422 research outputs found

    Objective measurement of upper limb activity and mobility during everyday behavior using ambulatory accelerometry: the upper limb activity monitor.

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    Ambulatory accelerometry is a technique that allows objective measurement of aspects of everyday human behavior. The aim of our research has been to develop, validate, and apply this technique, which recently resulted in an upper limb activity monitor (ULAM). The ULAM consists of body-mounted acceleration sensors connected to a waist-worn data recorder and allows valid and objective assessment of activity of both upper limbs during performance of also automatically detected mobility-related activities: lying, sitting, standing, walking, cycling, and general movement. The ULAM can be used to determine (limitations of) upper limb activity and mobility in freely moving subjects with upper limb disorders. This article provides a detailed description of its characteristics, summarizes the results of a feasibility study and four application studies in subjects having upper limb complex regional pain syndrome, discusses the most important practical, technical, and methodological issues that were encountered, and describes current and future research projects related to measuring (limitatio

    Atomic Mass Dependence of Hadron Production in Deep Inelastic Scattering on Nuclei

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    Hadron production in lepton-nucleus deep inelastic scattering is studied in an absorption model. In the proposed model, the early stage of hadronization in the nuclear medium is dominated by prehadron formation and absorption, controlled by flavor-dependent formation lengths and absorption cross sections. Computations for hadron multiplicity ratios are presented and compared with the HERMES experimental data for pions, kaons, protons and antiprotons. The mass-number dependence of hadron attenuation is shown to be sensitive to the underlying hadronization dynamics. Contrary to common expectations for absorption models, a leading term proportional to A^{2/3} is found. Deviations from the leading behavior arise at large mass-numbers and large hadron fractional momenta.Comment: 30 pages, 10 figures, v2: minor changes (legend in figs 5 & 6 is added), v3: additional explanations are added, v4: Version combines v3 and the erratum hep-ph/050803

    Carrier dynamics in conducting polymers: Case of PF6 doped Polypyrrole

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    Quantum Matter and Optic

    Particle interactions with single or multiple 3D solar reconnecting current sheets

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    The acceleration of charged particles (electrons and protons) in flaring solar active regions is analyzed by numerical experiments. The acceleration is modelled as a stochastic process taking place by the interaction of the particles with local magnetic reconnection sites via multiple steps. Two types of local reconnecting topologies are studied: the Harris-type and the X-point. A formula for the maximum kinetic energy gain in a Harris-type current sheet, found in a previous work of ours, fits well the numerical data for a single step of the process. A generalization is then given approximating the kinetic energy gain through an X-point. In the case of the multiple step process, in both topologies the particles' kinetic energy distribution is found to acquire a practically invariant form after a small number of steps. This tendency is interpreted theoretically. Other characteristics of the acceleration process are given, such as the mean acceleration time and the pitch angle distributions of the particles.Comment: 18 pages, 9 figures, Solar Physics, in pres

    Cranked Relativistic Hartree-Bogoliubov Theory: Superdeformed Bands in the A190A\sim 190 Region

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    Cranked Relativistic Hartree-Bogoliubov (CRHB) theory is presented as an extension of Relativistic Mean Field theory with pairing correlations to the rotating frame. Pairing correlations are taken into account by a finite range two-body force of Gogny type and approximate particle number projection is performed by Lipkin-Nogami method. This theory is applied to the description of yrast superdeformed rotational bands observed in even-even nuclei of the A190A\sim 190 mass region. Using the well established parameter sets NL1 for the Lagrangian and D1S for the pairing force one obtains a very successful description of data such as kinematic (J(1)J^{(1)}) and dynamic (J(2)J^{(2)}) moments of inertia without any adjustment of new parameters. Within the present experimental accuracy the calculated transition quadrupole moments QtQ_t agree reasonably well with the observed data.Comment: 6 pages including 4 PostScript figures, uses RevTex, revised version, Phys.Rev. C, Rapid Communications, in pres

    Identifying somatic changes in drug transporters using whole genome and transcriptome sequencing data of advanced tumors

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    Drug resistance is a perpetual problem in cancer therapy with many underlying mechanisms. Alterations in drug transport over the cancer cell membrane can severely alter intratumoral drug exposure, contributing to resistance. Here, we present the somatic mutational landscape of 48 ATP-binding cassette and 416 solute carrier transporter genes in a cohort (CPCT-02; NCT01855477) of 3290 patients with different types of advanced and metastasized cancer through analysis of whole genome and transcriptome sequencing. In order to identify potential stressor mechanisms, we stratified patients based on previous systemic therapies and subsequently investigated the enrichment of mutations and copy-number alterations of transporter genes. In tumors from patients pretreated with protein kinase inhibitors (PKIs), genes encoding for specific copper (SLC31A1 and SLC31A2, χ2-test adjusted p-values: 6.9e-09 and 2.5e-09) and nucleoside transporters (SLC28A2 and SLC28A3, χ2-test adjusted p-values: 3.5e-06 and 6.8e-07) were deleted significantly more frequently than in patients pretreated with chemotherapy. Moreover, we detected 16 transporters that were differentially expressed at RNA level between these treatment groups. These findings contradict mechanisms of selective pressure, as they would be expected to originate during treatment with chemotherapy rather than with PKIs. Hence, they might constitute primary drug resistance mechanisms and, therefore, warrant further study.</p

    Cell-free DNA mutations as biomarkers in breast cancer patients receiving tamoxifen

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    The aim was to identify mutations in serum cell-free DNA (cfDNA) associated with disease progression on tamoxifen treatment in metastatic breast cancer (MBC). Sera available at start of therapy, during therapy and at disease progression were selected from 10 estrogen receptor (ER)-positive breast cancer patients. DNA from primary tumor and normal tissue and cfDNA from minute amounts of sera were analyzed by targeted next generation sequencing (NGS) of 45 genes (1,242 exons). At disease progression, stop-gain single nucleotide variants (SNVs) for CREBBP (1 patient) and SMAD4 (1 patient) and non-synonymous SNVs for AKAP9 (1 patient), PIK3CA (2 patients) and TP53 (2 patients) were found. Mutations in CREBBP and SMAD4 have only been occasionally reported in breast cancer. All mutations, except for AKAP9, were also present in the primary tumor but not detected in all blood specimens preceding progression. More sensitive detection by deeper re-sequencing and digital PCR confirmed the occurrence of circulating tumor DNA (ctDNA) and these biomarkers in blood specimens
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