7,123 research outputs found

    The application of mechanical diagnosis and therapy in lateral epicondylalgia

    Get PDF
    Background: lateral epicondylalgia (LE) is a musculoskeletal diagnosis that causes pain and dysfunction in the lateral aspect of the elbow. Mechanical diagnosis and therapy (MDT) is an orthopaedic classification and treatment system based on mechanical and symptomatic response to repeated and sustained end-range movement. There has been no investigation of the association between MDT and patients diagnosed with LE. Case description: this report presents three patients matching the currently accepted diagnostic criteria for LE, two with a diagnosis of lateral epicondylitis (tennis elbow) from a medical doctor. These patients were classified and treated by a diplomat of MDT and two third-year doctoral students of physical therapy using MDT. Outcomes: short- and long-term (one year) outcomes were excellent, demonstrating rapid abolishment of symptoms and return to prior levels of function in 3–6 visits between 11–59 days. Patients demonstrated the ability to prevent and manage reoccurrence of symptoms independently without seeking further health care. Discussion: this case series raises questions about whether or not the pathologies traditionally associated with the aetiology of LE are actually at fault. Moreover, it raises questions about the utility of special tests typically utilized to identify those structures. The series provides preliminary evidence that MDT may be capable of providing effective short- and long-term outcomes in the management of LE. Level of Evidence: 4 Keywords: Mechanical diagnosis and therapy, Lateral epicondylalgia, Case serie

    Ferromagnetism, paramagnetism and a Curie-Weiss metal in an electron doped Hubbard model on a triangular lattice

    Get PDF
    Motivated by the unconventional properties and rich phase diagram of NaxCoO2 we consider the electronic and magnetic properties of a two-dimensional Hubbard model on an isotropic triangular lattice doped with electrons away from half-filling. Dynamical mean-field theory (DMFT) calculations predict that for negative inter-site hopping amplitudes (t<0) and an on-site Coulomb repulsion, U, comparable to the bandwidth, the system displays properties typical of a weakly correlated metal. In contrast, for t>0 a large enhancement of the effective mass, ferromagnetism and a Curie-Weiss magnetic susceptibility are found in a broad electron doping range. Our observation of Nagaoka ferromagnetism is consistent with the A-type antiferromagnetism (i.e. ferromagnetic layers stacked antiferromagnetically) observed in neutron scattering experiments on NaxCoO2. We propose that `Curie-Weiss metal' phase observed in NaxCoO2 is a consequence of the crossover from ``bad metal'' with incoherent quasiparticles at temperatures T>T* and Fermi liquid behavior with enhanced parameters below T*, where T* is a low energy coherence scale induced by strong local Coulomb electron correlations. We propose a model which contains the charge ordering phenomena observed in the system which, we propose, drives the system close to the Mott insulating phase even at large dopings.Comment: 24 pages, 15 figures; accepted for publication in Phys. Rev.

    Temperature Dependence of the Magnetic Susceptibility for Triangular-Lattice Antiferromagnets with spatially anisotropic exchange constants

    Get PDF
    We present the temperature dependence of the uniform susceptibility of spin-half quantum antiferromagnets on spatially anisotropic triangular-lattices, using high temperature series expansions. We consider a model with two exchange constants, J1J_1 and J2J_2 on a lattice that interpolates between the limits of a square-lattice (J1=0J_1=0), a triangular-lattice (J2=J1J_2=J_1), and decoupled linear chains (J2=0J_2=0). In all cases, the susceptibility which has a Curie-Weiss behavior at high temperatures, rolls over and begins to decrease below a peak temperature, TpT_p. Scaling the exchange constants to get the same peak temperature, shows that the susceptibilities for the square-lattice and linear chain limits have similar magnitudes near the peak. Maximum deviation arises near the triangular-lattice limit, where frustration leads to much smaller susceptibility and with a flatter temperature dependence. We compare our results to the inorganic materials Cs2_2CuCl4_4 and Cs2_2CuBr4_4 and to a number of organic molecular crystals. We find that the former (Cs2_2CuCl4_4 and Cs2_2CuBr4_4) are weakly frustrated and their exchange parameters determined through the temperature dependence of the susceptibility are in agreement with neutron-scattering measurements. In contrast, the organic materials are strongly frustrated with exchange parameters near the isotropic triangular-lattice limit.Comment: 10 pages, 9 figures and 1 table, revised versio

    Universal subgap optical conductivity in quasi-one-dimensional Peierls systems

    Get PDF
    Quasi-one-dimensional Peierls systems with quantum and thermal lattice fluctuations can be modeled by a Dirac-type equation with a Gaussian-correlated off-diagonal disorder. A powerful new method gives the exact disorder-averaged Green function used to compute the optical conductivity. The strong subgap tail of the conductivity has a universal scaling form. The frequency and temperature dependence of the calculated spectrum agrees with experiments on KCP(Br) and trans-polyacetylene.Comment: 11 pages (+ 3 figures), LATEX (REVTEX 3.0

    Psychologic modulation of the human immune response to varicella zoster

    Get PDF
    Psychoimmunology, the interrelationship between the brain/mind/psyche and the immune system, is now an established area of scientific research. Based on prior investigations we hypothesized that an experienced meditator could affect her delayed hypersensitivity reaction by a psychological process. A single-case study design was employed in which the subject was skin tested weekly with varicella zoster skin test reagent. After baseline immunologic studies, she was able, as hypothesized, to significantly reduce both the induration of her delayed hypersensitivity skin test reaction and in vitro lymphocyte stimulation to varicella zoster. Then, as predicted, she was able to allow her reaction to return to baseline. As a confirmation of what is to our knowledge this previously undescribed phenomenon, she was able to reproduce the entire sequence nine months later. It appears that this subject can intentionally modulate her immune response by a psychologic mechanism

    Synthesis of highly tetrahedral amorphous carbon by mixed-mode HiPIMS sputtering

    Get PDF
    Tetrahedral amorphous carbon films with an sp 3 content of 80% have been produced by high power impulse magnetron sputtering (HiPIMS) operating in a mixed sputtering/arc mode. In this mode, short-lived cathode spots form in the magnetic racetrack and produce large numbers of carbon ions. The spots move rapidly, inhibiting the formation of macroparticles. An argon pressure below 2.5 mTorr was critical for obtaining films with high sp 3 content, high stress, large Tauc gap and symmetrical Raman spectra, and all four quantities were strongly correlated

    Mott Transition, Compressibility Divergence and P-T Phase Diagram of Layered Organic Superconductors: An Ultrasonic Investigation

    Full text link
    The phase diagram of the organic superconductor κ\kappa-(BEDT-TTF)2_2Cu[N(CN)2_2Cl has been investigated by ultrasonic velocity measurements under helium gas pressure. Different phase transitions were identified trough several elastic anomalies characterized from isobaric and isothermal sweeps. Our data reveal two crossover lines that end on the critical point terminating the first-order Mott transition line. When the critical point is approached along these lines, we observe a dramatic softening of the velocity which is consistent with a diverging compressibility of the electronic degrees of freedom.Comment: 4 pages, 5 figure

    Integrable, oblique travelling waves in quasi-charge-neutral two-fluid plasmas

    No full text
    International audienceA Hamiltonian description of oblique travelling waves in a two-fluid, charge-neutral, electron-proton plasma reveals that the transverse momentum equations for the electron and proton fluids are exactly integrable in cases where the total transverse momentum flux integrals, Py(d) and Pz(d), are both zero in the de Hoffman Teller (dHT) frame. In this frame, the transverse electric fields are zero, which simplifies the transverse momentum equations for the two fluids. The integrable travelling waves for the case Py(d)=Pz(d)=0, are investigated based on the Hamiltonian trajectories in phase space, and also on the longitudinal structure equation for the common longitudinal fluid velocity component ux of the electron and proton fluids. Numerical examples of a variety of travelling waves in a cold plasma, including oscillitons, are used to illustrate the physics. The transverse, electron and proton velocity components ujy and ujz (j=e, p) of the waves exhibit complex, rosette type patterns over several periods for ux. The role of separatrices in the phase space, the rotational integral and the longitudinal structure equation on the different wave forms are discussed
    corecore