439 research outputs found

    Translating Social Science Concepts into Medical Education: A Model and a Curriculum

    Get PDF
    Most serious efforts aimed at linking social and behavioral sciences knowledge tomedical practice have included models which integrate social and behavioral scienceconcepts. We argue that such an integration is intellectually problematic due toan important analytic distinction between social sciences and psychological sciences.If the social explanation of illness is to become useful in medical education, adistinctly social model is necessary for conceptual clarity and for guidance of which isuseful for explicating the link between social science knowledge and medical practiceand for organizing the knowledge for teaching in medical schools

    Brush border myosin heavy chain phosphorylation is regulated by calcium and calmodulin

    Get PDF
    AbstractMyosin from chicken intestinal brush borders is phosphorylated on its heavy chains at threonine by a kinase isolated from brush borders. In contrast to other heavy chain kinases, the brush border kinase activity is dependent on calcium and calmodulin. The partially purified preparation also phosphorylated myosin on its light chains at serine, but in a calmodulin-independent manner. Phosphorylation of the light chains in the absence of calmodulin or both heavy and light chains in the presence of calmodulin activated its actinactivated ATPase activity about 10-fold, to about 50 nmolmin per mg

    Induced Anticlinic Ordering and Nanophase Segregation of Bow-Shaped Molecules in a Smectic Solvent

    Full text link
    Recent experiments indicate that doping low concentrations of bent-core molecules into calamitic smectic solvents can induce anticlinic and biaxial smectic phases. We have carried out Monte Carlo (MC) simulations of mixtures of rodlike molecules (hard spherocylinders with length/breadth ratio Lrod/D=5L_{\rm rod}/D = 5) and bow- or banana-shaped molecules (hard spherocylinder dimers with length/breadth ratio Lban/D=5L_{ban}/D = 5 or 2.5 and opening angle ψ\psi) to probe the molecular-scale organization and phase behavior of rod/banana mixtures. We find that a low concentration (3%) of Lban/D=5L_{ban}/D = 5 dimers induces anticlinic (SmCA_A) ordering in an untilted smectic (SmA) phase for 100∘≤ψ<150∘100^\circ \le \psi < 150^\circ. For smaller ψ\psi, half of each bow-shaped molecule is nanophase segregated between smectic layers, and the smectic layers are untilted. For Lban/D=2.5L_{ban}/D = 2.5, no tilted phases are induced. However, with decreasing ψ\psi we observe a sharp transition from {\sl intralamellar} nanophase segregation (bow-shaped molecules segregated within smectic layers) to {\sl interlamellar} nanophase segregation (bow-shaped molecules concentrated between smectic layers) near ψ=130∘\psi = 130^\circ. These results demonstrate that purely entropic effects can lead to surprisingly complex behavior in rod/banana mixtures.Comment: 5 pages Revtex, 7 postscript figure

    Nearly Space-Filling Fractal Networks of Carbon Nanopores

    Get PDF
    URL:http://link.aps.org/doi/10.1103/PhysRevLett.88.115502 DOI:10.1103/PhysRevLett.88.115502Small-angle x-ray scattering, nitrogen adsorption, and scanning tunneling microscopy show that a series of activated carbons host an extended fractal network of channels with dimension Dp = 2.8-3.0 (pore fractal), channel width 15-20Å (lower end of scaling), network diameter 3000-3400Å (upper end of scaling), and porosity of 0.3-0.6. We interpret the network as a stack of quasiplanar invasion percolation clusters, formed by oxidative removal of walls between closed voids of diameter of ∼10Å and held in registry by fibrils of the biological precursor, and point out unique applications.This work was supported by the Petroleum Research Fund, Grant No. 30602-AC9,5 (P. P.); the Department of Energy, Contracts No. W-7405-ENG-36 (P. P.) and No. DE-AC04-00A185000 (T. P. R.); and the Ceramic and Non-Metallic Materials Program at AFOSR (W. P. H.)

    Testing the Properties of Beam-Dose Monitors for VHEE-FLASH Radiation Therapy

    Get PDF
    Very High Energy Electrons (VHEE) of 50 - 250 MeV are an attractive choice for FLASH radiation therapy (RT). Before VHEE-FLASH RT can be considered for clinical use, a reliable dosimetric and beam monitoring system needs to be developed, able to measure the dose delivered to the patient in real-time and cut off the beam in the event of a machine fault to prevent overdosing the patient. Ionisation chambers are the standard monitors in conventional RT; however, their response saturates at the high dose rates required for FLASH. Therefore, a new dosimetry method is needed that can provide reliable measurements of the delivered dose in these conditions. Experiments using 200 MeV electrons were done at the CLEAR facility at CERN to investigate the properties of detectors such as diamond beam loss detectors, GEM foil detectors, and Timepix3 ASIC chips. From the tests, the GEM foil proved to be the most promising

    Combined X-Ray and Fully Leaky Guided Mode Studies of the Smectic Layer and Optic Tensor Configuration in a Ferroelectric Liquid-Crystal Cell

    Get PDF
    B. Hodder, J. Roy Sambles, S. Jenkins, and R. M. Richardson, Physical Review Letters, Vol. 85, pp. 3181 - 3184 (2000). "Copyright © 2000 by the American Physical Society."X-ray scattering together with optical characterization using fully leaky guided modes have been used for the first time to study the same ferroelectric liquid-crystal cell. This enables direct calculation of an accurate cone and chevron description of the liquid-crystal director profile since the layer structure and optic tensor configuration are both well known

    Early-stage breast cancer is not associated with the risk of marital dissolution in a large prospective study of women

    Get PDF
    Background: As breast cancer and its treatment are likely to interfere with traditional expectations of womanhood, it may affect marital stability. Methods: The risk of marital dissolution was analysed with respect to diagnosis of early-stage (T1-4N0-3M0) breast cancer in a cohort of 134 435 married Finnish women followed for a median of 17.0 married years. Age, socioeconomic status, education, number of children, duration of marriage and earlier marriages were taken into account and the effects of surgery, chemotherapy, radiotherapy and endocrine therapy were analysed separately. Results: Women with a diagnosis of early-stage breast cancer did not show increase in marital dissolution (hazard ratio -0.96, 95% confidence interval = 0.79-1.17). Neither the type of surgical procedure nor any of the oncologic treatments was associated with an increase in the risk of divorce. Conclusions: Any evidence of excess risk of marital breakdown after the diagnosis of early-stage breast cancer and its treatment was not demonstrated.Peer reviewe
    • …
    corecore