16 research outputs found

    Energy landscape, two-level systems and entropy barriers in Lennard-Jones clusters

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    We develop an efficient numerical algorithm for the identification of a large number of saddle points of the potential energy function of Lennard- Jones clusters. Knowledge of the saddle points allows us to find many thousand adjacent minima of clusters containing up to 80 argon atoms and to locate many pairs of minima with the right characteristics to form two-level systems (TLS). The true TLS are singled out by calculating the ground-state tunneling splitting. The entropic contribution to all barriers is evaluated and discussed.Comment: 4 pages, RevTex, 2 PostScript figure

    Potential Energy Landscape and Long Time Dynamics in a Simple Model Glass

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    We analyze the properties of a Lennard-Jones system at the level of the potential energy landscape. After an exhaustive investigation of the topological features of the landscape of the systems, obtained studying small size sample, we describe the dynamics of the systems in the multi-dimensional configurational space by a simple model. This consider the configurational space as a connected network of minima where the dynamics proceeds by jumps described by an appropriate master equation. Using this model we are able to reproduce the long time dynamics and the low temperature regime. We investigate both the equilibrium regime and the off-equilibrium one, finding those typical glassy behavior usually observed in the experiments such as: {\it i)} stretched exponential relaxation, {\it ii)} temperature-dependent stretching parameter, {\it iii)} breakdown of the Stokes-Einstein relation, and {\it iv)} appearance of a critical temperature below which one observes deviation from the fluctuation-dissipation relation as consequence of the lack of equilibrium in the system.Comment: 11 pages (Latex), 9 ps figure

    State encoding for low power embedded controllers

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    Power dissipation has become one of the main issues during embedded systems design in the recent years, due to the continuous increase of the integration level and the operating frequency. The present paper affords the problem of reducing the power dissipation in embedded controllers represented as Finite State Machines (FSMs). The aim of the work is to propose an approach to optimize state encoding for low power embedded FSMs, starting from a probabilistic description of the FSMs. Experimental results have been obtained by applying the proposed state encoding techniques to benchmark circuits. The results have also been compared to previous state encoding methods

    Endometrial Changes and Doppler Flow Evaluation in Postmenopausal Breast Cancer Patients on Tamoxifen (TAM): A Transvaginal Ultrasound (TVU)/Hysterescopy Study

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    The aim of the study was to assess the effect of TAM therapy on the endometrium and the usefulness of Doppler How assessment by TVU. 79 asymptomatic postmenopausal women (pmw) treated with TAM (20 mg/day) for at least 1 year were recruited. 20 healthy pmw served as controls. All patients (pts) underwent TVU to evaluate endometrial thickness (ET) and echotexture, and Doppler color flow was added to the assessments. FT value was increased during the 1st year of therap

    Endometrial changes in postmenopausal breast cancer patients receiving tamoxifen: a transvaginal ultrasound study

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    Abstract: The purpose of the study was to evaluate the effects of tamoxifen therapy on the endometrium by transvaginal sonography. Seventy-nine asymptomatic postmenopausal women treated with tamoxifen (20 mg/day) for at least one year were recruited. Twenty healthy postmenopausal women served as controls. All patients underwent transvaginal ultrasound to evaluate endometrial thickness and echotexture

    Doppler flow evaluation of endometrial conditions in postmenopausal breast cancer patients treated with tamoxifen

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    The aim of the study was to evaluate the usefulness of Doppler flow ultrasonography in the evaluation of 88 postmenopausal breast cancer patients treated with tamoxifen (20 mg/day for at least 1 year). Twenty healthy postmenopausal women served as controls. The PI and RI (mean+/-SD) in the tamoxifen group (1, 77+/-0, 47 and 0, 79+/-0, 1, respectively) were significantly lower than those of the control group (2, 64+/-0, 8 and 0, 92+/- 0, 1, respectively

    Endometrial changes in postmenopausal breast cancer patients receiving tamoxifen: a transvaginal ultrasound study

    No full text
    Abstract: The purpose of the study was to evaluate the effects of tamoxifen therapy on the endometrium by transvaginal sonography. Seventy-nine asymptomatic postmenopausal women treated with tamoxifen (20 mg/day) for at least one year were recruited. Twenty healthy postmenopausal women served as controls. All patients underwent transvaginal ultrasound to evaluate endometrial thickness and echotexture

    Doppler flow evaluation of endometrial conditions in postmenopausal breast cancer patients treated with tamoxifen

    No full text
    The aim of the study was to evaluate the usefulness of Doppler flow ultrasonography in the evaluation of 88 postmenopausal breast cancer patients treated with tamoxifen (20 mg/day for at least 1 year). Twenty healthy postmenopausal women served as controls. The PI and RI (mean+/-SD) in the tamoxifen group (1, 77+/-0, 47 and 0, 79+/-0, 1, respectively) were significantly lower than those of the control group (2, 64+/-0, 8 and 0, 92+/- 0, 1, respectively)

    Labor course and delivery in epidural analgesia: a case-control study

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    8nonenoneDECCA L; DALDOSS C; FRATELLI N; A. LOJACONO; SLOMPO M; STEGHER C; VALCAMONICO A; FRUSCA TDecca, L; Daldoss, C; Fratelli, N; Lojacono, Andrea; Slompo, M; Stegher, C; Valcamonico, A; Frusca, Tizian
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