4,874 research outputs found

    Obesity and the food environment: income and ethnicity differences among people with diabetes: the Diabetes Study of Northern California (DISTANCE).

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    ObjectiveIt is unknown whether any association between neighborhood food environment and obesity varies according to individual income and/or race/ethnicity. The objectives of this study were to test whether there was an association between food environments and obesity among adults with diabetes and whether this relationship differed according to individual income or race/ethnicity.Research design and methodsSubjects (n = 16,057) were participants in the Diabetes Study of Northern California survey. Kernel density estimation was used to create a food environment score for each individual's residence address that reflected the mix of healthful and unhealthful food vendors nearby. Logistic regression models estimated the association between the modeled food environment and obesity, controlling for confounders, and testing for interactions between food environment and race/ethnicity and income.ResultsThe authors found that more healthful food environments were associated with lower obesity in the highest income groups (incomes 301-600% and >600% of U.S. poverty line) among whites, Latinos, and Asians. The association was negative, but smaller and not statistically significant, among high-income blacks. On the contrary, a more healthful food environment was associated with higher obesity among participants in the lowest-income group (<100% poverty threshold), which was statistically significant for black participants in this income category.ConclusionsThese findings suggest that the availability of healthful food environments may have different health implications when financial resources are severely constrained

    Energy influx from an rf plasma to a substrate during plasma processing

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    The energy influx delivered by an rf plasma to a metal substrate has been studied by a calorimetric method with a thermal probe. By changing the substrate voltage, the influence of the kinetic energy of the charge carriers to the thermal power could be determined. The measured energy influx for an argon plasma can be explained mainly by ions, electrons, and their recombination. In the case of an oxygen plasma, where the energy influx is under comparable conditions about 50% higher, also other transfer mechanisms such as surface-aided atom association and relaxation of rovibrational states have to be taken into consideration

    Particles as probes for complex plasmas in front of biased surfaces

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    An interesting aspect in the research of complex (dusty) plasmas is the experimental study of the interaction of micro-particles with the surrounding plasma for diagnostic purposes. Local electric fields can be determined from the behaviour of particles in the plasma, e.g. particles may serve as electrostatic probes. Since in many cases of applications in plasma technology it is of great interest to describe the electric field conditions in front of floating or biased surfaces, the confinement and behaviour of test particles is studied in front of floating walls inserted into a plasma as well as in front of additionally biased surfaces. For the latter case, the behaviour of particles in front of an adaptive electrode, which allows for an efficient confinement and manipulation of the grains, has been experimentally studied in dependence on the discharge parameters and on different bias conditions of the electrode. The effect of the partially biased surface (dc, rf) on the charged micro-particles has been investigated by particle falling experiments. In addition to the experiments we also investigate the particle behaviour numerically by molecular dynamics, in combination with a fluid and particle-in-cell description of the plasma.Comment: 39 pages, 16 figures, submitted to New J. Phy

    Stent Design Properties and Deployment Ratio Influence Indexes of Wall Shear Stress: a Three-Dimensional Computational Fluid Dynamics Investigation within a Normal Artery

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    Restenosis limits the effectiveness of stents, but the mechanisms responsible for this phenomenon remain incompletely described. Stent geometry and expansion during deployment produce alterations in vascular anatomy that may adversely affect wall shear stress (WSS) and correlate with neointimal hyperplasia. These considerations have been neglected in previous computational fluid dynamics models of stent hemodynamics. Thus we tested the hypothesis that deployment diameter and stent strut properties (e.g., number, width, and thickness) influence indexes of WSS predicted with three-dimensional computational fluid dynamics. Simulations were based on canine coronary artery diameter measurements. Stent-to-artery ratios of 1.1 or 1.2:1 were modeled, and computational vessels containing four or eight struts of two widths (0.197 or 0.329 mm) and two thicknesses (0.096 or 0.056 mm) subjected to an inlet velocity of 0.105 m/s were examined. WSS and spatial WSS gradients were calculated and expressed as a percentage of the stent and vessel area. Reducing strut thickness caused regions subjected to low WSS (/cm2) to decrease by ∼87%. Increasing the number of struts produced a 2.75-fold increase in exposure to low WSS. Reducing strut width also caused a modest increase in the area of the vessel experiencing low WSS. Use of a 1.2:1 deployment ratio increased exposure to low WSS by 12-fold compared with stents implanted in a 1.1:1 stent-to-vessel ratio. Thinner struts caused a modest reduction in the area of the vessel subjected to elevated WSS gradients, but values were similar for the other simulations. The results suggest that stent designs that reduce strut number and thickness are less likely to subject the vessel to distributions of WSS associated with neointimal hyperplasia

    A supported self-help for recurrent depression in primary care; an economic evaluation alongside a multi-center randomised controlled trial

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    Background Major depression is a prevalent mental disorder with a high risk of relapse or recurrence. Only few studies have focused on the cost-effectiveness of interventions aimed at the prevention of relapse or recurrence of depression in primary care. Aim To evaluate the cost-effectiveness of a supported Self-help Preventive Cognitive Therapy (S-PCT) added to treatment-as-usual (TAU) compared with TAU alone for patients with a history of depression, currently in remission. Methods An economic evaluation alongside a multi-center randomised controlled trial was performed (n = 248) over a 12-month follow-up. Outcomes included relapse or recurrence of depression and quality-adjusted-life-years (QALYs) based on the EuroQol-5D. Analyses were performed from both a societal and healthcare perspective. Missing data were imputed using multiple imputations. Uncertainty was estimated using bootstrapping and presented using the cost-effectiveness plane and the Cost- Effectiveness Acceptability Curve (CEAC). Cost estimates were adjusted for baseline costs. Results S-PCT statistically significantly decreased relapse or recurrence by15% (95%CI 3;28) compared to TAU. Mean total societal costs were €2,114 higher (95%CI -112;4261). From a societal perspective, the ICER for recurrence of depression was 13,515. At a Willingness To Pay (WTP) of 22,000 €/recurrence prevented, the probability that S-PCT is cost-effective, in comparison with TAU, is 80%. From a healthcare perspective, the WTP at a probability of 80% should be 11,500 €/recurrence prevented. The ICER for QALYs was 63,051. The CEA curve indicated that at a WTP of 30,000 €/QALY gained, the probability that S-PCT is cost-effective compared to TAU is 21%. From a healthcare perspective, at a WTP of 30,000 €/QALY gained, the probability that S-PCT is cost-effective compared to TAU is 46%. Conclusions Though ultimately depending on the WTP of decision makers, we expect that for both relapse or recurrence and QALYs, S-PCT cannot be considered cost-effective compared to TAU

    Effectiveness of supported self-help in recurrent depression: a randomized controlled trial in primary care

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    Background: The burden and economic consequences of depression are high, mostly due to its recurrent nature. Due to current budget and time restraints, a preventive, low-cost, accessible minimal intervention is much needed. In this study, we evaluated the effectiveness of a supported self-help preventive cognitive therapy (S-PCT) added to treatment as usual (TAU) in primary care, compared to TAU alone. Methods: We conducted a randomized controlled trial among 248 patients with a history of depression, currently in full or partial remission or recovery. Participants were randomized to TAU augmented with S-PCT (n = 124) or TAU alone (n = 124). S-PCT consisted of an 8-week self-help intervention, supported by weekly telephone guidance by a counselor. The intervention included a self-help book that could be read at home. The primary outcome was the incidence of relapse or recurrence and was assessed over the telephone by the Structured Clinical Interview for DSM-IV axis 1 disorders. Participants were observed for 12 months. Secondary outcomes were depressive symptoms, quality of life (EQ-5D and SF-12), comorbid psychopathology, and self-efficacy. These secondary outcomes were assessed by digital questionnaires. Results: In the S-PCT group, 44 participants (35.5) experienced a relapse or recurrence, compared to 62 participants (50.0) in the TAU group (incidence rate ratio = 0.71, 95 CI 0.52-0.97; risk difference = 14, 95 CI 2-24, number needed to treat = 7). Compared to the TAU group, the S-PCT group showed a significant reduction in depressive symptoms over 12 months (mean difference-2.18; 95 CI-3.09 to-1.27) and a significant increase in quality of life (EQ-5D) (mean difference 0.04; 95 CI 0.004-0.08). S-PCT had no effect on comorbid psychopathology, self-efficacy, and quality of life based on the SF-12. Conclusions: A supported self-help preventive cognitive therapy, guided by a counselor in primary care, proved to be effective in reducing the burden of recurrent depression

    Enzyme-powered hollow mesoporous Janus nanomotors

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    The development of synthetic nanomotors for technological applications in particular for life science and nanomedicine is a key focus of current basic research. However, it has been challenging to make active nanosystems based on biocompatible materials consuming nontoxic fuels for providing self-propulsion. Here, we fabricate self-propelled Janus nanomotors based on hollow mesoporous silica nanoparticles (HMSNPs), which are powered by biocatalytic reactions of three different enzymes: catalase, urease, and glucose oxidase (GOx). The active motion is characterized by a mean-square displacement (MSD) analysis of optical video recordings and confirmed by dynamic light scattering (DLS) measurements. We found that the apparent diffusion coefficient was enhanced by up to 83%. In addition, using optical tweezers, we directly measured a holding force of 64 ± 16 fN, which was necessary to counteract the effective self-propulsion force generated by a single nanomotor. The successful demonstration of biocompatible enzyme-powered active nanomotors using biologically benign fuels has a great potential for future biomedical applications
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