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Background: The purpose of this study was to evaluate the performance of an insulin infusion protocol targeting a blood glucose (BG) level of 140-180 mg/dL and to characterize protocol adherence.Materials and Methods: This was a retrospective observational cohort study including patients for whom the protocol was ordered from January 2012 to May 2013. Performance metrics were assessed in all patients and in patients with an initial BG level of ≥200 mg/dL. Protocol adherence was assessed in a random subset of 50 patients without hypoglycemia and in all hypoglycemic patients.Results: In patients with an initial BG level of ≥200 mg/dL, the mean time to goal was 7.1 h. The rate of decline of BG level in the first 6 h was 16.4 mg/dL/h. Mean BG level was 167 mg/dL, with 43.9% of BG values within goal and 80.3% between 80 and 199 mg/dL. The rate of hypoglycemic events was 0.14 per 100 h. The mean protocol violation rate was higher in patients with hypoglycemia compared with those without (39.8 vs. 23.5 per 100 h, P = 0.002), and 60.7% of hypoglycemic events were attributable to protocol violations. The protocol violation rate (42.8 vs. 17.6 per 100 h; P < 0.001) and the odds of hypoglycemia (odds ratio = 5.2; 95% confidence interval, 1.6, 16.5) were higher in the cardiac surgery patients compared with other patients.Conclusions: This protocol provides adequate BG control within the clinically acceptable range of 80-199 mg/dL but not within the narrower range of 140-180 mg/dL, with a low incidence of hypoglycemia. Risk factors for hypoglycemia and barriers to protocol adherence in the cardiac surgery population should be elucidated. [ABSTRACT FROM AUTHOR]

This paper addresses the design of beam position monitor (BPM) devices suitable for fourth-generation diffraction-limited X-ray storage rings. Detailed investigations of the electromagnetic (EM) phenomena occurring inside the component under various working conditions are carried out by considering different BPM EM models defined by their geometry and materials. Moving from a theoretical characterization of the common round geometry, rhomboidal structures are studied through a careful numerical analysis relying on advanced computer-aided tools. Several critical elements, such as wakefields, pick-up signal extraction, and trapped and propagating modes, are explored from the simulation point of view and from the experimental one, by deploying a manufactured microwave test bench, which is employed to measure the radio frequency behavior of a BPM prototype built at Elettra Sincrotrone Trieste. The aim of the proposed study is to identify a satisfactory tradeoff between achievable performance and practical realizability for BPM devices operating in last-generation light sources. [ABSTRACT FROM AUTHOR]

In many resonant structures the damping of parasitic or higher order modes is indispensable to guarantee a correct and stable performance. This is particularly true in the microwave region in case of cavities or other resonant systems operating in accelerating structures, where the mitigation of spurious resonance effects is mandatory to achieve high quality particle beams. We present the results on the mode suppression in a real pillbox cavity by inserting a properly designed pyramidal metamaterial that acts as light, small volume damper for specific resonances in the range 3–4 GHz, only slightly perturbing other intrinsic modes. Measurements of the cavity response without and with the metamaterial absorber are presented and compared with full wave simulations. Field distribution for the pillbox intrinsic modes under scrutiny is also presented, showing that damping induced by the metamaterial critically depends on its relative position inside the cavity. [ABSTRACT FROM AUTHOR]

In this work, we propose to design a liquid crystal–based modular and extendable platform of cutting-edge optical technologies for studying materials based on the analysis of polarization and wavefront of light in the wavelength range of 10–50 μm, which is considered to work even in the longer wavelengths range. This platform will be driven by the future THz-FEL source TerRa@BriXSinO that produces high power radiation in THz-range from 6 THz up to 30 THz (Mid-/Far-IR). The lack of optical infrastructures in this range has been tackled by fabricating liquid crystal–based geometric phase components that have been specifically designed for this purpose. This is in order to optimally exploit all the source's potential for maximum accuracy and efficiency in determining polarization- and wavefront-sensitive properties of materials. We present an overview of a few experiments for characterizing bulk inhomogeneities, dielectric anisotropy, surface roughness, cracks, impact damages, and stress and strain effects with special emphasis on non-destructive tests on composite structures. The tools for wavefront shaping developed within our platform will be exploited to add a further degree of freedom, i.e., orbital angular momentum, to nonlinear optics techniques, such as Terahertz Hyper-Raman spectroscopy, for investigating chiral agents' properties. [ABSTRACT FROM AUTHOR]

Resistive-wall impedance constitutes a significant percentage of the total beam-coupling impedance budget of an accelerator. A number of different reduction techniques have been proposed during the years depending on the specific applications, ranging from higher order modes damping to solutions entailing high electrical-conductivity coatings of the pipe. This article investigates the use of metamaterial-based absorbers for sensibly reducing or nearly canceling the beam-coupling impedance. We design and fabricate subwavelength 2-D metallic resonant structures based on the split-ring resonator (SRR) geometry that can be employed as mode dampers in accelerating structures. A number of prototypes have been fabricated and measured in a “test model” pillbox cavity. Experimental results, combined with full-wave electromagnetic simulations, prove the efficiency of the SRR-based metamaterials. This article opens up to the possibility of considering metamaterials as a valid alternative to other devices for impedance mitigation in experimental setups commonly operating along a particle beamline, such as accelerating cavities or collimators, and more in general for the development of filters with a large out-of-band signal rejection in specific applications. [ABSTRACT FROM AUTHOR]

[Display omitted] • Laser surface structuring of copper for secondary electron emission reduction. • Femtosecond laser processing at different ambiences for 515 and 1030 nm. • Irradiation in air with 515 nm found to be the best for proposed application. • Impact of LIPSS on the copper surface resistance does not appear to be critical for present accelerators. • Laser surface processing to enhance performances of future particle accelerators. One of the main limitations for future high-performance accelerators operating with positively charged particles is the formation of an electron-cloud inside the beam vacuum chamber, giving rise to instabilities. The Secondary Electron Yield (SEY) of the beam-facing surfaces gives a measure of the mechanism which drives this phenomenon. The laser-induced periodic structure formation on Cu surfaces has been demonstrated as a promising process to reduce SEY. In view of applications in beam chambers, we studied the laser process influence on SEY for 515 and 1030 nm wavelength femtosecond pulses on copper in different ambiences (air, nitrogen, vacuum). Depending on used process conditions, the surface composition differs, structures with varying aspect ratio are formed, i.e., periodic ripples and large-scale channels. Treatment in air at 515 nm is the most efficient for the formation of deeper structures allowing SEY maximum reduction first down to 1.6–1.7 and then below unity upon electron irradiation, thereby totally suppressing electron-cloud. Increasing the laser fluence, SEY will further reduce due to surface roughness enhancement via nanoparticle redeposition. This study reveals the fundamental role of LIPSS treatments to enable surface treatment in large-scale accelerator installations, where particle-free components are desired, and paves the way to potential future applications. [ABSTRACT FROM AUTHOR]