867 research outputs found

    Doppler echocardiographic demonstration of the differential effects of right ventricular pressure and volume overload on left ventricular geometry and filling

    Get PDF
    AbstractTo compare the effects of isolated right ventricular pressure and volume overload on left ventricular diastolic geometry and filling, 11 patients with primary pulmonary hypertension, 11 patients with severe tricuspid regurgitation due to tricuspid valve resection and 11 normal subjects were studied with use of Doppler echocardiography techniques. Right ventricular systolic overload in primary pulmonary hypertension resulted in substantial leftword ventricular septal shift that was most marked at end-systole and early diastole and decreased substantially by end-diastole. Right ventricular diastolic overload after tricuspid valve resection resulted in maximal leftward ventricular septal shift at end-diastole sparing end-systole and early diastole. The early diastolic distortion of left ventricular geometry associated with right ventricular pressure overload resulted in prolongation of isovolumetric relaxation of the left ventricle (129 ± 39 ms) and a reduction in early diastolic finding compared with values in normal subjects.Late diastolic distortion of left ventricular geometry associated with right ventricular volume overload had no influence on the duration of left ventricular isovolumetric relaxatoon (52 ± 32 ms) but caused a reduction in the atrial systolic contribution to late distolic filling of the left ventricle compared with values in normal sujects. In patients with right ventricular pressure overload, 52 ± 16% of left ventricular filling occurred in early diastole compared with 78 ± 11% in patients with right ventricular volume overload (p < 0.001). The differential effects of systolic and diastolic right ventricular overload on the pattern of left ventricular filling appear to bt related to the timing of leftward ventricular septal displacement

    Dynamics of spin correlations in the spin-1/2 isotropic XY chain in a transverse field

    Full text link
    Dynamic xx spin pair correlation functions for the isotropic spin-1/2 XY chain are calculated numerically for long open chains in the presence of a transverse magnetic field at finite temperature. As an application we discuss the temperature dependence of the spin-spin relaxation time in PrCl_3.Comment: 2 pages, latex, 2 figures, abstract of the paper presented at Ampere Summer School ``Applications of Magnetic Resonance in Novel Materials'' Nafplion, Greece, 3-9 September, 2000, partially published in J. Phys. A: Math. Gen. 33, 3063 (2000

    Constant regulation for stable CD8 T-cell functional avidity and its possible implications for cancer immunotherapy.

    Get PDF
    The functional avidity (FA) of cytotoxic CD8 T cells impacts strongly on their functional capabilities and correlates with protection from infection and cancer. FA depends on TCR affinity, downstream signaling strength, and TCR affinity-independent parameters of the immune synapse, such as costimulatory and inhibitory receptors. The functional impact of coreceptors on FA remains to be fully elucidated. Despite its importance, FA is infrequently assessed and incompletely understood. There is currently no consensus as to whether FA can be enhanced by optimized vaccine dose or boosting schedule. Recent findings suggest that FA is remarkably stable in vivo, possibly due to continued signaling modulation of critical receptors in the immune synapse. In this review, we provide an overview of the current knowledge and hypothesize that in vivo, codominant T cells constantly "equalize" their FA for similar function. We present a new model of constant FA regulation, and discuss practical implications for T-cell-based cancer immunotherapy

    A compendium and functional characterization of mammalian genes involved in adaptation to Arctic or Antarctic environments

    Get PDF
    Many mammals are well adapted to surviving in extremely cold environments. These species have likely accumulated genetic changes that help them efficiently cope with low temperatures. It is not known whether the same genes related to cold adaptation in one species would be under selection in another species. The aims of this study therefore were: to create a compendium of mammalian genes related to adaptations to a low temperature environment; to identify genes related to cold tolerance that have been subjected to independent positive selection in several species; to determine promising candidate genes/pathways/organs for further empirical research on cold adaptation in mammals

    Weight Loss Strategies Associated With BMI in Overweight Adults With Type 2 Diabetes at Entry Into the Look AHEAD (Action for Health in Diabetes) Trial

    Get PDF
    OBJECTIVE—Intentional weight loss is recommended for those with type 2 diabetes, but the strategies patients attempt and their effectiveness for weight management are unknown. In this investigation we describe intentional weight loss strategies used and those related to BMI in a diverse sample of overweight participants with type 2 diabetes at enrollment in the Look AHEAD (Action for Health in Diabetes) clinical trial

    Observation of narrow baryon resonance decaying into pKs0pK^0_s in pA-interactions at 70GeV/c70 GeV/c with SVD-2 setup

    Full text link
    SVD-2 experiment data have been analyzed to search for an exotic baryon state, the Θ+\Theta^+-baryon, in a pKs0pK^0_s decay mode at 70GeV/c70 GeV/c on IHEP accelerator. The reaction pApKs0+XpA \to pK^0_s+X with a limited multiplicity was used in the analysis. The pKs0pK^0_s invariant mass spectrum shows a resonant structure with M=1526±3(stat.)±3(syst.)MeV/c2M=1526\pm3(stat.)\pm 3(syst.) MeV/c^2 and Γ<24MeV/c2\Gamma < 24 MeV/c^2. The statistical significance of this peak was estimated to be of 5.6σ5.6 \sigma. The mass and width of the resonance is compatible with the recently reported Θ+\Theta^+- baryon with positive strangeness which was predicted as an exotic pentaquark (uuddsˉuudd\bar{s}) baryon state. The total cross section for Θ+\Theta^+ production in pN-interactions for XF0X_F\ge 0 was estimated to be (30÷120)μb(30\div120) \mu b and no essential deviation from A-dependence for inelastic events (A0.7)(\sim A^{0.7}) was found.Comment: 8 pages, 7 figures, To be submitted to Yadernaya Fizika. v3-v5 - Some references added, minor typos correcte
    corecore