1,148 research outputs found

    Inscribed Radius Bounds for Lower Ricci Bounded Metric Measure Spaces with Mean Convex Boundary

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    Consider an essentially nonbranching metric measure space with the measure contraction property of Ohta and Sturm, or with a Ricci curvature lower bound in the sense of Lott, Sturm and Villani. We prove a sharp upper bound on the inscribed radius of any subset whose boundary has a suitably signed lower bound on its generalized mean curvature. This provides a nonsmooth analog to a result of Kasue (1983) and Li (2014). We prove a stability statement concerning such bounds and - in the Riemannian curvature-dimension (RCD) setting - characterize the cases of equality

    Effects of inhaled salmeterol and salbutamol (albuterol) on morning dips compared in intensive care patients recovering from an acute severe asthma attack

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    Objective: To assess the effect of a long-acting inhaled β 2-agonist, salmeterol (SM), compared to a short-acting inhaled β 2-agonist, salbutamol (or albuterol, SB), on the occurrence of morning dip (MD) in patients recovering from an acute severe asthma attack (ASA). Design: Prospective study Setting: 18-bed, medical intensive care unit (ICU) in a university hospital. Patients: 19 patients suffering from an ASA. Interventions: Serial measurements of the peak expiratory flow rate (PEFR), arterial blood gases, vital capacity and forced expiratory volume in one second (FEV1) were performed from admission. All patients were first treated with i. v. methyl prednisolone and i.v. SB. Once the PEFR was stable and > 35 % of predicted value, i. v. SB was stopped while i. v. steroids were maintained, and patients were randomised to either inhaled SB (9 patients, 400 μg every 4 h) or inhaled SM (10 patients, 100 μg every 12 h). Results: The mean admission PEFR was 26.1 ± 11.7 % of the predicted value and was not different between the two groups. MD was more frequent with SB (6/9 patients) than with SM (4/10). The severity of MD, expressed in 1/min fall in PEFR, was higher in SB than in SM (106 ± 25 vs 55±37;p<0.05). Discussion: MD is frequent in ASA. In ASA, SM appears to reduce the frequency and the severity of MD more than SB. The clinical implications of this observation, particularly a lowering of mortality and a shortening of the ICU stay, remain to be investigate

    Field-induced charge transport at the surface of pentacene single crystals: a method to study charge dynamics of 2D electron systems in organic crystals

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    A method has been developed to inject mobile charges at the surface of organic molecular crystals, and the DC transport of field-induced holes has been measured at the surface of pentacene single crystals. To minimize damage to the soft and fragile surface, the crystals are attached to a pre-fabricated substrate which incorporates a gate dielectric (SiO_2) and four probe pads. The surface mobility of the pentacene crystals ranges from 0.1 to 0.5 cm^2/Vs and is nearly temperature-independent above ~150 K, while it becomes thermally activated at lower temperatures when the induced charges become localized. Ruling out the influence of electric contacts and crystal grain boundaries, the results contribute to the microscopic understanding of trapping and detrapping mechanisms in organic molecular crystals.Comment: 14 pages, 4 figures. Submitted to J. Appl. Phy

    Plasma Magnetohydrodynamics and Energy Conversion

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    Contains reports on four research projects.National Science Foundation (Grant G-24073)United States Air Force, Aeronautical Systems Division, Aeronautical Accessories Laboratory, Wright-Patterson Air Force Base (Contract AF33(616)-7624

    Family consultation to reduce early hospital readmissions among patients with end stage kidney disease: A randomized controlled trial

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    Background and objectives The US Centers for Medicare and Medicaid Services have mandated reducing early (30-day) hospital readmissions to improve patient care and reduce costs. Patients with ESKD have elevated early readmission rates, due in part to complex medical regimens but also cognitive impairment, literacy difficulties, low social support, and mood problems. We developed a brief family consultation intervention to address these risk factors and tested whether it would reduce early readmissions. Design, setting, participants, & measurements One hundred twenty hospitalized adults with ESKD (mean age=58 years; 50% men; 86% black, 14% white) were recruited from an urban, inpatient nephrology unit. Patients were randomized to the family consultation (n=60) or treatment-as-usual control (n=60) condition. Family consultations, conducted before discharge at bedside or via telephone, educated the family about the patient’s cognitive and behavioral risk factors for readmission, particularly cognitive impairment, and how to compensate for them. Blinded medical record reviews were conducted 30 days later to determine readmission status (primary outcome) and any hospital return visit (readmission, emergency department, or observation; secondary outcome). Logistic regressions tested the effects of the consultation versus control on these outcomes. Results Primary analyses were intent-to-treat. The risk of a 30-day readmission after family consultation (n=12, 20%) was 0.54 compared with treatment-as-usual controls (n=19, 32%), although this effect was not statistically significant (odds ratio, 0.54; 95% confidence interval, 0.23 to 1.24; P=0.15). A similar magnitude, nonsignificant result was observed for any 30-day hospital return visit: family consultation (n=19, 32%) versus controls (n=28, 47%; odds ratio, 0.53; 95% confidence interval, 0.25 to 1.1; P=0.09). Per protocol analyses (excluding three patients who did not receive the assigned consultation) revealed similar results. Conclusions A brief consultation with family members about the patient’s cognitive and psychosocial risk factors had no significant effect on 30-day hospital readmission in patients with ESKD

    Uncovering the forces between nucleosomes using DNA origami

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    Revealing the energy landscape for nucleosome association may contribute to the understanding of higher-order chromatin structures and their impact on genome regulation. We accomplish this in a direct measurement by integrating two nucleosomes into a DNA origami-based force spectrometer, which enabled subnanometer-resolution measurements of nucleosome-nucleosome distance frequencies via single-particle electron microscopy imaging. From the data, we derived the Boltzmann-weighted distance-dependent energy landscape for nucleosome pair interactions. We find a shallow but long-range (similar to 6 nm) attractive nucleosome pair potential with a minimum of -1.6 kcal/mol close to direct contact distances. The relative nucleosome orientation had little influence, but histone H4 acetylation or removal of histone tails drastically decreased the interaction strength. Because of the weak and shallow pair potential, high-erorder nucleosome assemblies will be compliant and experience dynamic shape fluctuations in the absence of additional cofactors. Our results contribute to a more accurate description of chromatin and our force spectrometer provides a powerful tool for the direct and high-resolution study of molecular interactions using imaging techniques
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