42 research outputs found

    Prevalence, associated factors and outcomes of pressure injuries in adult intensive care unit patients: the DecubICUs study

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    Funder: European Society of Intensive Care Medicine; doi: http://dx.doi.org/10.13039/501100013347Funder: Flemish Society for Critical Care NursesAbstract: Purpose: Intensive care unit (ICU) patients are particularly susceptible to developing pressure injuries. Epidemiologic data is however unavailable. We aimed to provide an international picture of the extent of pressure injuries and factors associated with ICU-acquired pressure injuries in adult ICU patients. Methods: International 1-day point-prevalence study; follow-up for outcome assessment until hospital discharge (maximum 12 weeks). Factors associated with ICU-acquired pressure injury and hospital mortality were assessed by generalised linear mixed-effects regression analysis. Results: Data from 13,254 patients in 1117 ICUs (90 countries) revealed 6747 pressure injuries; 3997 (59.2%) were ICU-acquired. Overall prevalence was 26.6% (95% confidence interval [CI] 25.9–27.3). ICU-acquired prevalence was 16.2% (95% CI 15.6–16.8). Sacrum (37%) and heels (19.5%) were most affected. Factors independently associated with ICU-acquired pressure injuries were older age, male sex, being underweight, emergency surgery, higher Simplified Acute Physiology Score II, Braden score 3 days, comorbidities (chronic obstructive pulmonary disease, immunodeficiency), organ support (renal replacement, mechanical ventilation on ICU admission), and being in a low or lower-middle income-economy. Gradually increasing associations with mortality were identified for increasing severity of pressure injury: stage I (odds ratio [OR] 1.5; 95% CI 1.2–1.8), stage II (OR 1.6; 95% CI 1.4–1.9), and stage III or worse (OR 2.8; 95% CI 2.3–3.3). Conclusion: Pressure injuries are common in adult ICU patients. ICU-acquired pressure injuries are associated with mainly intrinsic factors and mortality. Optimal care standards, increased awareness, appropriate resource allocation, and further research into optimal prevention are pivotal to tackle this important patient safety threat

    Through-hole energy-density threshold of silicon induced by combined millisecond and nanosecond pulsed laser

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    We report herein the experimental investigation of the through-hole energy-density threshold of silicon irradiated by a double-pulse laser. The double pulse consists of a 1 ms pulse and a time-delayed 5 ns pulse and is referred to as a combined-pulse laser (CPL). A modified level-set method is used to calculate the process of millisecond laser drilling, and we study how the time delay affects the CPL. The results show that the through-hole energy-density threshold decreases with increasing delay time between the CPL pulses. In addition, the energy density of the nanosecond pulse strongly affects the through-hole energy-density threshold. We also consider the thickness and the doping concentration of the silicon wafers. Compared with the results for single-ms-pulse irradiation, the CPL produces a better through-hole energy-density threshold because the surface ablation caused by the nanosecond pulse increases the energy absorbed by the silicon wafer from the millisecond pulse

    Tunable Plasmonic Band-Pass Filter with Dual Side-Coupled Circular Ring Resonators

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    A wavelength band-pass filter with asymmetric dual circular ring resonators in a metal-insulator-metal (MIM) structure is proposed and numerically simulated. For the interaction of the local discrete state and the continuous spectrum caused by the side-coupled resonators and the baffle, respectively, the transmission spectrum exhibits a sharp and asymmetric profile. By adjusting the radius and material imbedded in one ring cavity, the off-to-on plasmon-induced absorption (PIA) optical response can be tunable achieved. In addition, the structure can be easily extended to other similar compact structures to realize the filtering task. Our structures have important potential applications for filters and sensors at visible and near-infrared regions

    Reaction mechanism and microstructure development of ZrSi2 melt-infiltrated Cf/SiC-ZrC-ZrB2 composites: The influence of preform pore structures

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    Reactive melt infiltration (RMI) is an effective method for fabrication of highly dense carbon fiber reinforced ultra-high temperature ceramic matrix composites (Cf/UHTCs). In this work, Cf/SiC-ZrC-ZrB2 composites were fabricated by infiltrating ZrSi2 melt into porous Cf/B4C-C preforms, where the physical and chemical reactions involved during the RMI process were identified and analyzed. Inhomogeneous infiltration between the inter- and intra-bundle pores was revealed, and was found to be strongly related to the pore structures of the Cf/B4C-C preform. It is indicated that the inhomogeneous infiltration can be mitigated remarkably with increasing porosity and pore size of the preform. The effect of pore size on the RMI process was also investigated by a quantitative model, which agrees very well with the experiment results. It further indicates that the inhomogeneous infiltration can also be relieved at elevated RMI temperature. However, excessive infiltration at elevated temperature or more porous preform may cause serious erosion on interphase and fibers, leading to mechanical properties deterioration of the final composites. Keywords: Reactive melt infiltration (RMI), Inhomogeneous infiltration, Pore structures, Mechanical propertie

    Investigation on the Continuous Wave Mode and the ms Pulse Mode Fiber Laser Drilling Mechanisms of the Carbon Fiber Reinforced Composite

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    The near infrared (NIR) laser drilling of a carbon fiber reinforced polymer (CFRP) composite in the continuous wave (CW) mode and the ms pulse mode was investigated by an experiment and a numerical simulation. The relationships between the laser penetrating time, entrance hole diameter, surface heat affected zone (HAZ) width, and material ablation rate and the laser irradiation time and laser peak power densities were obtained from the experiment. For the same average power density of the laser output, 3.5 kW/cm2, it was found that the ms pulse laser mode, which had a higher peak power density, had a higher drilling efficiency. When drilling the same holes, the pulse laser mode, which had the highest peak power density of 49.8 kW/cm2, had the lowest drilling time of 0.23 s and had the smallest surface HAZ width of 0.54 mm. In addition, it was found that the laser penetrating time decreased sharply when the peak power density was higher than 23.4 kW/cm2. After analyzing the internal gas pressure by the numerical simulation, it was considered that a large internal gas pressure appeared, which resulted from polymer pyrolysis, causing a large amount of the mechanical erosion of the composite material to improve the drilling efficiency. Therefore, the ms pulse laser showed its potential and advantage in laser drilling the CFRP composite
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