drop in the contact resistance that occurs in the Au-InP system upon sintering at 400 degrees Centigrade is shown to be a result of the formation of an Au (sub 2) P (sub 3) layer at the metal-semiconductor interface. Contact resistivities in the 10 (sup -6) ohm square centimeter range are obtained for as-deposited Au on InP when a thin (20 Angstrom) layer of Au (sub 2) P (sub 3) is introduced between the InP and the Au contacts.

  6. Crystal Structure of Faradaurate-279: Au279(SPh-tBu)84 Plasmonic Nanocrystal Molecules.

    PubMed

    Sakthivel, Naga Arjun; Theivendran, Shevanuja; Ganeshraj, Vigneshraja; Oliver, Allen G; Dass, Amala

    2017-11-01

    We report the discovery of an unprecedentedly large, 2.2 nm diameter, thiolate protected gold nanocrystal characterized by single crystal X-ray crystallography (sc-XRD), Au 279 (SPh-tBu) 84 named Faradaurate-279 (F-279) in honor of Michael Faraday's (1857) pioneering work on nanoparticles. F-279 nanocrystal has a core-shell structure containing a truncated octahedral core with bulk face-centered cubic-like arrangement, yet a nanomolecule with a precise number of metal atoms and thiolate ligands. The Au 279 S 84 geometry was established from a low-temperature 120 K sc-XRD study at 0.90 Å resolution. The atom counts in core-shell structure of Au 279 follows the mathematical formula for magic number shells: Au@Au 12 @Au 42 @Au 92 @Au 54 , which is further protected by a final shell of Au 48 . Au 249 core is protected by three types of staple motifs, namely: 30 bridging, 18 monomeric, and 6 dimeric staple motifs. Despite the presence of such diverse staple motifs, Au 279 S 84 structure has a chiral pseudo-D 3 symmetry. The core-shell structure can be viewed as nested, concentric polyhedra, containing a total of five forms of Archimedean solids. A comparison between the Au 279 and Au 309 cuboctahedral superatom model in shell-wise growth is illustrated. F-279 can be synthesized and isolated in high purity in milligram quantities using size exclusion chromatography, as evidenced by mass spectrometry. Electrospray ionization-mass spectrometry independently verifies the X-ray diffraction study based heavy atoms formula, Au 279 S 84 , and establishes the molecular formula with the complete ligands, namely, Au 279 (SPh-tBu) 84 . It is also the smallest gold nanocrystal to exhibit metallic behavior, with a surface plasmon resonance band around 510 nm.

  7. Effect of Au thickness on the evolution of self-assembled Au droplets on GaAs (111)A and (100)

    NASA Astrophysics Data System (ADS)

    Li, Ming-Yu; Sui, Mao; Kim, Eun-Soo; Lee, Jihoon

    2014-08-01

    In this paper, we report the effect of Au thickness on the self-assembled Au droplets on GaAs (111)A and (100). The evolution of Au droplets on GaAs (111)A and (100) with the increased Au thickness progress in the Volmer-Weber growth mode results in distinctive 3-D islands. Under an identical growth condition, depending on the thickness of Au deposition, the self-assembled Au droplets show different size and density distributions, while the average height is increased by approximately 420% and the diameter is increased by approximately 830%, indicating a preferential lateral expansion. Au droplets show an opposite evolution trend: the increased size along with the decreased density as a function of the Au thickness. Also, the density shifts on the orders of over two magnitude between 4.23 × 1010 and 1.16 × 108 cm-2 over the thickness range tested. At relatively thinner thicknesses below 4 nm, the self-assembled Au droplets sensitively respond to the thickness variation, evidenced by the sharper slopes of dimensions and density plots. The results are systematically analyzed and discussed in terms of atomic force microscopy (AFM), scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDS), cross-sectional surface line profiles, and Fourier filter transform (FFT) power spectra.

  8. Facile Synthesis of Quasi-One-Dimensional Au/PtAu Heterojunction Nanotubes and Their Application as Catalysts in an Oxygen-Reduction Reaction.

    PubMed

    Cai, Kai; Liu, Jiawei; Zhang, Huan; Huang, Zhao; Lu, Zhicheng; Foda, Mohamed F; Li, Tingting; Han, Heyou

    2015-05-11

    An intermediate-template-directed method has been developed for the synthesis of quasi-one-dimensional Au/PtAu heterojunction nanotubes by the heterogeneous nucleation and growth of Au on Te/Pt core-shell nanostructures in aqueous solution. The synthesized porous Au/PtAu bimetallic nanotubes (PABNTs) consist of porous tubular framework and attached Au nanoparticles (AuNPs). The reaction intermediates played an important role in the preparation, which fabricated the framework and provided a localized reducing agent for the reduction of the Au and Pt precursors. The Pt7 Au PABNTs showed higher electrocatalytic activity and durability in the oxygen-reduction reaction (ORR) in 0.1 M HClO4 than porous Pt nanotubes (PtNTs) and commercially available Pt/C. The mass activity of PABNTs was 218 % that of commercial Pt/C after an accelerated durability test. This study demonstrates the potential of PABNTs as highly efficient electrocatalysts. In addition, this method provides a facile strategy for the synthesis of desirable hetero-nanostructures with controlled size and shape by utilizing an intermediate template. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  9. The effect of Au nanoparticles on the strain-dependent electrical properties of CVD graphene

    NASA Astrophysics Data System (ADS)

    Bai, Jing; Nan, Haiyan; Qi, Han; Bing, Dan; Du, Ruxia

    2018-03-01

    We conducted an experimental study of the effect of Au nanoparticles (NPs) on the strain-dependent electrical properties in chemical vapor deposition grown graphene. We used 5-nm thick Au NPs as an effective cover (and doping) layer for graphene, and found that Au NPs decrease electrical resistance by two orders of magnitude. In addition, the Au NPs suppress the effect of strain on resistance because the intrinsic topological cracks and grain boundaries in graphene are filled with Au nanoparticles. This method has a big potential to advance industrial production of large-area, high-quality electronic devices and graphene-based transparent electrodes.

  10. Plasmonic enhancement of visible-light water splitting with Au-TiO2 composite aerogels.

    PubMed

    DeSario, Paul A; Pietron, Jeremy J; DeVantier, Devyn E; Brintlinger, Todd H; Stroud, Rhonda M; Rolison, Debra R

    2013-09-07

    We demonstrate plasmonic enhancement of visible-light-driven splitting of water at three-dimensionally (3D) networked gold-titania (Au-TiO2) aerogels. The sol-gel-derived ultraporous composite nanoarchitecture, which contains 1 to 8.5 wt% Au nanoparticles and titania in the anatase form, retains the high surface area and mesoporosity of unmodified TiO2 aerogels and maintains stable dispersion of the ~5 nm Au guests. A broad surface plasmon resonance (SPR) feature centered at ~550 nm is present for the Au-TiO2 aerogels, but not Au-free TiO2 aerogels, and spans a wide range of the visible spectrum. Gold-derived SPR in Au-TiO2 aerogels cast as films on transparent electrodes drives photoelectrochemical oxidation of aqueous hydroxide and extends the photocatalytic activity of TiO2 from the ultraviolet region to visible wavelengths exceeding 700 nm. Films of Au-TiO2 aerogels in which Au nanoparticles are deposited on pre-formed TiO2 aerogels by a deposition-precipitation method (DP Au/TiO2) also photoelectrochemically oxidize aqueous hydroxide, but less efficiently than 3D Au-TiO2, despite having an essentially identical Au nanoparticle weight fraction and size distribution. For example, 3D Au-TiO2 containing 1 wt% Au is as active as DP Au/TiO2 with 4 wt% Au. The higher photocatalytic activity of 3D Au-TiO2 derives only in part from its ability to retain the surface area and porosity of unmodified TiO2 aerogel. The magnitude of improvement indicates that in the 3D arrangement either a more accessible photoelectrochemical reaction interphase (three-phase boundary) exists or more efficient conversion of excited surface plasmons into charge carriers occurs, thereby amplifying reactivity over DP Au/TiO2. The difference in photocatalytic efficiency between the two forms of Au-TiO2 demonstrates the importance of defining the structure of Au[parallel]TiO2 interfaces within catalytic Au-TiO2 nanoarchitectures.

  11. Performance d'un hôpital de zone sanitaire au Benin: un exemple de modèle d’évaluation

    PubMed Central

    Ahanhanzo, Yolaine Glèlè; Ouédraogo, Landaogo Soutongonoma Lionel; Saizonou, Jacques

    2014-01-01

    Introduction Premier niveau de référence de la pyramide sanitaire du Bénin, les hôpitaux de zone sanitaire s'acquittent de leurs missions dans un contexte difficile. L'objectif de la présente étude a été d’évaluer la performance de l'hôpital de la zone sanitaire de Comè en 2013. Méthodes L’étude était transversale, descriptive et évaluative. Les services retenus ont été sélectionnés par choix raisonné du fait de leur contribution au paquet d'activités de l'hôpital. Les clients externes et internes ont été sélectionnés par commodité. Les membres du conseil de gestion de l'hôpital de zone, les responsables d'organisation à base communautaire, les partenaires techniques et financiers ainsi que des chefs d'arrondissement ont été sélectionné par choix raisonné. La performance de l'hôpital a été mesurée à travers trois critères que sont la qualité des prestations, leur équité d'accès et leur pérennité. L'analyse des données a été faite sur la base de critères en utilisant une cotation analytique puis temporelle. Résultats La performance de l'hôpital de la zone sanitaire de Comè était très faible au premier semestre 2013 avec une qualité des prestations cotée à 35%, une équité d'accès cotée à 50% et une pérennité des actions cotée à 11%. Seul le niveau d'application de la fonction gouvernance était moyen. La méconnaissance des attributions des représentants de la communauté dans les instances de l'hôpital a constitué une limite à leur implication dans l'exercice des fonctions de l'hôpital. Les partenaires techniques et financiers ont participé au renforcement institutionnel de l'hôpital en termes d'amélioration du plateau technique. Conclusion L'application des fonctions de l'hôpital et une meilleure implication de la communauté ainsi que des partenaires contribueront à l'amélioration de la performance de l'hôpital de la zone sanitaire de Comè. PMID:25400830

  12. Suppressing Isomerization of Phosphine-Protected Au9Cluster by Bond Stiffening Induced by a Single Pd Atom Substitution.

    PubMed

    Yamazoe, Seiji; Matsuo, Shota; Muramatsu, Satoru; Takano, Shinjiro; Nitta, Kiyofumi; Tsukuda, Tatsuya

    2017-07-17

    The fluxional nature of small gold clusters has been exemplified by reversible isomerization between [Au 9 (PPh 3 ) 8 ] 3+ with a crown motif (Au 9 (C)) and that with a butterfly motif (Au 9 (B)) induced by association and dissociation with compact counteranions (NO 3 - , Cl - ). However, structural isomerization was suppressed by substitution of the central Au atom of the Au 9 core in [Au 9 (PPh 3 ) 8 ] 3+ with a Pd atom: [PdAu 8 (PPh 3 ) 8 ] 2+ with a crown motif (PdAu 8 (C)) did not isomerize to that with a butterfly motif (PdAu 8 (B)) upon association with the counteranions. Density functional theory calculation showed that the energy difference between PdAu 8 (C) and PdAu 8 (B) is comparable to that between Au 9 (C) and Au 9 (B), indicating that the relative stabilities of the isomers are not a direct cause for the suppression of isomerization. Temperature dependence of Debye-Waller factors obtained by X-ray absorption fine-structure analysis revealed that the intracluster bonds of PdAu 8 (C) were stiffer than the corresponding bonds in Au 9 (C). Natural bond orbital analysis suggested that the radial Pd-Au and lateral Au-Au bonds in PdAu 8 (C) are stiffened due to the increase in the ionic nature and decrease in electrostatic repulsion between the surface Au atoms, respectively. We conclude that the formation of stiffer metal-metal bonds by Pd atom doping inhibits the isomerization from PdAu 8 (C) to PdAu 8 (B).

  13. Imaging {Au0-PAMAM} Gold-dendrimer Nanocomposites in Cells

    NASA Astrophysics Data System (ADS)

    Bielinska, Anna; Eichman, Jonathan D.; Lee, Inhan; Baker, James R.; Balogh, Lajos

    2002-10-01

    Dendrimer nanocomposites (DNC) are hybrid nanoparticles formed by the dispersion and immobilization of guest atoms or small clusters in dendritic polymer matrices. They have a great potential in biomedical applications due to their controlled composition, predetermined size, shape and variable surface functionalities. In this work, d=5-25 nm spherical nanoparticles composed of gold and poly(amidoamine) (PAMAM) dendrimers have been selected to demonstrate this nanoparticle based concept. {Au(0)n-PAMAM} gold dendrimer nanocomposites with a well-defined size were synthesized and imaged by transmission electron microscopy both in vitro and in vivo. DNC have also the potential to be used for imaging and drug delivery vehicles either by utilizing bioactive guests or through the incorporation of radioactive isotopes, such as Au-198.

  14. Laser induced nanostructures created from Au layer on polyhydroxybutyrate

    NASA Astrophysics Data System (ADS)

    Michaljaničová, I.; Slepička, P.; Juřík, P.; Švorčík, V.

    2017-11-01

    Nanostructures as well as composite materials expand the range of materials properties and allow use of these materials in new and highly specific applications. In this paper, we described laser modification of polyhydroxybutyrate films covered with thin gold layer, which led to the formation of various composite structures. The crucial for the composite structures creation was setting of appropriate laser parameters; 15 mJ cm-2 laser fluence and 6 000 pulses were recognized as the best. The morphology of structures was determined by the thickness of the Au layer. The most interesting formations, very porous with the biggest roughness, were observed after treatment of foils covered with 10 nm of Au. The morphology was observed by atomic force microscopy. The influence on roughness and the difference between projected area and surface area was also determined.

  15. Laccase/AuAg Hybrid Glucose Microfludic Fuel Cell

    NASA Astrophysics Data System (ADS)

    López-González, B.; Cuevas-Muñiz, F. M.; Guerra-Balcázar, M.; Déctor, A.; Arjona, N.; Ledesma-García, J.; Arriaga, L. G.

    2013-12-01

    In this work a hybrid microfluidic fuel cell was fabricated and evaluated with a AuAg/C bimetallic material for the anode and an enzymatic cathode. The cathodic catalyst was prepared adsorbing laccase and ABTS on Vulcan carbon (Lac-ABTS/C). This material was characterized by FTIR-ATR, the results shows the presence of absorption bands corresponding to the amide bounds. The electrochemical evaluation for the materials consisted in cyclic voltammetry (CV). The glucose electrooxidation reaction in AuAg/C occurs around - 0.3 V vs. NHE. Both electrocatalytic materials were placed in a microfluidic fuel cell. The fuel cell was fed with PBS pH 5 oxygen saturated solution in the cathodic compartment and 5 mM glucose + 0.3 M KOH in the anodic side. Several polarization curves were performed and the maximum power density obtained was 0.3 mWcm-2 .

  16. Neutron radiation tolerance of Au-activated silicon

    NASA Technical Reports Server (NTRS)

    Joyner, W. T.

    1987-01-01

    Double injection devices prepared by the introduction of deep traps, using the Au activation method have been found to tolerate gamma irradiation into the Gigarad (Si) region without significant degradation of operating characteristics. Silicon double injection devices, using deep levels creacted by Au diffusion, can tolerate fast neutron irradiation up to 10 to the 15th n/sq cm. Significant parameter degradation occurs at 10 to the 16th n/sq cm. However, since the actual doping of the basic material begins to change as a result of the transmutation of silicon into phosphorus for neutron fluences greater than 10 to the 17th/sq cm, the radiation tolerance of these devices is approaching the limit possible for any device based on initially doped silicon.

  17. Au-Ag-Cu nano-alloys: tailoring of permittivity

    NASA Astrophysics Data System (ADS)

    Hashimoto, Yoshikazu; Seniutinas, Gediminas; Balčytis, Armandas; Juodkazis, Saulius; Nishijima, Yoshiaki

    2016-04-01

    Precious metal alloys enables new possibilities to tailor materials for specific optical functions. Here we present a systematic study of the effects of a nanoscale alloying on the permittivity of Au-Ag-Cu metals at 38 different atomic mixing ratios. The permittivity was measured and analyzed numerically by applying the Drude model. X-ray diffraction (XRD) revealed the face centered cubic lattice of the alloys. Both, optical spectra and XRD results point towards an equivalent composition-dependent electron scattering behavior. Correlation between the fundamental structural parameters of alloys and the resulting optical properties is elucidated. Plasmonic properties of the Au-Ag-Cu alloy nanoparticles were investigated by numerical simulations. Guidelines for designing plasmonic response of nano- structures and their patterns are presented from the material science perspective.

  18. The AuScope Project and Trans-Tasman VLBI

    NASA Technical Reports Server (NTRS)

    Lovell, Jim; Dickey, John; Gulyaev, Sergei; Natusch, Tim; Titov, Oleg; Tingay, Steven

    2010-01-01

    Three 12-meter radio telescopes are being built in Australia (the AuScope project) and one in New Zealand. These facilities will be fully-equipped for undertaking S and X-band geodetic VLBI observations and correlation will take place on a software correlator (part of the AuScope project). All sites are equipped with permanent GPS receivers to provide co-location of several space geodetic techniques. The following scientific tasks of geodesy and astrometry are considered. 1. Improvement and densification of the International Celestial Reference Frame in the southern hemisphere; 2. Improvement of the International Terrestrial Reference Frame in the region; 3. Measurement of intraplate deformation of the Australian tectonic plate.

  19. Size dependence of Peltier cooling in ferromagnet/Au nanopillars

    NASA Astrophysics Data System (ADS)

    Bosu, Subrojati; Sakuraba, Yuya; Kubota, Takahide; Juarez-Acosta, Isaac; Sugiyama, Tomoko; Saito, Kesami; Olivares-Robles, Miguel A.; Takahashi, Saburo; Bauer, Gerrit E. W.; Takanashi, Koki

    2015-08-01

    We study Peltier cooling in current-perpendicular-to-plane multilayer nanopillars with diameters D varying from 60 to 430 nm and made from Au and various ferromagnets (FMs): Heusler compounds Co2MnSi and Co2FeSi (CFS) and conventional FM metals Fe and Co. We report an enhanced effective Peltier coefficient ΠCPP in resistance-current curves at small D (<120 nm). The maximum ΠCPP value of about 165 mV, found for the CFS/Au interface with D ˜ 60 nm, is 24 times higher than the bulk Peltier coefficient Πbulk (˜7 mV) and corresponds to a high cooling power of 43.6 MW/cm2.

  20. Plasmon Mapping in Au@Ag Nanocube Assemblies

    PubMed Central

    2014-01-01

    Surface plasmon modes in metallic nanostructures largely determine their optoelectronic properties. Such plasmon modes can be manipulated by changing the morphology of the nanoparticles or by bringing plasmonic nanoparticle building blocks close to each other within organized assemblies. We report the EELS mapping of such plasmon modes in pure Ag nanocubes, Au@Ag core–shell nanocubes, and arrays of Au@Ag nanocubes. We show that these arrays enable the creation of interesting plasmonic structures starting from elementary building blocks. Special attention will be dedicated to the plasmon modes in a triangular array formed by three nanocubes. Because of hybridization, a combination of such nanotriangles is shown to provide an antenna effect, resulting in strong electrical field enhancement at the narrow gap between the nanotriangles. PMID:25067991

  1. Analysis of the Change of Structure of Nuclear Graphites Due to Gaseous Corrosion by Injection of Molten Silver under Pressure; ANALYSE DE L'EVOLUTION DE LA STRUCTURE DES GRAPHITES NUCLEAIRES, DUE DE LA CORROSION GAZEUSE, AU MOYEN D'INJECTION SOUS PRESSION D'ARGENT FONDU

    SciTech Connect

    Magnier, P.

    1960-10-24

    Nuclear graphite was impregnated with molten silver in order to clarify certain aspects of the kinetics of the gas/graphite reaction, which seems to be bonded to the structure of the solid fissures. ln trying to vary the pressure of impregnation, it was possible to study several types of fissures, which were revealed later by eliminating the carbon almost entirely by incineration and by performing x radiography. lt was found that pressures of 3 x 6 kg per cm/ were sufficient to explore the principle fissures. The microscopic examination of the skeleton obtained by incineration revealed, under molds of extended conesmore » and of variable division along the graphite, some hot spots distributed on the surface of the silver filaments. These are comparable to the impurities already discovered by x radiography. (tr-auth)« less

  2. Contribution to the Study of Mineralogy, Geochemistry, and Methods of Prospecting for Carbonatities with Pyrichlore Using X Rays; CONTRIBUTION A L'ETUDE DE LA MINERALOGIE, DE LA GEOCHIMIE ET DES METHODES DE PROSPECTION DES CARBONATITES A PYROCHLORE AU MOYEN DES RAYONS X

    SciTech Connect

    Van Wambeke, L.

    1960-01-01

    The investigation of niobium-bearing carbonatites and the determination of the niobium content in mineral samples by x-ray fluorescence methods of analysis are reported. In addition, some practical applications of x-ray methods in the field of mineralogy, geochemistry, and ore prospecting are discussed. The main sources of niobium at present are found in granites, granitic pegmatites, and in derived alluvial or eluvial deposits. On the other hand, simple carbonatite deposits appear to be the main future source of niobium. X-ray fluorescence was used in preliminary prospecting for a rapid and semi- quantitative determination of niobium and other associated chemical elements (Sr,more » Ba, and rare eanths) in mineral samples. Radiometric prospecting is also helpful in the search for niobium-bearing carbonatites, especially when complemented with x-ray or optical spectroscopic analyses. In conjunction with field measurements (radiometry and paper chromatography), a niobium-bearing carbonatite was discovered in the Belgian Congo by means of x-ray spectroscopic analyses. Methods that are convenient for rapid estiraation of the niobium content in soils, carbonatites, and superficial manganese-iron ores were developed. These methods have a relatively gocd accuracy (less than 12%) and sensitivity (5 ppm to 20 ppm of Nb). Moreover, their efficiencies are much higher than the other proposed methods of niobium analysis. Between 100 and 200 analyses can be processed per day per man. The only disadvantage is related to the fact that the measurements must be made in a laboratory. (auth)« less

  3. A Study of Transonic Flutter of a Two-Dimensional Airfoil Using the U-g and p-k Methods (Une Etude sur les Vibrations Aeroelastiques en Regime Transsonique d’Un Profil Aerodynamique Bidimensionnel au Moyen des Methodes U-g et p-k)

    DTIC Science & Technology

    1984-11-01

    governing equation and presented results for a NACA64A10 airfoil with flap oscillations up to reduced frequency of 5. Isogai (Ref. 5) developed a similar...pitch oscillations similar to those presented in Figures 18 to 21 are not reported in this report. For a NACA64AO10 airfoil, Isogai (Ref. 5) gives some...Section 2.3 a viscous damping model far the airfoil motion is given. In the study of " dynamic response of wing to external loads, such as buffeting, often

  4. INVESTIGATION OF A STANDARD CHEMICAL FLOWSHEET FOR THE USE OF U(IV) IN THE PUREX 1st CYCLE BY MEANS OF COMPLEMENTARY STUDIES IN MIXER--SETTLERS; recherche d'un diagramme chimique standard pour l'emploi de l'U(IV) dans le 1 cycle purex, au moyen d'etudes complementaires en melangeurs-decanteurs (in French)

    SciTech Connect

    Salomon, L.; Lopez-Menchero, E.; Ilardi, S.

    1967-07-01

    The conditions for the use of U(IV) as plutonium reductant in the U/Pu partition cycle have been tested in mixer-settlers runs with HSP solutions for Pu concentration in the range 16 to 800 mg/l. The solvent degradation effect on the process as checked, on the one hand with Co{sub 60}-gamma-irradiated solutions, on the other hand with an HSP solution originated in the plant. The risks of re-oxidation in the air-lifts were considered, so that the performances of the process to be expected when phase ratio up to 10 are needed. (auth)

  5. Human Factors Issues for Controlling Uninhabited Aerial Vehicles: Preliminary Findings in Support of the Canadian Forces Joint Unmanned Aerial Vehicle Surveillance Target Acquisition System Project (Incidence des Facteurs Humains sur le Pilotage des Vehicules Aeriens Telepilotes: Constatations Preliminaires a L’Appui du Projet de Systeme Interarmees D’Acquisition D’Objectif au Moyen de Vehicules Aeriens Telepilotes de Surveillance des Forces Canadiennes)

    DTIC Science & Technology

    2010-11-01

    performance levels, health issues associated with shift work and fatigue include psychosomatic disorders such as colitis, gastroduodenitis, and peptic ...DRDC Toronto TR 2009-043 21 ulcers (Costa, 1999). Chronic fatigue can also lead to hypertension, and ischemic heart diseases. Finally

  6. Synthesis of Au-Pd Bimetallic Nanoflowers for Catalytic Reduction of 4-Nitrophenol

    PubMed Central

    Ma, Tao; Chen, Rongsheng; Zhang, Haijun

    2017-01-01

    Due to the great potential to improve catalytic performance, gold (Au) and palladium (Pd) bimetallic catalysts have prompted structure-controlled synthesis of Au-Pd nanoalloys bounded by high-index facets. In this work, we prepared Au-Pd bimetallic nanoflowers (NFs) with a uniform size, well-defined dendritic morphology, and homogeneous alloy structure in an aqueous solution by seed-mediated synthesis. The prepared bimetallic NFs were fully characterized using a combination of transmission electron microscopy, Ultraviolet-Visible (UV-vis) spectroscopy, inductively coupled plasma optical emission spectroscopy, and cyclic voltammetry measurements. The catalytic activities of the prepared Au-Pd nanoparticles for 4-nitrophenol reduction were also investigated, and the activities are in the order of Au@Pd NFs > Au-Pd NFs (Au1Pd1 core) > Au-Pd NFs (Au core), which could be related to the content and exposed different reactive surfaces of Pd in alloys. This result clearly demonstrates that the superior activities of Au-Pd alloy nanodendrites could be attributed to the synergy between Au and Pd in catalysts. PMID:28846598

  7. Au@TiO2 nanocomposites synthesized by X-ray radiolysis as potential radiosensitizers

    NASA Astrophysics Data System (ADS)

    Molina Higgins, Maria C.; Clifford, Dustin M.; Rojas, Jessika V.

    2018-01-01

    Gold nanoparticles decorated onto titania (anatase) supports were produced through X-ray radiolysis, at ambient temperature and pressure in a method that departs from traditional routes, providing an outstanding control of Au nanoparticle size and dispersion. Au@TiO2 nanocomposites (NCs) were fabricated using different absorbed doses in the presence of NaOH, or urea, supported by 5-10 or 10-30 nm titania, to determine their effects on the Au particle size distribution and loading. Au@TiO2 NCs fabricated at high absorbed doses (>7 kGy) had average Au NP size of 1.1 ± 0.1 nm. Large absorbed doses control Au NP size by generating an abundance of reducing species (e-aq, H•) resulting in an increase of Au seeds. At a lower absorbed dose (0.72 kGy), the ligand affected the Au particle size distribution and a reduction in size by 20% of the Au was observed using NaOH. Au NPs were tethered to titania through oxygen as indicated by X-ray photoelectron spectroscopy analysis. The Au@TiO2 NCs were tested for their radiosensitizing effect by monitoring decomposition of methylene blue under X-ray irradiation where the decomposition was increased by a factor of 1.8 after 15 min compared with pristine TiO2.

  8. Structural, electronic and magnetic properties of Au-based monolayer derivatives in honeycomb structure

    SciTech Connect

    Kapoor, Pooja, E-mail: pupooja16@gmail.com; Sharma, Munish; Ahluwalia, P. K.

    2016-05-23

    We present electronic properties of atomic layer of Au, Au{sub 2}-N, Au{sub 2}-O and Au{sub 2}-F in graphene-like structure within the framework of density functional theory (DFT). The lattice constant of derived monolayers are found to be higher than the pristine Au monolayer. Au monolayer is metallic in nature with quantum ballistic conductance calculated as 4G{sub 0}. Similarly, Au{sub 2}-N and Au{sub 2}-F monolayers show 4G{sub 0} and 2G{sub 0} quantum conductance respectively while semiconducting nature with calculated band gap of 0.28 eV has been observed for Au{sub 2}-O monolayer. Most interestingly, half metalicity has been predicted for Au{sub 2}-Nmore » and Au{sub 2}-F monolayers. Our findings may have importance for the application of these monolayers in nanoelectronic and spintronics.« less

  9. Visible Luminescence from Au Nanoparticles Stabilized with Aromatic Thiols

    SciTech Connect

    Pattabi, Rani M.; Pattabi, Manjunatha

    2011-07-15

    Photoemission in the visible range is reported from Au nanoparticles stabilized with two different organic thiols. The efficiency and wavelength of the emissions are found to be different for the different capping agents. The size of the particles was estimated from TEM and XRD measurements. The observed luminescence may arise from interband electronic transitions between the filled 5d{sup 10} and 6(sp){sup 1} conduction band modified by a metal-ligand charge transfer.

  10. Structure functions in decomposing Au-Pt systems

    NASA Astrophysics Data System (ADS)

    Glas, R.; Blaschko, O.; Rosta, L.

    1992-09-01

    The evolution of Au-Pt alloys quenched within the miscibility gap is investigated by small-angle neutron-scattering techniques. Moreover, in the vicinity of fundamental Bragg reflections the evolution of ``sideband'' satellites induced by a lattice-parameter modulation connected with the precipitation pattern is investigated by diffuse scattering methods. Structure functions are evaluated for a series of concentrations within the miscibility gap and compared to recent results of the literature.

  11. Microscale Alfven waves in the solar wind at 1 AU

    NASA Technical Reports Server (NTRS)

    Burlaga, L. F.; Turner, J. M.

    1974-01-01

    Analysis of IMP 1 (Explorer 43) plasma and magnetic field fluctuations on a scale of one hour revealed that linearly and circularly polarized Alfven waves are rarely present in the solar wind at 1 AU. The most prevalent microscale fluctuations appeared to be large-amplitude Alfven waves with small but non-zero fluctuations in the magnetic field intensity. These waves are present about 40% of the time and are predominantly propagating away from the sun.

  12. Development of the AuScope Australian Earth Observing System

    NASA Astrophysics Data System (ADS)

    Rawling, T.

    2017-12-01

    Advances in monitoring technology and significant investment in new national research initiatives, will provide significant new opportunities for delivery of novel geoscience data streams from across the Australian continent over the next decade. The AuScope Australian Earth Observing System (AEOS) is linking field and laboratory infrastructure across Australia to form a national sensor array focusing on the Solid Earth. As such AuScope is working with these programs to deploy observational infrastructure, including MT, passive seismic, and GNSS networks across the entire Australian Continent. Where possible the observational grid will be co-located with strategic basement drilling in areas of shallow cover and tied with national reflection seismic and sampling transects. This integrated suite of distributed earth observation and imaging sensors will provide unprecedented imaging fidelity of our crust, across all length and time scales, to fundamental and applied researchers in the earth, environmental and geospatial sciences. The AEOS will the Earth Science community's Square Kilometer Array (SKA) - a distributed telescope that looks INTO the earth rather than away from it - a 10 million SKA. The AEOS is strongly aligned with other community strategic initiatives including the UNCOVER research program as well as other National Collaborative Research Infrastructure programs such as the Terrestrial Environmental Research Network (TERN) and the Integrated Marine Observing System (IMOS) providing an interdisciplinary collaboration platform across the earth and environmental sciences. There is also very close alignment between AuScope and similar international programs such as EPOS, the USArray and EarthCube - potential collaborative linkages we are currently in the process of pursuing more fomally. The AuScope AEOS Infrastructure System is ultimately designed to enable the progressive construction, refinement and ongoing enrichment of a live, "FAIR" four

  13. Uncommon and Emissive {[Au2(C3H6NS2)2][Au(C3H6NS2)2]2(PF6)2} Mixed Au+ and Au3+ Pseudotetranuclear Crystalline Compound: Synthesis, Structural Characterization, and Optical Properties.

    PubMed

    Langaro, Ana P; Souza, Ana K R; Morassuti, Claudio Y; Lima, Sandro M; Casagrande, Gleison A; Deflon, Victor M; Nunes, Luiz A O; Da Cunha Andrade, Luis H

    2016-11-23

    An uncommon emissive pseudotetranuclear compound, {[Au 2 (C 3 H 6 NS 2 ) 2 ][Au(C 3 H 6 NS 2 ) 2 ] 2 (PF 6 ) 2 }, was synthesized and characterized in terms of its structure and optical properties. The synthesis produced a crystalline compound composed of four gold atoms with two different oxidation states (Au + and Au 3+ ) in the same crystalline structure. The title complex belonged to a triclinic crystalline system involving the centrosymmetric P1̅ space group. X-ray diffractometry and vibrational spectroscopy (infrared, Raman, and SERS) were used for structural characterization of the new crystal. The vibrational spectroscopy techniques supported the X-ray diffraction results and confirmed the presence of bonds including Au-Au and Au-S. Optical characterization performed using UV-vis spectroscopy showed that under ultraviolet excitation, the emissive crystalline complex presented characteristic broad luminescent bands centered at 420 and 670 nm.

  14. Synthesis and characterization of hollow magnetic nanospheres modified with Au nanoparticles for bio-encapsulation

    NASA Astrophysics Data System (ADS)

    Seisno, Satoshi; Suga, Kent; Nakagawa, Takashi; Yamamoto, Takao A.

    2017-04-01

    Hollow magnetic nanospheres modified with Au nanoparticles were successfully synthesized. Au/SiO2 nanospheres fabricated by a radiochemical process were used as templates for ferrite templating. After the ferrite plating process, Au/SiO2 templates were fully coated with magnetite nanoparticles. Dissolution of the SiO2 core lead to the formation of hollow magnetic nanospheres with Au nanoparticles inside. The hollow magnetic nanospheres consisted of Fe3O4 grains, with an average diameter of 60 nm, connected to form the sphere wall, inside which Au grains with an average diameter of 7.2 nm were encapsulated. The Au nanoparticles immobilized on the SiO2 templates contributed to the adsorption of the Fe ion precursor and/or Fe3O4 seeds. These hollow magnetic nanospheres are proposed as a new type of nanocarrier, as the Au grains could specifically immobilize biomolecules inside the hollow sphere.

  15. Growth of textured thin Au coatings on iron oxide nanoparticles with near infrared absorbance

    PubMed Central

    Ma, L L; Borwankar, A U; Willsey, B W; Yoon, K Y; Tam, J O; Sokolov, K V; Feldman, M D; Milner, T E; Johnston, K P

    2013-01-01

    A homologous series of Au-coated iron oxide nanoparticles, with hydrodynamic diameters smaller than 60 nm was synthesized with very low Auto-iron mass ratios as low as 0.15. The hydrodynamic diameter was determined by dynamic light scattering and the composition by atomic absorption spectroscopy and energy dispersive x-ray spectroscopy (EDS). Unusually low Au precursor supersaturation levels were utilized to nucleate and grow Au coatings on iron oxide relative to formation of pure Au nanoparticles. This approach produced unusually thin coatings, by lowering autocatalytic growth of Au on Au, as shown by transmission electron microscopy (TEM). Nearly all of the nanoparticles were attracted by a magnet indicating a minimal amount of pure Au particles The coatings were sufficiently thin to shift the surface plasmon resonance (SPR) to the near infrared (NIR), with large extinction coefficients., despite the small particle hydrodynamic diameters, observed from dynamic light scattering to be less than 60 nm. PMID:23238021

  16. Tuning surface plasmon resonance by the plastic deformation of Au nanoparticles within a diamond anvil cell

    NASA Astrophysics Data System (ADS)

    Bao, Yongjun; Zhao, Bin; Tang, Xinyu; Hou, Dongjie; Cai, Jian; Tang, Shan; Liu, Junsong; Wang, Fei; Cui, Tian

    2015-11-01

    In this work, surface plasmon resonance (SPR) is tuned by controlling the deformation of Au nanoparticles within a diamond anvil cell (DAC). Colloidal Au nanoparticles were loaded into a DAC and pressurized into a mixture of ice and Au nanoparticles. The Au nanoparticles were reshaped by their anisotropic compression of surrounding ice, which leads to the spectral variations of absorption peaks, broadening or red-shifting. These spectral features are well tuned by controlling the deformation process of Au nanoparticle with choosing the initial intended thickness of DAC gasket. The mechanical properties of Au nanoparticles are also revealed by the shape-dependent SPR in nanometer scale. This result provides us a way to fabricate Au nanoparticles into new shapes and tune SPR of metallic nanoparticles with pressure.

  17. Growth of Au on Pt Icosahedral Nanoparticles Revealed by Low-Dose In Situ TEM

    SciTech Connect

    Wu, Jianbo; Gao, Wenpei; Wen, Jianguo

    2015-03-09

    A growth mode was revealed by an in situ TEM study of nucleation and growth of Au on Pt icosahedral nanoparticles. Quantitative analysis of growth kinetics was carried out based on real- time TEM data, which show the process involves: 1) deposition of Au on corner sites of Pt icosahedral nanoparticles, 2) diffusion of Au from corners to terraces and edges, and 3) subsequent layer-by-layer growth of Au on Au surfaces to form Pt@Au core-shell nanoparticles. The in situ TEM results indicate diffusion of Au from corner islands to terraces and edges is a kinetically controlled growth, as evidenced bymore » a measurement of diffusion coefficients for these growth processes. We demonstrated that in situ electron microscopy is a valuable tool for quantitative study of nucleation and growth kinetics and can provide new insight into the design and precise control of heterogeneous nanostructures.« less

  18. Growth of Au on Pt icosahedral nanoparticles revealed by low-dose in situ TEM.

    PubMed

    Wu, Jianbo; Gao, Wenpei; Wen, Jianguo; Miller, Dean J; Lu, Ping; Zuo, Jian-Min; Yang, Hong

    2015-04-08

    A growth mode was revealed by an in situ TEM study of nucleation and growth of Au on Pt icosahedral nanoparticles. Quantitative analysis of growth kinetics was carried out based on real-time TEM data, which shows the process involves: (1) deposition of Au on corner sites of Pt icosahedral nanoparticles, (2) diffusion of Au from corners to terraces and edges, and (3) subsequent layer-by-layer growth of Au on Au surfaces to form Pt@Au core-shell nanoparticles. The in situ TEM results indicate diffusion of Au from corner islands to terraces and edges is a kinetically controlled growth, as evidenced by a measurement of diffusion coefficients for these growth processes. We demonstrated that in situ electron microscopy is a valuable tool for quantitative study of nucleation and growth kinetics and can provide new insight into the design and precise control of heterogeneous nanostructures.

  19. Le diagnostic anténatal de la trisomie 21 par l'hybridation in situ en fluorescence (FISH): à propos des premiers tests réalisés au Maroc

    PubMed Central

    Lamzouri, Afaf; Natiq, Abdelhafid; Tajir, Mariam; Sendid, Mohamed; Sefiani, Abdelaziz

    2012-01-01

    Introduction Le but de cette étude était de présenter les premiers résultats de diagnostic anténatal de la trisomie 21 par la technique d'hybridation in situ en fluorescence (FISH) au Maroc et discuter son intérêt dans le diagnostic rapide de cette aneuploïdie. Méthodes Ce travail a été réalisé chez 23 femmes avec des grossesses à haut risque de trisomie 21. La moyenne d’âge des gestantes étaient de 37,43 ans avec des extrêmes de 21 et 43 ans. Toutes étaient musulmanes mariées, mariage légitimé par la Charia, dont trois mariages consanguins, sauf une originaire de la République Démocratique du Congo qui était chrétienne et concubine. La majorité des femmes étaient fonctionnaires et avaient un niveau de scolarisation moyen à élevé. Toutes les patientes ont bénéficié d'une consultation de génétique médicale au cours de laquelle il leur a été donné des informations sur la technique, son intérêt et ses limites. Il s'agit de femmes enceintes qui avaient soit un âge maternel élevé ou des signes d'appel échographiques et/ ou biochimiques. Une des patientes était porteuse d'une translocation robertsonienne t(14;21) équilibrée. Une amniocentèse a été réalisée chez toutes les gestantes et aucun avortement n'a était induit par ce geste invasif. L’âge gestationnel moyen à la première consultation était de 14 semaines d'aménorrhée (SA) et à l'amniocentèse était de 16 SA et 5 jours. L'analyse FISH a été réalisée, après consentement des couples, sur des cellules non cultivées à partir des échantillons de liquides amniotiques, en utilisant des sondes spécifiques du chromosome 21. Résultats Parmi les 23 patientes qui ont bénéficiées d'un diagnostic anténatal de la trisomie 21 par la technique FISH, nous avons pu rassurer 21 d'entre elles, et nous avons détecté deux cas de trisomie 21 fœtal. Conclusion La technique FISH permet un diagnostic anténatal rapide, en moins de 48h, de la trisomie 21 sur

  20. The Au modified Ge(1 1 0) surface

    NASA Astrophysics Data System (ADS)

    Zhang, L.; Kabanov, N. S.; Bampoulis, P.; Saletsky, A. M.; Zandvliet, H. J. W.; Klavsyuk, A. L.

    2018-05-01

    The pristine Ge(1 1 0) surface is composed of Ge pentagons, which are arranged in relatively large (16 × 2) and c(8 × 10) unit cells. The deposition of sub-monolayer amounts of Au and mild annealing results into de-reconstructed Ge(1 1 0) regions completely free of Ge pentagons and regions composed of nanowires that are aligned along the high symmetry [ 1 1 bar 0 ] direction of the Ge(1 1 0) surface. The de-reconstructed Ge(1 1 0) regions consist of atomic rows that are aligned along the [ 1 1 bar 0 ] direction. A substantial fraction of these substrate rows are straight and resemble the atom rows of the unreconstructed, i.e. bulk terminated, Ge(1 1 0) surface, whereas the other substrate rows have a meandering appearance. These meandering atom rows are comprised of two types of atoms, one type that appears dim, whereas the other type appears bright in filled-state scanning tunneling microscopy images. Using density functional theory calculations, we have tested more than 20 different atomic models for the meandering atom rows. The density functional theory calculations reveal that it is energetically favorable for the deposited Au atoms to exchange position with Ge atoms in the first layer. Based on these findings we conclude that the bright atoms are Ge atoms, whereas the dim atoms are Au atoms.

  1. Synthesis and catalytic properties of Au-Pd nanoflowers.

    PubMed

    Xu, Jianguang; Wilson, Adria R; Rathmell, Aaron R; Howe, Jane; Chi, Miaofang; Wiley, Benjamin J

    2011-08-23

    Reduction of Pd ions by hydroquinone in the presence of gold nanoparticles and polyvinylpyrrolidone resulted in the formation of nanoflowers with a Au core and Pd petals. Addition of HCl to the synthesis halted the reduction by hydroquinone and enabled the acquisition of snapshots of the nanoflowers at different stages of growth. TEM images of the reaction after 10 s show that the nanoflower morphology resulted from the homogeneous nucleation of Pd clusters in solution and their subsequent attachment to gold seeds coated with a thin (0.8 ± 0.1 nm) shell of Pd. UV-visible spectra also indicate Pd clusters formed in the early stages of the reaction and disappeared as the nanoflowers grew. The speed at which this reaction can be halted is useful not only for producing a variety of bimetallic nanostructures with precisely controlled dimensions and morphologies but also for understanding the growth mechanism of these structures. The ability of the AuPd core-shell structure to catalyze the Suzuki coupling reaction of iodobenzene to phenylboronic acid was probed and compared against the activity of Pd nanocubes and thin-shelled AuPd core-shell nanoparticles. The results of this study suggest that Suzuki coupling was not affected by the surface structure or subsurface composition of the nanoparticles, but instead was primarily catalyzed by molecular Pd species that leached from the nanostructures. © 2011 American Chemical Society

  2. L'astronomie au féminin

    NASA Astrophysics Data System (ADS)

    Nazé, Yaël

    2006-03-01

    Qui détient le record des découvertes de comètes ? Une femme. Qui a permis de comprendre comment est organisée la population des étoiles ? Une femme. Qui a découvert la loi permettant d'arpenter l'Univers, a trouvé des phares dans l'espace, a compris le fonctionnement des forges stellaires et a bouleversé notre vision de l'Univers ? Encore et toujours une femme... Pourtant, quand on doit citer un astronome -- historique -- au hasard, on pense le plus souvent -- des hommes : Ptolémée, Galilée, Copernic ou, plus près de nous par exemple, Hubble. Certes, au cours des siècles, les femmes n'ont guère eu accès aux sciences en général et -- l'astronomie en particulier mais ce n'est pas une raison pour croire en l'absence totale de contributions dues au beau sexe ! C'est ce que dévoile ici l'auteur. Loin de toute forme de féminisme enragé, on suivra le parcours de quelques scientifiques importantes qui ont par hasard en commun une même particularité : leur sexe.

  3. Growth of Au nanocrystals on CdS nanorods

    NASA Astrophysics Data System (ADS)

    Yang, Heesun

    2006-08-01

    Nanorods of S2- rich CdS were synthesized by a reaction of excess S versus Cd precursors in the presence of ethylene diamine. The photoluminescence (PL) emission from the S2- rich CdS nanorods was broad with a peak at ˜710 nm, which was 40 nm longer in wavelength than the PL peak from Cd2+ rich CdS (˜670 nm) nanorods. The influence of surface electron or hole trap states on the luminescent pathway of CdS nanorods will be discussed to explain these shifts in wavelength. Nanocrystals of Au ˜2 nm in size were grown on S2- rich surfaces of CdS nanorods. Significant luminescence quenching was observed from the Au nanocrystals on the CdS nanorods due to interfacial charge separation. Change separation by the Au nanocrystals on the CdS resulted in enhanced photocatalytic degradation of Procion red mix-5B (PRB) dye in an aqueous solution under UV light irradiation.

  4. Temperature stabilizes rough Au/Ge(001) surface reconstructions

    NASA Astrophysics Data System (ADS)

    Seino, Kaori; Sanna, Simone; Schmidt, Wolf Gero

    2018-01-01

    The temperature-dependent energetics of self-assembled Au nanowires on Ge(001) surfaces is studied with the help of density-functional theory (DFT) calculations: By calculating the surface phonon modes within harmonic approximation the surface vibrational free energy is obtained to complement the zero-temperature DFT total energies. We consider several previously suggested structural models for a Au coverage between 0.75 and 1.75 monolayer and investigate a temperature range between 0 and 900 K. The stability of the investigated surface models is found to depend clearly on temperature. We find that the extended Ge bridge dimer model previously predicted to be most stable for a large range of preparation conditions is less prominent in the phase diagrams for finite temperatures. On the other hand, a model derived previously from the giant missing row structure with a higher Au coverage gets stabilized by temperature. These findings explain, at least partially, the discrepancies between experimental data and previous theoretical investigations neglecting temperature effects.

  5. Photoacoustic emission from Au nanoparticles arrayed on thermal insulation layer.

    PubMed

    Namura, Kyoko; Suzuki, Motofumi; Nakajima, Kaoru; Kimura, Kenji

    2013-04-08

    Efficient photoacoustic emission from Au nanoparticles on a porous SiO(2) layer was investigated experimentally and theoretically. The Au nanoparticle arrays/porous SiO(2)/SiO(2)/Ag mirror sandwiches, namely, local plasmon resonators, were prepared by dynamic oblique deposition (DOD). Photoacoustic measurements were performed on the local plasmon resonators, whose optical absorption was varied from 0.03 (3%) to 0.95 by varying the thickness of the dielectric SiO(2) layer. The sample with high absorption (0.95) emitted a sound that was eight times stronger than that emitted by graphite (0.94) and three times stronger than that emitted by the sample without the porous SiO(2) layer (0.93). The contribution of the porous SiO(2) layer to the efficient photoacoustic emission was analyzed by means of a numerical method based on a one-dimensional heat transfer model. The result suggested that the low thermal conductivity of the underlying porous layer reduces the amount of heat escaping from the substrate and contributes to the efficient photoacoustic emission from Au nanoparticle arrays. Because both the thermal conductivity and the spatial distribution of the heat generation can be controlled by DOD, the local plasmon resonators produced by DOD are suitable for the spatio-temporal modulation of the local temperature.

  6. Synthesis of Au-Pd Nanoflowers Through Nanocluster Assembly

    SciTech Connect

    Xu, Jianguang; Howe, Jane Y; Chi, Miaofang

    2011-01-01

    Reduction of Pd ions by hydroquinone in the presence of gold nanoparticles and polyvinylpyrrolidone resulted in the formation of nanoflowers with a Au core and Pd petals. Addition of HCl to the synthesis halted the reduction by hydroquinone and enabled the acquisition of snapshots of the nanoflowers at different stages of growth. TEM images of the reaction after 10 s show that the nanoflower morphology resulted from the homogeneous nucleation of Pd clusters in solution and their subsequent attachment to gold seeds coated with a thin (0.8 {+-} 0.1 nm) shell of Pd. UV-visible spectra also indicate Pd clusters formedmore » in the early stages of the reaction and disappeared as the nanoflowers grew. The speed at which this reaction can be halted is useful not only for producing a variety of bimetallic nanostructures with precisely controlled dimensions and morphologies but also for understanding the growth mechanism of these structures. The ability of the AuPd core-shell structure to catalyze the Suzuki coupling reaction of iodobenzene to phenylboronic acid was probed and compared against the activity of Pd nanocubes and thin-shelled AuPd core-shell nanoparticles. The results of this study suggest that Suzuki coupling was not affected by the surface structure or subsurface composition of the nanoparticles, but instead was primarily catalyzed by molecular Pd species that leached from the nanostructures.« less

  7. Synthesis and Catalytic Properties of Au Pd Nanoflowers

    SciTech Connect

    Xu, Jianguang; Wilson, Adria; Howe, Jane Y

    2011-01-01

    Reduction of Pd ions by hydroquinone in the presence of gold nanoparticles and polyvinylpyrrolidone resulted in the formation of nanoflowers with a Au core and Pd petals. Addition of HCl to the synthesis halted the reduction by hydroquinone and enabled the acquisition of snapshots of the nanoflowers at different stages of growth. TEM images of the reaction after 10 s show that the nanoflower morphology resulted from the homogeneous nucleation of Pd clusters in solution and their subsequent attachment to gold seeds coated with a thin (0.8 0.1 nm) shell of Pd. UV visible spectra also indicate Pd clusters formedmore » in the early stages of the reaction and disappeared as the nanoflowers grew. The speed at which this reaction can be halted is useful not only for producing a variety of bimetallic nanostructures with precisely controlled dimensions and morphologies but also for understanding the growth mechanism of these structures. The ability of the AuPd core shell structure to catalyze the Suzuki coupling reaction of iodobenzene to phenylboronic acid was probed and compared against the activity of Pd nanocubes and thin-shelled AuPd core shell nanoparticles. The results of this study suggest that Suzuki coupling was not affected by the surface structure or subsurface composition of the nanoparticles, but instead was primarily catalyzed by molecular Pd species that leached from the nanostructures.« less

  8. Surface dislocation nucleation controlled deformation of Au nanowires

    SciTech Connect

    Roos, B.; Kapelle, B.; Volkert, C. A., E-mail: volkert@ump.gwdg.de

    2014-11-17

    We investigate deformation in high quality Au nanowires under both tension and bending using in-situ transmission electron microscopy. Defect evolution is investigated during: (1) tensile deformation of 〈110〉 oriented, initially defect-free, single crystal nanowires with cross-sectional widths between 30 and 300 nm, (2) bending deformation of the same wires, and (3) tensile deformation of wires containing coherent twin boundaries along their lengths. We observe the formation of twins and stacking faults in the single crystal wires under tension, and storage of full dislocations after bending of single crystal wires and after tension of twinned wires. The stress state dependence of themore » deformation morphology and the formation of stacking faults and twins are not features of bulk Au, where deformation is controlled by dislocation interactions. Instead, we attribute the deformation morphologies to the surface nucleation of either leading or trailing partial dislocations, depending on the Schmid factors, which move through and exit the wires producing stacking faults or full dislocation slip. The presence of obstacles such as neutral planes or twin boundaries hinder the egress of the freshly nucleated dislocations and allow trailing and leading partial dislocations to combine and to be stored as full dislocations in the wires. We infer that the twins and stacking faults often observed in nanoscale Au specimens are not a direct size effect but the result of a size and obstacle dependent transition from dislocation interaction controlled to dislocation nucleation controlled deformation.« less

  9. Charm Meson Production in Au-Au Collisions at √ SNN = 200 Gev at Rhic

    NASA Astrophysics Data System (ADS)

    Vanfossen, Joseph A., Jr.

    dense surrounding medium, as the quarks traverse it. Such suppression is an indicator that the medium generated in relativistic heavy-ion collisions is strongly interacting. Theoretical models were successful in describing the suppression of light quarks but under-predicted the observed heavy-flavor suppression. The data triggered a new effort in modeling where theorists started taking into account the energy loss due to elastic collisions between the traversing parton and the surrounding medium. To fully understand the interplay between elastic and inelastic collision mechanisms of light and heavy partons and the hot medium, we needed precise data on heavy flavor production. Also, in order to be able to access the parent's kinematic information, one needs to perform a full topological reconstruction of the parent's decay. This will also allow for the separation of charm and bottom mesons. The study of D0 mesons, the lightest mesons with a charm quark, can be used to study the properties of the medium created in collisions, such as the density, flow, and thermalization of the medium. This dissertation presents an attempt to measure D0/D0bar ratios and D0 meson production in Au+Au collisions at sqrt(s_NN) = 200 GeV from fully reconstructed decays. For this purpose, we used a silicon tracker in STAR consisting of the Silicon Vertex Tracker (SVT) and the Silicon Strip Detector (SSD), along with the Time Projection Chamber (TPC) in a special run in the year 2007. We have developed new calibration and microvertexing techniques in the data analysis. We performed full secondary vertex reconstruction, to topologically reconstruct the secondary vertex of the D0 meson in the decay channel D0 -> K- + pi+ (B.R. = 3.89% and ct = 123 µm) and then performed a standard invariant mass analysis. At the same time we used a new tool (TMVA) in high energy physics for optimizing the signal to background ratio. However, precise measurements of open heavy flavor are difficult to obtain with

  10. Long Term Measurement of the Vapor Pressure of Gold in the Au-C System

    NASA Technical Reports Server (NTRS)

    Copland, Evan H.

    2009-01-01

    Incorporating the {Au(s,l) + graphite} reference in component activity measurements made with the multiple effusion-cell vapor source mass spectrometry (multicell KEMS) technique provides a fixed temperature defining ITS-90 (T(sub mp)(Au) = 1337.33K) and a systematic method to check accuracy. Over a 2 year period delta H sub(298)Au was determined by the 2nd and 3rd law methods in 25 separate experiments and were in the ranges 362.2 plus or minus 3.3 kJmol(sup -1) and 367.8 plus or minus 1.1 kJmol(sup -1), respectively. This 5 kJmol-1 discrepancy is transferred directly to the measured activities. This is unacceptable and the source of this discrepancy needs to be understood and corrected. Accepting the 2nd law value increases p(Au) by about 50 percent, brings the 2nd and 3rd law values into agreement and removes the T dependence in the 3rd law values. While compelling, there is no way to independently determine instrument sensitivities, S(sub Au), with T in a single experiment with KEMS. This lack of capability is stopping a deeper understanding of this problem. In addition, the Au-C phase diagram suggests a eutectic invariant reaction: L-Au(4.7at%C) = FCC-Au(0.08at%C) + C(graphite) at T(sub e) approximately 1323K. This high C concentration in Au(l) must reduce p(Au) in equilibrium with {Au(s,l) + graphite} and raises some critical questions about the Gibbs free energy functions of Au(s,l) and the Au fixed point (T(sub mp)(Au) = 1337.33K) which is always measured in graphite.

  11. Influence of Ti and Cr Adhesion Layers on Ultrathin Au Films.

    PubMed

    Todeschini, Matteo; Bastos da Silva Fanta, Alice; Jensen, Flemming; Wagner, Jakob Birkedal; Han, Anpan

    2017-10-25

    Efficient adhesion of gold thin films on dielectric or semiconductor substrates is essential in applications and research within plasmonics, metamaterials, 2D materials, and nanoelectronics. As a consequence of the relentless downscaling in nanoscience and technology, the thicknesses of adhesion layer and overlayer have reached tens of nanometers, and it is unclear if our current understanding is sufficient. In this report, we investigated how Cr and Ti adhesion layers influence the nanostructure of 2-20 nm thin Au films by means of high-resolution electron microscopy, complemented with atomic force microscopy and X-ray photoelectron spectroscopy. Pure Au films were compared to Ti/Au and Cr/Au bilayer systems. Both Ti and Cr had a striking impact on grain size and crystal orientation of the Au overlayer, which we interpret as the adhesion layer-enhanced wetting of Au and the formation of chemical bonds between the layers. Ti formed a uniform layer under the Au overlayer. Cr interdiffused with the Au layer forming a Cr-Au alloy. The crystal orientation of the Au layers was mainly [111] for all thin-film systems. The results showed that both adhesion layers were partially oxidized, and oxidation sources were scrutinized and found. A difference in bilayer electrical resistivity between Ti/Au and Cr/Au systems was measured and compared. On the basis of these results, a revised and more detailed adhesion layer model for both Ti/Au and Cr/Au systems was proposed. Finally, the implications of the results were analyzed, and recommendations for the selection of adhesion layers for nano-optics and nanoelectronics applications are presented.

  12. Experimental determination of the stabilities of Au 2S (cr) at 25 °C and Au(HS)2- at 25-250 °C

    NASA Astrophysics Data System (ADS)

    Tagirov, B. R.; Baranova, N. N.; Zotov, A. V.; Schott, J.; Bannykh, L. N.

    2006-07-01

    The solubility of (i) Au (cr), (ii) mixtures of crystalline Ag 2S-Ag 3AuS 2, and (iii) Ag 3AuS 2 (uytenbogaardtite)-AgAuS (petrovskaite) was measured at 25 °C, 1 bar, whereas the solubility of AgAuS (cr) was measured at 91-250 °C and P sat. These measurements were performed in aqueous sulphide solutions containing ˜0.012-0.12 m of total reduced sulfur. At 25 °C sealed glass ampoules were employed, and Ti autoclaves allowing sampling of experimental solutions were used at higher temperatures. It was found that under investigated experimental conditions AgAuS dissolves incongruently with the formation of Ag 3AuS 2. The values of the following equilibrium reaction constants were determined: Au+HS0(aq)+HS=Au(HS)2-+0.5H(i)K=K AgAuS+HS+0.5HS0(aq)=1.5AgS+Au(HS)2-(ii)K 1.5AgAuS+HS+0.5HS0(aq)=0.5AgAuS+Au(HS)2-(iii)K It was found that at 25 °C, 1 bar log K(i) = -5.62 ± 0.14, log K(ii) = -4.49 ± 0.26 and log K(iii) = -4.03 ± 0.15. Solubility data collected at higher temperatures resulted in the following values for log K(iii): -2.12 ± 0.25, -1.32 ± 0.12, and -1.04 ± 0.08 at 91, 150, and 250 °C, respectively (the latter value corresponds to the reaction 1.97 AgAuS+HS+0.5HS0(aq)=0.735AgAuS+Au(HS)2- because Ag 3AuS 2(cr) undergoes a phase transition at 183 °C). These values are in good agreement with log K(iii) = -2.81 ± 0.10 obtained at 80 °C by Zotov et al. (Zotov, A.V., Baranova, N.N., Bannykh, L.N., 1996. Solubility of the gold sulfides Au 2S and AgAuS in solutions containing hydrogen sulfide at 25-80 °C and pressures of 1 and 500 bar. Geochem. Int.34, 216-221). The values of K(ii) and K(iii) determined in the present study were combined with the thermodynamic properties of Ag-Au sulphides reported by Osadchii and Rappo (Osadchii, E.G., Rappo, O.A., 2004. Determination of standard thermodynamic properties of sulfides in the Ag-Au-S system by means of a solid-state galvanic cell. Am. Miner.89, 1405-1410), and thermodynamic properties for aqueous species and

  13. Exoplanet detection. A terrestrial planet in a ~1-AU orbit around one member of a ~15-AU binary.

    PubMed

    Gould, A; Udalski, A; Shin, I-G; Porritt, I; Skowron, J; Han, C; Yee, J C; Kozłowski, S; Choi, J-Y; Poleski, R; Wyrzykowski, Ł; Ulaczyk, K; Pietrukowicz, P; Mróz, P; Szymański, M K; Kubiak, M; Soszyński, I; Pietrzyński, G; Gaudi, B S; Christie, G W; Drummond, J; McCormick, J; Natusch, T; Ngan, H; Tan, T-G; Albrow, M; DePoy, D L; Hwang, K-H; Jung, Y K; Lee, C-U; Park, H; Pogge, R W; Abe, F; Bennett, D P; Bond, I A; Botzler, C S; Freeman, M; Fukui, A; Fukunaga, D; Itow, Y; Koshimoto, N; Larsen, P; Ling, C H; Masuda, K; Matsubara, Y; Muraki, Y; Namba, S; Ohnishi, K; Philpott, L; Rattenbury, N J; Saito, To; Sullivan, D J; Sumi, T; Suzuki, D; Tristram, P J; Tsurumi, N; Wada, K; Yamai, N; Yock, P C M; Yonehara, A; Shvartzvald, Y; Maoz, D; Kaspi, S; Friedmann, M

    2014-07-04

    Using gravitational microlensing, we detected a cold terrestrial planet orbiting one member of a binary star system. The planet has low mass (twice Earth's) and lies projected at ~0.8 astronomical units (AU) from its host star, about the distance between Earth and the Sun. However, the planet's temperature is much lower, <60 Kelvin, because the host star is only 0.10 to 0.15 solar masses and therefore more than 400 times less luminous than the Sun. The host itself orbits a slightly more massive companion with projected separation of 10 to 15 AU. This detection is consistent with such systems being very common. Straightforward modification of current microlensing search strategies could increase sensitivity to planets in binary systems. With more detections, such binary-star planetary systems could constrain models of planet formation and evolution. Copyright © 2014, American Association for the Advancement of Science.

  14. Beam-energy dependence of charge separation along the magnetic field in Au+Au collisions at RHIC.

    PubMed

    Adamczyk, L; Adkins, J K; Agakishiev, G; Aggarwal, M M; Ahammed, Z; Alekseev, I; Alford, J; Anson, C D; Aparin, A; Arkhipkin, D; Aschenauer, E C; Averichev, G S; Banerjee, A; Beavis, D R; Bellwied, R; Bhasin, A; Bhati, A K; Bhattarai, P; Bichsel, H; Bielcik, J; Bielcikova, J; Bland, L C; Bordyuzhin, I G; Borowski, W; Bouchet, J; Brandin, A V; Brovko, S G; Bültmann, S; Bunzarov, I; Burton, T P; Butterworth, J; Caines, H; Calderón de la Barca Sánchez, M; Cebra, D; Cendejas, R; Cervantes, M C; Chaloupka, P; Chang, Z; Chattopadhyay, S; Chen, H F; Chen, J H; Chen, L; Cheng, J; Cherney, M; Chikanian, A; Christie, W; Chwastowski, J; Codrington, M J M; Contin, G; Cramer, J G; Crawford, H J; Cui, X; Das, S; Davila Leyva, A; De Silva, L C; Debbe, R R; Dedovich, T G; Deng, J; Derevschikov, A A; Derradi de Souza, R; Dhamija, S; di Ruzza, B; Didenko, L; Dilks, C; Ding, F; Djawotho, P; Dong, X; Drachenberg, J L; Draper, J E; Du, C M; Dunkelberger, L E; Dunlop, J C; Efimov, L G; Engelage, J; Engle, K S; Eppley, G; Eun, L; Evdokimov, O; Eyser, O; Fatemi, R; Fazio, S; Fedorisin, J; Filip, P; Finch, E; Fisyak, Y; Flores, C E; Gagliardi, C A; Gangadharan, D R; Garand, D; Geurts, F; Gibson, A; Girard, M; Gliske, S; Greiner, L; Grosnick, D; Gunarathne, D S; Guo, Y; Gupta, A; Gupta, S; Guryn, W; Haag, B; Hamed, A; Han, L-X; Haque, R; Harris, J W; Heppelmann, S; Hirsch, A; Hoffmann, G W; Hofman, D J; Horvat, S; Huang, B; Huang, H Z; Huang, X; Huck, P; Humanic, T J; Igo, G; Jacobs, W W; Jang, H; Judd, E G; Kabana, S; Kalinkin, D; Kang, K; Kauder, K; Ke, H W; Keane, D; Kechechyan, A; Kesich, A; Khan, Z H; Kikola, D P; Kisel, I; Kisiel, A; Koetke, D D; Kollegger, T; Konzer, J; Koralt, I; Kotchenda, L; Kraishan, A F; Kravtsov, P; Krueger, K; Kulakov, I; Kumar, L; Kycia, R A; Lamont, M A C; Landgraf, J M; Landry, K D; Lauret, J; Lebedev, A; Lednicky, R; Lee, J H; LeVine, M J; Li, C; Li, W; Li, X; Li, X; Li, Y; Li, Z M; Lisa, M A; Liu, F; Ljubicic, T; Llope, W J; Lomnitz, M; Longacre, R S; Luo, X; Ma, G L; Ma, Y G; Madagodagettige Don, D M M D; Mahapatra, D P; Majka, R; Margetis, S; Markert, C; Masui, H; Matis, H S; McDonald, D; McShane, T S; Minaev, N G; Mioduszewski, S; Mohanty, B; Mondal, M M; Morozov, D A; Mustafa, M K; Nandi, B K; Nasim, Md; Nayak, T K; Nelson, J M; Nigmatkulov, G; Nogach, L V; Noh, S Y; Novak, J; Nurushev, S B; Odyniec, G; Ogawa, A; Oh, K; Ohlson, A; Okorokov, V; Oldag, E W; Olvitt, D L; Pachr, M; Page, B S; Pal, S K; Pan, Y X; Pandit, Y; Panebratsev, Y; Pawlak, T; Pawlik, B; Pei, H; Perkins, C; Peryt, W; Pile, P; Planinic, M; Pluta, J; Poljak, N; Porter, J; Poskanzer, A M; Pruthi, N K; Przybycien, M; Pujahari, P R; Putschke, J; Qiu, H; Quintero, A; Ramachandran, S; Raniwala, R; Raniwala, S; Ray, R L; Riley, C K; Ritter, H G; Roberts, J B; Rogachevskiy, O V; Romero, J L; Ross, J F; Roy, A; Ruan, L; Rusnak, J; Rusnakova, O; Sahoo, N R; Sahu, P K; Sakrejda, I; Salur, S; Sandweiss, J; Sangaline, E; Sarkar, A; Schambach, J; Scharenberg, R P; Schmah, A M; Schmidke, W B; Schmitz, N; Seger, J; Seyboth, P; Shah, N; Shahaliev, E; Shanmuganathan, P V; Shao, M; Sharma, B; Shen, W Q; Shi, S S; Shou, Q Y; Sichtermann, E P; Singaraju, R N; Skoby, M J; Smirnov, D; Smirnov, N; Solanki, D; Sorensen, P; Spinka, H M; Srivastava, B; Stanislaus, T D S; Stevens, J R; Stock, R; Strikhanov, M; Stringfellow, B; Sumbera, M; Sun, X; Sun, X M; Sun, Y; Sun, Z; Surrow, B; Svirida, D N; Symons, T J M; Szelezniak, M A; Takahashi, J; Tang, A H; Tang, Z; Tarnowsky, T; Thomas, J H; Timmins, A R; Tlusty, D; Tokarev, M; Trentalange, S; Tribble, R E; Tribedy, P; Trzeciak, B A; Tsai, O D; Turnau, J; Ullrich, T; Underwood, D G; Van Buren, G; van Nieuwenhuizen, G; Vandenbroucke, M; Vanfossen, J A; Varma, R; Vasconcelos, G M S; Vasiliev, A N; Vertesi, R; Videbæk, F; Viyogi, Y P; Vokal, S; Voloshin, S A; Vossen, A; Wada, M; Wang, F; Wang, G; Wang, H; Wang, J S; Wang, X L; Wang, Y; Wang, Y; Webb, G; Webb, J C; Westfall, G D; Wieman, H; Wissink, S W; Witt, R; Wu, Y F; Xiao, Z; Xie, W; Xin, K; Xu, H; Xu, J; Xu, N; Xu, Q H; Xu, Y; Xu, Z; Yan, W; Yang, C; Yang, Y; Yang, Y; Ye, Z; Yepes, P; Yi, L; Yip, K; Yoo, I-K; Yu, N; Zawisza, Y; Zbroszczyk, H; Zha, W; Zhang, J B; Zhang, J L; Zhang, S; Zhang, X P; Zhang, Y; Zhang, Z P; Zhao, F; Zhao, J; Zhong, C; Zhu, X; Zhu, Y H; Zoulkarneeva, Y; Zyzak, M

    2014-08-01

    Local parity-odd domains are theorized to form inside a quark-gluon plasma which has been produced in high-energy heavy-ion collisions. The local parity-odd domains manifest themselves as charge separation along the magnetic field axis via the chiral magnetic effect. The experimental observation of charge separation has previously been reported for heavy-ion collisions at the top RHIC energies. In this Letter, we present the results of the beam-energy dependence of the charge correlations in Au+Au collisions at midrapidity for center-of-mass energies of 7.7, 11.5, 19.6, 27, 39, and 62.4 GeV from the STAR experiment. After background subtraction, the signal gradually reduces with decreased beam energy and tends to vanish by 7.7 GeV. This implies the dominance of hadronic interactions over partonic ones at lower collision energies.

  15. Beam-energy dependence of the directed flow of protons, antiprotons, and pions in Au+Au collisions.

    PubMed

    Adamczyk, L; Adkins, J K; Agakishiev, G; Aggarwal, M M; Ahammed, Z; Alekseev, I; Alford, J; Anson, C D; Aparin, A; Arkhipkin, D; Aschenauer, E C; Averichev, G S; Banerjee, A; Beavis, D R; Bellwied, R; Bhasin, A; Bhati, A K; Bhattarai, P; Bichsel, H; Bielcik, J; Bielcikova, J; Bland, L C; Bordyuzhin, I G; Borowski, W; Bouchet, J; Brandin, A V; Brovko, S G; Bültmann, S; Bunzarov, I; Burton, T P; Butterworth, J; Caines, H; Calderón de la Barca Sánchez, M; Cebra, D; Cendejas, R; Cervantes, M C; Chaloupka, P; Chang, Z; Chattopadhyay, S; Chen, H F; Chen, J H; Chen, L; Cheng, J; Cherney, M; Chikanian, A; Christie, W; Chwastowski, J; Codrington, M J M; Contin, G; Cramer, J G; Crawford, H J; Cui, X; Das, S; Davila Leyva, A; De Silva, L C; Debbe, R R; Dedovich, T G; Deng, J; Derevschikov, A A; Derradi de Souza, R; Dhamija, S; di Ruzza, B; Didenko, L; Dilks, C; Ding, F; Djawotho, P; Dong, X; Drachenberg, J L; Draper, J E; Du, C M; Dunkelberger, L E; Dunlop, J C; Efimov, L G; Engelage, J; Engle, K S; Eppley, G; Eun, L; Evdokimov, O; Eyser, O; Fatemi, R; Fazio, S; Fedorisin, J; Filip, P; Finch, E; Fisyak, Y; Flores, C E; Gagliardi, C A; Gangadharan, D R; Garand, D; Geurts, F; Gibson, A; Girard, M; Gliske, S; Greiner, L; Grosnick, D; Gunarathne, D S; Guo, Y; Gupta, A; Gupta, S; Guryn, W; Haag, B; Hamed, A; Han, L-X; Haque, R; Harris, J W; Heppelmann, S; Hirsch, A; Hoffmann, G W; Hofman, D J; Horvat, S; Huang, B; Huang, H Z; Huang, X; Huck, P; Humanic, T J; Igo, G; Jacobs, W W; Jang, H; Judd, E G; Kabana, S; Kalinkin, D; Kang, K; Kauder, K; Ke, H W; Keane, D; Kechechyan, A; Kesich, A; Khan, Z H; Kikola, D P; Kisel, I; Kisiel, A; Koetke, D D; Kollegger, T; Konzer, J; Koralt, I; Kotchenda, L; Kraishan, A F; Kravtsov, P; Krueger, K; Kulakov, I; Kumar, L; Kycia, R A; Lamont, M A C; Landgraf, J M; Landry, K D; Lauret, J; Lebedev, A; Lednicky, R; Lee, J H; Levine, M J; Li, C; Li, W; Li, X; Li, X; Li, Y; Li, Z M; Lisa, M A; Liu, F; Ljubicic, T; Llope, W J; Lomnitz, M; Longacre, R S; Luo, X; Ma, G L; Ma, Y G; Madagodagettige Don, D M M D; Mahapatra, D P; Majka, R; Margetis, S; Markert, C; Masui, H; Matis, H S; McDonald, D; McShane, T S; Minaev, N G; Mioduszewski, S; Mohanty, B; Mondal, M M; Morozov, D A; Mustafa, M K; Nandi, B K; Nasim, Md; Nayak, T K; Nelson, J M; Nigmatkulov, G; Nogach, L V; Noh, S Y; Novak, J; Nurushev, S B; Odyniec, G; Ogawa, A; Oh, K; Ohlson, A; Okorokov, V; Oldag, E W; Olvitt, D L; Pachr, M; Page, B S; Pal, S K; Pan, Y X; Pandit, Y; Panebratsev, Y; Pawlak, T; Pawlik, B; Pei, H; Perkins, C; Peryt, W; Pile, P; Planinic, M; Pluta, J; Poljak, N; Porter, J; Poskanzer, A M; Pruthi, N K; Przybycien, M; Pujahari, P R; Putschke, J; Qiu, H; Quintero, A; Ramachandran, S; Raniwala, R; Raniwala, S; Ray, R L; Riley, C K; Ritter, H G; Roberts, J B; Rogachevskiy, O V; Romero, J L; Ross, J F; Roy, A; Ruan, L; Rusnak, J; Rusnakova, O; Sahoo, N R; Sahu, P K; Sakrejda, I; Salur, S; Sandweiss, J; Sangaline, E; Sarkar, A; Schambach, J; Scharenberg, R P; Schmah, A M; Schmidke, W B; Schmitz, N; Seger, J; Seyboth, P; Shah, N; Shahaliev, E; Shanmuganathan, P V; Shao, M; Sharma, B; Shen, W Q; Shi, S S; Shou, Q Y; Sichtermann, E P; Singaraju, R N; Skoby, M J; Smirnov, D; Smirnov, N; Solanki, D; Sorensen, P; Spinka, H M; Srivastava, B; Stanislaus, T D S; Stevens, J R; Stock, R; Strikhanov, M; Stringfellow, B; Sumbera, M; Sun, X; Sun, X M; Sun, Y; Sun, Z; Surrow, B; Svirida, D N; Symons, T J M; Szelezniak, M A; Takahashi, J; Tang, A H; Tang, Z; Tarnowsky, T; Thomas, J H; Timmins, A R; Tlusty, D; Tokarev, M; Trentalange, S; Tribble, R E; Tribedy, P; Trzeciak, B A; Tsai, O D; Turnau, J; Ullrich, T; Underwood, D G; Van Buren, G; van Nieuwenhuizen, G; Vandenbroucke, M; Vanfossen, J A; Varma, R; Vasconcelos, G M S; Vasiliev, A N; Vertesi, R; Videbæk, F; Viyogi, Y P; Vokal, S; Vossen, A; Wada, M; Wang, F; Wang, G; Wang, H; Wang, J S; Wang, X L; Wang, Y; Wang, Y; Webb, G; Webb, J C; Westfall, G D; Wieman, H; Wissink, S W; Witt, R; Wu, Y F; Xiao, Z; Xie, W; Xin, K; Xu, H; Xu, J; Xu, N; Xu, Q H; Xu, Y; Xu, Z; Yan, W; Yang, C; Yang, Y; Yang, Y; Ye, Z; Yepes, P; Yi, L; Yip, K; Yoo, I-K; Yu, N; Zawisza, Y; Zbroszczyk, H; Zha, W; Zhang, J B; Zhang, J L; Zhang, S; Zhang, X P; Zhang, Y; Zhang, Z P; Zhao, F; Zhao, J; Zhong, C; Zhu, X; Zhu, Y H; Zoulkarneeva, Y; Zyzak, M

    2014-04-25

    Rapidity-odd directed flow (v1) measurements for charged pions, protons, and antiprotons near midrapidity (y=0) are reported in sNN=7.7, 11.5, 19.6, 27, 39, 62.4, and 200 GeV Au+Au collisions as recorded by the STAR detector at the Relativistic Heavy Ion Collider. At intermediate impact parameters, the proton and net-proton slope parameter dv1/dy|y=0 shows a minimum between 11.5 and 19.6 GeV. In addition, the net-proton dv1/dy|y=0 changes sign twice between 7.7 and 39 GeV. The proton and net-proton results qualitatively resemble predictions of a hydrodynamic model with a first-order phase transition from hadronic matter to deconfined matter, and differ from hadronic transport calculations.

  16. Direct virtual photon production in Au+Au collisions at s N N = 200   GeV

    DOE PAGES

    Adamczyk, L.; Adkins, J. K.; Agakishiev, G.; ...

    2017-04-27

    Here we report the direct virtual photon invariant yields in the transverse momentum ranges 1< pT <3GeV/c and 5ee < 0.28GeV/c 2 for 0–80% minimum-bias Au+Au collisions atmore » $$\\sqrt{s}$$$_ {NN}$$ = 200GeV. A clear excess in the invariant yield compared to the nuclear overlap function T AA scaled p+p reference is observed in the p T range 1T <3GeV/c. For p T >6GeV/c the production follows T AA scaling. In conclusion, model calculations with contributions from thermal radiation and initial hard parton scattering are consistent within uncertainties with the direct virtual photon invariant yield.« less

  17. Dielectron Azimuthal Anisotropy at mid-rapidity in Au+Au collisions at root s=200GeV

    DOE PAGES

    Adamczyk, L.

    2014-12-11

    We report on the first measurement of the azimuthal anisotropy (v₂) of dielectrons (e⁺e⁻ pairs) at mid-rapidity from √( sNN)=200 GeV Au + Au collisions with the STAR detector at the Relativistic Heavy Ion Collider (RHIC), presented as a function of transverse momentum (p T) for different invariant-mass regions. In the mass region Mee<1.1 GeV/c² the dielectron v₂ measurements are found to be consistent with expectations from π⁰,η,ω, and Φ decay contributions. In the mass region 1.1ee<2.9GeV/c², the measured dielectron v₂ is consistent, within experimental uncertainties, with that from the cc¯ contributions.

  18. Alternative types of molecule-decorated atomic chains in Au-CO-Au single-molecule junctions.

    PubMed

    Balogh, Zoltán; Makk, Péter; Halbritter, András

    2015-01-01

    We investigate the formation and evolution of Au-CO single-molecule break junctions. The conductance histogram exhibits two distinct molecular configurations, which are further investigated by a combined statistical analysis. According to conditional histogram and correlation analysis these molecular configurations show strong anticorrelations with each other and with pure Au monoatomic junctions and atomic chains. We identify molecular precursor configurations with somewhat higher conductance, which are formed prior to single-molecule junctions. According to detailed length analysis two distinct types of molecule-affected chain-formation processes are observed, and we compare these results to former theoretical calculations considering bridge- and atop-type molecular configurations where the latter has reduced conductance due to destructive Fano interference.

  19. Beam-Energy Dependence of the Directed Flow of Protons, Antiprotons, and Pions in Au+Au Collisions

    NASA Astrophysics Data System (ADS)

    Adamczyk, L.; Adkins, J. K.; Agakishiev, G.; Aggarwal, M. M.; Ahammed, Z.; Alekseev, I.; Alford, J.; Anson, C. D.; Aparin, A.; Arkhipkin, D.; Aschenauer, E. C.; Averichev, G. S.; Banerjee, A.; Beavis, D. R.; Bellwied, R.; Bhasin, A.; Bhati, A. K.; Bhattarai, P.; Bichsel, H.; Bielcik, J.; Bielcikova, J.; Bland, L. C.; Bordyuzhin, I. G.; Borowski, W.; Bouchet, J.; Brandin, A. V.; Brovko, S. G.; Bültmann, S.; Bunzarov, I.; Burton, T. P.; Butterworth, J.; Caines, H.; Calderón de la Barca Sánchez, M.; Cebra, D.; Cendejas, R.; Cervantes, M. C.; Chaloupka, P.; Chang, Z.; Chattopadhyay, S.; Chen, H. F.; Chen, J. H.; Chen, L.; Cheng, J.; Cherney, M.; Chikanian, A.; Christie, W.; Chwastowski, J.; Codrington, M. J. M.; Contin, G.; Cramer, J. G.; Crawford, H. J.; Cui, X.; Das, S.; Davila Leyva, A.; De Silva, L. C.; Debbe, R. R.; Dedovich, T. G.; Deng, J.; Derevschikov, A. A.; Derradi de Souza, R.; Dhamija, S.; di Ruzza, B.; Didenko, L.; Dilks, C.; Ding, F.; Djawotho, P.; Dong, X.; Drachenberg, J. L.; Draper, J. E.; Du, C. M.; Dunkelberger, L. E.; Dunlop, J. C.; Efimov, L. G.; Engelage, J.; Engle, K. S.; Eppley, G.; Eun, L.; Evdokimov, O.; Eyser, O.; Fatemi, R.; Fazio, S.; Fedorisin, J.; Filip, P.; Finch, E.; Fisyak, Y.; Flores, C. E.; Gagliardi, C. A.; Gangadharan, D. R.; Garand, D.; Geurts, F.; Gibson, A.; Girard, M.; Gliske, S.; Greiner, L.; Grosnick, D.; Gunarathne, D. S.; Guo, Y.; Gupta, A.; Gupta, S.; Guryn, W.; Haag, B.; Hamed, A.; Han, L.-X.; Haque, R.; Harris, J. W.; Heppelmann, S.; Hirsch, A.; Hoffmann, G. W.; Hofman, D. J.; Horvat, S.; Huang, B.; Huang, H. Z.; Huang, X.; Huck, P.; Humanic, T. J.; Igo, G.; Jacobs, W. W.; Jang, H.; Judd, E. G.; Kabana, S.; Kalinkin, D.; Kang, K.; Kauder, K.; Ke, H. W.; Keane, D.; Kechechyan, A.; Kesich, A.; Khan, Z. H.; Kikola, D. P.; Kisel, I.; Kisiel, A.; Koetke, D. D.; Kollegger, T.; Konzer, J.; Koralt, I.; Kotchenda, L.; Kraishan, A. F.; Kravtsov, P.; Krueger, K.; Kulakov, I.; Kumar, L.; Kycia, R. A.; Lamont, M. A. C.; Landgraf, J. M.; Landry, K. D.; Lauret, J.; Lebedev, A.; Lednicky, R.; Lee, J. H.; LeVine, M. J.; Li, C.; Li, W.; Li, X.; Li, X.; Li, Y.; Li, Z. M.; Lisa, M. A.; Liu, F.; Ljubicic, T.; Llope, W. J.; Lomnitz, M.; Longacre, R. S.; Luo, X.; Ma, G. L.; Ma, Y. G.; Madagodagettige Don, D. M. M. D.; Mahapatra, D. P.; Majka, R.; Margetis, S.; Markert, C.; Masui, H.; Matis, H. S.; McDonald, D.; McShane, T. S.; Minaev, N. G.; Mioduszewski, S.; Mohanty, B.; Mondal, M. M.; Morozov, D. A.; Mustafa, M. K.; Nandi, B. K.; Nasim, Md.; Nayak, T. K.; Nelson, J. M.; Nigmatkulov, G.; Nogach, L. V.; Noh, S. Y.; Novak, J.; Nurushev, S. B.; Odyniec, G.; Ogawa, A.; Oh, K.; Ohlson, A.; Okorokov, V.; Oldag, E. W.; Olvitt, D. L.; Pachr, M.; Page, B. S.; Pal, S. K.; Pan, Y. X.; Pandit, Y.; Panebratsev, Y.; Pawlak, T.; Pawlik, B.; Pei, H.; Perkins, C.; Peryt, W.; Pile, P.; Planinic, M.; Pluta, J.; Poljak, N.; Porter, J.; Poskanzer, A. M.; Pruthi, N. K.; Przybycien, M.; Pujahari, P. R.; Putschke, J.; Qiu, H.; Quintero, A.; Ramachandran, S.; Raniwala, R.; Raniwala, S.; Ray, R. L.; Riley, C. K.; Ritter, H. G.; Roberts, J. B.; Rogachevskiy, O. V.; Romero, J. L.; Ross, J. F.; Roy, A.; Ruan, L.; Rusnak, J.; Rusnakova, O.; Sahoo, N. R.; Sahu, P. K.; Sakrejda, I.; Salur, S.; Sandweiss, J.; Sangaline, E.; Sarkar, A.; Schambach, J.; Scharenberg, R. P.; Schmah, A. M.; Schmidke, W. B.; Schmitz, N.; Seger, J.; Seyboth, P.; Shah, N.; Shahaliev, E.; Shanmuganathan, P. V.; Shao, M.; Sharma, B.; Shen, W. Q.; Shi, S. S.; Shou, Q. Y.; Sichtermann, E. P.; Singaraju, R. N.; Skoby, M. J.; Smirnov, D.; Smirnov, N.; Solanki, D.; Sorensen, P.; Spinka, H. M.; Srivastava, B.; Stanislaus, T. D. S.; Stevens, J. R.; Stock, R.; Strikhanov, M.; Stringfellow, B.; Sumbera, M.; Sun, X.; Sun, X. M.; Sun, Y.; Sun, Z.; Surrow, B.; Svirida, D. N.; Symons, T. J. M.; Szelezniak, M. A.; Takahashi, J.; Tang, A. H.; Tang, Z.; Tarnowsky, T.; Thomas, J. H.; Timmins, A. R.; Tlusty, D.; Tokarev, M.; Trentalange, S.; Tribble, R. E.; Tribedy, P.; Trzeciak, B. A.; Tsai, O. D.; Turnau, J.; Ullrich, T.; Underwood, D. G.; Van Buren, G.; van Nieuwenhuizen, G.; Vandenbroucke, M.; Vanfossen, J. A.; Varma, R.; Vasconcelos, G. M. S.; Vasiliev, A. N.; Vertesi, R.; Videbæk, F.; Viyogi, Y. P.; Vokal, S.; Vossen, A.; Wada, M.; Wang, F.; Wang, G.; Wang, H.; Wang, J. S.; Wang, X. L.; Wang, Y.; Wang, Y.; Webb, G.; Webb, J. C.; Westfall, G. D.; Wieman, H.; Wissink, S. W.; Witt, R.; Wu, Y. F.; Xiao, Z.; Xie, W.; Xin, K.; Xu, H.; Xu, J.; Xu, N.; Xu, Q. H.; Xu, Y.; Xu, Z.; Yan, W.; Yang, C.; Yang, Y.; Yang, Y.; Ye, Z.; Yepes, P.; Yi, L.; Yip, K.; Yoo, I.-K.; Yu, N.; Zawisza, Y.; Zbroszczyk, H.; Zha, W.; Zhang, J. B.; Zhang, J. L.; Zhang, S.; Zhang, X. P.; Zhang, Y.; Zhang, Z. P.; Zhao, F.; Zhao, J.; Zhong, C.; Zhu, X.; Zhu, Y. H.; Zoulkarneeva, Y.; Zyzak, M.; STAR Collaboration

    2014-04-01

    Rapidity-odd directed flow (v1) measurements for charged pions, protons, and antiprotons near midrapidity (y =0) are reported in √sNN =7.7, 11.5, 19.6, 27, 39, 62.4, and 200 GeV Au+Au collisions as recorded by the STAR detector at the Relativistic Heavy Ion Collider. At intermediate impact parameters, the proton and net-proton slope parameter dv1/dy|y=0 shows a minimum between 11.5 and 19.6 GeV. In addition, the net-proton dv1/dy|y=0 changes sign twice between 7.7 and 39 GeV. The proton and net-proton results qualitatively resemble predictions of a hydrodynamic model with a first-order phase transition from hadronic matter to deconfined matter, and differ from hadronic transport calculations.

  20. Direct virtual photon production in Au+Au collisions at √{sNN} = 200 GeV

    NASA Astrophysics Data System (ADS)

    Adamczyk, L.; Adkins, J. K.; Agakishiev, G.; Aggarwal, M. M.; Ahammed, Z.; Ajitanand, N. N.; Alekseev, I.; Anderson, D. M.; Aoyama, R.; Aparin, A.; Arkhipkin, D.; Aschenauer, E. C.; Ashraf, M. U.; Attri, A.; Averichev, G. S.; Bai, X.; Bairathi, V.; Behera, A.; Bellwied, R.; Bhasin, A.; Bhati, A. K.; Bhattarai, P.; Bielcik, J.; Bielcikova, J.; Bland, L. C.; Bordyuzhin, I. G.; Bouchet, J.; Brandenburg, J. D.; Brandin, A. V.; Brown, D.; Bunzarov, I.; Butterworth, J.; Caines, H.; Calderón de la Barca Sánchez, M.; Campbell, J. M.; Cebra, D.; Chakaberia, I.; Chaloupka, P.; Chang, Z.; Chankova-Bunzarova, N.; Chatterjee, A.; Chattopadhyay, S.; Chen, X.; Chen, X.; Chen, J. H.; Cheng, J.; Cherney, M.; Christie, W.; Contin, G.; Crawford, H. J.; Das, S.; De Silva, L. C.; Debbe, R. R.; Dedovich, T. G.; Deng, J.; Derevschikov, A. A.; Didenko, L.; Dilks, C.; Dong, X.; Drachenberg, J. L.; Draper, J. E.; Dunkelberger, L. E.; Dunlop, J. C.; Efimov, L. G.; Elsey, N.; Engelage, J.; Eppley, G.; Esha, R.; Esumi, S.; Evdokimov, O.; Ewigleben, J.; Eyser, O.; Fatemi, R.; Fazio, S.; Federic, P.; Federicova, P.; Fedorisin, J.; Feng, Z.; Filip, P.; Finch, E.; Fisyak, Y.; Flores, C. E.; Fujita, J.; Fulek, L.; Gagliardi, C. A.; Garand, D.; Geurts, F.; Gibson, A.; Girard, M.; Grosnick, D.; Gunarathne, D. S.; Guo, Y.; Gupta, A.; Gupta, S.; Guryn, W.; Hamad, A. I.; Hamed, A.; Harlenderova, A.; Harris, J. W.; He, L.; Heppelmann, S.; Heppelmann, S.; Hirsch, A.; Hoffmann, G. W.; Horvat, S.; Huang, B.; Huang, T.; Huang, H. Z.; Huang, X.; Humanic, T. J.; Huo, P.; Igo, G.; Jacobs, W. W.; Jentsch, A.; Jia, J.; Jiang, K.; Jowzaee, S.; Judd, E. G.; Kabana, S.; Kalinkin, D.; Kang, K.; Kauder, K.; Ke, H. W.; Keane, D.; Kechechyan, A.; Khan, Z.; Kikoła, D. P.; Kisel, I.; Kisiel, A.; Kochenda, L.; Kocmanek, M.; Kollegger, T.; Kosarzewski, L. K.; Kraishan, A. F.; Kravtsov, P.; Krueger, K.; Kulathunga, N.; Kumar, L.; Kvapil, J.; Kwasizur, J. H.; Lacey, R.; Landgraf, J. M.; Landry, K. D.; Lauret, J.; Lebedev, A.; Lednicky, R.; Lee, J. H.; Li, W.; Li, X.; Li, C.; Li, Y.; Lidrych, J.; Lin, T.; Lisa, M. A.; Liu, Y.; Liu, F.; Liu, H.; Liu, P.; Ljubicic, T.; Llope, W. J.; Lomnitz, M.; Longacre, R. S.; Luo, S.; Luo, X.; Ma, G. L.; Ma, Y. G.; Ma, L.; Ma, R.; Magdy, N.; Majka, R.; Mallick, D.; Margetis, S.; Markert, C.; Matis, H. S.; Meehan, K.; Mei, J. C.; Miller, Z. W.; Minaev, N. G.; Mioduszewski, S.; Mishra, D.; Mizuno, S.; Mohanty, B.; Mondal, M. M.; Morozov, D. A.; Mustafa, M. K.; Nasim, Md.; Nayak, T. K.; Nelson, J. M.; Nie, M.; Nigmatkulov, G.; Niida, T.; Nogach, L. V.; Nonaka, T.; Nurushev, S. B.; Odyniec, G.; Ogawa, A.; Oh, K.; Okorokov, V. A.; Olvitt, D.; Page, B. S.; Pak, R.; Pandit, Y.; Panebratsev, Y.; Pawlik, B.; Pei, H.; Perkins, C.; Pile, P.; Pluta, J.; Poniatowska, K.; Porter, J.; Posik, M.; Poskanzer, A. M.; Pruthi, N. K.; Przybycien, M.; Putschke, J.; Qiu, H.; Quintero, A.; Ramachandran, S.; Ray, R. L.; Reed, R.; Rehbein, M. J.; Ritter, H. G.; Roberts, J. B.; Rogachevskiy, O. V.; Romero, J. L.; Roth, J. D.; Ruan, L.; Rusnak, J.; Rusnakova, O.; Sahoo, N. R.; Sahu, P. K.; Salur, S.; Sandweiss, J.; Saur, M.; Schambach, J.; Schmah, A. M.; Schmidke, W. B.; Schmitz, N.; Schweid, B. R.; Seger, J.; Sergeeva, M.; Seyboth, P.; Shah, N.; Shahaliev, E.; Shanmuganathan, P. V.; Shao, M.; Sharma, A.; Sharma, M. K.; Shen, W. Q.; Shi, Z.; Shi, S. S.; Shou, Q. Y.; Sichtermann, E. P.; Sikora, R.; Simko, M.; Singha, S.; Skoby, M. J.; Smirnov, N.; Smirnov, D.; Solyst, W.; Song, L.; Sorensen, P.; Spinka, H. M.; Srivastava, B.; Stanislaus, T. D. S.; Strikhanov, M.; Stringfellow, B.; Sugiura, T.; Sumbera, M.; Summa, B.; Sun, Y.; Sun, X. M.; Sun, X.; Surrow, B.; Svirida, D. N.; Tang, A. H.; Tang, Z.; Taranenko, A.; Tarnowsky, T.; Tawfik, A.; Thäder, J.; Thomas, J. H.; Timmins, A. R.; Tlusty, D.; Todoroki, T.; Tokarev, M.; Trentalange, S.; Tribble, R. E.; Tribedy, P.; Tripathy, S. K.; Trzeciak, B. A.; Tsai, O. D.; Ullrich, T.; Underwood, D. G.; Upsal, I.; Van Buren, G.; van Nieuwenhuizen, G.; Vasiliev, A. N.; Videbæk, F.; Vokal, S.; Voloshin, S. A.; Vossen, A.; Wang, G.; Wang, Y.; Wang, F.; Wang, Y.; Webb, J. C.; Webb, G.; Wen, L.; Westfall, G. D.; Wieman, H.; Wissink, S. W.; Witt, R.; Wu, Y.; Xiao, Z. G.; Xie, W.; Xie, G.; Xu, J.; Xu, N.; Xu, Q. H.; Xu, Y. F.; Xu, Z.; Yang, Y.; Yang, Q.; Yang, C.; Yang, S.; Ye, Z.; Ye, Z.; Yi, L.; Yip, K.; Yoo, I.-K.; Yu, N.; Zbroszczyk, H.; Zha, W.; Zhang, Z.; Zhang, X. P.; Zhang, J. B.; Zhang, S.; Zhang, J.; Zhang, Y.; Zhang, J.; Zhang, S.; Zhao, J.; Zhong, C.; Zhou, L.; Zhou, C.; Zhu, X.; Zhu, Z.; Zyzak, M.

    2017-07-01

    We report the direct virtual photon invariant yields in the transverse momentum ranges 1 Au+Au collisions at √{sNN} = 200 GeV. A clear excess in the invariant yield compared to the nuclear overlap function TAA scaled p + p reference is observed in the pT range 1 6 GeV / c the production follows TAA scaling. Model calculations with contributions from thermal radiation and initial hard parton scattering are consistent within uncertainties with the direct virtual photon invariant yield.

  1. Beam-Energy Dependence of Charge Separation along the Magnetic Field in Au +Au Collisions at RHIC

    NASA Astrophysics Data System (ADS)

    Adamczyk, L.; Adkins, J. K.; Agakishiev, G.; Aggarwal, M. M.; Ahammed, Z.; Alekseev, I.; Alford, J.; Anson, C. D.; Aparin, A.; Arkhipkin, D.; Aschenauer, E. C.; Averichev, G. S.; Banerjee, A.; Beavis, D. R.; Bellwied, R.; Bhasin, A.; Bhati, A. K.; Bhattarai, P.; Bichsel, H.; Bielcik, J.; Bielcikova, J.; Bland, L. C.; Bordyuzhin, I. G.; Borowski, W.; Bouchet, J.; Brandin, A. V.; Brovko, S. G.; Bültmann, S.; Bunzarov, I.; Burton, T. P.; Butterworth, J.; Caines, H.; Calderón de la Barca Sánchez, M.; Cebra, D.; Cendejas, R.; Cervantes, M. C.; Chaloupka, P.; Chang, Z.; Chattopadhyay, S.; Chen, H. F.; Chen, J. H.; Chen, L.; Cheng, J.; Cherney, M.; Chikanian, A.; Christie, W.; Chwastowski, J.; Codrington, M. J. M.; Contin, G.; Cramer, J. G.; Crawford, H. J.; Cui, X.; Das, S.; Davila Leyva, A.; De Silva, L. C.; Debbe, R. R.; Dedovich, T. G.; Deng, J.; Derevschikov, A. A.; Derradi de Souza, R.; Dhamija, S.; di Ruzza, B.; Didenko, L.; Dilks, C.; Ding, F.; Djawotho, P.; Dong, X.; Drachenberg, J. L.; Draper, J. E.; Du, C. M.; Dunkelberger, L. E.; Dunlop, J. C.; Efimov, L. G.; Engelage, J.; Engle, K. S.; Eppley, G.; Eun, L.; Evdokimov, O.; Eyser, O.; Fatemi, R.; Fazio, S.; Fedorisin, J.; Filip, P.; Finch, E.; Fisyak, Y.; Flores, C. E.; Gagliardi, C. A.; Gangadharan, D. R.; Garand, D.; Geurts, F.; Gibson, A.; Girard, M.; Gliske, S.; Greiner, L.; Grosnick, D.; Gunarathne, D. S.; Guo, Y.; Gupta, A.; Gupta, S.; Guryn, W.; Haag, B.; Hamed, A.; Han, L.-X.; Haque, R.; Harris, J. W.; Heppelmann, S.; Hirsch, A.; Hoffmann, G. W.; Hofman, D. J.; Horvat, S.; Huang, B.; Huang, H. Z.; Huang, X.; Huck, P.; Humanic, T. J.; Igo, G.; Jacobs, W. W.; Jang, H.; Judd, E. G.; Kabana, S.; Kalinkin, D.; Kang, K.; Kauder, K.; Ke, H. W.; Keane, D.; Kechechyan, A.; Kesich, A.; Khan, Z. H.; Kikola, D. P.; Kisel, I.; Kisiel, A.; Koetke, D. D.; Kollegger, T.; Konzer, J.; Koralt, I.; Kotchenda, L.; Kraishan, A. F.; Kravtsov, P.; Krueger, K.; Kulakov, I.; Kumar, L.; Kycia, R. A.; Lamont, M. A. C.; Landgraf, J. M.; Landry, K. D.; Lauret, J.; Lebedev, A.; Lednicky, R.; Lee, J. H.; LeVine, M. J.; Li, C.; Li, W.; Li, X.; Li, X.; Li, Y.; Li, Z. M.; Lisa, M. A.; Liu, F.; Ljubicic, T.; Llope, W. J.; Lomnitz, M.; Longacre, R. S.; Luo, X.; Ma, G. L.; Ma, Y. G.; Madagodagettige Don, D. M. M. D.; Mahapatra, D. P.; Majka, R.; Margetis, S.; Markert, C.; Masui, H.; Matis, H. S.; McDonald, D.; McShane, T. S.; Minaev, N. G.; Mioduszewski, S.; Mohanty, B.; Mondal, M. M.; Morozov, D. A.; Mustafa, M. K.; Nandi, B. K.; Nasim, Md.; Nayak, T. K.; Nelson, J. M.; Nigmatkulov, G.; Nogach, L. V.; Noh, S. Y.; Novak, J.; Nurushev, S. B.; Odyniec, G.; Ogawa, A.; Oh, K.; Ohlson, A.; Okorokov, V.; Oldag, E. W.; Olvitt, D. L.; Pachr, M.; Page, B. S.; Pal, S. K.; Pan, Y. X.; Pandit, Y.; Panebratsev, Y.; Pawlak, T.; Pawlik, B.; Pei, H.; Perkins, C.; Peryt, W.; Pile, P.; Planinic, M.; Pluta, J.; Poljak, N.; Porter, J.; Poskanzer, A. M.; Pruthi, N. K.; Przybycien, M.; Pujahari, P. R.; Putschke, J.; Qiu, H.; Quintero, A.; Ramachandran, S.; Raniwala, R.; Raniwala, S.; Ray, R. L.; Riley, C. K.; Ritter, H. G.; Roberts, J. B.; Rogachevskiy, O. V.; Romero, J. L.; Ross, J. F.; Roy, A.; Ruan, L.; Rusnak, J.; Rusnakova, O.; Sahoo, N. R.; Sahu, P. K.; Sakrejda, I.; Salur, S.; Sandweiss, J.; Sangaline, E.; Sarkar, A.; Schambach, J.; Scharenberg, R. P.; Schmah, A. M.; Schmidke, W. B.; Schmitz, N.; Seger, J.; Seyboth, P.; Shah, N.; Shahaliev, E.; Shanmuganathan, P. V.; Shao, M.; Sharma, B.; Shen, W. Q.; Shi, S. S.; Shou, Q. Y.; Sichtermann, E. P.; Singaraju, R. N.; Skoby, M. J.; Smirnov, D.; Smirnov, N.; Solanki, D.; Sorensen, P.; Spinka, H. M.; Srivastava, B.; Stanislaus, T. D. S.; Stevens, J. R.; Stock, R.; Strikhanov, M.; Stringfellow, B.; Sumbera, M.; Sun, X.; Sun, X. M.; Sun, Y.; Sun, Z.; Surrow, B.; Svirida, D. N.; Symons, T. J. M.; Szelezniak, M. A.; Takahashi, J.; Tang, A. H.; Tang, Z.; Tarnowsky, T.; Thomas, J. H.; Timmins, A. R.; Tlusty, D.; Tokarev, M.; Trentalange, S.; Tribble, R. E.; Tribedy, P.; Trzeciak, B. A.; Tsai, O. D.; Turnau, J.; Ullrich, T.; Underwood, D. G.; Van Buren, G.; van Nieuwenhuizen, G.; Vandenbroucke, M.; Vanfossen, J. A.; Varma, R.; Vasconcelos, G. M. S.; Vasiliev, A. N.; Vertesi, R.; Videbæk, F.; Viyogi, Y. P.; Vokal, S.; Voloshin, S. A.; Vossen, A.; Wada, M.; Wang, F.; Wang, G.; Wang, H.; Wang, J. S.; Wang, X. L.; Wang, Y.; Wang, Y.; Webb, G.; Webb, J. C.; Westfall, G. D.; Wieman, H.; Wissink, S. W.; Witt, R.; Wu, Y. F.; Xiao, Z.; Xie, W.; Xin, K.; Xu, H.; Xu, J.; Xu, N.; Xu, Q. H.; Xu, Y.; Xu, Z.; Yan, W.; Yang, C.; Yang, Y.; Yang, Y.; Ye, Z.; Yepes, P.; Yi, L.; Yip, K.; Yoo, I.-K.; Yu, N.; Zawisza, Y.; Zbroszczyk, H.; Zha, W.; Zhang, J. B.; Zhang, J. L.; Zhang, S.; Zhang, X. P.; Zhang, Y.; Zhang, Z. P.; Zhao, F.; Zhao, J.; Zhong, C.; Zhu, X.; Zhu, Y. H.; Zoulkarneeva, Y.; Zyzak, M.; STAR Collaboration

    2014-08-01

    Local parity-odd domains are theorized to form inside a quark-gluon plasma which has been produced in high-energy heavy-ion collisions. The local parity-odd domains manifest themselves as charge separation along the magnetic field axis via the chiral magnetic effect. The experimental observation of charge separation has previously been reported for heavy-ion collisions at the top RHIC energies. In this Letter, we present the results of the beam-energy dependence of the charge correlations in Au +Au collisions at midrapidity for center-of-mass energies of 7.7, 11.5, 19.6, 27, 39, and 62.4 GeV from the STAR experiment. After background subtraction, the signal gradually reduces with decreased beam energy and tends to vanish by 7.7 GeV. This implies the dominance of hadronic interactions over partonic ones at lower collision energies.

  2. Beam-Energy Dependence of Directed Flow of Λ , Λ ¯, K±, Ks0, and ϕ in Au +Au Collisions

    NASA Astrophysics Data System (ADS)

    Adamczyk, L.; Adams, J. R.; Adkins, J. K.; Agakishiev, G.; Aggarwal, M. M.; Ahammed, Z.; Ajitanand, N. N.; Alekseev, I.; Anderson, D. M.; Aoyama, R.; Aparin, A.; Arkhipkin, D.; Aschenauer, E. C.; Ashraf, M. U.; Attri, A.; Averichev, G. S.; Bai, X.; Bairathi, V.; Barish, K.; Behera, A.; Bellwied, R.; Bhasin, A.; Bhati, A. K.; Bhattarai, P.; Bielcik, J.; Bielcikova, J.; Bland, L. C.; Bordyuzhin, I. G.; Bouchet, J.; Brandenburg, J. D.; Brandin, A. V.; Brown, D.; Bunzarov, I.; Butterworth, J.; Caines, H.; Calderón de la Barca Sánchez, M.; Campbell, J. M.; Cebra, D.; Chakaberia, I.; Chaloupka, P.; Chang, Z.; Chankova-Bunzarova, N.; Chatterjee, A.; Chattopadhyay, S.; Chen, X.; Chen, J. H.; Chen, X.; Cheng, J.; Cherney, M.; Christie, W.; Contin, G.; Crawford, H. J.; Das, S.; De Silva, L. C.; Dedovich, T. G.; Deng, J.; Derevschikov, A. A.; Didenko, L.; Dilks, C.; Dong, X.; Drachenberg, J. L.; Draper, J. E.; Dunkelberger, L. E.; Dunlop, J. C.; Efimov, L. G.; Elsey, N.; Engelage, J.; Eppley, G.; Esha, R.; Esumi, S.; Evdokimov, O.; Ewigleben, J.; Eyser, O.; Fatemi, R.; Fazio, S.; Federic, P.; Federicova, P.; Fedorisin, J.; Feng, Z.; Filip, P.; Finch, E.; Fisyak, Y.; Flores, C. E.; Fujita, J.; Fulek, L.; Gagliardi, C. A.; Garand, D.; Geurts, F.; Gibson, A.; Girard, M.; Grosnick, D.; Gunarathne, D. S.; Guo, Y.; Gupta, A.; Gupta, S.; Guryn, W.; Hamad, A. I.; Hamed, A.; Harlenderova, A.; Harris, J. W.; He, L.; Heppelmann, S.; Heppelmann, S.; Hirsch, A.; Horvat, S.; Huang, X.; Huang, B.; Huang, T.; Huang, H. Z.; Humanic, T. J.; Huo, P.; Igo, G.; Jacobs, W. W.; Jentsch, A.; Jia, J.; Jiang, K.; Jowzaee, S.; Judd, E. G.; Kabana, S.; Kalinkin, D.; Kang, K.; Kapukchyan, D.; Kauder, K.; Ke, H. W.; Keane, D.; Kechechyan, A.; Khan, Z.; Kikoła, D. P.; Kim, C.; Kisel, I.; Kisiel, A.; Kochenda, L.; Kocmanek, M.; Kollegger, T.; Kosarzewski, L. K.; Kraishan, A. F.; Krauth, L.; Kravtsov, P.; Krueger, K.; Kulathunga, N.; Kumar, L.; Kvapil, J.; Kwasizur, J. H.; Lacey, R.; Landgraf, J. M.; Landry, K. D.; Lauret, J.; Lebedev, A.; Lednicky, R.; Lee, J. H.; Li, C.; Li, X.; Li, Y.; Li, W.; Lidrych, J.; Lin, T.; Lisa, M. A.; Liu, P.; Liu, H.; Liu, Y.; Liu, F.; Ljubicic, T.; Llope, W. J.; Lomnitz, M.; Longacre, R. S.; Luo, S.; Luo, X.; Ma, Y. G.; Ma, L.; Ma, R.; Ma, G. L.; Magdy, N.; Majka, R.; Mallick, D.; Margetis, S.; Markert, C.; Matis, H. S.; Meehan, K.; Mei, J. C.; Miller, Z. W.; Minaev, N. G.; Mioduszewski, S.; Mishra, D.; Mizuno, S.; Mohanty, B.; Mondal, M. M.; Morozov, D. A.; Mustafa, M. K.; Nasim, Md.; Nayak, T. K.; Nelson, J. M.; Nie, M.; Nigmatkulov, G.; Niida, T.; Nogach, L. V.; Nonaka, T.; Nurushev, S. B.; Odyniec, G.; Ogawa, A.; Oh, K.; Okorokov, V. A.; Olvitt, D.; Page, B. S.; Pak, R.; Pandit, Y.; Panebratsev, Y.; Pawlik, B.; Pei, H.; Perkins, C.; Pile, P.; Pluta, J.; Poniatowska, K.; Porter, J.; Posik, M.; Pruthi, N. K.; Przybycien, M.; Putschke, J.; Qiu, H.; Quintero, A.; Ramachandran, S.; Ray, R. L.; Reed, R.; Rehbein, M. J.; Ritter, H. G.; Roberts, J. B.; Rogachevskiy, O. V.; Romero, J. L.; Roth, J. D.; Ruan, L.; Rusnak, J.; Rusnakova, O.; Sahoo, N. R.; Sahu, P. K.; Salur, S.; Sandweiss, J.; Saur, M.; Schambach, J.; Schmah, A. M.; Schmidke, W. B.; Schmitz, N.; Schweid, B. R.; Seger, J.; Sergeeva, M.; Seto, R.; Seyboth, P.; Shah, N.; Shahaliev, E.; Shanmuganathan, P. V.; Shao, M.; Sharma, A.; Sharma, M. K.; Shen, W. Q.; Shi, S. S.; Shi, Z.; Shou, Q. Y.; Sichtermann, E. P.; Sikora, R.; Simko, M.; Singha, S.; Skoby, M. J.; Smirnov, N.; Smirnov, D.; Solyst, W.; Song, L.; Sorensen, P.; Spinka, H. M.; Srivastava, B.; Stanislaus, T. D. S.; Strikhanov, M.; Stringfellow, B.; Suaide, A. A. P.; Sugiura, T.; Sumbera, M.; Summa, B.; Sun, Y.; Sun, X. M.; Sun, X.; Surrow, B.; Svirida, D. N.; Tang, Z.; Tang, A. H.; Taranenko, A.; Tarnowsky, T.; Tawfik, A.; Thäder, J.; Thomas, J. H.; Timmins, A. R.; Tlusty, D.; Todoroki, T.; Tokarev, M.; Trentalange, S.; Tribble, R. E.; Tribedy, P.; Tripathy, S. K.; Trzeciak, B. A.; Tsai, O. D.; Ullrich, T.; Underwood, D. G.; Upsal, I.; Van Buren, G.; van Nieuwenhuizen, G.; Vasiliev, A. N.; Videbæk, F.; Vokal, S.; Voloshin, S. A.; Vossen, A.; Wang, G.; Wang, Y.; Wang, F.; Wang, Y.; Webb, J. C.; Webb, G.; Wen, L.; Westfall, G. D.; Wieman, H.; Wissink, S. W.; Witt, R.; Wu, Y.; Xiao, Z. G.; Xie, G.; Xie, W.; Xu, J.; Xu, Z.; Xu, Q. H.; Xu, Y. F.; Xu, N.; Yang, S.; Yang, Y.; Yang, C.; Yang, Q.; Ye, Z.; Ye, Z.; Yi, L.; Yip, K.; Yoo, I.-K.; Yu, N.; Zbroszczyk, H.; Zha, W.; Zhang, Z.; Zhang, J. B.; Zhang, J.; Zhang, S.; Zhang, Y.; Zhang, X. P.; Zhang, J.; Zhang, S.; Zhao, J.; Zhong, C.; Zhou, C.; Zhou, L.; Zhu, X.; Zhu, Z.; Zyzak, M.; STAR Collaboration

    2018-02-01

    Rapidity-odd directed-flow measurements at midrapidity are presented for Λ , Λ ¯, K±, Ks0, and ϕ at √{sN N }=7.7 , 11.5, 14.5, 19.6, 27, 39, 62.4, and 200 GeV in Au +Au collisions recorded by the Solenoidal Tracker detector at the Relativistic Heavy Ion Collider. These measurements greatly expand the scope of data available to constrain models with differing prescriptions for the equation of state of quantum chromodynamics. Results show good sensitivity for testing a picture where flow is assumed to be imposed before hadron formation and the observed particles are assumed to form via coalescence of constituent quarks. The pattern of departure from a coalescence-inspired sum rule can be a valuable new tool for probing the collision dynamics.

  3. Elliptic and Hexadecapole Flow of Charged Hadrons in Au+Au Collisions at sNN=200GeV

    NASA Astrophysics Data System (ADS)

    Adare, A.; Afanasiev, S.; Aidala, C.; Ajitanand, N. N.; Akiba, Y.; Al-Bataineh, H.; Alexander, J.; Aoki, K.; Aramaki, Y.; Atomssa, E. T.; Averbeck, R.; Awes, T. C.; Azmoun, B.; Babintsev, V.; Bai, M.; Baksay, G.; Baksay, L.; Barish, K. N.; Bassalleck, B.; Basye, A. T.; Bathe, S.; Baublis, V.; Baumann, C.; Bazilevsky, A.; Belikov, S.; Belmont, R.; Bennett, R.; Berdnikov, A.; Berdnikov, Y.; Bickley, A. A.; Bok, J. S.; Boyle, K.; Brooks, M. L.; Buesching, H.; Bumazhnov, V.; Bunce, G.; Butsyk, S.; Camacho, C. M.; Campbell, S.; Chen, C.-H.; Chi, C. Y.; Chiu, M.; Choi, I. J.; Choudhury, R. K.; Christiansen, P.; Chujo, T.; Chung, P.; Chvala, O.; Cianciolo, V.; Citron, Z.; Cole, B. A.; Connors, M.; Constantin, P.; Csanád, M.; Csörgő, T.; Dahms, T.; Dairaku, S.; Danchev, I.; Das, K.; Datta, A.; David, G.; Denisov, A.; Deshpande, A.; Desmond, E. J.; Dietzsch, O.; Dion, A.; Donadelli, M.; Drapier, O.; Drees, A.; Drees, K. A.; Durham, J. M.; Durum, A.; Dutta, D.; Edwards, S.; Efremenko, Y. V.; Ellinghaus, F.; Engelmore, T.; Enokizono, A.; En'Yo, H.; Esumi, S.; Fadem, B.; Fields, D. E.; Finger, M., Jr.; Finger, M.; Fleuret, F.; Fokin, S. L.; Fraenkel, Z.; Frantz, J. E.; Franz, A.; Frawley, A. D.; Fujiwara, K.; Fukao, Y.; Fusayasu, T.; Garishvili, I.; Glenn, A.; Gong, H.; Gonin, M.; Goto, Y.; Granier de Cassagnac, R.; Grau, N.; Greene, S. V.; Grosse Perdekamp, M.; Gunji, T.; Gustafsson, H.-Å.; Haggerty, J. S.; Hahn, K. I.; Hamagaki, H.; Hamblen, J.; Hanks, J.; Han, R.; Hartouni, E. P.; Haslum, E.; Hayano, R.; Heffner, M.; Hegyi, S.; Hemmick, T. K.; Hester, T.; He, X.; Hill, J. C.; Hohlmann, M.; Holzmann, W.; Homma, K.; Hong, B.; Horaguchi, T.; Hornback, D.; Huang, S.; Ichihara, T.; Ichimiya, R.; Ide, J.; Ikeda, Y.; Imai, K.; Inaba, M.; Isenhower, D.; Ishihara, M.; Isobe, T.; Issah, M.; Isupov, A.; Ivanischev, D.; Jacak, B. V.; Jia, J.; Jin, J.; Johnson, B. M.; Joo, K. S.; Jouan, D.; Jumper, D. S.; Kajihara, F.; Kametani, S.; Kamihara, N.; Kamin, J.; Kang, J. H.; Kapustinsky, J.; Karatsu, K.; Kawall, D.; Kawashima, M.; Kazantsev, A. V.; Kempel, T.; Khanzadeev, A.; Kijima, K. M.; Kim, B. I.; Kim, D. H.; Kim, D. J.; Kim, E. J.; Kim, E.; Kim, S. H.; Kim, Y. J.; Kinney, E.; Kiriluk, K.; Kiss, Á.; Kistenev, E.; Kochenda, L.; Komkov, B.; Konno, M.; Koster, J.; Kotchetkov, D.; Kozlov, A.; Král, A.; Kravitz, A.; Kunde, G. J.; Kurita, K.; Kurosawa, M.; Kwon, Y.; Kyle, G. S.; Lacey, R.; Lai, Y. S.; Lajoie, J. G.; Lebedev, A.; Lee, D. M.; Lee, J.; Lee, K. B.; Lee, K.; Lee, K. S.; Leitch, M. J.; Leite, M. A. L.; Leitner, E.; Lenzi, B.; Liebing, P.; Linden Levy, L. A.; Liška, T.; Litvinenko, A.; Liu, H.; Liu, M. X.; Li, X.; Love, B.; Luechtenborg, R.; Lynch, D.; Maguire, C. F.; Makdisi, Y. I.; Malakhov, A.; Malik, M. D.; Manko, V. I.; Mannel, E.; Mao, Y.; Masui, H.; Matathias, F.; McCumber, M.; McGaughey, P. L.; Means, N.; Meredith, B.; Miake, Y.; Mignerey, A. C.; Mikeš, P.; Miki, K.; Milov, A.; Mishra, M.; Mitchell, J. T.; Mohanty, A. K.; Morino, Y.; Morreale, A.; Morrison, D. P.; Moukhanova, T. V.; Murata, J.; Nagamiya, S.; Nagle, J. L.; Naglis, M.; Nagy, M. I.; Nakagawa, I.; Nakamiya, Y.; Nakamura, T.; Nakano, K.; Newby, J.; Nguyen, M.; Nouicer, R.; Nyanin, A. S.; O'Brien, E.; Oda, S. X.; Ogilvie, C. A.; Okada, K.; Oka, M.; Onuki, Y.; Oskarsson, A.; Ouchida, M.; Ozawa, K.; Pak, R.; Pantuev, V.; Papavassiliou, V.; Park, I. H.; Park, J.; Park, S. K.; Park, W. J.; Pate, S. F.; Pei, H.; Peng, J.-C.; Pereira, H.; Peresedov, V.; Peressounko, D. Yu.; Pinkenburg, C.; Pisani, R. P.; Proissl, M.; Purschke, M. L.; Purwar, A. K.; Qu, H.; Rak, J.; Rakotozafindrabe, A.; Ravinovich, I.; Read, K. F.; Reygers, K.; Riabov, V.; Riabov, Y.; Richardson, E.; Roach, D.; Roche, G.; Rolnick, S. D.; Rosati, M.; Rosen, C. A.; Rosendahl, S. S. E.; Rosnet, P.; Rukoyatkin, P.; Ružička, P.; Sahlmueller, B.; Saito, N.; Sakaguchi, T.; Sakashita, K.; Samsonov, V.; Sano, S.; Sato, T.; Sawada, S.; Sedgwick, K.; Seele, J.; Seidl, R.; Semenov, A. Yu.; Seto, R.; Sharma, D.; Shein, I.; Shibata, T.-A.; Shigaki, K.; Shimomura, M.; Shoji, K.; Shukla, P.; Sickles, A.; Silva, C. L.; Silvermyr, D.; Silvestre, C.; Sim, K. S.; Singh, B. K.; Singh, C. P.; Singh, V.; Slunečka, M.; Soltz, R. A.; Sondheim, W. E.; Sorensen, S. P.; Sourikova, I. V.; Sparks, N. A.; Stankus, P. W.; Stenlund, E.; Stoll, S. P.; Sugitate, T.; Sukhanov, A.; Sziklai, J.; Takagui, E. M.; Taketani, A.; Tanabe, R.; Tanaka, Y.; Tanida, K.; Tannenbaum, M. J.; Tarafdar, S.; Taranenko, A.; Tarján, P.; Themann, H.; Thomas, T. L.; Togawa, M.; Toia, A.; Tomášek, L.; Torii, H.; Towell, R. S.; Tserruya, I.; Tsuchimoto, Y.; Vale, C.; Valle, H.; van Hecke, H. W.; Vazquez-Zambrano, E.; Veicht, A.; Velkovska, J.; Vértesi, R.; Vinogradov, A. A.; Virius, M.; Vrba, V.; Vznuzdaev, E.; Wang, X. R.; Watanabe, D.; Watanabe, K.; Watanabe, Y.; Wei, F.; Wei, R.; Wessels, J.; White, S. N.; Winter, D.; Wood, J. P.; Woody, C. L.; Wright, R. M.; Wysocki, M.; Xie, W.; Yamaguchi, Y. L.; Yamaura, K.; Yang, R.; Yanovich, A.; Ying, J.; Yokkaichi, S.; Young, G. R.; Younus, I.; You, Z.; Yushmanov, I. E.; Zajc, W. A.; Zhang, C.; Zhou, S.; Zolin, L.

    2010-08-01

    Differential measurements of the elliptic (v2) and hexadecapole (v4) Fourier flow coefficients are reported for charged hadrons as a function of transverse momentum (pT) and collision centrality or number of participant nucleons (Npart) for Au+Au collisions at sNN=200GeV. The v2,4 measurements at pseudorapidity |η|≤0.35, obtained with four separate reaction-plane detectors positioned in the range 1.0<|η|<3.9, show good agreement, indicating the absence of significant Δη-dependent nonflow correlations. Sizable values for v4(pT) are observed with a ratio v4(pT,Npart)/v22(pT,Npart)≈0.8 for 50≲Npart≲200, which is compatible with the combined effects of a finite viscosity and initial eccentricity fluctuations. For Npart≳200 this ratio increases up to 1.7 in the most central collisions.

  4. Measurements of Higher Order Flow Harmonics in Au+Au Collisions at sNN=200GeV

    NASA Astrophysics Data System (ADS)

    Adare, A.; Afanasiev, S.; Aidala, C.; Ajitanand, N. N.; Akiba, Y.; Al-Bataineh, H.; Alexander, J.; Aoki, K.; Aramaki, Y.; Atomssa, E. T.; Averbeck, R.; Awes, T. C.; Azmoun, B.; Babintsev, V.; Bai, M.; Baksay, G.; Baksay, L.; Barish, K. N.; Bassalleck, B.; Basye, A. T.; Bathe, S.; Baublis, V.; Baumann, C.; Bazilevsky, A.; Belikov, S.; Belmont, R.; Bennett, R.; Berdnikov, A.; Berdnikov, Y.; Bickley, A. A.; Bok, J. S.; Boyle, K.; Brooks, M. L.; Buesching, H.; Bumazhnov, V.; Bunce, G.; Butsyk, S.; Camacho, C. M.; Campbell, S.; Chen, C.-H.; Chi, C. Y.; Chiu, M.; Choi, I. J.; Choudhury, R. K.; Christiansen, P.; Chujo, T.; Chung, P.; Chvala, O.; Cianciolo, V.; Citron, Z.; Cole, B. A.; Connors, M.; Constantin, P.; Csanád, M.; Csörgő, T.; Dahms, T.; Dairaku, S.; Danchev, I.; Das, K.; Datta, A.; David, G.; Denisov, A.; Deshpande, A.; Desmond, E. J.; Dietzsch, O.; Dion, A.; Donadelli, M.; Drapier, O.; Drees, A.; Drees, K. A.; Durham, J. M.; Durum, A.; Dutta, D.; Edwards, S.; Efremenko, Y. V.; Ellinghaus, F.; Engelmore, T.; Enokizono, A.; En'Yo, H.; Esumi, S.; Fadem, B.; Fields, D. E.; Finger, M.; Finger, M., Jr.; Fleuret, F.; Fokin, S. L.; Fraenkel, Z.; Frantz, J. E.; Franz, A.; Frawley, A. D.; Fujiwara, K.; Fukao, Y.; Fusayasu, T.; Garishvili, I.; Glenn, A.; Gong, H.; Gonin, M.; Goto, Y.; Granier de Cassagnac, R.; Grau, N.; Greene, S. V.; Grosse Perdekamp, M.; Gunji, T.; Gustafsson, H.-Å.; Haggerty, J. S.; Hahn, K. I.; Hamagaki, H.; Hamblen, J.; Han, R.; Hanks, J.; Hartouni, E. P.; Haslum, E.; Hayano, R.; He, X.; Heffner, M.; Hemmick, T. K.; Hester, T.; Hill, J. C.; Hohlmann, M.; Holzmann, W.; Homma, K.; Hong, B.; Horaguchi, T.; Hornback, D.; Huang, S.; Ichihara, T.; Ichimiya, R.; Ide, J.; Ikeda, Y.; Imai, K.; Inaba, M.; Isenhower, D.; Ishihara, M.; Isobe, T.; Issah, M.; Isupov, A.; Ivanischev, D.; Jacak, B. V.; Jia, J.; Jin, J.; Johnson, B. M.; Joo, K. S.; Jouan, D.; Jumper, D. S.; Kajihara, F.; Kametani, S.; Kamihara, N.; Kamin, J.; Kang, J. H.; Kapustinsky, J.; Karatsu, K.; Kawall, D.; Kawashima, M.; Kazantsev, A. V.; Kempel, T.; Khanzadeev, A.; Kijima, K. M.; Kim, B. I.; Kim, D. H.; Kim, D. J.; Kim, E.; Kim, E. J.; Kim, S. H.; Kim, Y. J.; Kinney, E.; Kiriluk, K.; Kiss, Á.; Kistenev, E.; Kochenda, L.; Komkov, B.; Konno, M.; Koster, J.; Kotchetkov, D.; Kozlov, A.; Král, A.; Kravitz, A.; Kunde, G. J.; Kurita, K.; Kurosawa, M.; Kwon, Y.; Kyle, G. S.; Lacey, R.; Lai, Y. S.; Lajoie, J. G.; Lebedev, A.; Lee, D. M.; Lee, J.; Lee, K.; Lee, K. B.; Lee, K. S.; Leitch, M. J.; Leite, M. A. L.; Leitner, E.; Lenzi, B.; Li, X.; Liebing, P.; Linden Levy, L. A.; Liška, T.; Litvinenko, A.; Liu, H.; Liu, M. X.; Love, B.; Luechtenborg, R.; Lynch, D.; Maguire, C. F.; Makdisi, Y. I.; Malakhov, A.; Malik, M. D.; Manko, V. I.; Mannel, E.; Mao, Y.; Masui, H.; Matathias, F.; McCumber, M.; McGaughey, P. L.; Means, N.; Meredith, B.; Miake, Y.; Mignerey, A. C.; Mikeš, P.; Miki, K.; Milov, A.; Mishra, M.; Mitchell, J. T.; Mohanty, A. K.; Morino, Y.; Morreale, A.; Morrison, D. P.; Moukhanova, T. V.; Murata, J.; Nagamiya, S.; Nagle, J. L.; Naglis, M.; Nagy, M. I.; Nakagawa, I.; Nakamiya, Y.; Nakamura, T.; Nakano, K.; Newby, J.; Nguyen, M.; Nouicer, R.; Nyanin, A. S.; O'Brien, E.; Oda, S. X.; Ogilvie, C. A.; Oka, M.; Okada, K.; Onuki, Y.; Oskarsson, A.; Ouchida, M.; Ozawa, K.; Pak, R.; Pantuev, V.; Papavassiliou, V.; Park, I. H.; Park, J.; Park, S. K.; Park, W. J.; Pate, S. F.; Pei, H.; Peng, J.-C.; Pereira, H.; Peresedov, V.; Peressounko, D. Yu.; Pinkenburg, C.; Pisani, R. P.; Proissl, M.; Purschke, M. L.; Purwar, A. K.; Qu, H.; Rak, J.; Rakotozafindrabe, A.; Ravinovich, I.; Read, K. F.; Reygers, K.; Riabov, V.; Riabov, Y.; Richardson, E.; Roach, D.; Roche, G.; Rolnick, S. D.; Rosati, M.; Rosen, C. A.; Rosendahl, S. S. E.; Rosnet, P.; Rukoyatkin, P.; Ružička, P.; Sahlmueller, B.; Saito, N.; Sakaguchi, T.; Sakashita, K.; Samsonov, V.; Sano, S.; Sato, T.; Sawada, S.; Sedgwick, K.; Seele, J.; Seidl, R.; Semenov, A. Yu.; Seto, R.; Sharma, D.; Shein, I.; Shibata, T.-A.; Shigaki, K.; Shimomura, M.; Shoji, K.; Shukla, P.; Sickles, A.; Silva, C. L.; Silvermyr, D.; Silvestre, C.; Sim, K. S.; Singh, B. K.; Singh, C. P.; Singh, V.; Slunečka, M.; Soltz, R. A.; Sondheim, W. E.; Sorensen, S. P.; Sourikova, I. V.; Sparks, N. A.; Stankus, P. W.; Stenlund, E.; Stoll, S. P.; Sugitate, T.; Sukhanov, A.; Sziklai, J.; Takagui, E. M.; Taketani, A.; Tanabe, R.; Tanaka, Y.; Tanida, K.; Tannenbaum, M. J.; Tarafdar, S.; Taranenko, A.; Tarján, P.; Themann, H.; Thomas, T. L.; Togawa, M.; Toia, A.; Tomášek, L.; Torii, H.; Towell, R. S.; Tserruya, I.; Tsuchimoto, Y.; Vale, C.; Valle, H.; van Hecke, H. W.; Vazquez-Zambrano, E.; Veicht, A.; Velkovska, J.; Vértesi, R.; Vinogradov, A. A.; Virius, M.; Vrba, V.; Vznuzdaev, E.; Wang, X. R.; Watanabe, D.; Watanabe, K.; Watanabe, Y.; Wei, F.; Wei, R.; Wessels, J.; White, S. N.; Winter, D.; Wood, J. P.; Woody, C. L.; Wright, R. M.; Wysocki, M.; Xie, W.; Yamaguchi, Y. L.; Yamaura, K.; Yang, R.; Yanovich, A.; Ying, J.; Yokkaichi, S.; You, Z.; Young, G. R.; Younus, I.; Yushmanov, I. E.; Zajc, W. A.; Zhang, C.; Zhou, S.; Zolin, L.

    2011-12-01

    Flow coefficients vn for n=2, 3, 4, characterizing the anisotropic collective flow in Au+Au collisions at sNN=200GeV, are measured relative to event planes Ψn, determined at large rapidity. We report vn as a function of transverse momentum and collision centrality, and study the correlations among the event planes of different order n. The vn are well described by hydrodynamic models which employ a Glauber Monte Carlo initial state geometry with fluctuations, providing additional constraining power on the interplay between initial conditions and the effects of viscosity as the system evolves. This new constraint can serve to improve the precision of the extracted shear viscosity to entropy density ratio η/s.

  5. Transverse momentum dependence of η meson suppression in Au+Au collisions at sNN=200 GeV

    NASA Astrophysics Data System (ADS)

    Adare, A.; Afanasiev, S.; Aidala, C.; Ajitanand, N. N.; Akiba, Y.; Al-Bataineh, H.; Alexander, J.; Aoki, K.; Aphecetche, L.; Aramaki, Y.; Asai, J.; Atomssa, E. T.; Averbeck, R.; Awes, T. C.; Azmoun, B.; Babintsev, V.; Bai, M.; Baksay, G.; Baksay, L.; Baldisseri, A.; Barish, K. N.; Barnes, P. D.; Bassalleck, B.; Basye, A. T.; Bathe, S.; Batsouli, S.; Baublis, V.; Baumann, C.; Bazilevsky, A.; Belikov, S.; Belmont, R.; Bennett, R.; Berdnikov, A.; Berdnikov, Y.; Bickley, A. A.; Boissevain, J. G.; Bok, J. S.; Borel, H.; Boyle, K.; Brooks, M. L.; Buesching, H.; Bumazhnov, V.; Bunce, G.; Butsyk, S.; Camacho, C. M.; Campbell, S.; Chang, B. S.; Chang, W. C.; Charvet, J.-L.; Chen, C.-H.; Chernichenko, S.; Chi, C. Y.; Chiu, M.; Choi, I. J.; Choudhury, R. K.; Christiansen, P.; Chujo, T.; Chung, P.; Churyn, A.; Chvala, O.; Cianciolo, V.; Citron, Z.; Cole, B. A.; Connors, M.; Constantin, P.; Csanád, M.; Csörgő, T.; Dahms, T.; Dairaku, S.; Danchev, I.; Das, K.; Datta, A.; David, G.; Denisov, A.; D'Enterria, D.; Deshpande, A.; Desmond, E. J.; Dietzsch, O.; Dion, A.; Donadelli, M.; Drapier, O.; Drees, A.; Drees, K. A.; Dubey, A. K.; Durham, J. M.; Durum, A.; Dutta, D.; Dzhordzhadze, V.; Edwards, S.; Efremenko, Y. V.; Ellinghaus, F.; Engelmore, T.; Enokizono, A.; En'yo, H.; Esumi, S.; Eyser, K. O.; Fadem, B.; Fields, D. E.; Finger, M., Jr.; Finger, M.; Fleuret, F.; Fokin, S. L.; Fraenkel, Z.; Frantz, J. E.; Franz, A.; Frawley, A. D.; Fujiwara, K.; Fukao, Y.; Fusayasu, T.; Garishvili, I.; Glenn, A.; Gong, H.; Gonin, M.; Gosset, J.; Goto, Y.; Granier de Cassagnac, R.; Grau, N.; Greene, S. V.; Grosse Perdekamp, M.; Gunji, T.; Gustafsson, H.-Å.; Hadj Henni, A.; Haggerty, J. S.; Hahn, K. I.; Hamagaki, H.; Hamblen, J.; Hanks, J.; Han, R.; Hartouni, E. P.; Haruna, K.; Haslum, E.; Hayano, R.; Heffner, M.; Hegyi, S.; Hemmick, T. K.; Hester, T.; He, X.; Hill, J. C.; Hohlmann, M.; Holzmann, W.; Homma, K.; Hong, B.; Horaguchi, T.; Hornback, D.; Huang, S.; Ichihara, T.; Ichimiya, R.; Ide, J.; Iinuma, H.; Ikeda, Y.; Imai, K.; Imrek, J.; Inaba, M.; Isenhower, D.; Ishihara, M.; Isobe, T.; Issah, M.; Isupov, A.; Ivanischev, D.; Jacak, B. V.; Jia, J.; Jin, J.; Johnson, B. M.; Joo, K. S.; Jouan, D.; Jumper, D. S.; Kajihara, F.; Kametani, S.; Kamihara, N.; Kamin, J.; Kang, J. H.; Kapustinsky, J.; Karatsu, K.; Kawall, D.; Kawashima, M.; Kazantsev, A. V.; Kempel, T.; Khanzadeev, A.; Kijima, K. M.; Kikuchi, J.; Kim, B. I.; Kim, D. H.; Kim, D. J.; Kim, E. J.; Kim, E.; Kim, S. H.; Kim, Y. J.; Kinney, E.; Kiriluk, K.; Kiss, Á.; Kistenev, E.; Klay, J.; Klein-Boesing, C.; Kochenda, L.; Komkov, B.; Konno, M.; Koster, J.; Kotchetkov, D.; Kozlov, A.; Král, A.; Kravitz, A.; Kunde, G. J.; Kurita, K.; Kurosawa, M.; Kweon, M. J.; Kwon, Y.; Kyle, G. S.; Lacey, R.; Lai, Y. S.; Lajoie, J. G.; Layton, D.; Lebedev, A.; Lee, D. M.; Lee, J.; Lee, K. B.; Lee, K.; Lee, K. S.; Lee, T.; Leitch, M. J.; Leite, M. A. L.; Leitner, E.; Lenzi, B.; Liebing, P.; Linden Levy, L. A.; Liška, T.; Litvinenko, A.; Liu, H.; Liu, M. X.; Li, X.; Love, B.; Luechtenborg, R.; Lynch, D.; Maguire, C. F.; Makdisi, Y. I.; Malakhov, A.; Malik, M. D.; Manko, V. I.; Mannel, E.; Mao, Y.; Mašek, L.; Masui, H.; Matathias, F.; McCumber, M.; McGaughey, P. L.; Means, N.; Meredith, B.; Miake, Y.; Mignerey, A. C.; Mikeš, P.; Miki, K.; Milov, A.; Mishra, M.; Mitchell, J. T.; Mohanty, A. K.; Morino, Y.; Morreale, A.; Morrison, D. P.; Moukhanova, T. V.; Mukhopadhyay, D.; Murata, J.; Nagamiya, S.; Nagle, J. L.; Naglis, M.; Nagy, M. I.; Nakagawa, I.; Nakamiya, Y.; Nakamura, T.; Nakano, K.; Newby, J.; Nguyen, M.; Niita, T.; Nouicer, R.; Nyanin, A. S.; O'Brien, E.; Oda, S. X.; Ogilvie, C. A.; Okada, K.; Oka, M.; Onuki, Y.; Oskarsson, A.; Ouchida, M.; Ozawa, K.; Pak, R.; Palounek, A. P. T.; Pantuev, V.; Papavassiliou, V.; Park, I. H.; Park, J.; Park, S. K.; Park, W. J.; Pate, S. F.; Pei, H.; Peng, J.-C.; Pereira, H.; Peresedov, V.; Peressounko, D. Yu.; Pinkenburg, C.; Pisani, R. P.; Proissl, M.; Purschke, M. L.; Purwar, A. K.; Qu, H.; Rak, J.; Rakotozafindrabe, A.; Ravinovich, I.; Read, K. F.; Rembeczki, S.; Reygers, K.; Riabov, V.; Riabov, Y.; Richardson, E.; Roach, D.; Roche, G.; Rolnick, S. D.; Rosati, M.; Rosen, C. A.; Rosendahl, S. S. E.; Rosnet, P.; Rukoyatkin, P.; Ružička, P.; Rykov, V. L.; Sahlmueller, B.; Saito, N.; Sakaguchi, T.; Sakai, S.; Sakashita, K.; Samsonov, V.; Sano, S.; Sato, T.; Sawada, S.; Sedgwick, K.; Seele, J.; Seidl, R.; Semenov, A. Yu.; Semenov, V.; Seto, R.; Sharma, D.; Shein, I.; Shibata, T.-A.; Shigaki, K.; Shimomura, M.; Shoji, K.; Shukla, P.; Sickles, A.; Silva, C. L.; Silvermyr, D.; Silvestre, C.; Sim, K. S.; Singh, B. K.; Singh, C. P.; Singh, V.; Slunečka, M.; Soldatov, A.; Soltz, R. A.; Sondheim, W. E.; Sorensen, S. P.; Sourikova, I. V.; Sparks, N. A.; Staley, F.; Stankus, P. W.; Stenlund, E.; Stepanov, M.; Ster, A.; Stoll, S. P.; Sugitate, T.; Suire, C.; Sukhanov, A.; Sziklai, J.; Takagui, E. M.; Taketani, A.; Tanabe, R.; Tanaka, Y.; Tanida, K.; Tannenbaum, M. J.; Tarafdar, S.; Taranenko, A.; Tarján, P.; Themann, H.; Thomas, T. L.; Togawa, M.; Toia, A.; Tomášek, L.; Tomita, Y.; Torii, H.; Towell, R. S.; Tram, V.-N.; Tserruya, I.; Tsuchimoto, Y.; Vale, C.; Valle, H.; van Hecke, H. W.; Vazquez-Zambrano, E.; Veicht, A.; Velkovska, J.; Vértesi, R.; Vinogradov, A. A.; Virius, M.; Vrba, V.; Vznuzdaev, E.; Wang, X. R.; Watanabe, D.; Watanabe, K.; Watanabe, Y.; Wei, F.; Wei, R.; Wessels, J.; White, S. N.; Winter, D.; Wood, J. P.; Woody, C. L.; Wright, R. M.; Wysocki, M.; Xie, W.; Yamaguchi, Y. L.; Yamaura, K.; Yang, R.; Yanovich, A.; Ying, J.; Yokkaichi, S.; Young, G. R.; Younus, I.; You, Z.; Yushmanov, I. E.; Zajc, W. A.; Zaudtke, O.; Zhang, C.; Zhou, S.; Zolin, L.

    2010-07-01

    New measurements by the PHENIX experiment at the Relativistic Heavy Ion Collider for η production at midrapidity as a function of transverse momentum (pT) and collision centrality in sNN=200 GeV Au+Au and p+p collisions are presented. They indicate nuclear modification factors (RAA) which are similar in both magnitude and trend to those found in earlier π0 measurements. Linear fits to RAA as a function of pT in 5-20 GeV/c show that the slope is consistent with zero within two standard deviations at all centralities, although a slow rise cannot be excluded. Having different statistical and systematic uncertainties, the π0 and η measurements are complementary at high pT; thus, along with the extended pT range of these data they can provide additional constraints for theoretical modeling and the extraction of transport properties.

  6. Particularités de la cardiomyopathie du péripartum en Afrique: le cas du Togo sur une étude prospective de 41 cas au Centre Hospitalier et Universitaire Sylvanus Olympio de Lomé

    PubMed Central

    Pio, Machihude; Afassinou, Yaovi; Baragou, Soodougoua; Akue, Edem Goeh; Péssinaba, Souleymane; Atta, Borgatia; Ehlan, Koffi; Alate, Amouzou; Damorou, Findibe

    2014-01-01

    Introduction La cardiomyopathie du péripartum (CMPP) est une défaillance cardiaque dont l’étiologie demeure encore méconnue. Méthodes Il s'agit d'une étude prospective descriptive réalisée dans le service de cardiologie du CHU Sylvanus olympio de Lomé du 1er janvier 2010 au 30 avril 2012. Elle a concerné 41 patientes ayant présenté une insuffisance cardiaque entre le 8eme mois de la grossesse et les 5 premiers mois du post-partum. Résultats L’âge moyen des patientes était de 31,47 ans (extrêmes 21 et 44ans). L'incidence de la CMPP était de 1/362 grossesses. La parité moyenne était de 3,07 (extrêmes 1 et 6). Les symptômes étaient apparus dans le post-partum dans 90,24% des cas. Un retard important de diagnostic était observé. L'insuffisance cardiaque globale était le mode de décompensation dans 65,85%. Les signes électrocardiographiques étaient essentiellement la tachycardie sinusale (97,56%) et l'hypertrophie ventriculaire gauche (97,56%). L’échographie cardiaque a montré dans tous les cas une cardiomyopathie dilatée. Quatre cas de thrombus intraventriculaire gauche étaient notés. La FEVG était sévèrement altérée. L'HTAP était importante dans 56,09%. Conclusion La cardiomyopathie du péripartum est une complication cardiaque grave de la grossesse de cause inconnue, fréquente dans la population africaine. PMID:25309645

  7. Energy hyperspace for stacking interaction in AU/AU dinucleotide step: Dispersion-corrected density functional theory study.

    PubMed

    Mukherjee, Sanchita; Kailasam, Senthilkumar; Bansal, Manju; Bhattacharyya, Dhananjay

    2014-01-01

    Double helical structures of DNA and RNA are mostly determined by base pair stacking interactions, which give them the base sequence-directed features, such as small roll values for the purine-pyrimidine steps. Earlier attempts to characterize stacking interactions were mostly restricted to calculations on fiber diffraction geometries or optimized structure using ab initio calculations lacking variation in geometry to comment on rather unusual large roll values observed in AU/AU base pair step in crystal structures of RNA double helices. We have generated stacking energy hyperspace by modeling geometries with variations along the important degrees of freedom, roll, and slide, which were chosen via statistical analysis as maximally sequence dependent. Corresponding energy contours were constructed by several quantum chemical methods including dispersion corrections. This analysis established the most suitable methods for stacked base pair systems despite the limitation imparted by number of atom in a base pair step to employ very high level of theory. All the methods predict negative roll value and near-zero slide to be most favorable for the purine-pyrimidine steps, in agreement with Calladine's steric clash based rule. Successive base pairs in RNA are always linked by sugar-phosphate backbone with C3'-endo sugars and this demands C1'-C1' distance of about 5.4 Å along the chains. Consideration of an energy penalty term for deviation of C1'-C1' distance from the mean value, to the recent DFT-D functionals, specifically ωB97X-D appears to predict reliable energy contour for AU/AU step. Such distance-based penalty improves energy contours for the other purine-pyrimidine sequences also. © 2013 Wiley Periodicals, Inc. Biopolymers 101: 107-120, 2014. Copyright © 2013 Wiley Periodicals, Inc.

  8. Evolution of π0 Suppression in Au+Au Collisions from sNN=39 to 200 GeV

    NASA Astrophysics Data System (ADS)

    Adare, A.; Afanasiev, S.; Aidala, C.; Ajitanand, N. N.; Akiba, Y.; Akimoto, R.; Al-Ta'ani, H.; Alexander, J.; Angerami, A.; Aoki, K.; Apadula, N.; Aramaki, Y.; Asano, H.; Aschenauer, E. C.; Atomssa, E. T.; Awes, T. C.; Azmoun, B.; Babintsev, V.; Bai, M.; Bannier, B.; Barish, K. N.; Bassalleck, B.; Bathe, S.; Baublis, V.; Baumgart, S.; Bazilevsky, A.; Belmont, R.; Berdnikov, A.; Berdnikov, Y.; Bing, X.; Blau, D. S.; Boyle, K.; Brooks, M. L.; Buesching, H.; Bumazhnov, V.; Butsyk, S.; Campbell, S.; Castera, P.; Chen, C.-H.; Chi, C. Y.; Chiu, M.; Choi, I. J.; Choi, J. B.; Choi, S.; Choudhury, R. K.; Christiansen, P.; Chujo, T.; Chvala, O.; Cianciolo, V.; Citron, Z.; Cole, B. A.; Connors, M.; Csanád, M.; Csörgő, T.; Dairaku, S.; Datta, A.; Daugherity, M. S.; David, G.; Denisov, A.; Deshpande, A.; Desmond, E. J.; Dharmawardane, K. V.; Dietzsch, O.; Ding, L.; Dion, A.; Donadelli, M.; Drapier, O.; Drees, A.; Drees, K. A.; Durham, J. M.; Durum, A.; D'Orazio, L.; Edwards, S.; Efremenko, Y. V.; Engelmore, T.; Enokizono, A.; Esumi, S.; Eyser, K. O.; Fadem, B.; Fields, D. E.; Finger, M.; Finger, M., Jr.; Fleuret, F.; Fokin, S. L.; Frantz, J. E.; Franz, A.; Frawley, A. D.; Fukao, Y.; Fusayasu, T.; Gainey, K.; Gal, C.; Garishvili, A.; Garishvili, I.; Glenn, A.; Gong, X.; Gonin, M.; Goto, Y.; Granier de Cassagnac, R.; Grau, N.; Greene, S. V.; Grosse Perdekamp, M.; Gunji, T.; Guo, L.; Gustafsson, H.-Å.; Hachiya, T.; Haggerty, J. S.; Hahn, K. I.; Hamagaki, H.; Hanks, J.; Hashimoto, K.; Haslum, E.; Hayano, R.; He, X.; Hemmick, T. K.; Hester, T.; Hill, J. C.; Hollis, R. S.; Homma, K.; Hong, B.; Horaguchi, T.; Hori, Y.; Huang, S.; Ichihara, T.; Iinuma, H.; Ikeda, Y.; Imrek, J.; Inaba, M.; Iordanova, A.; Isenhower, D.; Issah, M.; Isupov, A.; Ivanischev, D.; Jacak, B. V.; Javani, M.; Jia, J.; Jiang, X.; Johnson, B. M.; Joo, K. S.; Jouan, D.; Kamin, J.; Kaneti, S.; Kang, B. H.; Kang, J. H.; Kang, J. S.; Kapustinsky, J.; Karatsu, K.; Kasai, M.; Kawall, D.; Kazantsev, A. V.; Kempel, T.; Khanzadeev, A.; Kijima, K. M.; Kim, B. I.; Kim, C.; Kim, D. J.; Kim, E.-J.; Kim, H. J.; Kim, K.-B.; Kim, Y.-J.; Kim, Y. K.; Kinney, E.; Kiss, Á.; Kistenev, E.; Klatsky, J.; Kleinjan, D.; Kline, P.; Komatsu, Y.; Komkov, B.; Koster, J.; Kotchetkov, D.; Kotov, D.; Král, A.; Krizek, F.; Kunde, G. J.; Kurita, K.; Kurosawa, M.; Kwon, Y.; Kyle, G. S.; Lacey, R.; Lai, Y. S.; Lajoie, J. G.; Lebedev, A.; Lee, B.; Lee, D. M.; Lee, J.; Lee, K. B.; Lee, K. S.; Lee, S. H.; Lee, S. R.; Leitch, M. J.; Leite, M. A. L.; Leitgab, M.; Lewis, B.; Lim, S. H.; Linden Levy, L. A.; Litvinenko, A.; Liu, M. X.; Love, B.; Maguire, C. F.; Makdisi, Y. I.; Makek, M.; Malakhov, A.; Manion, A.; Manko, V. I.; Mannel, E.; Masumoto, S.; McCumber, M.; McGaughey, P. L.; McGlinchey, D.; McKinney, C.; Mendoza, M.; Meredith, B.; Miake, Y.; Mibe, T.; Mignerey, A. C.; Milov, A.; Mishra, D. K.; Mitchell, J. T.; Miyachi, Y.; Miyasaka, S.; Mohanty, A. K.; Moon, H. J.; Morrison, D. P.; Motschwiller, S.; Moukhanova, T. V.; Murakami, T.; Murata, J.; Nagae, T.; Nagamiya, S.; Nagle, J. L.; Nagy, M. I.; Nakagawa, I.; Nakamiya, Y.; Nakamura, K. R.; Nakamura, T.; Nakano, K.; Nattrass, C.; Nederlof, A.; Nihashi, M.; Nouicer, R.; Novitzky, N.; Nyanin, A. S.; O'Brien, E.; Ogilvie, C. A.; Okada, K.; Oskarsson, A.; Ouchida, M.; Ozawa, K.; Pak, R.; Pantuev, V.; Papavassiliou, V.; Park, B. H.; Park, I. H.; Park, S. K.; Pate, S. F.; Patel, L.; Pei, H.; Peng, J.-C.; Pereira, H.; Peresedov, V.; Peressounko, D. Yu.; Petti, R.; Pinkenburg, C.; Pisani, R. P.; Proissl, M.; Purschke, M. L.; Qu, H.; Rak, J.; Ravinovich, I.; Read, K. F.; Reynolds, R.; Riabov, V.; Riabov, Y.; Richardson, E.; Roach, D.; Roche, G.; Rolnick, S. D.; Rosati, M.; Rukoyatkin, P.; Sahlmueller, B.; Saito, N.; Sakaguchi, T.; Samsonov, V.; Sano, M.; Sarsour, M.; Sawada, S.; Sedgwick, K.; Seidl, R.; Sen, A.; Seto, R.; Sharma, D.; Shein, I.; Shibata, T.-A.; Shigaki, K.; Shimomura, M.; Shoji, K.; Shukla, P.; Sickles, A.; Silva, C. L.; Silvermyr, D.; Sim, K. S.; Singh, B. K.; Singh, C. P.; Singh, V.; Slunečka, M.; Soltz, R. A.; Sondheim, W. E.; Sorensen, S. P.; Soumya, M.; Sourikova, I. V.; Stankus, P. W.; Stenlund, E.; Stepanov, M.; Ster, A.; Stoll, S. P.; Sugitate, T.; Sukhanov, A.; Sun, J.; Sziklai, J.; Takagui, E. M.; Takahara, A.; Taketani, A.; Tanaka, Y.; Taneja, S.; Tanida, K.; Tannenbaum, M. J.; Tarafdar, S.; Taranenko, A.; Tennant, E.; Themann, H.; Todoroki, T.; Tomášek, L.; Tomášek, M.; Torii, H.; Towell, R. S.; Tserruya, I.; Tsuchimoto, Y.; Tsuji, T.; Vale, C.; van Hecke, H. W.; Vargyas, M.; Vazquez-Zambrano, E.; Veicht, A.; Velkovska, J.; Vértesi, R.; Virius, M.; Vossen, A.; Vrba, V.; Vznuzdaev, E.; Wang, X. R.; Watanabe, D.; Watanabe, K.; Watanabe, Y.; Watanabe, Y. S.; Wei, F.; Wei, R.; White, S. N.; Winter, D.; Wolin, S.; Woody, C. L.; Wysocki, M.; Yamaguchi, Y. L.; Yang, R.; Yanovich, A.; Ying, J.; Yokkaichi, S.; You, Z.; Younus, I.; Yushmanov, I. E.; Zajc, W. A.; Zelenski, A.; Zolin, L.

    2012-10-01

    Neutral-pion π0 spectra were measured at midrapidity (|y|<0.35) in Au+Au collisions at sNN=39 and 62.4 GeV and compared with earlier measurements at 200 GeV in a transverse-momentum range of 1Au+Au collisions have the same power as in p+p collisions is ≈5 and 7GeV/c for sNN=200 and 62.4 GeV, respectively. For the sNN=39GeV data, it is not clear whether such a region is reached, and the xT dependence of the xT-scaling power-law exponent is very different from that observed in the sNN=62 and 200 GeV data, providing further evidence that initial-state effects and soft processes mask the in-medium suppression of hard-scattered partons to higher pT as the collision energy decreases.

  9. La fibroscopie digestive haute chez 2795 patients au centre hospitalier universitaire-campus de Lomé: les particularités selon le sexe

    PubMed Central

    Lawson-Ananissoh, Laté Mawuli; Bouglouga, Oumboma; Bagny, Aklesso; Kaaga, Laconi; Redah, Datouda

    2014-01-01

    Introduction Notre étude consistera à rapporter les indications et les lésions objectivées à la fibroscopie digestive haute et relever les particularités selon le sexe. Méthodes Étude rétrospective, descriptive sur des résultats de compte-rendu de la fibroscopie digestive haute menée en unité d'endoscopie digestive du service d'hépato-gastro-entérologie du CHU Campus de Lomé du 15 Mai 2009 au 31 Décembre 2013. Résultats La fibroscopie digestive haute a été réalisée chez 2795 patients dont 1188 hommes et 1607 femmes. L’âge moyen était de 40,65 ans (Extrêmes: 5 et 93 ans). La fibroscopie digestive haute était normale chez les femmes que chez les hommes avec une différence statistiquement significative (p = 0,000). Les principales indications étaient: les épigastralgies chez les femmes (p = 0,000); les hémorragies digestives hautes (p = 0,000) et l'hypertension portale (p = 0,000) chez les hommes; 3485 lésions pathologiques ont été observées. La pathologie inflammatoire prédominait (56,3%), la pathologie ulcéreuse (13,89%), la pathologie tumorale (2,01%). Les varices et la candidose œsophagiennes étaient significativement notées chez les hommes. Les ulcérations gastriques (p = 0,000), le reflux biliaire duodéno-gastrique (p = 0,017) étaient plus retrouvés chez les femmes et la gastropathie hypertensive beaucoup plus chez les hommes (p = 0,000). Que les lésions duodénales soient inflammatoires ou ulcéreuses associées ou non à une sténose bulbaire, elles étaient plus fréquentes chez les hommes. Conclusion De manière générale, il y avait une prédominance des lésions inflammatoires chez les femmes, les lésions tumorales et ulcéreuses chez les hommes PMID:25852805

  10. Place de la chirurgie dans la prise en charge des cancers du sein chez la femme au Centre Hospitalier Universitaire Yalgado Ouedraogo: à propos de 81 cas

    PubMed Central

    Zongo, Nayi; Millogo-Traore, Timonga Françoise Danielle; Bagre, Sidpawalmdé Carine; Bagué, Abdoul-Halim; Ouangre, Edgar; Zida, Maurice; Bambara, Aboubacar; Bambara, Tozoula Augustin; Traoré, Si Simon

    2015-01-01

    Etudier la place de la chirurgie dans la prise en charge des cancers du sein au centre hospitalier universitaire Yalgado Ouédraogo. Nous avons réalisé une étude prospective et descriptive sur dix (10) mois portant sur la place de la chirurgie dans le cancer du sein. Elle a eu pour cadre les services de gynécologie-obstétrique et de chirurgie viscérale et digestive du centre hospitalier universitaire Yalgado Ouédraogo. Ont été pris en compte les indications, les gestes et les résultats de la chirurgie. Nous avons colligé 81 cancers mammaires. Le délai moyen de consultation a été de 14,26 mois. Les tumeurs T3 à T4 représentaient 82,71% des cas. Trente-huit patientes (46,91%) ont été opérées. La chimiothérapie néo adjuvante a été réalisée dans 29,63% des cas. Trente-quatre patientes (41,97%) étaient opérables d'emblée. Il s'agissait de mastectomie selon Madden dans 94,74% des cas et de chirurgie de propreté dans 2 cas (5,26% des cas). Une chimiothérapie adjuvante a été réalisée chez 52,63% des patientes opérées. Des complications à type de lymphocèle ont été notées dans 23,68% des cas. Leur traitement a consisté en des ponctions évacuatrices. Les indications de la chirurgie sont limitées par le retard diagnostique corollaire de stades avancés des cancers du sein. L'absence de la radiothérapie rend délicate la pratique de la chirurgie conservatrice et la mastectomie occupe toujours une place importante. Un diagnostic précoce permettrait d'augmenter les indications chirurgicales. PMID:26848364

  11. Diabète en milieu urbain de Ouagadougou au Burkina Faso: profil épidémiologique et niveau de perception de la population adulte

    PubMed Central

    Millogo, Georges Rosario Christian; Yaméogo, Clément; Samandoulougou, André; Yaméogo, Nobila Valentin; Kologo, Koudougou Jonas; Toguyeni, Jean Yves; Zabsonré, Patrice

    2015-01-01

    Introduction L'accroissement rapide de la prévalence du diabète sucré en Afrique subsaharienne constitue un problème de santé public. L'Organisation Mondiale de la Santé (OMS) estime qu’à l'horizon 2025, l'augmentation la plus significative de la prévalence du diabète sera enregistrée dans les pays en développement. Ceux-ci devraient abriter 75% des patients diabétiques du monde. Outre ses complications métaboliques, le diabète est un facteur de risque cardiovasculaire majeur. Le but de notre étude était de decrire le profil épidémiologique du diabète et d’évaluer le niveau de perception de la maladie par une population africaine en milieu urb qwqain de Ouagadougou. Méthodes Le diabète a été défini chez tout sujet ayant une glycémie casuelle supérieure à 2 g/L ou une glycémie à jeun supérieur ou égale à 1,26 g/L (≥ 7 mmol/L) à deux controles d'une semaine d'intervalle. Etaient considérés diabétique, les sujets déjà suivis et ceux nouvellement dépistés par l'etude. Résultats L’étude a inclus 1532 personnes, d’âge compris entre 25 et 64 ans dont 55,6% d'hommes et 44,4% de femmes. L’âge moyen était 36,10 ± 11,19 ans. La tranche d’âge de 25 à 34 ans était la plus représentée avec une proportion de 57,1%. La glycémie moyenne était de 1,04 g/L, la proportion des femmes ayant une hyperglycémie était statistiquement plus importante que celle des hommes (p< 0,05). Près de 81,3% de la population ignoraient que le diabète était un facteur de risque cardiovasculaire. Conclusion Il est urgent de mettre en place un programme national de lutte contre le diabète sucré et les autres maladies non transmissibles au Burkina Faso. PMID:26524982

  12. Syndrome hémolytique et urémique de l'enfant au Centre Hospitalier Universitaire (CHU) de Dakar: à propos de quatre observations

    PubMed Central

    Thiongane, Aliou; Ndongo, Aliou Abdoulaye; Ba, Idrissa Demba; Boiro, Djibril; Faye, Papa Moctar; Keita, Younoussa; Ba, Aïssatou; Cissé, Djeynaba Fafa; Basse, Idrissa; Thiam, Lamine; Ly, Indou Déme; Niang, Babacar; Ba, Abou; Fall, Amadou Lamine; Diouf, Saliou; Ndiaye, Ousmane; Ba, Mamadou; Sarr, Mamadou

    2016-01-01

    Le syndrome hémolytique et urémique (SHU) est une cause fréquente d'insuffisance rénale aiguë (IRA) organique chez l'enfant. C'est une complication évolutive des gastroentérites aiguës (GEA) en particulier à Escherichia coli de l'enfant. Notre objectif était de décrire les aspects cliniques, thérapeutiques et évolutifs de cette affection chez quatre enfants. Nous avions colligé quatre cas de SHU. L’âge moyen était de 10,5 mois (5-15mois) exclusivement des garçons. L'examen clinique retrouvait une anémie de type hémolytique (pâleur et ictére), un syndrome oedémateux avec oligo-anurie (2 cas), une hypertension artérielle (1 patient), une GEA avec déshydratation sévère et choc hypovolémique (2 patients), des troubles de conscience. L'IRA était notée chez tous les patients de même que la thrombopénie et les schizocytes au frottis. Le Coombs direct était négatif. Il y avait une hyperkaliémie (3patients) dont 1 patient supérieure à 9,2 mmol/l, une hyponatrémie à 129mmol/l(1 patient) et une hypernatrémie à 153mmol/l (1 patient). Le shu était secondaire à une pneumonie à pneumocoque (1 patient), une GEA à E. coli (1 patient). Le traitement était essentiellement symptomatique et comprenait la restriction hydrique, la transfusion de concentrés érythrocytaires, les diurétiques, la dialyse péritonéale et l'hémodialyse. L’évolution était marquée par la survenue d'une insuffisance rénale chronique (1 patient) après 6 mois de suivi et la guérison (1 cas). Nous avions noté 3décés. Le SHU est la cause la plus fréquente d'IRA organique du nourrisson. Le diagnostic est essentiellement biologique, le traitement est surtout symptomatique. PMID:27642476

  13. Bonding properties of FCC-like Au 44 (SR) 28 clusters from X-ray absorption spectroscopy

    SciTech Connect

    Yang, Rui; Chevrier, Daniel M.; Zeng, Chenjie

    2017-11-01

    Thiolate-protected gold clusters with precisely controlled atomic composition have recently emerged as promising candidates for a variety of applications because of their unique optical, electronic, and catalytic properties. The recent discovery of the Au44(SR)28 total structure is considered as an interesting finding in terms of the face-centered cubic (FCC)-like core structure in small gold-thiolate clusters. Herein, the unique bonding properties of Au44(SR)28 is analyzed using temperature-dependent X-ray absorption spectroscopy (XAS) measurements at the Au L3-edge and compared with other FCC-like clusters such as Au36(SR)24 and Au28(SR)20. A negative thermal expansion was detected for the Au–Au bonds of the metal coremore » (the first Au–Au shell) and was interpreted based on the unique Au core structure consisting of the Au4 units. EXAFS fitting results from Au28(SR)20, Au36(SR)24, and Au44(SR)28 show a size-dependent negative thermal expansion behavior in the first Au–Au shell, further highlighting the importance of the Au4 units in determining the Au core bonding properties and shedding light on the growth mechanism of these FCC-like Au clusters.« less

  14. Antibacterial activity of Ag-Au alloy NPs and chemical sensor property of Au NPs synthesized by dextran.

    PubMed

    Bankura, Kalipada; Maity, Dipanwita; Mollick, Md Masud Rahaman; Mondal, Dibyendu; Bhowmick, Biplab; Roy, Indranil; Midya, Tarapada; Sarkar, Joy; Rana, Dipak; Acharya, Krishnendu; Chattopadhyay, Dipankar

    2014-07-17

    Gold and silver-gold alloy nanoparticles with mean diameter of 10nm and narrow size distribution were prepared by reduction of the correspondent metal precursors using aqueous dextran solution which acts as both a reducing and capping agent. The formation of nanoparticles was characterized by UV-vis spectroscopy, transmission electron microscopy (TEM), X-ray diffraction (XRD) and dynamic light scattering (DLS). The silver and gold nanoparticles exhibited absorption maxima at 425 and 551 nm respectively; while for the bimetallic Ag-Au alloy appeared 520 nm in between them. TEM images showed monodispersed particles in the range of 8-10nm. The crystallinity of the nanoparticles was assured by XRD analysis. DLS data gave particle size distribution. The dextran stabilized Au nanoparticles used as a colorimetric sensor for detection and estimation of pesticide present in water. The dextran stabilized Ag-Au alloy nanoparticles exhibited interesting antimicrobial activity against bacteria at micromolar concentrations. Copyright © 2014 Elsevier Ltd. All rights reserved.

  15. J/ψ suppression at forward rapidity in Au + Au collisions at sNN=200 GeV

    NASA Astrophysics Data System (ADS)

    Adare, A.; Afanasiev, S.; Aidala, C.; Ajitanand, N. N.; Akiba, Y.; Al-Bataineh, H.; Alexander, J.; Aoki, K.; Aramaki, Y.; Atomssa, E. T.; Averbeck, R.; Awes, T. C.; Azmoun, B.; Babintsev, V.; Bai, M.; Baksay, G.; Baksay, L.; Barish, K. N.; Bassalleck, B.; Basye, A. T.; Bathe, S.; Baublis, V.; Baumann, C.; Bazilevsky, A.; Belikov, S.; Belmont, R.; Bennett, R.; Berdnikov, A.; Berdnikov, Y.; Bickley, A. A.; Bok, J. S.; Boyle, K.; Brooks, M. L.; Buesching, H.; Bumazhnov, V.; Bunce, G.; Butsyk, S.; Camacho, C. M.; Campbell, S.; Chen, C.-H.; Chi, C. Y.; Chiu, M.; Choi, I. J.; Choudhury, R. K.; Christiansen, P.; Chujo, T.; Chung, P.; Chvala, O.; Cianciolo, V.; Citron, Z.; Cole, B. A.; Connors, M.; Constantin, P.; Csanád, M.; Csörgő, T.; Dahms, T.; Dairaku, S.; Danchev, I.; Das, K.; Datta, A.; David, G.; Denisov, A.; Deshpande, A.; Desmond, E. J.; Dietzsch, O.; Dion, A.; Donadelli, M.; Drapier, O.; Drees, A.; Drees, K. A.; Durham, J. M.; Durum, A.; Dutta, D.; Edwards, S.; Efremenko, Y. V.; Ellinghaus, F.; Engelmore, T.; Enokizono, A.; En'yo, H.; Esumi, S.; Fadem, B.; Fields, D. E.; Finger, M., Jr.; Finger, M.; Fleuret, F.; Fokin, S. L.; Fraenkel, Z.; Frantz, J. E.; Franz, A.; Frawley, A. D.; Fujiwara, K.; Fukao, Y.; Fusayasu, T.; Garishvili, I.; Glenn, A.; Gong, H.; Gonin, M.; Goto, Y.; Granier de Cassagnac, R.; Grau, N.; Greene, S. V.; Grosse Perdekamp, M.; Gunji, T.; Gustafsson, H.-Å.; Haggerty, J. S.; Hahn, K. I.; Hamagaki, H.; Hamblen, J.; Hanks, J.; Han, R.; Hartouni, E. P.; Haslum, E.; Hayano, R.; Heffner, M.; Hemmick, T. K.; Hester, T.; He, X.; Hill, J. C.; Hohlmann, M.; Holzmann, W.; Homma, K.; Hong, B.; Horaguchi, T.; Hornback, D.; Huang, S.; Ichihara, T.; Ichimiya, R.; Ide, J.; Ikeda, Y.; Imai, K.; Inaba, M.; Isenhower, D.; Ishihara, M.; Isobe, T.; Issah, M.; Isupov, A.; Ivanischev, D.; Jacak, B. V.; Jia, J.; Jin, J.; Johnson, B. M.; Joo, K. S.; Jouan, D.; Jumper, D. S.; Kajihara, F.; Kametani, S.; Kamihara, N.; Kamin, J.; Kang, J. H.; Kapustinsky, J.; Karatsu, K.; Kawall, D.; Kawashima, M.; Kazantsev, A. V.; Kempel, T.; Khanzadeev, A.; Kijima, K. M.; Kim, B. I.; Kim, D. H.; Kim, D. J.; Kim, E. J.; Kim, E.; Kim, S. H.; Kim, Y. J.; Kinney, E.; Kiriluk, K.; Kiss, Á.; Kistenev, E.; Kochenda, L.; Komkov, B.; Konno, M.; Koster, J.; Kotchetkov, D.; Kozlov, A.; Král, A.; Kravitz, A.; Kunde, G. J.; Kurita, K.; Kurosawa, M.; Kwon, Y.; Kyle, G. S.; Lacey, R.; Lai, Y. S.; Lajoie, J. G.; Lebedev, A.; Lee, D. M.; Lee, J.; Lee, K. B.; Lee, K.; Lee, K. S.; Leitch, M. J.; Leite, M. A. L.; Leitner, E.; Lenzi, B.; Liebing, P.; Linden Levy, L. A.; Liška, T.; Litvinenko, A.; Liu, H.; Liu, M. X.; Li, X.; Love, B.; Luechtenborg, R.; Lynch, D.; Maguire, C. F.; Makdisi, Y. I.; Malakhov, A.; Malik, M. D.; Manko, V. I.; Mannel, E.; Mao, Y.; Masui, H.; Matathias, F.; McCumber, M.; McGaughey, P. L.; Means, N.; Meredith, B.; Miake, Y.; Mignerey, A. C.; Mikeš, P.; Miki, K.; Milov, A.; Mishra, M.; Mitchell, J. T.; Mohanty, A. K.; Morino, Y.; Morreale, A.; Morrison, D. P.; Moukhanova, T. V.; Murata, J.; Nagamiya, S.; Nagle, J. L.; Naglis, M.; Nagy, M. I.; Nakagawa, I.; Nakamiya, Y.; Nakamura, T.; Nakano, K.; Newby, J.; Nguyen, M.; Nouicer, R.; Nyanin, A. S.; O'Brien, E.; Oda, S. X.; Ogilvie, C. A.; Okada, K.; Oka, M.; Onuki, Y.; Oskarsson, A.; Ouchida, M.; Ozawa, K.; Pak, R.; Pantuev, V.; Papavassiliou, V.; Park, I. H.; Park, J.; Park, S. K.; Park, W. J.; Pate, S. F.; Pei, H.; Peng, J.-C.; Pereira, H.; Peresedov, V.; Peressounko, D. Yu.; Pinkenburg, C.; Pisani, R. P.; Proissl, M.; Purschke, M. L.; Purwar, A. K.; Qu, H.; Rak, J.; Rakotozafindrabe, A.; Ravinovich, I.; Read, K. F.; Reygers, K.; Riabov, V.; Riabov, Y.; Richardson, E.; Roach, D.; Roche, G.; Rolnick, S. D.; Rosati, M.; Rosen, C. A.; Rosendahl, S. S. E.; Rosnet, P.; Rukoyatkin, P.; Ružička, P.; Sahlmueller, B.; Saito, N.; Sakaguchi, T.; Sakashita, K.; Samsonov, V.; Sano, S.; Sato, T.; Sawada, S.; Sedgwick, K.; Seele, J.; Seidl, R.; Semenov, A. Yu.; Seto, R.; Sharma, D.; Shein, I.; Shibata, T.-A.; Shigaki, K.; Shimomura, M.; Shoji, K.; Shukla, P.; Sickles, A.; Silva, C. L.; Silvermyr, D.; Silvestre, C.; Sim, K. S.; Singh, B. K.; Singh, C. P.; Singh, V.; Slunečka, M.; Soltz, R. A.; Sondheim, W. E.; Sorensen, S. P.; Sourikova, I. V.; Sparks, N. A.; Stankus, P. W.; Stenlund, E.; Stoll, S. P.; Sugitate, T.; Sukhanov, A.; Sziklai, J.; Takagui, E. M.; Taketani, A.; Tanabe, R.; Tanaka, Y.; Tanida, K.; Tannenbaum, M. J.; Tarafdar, S.; Taranenko, A.; Tarján, P.; Themann, H.; Thomas, T. L.; Togawa, M.; Toia, A.; Tomášek, L.; Torii, H.; Towell, R. S.; Tserruya, I.; Tsuchimoto, Y.; Vale, C.; Valle, H.; van Hecke, H. W.; Vazquez-Zambrano, E.; Veicht, A.; Velkovska, J.; Vértesi, R.; Vinogradov, A. A.; Virius, M.; Vrba, V.; Vznuzdaev, E.; Wang, X. R.; Watanabe, D.; Watanabe, K.; Watanabe, Y.; Wei, F.; Wei, R.; Wessels, J.; White, S. N.; Winter, D.; Wood, J. P.; Woody, C. L.; Wright, R. M.; Wysocki, M.; Xie, W.; Yamaguchi, Y. L.; Yamaura, K.; Yang, R.; Yanovich, A.; Ying, J.; Yokkaichi, S.; Young, G. R.; Younus, I.; You, Z.; Yushmanov, I. E.; Zajc, W. A.; Zhang, C.; Zhou, S.; Zolin, L.

    2011-11-01

    Heavy quarkonia are observed to be suppressed in relativistic heavy-ion collisions relative to their production in p+p collisions scaled by the number of binary collisions. In order to determine if this suppression is related to color screening of these states in the produced medium, one needs to account for other nuclear modifications including those in cold nuclear matter. In this paper, we present new measurements from the PHENIX 2007 data set of J/ψ yields at forward rapidity (1.2<|y|<2.2) in Au+Au collisions at sNN=200 GeV. The data confirm the earlier finding that the suppression of J/ψ at forward rapidity is stronger than at midrapidity, while also extending the measurement to finer bins in collision centrality and higher transverse momentum (pT). We compare the experimental data to the most recent theoretical calculations that incorporate a variety of physics mechanisms including gluon saturation, gluon shadowing, initial-state parton energy loss, cold nuclear matter breakup, color screening, and charm recombination. We find J/ψ suppression beyond cold-nuclear-matter effects. However, the current level of disagreement between models and d+Au data precludes using these models to quantify the hot-nuclear-matter suppression.

  16. Accouchement de jumeaux conjoints de découverte fortuite au cours du travail au CHU de Dakar

    PubMed Central

    Guèye, Mamour; Guèye, Serigne Modou Kane; Guèye, Mame Diarra Ndiaye; Diouf, Abdoul Aziz; Niang, Mouhamadou Mansour; Diallo, Moussa; Cissé, Mamadou Lamine; Moreau, Jean Charles

    2012-01-01

    L'objectif de cette étude était de rapporter 3 cas de jumeaux conjoints, discuter de l'importance du diagnostic anténatal et de décrire les particularités diagnostiques, thérapeutiques et évolutives. Sur 45700 accouchements du 1er Février 2009 au 31 Décembre 2011, 3 cas de jumeaux conjoints ont été enregistrés, soit 1 cas pour 15000 accouchements. Ces cas ont été diagnostiqués au cours du travail au décours d'une dystocie mécanique ou d'une césarienne réalisée pour une autre indication. Il s'agissait d'un cas de jumeaux conjoints thoraco-omphalopages, un cas de diprosopes et un cas de dicéphales. L'accouchement dans les trois cas était fait par voie haute permettant d'extraire des mort-nés frais. Nous insistons sur l'intérêt d'un diagnostic anténatal précoce par le recours à l’échographie afin d’éviter les accidents mécaniques d'un accouchement qui ne saurait s'accomplir par voie basse. PMID:23133702

  17. L’hyperthyroïdie de l’enfant au centre hospitalier universitaire de Dakar (Sénégal)

    PubMed Central

    Boiro, Djibril; Diédhiou, Demba; Niang, Babacar; Sow, Djiby; Mbodj, Mandiaye; Sarr, Anna; Ndongo, Aliou Abdoulaye; Thiongane, Aliou; Guèye, Modou; Thiam, Lamine; Seck, Ndiogou; Dieng, Yaay Joor; Ba, Abou; Ba, Idrissa Demba; Diallo, Ibrahima Mané; Ndiaye, Ousmane; Diop, Said Nourou

    2017-01-01

    Introduction L'hyperthyroïdie de l'enfant semble rare et constitue un problème de par son retentissement psychosomatique. L’objectif était de faire le point sur ses aspects épidémiologiques et diagnostiques chez l’enfant à Dakar. Méthodes Il s'agissait d'une étude multicentrique, descriptive sur 15 ans. Etaient analysés les aspects épidémiologiques, cliniques et étiologiques. Résultats 239 patients sélectionnés avec une prévalence de 2.4%, un sex ratio (H/F) de 0.36, un âge moyen de 10.8 ans. À l'inclusion, il s'agissait d'un ainé de famille (26.3%), d'une croissance avancée (36.9%), retardée (12.5%), d'une corpulence insuffisante (40.1%). L'étiologie était la maladie de Basedow dans 90.3% avec un facteur psychoaffectif dans 22.1%. Sur le plan clinique, prédominaient la tachycardie (92.4%), le goitre (91.1%), l'exophtalmie (81.8%), l'amaigrissement (69.8%) avec cependant une énurésie (30.2%) et des manifestations psychiques (3.1%). Les manifestations cardiovasculaires et cutanées étaient positivement associées avec l'âge (p < 0.05). Le goitre était associé au sexe féminin (p = 0.005), aux signes cardiovasculaires (p = 0.02), neuropsychiques (p = 0.03), cutanées (p = 0.03) et à la diarrhée (p = 0.03). La T4 libre était corrélée à l'âge (p = 0.007), la diarrhée (p = 0.021), l'anxiété (p = 0.024), la fréquence cardiaque (p = 0.00) et la maladie de Basedow (p = 0.04). Plus le goitre était volumineux, plus était augmentée la T4 libre (p = 0.007). Conclusion Conclusion: L'hyperthyroïdie de l'enfant se différencie de celle de l'adulte par les facteurs d'induction, les perturbations sur la croissance et l'énurésie. L’âge et le sexe semble favoriser le tableau clinique de thyrotoxicose et les signes associés. PMID:29138656

  18. A facile and green strategy for the synthesis of Au, Ag and Au-Ag alloy nanoparticles using aerial parts of R. hypocrateriformis extract and their biological evaluation.

    PubMed

    Godipurge, S S; Yallappa, S; Biradar, Naveen J; Biradar, J S; Dhananjaya, B L; Hegde, Gajanan; Jagadish, K; Hegde, Gurumurthy

    2016-12-01

    A facile and green strategy is reported here to synthesize gold (Au), silver (Ag) and gold-silver (Au-Ag) alloy nanoparticles (NPs) through bio-reduction reactions of aqueous corresponding metal precursors mediated by extracts of aerial parts of R. hypocrateriformis, which act as both reducing and stabilizing agents, under microwave irradiation. UV-vis spectrophotometer, XRD, FT-IR, FESEM/TEM, TGA and EDAX analysis were used to characterize the obtained NPs. The formation of NPs is evident from their surface plasmon resonance peak observed at λ max =∼550, 450 and 500nm for Au, Ag and Au-Ag alloy NPs respectively. XRD pattern revealed that fcc structure, while FT-IR spectra signify the presence of phytochemicals adsorbed on NPs. Such a biofunctionalized NPs were characterized by their weight loss, 30% due to thermal degradation of plant phytochemicals observed in TG analysis. The spherical shape of Au, Ag and Au-Ag alloy NPs (∼10-50nm) is observed by FE-SEM/TEM images. EDAX analysis confirms the expected elemental composition. Moreover, these NPs showed enhanced antimicrobial, antioxidant, and anticancer activities, though it is more pronounced for Au-Ag alloy NPs, which is due to the combining effect of phytochemicals, Au and Ag metals. Thus, the biosynthesized NPs could be applied as effective growth inhibitors for various biomedical applications. Copyright © 2016 Elsevier Inc. All rights reserved.

  19. Ag@Au concave cuboctahedra: A unique probe for monitoring Au-catalyzed reduction and oxidation reactions by surface-enhanced Raman spectroscopy

    DOE PAGES

    Zhang, Jiawei; Winget, Sarah A.; Wu, Yiren; ...

    2016-01-26

    In this paper, we report a facile synthesis of Ag@Au concave cuboctahedra by titrating aqueous HAuCl4 into a suspension of Ag cuboctahedra in the presence of ascorbic acid (AA), NaOH, and poly(vinylpyrrolidone) (PVP) at room temperature. Initially, the Au atoms derived from the reduction of Au 3+ by AA are conformally deposited on the entire surface of a Ag cuboctahedron. Upon the formation of a complete Au shell, however, the subsequently formed Au atoms are preferentially deposited onto the Au{100} facets, resulting in the formation of a Ag@Au cuboctahedron with concave structures at the sites of {111} facets. The concavemore » cuboctahedra embrace excellent SERS activity that is more than 70-fold stronger than that of the original Ag cuboctahedra at an excitation wavelength of 785 nm. The concave cuboctahedra also exhibit remarkable stability in the presence of an oxidant such as H 2O 2 because of the protection by a complete Au shell. These two unique attributes enable in-situ SERS monitoring of the reduction of 4-nitrothiophenol (4-NTP) to 4-aminothiophenol (4-ATP) by NaBH4 through a 4,4'-dimercaptoazobenzene ( trans-DMAB) intermediate and the subsequent oxidation of 4-ATP back to trans-DMAB upon the introduction of H 2O 2.« less

  20. (Tl, Au)/Si(1 1 1)[Formula: see text] 2D compound: an ordered array of identical Au clusters embedded in Tl matrix.

    PubMed

    Mihalyuk, A N; Hsing, C R; Wei, C M; Eremeev, S V; Bondarenko, L V; Tupchaya, A Y; Gruznev, D V; Zotov, A V; Saranin, A A

    2018-01-17

    Formation of the highly-ordered [Formula: see text]-periodicity 2D compound has been detected in the (Tl, Au)/Si(1 1 1) system as a result of Au deposition onto the Tl/Si(1 1 1) surface, its composition, structure and electronic properties have been characterized using scanning tunneling microscopy, angle-resolved photoelectron spectroscopy and density-functional-theory calculations. On the basis of these data, the structural model of the Tl-Au compound has been proposed, which adopts 12 Tl atoms and 10 Au atoms (in total, 22 atoms) per [Formula: see text] unit cell, i.e.  ∼1.71 ML of Tl and  ∼1.43 ML of Au (in total, ∼3.14 ML). Qualitatively, the model can be visualized as consisting of truncated-pyramid-like Au clusters with a Tl atom on top, while the other Tl atoms form a double layer around the Au clusters. The (Tl, Au)/Si(1 1 1)[Formula: see text] compound has been found to exhibit pronounced metallic properties at least down to temperatures as low as  ∼25 K, which makes it a promising object for studying electrical transport phenomena in the 2D metallic systems.

  1. (Tl, Au)/Si(1 1 1){\\sqrt7 \\times \\sqrt7} 2D compound: an ordered array of identical Au clusters embedded in Tl matrix

    NASA Astrophysics Data System (ADS)

    Mihalyuk, A. N.; Hsing, C. R.; Wei, C. M.; Eremeev, S. V.; Bondarenko, L. V.; Tupchaya, A. Y.; Gruznev, D. V.; Zotov, A. V.; Saranin, A. A.

    2018-01-01

    Formation of the highly-ordered \\sqrt7 × \\sqrt7 -periodicity 2D compound has been detected in the (Tl, Au)/Si(1 1 1) system as a result of Au deposition onto the Tl/Si(1 1 1) surface, its composition, structure and electronic properties have been characterized using scanning tunneling microscopy, angle-resolved photoelectron spectroscopy and density-functional-theory calculations. On the basis of these data, the structural model of the Tl-Au compound has been proposed, which adopts 12 Tl atoms and 10 Au atoms (in total, 22 atoms) per \\sqrt7 × \\sqrt7 unit cell, i.e.  ˜1.71 ML of Tl and  ˜1.43 ML of Au (in total, ˜3.14 ML). Qualitatively, the model can be visualized as consisting of truncated-pyramid-like Au clusters with a Tl atom on top, while the other Tl atoms form a double layer around the Au clusters. The (Tl, Au)/Si(1 1 1)\\sqrt7 × \\sqrt7 compound has been found to exhibit pronounced metallic properties at least down to temperatures as low as  ˜25 K, which makes it a promising object for studying electrical transport phenomena in the 2D metallic systems.

  2. Template growth of Au, Ni and Ni–Au nanoclusters on hexagonal boron nitride/Rh(111): a combined STM, TPD and AES study

    DOE PAGES

    Wu, Fanglue; Huang, Dali; Yue, Yuan; ...

    2017-09-12

    In this study, the template growth of Au, Ni, and Ni–Au bimetallic nanoclusters on hexagonal boron nitride/Rh(111), i.e. h-BN/Rh(111), was investigated via scanning tunneling microscopy (STM), temperature programmed-desorption (TPD), and Auger electron spectroscopy (AES). STM study shows that template growth of Au clusters on h-BN/Rh(111) forms mainly well-dispersed monolayer clusters. In contrast, Ni forms large multilayer clusters showing a relatively high diffusivity on h-BN/Rh(111) substrate. Ni–Au bimetallic clusters are effectively formed first by Au deposition followed by Ni deposition, with the Au clusters functioning as nucleation sites for the subsequently deposited Ni. Further structural analysis was carried out via TPDmore » and AES. The resulting TPD and AES data show the surface composition and charge transfer between Au and Ni of the bimetallic clusters. These results suggest that the h-BN/Rh(111) substrate represents a unique candidate for supporting Ni–Au bimetallic clusters in further catalytic reactions.« less

  3. Au@Pd Bimetallic Nanocatalyst for Carbon-Halogen Bond Cleavage: An Old Story with New Insight into How the Activity of Pd is Influenced by Au.

    PubMed

    Liu, Rui; Chen, Hui-Min; Fang, Li-Ping; Xu, Cuihong; He, Zuoliang; Lai, Yujian; Zhao, Huachao; Bekana, Deribachew; Liu, Jing-Fu

    2018-03-21

    AuPd bimetallic nanocatalysts exhibit superior catalytic performance in the cleavage of carbon-halogen bonds (C-X) in the hazardous halogenated pollutants. A better understanding of how Au atoms promote the reactivity of Pd sites rather than vaguely interpreting as bimetallic effect and determining which type of Pd sites are necessary for these reactions are crucial factors for the design of atomically precise nanocatalysts that make full use of both the Pd and Au atoms. Herein, we systematically manipulated the coordination number of Pd-Pd, d-orbital occupation state, and the Au-Pd interface of the Pd reactive centers and studied the structure-activity relationship of Au-Pd in the catalyzed cleavage of C-X bonds. It is revealed that Au enhanced the activity of Pd atoms primarily by increasing the occupation state of Pd d-orbitals. Meanwhile, among the Pd sites formed on the Au surface, five to seven contiguous Pd atoms, three or four adjacent Pd atoms, and isolated Pd atoms were found to be the most active in the cleavage of C-Cl, C-Br, and C-I bonds, respectively. Besides, neighboring Au atoms directly contribute to the weakening of the C-Br/C-I bond. This work provides new insight into the rational design of bimetallic metal catalysts with specific catalytic properties.

  4. Transformation of Au144(SCH2CH2Ph)60 to Au133(SPh-tBu)52 Nanomolecules: Theoretical and Experimental Study.

    PubMed

    Nimmala, Praneeth Reddy; Theivendran, Shevanuja; Barcaro, Giovanni; Sementa, Luca; Kumara, Chanaka; Jupally, Vijay Reddy; Apra, Edoardo; Stener, Mauro; Fortunelli, Alessandro; Dass, Amala

    2015-06-04

    Ultrastable gold nanomolecule Au144(SCH2CH2Ph)60 upon etching with excess tert-butylbenzenethiol undergoes a core-size conversion and compositional change to form an entirely new core of Au133(SPh-tBu)52. This conversion was studied using high-resolution electrospray mass spectrometry which shows that the core size conversion is initiated after 22 ligand exchanges, suggesting a relatively high stability of the Au144(SCH2CH2Ph)38(SPh-tBu)22 intermediate. The Au144 → Au133 core size conversion is surprisingly different from the Au144 → Au99 core conversion reported in the case of thiophenol, -SPh. Theoretical analysis and ab initio molecular dynamics simulations show that rigid p-tBu groups play a crucial role by reducing the cluster structural freedom, and protecting the cluster from adsorption of exogenous and reactive species, thus rationalizing the kinetic factors that stabilize the Au133 core size. This 144-atom to 133-atom nanomolecule's compositional change is reflected in optical spectroscopy and electrochemistry.

  5. Determination of Impact Parameters in Aligned Breakup of Projectile-like Fragments in $$^{197}$$Au + $$^{197}$$Au Collisions at 23$A$MeV

    DOE PAGES

    Cap, T.; Siwek-Wilczyńska, K.; Wilczynski, J.; ...

    2016-03-01

    Symmetric and asymmetric aligned breakup of projectile-like fragments inmore » $$^{197}$$Au + $$^{197}$$Au collisions at 23$A$,MeV was studied. Independently of the asymmetry, the reaction yields have been found peaked at a common, very narrow range of impact parameters.« less

  6. The Effect of Au/Ag Bimetallic Thin-Films on Surface Plasmon Resonance Properties Comparing with Those of Au and Ag Single Thin-Films.

    PubMed

    Kim, Seon Hoon; Kim, Tae Un; Jung, Haeng Yun; Ki, Hyun Chul; Kim, Doo Gun; Lee, Byung-Teak

    2018-03-01

    The surface plasmon resonance (SPR) properties of Au/Ag bimetallic thin-film nanostructures were investigated to improve the chemical stability and the figure of merit (FOM) in the SPR sensors. The SPR characteristics such as resonance angle, extinction ratio, and full width half maximum (FWHM) were calculated by the simulation of the finite-difference time-domain method and were measured using the laser with a 632.8 nm wavelength in the Kretschmann-Raether configuration. The measured resonance angle, extinction ratio, FWHM of Au(20 nm)/Ag(20 nm) thin-film nanostructure were found to be 44°, 0.8, and 1.4°, respectively. The FOM values were determined to be 56.9 for Au/Ag bimetallic thin-film, 47.9 for Au(50 nm) single thin-film, and 89.1 for Ag(50 nm) single thin-film. Also the sensitivity values were about 53.5, 57.0, and 57.8°/RIU for Au(50 nm), Ag(50 nm), and Au(20 nm)/Ag(20 nm) thin-film nanostructures in the SPR sensors, respectively. The SPR properties of Au/Ag bimetallic thin-film nanostructures were compared with those of the Au and Ag single thin-film nanostructures.

  7. Composite of Au-Pd nanoalloys/reduced graphene oxide toward catalytic selective organic transformation to fine chemicals

    NASA Astrophysics Data System (ADS)

    Zhang, Yanhui; Gao, Fei; Fu, Ming-Lai

    2018-01-01

    A facile, stabilizing-molecules-free strategy has been utilized for anchoring Au-Pd alloy nanoparticles onto the flat surface of two-dimensional (2D) reduced graphene oxide (RGO) nanosheets. Formation of Au-Pd nanoalloys and loading onto the RGO are accomplished simultaneously. The Au-Pd/reduced graphene oxide (Au-Pd/RGO) exhibits higher catalytic activity than both Au/RGO and Pd/RGO, prepared by the same approach toward selective oxidation of benzyl alcohol and selective reduction of nitroaromatics, the catalytic activity order can be in good agreement with the noble metal particles size distribution of the Au, Pd and Au-Pd/RGO.

  8. Facteurs de risque du décollement de rétine au Togo

    PubMed Central

    Maneh, Nidain; Tchapbou Moyou, Danièle Christelle; Nonon Saa, Kassoula Batomaguela; Amedome, Messan Kokou; Dzidzinyo, Kossi; Diatewa, Bénédicte Marèbe; Ayena, Koffi Didier; Banla, Mèba; Balo, Komi Patrice

    2017-01-01

    Introduction le décollement de rétine pose un problème de prise en charge dans les pays en développement par manque de plateau technique. Sa prévention passe par la connaissance et l'éviction de ses facteurs de risque. Le but de l'étude était d'identifier les facteurs de risque du décollement de rétine chez le Togolais. Méthode: il s'est agi d'une étude rétrospective et descriptive, réalisée dans le service d'ophtalmologie du Chu-Campus et dans un cabinet privé d'ophtalmologie de Lomé du 2 Janvier 2011 à 31 Décembre 2015. Ont été inclus dans l'étude les dossiers des patients portant le diagnostic de décollement de rétine. Le diagnostic de décollement de rétine avait été retenu devant: la présence d'un décollement de rétine à l'examen du fond d'œil ou à l'échographie oculaire. Méthodes il s'est agi d'une étude rétrospective et descriptive, réalisée dans le service d'ophtalmologie du Chu-Campus et dans un cabinet privé d'ophtalmologie de Lomé du 2 Janvier 2011 à 31 Décembre 2015. Ont été inclus dans l'étude les dossiers des patients portant le diagnostic de décollement de rétine. Le diagnostic de décollement de rétine avait été retenu devant: la présence d'un décollement de rétine à l'examen du fond d'œil ou à l'échographie oculaire. Résultats au total, 116 yeux de 100 patients avaient un décollement de rétine dont 40 à l'OD, 44 à l'OG et 16 bilatéraux (32yeux). L'âge moyen des patients était de 46,65 ± 16,46 ans [07 ans ; 87 ans], une prédominance masculine et avec un sex-ratio = 0,32 (F/H). Les diabétiques représentaient 17% et les patients drépanocytaires 16%. Les patients myopes représentaient 5%, les yeux pseudophaques représentaient 17,2% et les yeux aphaques 3,4%. Quatre déchirures rétiniennes (14,28 % des DR rhegmatogènes) étaient retrouvées dont 2 déchirures en supéro-temporal, une déchirure en inféro-nasal et une déchirure en inféro-temporal. Le décollement était total

  9. Biosynthesis of Au, Ag and Au-Ag bimetallic nanoparticles using protein extracts ofDeinococcus radioduransand evaluation of their cytotoxicity.

    PubMed

    Li, Jiulong; Tian, Bing; Li, Tao; Dai, Shang; Weng, Yulan; Lu, Jianjiang; Xu, Xiaolin; Jin, Ye; Pang, Renjiang; Hua, Yuejin

    2018-01-01

    Biosynthesis of noble metallic nanoparticles (NPs) has attracted significant interest due to their environmental friendly and biocompatible properties. In this study, we investigated syntheses of Au, Ag and Au-Ag bimetallic NPs using protein extracts of Deinococcus radiodurans , which demonstrated powerful metal-reducing ability. The obtained NPs were characterized and analyzed by various spectroscopy techniques. The D. radiodurans protein extract-mediated silver nanoparticles (Drp-AgNPs) were preferably monodispersed and stably distributed compared to D. radiodurans protein extract-mediated gold nanoparticles (Drp-AuNPs). Drp-AgNPs and Drp-AuNPs exhibited spherical morphology with average sizes of 37.13±5.97 nm and 51.72±7.38 nm and zeta potential values of -18.31±1.39 mV and -15.17±1.24 mV at pH 7, respectively. The release efficiencies of Drp-AuNPs and Drp-AgNPs measured at 24 h were 3.99% and 18.20%, respectively. During the synthesis process, Au(III) was reduced to Au(I) and further to Au(0) and Ag(I) was reduced to Ag(0) by interactions with the hydroxyl, amine, carboxyl, phospho or sulfhydryl groups of proteins and subsequently stabilized by these groups. Some characteristics of Drp-AuNPs were different from those of Drp-AgNPs, which could be attributed to the interaction of the NPs with different binding groups of proteins. The Drp-AgNPs could be further formed into Au-Ag bimetallic NPs via galvanic replacement reaction. Drp-AuNPs and Au-Ag bimetallic NPs showed low cytotoxicity against MCF-10A cells due to the lower level of intracellular reactive oxygen species (ROS) generation than that of Drp-AgNPs. These results are crucial to understand the biosynthetic mechanism and properties of noble metallic NPs using the protein extracts of bacteria. The biocompatible Au or Au-Ag bimetallic NPs are applicable in biosensing, bioimaging and biomedicine.

  10. Ion mobility mass spectrometry of Au25(SCH2CH2Ph)18 nanoclusters.

    PubMed

    Angel, Laurence A; Majors, Lance T; Dharmaratne, Asantha C; Dass, Amala

    2010-08-24

    Ion mobility mass spectrometry (IM-MS) can separate ions based on their size, shape, and charge as well as mass-to-charge ratios. Here, we report experimental IM-MS and IM-MS/MS data of the Au(25)(SCH(2)CH(2)Ph)(18)(-) nanocluster. The IM-MS of Au(25)(SCH(2)CH(2)Ph)(18)(-) exhibits a narrow, symmetric drift time distribution that indicates the presence of only one structure. The IM-MS/MS readily distinguishes between the fragmentation of the outer protecting layer, made from six [-SR-Au-SR-Au-SR-] "staples' where R = CH(2)CH(2)Ph, and the Au(13) core. The fragmentation of the staples is characterized by the predominant loss of Au(4)(SR)(4) from the cluster and the formation of eight distinct bands. The consecutive eight bands contain an increasing variety of Au(l)S(m)R(n)(-) product ions due to the incremental fragmentation of the outer layer of Au(21)X(14)(-), where X = S or SCH(2)CH(2)Ph. The mobility of species in each individual band shows that the lower mass species exhibit greater collision cross sections, facilitating the identification of the Au(l)S(m)R(n)(-) products. Below the bands, in the region 1200-2800 m/z, product ions relating to the fragmentation of the Au(13) core can be observed. In the low mass 50-1200 m/z region, fragment ions such as Au(SR)(2)(-), Au(2)(SR)(3)(-), Au(3)(SR)(4)(-), and Au(4)(SR)(5)(-) are also observed, corresponding to the large fragments Au(25-x)(SR)(18-(x+1)). The study shows that most of the dominant large fragments are of the general type Au(21)X(14)(-/+), and Au(17)X(10)(-/+) with electron counts of 8 and 6 in negative and positive mode, respectively. This suggests that geometric factors may outweigh electronic factors in the selection of Au(25)(SR)(18) structure.

  11. On-Chip Supercapacitor Electrode Based On Polypyrrole Deposited Into Nanoporous Au Scaffold

    NASA Astrophysics Data System (ADS)

    Lu, P.; Ohlckers, P.; Chen, X. Y.

    2016-11-01

    On-chip supercapacitors hold the potential promise for serving as the energy storage units in integrated circuit system, due to their much higher energy density in comparison with conventional dielectric capacitors, high power density and long-term cycling stability. In this study, nanoporous Au (NP-Au) film on-chip was employed as the electrode scaffold to help increase the electrolyte-accessible area for active material. Pseudo-capacitive polypyrrole (PPY) with high theoretical capacitance was deposited into the NP-Au scaffold, to construct the tailored NP-Au/PPY hybrid on-chip electrode with improved areal capacitance. Half cell test in three- electrode system revealed the improved capacitor performance of nanoporous Au supported PPY electrode, compared to the densely packed PPY nanowire film electrode on planer Au substrate (Au/PPY). The areal capacitance of 37 mF/cm2∼10 mV/s, 32 mF/cm2∼50 mV/s, 28 mF/cm2∼100 mV/s, 16 mF/cm2∼500 mV/s, were offered by NP-Au/PPY. Also, the cycling performance was enhanced via using NP-Au scaffold. The developed NP-Au/PPY on-chip electrode demonstrated herein paves a feasible pathway to employ dealloying derived porous metal as the scaffold for improving both the energy density and cycling performance for supercapacitor electrodes.

  12. Cu₂O-Au nanocomposites for enzyme-free glucose sensing with enhanced performances.

    PubMed

    Hu, Qiyan; Wang, Fenyun; Fang, Zhen; Liu, Xiaowang

    2012-06-15

    A facile method for the synthesis of Cu(2)O-Au nanocomposites has been reported by injecting Cu(2)O nanocubes into Au precursor directly with the assistance of ultrasound radiation at room temperature. The ultrasound radiation is not a necessary requirement but can make the distribution of Au nanoparticles more homogenous. The formation of Cu(2)O-Au nanocomposites is attributed to following two reasons. The first one is the difference in the reduction potential between Cu(2+)/Cu(2)O and AuCl(4)(-)/Au, which can also be considered as the driving force for the redox reaction. The other one is the low lattice mismatch between (200) planes of Cu(2)O and (200) facets of Au, which is favorable for the formation of heterostructure. The electrochemical investigation demonstrates that the performances of Cu(2)O nanocubes in enzyme-free glucose sensing have been improved significantly after the decoration of Au nanoparticles which may be derived from the polarization effect provided by Au nanoparticles. As-prepared Cu(2)O-Au nanocomposites have great potential in enzyme-free glucose sensing. Copyright © 2012 Elsevier B.V. All rights reserved.

  13. Microstructural analysis of Au/TiO2-SBA-15 nanocomposite.

    PubMed

    Gondo, Takashi; Kaneko, Kenji; Nishiyama, Takeshi; Yamada, Kazuhiro; Saghi, Zineb; Barnard, Jonathan S; Midgley, Paul A

    2014-08-01

    Properties of gold nanoparticles (AuNPs) are very different from bulk gold, in particular, highly dispersed AuNPs exhibit high catalytic activities on metal oxide supports. Catalytic activities of AuNPs are strongly dependent on: (i) size and morphology; (ii) synthesis methods; (iii) nature of the support; (iv) interaction between AuNPs and the support; and (v) oxidation state of AuNPs in the synthesized catalysts. A goal is to maintain the size and to prohibit aggregation of AuNPs, since aggregations deteriorate catalytic activities. Some strong interactions are therefore required between AuNPs and their supports to prevent the movement of AuNPs. SBA-15 is a promising material for the support of AuNPs since it has ordered two-dimensional hexagonal pore channels, uniform pore size ranging from 5 to 30 nm, narrow pore size distribution, thick amorphous walls ranging from 3 to 6 nm, and high surface area. In this study, SBA-15, TiO2-SBA-15 and TiO2-SBA-15-AuNP nanocomposites were synthesized by the sol-gel method and microstructural characterizations were carried out by both X-ray diffraction analysis and electron microscopy.

  14. Formation and stability of dense arrays of Au nanoclusters on hexagonal boron nitride/Rh(111)

    NASA Astrophysics Data System (ADS)

    Patterson, Matthew C.; Habenicht, Bradley F.; Kurtz, Richard L.; Liu, Li; Xu, Ye; Sprunger, Phillip T.

    2014-05-01

    We have studied the nucleation and growth of Au clusters at submonolayer and greater coverages on the h-BN nanomesh grown on Rh(111) by means of scanning tunneling microscopy (STM), x-ray photoelectron spectroscopy (XPS), and density functional theory (DFT). STM reveals that submonolayer Au deposited at 115 K nucleates within the nanomesh pores and remains confined to the pores even after warming to room temperature. Whereas there is a propensity of monoatomic high islands at low temperature, upon annealing, bi- and multilayer Au clusters emerge. Deposition of higher coverages of Au similarly results in Au clusters primarily confined to the nanomesh pores at room temperature. XPS analysis of core-level electronic states in the deposited Au shows strong final-state effects induced by restricted particle size dominating for low Au coverage, with indications that larger Au clusters are negatively charged by interaction through the h-BN monolayer. DFT calculations suggest that the structure of the Au clusters transitions from monolayer to bilayer at a size between 30 and 37 atoms per cluster, in line with our experiment. Bader charge analysis supports the negative charge state of deposited Au.

  15. Ag/Au/Pt trimetallic nanoparticles with defects: preparation, characterization, and electrocatalytic activity in methanol oxidation

    NASA Astrophysics Data System (ADS)

    Thongthai, Kontee; Pakawanit, Phakkhananan; Chanlek, Narong; Kim, Jun-Hyun; Ananta, Supon; Srisombat, Laongnuan

    2017-09-01

    Two series of Ag x /Au/Pt y trimetallic nanoparticles (Ag x Au1Pt2 with x ranging from 1-5 and Ag4Au1Pt y with y ranging from 1-3) were prepared by a sequential chemical reduction method that involved the deposition of Pt on preformed Ag/Au core-shell particles by systematically controlling the amount of Ag, Au, and Pt metal precursor solutions. The structural changes (the diameters and increased surface roughness from the defective features) and absorption patterns (the significant reduction of the peak intensities) of the nanoparticles examined with TEM and UV-vis spectroscopy indicated the selective incorporation of Pt on the Ag/Au nanoparticles regardless of their compositions. In addition, a combination of WDX, XRD, and XPS analyses quantitatively and qualitatively confirmed the successful formation of the Ag x Au1Pt2 and Ag4Au1Pt y trimetallic nanoparticles. Subsequently, these series of nanoparticles were deposited on multi-wall carbon nanotubes (MWCNTs) to evaluate their electrocatalytic property in the methanol oxidation reaction (MOR) as a function of their metal compositions. The results showed that the electrocatalytic activities of all Ag4/Au1/Pt y systems were higher than those of typical Pt on the MWCNTs. In particular, the Ag4Au1Pt2 nanoparticles exhibited the highest electrocatalytic property for the MOR, suggesting the importance of the proper combination of metal constituents and structures to regulate the activity in electrocatalytic systems.

  16. Engineering the Self-Assembly Induced Emission of Cu Nanoclusters by Au(I) Doping.

    PubMed

    Liu, Jiale; Wu, Zhennan; Tian, Ye; Li, Yanchun; Ai, Lin; Li, Tingting; Zou, Haoyang; Liu, Yi; Zhang, Xindong; Zhang, Hao; Yang, Bai

    2017-07-26

    Aggregation-induced emission (AIE) and self-assembly induced emission (SAIE) effects have been employed to tune the emission properties of metal nanoclusters (NCs). However, it is still not possible to further enhance the photoluminescence quantum yields (PLQYs) and control the emission colors of the NCs using AIE and SAIE. On the basis of our recent work studying the contribution of Cu(I) defects in the SAIE of Cu NCs, in this article, Au(I) was doped into Cu NC self-assembled nanosheets (NSASs) to construct a more stable Au(I)-centered state. As a result, the PLQYs, emission stability, and tunability of emission colors of the Cu NSASs were significantly improved. Detailed studies reveal that the doped Au(I) induces a Au(I)-Cu(I) metallophilic interaction, which leads to a ligand-to-Cu-Au charge transfer, which facilitates the relaxation of excited electrons via a radiative pathway, thereby enhancing the emission intensity. The charge transfer from Cu to Au lowers the energy, thus leading to the red-shift of PL emission. Au(I) is likely doped into the Cu NSASs rather than in individual NCs, because 0.3% Au doping is enough to alter the emission properties. By mixing Au(I)-doped Cu NSASs with different emission colors (due to different Au doping percentages) as color conversion materials on commercially available 365 nm GaN chips, a white light-emitting diode prototype is fabricated.

  17. Growth of large aspect ratio AuAg bimetallic nanowires on Si(110) substrate

    NASA Astrophysics Data System (ADS)

    Bhukta, Anjan; Guha, Puspendu; Satpati, Biswarup; Maiti, Paramita; Satyam, Parlapalli V.

    2017-06-01

    Large aspect ratio bimetallic nanowire structures comprise potential applications in areas such as higher catalytic activity and surface Raman enhancement spectroscopy (SERS) substrates. By using the highly anisotropic ultra-clean Si(110) surface and with initial growth of sub monolayer (ML) Ag on such surface, a high aspect ratio AuAg bimetallic nanostructures can be formed. We report on the formation of large aspect ratio (>7.2 ± 0.8) AuAg nanowires on ultra-clean Si(110) surfaces using 0.5 ML Ag followed by 3.0 ML Au using molecular beam epitaxy (MBE) at a growth temperature of 300 °C. Under similar growth conditions without pre-deposition of Ag and only with deposition of 3.0 ML of Au consequences smaller aspect ratio (2.1 ± 0.1) monometallic Au nanostructures. The enhancement in aspect ratio of the nanostructures is attributed to the formation of one dimensional Ag layer (prior to Au growth) and Au-Ag bimetallic intermixing at elevated temperature. Considering deposition of 3.0 ML Au, a regime of substrate temperature ≈ 270-330 °C is found to be optimum to growth some of high aspect ratio (>25.0) AuAg nanowires as well. Exterior of this regime, at lower temperature due to low mobility of the ad-atoms and at higher temperature due to probable inter-diffusion of Ag, such extremely high aspect ratio AuAg nanowires found to be infrequent to grow. For growth at substrate temperature 300 °C, mean aspect ratio of the AuAg nanostructures is gradually increased in accordance with Au thickness up to 3.0 ML due to preferential accumulation of ad-atoms (Au, Ag) along Si 〈 1 1 bar 0 〉 and thereafter reduces for adequate accumulation along Si 〈 001 〉 .

  18. High Activity of Au/K/TiO 2(110) for CO Oxidation: Alkali-Metal-Enhanced Dispersion of Au and Bonding of CO

    DOE PAGES

    Rodriguez, Jose A.; Grinter, David C.; Ramirez, Pedro J.; ...

    2018-02-14

    In this paper, images from scanning tunneling microscopy show high mobility for potassium (K) on an oxidized TiO 2(110) surface. At low coverages, the alkali metal occupies mainly terrace sites of the o-TiO 2(110) system. The results of X-ray photoelectron spectroscopy indicate that K is fully ionized. The electron transferred from K to the titania affects the reactivity of this oxide, favoring the dispersion of Au particles on the terraces of the o-TiO 2(110) surface. When small coverages of K and Au are present on the o-TiO 2(110) system, only a few K–Au pairs are formed and the alkali metalmore » affects Au chemisorption mainly through the oxide interactions. Addition of K to Au/o-TiO 2(110) enhances the reactivity of the system, opening new reaction paths for the adsorption and oxidation of carbon monoxide. CO can undergo disproportionation (2CO → C ads + CO 2,ads) on K/o-TiO 2(110) and Au/K/o-TiO 2(110) surfaces. The Au–KO x interface binds CO much better than plain Au–TiO 2, increasing the surface coverage of CO and facilitating its oxidation. Kinetic tests show that K promotes CO oxidation on Au/TiO 2. Finally, turnover frequencies of 2.1 and 10.8 molecules (Au site) -1 s –1 were calculated for oxidation of CO on Au/o-TiO 2(110) and Au/K/o-TiO 2(110) catalysts, respectively.« less

  19. Highly sensitive aptasensor based on synergetic catalysis activity of MoS2-Au-HE composite using cDNA-Au-GOD for signal amplification.

    PubMed

    Song, Hai-Yan; Kang, Tian-Fang; Lu, Li-Ping; Cheng, Shui-Yuan

    2017-03-01

    Single or few-layer nanosheets of MoS 2 (MoS 2 nanosheets) and a composite composed of MoS 2 nanosheets, Au nanoparticles (AuNPs) and hemin (HE) (denoted as MoS 2 -Au-HE) were prepared. The composites possessed high synergetic catalysis activity towards the electroreduction of hydrogen peroxide. Furthermore, glucose oxidase (GOD) and AuNPs were used as marker of the complementary DNA (cDNA) strand of kanamycin aptamer to prepare a conjugate (reffered as cDNA-Au-GOD) that was designed as the signal probe. Both cDNA-Au-GOD and MoS 2 -Au-HE were applied to fabricate aptasensor for kanamycin. MoS 2 -Au-HE acted as solid platform for kanamycin aptamer and signal transmitters. AuNPs were employed as the supporter of cDNA and GOD which catalyze dissolved oxygen to produce hydrogen peroxide in the presence of glucose. Then cathodic peak current of H 2 O 2 was recorded by differential pulse voltammetry (DPV). The electrochemical reduction of H 2 O 2 was catalyzed by MoS 2 -Au-HE that was modified onto the surface of a glassy carbon electrode (GCE). The cathodic peak current of H 2 O 2 was highly linearly decreased with an increase of kanamycin concentrations from 1.0ng/L to 1.0×10 5 ng/L, with a detection limit of 0.8ng/L. This aptasensor can be used to detect kanamycin in milk with high specificity, sensitivity and selectivity. Copyright © 2016 Elsevier B.V. All rights reserved.

  20. Échecs thérapeutiques chez les enfants infectés par le VIH en suivi de routine dans un contexte à ressources limitées au Cameroun

    PubMed Central

    Penda, Calixte Ida; Bebey, Francine Same; Mangamba, Danielle Kedy; Moukoko, Else Carole Eboumbou; Ngwa, Victoria; Makouet, Nicaise; Bissek, Anne-Cécile; Minkemdefo, Blaise Dupont; Tetanye, Ekoe; Ndombo, Paul Koki

    2013-01-01

    Introduction L'objectif de cette étude était de déterminer les facteurs associés aux échecs thérapeutiques chez les enfants infectés par le VIH à l'Hôpital Laquintinie de Douala. Méthodes Une étude transversale rétrospective a été menée sur une période de 5 mois en 2010, recrutant 222 enfants âgés de 1 à 18 ans et sous TARV depuis au moins 24 semaines. Les données sociodémographiques, cliniques, biologiques et de l'observance thérapeutique des patients ont été collectés à partir des dossiers des patients, et analysées avec le logiciel SPSS (version 16). Résultats 39 (17,6%) des enfants étaient en échec thérapeutique (délai moyen de survenue 26,8 mois) et 73,4% d'entre eux sont passés en seconde ligne. Les garçons avaient en moyenne un risque 5 fois plus élevé de faire un échec thérapeutique que les filles (OR=3,9; p=0,035). 94,4% des enfants suivis avaient un faible taux de CD4 à l'initiation (‘ 25%) associé au risque élevé d’échec thérapeutique (OR=5,2; p=0,007). Les enfants issus de famille monoparentale représentaient près de la moitié des cas d’échecs thérapeutiques. Sur 39 cas en échec thérapeutique, 41% des enfants étaient des orphelins. Parmi les enfants sous TARV, 46% prenaient leur trithérapie sous forme de médicaments séparés parmi lesquels 52,1% étaient en échec thérapeutique. Conclusion Les échecs thérapeutiques et le passage en seconde ligne dépendaient du contexte familial des enfants, de leur statut immunologique à l'initiation du traitement, de leur sexe et de la forme galénique du TARV. PMID:24171063

  1. La connectivite mixte: prévalence et caractéristiques cliniques chez le noir africain, étude de 7 cas au Gabon et revue de la littérature

    PubMed Central

    Missounga, Landry; Ba, Josaphat Iba; Nseng Nseng Ondo, Ingrid Rosalie; Nziengui Madjinou, Maria Ines Carine; Malekou, Doris; Mouendou Mouloungui, Emeline Gracia; Nzengue, Emmanuel Ecke; Boguikouma, Jean Bruno; Kombila, Moussavou

    2017-01-01

    La littérature rapporte que la connectivite mixte semble plus fréquente dans la population noire et chez les asiatiques. Le but de l'étude était de déterminer la prévalence de la connectivite mixte (CM) parmi les connectivites et l'ensemble des pathologies rhumatologiques dans une population hospitalière au Gabon; de décrire ensuite les caractéristiques cliniques de la maladie. Il s'agissait d'une étude rétrospective des dossiers de patients suivis pour connectivite mixte (critères de Kasukawa) et les autres entités de connectivites (critères ACR) en rhumatologie au CHU de Libreville entre janvier 2010 et décembre 2015. Pour chaque cas de CM, les manifestations articulaires et extra-articulaires, le taux d'anticorps anti-U1RNP, l'évolution, étaient les paramètres étudiés. Sept cas ont été colligés en 6 ans parmi 6050 patients et 67 cas de connectivites soit une prévalence de 0,11% et de 10,44% respectivement. Il s'agissait de 7 femmes (100%), d'âge moyen de 39,5 ans. Les signes articulaires comprenaient: polyarthrite, myalgies, doits boudinés et phénomène de Raynaud dans 87,5%, 87,5%, 28,6% et 14% respectivement. Les 7 patients avaient un taux d'anti-U1RNP élevé entre 5 et 35N (N≤7 UI). Un cas de décès par HTAP était constaté. Il s'agit de la série de CM la plus importante rapportée en Afrique noire. La maladie semble rare chez le noir africain, la raison pourrait être génétique. Les aspects démographiques et cliniques paraissent similaires chez les caucasiens, les asiatiques et les noirs hormis une faible fréquence du phénomène de Raynaud chez les noirs. PMID:28904690

  2. The effect of metal surface passivation on the Au-InP interaction

    NASA Technical Reports Server (NTRS)

    Fatemi, Navid S.; Weizer, Victor G.

    1989-01-01

    The effect of SiO2 encapsulation on reaction rates in the Au-InP system was studied. Scanning electron microscopy and x-ray photoelectron spectroscopy were used to investigate surface and/or interface morphologies and in-depth compositional profiles. It was found that the rate of dissolution of InP into Au and subsequent phase transformations are largely dependent on the condition of the free surface of the metalization. SiO2 capping of Au is reported for the first time to suppress the Au-InP reaction rate. The Au-InP interaction is shown to be quite similar to the Au-GaAs interaction despite differences in behavior of the group-V elements.

  3. Graphene oxide supported Au-Ag alloy nanoparticles with different shapes and their high catalytic activities

    NASA Astrophysics Data System (ADS)

    Wu, Tao; Ma, Junkui; Wang, Xingrui; Liu, Yue; Xu, Han; Gao, Jianping; Wang, Wei; Liu, Yu; Yan, Jing

    2013-03-01

    A simple method was developed to fabricate Au-Ag nanoparticle/graphene oxide nanocomposites (Au-Ag/GO) by using simultaneous redox reactions between AgNO3, HAuCl4 and GO. The Au-Ag/GO was characterized by x-ray photoelectron spectroscopy, transmission electron microscopy and energy dispersive x-ray spectroscopy. The GO nanosheets acted as the reducing agent and the support for the Au-Ag alloy nanoparticles. In addition, Au-Ag alloy nanoparticles with different shapes including core-shell-like, dendrimer-like and flower-like were obtained by simply modifying the concentration of the reactants and the reaction temperature. With no reducing or stabilizing agents added, the Au-Ag/GO nanocomposites show superior catalytic performance for the reduction of 4-nitrophenol and for the aerobic homocoupling of phenylboronic acid.

  4. Kondo effect in single cobalt phthalocyanine molecules adsorbed on Au(111) monoatomic steps

    NASA Astrophysics Data System (ADS)

    Zhao, Aidi; Hu, Zhenpeng; Wang, Bing; Xiao, Xudong; Yang, Jinlong; Hou, J. G.

    2008-06-01

    The Kondo effect in single dehydrogenated cobalt phthalocyanine (CoPc) molecules adsorbed on Au(111) monoatomic steps was studied with a low temperature scanning tunneling microscope. The CoPc molecules adsorbed on Au(111) monoatomic steps show two typical configurations, which can be dehydrogenated to reveal Kondo effect. Moreover, the Kondo temperatures (TK) measured for different molecules vary in a large range from ~150 to ~550 K, increasing monotonically with decreasing Co-Au distance. A simple model consisting of a single Co 3dz2 orbital and a Au 6s orbital is considered and gives a qualitative explanation to the dependence. The large variation of TK is attributed to the variation of the interaction between the magnetic-active cobalt ion and the Au substrate resulted from different Co-Au distances.

  5. Resonance energy transfer between fluorescent BSA protected Au nanoclusters and organic fluorophores

    NASA Astrophysics Data System (ADS)

    Raut, Sangram; Rich, Ryan; Fudala, Rafal; Butler, Susan; Kokate, Rutika; Gryczynski, Zygmunt; Luchowski, Rafal; Gryczynski, Ignacy

    2013-12-01

    Bovine serum albumin (BSA) protected nanoclusters (Au and Ag) represent a group of nanomaterials that holds great promise in biophysical applications due to their unique fluorescence properties and lack of toxicity. These metal nanoclusters have utility in a variety of disciplines including catalysis, biosensing, photonics, imaging and molecular electronics. However, they suffer from several disadvantages such as low fluorescence quantum efficiency (typically near 6%) and broad emission spectrum (540 nm to 800 nm). We describe an approach to enhance the apparent brightness of BSA Au clusters by linking them with a high extinction donor organic dye pacific blue (PB). In this conjugate PB acts as a donor to BSA Au clusters and enhances its brightness by resonance energy transfer (RET). We found that the emission of BSA Au clusters can be enhanced by a magnitude of two-fold by resonance energy transfer (RET) from the high extinction donor PB, and BSA Au clusters can act as an acceptor to nanosecond lifetime organic dyes. By pumping the BSA Au clusters using a high extinction donor, one can increase the effective brightness of less bright fluorophores like BSA Au clusters. Moreover, we prepared another conjugate of BSA Au clusters with the near infrared (NIR) dye Dylight 750 (Dy750), where BSA Au clusters act as a donor to Dy750. We observed that BSA Au clusters can function as a donor, showing 46% transfer efficiency to the NIR dye Dy750 with a long lifetime component in the acceptor decay through RET. Such RET-based probes can be used to prevent the problems of a broad emission spectrum associated with the BSA Au clusters. Moreover, transferring energy from BSA Au clusters to Dy750 will result in a RET probe with a narrow emission spectrum and long lifetime component which can be utilized in imaging applications.Bovine serum albumin (BSA) protected nanoclusters (Au and Ag) represent a group of nanomaterials that holds great promise in biophysical applications due to

  6. Formation of Au nanoparticles on CNTs three dimensional structure for LSPR biosensor application

    NASA Astrophysics Data System (ADS)

    Yang, Ming; Shimizu, Tetsuhide

    2017-02-01

    A 3D LSPR sensor was fabricated by using CNTs as support and depositing AuNPs on the support in this study. We proposed a simple process to arrange AuNPs to CNTs by using vacuum deposition and annealing for 3D LSPR sensor. In order to fabricate 3D LSPR sensor, CNTs was synthesized and patterned on quartz glass substrate by CVD method and photolithography. For the synthesis of AuNPs, Au thin film was deposited on glass and CNTs by vacuum deposition. After deposition, Au thin film on glass and CNTs was particulated by annealing. The performance of 3D LSPR sensor was confirmed using BSA for bio analysis. LSPR characteristics was measured and compared before and after adsorption of BSA. The detection limit was 100ng/ml and detection sensitivity was 10 times in comparison with 2D LSPR sensor of same AuNPs formation condition.

  7. Low-symmetry structures of Au32Z (Z = +1, 0, -1) clusters.

    PubMed

    Jalbout, Abraham F; Contreras-Torres, Flavio F; Pérez, Luis A; Garzón, Ignacio L

    2008-01-24

    In this work, we have explored new stable structures of the Au32Z (Z = +1, 0, -1) clusters. Theoretical calculations using density functional theory within the generalized-gradient approximation were performed. Our results show that, in the anion state (Au32-), low-symmetry (disordered) structures are preferred over the caged fullerene-like isomer. In addition, the cationic cluster (Au32+) also exhibits a disordered low-symmetry structure as its lowest energy configuration, but it is much closer in energy to the fullerene-like isomer. These results, obtained at T = 0 K, indicate that disordered structures for the Au32- and Au32+ clusters may be detected not only at room temperature, as was experimentally verified for the Au32- one, but also at much lower temperatures.

  8. Site Preference of Ternary Alloying Additions to AuTi

    NASA Technical Reports Server (NTRS)

    Bozzolo, Guillermo; Mosca, Hugo O.; Noebe, Ronald D.

    2006-01-01

    Atomistic modeling of the site substitution behavior of several alloying additions, namely. Na, Mg, Al, Si. Sc, V, Cr, Mn. Fe, Co, Ni, Cu, Zn, Y, Zr. Nb, Mo, Tc, Ru, Rh, Pd, Ag, Cd, Hf, Ta, W, Re, Os, Ir, and Pt in B2 TiAu is reported. The 30 elements can be grouped according to their absolute preference for a specific site, regardless of concentration, or preference for available sites in the deficient sublattice. Results of large scale simulations are also presented, distinguishing between additions that remain in solution from those that precipitate a second phase.

  9. Combat Identification (15au): Project Summary and Closeout Report

    DTIC Science & Technology

    2009-07-01

    effectué un examen de la recherche ayant trait au traitement de l’information humain dans le processus l’IDCbt. Une analyse de cette recherche a...represented by the Minister of National Defence, 2009 © Sa Majesté la Reine (en droit du Canada), telle que représentée par le ministre de la...examen des objectifs du projet, ainsi qu’une mise en perspective sur ce qui rend le travail nécessaire. Il y a un résumé des réussites du projet et

  10. Coronal Streamers in the Solar Wind at 1 AU

    DTIC Science & Technology

    1981-07-01

    activity [Feldman et al., 1978]. Second, is the essence of coronal streamers in, for example, eclipse even near solar minimum neither all periods of low...inferred from both depressed He+ + abundance (A(He)). The analysis of 1 AU measurements of the solar wind and eclipse and Borrini et al. E198IJ establishes...Feldman, W. C., J. R. Asbridge, and M. D. Montgomery, Double 1966. ion streams in the solar wind, J. Geophys. Res., 78, 2017 , 1973. Joselyn, J. A., and T

  11. Laser printing of Au/Si core-shell nanoparticles

    NASA Astrophysics Data System (ADS)

    Zograf, G. P.; Zuev, D. A.; Milichko, V. A.; Mukhin, I. S.; Baranov, M. A.; Ubyivovk, E. V.; Makarov, S. V.; Belov, P. A.

    2016-08-01

    We develop a novel method of core-shell nanoparticles fabrication based on laser ablation of multilayer thin films using femtosecond laser pulses. Transmission electron microscopy proves that the obtained structures have Si and Au separated parts. We theoretically show that the combination of high refractive index dielectric and plasmonic nanoparticles shows possibility of interplay between magnetic optical responses and plasmon resonances. This opens a possibility to manipulate by both scattering power pattern and local optical field enhancement via precise engineering of the core/shell nanoparticles.

  12. Intense magnetic fields at 1 AU: Solar cycle 20

    NASA Technical Reports Server (NTRS)

    Burlaga, L. F.; King, J. H.

    1978-01-01

    Of the intense magnetic fields (greater than 13 gamma) observed at 1 AU during solar cycle 20 (1973-1975), 92% were associated with shocks, stream interfaces, or cold magnetic enhancements (CMEs). Most (52%) of the magnetic field intensity enhancements occurred at stream interfaces; 27% occurred behind shocks without interfaces; and 11% occurred in CMEs. The most intense fields (25 gamma to 37 gamma) followed shocks. Magnetic field intensities at interfaces did not exceed 25 gamma, suggesting a mechanism such as a magnetoacoustic wave limits the intensity ahead of streams. Intense magnetic fields persist longest behind shocks.

  13. In vitro antiviral activity of poly (A-U) and ellipticines.

    PubMed

    Jamison, J; Krabill, K; Flowers, D; Tsai, C C

    1990-04-01

    The role of N2-methyl-9-hydroxy-ellipticine (NMHE) and N2,N6-dimethyl-9-hydroxy-ellipticine (DMHE) in modulating the antiviral activity of poly (A-U) was examined using a human foreskin fibroblast-vesicular stomatitis virus (HSF-VSV) bioassay in which the concentration of poly (A-U) was fixed at 0.05 mM or 0.2 mM while the NMHE or DMHE concentration was varied to produce variable NMHE (or DMHE)/ribonucleotide ratios ranging from 1:16 to 2:1. Poly (A-U), NMHE and DMHE tested individually were not efficacious antiviral agents. When the poly (A-U) was combined with the NMHE or DMHE, the antiviral activity of the poly (A-U) was potentiated 16- to 20-fold a NMHE (or DMHE)/ribonucleotide ratios in the region of 1/4. Poly (A-U), NMHE and DMHE induce beta-IFN. The interferon-inducing activity of the NMHE (or DMHE)/poly (A-U) combination was equal to the sum of the interferon-inducing activity of the poly (A-U) alone and the NMHE (or DMHE) alone. The direct viral inactivation study demonstrated that NMHE, DMHE, poly (A-U) and the NMHE (or DMHE)/poly (A-U) combinations did not inactivate VSV at concentrations near the 50% viral inhibitory dose. Photomicrographs of HSF cells incubated with NMHE alone or with a NMHE/poly (A-U) combination suggest that poly (A-U) affects the subcellular distribution of the NMHE by steering the NMHE to the nucleolus. These observations suggest that modulation of a nuclear process may be responsible for the enhanced antiviral activity.

  14. Cancer cell uptake behavior of Au nanoring and its localized surface plasmon resonance induced cell inactivation.

    PubMed

    Chu, Che-Kuan; Tu, Yi-Chou; Chang, Yu-Wei; Chu, Chih-Ken; Chen, Shih-Yang; Chi, Ting-Ta; Kiang, Yean-Woei; Yang, Chih-Chung

    2015-02-20

    Au nanorings (NRIs), which have the localized surface plasmon resonance (LSPR) wavelength around 1058 nm, either with or without linked antibodies, are applied to SAS oral cancer cells for cell inactivation through the LSPR-induced photothermal effect when they are illuminated by a laser of 1065 nm in wavelength. Different incubation times of cells with Au NRIs are considered for observing the variations of cell uptake efficiency of Au NRI and the threshold laser intensity for cell inactivation. In each case of incubation time, the cell sample is washed for evaluating the total Au NRI number per cell adsorbed and internalized by the cells based on inductively coupled plasma mass spectrometry measurement. Also, the Au NRIs remaining on cell membrane are etched with KI/I2 solution to evaluate the internalized Au NRI number per cell. The threshold laser intensities for cell inactivation before washout, after washout, and after KI/I2 etching are calibrated from the circular area sizes of inactivated cells around the illuminated laser spot center with various laser power levels. By using Au NRIs with antibodies, the internalized Au NRI number per cell increases monotonically with incubation time up to 24 h. However, the number of Au NRI remaining on cell membrane reaches a maximum at 12 h in incubation time. The cell uptake behavior of an Au NRI without antibodies is similar to that with antibodies except that the uptake NRI number is significantly smaller and the incubation time for the maximum NRI number remaining on cell membrane is delayed to 20 h. By comparing the threshold laser intensities before and after KI/I2 etching, it is found that the Au NRIs remaining on cell membrane cause more effective cancer cell inactivation, when compared with the internalized Au NRIs.

  15. Organic Inorganic Hybrid Solar Cell Efficiency Improvement By Employing Au Nanocluster

    DTIC Science & Technology

    2015-06-14

    this report we describe the incorporation of gold (Au) nanocluster in the PEDOT : PSS and the effect of this blend on the power-conversion efficiency...for public release; distribution is unlimited. Au nanocluster and PEDOT : PSS blend in the electricalPerformance of Hybrid silicon solar cell. The...UTSA Circle San Antonio, TX 78249 -1644 ABSTRACT Au nanocluster and PEDOT : PSS blend in the electricalPerformance of Hybrid silicon solar cell. Report

  16. Synthesis of Au-Ag Alloy Nanoparticles in Deionized Water by Pulsed Laser Ablation Technique.

    PubMed

    Norsyuhada, W; Shukri, W M; Bidin, Noriah; Islam, Shumaila; Krishnan, Ganesan

    2018-07-01

    Au-Ag alloy nanoparticles are physically synthesized using rapid, simple and efficient Q-switched Nd:YAG pulsed laser ablation in liquid technique (PLAL). Au and Ag colloidal solutions are separately prepared by 1064 nm laser ablation of metallic target (gold and silver) which is immersed in deionized water. Au-Ag alloy nanoparticles are prepared by irradiating the mixture of Au and Ag colloidal solutions with 532 nm of second harmonic wavelength of Nd:YAG laser at three different ratio, 3:1, 1:1 and 1:3 within different exposure times. The three of plasmon absorption bands of Au-Ag nanoparticles are shifted linearly to the lower wavelength [499.67 nm (3:1), 481.25 nm (1:1), 467.91 nm (1:3)], as compared to plasmon absorption spectra of pure Au (520 nm) and Ag (400 nm). Moreover, the change in colors are also observed from red (Au) and yellow (Ag) to orange, brown and green color due to the Au-Ag alloy formations, respectively. Transmission electron microscopy shows the Ag shell around the inner core of Au spherical metal with broad size distribution due to the three different volume ratio, respectively (1.7 nm, 0.7 nm, 1.4 nm). Energy-dispersive X-ray spectroscopy analysis confirms the presence of Au and Ag elements in Au-Ag alloy nanoparticles without any contaminations. Attenuated total reflectance fourier transform infrared spectroscopy analysis also confirms the homogenous Au-Ag alloys chemical bonding.

  17. The Au/Si eutectic bonding compatibility with KOH etching for 3D devices fabrication

    NASA Astrophysics Data System (ADS)

    Liang, Hengmao; Liu, Mifeng; Liu, Song; Xu, Dehui; Xiong, Bin

    2018-01-01

    KOH etching and Au/Si eutectic bonding are cost-efficient technologies for 3D device fabrication. Aimed at investigating the process compatibility of KOH etching and Au/Si bonding, KOH etching tests have been carried out for Au/bulk Si and Au/amorphous Si (a-Si) bonding wafers in this paper. For the Au/bulk Si bonding wafer, a serious underetch phenomenon occurring on the damage layer in KOH etching definitely results in packaging failure. In the microstructure analysis, it is found that the formation of the damage layer between the bonded layer and bulk Si is attributed to the destruction of crystal Si lattices in Au/bulk Si eutectic reaction. Considering the occurrence of underetch for Au/Si bonding must meet two requirements: the superfluous Si and the defective layer near the bonded layer, the Au/a-Si bonding by regulating the a-Si/Au thickness ratio is presented in this study. Only when the a-Si/Au thickness ratio is relatively low are there not underetch phenomena, of which the reason is the full reaction of the a-Si layer avoiding the formation of the damage layer for easy underetch. Obviously, the Au/a-Si bonding via choosing a moderate a-Si/Au thickness ratio (⩽1.5:1 is suggested) could be reliably compatible with KOH etching, which provides an available and low-cost approach for 3D device fabrication. More importantly, the theory of the damage layer proposed in this study can be naturally applied to relevant analyses on the eutectic reaction of other metals and single crystal materials.

  18. Cancer cell uptake behavior of Au nanoring and its localized surface plasmon resonance induced cell inactivation

    NASA Astrophysics Data System (ADS)

    Chu, Che-Kuan; Tu, Yi-Chou; Chang, Yu-Wei; Chu, Chih-Ken; Chen, Shih-Yang; Chi, Ting-Ta; Kiang, Yean-Woei; Yang, Chih-Chung

    2015-02-01

    Au nanorings (NRIs), which have the localized surface plasmon resonance (LSPR) wavelength around 1058 nm, either with or without linked antibodies, are applied to SAS oral cancer cells for cell inactivation through the LSPR-induced photothermal effect when they are illuminated by a laser of 1065 nm in wavelength. Different incubation times of cells with Au NRIs are considered for observing the variations of cell uptake efficiency of Au NRI and the threshold laser intensity for cell inactivation. In each case of incubation time, the cell sample is washed for evaluating the total Au NRI number per cell adsorbed and internalized by the cells based on inductively coupled plasma mass spectrometry measurement. Also, the Au NRIs remaining on cell membrane are etched with KI/I2 solution to evaluate the internalized Au NRI number per cell. The threshold laser intensities for cell inactivation before washout, after washout, and after KI/I2 etching are calibrated from the circular area sizes of inactivated cells around the illuminated laser spot center with various laser power levels. By using Au NRIs with antibodies, the internalized Au NRI number per cell increases monotonically with incubation time up to 24 h. However, the number of Au NRI remaining on cell membrane reaches a maximum at 12 h in incubation time. The cell uptake behavior of an Au NRI without antibodies is similar to that with antibodies except that the uptake NRI number is significantly smaller and the incubation time for the maximum NRI number remaining on cell membrane is delayed to 20 h. By comparing the threshold laser intensities before and after KI/I2 etching, it is found that the Au NRIs remaining on cell membrane cause more effective cancer cell inactivation, when compared with the internalized Au NRIs.

  19. Improvement on electrical conductivity and electron field emission properties of Au-ion implanted ultrananocrystalline diamond films by using Au-Si eutectic substrates

    SciTech Connect

    Sankaran, K. J.; Institute for Materials Research; Sundaravel, B.

    2015-08-28

    In the present work, Au-Si eutectic layer was used to enhance the electrical conductivity/electron field emission (EFE) properties of Au-ion implanted ultrananocrystalline diamond (Au-UNCD) films grown on Si substrates. The electrical conductivity was improved to a value of 230 (Ω cm){sup −1}, and the EFE properties was enhanced reporting a low turn-on field of 2.1 V/μm with high EFE current density of 5.3 mA/cm{sup 2} (at an applied field of 4.9 V/μm) for the Au-UNCD films. The formation of SiC phase circumvents the formation of amorphous carbon prior to the nucleation of diamond on Si substrates. Consequently, the electron transport efficiency of themore » UNCD-to-Si interface increases, thereby improving the conductivity as well as the EFE properties. Moreover, the salient feature of these processes is that the sputtering deposition of Au-coating for preparing the Au-Si interlayer, the microwave plasma enhanced chemical vapor deposition process for growing the UNCD films, and the Au-ion implantation process for inducing the nanographitic phases are standard thin film preparation techniques, which are simple, robust, and easily scalable. The availability of these highly conducting UNCD films with superior EFE characteristics may open up a pathway for the development of high-definition flat panel displays and plasma devices.« less

  20. PHENIX results on charged-hadron azimuthal anisotropies in Au + Au collisions at center-of-mass energies from 39 to 200 GeV

    NASA Astrophysics Data System (ADS)

    Shimomura, Maya; Phenix Collaboration

    2017-11-01

    The energy dependence of the azimuthal anisotropy of second (third) harmonics v2(v3) are measured for charged hadron as a function of the transverse momentum (pT) in several centrality bins in Au + Au collisions by the PHENIX experiment at RHIC. In each centrality, vn vs. pT agrees within the uncertainties from √{sNN} = 39 to 200 GeV. Also, the 2014 data significantly improve the statistical precision compared to previous results for v2 measurement in Au + Au collisions at √{sNN} = 200 GeV. The new measurement shows that v2 is positive up to pT = 10 GeV/c and charged hadron v2 is different from π0v2 for pT < 7 GeV/c. Moreover, forward/backward v2(v3) and local dN/dη are newly measured at 3 < | η | < 3.9 in asymmetric Cu + Au collisions. The result indicates that vn(Au-going)/ε are consistent to vn(Cu-going)/ε as a function of dN/dη when using ε determined from a combination of Au and Cu constituents.

  1. Hollow Au-Ag Nanoparticles Labeled Immunochromatography Strip for Highly Sensitive Detection of Clenbuterol

    NASA Astrophysics Data System (ADS)

    Wang, Jingyun; Zhang, Lei; Huang, Youju; Dandapat, Anirban; Dai, Liwei; Zhang, Ganggang; Lu, Xuefei; Zhang, Jiawei; Lai, Weihua; Chen, Tao

    2017-01-01

    The probe materials play a significant role in improving the detection efficiency and sensitivity of lateral-flow immunochromatographic test strip (ICTS). Unlike conventional ICTS assay usually uses single-component, solid gold nanoparticles as labeled probes, in our present study, a bimetallic, hollow Au-Ag nanoparticles (NPs) labeled ICTS was successfully developed for the detection of clenbuterol (CLE). The hollow Au-Ag NPs with different Au/Ag mole ratio and tunable size were synthesized by varying the volume ratio of [HAuCl4]:[Ag NPs] via the galvanic replacement reaction. The surface of hollow Ag-Au NPs was functionalized with 11-mercaptoundecanoic acid (MUA) for further covalently bonded with anti-CLE monoclonal antibody. Overall size of the Au-Ag NPs, size of the holes within individual NPs and also Au/Ag mole ratio have been systematically optimized to amplify both the visual inspection signals and the quantitative data. The sensitivity of optimized hollow Au-Ag NPs probes has been achieved even as low as 2 ppb in a short time (within 15 min), which is superior over the detection performance of conventional test strip using Au NPs. The optimized hollow Au-Ag NPs labeled test strip can be used as an ideal candidate for the rapid screening of CLE in food samples.

  2. Water-soluble Au25(Capt)18 nanoclusters: synthesis, thermal stability, and optical properties

    NASA Astrophysics Data System (ADS)

    Kumar, Santosh; Jin, Rongchao

    2012-06-01

    This work was motivated by the unsatisfactory stability of Au25(SG)18 in solution under thermal conditions (e.g. 70-90 °C for DNA melting). Thus, we searched for a better, water-soluble thiol ligand. Herein, we report a one-pot synthesis and investigation of the stability and optical properties of captopril (abbreviated Capt)-protected Au25(Capt)18 nanoclusters. The Au25(Capt)18 (anionic, counterion: Na+) nanoclusters were formed via size focusing under ambient conditions. Significantly, Au25(Capt)18 nanoclusters exhibit largely improved thermal stability compared to the glutathione (HSG) capped Au25(SG)18. Both Au25(Capt)18 and Au25(SG)18 nanoclusters show fluorescence centered at ~700 nm. The chiral ligands (Capt, SG, as well as chirally modified phenylethanethiol (PET*)) give rise to distinct chiroptical features. The high thermal stability and distinct optical properties of Au25(Capt)18 nanoclusters render this material quite promising for biological applications.This work was motivated by the unsatisfactory stability of Au25(SG)18 in solution under thermal conditions (e.g. 70-90 °C for DNA melting). Thus, we searched for a better, water-soluble thiol ligand. Herein, we report a one-pot synthesis and investigation of the stability and optical properties of captopril (abbreviated Capt)-protected Au25(Capt)18 nanoclusters. The Au25(Capt)18 (anionic, counterion: Na+) nanoclusters were formed via size focusing under ambient conditions. Significantly, Au25(Capt)18 nanoclusters exhibit largely improved thermal stability compared to the glutathione (HSG) capped Au25(SG)18. Both Au25(Capt)18 and Au25(SG)18 nanoclusters show fluorescence centered at ~700 nm. The chiral ligands (Capt, SG, as well as chirally modified phenylethanethiol (PET*)) give rise to distinct chiroptical features. The high thermal stability and distinct optical properties of Au25(Capt)18 nanoclusters render this material quite promising for biological applications. Electronic supplementary

  3. A facile strategy to fabricate Au/TiO2 nanotubes photoelectrode with excellent photoelectrocatalytic properties

    NASA Astrophysics Data System (ADS)

    Zhang, Guowei; Miao, Hui; Hu, Xiaoyun; Mu, Jianglong; Liu, Xixi; Han, Tongxin; Fan, Jun; Liu, Enzhou; Yin, Yunchao; Wan, Jun

    2017-01-01

    Highly ordered titanium dioxide nanotubes (TiO2 NTs) were prepared by a low-temperature hydrothermal process with Ti sheet as precursor in NaOH solutions. Gold nanoparticles (Au NPs) were then deposited on the surface of TiO2 NTs by a microwave-assisted chemical reduction route. The investigation reveal that the Au NPs are well dispersed on the surface of TiO2 NTs in metallic state, and Au NPs can effectively promote the separation of photogenerated electron-hole pairs. Besides, Au NPs also can enhance the visible light absorption of TiO2 NTs due to their localized surface plasmon resonance (LSPR) effect. The experimental results indicate that 0.5 Au/TiO2 NTs film with an photocurrent of 19.0 μA/cm2 exhibits the highest photoelectrocatalytic (PEC) activity, when under a low bias of 0.5 V, in the degradation of methylene blue (MB). Additionally, the mechanism for the enhanced PEC performance of Au/TiO2 NTs is preliminarily discussed. The Au NPs decorated TiO2 NTs displayed a more effective separation of photogenerated electron-hole pairs. The enhanced visible light absorption was owning to the Au NPs localized surface plasmon resonance (LSPR) effect. Finally, the mechanism for the enhanced PEC performance of Au/TiO2 NTs was also proposed.

  4. Urban Combat Advanced Training Technology (Technologie Avancee d’Entrainement au Combat Urbain)

    DTIC Science & Technology

    2010-04-01

    la satisfaction de son objectif. De plus des documents ont été donnés au SISO et à l’ITEC. Le...souhaitables. Si vous souhaitez recevoir une notification électronique de la disponibilité des rapports de la RTO au fur et à mesure de leur publication...INTRODUCTION Le groupe de travail (TG) sur la Technologie avancée d’entraînement au combat urbain (UCATT) a été constitué au sein du groupe de

  5. Nanoscale Wire Bonding of Individual Ag Nanowires on Au Substrate at Room Temperature

    NASA Astrophysics Data System (ADS)

    Peng, Peng; Guo, Wei; Zhu, Ying; Liu, Lei; Zou, Guisheng; Zhou, Y. Norman

    2017-07-01

    The controllable wire bonding of individual Ag nanowires onto a Au electrode was achieved at room temperature. The plastic deformation induced by pressure using nanoindentation could break the protective organic shell on the surface of the Ag nanowires and cause atomic contact to promote the diffusion and nanojoining at the Ag and Au interface. Severe slip bands were observed in the Ag nanowires after the deformation. A metallic bond was formed at the interface, with the Ag diffusing into the Au more than the Au diffused into the Ag. This nanoscale wire bonding might present opportunities for nanoscale packaging and nanodevice design.