Health impact of brief interventions by a registered dietitian during exercise sessions in a phase 2 cardiac rehabilitation setting

Weight management is integral to cardiovascular risk reduction. However, minimal weight loss is achieved during participation in many cardiac rehabilitation (CR) programs. The objective of the present study was to establish if brief interventions by a registered dietitian (RD) during cardiac rehabilitation sessions improved the health status of patients with cardiovascular disease. An RD provided individualized nutrition counseling, answered nutrition questions, and reviewed weekly progress in a CR program for a four-month period. At baseline and upon completion of 19 CR sessions, nutrition knowledge was assessed using a 38-question test, and body weight was measured. Upon completing CR, patients rated the degree at which they were making healthier food choices and how much they liked having an RD assessable during CR. After four months, the exercise physiologists (EPs) rated the value of having an RD in CR. Outcomes were collected on every patient who completed CR during this period, and values were compared to outcomes of patients who completed CR during the same timeframe one year earlier. Both groups received instruction regarding the traditional CR exercise program and four 45-minute weekly group nutrition education sessions. Forty-nine patients (36 males) completed CR with the RD present. Mean nutrition knowledge test scores improved from 59 ±1 4% to 72 ± 14%, (p = \u3c .001). After completing CR, patients reported making healthier food choices 8.1 ± 1.2 out of 10 on a Likert scale. Additionally, patients related the helpfulness of having an RD available to answer their nutrition questions 8.7 ± 4.8 out of 10. The group of patients who had an RD present during CR had a mean weight loss of 1.48 ± 7.1 lbs (range -18.8 to 16.4 lbs) when compared to the group who did not have access to an RD. Ten patients were referred for individual nutrition counseling with an outpatient RD. Exercise physiologists rated the value of having an RD as part of the health care team a 9.8 out of 10. There was a trend towards greater weight loss in the group of patients who had access to an RD in CR. i

Kinetic Analysis of Electrochemical Oxygen Reduction and Development of Ag-alloy Catalysts for Low Temperature Fuel Cells.

This dissertation applies insights from quantum chemical calculations and heterogeneous kinetic analysis to interpret macroscopic reactivity trends in electrochemical systems and design optimal electrocatalysts. Specifically we explore the mechanism of the electrochemical oxygen reduction reaction (ORR) on the surfaces of Pt (a near-optimal catalyst) and Ag electrodes. We have identified design criteria for improving the reaction rate in each case and developed cost-effective Ag-based alloy materials with activity approaching that of more costly Pt catalysts. We first demonstrate, using microkinetic modeling and density functional theory calculations, that deviations from ideal electrode kinetics (a linear potential vs. log current relationship) are inherent to the ORR and any multi-step heterogeneous electrocatalytic reaction. Deviations result from simultaneous changes in the rate of the rate-limiting elementary step and the number of available active sites on the electrode surface as potential is shifted. We show the ORR kinetic variations on Pt electrodes are well-reproduced by a simple description of changes in OH and H2O surface intermediate coverages, and that weaker binding materials exhibit higher rates due to higher active-site availability. In contrast, on Ag a very weak relation is found between adsorbate coverage and changes in the apparent rate law. This points to a strong role of under-coordinated active sites, which become poisoned at low potentials while the majority of the surface is still clean. Moving toward stronger binding on Ag should yield higher ORR activity by increasing turnover rates on the more predominant surface facets. Using the mechanistic insights mentioned, we illustrate the design of relatively inexpensive Ag-Co surface alloy nanoparticle electrocatalysts for ORR, with equivalent area-specific activity to commercial Pt-nanoparticles at realistic fuel cell operating conditions. The Ag-Co materials were identified with quantum chemical calculations and synthesized with a novel bimetallic precursor decomposition technique that generates a surface alloy, despite bulk immiscibility of the elements. Characterization studies show the origin of activity improvement comes from a ligand effect, in which Co perturbs Ag surface sites. We also explore bimetallic precursor decomposition to produce Ag-Ni and Ag-Fe alloys but find that the products exhibit substantial segregation and have ORR activities similar to monometallic Ag.PHDChemical EngineeringUniversity of Michigan, Horace H. Rackham School of Graduate Studieshttp://deepblue.lib.umich.edu/bitstream/2027.42/102423/1/ahole_1.pd

High-performance sparse matrix-vector multiplication on GPUs for structured grid computations

ABSTRACT In this paper, we address efficient sparse matrix-vector multiplication for matrices arising from structured grid problems with high degrees of freedom at each grid node. Sparse matrix-vector multiplication is a critical step in the iterative solution of sparse linear systems of equations arising in the solution of partial differential equations using uniform grids for discretization. With uniform grids, the resulting linear system A x = b has a matrix A that is sparse with a very regular structure. The specific focus of this paper is on sparse matrices that have a block structure due to the large number of unknowns at each grid point. Sparse matrix storage formats such as Compressed Sparse Row (CSR) and Diagonal format (DIA) are not the most effective for such matrices. In this work, we present a new sparse matrix storage format that takes advantage of the diagonal structure of matrices for stencil operations on structured grids. Unlike other formats such as the Diagonal storage format (DIA), we specifically optimize for the case of higher degrees of freedom, where formats such as DIA are forced to explicitly represent many zero elements in the sparse matrix. We develop efficient sparse matrix-vector multiplication for structured grid computations on GPU architectures using CUD

Insight into the oxidation mechanism of furanic compounds on Pt(111)

Partial oxidation of multifunctional oxygenates is of interest for the production of high-value chemicals, but the understanding of the mechanism on Pt catalysts is lacking. To probe the effects of oxygen in the reaction of furanics on Pt(111), temperature-programmed desorption (TPD), high-resolution electron energy loss spectroscopy (HREELS), electrochemical catalytic experiments, and density functional theory (DFT) calculations were conducted. The presence of oxygen on the Pt(111) surface significantly altered the reaction paths for furan and furfuryl alcohol oxidation. Although furan desorbed without reaction from clean Pt(111) during TPD, on the O precovered surface, extensive oxidation and decomposition reactions were observed. The main volatile products were H2O, CO, and CO2. HREEL spectra and DFT calculations indicated that furan initially reacted through oxygen addition to the ring to produce surface-adsorbed furanone intermediates. For furfuryl alcohol, the same desorption products were formed, but maleic anhydride was also detected as a trace product. HREELS and DFT calculations suggested that alcohol oxidation proceeded through dehydrogenation at the hydroxyl and methylene groups and subsequent oxidation to produce a carboxylate intermediate. The carboxylate intermediate underwent decarboxylation to form CO2 and surface furyl intermediates, which then underwent deep oxidation and decomposition. Thus, the presence of the oxygenated side chain on the furan ring for furfuryl alcohol strongly influenced the oxidation chemistry. Comparison of furfural electrocatalytic oxidation results on Pd (collected here) and Pt (from previous work) indicated that Pt is less active for C&ndash;C activation but more active for insertion of oxygen atoms into the furan ring, in line with the current and previously published surface science results.</p

Seed-mediated atomic-scale reconstruction of silver manganate nanoplates for oxygen reduction towards high-energy aluminum-air flow batteries

Aluminum-air batteries are promising candidates for next-generation high-energy-density storage, but the inherent limitations hinder their practical use. Here, we show that silver nanoparticle-mediated silver manganate nanoplates are a highly active and chemically stable catalyst for oxygen reduction in alkaline media. By means of atomic-resolved transmission electron microscopy, we find that the formation of stripe patterns on the surface of a silver manganate nanoplate originates from the zigzag atomic arrangement of silver and manganese, creating a high concentration of dislocations in the crystal lattice. This structure can provide high electrical conductivity with low electrode resistance and abundant active sites for ion adsorption. The catalyst exhibits outstanding performance in a flow-based aluminum-air battery, demonstrating high gravimetric and volumetric energy densities of similar to 2552 Wh kg(Al)(-1) and similar to 6890 Wh I-Al(-1) at 100 mA cm(-2), as well as high stability during a mechanical recharging process

Enhanced Electrocatalytic Oxygen Evolution in Au–Fe Nanoalloys

Oxygen evolution reaction (OER) is the most critical step in water splitting, still limiting the development of efficient alkaline water electrolyzers. Here we investigate the OER activity of Au–Fe nanoalloys obtained by laser-ablation synthesis in solution. This method allows a high amount of iron (up to 11 at %) to be incorporated into the gold lattice, which is not possible in Au–Fe alloys synthesized by other routes, due to thermodynamic constraints. The Au0.89Fe0.11 nanoalloys exhibit strongly enhanced OER in comparison to the individual pure metal nanoparticles, lowering the onset of OER and increasing up to 20 times the current density in alkaline aqueous solutions. Such a remarkable electrocatalytic activity is associated to nanoalloying, as demonstrated by comparative examples with physical mixtures of gold and iron nanoparticles. These results open attractive scenarios to the use of kinetically stable nanoalloys for catalysis and energy conversion

AN5D: Automated Stencil Framework for High-Degree Temporal Blocking on GPUs

Stencil computation is one of the most widely-used compute patterns in high performance computing applications. Spatial and temporal blocking have been proposed to overcome the memory-bound nature of this type of computation by moving memory pressure from external memory to on-chip memory on GPUs. However, correctly implementing those optimizations while considering the complexity of the architecture and memory hierarchy of GPUs to achieve high performance is difficult. We propose AN5D, an automated stencil framework which is capable of automatically transforming and optimizing stencil patterns in a given C source code, and generating corresponding CUDA code. Parameter tuning in our framework is guided by our performance model. Our novel optimization strategy reduces shared memory and register pressure in comparison to existing implementations, allowing performance scaling up to a temporal blocking degree of 10. We achieve the highest performance reported so far for all evaluated stencil benchmarks on the state-of-the-art Tesla V100 GPU

Abstracts from the 8th International Conference on cGMP Generators, Effectors and Therapeutic Implications

This work was supported by a restricted research grant of Bayer AG