1,382 research outputs found
Yellow laser performance of Dy in co-doped Dy,Tb:LiLuF
We present laser results obtained from a Dy-Tb co-doped
LiLuF crystal, pumped by a blue emitting InGaN laser diode, aiming for
the generation of a compact 578 nm source. We exploit the yellow Dy
transition F H to generate
yellow laser emission. The lifetime of the lower laser level is quenched via
energy transfer to co-doped Tb ions in the fluoride crystal. We report
the growth technique, spectroscopic study and room temperature continuous wave
(cw) laser results in a hemispherical cavity at 574 nm and with a highly
reflective output coupler at 578 nm. A yellow laser at 578 nm is very relevant
for metrological applications, in particular for pumping of the forbidden
SP Ytterbium clock transition, which is
recommended as a secondary representation of the second in the international
system (SI) of units. This paper was published in Optics Letters and is made
available as an electronic reprint with the permission of OSA. The paper can be
found at the following URL on the OSA website:
http://dx.doi.org/10.1364/OL.39.006628. Systematic or multiple reproduction or
distribution to multiple locations via electronic or other means is prohibited
and is subject to penalties under law.Comment: 8 pages, 5 figure
Edwards INSPIRIS RESILIA Valve for Aortic Valve Replacement Achieves Acute Reverse Remodelling of the Left Ventricle and Maintains Excellent Hemodynamic Profile after 1 Year in Young Adults
Objective: Mechanical aortic valve replacement (AVR) is still the recommended valve substitute in young adults, although cultural reasons have popularized bioprostheses also in these patients. Inde..
Cardioplegia between evolution and revolution: from depolarized to polarized cardiac arrest in adult cardiac surgery
Despite current advances in perioperative care, intraoperative myocardial protection during cardiac surgery has not kept the same pace. High potassium cardioplegic solutions were introduced in the 1950s, and in the early 1960s they were soon recognized as harmful. Since that time, surgeons have minimized many of the adverse effects by lowering the temperature of the heart, lowering K+ concentration, reducing contact K+ time, changing the vehicle from a crystalloid solution to whole-blood, adding many pharmacological protectants and modifying reperfusion conditions. Despite these attempts, high potassium remains a suboptimalway to arrest the heart. We briefly review the historical advances and failures of finding alternatives to high potassium, the drawbacks of a prolonged depolarized membrane, altered Ca2+ intracellular circuits and heterogeneity in atrial-ventricular K+ repolarization during reanimation. Many of these untoward effects may be alleviated by a polarized membrane, and we will discuss the basic science and clinical experience from a number of institutions trialling different alternatives, and our institution with a non-depolarizing adenosine, lidocaine and magnesium (ALM) cardioplegia. The future of polarized arrest is an exciting one and may play an important role in treating the next generation of patients who are older, and sicker with multiple comorbidities and require more complex operations with prolonged cross-clamping times
An investigation into modelling approaches for industrial symbiosis: a literature review
The aim of this paper is to understand how to model industrial symbiosis networks in order to favour its implementation and provide a framework to guide companies and policy makers towards it. Industrial symbiosis is a clear example of complex adaptive systems and traditional approaches (i.e., Input/Output analysis, Material flow analysis) are not capable to capture these dynamics behaviours. Therefore, the aim of this literature review is to investigate: i) the most used modelling and simulation approaches to analyse industrial symbiosis and ii) their characteristics in terms of simulation methods, interaction mechanisms and simulations software. Findings from our research suggest that a hybrid modelling and simulation approach, based on agent-based and system dynamics, could be an appropriate method for industrial symbiosis analysis and design
Prevalence and development of chronic critical illness in acute patients admitted to a respiratory intensive care setting
Introduction- Chronic Critical Illness (chronic CI) is a condition associated to patients surviving an episode of acute respiratory failure (ARF). The prevalence and the factors associated with the development of chronic CI in the population admitted to a Respiratory Intensive Care Unit (RICU) have not been yet elucidated. Methods- An observational prospective cohort study was undertaken at the RICU of the University Hospital of Modena (Italy). Patients mechanically ventilated with ARF in RICU were enrolled. Demographics, severity scores (APACHEII, SOFA, SAPSII), and clinical condition (septic shock, pneumonia, ARDS) were recorded on admission. Respiratory mechanics and inflammatory-metabolic blood parameters were measured both on admission and over the first week of stay. All variables were tested as predictors of chronic CI through univariate and multivariate analysis. Results- chronic CI occurred in 33 out of 100 patients observed. Higher APACHEII, the presence of septic shock, diaphragmatic dysfunction (DD) at sonography, multidrug-resistant (MDR) bacterial infection, the occurrence of a second infection during stay, and a C-reactive protein (CRP) serum level inceasing 7 days over admission were associated with chronic CI. Septic shock was the strongest predictor of chronic CI (AUC=0.92 p<0.0001). Conclusions- Chronic CI is frequent in patients admitted to RICU and mechanically ventilated due to ARF. Infection-related factors seem to play a major role as predictors of this syndrome
Creating a WhatsApp Dataset to Study Pre-teen Cyberbullying
Although WhatsApp is used by teenagers as one major channel of cyberbullying, such interactions remain invisible due to the app privacy policies that do not allow ex-post data collection. Indeed, most of the information on these phenomena rely on surveys regarding self-reported data. In order to overcome this limitation, we describe in this paper the activities that led to the creation of a WhatsApp dataset to study
cyberbullying among Italian students aged 12-13. We present not only the collected chats with annotations about user role and type of offense, but also the living lab created in a collaboration between researchers and schools to monitor and analyse cyberbullying. Finally, we discuss some open issues, dealing with ethical, operational and epistemic aspects
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