223 research outputs found

    Stability and Decay Rates of Non-Isotropic Attractive Bose-Einstein Condensates

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    Non-Isotropic Attractive Bose-Einstein condensates are investigated with Newton and inverse Arnoldi methods. The stationary solutions of the Gross-Pitaevskii equation and their linear stability are computed. Bifurcation diagrams are calculated and used to find the condensate decay rates corresponding to macroscopic quantum tunneling, two-three body inelastic collisions and thermally induced collapse. Isotropic and non-isotropic condensates are compared. The effect of anisotropy on the bifurcation diagram and the decay rates is discussed. Spontaneous isotropization of the condensates is found to occur. The influence of isotropization on the decay rates is characterized near the critical point.Comment: revtex4, 11 figures, 2 tables. Submitted to Phys. Rev.

    Using a Threading-Followed-by-Swelling Approach to Synthesize 2 Rotaxanes

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    We have developed a "threading-followed-by-swelling" protocol to synthesize [2]rotaxanes efficiently and atom economically. Our protocol employs cis-1-[(Z)-alk-1'enyl]-2-vinylcyclopropane units as the termini of the threadlike components; these end groups are converted into more-sizable cycloheptadiene motifs, which function as stopper units, through Cope rearrangements at elevated temperature. We used this approach to synthesize [2]rotaxanes in good yield from [2]pseudorotaxanes featuring either one or two swellable termini to interlock three different types of macrocycle. The chiral centers created by the swelling process were "erased" by hydrogenating the cycloheptadiene termini into the corresponding cycloheptane units, affording achiral molecular [2]rotaxanes as the only final products

    Characterization of elastic scattering near a Feshbach resonance in rubidium 87

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    The s-wave scattering length for elastic collisions between 87Rb atoms in the state |f,m_f>=|1,1> is measured in the vicinity of a Feshbach resonance near 1007 G. Experimentally, the scattering length is determined from the mean-field driven expansion of a Bose-Einstein condensate in a homogeneous magnetic field. The scattering length is measured as a function of the magnetic field and agrees with the theoretical expectation. The position and the width of the resonance are determined to be 1007.40 G and 0.20 G, respectively.Comment: 4 pages, 2 figures minor revisions: added Ref.6, included error bar

    A new record of Bengalia emarginata Malloch, 1927 (Diptera: Calliphoridae) from Malaysia

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    During a forensic entomological study conducted at an oil palm plantation in Tanjung Sepat, Kuala Langat, Selangor, a. Bengalia emarginata Malloch, 1927 (Diptera: Calliphoridae: Calliphorinae: Bengalini) was collected for the first time. Two adults were collected nearby the pig carcass by the first author and identified by the second. Prior to this finding, nine species of Bengalia were recorded from peninsular Malaysia or Borneo. Male of B. emarginata are different from Bengalia varicolor Fabricious by the following characters: Sternite 5 projection rounded with small identation and mid tibia double-fringed in ventral surface

    Natural Orbitals and BEC in traps, a diffusion Monte Carlo analysis

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    We investigate the properties of hard core Bosons in harmonic traps over a wide range of densities. Bose-Einstein condensation is formulated using the one-body Density Matrix (OBDM) which is equally valid at low and high densities. The OBDM is calculated using diffusion Monte Carlo methods and it is diagonalized to obtain the "natural" single particle orbitals and their occupation, including the condensate fraction. At low Boson density, na3<105na^3 < 10^{-5}, where n=N/Vn = N/V and aa is the hard core diameter, the condensate is localized at the center of the trap. As na3na^3 increases, the condensate moves to the edges of the trap. At high density it is localized at the edges of the trap. At na3104na^3 \leq 10^{-4} the Gross-Pitaevskii theory of the condensate describes the whole system within 1%. At na3103na^3 \approx 10^{-3} corrections are 3% to the GP energy but 30% to the Bogoliubov prediction of the condensate depletion. At na3102na^3 \gtrsim 10^{-2}, mean field theory fails. At na30.1na^3 \gtrsim 0.1, the Bosons behave more like a liquid 4^4He droplet than a trapped Boson gas.Comment: 13 pages, 14 figures, submitted Phys. Rev.

    Influence of Bleeding Risk on Outcomes of Radial and Femoral Access for Percutaneous Coronary Intervention: An Analysis From the GLOBAL LEADERS Trial

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    Background: Radial artery access has been shown to reduce mortality and bleeding events, especially in patients with acute coronary syndromes. Despite this, interventional cardiologists experienced in femoral artery access still prefer that route for percutaneous coronary intervention. Little is known regarding the merits of each vascular access in patients stratified by their risk of bleeding. Methods: Patients from the Global Leaders trial were dichotomized into low or high risk of bleeding by the median of the PRECISE-DAPT score. Clinical outcomes were compared at 30 days. Results: In the overall population, there were no statistical differences between radial and femoral access in the rate of the primary end point, a composite of all-cause mortality, or new Q-wave myocardial infarction (MI) (hazard ratio [HR] 0.70, 95% confidence interval [CI] 0.42-1.15). Radial access was associated with a significantly lower rate of the secondary safety end point, Bleeding Academic Research Consortium (BARC) 3 or 5 bleeding (HR 0.55, 95% CI 0.36-0.84). Compared by bleeding risk strata, in the high bleeding score population, the primary (HR 0.47, 95% CI 0.26-0.85; P = 0.012; Pinteraction = 0.019) and secondary safety (HR 0.57, 95% CI 0.35-0.95; P = 0.030; Pinteraction = 0.631) end points favoured radial access. In the low bleeding score population, however, the differences in the primary and secondary safety end points between radial and femoral artery access were no longer statistically significant. Conclusions: Our findings suggest that the outcomes of mortality or new Q-wave MI and BARC 3 or 5 bleeding favour radial access in patients with a high, but not those with a low, risk of bleeding. Because thisContexte : Il a et e d emontr e que l ’accès par l’artère radiale reduit la mortalite et les h emorragies, en particulier chez les patients presentant un syndrome coronarien aigu. Malgr e cela, les cardiologues interventionnels qui ont acquis de l’experience en matière d ’accès par l’artère femorale pr efèrent encore utiliser cette voie lorsqu ’ils doivent pratiquer une intervention coronarienne percutanee. On connaît mal l’interêt de chacune de ces techniques d ’accès vasculaire au regard du risque d’hemorragie. Methodologie : Les patients de l’essai GLOBAL LEADERS ont et e repartis en deux groupes, selon qu ’ils presentaient un risque d’hemorragie faible ou elev e d ’après le score PRECISE-DAPT median, puis les resultats cliniques ont et e compar es à 30 jours. Resultats : Dans l’ensemble de la population, aucune difference sta- tistiquement significative n’a et e observ ee entre l ’accès radial et l’accès femoral quant au critère d ’evaluation principal, compos e de la mortalite toutes causes confondues et d ’un nouvel infarctus du myocarde (IM) avec onde Q (rapport des risques instantanes [RRI] de 0,70; intervalle de confiance [IC] à 95 % : 0,42-1,15). L’accès radial a et e associe à un taux signi ficativement plus faible de survenue du critère secondaire d’evaluation de l ’innocuite, c ’est-à-dire une hemorragie de type 3 ou 5 selon la classification du BARC (Bleeding Academic Research Consortium) (RRI de 0,55; IC à 95 % : 0,36-0,84). Lorsqu’on compare les sujets en fonction du risque d’hemorragie, les critères d’evaluation de l ’innocuite principal (RRI de 0,47; IC à 95 % : 0,26- 0,85; p ¼ 0,012; pinteraction ¼ 0,019) et secondaire (RRI de 0,57; IC à 95 % : 0,35-0,95; p ¼ 0,030; pinteraction ¼ 0,631) sont favorables à l’accès radial au sein de la population presentant un risque d ’hemor- ragie elev e. Dans la population pr esentant un risque d ’hemorragie faible, les differences entre l ’accès radial et l’accès femoral quant aux critères d’evaluation de l ’innocuite principal et secondaire ne sont toutefois plus statistiquement significatives. Conclusions : Selon ces observations, les resultats concernant la mortalite ou la survenue d ’un nouvel IM avec onde Q et le risque d’hemorragie de type 3 ou 5 selon la classi fication du BARC indiquent que l’accès radial serait à privilegier lorsque le risque d ’hemorragie est elev e, mais pas lorsqu ’il est faible. Comme il ne s’agissait pas d’une analyse principale, il convient de considerer ces observations comme etant g en eratrices d ’hypothèses

    Two first-in-human studies of xentuzumab, a humanised insulin-like growth factor (IGF)-neutralising antibody, in patients with advanced solid tumours

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    BACKGROUND: Xentuzumab, an insulin-like growth factor (IGF)-1/IGF-2-neutralising antibody, binds IGF-1 and IGF-2, inhibiting their growth-promoting signalling. Two first-in-human trials assessed the maximum-tolerated/relevant biological dose (MTD/RBD), safety, pharmacokinetics, pharmacodynamics, and activity of xentuzumab in advanced/metastatic solid cancers. METHODS: These phase 1, open-label trials comprised dose-finding (part I; 3 + 3 design) and expansion cohorts (part II; selected tumours; RBD [weekly dosing]). Primary endpoints were MTD/RBD. RESULTS: Study 1280.1 involved 61 patients (part I: xentuzumab 10–1800 mg weekly, n = 48; part II: 1000 mg weekly, n = 13); study 1280.2, 64 patients (part I: 10–3600 mg three-weekly, n = 33; part II: 1000 mg weekly, n = 31). One dose-limiting toxicity occurred; the MTD was not reached for either schedule. Adverse events were generally grade 1/2, mostly gastrointestinal. Xentuzumab showed dose-proportional pharmacokinetics. Total plasma IGF-1 increased dose dependently, plateauing at ~1000 mg/week; at ≥450 mg/week, IGF bioactivity was almost undetectable. Two partial responses occurred (poorly differentiated nasopharyngeal carcinoma and peripheral primitive neuroectodermal tumour). Integration of biomarker and response data by Bayesian Logistic Regression Modeling (BLRM) confirmed the RBD. CONCLUSIONS: Xentuzumab was well tolerated; MTD was not reached. RBD was 1000 mg weekly, confirmed by BLRM. Xentuzumab showed preliminary anti-tumour activity

    Two years clinical outcomes with the state-of-the-art PCI for the treatment of bifurcation lesions: A sub-analysis of the SYNTAX II study

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    Background: Bifurcation PCI is associated with a lower rate of procedural success, especially in multivessel disease patients. We aimed to determine the impact of bifurcation treatment on 2-years clinical outcomes when a state-of-the-art PCI strategy (heart team decision-making using the SYNTAX score II, physiology guided coronary stenosis assessment, thin strut bioresorbable polymer drug-eluting stent, and intravascular ultrasound guidance) is followed. Methods: Three-ve
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