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Sample records for precoce au traitement

  1. 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

  2. Applications de la tranformee en ondelettes au traitement de l'information optique

    NASA Astrophysics Data System (ADS)

    Deschenes, Sylvain

    La these presente l'apport d'un outil mathematique recemment decouvert, la transformee en ondelettes, au traitement de l'information optique. Les ondelettes continues sont d'abords introduites et leur realisation optique est presentee. Ensuite, une ondelette repondant aux equations de Maxwell est developpee. Cette derniere permet de tisser des liens entre la transformee en ondelettes et le principe de Huygens utilise pour etudier la diffraction scalaire. La possibilite d'utiliser cette ondelette pour generer des faisceaux non diffractants est egalement discutee. Dans un deuxieme temps, les ondelettes discretes sont utilisees dans le but d'extraire des informations pertinentes dans une banque d'images infrarouges. Ces images representent les vues de vehicules prises a tous les cinq degres. La transformee en ondelettes genere une analyse multiresolution permettant d'extraire des contours moins bruites. Cette information est alors traitee par de nouveaux algorithmes de reconnaissance de forme dans un espace qui caracterise de facon invariante les objets 3-D.

  3. Arthrose due au genu varum: traitement par osteotomie tibiale de valgisation

    PubMed Central

    Moussa, Abdou Kadri; Lukulunga, Loubet Unyendje; Mahfoud, Mustapha; El Bardouni, Ahmed; Ismail, Farid; Kharmaz, Mohamed; Berrada, Mohammed Saleh; El Yaacoubi, Moradh

    2014-01-01

    Le traitement du genu varum est le plus souvent conservateur (ostéotomie tibiale de valgisation) permettant de corriger le trouble architectural afin de rétablir l'axe physiologique du membre inférieur. Le but de l’étude était d’évaluer les résultats du traitement et comparer à ceux de la littérature. Il s'est agi d'une étude rétrospective portant sur des patients présentant un genu varum qui s'est déroulée dans le Service de Chirurgie Orthopédique et Traumatologie de CHU Ibn SINA de RABAT, sur une période de 9 ans (2000 au 31 Décembre 2008). Nous avons inclus dans notre étude: les patients qui avaient un genu-varum clinique avec examen radiographique standard ainsi qu'un pangonogramme; traités par différents procédés d'ostéotomie tibiale de valgisation; avec un suivis d’ au moins deux ans. Nos critères d’évaluation ont été appréciés selon le score HSS. Nous avons colligé 115 cas de genu-varum par ostéotomie de valgisation. L’âge de nos patients variait entre 40 et 69 ans, avec une moyenne de 53 ans. Le pic de fréquence se situait entre 52et 63 ans. Le sexe féminin prédominait avec 87 cas (75,6%) avec un sex ratio 3,1. Un Indice de masse corporelle supérieur à 30 a été noté dans 44 cas (38%). Quant aux antécédents chirurgicaux,18 patients de la série (soit 14%) ont été opérés pour le genu varum d'un autre genou. Le délai de consultation a varié entre 4 mois à 6 ans, avec une moyenne de 2 ans. La douleur était le principal motif de consultation et était de siège médial dans 70% des cas et bicompartimental dans 30% cas. Il s'agissait d'une douleur mécanique dans 76% des cas, mixte 21% des cas et inflammatoire 4% des cas. La déformation du genou appréciée par l’écart intercondylien a été en moyenne de 8,7 cm avec des extrêmes de 3 cm et 33cm. Le bilan de l'imagerie médicale reposait essentiellement sur les radiographies standards du genou de face et de profil, ainsi que la goniométrie. Ces

  4. 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

  5. L’évaluation et le traitement du nourrisson exposé au virus d’immunodéficience humaine de type 1

    PubMed Central

    2004-01-01

    RÉSUMÉ Dans les pays industrialisés, des soins et un traitement sont offerts aux femmes enceintes et aux nourrissons, afin de faire chuter à 2 % ou moins le taux d’infection périnatale au virus d’immunodéficience humaine de type 1 (VIH-1). Le pédiatre joue un rôle de premier plan dans la prévention de la transmission du VIH-1 de la mère à l’enfant par le dépistage des nourrissons exposés au VIH dont l’infection au VIH de la mère n’a pas été diagnostiquée avant l’accouchement. Il prescrit une prophylaxie antirétrovirale à ces nourrissons, afin de réduire le risque d’acquisition de l’infection au VIH-1 et d’en éviter le plus possible la transmission par le lait maternel. De plus, le pédiatre peut soigner les nourrissons exposés au VIH-1 en les surveillant pour obtenir un dépistage précoce de l’infection au VIH-1 et évaluer les toxicités à court et à long terme de l’exposition aux antirétroviraux, assurer une chimioprophylaxie de la pneumonie à Pneumocystis et soutenir les familles qui vivent avec une infection au VIH-1, grâce à des conseils thérapeutiques aux parents ou aux soignants.

  6. Etude de l'anémie chez les enfants séropositifs au VIH naïfs au traitement antirétroviral à Lubumbashi, République Démocratique du Congo

    PubMed Central

    Mwadianvita, Costa Kazadi; Ilunga, Eric Kasamba; Djouma, Jackson; Wembonyama, Cecile Watu; Mutomb, Florence Mujing A; Ekwalanga, Michel Balaka; Kabongo, Joe; Mundongo, Henri; Mupoya, Kalombo; Wembonyama, Stanis; Kalenga Mwenze, Prosper; Nkoy, Albert Mwembo-Tambwe A

    2014-01-01

    Introduction Beaucoup d'enfants infectés par le VIH arrivent à la consultation dans un état d'anémie. Notre objectif était d’évaluer la prévalence et le typage de l'anémie chez ces enfants. Méthodes C'est une étude transversale réalisée dans 3 centres de prise en charge des Personnes Vivant avec le VIH à Lubumbashi de Mai 2010 à Mai 2011. La population d’étude était de 152 enfants, âgés de 6 à 180 mois, naïfs au traitement antirétroviral. Les statistiques descriptives usuelles ont été utilisées. Résultats La prévalence globale de l'anémie (définie comme l'hémoglobine < 11g/dl) était de 69,1% (n=105) et 11,4% avaient une anémie sévère (Hg < 7,0 g/dl). Parmi eux, 16% ont été transfusés au moins 1 fois. L'anémie sévère était positivement associée au stade clinique de la maladie (p=0,02). L'anémie microcytaire était majoritaire dans les deux tranches d’âge. Elle était plus hypochrome chez les enfants en âge préscolaire soit 9,5% et plus normochrome en âge scolaire soit 15,2%. L'anémie normocytaire était plus normochrome dans les deux tranches d’âge soit 12,4% en âge préscolaire et 6,7% en âge scolaire. L'anémie macrocytaire était rare. Conclusion Environ sept enfants sur dix, âgés de moins de 15 ans infectés par le VIH naïfs au traitement antirétroviral dans notre milieu sont anémiques. L'anémie est corrélée à la sévérité de la maladie. Il est important d'associer une prise en charge nutritionnelle et corriger l'anémie avant une trithérapie antirétrovirale. PMID:25018796

  7. Prévalence, facteurs associés et prédisposant au syndrome métabolique chez les personnes vivants avec le VIH sous traitement antirétroviral à Porto-Novo en 2014

    PubMed Central

    Adébayo, Alassani; Albert, Dovonou Comlan; Ericie, Sossou; Angelo, Attinsounon Cossi; Jules, Gninkoun; Armand, Wanvoegbe; Séraphin, Ahoui; Léopold, Codjo; Gabriel, Ade

    2015-01-01

    Introduction Le syndrome métabolique est associé aux maladies cardiovasculaires. L'infection au VIH est devenue aujourd'hui une maladie chronique. L'objectif de cette étude est de déterminer la prévalence, les facteurs associés et prédisposant au syndrome métabolique chez les patients infectés par le VIH sous traitement antirétroviral. Méthodes Il s'est agi d'une étude transversale, descriptive et analytique. La population d’étude est constituée des patients vivant avec le VIH sous antirétroviral suivis au Centre Hospitalier Universitaire de l'Ouémé-Plateau. Le syndrome métabolique a été défini selon les critères de la Fédération Internationale du Diabète. Résultats La population était constituée de 244 patients. La prévalence du syndrome métabolique était de 18,03% avec une prédominance féminine (74,6%). La moyenne d’âge était de 40,7 ± 9,71 ans. Les facteurs associés au syndrome métabolique étaient le sexe féminin, la sédentarité, l'antécédent d'HTA, le surpoids, l'apport énergétique élevé, l'apport lipidique élevé, la consommation d'alcool, la consommation de tabac et l'hypercholestérolémie. Les facteurs prédisposant au syndrome métabolique étaient la présence de l'HTA, le tour de taille élevé, l'hyperglycémie, l'hypocholestérolémie HDL et l'hypertriglycéridémie. Conclusion Le syndrome métabolique est fréquent chez les patients infectés par le VIH sous traitement antirétroviral. Une prévention prenant en compte les facteurs associés et prédisposant s'avère nécessaire. PMID:26966492

  8. Suivi par chromatographie gazeuse inverse de la transformation de la goethite en hématite au cours d'un traitement thermique

    NASA Astrophysics Data System (ADS)

    Brendlé, E.; Papirer, E.

    1998-05-01

    Inverse Gas Chromatography (IGC) is a method well suited for the study of the surface properties of divided solids and of the modifications that result from applied treatments. In this instance, IGC was used to follow the surface properties variations (adsorption energy of alkanes, nanomorphology, acid-base behavior) that occur when goethite, upon heat treatment, transforms into hematite. La chromatographie Gazeuse Inverse (CGI) s'avère comme une méthode de choix pour l'étude des propriétés de surface de solides divisés et des modifications qui accompagnent les traitements auxquels on les soumet. Dans cette étude, la CGI est utilisée pour suivre les variations des propriétés de surface (énergie d'adsorption des alcanes, nanomorphologie, caractère acide-base) se produisant lors de la transformation de la goethite en hématite consécutive à un traitement thermique.

  9. Approches actuelles au traitement du zona

    PubMed Central

    Bissonnette, R.; Leclerc, G.

    1992-01-01

    Herpes zoster is a very common pathology. A description of its clinical presentation and treatment in both immunocompromised and immunocompetent patients is provided. There is also a discussion of controversial aspects of treatment in the light of recent medical findings. ImagesFigure 1 PMID:21221384

  10. Les Abondances Chimiques dans les Galaxies Spirales de Type Precoce

    NASA Astrophysics Data System (ADS)

    Dutil, Yvan

    1998-09-01

    Les galaxies spriales presentent une distribution continue de formes et de proprietes physiques. A l'heure actuelle, il existe deux ecoles de pensee au sujet de la nature de ces proprietes morphologiques des galaxies. Pour certains elles sont innees, pour d'autres elles sont acquises. Les gradients d'abondance nebulaires, de par leur sensibilite aux mouvements a grande echelle du gaz et au taux de formation stellaire, offrent une possibilite de trancher dans ce debat. Toutefois, jusqu'ici, on a surtout observe les gradients d'abondance dans les galaxies de type tardif. Le premier objectif de cette these est d'enrichir l'echantillon de galaxies de type precoce observees. Le second objectif est de demontrer qu'il y a deja eu une barre dans les galaxies de type precoce et, si possible, de chercher des traces d'interactions dans ces galaxies. Dans le cadre de cette these, j'ai observe huit galaxies de type precoce. Mes observations indiquent que ces galaxies presentent des profils d'abondance dont les caracteristiques se rapprochent des galaxies barrees, meme si certaines ne presentent pas de barres. Ce resultat renforce l'hypothese selon laquelle les galaxies changent de type morphologique au cours du temps sous l'effet d'instabilites comme les barres.

  11. Etude des facteurs liés à l'observance au traitement antirétroviral chez les patients suivis à l'Unité de Prise En Charge du VIH/SIDA de l'Hôpital de District de Dschang, Cameroun

    PubMed Central

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

    2012-01-01

    Introduction Etudier les facteurs liés à l'observance au traitement antirétroviral chez les patients adultes suivis à l'Unité de Prise en Charge du VIH/SIDA (UPEC) de l'hôpital de District de Dschang. Méthodes Dans une étude descriptive transversale conduite à l'hôpital de District de Dschang, l'observance a été évaluée sur la base des déclarations des patients et sur la régularité du renouvellement de leurs ordonnances (observance calculée). Résultats Parmi les 389 patients répondant à nos critères d'inclusion, 356 ont été interrogés. La durée moyenne du suivi était de 27 mois. La moyenne d’âge était égale à 41 ans et le sexe ratio 2,46 en faveur du sexe féminin. Le statut sérologique était découvert pour 60,56% des patients à l'occasion d'un épisode maladif. Le niveau d'observance déclarée était significativement plus élevé que le niveau global de l'observance calculée (80,2% vs 51,5%, p<10−5). Les deux principales barrières à l'observance étaient l'oubli et le travail. Les patients référés dans cette UPEC étaient moins bien observants (p<10−4). L'observance au traitement antirétroviral était d'autant meilleure quand le taux de CD4 en début de traitement était élevé (p= 0,01) et que la durée du traitement était prolongée (p=0,00). Conclusion La discordance observée entre les résultats des deux méthodes utilisées pour estimer l'observance, tout en soulévant les contraintes liées à l’évaluation de l'observance thérapeutique, souligne l'importance des méthodes biologiques. Les facteurs individuels se sont avérés être les principales raisons de non-observance. Enfin, un accent devrait être mis sur les consultations d’éducation thérapeutique et le suivi psycho-social des patients sous traitement antirétroviral dans cette UPEC. PMID:22937195

  12. Evaluation du traitement antirétroviral chez les femmes enceintes VIH-1 positif, sur la transmission de l'infection de la mère à l'enfant: cas du Centre Médical Saint Camille de Ouagadougou, au Burkina Faso

    PubMed Central

    Soubeiga, Serge Theophile; Compaore, Rebecca; Djigma, Florencia; Zagre, Nicaise; Assengone, Elsa; Traore, Lassina; Diarra, Birama; Bisseye, Cyrille; Ouermi, Djeneba; Sagna, Tani; Karou, Simplice; Pietra, Virginio; Simpore, Jacques

    2015-01-01

    Introduction L'infection au VIH chez les nouveau-nés par leur mère peut être réduite grâce à des programmes de prévention de transmission mère-enfant du VIH (PTME). L'objectif dans cette étude était d’évaluer le traitement antirétroviral chez les femmes enceintes VIH-1 positif sur la transmission mère-enfant de l'infection au Centre Médical Saint Camille de Ouagadougou, Burkina Faso. Méthodes Des échantillons de spot de sang total ont été collectés chez 160 enfants âgés de 6 semaines, nés de mères VIH-1 positif et chez 40 enfants âgés de 2 à 13 mois provenant d'orphelinats et dont les mères étaient inconnues. Ces échantillons ont été testés avec le kit Abbott Real Time HIV-1 Qualitative. Un questionnaire a permis de connaitre les âges et les fonctions des femmes enceintes. Résultats Les femmes enceintes avaient un âge moyen global de 29,50±5,19 ans. Au total, 50,5% (101/200) ont été mises sous combinaison AZT/3TC/NVP et 29,5% (59/200) étaient sous prophylaxie (AZT/3TC). Le taux de transmission verticale du VIH-1 était de 0,0% (0/160) (p < 0,001) chez les enfants dont les mères étaient sous combinaison AZT/3TC/NVP ou sous prophylaxie AZT/3TC et de 15,0% (6/40) chez les enfants orphelins qui n’étaient pas inclus dans le protocole de la PTME. Conclusion Selon les résultats, le protocole de la PTME est efficace et réduit très significativement le risque de transmission du VIH-1 de la mère à l'enfant. De plus, le dépistage par PCR, des enfants orphelins infectés verticalement par le VIH, permet leur prise en charge thérapeutique précoce. PMID:26301003

  13. Evaluation des résultats après traitement des lésions intra épithéliales du col utérin par la cryothérapie: étude préliminaire au Centre Hospitalier Universitaire de Yaoundé: A propos de 21 cas

    PubMed Central

    Ndoua, Claude Cyrille Noa; Tebeu, Pierre Marie; Kemfang, Jean Dupont; Kasia, Jean Marie

    2015-01-01

    Nous rapportons les résultats d'une série de 21 cas de prise en charge par cryothérapie de lésions intra-épithéliales cervicales au Centre Hospitalier et Universitaire (CHU) de Yaoundé. Notre objectif principal était d’évaluer les résultats préliminaires de la prise en charge des lésions précancéreuses éligibles pour la cryothérapie. Il s'agissait d'une étude transversale descriptive qui s'est étalée sur 24 mois. Etaient inclus dans l’étude toutes les femmes traitées par cryothérapie. Nous avons exclu les patientes traitées par une autre méthode, les patientes perdues de vue et les dossiers incomplets. Le statut cervical a été déterminé à 6 semaines, 6 mois et 12 mois. Les complications précoces et tardives ont également été répertoriées. Au total 95.2% des lésions étaient cicatrisées à 6 semaines. A 6 mois, toutes les lésions avaient disparu et au 12ème mois, la guérison était effective chez 95.2% des patientes. Les saignements et l'hydrorrhée étaient les principales complications tardives avec des fréquences respectives de 66.7% et 95.2%. Aucun cas de sténose cervicale n'a été répertorié. La cryothérapie peut être utilisée comme méthode de traitement pour des lésions précancéreuses du col. PMID:26140068

  14. Les campagnes de dépistage du VIH, une stratégie efficace pour l’accès universel à la prévention et au traitement ? L’expérience du Burkina Faso

    PubMed Central

    Somé, J.F.; Desclaux, A.; Ky-Zerbo, O.; Lougué, M.; Kéré, S.; Obermeyer, C.; Simaga, F.

    2014-01-01

    Objectifs l’augmentation du taux de personnes qui connaissent leur statut VIH est un impératif, notamment en Afrique subsaharienne, ce qui impose d’évaluer les stratégies utilisées pour accroître la fréquentation des services de dépistage. Cet article vise à faire le bilan de la pertinence, de la faisabilité et de l’efficacité des campagnes nationales de dépistagemenées entre 2006 et 2010 au Burkina Faso. Méthodologie une analyse de toutes les données de fréquentation du conseil dépistage sur cette période a été faite, couplée à des entretiens avec les principaux acteurs intervenant dans le dépistage. Résultats les résultats montrent que les huit campagnes de dépistage organisées sur la période ont permis à 487 727 personnes de faire leur test VIH. Ce nombre représente 50 % du nombre total de personnes ayant fait leur test et contribue à hauteur de 24,6 % au dépistage des personnes séropositives identifiées au cours de cette période. Les campagnes ont touché des populations difficiles à atteindre (en particulier les jeunes), à un coût moindre. Conclusions cette stratégie est donc pertinente pour identifier les personnes VIH+. Son intérêt pour la prévention, important selon les soignants et au vu des populations jeunes qui y participent, devrait être mesuré par des études complémentaires. Les campagnes sont efficaces et coût-efficaces même dans un pays de niveau de prévalence faible. Ces résultats soulignent l’intérêt de la synergie entre les associations et les services de santé dans l’offre de services de conseil et dépistage. PMID:24681563

  15. Precocity Predicts Shorter Life for Major League Baseball Players: Confirmation of Mccann's Precocity-Longevity Hypothesis

    ERIC Educational Resources Information Center

    Abel, Ernest L.; Kruger, Michael L.

    2007-01-01

    We tested McCann's precocity-longevity hypothesis, which proposes that early career achievement is related to premature death, for Major League baseball players (N = 3,760). Age at debut was the definition for precocity. We controlled for possible artifacts of life expectancy selection, the "healthy worker" effect, player position, and body-mass…

  16. Oncoplastie avec conservation mammaire dans le traitement du cancer du sein: à propos de 16 cas

    PubMed Central

    Bouzoubaa, Wail; Laadioui, Meryam; Jayi, Sofia; Alaoui, Fatime Zahra Fdili; Bouguern, Hakima; Chaara, Hikmat; Melhouf, Moulay Abdelilah

    2015-01-01

    Le cancer du sein est actuellement le cancer le plus fréquent chez la femme, et pose un véritable problème diagnostique et thérapeutique. Le dépistage des lésions à un stade de plus en plus précoce, a permis une extension des indications du traitement conservateur radiochirurgical, qui était initialement limitées aux tumeurs de moins de 3 cm, unifocales, non inflammatoires. Par ailleurs, l'utilisation de traitements préopératoires permet d’étendre les indications du traitement conservateur à des tumeurs plus volumineuses. Parallèlement à cette extension des indications de conservation mammaire, on a observé le développement de nouvelles approches thérapeutiques notamment la chirurgie oncoplastique, technique du ganglion sentinelle et chirurgie stéréotaxique, dont les résultats initiaux sont très encouragent. A travers cette étude réalisée dans le service de gynécologie et obstétrique II du CHU HASSAN II de FES au MAROC, après l'analyse rétrospective de 16 patientes traitées par traitement conservateur et oncoplastie, nous avons voulus montrer notre aptitude a réalisé ses techniques chirurgicales et a bien prendre en charge ces patientes, mais aussi évaluer ces techniques en termes de résultat carcinologique et de résultat esthétique, aussi en terme de survie globale, survie sans métastase et en termes de récidive locale entre les plasties mammaires et les traitements usuels: mastectomie et traitement conservateur classique. PMID:26430477

  17. Acupuncture Au Laser He-Ne: Traitement Des Infections Rhinopharyngees

    NASA Astrophysics Data System (ADS)

    Dussert, Dr.

    1984-03-01

    Mesdames, Messieurs, y a 23 mois, je recevais l'urgence suivante dans mon cabinet medical : 1) Un homme de 53 ans, dyspneioue (cliniquement it etait en Bradypnee expiratoire). Il venait d'être hospitalise 1 mois et avait ete place sous cortisone. Je le fais assoir, et j'irradie avec un laser sur chacun des ganglions stellaires pendant 6 minutes je debloque ce malade qui se met e respirer normalement. 2) Quelques temps apres : C'est un enfant de 7 ans que je regois en crise d'asthme. J'irradie sur chacun des ganglions stellaires pendant 4 minutes une onde laser d'impulsion 6 et en basse freouence. L'enfant voit s'estomper la crise d'asthme. Devant ces deux cas, je decide d'organiser un travail de recherche.

  18. Appendicite aigue non compliquée: y a-t- il une place pour le traitement conservateur

    PubMed Central

    El Khader, Ahmed; Lahkim, Mohamed; El Barni, Rachid; Achour, Abdessamad

    2015-01-01

    Le but de cette étude a été d’évaluer l'efficacité de l'antibiothérapie seule dans le traitement des appendicites aigues non compliquées. C'est une étude prospective, intéressant 68 patients ayant eu une appendicite aigue simple, de confirmation radiologique, traités par l'amoxicilline associée à l'acide clavulanique pendant 10 jours. L'appendicectomie a été réalisée en cas d'aggravation ou en cas de non amélioration au bout de 48heures de traitement. Le traitement conservateur a été efficace dans 82,35% avec une résolution complète des symptômes chez 56 patients. Les 12 cas restants (17,65%) ont subit une appendicectomie. l'appendicite a été gangréneuse dans 8 cas et phlegmoneuse dans 4 cas. Cinq des 56 patients, qui ont bien évolué sous traitement conservateur, ont été réadmis et opérés pour récidive, soit 8,9%. Deux cas ont eu une appendicite compliquée. L'appendicectomie reste le traitement de référence pour l'appendicite aigue, mais le traitement antibiotique peut être proposé en première intension à des patients présentant une appendicite aigue non compliquée. PMID:26327981

  19. Traitement endoscopique des complications biliaires de l'hydatidose hépatique

    PubMed Central

    Massit, Hanane; Seddik, Hassan; Basr, Hanane; Benkirane, Ahmed

    2015-01-01

    L'objectif était d’évaluer l'efficacité du traitement endoscopique des complications biliaires de l'hydatidose hépatique. Ont été inclus 36 patients hospitalisés pour prise en charge endoscopique des complications biliaires du kyste hydatique du foie (KHF) sur une période de 13 ans, d'un âge moyen de 46 ans et avec une prédominance masculine dans 63% des cas. La prévalence des complications biliaires du KHF est de 2,3% dans notre série. La cholangiopancréatographie rétrograde endoscopique (CPRE) a permis d'objectiver une fistule kystobiliaire dans 35% des cas, des images lacunaires dans la voie biliaire principale (VBP) dans 70% des cas en rapport avec du matériel hydatique. La sphinctérotomie endoscopique (SE) a été réalisée chez tous les patients permettant l'extraction de matériel hydatique par ballonnet d'extraction ou par panier Dormia, ainsi qu'une dilatation de la VBP par bougie. L’évolution a été marquée par la disparition de l'ictère au bout de 5 à 12 jours en moyenne après le geste endoscopique et par le tarissement de la fistule biliaire externe au bout de 10 à 12 jours. Aucune complication liée au traitement endoscopique n'a été objectivée. Trois patients ont évolué vers une cholangite sclérosante qui s'est compliquée d'une cirrhose biliaire secondaire au bout de 3 ans. Le traitement endoscopique des complications biliaires d'hydatidose hépatique est une thérapie sûre et efficace avec une faible morbidité et mortalité. PMID:26834920

  20. Evaluation du niveau de connaissance des patients sur la gestion du traitement par les antis vitamines K dans le service de cardiologie de Ouagadougou

    PubMed Central

    Samadoulougou, André; Temoua Naibe, Dangwé; Mandi, Germain; Yameogo, Relwendé Aristide; Kabore, Elisé; Millogo, Georges; Yameogo, Nobila Valentin; Kologo, Jonas Koudougou; Thiam/Tall, Anna; Toguyeni, Boubacar Jean Yves; Zabsonre, Patrice

    2014-01-01

    Introduction Les antivitamines K (AVK), traitement anticoagulant oral le plus largement prescrit, posent un réel problème de santé publique du fait de leur risque iatrogène. L'objectif de cette étude était de préciser le niveau de connaissance des patients sur la gestion de leur traitement par les AVK. Méthodes Il s'est agi d'une enquête transversale descriptive réalisée au CHU-Yalgado Ouédraogo, sur une période de 03 mois : du 1er mars au 31 mai 2012. Un questionnaire a été administré aux patients bénéficiant d'un traitement AVK depuis au moins un mois. Résultats Soixante-dix patients ont été inclus dans l'étude dont 30 hommes. L'âge moyen était de 49 ans ± 16 ans. Les cardiopathies et la maladie thromboembolique veineuse justifiant l'institution du traitement AVK étaient retrouvées respectivement dans 58,6% et 41,4% des cas. Le nom de l'AVK et la raison exacte du traitement étaient connus respectivement dans 91,4% et 67,1% des cas. Plus de la moitié des patients (68,6%) savaient que les AVK rendaient le sang plus fluide. Quarante-six patients (65,7%) citaient l'INR comme examen biologique de surveillance du traitement et seulement 28 patients (40%) connaissaient les valeurs cibles. La majorité des patients ne connaissait pas les risques encourus en cas de surdosage (72,8%) et de sous-dosage (71,4%). Une automédication par anti-inflammatoire non stéroïdien était signalée par 18 patients (25,7%). Les choux (74,3%) et la laitue (62,9%), aliments à consommer avec modération, étaient les plus cités. Conclusion Les connaissances des patients sur la gestion des AVK étaient fragmentaires et insuffisantes pour assurer la sécurité et l'efficacité du traitement. La création d'un programme d'éducation thérapeutique sur les AVK s'avère alors nécessaire. PMID:25870741

  1. Traitement chirurgical des fractures articulaires du calcanéum par plaque vissée

    PubMed Central

    Hammou, Nassreddine; Abid, Hatim; Shimi, Mohammed; El Ibrahimi, Abdelhalim; El Mrini, Abdelmajid

    2015-01-01

    Les fractures du calcanéum sont peu fréquentes mais le plus souvent graves. Le traitement chirurgical par plaque vissée est ardemment défendu. L'objectif de notre travail rétrospectif est d’évaluer les résultats du traitement chirurgical des fractures articulaires du calcanéum à travers une série de 12 patients opérée aux service d'orthopédie du CHU Hassan II de Fès sur une durée de 3 ans, et les comparer aux données de la littérature. L’âge moyen dans notre série était de 34 ans, le geste opératoire était réalisé au 7ème jour. Tous nos patient ont bénéficie d'une réduction à foyer ouvert avec une ostéosynthèse par plaques vissées. Le recul moyen était de 12 mois et les résultats fonctionnels ont été évaluer selon le score de Kitaoka. PMID:26161214

  2. Les bisphosphonates dans le traitement de l’ostéoporose

    PubMed Central

    Brown, Jacques P.; Morin, Suzanne; Leslie, William; Papaioannou, Alexandra; Cheung, Angela M.; Davison, Kenneth S.; Goltzman, David; Hanley, David Arthur; Hodsman, Anthony; Josse, Robert; Jovaisas, Algis; Juby, Angela; Kaiser, Stephanie; Karaplis, Andrew; Kendler, David; Khan, Aliya; Ngui, Daniel; Olszynski, Wojciech; Ste-Marie, Louis-Georges; Adachi, Jonathan

    2014-01-01

    Résumé Objectif Exposer l’efficacité et les risques du traitement par les bisphosphonates dans la prise en charge de l’ostéoporose et décrire les patients qui seraient de bons candidats aux congés thérapeutiques. Qualité des données Une recherche dans MEDLINE (PubMed, jusqu’au 31 décembre 2012) a permis de relever les publications pertinentes pour l’inclusion. La plupart des données probantes citées sont de niveau II (tirées d’essais non randomisés, de cohorte et d’autres essais comparatifs). Message principal L’efficacité des bisphosphonates de premier recours homologués pour la prévention des fractures a été éprouvée dans le cadre d’essais cliniques randomisés et contrôlés. Cependant, l’usage clinique répandu et prolongé des bisphosphonates a donné lieu à des rapports de manifestations indésirables rares, mais graves. L’ostéonécrose maxillaire et les fractures atypiques sous-trochantériennes ou diaphysaires du fémur seraient liées à l’emploi des bisphosphonates dans le traitement de l’ostéoporose, mais ces manifestations sont extrêmement rares et lorsqu’elles surviennent, elles sont accompagnées d’autres comorbidités ou de l’emploi concomitant de médicaments. Les congés thérapeutiques ne peuvent être envisagés que chez les patients à faible risque et dans un groupe restreint de patients dont le risque de fracture est modéré après un traitement de 3 à 5 ans. Conclusion Lorsque les bisphosphonates sont prescrits à des patients dont le risque de fracture est élevé, leur effet de prévention des fractures l’emporte de loin sur leurs torts potentiels. Chez les patients qui prennent des bisphosphonates depuis 3 à 5 ans, il faut réévaluer le besoin de poursuivre le traitement.

  3. Curiethérapie dans le traitement palliatif du cancer de l’œsophage

    PubMed Central

    Toulba, Ahmedou; Bakkali, Hanae; Boutayeb, Salwa; Kebdani, Tayeb; Ahid, Samir; Benjaafar, Noureddine

    2015-01-01

    Les patients atteints du cancer de l’œsophage ont souvent une maladie localement avancée, la dysphagie est le symptôme majeur chez la plupart de ces patients, plusieurs modalités thérapeutiques ont été utilisées pour améliorer cette dysphagie. Le but de ce travail est d’étudier l'efficacité et la tolérance de la curiethérapie haut débit de dose (HDR) endo-luminale dans le traitement palliatif des cancers de l’œsophage inopérable. Sur une période de 15 ans, l’étude a inclus les patients atteints de cancer de l’œsophage inopérable et/ou métastatique avec une dysphagie, sans extension à l'hypopharynx ou a la trachée et qui ont bénéficié d'une curiethérapie HDR avec ou sans radiothérapie externe à visée palliative. Au total 46 patients ont été inclus dans l’étude, 58,7% étaient des hommes, 42,2% avaient une dysphagie grade 2 et 37,8% étaient aphagiques, 78,6% des patients étaient performance satus PS 2, l'amaigrissement à été trouvé chez 81,4%, la localisation de la tumeur était surtout au niveau du tiers moyen et inférieur dans 97,8%, la hauteur médiane de la tumeur était de 7 cm (5,5-9), le carcinome épidermoïde était le type histologique le plus fréquent chez 31 patients (70,5%). Après un médiane de suivi de 5 mois, l'amélioration de la dysphagie a été retrouvée chez 76% des malades (p1]. L′incidence la plus élevée est observée dans certains pays notamment en Asie et en Afrique, et l′incidence dans les pays développés occidentaux est en augmentation [2]. Selon le registre du cancer de Rabat 2006-2008, le cancer de l’œsophage est rare et constitue 1,5% de tous les cancers chez l'homme [3]. Le taux de survie globale à 5 ans est de 8%, avec 80% des décès liés à l’évolution locale de la maladie [4]. Pour la minorité des patients avec une maladie localisée, le traitement par radiochimiothérapie concomitante avec ou sans chirurgie permet une amélioration de la survie [5]. Plus de 50

  4. Traitement arthroscopique d'une fracture articulaire de la glène: nouvelle astuce

    PubMed Central

    Hamoudi, Samir; Alassaf, Ihab; Boussakri, Hassan; Ntrataze, Philbert; Dumez, Jean François

    2015-01-01

    Le traitement des fractures de la glène scapulaire constitue un sujet de débat dans la littérature. Les auteurs décrivent une observation d'un patient âgé de 22 ans qui présente une fracture articulaire de la glène classée stade III de Ideberg traitée chirurgicalement sous arthroscopie. Nous exposons une nouvelle technique chirurgicale utilisant un matériel simple et nous la recommandons pour ce type de fracture qui constitue une alternative efficace. Globalement, nos résultats cliniques et anatomiques immédiats et à moyen terme, au dernier recul, sont excellents. PMID:26161191

  5. Le traitement familial des enfants et des adolescents anorexiques : Des lignes directrices pour le médecin communautaire

    PubMed Central

    Findlay, S; Pinzon, J; Taddeo, D; Katzman, DK

    2010-01-01

    L’anorexie mentale (AM) est une maladie grave qui met la vie en danger et qui fait généralement son apparition pendant l’adolescence. Les données probantes au sujet du traitement optimal de l’AM chez les enfants et les adolescents sont en croissance, mais il reste beaucoup à apprendre. Même si les démarches thérapeutiques actuelles varient au Canada et ailleurs, les données jusqu’à présent indiquent que le traitement familial (TF) est le plus efficace pour les enfants et les adolescents anorexiques. Un élément essentiel du modèle de TF, c’est que les parents sont investis de la responsabilité de rétablir la santé physique de leur enfant et de s’assurer de la reprise complète de son poids. Le médecin qui comprend les principes fondamentaux et la philosophie du TF peut mettre en place les éléments de cette intervention fondée sur des faits probants auprès des jeunes patients anorexiques et de leur famille.

  6. Quelle est la place de la toxine botulique dans le traitement de l’hyperplasie bénigne de prostate?

    PubMed Central

    Mazdar, Adil; Bedouche, Ali; Zoughari, Sinane; Ibrahimi, Ahmed; Sayegh, Hachem El; Iken, Ali; Benslimane, Lounis; Nouini, Yassine

    2016-01-01

    La toxine botulique (TB) a fait son apparition en urologie dans le champ de la neuro-urologie comme traitement de la dyssynergie vésico-sphinctérienne et de l'incontinence par hyperactivité détrusorienne neurogène. Son action est maintenant clairement démontrée et constitue désormais un traitement largement utilisé dans l'hyperactivité vésicale neurogène. La toxine botulique peut-elle constituer un traitement efficace de l'hyperplasie bénigne de prostate (HBP)? L’injection intraprostatique de TB a récemment été étudiée dans le traitement de l’HBP. Elle semble permettre une amélioration importante des symptômes urinaires sans effets secondaires significatifs et pourrait donc représenter une alternative mini-invasive intéressante aux traitements classiques de l’HBP. Les avantages de son utilisation sont la simplicité de sa mise en oeuvre, l'absence d'effets secondaires rapportés et sa durée d'action prolongée. Des études soigneusement menées, prospectives, contrôlées portant sur des effectifs plus grands sont désormais nécessaires pour confirmer ces premiers résultats. Nous proposons a à travers ce travail une exposition des connaissances actuelles des mécanismes d’action de la TB au niveau prostatique et les résultats des principales études cliniques dans l’HBP. PMID:28154664

  7. Verrue géante et récalcitrante: succès d'un traitement par photothérapie dynamique

    PubMed Central

    Meziane, Mariame; Bettioui, Asmae; Krich, Sanae; Mernissi, Fatima-zahra

    2013-01-01

    La photothérapie dynamique (PDT) utilisant l'acide methyl ester amino-levulinique est essentiellement utilisée dans les pathologies cutanées cancéreuses et précancéreuses. Son application au traitement des verrues est de description récente. Nous rapportons le cas d'un patient immunocompétent ayant une verrue géante et récalcitrante de la main droite traitée avec succès par la PDT, et discutons les difficultés de la prise en charge de ces verrues et l'intérêt de ce traitement dans l'obtention d'une bonne réponse thérapeutique et cosmétique avec peu de risque de récidive. PMID:24570800

  8. [Teenagers and age of first drinking: A disturbing precocity?].

    PubMed

    Picherot, G; Urbain, J; Dreno, L; Caldagues, E; Caquard, M; Pernel, A-S; Amar, M

    2010-05-01

    Age of first drink in France and Western countries is early. National and international surveys confirm this early onset. Drunkenness, which is the most obvious drinking outcome, seems to rise amongst young adolescents. Consequences of this precocity are considerable. At short-term, drunk teenagers are more frequently victims of accidents. In addition, they are more vulnerable to sexual abuses, as victims but also as perpetrators. At medium- and long-terms, the early development of alcohol use is linked to higher levels of later drinking dependence. Three explanatory ways for this precocity are developed: family's influence, role of advertising and media, and role of peers. When alcohol meets adolescence, it is sometimes a real storm. Prevention is uneasy because of the very commonplace of alcohol at home. It can concern family level or society level. As for tobacco, society intervention is needed to delay age of first drink and limit teenager alcohol use but this should not involved adolescents condemnation.

  9. Traitement chirurgical initial des brûlures de la main de l’enfant. Revue

    PubMed Central

    Goffinet, L.; Breton, A.; Gavillot, C.; Barbary, S.; Journeau, P.; Lascombes, P.; Dautel, G.

    2015-01-01

    Summary Trente cinq revues concernant la prise en charge chirurgicale de la main brûlée de l’enfant sont indexées dans Pub- Med. Elles portent sur l’indication de la cicatrisation dirigée versus chirurgie, les techniques et délais d’instauration des traitements par excision-greffe, le calendrier et la nature du traitement de réadaptation et la surveillance. L’enfant présente un risque accru de brides cicatricielles, nécessitant un suivi médico-chirurgical attentif et prolongé. L’objet de cet article est de rapporter les spécificités chirurgicales de la prise en charge de ces brûlures. Cette revue de la littérature, réalisée au moyen de la base PubMed (publication entre 2005 et 2011) à partir des mots-clés « hand AND/OR child AND/OR burn » retrouve 67 publications utiles au sein de 171 références. Les données rapportées ont été comparées aux ouvrages de références français et américains. Des données contradictoires sont rapportées concernant la délai de l’excision et de la greffe, avec seulement deux études comparatives comportant de nombreux biais. L’état de la science n’apporte pas d’éléments de preuve suffisant en raison d’un manque de puissance statistique des études, mais de nombreux avis d’expert explorant chaque type d’indication permet d’établir une stratégie claire, guidant les indications thérapeutiques. Il apparaît donc indispensable de réaliser des études prospectives incluant ces patients depuis le suivi initial jusqu’au suivi à long terme, pour augmenter le niveau de preuve de cette stratégie. PMID:27279807

  10. Le rôle de l’omalizumab dans le traitement de l’asthme allergique grave

    PubMed Central

    Chapman, Kenneth R; Cartier, André; Hébert, Jacques; McIvor, R Andrew; Schellenberg, R Robert

    2006-01-01

    CONTEXTE : Un nouveau traitement anti-immunoglobuline E (anti-IgE) contre l’asthme, l’omalizumab, a été approuvé au Canada. OBJECTIF : Passer en revue les données fondamentales et cliniques sur l’omalizumab et examiner le rôle possible de ce médicament dans la prise en charge de l’asthme au Canada. MÉTHODOLOGIE : Une recherche documentaire a été effectuée dans MEDLINE afin de repérer les études menées de 1960 à 2006 sur l’omalizumab. La recherche a également porté sur les résumés de réunions scientifiques récentes dans le domaine des maladies respiratoires et des allergies; par ailleurs, toute donnée non publiée a été demandée au fabricant. Après avoir revu et résumé les données, un comité mixte constitué de spécialistes des maladies respiratoires et des allergies a rédigé un ensemble de recommandations relatives à l’utilisation de l’omalizumab. RÉSULTATS : L’omalizumab est un anticorps monoclonal humanisé qui se lie au domaine C epsilon 3 de la molécule d’IgE pour former des complexes immuns solubles qui sont éliminés par le système réticulo-endothélial. L’administration d’injections sous-cutanées espacées de deux ou de quatre semaines à la dose recommandée entraîne une diminution rapide des taux d’IgE circulantes libres. Lors de deux essais cliniques de phase III menés auprès de 1 405 adultes et adolescents atteints d’asthme modéré à grave qui recevaient des doses moyennes stables de corticostéroïdes en inhalation (CSI), l’omalizumab a diminué les taux d’exacerbation par rapport au placebo et a été associé à une amélioration des symptômes ainsi qu’à une épargne plus importante des corticostéroïdes. Dans un essai mené auprès de 419 patients atteints d’asthme grave non maîtrisé malgré l’utilisation de doses élevées de CSI et de la prise concomitante d’agonistes bêta-2 à action prolongée, les exacerbations graves étaient de 50 % moins fréquentes chez

  11. Traitement superficiel d'acier par laser excimère

    NASA Astrophysics Data System (ADS)

    Pereira, A.; Cros, A.; Delaporte, Ph.; Marine, W.; Sentis, M.

    2003-06-01

    Motivée par des nécessités économiques et environnementales, l'industrie est amenée à développer de nouveaux procédés propres, notamment pour les applications concernant la préparation de surface (nettoyage, décapage...). Dans ce domaine, l'utilisation du laser excinière présente de nombreux avantages. En effet, en raison d'un temps d'interaction de courte durée (ns), suivi d'un échauffement et d'un refroidissement rapide de la zone irradiée sur une profondeur très fine (μm), il est possible de modifier localement les propriétés physico-chimiques d'une surface sans changer les propriétés intrinsèques du matériau. Le but de nos travaux a consisté en l'étude des effets d'un traitement par laser excimère (XeCI) sur les propriétés chimiques (XPS et AES), structurales (XRD et GIXRD) et morphologiques (MEB) de surface d'acier. Outre le nettoyage de la surface, les analyses chimiques réalisées sur de l'acier ont mis en évidence pour des densités d'énergie importantes la formation d'une couche de Fe2O3 au détriment de FeOOH. Les observations MEB ont révélé la création de structures sphériques nanométriques. Ce traitement permet notamment d'améliorer la tenue à la corrosion de la surface.

  12. Évolution des lignes directrices sur le traitement de la dyslipidémie

    PubMed Central

    John Bosomworth, N.

    2014-01-01

    Résumé Objectif Comprendre comment les nouvelles lignes directrices sur la prise en charge du risque cardiovasculaire publiées par l’American Heart Association et l’American College of Cardiology (AHA-ACC) peuvent être interprétées et utilisées dans le contexte canadien. Sources des données Les lignes directrices de l’AHA-ACC ont été examinées, de même que toutes les références. Des recherches indépendantes dans PubMed ont été effectuées pour inclure l’ajout aux statines d’autres antihyperlipidémiants et l’emploi de calculatrices médicales visant à aider le patient à comprendre. Message principal Les nouvelles lignes directrices de l’AHA-ACC s’appuient sur les meilleures données probantes disponibles actuellement en matière de traitement de la dyslipidémie. Cela inclut le risque cardiovasculaire (CV) sur 10 ans comme seuil thérapeutique au lieu du taux de cholestérol des lipoprotéines de faible densité, de même que l’abandon des cibles thérapeutiques de lipoprotéines de faible densité. On met de plus en plus l’accent sur les interventions alimentaires et l’exercice, avec l’amorce d’un effort pour quantifier l’effet de ces interventions. Les statines constituent la principale intervention pharmacologique, et l’ajout d’autres médicaments pour accentuer la baisse lipidique n’est plus recommandé. En ce qui concerne l’application au Canada, les tables de risque de Framingham sont plus appropriées pour évaluer le risque que les équations de cohortes regroupées utilisées aux États-Unis. Les calculatrices du risque de maladie cardiovasculaire (MCV) devraient contenir de l’information sur l’âge cardiovasculaire et devraient pouvoir illustrer le risque et les interventions de rechange afin d’aider le patient à comprendre et de favoriser la prise de décision éclairée. Conclusion L’attention sur les meilleures données probantes concernant le risque CV peut simplifier le traitement de la

  13. Facteurs prédictifs de l’échec de traitement antituberculeux en Guinée Conakry

    PubMed Central

    Nimagan, Souleymane; Bopaka, Regis Gothard; Diallo, Mamadou Mouctar; Diallo, Boubacar Djelo; Diallo, Mamadou Bailo; Sow, Oumou Younoussa

    2015-01-01

    La tuberculose est un véritable problème de santé publique. C'est une maladie guérissable et cette guérison passe par une bonne prise en charge thérapeutique. Il arrive parfois on assiste à l’échec thérapeutique, d'où l'intérêt de notre étude portant sur les facteurs prédictifs de ses échecs. Dans l'espace d'une année sur 1300 cas de tuberculose toute forme confondue, 700 cas de tuberculose pulmonaire à microscopie positive ont été répertorié dont 100 cas transférés. La tranche d’âge de 15-25 ans a été la plus touchée avec un sexe-ratio de 2 en faveur des hommes et 41,66% de nos malades ont été les ouvriers suivis de 20,83% des commerçants. La majorité de nos patients provenait de Conakry soit 99, 5%. Sur 600 patients suivis les nouveaux cas représentaient 83,33% et l’échec thérapeutique représentait 12 cas soit 2%. L'interruption du traitement représente le principal facteur de l’échec. Les facteurs qui ont influencé la régularité des malades au traitement ont été multiples. Des facteurs liés à l'organisation du système de santé, la rupture des médicaments antituberculeux, l’éducation sanitaire insuffisante, les contraintes de la supervision du traitement, l'implication insuffisante et la vente des médicaments par le personnel de santé. Des facteurs liés aux patients eux-mêmes, la crainte de perte d'emploi, les contraintes financières. Les renforcements de l'organisation du système sanitaire et l’éducation thérapeutiques pourront réduire le taux d’échec du traitement antituberculeux. L'amélioration de la qualité de la prise en charge des malades en situation d’échec devrait passer par une culture systématique des expectorations avec antibiogramme. PMID:26889327

  14. Le traitement conservateur de la pyélonéphrite emphysémateuse chez les patients diabétiques: à propos de cinq observations

    PubMed Central

    El Majdoub, Aziz; Khallouk, Abdelhak; Farih, Moulay Hassan

    2016-01-01

    La pyélonéphrite aigue emphysémateuse (PNE) est une forme grave d'infection rénale. Elle est grevée d'une lourde mortalité en dehors d'un traitement rapide et efficace. Notre travail vise à préciser les caractéristiques cliniques et paracliniques ainsi que les particularités de la prise en charge thérapeutique de cette pathologie et nous mettons l'accent sur la possibilité d'un traitement conservateur chez le diabétique. Nous avons analysé les dossiers médicaux des patients traités pour PNE au service d'urologie du CHU Hassan II de Fès entre Janvier 2004 et janvier 2010. Pour chaque dossier, nous avons précisé les caractéristiques cliniques, paracliniques et thérapeutiques ainsi que l'évolution après traitement. Il s'agissait de 5 patientes dont l'âge moyen était de 45,6 ans. Elles étaient toutes diabétiques. Une obstruction d'origine lithiasique des voies excrétrices supérieures a été retrouvée chez 3 patientes (60%). Le diagnostic avait été porté par l'intermédiaire de la tomodensitométrie (TDM) abdominale. Toutes les patientes avaient bénéficié des mesures de réanimation associant notamment une antibiothérapie et insulinothérapie. Le traitement chirurgical était conservateur dans tous les cas. En effet, un drainage chirurgical des collections péri rénales était réalisé dans deux cas, un drainage rénal percutané dans un cas et un drainage par une sonde urétérale double JJ dans 2 cas. L'évolution clinique et radiologique était excellente avec conservation rénale chez toutes les patientes. La pyélonéphrite emphysémateuse est une complication rare et grave, en particulier chez un patient diabétique. Le diagnostic positif sur la TDM. Le traitement chirurgical doit être conservateur au maximum, en dehors des formes graves, surtout chez le patient diabétique qui est un risque potentiel d'insuffisance rénale chronique. PMID:28292113

  15. Le traitement conservateur du cancer du sein: expérience d'une équipe tunisienne

    PubMed Central

    Dimassi, Kaouther; Gharsa, Anissa; Chanoufi, Mohammed Badis; Sfar, Ezzeddine; Chelli, Dalenda

    2014-01-01

    En Tunisie, le cancer du sein touche des femmes jeunes avec une taille moyenne au moment du diagnostic à 5 cm. Ces particularités font que la chirurgie radicale reste prédominante. Nous présentons dans ce travail l'expérience de notre équipe en matière de chirurgie conservatrice du cancer du sein. Le but de ce travail est d’évaluer les résultats de ce traitement. Etude rétrospective longitudinale, sur une période de 75 mois. Nous avons inclus toutes les patientes ayant bénéficié d'un traitement conservateur pour une tumeur maligne du sein. Ont été analysés: les caractéristiques épidémiologiques, les aspects radiologiques et histologiques. Le suivi des malades s'est basé sur la détection des récidives. Nous avons évalué le résultat esthétique à la fin de la radiothérapie. Le traitement conservateur a été réalisé dans 23.8% des cas. Le taux de récidives locales était de 6.8% avec une corrélation significative pour une taille tumorale > 30 mm (p= 0.009), l'association d'une composante intracanalaire (p= 0.035), le statut triple négatif (p= 0.003) et des marges d'exérèse < 5mm sans recoupes per-opératoires (p = 0.045). Les facteurs suivants étaient significativement liés au risque de survenue de métastases à distance: le statut triple négatif (p= 0.003), taille tumorale > 30mm (p = 0.006) et l'atteinte ganglionnaire (p = 0.001). Le résultat esthétique était satisfaisant dans 90% des cas. L'augmentation du nombre de patientes pouvant bénéficier d'une chirurgie conservatrice, doit passer impérativement par le développement et la promotion du diagnostic précoce et du dépistage par la mammographie. PMID:25810795

  16. Colectomie laparoscopique versus colectomie par laparotomie dans le traitement des adénocarcinomes coliques non métastatiques

    PubMed Central

    Bayar, Rached; Mzoughi, Zeineb; Djebbi, Achref; Halek, Ghassen; Khalfallah, Mohamed Taher

    2016-01-01

    Introduction La colectomie laparoscopique pour cancer colorectal constitue, de plus en plus, le traitement de référence. L’objectif de notre travail est de montrer que les résultats à court terme etla sécurité oncologique que procure la voie laparoscopique sont au moins équivalents à ceux de la laparotomie dans le traitement des adénocarcinomes coliques non métastatiques. Nous nous proposons également d’étudier l’impact de la courbe d’apprentissage sur les résultats de la laparoscopie dans ces cancers. Méthodes Il s’agit d’une étude rétrospective incluant tousles patients opérés pour des adénocarcinomes coliques résécablessur une période de 6 ans. La population de l’étude était répartie en 2 groupes, selon la voie d’abord utilisée initialement. Le groupe « OC » comprenait 35 patients opérés par laparotomie médiane et le groupe « LAC » comprenait 30 patients opérés par laparoscopie. Toutes les données étaient analysées au moyen du logiciel SPSS version 19.0. Résultats Notre étude n’a pas montré de différence significative dans les résultats à court terme entre les 2 groupes à savoir la morbidité per-opératoire, le séjour hospitalier, le séjour en milieu de réanimation ainsi que la morbi-mortalité postopératoire. Concernant les résultats à long terme, il n’y avait également pas de différence significative en termes de complications tardives, type de récidive, survie globale et survie sans récidive. La sécurité oncologique, attestée par les limites de résections et le nombre de ganglions prélevés, n’était pas significativement différente entre les deux groupes. Le temps opératoire était significativement plus long en laparoscopie (p < 0,001). Le taux de conversion était de 33%. Il est passé de 67% au cours des 2 premières années de l’étude à 13% au cours des 2 dernières années. La conversion de la laparoscopie en laparotomie n’avait pas d’impact significatif ni sur

  17. Superposition tridimensionnelle (3-D) sur la base du crâne pour l’évaluation longitudinale des effets de la croissance et du traitement

    PubMed Central

    Cevidanes, Lucia H.S.; Styner, Martin; Proffit, William R.; Ngom, Traduit par Papa Ibrahima

    2010-01-01

    RÉSUMÉ – Pour évaluer les modifications liées à la croissance ou au traitement, il est nécessaire de superposer les céphalogrammes successifs sur une structure stable. En céphalométrie bidimensionnelle (2-D), la base du crâne est souvent utilisée pour les superpositions parce que les changements qu’elle subit après le développement cérébral sont mineurs. Toutefois, sur les céphalogrammes de profil et de face, les points de repère basicraniens sont peu fiables. Dans cet article, nous présentons une nouvelle méthode de superposition tridimensionnelle (3-D) basée sur un enregistrement entièrement automatisé des intensités de voxels, au niveau de la surface de la base du crâne. Le progiciel utilisé permet l’évaluation quantitative des modifications qui apparaissent dans le temps, grâce au calcul de la distance euclidienne entre les surfaces du modèle tridimensionnel. Il permet également l’appréciation visuelle de l’emplacement et de l’importance des modifications au niveau des maxillaires, grâce à une surimpression graphique. Les modifications sont visualisées par comparaison à des tables de correspondance de couleur. On peut ainsi réaliser une étude détaillée des modes d’adaptation chez les patients dont la croissance et/ou le traitement ont provoqué des modifications squelettiques cliniquement significatives. PMID:19954732

  18. Traitement de surface par explosif du cuivre polycristallin : caractérisation microstructurale et comportement en fatigue plastique

    NASA Astrophysics Data System (ADS)

    Gerland, M.; Dufour, J. P.; Presles, H. N.; Violan, P.; Mendez, J.

    1991-10-01

    A new surface treatment technique with a primary explosive deposited in thin layer was applied to a polycrystalline pure copper. After treatment, surface roughness remains of high quality especially when compared to shot peened surfaces. The treated zone extends over several hundreds microns in depth and the microhardness profile exhibits a significant increasing of hardness with a maximum reaching 100% at the surface. The transmission electron microscopy shows a microstructure which changes with depth : below the surface, there is a thin recrystallized layer with very small grains followed by a region with numerous mechanical twins the density of which decreases when depth increases. Tested in fatigue with a constant plastic strain amplitude, the treated copper specimens exhibit a strong hardening from the first cycles compared to the untreated specimen ; however this initial hardening erases after 2% of the fatigue life. The fatigue resistance is not modified by the treatment. Une nouvelle technique de traitement de surface à l'aide d'un explosif primaire déposé en couche mince a été utilisée sur du cuivre pur polycristallin. L'état de surface après traitement reste de très bonne qualité, surtout comparé aux surfaces grenaillées. La zone traitée s'étend sur une profondeur de quelques centaines de microns et le profil de microdureté montre une importante augmentation de dureté avec un maximum en surface pouvant atteindre 100%. La micrcrostructure, observée par microscopie électronique en transmission, est caractérisée par une fine recristallisation en surface, puis par un abondant maclage dont la densité décroît lorsque la profondeur augmente. Testé en fatigue à déformation plastique imposée, le cuivre traité présente un fort écrouissage initial dès les premiers cycles, mais qui s'efface progressivement au cours du cyclage après 2% de la durée de vie, cette dernière n'étant pas modifiée par le traitement.

  19. Facteurs prédictifs de la réponse à la CERA chez les hémodialysés chroniques naïfs de traitement par agent stimulant l’érythropoïèse

    PubMed Central

    Ezziani, Mariam; Najdi, Adil; Mikou, Souad; Hanin, Hakim; Arrayhani, Mohammed; Houssaini, Tarik Sqalli

    2015-01-01

    La correction et la stabilité du taux d'hémoglobine est un objectif majeur du traitement de l'anémie chez les hémodialysés chroniques. Toutefois, la cible d'hémoglobine > 11g/dl fixée par les recommandations demeure difficile à atteindre dans notre contexte. Le but de cette étude est d’évaluer la réponse au traitement par CERA (continuous erythropoietin receptor activator) chez une population d'hémodialysés chroniques naïfs de tout traitement par agent stimulant de l’érythropoïèse et étudier les différents facteurs associés à une mauvaise réponse au traitement. Il s'agit une étude prospective mono centrique faite au sein d'une population d’ hémodialysés chroniques. Ont été inclus les patients en hémodialyse depuis plus de 12 mois, naïfs de tout traitement par agent stimulant de l’érythropoïèse (ASE) et ayant un taux d'hémoglobine(Hb) < 10g/dl. L'administration régulière de la CERA et l'ajustement des doses ont été faits selon les recommandations. L’évaluation de la réponse, en fin de traitement, a porté sur l'atteinte ou non d'un taux d'hémoglobine cible > 11g/dl. Sur 87 patients en hémodialyse périodique, 22 (25,3%) sont naïfs de tout traitement par ASE. Il s'agit de 13 hommes et 9 femmes avec un âge moyen de 46 ± 19 ans et une ancienneté en hémodialyse de 67 ± 59 mois. Le taux initial d'hémoglobine est de 7,8 ± 1,3 g/dl. Au bout de 4 mois de traitement régulier par la CERA, le taux final d'Hb est de 10,9 ± 2,1g/dl et 63,6% des patients ont atteint la cible d'Hb > 11g/dl. La dose moyenne de CERA à la fin de l’étude est de 0,89 ± 0,35 µg/kg/15j. L'analyse des facteurs prédictifs montre que la réponse finale dépend du taux d'Hb initial (p = 0,002). En effet, quand le taux d'Hb initial est > 8 g/dl, le taux de réponse est de 88% vs 46% lorsque le taux d'Hb < 8g/dl (p1-3]. Cette complication commune de la maladie rénale chronique est multifactorielle dont le déficit en érythropoïétine est le

  20. Arrêt cardiaque au cours d'une chirurgie de kyste hydatique du foie

    PubMed Central

    Ouzzad, Omar; Kechna, Hicham; Moudden, Mohamed Karim; Chkoura, Khalid; Hanafi, Sidi Mohamed

    2015-01-01

    L'hydatidose est une pathologie fréquente qui reste encore endémique au Maroc. Sa localisation privilégiée est le foie. Son traitement repose essentiellement sur la chirurgie. Celui-ci est parfois incriminé dans la survenue de réactions allergiques sévères pouvant menacer le pronostic vital. Nous rapportons un nouveau cas de réaction anaphylactique sévère de grade IV peropératoire au cours d'une chirurgie de kystes hydatiques multiples du foie. Nous insistons sur la nécessité de sa reconnaissance rapide afin d'instaurer rapidement un traitement efficace. La prévention de cet accident est basée sur des précautions chirurgicales pour éviter les fuites ou les ruptures accidentelles peropératoires des kystes hydatiques. PMID:26664533

  1. La plastie en rail dans le traitement des brides rétractiles du creux poplite

    PubMed Central

    Achbouk, A.; Khales, A.; Bourra, K.; Tourabi, K.; Ababou, K.; Ihrai, H.

    2011-01-01

    Summary Les Auteurs décrivent le cas d’un patient âgé de 45 ans atteint de brûlures thermiques par flammes suite à la déflagration d’une bonbonne de gaz. Les lésions initiales intéressaient les quatre membres (en particulier, le genou) et le tronc. La prise en charge initiale a consisté en une excision-greffe précoce des membres. L’évolution a été marquée par la survenue de cicatrices hypertrophiques au niveau des zones non greffées et à la bordure de la greffe ainsi que la survenue de brides rétractiles. Devant l’handicap fonctionnel engendré par la bride à cause de la limitation importante de l’extension, le patient a été admis pour cure chirurgicale. Grâce à la technique en rail décrite, le patient a pu récupérer une fonction normale du genou. Les suites ont été simples avec une durée d’hospitalisation d’un mois. Le résultat esthétique est relativement satisfaisant. La technique en rail est un moyen parmi l’arsenal thérapeutique qui permet de traiter la bride du creux poplité. Sa simplicité, sa facilité technique et son résultat satisfaisant ainsi que ses suites simples permettent de la rendre une technique très prisée dans le traitement de ce type de bride. PMID:21991240

  2. Traitement chirurgical des lésions sacro-iliaques dans les fractures instables de l’anneau pelvien par vissage sacro-iliaque percutané

    PubMed Central

    Karabila, Mohamed Amine; Hmouri, Ismail; Madani, Tarik; Mhamdi, Younes; Azouz, Mohamed; Kharmaz, Mohamed; Ouadaghiri, Mohamed; Lamrani, Moulay Omar; Lahlou, Abdou; Bardouni, Ahmed; Mahfoud, Mustapha; Berrada, Mohamed Saleh; Vasile, Christian

    2016-01-01

    Les fractures du bassin, le plus souvent multiples, sont fréquemment instables et surviennent le plus souvent dans des contextes traumatiques violents. Le traitement orthopédique de ces lésions est souvent pénible pour le patient et pour le personnel médical nécessitant une décharge au lit ou parfois des tractions qui peuvent aller jusqu'à 45 jours et peut compromettre la statique et la marche, le traitement chirurgical à ciel ouvert est un geste difficile, grevé d'une morbidité non négligeable avec un risque vasculaire (plexus veineux), nerveux (racines sacrées) ou septique notamment à prendre en compte, elle est donc généralement réservée aux formes neurologiques et fortement déplacées. La fixation percutanée sous radioscopie dans les fractures instables du bassin type B et C permet la synthèse des lésions postérieures source d’instabilité en fixant l’os coxal avec le corps de S1 ou S2 et la reprise rapide de la rééducation et de la marche. PMID:27795765

  3. Traitement chirurgical d'une luxation fracture parcellaire de la tete femorale pipkin II irreductible: à propos d'un cas

    PubMed Central

    Abid, Hatim; Mechchat, Atif; El Idrissi, Mohammed; Shimi, Mohammed; El Ibrahimi, Abdelhalim; El Mrini, Abdelmajid

    2014-01-01

    L'irréductibilité d'une luxation-fracture parcellaire de la tête fémorale est une entité pathologique rare dont le traitement est chirurgical. Dans la littérature, les avis des auteurs divergent concernant le choix de la voie d'abord, mais la conservation du fragment céphalique est la règle. Indépendamment de la qualité de la prise en charge, les résultats mauvais et passables sont très importants estimés à 50% au bout de 10 ans, et l’évolution arthrosique à long terme semble être inéluctable. PMID:25489358

  4. Quatrième conférence consensuelle sur le diagnostic et le traitement de la démence

    PubMed Central

    Moore, Ainsley; Patterson, Christopher; Lee, Linda; Vedel, Isabelle; Bergman, Howard

    2014-01-01

    Résumé Objectif Revoir les stratégies diagnostiques de la maladie d’Alzheimer, actualiser les recommandations concernant le traitement des symptômes de démence et proposer une approche thérapeutique à la démence d’apparition précoce et d’évolution rapide. Composition du comité Des spécialistes et des délégués de diverses régions du Canada et représentant diverses disciplines pertinentes ont discuté et se sont mis d’accord sur les révisions à apporter aux lignes directrices de 2006. Méthodologie On a eu recours au système GRADE (grading of recommendations, assessment, development, and evaluation) pour évaluer le consensus concernant les recommandations, lequel était défini comme suit : lorsque 80 % ou plus des participants ont voté en faveur de la recommandation. La cote des données probantes est rapportée lorsque cela est possible. Rapport important pour les médecins de famille, malgré les progrès effectués dans les domaines des biomarqueurs liquidiens et de la neuro-imagerie, le diagnostic de démence au Canada demeure fondamentalement clinique. De nouveaux critères cliniques essentiels de diagnostic de la maladie d’Alzheimer en reconnaissent dorénavant les formes moins fréquentes et non amnestiques. La démence précoce, une affection rare, mais importante, devrait inciter les médecins à aiguiller les patients vers un spécialiste ayant accès à des conseillers en génétique. La démence d’évolution rapide, mal définie dans la littérature, faciliterait le dépistage de cette affection rare, mais importante. Les inhibiteurs de la cholinestérase sont maintenant indiqués pour le traitement d’affections autres que la maladie d’Alzheimer. Des lignes directrices concernant l’arrêt du traitement, lesquelles n’existaient pas auparavant, sont également apparues. De nouvelles données probantes sur le recours à la mémantine, aux antidépresseurs et à d’autres agents psychotropes dans le traitement de la

  5. Traitement chirurgical à ciel ouvert des ruptures récentes du tendon calcanéen

    PubMed Central

    Mahdane, Hicham; Khaissidi, Abdesslam; Hammou, Nasserdine; Elidrissi, Mohammed; Mohamed, Shimi; Elibrahim, Abdelhalim; Elmrini, Abdelmajid

    2014-01-01

    Les ruptures du tendon calcanéen quelles soient sous cutanées ou par section direct sont de plus en plus fréquentes. Plusieurs techniques chirurgicales, qu'elles soient à ciel ouvert ou percutanées ont été mises au point pour traitée ce type de lésion. À travers une étude rétrospective descriptive sur la prise en charge chirurgicale des ruptures de tendon calcanéen fraiches. Nous avons analysé les résultats fonctionnels de 38 patients, tous opéré par une chirurgie à ciel ouvert. Les points forts de notre étude étaient l'absence de rupture itérative, principale complication du traitement chirurgicale des ruptures du tendon calcanéen, un faible taux de complications liées à la chirurgie à ciel ouvert, ainsi que les résultats fonctionnels satisfaisants. PMID:25419282

  6. Formal Operational Precocity and Achievement in Biology among Some Nigerian High School Students.

    ERIC Educational Resources Information Center

    Ehindero, Olusola Joseph

    1979-01-01

    Compares the performances on a battery of six Piagetian tasks of 80 Nigerian high school students classified as high and low achievers in biology. The relationship between performance of very bright biology students (high achievers) and intellectual precocity is also investigated. (HM)

  7. Chronicle of Academic and Artistic Precocity, Vol. 1, No. 1, January/February 1982.

    ERIC Educational Resources Information Center

    Chronicle of Academic and Artistic Precocity, 1982

    1982-01-01

    The chronicle provides information on programs and other topics relevant to the education of gifted and talented students. The following are among the articles contained in this introductory publication: "PSAP: Its First Two-and-a-Half-Years" (about the Project for the Study of Academic Precocity) by C. Blurton; tips relating to parental support…

  8. Coût clinique des retards dans le changement de traitement

    PubMed Central

    Walmsley, Sharon

    2007-01-01

    La prise en charge des patients séropositifs pour le VIH ayant déjà reçu un traitement continue de s’améliorer et d’évoluer. Les nouvelles lignes directrices semblent indiquer que l’objectif du traitement devrait être une suppression virologique maximale. La meilleure façon d’y parvenir consiste à utiliser une combinaison d’agents auxquels le virus sera le plus vraisemblablement sensible et, si possible, des agents appartenant à une nouvelle classe thérapeutique. Les cas discutés démontrent comment l’utilisation d’un schéma thérapeutique puissant à titre de traitement de sauvetage peut avoir de bons résultats virologiques, immunologiques et cliniques. Toutefois, si le traitement de sauvetage retenu n’est pas assez puissant pour atteindre ces objectifs, la durabilité de la réponse est limitée. Ce qu’il faut retenir ici, c’est que ces stratégies devraient reposer sur la puissance du schéma thérapeutique et qu’il ne faut pas retarder l’instauration des agents en cas d’échec d’une stratégie.

  9. Le traitement chirurgical des cals vicieux des deux os de l'avant-bras: à propos d'une série de 11 cas

    PubMed Central

    Elidrissi, Mohammed; Mechchat, Atif; Abid, Hatim; Shimi, Mohammed; Elibrahimi, Abdelhalim; Elmrini, Abdelmajid

    2013-01-01

    Le but de cette étude est de présenter l'expérience du service de chirurgie ostéoarticulaire B4, de CHU Hassan II de Fès Maroc, dans la prise en charge chirurgicale des cals vicieux des deux os de l'avant-bras. C'est une étude rétrospective étalée entre janvier 2008 et décembre 2011 incluant onze cas de cal vicieux de l'avant-bras chez des adultes, colligés au service de chirurgie ostéoarticulaire B4 du CHU Hassan II de Fès. Pour chaque patient nous avons étudié: Sur le plan clinique: la profession, la nature du traumatisme initial, le traitement initial, l'amplitude de pronosupination. Sur le plan radiologique: l'aspect radiologique du cal. La limitation de la pronosupination était le principal motif de consultation, trois patients ont consulté pour la déformation. Le recul moyen est de 18 mois, avec des extrêmes de 5 mois et 48 mois. La prise en charge chirurgicale avait permis d'améliorer de façon variable chez tous les patients les amplitudes de pronosupination de 58° en moyenne. Les résultats étaient bons chez 5 patients, moyens chez 5 et mauvais chez un patient. Le traitement conservateur des fractures des deux os de l'avant-bras est incriminé dans la genèse des cals vicieux de l'avant-bras. Le traitement chirurgical de ceux-ci fait appel à une ostéotomie de correction. Dans notre étude nous avons montré l'intérêt du rétablissement des axes du radius et de l'ulna pour la restauration de la fonction de pronosupination, grâce à cette ostéotomie. PMID:23560124

  10. Traitement orthopédique d'une fracture pathologique du fémur sur malformation veineuse: à propos d'un cas

    PubMed Central

    Guelzim, Soufiane; Lamrani, Omar; Kharmaz, Mohammed; Lahlou, Abdo; Elouadghiri, Mohammed; El Bardouni, Ahmed; Mahfoud, Mustapha; Berrada, Mohammed Saleh; El Yaccoubi, Mouradh

    2015-01-01

    Les malformations vasculaires artérioveineuse, veineuse ou lymphatique représentent des défects localisés dans la morphogénèse vasculaire. Elles peuvent survenir dans tous les organes, mais prédominent au niveau de membres, plus souvent dans la peau, les espaces celluleux ou les muscles. Le bilan de nombreuses malformations a été transformé par l'utilisation de l'angioscanner avec reconstruction ou de l'IRM. Les auteurs rapportent un cas de fracture pathologique du fémur proximal gauche sur malformation veineuse, chez une patiente de 35 ans. Le diagnostic a été porté sur un faisceau d'arguments cliniques et paracliniques. La radiographie standard a montré une fracture diaphysaire du tiers supérieur du fémur gauche sur os pathologique. L'IRM de la cuisse gauche ainsi qu'un phléboscanner des membres inférieurs ont objectivé un aspect en faveur d'une malformation veineuse. Vu le déplacement minime de la fracture et le risque très important de saignement peropératoire, la patiente a bénéficié d'un traitement orthopédique; l’évolution a été simple, marquée par une consolidation au sixième mois. PMID:26600903

  11. Mécanismes et traitement de l’anémie aiguë chez le brûlé grave

    PubMed Central

    Siah, S.; El Khatib, K.; Messaoudi, N.

    2016-01-01

    Summary Les brûlés graves présentent souvent, au cours de la phase aiguë, des anémies plus au moins profondes pouvant nécessiter des transfusions. L’anémie du brûlé a deux origines principales: le saignement péri-opératoire (des stratégies doivent être mises en place pour le réduire) et l’anémie de réanimation (que l’on peut en partie réduire en évitant les bilans inutiles) chez un patient ayant des troubles de l’hématopoïèse. Le traitement, chez ces patients à l’hématopoïèse altérée, repose sur la transfusion. Celle-ci n’est pas dénuée d’effets secondaires et une stratégie transfusionnelle restrictive doit être appliquée. PMID:28149231

  12. Association between insulin resistance and estrogen in sexual precocity of obese children

    PubMed Central

    Lin, Shixia; Ji, Wei

    2016-01-01

    The aim of the study was to examine the association between sexual precocity and high-molecular weight (HMW)-adiponectin and investigate the correlation of insulin resistance and estrogen levels in obese children. In total, 60 obese children (30 boys and 30 girls) with sexual precocity were included in group A, 60 obese children (30 boys and 30 girls) without sexual precocity were included in group B, and 60 average weight children (30 boys and 30 girls) were included in group C. The levels of HMW adiponectin, fasting blood glucose, fasting insulin, luteinizing hormone (LH) peak, estradiol and testosterone were measured. The results showed that the HMW-adiponectin level of group A was the lowest and that of group C was the highest. The difference was statistically significant (P<0.05). The homeostasis model assessment of insulin resistance (HOMA-IR) and estradiol levels of group A were significantly higher than those of group B, and group B was higher than that of group C. LH peak and testosterone levels of group A were the lowest while those of group C were the highest. The differences were statistically significant (P<0.05). A subgroup analysis showed that the above results were more significant in girls. The Pearson correlation analysis revealed that the level of HMW-adiponectin was negatively correlated with HOMA-IR and estradiol (P<0.05), and positively correlated with the LH peak (P<0.05). In conclusion, sexual precocity of obese children may be associated with insulin resistance, and the link may be HMW-adiponectin. PMID:27703507

  13. Variation in growth form and precocity at birth in eutherian mammals.

    PubMed Central

    Gaillard, J M; Pontier, D; Allaine, D; Loison, A; Herve, J C; Heizmann, A

    1997-01-01

    Using the flexible Chapman-Richards model for describing the growth curves from birth to adulthood of 69 species of eutherian mammals, we demonstrate that growth form differs among eutherian mammals. Thereby the commonly used Gompertz model can no longer be considered as the general model for describing mammalian growth. Precocial mammals have their peak growth rate earlier in the growth process than altricial mammals. However, the position on the altricial-precocial continuum accounts for most growth-form differences only between mammalian lineages. Within mammalian genera differences in growth form are not related to precocity at birth. This indicates that growth form may have been associated with precocity at birth early in mammalian evolution, when broad patterns of body development radiated. We discuss four non-exclusive interpretations to account for the role of precocity at birth on the observed variation in growth form among mammals. Precocial and altricial mammals could differ according to (i) the distribution of energy output by the mother, (ii) the ability of the young to assimilate the milk yield, (iii) the allocation of energy by the young between competing functions and (iv) the position of birth between conception and attainment of physical maturity. PMID:9225478

  14. Un kyste hydatique osseux: une localisation rare au niveau de l’os iliaque

    PubMed Central

    Nhamoucha, Yassine; Alaoui, Othmane; Doumbia, Aliou; Oukhoya, Mohammed; Abdellaoui, Hicham; Tazi, Mohammed; Chater, Lamyae; Atarraf, Karima; Arroud, Mounir; Afifi, Abderahman

    2016-01-01

    L'hydatidose est une affection parasitaire liée au développement chez l'homme de la forme larvaire d'un cestode, à savoir un tænia de très petite taille dénommé Echinococcus Granulosus. Cette anthropozoonose présente une diversité de formes anatomoradiologiques lié aux nombreux aspects topographiques et évolutifs des kystes. L'hydatidose osseuse est rare, elle ne représente que 0,9 à 2,5% de l'ensemble des localisations. Nous rapportons l'observation d'un enfant de 9 ans, qui a été admis chez nous pour une boiterie fébrile avec une masse au niveau de la fosse iliaque droite, révélant un kyste hydatique au dépend de l'os iliaque. Le bilan lésionnel avait objectivé un kyste hydatique de l'os iliaque avec extension aux parties molles adjacentes. Le traitement chirurgical conclu a un kyste surinfecté d'ou la réalisation d'une exérèse chirurgicale du kyste avec drainage. L'ostéopathie hydatique est infiltrante, diffuse, lente et progressive, ce qui rend le diagnostic tardif et qui compromet la qualité du traitement. PMID:27800081

  15. Insights into Sexual Precocity of Female Oriental River Prawn Macrobrachium nipponense through Transcriptome Analysis

    PubMed Central

    Jiang, Hongxia; Li, Xilian; Sun, Yuhang; Hou, Fujun; Zhang, Yufei; Li, Fei; Gu, Zhimin; Liu, Xiaolin

    2016-01-01

    Background The oriental river prawn (Macrobrachium nipponense) is the most prevalent aquaculture species in China. The sexual precocity in this species has received considerable attention in recent years because more and more individuals matured at a small size, which devalues the commercial production. In this study, we developed deep-coverage transcriptomic sequencing data for the ovaries of sexually precocious and normal sexually mature M. nipponense using next-generation RNA sequencing technology and attempted to provide the first insight into the molecular regulatory mechanism of sexual precocity in this species. Results A total of 63,336 unigenes were produced from the ovarian cDNA libraries of sexually precocious and normal sexually mature M. nipponense using Illumina HiSeq 2500 platform. Through BLASTX searches against the NR, STRING, Pfam, Swissprot and KEGG databases, 15,134 unigenes were annotated, accounting for 23.89% of the total unigenes. 5,195 and 3,227 matched unigenes were categorized by GO and COG analysis respectively. 15,908 unigenes were consequently mapped into 332 KEGG pathways, and many reproduction-related pathways and genes were identified. Moreover, 26,008 SSRs were identified from 18,133 unigenes. 80,529 and 80,516 SNPs were yielded from ovarian libraries of sexually precocious and normal sexually mature prawn, respectively, and 29,851 potential SNPs between these two groups were also predicted. After comparing the ovarian libraries of sexually precocious and normal sexually mature prawn, 549 differentially expressed genes (DEGs) and 9 key DEGs that may be related to sexual precocity of M. nipponense were identified. 20 DEGs were selected for validation by quantitative real-time PCR (QPCR) and 19 DEGs show consistent expression between QPCR and RNAseq-based differential expression analysis datasets. Conclusion This is the first report on the large-scale RNA sequencing of ovaries of sexually precocious and normal sexually mature M

  16. Faut-il préférer une technique chirurgicale dans le traitement des ruptures du tendon d'Achille?

    PubMed Central

    Hani, Redouane; Kharmaz, Mohammed; Berrada, Mohammed Saleh

    2015-01-01

    La rupture du tendon d'Achille est de plus en plus fréquente dans le monde et dans notre pays en raison du développement considérable des activités sportives, de l'accroissement de leur intensité et de l'absence de moyens de prévention. Notre travail porte sur une étude concernant 58 cas de rupture du tendon d'Achille, avec un recul moyen compris entre 5 mois et 80 mois. L’âge moyen était de 36 ans, tous les patients inclus ont tous bénéficier d'un traitement chirurgical. Le but de notre étude étant de souligner la supériorité d'une technique chirurgicale par rapport à une autre dans la prise en charge, ainsi qu'une mise au point sur les différents aspects épidémiologiques, cliniques, thérapeutiques et post-thérapeutiques de cette lésion. PMID:26161208

  17. La pubalgie du sportif de haut niveau: place du traitement chirurgical, à propos d'une série continue de 100 cas

    PubMed Central

    Boukhris, Jalal; Mojib, Rifi; Mezghani, Sami; Jaeger, Jean Henri

    2014-01-01

    Parmi tous les syndromes de surmenage liés à la pratique sportive, la pubalgie est certainement un des plus invalidants. C'est un syndrome douloureux de la région inguino-pubienne qui touche particulièrement le joueur du football. Les formes inguino-pariètales sont de loin les plus fréquentes. Le traitement médical est entrepris dans la majorité des cas, mais il semble être moins efficace dans ce sport en particulier. La chirurgie occupe une place prédominante dans la prise en charge. Nous rapportons l'expérience de la prise en charge chirurgicale de 100 sportifs de haut niveau au sein de notre établissement, selon la technique de Nesovic, ainsi que leurs devenirs sportifs et nous discutons nos résultats en se comparant aux données de la littérature récente. PMID:25574333

  18. L'ostéotomie de scarf dans le traitement de l'hallux valgus: à propos de 19 cas

    PubMed Central

    Boussakri, Hassan; Bachiri, Mohammed; Elidrissi, Mohammed; Shimi, Mohammed; Elibrahimi, Abdelhalim; Elmrini, Abdelmajid

    2014-01-01

    L'ostéotomie de Scarf constitue une technique chirurgicale bien décrite, grâce à ses résultats excellents, elle est considérée comme un traitement de choix de l'hallux valgus. Le but de ce travail est de décrire le profil épidémiologique et radio-clinique des hallux valgus, ainsi qu’évaluer les résultats radiologiques et fonctionnels des patients traités par la technique classique d'ostéotomie de Scarf. Nous avons mené une étude rétrospective, concernant 22 ostéotomies de Scarf chez 19 patients, opérés d'hallux valgus entre mai 2009 et janvier 2013. Le recul moyen était de 22,5 mois (3-42 mois). L'âge moyen des patients au moment de l'intervention était de 49 ans, avec des extrêmes de 19 et 75 ans. Tous les patients ont bénéficié d'une évaluation clinique et radiologique préopératoire et postopératoire ainsi qu'une analyse statistique. Au dernier recul, selon des critères subjectifs, nos résultats étaient très satisfaisants dans 42%, satisfaisants dans 52% et déçus dans 6%, et en fonction du score de l'AOFAS, les résultats étaient nettement améliorée avec un AOFAS préopératoire de 57% à 84% en postopératoire. Concernant les résultats radiologiques, la déformation métatarsophalangienne (angle M1P1) a été corrigée (43,63 °-12,8°) avec une p très significative (p <0,001). D'autre part une amélioration de l'Angle moyen M1M2, passer de 18,18° préopératoire à 12,95° au dernier recul, avec une correction significative (p <0,001). Le valgus épiphysaire de premier métatarsien (AADM) a été statistiquement amélioré (p <0,001), passer de 24,45° à 7,91°. Concernant les complications nous avons noté un cas de sepsis précoce superficiel géré par une antibiothérapie adaptée, deux cas de névrome et un cas d'ostéonécrose. Par contre on n'a pas noté aucune fracture per opératoire du premier métatarsien. Nous concluons que l'ostéotomie de Scarf est une technique reproductible fiable, en pleine

  19. Système de traitement acousto-optique de signaux numériques

    NASA Astrophysics Data System (ADS)

    Goutin, P.; Logette, P.; Rouvaen, J. M.; Bridoux, E.

    1991-10-01

    The transversal filter is a fundamental device in numerical signal processing. Among all available techniques, the acousto-optic convolution is very well matched to this function. Some penalties occur however, for very long input signals, owing to the physical configuration of the convolver and to the propagation of acoustic waves in its bulk. This calls for the study of a convenient computation algorithm taking all the constraints into account. The realization of an hybrid processor enabled us to evaluate its main characteristics using experiments like autoconvolution, F.I.R. filtering, Golay's and Barker's codes or matrix multiplication. Since the built system is actually a prototype, a number of extensions and improvements are presented, which may lead to the optimization of the processing speed. L'élément fondamental du traitement numérique du signal est le filtre transversal. Parmi les techniques utilisables, la convolution acousto-optique est particulièrement bien adaptée à cette fonction. Les difficultés de cette opération, pour le traitement d'un signal d'entrée relativement long, proviennent de la configuration propre du convoluteur et du phénomène de propagation. Celles-ci vont nécessiter l'étude d'un algorithme de calcul respectant certaines contraintes. La réalisation du processeur hybride nous a permis d'en évaluer les caractéristiques à partir des résultats expérimentaux tels que : autoconvolutions, filtrage F.I.R., corrélations, codes de Golay, codes de Barker et multiplication matricielle. Le fait même de la nature prototype du système réalisé nous amène à présenter un grand nombre d'extensions et d'améliorations qui permettent d'optimiser fortement la vitesse de traitement.

  20. Influence du traitement thermique sur l'usinabilite du laiton monophase

    NASA Astrophysics Data System (ADS)

    Cholley, Airy

    La connaissance des proprietes et du comportement d'un materiau en usinage est primordiale pour optimiser son utilisation et obtenir une usinabilite maximale. Dans ce but, l'etude de la modification de la ductilite par traitement thermiques sur plusieurs criteres d'usinabilite tels que les efforts de coupe, la rugosite, les bavures et la formation du copeau a ete menee sur le laiton monophase. A cette fin, l'influence du traitement thermique sur la microstructure du laiton a d'abord ete etudiee. La taille des grains et la durete ont permis de determiner les proprietes mecaniques des etats metallurgiques. Des essais de percage ont ensuite ete effectues sur les etats metallurgiques H01 (99HV), OS100 (88HV) et OS250 (47HV) pour regarder l'influence du traitement thermique sur l'usinabilite. Cette etude experimentale a permis de comprendre l'influence du taux de laminage et de la temperature de recuit sur les proprietes mecaniques. Les essais d'usinabilite ont ensuite permis de prouver que les efforts de coupe sont dependants des conditions de coupe mais pas de la ductilite dans les etats metallurgiques testes. La taille des bavures augmente avec la ductilite et la vitesse de coupe, et diminue avec l'avance. La rugosite de la surface des trous apres l'usinage a egalement ete etudiee. Il a aussi ete prouve par une etude sur les copeaux que la temperature croit avec la vitesse de coupe. L'analyse de la segmentation des copeaux n'a en revanche pas permis de trouver une correlation significative avec les traitements thermiques testes. Enfin, le revetement de l'outil a montre une grande importance sur l'usinabilite du materiau. Il a ete conclu que l'usinabilite du laiton C26000 (CuZn30) est meilleure lorsqu'on travaille dans un etat metallurgique dur. Ces conclusions sont valables pour le laiton monophase etudie, il serait interessant d'examiner aussi le cas des laitons biphases.

  1. Les perdus de vue en radiothérapie: expérience de l'Institut National d'Oncologie au Maroc

    PubMed Central

    Mezouri, Imane; Chenna, Hanane; Bellefqih, Sara; Elkacemi, Hanan; Kebdani, Tayeb; Benjaafar, Noureddine

    2014-01-01

    Les perdus de vue (PDV) sont toute personne incluse dans un programme et dont on est sans nouvelles depuis six mois. L'objectif de cette étude est de fournir une description objective du problème des malades PDV au service de radiothérapie à l'Institut National d'Oncologie (INO), elle permet d’étudier l'impact des facteurs socio-économiques, démographiques et ceux liés à la maladie entraînant l'abandon du traitement par le patient. Nous avons réalisé une étude rétrospective de 77 patients PDV parmi 2254 patient admis à l'INO du premier janvier au 31 décembre 2011 pour traitement par radiothérapie. La présente analyse a mis en évidence que les taux d'abandon sont associés à des facteurs liés à la maladie et qu’à la fois le patient et le médecin doivent être formés et être conscients de la façon dont les stades avancés de la maladie, le mauvais statut de performance ainsi que la combinaison des autres problèmes de santé peuvent suffisamment conduire le patient à l'abandon du traitement. PMID:25584129

  2. Tuberculose hépatique nodulaire: complication inhabituelle au cours de la maladie de Wilson

    PubMed Central

    Zinebi, Ali; Rkiouak, Adil; Akhouad, Youssef; Reggad, Ahmed; Kasmy, Zohor; Boudlal, Mostapha; Rabhi, Monsef; Ennibi, Khalid; Chaari, Jilali

    2014-01-01

    La tuberculose hépatique nodulaire est rare. Nous rapportons une forme pseudo-tumorale dont le tableau clinico-biologique et radiologique initial était aspécifique. Il s'agit d'un jeune marocain suivi pour maladie de Wilson et présentant une fièvre au long cours. L'imagerie met en évidence une lésion nodulaire hépatique non spécifique. L'examen anatomo-pathologique au cours d'une biopsie écho guidée du nodule hépatique permit de porter le diagnostic. L’évolution clinique est favorable sous traitement spécifique. PMID:24932333

  3. Traitement préventif intermittent à la sulfadoxine – pyriméthamine du paludisme chez les femmes enceintes: efficacité et observance dans deux hôpitaux urbains du Burkina Faso

    PubMed Central

    Bamba, Sanata; Séré, Adama; Nikiéma, Rodrigues; Halidou, Tinto; Thiéba, Blandine; Dao, Blami; Guiguemdé, Robert Tinga

    2013-01-01

    Introduction La présente étude prospective se propose dévaluer l'efficacité thérapeutique du traitement préventif intermittent à la sulfadoxine - pyriméthamine et son observance chez la femme enceinte dans deux hôpitaux urbains au Burkina Faso. Méthodes Chaque femme répondant aux critères d'inclusion a été soumise à un questionnaire pour la collecte des données socio - démographiques et des renseignements sur la grossesse. A l'accouchement, une apposition placentaire a été réalisée systématiquement. La lecture a été faite au microscope à lobjectif 100 à immersion. Résultats Au total, 542 femmes ont été incluses avec un âge moyen de 26,0 ± 6,45 ans (extrêmes 13- 43 ans). Le taux de couverture du TPI à la sulfadoxine- pyriméthamine a été de 80%. Le taux d'infestation placentaire a été de 4,7%. Il a diminué avec le nombre de dose de traitement préventif intermittent. Il a augmenté cependant de juillet à octobre. De 42,9% en octobre, il a diminué significativement à 9,5% en novembre (p < 0,05). Le taux global de bonne d'observance a été de 55%. Il a augmenté avec l’âge (p < 0,05). Conclusion Le taux de couverture de la sulfadoxine - pyriméthamine a été de 80%. Ce résultat est en conformité avec les objectifs du plan stratégique 2006-2010 de lutte contre le paludisme au Burkina Faso, qui préconisait un taux de couverture en sulfadoxine - pyriméthamine de 80% pour 2010. L'augmentation de la fréquence d'infestation de juillet à octobre, serait liée à la recrudescence de la transmission palustre pendant la saison des pluies (mai-octobre). PMID:23717719

  4. Genetic association between temperament and sexual precocity indicator traits in Nellore cattle.

    PubMed

    Valente, T S; Sant'Anna, A C; Baldi, F; Albuquerque, L G; da Costa, Mateus J R Paranhos

    2015-08-01

    The aim of this study was to estimate the genetic associations between temperament and sexual precocity indicators in Nellore cattle. Temperament was evaluated at approximately 550 days of age, using three traits: i) movement score (MOV), recording the animals' movement inside the crush; ii) temperament score (TS) for assessing the reactions of animals in a corral pen; and iii) flight speed test (FS), recording the speed (in m/s) at which the animals exit the crush after being weighed. Three sexual precocity indicators were used: i) age at first calving (AFC, in days); ii) occurrence of precocious pregnancy (OPP, as a binary trait); and iii) yearling scrotal circumference (SC, in cm). The (co)variance and genetic parameters were estimated by Bayesian Inference via Gibbs sampling, assuming a linear animal model for FS, AFC and SC and a threshold animal model for MOV, TS and OPP in multitrait analyses. The mean posterior heritability estimates for MOV, FS, TS, AFC, OPP and SC were 0.11 ± 0.03, 0.27 ± 0.07, 0.16 ± 0.09, 0.09 ± 0.01, 0.44 ± 0.06 and 0.43 ± 0.02, respectively. The mean posterior correlation estimates were: 0.13 ± 0.14 (MOV-AFC), -0.03 ± 0.16 (MOV-OPP), 0.08 ± 0.10 (MOV-SC), 0.14 ± 0.11 (FS-AFC), -0.19 ± 0.15 (FS-OPP), -0.07 ± 0.08 (FS-SC), 0.09 ± 0.09 (TS-AFC), -0.03 ± 0.09 (TS-OPP) and -0.28 ± 0.08 (TS-SC). These results indicate that all the traits had sufficient genetic variability to respond to selection. The low magnitude of the genetic correlations indicated that selection for improvements in sexual precocity would not change the temperament of Nellore cattle. In order to obtain genetic progress in cattle temperament, direct selection for these traits is recommended.

  5. Genome-Wide Association Study for Indicator Traits of Sexual Precocity in Nellore Cattle

    PubMed Central

    Irano, Natalia; de Camargo, Gregório Miguel Ferreira; Costa, Raphael Bermal; Terakado, Ana Paula Nascimento; Magalhães, Ana Fabrícia Braga; Silva, Rafael Medeiros de Oliveira; Dias, Marina Mortati; Bignardi, Annaiza Braga; Baldi, Fernando; Carvalheiro, Roberto; de Oliveira, Henrique Nunes; de Albuquerque, Lucia Galvão

    2016-01-01

    The objective of this study was to perform a genome-wide association study (GWAS) to detect chromosome regions associated with indicator traits of sexual precocity in Nellore cattle. Data from Nellore animals belonging to farms which participate in the DeltaGen® and Paint® animal breeding programs, were used. The traits used in this study were the occurrence of early pregnancy (EP) and scrotal circumference (SC). Data from 72,675 females and 83,911 males with phenotypes were used; of these, 1,770 females and 1,680 males were genotyped. The SNP effects were estimated with a single-step procedure (WssGBLUP) and the observed phenotypes were used as dependent variables. All animals with available genotypes and phenotypes, in addition to those with only phenotypic information, were used. A single-trait animal model was applied to predict breeding values and the solutions of SNP effects were obtained from these breeding values. The results of GWAS are reported as the proportion of variance explained by windows with 150 adjacent SNPs. The 10 windows that explained the highest proportion of variance were identified. The results of this study indicate the polygenic nature of EP and SC, demonstrating that the indicator traits of sexual precocity studied here are probably controlled by many genes, including some of moderate effect. The 10 windows with large effects obtained for EP are located on chromosomes 5, 6, 7, 14, 18, 21 and 27, and together explained 7.91% of the total genetic variance. For SC, these windows are located on chromosomes 4, 8, 11, 13, 14, 19, 22 and 23, explaining 6.78% of total variance. GWAS permitted to identify chromosome regions associated with EP and SC. The identification of these regions contributes to a better understanding and evaluation of these traits, and permits to indicate candidate genes for future investigation of causal mutations. PMID:27494397

  6. La pubalgie du sportif: mise au point à propos d'une étude rétrospective de 128 joueurs

    PubMed Central

    Mahmoudi, Ammar; Frioui, Samia; Jemni, Sonia; Khachnaoui, Faycel; Dahmene, Younes

    2015-01-01

    La pubalgie du sportif de haut niveau représente une entité nosologique à part entière, tant en raison du mécanisme à l'origine de la pathologie que des lésions objectivables au niveau de la paroi abdominale. C'est un syndrome douloureux de la région inguino-pubienne qui touche particulièrement les footballeurs. Son étiologie est attribuée à la répétition de mouvements des membres inférieurs et du tronc associant rotation et adduction forcées. Son incidence est nettement plus élevée chez les hommes. Après avoir écarté une pathologie d'organe, le patient devrait bénéficier tout au début de son traitement conservateur d'une IRM afin d'effectuer un bilan lésionnel complet qui, selon les situations, permet d’écourter le traitement conservateur et de proposer un traitement chirurgical optimal. Le traitement doit être résolument conservateur pendant 3 mois. La rééducation est le plus souvent le traitement de première intention. Les patients présentant une persistance des symptômes sont candidats à la chirurgie. L'intervention de Nesovic est le traitement de choix chez les sportifs de haut niveau et qui permet, dans la très grande majorité des cas, une reprise sans aucune limitation de l'activité sportive antérieure. La technique de Bassini semble être moins lourde que celle de Nesovic, puisqu'elle est moins invasive. Une prise en charge multidisciplinaire centrée sur l'athlète avant et après l'intervention permet un retour aux activités physiques après quelques mois. Nous rapportons l'expérience de la prise en charge de 128 joueurs opérés selon la technique de Bassini et nous comparons nos résultats avec celles de la littérature. PMID:26966484

  7. New Information Processing Techniques for Military Systems (les Nouvelles techniques de traitement de l’information pour les systemes militaires)

    DTIC Science & Technology

    2001-04-01

    la diffusion de l’information ainsi que des capteurs permettront d’élaborer des concepts de systèmes très novateurs dans le but d’améliorer...traitement du langage naturel xi Information Systems Technology Panel CHAIRMAN DEPUTY CHAIRMAN Dr M VANT Dr R JACQUART Deputy Director General Directeur du

  8. Sidération myocardique au cours d'une intoxication au monoxyde de carbone (CO) chez une femme enceinte

    PubMed Central

    Coulibaly, Mahamadoun; Berdai, Mohamed Adnane; Labib, Smael; Harandou, Mustapha

    2015-01-01

    L'intoxication au monoxyde de carbone (CO) est la première cause de décès par intoxication en France. La littérature est ancienne et peu connue. Les signes les plus fréquents de l'intoxication sont la triade: Céphalées; asthénie, faiblesse musculaire surtout des membres inférieurs. Ses conséquences sont potentiellement graves pour le fœtus quand elle survient chez la femme enceinte, il est particulièrement exposé au risque d'hypoxie en raison de la forte affinité de son hémoglobine pour le CO qui traverse aisément le placenta. Les événements cardiovasculaires ne sont pas rares et peuvent être responsable d'une morbi-mortalité assez importante qui peuvent être d'apparition rapide ou secondaire mais régressent habituellement en quelques jours. Des SCA peuvent survenir lors d'une une intoxication au CO avec à l'extrême infarctus myocardique avec surélévation du segment ST. Il paraît légitime de proposer pour toutes les patientes: l’éloignement maternel de la source de CO; l'oxygénothérapie à 100% au masque facial par les services de secours et pendant le transfert; le traitement par oxygénothérapie hyperbare pour toutes les femmes enceintes, le plus rapidement possible et quelque soit l’âge gestationnel. PMID:26405502

  9. Évolution des conditions d’initiation du traitement antirétroviral des patients infectés par le VIH en Afrique de l’Ouest

    PubMed Central

    Bashi, J.; Balestre, E.; Messou, E.; Maiga, M.; Coffie, P.A.; Zannou, D.M.; Ba-Gomis, O.; Traore, H.A.; Eholie, S.; Minga, A.; Sow, P.S.; Bissagnene, E.; Dabis, F.; Ekouevi, D.K.

    2013-01-01

    Résumé Objectif Étudier entre 1996 et 2006, l’évolution des schémas thérapeutiques et du profil clinique et immunologique des patients infectés par le VIH au début du traitement antirétroviral (TARV) en Afrique de l’Ouest. Cadre et méthode Les données issues de 12 centres cliniques adultes (IeDEA West Africa réseau collaboratif de prise en charge de l’infection à VIH) de cinq pays (Bénin, Cote d’Ivoire, Sénégal, Gambie, Mali) ont été mises en commun et analysées. Les patients âgés de 16 ans et plus dont le sexe, la date de naissance et la date d’initiation du TARV étaient connus ont été inclus dans cette étude. Résultats Quatorze mille quatre-cent-quatre-vingt-seize patients avaient débuté un TARV entre 1996–2006 avec 55 % des patients l’ayant débuté entre 2005–2006. La proportion de femmes était de 46 % en 1996–2000 et de 63 % en 2005–2006. L’âge médian à la mise sous traitement était constant: 35 ans chez les femmes et 40 ans chez les hommes. La proportion de patients qui ont débuté le TARV avec un taux de CD4 inférieur à 200 cellules/µl était de 54 % en 1996–2000 et de 64 % en 2005–2006. Les combinaisons thérapeutiques les plus prescrites étaient: AZT/3TC (ou d4T/DDI)/IDV (27 %) en 1996–2000; d4T (ou AZT)/3TC/EFV (59 %) en 2003–2004; et d4T/3TC/NVP (49 %) en 2005–2006. Les traitements de première ligne recommandés par l’OMS étaient débutés dans 83 % de cas en 2005–2006. Conclusion De nouvelles approches pour débuter un TARV plus précocement doivent être développées pour améliorer la survie des patients sous TARV. PMID:20045273

  10. Tumeur du sac vitellin du testicule au stade IIIc métastatique : à propos d’un cas

    PubMed Central

    Zizi, Mohamed; Ziouziou, Imad; El Yacoubi, Souhail; Khmou, Mouna; Jahid, Ahmed; Mahassini, Najat; Karmouni, Tariq; El Khader, Khalid; Koutani, Abdellatif; Andaloussi, Ahmed Iben Attya

    2014-01-01

    Résumé Les tumeurs du sac vitellin du testicule sont rares chez l’adulte. Ces tumeurs se caractérisent par un mauvais pronostic à un stade métastatique avancé. Cependant, nous rapportons, dans le présent article, le cas clinique d’un adulte de 32 ans qui présentait une tumeur du sac vitellin du testicule au stade IIIc métastatique. Ce patient a subi une orchidectomie haute, accompagnée de quatre cycles de chimiothérapie à base de bléomycine, d’étoposide et de cisplatine. Il a répondu complètement au traitement, moyennant un recul de deux ans. PMID:25295144

  11. @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.

  12. Cancer du sein bilatéral synchrone: expériences du centre Mohammed VI pour le traitement des cancers CHU Ibn Rochd Casablanca

    PubMed Central

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

    2016-01-01

    Les cancers du sein bilatéraux synchrones (CSBS) sont des maladies qui se caractérisent par une importante hétérogénéité clinique et morphologique avec une fréquence entre 1,5 et 3,2%. Les femmes traitées pour un cancer du sein unilatéral sont à haut risque de développer un cancer au niveau controlatéral. Le dépistage et les progrès de l’imagerie mammaire ont permis une augmentation de découverte des CSBS. L’objectif de notre travail est d’étudier les caractéristiques épidémiologiques, cliniques, histologiques, et thérapeutiques du cancer du sein bilatéral. Il s’agit d’une étude transversale étalée sur deux années des patientes prise en charge au centre Mohammed VI pour le traitement des cancers. L’analyse statistique des résultats a été réalisée par le logiciel R. 31 patientes ont présenté un CSBS, représentant 2,4% des cas du cancer du sein dans notre Centre. L’âge moyen était 47,8 ± 8,4 ans, 22,6% utilisaient des contraceptifs oraux. Une histoire familiale de cancer du sein était observée dans 22,6% des cas. Le type histologique le plus fréquent était le carcinome canalaire infiltrant (58,1%), Le grade SBR II et III étaient fréquents (38,7%). Les récepteurs hormonaux entaient positifs, aux progestérones (38,7%) et aux œstrogènes (41,9%). Le récepteur HER2 était surexprimé dans 20,0% des cas. 29,0% des cas ont bénéficié d’une hormonothérapie et 3,2% de thérapies ciblées. Notre étude a montré que le cancer du sein bilatéral représente une proportion faible, mais avec certaines particularités cliniques, différant du cancer du sein unilatéral. PMID:28292084

  13. Qualité des eaux de la station de traitement de la ville de Skikda, Algérie Essais d'optimisation de la clarification

    NASA Astrophysics Data System (ADS)

    Meghzili, B.; Medjram, M. S.; Achour, S.

    2005-05-01

    A cause de la sécheresse qui a sévit durant une décennie, la station de traitement de l'eau potable de la ville de Skikda Algérie, en vue de combler le déficit en eau, utilise un mélange des eaux de surface (barrage) et des eaux souterraines (forage). Les résultats des analyses physico-chimiques de ces eaux montrent la présence de micropolluants, notamment le mercure, avec une concentration de 0.035 mg/l pour les eaux de surface et une concentration de 0.02 mg/l pour les eaux souterraines. Ces résultats obtenus, montrent également que la concentration en matières organiques dépasse, pour les deux sources, les normes OMS. Afin de réduire les effets de cette pollution, nous avons calculé les doses nécessaires des différents réactifs utilisés sur la base des essais d'optimisation réalisés en laboratoire. Les résultats obtenus nous ont permis de conclure que les doses de 30 à 60 mg/l de sulfate d'aluminium (S.A) sont nécessaires à une bonne élimination de la turbidité et des matières organiques (M.O) et que l'utilisation du charbon active en poudre (C.A.P) permet la réduction de la teneur en mercure au dessous du seuil admissible. L'utilisation d'un adjuvant (chaux vive) permet d'améliorer les résultats surtout pour la turbidité (4 mg/l). Une préchloration au break point semble intéressante pour améliorer la phase de floculation.

  14. Suivi après le traitement du cancer du sein

    PubMed Central

    Sisler, Jeffrey; Chaput, Geneviève; Sussman, Jonathan; Ozokwelu, Emmanuel

    2016-01-01

    Résumé Objectif Offrir aux médecins de famille un résumé des recommandations fondées sur les données probantes pour guider les soins aux survivantes traitées pour le cancer du sein. Qualité des données Une recherche documentaire a été effectuée dans MEDLINE entre 2000 et 2016 à l’aide des mots-clés anglais suivants : breast cancer, survivorship, follow-up care, aftercare, guidelines et survivorship care plans, en se concentrant sur la revue des lignes directrices publiées récemment par les organismes nationaux de cancérologie. Les données étaient de niveaux I à III. Message principal Les soins aux survivantes comportent 4 facettes : surveillance et dépistage, prise en charge des effets à long terme, promotion de la santé et coordination des soins. La surveillance des récidives ne se traduit que par une mammographie annuelle, et le dépistage d’autres cancers doit suivre les lignes directrices basées sur la population. La prise en charge des effets à long terme du cancer et de son traitement aborde des problèmes courants tels la douleur, la fatigue, le lymphœdème, la détresse et les effets indésirables des médicaments, de même que les préoccupations à long terme comme la santé du cœur et des os. La promotion de la santé met en relief les bienfaits de l’activité chez les survivantes du cancer, avec l’accent mis sur l’activité physique. Les soins aux survivantes sont de meilleure qualité lorsque divers services et professionnels de la santé participent aux soins, et le médecin de famille joue un rôle important dans la coordination des soins. Conclusion Les médecins de famille sont de plus en plus souvent les principaux fournisseurs de soins de suivi après le traitement du cancer du sein. Le cancer du sein doit être considéré comme une affection médicale chronique, même chez les femmes en rémission, et les patientes profitent de la même approche que celle utilisée pour les autres affections chroniques en

  15. Spin resonance transport properties of a single Au atom in S-Au-S junction and Au-Au-Au junction

    NASA Astrophysics Data System (ADS)

    Fangyuan, Wang; Guiqin, Li

    2016-07-01

    The spin transport properties of S-Au-S junction and Au-Au-Au junction between Au nanowires are investigated with density functional theory and the non-equilibrium Green's function. We mainly focus on the spin resonance transport properties of the center Au atom. The breaking of chemical bonds between anchor atoms and center Au atom significantly influences their spin transmission characteristics. We find the 0.8 eV orbital energy shift between anchor S atoms and the center Au atom can well protect the spin state stored in the S-Au-S junction and efficiently extract its spin state to the current by spin resonance mechanism, while the spin interaction of itinerant electrons and the valence electron of the center Au atom in the Au-Au-Au junction can extract the current spin information into the center Au atom. Fermi energy drift and bias-dependent spin filtering properties of the Au-Au-Au junction may transform information between distance, bias, and electron spin. Those unique properties make them potential candidates for a logical nanocircuit. Project supported by the National Basic Research Program of China (Grants No. 2011CB921602) and the National Natural Science Foundation of China (Grants No. 20121318158).

  16. Connaissances, attitudes et pratiques de la population de l'aire de santé SAMBWA en rapport avec le traitement de l'onchocercose à l'ivermectine sous directives communautaires

    PubMed Central

    Philippe, Cilundika Mulenga; Bienvenu, Yogolelo Asani; Francoise, Malonga Kaj; Eric, Mukomena Sompwe; Abdon, Mukalay wa Mukalay; Luboya, Oscar Numbi

    2014-01-01

    Introduction L'onchocercose constitue un problème majeur de santé publique et l'on a noté environ 13 millions de personnes affectées et 26 millions exposées au cours de l'année 2012 en RDC. L'objectif de notre étude est fournir les données sur le niveau de connaissance, d'attitudes et des pratiques de la communauté huit ans après le lancement de la distribution de l'ivermectine sous directives communautaires. Méthodes Il s'agit d'une étude descriptive transversale dans la communauté de l'aire de santé SAMBWA de la zone de santé de KAFUBU. La population cible de l’étude est toute personne de la communauté âgée de 15 à 65 ans. Les paramètres étudiés sont: âge, niveau d'instruction, connaissance de la maladie en langue locale et des signes, attitudes devant les personnes atteintes, perception de la maladie, utilisation des pratiques traditionnelles, association entre le niveau d'instruction et la connaissance de savoir si l'on peut suivre un traitement. Résultats La moyenne d’âge des répondants était de 38±14 ans et 67,54% des enquêtés étaient de niveau primaire. L’étude a montré que 99,53% des répondants connaissaient le terme onchocercose en langue locale (UBUMFUKU) et un niveau moyen de connaissance en ce qui concerne les lésions de la peau (66,9%) était noté. 1,9% des répondants craignaient les personnes atteintes et 42,2% des répondants percevaient l'onchocercose comme une maladie. Une proportion de 55% qui prenaient les plantes comme médicament. Il y avait association significative entre le niveau d'instruction et la connaissance de suivre un traitement contre l'onchocercose (p: 0,008). Conclusion Ces résultats interpellent en ce qui concerne la sensibilisation de la communauté sur l'onchocercose. Les stratégies de lutte contre l'onchocercose devraient prendre en compte ces différentes insuffisances de la communauté pour améliorer le traitement des masses par l'ivermectine tant au niveau du ménage que des

  17. Le domaine des co-infections et des maladies concomitantes du Réseau canadien pour les essais VIH des IRSC : lignes directrices canadiennes pour la prise en charge et le traitement de la co-infection par le VIH et l’hépatite C chez les adultes

    PubMed Central

    Hull, Mark; Giguère, Pierre; Klein, Marina; Shafran, Stephen; Tseng, Alice; Côté, Pierre; Poliquin, Marc; Cooper, Curtis

    2014-01-01

    HISTORIQUE : De 20 % à 30 % des Canadiens qui vivent avec le VIH sont co-infectés par le virus de l’hépatite C (VHC), lequel est responsable d’une morbidité et d’une mortalité importantes. La prise en charge du VIH et du VHC est plus complexe en raison de l’évolution accélérée de la maladie hépatique, du choix et des critères d’initiation de la thérapie antirétrovirale et du traitement anti-VHC, de la prise en charge de la santé mentale et des toxicomanies, des obstacles socioéconomiques et des interactions entre les nouvelles thérapies antivirales à action directe du VHC et les antirétroviraux OBJECTIF : Élaborer des normes nationales de prise en charge des adultes co-infectés par le VHC et le VIH dans le contexte canadien. MÉTHODOLOGIE : Le Réseau canadien pour les essais VIH des Instituts de recherche en santé du Canada a réuni un groupe d’experts possédant des compétences cliniques en co-infection par le VIH et le VHC pour réviser les publications à jour ainsi que les lignes directrices et les protocoles en place. Après une vaste sollicitation afin d’obtenir des points de vue, le groupe de travail a approuvé des recommandations consensuelles, qu’il a caractérisées au moyen d’une échelle de qualité des preuves fondée sur la classe (bienfaits par rapport aux préjudices) et sur la catégorie (degré de certitude). RÉSULTATS : Toutes les personnes co-infectées par le VIH et le VHC devraient subir une évaluation en vue de recevoir un traitement du VHC. Les personnes qui ne sont pas en mesure d’entreprendre un traitement du VHC devraient être soignées pour le VIH afin de ralentir l’évolution de la maladie hépatique. La norme de traitement du VHC de génotype 1 est un régime comprenant de l’interféron pégylé et de la ribavirine dosée en fonction du poids, associés à un inhibiteur de la protéase du VHC. Pour les génotypes 2 ou 3, une bithérapie classique est recommandée pendant 24 semaines s

  18. Precocity of Gnathostoma turgidum in naturally infected four-eyed opossum Philander opossum pallidus from Temascal, Oaxaca, Mexico.

    PubMed

    Almeyda-Artigas, Roberto Javier; Mosqueda-Cabrera, Miguel Angel; Sánchez-Núñez, Edmundo

    2010-01-01

    Two female advanced third-stage larvae of Gnathostoma turgidum recovered from the liver of one naturally infected four-eyed opossum Philander opossum pallidus collected in Oaxaca, Mexico, were morphologically examined. Because of some characteristics, the larvae do not fit into the typical advanced third-stage. The body shows a size at least three times larger than expected and rows of spines only in the anterior part of the body surface. Consequently, in this research, we document for the first time the precocity in third-stage larvae of G. turgidum, and we also highlight some facts about the fourth larval stage occurring in spirurins.

  19. La Greffe de Peau dans le Traitement des Sequelles de la Main Brulee. A Propos de 152 Cas - Experience du Service de Chirurgie Plastique du Centre Hospitalier Universitaire Ibn-Sina, Rabat, Maroc

    PubMed Central

    El Mazouz, S.; Fejjal, N.; Hafidi, J.; Cherkab, L.; Mejjati, H.; Belfqih, R.; Gharib, N.; Abbassi, A.

    2010-01-01

    Summary La main est fréquemment exposée aux brûlures, entraînant des séquelles esthétiques et fonctionnelles. Le traitement de ces séquelles est surtout chirurgical et consiste en la greffe de peau, dont le type dépend de la localisation de la brûlure et du type des séquelles. Dans ce travail rétrospectif, nous rapportons une série de 152 cas de brûlures des mains colligés au service de chirurgie plastique du Centre Hospitalier Universitaire Ibn-Sina de Rabat sur une période de dix ans, allant de 1998 à 2007. Les indications thérapeutiques dépendent du type de séquelles et de la localisation de la brûlure. En tout, 97 patients ont bénéficié d'une greffe cutanée, dont 76% par greffe de peau totale, 21% par greffe de peau demi-épaisse et 3% par peau fine. Les séquelles des brûlures des mains posent un problème thérapeutique majeur, malgré la diversité des procédés chirurgicaux, d'où l'intérêt de la prévention. PMID:21991196

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

    SciTech Connect

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

    2015-08-17

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

  1. Solid-Phase Equilibria in the Au-As, Au-Ga-Sb, Au-In-As, and Au-In-Sb Ternaries.

    DTIC Science & Technology

    1986-02-28

    AD6i5 469 SOLID- PHASE EQUILIBRIA IN THE Ru-As AU-GA-SB AU-IN-AS- 1/17 AND AU-IN-SB TERNAR (U) CALIFORNIA UNIV LOS ANGELES DEPT OF CHEMISTRY AND...REPORT & PERIOD COVERED SOLID- PHASE EQUILIBRIA IN THE Au-Ga-As, Au-Ga-Sb Thchnical Report Au-In-As, and Au-In-Sb TEARIEIS S. PERFORMING ORG. REPORT NUMBER...CLASSIFICATION OF THIS PAGEMI*n Does Entepd) 4./ lie- . .- - - - - -- -- Solid Phase Equilibria in the Au-Ga-As, Au-Ga-Sb, Au-In-As, and Au-In-Sb Ternaries C

  2. Les neuropathies liées au VIH/SIDA: une étude clinique chez les patients infectés par le VIH au Centre d'Excellence VIH/SIDA de l'Université de Lubumbashi

    PubMed Central

    Kabongo, Joe Katabwa; Kaputu-Kalala-Malu, Célestin; Luboya, Oscar; Mutombo, Valerien; Ntambwe, Abel; Mapatano, Mala Ali; Mukendi, Kavulu Mayamba

    2015-01-01

    Introduction En vue d'améliorer la prise en charge des patients souffrant de neuropathie (NP) associées à l'infection HIV, nous avons essayé de déterminer le profil clinique des personnes souffrant de NP au cours du suivi thérapeutique de leur infection HIV. Méthodes Il s'agit d'une étude transversale (n= 101) menée au centre d'excellence depuis 1 an. Notre analyse est essentiellement clinique. Par un examen clinique minutieux, nous avons recherché tous les symptômes et signes cliniques des NP. Subjectivement, les douleurs dominent le tableau. Pour affiner leur diagnostic, nous avons utilisé l’échelle DN4 (Diagnostic des douleurs neuropathiques) et l’échelle EVA (Evaluation de la gravité des douleurs). Nous avons ensuite analysé nos données en fonction de certains autres facteurs épidémiologiques tels que le taux des CD4, le traitement anti-HIV etc. Résultats Les 101 patients représentent 3,12% de la cohorte générale; 53,3% des patients présentent une abolition des réflexes ostéotendineux des membres inférieurs; 77,89% présentent une hypoesthésie thermo algique en chaussette et en gants; 25% ont présenté une amyotrophie des membres inférieurs; 76,5% ont été soumis à un traitement antirétroviral contenant la stavudine; 11,7% ont pris la didanosine (DDI) et Abacavir (ABC). 84% ont une moyenne de CD4 de 292 cel/mm3. Conclusion La NP altère la qualité de vie de nos patients et diminue l'adhérence au traitement antirétroviral. Plusieurs facteurs sont incriminés dans la survenue de la NP, l'effet direct des antirétroviraux, l'effet inflammatoire dysimmunitaire, l'effet infectieux lié aux infections opportunistes. D'autres facteurs seront recherchés et analysés ultérieurement. PMID:26185582

  3. Rubans Ag/Bi 2212 préparés par alternance de dépôts électrolytiques et de traitements thermiques

    NASA Astrophysics Data System (ADS)

    Legendre, F.; Régnier, P.; Schmirgeld-Mignot, L.; Poissonnet, S.

    1998-02-01

    paisseur au lieu de les refroidir très lentement, nous ne les maintenons que brièvement dans l'état fondu, puis nous les trempons jusqu'à la température ambiante. Nous synthétisons alors la phase Bi 2212 sans repasser au-dessus de son point de fusion. Afin d'optimiser le procédé, nous avons caractérisé la microstructure de nos échantillons à chacune des étapes de leur élaboration. Nous présentons dans cet article la comparaison entre le procédé classique de fusion partielle et le nôtre, ainsi que la corrélation entre les traitements thermiques et les propriétés électriques. Au stade actuel de l'optimisation, nous préparons de façon reproductible des échantillons présentant une densité de courant critique de transport d'environ 30 000 A/cm^2 à 77 K et 300 000 A/cm^2 à 4,2 K, ce qui correspond à des courants de transport de respectivement 6,3 et 63 Ampères pour des échantillons de 3 mm de large, avec un rapport substrat sur supra de 7. Nous avons de plus vérifié que le courant critique était proportionnel à la largeur de l'échantillon, conduisant à un courant critique de 42 A à 77 K et 100 A à 63 K pour les échantillons les plus larges que nous ayons testés (20 mm).

  4. 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

  5. Difficulté de la prise en charge de la Leucémie aiguë au cours de la grossesse au Maroc

    PubMed Central

    Tissir, Rajaa; Lamchahab, Mouna; Benhassou, Mustapha; Quachouh, Meryeme; Rachid, Mohammed; Benchakroun, Said; Quessar, Asmaa

    2012-01-01

    L'association de la leucémie aiguë (LA) et grossesse est rare. Son incidence est estimée à 1/100 000 grossesses. Dans les 2/3 des cas ce sont des leucémies aiguës myéloblastiques. Le diagnostic est généralement fait pendant le 2ème et le 3ème trimestre. Elle pose un problème éthique et thérapeutique car La chimiothérapie au cours de la grossesse expose le fœtus aux complications. Tout retard ou changement de traitement pour sauvetage fœtal risque d'aggraver le pronostic maternel. L'objectif de ce travail est de décrire les particularités de la prise en charge de la leucémie aiguë chez la femme enceinte. Etude prospective descriptive des femmes enceintes atteintes de leucémie aiguë colligées au service d'hématologie et d'oncologie pédiatrique à l'hôpital 20 Août du CHU IBN ROCHD de Casablanca depuis janvier 2009 à Août 2011. Le diagnostic de LA est fait selon les critères de l'OMS. Le traitement était instauré après consentement des patientes selon le type de LA. Huit cas de leucémies aiguës au cours de la grossesse sont colligés au service d'hématologie et d'oncologie pédiatrique à l'hôpital 20 Août du CHU IBN ROCHD de Casablanca. Sept leucémies aiguës myéloblastiques et une leucémie aiguë lymphoblastique. Quatre cas ont été diagnostiqués durant le 1er trimestre de la grossesse, Un cas pendant le 2ème trimestre et 3 cas pendant le 3ème trimestre. L'accouchement est par césarienne programmée dans 2 cas et par voie basse dans 3 cas dont un est prématuré, 2 fausses couches et une mort fœtal après décès maternel. Trois patientes ont reçue la chimiothérapie durant la grossesse après consentement éclairé et les 5 autres après l'accouchement. Les 5 nouveau-nés sont bien portants avec un bilan malformatif négatif. L'association de la leucémie aiguë et grossesse est un évènement rare. Elle nécessite une prise en charge multidisciplinaire tenant compte des impératifs de la maladie et de son traitement

  6. Magnetoresistance of Au films

    DOE PAGES

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

    2014-12-10

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

  7. Bloc atrio-ventriculaire transitoire au cours d'un goitre multinodulaire: à propos d'un cas

    PubMed Central

    Millogo, Georges Rosario Christian; Konaté, Lassina; Samandoulougou, André; Kambiré, Yibar; Yaméogo, Nobila Valentin; Kologo, Koudougou Jonas; Tindano, Caleb; Toguyeni, Jean Yves; Zabsonré, Patrice

    2014-01-01

    Les troubles de conduction auriculo-ventriculaire sont relativement fréquents en Afrique grâce à l’élévation de l'expérience de vie dans nos sociétés en pleine transition épidémiologique. Ces troubles sont le plus souvent dus à une dégénérescence du tissu de conduction. La prise en charge des troubles conductifs (BAV3) consiste en l'implantation d'un stimulateur cardiaque définitif. Mais cette thérapeutique doit être précédée par une enquête étiologique pour détecter les autres causes de BAV transitoire. Nous rapportons l'observation d'une patiente de 75 ans, admise pour bloc auriculo-ventriculaire 2/1 et un goitre multi-nodulaire hyperthyroïdique; le traitement avec des antithyroïdiens de synthèse a vu la disparition du trouble conductif. Les BAV au cours de l'hyperthyroïdie sont rares, mais bien décrits. L’évolution est favorable sous traitement par antithyroïdiens de synthèse. Il ne faudrait donc pas implanter des pacemakers définitifs en première intention. PMID:25667715

  8. Evaluation de la tolérance et de l'efficacité du traitement de l'hépatite virale chronique C chez les patients drépanocytaires homozygotes

    PubMed Central

    El Agheb, Mohamed Ould Mohamed; Grange, Jean-Didier

    2015-01-01

    La drépanocytose est une maladie génétique à transmission autosomale codominante. Les patients homozygotes ont des crises hémolytiques qui génèrent les symptômes cliniques. Il s'agit d'une maladie fréquente. En France, la plupart des cas hospitalisés sont observés en Ile de France et aux Antilles. Le pronostic des patients s'est beaucoup amélioré ces dernières années. L’âge médian au décès a doublé en 20 ans. Il est passé de 18 à 36 ans, témoignant d'une meilleure prise en charge des malades. De ce fait, les complications hépatiques de la maladie, et notamment celles liées à l'hépatite virale chronique C, sont de plus en plus fréquentes. La Ribavirine étant contre indiquée dans le traitement de l'hépatite C chez les malades atteints d'anémie hémolytique (talassémie, drépanocytose), il n'existe que très peu de cas publiés dans les littératures et aucun cas traité par trithérapie antivirale incluant un inhibiteur de protéase. Le but de ce travail était d’évaluer la tolérance, l'efficacité du traitement de l'hépatite virale chronique C chez des patients drépanocytaires homozygotes. Dans la cohorte de patients drépanocytaires homozygotes adultes de l'hôpital Tenon (n = 560), la prévalence de l'hépatite C chez les derepanocytaires était de 7% (n = 38) en 2012. Il s'agissait de 15 hommes et 23 femmes âgés de 20 à 59 ans. Vingt-cinq patients avaient reçu plus de 10 transfusions et 13 patients avaient reçu moins de 10 transfusions au cours des années précédant le bilan. La répartition des génotypes était: G1 (n = 7); G2 (n = 2); G3 (n = 1); G4 (n = 6); G inconnu (n = 22). Neuf patients ont été traités dont 8 par bithérapie (Peg/Rbv) et 1 par trithérapie (télaprevir). La posologie de ribavirine était supérieure ou égale à 800mg/jour chez 7 patients et inférieure à cette dose chez les deux autres patients. Le score METAVIR de fibrose était: F1 (n = 3), F2 (n = 4) et F 3 (n = 1);un patient n'a pas

  9. meson production in Au+Au collisions at in STAR

    NASA Astrophysics Data System (ADS)

    Zhou, Long; STAR collaboration

    2017-01-01

    In this article, we report the measurements of the nuclear modification factor (R AA) and elliptic flow (v 2) for in Au+Au collisions at from the STAR experiment. These results are compared with the results of other open charm mesons to study the hadronization mechanism of the charm quarks and disentangle the transport properties of quark-gluon plasma and hadronic phase [1]. We found that the nuclear modification factor for D s are systematically higher than unity and D 0 R AA. The ratio of D s /D 0 for 10-40% central Au+Au collisions is also higher than that in p+p collisions as predicted by PYTHIA. The D s /D 0 ratio is also compared to that in Pb+Pb collisions at measured by the ALICE experiment. Our results indicate an enhancement of D s meson production in Au+Au collisions.

  10. La place du clou Telegraph court dans le traitement des fractures de l'extrémité supérieure de l'humérus: à propos de 19 cas

    PubMed Central

    karabila, Mohamed Amine; Hmouri, Ismail; Mhamdi, Younes; Azouz, Mohamed; Madani, Tarik; Kharmaz, Mohamed; Ouadaghiri, Mohamed; Lamrani, Moulay Omar; Bardouni, Ahmed; Lahlou, Abdou; Mahfoud, Mustapha; Berrada, Mohamed Saleh; Montbarbon, Éric; Beaudouin, Emmanuel

    2016-01-01

    La fracture de l'extrémité supérieure de l'humérus est la troisième fracture en fréquence chez les sujets âgés et leur répartition est bimodale touchant préférentiellement le sujet âgé ostéoporotique après un traumatisme à faible énergie ou plus rarement le sujet jeune par mécanisme à forte cinétique. Le traitement des fractures complexes de l'humérus proximal est le sujet de nombreuses controverses Le clou Telegraph constitue une approche thérapeutique très efficace pour les fractures déplacées de l'extrémité supérieure de l'humérus, de technique chirurgicale facile mais avec une courbe d'apprentissage et permettant un protocole de rééducation dans l'immédiat de l'intervention. C'est un matériel d'enclouage antérograde de 15 cm de long, plein verrouillé en proximal et en distal, le verrouillage proximal est assuré par 4 vis spongieuses, de filetage long, stables dans le clou et cela confère une solidité tout-à-fait remarquable à ce montage alors que le verrouillage distal est assuré au niveau du V deltoïdien en zone avasculaire et là où il n'y a pas de passage nerveux. L’étude présentée concerne 19 patients traités par un clou Telegraph court dans le traitement des fractures de l'extrémité supérieure de l'humérus entre 2013 et 2015 et elle a pour but d'analyser les résultats radio-cliniques et d’évaluer la répercussion de cette technique sur la fonction de l’épaule. Le clou Telegraph proposé depuis plus de 12 ans à peu près, a rencontré et continue de rencontrer un réel succès. Il permet de traiter très efficacement les fractures simples type 2 et 3, mais aussi les fractures impactées en valgus à 4 fragments. L'ostéosynthèse par clou Telegraph est une solution efficace, rapide et reproductible dans le traitement chirurgical des fractures de l'extrémité supérieur de l'humérus même en cas des fractures complexes et permet une reprise rapide de la mobilité de l’épaule. PMID:27583100

  11. 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

  12. L’arthroplastie totale de la hanche dans le traitement des luxations congénitales de la hanche chez l’adulte: à propos de 15 cas

    PubMed Central

    El Ayoubi, Abdelghani; Nasri, Mohamed; Krite, Ali; Idrissi, Mohamed El; Shimi, Mohamed; Ibrahimi, Abdelhalim El; Elmrini, Abdelmajid

    2016-01-01

    L’arthroplastie totale de la hanche sur luxation congénitale représente un défit pour le chirurgien orthopédiste. Il est maintenant bien établi que le traitement de la maladie congénitale de la hanche chez l’adulte présente un vrai « miracle fonctionnel ». L’évolution des techniques chirurgicales et des matériaux a permis d’élargir les indications de remplacement prothétique jusqu’aux cas les plus complexes allant ainsi à l’encontre de Charnley et Feagin qui écrivaient, en 1973, qu’il n’existait pas de place pour l’arthroplastie totale de la hanche dans les luxations invétérées. Il s’agissait d’une étude rétrospective d’une série de 15 PTH sur luxation congénital de la hanche chez l’adulte, le recueil des données sociodémographiques, cliniques, paracliniques et thérapeutiques s’est fait à l’aide d’une étude des dossiers médicaux des 15 patients et aussi en répondant à un questionnaire au dernier recul. L’âge moyen de nos patients a été de 28 ans; avec une prédominance féminine sex ratio 2F/1H. Il s’agissait d’une dysplasie sévère stade VI selon la classification de crow chez 4 cas, type III chez 9 cas, et seulement 2 cas type II. Tous les patients ont bénéficiés d’une arthroplastie totale de la hanche cimentée, avec anneau de soutien chez 9 cas, et une butté osseuse chez 2 cas. Au dernier recul les résultats fonctionnel selon le score PMA sont excellents et très bon dans 74% des cas. La prise en charge chirurgicale des luxations congénitales de la hanche à l’âge adulte doit obéir et répondre à un cahier de charges lourdes, il s’agissait souvent d’une population jeune et féminine exigeante sur le plan fonctionnel et esthétique. Plusieurs techniques chirurgicales ont été décrites en essayant de résoudre les problèmes liées à cette pathologie, hypoplasie cotyloïdienne et fémorale, l’inégalité des membres inférieurs, etc. L’arthroplastie totale de la hanche

  13. 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

  14. Les infections à Pseudomonas aeruginosa au service des maladies infectieuses du CHU YO, Burkina Faso: à propos deux cas

    PubMed Central

    Mamoudou, Savadogo; Lassina, Dao; Fla, Koueta

    2015-01-01

    Nous rapportons deux cas d'infection à Pseudomonas aeruginosa: un cas de méningite et un cas d'infection urinaire. Les auteurs rappellent qu’à côté des étiologies classiques des méningites et des infections urinaires, des germes résistants comme Pseudomonas aeruginosa peuvent être responsables d'infections à localisation méningées et urinaires et dont il faut connaître pour une bonne prise en charge. Le traitement de ces infections requiert un antibiogramme au regard de la grande capacité de résistance de Pseudomonas aeruginosa en milieu hospitalier. La limitation des gestes invasifs et l'application rigoureuse des mesures de prévention des infections en milieu hospitalier contribueront à lutter efficacement contre ces infections en milieu de soins. PMID:26491521

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

    PubMed Central

    2013-01-01

    Porphyrin/Au and Au/porphyrin/Au systems were prepared by vacuum evaporation and vacuum sputtering onto glass substrate. The surface morphology of as-prepared systems and those subjected to annealing at 160°C was studied by optical microscopy, atomic force microscopy, and scanning electron microscopy techniques. Absorption and luminescence spectra of as-prepared and annealed samples were measured. Annealing leads to disintegration of the initially continuous gold layer and formation of gold nanoclusters. An amplification of Soret band magnitude was observed on the Au/meso-tetraphenyl porphyrin (TPP) system in comparison with mere TPP. Additional enhancement of luminescence was observed after the sample annealing. In the case of sandwich Au/porphyrin/Au structure, suppression of one of the two porphyrins’ luminescence maxima and sufficient enhancement of the second one were observed. PMID:24373347

  16. Fièvre bilieuse hémoglobinurique (FBH) de révélation tardive: à propos d'un cas au CHU de Dakar

    PubMed Central

    Thiongane, Aliou; Ndongo, Aliou Abdoulaye; Faye, Papa Moctar; Sylla, Assane; Kéïta, Younoussa; Boiro, Djibril; Basse, Idrissa; Guèye, Ndèye Ramatoulaye Diagne; Ndiaye, Ousmane

    2015-01-01

    La fièvre bilieuse hémoglobinurique (FBH) est une forme grave du paludisme; caractérisée par la survenue d'une hémolyse intravasculaire aiguë se traduisant par une anémie hémolytique, une insuffisance rénale aiguë et une hypovolémie. Son diagnostic repose essentiellement sur la clinique notamment la couleur des urines d'aspect rouge porto. Nous rapportons un cas de fièvre bilieuse hémoglobinurique chez un jeune garçon de 10 ans originaire et vivant dans une zone d'endémie palustre, colligé dans un CHU de Dakar (Sénégal). V.G est un garçon de 10 ans qui était hospitalisé pendant 2 jours au service des urgences dans un centre de santé de proximité pour une fièvre associée à des vomissements qui évoluaient depuis 3 jours. Le test de diagnostic rapide (TDR) au paludisme était positif à la présence d'antigènes de Plasmodium falciparum dans le sang. Un traitement à base de quinine injectable (25 mg/kg/j), a été entrepris pendant 03 jours. Au quatrième jour, sont apparues une hémolyse intravasculaire aiguë et une hémoglobinurie avec une insuffisance rénale aiguë anurique. La goutte épaisse était revenue négative et le traitement par la quinine injectable arrêté. Le relais a été fait avec les dérivés de l'artémisinine. Trois (03) séances d'hémodialyse ont été réalisées. L’évolution était favorable, par la reprise de la diurèse et la normalisation de la fonction rénale. La FBH existe encore dans notre pratique quotidienne. Il faut y penser devant l'apparition brutale d'une hémolyse avec insuffisance rénale aiguë et urines rouges porto au cours du traitement d'un paludisme. PMID:26966497

  17. L'intervention de Castaing dans le traitement chirurgical de l'instabilité chronique latérale de la cheville (à propos d'une série continue de 52 cas)

    PubMed Central

    Boukhris, Jalal; Mojib, Rifi; Mezghani, Sami; Jaeger, Jean Henri

    2014-01-01

    L'instabilité chronique de la cheville est l'une des évolutions possibles dans l'histoire naturelle de l'entorse aigüe de cheville. Elle représente 10% à 30% des séquelles d'entorses. Le traitement chirurgical est réservé aux patients ayant une instabilité de cheville persistante après rééducation à l'origine d'une gêne invalidante. La technique de ligamentoplastie utilisant le court fibulaire selon Castaing est la plus répondue en France. La simplicité du geste et ses bons résultats nous ont incités à poursuivre cette voie. Il s'agit d´une étude rétrospective à propos de 52 patients ayant bénéficié d'une ligamentoplastie au court fibulaire selon Castaing entre Janvier 2000 et Décembre 2010. Le recul minimum était d'un an. L’évaluation des patients reposait sur le score de Karlson et le “Ankle score” Molander et Olerud. Les patients sont satisfaits ou très satisfaits de l'intervention dans 80% des cas revus. Les résultats fonctionnels de nos patients sont comparables à ceux publiés dans la littérature. Le prélèvement du transplant du court fibulaire ne semble pas avoir de retentissement sur la stabilité de la cheville. Les patients conservent une éversion du pied satisfaisante avec une force comparable au côté opposé. L’évolution arthrosique de la cheville ne semble pas significative après cette chirurgie. Le point faible de notre étude est le nombre des patients perdus de vue, cela est lié à la jeunesse de la population opérée et au recrutement du service d'envergure nationale. PMID:25469182

  18. Atteinte pulmonaire sévère au cours de la vascularite hypocomplémentémique urticarienne

    PubMed Central

    Raoufi, Mohammed; Laine, Mustapha; Amrani, Hicham Naji; Souhi, Hicham; Janah, Hicham; Elouazzani, Hanane; Rhorfi, Ismail Abderrahmane; Abid, Ahmed

    2016-01-01

    L'atteinte pulmonaire au cours de la vascularite urticarienne hypocomplémentémique (VUH) ou syndrome de Mc duffie est très rare et de pronostique péjoratif. Nous rapportons le cas d'une patiente âgée de 55 ans suivie pour VUH depuis 20 ans. Le diagnostic était retenu sur les lésions urticariennes, l'inflammation occulaire, le test positif C1q-p par immunodiffusion, avec un faible du taux de C1q. La patiente a été traitée par des cycles à base de cyclophosphamide, des corticoïdes et des cures de rituximab alors qu'elle a développé une dyspnée actuellement classe III (classification NYHA). Le bilan clinico-radiologique et fonctionnel a montré une distension thoracique et une broncho-pneumopathie obstructive sévère non amélioré par le traitement systémique. Un traitement par aérosolthérapie a été démarré et la patiente présentait une nette amélioration clinique. L'atteinte pulmonaire au cours de la vascularite urticarienne hypocomplémentémique de Mc duffie conditionne le pronostique vital à cours terme. La connaissance des différentes formes de cette atteinte ouvre de nouvelles perspectives thérapeutiques. PMID:28154640

  19. Effet paradoxal du type d’excision sur la prise et le délai de cicatrisation des greffes expansées pour le traitement des brûlures aiguës: a propos de 1129 cas

    PubMed Central

    Guibert, M.; Chaouat, M.; Boccara, D.; Marco, O.; Lavocat, R.; Alameri, O.; Deslandes, E.; Montlahuc, C.; Mimoun, M.

    2016-01-01

    Summary La greffe de peau mince expansée est très employée dans le traitement des brûlures aiguës. Nous avons étudié l’influence de la préparation du sous-sol sur le taux de prise et le délai de cicatrisation des greffes expansées. Nous avons analysé rétrospectivement les 1 129 greffes expansées réalisées dans notre service entre 1995 et 2005 pour le traitement des brûlures aiguës. Leur taux de prise a été significativement meilleur après une préparation du sous-sol par avulsion (82%) par rapport à une préparation du sous-sol par excision tangentielle (75%). Ce taux était meilleur lorsque l’avulsion était pratiquée dans les 7 jours suivant la brûlure (83% vs 73%). Pour une prise en charge entre 7 et 21 jours, ce taux a semblé être meilleur après excision tangentielle, mais de façon non significative. La durée d’évolution jusqu’à cicatrisation était significativement raccourcie pour une préparation du sous-sol par excision tangentielle par rapport à une préparation du sous-sol par avulsion. Ces résultats montrent, paradoxalement, qu’une préparation du sous-sol par avulsion favorise la prise des greffes expansées mais rallonge leur délai de cicatrisation au contraire de l’excision tangentielle. PMID:28149235

  20. Magnetoresistance of Au films

    SciTech Connect

    Zhang, D. L. Song, X. H.; Zhang, X.; Zhang, X.-G.

    2014-12-14

    Classical magnetoresistance (MR) in nonmagnetic metals are conventionally understood in terms of the Kohler rule, with violation usually viewed as anomalous electron transport, in particular, as evidence of non-Fermi liquid behavior. Measurement of the MR of Au films as a function of temperature and film thickness reveals a strong dependence on grain size distribution and clear violation of the Kohler rule. Using a model of random resistor network, we show that this result can be explained if the MR arises entirely from inhomogeneity due to grain boundary scattering and thermal activation of grain boundary atoms. Consequently, the Kohler rule should not be used to distinguish normal and anomalous electron transport in solids.

  1. On the electron affinity of Au3

    NASA Technical Reports Server (NTRS)

    Bauschlicher, Charles W., Jr.

    1989-01-01

    The EA of Au3 is estimated to be 3.93 eV. The calculations also show that the feature in the photodetachment spectrum at about 2 eV electron binding energy is due to a two-photon process involving fragmentation of Au3(-) to Au and Au2(-) and subsequent photodetachment of Au2(-). Au3 is found to have a 2B2 ground state that is only slightly distorted from an equilateral triangle.

  2. Determination of relative sensitivity factors during secondary ion sputtering of silicate glasses by Au+, Au2+ and Au3+ ions.

    PubMed

    King, Ashley; Henkel, Torsten; Rost, Detlef; Lyon, Ian C

    2010-01-01

    In recent years, Au-cluster ions have been successfully used for organic analysis in secondary ion mass spectrometry. Cluster ions, such as Au(2)(+) and Au(3)(+), can produce secondary ion yield enhancements of up to a factor of 300 for high mass organic molecules with minimal sample damage. In this study, the potential for using Au(+), Au(2)(+) and Au(3)(+) primary ions for the analysis of inorganic samples is investigated by analyzing a range of silicate glass standards. Practical secondary ion yields for both Au(2)(+) and Au(3)(+) ions are enhanced relative to those for Au(+), consistent with their increased sputter rates. No elevation in ionization efficiency was found for the cluster primary ions. Relative sensitivity factors for major and trace elements in the standards showed no improvement in quantification with Au(2)(+) and Au(3)(+) ions over the use of Au(+) ions. Higher achievable primary ion currents for Au(+) ions than for Au(2)(+) and Au(3)(+) allow for more precise analyses of elemental abundances within inorganic samples, making them the preferred choice, in contrast to the choice of Au(2)(+) and Au(3)(+) for the analysis of organic samples. The use of delayed secondary ion extraction can also boost secondary ion signals, although there is a loss of overall sensitivity.

  3. Traitement des conditions aux limites intérieures et extérieures pour la simulation numérique unidimensionnelle de l'écoulement de l'eau dans les canaux à surface libre

    NASA Astrophysics Data System (ADS)

    Abdallah, M.; Vazquez, J.; Mose, R.; Zoaeter, M.

    2005-05-01

    Dans ce papier, on décrit le traitement des conditions aux limites intérieures et extérieures couplé avec la méthode explicite aux différences finies de Roe pour le développement d'une modélisation unidimensionnelle qui sert à résoudre les équations de Saint-Venant décrivant l'écoulement de l'eau à surface libre. Les deux méthodes les plus utilisées pour trouver la solution aux nœuds intérieurs et extérieurs définissant les conditions aux limites intérieures et extérieures d'un schéma numérique sont décrites et comparées dans deux exemples: Le premier traite le problème du ressaut hydraulique et le second décrit l'écoulement de l'eau au dessus des seuils. Deux types de discrétisation du terme source, pointwise et upwind, sont considérés et comparés aussi. Les résultats obtenus et comparés avec la solution analytique dans le cas du ressaut, et avec les résultats numériques déjà publiés dans le cas des seuils, montrent l'avantage de la méthode des caractéristiques sur la méthode de l'extrapolation pour les conditions aux limites, et la discrétisation upwind du terme source sur la discrétisation pointwise.

  4. Sexual precocity of Nellore bulls that are offspring of super precocious, precocious and normal cows in extensive farming conditions.

    PubMed

    Siqueira, J B; Oba, E; Pinho, R O; Guimarães, S E F; Neto, T M; Guimarães, J D

    2014-10-01

    The objective of this work was to verify that mothers classified as super precocious (M1) and precocious (M2) produce more precocious bulls than females classified as normal (M3). This study included 21,186 animals with an average age of 21.29 ± 1.77 months that underwent a breeding soundness evaluation from 1999 to 2008. Of these animals, 2019, 6059 and 13,108 were offspring of M1, M2 and M3 females, respectively. In the breeding soundness examination, the animals were classified as sound for reproduction, sound under a natural mating regime, unsound for reproduction and discarded. To compare the averages obtained for each category of mother within the individual breeding soundness classes, a chi-square test with a 5% error probability was used, considering the effects of year and month of birth and farm. For the three classes of mothers (M1, M2 and M3), 67.26, 67.22 and 64.16% of bull calves were considered sound for reproduction and 19.71, 19.46 and 21.90% were considered unsound for reproduction, respectively. There was no difference in the frequency of animals that were sound for reproduction under the natural breeding regime between the three classes of mothers (8.87, 9.31 and 9.19%, respectively). There was a difference between the numbers of precocious and normal females that were discarded, with frequencies of 4.01 and 4.75%, respectively (p < 0.05). There were differences in year and month of birth and farm between super precocious and precocious cows in relation to the breeding soundness classification of the animals. It was concluded that the bull offspring of super precocious and precocious cows presented a higher percentage of approval in the breeding soundness examination than the bull offspring of normal cows, demonstrating that the selection for precocity of females has contributed to an increase in the sexual precocity of the herd in relation to the sexual maturity of bulls.

  5. Pion Interferometry in AU+AU Collisions at the AGS

    SciTech Connect

    Lee, J. H.

    1999-01-09

    Two-pion Bose-Einstein correlations have been studied using the BNL-E866 Forward Spectrometer in 11.6 A {center_dot} GeV/c Au + Au collisions. The data were analyzed using three-dimensional correlation parameterizations to study transverse momentum-dependent source parameters. The freeze-out time and the duration of emission were derived from the source radii parameters.

  6. Optical nonlinearities of Au nanoparticles and Au/Ag coreshells.

    PubMed

    Seo, Jae Tae; Yang, Qiguang; Kim, Wan-Joong; Heo, Jinhwa; Ma, Seong-Min; Austin, Jasmine; Yun, Wan Soo; Jung, Sung Soo; Han, Sang Woo; Tabibi, Bagher; Temple, Doyle

    2009-02-01

    Au nanoparticles exhibited both negative and positive nonlinear absorptions with ground-state plasmon bleaching and free-carrier absorption that could be origins of the saturable and reverse-saturable optical properties. Au/Ag coreshells displayed only positive nonlinear absorption and reverse-saturable optical properties as a function of excitation intensity at the edge of surface-plasmon resonance, which implies no ground-state plasmon bleaching and the existence of two-photon absorption.

  7. Les séquelles de brûlures cervicales: aspects épidémiologique, clinique et thérapeutique au Maroc

    PubMed Central

    Rafik, Amine; Chabak, Hakim; Diouri, Mounia; Bahechar, Naïma; Chlihi, Abdessamad

    2015-01-01

    Les séquelles de brûlures cervicales représentent une entité fréquente des séquelles de brûlure, elles affectent la fonction, l'esthétique et l’état psychologique des patients et peuvent être de traitement difficile. Il s'agit d'une étude rétrospective étalée sur 5 ans de Mars 2009 au Octobre2014, réalisée au centre national des brûlés et de chirurgie plastique au CHU Ibn Rochd Casablanca. Nous avons analysé les caractéristiques épidémiologiqueset cliniques ainsi que les indications et les résultats thérapeutiques chez 300 patients présentant des rétractions cervicales post-brûlure, suivis dans notre formation. Les jeunes femmes étaient le plus souvent touchées (56%). la brûlure thermique par flamme de butane dans le cadre d'accident domestique était l’étiologie la plus fréquente (91%).75% des patients ont été pris en charge dans un délai de 18 mois après avoir présenté une incapacité fonctionnelle. Les brides cervicales modérées et sévères sont les plus fréquentes et représentent respectivement 60% et 16% des cas. Le traitement chirurgical a fait appel aux greffes cutanées dans 67%des cas, aux plasties locales dans 24%des cas et aux lambeaux dans 24% des cas, les résultats sont jugés bons dans 75%des cas et moyens dans 18% des cas, tandis que les cas restants (7%) ont nécessité une reprise chirurgicale. Le traitement des brides cervicales doit être associé à un programme de rééducation adapté, afin d'assurer la pérennité des résultats fonctionnels et esthétiques. PMID:26301017

  8. Les pyélonephrites aigues de la femme enceinte: place du traitement médical et indications d'un drainage de la voie excrétrice supérieure (y'a-t-il des facteurs prédictifs cliniques, biologiques et radiologiques pour rendre le drainage licite?)

    PubMed Central

    El Bahri, Abdessamad; Janane, Abdellatif; Chafiki, Jaouad; Arnaud, Tayiri; Ghadouane, Mohammed; Ameur, Ahmed; Abbar, Mohammed

    2015-01-01

    Les pyélonéphrites aigues gravidiques (PNAg) sont fréquentes et peuvent avoir des conséquences maternelles et fœtales graves. Le but de notre étude était de déterminer les facteurs prédictifs cliniques, biologiques et radiologiques qui permettent de se limiter au traitement médical ou d'associer un drainage de la voie excrétrice supérieure dans la prise en charge des PNAg. Nous rapportons, de façon rétrospective une série de 26 cas dans les services d'Urologie et de Gynécologie de l'Hôpital Militaire d'Instruction Mohamed V de Rabat (Maroc) sur une période allant du 1er Janvier 2010 au 30 Aout 2012. Toutes les patientes avaient une PNAg symptomatique objectivée par l'ECBU et/ou l’échographie rénale. La fréquence de la pyélonéphrite aigue gravidique par rapport aux pyélonéphrites aigues en général a été de 27,95% avec une prédominance chez les primipares de 53,84%. Son pic de fréquence se situe à 73,08% pour les gestantes âgées de 19 à 37 ans ainsi qu'au troisième trimestre (77%) de la grossesse. La triade clinique fièvre, lombalgie, troubles mictionnels et l’échographie rénale sont les éléments importants du diagnostic. L'antibiothérapie probabiliste a été débuté d'emblée et adaptée en fonctions des résultats de l'examen cytobactériologique des urines. Sa durée est de trois à six semaines en fonction de l’évolution clinique. La protéine C réactive est un marqueur de progression de la maladie ou de l'efficacité thérapeutique. Les principaux facteurs prédictifs du drainage de la voie excrétrice supérieure sont: persistance de la symptomatologie clinique, du syndrome infectieux et des anomalies visibles à l’échographie rénale ainsi que l'altération de la fonction rénale. La montée de la sonde JJ est le principal traitement urologique. Le traitement médical repose sur l'antibiothérapie probabiliste qui sera adaptée Ultérieurement en fonction des résultats de l'antibiogramme. Les facteurs pr

  9. Improved Agrobacterium-mediated transformation and high efficiency of root formation from hypocotyl meristem of spring Brassica napus 'Precocity' cultivar.

    PubMed

    Liu, X X; Lang, S R; Su, L Q; Liu, X; Wang, X F

    2015-12-14

    Rape seed (Brassica napus L.) is one of the most important oil seed crops in the world. Genetic manipulation of rapeseed requires a suitable tissue culture system and an efficient method for plant regeneration, as well as an efficient transformation procedure. However, development of transgenic B. napus has been problematic, and current studies are limited to cultivated varieties. In this study, we report a protocol for regeneration of transgenic rape after Agrobacterium-mediated transformation of hypocotyls from the spring B. napus 'Precocity' cultivar. We analyzed the effects of plant growth regulators in the medium on regeneration. Additionally, factors affecting the transformation efficiency, including seedling age, Agrobacterium concentration, infection time, and co-cultivation time, were assessed by monitoring GUS expression. Results from these experiments revealed that transformation was optimized when the meristematic parts of the hypocotyls were taken from 8 day-old seedlings, cultured on Murashinge and Skoog basal media containing 0.1 mg/L 1-naphthaleneacetic acid and 2.5 mg/L 6-benzylaminopurine, and incubated in Agrobacterium suspension (OD600 = 0.5) for 3 to 5 min, followed by 2 days of co-cultivation. Integration of T-DNA into the plant genome was confirmed by polymerase chain reaction (PCR), b-glucuronidase histochemical staining, and quantitative real-time PCR. The protocols developed for regeneration, transformation, and rooting described in this study could help to accelerate the development of transgenic spring rape varieties with novel features.

  10. Fabrication de transistors mono-electroniques en silicium pour le traitement classique et quantique de l'information: une approche nanodamascene

    NASA Astrophysics Data System (ADS)

    Harvey-Collard, Patrick

    Les transistors mono-electroniques (SETs) sont des dispositifs ayant un grand potentiel d'applications, comme la detection de charge ultra-sensible, la logique a basse consommation de puissance, la memoire ou la metrologie. De plus, la possibilite de pieger un seul electron et de manipuler son etat de spin pourrait permettre des applications en informatique quantique. Le silicium est un materiau interessant pour fabriquer l'ilot d'un SET. Son gap semi-conducteur permet le fonctionnement du dispositif dans le regime a un seul electron ou trou et pourrait permettre d'etendre la plage d'operation du SET en temperature en augmentant l'energie d'addition du diamant central de la valeur du gap. En outre, le silicium beneficie de plus de quarante annees d'expertise en microfabrication et d'une compatibilite avec la technologie metal--oxyde--semi-conducteur complementaire (CMOS). Cependant, la fabrication de ces dispositifs fait face a de serieuses limitations a cause de la taille nanometrique requise pour l'ilot. A ce jour, les procedes de fabrication proposes permettant l'operation a la temperature ambiante sont trop peu reproductibles pour permettre des applications a grande echelle. Dans ce memoire de maitrise, la fabrication de transistors mono-electroniques en silicium (Si-SETs) pour le traitement classique et quantique de l'information est realisee avec un procede nanodamascene. Le polissage chimico-mecanique (CMP) est introduit comme etape clef de la fabrication du transistor, permettant le controle au nanometre pres (nanodamascene) de l'epaisseur du transistor. Cet outil permet la fabrication de dispositifs ayant une geometrie auparavant impossible a realiser et ouvre la porte a l'innovation technologique. De plus, un procede de gravure du silicium par plasma a couplage inductif (ICP) est developpe pour permettre la fabrication de nanostructures de silicium sur une nanotopographie alliant le nano et le 3D. Les Si-SETs fabriques sont caracterises a basse

  11. Al-Au-La (010)

    NASA Astrophysics Data System (ADS)

    Carow-Watamura, U.; Louzguine, D. V.; Takeuchi, A.

    This document is part of Part 1 http://dx.doi.org/10.1007/9getType="URL"/> 'Systems from Ag-Al-Ca to Au-Pd-Si' of Subvolume B 'Physical Properties of Ternary Amorphous Alloys' of Volume 37 'Phase Diagrams and Physical Properties of Nonequilibrium Alloys' of Landolt-Börnstein - Group III 'Condensed Matter'. It contains the Chapter 'Al-Au-La (010)' with the content:

  12. Résection laparoscopique d'une duplication gastrique chez l'adulte: traitement avec succès pour une pathologie rare

    PubMed Central

    Toumi, Omar; Hssine, Hiba Ben; Noomen, Faouzi; Jabra, Sadok Ben; Korbi, Ibtissem; Abdelmoula, Ali; Trimech, Mayada; Mansour, Wafa Ben; Faiez, Boughanmi; Khlifa, Mohamed Ben; Rabah, Hatem; Mahmoudi, Ammar; Nasr, Mohamed; Zouari, Khadija; Saffar, Hammouda; Hamdi, Abdel Aziz

    2015-01-01

    Les duplications de l'appareil digestif sont les malformations congénitales rares qui peuvent toucher tout l'appareil digestive depuis la bouche jusqu’ à l'anus. Certaines duplications sont asymptomatiques et sont diagnostiqués dans la plupart des cas pendant l'enfance. La prise en charge de la duplication gastrique est essentiellement chirurgicale. Le traitement de choix est l'exérèse complète de la duplication gastrique. Les auteurs rapportent un cas inhabituel de duplication gastrique complètement reséquée par laparoscopie. A notre connaissance, ceci est le premier cas d'une duplication gastrique traitée avec succès par laparoscopie dans la littérature Tunisienne. La Résection laparoscopique peut être ajoutée à l'arsenal thérapeutique dans le traitement chirurgical de duplications du tube digestif. PMID:26889326

  13. A Grand Avenue to Au Nanocluster Electrochemiluminescence.

    PubMed

    Hesari, Mahdi; Ding, Zhifeng

    2017-02-21

    In most cases of semiconductor quantum dot nanocrystals, the inherent optical and electrochemical properties of these interesting nanomaterials do not translate into expected efficient electrochemiluminescence or electrogenerated chemiluminescence (ECL) because of the surface-state induction effect. Thus, their low ECL efficiencies, while very interesting to explore, limit their applications. As their electrochemistry is not well-defined, insight into their ECL mechanistic details is also limited. Alternatively, gold nanoclusters possess monodispersed sizes with atomic precision, low and well defined HOMO-LUMO energy gaps, and stable optical and electrochemical properties that make them suitable for potential ECL applications. In this Account, we demonstrate strong and sustainable ECL of gold nanoclusters Au25(z) (i.e., Au25(SR)18(z), z = 1-, 0, 1+), Au38(SR)24, and Au144(SR)60, where the ligand SR is 2-phenylethanethiol. By correlation of the optical and electrochemical features of Au25 nanoclusters, a Latimer-type diagram can be constructed to reveal thermodynamic relationships of five oxidation states (Au25(2+), Au25(+), Au25(0), Au25(-), and Au25(2-)) and three excited states (Au25(-)*, Au25(0)*, and Au25(+)*). We describe ECL mechanisms and reaction kinetics by means of conventional ECL-voltage curves and novel spooling ECL spectroscopy. Notably, their ECL in the presence of tri-n-propylamine (TPrA), as a coreactant, is attributed to emissions from Au25(-)* (950 nm, strong), Au25(0)* (890 nm, very strong), and Au25(+)* (890 nm, very strong), as confirmed by the photoluminescence (PL) spectra of the three Au25 clusters electrogenerated in situ. The ECL emissions are controllable by adjustment of the concentrations of TPrA· and Au25(-), Au25(0), and Au25(+) species in the vicinity of the working electrode and ultimately the applied potential. It was determined that the Au25(-)/TPrA coreactant system should have an ECL efficiency of >50% relative to the Ru(bpy)3

  14. A study of the electronic properties of Au nanowires and Au nanoislands on Au(111) surfaces.

    PubMed

    Schouteden, K; Lijnen, E; Muzychenko, D A; Ceulemans, A; Chibotaru, Liviu F; Lievens, P; Van Haesendonck, C

    2009-09-30

    By means of ion bombardment of clean Au(111) films, atomically flat nanoparticles of various shapes and sizes were created, ranging from several tens of nm(2) down to only a few nm(2). Both two-dimensional Au islands as well as one-dimensional Au nanowire-like structures have been investigated by means of low-temperature scanning tunneling microscopy and spectroscopy. We were able to probe their local electronic structure in a broad energy range, which was found to be dominated by pronounced size-dependent confinement effects. Mapping of the local density of states revealed complex standing wave patterns that arise due to interference of scattered Au surface state electrons at the edges of the Au nanoparticles. The observed phenomena could be modeled with high accuracy by theoretical particle-in-a-box calculations based on a variational method that can be applied to '2D boxes' of arbitrary polygonal shape and that we have previously successfully applied to explain the electronic wave patterns on Co islands on Au(111). Our findings support the general validity of this particle-in-a-box model.

  15. Intérêt de la thérapie antivirale par voie orale dans le traitement des nécroses rétiniennes aigues

    PubMed Central

    Haouzi, Samia El; Jait, Amina; Lezrek, Omar; Samira, Tachfouti; Amina, Laghmari; Cherkaoui, Ouafa; Abdellouahed, Karman; Daoudi, Rajae

    2016-01-01

    Le syndrome de nécrose rétinienne aiguë (RNA) est un syndrome uvéitique rare mais dévastateur pour la vue (pronostic visuel ++). Son diagnostic doit être précoce du fait de sa gravité et du risque de bilatéralisation. C’est une entité rare causée par les virus du groupe Herpès. Chez les patients immunodéprimés, les complications de l’ARN syndrome conduisent souvent à une perte d’acuité visuelle. La confirmation de ce diagnostic dès la découverte de la maladie par la réaction de polymérase en chaîne (PCR) et par le coefficient de charge immunitaire (CCI) le plus souvent par ponction d’humeur aqueuse permet d’optimiser la prise en charge en diminuant le temps nécessaire à une confirmation diagnostique. L’ARN syndrome est de très mauvais pronostic spontané. Des études récentes ont montré que la thérapie orale antivirale (valaciclovir, famciclovir et valganciclovir) et intravitréenne sans traitement intraveineux initial est un traitement efficace de l’ARN. Nous présentons ici le tableau clinique d’un jeune patient âgé de 39 ans admis aux urgences pour baisse d’acuité visuelle. L’examen ophtalmologique a objectivé une nécrose rétinienne aigue unilatérale. Il fut traité par une thérapie antivirale orale (valaciclovir) associée à une corticothérapie et l’évolution était très favorable. Le pronostic de la nécrose rétinienne aiguë ou ARN syndrome est le plus souvent sévère. Le traitement de cette affection doit être le plus précoce possible afin de limiter une bilatéralisation et la survenue des complications. Cette observation confirme que la thérapie orale antivirale (valaciclovir, famciclovir et valganciclovir) sans traitement intraveineux initial est un traitement efficace de l’ARN. PMID:27795766

  16. Problèmes inverses en traitement du signal et de l'image

    NASA Astrophysics Data System (ADS)

    Demoment, G.

    2002-03-01

    Dans de nombreux domaines de la physique appliquée, nous sommes confrontés au problème de la détermination de la distribution temporelle, ou bien spatiale, ou bien encore fréquentielle, d'une grandeur scalaire ou vectorielle, à partir des mesures directes ou indirectes. La caractéristique commune de tels problèmes est qu'ils sont souvent, mal-posés ou mal-conditionnés. Nous passons en revue des résultats mathématiques de base sur ces problèmes inverses et nous introduisons tout d'abord les caractéristiques essentielles de la théorie de la régularisation. Puis, utilisant une nouvelle approche de la théorie de l'information et des outils généraux de l'analyse convexe, nous montrons que beaucoup des critères de régularisation existants, qui ont été introduits dans la littérature par des approches très différentes, peuvent être interprétés comme des cas particuliers d'une entropie, malgré leur apparente diversité. Finalement, nous discutons de ses limitations et nous présentons l'approche bayésienne qui permet d'introduire des propriétés géométriques locales à l'aide des champs de Markov et des fonctions d'énergie locales associées, et qui offre sans doute les réponses les plus complètes aux divers problèmes rencontrés lors d'une inversion.

  17. Traitement intra-artériel des métastases hépatiques de cancer colorectal

    PubMed Central

    Pellerin, O.; Geschwind, J.-F.

    2015-01-01

    Le cancer colorectal représente un problème majeur de santé publique. Son incidence annuelle mondiale est d’environ un million de cas et la mortalité annuelle est de plus de 500 000 cas par an. Le foie est l’organe le plus fréquemment touché par les métastases. Leur survenue est observée dans 40 à 60% des cas (contemporaines dans 25% des cas). Bien que la résection chirurgicale soit le seul traitement curatif, nombre de patients ne peuvent en bénéficier en raison de l’importante diffusion des métastases hépatiques. Chimiothérapies et biothérapies systémiques sont les options conventionnelles de la prise en charge des métastases hépatiques multiples. C’est dans ces situations cliniques que les thérapies intra-artérielles peuvent jouer un rôle important. Dans cet article, nous présenterons les différentes thérapies endovasculaires applicables aux métastases hépatiques de cancers colorectaux, avec leurs indications, résultats et complications éventuelles. PMID:21944243

  18. Optimisation des proprietes fonctionnelles des alliages a memoire de forme suite a l'application de traitements thermomecaniques

    NASA Astrophysics Data System (ADS)

    Demers, Vincent

    L'objectif de ce projet est de determiner les conditions de laminage et la temperature de traitement thermique maximisant les proprietes fonctionnelles de l'alliage a memoire de forme Ti-Ni. Les specimens sont caracterises par des mesures de calorimetrie, de microscopie optique, de gene ration de contrainte, de deformation recuperable et des essais mecaniques. Pour un cycle unique, l'utilisation d'un taux d'ecrouissage e=1.5 obtenu avec l'application d'une force de tension FT = 0.1sigma y et d'une huile minerale resulte en un echantillon droit, sans microfissure et qui apres un recuit a 400°C, produit un materiau nanostructure manifestant des proprietes fonctionnelles deux fois plus grandes que le meme materiau ayant une structure polygonisee. Pour des cycles repetes, les memes conditions de laminage sont valables mais le niveau de deformation optimal est situe entre e=0.75-2, et depend particulierement du mode de sollicitation, du niveau de stabilisation et du nombre de cycles a la rupture requis par l'application.

  19. Les déterminants du statut “perdu de vue” chez les patients pris en charge pour cancer au Maroc: situation avant le Plan Cancer

    PubMed Central

    Najdi, Adil; Berraho, Mohamed; Bendahhou, Karima; Obtel, Majdouline; Zidouh, Ahmed; Errihani, Hassan; Nejjari, Chakib

    2014-01-01

    Introduction Le cancer au Maroc représente un problème majeur de santé publique, sa prise en charge doit être globale, active et complète pour tous les patients. L'objectif de ce travail était d'estimer la fréquence des perdus de vue « PDV » en oncologie au Maroc durant la première année de suivi et de déterminer les facteurs associés à ce problème. Méthodes Par une étude rétrospective portant sur 2854 dossiers de malades hospitalisés dans les trois principaux centres d'oncologie au Maroc depuis janvier 2003 jusqu’à juin 2007 et concernant les cinq principales localisations de cancer au Maroc, nous avons cherché la date des dernières nouvelles des patients ayant un recul de 18 mois minimum afin de déterminer le statut de ces malades après un an de suivi. Résultats La moyenne d’âge était de 52±14 ans, une proportion féminine de 63%, les sujets actifs constituaient 28%, les mariés 71%, les analphabètes 51%, 70% des patients habitaient en milieu urbain et seulement 11% des malades disposaient d'une couverture sociale. La localisation cancéreuse la plus fréquente était le poumon (23,8%) suivie du colon-rectum (23,5%) puis le col (21,9%), le sein (20,4%) et les lymphomes (10,4%). Le taux des «PDV» à un an de suivi était de 48%, ce statut était significativement lié au sexe, à l’âge, au NSE et au statut matrimonial. Sur le plan médical, le statut «PDV» était lié à la localisation du cancer, au stade de diagnostic et au type de traitement reçu. Conclusion Notre étude a mis en évidence la grande ampleur du problème des PDV en cancérologie au Maroc ainsi que ces déterminants. Ces résultats incitent tous les acteurs dans le domaine de la cancérologie à collaborer ensemble pour prendre les mesures qui s'imposent pour y pallier PMID:25400850

  20. Arthropathie destructrice des épaules au cours d'une acromégalie

    PubMed Central

    Akasbi, Nessrine; Tahiri, Latifa; Lyhyaoui, Ouafae; Elidrissi, Mohammed; Sqalli Houssaini, Ghita; Elmrini, Abdelmajid; Ajdi, Farida; Taoufik, Harzy

    2011-01-01

    L'acromégalie est une maladie endocrinienne rare, en rapport avec une hypersécrétion d'hormone de croissance. Elle a des conséquences rhumatologiques: l'arthropathie périphérique, l'atteinte rachidienne et les syndromes canalaires. L'atteinte articulaire accompagne une acromégalie active, sa survenue après un traitement radical et une rémission complète est rare. Nous présentons le cas d'une patiente de 70 ans ayant un antécédent d'acromégalie sur adénome hypophysaire il y a 25 ans, traitée chirurgicalement et déclarée en rémission complète, a développé une arthropathie destructrice des deux épaules. Le but de notre observation est de mettre le point sur la possibilité d'une atteinte articulaire au cours de l'acromégalie et de son retentissement fonctionnelle. PMID:22187594

  1. Photoneutron cross sections for Au

    SciTech Connect

    Itoh, O.; Utsunomiya, H.; Akimune, H.; Yamagata, T.; Kondo, T.; Kamata, M.; Toyokawa, H.; Harada, H.; Kitatani, F.; Goko, S.; Nair, C.; Lui, Y.-W.

    2011-10-28

    Photoneutron cross sections were measured for Au in the entire energy range of the ({gamma},n) channel based on a direct neutron-counting technique with quasimonochromatic {gamma} rays produced in inverse Compton-scattering of laser photons with relativistic electrons. We present results of the measurement in comparison with the past data.

  2. La rupture intra péritonéale d’un kyste hydatique au cours de la grossesse: à propos d’un cas rare

    PubMed Central

    Rachad, Myriam; Fdili, Fatim Zahra; Slimani, Ouafae; Chaara, Hikmat; Bouguern, Hakima; Melhouf, Moulay Adbelillah

    2012-01-01

    Le kyste hydatique est une parasitose qui sévit à l’état endémique au Maroc. Cependant sa rupture au cours de la grossesse reste rare. Nous rapportons le cas d’une patiente de 23 ans, admise aux urgences en état de choc avec bouffissure du visage sur aménorrhée de 8 semaines, chez laquelle le diagnostic d’hydatidose à la fois hépatique et pelvienne, avec éventuelle rupture de l’un des kystes hépatiques a été posé par la radiologie. Après mesures de réanimation, le traitement chirurgical a été instauré, avec bonne évolution. Nous essayons à partir de ce cas et à travers une revue de littérature, de préciser les difficultés diagnostiques et thérapeutiques rencontrées dans la prise en charge des kystes hydatiques, surtout compliquées, au cours de la grossesse. PMID:22368744

  3. Torsion d'annexe au second trimestre de la grossesse, à propos de deux cas

    PubMed Central

    Ayachi, Amira; Blel, Zeineb; Khelifa, Nahed; Mkaouer, Lassaad; Bouchahda, Rim; Mourali, Mechaal

    2016-01-01

    Les douleurs pelviennes aigues pendant la grossesse peuvent poser un problème de diagnostic différentiel.Nous rapportons deux cas de torsion d'annexes au deuxième trimestre de la grossesse afin d'attirer l'attention sur ce diagnostic, dont seule une prise en charge précoce permet d'éviter des lésions irréversibles dues à l'ischémie, pouvant mettre en jeu le pronostic ultérieur de fertilité. La première patiente, G1P0, enceinte à 20 SA, s'est présenté initialement pour un syndrome appendiculaire. Une incision de Mac Burney, au cours de l'exploration, a montré un ovaire droit nécrosé et une ovariectomie a été faite. Les suites post opératoires étaient simples. La seconde patiente, G2P2, s'est présenté aux urgences avec des douleurs aigues de la fosse iliaque gauche à 26 SA. La laparotomie a mis en évidence une torsion d'une hydatide de Morgani, dont l'aspect nécrosé dû à une torsion, a orienté vers une ablation de l'hydatide. Pour les deux patientes, aucune complication postopératoire n'a été relevée. La torsion d'annexe est une urgence à ne pas méconnaître devant toute douleur pelvienne aigue chez la femme enceinte. Le traitement conservateur est actuellement le gold standard et une prise en charge appropriée est nécessaire pour éviter d'éventuelles complications maternelles et fœtales. PMID:28292076

  4. Spiral Patterning of Au Nanoparticles on Au Nanorod Surface to Form Chiral AuNR@AuNP Helical Superstructures Templated by DNA Origami.

    PubMed

    Shen, Chenqi; Lan, Xiang; Zhu, Chenggan; Zhang, Wei; Wang, Leyu; Wang, Qiangbin

    2017-02-20

    Plasmonic motifs with precise surface recognition sites are crucial for assembling defined nanostructures with novel functionalities and properties. In this work, a unique and effective strategy is successfully developed to pattern DNA recognition sites in a helical arrangement around a gold nanorod (AuNR), and a new set of heterogeneous AuNR@AuNP plasmonic helices is fabricated by attaching complementary-DNA-modified gold nanoparticles (AuNPs) to the predesigned sites on the AuNR surface. AuNR is first assembled to one side of a bifacial rectangular DNA origami, where eight groups of capture strands are selectively patterned on the other side. The subsequently added link strands make the rectangular DNA origami roll up around the AuNR into a tubular shape, therefore giving birth to a chiral patterning of DNA recognition sites on the surface of AuNR. Following the hybridization with the AuNPs capped with the complementary strands to the capture strands on the DNA origami, left-handed and right-handed AuNR@AuNP helical superstructures are precisely formed by tuning the pattern of the recognition sites on the AuNR surface. Our strategy of nanoparticle surface patterning innovatively realizes hierarchical self-assembly of plasmonic superstructures with tunable chiroptical responses, and will certainly broaden the horizon of bottom-up construction of other functional nanoarchitectures with growing complexity.

  5. Détermination de l'énergie de surface d'alumines et de titanates de baryum utilisés pour la préparation de céramiques : influence d'un traitement thermique

    NASA Astrophysics Data System (ADS)

    Papirer, E.; Perrin, J. M.; Siffert, B.; Philipponneau, G.

    1991-05-01

    grandement sur les valeurs de γ^D_S et d'I_{sp} et, deuxièmement, que le traitement thermique de certaines alumines (en dessous de 500 °C) modifie de façon inattendue ces mêmes grandeurs. Dans ce cas les résultats s'expliquent en admettant l'existence, en surface de cette poudre, d'une couche d'oxyde hydraté formée au cours de son vieillissement en atmosphère humide. Cette couche, de type boehmite, se transforme en alumine γ vers 350-400 °C, transformation qui s'accompagne d'importantes modifications de γ^D_S. Cette étude souligne I'importance qu'il y a lieu d'attacher au contrôle physicochimique et au conditionnement thermique des poudres pour céramique.

  6. New Structure Model of Au22(SR)18: Bitetrahederon Golden Kernel Enclosed by [Au6(SR)6] Au(I) Complex.

    PubMed

    Pei, Yong; Tang, Jian; Tang, Xianqiong; Huang, Yunqing; Zeng, Xiao Cheng

    2015-04-16

    The study of atomic structure of thiolate-protected gold with decreased core size is important to explore the structural evolution from Au(I) complex to Au nanoclusters. In this work, we theoretically predicted the structure of recently synthesized four valence electron (4e) Au22(SR)18 cluster. The Au22(SR)18 cluster is proposed to possess a bitetrahedron Au7 kernel that is surrounded by a unique [Au6(SR)6] Au(I) complex and three Au3(SR)4 staple motifs. More interestingly, the Au22(SR)18 exhibits structural connections with Au24(SR)20 and Au20(SR)16. The stability of Au22(SR)18 can be understood from the superatom electronic configuration of the Au kernel as well as the formation of superatomic network. The present study can offer new insight into the structural evolution as well as electronic structure of thiolate-protected Au nanoclusters.

  7. Onset of nuclear matter expansion in Au+Au collisions

    NASA Astrophysics Data System (ADS)

    Crochet, P.; Rami, F.; Gobbi, A.; Dona, R.; Coffin, J. P.; Fintz, P.; Guillaume, G.; Jundt, F.; Kuhn, C.; Roy, C.; de Schauenburg, B.; Tizniti, L.; Wagner, P.; Alard, J. P.; Amouroux, V.; Andronic, A.; Basrak, Z.; Bastid, N.; Belyaev, I.; Best, D.; Biegansky, J.; Buta, A.; Čaplar, R.; Cindro, N.; Dupieux, P.; Dželalija, M.; Fan, Z. G.; Fodor, Z.; Fraysse, L.; Freifelder, R. P.; Berrmann, N.; Hildenbrand, K. D.; Hong, B.; Jeong, S. C.; Kecskemeti, J.; Kirejczyk, M.; Koncz, P.; Korolija, M.; Kotte, R.; Lebedev, A.; Leifels, Y.; Manko, V.; Moisa, D.; Mösner, J.; Neubert, W.; Pelte, D.; Petrovici, M.; Pinkenburg, C.; Pras, P.; Ramillien, V.; Reisdorf, W.; Ritman, J. L.; Sadchikov, A. G.; Schüll, D.; Seres, Z.; Sikora, B.; Simion, V.; Siwek-Wilczyńska, K.; Sodan, U.; Teh, K. M.; Trzaska, M.; Vasiliev, M.; Wang, G. S.; Wessels, J. P.; Wienold, T.; Wisniewski, K.; Wohlfarth, D.; Zhilin, A.; FOPI Collaboration

    1997-02-01

    Using the FOPI detector at GSI Darmstadt, excitation functions of collective flow components were measured for the Au+Au system, in the reaction plane and out of this plane, at seven incident energies ranging from 100 A MeV to 800 A MeV. The threshold energies, corresponding to the onset of sideward-flow (balance energy) and squeeze-out effect (transition energy), are extracted from extrapolations of these excitation functions toward lower beam energies for charged products with Z ⩾ 2. The transition energy is found to be larger than the balance energy. The impact parameter dependence of both balance and transition energies, when extrapolated to central collisions, suggests comparable although slightly higher values than the threshold energy for the radial flow. The relevant parameter seems to be the energy deposited into the system in order to overcome the attractive nuclear forces.

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

    NASA Astrophysics Data System (ADS)

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

    2001-11-01

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

  9. Successful synthesis and thermal stability of immiscible metal Au-Rh, Au-Ir and Au-Ir-Rh nanoalloys.

    PubMed

    Shubin, Yury; Plusnin, Pavel; Sharafutdinov, Marat; Makotchenko, Evgenia; Korenev, Sergey

    2017-04-06

    We successfully prepared face-centred cubic nanoalloys in systems of Au-Ir, Au-Rh and Au-Ir-Rh, with large bulk miscibility gaps, in one-run reactions under thermal decomposition of specially synthesised single-source precursors, namely, [AuEn2][Ir(NO2)6], [AuEn2][Ir(NO2)6]х[Rh(NO2)6]1-х and [AuEn2][Rh(NO2)6]. The precursors employed contain all desired metals "mixed" at the molecular level, thus providing significant advantages for obtaining alloys. The observations using HR TEM show that the nanoalloy structures are composed of well-dispersed aggregates of crystalline domains with a mean size of 5±3 nm. EDX and XRD measurements confirm the formation of AuIr, AuRh, AuIr0.75Rh0.25, AuIr0.50Rh0.50 and AuIr0.25Rh0.75 metastable solid solutions. In-situ real-time synchrotron XRD was used to study the formation mechanism of nanoalloys. The observed transformations are described by the "conversion chemistry" mechanism characterised by the primary development of particles comprising atoms of only one type, followed by a chemical reaction resulting in the final formation of a nanoalloy. The obtained metastable nanoalloys exhibit essential thermal stability. Exposure to 180 ºC for 30 h does not cause any dealloying process.

  10. Influence du taux d'humidité et de traitements de surface (laser et implantations d'ions) sur la corrosion atmosphérique de matériaux utilisés en connectique (nickel doré)

    NASA Astrophysics Data System (ADS)

    Perrin, C.; Simon, D.

    1999-07-01

    suppress the porosities of the gold layer. These treatments lead to a remarkable improvement of the corrosion resistance of the material. La première partie de ce travail est une étude qualitative et quantitative de la corrosion d'un matériau utilisé en connectique, constitué de laiton recouvert d'un dépôt de nickel électrochimique de 5 μm et d'un dépôt d'or de 0,4 μm ou de 1 μm. Les essais de corrosion ont été conduits dans de l'air synthétique humide (taux d'humidité variable entre 15 % et 90 %) contenant de faibles quantités de NO2 (0,2 vpm), SO2 (0,2 vpm), Cl2 (0,01 vpm). Le comportement du matériau en fonction du taux d'humidité a été étudié. Les résultats obtenus montrent que les produits de corrosion croissent sous forme d'amas bien localisés. Ces amas sont constitués principalement de nitrates, sulfates, chlorures et hydroxydes de nickel et de zinc. La quantité de produits formés et la proportion de sulfates croissent avec le taux d'humidité. En revanche, le rapport zinc/nickel croît lorsque le taux d'humidité diminue. Nous avons identifié les composés formés, essentiellement grâce à une méthode développée au laboratoire associant la microgravimétrie, la chromatographie ionique et l'absorption atomique, et également par analyse X. Ces études ont montré que la protection du nickel par l'or exige un dépôt d'or parfaitement étanche. Il semble que très souvent les porosités responsables de l'apparition d'une corrosion traversent à la fois la couche d'or et de nickel, entraînant l'attaque du zinc par corrosion galvanique. Les analyses effectuées au MEB ont permis de montrer qu'il existait probablement dans ces porosités des composés organiques liés à l'élaboration de ces couches et que lors de l'attaque galvanique du nickel et du zinc, le carbone est rejeté à la périphérie des amas. La quantité de carbone présent dans la couche a pu être déterminée par des analyses nucléaires réalisées au Van De Graaff

  11. Les fractures de jambe à fibula intact: traitement orthopédique ou enclouage centromédullaire? (étude comparative à propos de 60 cas)

    PubMed Central

    Abouchane, Merouane; Fadili, Assia; Belmoubarik, Amine; EL Andaloussi, Yassir; Nechad, Mohammed

    2015-01-01

    La fracture de jambe à fibula intact (FJFI) est caractérisée par un potentiel de déplacement minime ainsi le pronostic semble bon, souvent associées à des difficultés de réduction de consolidation ou de cal vicieux. Notre but est de comparer les résultats du traitement orthopédique et de l'enclouage centromédullaire (ECM). Entre janvier 2006 et janvier 2011, on a traité 60 fractures de jambe à fibula intact. 31 patients ont bénéficié d'un ECM, dont 14 fois était statique, 16 fois dynamique et simple une fois, avec un appui compris entre le 2eme jour (pour la plupart des patients) et la sixième semaine. 29 patients ont bénéficiés d'un traitement orthopédique après réduction par plâtre cruro-pédieux avec libération du genou après 4 semaines avec appui total chez la plupart des patients. La durée de consolidation été de 4 mois en moyenne pour les patients traites par ECM et de 6 mois pour les patients traites orthopédiquement. On a noté 3 cas de pseudarthrose dans notre série d’étude soit 5%: 2 observées chez le groupe de l'ECM soit 6,4% et un cas pour le groupe du traitement orthopédique soit 3,8%. 6 cas de déplacement secondaires ont été note chez les patients traites orhtopédiquement à j15 du traitement, pour 5 patients le déplacement été jugé tolérable et pour un seul patient (trouble angulaire supérieur à 10°) ayant nécessité un ECM. 13 cas soit 54% de cal vicieux angulaire supérieur à 10 dans notre série tous traités orthopédiquement versus aucun cas de cal vicieux chez les patients du groupe du traitement par ECM. Cliniquement: tous les patients traités par ECM ont présenté une mobilité du genou et de la cheville normale. Les patients traités orthopédiquement ont tous bénéficié d'une rééducation du genou libération du genou et confection d'un plâtre type Sarmiento et celle de la cheville après son ablation définitive, ainsi aucun de nos patients n'a gardé une raideur après avoir termin

  12. Urétéroscopie souple laser dans le traitement des calculs du haut appareil urinaire: résultats a propos de 166 interventions

    PubMed Central

    Padja, Essodina; Ibarra, Venceslas Amboulou; Lmezguidi, Khalid; Janane, Abdellatif; Ghadouane, Mohamed; Ameur, Ahmed; Abbar, Mohamed

    2015-01-01

    L’évolution de la technique opératoire fait de l'urétéroscopie souple –Laser (URSS-L) une méthode efficace et sure dans le traitement des calculs du haut appareil urinaire (HAU). Elle apparait comme une option salvatrice après échec des autres options thérapeutiques. Son coût limite son accessibilité et restreint ses indications dans certains contextes socio-économiques. Nous rapportons l'expérience du service sur les indications, les résultats et les complications de l'URSS-L dans le traitement des calculs du HAU. C'est une étude rétrospective sur 4ans concernant 130 patients ayant des calculs du HAU. Un scanner permettait de déterminer les caractéristiques des calculs avant l'intervention et de faire un contrôle après afin de juger de l'efficacité du traitement. Une analyse statistique évaluait l'influence des différents paramètres des calculs sur l'efficacité de l'intervention. Un suivi était réalisé afin de détecter les complications. L’âge moyen des patients était de 52 ± 17ans. 166 interventions étaient faites en 3 séries. Les indications étaient de première intention dans 50.32% suivi des échecs de LEC. La durée moyenne de l'intervention était de 73min ± 25min pour une taille moyenne des calculs de 13.78mm ± 5mm. Le taux de succès global était de 78.91% (78.71%; 80%; 100%) respectivement après la 1ère, la 2ème et la 3ème série. Aucun paramètre n'influençait significativement le taux de succès. 14.45% de complications était enregistré. L'URSS-L est une méthode aussi efficace que sure dans le traitement des calculs du HAU nous motivant malgré son coût, à élargir ses indications en première intention lorsque les calculs répondent aux critères de choix. PMID:26600912

  13. Travaux du laboratoire de traitement du langage et de la parole (Laboratory Work in the Treatment of Language and Linguistics).

    ERIC Educational Resources Information Center

    Grosjean, Francois, Ed.

    1994-01-01

    Research papers on language and linguistics include: "Enchainement des mots et acces au lexique en francais" ("Word Order and Lexical Access in French") (Besson); "L'apport de la coarticulation dans la perception de consonnes occlusives et constrictives" ("The Contribution of Coarticulation to the Perception of…

  14. Facteurs prédictifs de l’échec du Traitement Préventif Intermittent du paludisme à la sulfadoxine – pyriméthamine (TPIp-SP) dans une population de femmes enceintes à Yaoundé

    PubMed Central

    Essiben, Félix; Foumane, Pascal; de Nguefack, Marcelle Aurelie Tsafack; Eko, Filbert Eko; Njotang, Philip Nana; Enow, Robinson Mbu; Mboudou, Emile Telesphore

    2016-01-01

    Introduction Le traitement préventif intermittent à la sulfadoxine-pyriméthamine (TPIp-SP) est recommandé pour prévenir le paludisme pendant la grossesse. Nous avons recherché les facteurs associés à l’échec de cette stratégie. Méthodes Nous avons mené une étude cas - témoins dans deux formations sanitaires de Yaoundé, du 1er Mai 2014 au 30 Avril 2015. Les femmes enceintes sous TPIp-SP hospitalisées pour paludisme ayant un Test de Diagnostic Rapide (TDR) positif (cas) étaient comparées aux femmes enceintes sous TPIp-SP ayant un TDR négatif (témoins). Les logiciels Epi info 7 et SPSS 18.0 ont été utilisés avec P < 0,05 comme seuil de significativité. Résultats Nous avons recruté 234 sujets, 109 cas (46,6%) et 125 témoins (53,4%). Les facteurs associés retrouvés étaient: la primiparité (P=0,03; OR=1,15; IC= 0,32 - 4,10), la non utilisation de la MILDA (P=0,006; OR= 2,31; IC= 1,26 - 4,25), un antécédent d'hospitalisation pour paludisme (P=0,007; OR= 2,19; IC= 1,23 - 3,89), le début de la TPIp-SP après la 28ème semaine de grossesse (P=0,001, OR= 3,55; IC= 1,7 - 7,61). Après régression logistique, la primiparité (P=0,024; OR=2,01; IC=1,1-3,7) et un antécédent d'hospitalisation pour paludisme (P=0,001; OR=2,83; IC=1,50-5,4) restaient associés à l’échec du TPIp-SP. Conclusion Un antécédent d'hospitalisation pour accès palustre et la primiparité sont des facteurs prédictifs indépendants de l’échec de la TPIp-SP. PMID:27303570

  15. d + Au hadron correlation measurements at PHENIX

    SciTech Connect

    Anne M. Sickles

    2014-05-13

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

  16. Eversion congénitale bilatérale des paupières: prise en charge d’un cas selon l’approche conservatrice au Centre Hospitalier Universitaire de Yaoundé, Cameroun

    PubMed Central

    Monebenimp, Francisca; Kagmeni, Gilles; Chelo, David; Bilong, Yannick; Moukouri, Ernest

    2012-01-01

    L’éversion congénitale des paupières est une affection rare. Son traitement en première intention est généralement conservateur, constitué de lubrifiant, d’antibiotiques, de manœuvres d’inversion de la paupière éversée et d’une éducation des parents. Nous présentons le cas d’un nouveau-né de huit heures de vie ayant une éversion congénitale bilatérale des paupières avec surinfection bactérienne. La ponction à l’aiguille de la conjonctive œdémateuse associée au traitement topique avec du sérum salé isotonique et des antibiotiques ont accéléré le processus de guérison. Une récidive n’a pas été observée lors des pleurs après trois semaines d’inversion des paupières. PMID:22514768

  17. La greffe de peau totale dans le traitement des séquelles de brûlures de la main et des doigts: A propos de 84 cas

    PubMed Central

    Boukind, S.; Droussi, H.; Elatiqi, O.K.; Dlimi, M.; Dhaidah, O.; Ejjiyar, M.; Quaboul, M.; Dehhaze, A.; Fkhar, S.; Elamrani, D.; Benchamkha, Y.; Ettalbi, S.

    2014-01-01

    Summary Nous avons mené une étude rétrospective s’étendant de septembre 2004 à septembre 2012 sur les données de à propos de 84 patients présentant des séquelles de brûlure majeures de la main. Ces patients étaient traités chirurgicalement par une greffe de peau totale. Le but de cette étude est, donc, d’insister sur la simplicité de cette technique et surtout son efficacité et sa fiabilité. L’âge moyen de la survenue de la brûlure était de 4 ans. L’âge moyen de nos patients était de 18,3 ans (2-62 ans), avec prédominance masculine dans 60% des cas. L’agent causal le plus fréquent était un agent thermique - le plus souvent un liquide chaud (56%). Le délai moyen entre la fin de la cicatrisation et la prise en charge des séquelles était de 36 mois (2 mois - 16 ans). Dans 69 cas (82.5%), les lésions étaient localisées au niveau de la face palmaire de la main. Les séquelles ont été dominées par les rétractions digitales (65%) dont le déficit fonctionnel est évident. Une greffe de peau totale a été réalisée chez tous nos patients après libération des brides et excision des placards cicatriciels. Les rétractions commissurales ont été traitées par des plasties en Z. Dans 95% des cas, le prélèvement de peau totale était réalisé au niveau du pli inguinal. Le recul moyen était de 5,5 ans (1-8 ans). 11 patients ont été perdus de vu. Les résultats après cicatrisation complète et rééducation ont été jugés satisfaisants (bons) dans 62 cas (85%), et assez bons dans 11 cas (15%). Un traitement initial bien conduit et effectué dans les meilleures conditions permet non seulement de réduire le nombre de séquelles des brûlures mais encore de les rendre moins sévères. PMID:26336368

  18. 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

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

    SciTech Connect

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

    2004-04-20

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

  20. La place du traitement non opératoire des contusions abdominales dans les pays en voie de développement

    PubMed Central

    Rabbani, Khalid; Narjis, Youssef; Louzi, Abdelouahed; Benelkhaiat, Redouane; Finech, Benacer

    2015-01-01

    Le traitement non opératoire des contusions de l'abdomen représente une approche thérapeutique nouvelle des traumatismes fermés de l'abdomen. La disponibilité d'un plateau technique performant constitue classiquement une des principales conditions pour la réussite de cette attitude. Nous essayons d’étudier les différents aspects épidémiologiques, diagnostiques et thérapeutiques de cette affection dans le contexte d'un pays en voie de développement, à travers les résultats d'une série de 106 malades. une série de 106 patients est prise en charge par le traitement non opératoire. La gravité des lésions est appréciée par les données cliniques et paracliniques, ainsi que la morbidité et la mortalité sont analysées. les accidents de la circulation étaient la première cause des contusions abdominales, dans notre contexte. Les lésions hépatiques étaient les plus fréquentes (65% des cas), suivit des lésions spléniques chez 19 patients. La notion de polytraumatisme était très fréquente. La durée moyenne de surveillance était de 9,5 jours. Seize malades étaient transfusés, et le nombre moyen de culots globulaires (CG) était de 3,5 culots par patient. Une laparotomie en urgence était indiquée chez 10 patients (9.4%) devant l'instabilité hémodynamique. Trois malades ont nécessité un traitement chirurgical secondaire. On avait noté un taux de mortalité de 3.7% soit 4 cas. il semble à partir de notre expérience que l'abstention chirurgicale peut constituer, dans des conditions strictes de surveillance, une alternative thérapeutique de référence dans les pays en voie de développement, sûre et justifiée à une chirurgie d'urgence toujours difficile. PMID:26097636

  1. Coinfection pulmonaire par pneumocystis jirovecii et pseudomonas aeruginosa au cours du SIDA: à propos de deux cas

    PubMed Central

    Mamoudou, Savadogo; Bellaud, Guillaume; Ana, Canestri; Gilles, Pialoux

    2015-01-01

    Rapporter deux cas cliniques de coinfections pulmonaires par Pneumocystis jirovecii et par Pseudomonas aeruginosa chez des patients vivant avec le VIH. Les deux patients étaient âgés respectivement de 32 ans et 46 ans. Un patient a été pris en charge à l'hôpital Yalgado Ouédraogo de Ouagadougou au Burkina Faso et l'autre a été pris en charge à l'hôpital Ténon de Paris, en France. Les deux souffraient de pneumopathie confirmée à la radiographie et à la tomodensitométrie. L'un des patients était sévèrement immuno déprimé, contrairement à l'autre. L'examen bactériologique dans les crachats avait permis d'isoler Pseudomonas aeruginosa et Pneumocystis jirovecii chez les deux patients. Sous traitement, l’évolution a été favorable. Les coinfections morbides sont relativement fréquentes chez les patients vivant avec le VIH. Devant une symptomatologie respiratoire du sujet vivant avec le VIH, il faut savoir rechercher en plus du Bacille de Koch, Pneumocystis jirovecii et Pseudomonas aeruginosa par un lavage broncho alvéolaire. PMID:26516396

  2. 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

  3. Rôle de la radiothérapie dans le traitement de l'améloblastome: à propos de deux cas

    PubMed Central

    El Mazghi, Abderrahman; Bouhafa, Touria; El Kacemi, Hanan; Loukili, Kaoutar; Chbani, Laila; Kebdani, Taieb; Hassouni, Khalid

    2014-01-01

    L'améloblastome est une tumeur odontogène bénigne mais à pouvoir agressif et invasif local important. C'est une tumeur rare, elle représente 1% des tumeurs des maxillaires. Le rôle de la radiothérapie dans son traitement est actuellement démontré pour les tumeurs inopérables. Nous rapportons 2 cas d'améloblastomes mandibulaires chez deux patients qui ont bénéficié d'une radiothérapie externe à la dose de 60 Gy. L’évolution a été marquée par une rémission complète de la maladie dans les deux cas avec un recul de 2 et 5 ans. PMID:25722762

  4. Stabilization of Au at edges of bimetallic PdAu nanocrystallites.

    PubMed

    Yudanov, Ilya V; Neyman, Konstantin M

    2010-05-21

    Density functional calculations were performed to study the distribution of Au atoms in bimetallic PdAu nanoparticles. A series of Pd(79-n)Au(n) clusters of truncated octahedral shape with different content of Au ranging from n = 1 to 60 was used to model such bimetallic nanosystems. Segregation of Au to the particle surface is found to be thermodynamically favorable. The most stable sites for Au substitution are located at the edges of the PdAu nanoclusters. The stabilization at the edges is rationalized by their higher flexibility for surface relaxation which minimizes the strain induced by larger atomic radius of Au as compared to Pd. This stabilization of Au at the edges indicates the possibility to synthesize PdAu particles with Pd atoms located mainly on the facets, and edges "decorated" by Au atoms. Such nanocrystallites are expected to exhibit peculiar catalytic properties and, being thermodynamically stable, should be prone to retaining their initial shape under catalytic conditions.

  5. Impact of Ni/Ge/Au/Ti/Au and Ti/Pt/Au collector metal on GaInP/GaAs HBT characteristics

    NASA Astrophysics Data System (ADS)

    Park, Jae-Woo; Mohammadi, Saeed; Pavlidis, Dimitris

    2000-10-01

    The collector-emitter offset voltage of GaInP/GaAs HBTs grown by chemical-beam epitaxy with reduced toxicity precursors is investigated for Ni/Ge/Au/Ti/Au and Ti/Pt/Au collector contact metals. The offset voltage for HBTs with Ti/Pt/Au collector metal is increased by 0.26 V compared to Ni/Ge/Au/Ti/Au due to the 0.26 eV barrier existing between the n-GaAs subcollector and the Ti/Pt/Au contact metal. Other parameters affected by the collector contact barrier and impacting transistor performance include DC gain, microwave and power performance.

  6. Heterostructured CIGS-Au nanoparticles: from Au-CIGS side-by-side structure to Au-core/CIGS-shell configuration.

    PubMed

    Xu, Yeming; Li, Quan

    2011-08-01

    Heterostructured Au-Copper Indium Gallium Selenide (CIGS) nanoparticles (nps) with Au-CIGS side-by-side and Au-core/CIGS-shell configurations have been synthesized in a controllable manner using seed mediated growth. Detailed microstructure analysis reveals that (112) planes in the tetragonal chalcopyrite CIGS serve as the predominant termination surfaces during single phase CIGS nanoparticle growth. Preferential nucleation of Au on such planes determines the Au-CIGS side-by-side configuration when the pre-synthesized CIGS nps are used as the seeds for further Au growth. Reversing the growth sequence by employing Au nano-seeds results in Au-core/CIGS-shell configuration, as determined by the non-preferential nucleation of CIGS on the spherical Au nanoparticle surface. The different morphological configurations of the heterostructures are found to modify the surface plasmon resonance of Au in the corresponding samples.

  7. Au Fixed Point Development at NRC

    NASA Astrophysics Data System (ADS)

    Dedyulin, S. N.; Gotoh, M.; Todd, A. D. W.

    2017-04-01

    Two Au fixed points filled using metal of different nominal purities in carbon crucibles have been developed at the National Research Council Canada (NRC). The primary motivation behind this project was to provide the means for direct thermocouple calibrations at the Au freezing point (1064.18°C). Using a Au fixed point filled with the metal of maximum available purity [99.9997 % pure according to glow discharge mass spectroscopy (GDMS)], multiple freezing plateaus were measured in a commercial high-temperature furnace. Four Pt/Pd thermocouples constructed and calibrated in-house were used to measure the freezing plateaus. From the calibration at Sn, Zn, Al and Ag fixed points, the linear deviation function from the NIST-IMGC reference function (IEC 62460:2008 Standard) was determined and extrapolated to the freezing temperature of Au. For all the Pt/Pd thermocouples used in this study, the measured EMF values agree with the extrapolated values within expanded uncertainty, thus substantiating the use of 99.9997 % pure Au fixed point cell for thermocouple calibrations at NRC. Using the Au fixed point filled with metal of lower purity (99.99 % pure according to GDMS), the effect of impurities on the Au freezing temperature measured with Pt/Pd thermocouple was further investigated.

  8. Synthesis of Au microwires by selective oxidation of Au-W thin-film composition spreads.

    PubMed

    Hamann, Sven; Brunken, Hayo; Salomon, Steffen; Meyer, Robert; Savan, Alan; Ludwig, Alfred

    2013-02-01

    We report on the stress-induced growth of Au microwires out of a surrounding Au-W matrix by selective oxidation, in view of a possible application as 'micro-Velcro'. The Au wires are extruded due to the high compressive stress in the tungsten oxide formed by oxidation of elemental W. The samples were fabricated as a thin-film materials library using combinatorial sputter deposition followed by thermal oxidation. Sizes and shapes of the Au microwires were investigated as a function of the W to Au ratio. The coherence length and stress state of the Au microwires were related to their shape and plastic deformation. Depending on the composition of the Au-W precursor, the oxidized samples showed regions with differently shaped Au microwires. The Au48W52 composition yielded wires with the maximum length to diameter ratio due to the high compressive stress in the tungsten oxide matrix. The values of wire length (35 μm) and diameter (2 μm) achieved at the Au48W52 composition are suitable for micro-Velcro applications.

  9. Au/Au@polythiophene core/shell nanospheres for heterogeneous catalysis of nitroarenes.

    PubMed

    Shin, Hye-Seon; Huh, Seong

    2012-11-01

    Monodisperse Au/Au@polythiophene core/shell nanospheres were facilely prepared through the reduction of gold precursor, AuCl₄⁻, by 2-thiopheneacetonitrile in an aqueous solution. Concomitantly, 2-thiopheneacetonitrile polymerized during this redox process. As a result, Au nanoparticle was encapsulated by conductive polymer shell to afford novel core/shell nanospheres. Interestingly, the shell was composed of very tiny Au nanoparticles surrounded with thiophene polymers. Thus, the new material is best described as Au/Au@polythiophene core/shell nanospheres. FT-IR spectroscopy revealed that the Au nanoparticles were coordinated by the C≡N groups of the polythiophene shell. Some of the C≡N groups were partially hydrolyzed into COOH groups during the redox process because of the acidic reaction condition. The shell was conductive based on the typical ohmic behavior found in electrical measurement. The Au/Au@polythiophene core/shell nanospheres were found to be very active catalysts for the hydrogenation of various nitroarene compounds into corresponding aminoarene compounds in the presence of NaBH₄. Both hydrophilic and hydrophobic nitroarenes were efficiently hydrogenated under mild conditions.

  10. Au40: A Large Tetrahedral Magic Cluster

    SciTech Connect

    Jiang, Deen; Walter, Michael

    2011-01-01

    40 is a magic number for tetrahedral symmetry predicted in both nuclear physics and the electronic jellium model. We show that Au{sub 40} could be such a magic cluster from density functional theory-based basin hopping for global minimization. The putative global minimum found for Au{sub 40} has a twisted pyramid structure, reminiscent of the famous tetrahedral Au{sub 20}, and a sizable HOMO-LUMO gap of 0.69 eV, indicating its molecular nature. Analysis of the electronic states reveals that the gap is related to shell closings of the metallic electrons in a tetrahedrally distorted effective potential.

  11. 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

  12. Genetics of slaughter precocity, carcass weight, and carcass weight gain in Chianina, Marchigiana, and Romagnola young bulls under protected geographical indication.

    PubMed

    Sbarra, F; Mantovani, R; Quaglia, A; Bittante, G

    2013-06-01

    The aim of this study was to estimate the heritability and genetic correlation of age at slaughter (AS), as an indicator of slaughter precocity, carcass weight (CW), and CW gain (CWG = CW × AS(-1)) obtained from young bulls of 3 Italian autochthonous beef cattle breeds [i.e., Chianina (CHI), Marchigiana (MAR), and Romagnola (ROM)]. In addition, the study aimed at evaluating the effect of corrected or uncorrected CW for AS, and analyzing the relationship between adjusted or unadjusted CW with CWG in term of changes in rank correlation in groups of sires with high accuracy. Data were obtained from the Consortium of protected geographical indication (PGI) "Vitellone Bianco dell'Appennino Centrale" (i.e., white young bull of Central Apennines), approved by the European Union. After editing, 20,872 complete records were retained for subsequent Bayesian analysis. Univariate animal model produced h(2) estimates of medium value for AS (i.e., from 0.28 for CHI to 0.39 for the ROM breed). The CW presented h(2) estimates less than AS, ranging from 0.13 for CHI to 0.24 for ROM bulls. The adjustment of CW by AS (CWU-AS) increased the h(2) values for CW in all breeds (i.e., from 0.20 to 0.29). Point estimate of genetic correlations between AS and CW obtained by a bivariate analysis were moderate to low, and negative in all breeds (from -0.08 to -0.29). Rerankings of sire for univariate CW (CWU) analysis and CWU-AS were more noticeable for CHI and ROM (rank correlation of 0.875 and 0.897, respectively) than for the MAR breed (rank correlation of 0.967). Comparing bivariate EBV for CW with EBV for CWU or CWU-AS increased rank correlation to 0.937 for ROM, but for CHI it remained lower (i.e., 0.861), indicating a possible large reranking of sires by correcting CW for AS in this breed. Daily CWG presented h(2) estimates greater than CW and similar or greater than AS. It appears to be a good indicator of instant growth rate capacity of the animal but lacking information on the

  13. Réponse spectrale de photopiles de haut rendement au silicium multicristallin

    NASA Astrophysics Data System (ADS)

    Nam, Le Quang; Rodot, M.; Nijs, J.; Ghannam, M.; Coppye, J.

    1992-07-01

    The conversion efficiency of polycrystalline silicon solar cells has been raised to 15.6 % (for an area of 4 cm^2), using simple processes to improve the base and the back and front surfaces. Spectral response measurements are presented and analyzed using a classical model, in order to reach the main physical parameters. It is found that the initial gettering procedure designed by Martinuzzi an Sarti raises the electron diffusion length in the base to values well above wafer thickness (180 μm) ; that owing to a p/p^+ back junction, the back surface recombination rate is reduced to 10-10^2 cm/s; that owing to the emitter back-etchnig and passivation the front surface recombination rate is reduced to <10^4 cm/s. These results explain the high efficiency. Improvement possibilities are discussed. L'amélioration, par des procédés simples, de la base, de la face arrière et de l'émetteur a permis de porter, le rendement de conversion de photopiles au silicium polycristallin à 15,6 % pour une surface de 4 cm^2. On présente des mesures de réponse spectrale qui, interprétées par un modèle classique, permettent de déterminer les parmètres physiques essentiels. On trouve que le traitement de “gettering” des plaquettes de silicium, mis au point par Marinuzzi et Sarti, porte la longueur de diffusion des électrons dans la base à des valeurs très supérieures à l'épaisseur de la plaquette (180 μm) ; que la préqence d'une jonction p/p^+ en face arrière abaisse le taux de recombinaison à 10-10^2 cm/s ; que l'amincissement et la passivation de l'émetteur abaissent le taux de recombinaison en ace avant à <10^4 cm/s. On explique ainsi les bons rendements obtenus, et on indique les voies d'amélioration possible.

  14. Ir-induced activation of Au towards CO adsorption: Ir films deposited on Au{111}

    NASA Astrophysics Data System (ADS)

    Zhang, Tianfu; Driver, Stephen M.; Pratt, Stephanie J.; Jenkins, Stephen J.; King, David A.

    2016-06-01

    We have investigated the interaction of CO with Ir/Au{111} bimetallic surfaces, and the influence of morphology changes as Ir moves sub-surface into the Au bulk, using reflection-absorption infrared spectroscopy (RAIRS). The presence of Ir stabilises CO on exposed regions of the Au surface at temperatures up to around 200 K: we attribute this to low-coordinated Au sites, probably associated with lifting of the clean-surface 'herringbone' reconstruction by Ir deposition. The highest density of active Au sites is obtained after annealing the bimetallic surface to 500-600 K: we attribute this to morphology changes associated with the movement of Ir into bulk Au.

  15. Regulating the surface plasmon resonance coupling between Au-nanoparticle and Au-film

    NASA Astrophysics Data System (ADS)

    Wang, Shuang; Li, Kewu; Zhang, Rui; Jing, Ning; Chen, Youhua; Chen, Yuanyuan; Wang, Zhibin

    2017-01-01

    In this paper, we report the coupling between the localized surface plasmon resonance (LSPR) of Au-nanoparticles and surface plasmon resonance (SPR) of the Au-film. According to the conditions for SPR excitation of the classical Kretschmann-Raether structure with 50nm Au thin film, the commonly used classes of spherical Au-nanoparticle is studied and optimized. We used the finite element analysis (COMSOL Multiphysics 5.0), to simulate the coupling. The results from calculation and simulation indicate that the resonant plasmonic coupling between Au-nanoparticles and Au-film could lead to a large field enhancement and thus improve SPR. We demonstrate that the resonant plasmonic coupling could be regulated by the size of nanoparticles, the distance between nanoparticles .

  16. Directional light scattering from individual Au nanocup

    NASA Astrophysics Data System (ADS)

    Bai, Jinjun; Li, Yong; Zhao, Bo

    2017-03-01

    We investigate the optical scattering properties of gold nanocup with different orientation and fractional height by full vector finite element method. All of the scattering cross section, the distribution of electric field intensity, and the ability of directional light scattering are simulated, respectively. It is demonstrated that the scattering cross section of Au nanocup is a superposition of scattering spectrum of a transverse mode and an axial mode. The wavelength and the intensity of the maximum value of the scattering cross section increase initially then reduce with the fractional height increasing for transverse mode, while they increase monotonously with the fractional height increasing for axial mode. Furthermore, the calculation results show that the ability of redirecting incident light of Au nanocup mainly depends on the transverse mode. And the deflected angle of scattering increases with the fractional height of Au nanocup decreasing. These results indicate that Au nanocup has a promising application in the planar plasmon devices.

  17. PHENIX results on jets in d + Au

    NASA Astrophysics Data System (ADS)

    Hanks, J. Ali

    2016-12-01

    We present recently published results [A. Adare, et al., arxiv:arXiv:1509.04657] on fully reconstructed R=0.3 anti-kt jets measured in p+p and d+Au collisions at 200 GeV center-of-mass energy. The jet yields for four centrality classes along with the p+p reference are presented, as well as both the minimum bias RdAu and centrality dependent RdAu and RCP. We find that while the minimum bias RdA is consistent with unity, providing a strong constraint on models including cold-nuclear-matter effects or energy loss in small systems, the centrality dependent RdAu show a striking variation which presents a challenge to models attempting to describe the interplay between soft and hard processes in these systems.

  18. 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 2014 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.

  19. Thermal Expansion of AuIn2

    SciTech Connect

    Saw, C K; Siekhaus, W J

    2004-07-12

    The thermal expansion of AuIn{sub 2} gold is of great interest in soldering technology. Indium containing solders have been used to make gold wire interconnects at low soldering temperature and over time, AuIn{sub 2} is formed between the gold wire and the solder due to the high heat of formation and the high inter-metallic diffusion of indium. Hence, the thermal expansion of AuIn{sub 2} alloy in comparison with that of the gold wire and the indium-containing solder is critical in determining the integrity of the connection. We present the results of x-ray diffraction measurement of the coefficient of linear expansion of AuIn{sub 2} as well as the bulk expansion and density changes over the temperature range of 30 to 500 C.

  20. Counterion-Mediated Assembly of Spherical Nucleic Acid-Au Nanoparticle Conjugates (SNA-AuNPs)

    NASA Astrophysics Data System (ADS)

    Kewalramani, Sumit; Moreau, Liane; Guerrero-García, Guillermo; Mirkin, Chad; Olvera de La Cruz, Monica; Bedzyk, Michael; Afosr Muri Team

    2015-03-01

    Controlled crystallization of colloids from solution has been a goal of material scientists for decades. Recently, nucleic acid functionalized spherical Au nanoparticles (SNA-AuNPs) have been programmed to assemble in a wide variety of crystal structures. In this approach, the assembly is driven by Watson-Crick hybridization between DNAs coating the AuNPs. Here, we show that counterions can induce ordered assembly of SNA-AuNPs in bulk solutions, even in the absence of base pairing interactions. The electrostatics-driven assembly of spherical nucleic acid-Au nanoparticle conjugates (SNA-AuNPs) is probed as a function of counterion concentration and counterion valency [ +1 (Na+) or +2 (Ca2+) ] by in situ solution X-ray scattering. Assemblies of AuNPs capped with single-stranded (ss-) or double-stranded (ds-) DNA are examined. SAXS reveals disordered (gas-like) --> face-centered-cubic (FCC) --> glass-like phase transitions with increasing solution ionic strength. These studies demonstrate how non-base-pairing interactions can be tuned to create crystalline assemblies of SNA-AuNPs. The dependence of the inter-SNA-AuNP interactions on counterion valency and stiffness of the DNA corona will be discussed.

  1. DFT study on cysteine adsorption mechanism on Au(111) and Au(110)

    SciTech Connect

    Buimaga-Iarinca, Luiza; Floare, Calin G.; Calborean, Adrian; Turcu, Ioan

    2013-11-13

    Periodic density functional theory calculations were used to investigate relevant aspects of adsorption mechanisms of cysteine dimers in protonated form on Au(111) and Au(110) surfaces. The projected densities of states are explicitly discussed for all main chemical groups of cysteine, i.e. the amino group (NH2), the thiol group (SH) and the carboxylic group (COOH) to identify differences in adsorption mechanism. Special emphasis is put on the analysis of changes in the electronic structure of molecules adsorbed on Au(111) and Au(110) surfaces as well as the accompanying charge transfer mechanisms at molecule-substrate interaction.

  2. Systematic Measurements of Identified Particle Spectra in pp, d+Au and Au+Au Collisions from STAR

    SciTech Connect

    STAR Coll

    2009-04-11

    Identified charged particle spectra of {pi}{sup {+-}}, K{sup {+-}}, p and {bar p} at mid-rapidity (|y| < 0.1) measured by the dE/dx method in the STAR-TPC are reported for pp and d + Au collisions at {radical}s{sub NN} = 200 GeV and for Au + Au collisions at 62.4 GeV, 130 GeV, and 200 GeV. Average transverse momenta, total particle production, particle yield ratios, strangeness and baryon production rates are investigated as a function of the collision system and centrality. The transverse momentum spectra are found to be flatter for heavy particles than for light particles in all collision systems; the effect is more prominent for more central collisions. The extracted average transverse momentum of each particle species follows a trend determined by the total charged particle multiplicity density. The Bjorken energy density estimate is at least several GeV/fm{sub 3} for a formation time less than 1 fm/c. A significantly larger net-baryon density and a stronger increase of the net-baryon density with centrality are found in Au + Au collisions at 62.4 GeV than at the two higher energies. Antibaryon production relative to total particle multiplicity is found to be constant over centrality, but increases with the collision energy. Strangeness production relative to total particle multiplicity is similar at the three measured RHIC energies. Relative strangeness production increases quickly with centrality in peripheral Au + Au collisions, to a value about 50% above the pp value, and remains rather constant in more central collisions. Bulk freeze-out properties are extracted from thermal equilibrium model and hydrodynamics-motivated blast-wave model fits to the data. Resonance decays are found to have little effect on the extracted kinetic freeze-out parameters due to the transverse momentum range of our measurements. The extracted chemical freeze-out temperature is constant, independent of collision system or centrality; its value is close to the predicted phase

  3. Fully Cationized Gold Clusters: Synthesis of Au25(SR(+))18.

    PubMed

    Ishida, Yohei; Narita, Kunihiro; Yonezawa, Tetsu; Whetten, Robert L

    2016-10-06

    Although many thiolate-protected Au clusters with different numbers of Au atoms and a variety of thiolate ligands have been synthesized, to date there has been no report of a fully cationized Au cluster protected with cationic thiolates. Herein, we report the synthesis of the first member of a new series of thiolate-protected Au cluster molecules: a fully cationized Au25(SR(+))18 cluster.

  4. Using supported Au nanoparticles as starting material for preparing uniform Au/Pd bimetallic catalysts.

    PubMed

    Villa, Alberto; Wang, Di; Su, Dangsheng; Veith, Gabriel M; Prati, Laura

    2010-03-07

    One of the best methods for producing bulk homogeneous (composition) supported bimetallic AuPd clusters involves the immobilization of a protected Au seed followed by the addition of Pd. This paper investigates the importance of this gold seed in controlling the resulting bimetallic AuPd clusters structures, sizes and catalytic activities by investigating three different gold seeds. Uniform Au-Pd alloy were obtained when a steric/electrostatic protecting group, poly(vinyl alcohol) (PVA), was used to form the gold clusters on activated carbon (AC). In contrast Au/AC precursors prepared using Au nanoparticles with only electrostatic stabilization (tetrakis(hydroxypropyl)phosphonium chloride (THPC)), or no stabilization (magnetron sputtering) produced inhomogeneous alloys and segregation of the gold and palladium. The uniform alloyed catalyst (Pd@Au(PVA)/AC) is the most active and selective catalyst, while the inhomogenous catalysts are less active and selective. Further study of the PVA protected Au clusters revealed that the amount of PVA used is also critical for the preparation of uniform alloyed catalyst, their stability, and their catalytic activity.

  5. Using supported Au nanoparticles as starting material for preparing uniform Au/Pd bimetallic catalysts

    SciTech Connect

    Villa, Alberto; Prati, Laura; Su, Dangshen; Wang, Di; Veith, Gabriel M

    2010-01-01

    One of the best methods for producing bulk homogeneous (composition) supported bimetallic AuPd clusters involves the immobilization of a protected Au seed followed by the addition of Pd. This paper investigates the importance of this gold seed in controlling the resulting bimetallic AuPd clusters structures, sizes and catalytic activities by investigating three different gold seeds. Uniform Au-Pd alloy were obtained when a steric/electrostatic protecting group, poly(vinyl alcohol) (PVA), was used to form the gold clusters on activated carbon (AC). In contrast Au/AC precursors prepared using Au nanoparticles with only electrostatic stabilization (tetrakis(hydroxypropyl)phosphonium chloride (THPC)), or no stabilization (magnetron sputtering) produced inhomogeneous alloys and segregation of the gold and palladium. The uniform alloyed catalyst (Pd{at}Au{sub PVA}/AC) is the most active and selective catalyst, while the inhomogenous catalysts are less active and selective. Further study of the PVA protected Au clusters revealed that the amount of PVA used is also critical for the preparation of uniform alloyed catalyst, their stability, and their catalytic activity.

  6. LaAu2 and CeAu2 surface intermetallic compounds grown by high-temperature deposition on Au(111)

    NASA Astrophysics Data System (ADS)

    Ormaza, M.; Fernández, L.; Lafuente, S.; Corso, M.; Schiller, F.; Xu, B.; Diakhate, M.; Verstraete, M. J.; Ortega, J. E.

    2013-09-01

    We report on the crystal structure and electronic bands of LaAu2 and CeAu2 surface intermetallic compounds grown by high-temperature deposition on Au(111). By scanning-tunneling microscopy we study the formation of different alloy phases as a function of growth temperature and lanthanide coverage. We determine the specific growth conditions to achieve monolayers and bilayers of LaAu2 and CeAu2 with high crystalline quality. Due to lattice mismatch with the underlying Au substrate, both LaAu2 and CeAu2 exhibit long-range moiré patterns, which can serve as templates for further nanostructure growth. By angle-resolved photoemission we map the two-dimensional band structure of these surface alloys, discussing the nature of the different spectral features in the light of first-principles calculations.

  7. Adsorbate-modified Electron Relaxation in Au-Au_2S Nanoshells

    NASA Astrophysics Data System (ADS)

    Westcott, Sarah; Averitt, Richard; Wolfgang, John; Nordlander, Peter; Halas, Naomi

    2001-03-01

    Au-Au_2S nanoshells are 50 nm nanoparticles consisting of an Au_2S core encapsulated by a thin (<5 nm) Au shell. Their optical properties are determined by the metallic shell layer, whose inner and outer radii control plasmon frequency and whose thickness determines plasmon linewidth[1]. We studied the time-resolved relaxation of hot electrons in the Au shell, using degenerate pump-probe spectroscopy. The electron relaxation for nanoshells in solution was appreciably slower than relaxation for bulk gold, moreover, adsorbed molecules on the nanoshell surface strongly modify this relaxation. Density functional theory calculations indicate that the molecules providing the strongest modification of relaxation possess the largest induced dipole moments above a metal surface, indicating that the adsorbate-induced perturbation of the nanoshell electron dynamics appears to be primarily electronic in nature. [1] R. D. Averitt, D. Sarkar and N. J. Halas, Phys. Rev. Lett. 78, 4217 (1997).

  8. 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

  9. Traitements didactiques preventifs d'un type de conceptions erronees en sciences physiques chez des eleves du secondaire

    NASA Astrophysics Data System (ADS)

    Blondin, Andre

    hypotheses avec la cohorte suivante d'eleves chez qui se repetaient les memes conditions d'apprentissage. Nous avons utilise le design de recherche "posttest only" de Campbell et Stanley. En mai, apres le moment prevu dans la planification du programme pour donner le probleme aux eleves, nous avons suggere deux facons differentes de reviser la solution de ce probleme. Les eleves du premier groupe experimental ont revise sans que soit activee la connaissance anterieure apprehendee de la rotation de la Terre. Les eleves du deuxieme groupe experimental ont ete confrontes, par des questions et une simulation, au fait que la rotation de la Terre n'est pas une connaissance pertinente pour resoudre le probleme. Les groupes temoins et les groupes experimentaux ont ete choisis au hasard dans le bassin des ecoles secondaires de la commission scolaire. (Abstract shortened by UMI.)

  10. Jets and dijets in Au+Au and p+p collisions at RHIC

    SciTech Connect

    Hardtke, D.; STAR Collaboration

    2002-12-09

    Recent data from RHIC suggest novel nuclear effects in the production of high p{sub T} hadrons. We present results from the STAR detector on high p{sub T} angular correlations in Au+Au and p+p collisions at {radical}S = 200 GeV/c. These two-particle angular correlation measurements verify the presence of a partonic hard scattering and fragmentation component at high p{sub T} in both central and peripheral Au+Au collisions. When triggering on a leading hadron with p{sub T}>4 GeV, we observe a quantitative agreement between the jet cone properties in p+p and all centralities of Au+Au collisions. This quantitative agreement indicates that nearly all hadrons with p{sub T}>4 GeV/c come from jet fragmentation and that jet fragmentation properties are not substantially modified in Au+Au collisions. STAR has also measured the strength of back-to-back high p{sub T} charged hadron correlations, and observes a small suppression of the back-to-back correlation strength in peripheral collisions, and a nearly complete disappearance o f back-to-back correlations in central Au+Au events. These phenomena, together with the observed strong suppression of inclusive yields and large value of elliptic flow at high p{sub T}, are consistent with a model where high p{sub T} hadrons come from partons created near the surface of the collision region, and where partons that originate or propagate towards the center of the collision region are substantially slowed or completely absorbed.

  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. 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.

  13. Les campagnes communautaires de promotion du depistage VIH en Afrique de l’Ouest : perceptions des usagers au Burkina Faso

    PubMed Central

    Desclaux, Alice; Ky-Zerbo, Odette; Somé, Jean-François; Makhlouf-Obermeyer, Carla

    2014-01-01

    Résumé La politique actuelle de lutte contre le sida qui repose sur l’extension de l’accès aux traitements et à la prévention exige qu’une proportion élevée de la population connaisse son statut en matière de VIH. Pour cela, l’OMS a proposé le développement de stratégies communautaires délivrant le dépistage et le conseil au-delà des services de soins, comme le test à domicile ou les campagnes de sensibilisation et dépistage de grande envergure, appliqués en Afrique australe et de l’Est. Pour définir les stratégies pertinentes dans des régions de basse prévalence comme l’Afrique de l’Ouest, les expériences communautaires de promotion du dépistage doivent y être évaluées. Cet article présente une évaluation des campagnes au Burkina Faso du point de vue des usagers. Dans le cadre d’un projet sur les pratiques et l’éthique du dépistage dans quatre pays africains (MATCH), une enquête qualitative spécifique a été menée pendant la campagne de 2008, auprès de personnes ayant fait le test pendant la campagne, ayant fait le test hors campagne ou n’ayant pas fait le test. Les appréciations sont globalement très favorables aux campagnes, notamment à cause de l’information dispensée, l’accessibilité des sites, la gratuité du test, la qualité des services et l’effet d’entrainement. Les limites ou critiques sont essentiellement liées à l’affluence ou à la crainte de ne pas être soutenu en cas de résultat positif. La démarche de recours au test ne fait plus l’objet de suspicion, au moins pendant la campagne. Cette « normalisation » du recours au test et la mobilisation collective facilitent des pratiques en groupe, ce qui peut rendre difficile de garder son statut VIH secret. L’évaluation des campagnes par les usagers les présente comme une opportunité pour accéder facilement au test et pour communiquer à ce sujet dans divers espaces sociaux à partir des informations délivrées sur le VIH

  14. Au-Ag@Au Hollow Nanostructure with Enhanced Chemical Stability and Improved Photothermal Transduction Efficiency for Cancer Treatment.

    PubMed

    Jiang, Tongtong; Song, Jiangluqi; Zhang, Wenting; Wang, Hao; Li, Xiaodong; Xia, Ruixiang; Zhu, Lixin; Xu, Xiaoliang

    2015-10-07

    Despite the fact that Au-Ag hollow nanoparticles (HNPs) have gained much attention as ablation agents for photothermal therapy, the instability of the Ag element limits their applications. Herein, excess Au atoms were deposited on the surface of a Au-Ag HNP by improving the reduction power of l-ascorbic acid (AA) and thereby preventing the reaction between HAuCl4 and the Ag element in the Au-Ag alloy nanostructure. Significantly, the obtained Au-Ag@Au HNPs show excellent chemical stability in an oxidative environment, together with remarkable increase in extinction peak intensity and obvious narrowing in peak width. Moreover, finite-difference time-domain (FDTD) was used to simulate the optical properties and electric field distribution of HNPs. The calculated results show that the proportion of absorption cross section in total extinction cross section increases with the improvement of Au content in HNP. As predicted by the theoretical calculation results, Au-Ag@Au nanocages (NCs) exhibit a photothermal transduction efficiency (η) as high as 36.5% at 808 nm, which is higher than that of Au-Ag NCs (31.2%). Irradiated by 808 nm laser at power densities of 1 W/cm(2), MCF-7 breast cancer cells incubated with PEGylated Au-Ag@Au NCs were seriously destroyed. Combined together, Au-Ag@Au HNPs with enhanced chemical stability and improved photothermal transduction efficiency show superior competitiveness as photothermal agents.

  15. The role of interfaces in the magnetoresistance of Au/Fe/Au/Fe/GaAs(001)

    SciTech Connect

    Enders, A.; Monchesky, T. L.; Myrtle, K.; Urban, R.; Heinrich, B.; Kirschner, J.; Zhang, X.-G.; Butler, W. H.

    2001-06-01

    The electron transport and magnetoresistance (MR) were investigated in high quality crystalline epitaxial Fe(001) and Au(001) films and exchange coupled Au/Fe/Au/Fe/GaAs(001) trilayer structures. Fits to the experimental data were based on the semiclassical Boltzmann equation, which incorporates the electronic properties obtained from first-principles local density functional calculations. The fits require a surprisingly high asymmetry for the spin dependent electron lifetimes in Fe, {tau}{sup {down_arrow}}/{tau}{sup {up_arrow}}=10 at room temperature. Despite the large atomic terraces at the Au/vacuum and Fe/GaAs interfaces the scattering at the outer interfaces was found to be diffuse. The origin of MR in Au/Fe/Au/Fe/GaAs(001) structures is due to electron channeling in the Au spacer layer. The measured MR is consistent with the diffusivity parameters s{sup {up_arrow}}=0.55, s{sup {down_arrow}}=0.77 at the metal{endash}metal interfaces. {copyright} 2001 American Institute of Physics.

  16. Synthesis of ultrathin face-centered-cubic au@pt and au@pd core-shell nanoplates from hexagonal-close-packed au square sheets.

    PubMed

    Fan, Zhanxi; Zhu, Yihan; Huang, Xiao; Han, Yu; Wang, Qingxiao; Liu, Qing; Huang, Ying; Gan, Chee Lip; Zhang, Hua

    2015-05-04

    The synthesis of ultrathin face-centered-cubic (fcc) Au@Pt rhombic nanoplates is reported through the epitaxial growth of Pt on hexagonal-close-packed (hcp) Au square sheets (AuSSs). The Pt-layer growth results in a hcp-to-fcc phase transformation of the AuSSs under ambient conditions. Interestingly, the obtained fcc Au@Pt rhombic nanoplates demonstrate a unique (101)f orientation with the same atomic arrangement extending from the Au core to the Pt shell. Importantly, this method can be extended to the epitaxial growth of Pd on hcp AuSSs, resulting in the unprecedented formation of fcc Au@Pd rhombic nanoplates with (101)f orientation. Additionally, a small amount of fcc (100)f -oriented Au@Pt and Au@Pd square nanoplates are obtained with the Au@Pt and Au@Pd rhombic nanoplates, respectively. We believe that these findings will shed new light on the synthesis of novel noble bimetallic nanostructures.

  17. Nanoporous Au structures by dealloying Au/Ag thermal- or laser-dewetted bilayers on surfaces

    NASA Astrophysics Data System (ADS)

    Ruffino, F.; Torrisi, V.; Grillo, R.; Cacciato, G.; Zimbone, M.; Piccitto, G.; Grimaldi, M. G.

    2017-03-01

    Nanoporous Au attracts great technological interest and it is a promising candidate for optical and electrochemical sensors. In addition to nanoporous Au leafs and films, recently, interest was focused on nanoporous Au micro- and nano-structures on surfaces. In this work we report on the study of the characteristics of nanoporous Au structures produced on surfaces. We developed the following procedures to fabricate the nanoporous Au structures: we deposited thin Au/Ag bilayers on SiO2 or FTO (fluorine-doped tin oxide) substrates with thickness xAu and xAg of the Au and Ag layers; we induced the alloying and dewetting processes of the bilayers by furnace annealing processes of the bilayers deposited on SiO2 and by laser irradiations of the bilayers deposited on FTO; the alloying and dewetting processes result in the formation of AuxAgy alloy sub-micron particles being x and y tunable by xAu and xAg. These particles are dealloyed in HNO3 solution to remove the Ag atoms. We obtain, so, nanoporous sub-micron Au particles on the substrates. Analyzing the characteristics of these particles we find that: a) the size and shape of the particles depend on the nature of the dewetting process (solid-state dewetting on SiO2, molten-state dewetting on FTO); b) the porosity fraction of the particles depends on how the alloying process is reached: about 32% of porosity for the particles fabricated by the furnace annealing at 900 °C, about 45% of porosity for the particles fabricated by the laser irradiation at 0.5 J/cm2, in both cases independently on the Ag concentration in the alloy; c) After the dealloying process the mean volume of the Au particles shrinks of about 39%; d) After an annealing at 400 °C the nanoporous Au particles reprise their initial volume while the porosity fraction is reduced. Arguments to justify these behaviors are presented.

  18. SHG anisotropy in Au/Co/Au/Cu/vicinal Si(1 1 1)

    NASA Astrophysics Data System (ADS)

    Cheikh-Rouhou, W.; Sampaio, L. C.; Bartenlian, B.; Beauvillain, P.; Brun, A.; Ferré, J.; Georges, P.; Jamet, J.-P.; Mathet, V.; Stupakewicz, Andrei

    2002-02-01

    The second harmonic generation (SHG) reflectivity on magnetic multilayers is a very sensitive technique to reveal the crystallography of buried interfaces. We have used the azimuthal anisotropy of SHG to demonstrate that the vicinal character of Si(1 1 1) substrate is duplicated in the metallic multilayer Au/Co/Au/Cu. The magnetic properties of these multilayers as anisotropy and magneto-optic polar Kerr rotation were studied by linear magneto-optic effects in correlation with SHG experiments, by varying the Co and Au buffer thicknesses as well as the Cu buffer deposition condition.

  19. Time Dependent Universal Conductance Fluctuations In AuPd, Ag, And Au Wires

    NASA Astrophysics Data System (ADS)

    Trionfi, A.; Lee, S.; Natelson, D.

    2006-09-01

    Quantum transport phenomena allow experimental determinations of the phase coherence information in metals. We report quantitative comparisons of inferred coherence lengths from independent measurements of the weak localization magnetoresistance and time-dependent universal conductance fluctuations' magnetic field dependence. Strong agreement is observed in both quasi-2D and quasi-1D AuPd samples. However, quantitative agreement is not seen in quasi-1D Ag wires below 10 K and quasi-1D Au wires below 14 K. A possible explanation for this disagreement will be discussed. Attempts to produce changes in the coherence length in Au by annealing have also been made and results will be reported.

  20. Revisiting the S-Au(111) interaction: Static or Dynamic?

    SciTech Connect

    Biener, M M; Biener, J; Friend, C M

    2004-08-17

    The chemical inertness typically observed for Au does not imply a general inability to form stable bonds with non-metals but is rather a consequence of high reaction barriers. The Au-S interaction is probably the most intensively studied interaction of Au surfaces with non-metals as, for example, it plays an important role in Au ore formation, and controls the structure and dynamics of thiol-based self-assembled-monolayers (SAMs). In recent years a quite complex picture of the interaction of sulfur with Au(111) surfaces emerged, and a variety of S-induced surface structures was reported under different conditions. The majority of these structures were interpreted in terms of a static Au surface, where the positions of the Au atoms remain essentially unperturbed. Here we demonstrate that the Au(111) surface exhibits a very dynamic character upon interaction with adsorbed sulfur: low sulfur coverages modify the surface stress of the Au surface leading to lateral expansion of the surface layer; large-scale surface restructuring and incorporation of Au atoms into a growing two-dimensional AuS phase were observed with increasing sulfur coverage. These results provide new insight into the Au-S surface chemistry, and reveal the dynamic character of the Au(111) surface.

  1. Suppression of Upsilon production in d + Au and Au + Au collisions at root s(NN) = 200 GeV (vol 735, pg 127, 2014)

    SciTech Connect

    Adamczyk, L.; Adkins, J. K.; Agakishiev, G.; Aggarwal, M. M.; Ahammed, Z.; Alekseev, I.; Alford, J.; Anson, C. D.; Aparin, A.; Arkhipkin, D.; Gliske, S.; Krueger, K.; Spinka, H. M.; Underwood, D. G.

    2014-07-30

    We report measurements of Υ meson production in p + p, d +Au, and Au+Aucollisions 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 (1S + 2S + 3S) in the rapidity range |y| < 1 in d + Aucollisions 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 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 Υ mesons in Au + Aucollisions. 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.

  2. The fast diffusion of Au IN Pb

    NASA Technical Reports Server (NTRS)

    Mclellan, R. B.; Ko, C.; Brotzen, F. R.

    1990-01-01

    A treatment of the phenomenon of fast diffusion in lead is presented. The model used is based upon the fast diffusion of free solute interstitials. The very large negative enhancement coefficients found in the Pb-(Au, Ag) systems is explained by the formation of first and second order clusters of vacancies and substitutional solute atoms.

  3. 22 CFR 62.31 - Au pairs.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 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...

  4. 22 CFR 62.31 - Au pairs.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 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...

  5. 22 CFR 62.31 - Au pairs.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 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...

  6. 22 CFR 62.31 - Au pairs.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 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...

  7. 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...

  8. Systematics of Global Observables in Cu+Cu and Au+Au Collisions at RHIC Energies

    SciTech Connect

    Nouicer, Rachid

    2006-07-11

    Charged particles produced in Cu+Cu collisions at {radical}(s{sub NN}) = 200 and 62.4 GeV have been measured in the PHOBOS experiment at RHIC. The comparison of the results for Cu+Cu and Au+Au for the most central collisions at the same energy reveals that the particle density per nucleon participant pair and the extended longitudinal scaling behavior are similar in both systems. This implies that for the most central events in symmetric nucleus-nucleus collisions the particle density per nucleon participant pair does not depend on the size of the two colliding nuclei but only on the collision energy. Also the extended longitudinal scaling seems independent of the colliding energy and species for central collisions. In addition, there is an overall factorization of dNch/d{eta} shapes as a function of collision centraliry between Au+Au and Cu+Cu collisions at the same energy.

  9. Charged-Particle Pseudorapidity Density Distributions from Au+Au Collisions at

    SciTech Connect

    Back, B. B.; Baker, M. D.; Barton, D. S.; Betts, R. R.; Bindel, R.; Budzanowski, A.; Busza, W.; Carroll, A.; Decowski, M. P.; Garcia, E.

    2001-09-03

    The charged-particle pseudorapidity density dN{sub ch}/d{eta} has been measured for Au+Au collisions at s{sub NN}=130 GeV at RHIC, using the PHOBOS apparatus. The total number of charged particles produced for the 3% most-central Au+Au collisions for |{eta}|{<=}5.4 is found to be 4200{+-}470 . The evolution of dN{sub ch}/d{eta} with centrality is discussed, and compared to model calculations and to data from proton-induced collisions. The data show an enhancement in charged-particle production at midrapidity, while in the fragmentation regions, the results are consistent with expectations from pp and pA scattering.

  10. High Resolution Photoelectron Spectroscopy of Au_2^- and Au_4^- by Photoelectron Imaging

    NASA Astrophysics Data System (ADS)

    Leon, Iker; Yang, Zheng; Wang, Lai-Sheng

    2013-06-01

    We report high resolution photoelectron spectra of Au_2^- and Au_4^- obtained with a newly-built photoelectron imaging apparatus. Gold anions are produced by laser vaporization and the desired specie is mass selected and focused into the collinear velocity-map imaging (VMI) lens assembly. The design of the imaging lens has allowed us to obtain less than 0.9% energy resolution for high kinetic energy electrons ( > 1eV) while maintaining wavenumber resolution for low kinetic energy electrons. Although gold dimer and tetramer have been studied in the past, we present spectroscopic results under high resolution. For Au_2^-, we report high resolution spectra with an accurate determination of the electron affinity together with a complete vibrational assignment, for both the anion and neutral ground states, while for Au_4^-, we are able to resolve a low frequency mode and obtain accurately the adiabatic detachment energy.

  11. Magnetic disorder in nanostructured Fe7Au93 films and Fe14Au86 powders

    NASA Astrophysics Data System (ADS)

    Alba Venero, D.; Fernández Barquín, L.; Alonso, J.; Svalov, A.; Fdez-Gubieda, M. L.

    2010-01-01

    Thin films and powders of dilute Fe-Au alloys have been produced by DC-magnetron sputtering and high-energy milling, respectively. Energy disperse X-ray spectroscopy gives Fe7Au93 for the films and Fe14Au86 for the powders. The film, with a thickness below 200 nm measured by atomic force microscopy, was deposited onto a Si(100) substrate. X-ray diffraction reveals a major presence of fcc-Au peaks masking the bcc-Fe phase. The (1 0-300 K) DC-susceptibility (H = 100-1000 Oe) shows a clear cusp in the films in contrast to the powders, with a reentrant spin glass-like behavior.

  12. Au/ZnO nanoarchitectures with Au as both supporter and antenna of visible-light

    NASA Astrophysics Data System (ADS)

    Liu, Tianyu; Chen, Wei; Hua, Yuxiang; Liu, Xiaoheng

    2017-01-01

    In this paper, we fabricate Au/ZnO nanostructure with smaller ZnO nanoparticles loaded onto bigger gold nanoparticles via combining seed-mediated method and sol-gel method. The obtained Au/ZnO nanocomposites exhibit excellent properties in photocatalysis process like methyl orange (MO) degradation and oxidative conversion of methanol into formaldehyde under visible light irradiation. The enhanced properties were ascribed to the surface plasmon resonance (SPR) effect of Au nanoparticles, which could contribute to the separation of photo-excited electrons and holes and facilitate the process of absorbing visible light. This paper contributes to the emergence of multi-functional nanocomposites with possible applications in visible-light driven photocatalysts and makes the Au/ZnO photocatalyst an exceptional choice for practical applications such as environmental purification of organic pollutants in aqueous solution and the synthesis of fine chemicals and intermediates.

  13. Observation of a Strongly Enhanced Magnetic Susceptibility of Pd in Au-Pd-Au Sandwiches

    NASA Astrophysics Data System (ADS)

    Brodsky, M. B.; Freeman, A. J.

    1980-07-01

    Exceptionally large increases in the magnetic susceptibility (indicating nearly magnetic ordering) of thin films of Pd sandwiched between thicker Au films have been observed at low temperatures-presumably due to the expansion of the Pd average lattice constant by the Au. The large resultant Stoner factors and the modified paramagnon model of Levin and Valls indicate the possibility of observing p-wave superconductivity in Pd structures with reduced proximity effects.

  14. Net charge fluctuations in Au + Au interactions at sqrt[s(NN)]=130 GeV.

    PubMed

    Adcox, K; Adler, S S; Ajitanand, N N; Akiba, Y; Alexander, J; Aphecetche, L; Arai, Y; Aronson, S H; Averbeck, R; Awes, T C; Barish, K N; Barnes, P D; Barrette, J; Bassalleck, B; Bathe, S; Baublis, V; Bazilevsky, A; Belikov, S; Bellaiche, F G; Belyaev, S T; Bennett, M J; Berdnikov, Y; Botelho, S; Brooks, M L; Brown, D S; Bruner, N; Bucher, D; Buesching, H; Bumazhnov, V; Bunce, G; Burward-Hoy, J; Butsyk, S; Carey, T A; Chand, P; Chang, J; Chang, W C; Chavez, L L; Chernichenko, S; Chi, C Y; Chiba, J; Chiu, M; Choudhury, R K; Christ, T; Chujo, T; Chung, M S; Chung, P; Cianciolo, V; Cole, B A; D'Enterria, D G; David, G; Delagrange, H; Denisov, A; Deshpande, A; Desmond, E J; Dietzsch, O; Dinesh, B V; Drees, A; Durum, A; Dutta, D; Ebisu, K; Efremenko, Y V; El Chenawi, K; En'yo, H; Esumi, S; Ewell, L; Ferdousi, T; Fields, D E; Fokin, S L; Fraenkel, Z; Franz, A; Frawley, A D; Fung, S-Y; Garpman, S; Ghosh, T K; Glenn, A; Godoi, A L; Goto, Y; Greene, S V; Grosse Perdekamp, M; Gupta, S K; Guryn, W; Gustafsson, H-A; Haggerty, J S; Hamagaki, H; Hansen, A G; Hara, H; Hartouni, E P; Hayano, R; Hayashi, N; He, X; Hemmick, T K; Heuser, J M; Hibino, M; Hill, J C; Ho, D S; Homma, K; Hong, B; Hoover, A; Ichihara, T; Imai, K; Ippolitov, M S; Ishihara, M; Jacak, B V; Jang, W Y; Jia, J; Johnson, B M; Johnson, S C; Joo, K S; Kametani, S; Kang, J H; Kann, M; Kapoor, S S; Kelly, S; Khachaturov, B; Khanzadeev, A; Kikuchi, J; Kim, D J; Kim, H J; Kim, S Y; Kim, Y G; Kinnison, W W; Kistenev, E; Kiyomichi, A; Klein-Boesing, C; Klinksiek, S; Kochenda, L; Kochetkov, V; Koehler, D; Kohama, T; Kotchetkov, D; Kozlov, A; Kroon, P J; Kurita, K; Kweon, M J; Kwon, Y; Kyle, G S; Lacey, R; Lajoie, J G; Lauret, J; Lebedev, A; Lee, D M; Leitch, M J; Li, X H; Li, Z; Lim, D J; Liu, M X; Liu, X; Liu, Z; Maguire, C F; Mahon, J; Makdisi, Y I; Manko, V I; Mao, Y; Mark, S K; Markacs, S; Martinez, G; Marx, M D; Masaike, A; Matathias, F; Matsumoto, T; McGaughey, P L; Melnikov, E; Merschmeyer, M; Messer, F; Messer, M; Miake, Y; Miller, T E; Milov, A; Mioduszewski, S; Mischke, R E; Mishra, G C; Mitchell, J T; Mohanty, A K; Morrison, D P; Moss, J M; Mühlbacher, F; Muniruzzaman, M; Murata, J; Nagamiya, S; Nagasaka, Y; Nagle, J L; Nakada, Y; Nandi, B K; Newby, J; Nikkinen, L; Nilsson, P; Nishimura, S; Nyanin, A S; Nystrand, J; O'Brien, E; Ogilvie, C A; Ohnishi, H; Ojha, I D; Ono, M; Onuchin, V; Oskarsson, A; Osterman, L; Otterlund, I; Oyama, K; Paffrath, L; Palounek, A P T; Pantuev, V S; Papavassiliou, V; Pate, S F; Peitzmann, T; Petridis, A N; Pinkenburg, C; Pisani, R P; Pitukhin, P; Plasil, F; Pollack, M; Pope, K; Purschke, M L; Ravinovich, I; Read, K F; Reygers, K; Riabov, V; Riabov, Y; Rosati, M; Rose, A A; Ryu, S S; Saito, N; Sakaguchi, A; Sakaguchi, T; Sako, H; Sakuma, T; Samsonov, V; Sangster, T C; Santo, R; Sato, H D; Sato, S; Sawada, S; Schlei, B R; Schutz, Y; Semenov, V; Seto, R; Shea, T K; Shein, I; Shibata, T-A; Shigaki, K; Shiina, T; Shin, Y H; Sibiriak, I G; Silvermyr, D; Sim, K S; Simon-Gillo, J; Singh, C P; Singh, V; Sivertz, M; Soldatov, A; Soltz, R A; Sorensen, S; Stankus, P W; Starinsky, N; Steinberg, P; Stenlund, E; Ster, A; Stoll, S P; Sugioka, M; Sugitate, T; Sullivan, J P; Sumi, Y; Sun, Z; Suzuki, M; Takagui, E M; Taketani, A; Tamai, M; Tanaka, K H; Tanaka, Y; Taniguchi, E; Tannenbaum, M J; Thomas, J; Thomas, J H; Thomas, T L; Tian, W; Tojo, J; Torii, H; Towell, R S; Tserruya, I; Tsuruoka, H; Tsvetkov, A A; Tuli, S K; Tydesjö, H; Tyurin, N; Ushiroda, T; van Hecke, H W; Velissaris, C; Velkovska, J; Velkovsky, M; Vinogradov, A A; Volkov, M A; Vorobyov, A; Vznuzdaev, E; Wang, H; Watanabe, Y; White, S N; Witzig, C; Wohn, F K; Woody, C L; Xie, W; Yagi, K; Yokkaichi, S; Young, G R; Yushmanov, I E; Zajc, W A; Zhang, Z; Zhou, S

    2002-08-19

    Data from Au + Au interactions at sqrt[s(NN)]=130 GeV, obtained with the PHENIX detector at the Relativistic Heavy-Ion Collider, are used to investigate local net charge fluctuations among particles produced near midrapidity. According to recent suggestions, such fluctuations may carry information from the quark-gluon plasma. This analysis shows that the fluctuations are dominated by a stochastic distribution of particles, but are also sensitive to other effects, like global charge conservation and resonance decays.

  15. Transverse expansion in Au + Au collisions at RHIC

    SciTech Connect

    Cheng, Y.; Liu, F.; Liu, K.; Schweda, K.; Xu, N.

    2003-06-24

    Using the RQMD model, transverse momentum distributions and particle ratios are studied for {sup 197}Au + {sup 197}Au collisions at {radical}s{sub NN} = 200 GeV. In particular, they present results on the mean transverse momentum of charged pions, charged kaons, protons and anti-protons and compare with experimental measurements. They discuss an approach to study early partonic collectivity in high energy nuclear collisions.

  16. Strangeness production in Au+Au collisions at the AGS: recent results from E917.

    SciTech Connect

    Chang, W.-C.; Back, B. B.; Betts, R. R.; Britt, H. C.; Chang, W. C.; Gillitzer, A.; Henning, W. F.; Hofman, D. J.; Holzman, B.; Nanal, V.; Wuosmaa, A. H.

    1999-03-30

    Strangeness production in Au+Au collisions has been measured via the yields of K{sup +} , K{sup {minus}} at 6, 8 AGeV and of {bar {Lambda}} at 10.8 AGeV beam kinetic energy in experiment E917. By varying the collision centrally and beam energy, a systematic search for indications of new phenomena and in-medium effects under high baryon density is undertaken.

  17. Le don après un décès d'origine cardiocirculatoire au Canada

    PubMed Central

    Shemie, Sam D.; Baker, Andrew J.; Knoll, Greg; Wall, William; Rocker, Graeme; Howes, Daniel; Davidson, Janet; Pagliarello, Joe; Chambers-Evans, Jane; Cockfield, Sandra; Farrell, Catherine; Glannon, Walter; Gourlay, William; Grant, David; Langevin, Stéphan; Wheelock, Brian; Young, Kimberly; Dossetor, John

    2006-01-01

    Résumé Ces recommandations sont le fruit d'un processus multidisciplinaire national ayant duré un an et visant à déterminer si et comment l'on pourrait procéder au don d'organes après un décès d'origine cardiocirculatoire («don après le décès cardiocirculatoire», ou DDC) au Canada. Le forum national organisé en février 2005 a permis aux participants de discuter et d'élaborer des recommandations sur les principes, interventions et pratiques se rapportant au DDC. Les aspects éthiques et juridiques ont été abordés dans les discussions. À la fin du Forum, la majorité des participants ont été favorables à l'implantation de programmes de DDC au Canada. Les participants du Forum ont également convenu qu'il fallait formuler et prôner des valeurs fondamentales pour orienter l'élaboration de programmes et de protocoles basés sur le cadre médical, éthique et juridique établi lors de cette réunion. Même si la possibilité d'un don d'organes et de tissus doit faire partie intégrante des soins de fin de vie, il faut insister sur le fait que le devoir de diligence envers les patients mourants et leurs familles doit demeurer la priorité des équipes soignantes. La complexité et les répercussions profondes du décès sont reconnues et doivent être respectées, de même que les différences personnelles, ethnoculturelles et religieuses face à la mort et au don d'organes. Les décisions d'arrêter le traitement de maintien des fonctions vitales, la prise en charge des derniers moments de la vie et le diagnostic de décès selon des critères cardiocirculatoires doivent être distincts et indépendants des processus de don et transplantation. Ce rapport contient des recommandations destinées aux gestionnaires de program, aux autorités sanitaires régionales et aux instances appelés à élaborer les protocoles de DDC. Les programmes doivent être conçus en fonction des éléments suivants : direction et planification locales, éducation et

  18. 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.

  19. Low specific contact resistivity to graphene achieved by AuGe/Ni/Au and annealing process

    NASA Astrophysics Data System (ADS)

    Yu, Shu-Zhen; Song, Yan; Dong, Jian-Rong; Sun, Yu-Run; Zhao, Yong-Ming; He, Yang

    2016-11-01

    Low metal-graphene contact resistance is important in making high-performance graphene devices. In this work, we demonstrate a lower specific contact resistivity of Au0.88Ge0.12/Ni/Au-graphene contact compared with Ti/Au and Ti/Pt/Au contacts. The rapid thermal annealing process was optimized to improve AuGe/Ni/Au contact resistance. Results reveal that both pre- and post-annealing processes are effective for reducing the contact resistance. The specific contact resistivity decreases from 2.5 × 10-4 to 7.8 × 10-5 Ω·cm2 by pre-annealing at 300 °C for one hour, and continues to decrease to 9.5 × 10-7 Ω·cm2 after post-annealing at 490 °C for 60 seconds. These approaches provide reliable means of lowering contact resistance. Project supported by the National Natural Science Foundation of China (Grant No. 61376065) and the Science and Technology Project of Suzhou, China (Grant No. ZXG2013044).

  20. Magnetism of Au Nanoparticles on Sulfolubus Acidocaldarius S-Layer

    NASA Astrophysics Data System (ADS)

    Bartolome, Juan; Bartolome, F.; Garcia, L. M.; Figueroa, A. I.; Herrmannsdoerfer, T.; Skrotzki, R.; Schoenemann, R.; Wosnitza, J.; Selenska-Pobell, S.; Geissler, A.; Reitz, T.; Wilhelm, F.; Rogalev, A.

    2011-03-01

    Au nanoparticles (NP) with diameters of a few nm have been synthesized on a protein S-layer of Sulfolobus Acidocaldarius bacteria. SQUID magnetization (1.8 K T 300 Kand 0 B 7 T) showssuperparamagneticbehavioratlow - T . ItsoriginlaysattheAuNP ' s , ashasbeenprovenbyAuL 2,3- edgeXMCDspectroscopy , performedintherange 2.2 T 20 KanduptoB app = 17 T . XMCDanalysisyieldsatotalmagneticmomentperAuatom μAu = 0.050 (1) μB , aparticleaveragemomentm part = 2.3 μB , Auorbitaltospinmomentratioofm L / m S = 0.29 Curie and - like superparamagnetism. Au - S bonds are detected by S K - edge XAS measurements. Besides , EXAFS at the Au L 3 -edge shows that the Au NP internal structure is fcc, and Au-S bonds are located at the particle surface. An increase of the hole charge carrier density in the Au 5d band due to electron transfer with the S-layer explains the Au magnetism. The observed magnetic moment per Au atom is 25 times larger than those previously found by XMCD in Au-thiol capped NPs.

  1. Controlling Au Nanorod Dispersion in Thin Film Polymer Blends

    NASA Astrophysics Data System (ADS)

    Hore, Michael J. A.; Composto, Russell J.

    2012-02-01

    Dispersion of Au nanorods (Au NRs) in polymer thin films is studied using a combination of experimental and theoretical techniques. Here, we incorporate small volume fractions of polystyrene-functionalized Au NRs (φrod 0.05) into polystyrene (PS) thin films. By controlling the ratio of the brush length (N) to that of the matrix polymers (P), we can selectively obtain dispersed or aggregated Au NR structures in the PS-Au(N):PS(P) films. A dispersion map of these structures allows one to choose N and P to obtain either uniformly dispersed Au NRs or aggregates of closely packed, side-by-side aligned Au NRs. Furthermore, by blending poly(2,6-dimethyl-p-phenylene oxide) (PPO) into the PS films, we demonstrate that the Au nanorod morphology can be further tuned by reducing depletion-attraction forces and promoting miscibility of the Au NRs. These predictable structures ultimately give rise to tunable optical absorption in the films resulting from surface plasmon resonance coupling between the Au NRs. Finally, self-consistent field theoretic (SCFT) calculations for both the PS-Au(N):PS(P) and PS-Au(N):PS(P):PPO systems provide insight into the PS brush structure, and allow us to interpret morphology and optical property results in terms of wet and dry PS brush states.

  2. 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

  3. 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

  4. 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.

  5. Cationic Au(III) versus Au(I) : 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.

  6. Hématome spontané du méso de l'angle colique droit et du colon transverse compliquant un traitement par anti vitamine K: à propos d'un cas et revue de la littérature

    PubMed Central

    Traoré, Ibrahim Alain; Zaré, Cyprien; Barro, Sié Drissa; Guibla, Ismaël

    2016-01-01

    L'hématome spontané du méso de l'angle colique droit et du transverse est une complication rare du traitement anticoagulant par antivitamine K. Nous rapportons un cas d'hématome spontané du méso de l'angle colique droit et du transverse associé à un hémopéritoine de grande abondance chez un patient traité par antivitamine K pour embolie pulmonaire consécutive à une fracture des plateaux tibiaux droits. Le diagnostic doit être fait en urgence. L’échographie abdominale et la tomodensitométrie confirment le diagnostic. Le traitement non opératoire est la règle. Le traitement chirurgical est indiqué en cas de complications telles que la rupture de l'hématome. PMID:27217878

  7. Angio-Behçet thoracique - régression totale sous traitement immuno-suppresseur (à propos d'un cas)

    PubMed Central

    Berrady, Rhizlane; Khammar, Zineb; Lahlou, Mariam; Boukhrissa, Amal; Bono, Wafaa

    2014-01-01

    La maladie de Behçet est une Vascularite multisystémique d’étiologie obscure. L'angio-Behçet thoracique est en rapport avec le tropisme vasculaire bien connu de la maladie, et les anévrysmes des artères pulmonaires constituent une des complications majeures de cette maladie. Nous rapportons le cas d'un patient qui s'est présenté en consultation pour douleur thoracique avec toux et crachats hémoptoïques. Le diagnostic d'une maladie de Behçet est retenu sur des arguments cliniques et confirmé par un angioscanner thoracique qui a objectivé des dilatations anévrysmales des bronches lobaires et segmentaires des deux artères pulmonaires. Devant l'urgence thérapeutique, un bolus de solumédrol sur trois jours est réalisé relayé par un bolus de cyclophosphamide. Après 12 mois de suivi, le patient rapporte une nette amélioration clinique. L'angio-scanner de contrôle note une disparition totale des anévrysmes des artères pulmonaires. L'atteinte thoracique de l'angio-Behçet est grave et met en jeu le pronostic vital, le traitement médical de ces anévrysmes à base d'immunosuppresseur permet une évolution favorable. PMID:25404976

  8. Centrality dependence of direct photon production in (square root)S(NN) = 200 GeV Au + Au collisions.

    PubMed

    Adler, S S; Afanasiev, S; Aidala, C; Ajitanand, N N; Akiba, Y; Alexander, J; Amirikas, R; Aphecetche, L; Aronson, S H; Averbeck, R; Awes, T C; Azmoun, R; Babintsev, V; Baldisseri, A; Barish, K N; Barnes, P D; Bassalleck, B; Bathe, S; Batsouli, S; Baublis, V; Bazilevsky, A; Belikov, S; Berdnikov, Y; Bhagavatula, S; Boissevain, J G; Borel, H; Borenstein, S; Brooks, M L; Brown, D S; Bruner, N; Bucher, D; Buesching, H; Bumazhnov, V; Bunce, G; Burward-Hoy, J M; Butsyk, S; Camard, X; Chai, J-S; Chand, P; Chang, W C; Chernichenko, S; Chi, C Y; Chiba, J; Chiu, M; Choi, I J; Choi, J; Choudhury, R K; Chujo, T; Cianciolo, V; Cobigo, Y; Cole, B A; Constantin, P; d'Enterria, D; David, G; Delagrange, H; Denisov, A; Deshpande, A; Desmond, E J; Devismes, A; Dietzsch, O; Drapier, O; Drees, A; du Rietz, R; Durum, A; Dutta, D; Efremenko, Y V; El Chenawi, K; Enokizono, A; En'yo, H; Esumi, S; Ewell, L; Fields, D E; Fleuret, F; Fokin, S L; Fox, B D; Fraenkel, Z; Frantz, J E; Franz, A; Frawley, A D; Fung, S-Y; Garpman, S; Ghosh, T K; Glenn, A; Gogiberidze, G; Gonin, M; Gosset, J; Goto, Y; Granier de Cassagnac, R; Grau, N; Greene, S V; Perdekamp, M Grosse; Guryn, W; Gustafsson, H-A; Hachiya, T; Haggerty, J S; Hamagaki, H; Hansen, A G; Hartouni, E P; Harvey, M; Hayano, R; Hayashi, N; He, X; Heffner, M; Hemmick, T K; Heuser, J M; Hibino, M; Hill, J C; Holzmann, W; Homma, K; Hong, B; Hoover, A; Ichihara, T; Ikonnikov, V V; Imai, K; Isenhower, D; Ishihara, M; Issah, M; Isupov, A; Jacak, B V; Jang, W Y; Jeong, Y; Jia, J; Jinnouchi, O; Johnson, B M; Johnson, S C; Joo, K S; Jouan, D; Kametani, S; Kamihara, N; Kang, J H; Kapoor, S S; Katou, K; Kelly, S; Khachaturov, B; Khanzadeev, A; Kikuchi, J; Kim, D H; Kim, D J; Kim, D W; Kim, E; Kim, G-B; Kim, H J; Kistenev, E; Kiyomichi, A; Kiyoyama, K; Klein-Boesing, C; Kobayashi, H; Kochenda, L; Kochetkov, V; Koehler, D; Kohama, T; Kopytine, M; Kotchetkov, D; Kozlov, A; Kroon, P J; Kuberg, C H; Kurita, K; Kuroki, Y; Kweon, M J; Kwon, Y; Kyle, G S; Lacey, R; Ladygin, V; Lajoie, J G; Lebedev, A; Leckey, S; Lee, D M; Lee, S; Leitch, M J; Li, X H; Lim, H; Litvinenko, A; Liu, M X; Liu, Y; Maguire, C F; Makdisi, Y I; Malakhov, A; Manko, V I; Mao, Y; Martinez, G; Marx, M D; Masui, H; Matathias, F; Matsumoto, T; McGaughey, P L; Melnikov, E; Messer, F; Miake, Y; Milan, J; Miller, T E; Milov, A; Mioduszewski, S; Mischke, R E; Mishra, G C; Mitchell, J T; Mohanty, A K; Morrison, D P; Moss, J M; Mühlbacher, F; Mukhopadhyay, D; Muniruzzaman, M; Murata, J; Nagamiya, S; Nagle, J L; Nakamura, T; Nandi, B K; Nara, M; Newby, J; Nilsson, P; Nyanin, A S; Nystrand, J; O'Brien, E; Ogilvie, C A; Ohnishi, H; Ojha, I D; Okada, K; Ono, M; Onuchin, V; Oskarsson, A; Otterlund, I; Oyama, K; Ozawa, K; Pal, D; Palounek, A P T; Pantuev, V; Papavassiliou, V; Park, J; Parmar, A; Pate, S F; Peitzmann, T; Peng, J-C; Peresedov, V; Pinkenburg, C; Pisani, R P; Plasil, F; Purschke, M L; Purwar, A K; Rak, J; Ravinovich, I; Read, K F; Reuter, M; Reygers, K; Riabov, V; Riabov, Y; Roche, G; Romana, A; Rosati, M; Rosnet, P; Ryu, S S; Sadler, M E; Saito, N; Sakaguchi, T; Sakai, M; Sakai, S; Samsonov, V; Sanfratello, L; Santo, R; Sato, H D; Sato, S; Sawada, S; Schutz, Y; Semenov, V; Seto, R; Shaw, M R; Shea, T K; Shibata, T-A; Shigaki, K; Shiina, T; Silva, C L; Silvermyr, D; Sim, K S; Singh, C P; Singh, V; Sivertz, M; 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; Sullivan, J P; Takagui, E M; Taketani, A; Tamai, M; Tanaka, K H; Tanaka, Y; Tanida, K; Tannenbaum, M J; Tarján, P; Tepe, J D; Thomas, T L; Tojo, J; Torii, H; Towell, R S; Tserruya, I; Tsuruoka, H; Tuli, S K; Tydesjö, H; Tyurin, N; van Hecke, H W; Velkovska, J; Velkovsky, M; Veszprémi, V; Villatte, L; Vinogradov, A A; Volkov, M A; Vznuzdaev, E; Wang, X R; Watanabe, Y; White, S N; Wohn, F K; Woody, C L; Xie, W; Yang, Y; Yanovich, A; Yokkaichi, S; Young, G R; Yushmanov, I E; Zajc, W A; Zhang, C; Zhou, S; Zhou, S J; Zolin, L

    2005-06-17

    The first measurement of direct photons in Au + Au collisions at (square root)S(NN) = 200 GeV is presented. The direct photon signal is extracted as a function of the Au + Au collision centrality and compared to next-to-leading order perturbative quantum chromodynamics calculations. The direct photon yield is shown to scale with the number of nucleon-nucleon collisions for all centralities.

  9. 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

  10. 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

  11. 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.

  12. Les grosses bourses aiguës au centre hospitalier de Louga, Sénégal: aspects épidémiologiques, étiologiques et thérapeutiques

    PubMed Central

    Diabaté, Ibrahima; Ouédraogo, Bouréima; Thiam, Mbaye

    2016-01-01

    Introduction Les grosses bourses aiguës (GBA) sont des motifs fréquents de consultation en urgence. Cette étude vise à déterminer la fréquence hospitalière des GBA au Centre Hospitalier Régional Amadou Sakhir Mbaye (CHRASM) de Louga au Sénégal, à identifier les formes cliniques et à évaluer les modalités de prise en charge. Méthodes Il s’agit d’une étude rétrospective, descriptive portant sur 114 patients reçus pour GBA au CHRASM de Louga, de mai 2010 à août 2013. Les variables étudiées étaient: la fréquence des GBA parmi les grosses bourses (GB) et les urgences urologiques, l’âge, le délai de consultation, les causes, le traitement, l’évolution post-thérapeutique et la durée d’hospitalisation. Résultats Au cours de la période d’étude, 356 GB et 420 urgences urologiques ont été enregistrées. Ainsi, les 114 cas de GBA recensés représentaient 32,0 % des GB et 27,1 % des urgences urologiques. La moyenne d’âge était de 42,25 ± 25ans (extrêmes de 5 mois et 89 ans). Le délai moyen de consultation était de 4 jours. Le diagnostic évoqué à l’admission était: une orchi-épididymite aiguë (n=66), une GBA abcédée (n=18), une suspicion de torsion du cordon spermatique (n=14), une GBA traumatique (10 cas), une hernie inguino-scrotale étranglée (06 cas). Le traitement a été exclusivement médical dans 66 cas (57,8 %). L’exploration chirurgicale qui était indiquée chez 48 patients, a été effectuée chez 45 d’entre eux (93,7 %), trois patients (6,2 %) l’ont refusé. Au total, il y a eu 9 cas d’orchidectomies et 36 procédures conservatrices. La durée moyenne d’hospitalisation était de 3± 2 jours. Quatre vingt et un patients (71,0 %) ont été hospitalisés pendant 24 heures au moins; ils étaient répartis en 42 patients chirurgicaux et 39 patients médicaux. Aucun cas de décès n’a été enregistré. Conclusion Les GBA sont fréquentes dans notre structure, tous les âges sont concern

  13. 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.

  14. From the ternary Eu(Au/In)2 and EuAu4(Au/In)2 with remarkable Au/In distributions to a new structure type: The gold-rich Eu5Au16(Au/In)6 structure

    DOE PAGES

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

    2015-08-13

    The ternary Eu(Au/In)2 (EuAu0.46In1.54(2)) (I), EuAu4(Au/In)2 (EuAu4+xIn2–x with x = 0.75(2) (II), 0.93(2), and 1.03(2)), and Eu5Au16(Au/In)6 (Eu5Au17.29In4.71(3)) (III) have been synthesized, and their structures were characterized by single-crystal X-ray diffraction. I and II crystallize with the CeCu2-type (Pearson Symbol oI12; Imma; Z = 4; a = 4.9018(4) Å; b = 7.8237(5) Å; c = 8.4457(5) Å) and the YbAl4Mo2-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 of an Au/In-mixed diamond-related host lattice encapsulating Eu atoms, while the structure of II features ribbons of distorted, squaredmore » Au8 prisms enclosing Eu, Au, and In atoms. Combination of these structural motifs leads to a new structure type as observed for Eu5Au16(Au/In)6 (Eu5Au17.29In4.71(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 EuAu2–“EuAu4In2”. The site preferences of the disordered Au/In positions in II were investigated for different hypothetical “EuAu4(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 “EuAu5In” and “EuAu4In2” 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

  15. 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.

  16. Au20Si12: A hollow Catalan pentakis dodecahedron.

    PubMed

    Guo, J J; Zhao, H Y; Wang, J; Ai, L Y; Liu, Y

    2017-02-14

    A stable hollow Au20Si12 cage with Ih symmetry has been predicted using first-principles density functional theory. The stability of the cage-like Au20Si12 structure is verified by vibrational frequency analysis and molecular dynamics simulations. A relatively large highest occupied molecular orbital-lowest unoccupied molecular orbital gap of 1.057 eV is found. Electronic structure analysis shows that clearly p-d hybridizations between Si atoms and Au atoms are of great importance for the stability of Au20Si12 cage. The cage-like Au20Si12 structure may have potential applications in semiconductor industry and microelectronics.

  17. 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.

  18. Au20Si12: A hollow Catalan pentakis dodecahedron

    NASA Astrophysics Data System (ADS)

    Guo, J. J.; Zhao, H. Y.; Wang, J.; Ai, L. Y.; Liu, Y.

    2017-02-01

    A stable hollow Au20Si12 cage with Ih symmetry has been predicted using first-principles density functional theory. The stability of the cage-like Au20Si12 structure is verified by vibrational frequency analysis and molecular dynamics simulations. A relatively large highest occupied molecular orbital-lowest unoccupied molecular orbital gap of 1.057 eV is found. Electronic structure analysis shows that clearly p-d hybridizations between Si atoms and Au atoms are of great importance for the stability of Au20Si12 cage. The cage-like Au20Si12 structure may have potential applications in semiconductor industry and microelectronics.

  19. Evaluation des prescriptions antibiotiques au service des urgences de l’Hôpital Militaire d’Instruction Mohammed V (HMIMV)

    PubMed Central

    Elbouti, Anass; Rafai, Mostafa; Chouaib, Naoufal; Jidane, Said; Belkouch, Ahmed; Bakkali, Hicham; Belyamani, Lahcen

    2016-01-01

    Cette étude à pour objectifs de décrire les pratiques des prescriptions, évaluer leur pertinence et leur conformité aux règles d’utilisations et étudier les facteurs susceptibles de les influencer. Il s’agit d’une étude transversale d’évaluation des prescriptions antibiotiques portant sur 105 patients réalisée au service des urgences médico-chirurgicales de l’H.M.I.Med V de Rabat sur une période d’un mois. Le recueil des données était fait à l’aide d’un questionnaire rapportant les données démographiques et anamnestiques, les antécédents, la notion d’allergie, les données spécifiques de l’examen clinique, les données para cliniques, la prescription détaillée de l’antibiotique. Les données récoltées ont été ensuite évaluées par un médecin référent, chargé d’indiquer les éventuelles erreurs de traitement. Parmi les infections ayant motivé la prescription des antibiotiques, les affections des systèmes respiratoires et urinaires étaient au premier rang, les familles d’antibiotiques les plus couramment employées sont les pénicillines, les quinolones et les céphalosporines. 74 prescriptions soit (70,5%) étaient à la fois pertinentes et conformes contre 9 prescriptions soit (8,6%) justifiées mais non pertinentes et 6 prescriptions soit (5,7%) étaient jugées injustifiées par le médecin référent par absence d’infection. Les évaluations des pratiques médicales sont rarement menées dans les établissements de santé; c’est dans ce cadre que nous avons voulu nous inscrire en produisant cette étude afin d’améliorer la pertinence de nos prescriptions antibiotiques et d’optimiser leur conformité aux différentes recommandations. PMID:28292124

  20. Synthesis, structure, and bonding in K12Au21Sn4. A polar intermetallic compound with dense Au20 and open AuSn4 layers

    SciTech Connect

    Li, Bin; Kim, Sung-Jin; Miller, Gordon J.; and Corbett, John D.

    2009-10-29

    The new phase K{sub 12}Au{sub 21}Sn{sub 4} has been synthesized by direct reaction of the elements at elevated temperatures. Single crystal X-ray diffraction established its orthorhombic structure, space group Pmmn (No. 59), a = 12.162(2); b = 18.058(4); c = 8.657(2) {angstrom}, V = 1901.3(7) {angstrom}{sup 3}, and Z = 2. The structure consists of infinite puckered sheets of vertex-sharing gold tetrahedra (Au{sub 20}) that are tied together by thin layers of alternating four-bonded-Sn and -Au atoms (AuSn{sub 4}). Remarkably, the dense but electron-poorer blocks of Au tetrahedra coexist with more open and saturated Au-Sn layers, which are fragments of a zinc blende type structure that maximize tetrahedral heteroatomic bonding outside of the network of gold tetrahedra. LMTO band structure calculations reveal metallic properties and a pseudogap at 256 valence electrons per formula unit, only three electrons fewer than in the title compound and at a point at which strong Au-Sn bonding is optimized. Additionally, the tight coordination of the Au framework atoms by K plays an important bonding role: each Au tetrahedra has 10 K neighbors and each K atom has 8-12 Au contacts. The appreciably different role of the p element Sn in this structure from that in the triel members in K{sub 3}Au{sub 5}In and Rb{sub 2}Au{sub 3}Tl appears to arise from its higher electron count which leads to better p-bonding (valence electron concentrations = 1.32 versus 1.22).

  1. Polymers effects on synthesis of AuNPs, and Au/Ag nanoalloys: indirectly generated AuNPs and versatile sensing applications including anti-leukemic agent.

    PubMed

    Jahan, Shanaz; Mansoor, Farrukh; Kanwal, Shamsa

    2014-03-15

    Polymers either serve as shielding or capping agents to restrict the nanoparticle size. This study demonstrates the polymer depositions and their effects in synthesis and sharp stabilization of gold nanoparticles (AuNPs) and to develop gold/silver nanoalloys (Au/Ag nanoalloys). Effects of different polymers are tested to justify their role in synthesis and stability of phloroglucinol (PG) coated AuNPs and Au/Ag nanoalloys. Cationic and anionic i.e. [Polydiallyldimethylammonium](+) (PDDA), [Polyethyleneimine](+) (PEI), [Polystyrene sulfonate](2-) (PSS) and neutral polymer Polychlorotriflouroethylene (PCTFE) produce praiseworthy stable AuNPs and Au/Ag nanoalloy. To prove polymer effects characterization protocols including UV-vis, Fluorescence (PL), IR and AFM imaging are performed to fully investigate the mechanism and size characteristics of these nanoparticles/nanoalloys. In this study sharp size controlling/sheilding effects were observed particularly with cationic polymers simply through the favorable electrostatic interactions with the terminal ends of PG Potent/significant detection of doxorubicin (DOX, an antileukemic agent) via fluorescence resonance energy transfer (FRET) between PEI shielded AuNPs (AuNPEI) and DOX was achieved upto 10 pM level, while PDDA protected AuNPs facilitated the detection of ascorbic acid based on fluorescence enhancement effects in wide range (10-200 nM) and with detection limit of 200 pM. Similarly sensing performance of PEI stabilized Au/Ag nanoalloys on addition of halides (Cl(-), Br(-), I(-)) is evaluated through red shifted SPR along with continuous increase in absorbance and also through AFM. Moreover the addition of halide ions also helped the regeneration of AuNPs by taking away silver from the Au/Ag nanoalloys enabling their detections upto subnanomolar levels.

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

    NASA Astrophysics Data System (ADS)

    Palyanova, Galina A.; Seryotkin, Yurii V.; Kokh, Konstantin A.; Bakakin, Vladimir V.

    2016-09-01

    Au-Ag selenides were synthesized by heating stoichiometric mixtures of elementary substances of initial compositions Ag2-xAuxSe 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 Ag2Se - Ag1.94Au0.06Se, fischesserite Ag3AuSe2 - Ag3.2Au0.8Se2 and gold selenide AuSe - Au0.94Ag0.06Se. Solid solutions and AgAuSe phases were added to 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.

  3. Fluorescence quenching of uranine on confeito-like Au nanoparticles.

    PubMed

    Ujihara, Masaki; Dang, Nhut Minh; Imae, Toyoko

    2014-07-01

    Effect of structure and size of Au nanoparticles (AuNPs) on fluorescence behavior of uranine was examined. Confeito-like AuNPs with different sizes (30 nm, 60 nm and 100 nm, respectively) had plasmon absorption bands at 555, 600 and 660 nm, while the band of spherical AuNP (20 nm in size) was at 525 nm. Fluorescence of uranine was significantly quenched by the small and medium confeito-like AuNPs, and the quenching effect by the large particle was less. In comparison, the spherical AuNP quenched more remarkable than the confeito-like AuNPs. A mechanism of resonance energy transfer from uranine to AuNPs via the surface plasmon was suggested, and the strong quenching effect of the small AuNPs could be explained by the energy transfer from adsorbed uranine molecules to AuNPs. These behaviors indicate that the large confeito-like AuNPs can be a preferable nano-probe and useful for plasmonic devices, which can tune or maintain the fluorescence properties of other markers.

  4. Collision-spike sputtering of Au nanoparticles

    DOE PAGES

    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 this specific 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; the remaindermore » is transported away by the transmitted projectile and the ejecta. 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

  5. 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 this specific 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; the remainder is transported away by the transmitted projectile and the ejecta. The sputter yield of supported nanoparticles is estimated to be around 80% of that of free nanoparticles due to the suppression of forward sputtering.

  6. Collision-spike Sputtering of Au Nanoparticles.

    PubMed

    Sandoval, Luis; Urbassek, Herbert M

    2015-12-01

    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; the remainder is transported away by the transmitted projectile and the ejecta. The sputter yield of supported nanoparticles is estimated to be around 80 % of that of free nanoparticles due to the suppression of forward sputtering.

  7. 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

  8. Monolithic Nanocrystalline Au Fabricated by the Compaction of Nanoscale Foam

    SciTech Connect

    Hodge, A M; Biener, J; Hsiung, L M; Hamza, A V; Satcher Jr., J H

    2004-07-28

    We describe a two-step dealloying/compaction process to produce nanocrystalline Au. First, nanocrystalline/nanoporous Au foam is synthesized by electrochemically-driven dealloying. The resulting Au foams exhibit porosities of 60 and 70% with pore sizes of {approx} 40 and 100 nm, respectively, and a typical grain size of <50 nm. Second, the nanoporous foams are fully compacted to produce nanocrystalline monolithic Au. The compacted Au was characterized by TEM and X-ray diffraction and tested by depth-sensing nanoindentation. The compacted nanocrystalline Au exhibits an average grain size of <50 nm and hardness values ranging from 1.4 to 2.0 GPa, which are up to 4.5 times higher than the hardness values obtained from polycrystalline Au.

  9. Mechanical properties and grindability of experimental Ti-Au alloys.

    PubMed

    Takahashi, Masatoshi; Kikuchi, Masafumi; Okuno, Osamu

    2004-06-01

    Experimental Ti-Au alloys (5, 10, 20 and 40 mass% Au) were made. Mechanical properties and grindability of the castings of the Ti-Au alloys were examined. As the concentration of gold increased to 20%, the yield strength and the tensile strength of the Ti-Au alloys became higher without markedly deteriorating their ductility. This higher strength can be explained by the solid-solution strengthening of the a titanium. The Ti-40%Au alloy became brittle because the intermetallic compound Ti3Au precipitated intensively near the grain boundaries. There was no significant difference in the grinding rate and grinding ratio among all the Ti-Au alloys and the pure titanium at any speed.

  10. Electric Field Induced Surface Modification of Au

    SciTech Connect

    Erchak, A.A.; Franklin, G.F.; Houston, J.E.; Mayer, T.M.; Michalske, T.A.

    1999-02-15

    We discuss the role of localized high electric fields in the modification of Au surfaces with a W probe using the Interfacial Force Microscope. Upon bringing a probe close to a Au surface, we measure both the interfacial force and the field emission current as a function of separation with a constant potential of 100 V between tip and sample. The current initially increases exponentially as the separation decreases. However, at a distance of less than {approximately} 500{angstrom} the current rises sharply as the surface begins to distort and rapidly close the gap. Retraction of the tip before contact is made reveals the formation of a mound on the surface. We propose a simple model, in which the localized high electric field under the tip assists the production of mobile Au adatoms by detachment from surface steps, and a radial field gradient causes a net flux of atoms toward the tip by surface diffusion. These processes give rise to an unstable surface deformation which, if left unchecked, results in a destructive mechanical contact. We discuss our findings with respect to earlier work using voltage pulses in the STM as a means of nanofabrication.

  11. Fahrzeug-Außengeräusch

    NASA Astrophysics Data System (ADS)

    Genuit, Klaus

    Wirtschaftliches Wachstum ist mit steigenden Anforderungen an Mobilität und Transport verknüpft. Zukunftsorientierter Fortschritt muss hierbei die Wirkungen von Verkehrsgeräuschen auf Mensch und Umwelt berücksichtigen, um eine hohe Lebensqualität sicherstellen zu können. Mehr als die Hälfte der Bevölkerung in der EU fühlt sich durch Verkehrslärm belästigt oder befürchtet direkte Auswirkungen auf Gesundheit und Wohlbefinden. Nach einer repräsentativen Umfrage des Umweltbundesamtes fühlen sich durch Straßenverkehrslärm 20 % der Bevölkerung stark oder wesentlich belästigt (UBA 2008). Daher ist das "Fahrzeug-Außengeräusch“ Gegenstand zahlreicher Forschungsprojekte zu Themen wie Identifikation wesentlicher Geräuschquellen, Zusammenhang zwischen Verkehrsgeräusch und Belästigung, medizinische Folgen aufgrund chronischer Lärmexposition, Geräuschqualität, Entwicklung neuer Methoden und Technologien zur Fahrzeug-Außengeräuschmessung und das Fahrzeug-Außengeräusch als wesentliches Produktattribut, das aktiver Gestaltung bedarf.

  12. 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.

  13. Étude par chromatographie gazeuse inverse, à concentration finie, des propriétés de surface d'échantillons obtenus par traitement thermique de la goethite : distribution des sites d'adsorption des alcanes

    NASA Astrophysics Data System (ADS)

    Brendlé, E.; Balard, H.; Papirer, E.

    1998-07-01

    Inverse Gas Chromatography (IGC), at finite concentration conditions, was applied for the evaluation of the surface properties of hematite samples obtained by heat treatment of goethite. From the alkane adsorption isotherms, the distribution of surface sites according to the adsorption energy is determined. It is shown that the surface of hematite undergoes significant changes when heated up to 500 circC. La chromatographie Gazeuse Inverse (CGI), à concentration finie, a été utilisée pour évaluer les propriétés de surface d'échantillons d'hématite obtenus par traitement thermique de la goethite. A partir des isothermes d'adsorption des alcanes, on détermine la courbe de distribution des sites de surface en fonction de l'énergie d'adsorption de molécules sondes. On montre que ces courbes évoluent en fonction du traitement thermique de la goethite et traduisent une importante modification de surface de l'hématite formée après un chauffage à 500 circC.

  14. PION INTERFEREMETRY FROM P+P TO AU+AU IN STAR.

    SciTech Connect

    CHAJECKI, Z.

    2005-08-15

    The geometric substructure of the particle-emitting source has been characterized via two-particle interferometry by the STAR collaboration for all energies and colliding systems at RHIC. We present systematic studies of charged pion interferometry. The collective nature of the source is revealed through the m{sub T} dependence of HBT radii for all particle types. Preliminary results suggest a scaling in the pion HBT radii with overall system size, as central Au+Au collisions are compared to peripheral collisions as well as with Cu+Cu and even with d+Au and p+p collisions, naively suggesting comparable flow strength in all systems. To probe this issue in greater detail, multidimensional correlation functions are studied using a spherical decomposition method. This allows clear identification of source anisotropy and, for the light systems, the presence of significant long-range non-femtoscopic correlations.

  15. Simulation of Electric Field in Semi Insulating Au/CdTe/Au Detector under Flux

    SciTech Connect

    Franc, J.; James, R.; Grill, R.; Kubat, J.; Belas, E.; Hoschl, P.; Moravec, P.; Praus, P.

    2009-08-02

    We report our simulations on the profile of the electric field in semi insulating CdTe and CdZnTe with Au contacts under radiation flux. The type of the space charge and electric field distribution in the Au/CdTe/Au structure is at high fluxes result of a combined influence of charge formed due to band bending at the electrodes and from photo generated carriers, which are trapped at deep levels. Simultaneous solution of drift-diffusion and Poisson equations is used for the calculation. We show, that the space charge originating from trapped photo-carriers starts to dominate at fluxes 10{sup 15}-10{sup 16}cm{sup -2}s{sup -1}, when the influence of contacts starts to be negligible.

  16. Spin transport in Au films: An investigation by spin pumping

    NASA Astrophysics Data System (ADS)

    Montoya, Eric; Kardasz, Bartek; Burrowes, Capucine; Huttema, Wendell; Girt, Erol; Heinrich, Bret

    2012-04-01

    The thickness and temperature dependence of spin transport in Au has been investigated in multilayer films via the spin pumping effect. To study spin transport in Au, single layer GaAs/16Fe/(d)Au(001) and double layer GaAs/16Fe/(d)Au/12Fe/20Au(001) were investigated using ferromagnetic resonance (FMR), where d = 20, 300, and the numerals preceding Fe and Au indicate the layer thickness in atomic layers (AL). FMR measurements were performed at frequencies ranging from 27.3 to 40.6 GHz and at temperatures ranging from 88 to 295 K. By measuring the total Gilbert damping in the 16Fe layer as a function of d and temperature for both single and double magnetic layer structures and by utilizing the spin diffusion equation, one is able to determine the spin mixing conductance, g↑↓, at the Fe/Au interface, and the spin flip relaxation time, τsf, in Au as a function of temperature. The temperature dependence of the momentum relaxation time, τm, in Au was measured independently by means of electron transport measurements in a van der Pauw configuration. It has been found that the spin flip relaxation time, τsf, in Au is dominated by phonon interactions.

  17. Photoemission study of Au on a-Si:H

    NASA Astrophysics Data System (ADS)

    Pi, Tun-Wen; Yang, A.-B.; Olson, C. G.; Lynch, D. W.

    1990-11-01

    We report a high-resolution photoemission study of Au evaporated on rf-sputtered a-Si:H at room temperature. Three regions of coverage can be classified according to the behavior of the valence-band and core-level spectra: an unreacted region with an equivalent thickness of 2 Å, followed by an intermixed Au/a-Si overlayer (~9 Å), and a dual-phase region at higher coverage. Au adatoms are dispersed in the unreacted region. They subsequently cluster in the intermixed region, where they attach to Si atoms that are not hydrogen bonded, suggesting that the intermixed Si is mainly from those that have dangling bonds. In the dual-phase region, two sets of Au 4f core levels evolve with higher binding energy, one from Au intermixed with Si, and the lower one exhibiting pure gold character. The interface eventually ends up with the sequence: a-Si:H(sub.)+(pure Au mixed with intermixed Au/Si)+(vac). This is unlike the case of Au on c-Si, which has a pure gold layer sandwiched by intermixed Au/Si complexes along the surface normal. Traces of silicon atoms on top of composite surfaces appear even at the highest coverage, 205 Å, of the gold deposit. The applicability of the four models previously used for the Au/c-Si interface is also briefly discussed.

  18. Charged particle multiplicities in ultra-relativistic Au+Au and Cu+Cu collisions.

    SciTech Connect

    Alver, B.; Back, B. B.; Baker, M. D.; Ballintijn, M.; Barton, D. S.; PHOBOS Collaboration; Physics; Massachusetts Inst. of Tech.; BNL

    2006-01-01

    The PHOBOS collaboration has carried out a systematic study of charged particle multiplicities in Cu+Cu and Au+Au collisions at the Relativistic Heavy-Ion Collider (RHIC) at Brookhaven National Laboratory. A unique feature of the PHOBOS detector is its ability to measure charged particles over a very wide angular range from 0.5 to 179.5 deg. corresponding to |eta|<5.4. The general features of the charged particle multiplicity distributions as a function of pseudo-rapidity, collision energy and centrality, as well as system size, are discussed.

  19. Gold nanoparticle (AuNPs) and gold nanopore (AuNPore) catalysts in organic synthesis.

    PubMed

    Takale, Balaram S; Bao, Ming; Yamamoto, Yoshinori

    2014-04-07

    Organic synthesis using gold has gained tremendous attention in last few years, especially heterogeneous gold catalysis based on gold nanoparticles has made its place in almost all organic reactions, because of the robust and green nature of gold catalysts. In this context, gold nanopore (AuNPore) with a 3D metal framework is giving a new dimension to heterogeneous gold catalysts. Interestingly, AuNPore chemistry is proving better than gold nanoparticles based chemistry. In this review, along with recent advances, major discoveries in heterogeneous gold catalysis are discussed.

  20. 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.

  1. Two-Particle Interferometry of 200 GeV Au+Au Collisions at PHENIX

    SciTech Connect

    Heffner, M

    2004-04-19

    The PHENIX experiment has measured pion-pion, kaon-kaon, and proton-proton correlations in Au+Au collisions at {radical}S{sub NN} = 200GeV. The correlations are fit to extract radii using both the Bowler Coulomb correction and full calculation of the two-particle wave function. The resulting radii are similar for all three species and decrease with increasing k{sub t} as expected for collective flow. The R{sub out} and R{sub side} radii are approximately equal indicating a short emission duration.

  2. Elliptic Flow in Au+Au Collisions at √sNN = 130 GeV

    NASA Astrophysics Data System (ADS)

    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, Yu. 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. Kh.; 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, Yu. A.; Matyushevski, E. A.; McParland, C.; McShane, T. S.; Meier, J.; Melnick, Yu.; 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.

    2001-01-01

    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 sNN = 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.

  3. Reviewing hadron production at SIS energies featuring the new HADES Au + Au data

    NASA Astrophysics Data System (ADS)

    Lorenz, M.

    2014-11-01

    We present the first preliminary results on the production of hadrons with strangeness content (K+, K-, Ks0 , Λ and ϕ) in Au + Au collisions at 1.23 A GeV incident energy measured with HADES. At the corresponding center of mass energy of √{ s} = 2.4 GeV all hadrons carrying strangeness are produced below their free nucleon-nucleon threshold. While the K- /K+ ratio nicely fits the trend observed at higher energies, we find a strong rise of the ϕ /K- ratio. The presented particle ratios are compared to a statistical model fit and put into the context of previously obtained systematics on strangeness production.

  4. 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.

  5. An atomistic view of the interfacial structures of AuRh and AuPd nanorods

    NASA Astrophysics Data System (ADS)

    Chantry, Ruth L.; Atanasov, Ivailo; Siriwatcharapiboon, Wilai; Khanal, Bishnu P.; Zubarev, Eugene R.; Horswell, Sarah L.; Johnston, Roy L.; Li, Z. Y.

    2013-07-01

    In this work we address the challenge of furthering our understanding of the driving forces responsible for the metal-metal interactions in industrially relevant bimetallic nanocatalysts, by taking a comparative approach to the atomic scale characterization of two core-shell nanorod systems (AuPd and AuRh). Using aberration-corrected scanning transmission electron microscopy, we show the existence of a randomly mixed alloy layer some 4-5 atomic layers thick between completely bulk immiscible Au and Rh, which facilitates fully epitaxial overgrowth for the first few atomic layers. In marked contrast in AuPd nanorods, we find atomically sharp segregation resulting in a quasi-epitaxial, strained interface between bulk miscible metals. By comparing the two systems, including molecular dynamics simulations, we are able to gain insights into the factors that may have influenced their structure and chemical ordering, which cannot be explained by the key structural and energetic parameters of either system in isolation, thus demonstrating the advantage of taking a comparative approach to the characterization of complex binary systems. This work highlights the importance of achieving a fundamental understanding of reaction kinetics in realizing the atomically controlled synthesis of bimetallic nanocatalysts.In this work we address the challenge of furthering our understanding of the driving forces responsible for the metal-metal interactions in industrially relevant bimetallic nanocatalysts, by taking a comparative approach to the atomic scale characterization of two core-shell nanorod systems (AuPd and AuRh). Using aberration-corrected scanning transmission electron microscopy, we show the existence of a randomly mixed alloy layer some 4-5 atomic layers thick between completely bulk immiscible Au and Rh, which facilitates fully epitaxial overgrowth for the first few atomic layers. In marked contrast in AuPd nanorods, we find atomically sharp segregation resulting in a quasi

  6. Domain wall dynamics in a spin-reorientation transition system Au/Co/Au

    SciTech Connect

    Roy, Sujoy; Seu, Keoki; Turner, Joshua J.; Park, Sungkyun; Kevan, Steve; Falco, Charles M.

    2009-05-14

    We report measurements of domain wall dynamics in an ultrathin Au/Co/Au system that exhibits a spin reorientation phase transition as a function of temperature.The domain walls exhibit cooperative motion throughout the temperature range of 150 - 300 K. The decay times were found to exhibit a maximum at the transition temperature. The slowdown has been explained as due to formation of a double well in the energy landscape by the different competing interactions. Our results show that the complex, slow dynamics can provide a more fundamental understanding of magnetic phase transitions.

  7. Collective motion in selected central collisions of Au on Au at 150A MeV

    NASA Astrophysics Data System (ADS)

    Jeong, S. C.; Herrmann, N.; Fan, Z. G.; Freifelder, R.; Gobbi, A.; Hildenbrand, K. D.; Krämer, M.; Randrup, J.; Reisdorf, W.; Schüll, D.; Sodan, U.; Teh, K.; Wessels, J. P.; Pelte, D.; Trzaska, M.; Wienold, T.; Alard, J. P.; Amouroux, V.; Basrak, Z.; Bastid, N.; Belayev, I. M.; Berger, L.; Bini, M.; Blaich, Th.; Boussange, S.; Buta, A.; Čaplar, R.; Cerruti, C.; Cindro, N.; Coffin, J. P.; Dona, R.; Dupieux, P.; Erö, J.; Fintz, P.; Fodor, Z.; Fraysse, L.; Frolov, S.; Grigorian, Y.; Guillaume, G.; Hölbling, S.; Houari, A.; Jundt, F.; Kecskemeti, J.; Koncz, P.; Korchagin, Y.; Kotte, R.; Kuhn, C.; Ibnouzahir, M.; Legrand, I.; Lebedev, A.; Maguire, C.; Manko, V.; Maurenzig, P.; Mgebrishvili, G.; Mösner, J.; Moisa, D.; Montarou, G.; Montbel, I.; Morel, P.; Neubert, W.; Olmi, A.; Pasquali, G.; Petrovici, M.; Poggi, G.; Rami, F.; Ramillien, V.; Sadchikov, A.; Seres, Z.; Sikora, B.; Simion, V.; Smolyankin, S.; Tezkratt, R.; Vasiliev, M. A.; Wagner, P.; Wilhelmi, Z.; Wohlfarth, D.; Zhilin, A. V.

    1994-05-01

    Using the FOPI facility at GSI Darmstadt complete data of Au on Au collisions at 150A MeV were collected for charged products (Z=1-15) at laboratory angles 1°<=Θlab<=30°. Central collisions were selected by applying various criteria. The kinetic energy spectra of fragments from an isolated midrapidity source are investigated in detail for center-of-mass angles 25°<=Θc.m.<=45°. The heavy products (Z>=3) are used to determine the collective energy which is found to be at least 10A MeV.

  8. Centrality and Transverse Momentum Dependence of HBT Radii in Au+Au Collisions

    NASA Astrophysics Data System (ADS)

    Schweid, Benjamin

    2017-01-01

    The expansion dynamics of relativistic heavy ion collisions is influenced by the transport properties of the created medium, as well as the path of the reaction trajectory in the (T ,μB)-plane. Such an influence can manifest as quantifiable changes in the magnitude of the space-time extent of the emission source, characterized by the so-called HBT radii Rout, Rside and Rlong. We will present and discuss recent HBT measurements which extend the upper momentum range of measurements that have been made in the STAR detector for Au+Au collisions at several collision centralities and beam energies.

  9. Onset of nuclear vaporization in [sup 197]Au+[sup 197]Au collisions

    SciTech Connect

    Tsang, M.B.; Hsi, W.C.; Lynch, W.G.; Bowman, D.R.; Gelbke, C.K.; Lisa, M.A.; Peaslee, G.F. ); Kunde, G.J.; Begemann-Blaich, M.L.; Hofmann, T.; Hubele, J.; Kempter, J.; Kreutz, P.; Kunze, W.D.; Lindenstruth, V.; Lynen, U.; Mang, M.; Mueller, W.F.J.; Neumann, M.; Ocker, B.; Ogilvie, C.A.; Pochodzalla, J.; Rosenberger, F.; Sann, H.; Schuettauf, A.; Serfling, V.; Stroth, J.; Trautmann, W.; Tucholski, A.; Woerner, A.; Zude, E.; Zwieglinski, B. ); Aiello, S.; Imme, G.; Pappalardo, V.; Raciti, G. ); Charity, R.J.; Sobotka, L.G. ); Iori, I.; Moroni, A.; Scardoni, R.; Ferr

    1993-09-06

    Multifragmentation has been measured for [sup 197]Au+[sup 197]Au collisions at [ital E]/[ital A]=100, 250, and 400 MeV. The mean fragment multiplicity increases monotonically with the charged particle multiplicity at [ital E]/[ital A]=100 MeV, but decreases for central collisions with incident energy, consistent with the onset of nuclear vaporization. Molecular dynamics calculations follow some trends but underpredict the observed fragment multiplicities. Including the statistical decay of excited residues improves the agreement for peripheral collisions but worsens it for central collisions.

  10. Manipulation of superparamagnetic beads on patterned Au/Co/Au multilayers with perpendicular magnetic anisotropy

    NASA Astrophysics Data System (ADS)

    Jarosz, A.; Holzinger, D.; Urbaniak, M.; Ehresmann, A.; Stobiecki, F.

    2016-08-01

    The magnetophoresis of water-suspended 4 μm-diameter superparamagnetic beads above topographically patterned, sputter deposited Ti(4 nm)/Au(60 nm)/[Co(0.7 nm)/Au(1 nm)] × 3 multilayers with perpendicular magnetic anisotropy was investigated. The results impressively demonstrate that the magnetic stray field landscape above the stripe structure when superimposed with an external, slowly rotating, field enables the directed transport of magnetic beads across the stripe panel with velocities up to 12 μm s-1.

  11. Effect of Au clustering on ferromagnetism in Au doped TiO2 films: theory and experiments investigation

    NASA Astrophysics Data System (ADS)

    Zou, Zhaorui; Zhou, Zhongpo; Wang, Haiying; Yang, Zongxian

    2017-01-01

    In this paper, we investigated the physical properties especially the magnetic properties of the TiO2 films and Au cluster doped TiO2 films fabricated by sol-gel and sputtering methods combined experiments and first-principles calculations. All the samples annealed under air and N2 atmosphere respectively exhibit room temperature ferromagnetism with the crystal phase of anatase. The values of the saturation magnetizations are in the order of Au δ-doped TiO2 (annealed in N2)>undoped TiO2 (annealed in air)>Au δ-doped TiO2 (annealed in air). The first principles calculation results show that the formation energy of Au cluster doped TiO2 films is lower than that of the oxygen vacancy and Au cluster codoped TiO2 films. The effects of the Au cluster dopant are the retard of the formation of surface oxygen vacancy and the electrons transfer from 3d states of Ti atoms to Au 5d states in Au cluster doped TiO2 films. The codoping of surface oxygen vacancies, bulk oxygen vacancies and Au clusters led to the spin-split of Ti 3d and O 2p in Au cluster doped TiO2 films (annealed in N2) which yield the highest saturation magnetization.

  12. Au/Pd core-shell nanoparticles with varied hollow Au cores for enhanced formic acid oxidation

    PubMed Central

    2013-01-01

    A facile method has been developed to synthesize Au/Pd core-shell nanoparticles via galvanic replacement of Cu by Pd on hollow Au nanospheres. The unique nanoparticles were characterized by X-ray diffraction, X-ray photoelectron spectroscopy, transmission electron microscopy, ultraviolet–visible spectroscopy, and electrochemical measurements. When the concentration of the Au solution was decreased, grain size of the polycrystalline hollow Au nanospheres was reduced, and the structures became highly porous. After the Pd shell formed on these Au nanospheres, the morphology and structure of the Au/Pd nanoparticles varied and hence significantly affected the catalytic properties. The Au/Pd nanoparticles synthesized with reduced Au concentrations showed higher formic acid oxidation activity (0.93 mA cm-2 at 0.3 V) than the commercial Pd black (0.85 mA cm-2 at 0.3 V), suggesting a promising candidate as fuel cell catalysts. In addition, the Au/Pd nanoparticles displayed lower CO-stripping potential, improved stability, and higher durability compared to the Pd black due to their unique core-shell structures tuned by Au core morphologies. PMID:23452438

  13. Au/Pd core-shell nanoparticles with varied hollow Au cores for enhanced formic acid oxidation

    NASA Astrophysics Data System (ADS)

    Hsu, Chiajen; Huang, Chienwen; Hao, Yaowu; Liu, Fuqiang

    2013-03-01

    A facile method has been developed to synthesize Au/Pd core-shell nanoparticles via galvanic replacement of Cu by Pd on hollow Au nanospheres. The unique nanoparticles were characterized by X-ray diffraction, X-ray photoelectron spectroscopy, transmission electron microscopy, ultraviolet-visible spectroscopy, and electrochemical measurements. When the concentration of the Au solution was decreased, grain size of the polycrystalline hollow Au nanospheres was reduced, and the structures became highly porous. After the Pd shell formed on these Au nanospheres, the morphology and structure of the Au/Pd nanoparticles varied and hence significantly affected the catalytic properties. The Au/Pd nanoparticles synthesized with reduced Au concentrations showed higher formic acid oxidation activity (0.93 mA cm-2 at 0.3 V) than the commercial Pd black (0.85 mA cm-2 at 0.3 V), suggesting a promising candidate as fuel cell catalysts. In addition, the Au/Pd nanoparticles displayed lower CO-stripping potential, improved stability, and higher durability compared to the Pd black due to their unique core-shell structures tuned by Au core morphologies.

  14. Au/Pd core-shell nanoparticles with varied hollow Au cores for enhanced formic acid oxidation.

    PubMed

    Hsu, Chiajen; Huang, Chienwen; Hao, Yaowu; Liu, Fuqiang

    2013-03-01

    A facile method has been developed to synthesize Au/Pd core-shell nanoparticles via galvanic replacement of Cu by Pd on hollow Au nanospheres. The unique nanoparticles were characterized by X-ray diffraction, X-ray photoelectron spectroscopy, transmission electron microscopy, ultraviolet-visible spectroscopy, and electrochemical measurements. When the concentration of the Au solution was decreased, grain size of the polycrystalline hollow Au nanospheres was reduced, and the structures became highly porous. After the Pd shell formed on these Au nanospheres, the morphology and structure of the Au/Pd nanoparticles varied and hence significantly affected the catalytic properties. The Au/Pd nanoparticles synthesized with reduced Au concentrations showed higher formic acid oxidation activity (0.93 mA cm-2 at 0.3 V) than the commercial Pd black (0.85 mA cm-2 at 0.3 V), suggesting a promising candidate as fuel cell catalysts. In addition, the Au/Pd nanoparticles displayed lower CO-stripping potential, improved stability, and higher durability compared to the Pd black due to their unique core-shell structures tuned by Au core morphologies.

  15. Electrostatic assembles and optical properties of Au CdTe QDs and Ag/Au CdTe QDs

    NASA Astrophysics Data System (ADS)

    Yang, Dongzhi; Wang, Wenxing; Chen, Qifan; Huang, Yuping; Xu, Shukun

    2008-09-01

    Au-CdTe and Ag/Au-CdTe assembles were firstly investigated through the static interaction between positively charged cysteamine-stabilized CdTe quantum dots (QDs) and negatively charged Au or core/shell Ag/Au nano-particles (NCs). The CdTe QDs synthesized in aqueous solution were capped with cysteamine which endowed them positive charges on the surface. Both Au and Ag/Au NCs were prepared through reducing precursors with gallic acid obtained from the hydrolysis of natural plant poly-phenols and favored negative charges on the surface of NCs. The fluorescence spectra of CdTe QDs exhibited strong quenching with the increase of added Au or Ag/Au NCs. Railey resonance scattering spectra of Au or Ag/Au NCs increased firstly and decreased latter with the concentration of CdTe QDs, accompanied with the solution color changing from red to purple and colorless at last. Experimental results on the effects of gallic acid, chloroauric acid tetrahydrate and other reagents demonstrated the static interaction occurred between QDs and NCs. This finding reveals the possibilities to design and control optical process and electromagnetic coupling in hybrid structures.

  16. Le traitement des donnees linguistiques non standard. (Actes des Rencontres Besancon-Neuchatel (Neuchatel, 29-30 janvier, 1993). (The Treatment of Non-Standard Linguistic Data). Proceedings of the Besancon-Neuchatel Conference (Neuchatel, Switzerland, January 29-30, 1993).

    ERIC Educational Resources Information Center

    Reichler-Beguelin, Marie-Jose, Ed.

    1993-01-01

    Papers from the conference on linguistic anomaly include: "La definition interactive de la deviance en situation exolingue et bilingue" ("The Interactive Definition of Deviation in Exolinguistic and Bilingual Situations") (Bernard Py); "La negociation ratee: pratiques sociales et methodes interactives du traitement de la…

  17. Atomic and molecular adsorption on Au(111)

    SciTech Connect

    Santiago-Rodríguez, Yohaselly; Herron, Jeffrey A.; Curet-Arana, María C.; Mavrikakis, Manos

    2014-09-01

    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: NH3 < NO < CO < CH3 < HCO < NH2 < COOH < OH < HCOO < CNH2 < H < N < NH < NOH < COH < Cl,< HCO3 < CH2 < CN b HNO < O < F < S < C < CH. Although the atomic species preferred to bind at the three-fold fcc site, no tendency was observed in site preference for the molecular species and fragments. The intramolecular and adsorbate-surface vibrational frequencies were calculated for all the adsorbates on their most energetically stable adsorption site. Most of the theoretical binding energies and frequencies agreed with experimental values reported in the literature. In general, the values obtained with the PW91 functional are more accurate than RPBE in reproducing these experimental binding energies. The energies of the adsorbed species were used to calculate the thermochemical potential energy surfaces for decomposition of CO, NO, N2, NH3 and CH4, oxidation of CO, and hydrogenation of CO, CO2 and NO, giving insight into the thermochemistry of these reactions on gold nanoparticles. These potential energy surfaces demonstrated that: the decomposition of species is not energetically favorable on Au(111); the desorption of NH3, 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.

  18. Ultranarrow AuPd and Al wires

    SciTech Connect

    Altomare, Fabio; Chang, Albert M.; Melloch, Michael R.; Hong Yuguang; Tu, Charles W.

    2005-04-25

    In this letter, we discuss a versatile template technique aimed to the fabrication of sub-10 nm wide wires. Using this technique, we have measured AuPd wires, 12 nm wide and as long as 20 {mu}m. Even materials that form a strong superficial oxide, and thus not suited to be used in combination with other techniques, can be employed. In particular, we have measured Al wires, with lateral width smaller or comparable to 10 nm, and length exceeding 10 {mu}m.

  19. Observation of sputtering damage on Au(111)

    NASA Astrophysics Data System (ADS)

    Michely, Thomas; Besocke, Karl H.; Comsa, George

    1990-05-01

    The morphology of a Au(111) surface has been observed with the STM (scanning tunneling microscope) after ion bombardment with 2.5 keV Ne + ions at about 400 K. Mostly triangular and hexagonal shaped vacancy islands are seen in the STM topographs. They are bounded by monatomic steps, oriented along the closed packed <110> directions. The general morphology confirms the conclusions inferred from TEAS (thermal energy atom scattering) measurements on ion bombarded Pt(111) surfaces. The observation of a propensity for the formation of {100} microfacetted <110> ledges is discussed.

  20. Problématique de la prise en charge des cancers du sein au Sénégal: une approche transversale

    PubMed Central

    Gueye, Serigne Modou Kane; Gueye, Mamour; Coulbary, Sophie Aminata; Diouf, Alassane; Moreau, Jean Charles

    2016-01-01

    L’heure où les thérapeutiques innovantes se multiplient dans le cancer du sein, des pays moins nantis comme le Sénégal accusent encore un retard considérable dans la prise en charge globale de ce type de cancer. Au Sénégal, même si la prise en charge des cancers du sein avancés est actuellement bien codifiée, les résultats en terme de survie et de morbidités sont encore médiocres vu les retards diagnostiques et les traitements mutilants, parfois onéreux et mal tolérés, devenus nécessaires. Pour ces cancers avancés, les défis qui restent à relever résident dans l’érection de centres de soins palliatifs et le développement de la pluridisciplinarité pour améliorer la qualité de vie et l’accompagnement des malades. En revanche, pour les cancers infracliniques ou potentiellement guérissables, les défis restent immenses car il s’agira de les dépister, de bien les localiser et les diagnostiquer aussitôt (biopsie écho guidée ou stéréotaxique) mais également de les opérer de façon précise et entière (repérage – exérèse in sano et radiographie de pièce opératoire) tout en limitant les complications comme celles du curage classique (biopsie du ganglion sentinelle). Il s’agit là autant d’objectifs auxquels nos structures de santé ne sont pas toujours préparées. Cette mise au point est une analyse situationnelle sur les écueils contextuels qui grèvent encore la prise en charge globale des cancers du sein au Sénégal. PMID:28154696

  1. Evaluation of the Olympus AU 400 clinical chemistry analyzer.

    PubMed

    Bilić, A; Alpeza, I; Rukavina, A S

    2000-01-01

    The performance of the Olympus AU 400 clinical chemistry analyzer was evaluated according to the guidelines of the European Committee for Clinical Laboratory Standards. The following analytes were tested: glucose, urea, creatinine, calcium, AST, ALT, CK, LDH, ALP and amylase. The Olympus AU 400 was compared with the Olympus AU 800. Coefficients of correlation showed high correlation between the compared analyzers. Other performances (intra- and inter-assay variation, carry-over and interferences) of the analyzer were satisfactory.

  2. Enhanced Photoresponse of Conductive Polymer Nanowires Embedded with Au Nanoparticles.

    PubMed

    Zhang, Junchang; Zhong, Liubiao; Sun, Yinghui; Li, Anran; Huang, Jing; Meng, Fanben; Chandran, Bevita K; Li, Shuzhou; Jiang, Lin; Chen, Xiaodong

    2016-04-20

    A conductive polymer nanowire embedded with a 1D Au nanoparticle chain with defined size, shape, and interparticle distance is fabricated which demonstrates enhanced photoresponse behavior. The precise and controllable positioning of 1D Au nanoparticle chain in the conductive polymer nanowire plays a critical role in modulating the photoresponse behavior by excitation light wavelength or power due to the coupled-plasmon effect of 1D Au nanoparticle chain.

  3. RHIC performance for FY2011 Au+Au heavy ion run

    SciTech Connect

    Marr, G.; Ahrens, L.; Bai, M.; Beebe-Wang, J.; Blackler, I.; Blaskiewicz, M.; Brennan, J.M.; Brown, K.A.; Bruno, D.; Butler, J.; Carlson, C.; Connolly, R.; D'Ottavio, T.; Drees, K.A.; Fedotov, A.V.; Fischer, W.; Fu, W.; Gardner, C.J.; Gassner, D.M.; Glenn, J.W.; Gu, X.; Harvey, M.; Hayes, T.; Hoff, L.; Huang, H.; Ingrassia, P.F.; Jamilkowski, J.P.; Kling, N.; Lafky, M.; Laster, J.S.; Liu, C.; Luo, Y.; Mapes, M.; Marusic, A.; Mernick, K.; Michnoff, R.J.; Minty, M.G.; Montag, C.; Morris, J.; Naylor, C.; Nemesure, S.; Polizzo, S.; Ptitsyn, V.; Robert-Demolaize, G.; Roser, T.; Sampson, P.; Sandberg, J.; Schoefer, V.; Schultheiss, C.; Severino, F.; Shrey, T.; Smith, K.; Steski, D.; Tepikian, S.; Thieberger, P.; Trbojevic, D.; Tsoupas, N.; Tuozzolo, J.E.; VanKuik, B.; Wang, G.; Wilinski, M.; Zaltsman, A.; Zeno, K.; Zhang, S.Y.

    2011-09-04

    Following the Fiscal Year (FY) 2010 (Run-10) Relativistic Heavy Ion Collider (RHIC) Au+Au run, RHIC experiment upgrades sought to improve detector capabilities. In turn, accelerator improvements were made to improve the luminosity available to the experiments for this run (Run-11). These improvements included: a redesign of the stochastic cooling systems for improved reliability; a relocation of 'common' RF cavities to alleviate intensity limits due to beam loading; and an improved usage of feedback systems to control orbit, tune and coupling during energy ramps as well as while colliding at top energy. We present an overview of changes to the Collider and review the performance of the collider with respect to instantaneous and integrated luminosity goals. At the conclusion of the FY 2011 polarized proton run, preparations for heavy ion run proceeded on April 18, with Au+Au collisions continuing through June 28. Our standard operations at 100 GeV/nucleon beam energy was bracketed by two shorter periods of collisions at lower energies (9.8 and 13.5 GeV/nucleon), continuing a previously established program of low and medium energy runs. Table 1 summarizes our history of heavy ion operations at RHIC.

  4. Photoionization of Au+ ions and developments in the synthesis of the metallofullerene Au@C60

    NASA Astrophysics Data System (ADS)

    Bogolub, Kyren; Macaluso, David; Mueller, Allison; Johnson, Andrea; Müller, Alfred; Schippers, Stefan; Hellhund, Jonas; Borovik, Alexander; Anders, Andre; Aguilar, Alex; Kilcoyne, A. L. David

    2014-05-01

    Single photoionization of Au+ ions was investigated via the merged-beams technique at AMO Beamline 10.0.1.2 of the Advanced Light Source at Lawrence Berkeley National Laboratory. The relative single photoionization yield was measured as a function of photon energy in the 45 eV to 120 eV energy range. These measurements were made in preparation for future photoionization studies of the endohedral metallofullerene Au@C60, the production of which was also investigated. In proof-of-principle measurements a mass-resolved beam of Au@C60+was produced with a primary ion beam current in the single picoamp range without optimization of the ion source or synthesis parameters. Plans are presented for improved metallofullere production yield to be used in photoionization measurements of the endohedral fullerene ions in conjunction with the continuing study of pure Au. We would like to acknowledge the generous sharing of equipment vital to this work by Andre Anders, the Plasma Applications group leader at the Advanced Light Source, LBNL.

  5. An atomistic view of the interfacial structures of AuRh and AuPd nanorods.

    PubMed

    Chantry, Ruth L; Atanasov, Ivailo; Siriwatcharapiboon, Wilai; Khanal, Bishnu P; Zubarev, Eugene R; Horswell, Sarah L; Johnston, Roy L; Li, Z Y

    2013-08-21

    In this work we address the challenge of furthering our understanding of the driving forces responsible for the metal-metal interactions in industrially relevant bimetallic nanocatalysts, by taking a comparative approach to the atomic scale characterization of two core-shell nanorod systems (AuPd and AuRh). Using aberration-corrected scanning transmission electron microscopy, we show the existence of a randomly mixed alloy layer some 4-5 atomic layers thick between completely bulk immiscible Au and Rh, which facilitates fully epitaxial overgrowth for the first few atomic layers. In marked contrast in AuPd nanorods, we find atomically sharp segregation resulting in a quasi-epitaxial, strained interface between bulk miscible metals. By comparing the two systems, including molecular dynamics simulations, we are able to gain insights into the factors that may have influenced their structure and chemical ordering, which cannot be explained by the key structural and energetic parameters of either system in isolation, thus demonstrating the advantage of taking a comparative approach to the characterization of complex binary systems. This work highlights the importance of achieving a fundamental understanding of reaction kinetics in realizing the atomically controlled synthesis of bimetallic nanocatalysts.

  6. Aspects épidémiologique, clinique, thérapeutique et évolutif de la maladie de Basedow en Médecine Interne au CHU Ledantec Dakar (Sénégal)

    PubMed Central

    Diagne, Nafissatou; Faye, Atoumane; Ndao, Awa Cheikh; Djiba, Boundia; Kane, Baidy Sy; Ndongo, Souhaibou; Pouye, Abdoulaye

    2016-01-01

    La maladie de Basedow est une affection auto immune associant une thyrotoxicose à des manifestations de fréquence variable comme le goitre, l'ophtalmopathie et le myxœdème prétibial. Son diagnostic est souvent facile, tandis que sa prise en charge demeure encore difficile. L'instauration d'un traitement médical simple expose à un risque de récidive. Au Sénégal et en Afrique Sub-saharienne peu d'études ont porté sur la maladie de Basedow. L'objectif de l'étude était de décrire les aspects épidémiologique, clinique, thérapeutique et évolutif de la maladie de Basedow en milieu hospitalier à Dakar. Il s'agissait d'une étude rétrospective menée du 1er janvier 2010 au 31 décembre 2013 dans le service de Médecine Interne du centre hospitalier universitaire Aristide Le Dantec. Durant la période, 108 patients suivis en consultation externe pour maladie de Basedow, ont été inclus sur un total de 834 patients suivis en consultation externe. le diagnostic a été retenu devant les signes cliniques, biologiques et immunologiques. Cent huit patients, atteints de maladie de Basedow ont été inclus sur un total de 834 consultations. Le sex ratio était de 7,3 et la moyenne d'âge de 34,6 ans. Les principaux motifs de consultation étaient : les palpitations et l'amaigrissement dans respectivement 46,3% et 39,8% des cas. Le syndrome de thyrotoxicose était présent chez 93,5% des patients, un goitre était noté chez 87% des patients et une exophtalmie chez 78,7% des patients. La principale complication était à type de cardiothyréose retrouvée chez 11,1% des patients. Tous les patients ont eu un traitement par antithyroïdiens de synthèse. L'évolution a été favorable dans 19,4% des cas. Une récidive à été notée dans 57% des cas et dans 23,1% des cas les patients ont été perdus de vue. La maladie de Basedow est la cause de la plus fréquente d'hyperthyroïdie. Le tableau est dominé par les manifestations cliniques liées à l'hyper m

  7. Divided café-au-lait macule of the mouth.

    PubMed

    Sergay, Amanda; Silverberg, Nanette B

    2007-05-01

    We describe a 4-year-old, otherwise healthy boy with a congenital history of a perioral and labial segmental café-au-lait macule, who was noted to have unilateral localized gingival hyperpigmentation that aligned with the café-au-lait macule. This case is highly illustrative of the embryologic timing of the genetic event locally, which leads to café-au-lait type hyperpigmentation. Because the facial features and the ectoderm overlying the facial muscles develop around the third to fourth week of gestation, the distribution of this café-au-lait macule suggests development at the same time.

  8. Preparations for p-Au run in 2015

    SciTech Connect

    Liu, C.

    2014-12-31

    The p-Au particle collision is a unique category of collision runs. This is resulted from the different charge mass ratio of the proton and fully stripped Au ion (1 vs.79/197). The p-Au run requires a special acceleration ramp, and movement of a number of beam components as required by the beam trajectories. The DX magnets will be moved for the first time in the history of RHIC. In this note, the planning and preparations for p-Au run will be presented.

  9. Do methanethiol adsorbates on the Au(111) surface dissociate?

    PubMed

    Zhou, Jian-Ge; Hagelberg, Frank

    2006-07-28

    The interaction of methanethiol molecules CH3SH with the Au(111) surface is investigated, and it is found for the first time that the S-H bond remains intact when the methanethiol molecules are adsorbed on the regular Au(111) surface. However, it breaks if defects are present in the Au(111) surface. At low coverage, the fcc region is favored for S atom adsorption, but at saturated coverage the adsorption energies at various sites are almost isoenergetic. The presented calculations show that a methanethiol layer on the regular Au(111) surface does not dimerize.

  10. Do Methanethiol Adsorbates on the Au(111) Surface Dissociate?

    NASA Astrophysics Data System (ADS)

    Zhou, Jian-Ge; Hagelberg, Frank

    2006-07-01

    The interaction of methanethiol molecules CH3SH with the Au(111) surface is investigated, and it is found for the first time that the S-H bond remains intact when the methanethiol molecules are adsorbed on the regular Au(111) surface. However, it breaks if defects are present in the Au(111) surface. At low coverage, the fcc region is favored for S atom adsorption, but at saturated coverage the adsorption energies at various sites are almost isoenergetic. The presented calculations show that a methanethiol layer on the regular Au(111) surface does not dimerize.

  11. Design of Au/SPIO composite nanoparticle for facile and biocompatible surface functionalization via Au-S bond

    NASA Astrophysics Data System (ADS)

    Seino, Satoshi; Shibata, Yujin; Yamanaka, Masayuki; Nakagawa, Takashi; Mukai, Yohei; Nakagawa, Shinsaku; Yamamoto, Takao A.

    2013-01-01

    Immobilization of Au nanoparticles on super-paramagnetic iron-oxide (SPIO) enables facile and biocompatible surface functionalization via Au-S bond. Au/SPIO composite nanoparticle is easily modified by thiol-modified polyethylene glycol (PEG-SH), and they are successfully applied on MR tumor imaging. However, its large hydrodynamic size ( 150 nm) still causes the accumulation to liver in vivo. In this study, we controlled the hydrodynamic size of Au/SPIO by testing different raw SPIOs and stabilizing polymers. As the best candidate, Au/Molday-ION which was synthesized from Molday-ION and polyvinyl alcohol comprised the hydrodynamic size of 56 nm. Moreover, PEGylated Au/Molday-ION showed excellent dispersibility in blood serum, with the hydrodynamic size of 65 nm. This surface functionalization strategy is effective for the constructions of magnetic nanocarriers for in vivo applications.

  12. Initial stages of Cu3Au(111) oxidation: oxygen induced Cu segregation and the protective Au layer profile.

    PubMed

    Tsuda, Yasutaka; Oka, Kohei; Makino, Takamasa; Okada, Michio; Diño, Wilson Agerico; Hashinokuchi, M; Yoshigoe, Akitaka; Teraoka, Yuden; Kasai, Hideaki

    2014-02-28

    We report results of our experimental and theoretical studies on the Au concentration profile of Cu3Au(111) during oxidation by a hyperthermal O2 molecular beam at room temperature, using X-ray photoemission spectroscopy (XPS), in conjunction with synchrotron radiation (SR), and density functional theory (DFT). Before O2 exposure, we observe strong Au segregation to the top layer, i.e., Au surface enrichment of the clean surface. We also observe a gradual Cu surface enrichment, and Au enrichment of the second and third (subsurface) layers, with increasing O coverage. Complete Cu segregation to the surface occurs at 0.5 ML O surface coverage. The Au-rich second and third layers of the oxidized surface demonstrate the protective layer formation against oxidation deeper into the bulk.

  13. 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.

  14. Meteoroids at 1 AU: Dynamic and Properties

    NASA Astrophysics Data System (ADS)

    McDonnell, J. A. M.; McBride, N.

    1996-12-01

    Lines of evidence from both retrieved spacecraft and meteoroid studies have been examined to define the properties and understanding of the particulate impact environment at 1 AU. Key studies include: From LDEF and Eureca experiments comprising both thin foils and thick targets, exposed under identical exposures, have permitted physical properties of the meteoroids to be deduced such as shape factor and density. Comparison of such detectors pointing in different directions on the same spacecraft permits the velocity of meteoroids to be assessed and compared with that of radar meteoroids. Results are compared with velocity distributions currently used for ESABASE. Comparison of science experiments exposed on LDEF and Eureca, where different altitude stabilisation configurations apply, leads to a measure for the upper limit of space debris without recourse to chemical analyses. Radar meteoroids provide the only effective measure of the velocity distribution at 1 AU; but the meteor phenomenon differs (in sensitivity to velocity) from the impact cratering. Modelling has been performed, therefore, to derive Apex to Anti-Apex flux distributions appropriate to spacecraft environment modelling as in e.g. ESABASE. High sensitivity in-situ detectors in deep space, in particular HEOS II and Pioneers 8 and 9, provide evidence of the changing distributions and directivity of meteoroids and a swing to beta meteoroids which are being expelled from the solar system. Advances in the characterisation of these populations are presented.

  • Mesomorphic Lamella Rolling of Au in Vacuum

    NASA Astrophysics Data System (ADS)

    Huang, Chang-Ning; Chen, Shuei-Yuan; Shen, Pouyan

    2009-07-01

    Lamellar nanocondensates in partial epitaxy with larger-sized multiply twinned particles (MTPs) or alternatively in the form of multiple-walled tubes (MWTs) having nothing to do with MTP were produced by the very energetic pulse laser ablation of Au target in vacuum under specified power density and pulses. Transmission electron microscopic observations revealed (111)-motif diffraction and low-angle scattering. They correspond to layer interspacing (0.241-0.192 nm) and the nearest neighbor distance (ca. 0.74-0.55 nm) of atom clusters within the layer, respectively, for the lamella, which shows interspacing contraction with decreasing particle size under the influence of surface stress and rolls up upon electron irradiation. The uncapped MWT has nearly concentric amorphous layers interspaced by 0.458-0.335 nm depending on dislocation distribution and becomes spherical onions for surface-area reduction upon electron dosage. Analogous to graphene-derived tubular materials, the lamella-derived MWT of Au could have pentagon-hexagon pair at its zig-zag junction and useful optoelectronic properties worthy of exploration.

  • Mesomorphic Lamella Rolling of Au in Vacuum

    PubMed Central

    2009-01-01

    Lamellar nanocondensates in partial epitaxy with larger-sized multiply twinned particles (MTPs) or alternatively in the form of multiple-walled tubes (MWTs) having nothing to do with MTP were produced by the very energetic pulse laser ablation of Au target in vacuum under specified power density and pulses. Transmission electron microscopic observations revealed (111)-motif diffraction and low-angle scattering. They correspond to layer interspacing (0.241–0.192 nm) and the nearest neighbor distance (ca. 0.74–0.55 nm) of atom clusters within the layer, respectively, for the lamella, which shows interspacing contraction with decreasing particle size under the influence of surface stress and rolls up upon electron irradiation. The uncapped MWT has nearly concentric amorphous layers interspaced by 0.458–0.335 nm depending on dislocation distribution and becomes spherical onions for surface-area reduction upon electron dosage. Analogous to graphene-derived tubular materials, the lamella-derived MWT of Au could have pentagon–hexagon pair at its zig-zag junction and useful optoelectronic properties worthy of exploration. PMID:20628452

  • IMAGING PROMINENCE ERUPTIONS OUT TO 1 AU

    SciTech Connect

    Wood, Brian E.; Howard, Russell A.; Linton, Mark G.

    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 a 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.

  • Component conversion from pure Au nanorods to multiblock Ag-Au-Ag nanorods assisted by Pt nanoframe templates

    NASA Astrophysics Data System (ADS)

    Lee, Sangji; Jang, Hee-Jeong; Jang, Ho Young; Kim, Seong Kyu; Park, Sungho

    2016-06-01

    We developed a new method for synthesizing multiblock Ag-Au-Ag nanorods using Pt nanoframes that had been deposited on the edges of Au nanorod seeds. As a function of Au etching time, the length of the Au nanorod decreased symmetrically starting from the two ends, leading to the formation of empty inner space at the ends. Subsequent reduction of Ag ions could be selectively performed in the inner space confined by Pt nanoframes and the resulting Ag-Au-Ag nanorods exhibited characteristic LSPR modes originating from each block component (in a transverse direction) and SPR coupling (in a longitudinal direction). The high quality of the resulting multiblock nanorods enabled observation of the longitudinal quadrupole mode that was induced by Ag-Au SPR coupling in a long axis. The mode exhibited high sensitivity in accordance with the change in the surrounding media, demonstrating great potential for sensor applications.We developed a new method for synthesizing multiblock Ag-Au-Ag nanorods using Pt nanoframes that had been deposited on the edges of Au nanorod seeds. As a function of Au etching time, the length of the Au nanorod decreased symmetrically starting from the two ends, leading to the formation of empty inner space at the ends. Subsequent reduction of Ag ions could be selectively performed in the inner space confined by Pt nanoframes and the resulting Ag-Au-Ag nanorods exhibited characteristic LSPR modes originating from each block component (in a transverse direction) and SPR coupling (in a longitudinal direction). The high quality of the resulting multiblock nanorods enabled observation of the longitudinal quadrupole mode that was induced by Ag-Au SPR coupling in a long axis. The mode exhibited high sensitivity in accordance with the change in the surrounding media, demonstrating great potential for sensor applications. Electronic supplementary information (ESI) available. See DOI: 10.1039/c6nr03484e

  • Reduction of Fermi level pinning at Au-MoS2 interfaces by atomic passivation on Au surface

    NASA Astrophysics Data System (ADS)

    Min, Kyung-Ah; Park, Jinwoo; Wallace, Robert M.; Cho, Kyeongjae; Hong, Suklyun

    2017-03-01

    Monolayer molybdenum disulfide (MoS2), which is a semiconducting material with direct band gap of ˜1.8 eV, has drawn much attention for application in field effect transistors (FETs). In this connection, it is very important to understand the Fermi level pinning (FLP) which occurs at metal-semiconductor interfaces. It is known that MoS2 has an n-type contact with Au, which is a high work function metal, representing the strong FLP at Au-MoS2 interfaces. However, such FLP can obstruct the attainment of high performance of field effect devices. In this study, we investigate the reduction of FLP at Au-MoS2 interfaces by atomic passivation on Au(111) using first-principles calculations. To reduce the FLP at Au-MoS2 interfaces, we consider sulfur, oxygen, nitrogen, fluorine, and hydrogen atoms that can passivate the surface of Au(111). Calculations show that passivating atoms prevent the direct contact between Au(111) and MoS2, and thus FLP at Au-MoS2 interfaces is reduced by weak interaction between atom-passivated Au(111) and MoS2. Especially, FLP is greatly reduced at sulfur-passivated Au-MoS2 interfaces with the smallest binding energy. Furthermore, fluorine-passivated Au(111) can form ohmic contact with MoS2, representing almost zero Schottky barrier height (SBH). We suggest that SBH can be controlled depending on the passivating atoms on Au(111).

  • 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

    1. Partial oxidation of methanol catalyzed with Au/TiO2, Au/ZrO2 and Au/ZrO2-TiO2 catalysts

      NASA Astrophysics Data System (ADS)

      Hernández-Ramírez, E.; Wang, J. A.; Chen, L. F.; Valenzuela, M. A.; Dalai, A. K.

      2017-03-01

      Mesoporous TiO2, ZrO2 and ZrO2-TiO2 mixed oxides were synthesized by the sol-gel method and the Au/TiO2, Au/ZrO2 and Au/ZrO2-TiO2 catalysts were prepared by deposition-precipitation method using urea solution as a precipitating agent. These materials were characterized by UV-vis spectroscopy, X-ray diffraction (XRD), N2 adsorption-desorption isotherms, transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), and in situ FTIR-pyridine (FTIR-Py) adsorption. XRD patterns of the samples confirmed the formation of ZrTiO4 phase in the ZrO2-TiO2 mixed oxides. TEM micrographs showed that nanosized gold particles on the catalyst had an average diameter smaller than 5 nm. Metallic gold (Au0) and oxidized Au species (Aunδ+) on the surface of the catalysts were evidenced by UV-vis and XPS characterization. In the partial oxidation of methanol (POM) reaction, among the six catalysts, the high metallic Au0/Au+ ratio and low surface acidity in the Au/ZrO2 catalysts are chiefly responsible for the highest hydrogen production rate in the whole temperature range between 210 and 300 °C. Methanol decomposition as secondary reaction was favored on TiO2-based catalysts at higher temperature, producing a large amount of CO. Formation of ZrO2-TiO2 solid solution resulted in generation of both Brønsted and Lewis acid sites; as a result, dehydrogenation and oxidative dehydrogenation of methanol was allowed over Au/ZrO2-TiO2 catalysts.

    2. Strange baryon resonance production in sqrt s NN=200 GeV p+p and Au+Au collisions.

      PubMed

      Abelev, B I; Aggarwal, M M; Ahammed, Z; Amonett, J; Anderson, B D; Anderson, M; Arkhipkin, D; Averichev, G S; Bai, Y; Balewski, J; Barannikova, O; Barnby, L S; Baudot, J; Bekele, S; Belaga, V V; Bellingeri-Laurikainen, A; Bellwied, R; Benedosso, F; Bhardwaj, S; Bhasin, A; Bhati, A K; Bichsel, H; Bielcik, J; Bielcikova, J; Bland, L C; Blyth, S-L; Bonner, B E; Botje, M; Bouchet, J; Brandin, A V; Bravar, A; Burton, T P; Bystersky, M; Cadman, R V; Cai, X Z; Caines, H; Calderón de la Barca Sánchez, M; Castillo, J; Catu, O; Cebra, D; Chajecki, Z; Chaloupka, P; Chattopadhyay, S; Chen, H F; Chen, J H; Cheng, J; Cherney, M; Chikanian, A; Christie, W; Coffin, J P; Cormier, T M; Cosentino, M R; Cramer, J G; Crawford, H J; Das, D; Das, S; Dash, S; Daugherity, M; de Moura, M M; Dedovich, T G; DePhillips, M; Derevschikov, A A; Didenko, L; Dietel, T; Djawotho, P; Dogra, S M; Dong, W J; Dong, X; Draper, J E; Du, F; Dunin, V B; Dunlop, J C; Dutta Mazumdar, M R; Eckardt, V; Edwards, W R; Efimov, L G; Emelianov, V; Engelage, J; Eppley, G; Erazmus, B; Estienne, M; Fachini, P; Fatemi, R; Fedorisin, J; Filimonov, K; Filip, P; Finch, E; Fine, V; Fisyak, Y; Fu, J; Gagliardi, C A; Gaillard, L; Ganti, M S; Gaudichet, L; Ghazikhanian, V; Ghosh, P; Gonzalez, J E; Gorbunov, Y G; Gos, H; Grebenyuk, O; Grosnick, D; Guertin, S M; Guimaraes, K S F F; Gupta, N; Gutierrez, T D; Haag, B; Hallman, T J; Hamed, A; Harris, J W; He, W; Heinz, M; Henry, T W; Hepplemann, S; Hippolyte, B; Hirsch, A; Hjort, E; Hoffman, A M; Hoffmann, G W; Horner, M J; Huang, H Z; Huang, S L; Hughes, E W; Humanic, T J; Igo, G; Jacobs, P; Jacobs, W W; Jakl, P; Jia, F; Jiang, H; Jones, P G; Judd, E G; Kabana, S; Kang, K; Kapitan, J; Kaplan, M; Keane, D; Kechechyan, A; Khodyrev, V Yu; Kim, B C; Kiryluk, J; Kisiel, A; Kislov, E M; Klein, S R; Kocoloski, A; Koetke, D D; Kollegger, T; Kopytine, M; Kotchenda, L; Kouchpil, V; Kowalik, K L; Kramer, M; Kravtsov, P; Kravtsov, V I; Krueger, K; Kuhn, C; Kulikov, A I; Kumar, A; Kuznetsov, A A; Lamont, M A C; Landgraf, J M; Lange, S; LaPointe, S; Laue, F; Lauret, J; Lebedev, A; Lednicky, R; Lee, C-H; Lehocka, S; LeVine, M J; Li, C; Li, Q; Li, Y; Lin, G; Lin, X; Lindenbaum, S J; Lisa, M A; Liu, F; Liu, H; Liu, J; Liu, L; Liu, Z; Ljubicic, T; Llope, W J; Long, H; Longacre, R S; Love, W A; Lu, Y; Ludlam, T; Lynn, D; Ma, G L; Ma, J G; Ma, Y G; Magestro, D; Mahapatra, D P; Majka, R; Mangotra, L K; Manweiler, R; Margetis, S; Markert, C; Martin, L; Matis, H S; Matulenko, Yu A; McClain, C J; McShane, T S; Melnick, Yu; Meschanin, A; Millane, J; Miller, M L; Minaev, N G; Mioduszewski, S; Mironov, C; Mischke, A; Mishra, D K; Mitchell, J; Mohanty, B; Molnar, L; Moore, C F; Morozov, D A; Munhoz, M G; Nandi, B K; Nattrass, C; Nayak, T K; Nelson, J M; Netrakanti, P K; Nogach, L V; Nurushev, S B; Odyniec, G; Ogawa, A; Okorokov, V; Oldenburg, M; Olson, D; Pachr, M; Pal, S K; Panebratsev, Y; Panitkin, S Y; Pavlinov, A I; Pawlak, T; Peitzmann, T; Perevoztchikov, V; Perkins, C; Peryt, W; Phatak, S C; Picha, R; Planinic, M; Pluta, J; Poljak, N; Porile, N; Porter, J; Poskanzer, A M; Potekhin, M; Potrebenikova, E; Potukuchi, B V K S; Prindle, D; Pruneau, C; Putschke, J; Rakness, G; Raniwala, R; Raniwala, S; Ray, R L; Razin, S V; Reinnarth, J; Relyea, D; Retiere, F; Ridiger, A; Ritter, H G; Roberts, J B; Rogachevskiy, O V; Romero, J L; Rose, A; Roy, C; Ruan, L; Russcher, M J; Sahoo, R; Sakuma, T; Salur, S; Sandweiss, J; Sarsour, M; Sazhin, P S; Schambach, J; Scharenberg, R P; Schmitz, N; Schweda, K; Seger, J; Selyuzhenkov, I; Seyboth, P; Shabetai, A; Shahaliev, E; Shao, M; Sharma, M; Shen, W Q; Shimanskiy, S S; Sichtermann, E; Simon, F; Singaraju, R N; Smirnov, N; Snellings, R; Sood, G; Sorensen, P; Sowinski, J; Speltz, J; Spinka, H M; Srivastava, B; Stadnik, A; Stanislaus, T D S; Stock, R; Stolpovsky, A; Strikhanov, M; Stringfellow, B; Suaide, A A P; Sugarbaker, E; Sumbera, M; Sun, Z; Surrow, B; Swanger, M; Symons, T J M; Szanto de Toledo, A; Tai, A; Takahashi, J; Tang, A H; Tarnowsky, T; Thein, D; Thomas, J H; Timmins, A R; Timoshenko, S; Tokarev, M; Trainor, T A; Trentalange, S; Tribble, R E; Tsai, O D; Ulery, J; Ullrich, T; Underwood, D G; Buren, G Van; van der Kolk, N; van Leeuwen, M; Molen, A M Vander; Varma, R; Vasilevski, I M; Vasiliev, A N; Vernet, R; Vigdor, S E; Viyogi, Y P; Vokal, S; Voloshin, S A; Waggoner, W T; Wang, F; Wang, G; Wang, J S; Wang, X L; Wang, Y; Watson, J W; Webb, J C; Westfall, G D; Wetzler, A; Whitten, C; Wieman, H; Wissink, S W; Witt, R; Wood, J; Wu, J; Xu, N; Xu, Q H; Xu, Z; Yepes, P; Yoo, I-K; Yurevich, V I; Zhan, W; Zhang, H; Zhang, W M; Zhang, Y; Zhang, Z P; Zhao, Y; Zhong, C; Zoulkarneev, R; Zoulkarneeva, Y; Zubarev, A N; Zuo, J X

      2006-09-29

      We report the measurements of Sigma(1385) and Lambda(1520) production in p+p and Au+Au collisions at sqrt[s{NN}]=200 GeV from the STAR Collaboration. The yields and the p(T) spectra are presented and discussed in terms of chemical and thermal freeze-out conditions and compared to model predictions. Thermal and microscopic models do not adequately describe the yields of all the resonances produced in central Au+Au collisions. Our results indicate that there may be a time span between chemical and thermal freeze-out during which elastic hadronic interactions occur.

    3. 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.; Boldyrev, Alexander I.

      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-) can 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.

    4. Tuberculose chez le personnel de santé du secteur public au Burundi: fréquence et facteurs de risque

      PubMed Central

      Mukuku, Olivier; Ruhindiza, Bienvenu Mukuku; Mupepe, Alexis Kumba; Sawadogo, Michel

      2013-01-01

      Introduction Le but de cette étude était de déterminer la fréquence de la tuberculose (TB) chez le personnel de santé du secteur public en charge des patients tuberculeux et d’évaluer les facteurs de risque de contracter la tuberculose chez ce personnel au Burundi. Méthodes Il s’agit d’une étude transversale à visée analytique réalisée auprès de 300 travailleurs prestant dans 30 centres de dépistage et de traitement de la TB (CDT) au Burundi du 16 octobre au 15 novembre 2012. Les paramètres sociodémographiques et professionnels ainsi que l’antécédent de vaccination BCG de travailleurs ayant été touché par la TB ont été analysé et comparé à ceux de travailleurs qui ne l’ont pas été. Le seuil de signification a été fixé à p < 0,05. Résultats La fréquence de la TB chez le personnel de santé est de 15%. Le risque de souffrir de la TB est de près de 4 fois chez les travailleurs âgés d’au moins 50 ans (OR=3,73; 1,53-9,08), chez ceux qui n’ont jamais reçu de vaccin de BCG (OR=3,73; 1,24-11,03), chez ceux qui n’ont pas de cicatrice vaccinale de BCG (OR=3,80; 1,67-8,62) et chez ceux qui travaillent depuis au moins 6 ans dans un CDT (OR=3,79; 1,44-9,96); ce risque est de 9 fois chez ceux qui sont mariés (OR=9,42; 1,26-70,23), de 8 fois chez ceux qui n’aèrent pas leurs salles de travail (OR=8,20; 1,48-48,23) et de 6 fois chez ceux qui ont comme profession nettoyeur ou aide-soignant (OR=6,12; 2,92-12,82). Par contre, aucune corrélation statistiquement significative n’a été observée entre le fait de souffrir de la TB et le sexe mais aussi le nombre d’heures de contact d’un travailleur avec un patient tuberculeux (p>0,05). Conclusion L’âge, l’antécédent de vaccination de BCG ainsi que la majorité de paramètres professionnels sont en association avec la maladie TB des travailleurs de CDT. D’où, la maîtrise de certains facteurs de risque s’avère important pour faire face au fardeau de la TB parmi

    5. Graphite oxide-coated Au nanoparticles for improved SERS sensing

      NASA Astrophysics Data System (ADS)

      Liu, Bingfei; Wang, Qi; Tian, Tian; Mao, Guoming; Liu, Hao; Ren, Xiao Min

      2016-11-01

      Surface-enhanced Raman scattering (SERS) is an effective spectral analysis technique as its advantage of molecular fingerprint, ultra-sensitivity and non-contact. It is the most popular and easiest method to create SERS metal nanoparticles (NPs) combining magnetron sputtering deposition of noble metal with rapid annealing. In this study, we have demonstrated an approach to improve the SERS effect by using graphene oxide (GO) Au NPs composite structure. Here, we obtain the Au NPs coated SOI substrate prepared by magnetron sputtering 4 nm Au film and followed by rapid annealing treatment. The experimental results indicate that the SERS intensity is maximum of the Au NPs coated SOI substrate with the average particle diameter of 20 nm when the rapid annealing time is 30s and temperature is 500 degrees. Then, graphene oxide solution is spin coated on the Au NPs to form the GO-Au NPs composite structure. The morphology of GO-Au NPs have been characterized by scanning electron microscope (SEM). Rhodamine 6G (R6G) is used as the probe molecule to detect the SERS intensity. The GO-Au NPs has an excellent SERS effect which can detect R6G as low as 10-9M. Besides, compared to the Au NPs without GO the GO-Au NPs has two times Raman intensity enhancement of bands at 774 cm-1 because of the GO improving the SERS properties through strong ability of adsorption the probe molecule and chemical enhancement effect. Therefore, the GO-Au NPs composite structure shows a promising future to detect low concentration material.

    6. La prévention et le traitement des infections bactériennes chez les enfants aspléniques ou hypospléniques

      PubMed Central

      1999-01-01

      L’asplénie, qu’elle soit fonctionnelle ou anatomique, s’associe à un accroissement du risque d’infection potentiellement fatale ou constituant un danger de septicémie postsplénectomie (SPS). En raison du risque accru de bactériémie par des bactéries encapsulées chez les enfants aspléniques, la vaccination visant à prévenir une infection au Streptococcus pneumoniae, à l’Haemophilus influenzae de type b (Hib) et au Neiserria meningitidis est recommandée. Malgré la prévalence croissante de S pneumoniae pénicillinorésistant, on recommande aussi l’usage de pénicilline prophylactique chez les enfants aspléniques de moins de cinq ans, et pendant au moins un an après une splénectomie. La poursuite de la prophylaxie antibiotique après cette période dépend de la situation clinique de chaque enfant et de la prévalence de S pneumoniae pénicillinorésistant au sein de la collectivité. Lorsque des enfants aspléniques font de la fièvre ou présentent des symptômes non spécifiques, ils devraient faire l’objet d’une évaluation immédiate. Si on présume la présence de septicémie bactérienne, il faut procéder à une analyse du sang et des autres liquides organiques pertinents et entreprendre sur-le-champ une antibiothérapie à large spectre par voie parentérale, laquelle doit agir également contre les souches de S pneumoniae présentes dans la collectivité. Chez les enfants aspléniques souffrant d’une septicémie foudroyante à S pneumoniae, le taux de mortalité est élevé, malgré l’utilisation rapide d’une antibiothérapie convenable, d’où l’importance des mesures préventives.

    7. Registration of ‘AU-1101’ peanut

      Technology Transfer Automated Retrieval System (TEKTRAN)

      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-...

    8. Microstructural evolution of eutectic Au-Sn solder joints

      SciTech Connect

      Song, Ho Geon

      2002-05-01

      Current trends toward miniaturization and the use of lead(Pb)-free solder in electronic packaging present new problems in the reliability of solder joints. This study was performed in order to understand the microstructure and microstructural evolution of small volumes of nominally eutectic Au-Sn solder joints (80Au-20Sn by weight), which gives insight into properties and reliability.

    9. Influence du traitement ionisant par rayonnement γ sur le pouvoir antioxydant de fractions polyphénoliques issues de substances d'origine végétale

      NASA Astrophysics Data System (ADS)

      Stuyck, S.; Connaulte, J.; Lesgards, G.; Prost, M.; Raffi, J.

      1998-04-01

      Ionizing radiation of vegetables is a cleaning up and preservation physical treatment which consists in submitting them to γ radiation, X radiation or electrons beam. This study deals with the influence of γ radiation on antioxidative effect of vegetables polyphenolic parts. In that purpose, we use a simple biological test based on erythrocytes haemolysis. Le traitement ionisant des produits végétaux est un procédé physique d'assainissement et de conservation qui consiste à les soumettre à l'action de rayonnements γ, de rayons X ou de faisceaux d'électrons. Ce travail porte sur l'étude de l'influence des rayonnements γ sur le pouvoir antioxydant de fractions polyphénoliques issues de substances d'origine végétale. Pour cela, un test biologique basé sur l'hémolyse d'érythrocytes est utilisé.

    10. Evidence from d+Au measurements for final-state suppression of high-p(T) hadrons in Au+Au collisions at RHIC.

      PubMed

      Adams, J; Adler, C; Aggarwal, M M; Ahammed, Z; Amonett, J; Anderson, B D; Anderson, M; Arkhipkin, D; Averichev, G S; Badyal, S K; Balewski, J; Barannikova, O; Barnby, L S; Baudot, J; Bekele, S; Belaga, V V; Bellwied, R; Berger, J; Bezverkhny, B I; Bhardwaj, S; Bhaskar, P; Bhati, A K; Bichsel, H; Billmeier, A; Bland, L C; Blyth, C O; Bonner, B E; Botje, M; Boucham, A; Brandin, A; Bravar, A; Cadman, R V; Cai, X Z; Caines, H; Calderón de la Barca Sánchez, M; Carroll, J; Castillo, J; Castro, M; Cebra, D; Chaloupka, P; Chattopadhyay, S; Chen, H F; Chen, Y; Chernenko, S P; Cherney, M; Chikanian, A; Choi, B; Christie, W; Coffin, J P; Cormier, T M; Cramer, J G; Crawford, H J; Das, D; Das, S; Derevschikov, A A; Didenko, L; Dietel, T; Dong, X; Draper, J E; Du, F; Dubey, A K; Dunin, V B; Dunlop, J C; Dutta Majumdar, M R; Eckardt, V; Efimov, L G; Emelianov, V; Engelage, J; Eppley, G; Erazmus, B; Fachini, P; Faine, V; Faivre, J; Fatemi, R; Filimonov, K; Filip, P; Finch, E; Fisyak, Y; Flierl, D; Foley, K J; Fu, J; Gagliardi, C A; Ganti, M S; Gagunashvili, N; Gans, J; Gaudichet, L; Germain, M; Geurts, F; Ghazikhanian, V; Ghosh, P; Gonzalez, J E; Grachov, O; Grigoriev, V; Gronstal, S; Grosnick, D; Guedon, M; Guertin, S M; Gupta, A; Gushin, E; Gutierrez, T D; Hallman, T J; Hardtke, D; Harris, J W; Heinz, M; Henry, T W; Heppelmann, S; Herston, T; Hippolyte, B; Hirsch, A; Hjort, E; Hoffmann, G W; Horsley, M; Huang, H Z; Huang, S L; Humanic, T J; Igo, G; Ishihara, A; Jacobs, P; Jacobs, W W; Janik, M; Johnson, I; Jones, P G; Judd, E G; Kabana, S; Kaneta, M; Kaplan, M; Keane, D; Kiryluk, J; Kisiel, A; Klay, J; Klein, S R; Klyachko, A; Koetke, D D; Kollegger, T; Konstantinov, A S; Kopytine, M; Kotchenda, L; Kovalenko, A D; Kramer, M; Kravtsov, P; Krueger, K; Kuhn, C; Kulikov, A I; Kumar, A; Kunde, G J; Kunz, C L; Kutuev, R Kh; Kuznetsov, A A; Lamont, M A C; Landgraf, J M; Lange, S; Lansdell, C P; Lasiuk, B; Laue, F; Lauret, J; Lebedev, A; Lednický, R; Leontiev, V M; LeVine, M J; Li, C; Li, Q; Lindenbaum, S J; Lisa, M A; Liu, F; Liu, L; Liu, Z; Liu, Q J; Ljubicic, T; Llope, W J; Long, H; Longacre, R S; Lopez-Noriega, M; Love, W A; Ludlam, T; Lynn, D; Ma, J; Ma, Y G; Magestro, D; Mahajan, S; Mangotra, L K; Mahapatra, D P; Majka, R; Manweiler, R; Margetis, S; Markert, C; Martin, L; Marx, J; Matis, H S; Matulenko, Yu A; McShane, T S; Meissner, F; Melnick, Yu; Meschanin, A; Messer, M; Miller, M L; Milosevich, Z; Minaev, N G; Mironov, C; Mishra, D; Mitchell, J; Mohanty, B; Molnar, L; Moore, C F; Mora-Corral, M J; Morozov, V; de Moura, M M; Munhoz, M G; Nandi, B K; Nayak, S K; Nayak, T K; Nelson, J M; Nevski, P; Nikitin, V A; Nogach, L V; Norman, B; Nurushev, S B; Odyniec, G; Ogawa, A; Okorokov, V; Oldenburg, M; Olson, D; Paic, G; Pandey, S U; Pal, S K; Panebratsev, Y; Panitkin, S Y; Pavlinov, A I; Pawlak, T; Perevoztchikov, V; Peryt, W; Petrov, V A; Phatak, S C; Picha, R; Planinic, M; Pluta, J; Porile, N; Porter, J; Poskanzer, A M; Potekhin, M; Potrebenikova, E; Potukuchi, B V K S; Prindle, D; Pruneau, C; Putschke, J; Rai, G; Rakness, G; Raniwala, R; Raniwala, S; Ravel, O; Ray, R L; Razin, S V; Reichhold, D; Reid, J G; Renault, G; Retiere, F; Ridiger, A; Ritter, H G; Roberts, J B; Rogachevski, O V; Romero, J L; Rose, A; Roy, C; Ruan, L J; Rykov, V; Sahoo, R; Sakrejda, I; Salur, S; Sandweiss, J; Savin, I; Schambach, J; Scharenberg, R P; Schmitz, N; Schroeder, L S; Schweda, K; Seger, J; Seliverstov, D; Seyboth, P; Shahaliev, E; Shao, M; Sharma, M; Shestermanov, K E; Shimanskii, S S; Singaraju, R N; Simon, F; Skoro, G; Smirnov, N; Snellings, R; Sood, G; Sorensen, P; Sowinski, J; Spinka, H M; Srivastava, B; Stanislaus, S; Stock, R; Stolpovsky, A; Strikhanov, M; Stringfellow, B; Struck, C; Suaide, A A P; Sugarbaker, E; Suire, C; Sumbera, M; Surrow, B; Symons, T J M; Szanto de Toledo, A; Szarwas, P; Tai, A; Takahashi, J; Tang, A H; Thein, D; Thomas, J H; Tikhomirov, V; Tokarev, M; Tonjes, M B; Trainor, T A; Trentalange, S; Tribble, R E; Trivedi, M D; Trofimov, V; Tsai, O; Ullrich, T; Underwood, D G; Van Buren, G; VanderMolen, A M; Vasiliev, A N; Vasiliev, M; Vigdor, S E; Viyogi, Y P; Voloshin, S A; Waggoner, W; Wang, F; Wang, G; Wang, X L; Wang, Z M; Ward, H; Watson, J W; Wells, R; Westfall, G D; Whitten, C; Wieman, H; Willson, R; Wissink, S W; Witt, R; Wood, J; Wu, J; Xu, N; Xu, Z; Xu, Z Z; Yakutin, A E; Yamamoto, E; Yang, J; Yepes, P; Yurevich, V I; Zanevski, Y V; Zborovský, I; Zhang, H; Zhang, H Y; Zhang, W M; Zhang, Z P; Zołnierczuk, P A; Zoulkarneev, R; Zoulkarneeva, J; Zubarev, A N

      2003-08-15

      We report measurements of single-particle inclusive spectra and two-particle azimuthal distributions of charged hadrons at high transverse momentum (high p(T)) in minimum bias and central d+Au collisions at sqrt[s(NN)]=200 GeV. The inclusive yield is enhanced in d+Au collisions relative to binary-scaled p+p collisions, while the two-particle azimuthal distributions are very similar to those observed in p+p collisions. These results demonstrate that the strong suppression of the inclusive yield and back-to-back correlations at high p(T) previously observed in central Au+Au collisions are due to final-state interactions with the dense medium generated in such collisions.

    11. A family of Au-Tl loosely bound butterfly clusters.

      PubMed

      Fernández, Eduardo J; López-de-Luzuriaga, José M; Olmos, M Elena; Pérez, Javier; Laguna, Antonio; Lagunas, M Cristina

      2005-08-22

      By treatment of the polymeric species [AuTl(C6Cl5)2]n with ketones or with acetylacetone and 4,4'-bipyridine, the new tetranuclear complexes [Au2Tl2(C6Cl5)4] x L (L = PhMeC=O, acacH) or [Au2Tl2(C6Cl5)4(bipy)] x (acacH) have been prepared. Their crystal structures have been determined by X-ray diffraction methods and they all present a central Au2Tl2 core formed via one Tl...Tl and four Au...Tl unsupported interactions resulting in a loosely bound butterfly cluster. These complexes are strongly luminescent in both the solid state and solution showing an optical behavior in agreement with the maintenance of the Tl...Tl contact even in solution.

    12. Sputtering of Au induced by single Xe ion impacts

      SciTech Connect

      Birtcher, R. C.; Donnelly, S. E.

      1999-12-06

      Sputtering of Au thin films has been determined for Xe ions with energies between 50 and 600 keV. In-situ transmission electron microscopy was used to observe sputtered Au during deposition on a carbon foil near the specimen. Total reflection and transmission sputtering yields for a 62 nm thick Au thin film were determined by ex-situ measurement of the total amount of Au on the carbon foils. In situ observations show that individual Xe ions eject Au nanoparticles as large as 7 nm in diameter with an average diameter of approximately 3 nm. Particle emission correlates with crater formation due to single ion impacts. Nanoparticle emission contributes significantly to the total sputtering yield for Xe ions in this energy range in either reflection or transmission geometry.

    13. 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 Au4S5. 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 model is developedmore » 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

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

      SciTech Connect

      Walen, Holly; Liu, Da -Jiang; Oh, Junepyo; Yang, Hyun Jin; Kim, Yousoo; Thiel, P. A.

      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 Au4S5. 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 model 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.

    15. Synthesis, characterization and SERS activity of Au-Ag nanorods.

      PubMed

      Philip, Daizy; Gopchandran, K G; Unni, C; Nissamudeen, K M

      2008-09-01

      The formation mechanism and morphology of Au-Ag bimetallic colloidal nanoparticles depend on the composition. Ag coated Au colloidal nanoparticles have been prepared by deposition of Ag through chemical reduction on performed Au colloid. The composition of the Au100-x-Agx particles was varied from x=0 to 50. The obtained colloids were characterized by UV-vis spectroscopy and transmission electron microscopy (TEM). The Au80-Ag20 colloid consists of alloy nanorods with dimension of 25nm x 100nm. The activity of these nanorods in surface enhanced Raman spectroscopy (SERS) was checked by using sodium salicylate as an adsorbate probe. Intense SERS bands are observed indicating its usefulness as a SERS substrate in near infrared (NIR) laser excitation.

    16. Hémophagocytose et coagulation intravasculaire disséminée au cours de la leishmaniose viscérale de l'adulte: trois nouveaux cas

      PubMed Central

      Boukhris, Imène; Azzabi, Samira; Chérif, Eya; Kéchaou, Ines; Mahjoub, Sonia; Kooli, Chékib; Aoun, Karim; Khalfallah, Narjes

      2015-01-01

      Les atteintes cliniques et biologiques communes au syndrome d'activation macrophagique (SAM) et à la leishmaniose viscérale (LV) rendent le diagnostic étiologique du SAM très difficile. Cette association est rare et grave. Nous rapportons trois nouvelles observations de SAM secondaire à une LV, compliquées de coagulation intravasculaire disséminée (CIVD). Il s'agissait de trois hommes, âgés respectivement de 31, 20 et 60 ans. Le tableau était fait de fièvre et de splénomégalie associés à une pancytopénie et une CIVD. Le diagnostic de LV était fait par le myélogramme, les sérologies et la polymerase chain reaction. Chez l'un de nos patients, une deuxième sérologie était nécessaire. Tous nos patients étaient traités par Glucantime® avec une bonne évolution. Un cas de pancréatite aigue était noté. En en zones d'endémie, devant un SAM compliqué de CIVD, une LV doit être recherchée, en répétant si nécessaire certaines explorations initialement négatives. Le pronostic dépend de la rapidité du traitement spécifique. PMID:26848343

    17. Local structure of disordered Au-Cu and Au-Ag alloys

      NASA Astrophysics Data System (ADS)

      Frenkel, A. I.; Machavariani, V. Sh.; Rubshtein, A.; Rosenberg, Yu.; Voronel, A.; Stern, E. A.

      2000-10-01

      X-ray-absorption fine structure (XAFS) and x-ray-diffraction (XRD) measurements of disordered alloys AuxCu1-x and Au0.5Ag0.5 prepared by melt spinning were performed. In the Au0.5Ag0.5 alloy, no significant local deviations of the atoms from the average fcc lattice were detected while in AuxCu1-x alloys, significant deviations of atoms from the average fcc lattice were found. Mean-square vibrations of the Cu-Cu distances revealed by the XAFS in AuxCu1-x alloys indicate the weakening of contact between Cu atoms in the dilute limit. Our computer simulation for AuxCu1-x clusters of 105 atoms reproduces the main features of both the XAFS and XRD data.

    18. 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 and 56A GeV as one goes from the SPS to RHIC.

    19. STAR physics program and technical challenges with the RHIC energy scan with Au + Au collisions

      NASA Astrophysics Data System (ADS)

      Odyniec, G.; STAR Collaboration

      2008-10-01

      The future STAR physics program includes an Au + Au energy scan extending to low \\sqrt{s_{NN}} . Among other things, this energy scan will provide a unique opportunity to search for the phase boundary between quark-gluon plasma (QGP) and hadronic gas (HG), and a key landmark, a possible critical point, in the QCD phase diagram. Due to its large uniform acceptance and (with the addition of the time-of-flight detector) excellent particle identification capabilities, by the time of Run 10 (in 2010) STAR will be uniquely positioned to cover this physics in unprecedented depth and detail, as well as other novel physics possibilities. Running at very low energies poses major new challenges for accelerator experts at RHIC and for physicists preparing for data taking. We report on the status of STAR preparation for Run 10.

    20. Flow harmonics of Au+Au collisions at 1.23 AGeV with HADES

      NASA Astrophysics Data System (ADS)

      Kardan, Behruz

      2016-08-01

      Collective flow phenomena are a sensitive probe for the properties of extreme QCD matter. However, their interpretation relies on the understanding of the initial conditions e.g. the eccentricity of the nuclear overlap region. HADES [1] provides a large acceptance combined with a high mass-resolution and therefore allows to study di-electron and hadron production in heavy-ion collisions with unprecedented precision. In this contribution, the capability of HADES to study flow harmonics by utilizing multi-particle azimuthal correlation techniques is discussed. Due to the high statistics of seven billion Au+Au collisions at 1.23 AGeV collected in 2012, a systematic study of higher-order flow harmonics, the differentiation between collective and non-flow effects, and as well the multi-differential (p t, rapidity, centrality) analysis is possible.

    1. 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.

    2. 200 A GeV Au + Au collisions serve a nearly perfect quark-gluon liquid.

      PubMed

      Song, Huichao; Bass, Steffen A; Heinz, Ulrich; Hirano, Tetsufumi; Shen, Chun

      2011-05-13

      A new robust method to extract the specific shear viscosity (η/s)(QGP) of a quark-gluon plasma (QGP) at temperatures T(c) < T ≲ 2T(c) from the centrality dependence of the eccentricity-scaled elliptic flow v2/ε measured in ultrarelativistic heavy-ion collisions is presented. Coupling viscous fluid dynamics for the QGP with a microscopic transport model for hadronic freeze-out we find for 200 A GeV Au + Au collisions that v2/ε is a universal function of multiplicity density (1/S)(dN(ch)/dy) that depends only on the viscosity but not on the model used for computing the initial fireball eccentricity ε. Comparing with measurements we find 1<4π(η/s)(QGP) < 2.5 where the uncertainty range is dominated by model uncertainties for the values of ε used to normalize the measured v2.

    3. Collective global dynamics in Au+Au collisions at the BNL AGS

      NASA Astrophysics Data System (ADS)

      Bravina, L.; Csernai, L. P.; Lévai, P.; Strottman, D.

      1994-10-01

      Signatures of collective effects are studied in the quark gluon string model and in the fluid dynamical model for Au+Au collisions at 11.6A GeV/c. In the fluid dynamical model the dependence of observables on the quark-gluon plasma (QGP) formation in the equation of state is pointed out although the maximal total amount of pure QGP formed is only about 8 fm3 in these reactions. In contrast to the baryon rapidity distribution, the in-plane transverse flow and especially the squeeze-out effect are particularly sensitive to the EOS. In the QGSM the lifetime and extent of baryon density in strings are studied. The QGSM picture is very similar to the one obtained in the fluid dynamical model with a pure hadronic EOS.

    4. Sideward flow in Au + Au collisions at 400 A.MeV

      NASA Astrophysics Data System (ADS)

      Ramillien, V.; Dupieux, P.; Alard, J. P.; Amouroux, V.; Bastid, N.; Berger, L.; Boussange, S.; Fraysse, L.; Ibnouzahir, M.; Montarou, G.; Montbel, I.; Pras, P.; Basrak, Z.; Belayev, I. M.; Bini, M.; Blaich, Th.; Buta, A.; Caplar, R.; Cerruti, C.; Cindro, N.; Coffin, J. P.; Donà, R.; Erö, J.; Fan, Z. G.; Fintz, P.; Fodor, Z.; Freifelder, R.; Frolov, S.; Gobbi, A.; Gregorian, Y.; Guillaume, G.; Hartnack, C.; Herrmann, N.; Hildenbrand, K. D.; Hölbling, S.; Houari, A.; Jeong, S. C.; Jundt, F.; Kecskemeti, J.; Koncz, P.; Korchagin, Y.; Kotte, R.; Krämer, M.; Khun, C.; Legrand, I.; Lebedev, A.; Maguire, C.; Manko, V.; Maurenzig, P.; Mgebrishvili, G.; Mösner, J.; Moisa, D.; Neubert, W.; Olmi, A.; Pasquali, G.; Pelte, D.; Petrovici, M.; Poggi, G.; Rami, F.; Reisdorf, W.; Sadchikov, A.; Schüll, D.; Seres, Z.; Sikora, B.; Simion, V.; Smolyankin, S.; Sodan, U.; Teh, K.; Tezkratt, R.; Trzaska, M.; Vasiliev, M. A.; Wagner, P.; Wessels, J. P.; Wienold, T.; Wilhelmi, Z.; Wohlfarth, D.; Zhilin, A. V.; FOPI Collaboration

      1995-02-01

      We present new experimental data obtained with the FOPI detector at SIS, for the Au + Au heavy-ion collisions at 400 A MeV incident energy. The sideward flow, determined from a method without reaction-plane reconstruction, and the nuclear stopping are studied as a function of the centrality of the collisions. In order to study the nuclear in-medium effects, which act on the NN cross sections and potential and hence on experimental observables like the nuclear-matter flow and stopping, these results are compared with the predictions of two different QMD versions. The first one offers a fully microscopic calculation of the cross sections and potential in the G-matrix formalism and naturally includes the in-medium effects (this version is for the first time confronted with experiment). The second one uses a standard Skyrme potential plus a momentum-dependent term in order to mimic the in-medium effects.

    5. Charge transport in single Au / alkanedithiol / Au junctions: coordination geometries and conformational degrees of freedom.

      PubMed

      Li, Chen; Pobelov, Ilya; Wandlowski, Thomas; Bagrets, Alexei; Arnold, Andreas; Evers, Ferdinand

      2008-01-09

      Recent STM molecular break-junction experiments have revealed multiple series of peaks in the conductance histograms of alkanedithiols. To resolve a current controversy, we present here an in-depth study of charge transport properties of Au|alkanedithiol|Au junctions. Conductance histograms extracted from our STM measurements unambiguously confirm features showing more than one set of junction configurations. On the basis of quantum chemistry calculations, we propose that certain combinations of different sulfur-gold couplings and trans/gauche conformations act as the driving agents. The present study may have implications for experimental methodology: whenever conductances of different junction conformations are not statistically independent, the conductance histogram technique can exhibit a single series only, even though a much larger abundance of microscopic realizations exists.

    6. 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.

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

      SciTech Connect

      Renk, Thorsten; Eskola, Kari J.

      2007-08-15

      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 p{sub T} 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.

    8. 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.

    9. PHENIX Measurements of Single Electrons from Charm and Bottom Decays at Midrapidity in Au + Au Collisions

      NASA Astrophysics Data System (ADS)

      McGlinchey, D.

      2016-12-01

      Heavy quarks are an ideal probe of the quark gluon plasma created in heavy ion collisions. They are produced in the initial hard scattering and therefore experience the full evolution of the medium. PHENIX has previously measured the modification of heavy quark production in Au+Au collisions at √{sNN} = 200 GeV via electrons from semileptonic decays, which indicated substantial modifications of the parent hadron momentum distribution. The PHENIX barrel silicon vertex detector (VTX), installed in 2011, allows for the separation of electrons from charm and bottom hadron decays through the use of displaced vertex measurements. These proceedings present the results of the completed analysis of the 2011 data set using the VTX.

    10. MODELING THE ACCRETION STRUCTURE OF AU Mon

      SciTech Connect

      Atwood-Stone, Corwin; Miller, Brendan P.; Richards, Mercedes T.; Budaj, Jan; Peters, Geraldine J. E-mail: mbrendan@umich.edu E-mail: budaj@ta3.sk

      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 is 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.

    11. From the ternary Eu(Au/In)2 and EuAu4(Au/In)2 with remarkable Au/In distributions to a new structure type: The gold-rich Eu5Au16(Au/In)6 structure

      SciTech Connect

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

      2015-08-13

      The ternary Eu(Au/In)2 (EuAu0.46In1.54(2)) (I), EuAu4(Au/In)2 (EuAu4+xIn2–x with x = 0.75(2) (II), 0.93(2), and 1.03(2)), and Eu5Au16(Au/In)6 (Eu5Au17.29In4.71(3)) (III) have been synthesized, and their structures were characterized by single-crystal X-ray diffraction. I and II crystallize with the CeCu2-type (Pearson Symbol oI12; Imma; Z = 4; a = 4.9018(4) Å; b = 7.8237(5) Å; c = 8.4457(5) Å) and the YbAl4Mo2-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 of an Au/In-mixed diamond-related host lattice encapsulating Eu atoms, while the structure of II features ribbons of distorted, squared Au8 prisms enclosing Eu, Au, and In atoms. Combination of these structural motifs leads to a new structure type as observed for Eu5Au16(Au/In)6 (Eu5Au17.29In4.71(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 EuAu2–“EuAu4In2”. The site preferences of the disordered Au/In positions in II were investigated for different hypothetical “EuAu4(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 “EuAu5In” and “EuAu4In2” 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.

    12. Fabrication of Au nanotube arrays and their plasmonic properties

      NASA Astrophysics Data System (ADS)

      Zhu, Haojun; Chen, Huanjun; Wang, Jianfang; Li, Quan

      2013-04-01

      Large-scale Au nanotube arrays on ITO/glass with tunable inner diameters and wall thicknesses were fabricated via a CdSe nanotube array templating method. The initial tubular morphology of the CdSe-nanotube template was maintained during the synthesis, while the composition was converted from CdSe to Au. The obtained Au nanotube arrays showed two surface plasmon resonances in the extinction spectrum, mainly contributed by electron oscillation along the transverse and the longitudinal directions. When used as the substrate for surface-enhanced Raman spectroscopy (SERS), the Raman scattering of the probe molecules (4-mercaptobenzoic acid) was amplified by approximately 4 orders of magnitude, mainly due to the plasmonic enhancement effect of the Au nanotube arrays.Large-scale Au nanotube arrays on ITO/glass with tunable inner diameters and wall thicknesses were fabricated via a CdSe nanotube array templating method. The initial tubular morphology of the CdSe-nanotube template was maintained during the synthesis, while the composition was converted from CdSe to Au. The obtained Au nanotube arrays showed two surface plasmon resonances in the extinction spectrum, mainly contributed by electron oscillation along the transverse and the longitudinal directions. When used as the substrate for surface-enhanced Raman spectroscopy (SERS), the Raman scattering of the probe molecules (4-mercaptobenzoic acid) was amplified by approximately 4 orders of magnitude, mainly due to the plasmonic enhancement effect of the Au nanotube arrays. Electronic supplementary information (ESI) available: Basic characterizations, optical and SERS properties of Au nanotube arrays obtained from CdSe nanowire arrays; SERS spectra of Au-sputtered ITO/glass and bare ITO/glass; the calculation details of the enhancement factor. See DOI: 10.1039/c3nr33658a

    13. Thiophenol and thiophenol radical and their complexes with gold clusters Au 5 and Au 6

      NASA Astrophysics Data System (ADS)

      Remacle, F.; Kryachko, E. S.

      2004-12-01

      The longstanding controversy between experiment and theory regarding which conformer of thiophenol, planar or perpendicular, is the most stable and what is the magnitude of the corresponding rotational barrier of the S-H group is discussed. We propose a variety of rather modest high-level computational methods within the density theory, which corroborate the experimental data. These methods demonstrate that the planar structure of thiophenol is the most stable and the magnitude of the rotational barrier falls within the experimental range of 3.35±0.84 kJ mol -1. However, the barrier is of the order of RT at room temperature, which might prevent to clearly identify the most stable conformer of thiophenol in experiments and leads to a large-amplitude motion of the thiolic hydrogen. On the other hand, such low value of the barrier may lead to some error in evaluating the thermodynamic properties of thiophenol within the rigid-rotor-harmonic oscillator model, in particular for the bond dissociation enthalpy. We also show the existence of a large entropy contribution to the Gibbs free energy difference between the planar and perpendicular conformers which is the order of the rotational barrier (≈4 kJ mol -1). This might be of interest for experimental study. The most stable complexes of thiophenol with the gold clusters Au 5 and Au 6 are also investigated. It is shown that the sulfur atom prefers to anchor to two- and three-coordinated atoms of gold in these clusters to form a strongly directional gold-sulfur bond. The hydrogen abstraction from the S-H group of thiophenol bonded to the two-coordinated gold atom in Au 5 yields the bridging Au-S dibond and results in a spectacular reduction of the bond dissociation energy of thiophenol by nearly a factor of three.

    14. 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.

    15. 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.

    16. Atteinte cardiaque au cours de la dystrophie myotonique de Steinert: expérience marocaine, à propos de 18 cas

      PubMed Central

      Saghi, Ghita; Bouhouch, Rachida; Salaheddine, Loubna; Birouk, Nezha; Nadifi, Salama; Fellat, Ibtissam; Cherti, Mohamed

      2015-01-01

      La maladie de Steinert ou dystrophie myotonique de type 1 (DM1) est une maladie génétique à transmission autosomique dominante caractérisée par une myotonie et une atteinte de plusieurs organes dont le cœur. L'atteinte cardiaque est la plus grave des atteintes systémiques puisqu'elle conditionne le pronostic vital. Ce travail a pour but de déterminer les anomalies cardiaques rencontrées au cours de la DM1 et de mettre en exergue l'intérêt d'un examen cardiaque rigoureux et régulier, indépendamment de la sévérité de l'atteinte neuromusculaire, ainsi que l'apport des examens cardiaques complémentaires et notamment l'exploration électrophysiologique. 18 patients atteints de DM1 ont bénéficiés d'une exploration cardiaque systématique. Il s'agit de 9 hommes et de 9 femmes, d’âge moyen de 41,8 +/- 16,2 ans. 66 p.100 des patients sont symptomatiques sur le plan cardiovasculaire. Les anomalies électrocardiographiques sont dominées par un trouble de la conduction intra-ventriculaire dans 16 p.100 des cas et un BAV de 1er degré dans 16 p.100 des cas. L'Holter ECG objective une hyperexcitabilité à l’étage atrial et/ou ventriculaire dans 50p.100 des cas. L'ETT est normale chez 95 p.100 des patients. L'exploration électrophysiologique, réalisée chez 4 patients symptomatiques, a objectivé un bloc tronculaire dans un cas ayant conduit à l'implantation d'un PM double chambre. Un seul patient est décédé suite à une détresse respiratoire. Enfin, on n'a pas noté de corrélation entre l'atteinte cardiaque et neuromusculaire. Une exploration cardiaque est indispensable chez tout patient atteint de DM1, en dépit de l'absence de symptômes, et un bilan annuel minimal s'impose pour guetter un éventuel trouble rythmique et/ou conductif, fatal en l'absence de traitement adéquat. PMID:26097635

    17. Autonomous Repair Mechanism of Creep Damage in Fe-Au and Fe-Au-B-N Alloys

      NASA Astrophysics Data System (ADS)

      Zhang, S.; Kwakernaak, C.; Tichelaar, F. D.; Sloof, W. G.; Kuzmina, M.; Herbig, M.; Raabe, D.; Brück, E.; van der Zwaag, S.; van Dijk, N. H.

      2015-12-01

      The autonomous repair mechanism of creep cavitation during high-temperature deformation has been investigated in Fe-Au and Fe-Au-B-N alloys. Combined electron-microscopy techniques and atom probe tomography reveal how the improved creep properties result from Au precipitation within the creep cavities, preferentially formed on grain boundaries oriented perpendicular to the applied stress. The selective precipitation of Au atoms at the free creep cavity surface results in pore filling, and thereby, autonomous repair of the creep damage. The large difference in atomic size between the Au and Fe strongly hampers the nucleation of precipitates in the matrix. As a result, the matrix acts as a reservoir for the supersaturated solute until damage occurs. Grain boundaries and dislocations are found to act as fast transport routes for solute gold from the matrix to the creep cavities. The mechanism responsible for the self-healing can be characterized by a simple model for cavity growth and cavity filling.

    18. Observation of D0 meson nuclear modifications in Au+Au collisions at sNN=200 GeV

      DOE PAGES

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

      2014-09-30

      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+Aucollisions 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 andmore » coalescence hadronization describe our measurements.« less

    19. Au@AuPt nanoparticles embedded in B-doped graphene: A superior electrocatalyst for determination of rutin

      NASA Astrophysics Data System (ADS)

      Chen, Xianlan; Yang, Guangming; Feng, Shaoping; Shi, Ling; Huang, Zhaolong; Pan, Haibo; Liu, Wei

      2017-04-01

      A hydrothermal approach was used to prepare B-doped graphene with B2O3 as reductant and boron source. Results reveal that the boron atoms have been successfully embedded into graphene with a high content of a total B species (2.85 at.%). Then, B-doped graphene was exfoliated further into monolayer nanosheet by impregnating Au@AuPt core-shell nanoparticles (Au@AuPt NPs) because boron atom creates a net positive charge, which facilitates Au@AuPt NPs adsorption to form Au@AuPt NPs/B-doped graphene hybrid nanocatalysts. After that, the Au@AuPt NPs/B-doped hybrid suspension was dropped on glassy carbon electrode for sensing rutin. In this way, the dispersed carboxyl units of B-doped graphene can form hydrogen bonding with the phenolic hydroxyl groups of rutin, making rutin enrich easily on modified electrode surface to enhance the electrochemical response. At the same time, its electrochemical mechanism on the modified electrode was elucidated using cyclic voltammetry. It was found that its electrochemical behavior on modified electrode surface was a surface-controlled quasi-reversible process, and the charge transfer coefficient (α) and electron transfer number (n) were 0.296 and 2, respectively. This electrochemical sensor for rutin provided a wide linear response range of 2.00 × 10-9-4.00 × 10-6 M with the detection limit (S/N = 3) of 2.84 × 10-10 M. The proposed method was applied successfully to selective determination of rutin in Tablets with acceptable recovery range (97.23-101.65%).

    20. Medium-sized Au40(SR)24 and Au52(SR)32 nanoclusters with distinct gold-kernel structures and spectroscopic features

      NASA Astrophysics Data System (ADS)

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

      2016-01-01

      We have analyzed the structures of two medium-sized thiolate-protected gold nanoparticles (RS-AuNPs) Au40(SR)24 and Au52(SR)32 and identified the distinct structural features in their Au kernels [Sci. Adv., 2015, 1, e1500425]. We find that both Au kernels of the Au40(SR)24 and Au52(SR)32 nanoclusters can be classified as interpenetrating cuboctahedra. Simulated X-ray diffraction patterns of the RS-AuNPs with the cuboctahedral kernel are collected and then compared with the X-ray diffraction patterns of the RS-AuNPs of two other prevailing Au-kernels identified from previous experiments, namely the Ino-decahedral kernel and icosahedral kernel. The distinct X-ray diffraction patterns of RS-AuNPs with the three different types of Au-kernels can be utilized as signature features for future studies of structures of RS-AuNPs. Moreover, the simulated UV/Vis absorption spectra and Kohn-Sham orbital energy-level diagrams are obtained for the Au40(SR)24 and Au52(SR)32, on the basis of time-dependent density functional theory computation. The extrapolated optical band-edges of Au40(SR)24 and Au52(SR)32 are 1.1 eV and 1.25 eV, respectively. The feature peaks in the UV/Vis absorption spectra of the two clusters can be attributed to the d --> sp electronic transition. Lastly, the catalytic activities of the Au40(SR)24 and Au52(SR)32 are examined using CO oxidation as a probe. Both medium-sized thiolate-protected gold clusters can serve as effective stand-alone nanocatalysts.We have analyzed the structures of two medium-sized thiolate-protected gold nanoparticles (RS-AuNPs) Au40(SR)24 and Au52(SR)32 and identified the distinct structural features in their Au kernels [Sci. Adv., 2015, 1, e1500425]. We find that both Au kernels of the Au40(SR)24 and Au52(SR)32 nanoclusters can be classified as interpenetrating cuboctahedra. Simulated X-ray diffraction patterns of the RS-AuNPs with the cuboctahedral kernel are collected and then compared with the X-ray diffraction patterns of the RS-Au

    1. Synthese, etude structurale et electrochimique des materiaux d'electrode positive d'oxydes mixtes lithium cobalt nickel oxide (0 /= 1) pour les batteries rechargeables au lithium

      NASA Astrophysics Data System (ADS)

      Grincourt, Yves

      Depuis une dizaine d'annees, on observe un interet grandissant pour les batteries rechargeables au lithium de tension superieure a 4 volts. La commercialisation de ces batteries pour l'electronique grand marche tend de plus en plus a supplanter celle des accumulateurs Ni-Cd et Ni-MH, de tension nominate 1,2 V. Ces batteries au lithium font appel a des materiaux d'electrode positive (cathode a la decharge) du type oxydes mixtes de metaux de transition LiMnO 2, LiMn2O4, LiNiO2 ou LiCoO2. Si le compose LiCoO2 est relativement aise a synthetiser, il n'en demeure pas moins que le cobalt reste un metal plus couteux compare au nickel et au manganese. La synthese de LiNiO2, quart a elle, demeure un probleme du point de vue stoechiometrique. Un defaut de lithium (5 a 10% molaire) conduira a des proprietes electrochimiques mediocres de la batterie. Dans cette etude nous nous proposons donc de preparer par voie humide et par voie seche les materiaux d'electrode positive de la famille LiCoyNi1-yO2 aver (0 ≤ y ≤ 1) et d'etudier en detail l'influence du pourcentage de nickel et de cobalt sur les proprietes electrochimiques des oxydes mixtes Li-Ni-Co. Une des caracteristiques est la morphologie plus fine des poudres de materiaux, observes par microscopie electronique a balayage (MEB). Un traitement thermique a plus basse temperature (750°C) que pour LiCoO2 (850°C) ainsi qu'un leger exces de lithium dans la preparation, ont permis d'aboutir a un materiau de stoechiometrie quasi parfaite. Neanmoins, le role de pilfer joue par 2 a 4% de moles de Ni2+ presents sur les sites lithium, permet de conserver intacte la structure hexagonale de la maille entre deux cycles consecutifs. Afin de mieux comprendre l'influence du vieillissement dune demi-pile Li/LiMeO2 (Me = Ni, Co) a temperature ambiante, des etudes electrochimiques et d'impedance spectroscopique ont ete menees en parallele. Le vieillissement de la cellule s'accompagne seulement dune chute de son potentiel due a son auto

    2. Electron transfer catalysis with monolayer protected Au25 clusters

      NASA Astrophysics Data System (ADS)

      Antonello, Sabrina; Hesari, Mahdi; Polo, Federico; Maran, Flavio

      2012-08-01

      Au25L18 (L = S(CH2)2Ph) clusters were prepared and characterized. The resulting monodisperse clusters were reacted with bis(pentafluorobenzoyl) peroxide in dichloromethane to form Au25L18+ quantitatively. The kinetics and thermodynamics of the corresponding electron transfer (ET) reactions were characterized via electrochemistry and thermochemical calculations. Au25L18+ was used in homogeneous redox catalysis experiments with a series of sym-substituted benzoyl peroxides, including the above peroxide, bis(para-cyanobenzoyl) peroxide, dibenzoyl peroxide, and bis(para-methoxybenzoyl) peroxide. Peroxide dissociative ET was catalyzed using both the Au25L18/Au25L18- and the Au25L18+/Au25L18 redox couples as redox mediators. Simulation of the CV curves led to determination of the ET rate constant (kET) values for concerted dissociative ET to the peroxides. The ET free energy ΔG° could be estimated for all donor-acceptor combinations, leading to observation of a nice activation-driving force (log kETvs. ΔG°) relationship. Comparison with the kET obtained using a ferrocene-type donor with a formal potential similar to that of Au25L18/Au25L18- showed that the presence of the capping monolayer affects the ET rate rather significantly, which is attributed to the intrinsic nonadiabaticity of peroxide acceptors.Au25L18 (L = S(CH2)2Ph) clusters were prepared and characterized. The resulting monodisperse clusters were reacted with bis(pentafluorobenzoyl) peroxide in dichloromethane to form Au25L18+ quantitatively. The kinetics and thermodynamics of the corresponding electron transfer (ET) reactions were characterized via electrochemistry and thermochemical calculations. Au25L18+ was used in homogeneous redox catalysis experiments with a series of sym-substituted benzoyl peroxides, including the above peroxide, bis(para-cyanobenzoyl) peroxide, dibenzoyl peroxide, and bis(para-methoxybenzoyl) peroxide. Peroxide dissociative ET was catalyzed using both the Au25L18/Au25L18- and

    3. 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.

    4. Corrosion behavior and microstructures of experimental Ti-Au alloys.

      PubMed

      Takahashi, Masatoshi; Kikuchi, Masafumi; Takada, Yukyo; Okuno, Osamu; Okabe, Toru

      2004-06-01

      Anodic polarization was performed in 0.9% NaCl and 1% lactic acid solutions to characterize the relationship between the corrosion behavior and microstructures of cast Ti-Au (5-40%) alloys. An abrupt increase in the current density occurred at approximately 0.6 V vs. SCE for the 30% and 40% Au alloys in the 0.9% NaCl solution. The microstructures after corrosion testing indicated that this breakdown may have been caused by the preferential dissolution of the Ti3Au. However, the potential for preferential dissolution was higher than the breakdown potential of stainless steel or Co-Cr alloy, which meant that the corrosion resistance of the Ti-Au alloys was superior. In 1% lactic acid solution, the corrosion resistance of the Ti-Au alloys was excellent, with no breakdown at any composition. In the present test solutions, the Ti-Au alloys up to 20% Au had good corrosion resistance comparable to that for pure titanium.

    5. EXAFS and XANES structural characterization of bimetallic AuPd vapor derived catalysts

      NASA Astrophysics Data System (ADS)

      Balerna, A.; Evangelisti, C.; Schiavi, E.; Vitulli, G.; Bertinetti, L.; Martra, G.; Mobilio, S.

      2013-04-01

      Using an innovative procedure known as metal vapor synthesis (MVS) to prepare bimetallic catalysts, starting from Au and Pd vapors, [AuPd] co-evaporated and [Au][Pd] separately evaporated bimetallic catalysts were achieved. After being tested, the catalytic activity and selectivity of the [AuPd] catalyst turned out to be higher than the [Au][Pd] ones. Using EXAFS spectroscopy it was shown that, in the [AuPd] samples, small bimetallic AuPd nanoparticles were present, having an Au rich core surrounded by an AuPd alloyed shell while in the [Au][Pd] sample there was the presence of monometallic Au and Pd nanoparticles showing some alloying only in the boundary regions. The EXAFS results were also qualitatively confirmed by the XANES spectra.

    6. Crystal Structure of the PdAu24(SR)180 Superatom

      PubMed Central

      Tofanelli, Marcus A.; Ni, Thomas W.; Phillips, Billy D.

      2016-01-01

      The single-crystal x-ray structure of Pd doped Au25(SR)18 was solved. The crystal structure reveals that in PdAu24(SR)18, the Pd atom is localized only to the centroid of the Au25(SR)18 cluster. This single crystal x-ray structure shows that PdAu24(SR)180 is well conceptualized with superatom theory. The PdAu24(SR)180 charge state is structurally isoelectronic with Au25(SR)18+1 as determined by a first order Jahn-Teller effect of similar magnitude and by electrochemical comparison. The previously reported increased stability of PdAu24(SR)18 can be rationalized in terms of Pd-Au bonds that are shorter than the Au-Au bonds in Au25(SR)18. PMID:26760220

    7. Structural, electronic and magnetic properties of Au-based monolayer derivatives in honeycomb structure

      NASA Astrophysics Data System (ADS)

      Kapoor, Pooja; Sharma, Munish; Kumar, Ashok; Ahluwalia, P. K.

      2016-05-01

      We present electronic properties of atomic layer of Au, Au2-N, Au2-O and Au2-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 4G0. Similarly, Au2-N and Au2-F monolayers show 4G0 and 2G0 quantum conductance respectively while semiconducting nature with calculated band gap of 0.28 eV has been observed for Au2-O monolayer. Most interestingly, half metalicity has been predicted for Au2-N and Au2-F monolayers. Our findings may have importance for the application of these monolayers in nanoelectronic and spintronics.

    8. Controlling Au Photodeposition on Large ZnO Nanoparticles.

      PubMed

      Fernando, Joseph F S; Shortell, Matthew P; Noble, Christopher J; Harmer, Jeffrey R; Jaatinen, Esa A; Waclawik, Eric R

      2016-06-08

      This study investigated how to control the rate of photoreduction of metastable AuCl2(-) at the solid-solution interface of large ZnO nanoparticles (NPs) (50-100 nm size). Band-gap photoexcitation of electronic charge in ZnO by 370 nm UV light yielded Au NP deposition and the formation of ZnO-Au NP hybrids. Au NP growth was observed to be nonepitaxial, and the patterns of Au photodeposition onto ZnO NPs observed by high-resolution transmission electron microscopy were consistent with reduction of AuCl2(-) at ZnO facet edges and corner sites. Au NP photodeposition was effective in the presence of labile oleylamine ligands attached to the ZnO surface; however, when a strong-binding dodecanethiol ligand coated the surface, photodeposition was quenched. Rates of interfacial electron transfer at the ZnO-solution interface were adjusted by changing the solvent, and these rates were observed to strongly depend on the solvent's permittivity (ε) and viscosity. From measurements of electron transfer from ZnO to the organic dye toluidine blue at the ZnO-solution interface, it was confirmed that low ε solvent mixtures (ε ≈ 9.5) possessed markedly higher rates of photocatalytic interfacial electron transfer (∼3.2 × 10(4) electrons·particle(-1)·s(-1)) compared to solvent mixtures with high ε (ε = 29.9, ∼1.9 × 10(4) electrons·particle(-1)·s(-1)). Dissolved oxygen content in the solvent and the exposure time of ZnO to band-gap, near-UV photoexcitation were also identified as factors that strongly affected Au photodeposition behavior. Production of Au clusters was favored under conditions that caused electron accumulation in the ZnO-Au NP hybrid. Under conditions where electron discharge was rapid (such as in low ε solvents), AuCl2(-) precursor ions photoreduced at ZnO surfaces in less than 5 s, leading to deposition of several small, isolated ∼6 nm Au NP on the ZnO host instead.

    9. 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.

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

      SciTech Connect

      Cheng, Zhongzhou; Wang, Zhenxing E-mail: hej@nanoctr.cn; Shifa, Tofik Ahmed; Wang, Fengmei; Zhan, Xueying; Xu, Kai; He, Jun E-mail: hej@nanoctr.cn; Liu, Quanlin

      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 optimize the type-II structures for photocatalytic water splitting.

    11. 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

    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

      SciTech Connect

      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 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 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.

    13. 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 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 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

    14. Gold surfaces and nanoparticles are protected by Au(0)-thiyl species and are destroyed when Au(I)-thiolates form.

      PubMed

      Reimers, Jeffrey R; Ford, Michael J; Halder, Arnab; Ulstrup, Jens; Hush, Noel S

      2016-03-15

      The synthetic chemistry and spectroscopy of sulfur-protected gold surfaces and nanoparticles is analyzed, indicating that the electronic structure of the interface is Au(0)-thiyl, with Au(I)-thiolates identified as high-energy excited surface states. Density-functional theory indicates that it is the noble character of gold and nanoparticle surfaces that destabilizes Au(I)-thiolates. Bonding results from large van der Waals forces, influenced by covalent bonding induced through s-d hybridization and charge polarization effects that perturbatively mix in some Au(I)-thiolate character. A simple method for quantifying these contributions is presented, revealing that a driving force for nanoparticle growth is nobleization, minimizing Au(I)-thiolate involvement. Predictions that Brust-Schiffrin reactions involve thiolate anion intermediates are verified spectroscopically, establishing a key feature needed to understand nanoparticle growth. Mixing of preprepared Au(I) and thiolate reactants always produces Au(I)-thiolate thin films or compounds rather than monolayers. Smooth links to O, Se, Te, C, and N linker chemistry are established.

    15. Crystal structures and magnetic properties of CeAu 4Si 2 and CeAu 2Si 2

      NASA Astrophysics Data System (ADS)

      Sefat, Athena S.; Palasyuk, Andriy M.; Bud'ko, Sergey L.; Corbett, John D.; Canfield, Paul C.

      2008-02-01

      Single crystals of CeAu 4Si 2 and CeAu 2Si 2 have been grown out of ternary fluxes rich in Au, and the former, also by sintering the stoichiometric composition at 750 °C. The single-crystal X-ray refinement result for CeAu 4Si 2 is orthorhombic, Cmmm (No. 65, Z=2), different from a tetragonal result found from an X-ray powder diffraction refinement [H. Nakashima, et al., J. Alloys Compds. 424 (2006) 7]. For CeAu 2Si 2, this is the first report of the stoichiometric crystalline phase, in the known tetragonal I4/ mmm structure. The anisotropic field- and temperature-dependent magnetizations, as well as specific heat and resistivity data are compared. Although both compounds have related structural packing, they present unique magnetic features. CeAu 2Si 2 is a typical antiferromagnet with TN=8.8(1) K and CeAu 4Si 2 features a ferromagnetic component below Tc=3.3(1) K. Both phases have effective moments close in value to that of free Ce 3+.

    16. Crystal structures and magnetic properties of CsAu4Si2 and CeAu2Si2

      SciTech Connect

      Sefat, A.; Palasyuk, A.; Bud'ko, S.; Corbett, J.; Canfield, P.

      2007-12-03

      Single crystals of CeAu{sub 4}Si{sub 2} and CeAu{sub 2}Si{sub 2} have been grown out of ternary fluxes rich in Au, and the former, also by sintering the stoichiometric composition at 750 C. The single-crystal X-ray refinement result for CeAu{sub 4}Si{sub 2} is orthorhombic, Cmmm (No. 65, Z=2), different from a tetragonal result found from an X-ray powder diffraction refinement [H. Nakashima, et al., J. Alloys Compds. 424 (2006) 7]. For CeAu{sub 2}Si{sub 2}, this is the first report of the stoichiometric crystalline phase, in the known tetragonal I4/mmm structure. The anisotropic field- and temperature-dependent magnetizations, as well as specific heat and resistivity data are compared. Although both compounds have related structural packing, they present unique magnetic features. CeAu{sub 2}Si{sub 2} is a typical antiferromagnet with T{sub N} = 8.8(1) K and CeAu{sub 4}Si{sub 2} features a ferromagnetic component below T{sub c}=3.3(1) K. Both phases have effective moments close in value to that of free Ce{sup 3+}.

    17. Effects of Au layer thickness and number of bilayers on the properties of Au/ZnO multilayers

      SciTech Connect

      Cespedes, Eva; Prieto, Carlos; Babonneau, David; Sousa Meneses, Domingos de; Fonda, Emiliano; Lyon, Olivier; Briand, Emrick; Traverse, Agnes

      2011-05-01

      Multilayered films of Au/ZnO were prepared by physical vapor deposition. Varying the Au thickness, t{sub Au}, and the number of bilayers, n, allowed us to investigate the role of these parameters on the sample structural and electronic properties. X-ray diffraction, X-ray absorption spectroscopy, grazing incidence small angle X-ray scattering and transmission electron microscopy experiments, have been combined to UV-visible and infrared spectroscopy to characterize the multilayers in the as-prepared state and after annealing. In the as-prepared state, the strong Au and ZnO lattice interaction leads to ZnO epitaxy on Au. Gold appears either as continuous layers or in form of nanoparticles. ZnO experiences a structural transformation from wurztite to rock salt monitored by the Au morphology. Annealing at 500 deg. C destroys the lattice matching. The electronic and optical properties of the systems are understood in line with the Au morphology and ZnO structural state.

    18. 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

    19. Characterization of Pt-Au and Ni-Au Clusters on TiO2(110)

      SciTech Connect

      S Tenney; W He; J Ratliff; D Mullins; D Chen

      2011-12-31

      The surface composition and properties of Pt-Au and Ni-Au clusters on TiO{sub 2}(110) have been studied by scanning tunneling microscopy (STM), low energy ion scattering (LEIS) and soft X-ray photoelectron spectroscopy (sXPS). STM studies show that bimetallic clusters are formed during sequential deposition of the two metals, regardless of the order of deposition. At the 2 ML of Au/2 ML of Pt or Ni coverages studied here, the second metal contributes to the growth of existing clusters rather than forming new pure metal clusters. LEIS experiments demonstrate that the surfaces of the bimetallic clusters are almost 100% Au when 2 ML of Au is deposited on top of 2 ML of Pt or Ni. However, a much larger fraction of Pt or Ni (50 and 20%, respectively) remains at the surface when 2 ML of Pt or Ni is deposited on 2 ML of Au, most likely due to limited diffusion of atoms within the clusters at room temperature. According to sXPS investigations, the binding energies of the metals in the bimetallic clusters are shifted from those observed for pure metal clusters; the Pt(4f{sub 7/2}) and Ni(3p{sub 3/2}) peaks are shifted to lower binding energies while the position of the Au(4f{sub 7/2}) peak is dominated by surface core level shifts. Pure Pt clusters as well as 0.4 ML of Au on 2 ML of Pt clusters reduce the titania support upon encapsulation after annealing to 800 K, whereas 2 ML of Au on 2 ML of Pt clusters do not reduce titania, presumably because there is no Pt at the surface of the clusters. Pure Ni clusters are also known to become encapsulated upon heating, but the reduction of titania is much less extensive compared to that of pure Pt clusters.

    20. Recherche de leptons lourds au LEP 2

      NASA Astrophysics Data System (ADS)

      Tafirout, Reda

      En 1989, la mise en opération de la première phase du LEP (le LEP 1), au CERN, a une Energie correspondant a la résonance du boson Z0, a permis d'étudier et de confirmer avec une grande précision le Modèle Standard des interactions électrofaibles. Malgré le succès remarquable de ce modèle à décrire toutes les données expérimentales recueillies jusqu'à ce jour en physique des hautes énergies, ce dernier laisse plusieurs questions sans réponse. Il n'explique pas entre autres pourquoi il n'y a que trois familles de particules dont le neutrino associé est léger et la hiérarchie des masses observées des fermions reste une énigme. Ici, nous nous intéressons à l'existence éventuelle de nouveaux fermions, tels que prédits par des extensions du Modèle Standard. Ces nouveaux fermions ont été recherches au LEP 1, mais en vain, et une limite inférieure sur leur masse d'environ MZ/2 a pu être imposée. La deuxième phase du LEP (le LEP 2) qui a débuté dans l'automne 1995 avec une énergie disponible de √s = 130, et 136 GeV, puis dans l'été 1996 a √s = 161 GeV a permis d'améliorer ces limites. Nous présentons ici la recherche de leptons lourds, neutres (N) et chargés (L+/-), effectuée à partir des données recueillies dans l'automne 1996 avec le détecteur de la collaboration OPAL au LEP 2, à des énergies au centre de masse de √s = 170 et 172 GeV. La luminosité totale intégrée fut de 10.3 pb-1. Un nouveau générateur, EXOTIC, conçu et développé a cette fin, a été utilise pour la simulation des échantillons d'événements Monte Carlo qui ont servi à comparer les données obtenues avec les prédictions théoriques. Plus spécifiquement, nous avons recherché le processus e+e- --> NN où N, pouvant être de type Dirac ou Majorana, se désintègre en un lepton léger standard (e, μ, ou τ) et un boson W+/- virtuel (W+/-*). Pour un N de type Dirac, une limite inférieure sur la masse à 95% de niveau de confiance est obtenue

    1. The AuScope geodetic VLBI array

      NASA Astrophysics Data System (ADS)

      Lovell, J. E. J.; McCallum, J. N.; Reid, P. B.; McCulloch, P. M.; Baynes, B. E.; Dickey, J. M.; Shabala, S. S.; Watson, C. S.; Titov, O.; Ruddick, R.; Twilley, R.; Reynolds, C.; Tingay, S. J.; Shield, P.; Adada, R.; Ellingsen, S. P.; Morgan, J. S.; Bignall, H. E.

      2013-06-01

      The AuScope geodetic Very Long Baseline Interferometry array consists of three new 12-m radio telescopes and a correlation facility in Australia. The telescopes at Hobart (Tasmania), Katherine (Northern Territory) and Yarragadee (Western Australia) are co-located with other space geodetic techniques including Global Navigation Satellite Systems (GNSS) and gravity infrastructure, and in the case of Yarragadee, satellite laser ranging (SLR) and Doppler Orbitography and Radiopositioning Integrated by Satellite (DORIS) facilities. The correlation facility is based in Perth (Western Australia). This new facility will make significant contributions to improving the densification of the International Celestial Reference Frame in the Southern Hemisphere, and subsequently enhance the International Terrestrial Reference Frame through the ability to detect and mitigate systematic error. This, combined with the simultaneous densification of the GNSS network across Australia, will enable the improved measurement of intraplate deformation across the Australian tectonic plate. In this paper, we present a description of this new infrastructure and present some initial results, including telescope performance measurements and positions of the telescopes in the International Terrestrial Reference Frame. We show that this array is already capable of achieving centimetre precision over typical long-baselines and that network and reference source systematic effects must be further improved to reach the ambitious goals of VLBI2010.

    2. 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.

    3. 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.

    4. Ethylene binding to Au/Cu alloy nanoparticles

      NASA Astrophysics Data System (ADS)

      Gammage, Michael D.; Stauffer, Shannon; Henkelman, Graeme; Becker, Michael F.; Keto, John W.; Kovar, Desiderio

      2016-11-01

      Weak chemisorption of ethylene has been shown to be an important characteristic in the use of metals for the separation of ethylene from ethane. Previously, density functional theory (DFT) has been used to predict the binding energies of various metals and alloys, with Ag having the lowest chemisorption energy amongst the metals and alloys studied. Here Au/Cu alloys are investigated by a combination of DFT calculations and experimental measurements. It is inferred from experiments that the binding energy between a Au/Cu alloy and ethylene is lower than to either of the pure metals, and DFT calculations confirm that this is the case when Au segregates to the particle surface. Implications of this work suggest that it may be possible to further tune the binding energy with ethylene by compositional and morphological control of films produced from Au-surface segregated alloys.

    5. Tunable optical properties of nano-Au on vanadium dioxide

      NASA Astrophysics Data System (ADS)

      Xu, Gang; Huang, Chun-Ming; Tazawa, Masato; Jin, Ping; Chen, Li-Hua

      2009-03-01

      The optical properties of Au nanoparticles deposited on thermochromic thin films of VO2 are investigated using spectroscopy. A localized modification on the transmittance spectrum of VO2 film is formed due to the presence of Au nanoparticles which exhibit localized surface plasmon resonance (LSPR) in the visible-near IR region. The position of the modification wavelength region shows a strong dependence on the Au mass thickness and shifts toward the red as it increases. On the other hand, it was found that the LSPR of Au nanoparticles can be thermally tunable because of the thermochromism of the supporting material of VO2. The LSPR wavelength, λSPR, shifts to the blue with increasing temperature, and shifts back to the red as temperature decreases. A fine tuning is achieved when the temperature is increased in a stepwise manner.

    6. Solvent: A Key in Digestive Ripening for Monodisperse Au Nanoparticles

      NASA Astrophysics Data System (ADS)

      Wang, Peng; Qi, Xuan; Zhang, Xuemin; Wang, Tieqiang; Li, Yunong; Zhang, Kai; Zhao, Shuang; Zhou, Jun; Fu, Yu

      2017-01-01

      This work has mainly investigated the influence of the solvent on the nanoparticles distribution in digestive ripening. The experiments suggested that the solvents played a key role in digestive ripening of Au nanoparticles (Au NPs). For the benzol solvents, the resulting size distribution of Au NPs was inversely related to the solvent polarity. It may be interpreted by the low Gibbs free energy of nanoparticles in the high polarity medium, which was supposedly in favor of reducing the nanoparticles distribution. Through digestive ripening in the highly polar benzol solvent of p-chlorotoluene, monodisperse Au NPs with relative standard deviation (RSD) of 4.8% were achieved. This indicated that digestive ripening was an effective and practical way to prepare high-quality nanoparticles, which holds great promise for the nanoscience and nanotechnology.

    7. Assembling Bare Au Nanoparticles at Positively Charged Templates

      PubMed Central

      Wang, Wenjie; Zhang, Honghu; Kuzmenko, Ivan; Mallapragada, Surya; Vaknin, David

      2016-01-01

      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), display less in-plane regular packing compared to bare AuNPs. PMID:27225047

    8. Dynamic features of rod-shaped Au nanoclusters

      NASA Astrophysics Data System (ADS)

      So, Woong Young; Das, Anindita; Wang, Shuxin; Zhao, Shuo; Byun, Hee Young; Lee, Dana; Kumar, Santosh; Jin, Rongchao; Peteanu, Linda A.

      2015-08-01

      Gold nanoclusters hold many potential applications such as biosensing and optics due to their emission characteristics, small size, and non-toxicity. However, their low quantum yields remain problematic for further applications, and their fluorescence mechanism is still unclear. To increase the low quantum yields, various methods have been performed: doping, tuning structures, and changing number of gold atoms. In the past, most characterizations have been performed on spherical shaped nanoclusters; in this paper, several characterizations of various rod-shaped Au nanoclusters specifically on Au25 are shown. It has been determined that the central gold atom in Au25 nano-rod is crucial in fluorescence. Furthermore, single molecule analysis of silver doped Au25 nano-rod revealed that it has more photo-stability than conjugated polymers and quantum dots.

    9. Assembling Bare Au Nanoparticles at Positively Charged Templates

      DOE PAGES

      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

    10. Assembling Bare Au Nanoparticles at Positively Charged Templates

      SciTech Connect

      Wang, Wenjie; Zhang, Honghu; Kuzmenko, Ivan; Mallapragada, Surya; Vaknin, David

      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), display less in-plane regular packing compared to bare AuNPs.

    11. Assembling Bare Au Nanoparticles at Positively Charged Templates

      NASA Astrophysics Data System (ADS)

      Wang, Wenjie; Zhang, Honghu; Kuzmenko, Ivan; Mallapragada, Surya; Vaknin, David

      2016-05-01

      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), display less in-plane regular packing compared to bare AuNPs.

    12. 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

    13. Intrinsic spin Seebeck effect in Au/YIG.

      PubMed

      Qu, D; Huang, S Y; Hu, Jun; Wu, Ruqian; Chien, C L

      2013-02-08

      The acute magnetic proximity effects in Pt/YIG compromise the suitability of Pt as a spin current detector. We show that Au/YIG, with no anomalous Hall effect and a negligible magnetoresistance, allows the measurements of the intrinsic spin Seebeck effect with a magnitude much smaller than that in Pt/YIG. The experiment results are consistent with the spin polarized density functional calculations for Pt with a sizable and Au with a negligible magnetic moment near the interface with YIG.

    14. Melting curve of metals Cu, Ag and Au under pressure

      NASA Astrophysics Data System (ADS)

      Tam, Pham Dinh; Hoc, Nguyen Quang; Tinh, Bui Duc; Tan, Pham Duy

      2016-01-01

      In this paper, the dependence of the melting temperature of metals Cu, Ag and Au under pressure in the interval from 0 kbar to 40 kbar is studied by the statistical moment method (SMM). This dependence has the form of near linearity and the calculated slopes of melting curve are 3.9 for Cu, 5.7 for Ag and 6 for Au. These results are in good agreement with the experimental data.

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

      SciTech Connect

      Wang, Jun; McEntee, Monica; Tang, Wenjie; Neurock, Matthew; Baddorf, Arthur P.; Maksymovych, Petro; Yates, Jr, John T.

      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 Au 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.

    16. Synthetic routes to [Au(NHC)(OH)] (NHC = N-heterocyclic carbene) complexes.

      PubMed

      Gómez-Suárez, Adrián; Ramón, Rubén S; Slawin, Alexandra M Z; Nolan, Steven P

      2012-05-14

      New procedures for the synthesis of [Au(NHC)(OH)] are reported. Initially, a two-step reaction via the digold complex [{Au(NHC)}(2)(μ-OH)][BF(4)] was probed, enabling the preparation of the novel [Au(SIPr)(OH)] complex and of its previously reported congener [Au(IPr)(OH)]. After further optimization, a one-step procedure was developed.

    17. Derivatives of the thiolate-protected gold cluster Au25(SR)18 -1

      NASA Astrophysics Data System (ADS)

      Lopez-Acevedo, O.; Häkkinen, H.

      2011-07-01

      Loss of small fragments (like AuL, Au2L3, Au4L4) have been found systematically in several MALDI and FAB experiments on thiolate-protected gold clusters of different sizes. When using the cluster Au25L18 -1 as parent cluster, the fragmented cluster Au21L14 -1 has been reported to be obtained in high proportion (L = SCH2CH2Ph). Here we analyse a few possible fragmentation patterns of the well-known parent cluster Au25L18 -1 (L = SCH3). Using DFT calculations we study the different atomic configurations obtained after a AuL fragment is lost from Au25L18 -1. We found energetically favourable configurations that can be written as Au13 [Au2L3]6- z [AuL2] z -1, where the modification can be described as a replacement of the long protecting unit by a short one (Au2L3 → AuL2). A full replacement ( z = 6) gives rise to a protected Au19L12 -1 cluster. This mechanism does not modify the super-atomic electronic structure of the gold core, i.e., all these fragments remain an 8 electron super-atom clusters exactly like the parent Au25L18 -1. We suggest that the Au19L12 -1 cluster could be realized by using a bulky thiolate, such as the tert-butyl thiolate SC(CH3)3.

    18. 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.

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

      SciTech Connect

      De Corte, S.; Fitts, J.; Hennebel, T.; Sabbe, T.; Bliznuk, V.; Verschuere, S.; van der Lelie, D.; Verstraete, W.; Boon, N.

      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 diclofenac 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.

    20. Interfacial reactions in the Sn-Ag/Au couples

      NASA Astrophysics Data System (ADS)

      Chen, Sinn-Wen; Yen, Yee-Wen

      2001-09-01

      Ag-Sn alloys are one of the most promising lead-free solders. Their reactions with Au substrates have been examined by using the reaction couple technique. Sn-3.5wt.%Ag/Au and Sn-25wt.%Ag/Au couples have been prepared and reacted at 120, 150, 180 and 200 C for various lengths of time. Three phases, δ-AuSn, ɛ2-AuSn2, and η-AuSn4, are found in all the couples. The thickness of the reaction layers inccreases with higher temperatures and longer reaction time, and their growth rates are described by using the parabolic law. Arrhenius equation is used to describe the temperature dependence of the growth rates. The activation energy of the growth of the intermetallic layers in both kinds of the reaction couples is similar and is determined to be 76.74 KJ/mole. Based on the reaction path knowledge and interfacial morphology, it is concluded that Sn is the fastest diffusion species in the couples.

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

      NASA Astrophysics Data System (ADS)

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

      2015-11-01

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

    2. RHIC PERFORMANCE DURING THE FY10 200 GeV Au+Au HEAVY ION RUN

      SciTech Connect

      Brown, K.A.; Ahrens, L.; Bai, M.; Beebe-Wang, J.; Blaskiewicz, M.; Brennan, J.; Bruno, D.; Carlson, C.; Connolly, R.; de Maria, R.; D’Ottavio, T.; Drees, A.; Fischer, W.; Fu, W.; Gardner, C.; Gassner, D.; Glenn, J.W.; Hao, Y.; Harvey, M.; Hayes, T.; Hoff, L.; Huang, H.; Laster, J.; Lee, R.; Litvinenko, V.; Luo, Y.; MacKay, W.; Marr, G.; Marusic, A.; Mernick, K.; Michnoff, R.; Minty, M.; Montag, C.; Morris, J.; Nemesure, S.; Oerter, B.; Pilat, F.; Ptitsyn, V.; Robert-Demolaize, G.; Roser, T.; Russo, T.; Sampson, P.; Sandberg, J.; Satogata, T.; Severino, F.; Schoefer, V.; Schultheiss, C.; Smith, K.; Steski, D.; Tepikian, S.; Theisen, C.; Thieberger, P.; Trbojevic, D.; Tsoupas, N.; Tuozzolo, J.; Wang, G.; Wilinski, M.; Zaltsman, A.; Zeno, K.; Zhang, S.Y.

      2010-05-23

      Since the last successful RHIC Au+Au run in 2007 (Run-7), the RHIC experiments have made numerous detector improvements and upgrades. In order to benefit from the enhanced detector capabilities and to increase the yield of rare events in the acquired heavy ion data a significant increase in luminosity is essential. In Run-7 RHIC achieved an average store luminosity of = 12 x 10{sup 26} cm{sup -2} s{sup -1} by operating with 103 bunches (out of 111 possible), and by squeezing to {beta}* = 0.85 m. This year, Run-10, we achieved = 20 x 10{sup 26} cm{sup -2} s{sup -1}, which put us an order of magnitude above the RHIC design luminosity. To reach these luminosity levels we decreased {beta}* to 0.75 m, operated with 111 bunches per ring, and reduced longitudinal and transverse emittances by means of bunched-beam stochastic cooling. In addition we introduced a lattice to suppress intra-beam scattering (IBS) in both RHIC rings, upgraded the RF control system, and separated transition crossing times in the two rings. We present an overview of the changes and the results of Run-10 performance.

    3. A first look at Au+Au collisions at RHIC energies using the PHOBOS detector.

      SciTech Connect

      Back, B. B.; George, N.; Wousmaa, A. H.; Baker, M. D.; Barton, D. S.; PHOBOS Collaboration; Physics

      2003-05-01

      The PHOBOS detector has been used to study Au + Au collisions at {radical}sNN = 56,130, and 200 GeV Several global observables have been measured and the results are compared with theoretical models. These observables include the charged-particle multiplicity measured as a function of beam energy, pseudo-rapidity, and centrality of the collision. A unique feature of the PHOBOS detector is its almost complete angular coverage such that these quantities can be studied over a pseudo-rapidity interval of |{eta}|{<=}5.4. This allows for an almost complete integration of the total charged particle yield, which is found to be about N{sub ch}{sup tot} = 4200 {+-}470 at {radical}sNN = 130 GeV and N{sub ch}{sup tot} = 5300 {+-}530 at {radical}sNN = 200 GeV. The ratio of anti-particles to particles emitted in the mid-rapidity region has also been measured using the PHOBOS magnetic spectrometer. Of particular interest is the ratio of anti-protons to protons in the mid-rapidity region, which was found to be (i.e.921-1) at {radical}sNN = 130 GeV. This high value suggests that an almost baryon-free region has been produced in the collisions.

    4. Dilepton Results from HADES Using Au+Au Data at 1.23 AGeV

      NASA Astrophysics Data System (ADS)

      Franco, C.

      The High Acceptance DiElectron Spectrometer (HADES) at GSI was designed to investigate the properties of hadrons inside dense nuclear matter. The latter is created in heavy-ion collisions at energies of 1-2 AGeV. HADES is currently the only running experiment that studies the region in the QCD phase diagram of very high net-baryon densities and low temperatures. Similar conditions are also present in one of the most fascinating objects of the universe: the neutron stars. Therefore, HADES has also the potential to improve our knowledge concerning the properties of such stars. The best probes that one can use to investigate a strongly interacting baryon-rich medium are the dileptons emerging from virtual photon decays. Since electromagnetic probes decouple from the dense interaction region once they are produced, their phase space distributions carry information about the temperature and structure of the dense QCD medium. Preliminary dilepton results from the Au+Au data of HADES at 1.23 AGeV will be presented. The analysis method will also be discussed.

    5. Coherent electron-positron pair production in ultra-peripheral AuAu collisions at STAR

      NASA Astrophysics Data System (ADS)

      Rehbein, Matthew; STAR Collaboration

      2016-09-01

      The focus of this study is coherent photoproduction of electron-positron pairs in 200 GeV ultraperipheral AuAu collisions detected by STAR, with an integrated luminosity of 1.9 inverse nanobarns. Because hadronic interactions are suppressed in ultra-peripheral collisions, these events provide an opportunity to study purely electromagnetic interaction in the non-perturbative regime. This presentation will provide a description of the techniques used to select exclusive electron-positron events, as well as the resulting kinematic distributions for pair invariant mass greater than 0.35 GeV, pair transverse momentum less than 0.1 GeV, and absolute value of pair pseudorapidity less than 0.8. Efficiency correction techniques will also be discussed. In previous measurements at the same energy at STAR, the shape of the transverse momentum distribution could not be fully described by the equivalent photon approximation (EPA). Measurements at the LHC indicate that the cross section is reduced by approximately 25 percent compared to the EPA. This study ultimately seeks to examine these effects in more detail at RHIC energies. Partial funding provided by DOE Grant #DE-FG02-96ER40991.

    6. 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 .

    7. PHENIX results on low-mass dileptons in Au + Au collisions with the Hadron Blind Detector

      NASA Astrophysics Data System (ADS)

      Makek, M.

      2016-12-01

      We present e+e- continuum measurement in Au+Au collisions at √{sNN} = 200 GeV from the RHIC 2010 run with the Hadron Blind Detector upgrade of PHENIX. The measurement reaches a high purity of the electron sample of ≥ 95% at all centralities and provides an excellent qualitative and quantitative understanding of the background. The e+e- invariant yields show an enhancement in the low-mass region (mee = 0.30 - 0.76 GeV /c2) compared to the expectations from hadronic sources, but not as large as the one previously reported by PHENIX. The observed excess is well reproduced by models incorporating the broadening of the ρ meson due to scattering off baryons in the hot hadronic gas. The measured invariant yields in the intermediate-mass region (mee = 1.2 - 2.8 GeV /c2) leave room for additional sources when compared to the cocktail dominated by the semileptonic decays of heavy flavor mesons.

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

      SciTech Connect

      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, 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. As a result, 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.

    9. 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, 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. As a result, we alsomore » 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.« less

    10. 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.

    11. 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.; Chu, Y. Y.; Cianciolo, V.; Cole, B. A.; Crawford, H. J.; Cumming, J. B.; Debbe, R.; Dunlop, J. C.; Eldredge, W.; Engelage, J.; Fung, S.-Y.

      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.

    12. Scaling properties of proton and antiproton production in sqrt[s(NN)]=200 GeV Au+Au collisions.

      PubMed

      Adler, S S; Afanasiev, S; Aidala, C; Ajitanand, N N; Akiba, Y; Alexander, J; Amirikas, R; Aphecetche, L; Aronson, S H; Averbeck, R; Awes, T C; Azmoun, R; Babintsev, V; Baldisseri, A; Barish, K N; Barnes, P D; Bassalleck, B; Bathe, S; Batsouli, S; Baublis, V; Bazilevsky, A; Belikov, S; Berdnikov, Y; Bhagavatula, S; Boissevain, J G; Borel, H; Borenstein, S; Brooks, M L; Brown, D S; Bruner, N; Bucher, D; Buesching, H; Bumazhnov, V; Bunce, G; Burward-Hoy, J M; Butsyk, S; Camard, X; Chai, J-S; Chand, P; Chang, W C; Chernichenko, S; Chi, C Y; Chiba, J; Chiu, M; Choi, I J; Choi, J; Choudhury, R K; Chujo, T; Cianciolo, V; Cobigo, Y; Cole, B A; Constantin, P; d'Enterria, D G; David, G; Delagrange, H; Denisov, A; Deshpande, A; Desmond, E J; Dietzsch, O; Drapier, O; Drees, A; du Rietz, R; Durum, A; Dutta, D; Efremenko, Y V; El Chenawi, K; Enokizono, A; En'yo, H; Esumi, S; Ewell, L; Fields, D E; Fleuret, F; Fokin, S L; Fox, B D; Fraenkel, Z; Frantz, J E; Franz, A; Frawley, A D; Fung, S-Y; Garpman, S; Ghosh, T K; Glenn, A; Gogiberidze, G; Gonin, M; Gosset, J; Goto, Y; Granier de Cassagnac, R; Grau, N; Greene, S V; Grosse Perdekamp, G; Guryn, W; Gustafsson, H-A; Hachiya, T; Haggerty, J S; Hamagaki, H; Hansen, A G; Hartouni, E P; Harvey, M; Hayano, R; He, X; Heffner, M; Hemmick, T K; Heuser, J M; Hibino, M; Hill, J C; Holzmann, W; Homma, K; Hong, B; Hoover, A; Ichihara, T; Ikonnikov, V V; Imai, K; Isenhower, L D; Ishihara, M; Issah, M; Isupov, A; Jacak, B V; Jang, W Y; Jeong, Y; Jia, J; Jinnouchi, O; Johnson, B M; Johnson, S C; Joo, K S; Jouan, D; Kametani, S; Kamihara, N; Kang, J H; Kapoor, S S; Katou, K; Kelly, S; Khachaturov, B; Khanzadeev, A; Kikuchi, J; Kim, D H; Kim, D J; Kim, D W; Kim, E; Kim, G-B; Kim, H J; Kistenev, E; Kiyomichi, A; Kiyoyama, K; Klein-Boesing, C; Kobayashi, H; Kochenda, L; Kochetkov, V; Koehler, D; Kohama, T; Kopytine, M; Kotchetkov, D; Kozlov, A; Kroon, P J; Kuberg, C H; Kurita, K; Kuroki, Y; Kweon, M J; Kwon, Y; Kyle, G S; Lacey, R; Ladygin, V; Lajoie, J G; Lebedev, A; Leckey, S; Lee, D M; Lee, S; Leitch, M J; Li, X H; Lim, H; Litvinenko, A; Liu, M X; Liu, Y; Maguire, C F; Makdisi, Y I; Malakhov, A; Manko, V I; Mao, Y; Martinez, G; Marx, M D; Masui, H; Matathias, F; Matsumoto, T; McGaughey, P L; Melnikov, E; Messer, F; Miake, Y; Milan, J; Miller, T E; Milov, A; Mioduszewski, S; Mischke, R E; Mishra, G C; Mitchell, J T; Mohanty, A K; Morrison, D P; Moss, J M; Mühlbacher, F; Mukhopadhyay, D; Muniruzzaman, M; Murata, J; Nagamiya, S; Nagle, J L; Nakamura, T; Nandi, B K; Nara, M; Newby, J; Nilsson, P; Nyanin, A S; Nystrand, J; O'Brien, E; Ogilvie, C A; Ohnishi, H; Ojha, I D; Okada, K; Ono, M; Onuchin, V; Oskarsson, A; Otterlund, I; Oyama, K; Ozawa, K; Pal, D; Palounek, A P T; Pantuev, V S; Papavassiliou, V; Park, J; Parmar, A; Pate, S F; Peitzmann, T; Peng, J-C; Peresedov, V; Pinkenburg, C; Pisani, R P; Plasil, F; Purschke, M L; Purwar, A; Rak, J; Ravinovich, I; Read, K F; Reuter, M; Reygers, K; Riabov, V; Riabov, Y; Roche, G; Romana, A; Rosati, M; Rosnet, P; Ryu, S S; Sadler, M E; Saito, N; Sakaguchi, T; Sakai, M; Sakai, S; Samsonov, V; Sanfratello, L; Santo, R; Sato, H D; Sato, S; Sawada, S; Schutz, Y; Semenov, V; Seto, R; Shaw, M R; Shea, T K; Shibata, T-A; Shigaki, K; Shiina, T; Silva, C L; Silvermyr, D; Sim, K S; Singh, C P; Singh, V; Sivertz, M; 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; Sullivan, J P; Takagui, E M; Taketani, A; Tamai, M; Tanaka, K H; Tanaka, Y; Tanida, K; Tannenbaum, M J; Tarján, P; Tepe, J D; Thomas, T L; Tojo, J; Torii, H; Towell, R S; Tserruya, I; Tsuruoka, H; Tuli, S K; Tydesjö, H; Tyurin, N; Van Hecke, H W; Velkovska, J; Velkovsky, M; Villatte, L; Vinogradov, A A; Volkov, M A; Vznuzdaev, E; Wang, X R; Watanabe, Y; White, S N; Wohn, F K; Woody, C L; Xie, W; Yang, Y; Yanovich, A; Yokkaichi, S; Young, G R; Yushmanov, I E; Zajc, W A; Zhang, C; Zhou, S; Zolin, L

      2003-10-24

      We report on the yield of protons and antiprotons, as a function of centrality and transverse momentum, in Au+Au collisions at sqrt[s(NN)]=200 GeV measured at midrapidity by the PHENIX experiment at the BNL Relativistic Heavy Ion Collider. In central collisions at intermediate transverse momenta (1.5Au+Au, p+p, and e(+)e(-) collisions. This enhancement is limited to p(T)<5 GeV/c as deduced from the ratio of charged hadrons to pi(0) measured in the range 1.5

    13. Centrality definition using mid-rapidity E T distributions from p+Be to Au+Au at AGS energies

      NASA Astrophysics Data System (ADS)

      Tannenbaum, M. J.; E802 Collaboration

      1999-12-01

      Measurements by the E802 Collaboration of the A-dependence and pseudorapidity interval (δη) dependence of mid-rapidity E T distributions in a half-azimuth electromagnetic calorimeter are presented for p+Be, p+Au, O+Cu, Si+Au and Au+Au collisions at the BNL-AGS. The issues addressed are 1) whether the shapes of the upper edges of the E T distributions vary with δη similarly to the variation in shapes of mid-rapidity charged particle distributions and 2) how small a δη interval would still give a meaningful characterization of the 'nuclear geometry' of a reaction. A new way of plotting E T distributions was found from which the reaction dynamics could be read directly.

    14. Measuring dynamical K/π and p/π fluctuations in AuAu collisions from the STAR experiment

      NASA Astrophysics Data System (ADS)

      Tarnowsky, T.

      2012-05-01

      Results from new measurements of dynamical K/π and p/π ratio fluctuations are presented. Dynamical fluctuations in global conserved quantities such as baryon number, strangeness, or charge may be observed near a QCD critical point. The STAR experiment has previously acquired data in AuAu collisions at the energies √{s_{NN} } = 200, 130, 62.4, and 19.6 GeV and CuCu collisions at √{s_{NN} } = 200, 62.4, and 22.4 GeV. The commencing of a QCD critical point search at RHIC has extended the reach of possible measurements of dynamical K/π and p/π ratio fluctuations from AuAu collisions to lower energies. New results are compared to previous measurements and to theoretical predictions from the UrQMD model.

    15. An ultrafast look at Au nanoclusters.

      PubMed

      Yau, Sung Hei; Varnavski, Oleg; Goodson, Theodore

      2013-07-16

      In the past 20 years, researchers studying nanomaterials have uncovered many new and interesting properties not found in bulk materials. Extensive research has focused on metal nanoparticles (>3 nm) because of their potential applications, such as in molecular electronics, image markers, and catalysts. In particular, the discovery of metal nanoclusters (<3 nm) has greatly expanded the horizon of nanomaterial research. These nanosystems exhibit molecular-like characteristics as their size approaches the Fermi-wavelength of an electron. The relationships between size and physical properties for nanomaterials are intriguing, because for metal nanosystems in this size regime both size and shape determine electronic properties. Remarkably, changes in the optical properties of nanomaterials have provided tremendous insight into the electronic structure of nanoclusters. The success of synthesizing monolayer protected clusters (MPCs) in the condensed phase has allowed scientists to probe the metal core directly. Au MPCs have become the "gold" standard in nanocluster science, thanks to the rigorous structural characterization already accomplished. The use of ultrafast laser spectroscopy on MPCs in solution provides the benefit of directly studying the chemical dynamics of metal nanoclusters (core), and their nonlinear optical properties. In this Account, we investigate the optical properties of MPCs in the visible region using ultrafast spectroscopy. Based on fluorescence up-conversion spectroscopy, we propose an emission mechanism for these nanoclusters. These clusters behave differently from nanoparticles in terms of emission lifetimes as well as two-photon cross sections. Through further investigation of the transient (excited state) absorption, we have found many unique phenomena of nanoclusters, such as quantum confinement effects and vibrational breathing modes. In summary, based on the differences in the optical properties, the distinction between nanoclusters and

    16. 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.

    17. Longitudinal flow of protons from (2-8)A GeV central Au+Au collisions.

      PubMed

      Klay, J L; Ajitanand, N N; Alexander, J M; Anderson, M G; Best, D; Brady, F P; Case, T; Caskey, W; Cebra, D; Chance, J L; Chung, P; Cole, B; Crowe, K; Das, A C; Draper, J E; Gilkes, M L; Gushue, S; Heffner, M; Hirsch, A S; Hjort, E L; Huo, L; Justice, M; Kaplan, M; Keane, D; Kintner, J C; Krofcheck, D; Lacey, R A; Lauret, J; Law, C; Lisa, M A; Liu, H; Liu, Y M; McGrath, R; Milosevich, Z; Odyniec, G; Olson, D L; Panitkin, S Y; Pinkenburg, C; Porile, N T; Rai, G; Ritter, H G; Romero, J L; Scharenberg, R; Schroeder, L; Srivastava, B; Stone, N T B; Symons, T J M; Wang, S; Wells, R; Whitfield, J; Wienold, T; Witt, R; Wood, L; Zhang, W N

      2002-03-11

      Rapidity distributions of protons from central 197Au+197Au collisions measured by the E895 Collaboration in the energy range from (2-8)A GeV at the Brookhaven AGS are presented. Longitudinal flow parameters derived using a thermal model including collective longitudinal expansion are extracted from these distributions. The results show an approximately linear increase in the longitudinal flow velocity, (L), as a function of the logarithm of beam energy.

    18. Measurement of inclusive antiprotons from Au+Au collisions at square root of s(NN) = 130 GeV.

      PubMed

      Adler, C; Ahammed, Z; Allgower, C; Amonett, J; Anderson, B D; Anderson, M; Averichev, G S; Balewski, J; Barannikova, O; Barnby, L S; Baudot, J; Bekele, S; Belaga, V V; Bellwied, R; Berger, J; Bichsel, H; Bland, L C; Blyth, C O; Bonner, B E; Boucham, A; Brandin, A; Cadman, R V; Caines, H; Calderón de la Barca Sánchez, M; Cardenas, A; Carroll, J; Castillo, J; Castro, M; Cebra, D; Chattopadhyay, S; Chen, M L; Chen, Y; Chernenko, S P; Cherney, M; Chikanian, A; Choi, B; Christie, W; Coffin, J P; Cormier, T M; Cramer, J G; Crawford, H J; DeMello, M; Deng, W S; Derevschikov, A A; Didenko, L; Draper, J E; Dunin, V B; Dunlop, J C; Eckardt, V; Efimov, L G; Emelianov, V; Engelage, J; Eppley, G; Erazmus, B; Fachini, P; Faine, V; Filimonov, K; Finch, E; Fisyak, Y; Flierl, D; Foley, K J; Fu, J; Gagliardi, C A; Gagunashvili, N; Gans, J; Gaudichet, L; Germain, M; Geurts, F; Ghazikhanian, V; Grabski, J; Grachov, O; Grigoriev, V; Guedon, M; Gushin, E; Hallman, T J; Hardtke, D; Harris, J W; Heffner, M; Heppelmann, S; Herston, T; Hippolyte, B; Hirsch, A; Hjort, E; Hoffmann, G W; Horsley, M; Huang, H Z; Humanic, T J; Hümmler, H; Igo, G; Ishihara, A; Ivanshin, Y I; Jacobs, P; Jacobs, W W; Janik, M; Johnson, I; Jones, P G; Judd, E; Kaneta, M; Kaplan, M; Keane, D; Kisiel, A; Klay, J; Klein, S R; Klyachko, A; Konstantinov, A S; Kotchenda, L; Kovalenko, A D; Kramer, M; Kravtsov, P; Krueger, K; Kuhn, C; Kulikov, A I; 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; Lednický, R; Leontiev, V M; LeVine, M J; Li, Q; Lindenbaum, S J; Lisa, M A; Liu, F; Liu, L; Liu, Z; Liu, Q J; Ljubicic, T; Llope, W J; LoCurto, G; Long, H; Longacre, R S; Lopez-Noriega, M; Love, W A; Lynn, D; Majka, R; Margetis, S; Martin, L; Marx, J; Matis, H S; Matulenko, Y A; McShane, T S; Meissner, F; Melnick, Y; Meschanin, A; Messer, M; Miller, M L; Milosevich, Z; Minaev, N G; Mitchell, J; Moiseenko, V A; Moore, C F; Morozov, V; de Moura, M M; Munhoz, M G; Mutchler, G S; Nelson, J M; Nevski, P; Nikitin, V A; Nogach, L V; Norman, B; Nurushev, S B; Odyniec, G; Ogawa, A; Okorokov, V; Oldenburg, M; Olson, D; Paic, G; Pandey, S U; Panebratsev, Y; Panitkin, S Y; Pavlinov, A I; Pawlak, T; Perevoztchikov, V; Peryt, W; Petrov, V A; Platner, E; Pluta, J; Porile, N; Porter, J; Poskanzer, A M; Potrebenikova, E; Prindle, D; Pruneau, C; Radomski, S; Rai, G; Ravel, O; Ray, R L; Razin, S V; Reichhold, D; Reid, J G; Retiere, F; Ridiger, A; Ritter, H G; Roberts, J B; Rogachevski, O V; Romero, J L; Roy, C; Rykov, V; Sakrejda, I; Sandweiss, J; Saulys, A C; Savin, I; Schambach, J; Scharenberg, R P; Schmitz, N; Schroeder, L S; Schüttauf, A; Schweda, K; Seger, J; Seliverstov, D; Seyboth, P; Shahaliev, E; Shestermanov, K E; Shimanskii, S S; Shvetcov, V S; Skoro, G; Smirnov, N; Snellings, R; Sowinski, J; Spinka, H M; Srivastava, B; Stephenson, E J; Stock, R; Stolpovsky, A; Strikhanov, M; Stringfellow, B; Struck, C; Suaide, A A; Sugarbaker, E; Suire, C; Sumbera, M; Symons, T J; de Toledo, A S; Szarwas, P; Takahashi, J; Tang, A H; Thomas, J H; Thompson, M; Tikhomirov, V; Trainor, T A; Trentalange, S; Tribble, R E; Tokarev, M; Tonjes, M B; Trofimov, V; Tsai, O; Turner, K; Ullrich, T; Underwood, D G; Van Buren, G; VanderMolen, A M; Vanyashin, A; Vasilevski, I M; Vasiliev, A N; Vigdor, S E; Voloshin, S A; Wang, F; Ward, H; Watson, J W; Wells, R; Wenaus, T; Westfall, G D; Whitten, C; Wieman, H; Willson, R; Wissink, S W; Witt, R; Xu, N; Xu, Z; Yakutin, A E; Yamamoto, E; Yang, J; Yepes, P; Yurevich, V I; Zanevski, Y V; Zborovský, I; Zhang, H; Zhang, W M; Zoulkarneev, R; Zubarev, A N

      2001-12-24

      We report the first measurement of inclusive antiproton production at midrapidity in Au+Au collisions at square root of s(NN) = 130 GeV by the STAR experiment at RHIC. The antiproton transverse mass distributions in the measured transverse momentum range of 0.25

    19. Strangeness in Au+Au collisions at √sNN = 130 GeV observed with the STAR detector

      NASA Astrophysics Data System (ADS)

      Barnby, Lee S.; STAR Collaboration; Adler, C.; Ahammed, Z.; Allgower, C.; Amonett, J.; Anderson, B. D.; Anderson, M.; Averichev, G. S.; Balewski, J.; Barannikova, O.; Barnby, L. S.; Baudot, J.; Bekele, S.; Belaga, V. V.; Bellwied, R.; Berger, J.; Bichsel, H.; Bland, L. C.; Blyth, C. O.; Bonner, B. E.; Boucham, A.; Brandin, A.; Cadman, R. V.; Caines, H.; Calderón de la Barca Sánchez, M.; Cardenas, A.; Carroll, J.; Castillo, J.; Castro, M.; Cebra, D.; Chattopadhyay, S.; Chen, M. L.; Chen, Y.; Chernenko, S. P.; Cherney, M.; Chikanian, A.; Choi, B.; Christie, W.; Coffin, J. P.; Cormier, T. M.; Cramer, J. G.; Crawford, H. J.; Deng, W. S.; Derevschikov, A. A.; Didenko, L.; Draper, J. E.; Dunin, V. B.; Dunlop, J. C.; Eckardt, V.; Efimov, L. G.; Emelianov, V.; Engelage, J.; Eppley, G.; Erazmus, B.; Fachini, P.; Faine, V.; Filimonov, K.; Finch, E.; Fisyak, Y.; Flierl, D.; Foley, K. J.; Fu, J.; Gagliardi, C. A.; Gagunashvili, N.; Gans, J.; Gaudichet, L.; Germain, M.; Geurts, F.; Ghazikhanian, V.; Grabski, J.; Grachov, O.; Grigoriev, V.; Guedon, M.; Gushin, E.; Hallman, T. J.; Hardtke, D.; Harris, J. W.; Heffner, M.; Heppelmann, S.; Herston, T.; Hippolyte, B.; Hirsch, A.; Hjort, E.; Hoffmann, G. W.; Horsley, M.; Huang, H. Z.; Humanic, T. J.; Hümmler, H.; Igo, G.; Ishihara, A.; Ivanshin, Yu. I.; Jacobs, P.; Jacobs, W. W.; Janik, M.; Johnson, I.; Jones, P. G.; Judd, E. G.; Kaneta, M.; Kaplan, M.; Keane, D.; Kiryluk, J.; Kisiel, A.; Klay, J.; Klein, S. R.; Klyachko, A.; Konstantinov, A. S.; Kotchenda, L.; Kovalenko, A. D.; Kramer, M.; Kravtsov, P.; Krueger, K.; Kuhn, C.; Kulikov, A. I.; Kunde, G. J.; Kunz, C. L.; Kutuev, R. Kh.; Kuznetsov, A. A.; Lakehal-Ayat, L.; Lamont, M. A. C.; Landgraf, J. M.; Lange, S.; Lansdell, C. P.; Lasiuk, B.; Laue, F.; Lebedev, A.; Lednický, R.; Leontiev, V. M.; LeVine, M. J.; Li, Q.; Lindenbaum, S. J.; Lisa, M. A.; Liu, F.; Liu, L.; Liu, Z.; Liu, Q. J.; Ljubicic, T.; Llope, W. J.; Curto, G. Lo; Long, H.; Longacre, R. S.; Lopez-Noriega, M.; Love, W. A.; Lynn, D.; Majka, R.; Margetis, S.; Markert, C.; Martin, L.; Marx, J.; Matis, H. S.; Matulenko, Yu. A.; McShane, T. S.; Meissner, F.; Melnick, Yu.; Meschanin, A.; Messer, M.; Miller, M. L.; Milosevich, Z.; Minaev, N. G.; Mitchell, J.; Moiseenko, V. A.; Moore, C. F.; Morozov, V.; de Moura, M. M.; Munhoz, M. G.; Nelson, J. M.; Nevski, P.; Nikitin, V. A.; Nogach, L. V.; Norman, B.; Nurushev, S. B.; Odyniec, G.; Ogawa, A.; Okorokov, V.; Oldenburg, M.; Olson, D.; Paic, G.; Pandey, S. U.; Panebratsev, Y.; Panitkin, S. Y.; Pavlinov, A. I.; Pawlak, T.; Perevoztchikov, V.; Peryt, W.; Petrov, V. A.; Pluta, J.; Porile, N.; Porter, J.; Poskanzer, A. M.; Potrebenikova, E.; Prindle, D.; Pruneau, C.; Radomski, S.; Rai, G.; Ravel, O.; Ray, R. L.; Razin, S. V.; Reichhold, D.; Reid, J. G.; Retiere, F.; Ridiger, A.; Ritter, H. G.; Roberts, J. B.; Rogachevski, O. V.; Romero, J. L.; Roy, C.; Rykov, V.; Sakrejda, I.; Sandweiss, J.; Saulys, A. C.; Savin, I.; Schambach, J.; Scharenberg, R. P.; Schmitz, N.; Schroeder, L. S.; Schüttauf, A.; Schweda, K.; Seger, J.; Seliverstov, D.; Seyboth, P.; Shahaliev, E.; Shestermanov, K. E.; Shimanskii, S. S.; Shvetcov, V. S.; Skoro, G.; Smirnov, N.; Snellings, R.; Sorensen, P.; Sowinski, J.; Spinka, H. M.; Srivastava, B.; Stephenson, E. J.; Stock, R.; Stolpovsky, A.; Strikhanov, M.; Stringfellow, B.; Struck, C.; Suaide, A. A. P.; Sugarbaker, E.; Suire, C.; umbera, M.; Symons, T. J. M.; Szanto de Toledo, A.; Szarwas, P.; Tai, A.; Takahashi, J.; Tang, A. H.; Thomas, J. H.; Thompson, M.; Tikhomirov, V.; Tokarev, M.; Tonjes, M. B.; Trainor, T. A.; Trentalange, S.; Tribble, R. E.; Trofimov, V.; Tsai, O.; Turner, K.; Ullrich, T.; Underwood, D. G.; Van Buren, G.; Vander Molen, A. M.; Vasilevski, I. M.; Vasiliev, A. N.; Vigdor, S. E.; Voloshin, S. A.; Wang, F.; Ward, H.; Watson, J. W.; Wells, R.; Wenaus, T.; Westfall, G. D.; Whitten, C., Jr.; Wieman, H.; Willson, R.; Wissink, S. W.; Witt, R.; Wood, J.; Xu, N.; Xu, Z.; Yakutin, A. E.; Yamamoto, E.; Yang, J.; Yepes, P.; Yurevich, V. I.; Zanevski, Y. V.; Zborovský, I.; Zhang, H.; Zhang, W. M.; Zoulkarneev, R.; Zubarev, A. N.

      2002-07-01

      The STAR detector has made a variety of measurements of strange and other hadronic species in Au+Au collisions at √sNN = 130 GeV. A comparison of kaon and pion production enables an examination of the systematics of strangeness production with energy by comparing them to lower energy collisions. Anti-baryon to baryon ratios indicate a much reduced net-baryon density and transverse momentum spectra show that a picture of transverse expansion seems appropriate.

    20. 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.

    1. 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.

    2. 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

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

      SciTech Connect

      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 to 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.

    4. Measurements of DS± -meson production in Au + Au collisions at √{sNN} = 200 GeV in STAR

      NASA Astrophysics Data System (ADS)

      Nasim, Md.

      2016-12-01

      We present the first measurement of the nuclear modification factor RAA and elliptic flow v2 of Ds in Au+Au collisions at √{sNN} = 200 GeV with the STAR detector. These results have been compared with those of other open charm mesons and strange mesons to determine how the (possibly) strangeness equilibrated partonic matter affects the Ds meson production. We find that the nuclear modification factor of DS are systematically higher than unity and that of D0. The ratio Ds /D0 is shown as a function of transverse momentum for the 10-40% most central Au+Au collisions and compared with that in p + p collisions obtained from PYTHIA. It is also compared with that in Pb+Pb collisions at 2.76 TeV by the ALICE experiment. Our measurement indicates a hint of enhancement of DS production in Au+Au collisions with respect to p + p collisions as compared to non-strange D mesons.

    5. Theoretical investigation of superconductivity in SrAuSi3 and SrAu2Si2

      NASA Astrophysics Data System (ADS)

      Arslan, Enes; Karaca, Ertuǧrul; Tütüncü, H. M.; Başoglu, A.; Srivastava, G. P.

      2016-08-01

      The structural and electronic properties of BaNiSn3-type SrAuSi3 and ThCr2Si2-type SrAu2Si2 have been investigated by using the planewave pseudopotential method and the density functional theory. The electronic structures and phonon dispersion relations of these two materials have been analyzed with and without the inclusion of spin-orbit interaction, and similarities and differences highlighted. By integrating the Eliashberg spectral function α2F(ω), the average electron-phonon coupling parameter is determined to be λ=0.47 for SrAuSi3 and 0.42 for SrAu2Si2. The largest contribution to the electron-phonon coupling for SrAuSi3 comes from the Si p electrons near the Fermi energy and Si-related vibrations. Using a reasonable value of μ* = 0.12 for the effective Coulomb repulsion parameter, the superconducting critical temperature Tc for SrAuSi3 is found to be 1.47 K which compares very well with its experimental value of 1.54 K.

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

      NASA Astrophysics Data System (ADS)

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

      2011-06-01

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

    7. 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.

    8. Sulfur-induced mobilization of Au surface atoms on Au(1 1 1) studied by real-time STM

      NASA Astrophysics Data System (ADS)

      Biener, Monika M.; Biener, Juergen; Friend, Cynthia M.

      2007-04-01

      The interaction of sulfur with gold surfaces has attracted considerable interest due to numerous technological applications such as the formation of self-assembled monolayers and as a chemical sensor. Here, we report on the interaction of sulfur with Au(1 1 1) at two different temperatures (300 K and 420 K) studied by real-time scanning tunnelling microscopy, low energy electron diffraction and Auger electron spectroscopy. In the low coverage regime (<0.1 ML), S adsorption lifts the herringbone reconstruction of the clean Au(1 1 1) surface indicating a lateral expansion of the surface layer. An ordered (√3 × √3) R30° sulfur adlayer develops as the coverage reaches ˜0.3 ML. At higher S coverages (>0.3 ML) gold surface atoms are removed from regular terrace sites and incorporated into a growing gold sulfide phase. At 300 K this process leads to the formation of a rough pit and mound surface morphology. This gold sulfide exhibits short-range order and an incommensurate, long-range ordered AuS phase develops upon annealing at 450-525 K. In contrast, formation of an ordered AuS phase via rapid step-retraction rather than etch pit formation is observed during S-interaction with Au(1 1 1) surfaces at 420 K. Our results shed new light on the S-Au(1 1 1) interaction.

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

      SciTech Connect

      Reddy, K. M. Punnoose, Alex; Hanna, Charles; Padture, Nitin P.

      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 positive 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.

    10. Crystal structure and magnetic behavior in CeAu2Si2 and CeAu4Si2

      NASA Astrophysics Data System (ADS)

      Palasyuk, Andriy M.; Corbett, John D.; Sefat, Athena S.; Canfield, Paul C.

      2007-03-01

      Interest in Ce-based compounds of systems like CeCu2Si2, CePd2Si2 and CeRu2Si2 has attracted much interest due to magnetic ordering, heavy Fermion behavior and superconductivity. This work is a comparative study of crystal structure and properties of CeAuxSi2 flux-grown crystals with x=2, 4. For CeAuxSi2 system, we have studied structure and anisotropic field- and temperature-dependent magnetization M(H, T). The single-crystal x-ray data indicate that CeAu4Si2 has CeRe4Si2-type structure and is orthorhombic (Cmmm) and CeAu2Si2 is tetragonal (I4/mmm). Although there is an extra layer of Au atoms in the CeAu4Si2 structure the magnetic ordering temperatures of CeAu2Si2and CeAu4Si2 are remarkably similar. In this work we will examine and discuss the similarities and differences between the thermodynamic, transport and structural properties of these related materials.

    11. 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

    12. 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

    13. Disappearance of back-to-back high-pT hadron correlations in central Au+Au collisions at sqrt[s NN ] =200 GeV.

      PubMed

      Adler, C; Ahammed, Z; Allgower, C; Amonett, J; Anderson, B D; Anderson, M; Averichev, G S; Balewski, J; Barannikova, O; Barnby, L S; Baudot, J; Bekele, S; Belaga, V V; Bellwied, R; Berger, J; Bichsel, H; Billmeier, A; Bland, L C; Blyth, C O; Bonner, B E; Boucham, A; Brandin, A; Bravar, A; Cadman, R V; Caines, H; Calderón de la Barca Sánchez, M; Cardenas, A; Carroll, J; Castillo, J; Castro, M; Cebra, D; Chaloupka, P; Chattopadhyay, S; Chen, Y; Chernenko, S P; Cherney, M; Chikanian, A; Choi, B; Christie, W; Coffin, J P; Cormier, T M; Corral, M M; Cramer, J G; Crawford, H J; Derevschikov, A A; Didenko, L; Dietel, T; Draper, J E; Dunin, V B; Dunlop, J C; Eckardt, V; Efimov, L G; Emelianov, V; Engelage, J; Eppley, G; Erazmus, B; Fachini, P; Faine, V; Faivre, J; Fatemi, R; Filimonov, K; Finch, E; Fisyak, Y; Flierl, D; Foley, K J; Fu, J; Gagliardi, C A; Gagunashvili, N; Gans, J; Gaudichet, L; Germain, M; Geurts, F; Ghazikhanian, V; Grachov, O; Grigoriev, V; Guedon, M; Gushin, E; Hallman, T J; Hardtke, D; Harris, J W; Henry, T W; Heppelmann, S; Herston, T; Hippolyte, B; Hirsch, A; Hjort, E; Hoffmann, G W; Horsley, M; Huang, H Z; Humanic, T J; Igo, G; Ishihara, A; Ivanshin, Yu I; Jacobs, P; Jacobs, W W; Janik, M; Johnson, I; Jones, P G; Judd, E G; Kaneta, M; Kaplan, M; Keane, D; Kiryluk, J; Kisiel, A; Klay, J; Klein, S R; Klyachko, A; Kollegger, T; Konstantinov, A S; Kopytine, M; Kotchenda, L; Kovalenko, A D; Kramer, M; Kravtsov, P; Krueger, K; Kuhn, C; Kulikov, A I; Kunde, G J; Kunz, C L; Kutuev, R Kh; Kuznetsov, A A; Lakehal-Ayat, L; Lamont, M A C; Landgraf, J M; Lange, S; Lansdell, C P; Lasiuk, B; Laue, F; Lauret, J; Lebedev, A; Lednický, R; Leontiev, V M; LeVine, M J; Li, Q; Lindenbaum, S J; Lisa, M A; Liu, F; Liu, L; Liu, Z; Liu, Q J; Ljubicic, T; Llope, W J; LoCurto, G; Long, H; Longacre, R S; Lopez-Noriega, M; Love, W A; Ludlam, T; Lynn, D; Ma, J; Magestro, D; Majka, R; Margetis, S; Markert, C; Martin, L; Marx, J; Matis, H S; Matulenko, Yu A; McShane, T S; Meissner, F; Melnick, Yu; Meschanin, A; Messer, M; Miller, M L; Milosevich, Z; Minaev, N G; Mitchell, J; Moore, C F; Morozov, V; de Moura, M M; Munhoz, M G; Nelson, J M; Nevski, P; Nikitin, V A; Nogach, L V; Norman, B; Nurushev, S B; Odyniec, G; Ogawa, A; Okorokov, V; Oldenburg, M; Olson, D; Paic, G; Pandey, S U; Panebratsev, Y; Panitkin, S Y; Pavlinov, A I; Pawlak, T; Perevoztchikov, V; Peryt, W; Petrov, V A; Planinic, M; Pluta, J; Porile, N; Porter, J; Poskanzer, A M; Potrebenikova, E; Prindle, D; Pruneau, C; Putschke, J; Rai, G; Rakness, G; Ravel, O; Ray, R L; Razin, S V; Reichhold, D; Reid, J G; Renault, G; Retiere, F; Ridiger, A; Ritter, H G; Roberts, J B; Rogachevski, O V; Romero, J L; Rose, A; Roy, C; Rykov, V; Sakrejda, I; Salur, S; Sandweiss, J; Savin, I; Schambach, J; Scharenberg, R P; Schmitz, N; Schroeder, L S; Schüttauf, A; Schweda, K; Seger, J; Seliverstov, D; Seyboth, P; Shahaliev, E; Shestermanov, K E; Shimanskii, S S; Simon, F; Skoro, G; Smirnov, N; Snellings, R; Sorensen, P; Sowinski, J; Spinka, H M; Srivastava, B; Stephenson, E J; Stock, R; Stolpovsky, A; Strikhanov, M; Stringfellow, B; Struck, C; Suaide, A A P; Sugarbaker, E; Suire, C; Sumbera, M; Surrow, B; Symons, T J M; Szanto de Toledo, A; Szarwas, P; Tai, A; Takahashi, J; Tang, A H; Thein, D; Thomas, J H; Thompson, M; Tikhomirov, V; Tokarev, M; Tonjes, M B; Trainor, T A; Trentalange, S; Tribble, R E; Trofimov, V; Tsai, O; Ullrich, T; Underwood, D G; Van Buren, G; VanderMolen, A M; Vasilevski, I M; Vasiliev, A N; Vigdor, S E; Voloshin, S A; Wang, F; Ward, H; Watson, J W; Wells, R; Westfall, G D; Whitten, C; Wieman, H; Willson, R; Wissink, S W; Witt, R; Wood, J; Xu, N; Xu, Z; Yakutin, A E; Yamamoto, E; Yang, J; Yepes, P; Yurevich, V I; Zanevski, Y V; Zborovský, I; Zhang, H; Zhang, W M; Zoulkarneev, R; Zubarev, A N

      2003-02-28

      Azimuthal correlations for large transverse momentum charged hadrons have been measured over a wide pseudorapidity range and full azimuth in Au+Au and p+p collisions at sqrt[s(NN)]=200 GeV. The small-angle correlations observed in p+p collisions and at all centralities of Au+Au collisions are characteristic of hard-scattering processes previously observed in high-energy collisions. A strong back-to-back correlation exists for p+p and peripheral Au+Au. In contrast, the back-to-back correlations are reduced considerably in the most central Au+Au collisions, indicating substantial interaction as the hard-scattered partons or their fragmentation products traverse the medium.

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

      NASA Astrophysics Data System (ADS)

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

      2015-05-01

      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.

    15. Disappearance of back-to-back high p {sub T} hadron correlations in central Au+Au collisions at {radical}s{sub NN} = 200 GeV

      SciTech Connect

      Adler, C.; Ahammed, Z.; Allgower, C.; Amonett, J.; Anderson, B.D.; Anderson, M.; Averichev, G.S.; Balewski, J.; Barannikova, O.; Barnby, L.S.; Baudot, J.; Bekele, S.; Belaga, V.V.; Bellwied, R.; Berger, J.; Bichsel, H.; Billmeier, A.; Bland, L.C.; Blyth, C.O.; Bonner, B.E.; Boucham, A.; Brandin, A.; Bravar, A.; Cadman, R.V.; Caines, H.; Calderon de la Barca Sanchez, M.; Cardenas, A.; Carroll, J.; Castillo, J.; Castro, M.; Cebra, D.; Chaloupka, P.; Chattopadhyay, S.; Chen, Y.; Chernenko, S.P.; Cherney, M.; Chikanian, A.; Choi, B.; Christie, W.; Coffin, J.P.; Cormier, T.M.; Corral, M.M.; Cramer, J.G.; Crawford, H.J.; Derevschikov, A.A.; Didenko, L.; Dietel, T.; Draper, J.E.; Dunin, V.B.; Dunlop, J.C.; Eckardt, V.; Efimov, L.G.; Emelianov, V.; Engelage, J.; Eppley, G.; Erazmus, B.; Fachini, P.; Faine, V.; Faivre, J.; Fatemi, R.; Filimonov, K.; Finch, E.; Fisyak, Y.; Flierl, D.; Foley, K.J.; Fu, J.; Gagliardi, C.A.; Gagunashvili, N.; Gans, J.; Gaudichet, L.; Germain, M.; Geurts, F.; Ghazikhanian, V.; Grachov, O.; Grigoriev, V.; Guedon, M.; Gushin, E.; Hallman, T.J.; Hardtke, D.; Harris, J.W.; Henry, T.W.; Heppelmann, S.; Herston, T.; Hippolyte, B.; Hirsch, A.; Hjort, E.; Hoffmann, G.W.; Horsley, M.; Huang, H.Z.; Humanic, T.J.; Igo, G.J.; Ishihara, A.; Ivanshin, Yu.I.; Jacobs, P.; Jacobs, W.W.; Janik, M.; Johnson, I.; Jones, P.G.; Judd, E.G.; Kaneta, M.; Kaplan, M.; Keane, D.; Kiryluk, J.; Kisiel, A.; Klay, J.; Klein, S.R.; Klyachko, A.; Kollegger, T.; Konstantinov, A.S.; Kopytine, M.; Kotchenda, L.; Kovalenko, A.D.; Kramer, M.; Kravtsov, P.; Krueger, K.; Kuhn, C.; Kulikov, A.I.; Kunde, G.J.; Kunz, C.L.; Kutuev, R.Kh.; Kuznetsov, A.A.; Lakehal-Ayat, L.; Lamont, M.A.C.; Landgraf, J.M.; Lange, S.; Lansdell, C.P.; Lasiuk, B.; Laue, F.; Lauret, J.; Lebedev, A.; Lednicky, R.; Leontiev, V.M.; LeVine, M.J.; Li , Q.; Lindenbaum, S.J.; Lisa, M.A.; Liu, F.; Liu, L.; Liu, Z.; Liu, Q.J.; Ljubicic, T.; Llope, W.J.; LoCurto, G.; et al.

      2002-10-25

      Azimuthal correlations for large transverse momentum charged hadrons have been measured over a wide pseudo-rapidity range and full azimuth in Au+Au and p+p collisions at = {radical}s{sub NN} = 200 GeV. The small-angle correlations observed in p+p collisions and at all centralities of Au+Au collisions are characteristic of hard-scattering processes already observed in elementary collisions. A strong back-to-back correlation exists for p+p and peripheral Au + Au. In contrast, the back-to-back correlations are reduced considerably in the most central Au+Au collisions, indicating substantial interaction as the hard-scattered partons or their fragmentation products traverse the medium.

    16. Formation of one-dimensional Ag-Au solid solution colloids with Au nanorods as seeds, their alloying mechanisms, and surface plasmon resonances

      NASA Astrophysics Data System (ADS)

      Guo, Tao; Tan, Yiwei

      2012-12-01

      In this work, one dimensional (1D) Ag-Au solid solution nanoalloys were synthesized by rapidly diffusing Ag into the preformed Au nanorod (AuNR) seeds at ambient temperature in aqueous solution. By varying the molar ratio of AgCl/AuNR (in gold atoms), two kinds of 1D Ag-Au alloy nanostructures with a narrow size distribution--AgAu nanowires and Ag33Au67 nanorods--could be obtained in high yields when NaCl and polyvinylpyrrolidone (PVP) were used as an additive and capping reagent, respectively. Based on HRTEM imaging combined with a series of control experiments, it is conceivable that vacancy/defect-motivated interdiffusion of Ag and Au atoms coupled with oxidative etching is a crucial stage in the mechanism responsible for this room-temperature alloying process, and the subsequent conjugation of the fused Ag-Au alloyed nanostructures is associated with the formation of the AgAu nanowires. The resulting 1D Ag-Au nanoalloys form stable colloidal dispersions and show unique localized surface plasmon resonance (LSPR) peaks in the ensemble extinction spectra.In this work, one dimensional (1D) Ag-Au solid solution nanoalloys were synthesized by rapidly diffusing Ag into the preformed Au nanorod (AuNR) seeds at ambient temperature in aqueous solution. By varying the molar ratio of AgCl/AuNR (in gold atoms), two kinds of 1D Ag-Au alloy nanostructures with a narrow size distribution--AgAu nanowires and Ag33Au67 nanorods--could be obtained in high yields when NaCl and polyvinylpyrrolidone (PVP) were used as an additive and capping reagent, respectively. Based on HRTEM imaging combined with a series of control experiments, it is conceivable that vacancy/defect-motivated interdiffusion of Ag and Au atoms coupled with oxidative etching is a crucial stage in the mechanism responsible for this room-temperature alloying process, and the subsequent conjugation of the fused Ag-Au alloyed nanostructures is associated with the formation of the AgAu nanowires. The resulting 1D Ag-Au

    17. Identified particle distributions in pp and Au+Au collisions at square root of (sNN)=200 GeV.

      PubMed

      Adams, J; Adler, C; Aggarwal, M M; Ahammed, Z; Amonett, J; Anderson, B D; Anderson, M; Arkhipkin, D; Averichev, G S; Badyal, S K; Balewski, J; Barannikova, O; Barnby, L S; Baudot, J; Bekele, S; Belaga, V V; Bellwied, R; Berger, J; Bezverkhny, B I; Bhardwaj, S; Bhaskar, P; Bhati, A K; Bichsel, H; Billmeier, A; Bland, L C; Blyth, C O; Bonner, B E; Botje, M; Boucham, A; Brandin, A; Bravar, A; Cadman, R V; Cai, X Z; Caines, H; Calderón de la Barca Sánchez, M; Carroll, J; Castillo, J; Castro, M; Cebra, D; Chaloupka, P; Chattopadhyay, S; Chen, H F; Chen, Y; Chernenko, S P; Cherney, M; Chikanian, A; Choi, B; Christie, W; Coffin, J P; Cormier, T M; Cramer, J G; Crawford, H J; Das, D; Das, S; Derevschikov, A A; Didenko, L; Dietel, T; Dong, X; Draper, J E; Du, F; Dubey, A K; Dunin, V B; Dunlop, J C; Dutta Majumdar, M R; Eckardt, V; Efimov, L G; Emelianov, V; Engelage, J; Eppley, G; Erazmus, B; Estienne, M; Fachini, P; Faine, V; Faivre, J; Fatemi, R; Filimonov, K; Filip, P; Finch, E; Fisyak, Y; Flierl, D; Foley, K J; Fu, J; Gagliardi, C A; Ganti, M S; Gutierrez, T D; Gagunashvili, N; Gans, J; Gaudichet, L; Germain, M; Geurts, F; Ghazikhanian, V; Ghosh, P; Gonzalez, J E; Grachov, O; Grigoriev, V; Gronstal, S; Grosnick, D; Guedon, M; Guertin, S M; Gupta, A; Gushin, E; Hallman, T J; Hardtke, D; Harris, J W; Heinz, M; Henry, T W; Heppelmann, S; Herston, T; Hippolyte, B; Hirsch, A; Hjort, E; Hoffmann, G W; Horsley, M; Huang, H Z; Huang, S L; Humanic, T J; Igo, G; Ishihara, A; Jacobs, P; Jacobs, W W; Janik, M; Johnson, I; Jones, P G; Judd, E G; Kabana, S; Kaneta, M; Kaplan, M; Keane, D; Kiryluk, J; Kisiel, A; Klay, J; Klein, S R; Klyachko, A; Koetke, D D; Kollegger, T; Konstantinov, A S; Kopytine, M; Kotchenda, L; Kovalenko, A D; Kramer, M; Kravtsov, P; Krueger, K; Kuhn, C; Kulikov, A I; Kumar, A; Kunde, G J; Kunz, C L; Kutuev, R Kh; Kuznetsov, A A; Lamont, M A C; Landgraf, J M; Lange, S; Lansdell, C P; Lasiuk, B; Laue, F; Lauret, J; Lebedev, A; Lednický, R; Leontiev, V M; LeVine, M J; Li, C; Li, Q; Lindenbaum, S J; Lisa, M A; Liu, F; Liu, L; Liu, Z; Liu, Q J; Ljubicic, T; Llope, W J; Long, H; Longacre, R S; Lopez-Noriega, M; Love, W A; Ludlam, T; Lynn, D; Ma, J; Ma, Y G; Magestro, D; Mahajan, S; Mangotra, L K; Mahapatra, D P; Majka, R; Manweiler, R; Margetis, S; Markert, C; Martin, L; Marx, J; Matis, H S; Matulenko, Yu A; McShane, T S; Meissner, F; Melnick, Yu; Meschanin, A; Messer, M; Miller, M L; Milosevich, Z; Minaev, N G; Mironov, C; Mishra, D; Mitchell, J; Mohanty, B; Molnar, L; Moore, C F; Mora-Corral, M J; Morozov, V; de Moura, M M; Munhoz, M G; Nandi, B K; Nayak, S K; Nayak, T K; Nelson, J M; Nevski, P; Nikitin, V A; Nogach, L V; Norman, B; Nurushev, S B; Odyniec, G; Ogawa, A; Okorokov, V; Oldenburg, M; Olson, D; Paic, G; Pandey, S U; Pal, S K; Panebratsev, Y; Panitkin, S Y; Pavlinov, A I; Pawlak, T; Perevoztchikov, V; Peryt, W; Petrov, V A; Phatak, S C; Picha, R; Planinic, M; Pluta, J; Porile, N; Porter, J; Poskanzer, A M; Potekhin, M; Potrebenikova, E; Potukuchi, B V K S; Prindle, D; Pruneau, C; Putschke, J; Rai, G; Rakness, G; Raniwala, R; Raniwala, S; Ravel, O; Ray, R L; Razin, S V; Reichhold, D; Reid, J G; Renault, G; Retiere, F; Ridiger, A; Ritter, H G; Roberts, J B; Rogachevski, O V; Romero, J L; Rose, A; Roy, C; Ruan, L J; Sahoo, R; Sakrejda, I; Salur, S; Sandweiss, J; Savin, I; Schambach, J; Scharenberg, R P; Schmitz, N; Schroeder, L S; Schweda, K; Seger, J; Seliverstov, D; Seyboth, P; Shahaliev, E; Shao, M; Sharma, M; Shestermanov, K E; Shimanskii, S S; Singaraju, R N; Simon, F; Skoro, G; Smirnov, N; Snellings, R; Sood, G; Sorensen, P; Sowinski, J; Spinka, H M; Srivastava, B; Stanislaus, S; Stock, R; Stolpovsky, A; Strikhanov, M; Stringfellow, B; Struck, C; Suaide, A A P; Sugarbaker, E; Suire, C; Sumbera, M; Surrow, B; Symons, T J M; de Toledo, A Szanto; Szarwas, P; Tai, A; Takahashi, J; Tang, A H; Thein, D; Thomas, J H; Tikhomirov, V; Tokarev, M; Tonjes, M B; Trainor, T A; Trentalange, S; Tribble, R E; Trivedi, M D; Trofimov, V; Tsai, O; Ullrich, T; Underwood, D G; Van Buren, G; VanderMolen, A M; Vasiliev, A N; Vasiliev, M; Vigdor, S E; Viyogi, Y P; Voloshin, S A; Waggoner, W; Wang, F; Wang, G; Wang, X L; Wang, Z M; Ward, H; Watson, J W; Wells, R; Westfall, G D; Whitten, C; Wieman, H; Willson, R; Wissink, S W; Witt, R; Wood, J; Wu, J; Xu, N; Xu, Z; Xu, Z Z; Yakutin, A E; Yamamoto, E; Yang, J; Yepes, P; Yurevich, V I; Zanevski, Y V; Zborovský, I; Zhang, H; Zhang, H Y; Zhang, W M; Zhang, Z P; Zołnierczuk, P A; Zoulkarneev, R; Zoulkarneeva, J; Zubarev, A N

      2004-03-19

      Transverse mass and rapidity distributions for charged pions, charged kaons, protons, and antiprotons are reported for square root of [sNN]=200 GeV pp and Au+Au collisions at Relativistic Heary Ion Collider (RHIC). Chemical and kinetic equilibrium model fits to our data reveal strong radial flow and long duration from chemical to kinetic freeze-out in central Au+Au collisions. The chemical freeze-out temperature appears to be independent of initial conditions at RHIC energies.

    18. 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

    19. The characteristics of solar wind magnetic field during the negative-AU and large-AU (>1200nT) events

      NASA Astrophysics Data System (ADS)

      Lyu, L. H.; Kao, W.

      2014-12-01

      The negative-AU events are relatively unusual, which have caught our attention. To understand the cause of negative AU, we first eliminate the ring-current effect by considering only the events with AUAU has strong negative Bz and By components during these negative-AU events. We also found that one of the negative AU events has been reported by Feldstein et al. (2006). They associated the enhancement of westward electric jet by the negative IMF-By component based on previous models obtained independently by Friis-Christensen et al. (1972) and Sumaruk & Feldstein (1973). Enhancement of electric jet in opposite direction is expected to be found when the IMF-By is positive. To verify their models we also examine the strong AU events with AU > 1200nT. We found that these large-AU events are associated with IMF-Bz<0 and IMF-By >0. Both negative-AU and large-AU events tend to occur during the beginning of the main phase of a strong magnetic storm with Kp= 7~9. The enhancement of Cowling electrojet has been proposed by Kan et al. (2011) for the triggering of substorm onset. We will discuss the possibility that a similar enhancement process might take place in the dayside auroral oval during these extreme AU events.

    20. 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

    1. Place de l’embrochage fasciculé selon Hackethal dans le traitement des fractures de l’humérus: à propos de 80 cas

      PubMed Central

      Margad, Omar; Boukhris, Jalal; Sallahi, Hicham; Daoudi, Mohamed; Azriouil, Ouahb; Koulali, Khalid

      2016-01-01

      Le débat principal autour des fractures de l’humérus se centre sur les indications thérapeutiques car tout type de stabilisation orthopédique ou chirurgicale trouve des défenseurs parfois inconditionnels et véhéments. A travers cette étude rétrospective, nous avons revu 80 patients traités initialement par embrochage fasciculé centromédullaire selon Hackethal au service de traumatologie orthopédie de l’hôpital militaire Avicenne entre janvier 2000 et janvier 2012. Les fractures ont été classées selon la classification AO et selon la classification de Hackethal modifiée par De La Caffinière. L’évaluation fonctionnelle a utilisé la classification de Stewart et Hundley modifiée. Nous avons obtenu 60 très bons résultats, 6 bons résultats, 2 assez bons résultats et 2 mauvais résultats. Les deux mauvais résultats étaient des cas de pseudarthrose. Nous n’avons pas noté de paralysie radiale iatrogène, ni d’infection, ni de migration de broches. Le délai moyen de consolidation a été de 9semaines et 6 jours. C’est une méthode fiable, de réalisation facile et à faible cout économique, qui fournit une bonne stabilisation du foyer de fracture permettant ainsi la mobilisation précoce avec des résultats fonctionnels excellents. PMID:27800106

    2. Intriguing centrality dependence of the Au-Au source size at the AGS

      SciTech Connect

      Baker, M.D.; The E802 Collaboration

      1996-06-01

      One of the main goals of high energy heavy ion physics is to establish the existence of a deconfined phase of nuclear matter--the quark-gluon plasma--at high temperatures or densities. One possible signature of such a phase transition, especially if it were first order, would be a larger source size or lifetime than a similar hadronic system. At current AGS energies, we attempt to form a quark- gluon plasma by achieving a high baryon density for a period of time in the center of the collision region. For a given density threshold, the size of this high density region should be a strong function of the impact parameter: the more central the event, the larger the high density region. Therefore, one possible signature of a quark-gluon plasma would be a sudden change in system lifetime or size as a function of the centrality of the collision. In this talk we present an intriguing effect which was not predicted for simple hadronic systems: a rapid increase of the HBT-measured source radius parameter for pion pairs with increasing centrality for Au-Au collisions at a beam momentum of 11.45 A GeV/c on a fixed target. Experience has shown, however, that we must be cautious in our interpretation. A complete understanding of the collision dynamics at a given energy must be built up from several measurements and new, but conventional, hadronic explanations must be considered for such unexpected effects. More study is needed, therefore, before any strong conclusions can be reached.

    3. 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.

    4. 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.

      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.

    5. Blue luminescence of Au nanoclusters embedded in silica matrix

      SciTech Connect

      Dhara, S.; Chandra, Sharat; Magudapathy, P.; Kalavathi, S.; Panigrahi, B.K.; Nair, K.G.M.; Sastry, V.S.; Hsu, C.W.; Wu, C.T.; Chen, K.H.; Chen, L.C.

      2004-12-22

      Photoluminescence study using the 325 nm He-Cd excitation is reported for the Au nanoclusters embedded in SiO{sub 2} matrix. Au clusters are grown by ion beam mixing with 100 KeV Ar{sup +} irradiation on Au [40 nm]/SiO{sub 2} at various fluences and subsequent annealing at high temperature. The blue bands above {approx}3 eV match closely with reported values for colloidal Au nanoclusters and supported Au nanoislands. Radiative recombination of sp electrons above Fermi level to occupied d-band holes are assigned for observed luminescence peaks. Peaks at 3.1 and 3.4 eV are correlated to energy gaps at the X- and L-symmetry points, respectively, with possible involvement of relaxation mechanism. The blueshift of peak positions at 3.4 eV with decreasing cluster size is reported to be due to the compressive strain in small clusters. A first principle calculation based on density functional theory using the full potential linear augmented plane wave plus local orbitals formalism with generalized gradient approximation for the exchange correlation energy is used to estimate the band gaps at the X- and L-symmetry points by calculating the band structures and joint density of states for different strain values in order to explain the blueshift of {approx}0.1 eV with decreasing cluster size around L-symmetry point.

    6. Au/metal oxides for low temperature CO oxidation

      SciTech Connect

      Srinivas, G.; Wright, J.; Bai, C.S.; Cook, R.

      1996-12-31

      Oxidation of carbon monoxide is important for several operations including fuel cells and carbon dioxide lasers. Room temperature CO oxidation has been investigated on a series of Au/metal oxide catalysts at conditions typical of spacecraft atmospheres; CO = 50 ppm, CO{sub 2} = 7,000 ppm, H{sub 2}O = 40% (RH) at 25{degrees}C, balance = air, and gas hourly space velocities of 7,000-60,000 hr{sup -1}. The addition of Au increases the room temperature CO oxidation activity of the metal oxides dramatically. All the Au/metal oxides deactivate during the CO oxidation reaction, especially in the presence of CO{sub 2} in the feed. The stability of the Au/metal oxide catalysts decreases in the following order: TiO{sub 2} > Fe{sub 2}O{sub 3} > NiO > Co{sub 3}O{sub 4}. The stability appears to decrease with an increase in the basicity of the metal oxides. In situ FTIR of CO adsorption on Au/TiO{sub 2} at 25{degrees}C indicates the formation of adsorbed CO, carboxylate, and carbonate species on the catalyst surface.

    7. 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.

    8. Acetanilide mediated reversible assembly and disassembly of Au nanoparticles.

      PubMed

      Murugadoss, A; Kar, Manoranjan; Chattopadhyay, Arun

      2008-08-01

      Herein we report the generation of Au nanoparticles (NPs) by sparingly soluble acetanilide in water. We also report the formation of linear chain-like superstructures of self-assembled Au NPs, in the presence of excess acetanilide. This was achieved in two different ways. In the first method, acetanilide was added, with increasing concentration, into aqueous HAuCl(4) to produce Au NPs as well as for the formation of assembly, which varied according to the concentration of acetanilide. The other route involved formation of spherical Au NPs at the lowest concentration of acetanilide, which was followed by the formation of assembly of various lengths upon further addition of variable amount of acetanilide. The assemblies were stable in aqueous solution for days with characteristic UV-vis absorption spectra consisting of two peaks. While the wavelength of the first peak remained the same, the position of the second peak changed to longer wavelength with increasing acetanilide concentration. Interestingly, the linear chain-like arrays could be broken into individual particles by first dilution of the solution concentration followed by treatment with ultrasonic waves. The individual Au NPs again formed linear chain-like arrays upon addition of excess acetanilide.

    9. Au nanoinjectors for electrotriggered gene delivery into the cell nucleus.

      PubMed

      Kang, Mijeong; Kim, Bongsoo

      2015-01-01

      Intracellular delivery of exogenous materials is an essential technique required for many fundamental biological researches and medical treatments. As our understanding of cell structure and function has been improved and diverse therapeutic agents with a subcellular site of action have been continuously developed, there is a demand to enhance the performance of delivering devices. Ideal intracellular delivery devices should convey various kinds of exogenous materials without deteriorating cell viability regardless of cell type and, furthermore, precisely control the location and the timing of delivery as well as the amount of delivered materials for advanced researches.In this chapter the development of a new intracellular delivery device, a nanoinjector made of a Au (gold) nanowire (a Au nanoinjector) is described in which delivery is triggered by external application of an electric pulse. As a model study, a gene was delivered directly into the nucleus of a neuroblastoma cell, and successful delivery without cell damage was confirmed by the expression of the delivered gene. The insertion of a Au nanoinjector directly into a cell can be generally applied to any kind of cell, and a high degree of surface modification of Au allows attachment of diverse materials such as proteins, small molecules, or nanoparticles as well as genes on Au nanoinjectors. This expands their applicability, and it is expected that they will provide important information on the effects of delivered exogenous materials and consequently contribute to the development of related therapeutic or clinical technologies.

    10. Observations of high spin states in {sup 179}Au

      SciTech Connect

      Carpenter, M.P.; Ahmad, I.; Blumenthal, D.J.

      1995-08-01

      As part of a current study on the properties of the {pi} i{sub 13/2} intruder state in the A = 175-190 region, we conducted an experiment at ATLAS to observe high spin states in {sup 179}Au utilizing the reaction {sup 144}Sm({sup 40}Ar,p4n) at beam energies of 207 MeV and 215 MeV. To aid in the identification of {sup 179}Au, and to filter out the large amount of events from fission by-products, the Fragment Mass Analyzer was utilized in conjunction with ten Compton-suppression germanium detectors. In total, 11 x 10{sup 6} {gamma}-{gamma} and 4 x 10{sup 5} {gamma}-recoil events were collected. By comparing {gamma}-rays in coincidence with an A = 179 recoil mass gate and {gamma}-rays in coincidence with Au K{alpha} and K{beta} X-rays, ten {gamma}-rays were identified as belonging to {sup 179}Au. Based on {gamma}-ray coincidence relationships and on comparisons with neighboring odd-A Au nuclei, we constructed a tentative level scheme and assigned a rotational-like sequence to the {pi} i{sub 13/2} proton configuration.

    11. Blue luminescence of Au nanoclusters embedded in silica matrix.

      PubMed

      Dhara, S; Chandra, Sharat; Magudapathy, P; Kalavathi, S; Panigrahi, B K; Nair, K G M; Sastry, V S; Hsu, C W; Wu, C T; Chen, K H; Chen, L C

      2004-12-22

      Photoluminescence study using the 325 nm He-Cd excitation is reported for the Au nanoclusters embedded in SiO(2) matrix. Au clusters are grown by ion beam mixing with 100 KeV Ar(+) irradiation on Au [40 nm]/SiO(2) at various fluences and subsequent annealing at high temperature. The blue bands above approximately 3 eV match closely with reported values for colloidal Au nanoclusters and supported Au nanoislands. Radiative recombination of sp electrons above Fermi level to occupied d-band holes are assigned for observed luminescence peaks. Peaks at 3.1 and 3.4 eV are correlated to energy gaps at the X- and L-symmetry points, respectively, with possible involvement of relaxation mechanism. The blueshift of peak positions at 3.4 eV with decreasing cluster size is reported to be due to the compressive strain in small clusters. A first principle calculation based on density functional theory using the full potential linear augmented plane wave plus local orbitals formalism with generalized gradient approximation for the exchange correlation energy is used to estimate the band gaps at the X- and L-symmetry points by calculating the band structures and joint density of states for different strain values in order to explain the blueshift of approximately 0.1 eV with decreasing cluster size around L-symmetry point.

    12. Interfacial Reaction Characteristics of Au Stud/Sn/Cu Pillar Bump During Annealing and Current Stressing.

      PubMed

      Kim, Jun-Beom; Lee, Byeong-Rok; Kim, Sung-Hyuk; Park, Jong-Myeong; Park, Young-Bae

      2015-11-01

      In this work, intermetallic compound (IMC) growth behavior in Au stud/Sn/Cu pillar bumps was investigated under annealing and current stressing conditions. AuSn2 and AuSn4 IMCs formed at the interface between the Au studs and Sn after bonding. The AuSn2 phase grew significantly as the stressing time increased, causing micro-voids to form near the (Cu, Au)6Sn5, AuSn2 and AuSn4 IMC interfaces. The interfacial reactions resulting from current stressing took place quicker than observed for pure annealing. The apparent activation energies for the growth of the AuSn2 phase during annealing and current stressing were 0.52 eV and 0.47 eV, respectively, which may be closely related to the acceleration of the interfacial reaction by electron wind forces during current stressing.

    13. Study on antibacterial activity of chemically synthesized PANI-Ag-Au nanocomposite

      NASA Astrophysics Data System (ADS)

      Boomi, Pandi; Prabu, Halliah Gurumallesh; Manisankar, Paramasivam; Ravikumar, Sundaram

      2014-05-01

      Pristine polyaniline (PANI), PANI-Ag, PANI-Au and PANI-Ag-Au nanocomposites have been successfully synthesized by chemical oxidative polymerization method using aniline as monomer, ammonium persulphate as oxidant and metal (Ag, Au and Ag-Au) colloids. UV-Vis analysis exhibited surface Plasmon resonances of Ag, Au, Ag-Au nanoparticles. FT-IR spectra revealed the shift in peak position of N-H stretching. X-ray diffraction (XRD) results confirm the presence of Ag, Au and Au-Ag nanoparticles. HR-TEM images show nanosizes of Ag, Au, Ag-Au and the incorporation of such nanoparticles into the PANI matrix. Pristine PANI, PANI-Ag, PANI-Au and PANI-Ag-Au nanocomposites were tested for antibacterial activity by agar well diffusion method. PANI-Ag-Au nanocomposite exhibited higher antibacterial activity against both gram-positive [Streptococcus sp. (MTCC 890), Staphylococcus sp. (MTCC 96)] and gram-negative bacteria [Escherichia coli (MTCC 1671) and Klebsiella sp. (MTCC 7407)] when compared with PANI-Ag nanocomposite, PANI-Au nanocomposite and pristine PANI. The novelty of this study is the polymer-bimetal synthesis and its antibacterial potential.

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

      SciTech Connect

      Hoffmann, F. M.; Hrbek, J.; Ma, S.; Park, J. B.; Rodriguez, J. A.; Stacchiola, D. J.; Senanayake, S. D.

      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 defined defects that offer an attractive alternative to vicinal surfaces or nanoparticles commonly employed in catalysis science.

    15. 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

    16. Electrochemical Reduction of CO2 at Functionalized Au Electrodes.

      PubMed

      Fang, Yuxin; Flake, John C

      2017-03-08

      Electrochemical reduction of CO2 provides an opportunity to store renewable energy as fuels with much greater energy densities than batteries. Product selectivity of the reduction reaction is known to be a function of the electrolyte and electrode; however, electrodes modified with functional ligands may offer new methods to control selectivity. Here, we report the electrochemical reduction of CO2 at functionalized Au surfaces with three thiol-tethered ligands: 2-mercaptopropionic acid, 4-pyridinylethanemercaptan, and cysteamine. Remarkably, Au electrodes modified with 4-pyridinylethanemercaptan show a 2-fold increase in Faradaic efficiency and 3-fold increase in formate production relative to Au foil. Conversely, electrodes with 2-mercaptopropionic acid ligands show nearly 100% Faradaic efficiency toward the hydrogen evolution reaction, while cystemine-modified electrodes show 2-fold increases in both CO and H2 production. We propose a proton-induced desorption mechanism associated with pKa of the functionalized ligand as responsible for the dramatic selectivity changes.

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

      NASA Astrophysics Data System (ADS)

      Hoffmann, F. M.; Hrbek, J.; Ma, S.; Park, J. B.; Rodriguez, J. A.; Stacchiola, D. J.; Senanayake, S. D.

      2016-08-01

      Low-coordinated sites are surface defects whose presence can transform a surface of inert or noble metal such as Au into an active catalyst. Starting with a well-ordered Au(111) surface we prepared by ion sputtering gold surfaces modified by pits, 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. Pitted nanostructured surfaces can serve as interesting and easily prepared models of catalytic surfaces with defined defects that offer an attractive alternative to vicinal surfaces or nanoparticles commonly employed in catalysis science.

    18. Au Nanowire-Striped Cu3P Platelet Photoelectrocatalysts.

      PubMed

      Dutta, Anirban; Samantara, Aneeya K; Adhikari, Samrat Das; Jena, Bikash Kumar; Pradhan, Narayan

      2016-03-17

      A stripy pattern of continuous epitaxial growth of thin Au nanowires on plasmonic Cu3P platelets is reported. The obtained Au-Cu3P heterostructures retain their wide area interfacial heterojunction, which is typically not observed in metal-semiconductor heterostructures. This is performed by phosphine-mediated in situ reduction of Au ions on specific facets of Cu3P platelets. The intriguing stripy movements of nanowires are regulated by strong surface binding ligands. Because this is a dual plasmon heterostructure with wide visible absorption window, these are further explored as a photoelectrocatalyst for efficient hole transfer and sensing of an important biomolecule, nicotinamide adenine dinucleotide (NADH). The observed anodic photocurrent was 30 times higher in the presence of NADH, and this proves that the heterostructured material is an ideal photosenser and an efficient catalyst for solar energy conversion.

    19. Study of copper underpotential deposition on Au(111) surfaces

      NASA Astrophysics Data System (ADS)

      Xu, J. G.; Wang, X. W.

      1998-06-01

      First-principles total energy calculations are carried out to study the structure of copper underpotential deposition on Au(111) surfaces in sulfuric acid solutions. The norm-conserving method is used to construct the pseudopotentials of all the elements involved. The copper adlayer structure under various copper coverage is investigated. The results show that the proposed honeycomb structure with 2/3 monolayer copper coverage is unstable without the co-adsorption of sulfate. The co-adsorbed sulfate is found to bind to copper. The calculated structural parameters are in general agreement with those obtained from a recent X-ray experiment. In addition, the sulfate adsorption on clean Au(111) surface is studied. The results show that sulfate molecule binds much more weakly with clean Au(111) surfaces. Total energy calculations for bisulfate adsorption suggest that even though it is the dominant species in acidic electrolyte, the adsorbed bisulfate may dissociate thus leave sulfate adsorbed on the surface.

    20. 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.

    1. Molten Au/Ge alloy migration in Ge nanowires.

      PubMed

      Liu, Qian; Zou, Rujia; Wu, Jianghong; Xu, Kaibing; Lu, Aijiang; Bando, Yoshio; Golberg, Dmitri; Hu, Junqing

      2015-05-13

      Herein, we report time-resolved in situ transmission electron microscopy observation of Au particle melting at a Ge nanowire tip, subsequent forming of Au/Ge alloy liquid, and its migrating within the Ge nanowire. The migration direction and position of the Au/Ge liquid can be controlled by the applied voltage and the migration speed shows a linear deceleration in the nanowire. In a migration model proposed, the relevant dynamic mechanisms (electromigration, thermodiffusion, and viscous force, etc.) are discussed in detail. This work associated with the liquid mass transport in the solid nanowires should provide new insights into the crystal growth, interface engineering, and fabrication of the heterogeneous nanostructure-based devices.

    2. Fundamental interaction between Au quantum dots and DNA

      NASA Astrophysics Data System (ADS)

      Karna, Molleshree; Mallick, Govind; Karna, Shashi

      2010-03-01

      Semiconductor quantum dots (QDs) and metal nanoparticles (NPs) have attracted a great deal of attention in biology community due to their application as fluorescent labels and sensors. The optical properties of QDs and NPs allow them to be effective imaging agents. However, QDs have the potential to be used as more than just sensors and labels. Their biological sensing abilities include identifying target DNA through a linker followed by color change and electrical signaling. If this property can be combined with the direct binding of QDs with DNA, many other applications in bio-nanotechnological field are possible. In this paper, we investigate the interaction between colloidal Au QDs and 30-base sequence single strand DNA. Our preliminary results indicate that the DNA strand tend to form different structures in the presence of Au QDs. Furthermore, small as well as large agglomerated Au particles appear to be linked along the DNA strand.

    3. 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.

    4. Au-Based Catalysts: Electrochemical Characterization for Structural Insights.

      PubMed

      Pifferi, Valentina; Chan-Thaw, Carine E; Campisi, Sebastiano; Testolin, Anna; Villa, Alberto; Falciola, Luigi; Prati, Laura

      2016-02-25

      Au-based catalysts are widely used in important processes because of their peculiar characteristics. The catalyst performance depends strongly on the nature and structure of the metal nanoparticles, especially in the case of bimetallic catalysts where synergistic effects between the two metals can be occasionally seen. In this paper, it is shown that electrochemical characterisation (cyclovoltammetry CV and electrochemical impedance spectroscopy EIS) of AuPd systems can be used to determine the presence of an electronic interaction between the two metals, thus providing a strong support in the determination of the nature of the synergy between Au and Pd in the liquid phase oxidation of alcohols. However, it seems likely that the strong difference in the catalytic behavior between the single metals and the bimetallic system is connected not only to the redox behaviour, but also to the energetic balance between the different elementary steps of the reaction.

    5. Two-stage melting of Au-Pd nanoparticles.

      PubMed

      Mejía-Rosales, Sergio J; Fernandez-Navarro, Carlos; Pérez-Tijerina, Eduardo; Montejano-Carrizales, Juan Martín; José-Yacamán, Miguel

      2006-07-06

      Several series of molecular dynamics runs were performed to simulate the melting transition of bimetallic cuboctahedral nanoparticles of gold-palladium at different relative concentrations to study their structural properties before, in, and after the transition. The simulations were made in the canonical ensemble, each series covering a range of temperatures from 300 to 980 K, using the Rafii-Tabar version of the Sutton and Chen interatomic potential for metallic alloys. We found that the melting transition temperature has a strong dependence on the relative concentrations of the atomic species. We also found that, previous to the melting transition, the outer layer of the nanoparticle gets disordered in what can be thought as a premelting stage, where Au atoms near the surface migrate to the surface and remain there after the particle melts as a whole. The melting of the surface below Tm is consistent with studies of the interaction of a TEM electron beam with Au and Au-Pd nanoparticles.

    6. Level densities and thermodynamical properties of Pt and Au isotopes

      NASA Astrophysics Data System (ADS)

      Giacoppo, F.; Bello Garrote, F. L.; Bernstein, L. A.; Bleuel, D. L.; Eriksen, T. K.; Firestone, R. B.; Görgen, A.; Guttormsen, M.; Hagen, T. W.; Kheswa, B. V.; Klintefjord, M.; Koehler, P. E.; Larsen, A. C.; Nyhus, H. T.; Renstrøm, T.; Sahin, E.; Siem, S.; Tornyi, T.

      2014-11-01

      The nuclear level densities of Pt-196194 and Au,198197 below the neutron separation energy have been measured using transfer and scattering reactions. All the level density distributions follow the constant-temperature description. Each group of isotopes is characterized by the same temperature above the energy threshold corresponding to the breaking of the first Cooper pair. A constant entropy excess Δ S =1.9 kB and 1.1 kB is observed in 195Pt and 198Au with respect to 196Pt and 197Au, respectively, giving information on the available single-particle level space for the last unpaired valence neutron. The breaking of nucleon Cooper pairs is revealed by sequential peaks in the microcanonical caloric curve.

    7. Nanoscale arrangement of diblock copolymer micelles with Au nanorods

      NASA Astrophysics Data System (ADS)

      Kim, Hwan; Lim, Yirang; Kim, Sehee; Kim, Sung-Soo; Sohn, Byeong-Hyeok

      2014-11-01

      We fabricated a single-layered film consisting of spherical micelles of diblock copolymers and one-dimensional Au nanorods that were surface modified with the same polymer as the corona block of the copolymers. When the diameters of micelles were larger than the lengths of the nanorods, spherical micelles arranged in a hexagonal configuration surrounded by nanorods with their long axes perpendicular to the radial direction of the micelles. This arrangement provided selective organization of the Au nanorods and Ag nanoparticles which were selectively synthesized within the cores of the copolymer micelles. Thus, position-selective arrangement of Au nanorods and Ag nanoparticles was demonstrated at the nanometer scale such that a homogenous distribution of two different nanomaterials over a large area without aggregation was achieved.

    8. Crystallography of Martensite in TiAu Shape Memory Alloy

      NASA Astrophysics Data System (ADS)

      Inamura, T.; Hosoda, H.

      2011-01-01

      The twin structure, habit plane orientation, and morphology of B19 martensite in TiAu, which is a candidate shape memory alloy (SMA) for high-temperature and biomedical applications, were investigated by conventional transmission electron microscopy. Almost all internal twins were {111} type I twins as lattice-invariant deformation (LID). The <211> type II twin was scarcely observed in TiAu, unlike in TiPd and TiPt SMAs. The habit plane roughly corresponded to the twinning plane ( K 1 plane) of the <211> type II twin because of the superb lattice parameter ratio of TiAu. As a result, an energy-minimizing microstructure referred to as "twins within twins" appears as the major microstructure. The selection rules for the twinning of LID are also discussed considering the results of extensive studies on LID in SMAs.

    9. Zigzag Assembly of Carbon Nanotubes inside Au Microtrenches.

      PubMed

      Cao, Anyuan; Ajayan, Pulickel M

      2004-05-20

      We report the self-assembly of zigzag patterns consisting of aligned carbon nanotubes inside Au microtrenches by chemical vapor deposition using ferrocene/xylene solution as the precursor. The zigzag nanotubes have uniform size and constant interpattern distance, which can be controlled by simply changing the width of the Au trenches. We demonstrated the tunable length and orientation of nanotubes during self-assembly, leading to a predictable motion of zigzag patterns. A growth model was proposed for the zigzag assembly of nanotubes, including the formation and subsequent splitting of an amorphous carbon layer on the pattern top. Rows of nanotube micropatterns regularly distributed along the Au trench are potential candidates as integrated arrays of thermal or mechanical detectors and actuators.

    10. Influence of the S-Au Bond Strength on the Magnetic Behavior of S-Capped Au Nanoparticles

      NASA Astrophysics Data System (ADS)

      Vázquez, María J. Rodríguez; Rivas, José; López-Quintela, M. Arturo; Mosquera, Antonio Mouriño; Torneiro, Mercedes

      Recently, large permanent atomic magnetic moments have been found in Au nanoparticles capped with thiols. It is assumed that the formation of localized Au-S bonds at the particle surface induces the damping of the surface plasmon resonance and the appearance of a ferromagnetic-like behavior. In this work we will show for the first time that thioethers can also induce both phenomena, i.e., the damping of the plasmon band and the appearance of permanent magnetic moments. Furthermore, we have studied the influence of the Au-S bond strength on both phenomena using two different synthesized thioether ligands. It will be shown that, although both ligands can induce a complete damping of the plasmon band, only with one of the ligands (the one corresponding to the stronger S-Au bond) the appearance of a ferromagnetic-like order is observed. This is an indication of the extreme sensitivity of the magnetism on the strength of the charge transfer at the S-Au bond.

    11. Measurement of direct photons in Au+Au collisions at √(s(NN))=200 GeV.

      PubMed

      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; Bucher, D; Buesching, H; Bumazhnov, V; Bunce, G; Burward-Hoy, J M; Butsyk, S; Campbell, S; Chai, J-S; Chernichenko, S; Chi, C Y; Chiba, J; Chiu, M; Choi, I J; Chujo, T; Cianciolo, V; Cleven, C R; Cobigo, Y; Cole, B A; Comets, M P; Connors, M; Constantin, P; Csanád, M; Csörgő, T; Dahms, T; Das, K; David, G; Delagrange, H; Denisov, A; d'Enterria, D; Deshpande, A; Desmond, E J; Dietzsch, O; Dion, A; Drachenberg, J L; Drapier, O; Drees, A; Dubey, A K; Durum, A; Dzhordzhadze, V; Efremenko, Y V; Egdemir, J; Enokizono, A; En'yo, H; Espagnon, B; Esumi, S; Fields, D E; Fleuret, F; Fokin, S L; Forestier, B; 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; 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; Hiejima, H; Hill, J C; Hobbs, R; Holmes, M; Holzmann, W; Homma, K; Hong, B; Horaguchi, T; Hur, M G; Ichihara, T; Iinuma, H; Imai, K; Imrek, J; Inaba, 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; Joo, K S; Jouan, D; Kajihara, F; Kametani, S; Kamihara, N; Kaneta, M; Kang, J H; Kawagishi, T; Kazantsev, A V; Kelly, S; Khanzadeev, A; Kim, D J; Kim, E; Kim, Y-S; Kinney, E; Kiss, A; Kistenev, E; Kiyomichi, A; Klein-Boesing, C; Kochenda, L; Kochetkov, V; Komkov, B; Konno, M; Kotchetkov, D; Kozlov, A; Kroon, P J; Kunde, G J; Kurihara, N; Kurita, K; Kweon, M J; Kwon, Y; Kyle, G S; Lacey, R; Lajoie, J G; Lebedev, A; Le 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; Masui, H; Matathias, F; McCain, M C; McGaughey, P L; Miake, Y; Miller, T E; Milov, A; Mioduszewski, S; Mishra, G C; Mitchell, J T; Morrison, D P; Moss, J M; Moukhanova, T V; Mukhopadhyay, D; 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; Ozawa, K; Pak, R; Pal, D; Palounek, A P T; Pantuev, V; Papavassiliou, V; Park, J; Park, W J; Pate, S F; Pei, H; Peng, J-C; Pereira, H; Peresedov, V; Peressounko, D Yu; Pinkenburg, C; Pisani, R P; Purschke, M L; Purwar, A K; Qu, H; 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; Sato, H D; Sato, S; Sawada, S; 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; Vale, C; Valle, H; van Hecke, H W; Velkovska, J; Vértesi, R; Vinogradov, A A; Vznuzdaev, E; Wagner, M; Wang, X R; Watanabe, Y; Wessels, J; White, S N; Willis, N; Winter, D; 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; Zimányi, J; Zolin, L

      2012-10-12

      We report the measurement of direct photons at midrapidity in Au+Au collisions at √(s(NN))=200 GeV. The direct photon signal was extracted for the transverse momentum range of 4 GeV/cAu+Au collision centralities using the measured p+p direct photon spectrum and compared to theoretical predictions. R(AA) was found to be consistent with unity for all centralities over the entire measured p(T) range. Theoretical models that account for modifications of initial direct photon production due to modified parton distribution functions in Au and the different isospin composition of the nuclei predict a modest change of R(AA) from unity. They are consistent with the data. Models with compensating effects of the quark-gluon plasma on high-energy photons, such as suppression of jet-fragmentation photons and induced-photon bremsstrahlung from partons traversing the medium, are also consistent with this measurement.

    12. Structure and mobility of metal clusters in MOFs: Au, Pd, and AuPd clusters in MOF-74.

      PubMed

      Vilhelmsen, Lasse B; Walton, Krista S; Sholl, David S

      2012-08-01

      Understanding the adsorption and mobility of metal-organic framework (MOF)-supported metal nanoclusters is critical to the development of these catalytic materials. We present the first theoretical investigation of Au-, Pd-, and AuPd-supported clusters in a MOF, namely MOF-74. We combine density functional theory (DFT) calculations with a genetic algorithm (GA) to reliably predict the structure of the adsorbed clusters. This approach allows comparison of hundreds of adsorbed configurations for each cluster. From the investigation of Au(8), Pd(8), and Au(4)Pd(4) we find that the organic part of the MOF is just as important for nanocluster adsorption as open Zn or Mg metal sites. Using the large number of clusters generated by the GA, we developed a systematic method for predicting the mobility of adsorbed clusters. Through the investigation of diffusion paths a relationship between the cluster's adsorption energy and diffusion barrier is established, confirming that Au clusters are highly mobile in the MOF-74 framework and Pd clusters are less mobile.

    13. The electric dipole moments in the ground states of gold oxide, AuO, and gold sulfide, AuS

      NASA Astrophysics Data System (ADS)

      Zhang, Ruohan; Yu, Yuanqin; Steimle, Timothy C.; Cheng, Lan

      2017-02-01

      The B2Σ- - X2Π3/2(0,0) bands of a cold molecular beam sample of gold monoxide, AuO, and gold monosulfide, AuS, have been recorded at high resolution both field free and in the presence of a static electric field. The observed electric field induced splittings and shifts were analyzed to produce permanent electric dipole moments, μ→ e l, of 2.94±0.06 D and 2.22±0.05 D for the X2Π3/2(v = 0) states of AuO and AuS, respectively. A molecular orbital correlation diagram is used to rationalize the trend in ground state μ→ e l values for AuX (X = F, Cl, O, and S) molecules. The experimentally determined μ→ e l are compared to those computed at the coupled-cluster singles and doubles (CCSD) level augmented with a perturbative inclusion of triple excitations (CCSD(T)) level of theory.

    14. Final Technical Report: First Principles Investigations for the Ensemble Effects of PdAu and PtAu Bimetallic Nanocatalysts

      SciTech Connect

      Ruqian Wu

      2012-05-18

      Bimetallic surfaces with tunable chemical properties have attracted broad attention in recent years due to their ample potential for heterogeneous catalysis applications. The local chemical properties of constituents are strongly altered from their parent metals by 'ligand effect', a term encompassing the influences of charge transfer, orbital rehybridization and lattice strain. In comparison to the aforementioned, the 'ensemble effect' associated with particular arrangements of the active constituents have received much less attention, despite their notable importance towards the determination of reactivity and selectivity of bimetallic catalysts. We performed theoretical studies for understanding the ensemble effects on bimetallic catalysis: (i) simulations for the formation of different ensembles on PdAu and PtAu nanoclusters; (ii) studies of the size, shape, and substrate dependence of their electronic properties; and (iii) simulations for model reactions such as CO oxidation, methanol, ethylene and water dehydrogenation on PdAu and PtAu nanoclusters. In close collaboration with leading experimental groups, our theoretical research elucidated the fundamentals of Au based bimetallic nanocatalysts.

    15. Bi-functional Au/FeS (Au/Co3O4) composite for in situ SERS monitoring and degradation of organic pollutants

      NASA Astrophysics Data System (ADS)

      Ma, Shuzhen; Cai, Qian; Lu, Kailing; Liao, Fan; Shao, Mingwang

      2016-01-01

      The bi-functional Au/FeS (Au/Co3O4) composite was fabricated by in situ reducing Au nanoparticles onto the surface of FeS (Co3O4). The as-prepared FeS possessed a multi-structure composed of plenty of nanoplates, which were coated by Au nanoparticles with an average size of 47.5 nm. While the Co3O4 showed a thin hexagonal sheet containing Au nanoparticles on its surface with an average size of 79.0 nm. Both the as-prepared Au/FeS and Au/Co3O4 composites exhibited excellent SERS performance, capable of enhancing the Raman signals of R6G molecules with the enhancement factor up to 1.81 × 106 and 7.60 × 104, respectively. Moreover, Au/FeS (Au/Co3O4) composite also has been verified to have intrinsic peroxidase-like activity, which could decompose H2O2 into hydroxyl radicals and then degrade organic pollutants into small molecules. Therefore, SERS can be used to real-time and in situ monitoring the degradation process of R6G molecules, employing the Au/FeS (Au/Co3O4) composite both as SERS substrate and catalyst.

    16. Formation of one-dimensional Ag-Au solid solution colloids with Au nanorods as seeds, their alloying mechanisms, and surface plasmon resonances.

      PubMed

      Guo, Tao; Tan, Yiwei

      2013-01-21

      In this work, one dimensional (1D) Ag-Au solid solution nanoalloys were synthesized by rapidly diffusing Ag into the preformed Au nanorod (AuNR) seeds at ambient temperature in aqueous solution. By varying the molar ratio of AgCl/AuNR (in gold atoms), two kinds of 1D Ag-Au alloy nanostructures with a narrow size distribution--AgAu nanowires and Ag(33)Au(67) nanorods--could be obtained in high yields when NaCl and polyvinylpyrrolidone (PVP) were used as an additive and capping reagent, respectively. Based on HRTEM imaging combined with a series of control experiments, it is conceivable that vacancy/defect-motivated interdiffusion of Ag and Au atoms coupled with oxidative etching is a crucial stage in the mechanism responsible for this room-temperature alloying process, and the subsequent conjugation of the fused Ag-Au alloyed nanostructures is associated with the formation of the AgAu nanowires. The resulting 1D Ag-Au nanoalloys form stable colloidal dispersions and show unique localized surface plasmon resonance (LSPR) peaks in the ensemble extinction spectra.

    17. Anoplastie périnéale simple pour le traitement des malformations anorectales basses chez l'adulte, à propos de deux cas

      PubMed Central

      Echchaoui, Abdelmoughit; Benyachou, Malika; Hafidi, Jawad; Fathi, Nahed; Mohammadine, Elhamid; ELmazouz, Samir; Gharib, Nour-eddine; Abbassi, Abdellah

      2014-01-01

      Les malformations anorectales chez l'adulte sont des anomalies congénitales rares du tube digestif qui prédominent chez le sexe féminin. Notre étude porte sur deux observations de malformation anorectale basses vues et traitées au stade adulte par les 2 équipes (plasticiens et viscéralistes) à l'Hôpital Avicenne à Rabat. Il s'agit d'un homme de 24 ans avec une dyschésie anale l'autre cas est une femme de 18 ans avec une malformation anovulvaire Les caractéristiques cliniques combinées avec les imageries radiologiques (lavement baryté, et la manométrie anorectale) ont confirmé qu'il s'agit d'une malfomation anorectale basse. Les deux cas sont corrigés par une reconstruction sphinctérienne, réimplantation anale avec anoplastie périnéale. Les suites opératoires étaient simples, pas de souffrance cutanée ou nécrose, avec changement de pansement gras chaque jour. Le résultat fonctionnel (la continence) était favorable pour les 2 patients. La présentation des MAR à l’âge adulte est rare, d’étiologie mal connu, elles apparaissent selon le mode sporadique. Les caractéristiques cliniques, couplées à l'imagerie (lavement baryté, IRM pelvienne), l'endoscopie et la manométrie anorectale, permettent de confirmer le diagnostic et classer ces anomalies en 3 types: basses, intermédiaires, et hautes. Les formes basses sont traités d'emblée par une réimplantation anale et anoplastie périnéale simple tels nos deux cas, elles peuvent être traités dans certains cas par un abaissement anorectale associé à une plastie V-Y permettant ainsi un emplacement anatomique correct de l'anus; alors que les formes hautes ou intermédiaires relèvent d'une chirurgie complexe avec souvent une dérivation digestive transitoire. Contrairement aux autres formes, Les formes basses ont un pronostic fonctionnel favorable. PMID:25667689

    18. Common suppression pattern of eta and pi0 mesons at high transverse momentum in Au + Au collisions at square root S(NN) = 200 GeV.

      PubMed

      Adler, S S; Afanasiev, S; Aidala, C; Ajitanand, N N; Akiba, Y; Alexander, J; Amirikas, R; Aphecetche, L; Aronson, S H; Averbeck, R; Awes, T C; Azmoun, R; Babintsev, V; Baldisseri, A; Barish, K N; Barnes, P D; Bassalleck, B; Bathe, S; Batsouli, S; Baublis, V; Bazilevsky, A; Belikov, S; Berdnikov, Y; Bhagavatula, S; Boissevain, J G; Borel, H; Borenstein, S; Brooks, M L; Brown, D S; Bruner, N; Bucher, D; Buesching, H; Bumazhnov, V; Bunce, G; Burward-Hoy, J M; Butsyk, S; Camard, X; Chai, J-S; Chand, P; Chang, W C; Chernichenko, S; Chi, C Y; Chiba, J; Chiu, M; Choi, I J; Choi, J; Choudhury, R K; Chujo, T; Cianciolo, V; Cobigo, Y; Cole, B A; Constantin, P; d'Enterria, D; David, G; Delagrange, H; Denisov, A; Deshpande, A; Desmond, E J; Devismes, A; Dietzsch, O; Drapier, O; Drees, A; du Rietz, R; Durum, A; Dutta, D; Efremenko, Y V; Chenawi, K El; Enokizono, A; En'yo, H; Esumi, S; Ewell, L; Fields, D E; Fleuret, F; Fokin, S L; Fox, B D; Fraenkel, Z; Frantz, J E; Franz, A; Frawley, A D; Fung, S-Y; Garpman, S; Ghosh, T K; Glenn, A; Gogiberidze, G; Gonin, M; Gosset, J; Goto, Y; de Cassagnac, R Granier; Grau, N; Greene, S V; Perdekamp, M Grosse; Guryn, W; Gustafsson, H-A; Hachiya, T; Haggerty, J S; Hamagaki, H; Hansen, A G; Hartouni, E P; Harvey, M; Hayano, R; Hayashi, N; He, X; Heffner, M; Hemmick, T K; Heuser, J M; Hibino, M; Hiejima, H; Hill, J C; Holzmann, W; Homma, K; Hong, B; Hoover, A; Ichihara, T; Ikonnikov, V V; Imai, K; Isenhower, D; Ishihara, M; Issah, M; Isupov, A; Jacak, B V; Jang, W Y; Jeong, Y; Jia, J; Jinnouchi, O; Johnson, B M; Johnson, S C; Joo, K S; Jouan, D; Kametani, S; Kamihara, N; Kang, J H; Kapoor, S S; Katou, K; Kelly, S; Khachaturov, B; Khanzadeev, A; Kikuchi, J; Kim, D H; Kim, D J; Kim, D W; Kim, E; Kim, G-B; Kim, H J; Kistenev, E; Kiyomichi, A; Kiyoyama, K; Klein-Boesing, C; Kobayashi, H; Kochenda, L; Kochetkov, V; Koehler, D; Kohama, T; Kopytine, M; Kotchetkov, D; Kozlov, A; Kroon, P J; Kuberg, C H; Kurita, K; Kuroki, Y; Kweon, M J; Kwon, Y; Kyle, G S; Lacey, R; Ladygin, V; Lajoie, J G; Lebedev, A; Leckey, S; Lee, D M; Lee, S; Leitch, M J; Li, X H; Lim, H; Litvinenko, A; Liu, M X; Liu, Y; Maguire, C F; Makdisi, Y I; Malakhov, A; Manko, V I; Mao, Y; Martinez, G; Marx, M D; Masui, H; Matathias, F; Matsumoto, T; McGaughey, P L; Melnikov, E; Messer, F; Miake, Y; Milan, J; Miller, T E; Milov, A; Mioduszewski, S; Mischke, R E; Mishra, G C; Mitchell, J T; Mohanty, A K; Morrison, D P; Moss, J M; Mühlbacher, F; Mukhopadhyay, D; Muniruzzaman, M; Murata, J; Nagamiya, S; Nagle, J L; Nakamura, T; Nandi, B K; Nara, M; Newby, J; Nilsson, P; Nyanin, A S; Nystrand, J; O'Brien, E; Ogilvie, C A; Ohnishi, H; Ojha, I D; Okada, K; Ono, M; Onuchin, V; Oskarsson, A; Otterlund, I; Oyama, K; Ozawa, K; Pal, D; Palounek, A P T; Pantuev, V; Papavassiliou, V; Park, J; Parmar, A; Pate, S F; Peitzmann, T; Peng, J-C; Peresedov, V; Pinkenburg, C; Pisani, R P; Plasil, F; Purschke, M L; Purwar, A K; Rak, J; Ravinovich, I; Read, K F; Reuter, M; Reygers, K; Riabov, V; Riabov, Y; Roche, G; Romana, A; Rosati, M; Rosnet, P; Ryu, S S; Sadler, M E; Sahlmueller, B; Saito, N; Sakaguchi, T; Sakai, M; Sakai, S; Samsonov, V; Sanfratello, L; Santo, R; Sato, H D; Sato, S; Sawada, S; Schutz, Y; Semenov, V; Seto, R; Shaw, M R; Shea, T K; Shibata, T-A; Shigaki, K; Shiina, T; Silva, C L; Silvermyr, D; Sim, K S; Singh, C P; Singh, V; Sivertz, M; 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; Sullivan, J P; Takagui, E M; Taketani, A; Tamai, M; Tanaka, K H; Tanaka, Y; Tanida, K; Tannenbaum, M J; Tarján, P; Tepe, J D; Thomas, T L; Tojo, J; Torii, H; Towell, R S; Tserruya, I; Tsuruoka, H; Tuli, S K; Tydesjö, H; Tyurin, N; van Hecke, H W; Velkovska, J; Velkovsky, M; Veszprémi, V; Villatte, L; Vinogradov, A A; Volkov, M A; Vznuzdaev, E; Wang, X R; Watanabe, Y; White, S N; Wohn, F K; Woody, C L; Xie, W; Yang, Y; Yanovich, A; Yokkaichi, S; Young, G R; Yushmanov, I E; Zajc, W A; Zhang, C; Zhou, S; Zhou, S J; Zolin, L

      2006-05-26

      Inclusive transverse momentum spectra of eta mesons have been measured within p(T) = 2-10 GeV/c at midrapidity by the PHENIX experiment in Au + Au collisions at square root S(NN) = 200 GeV. In central Au+Au the eta yields are significantly suppressed compared to peripheral Au + Au, d + Au, and p + p yields scaled by the corresponding number of nucleon-nucleon collisions. The magnitude, centrality, and p(T) dependence of the suppression is common, within errors, for eta and pi0. The ratio of eta to pi0 spectra at high p(T) amounts to 0.40 < R(eta/pi)0 < 0.48 for the three systems, in agreement with the world average measured in hadronic and nuclear reactions and, at large scaled momentum, in e+e- collisions.

    19. Surface structure determination of Au(1 ML)/Fe(15 ML)/Au(100) using angle-resolved photoemission extended fine structure

      NASA Astrophysics Data System (ADS)

      Kellar, S. A.; Chen, Y.; Huff, W. R. A.; Moler, E. J.; Hussain, Z.; Shirley, D. A.

      1998-01-01

      We have determined the atomic surface structure of a thin film of Fe (15 ML) grown on the Au(100) surface, Au(1 ML)/Fe(15 ML)/Au(100), with angle-resolved photoemission extended fine structure (ARPEFS) using the Au 4f7/2 core level. We have confirmed that a bcc crystalline Fe film grows epitaxially on the Au(100) substrate with 1 ML of Au atoms remaining on the surface using angle-resolved photoemission spectroscopy. We analyzed the ARPEFS oscillations using an electron-scattering code based on the Rehr-Albers scattering matrix formalism. Our analysis finds that the surface Au atoms are positioned in the fourfold hollow sites 1.67+/-0.02 Å above the Fe surface. We also find that the grown Fe layers are very like bulk bcc Fe, with an interlayer spacing of 1.43+/-0.03 Å.

    20. 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

    1. 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.

    2. Graphene nanoribbons synthesized from molecular precursor polymerization on Au(110)

      SciTech Connect

      Massimi, Lorenzo; Ourdjini, Oualid; Della Pia, Ada; Mariani, Carlo; Betti, Maria Grazia; Cavaliere, Emanuele; Gavioli, Luca

      2015-06-23

      A spectroscopic study of 10,10-dibromo-9,9 bianthracene (DBBA) molecules deposited on the Au(110) surface is presented, by means of ultraviolet and X-ray photoemission, and X-ray absorption spectroscopy. Through a thermally activated procedure, these molecular precursors polymerize and eventually form graphene nanoribbons (GNRs) with atomically controlled shape and width, very important building blocks for several technological applications. The GNRs observed by scanning tunneling microscopy (STM) appear as short segments on top of the gold surface reconstruction, pointing out the delicate balance among surface diffusion and surface corrugation in their synthesis on the Au(110) surface.

    3. Dielectric function dependence on temperature for Au and Ag

      NASA Astrophysics Data System (ADS)

      Chen, Yu-Jen; Lee, Meng-Chang; Wang, Chih-Ming

      2014-08-01

      The dielectric functions of Au and Ag are measured using a spectral ellipsometer. The temperature dependence parameters ωp, τ, and ɛ∞, in the Drude-Sommerfeld model have been studied. Furthermore, we provide an empirical function to describe the temperature dependence of the dielectric function for Au and Ag. The empirical function shows a good agreement with previous results. Through the empirical function, one can obtain the dielectric constant at arbitrary temperature and wavelength. This database is useful for the applications that use surface plasmon (SP) resonance at high temperatures, such as the plasmonic thermal emitter, SP-assisted thermal cancer treatment and so on.

    4. 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

    5. 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.

    6. 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.

    7. Atomic Structure of Au329(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 Au329(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 Au260 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.

    8. Theoretical study of CO oxidation on cationic, neutral, and anionic AuM dimers (M = Pd and Ag).

      PubMed

      Chen, Xuan; Lu, Rui-Feng; Kan, Er-Jun; Liu, Yu-Zhen; Xiao, Chuan-Yun; Deng, Kai-Ming

      2014-06-01

      The CO and O2 adsorption as well as CO oxidation on cationic, neutral, and anionic AuM dimers (M = Pd, Ag) are studied by density functional calculations. Our results show that CO and O2 are adsorbed more stably on AuPd dimers than on AuAg dimers with corresponding charge state. O2 is favorable to be adsorbed on Pd atom in AuPd(+), AuPd and AuPd(-) dimers. CO is adsorbed on Pd in AuPd and AuPd(-), while it is favorable to be adsorbed on Au in AuPd(+). For AuAg dimers, O2 is adsorbed on Ag in AuAg and AuAg(-), and it is adsorbed on Au in AuAg(+). CO is adsorbed on Ag in AuPd(-), while it is adsorbed on Au in AuAg and AuAg(+). The CO oxidation reaction is explored along two possible pathways: path-1 involves CO attacking the initial complexes of AuM dimers and O2, and path-2 is related to O2 interacting with the complexes of AuM dimers and CO. The charge state of AuM dimers has a substantial effect on CO oxidation. The reaction on AuPd(-) prefers path-1, and AuPd(+) mediated reaction proceeds along path-2, while CO oxidation on AuPd is difficult along both paths. For AuAg, both pathways are viable for AuAg(-) mediated reactions, while AuAg and AuAg(+) mediated reactions prefer path-2. Moreover, the energy barriers of CO oxidation on neutral AuAg is comparable with those on AuPd in all charge states while the energy barriers for AuAg(-) and AuAg(+) are considerably lower than those for all AuPd dimmers, indicating the impurity atom also plays a significant role in the catalytic activity. Furthermore, AuAg(-) is proposed to be the most active species due to the lowest barrier involved in the reaction.

    9. Site-specific growth of Au-Pd alloy horns on Au nanorods: a platform for highly sensitive monitoring of catalytic reactions by surface enhancement Raman spectroscopy.

      PubMed

      Huang, Jianfeng; Zhu, Yihan; Lin, Ming; Wang, Qingxiao; Zhao, Lan; Yang, Yang; Yao, Ke Xin; Han, Yu

      2013-06-12

      Surface-enhanced Raman scattering (SERS) is a highly sensitive probe for molecular detection. The aim of this study was to develop an efficient platform for investigating the kinetics of catalytic reactions with SERS. To achieve this, we synthesized a novel Au-Pd bimetallic nanostructure (HIF-AuNR@AuPd) through site-specific epitaxial growth of Au-Pd alloy horns as catalytic sites at the ends of Au nanorods. Using high-resolution electron microscopy and tomography, we successfully reconstructed the complex three-dimensional morphology of HIF-AuNR@AuPd and identified that the horns are bound with high-index {11l} (0.25 < l < 0.43) facets. With an electron beam probe, we visualized the distribution of surface plasmon over the HIF-AuNR@AuPd nanorods, finding that strong longitudinal surface plasmon resonance concentrated at the rod ends. This unique crystal morphology led to the coupling of high catalytic activity with a strong SERS effect at the rod ends, making HIF-AuNR@AuPd an excellent bifunctional platform for in situ monitoring of surface catalytic reactions. Using the hydrogenation of 4-nitrothiophenol as a model reaction, we demonstrated that its first-order reaction kinetics could be accurately determined from this platform. Moreover, we clearly identified the superior catalytic activity of the rod ends relative to that of the rod bodies, owing to the different SERS activities at the two positions. In comparison with other reported Au-Pd bimetallic nanostructures, HIF-AuNR@AuPd offered both higher catalytic activity and greater detection sensitivity.

    10. Acid/base-controlled AuI/Au0 reductive transformations of the monogold [(μ14-Au)Pd22(CO)20(PEt3)8]+ monocation into three different neutral digold nanoclusters: Au2Pd21(CO)20(PEt3)10, Au2Pd28(CO)26(PEt3)10, and new five-layer hexagonal close-packed (μ12-Au)2Pd42(CO)30(PEt3)12 with a trigonal-bipyramidal AuPd3Au kernel.

      PubMed

      Mednikov, Evgueni G; Dahl, Lawrence F

      2015-02-02

      The monogold [(μ(14)-Au)Pd(22)(CO)(20)(PEt(3))(8)](+) nanocation (2, with a [(CF(3)CO(2))(2)H](-) counterion) is shown to be a versatile precursor for the generation of three different neutral Au-Pd nanoclusters with double gold content in their distinctly dissimilar bimetallic architectures. These carbon monoxide (CO)-induced conversions are based on the reduction of Au(I) to Au(0) that is controlled by the reaction medium. Under basic and acidic conditions, the known Au(2)Pd(21)(CO)(20)(PEt(3))(10) (3; >90% yield) and Au(2)Pd(28)(CO)(26)(PEt(3))(10) (4; ∼40% yield), respectively, were obtained, whereas neutral conditions gave rise to the new (μ(12)-Au)(2)Pd(42)(CO)(30)(PEt(3))(12) (1; ∼10-20% yield; all yields based on gold). The molecular structure of 1, established from a 100 K CCD X-ray diffraction study, consists of a five-layer hexoganol close-packed (hcp) Au(2)Pd(42) framework of pseudo-D(3)h symmetry (crystallographic D(3) site symmetry) of the Pd(6)/AuPd(9)/Pd(12)/AuPd(9)/Pd(6) layer sequence, with the Au atoms centering two identical hcp (μ(12)-Au)Pd(12) face-fused anti-cuboctahedral fragments. The 12 Et(3)-attached P atoms are coordinated to the triangular vertex Pd atoms in the four outer layers (except the middle Pd(12)); all five layers are stapled by interlayer bridging COs. The radial Au(cent)-Pd mean distance of 2.79 Å within the two symmetry-equivalent (μ(12)-Au)Pd(12) anti-cuboctahedral fragments of 1 is identical with the radial Pd(cent)-Pd mean distances within hcp (μ(12)-Pd)Pd(12) anti-cuboctahedral fragments of the two geometrically related nondistorted layered structures of Pd(52)(CO)(36)(PEt(3))(14) and [Ni(9)Pd(33)(CO)(41)(PPh(3))(6)](4-) ([PPh(4)](+) counterion), indicating a strain-free structural effect upon the substitution of Au for Pd in their analogous hcp layer-stacked arrangements. It provides prime evidence for an extension to 1 of our previous self-consistent experimental/theoretical-based hypothesis for

    11. Pion Interferometry of square root of (s(NN)) =130 GeV Au + Au collisions at RHIC.

      PubMed

      Adler, C; Ahammed, Z; Allgower, C; Amonett, J; Anderson, B D; Anderson, M; Averichev, G S; Balewski, J; Barannikova, O; Barnby, L S; Baudot, J; Bekele, S; Belaga, V V; Bellwied, R; Berger, J; Bichsel, H; Bland, L C; Blyth, C O; Bonner, B E; Bossingham, R; Boucham, A; Brandin, A; Cadman, R V; Caines, H; Calderón De La Barca Sánchez, M; Cardenas, A; Carroll, J; Castillo, J; Castro, M; Cebra, D; Chattopadhyay, S; Chen, M L; Chen, Y; Chernenko, S P; Cherney, M; Chikanian, A; Choi, B; Christie, W; Coffin, J P; Conin, L; Cormier, T M; Cramer, J G; Crawford, H J; DeMello, M; Deng, W S; Derevschikov, A A; Didenko, L; Draper, J E; Dunin, V B; Dunlop, J C; Eckardt, V; Efimov, L G; Emelianov, V; Engelage, J; Eppley, G; Erazmus, B; Fachini, P; Faine, V; Finch, E; Fisyak, Y; Flierl, D; Foley, K J; Fu, J; Gagunashvili, N; Gans, J; Gaudichet, L; Germain, M; Geurts, F; Ghazikhanian, V; Grabski, J; Grachov, O; Greiner, D; Grigoriev, V; Guedon, M; Gushin, E; Hallman, T J; Hardtke, D; Harris, J W; Heffner, M; Heppelmann, S; Herston, T; Hippolyte, B; Hirsch, A; Hjort, E; Hoffmann, G W; Horsley, M; Huang, H Z; Humanic, T J; Hümmler, H; Igo, G; Ishihara, A; Ivanshin, Y I; Jacobs, P; Jacobs, W W; Janik, M; Johnson, I; Jones, P G; Judd, E; Kaneta, M; Kaplan, M; Keane, D; Kisiel, A; Klay, J; Klein, S R; Klyachko, A; Konstantinov, A S; Kotchenda, L; Kovalenko, A D; Kramer, M; Kravtsov, P; Krueger, K; Kuhn, C; Kulikov, A I; 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; Lednický, R; Leontiev, V M; LeVine, M J; Li, Q; Li, Q; Lindenbaum, S J; Lisa, M A; Ljubicic, T; Llope, W J; LoCurto, G; Long, H; Longacre, R S; Lopez-Noriega, M; Love, W A; Lynn, D; Majka, R; Margetis, S; Martin, L; Marx, J; Matis, H S; Matulenko, Y A; McShane, T S; Meissner, F; Melnick, Y; Meschanin, A; Messer, M; Miller, M L; Milosevich, Z; Minaev, N G; Mitchell, J; Moiseenko, V A; Moltz, D; Moore, C F; Morozov, V; de Moura, M M; Munhoz, M G; Mutchler, G S; Nelson, J M; Nevski, P; Nikitin, V A; Nogach, L V; Norman, B; Nurushev, S B; Odyniec, G; Ogawa, A; Okorokov, V; Oldenburg, M; Olson, D; Paic, G; Pandey, S U; Panebratsev, Y; Panitkin, S Y; Pavlinov, A I; Pawlak, T; Perevoztchikov, V; Peryt, W; Petrov, V A; Pinganaud, W; Platner, E; Pluta, J; Porile, N; Porter, J; Poskanzer, A M; Potrebenikova, E; Prindle, D; Pruneau, C; Radomski, S; Rai, G; Ravel, O; Ray, R L; Razin, S V; Reichhold, D; Reid, J G; Retiere, F; Ridiger, A; Ritter, H G; Roberts, J B; Rogachevski, O V; Romero, J L; Roy, C; Russ, D; Rykov, V; Sakrejda, I; Sandweiss, J; Saulys, A C; Savin, I; Schambach, J; Scharenberg, R P; Schweda, K; Schmitz, N; Schroeder, L S; Schüttauf, A; Seger, J; Seliverstov, D; Seyboth, P; Shahaliev, E; Shestermanov, K E; Shimanskii, S S; Shvetcov, V S; Skoro, G; Smirnov, N; Snellings, R; Sowinski, J; Spinka, H M; Srivastava, B; Stephenson, E J; Stock, R; Stolpovsky, A; Strikhanov, M; Stringfellow, B; Stroebele, H; Struck, C; Suaide, A A; Sugarbaker, E; Suire, C; Sumbera, M; Symons, T J; Szanto De Toledo, A; Szarwas, P; Takahashi, J; Tang, A H; Thomas, J H; Tikhomirov, V; Trainor, T A; Trentalange, S; Tokarev, M; Tonjes, M B; Trofimov, V; Tsai, O; Turner, K; Ullrich, T; Underwood, D G; Van Buren, G; VanderMolen, A M; Vanyashin, A; Vasilevski, I M; Vasiliev, A N; Vigdor, S E; Voloshin, S A; Wang, F; Ward, H; Watson, J W; Wells, R; Wenaus, T; Westfall, G D; Whitten, C; Wieman, H; Willson, R; Wissink, S W; Witt, R; Xu, N; Xu, Z; Yakutin, A E; Yamamoto, E; Yang, J; Yepes, P; Yokosawa, A; Yurevich, V I; Zanevski, Y V; Zborovský, I; Zhang, W M; Zoulkarneev, R; Zubarev, A N

      2001-08-20

      Two-pion correlation functions in Au+Au collisions at square root of [s(NN)] = 130 GeV have been measured by the STAR (solenoidal tracker at RHIC) detector. The source size extracted by fitting the correlations grows with event multiplicity and decreases with transverse momentum. Anomalously large sizes or emission durations, which have been suggested as signals of quark-gluon plasma formation and rehadronization, are not observed. The Hanbury Brown-Twiss parameters display a weak energy dependence over a broad range in square root of [s(NN)].

    12. Pion-Kaon correlations in central Au+Au collisions at square root [sNN] = 130 GeV.

      PubMed

      Adams, J; Adler, C; Aggarwal, M M; Ahammed, Z; Amonett, J; Anderson, B D; Anderson, M; Arkhipkin, D; Averichev, G S; Badyal, S K; Balewski, J; Barannikova, O; Barnby, L S; Baudot, J; Bekele, S; Belaga, V V; Bellwied, R; Berger, J; Bezverkhny, B I; Bhardwaj, S; Bhaskar, P; Bhati, A K; Bichsel, H; Billmeier, A; Bland, L C; Blyth, C O; Bonner, B E; Botje, M; Boucham, A; Brandin, A; Bravar, A; Cadman, R V; Cai, X Z; Caines, H; Calderón de la Barca Sánchez, M; Carroll, J; Castillo, J; Castro, M; Cebra, D; Chaloupka, P; Chattopadhyay, S; Chen, H F; Chen, Y; Chernenko, S P; Cherney, M; Chikanian, A; Choi, B; Christie, W; Coffin, J P; Cormier, T M; Cramer, J G; Crawford, H J; Das, D; Das, S; Derevschikov, A A; Didenko, L; Dietel, T; Dong, X; Draper, J E; Du, F; Dubey, A K; Dunin, V B; Dunlop, J C; Dutta Majumdar, M R; Eckardt, V; Efimov, L G; Emelianov, V; Engelage, J; Eppley, G; Erazmus, B; Fachini, P; Faine, V; Faivre, J; Fatemi, R; Filimonov, K; Filip, P; Finch, E; Fisyak, Y; Flierl, D; Foley, K J; Fu, J; Gagliardi, C A; Ganti, M S; Gutierrez, T D; Gagunashvili, N; Gans, J; Gaudichet, L; Germain, M; Geurts, F; Ghazikhanian, V; Ghosh, P; Gonzalez, J E; Grachov, O; Grigoriev, V; Gronstal, S; Grosnick, D; Guedon, M; Guertin, S M; Gupta, A; Gushin, E; Hallman, T J; Hardtke, D; Harris, J W; Heinz, M; Henry, T W; Heppelmann, S; Herston, T; Hippolyte, B; Hirsch, A; Hjort, E; Hoffmann, G W; Horsley, M; Huang, H Z; Huang, S L; Humanic, T J; Igo, G; Ishihara, A; Jacobs, P; Jacobs, W W; Janik, M; Johnson, I; Jones, P G; Judd, E G; Kabana, S; Kaneta, M; Kaplan, M; Keane, D; Kiryluk, J; Kisiel, A; Klay, J; Klein, S R; Klyachko, A; Koetke, D D; Kollegger, T; Konstantinov, A S; Kopytine, M; Kotchenda, L; Kovalenko, A D; Kramer, M; Kravtsov, P; Krueger, K; Kuhn, C; Kulikov, A I; Kumar, A; Kunde, G J; Kunz, C L; Kutuev, R Kh; Kuznetsov, A A; Lamont, M A C; Landgraf, J M; Lange, S; Lansdell, C P; Lasiuk, B; Laue, F; Lauret, J; Lebedev, A; Lednický, R; Leontiev, V M; LeVine, M J; Li, C; Li, Q; Lindenbaum, S J; Lisa, M A; Liu, F; Liu, L; Liu, Z; Liu, Q J; Ljubicic, T; Llope, W J; Long, H; Longacre, R S; Lopez-Noriega, M; Love, W A; Ludlam, T; Lynn, D; Ma, J; Ma, Y G; Magestro, D; Mahajan, S; Mangotra, L K; Mahapatra, D P; Majka, R; Manweiler, R; Margetis, S; Markert, C; Martin, L; Marx, J; Matis, H S; Matulenko, Yu A; McShane, T S; Meissner, F; Melnick, Yu; Meschanin, A; Messer, M; Miller, M L; Milosevich, Z; Minaev, N G; Mironov, C; Mishra, D; Mitchell, J; Mohanty, B; Molnar, L; Moore, C F; Mora-Corral, M J; Morozov, V; de Moura, M M; Munhoz, M G; Nandi, B K; Nayak, S K; Nayak, T K; Nelson, J M; Nevski, P; Nikitin, V A; Nogach, L V; Norman, B; Nurushev, S B; Odyniec, G; Ogawa, A; Okorokov, V; Oldenburg, M; Olson, D; Paic, G; Pandey, S U; Pal, S K; Panebratsev, Y; Panitkin, S Y; Pavlinov, A I; Pawlak, T; Perevoztchikov, V; Peryt, W; Petrov, V A; Phatak, S C; Picha, R; Planinic, M; Pluta, J; Porile, N; Porter, J; Poskanzer, A M; Potekhin, M; Potrebenikova, E; Potukuchi, B V K S; Prindle, D; Pruneau, C; Putschke, J; Rai, G; Rakness, G; Raniwala, R; Raniwala, S; Ravel, O; Ray, R L; Razin, S V; Reichhold, D; Reid, J G; Renault, G; Retiere, F; Ridiger, A; Ritter, H G; Roberts, J B; Rogachevski, O V; Romero, J L; Rose, A; Roy, C; Ruan, L J; Rykov, V; Sahoo, R; Sakrejda, I; Salur, S; Sandweiss, J; Savin, I; Schambach, J; Scharenberg, R P; Schmitz, N; Schroeder, L S; Schweda, K; Seger, J; Seliverstov, D; Seyboth, P; Shahaliev, E; Shao, M; Sharma, M; Shestermanov, K E; Shimanskii, S S; Singaraju, R N; Simon, F; Skoro, G; Smirnov, N; Snellings, R; Sood, G; Sorensen, P; Sowinski, J; Spinka, H M; Srivastava, B; Stanislaus, S; Stock, R; Stolpovsky, A; Strikhanov, M; Stringfellow, B; Struck, C; Suaide, A A P; Sugarbaker, E; Suire, C; Sumbera, M; Surrow, B; Symons, T J M; Szanto de Toledo, A; Szarwas, P; Tai, A; Takahashi, J; Tang, A H; Thein, D; Thomas, J H; Tikhomirov, V; Tokarev, M; Tonjes, M B; Trainor, T A; Trentalange, S; Tribble, R E; Trivedi, M D; Trofimov, V; Tsai, O; Ullrich, T; Underwood, D G; Van Buren, G; VanderMolen, A M; Vasiliev, A N; Vasiliev, M; Vigdor, S E; Viyogi, Y P; Voloshin, S A; Waggoner, W; Wang, F; Wang, G; Wang, X L; Wang, Z M; Ward, H; Watson, J W; Wells, R; Westfall, G D; Whitten, C; Wieman, H; Willson, R; Wissink, S W; Witt, R; Wood, J; Wu, J; Xu, N; Xu, Z; Xu, Z Z; Yakutin, A E; Yamamoto, E; Yang, J; Yepes, P; Yurevich, V I; Zanevski, Y V; Zborovský, I; Zhang, H; Zhang, H Y; Zhang, W M; Zhang, Z P; Zołnierczuk, P A; Zoulkarneev, R; Zoulkarneeva, J; Zubarev, A N

      2003-12-31

      Pion-kaon correlation functions are constructed from central Au+Au STAR data taken at sqrt[s(NN)]=130 GeV by the STAR detector at the Relativistic Heavy Ion Collider (RHIC). The results suggest that pions and kaons are not emitted at the same average space-time point. Space-momentum correlations, i.e., transverse flow, lead to a space-time emission asymmetry of pions and kaons that is consistent with the data. This result provides new independent evidence that the system created at RHIC undergoes a collective transverse expansion.

    13. 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.

    14. ΛΛ correlation function in Au + Au collisions at √sNN = 200 GeV

      DOE PAGES

      Adamczyk, L.

      2015-01-12

      In this study, we present ΛΛ correlation measurements in heavy-ion collisions for Au+Au collisions at √sNN = 200 GeV using the STAR experiment at the Relativistic Heavy-Ion Collider (RHIC). 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 ΛΛ correlation function and interaction parameters for di-hyperon searches are discussed.

    15. V0 Reconstruction of Strange Hadrons in Au+Au Collisions at 1.23 AGeV with HADES

      NASA Astrophysics Data System (ADS)

      Scheib, T.; HADES Collaboration

      2015-04-01

      Preliminary results on the production of weakly decaying strange hadrons are reported for collisions of Au+Au at 1.23 AGeV beam energy studied with the HADES detector at GSI in Darmstadt. At this collision energy all strange particles are created below their elementary threshold. The reconstruction of the investigated particles (i.e. Λ and K0s) via the topology of their charged decay products (V0 reconstruction) is presented in detail. From the corrected yields of Λ and K0s the ratio K0S/Λ can be calculated and included into a statistical model fit.

    16. Electron identification in Au+Au collisions at 1.23 GeV/u using multivariate analysis

      NASA Astrophysics Data System (ADS)

      Harabasz, Szymon; Hades Collaboration

      2014-04-01

      Au+Au collisions at a beam kinetic energy of 1.23 GeV/u have been measured by HADES in 2012. Lepton identification in this experiment has been done using a multivariate algorithm based on an artificial neural network. In the proceedings, details of the identification method and its assessment in terms of purity of the final lepton sample are presented. The obtained purity reaches 95% and the amount of identified electrons and positrons is sufficient to perform further steps of the physics analysis with e+e- pairs.

    17. ΛΛ correlation function in Au + Au collisions at √sNN = 200 GeV

      SciTech Connect

      Adamczyk, L.

      2015-01-12

      In this study, we present ΛΛ correlation measurements in heavy-ion collisions for Au+Au collisions at √sNN = 200 GeV using the STAR experiment at the Relativistic Heavy-Ion Collider (RHIC). 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 ΛΛ correlation function and interaction parameters for di-hyperon searches are discussed.

    18. Production of {phi} meson in Au+Au collisions at 11.7 A GeV/c.

      SciTech Connect

      Back, B. B.; Betts, R. R.; Chang, J.; Chang, W. C.; Chi, C. Y.; E917 Collaboration; Gillitzer, A.; Henning, W. F.; Hofman, D. J.; Nanal, V.; Wuosmaa, A. H.

      1999-06-29

      First Measurement of {phi} meson production in Au+Au collisions has been conducted by E917 at BNL-AGS via selecting events with identified K{sup +}K{sup {minus}} pairs. Preliminary results on the invariant mass spectra of K{sup +}K{sup {minus}} pairs and the m{sub T} spectra are presented. Also, the inverse slope T, dN/dy, the ratio of {phi}/K{sup {minus}}, ratio of {phi}/K{sup +}K{sup {minus}} and their centrality dependences are extracted in a rapidity range of y = 0.9-1.4. Indications on the possible mechanisms of {phi} production are discussed.

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

      PubMed

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