926 research outputs found
Effect of cardiometabolic risk factors on hypertension management: a cross-sectional study among 28 physician practices in the United States
<p>Abstract</p> <p>Objective</p> <p>This cross-sectional study sought to determine the prevalence of cardiometabolic risk factor clusters (CMRFCs) and their effect on BP control among hypertensive patients from 28 US physician practices.</p> <p>Methods</p> <p>Each participating practice identified a random sample of 150-300 adults aged ≥ 18 years diagnosed with hypertension. The primary outcome variable was BP control (BP < 140/90 mmHg for non-diabetic and <130/80 mmHg for diabetic patients). CMRFCs included hypertension in addition to obesity, dyslipidemia, and diabetes.</p> <p>Results</p> <p>Overall, 6,527 hypertensive patients were identified for study inclusion. More than half (54.3%) were female, and mean age was 64.7 years. Almost half (48.7%) were obese (BMI ≥ 30 kg/m<sup>2</sup>). About 1 in every 4 patients (25.3%) had diabetes, and 60.7% had dyslipidemia. Mean blood pressure was 132.5/77.9 mmHg, and 55.0% of all patients had controlled BP; 62.4% of non-diabetic patients, and 33.3% of diabetic hypertensive patients, had BP controlled to recommended levels. Most (81.7%) hypertensive patients had ≥ 1 cardiometabolic risk factor, and 12.2% had all 3 risk factors. As compared to hypertensive patients without additional risk factors, adjusted odds ratios for BP control were significantly lower for all combinations of CMRFCs (ORs 0.15-0.83, all p < 0.04), with the exception of patients who had only dyslipidemia in addition to hypertension (OR = 1.09, p = NS). Prescriber adherence to recommended hypertension treatment guidelines for patients with diabetes, heart failure, or prior myocardial infarction was high. Although patients with risk factors were prescribed more antihypertensive medications than those without, hypertensive patients with all 3 risk factors were prescribed a mean of 2.4 antihypertensive medications compared to 1.7 for those with no risk factors; odds of BP control in these patients, however, was 0.23 [95% CI 0.19-0.29] that of patients with no other CMRFCs.</p> <p>Conclusions</p> <p>Across 28 US practices, only 18% of hypertensive patients did not have any additional cardiometabolic risk factors. The high prevalence of CMRFCs presents a challenge to effective hypertension management.</p
Janus II: a new generation application-driven computer for spin-system simulations
This paper describes the architecture, the development and the implementation
of Janus II, a new generation application-driven number cruncher optimized for
Monte Carlo simulations of spin systems (mainly spin glasses). This domain of
computational physics is a recognized grand challenge of high-performance
computing: the resources necessary to study in detail theoretical models that
can make contact with experimental data are by far beyond those available using
commodity computer systems. On the other hand, several specific features of the
associated algorithms suggest that unconventional computer architectures, which
can be implemented with available electronics technologies, may lead to order
of magnitude increases in performance, reducing to acceptable values on human
scales the time needed to carry out simulation campaigns that would take
centuries on commercially available machines. Janus II is one such machine,
recently developed and commissioned, that builds upon and improves on the
successful JANUS machine, which has been used for physics since 2008 and is
still in operation today. This paper describes in detail the motivations behind
the project, the computational requirements, the architecture and the
implementation of this new machine and compares its expected performances with
those of currently available commercial systems.Comment: 28 pages, 6 figure
Understanding the structure and reactivity of NiCu nanoparticles: An atomistic model
The structure of bimetallic NiCu nanoparticles (NP) is investigated as a function of their composition and size by means of Lattice MonteCarlo (LMC) and molecular dynamics (MD) simulations. According to our results, copper segregation takes place at any composition of the particles. We found that this feature is not size-dependent. In contrast, nickel segregation depends on the NP size. When the size increases, Ni atoms tend to remain in the vicinity of the surface and deeper. For smaller NPs, Ni atoms are located at the surface as well. Our results also showed that most of the metal atoms segregated at the surface area were found to decorate edges and/or form islands. Our findings agree qualitatively with the experimental data found in the literature. In addition, we comment on the reactivity of these nanoparticles.Fil: Quaino, Paola Monica. Universidad Nacional del Litoral. Instituto de QuĂmica Aplicada del Litoral. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Centro CientĂfico TecnolĂłgico Conicet - Santa Fe. Instituto de QuĂmica Aplicada del Litoral.; Argentina. Universidad Nacional del Litoral. Facultad de IngenierĂa QuĂmica. Programa de ElectroquĂmica Aplicada e IngenierĂa ElectroquĂmica; Argentina. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas; ArgentinaFil: Belletti, Gustavo Daniel. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas; Argentina. Universidad Nacional del Litoral. Instituto de QuĂmica Aplicada del Litoral. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Centro CientĂfico TecnolĂłgico Conicet - Santa Fe. Instituto de QuĂmica Aplicada del Litoral.; Argentina. Universidad Nacional del Litoral. Facultad de IngenierĂa QuĂmica. Programa de ElectroquĂmica Aplicada e IngenierĂa ElectroquĂmica; ArgentinaFil: Shermukhamedov, S. A.. Kazan National Research Technological University; RusiaFil: Glukhov, D. V.. Kazan National Research Technological University; RusiaFil: Santos, Elizabeth del Carmen. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Centro CientĂfico TecnolĂłgico Conicet - CĂłrdoba. Instituto de FĂsica Enrique Gaviola. Universidad Nacional de CĂłrdoba. Instituto de FĂsica Enrique Gaviola; Argentina. Institute of Theoretical Chemistry; Alemania. Universitat Ulm; AlemaniaFil: Schmickler, Wolfgang. Universitat Ulm; Alemania. Institute of Theoretical Chemistry; AlemaniaFil: Nazmutdinov, Renat. Kazan National Research Technological University; Rusi
Simulating spin systems on IANUS, an FPGA-based computer
We describe the hardwired implementation of algorithms for Monte Carlo
simulations of a large class of spin models. We have implemented these
algorithms as VHDL codes and we have mapped them onto a dedicated processor
based on a large FPGA device. The measured performance on one such processor is
comparable to O(100) carefully programmed high-end PCs: it turns out to be even
better for some selected spin models. We describe here codes that we are
currently executing on the IANUS massively parallel FPGA-based system.Comment: 19 pages, 8 figures; submitted to Computer Physics Communication
Effects of biochar addition on long-term behaviour of concrete and mortar
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Biochar-based cement pastes and mortars with enhanced mechanical properties
Nowadays, the environmental impact of cementitious material industry and more generally of building activities is matter of concern, especially in terms of their effects on climate change and consumption of natural resources. Within this context, the aim of this paper is the investigation of the role of biochar, a solid carbonaceous by-product material resulting from biomass pyrolysis/gasification of residual biomass, as a sustainable ingredient for the production of cementitious materials, combining carbon sink properties with enhanced mechanical behavior. Although biochar is mainly investigated as agricultural amendment, there is also evidence that biochar may be an eco-friendly material to improve the sustainable performance of cementitious materials. As outlined in literature, biochar can be used as filler to modify the nanogranular nature of cement matrix, or as substitute of clinker to reduce the emissions of greenhouse gases related to cement production. In this work, biochar is added as micro-nano particles in different cementitious composites, i.e. cement pastes and mortars, as a function of filler or partial substitute of cement. The main mechanical properties of biochar-based materials are then investigated to determine the optimal percentage of biochar addition
An in-depth view of the microscopic dynamics of Ising spin glasses at fixed temperature
Using the dedicated computer Janus, we follow the nonequilibrium dynamics of
the Ising spin glass in three dimensions for eleven orders of magnitude. The
use of integral estimators for the coherence and correlation lengths allows us
to study dynamic heterogeneities and the presence of a replicon mode and to
obtain safe bounds on the Edwards-Anderson order parameter below the critical
temperature. We obtain good agreement with experimental determinations of the
temperature-dependent decay exponents for the thermoremanent magnetization.
This magnitude is observed to scale with the much harder to measure coherence
length, a potentially useful result for experimentalists. The exponents for
energy relaxation display a linear dependence on temperature and reasonable
extrapolations to the critical point. We conclude examining the time growth of
the coherence length, with a comparison of critical and activated dynamics.Comment: 38 pages, 26 figure
Ianus: an Adpative FPGA Computer
Dedicated machines designed for specific computational algorithms can
outperform conventional computers by several orders of magnitude. In this note
we describe {\it Ianus}, a new generation FPGA based machine and its basic
features: hardware integration and wide reprogrammability. Our goal is to build
a machine that can fully exploit the performance potential of new generation
FPGA devices. We also plan a software platform which simplifies its
programming, in order to extend its intended range of application to a wide
class of interesting and computationally demanding problems. The decision to
develop a dedicated processor is a complex one, involving careful assessment of
its performance lead, during its expected lifetime, over traditional computers,
taking into account their performance increase, as predicted by Moore's law. We
discuss this point in detail
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