720 research outputs found
Benchmarks of Diabetes Care in Men Living With Treated HIV-Infection: A Tertiary Center Experience
Treated human immunodeficiency virus (HIV) infection is associated with high rates of type 2 diabetes mellitus (DM), metabolic syndrome and central obesity/body fat partitioning disorders. To our knowledge, there are no available data comparing diabetes care in people with both HIV+DM vs. DM alone (DM-controls) within the same service and evaluating if benchmarked standards of care are being met in people with HIV+DM. This study evaluated the frequency that people with HIV+DM met the benchmarked American Diabetes Association (ADA) standards of care in diabetes (targets for HbA1c, blood pressure, lipid levels, complication screening, and healthy weight), compared to age- and sex- matched controls with diabetes, in an urban teaching hospital. The frequency of diabetes complications and rates of obesity and metabolic syndrome were also examined. All participants were male; individuals with HIV+DM (n = 30) were similar to DM-controls (n = 30) for age, diabetes duration and smoking status, but were more frequently non-obese compared to DM controls (92 vs. 55%, respectively, p = 0.003). Only 41% of HIV+DM met HbA1c targets, compared with 70% of DM-controls (p = 0.037). Blood pressure targets were poorly met in both HIV+DM and DM-controls: 43 vs. 23%, respectively (p = 0.12); LDL cholesterol targets were met in 65 vs. 67% (p = 1.0). Benchmarked complication screening rates were similar between HIV+DM vs. DM-controls for annual foot examination (53 vs. 67%, respectively, p = 0.29); biennial retinal examination (83 vs. 77%, respectively, p = 0.52); and annual urinary albumin measurement (77 vs. 67%, respectively, p = 0.39). The prevalence of diabetes complications was similar between HIV+DM compared to DM-controls: macrovascular complications were present in 23% in both groups (p = 1.0); the prevalence of microvascular complications was 40 vs. 30%, respectively (p = 0.51). Achieving the standard of care benchmarks for diabetes in people with both HIV-infection and diabetes is of particular importance to mitigate against the accelerated cardiometabolic outcomes observed in those with treated HIV infection. HIV+DM were less likely to achieve HbA1c targets than people with diabetes, but without HIV. People with HIV+DM may require specific strategies to ensure care benchmarks are met
Results of 1/4-Scale Experiments. Vapor Simulant And Liquid Jet A Tests
A quarter-scale engineering model of the center wing tank (CWT) of a 747-100 was constructed. This engineering model replicated the compartmentalization, passageways, and venting to the atmosphere. The model was designed to scale the fluid dynamical and combustion aspects of the explosion, not the structural failure of the beams or spars. The effect of structural failure on combustion was examined by using model beams and spars with deliberately engineered weak connections to the main tank structure. The model was filled with a simulant fuel (a mixture of propane and hydrogen) and ignited with a hot wire. The simulant fuel was chosen on the basis of laboratory testing to model the combustion characteristics (pressure rise and flame speed) of Jet A vapor created by a Jet A liquid layer at 50C at an altitude of 13.8 kft.
A series of experiments was carried out in this model in order to: (a) investigate combustion in a CWT geometry; and (b) provide guidance to the TWA 800 crash investigation. The results of the experiments were observed with high-speed film, video, and still cameras, fast and slow pressure sensors, thermocouples, photodetectors, and motion sensors. A special pseudo-schlieren system was used to visualize flame propagation within the tank. This report describes the test program, facility, instrumentation, the first 30 experiments, comparisons between experiments, and performance of the instrumentation; then examines the significance of these results to the TWA 800 crash investigation.
The key results of this study are:
Flame Motion: The motion of flame was dominated by the effects of turbulence created by jetting through the passageways and vent stringers. A very rapid combustion event (lasting 10 to 20 ms) occurred once the flame traveled outside of the ignition bay and interacted with the turbulent flow. Most of the gas within the tank was burned during this rapid event.
Compartments: The combustion time decreased with an increasing number of compartments (bays) within the tank. With six bays, combustion took only 100 to 150 ms to be completed from the time of ignition until the end of the rapid combustion phase. The total combustion event was three to four times shorter with compartments than without.
Venting: Venting to the outside of the tank through the model vent stringers had a negligible effect on the combustion progress or on the peak pressure reached at the end of the burn.
Ignition Location: Variation of the ignition location produced distinctive pressure loads on the structural components.
Liquid Fuel: Lofting of a cold liquid fuel layer was produced by the combustion-induced gas motion. Although this spray of liquid eventually ignited and burned, it did not contribute to the pressure loading.
Structural Failure: Structural failure resulted in flame acceleration, decreasing the overall combustion time.
TWA 800 Investigation: The pressure loads were sufficiently high, up to 4 bar, and the combustion events were sufficiently short, that the forward portion (spanwise beam 3, front spar) of the CWT structure would fail as a direct consequence of the explosion. A combination of pressure loads was produced in some tests consistent with the TWA 800 wreckage. Replica tests, structural modeling, and sensitivity studies on fuel concentration are needed before any conclusions can be drawn about probable ignition locations.
Cargo Bay: Tests with a simplified model of a half-full cargo bay indicated that repeated pressure waves with an amplitude of 1 bar or less are produced when an explosion scenario similar to TWA 800 is tested.
Future Testing: Future studies should include replica tests, tests with Jet A vapor and warm liquid Jet A layers, and sensitivity tests to examine ignition location, fuel concentration, and vent area perturbations.
Summary: Explosion tests in a 747-100 CWT model reveal that a very complex pattern of combustion occurs due the interaction of the flame and the flow-generated turbulence. A wide range of structural load patterns occur, depending on the location of the ignition source. Some of these load patterns are consistent with damage believed to be associated with the initial explosion event in TWA 800. Sensitivity of the loading to the ignition location indicates that narrowing down the ignition location in TWA 800 may be possible. However, the complexity of the combustion and structural failure processes in the actual center wing tank mandates extremely careful consideration of the uncertainties that enter into this process
On the Evaluation of the Hyperthermic Efficiency of Magnetic Scaffolds
Goal: Deep-seated tumors (DST) can be treated using thermoseeds exposed to a radiofrequency magnetic field for performing local interstitial hyperthermia treatment (HT). Several research efforts were oriented to the manufacturing of novel biocompatible magnetic nanostructured thermo-seeds, called magnetic scaffolds (MagS). Several iron-doped bioceramics or magnetic polymers in various formulations are available. However, the crucial evaluation of their heating potential has been carried out with significantly different, lab specific, variable experimental conditions and protocols often ignoring the several error sources and inaccuracies estimation. Methods: This work comments and provides a perspective analysis of an experimental protocol for the estimation methodology of the specific absorption rate (SAR) of MagS for DST HT. Numerical multiphysics simultions have been performed to outline the theoretical framework. After the in silico analysis, an experimental case is considered and tested. Results: From the simulations, we found that large overestimation in the SAR values can be found, due to the axial misplacement in the radiofrequency coil, while the radial misplacement has a lower impact on the estimated SAR value. Conclusions: The averaging of multiple temperature records is needed to reliably and effectively estimate the SAR of MagS for DST HT
Current status and updated recommendations for diagnosis and treatment of plasma cell myeloma in Switzerland
The availability of drugs such as thalidomide, bortezomib and lenalidomide changed the landscape in myeloma treatment and has extended the median survival up to 10 years with a substantial improvement in quality of life. This development prompted a Swiss expert panel to re-evaluate the current status and formulate updated clinical recommendations for the diagnosis and treatment of plasma cell myeloma. These recommendations should help clinicians in their decision making to achieve the best outcome based on currently available data
Hodgkin's lymphoma in remission after first-line therapy: which patients need FDG-PET/CT for follow-up?
Background: The purpose of the study was to evaluate the impact of 2-[fluorine-18]fluoro-2-deoxy-D-glucose-positron emission tomography (FDG-PET)/computed tomography (CT) during follow-up of patients with Hodgkin's lymphoma. Patients and methods: Patients in complete remission or an unconfirmed complete remission after first-line therapy who received FDG-PET/CT during their follow-up were analyzed retrospectively. Confirmatory biopsy was mandatory in case of recurrence. Results: Overall, 134 patients were analyzed. Forty-two (31.3%) patients had a recurrence. The positive predictive value of FDG-PET/CT was 0.98. Single-factor analysis identified morphological residual mass [P = 0.0005, hazard ratio (HR) 3.4, 95% confidence interval (CI) 1.7-6.6] and symptoms (P 24 months). Conclusions: Asymptomatic patients without morphological residues and an early stage of disease do not need a routine FDG-PET/CT for follow-up. Asymptomatic patients with morphological residues should receive routine follow-up FDG-PET/CT for the first 24 months. Only patients with advanced initial stage do need a routine follow-up FDG-PET/CT beyond 24 month
Risk-adapted FDG-PET/CT-based follow-up in patients with diffuse large B-cell lymphoma after first-line therapy
Background: The purpose of this study was to evaluate the impact of 2-[fluorine-18]fluoro-2-deoxy-D-glucose-positron emission tomography/computed tomography (FDG-PET/CT) during follow-up of patients with diffuse large B-cell lymphoma (DLBCL) being in complete remission or unconfirmed complete remission after first-line therapy. Patients and methods: DLBCL patients receiving FDG-PET/CT during follow-up were analyzed retrospectively. Confirmatory biopsy was mandatory in cases of suspected disease recurrence. Results: Seventy-five patients were analyzed and 23 (30%) had disease recurrence. The positive predictive value (PPV) of FDG-PET/CT was 0.85. Patients >60 years [P = 0.036, hazard ratio (HR) = 3.82, 95% confidence interval (CI) 1.02-7.77] and patients with symptoms indicative of a relapse (P = 0.015; HR = 4.1; 95% CI 1.20-14.03) had a significantly higher risk for relapse. A risk score on the basis of signs of relapse, age >60 years, or a combination of these factors identified patients at high risk for recurrence (P = 0.041). Conclusions: FDG-PET/CT detects recurrent DLBCL after first-line therapy with high PPV. However, it should not be used routinely and if only in selected high-risk patients to reduce radiation burden and costs. On the basis of our retrospective data, FDG-PET/CT during follow-up is indicated for patients 60 years with and without clinical signs of relaps
RESPOND – A patient-centred program to prevent secondary falls in older people presenting to the emergency department with a fall: Protocol for a multi-centre randomised controlled trial
Introduction: Participation in falls prevention activities by older people following presentation to the Emergency Department (ED) with a fall is suboptimal. This randomised controlled trial (RCT) will test the RESPOND program which is designed to improve older persons’ participation in falls prevention activities through delivery of patient-centred education and behaviour change strategies. Design and setting: An RCT at two tertiary referral EDs in Melbourne and Perth, Australia. Participants: Five-hundred and twenty eight community-dwelling people aged 60-90 years presenting to the ED with a fall and discharged home will be recruited. People who: require an interpreter or hands-on assistance to walk; live in residential aged care or >50 kilometres from the trial hospital; have terminal illness, cognitive impairment, documented aggressive behaviour or history of psychosis; are receiving palliative care; or are unable to use a telephone will be excluded. Methods: Participants will be randomly allocated to the RESPOND intervention or standard care control group. RESPOND incorporates: (1) home-based risk factor assessment; (2) education, coaching, goal setting, and follow-up telephone support for management of one or more of four risk factors with evidence of effective intervention; and (3) healthcare provider communication and community linkage delivered over six months. Primary outcomes are falls and fall injuries per-person-year. Discussion: RESPOND builds on prior falls prevention learnings and aims to help individuals make guided decisions about how they will manage their falls risk. Patient-centred models have been successfully trialled in chronic and cardiovascular disease however evidence to support this approach in falls prevention is limited. Trial registration. The protocol for this study is registered with the Australian New Zealand Clinical Trials Registry (ACTRN12614000336684)
Path Integral Monte Carlo Approach to the U(1) Lattice Gauge Theory in (2+1) Dimensions
Path Integral Monte Carlo simulations have been performed for U(1) lattice
gauge theory in (2+1) dimensions on anisotropic lattices. We extractthe static
quark potential, the string tension and the low-lying "glueball" spectrum.The
Euclidean string tension and mass gap decrease exponentially at weakcoupling in
excellent agreement with the predictions of Polyakov and G{\" o}pfert and Mack,
but their magnitudes are five times bigger than predicted. Extrapolations are
made to the extreme anisotropic or Hamiltonian limit, and comparisons are made
with previous estimates obtained in the Hamiltonian formulation.Comment: 12 pages, 16 figure
Vibrational Properties of Nanoscale Materials: From Nanoparticles to Nanocrystalline Materials
The vibrational density of states (VDOS) of nanoclusters and nanocrystalline
materials are derived from molecular-dynamics simulations using empirical
tight-binding potentials. The results show that the VDOS inside nanoclusters
can be understood as that of the corresponding bulk system compressed by the
capillary pressure. At the surface of the nanoparticles the VDOS exhibits a
strong enhancement at low energies and shows structures similar to that found
near flat crystalline surfaces. For the nanocrystalline materials an increased
VDOS is found at high and low phonon energies, in agreement with experimental
findings. The individual VDOS contributions from the grain centers, grain
boundaries, and internal surfaces show that, in the nanocrystalline materials,
the VDOS enhancements are mainly caused by the grain-boundary contributions and
that surface atoms play only a minor role. Although capillary pressures are
also present inside the grains of nanocrystalline materials, their effect on
the VDOS is different than in the cluster case which is probably due to the
inter-grain coupling of the modes via the grain-boundaries.Comment: 10 pages, 7 figures, accepted for publication in Phys. Rev.
Potential of the Julia programming language for high energy physics computing
Research in high energy physics (HEP) requires huge amounts of computing and
storage, putting strong constraints on the code speed and resource usage. To
meet these requirements, a compiled high-performance language is typically
used; while for physicists, who focus on the application when developing the
code, better research productivity pleads for a high-level programming
language. A popular approach consists of combining Python, used for the
high-level interface, and C++, used for the computing intensive part of the
code. A more convenient and efficient approach would be to use a language that
provides both high-level programming and high-performance. The Julia
programming language, developed at MIT especially to allow the use of a single
language in research activities, has followed this path. In this paper the
applicability of using the Julia language for HEP research is explored,
covering the different aspects that are important for HEP code development:
runtime performance, handling of large projects, interface with legacy code,
distributed computing, training, and ease of programming. The study shows that
the HEP community would benefit from a large scale adoption of this programming
language. The HEP-specific foundation libraries that would need to be
consolidated are identifiedComment: 32 pages, 5 figures, 4 table
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