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Critical Care (London, England) Oct 2023Although the defining elements of "acute respiratory distress syndrome" (ARDS) have been known for over a century, the syndrome was first described in 1967. Since then,... (Review)
Review
Although the defining elements of "acute respiratory distress syndrome" (ARDS) have been known for over a century, the syndrome was first described in 1967. Since then, despite several revisions of its conceptual definition, it remains a matter of debate whether ARDS is a discrete nosological entity. After almost 60 years, it is appropriate to examine how critical care has modeled this fascinating syndrome and affected patient's outcome. Given that the diagnostic criteria of ARDS (e.g., increased pulmonary vascular permeability and diffuse alveolar damage) are difficult to ascertain in clinical practice, we believe that a step forward would be to standardize the assessment of pulmonary and extrapulmonary involvement in ARDS to ensure that each patient can receive the most appropriate and effective treatment. The selection of treatments based on arbitrary ranges of PaO/FiO lacks sufficient sensitivity to individualize patient care.
Topics: Humans; Respiratory Distress Syndrome; Lung; Treatment Outcome; Critical Care
PubMed: 37907946
DOI: 10.1186/s13054-023-04699-w -
Journal of Clinical Medicine Oct 2023Insulin resistance (IR) is a rather common condition that is often diagnosed on the basis of an arbitrary "increased insulin value" or the presence of symptoms...
Insulin resistance (IR) is a rather common condition that is often diagnosed on the basis of an arbitrary "increased insulin value" or the presence of symptoms indicative of the Metabolic Syndrome [...].
PubMed: 37835038
DOI: 10.3390/jcm12196394 -
Trials Oct 2023In this commentary, we discuss a recent article in Trials that raised concerns about the number of poorly performed randomised trials in the medical literature and...
In this commentary, we discuss a recent article in Trials that raised concerns about the number of poorly performed randomised trials in the medical literature and discuss the trials literature more widely. Although we all aim for higher methodological standards in trials, we argue that (i) the idea that 'most randomised trials are bad', which the recent article concludes is an overly simplistic representation of the situation, and (ii) the suggestion that an increased focus on methodological review during trial development (e.g. ethical boards performing some assessment of the methodologists on a trial), while well meaning, may have negative unintended consequences. We therefore propose that (a) trials should be assessed on their merits and weaknesses, including an assessment of risk of bias but placing that in a wider context; (b) we should recognise that although the methodological conduct of trials is of utmost importance, interventions that aim to improve this could have unintended consequences-such as bureaucracy-that have an overall negative effect; and (c) we should therefore generate an evidence base for policy interventions to improve conduct of trials rather than applying arbitrary rules.
Topics: Humans; Bias; Randomized Controlled Trials as Topic; Research Design
PubMed: 37864198
DOI: 10.1186/s13063-023-07706-1 -
Optics Express Sep 2023A group-delay-unit-based integrated silicon photonic integrated circuit (PIC) is employed as a reconfigurable analog radio frequency decoder, which provides a real-time...
A group-delay-unit-based integrated silicon photonic integrated circuit (PIC) is employed as a reconfigurable analog radio frequency decoder, which provides a real-time temporal and spectral analysis of any arbitrary multi-tone signal in the micro- and mm-wave range. The circuit is based on cascaded Mach-Zehnder interferometer embedded silicon microring resonators as variable delay units. The temporal decoding of the multi-tone input signal is demonstrated by tuning the signal with respect to the ring resonator delay and resonance. A one-to-one conformal time-to-frequency mapping provides real-time spectral decoding of the signal under test without additional digital signal processing. The idea is validated by several experimental results with single-tone and two-tone input signals in a compact, low-power, silicon PIC. The proposed real-time temporal analog frequency decoder may be very intriguing for high-speed, low-latency wireless applications, such as autonomous driving and 6G.
PubMed: 37710564
DOI: 10.1364/OE.494674 -
Nature Communications Oct 2023Dispersion decomposes compound light into its monochromatic components, which is detrimental to broadband imaging but advantageous for spectroscopic applications....
Dispersion decomposes compound light into its monochromatic components, which is detrimental to broadband imaging but advantageous for spectroscopic applications. Metasurfaces provide a unique path to modulate the dispersion by adjusting structural parameters on a two-dimensional plane. However, conventional linear phase compensation does not adequately match the meta-unit's dispersion characteristics with required complex dispersion, hindering at-will dispersion engineering over a very wide bandwidth particularly. Here, we propose an asymptotic phase compensation strategy for ultra-broadband dispersion-controlled metalenses. Metasurfaces with extraordinarily high aspect ratio nanostructures have been fabricated for arbitrary dispersion control in ultra-broad bandwidth, and we experimentally demonstrate the single-layer achromatic metalenses in the visible to infrared spectrum (400 nm~1000 nm, NA = 0.164). Our proposed scheme provides a comprehensive theoretical framework for single-layer meta-optics, allowing for arbitrary dispersion manipulation without bandwidth restrictions. This development is expected to have significant applications in ultra-broadband imaging and chromatography detection, among others.
PubMed: 37863896
DOI: 10.1038/s41467-023-42268-5 -
Discrete & Computational Geometry 2024Let be a set of in the plane, so that every site has an . Let be the defined by , i.e., the graph with vertex set and an edge between two distinct sites if and...
Let be a set of in the plane, so that every site has an . Let be the defined by , i.e., the graph with vertex set and an edge between two distinct sites if and only if the disks with centers , and radii , intersect. Our goal is to design data structures that maintain the connectivity structure of as sites are inserted and/or deleted in . First, we consider , i.e., we fix , for all sites . For this case, we describe a data structure that has amortized update time and query time. Second, we look at disk graphs , i.e., for all , we have , for a parameter that is known in advance. Here, we not only investigate the fully dynamic case, but also the incremental and the decremental scenario, where only insertions or only deletions of sites are allowed. In the fully dynamic case, we achieve amortized expected update time and query time . This improves the currently best update time by a factor of . In the incremental case, we achieve logarithmic dependency on , with a data structure that has amortized query time and amortized expected update time, where denotes the inverse Ackermann function. For the decremental setting, we first develop an efficient decremental data structure: given two sets and of disks in the plane, we can delete disks from , and upon each deletion, we receive a list of all disks in that no longer intersect the union of . Using this data structure, we get decremental data structures with a query time of that supports deletions in overall expected time for disk graphs with bounded radius ratio and overall expected time for disk graphs with arbitrary radii, assuming that the deletion sequence is oblivious of the internal random choices of the data structures.
PubMed: 38192901
DOI: 10.1007/s00454-023-00621-x -
Biology of Sport Jul 2023The aims of this scoping review were (i) to characterize the main methodological approaches to assessing individualized running speed thresholds in team sports players;... (Review)
Review
The aims of this scoping review were (i) to characterize the main methodological approaches to assessing individualized running speed thresholds in team sports players; (ii) to assess the use of traditional arbitrary (absolute) thresholds compared to individualized running speed thresholds in team sports players; (iii) to provide an evidence gap map (EGM) about the approaches and study designs employed in investigations in team sports and (iv) to provide directions for future research and practical applications for the strength and conditioning field. Methods studies were searched for in the following databases: (i) PubMed; (ii) Scopus; (iii) SPORTDiscus and (iv) Web of Science. The search was conducted on 15/07/2022. Risk of bias was assessed using the Risk of Bias Assessment Tool for Nonrandomized Studies (RoBANS). From 3,195 potentially relevant articles, 36 were eligible for inclusion in this review. Of the 36 included articles, 27 (75%) focused on the use of arbitrary and individualized running speed thresholds to describe the locomotor demands (e.g., high intensity running) of players. Thirty-four articles used individualized speed running thresholds based on physical fitness assessments (e.g., 40-m linear sprint) or physical performance (e.g., maximal acceleration). This scoping review supported the need for a greater focus to be placed on improving the methodological aspects of using individualized speed running thresholds in team sports. More than just creating alternatives to arbitrary thresholds, it is essential to increase the replicability of methodological conditions whilst ensuring that research comparing the most adequate measures and approaches to individualization takes into consideration the population and context of each study.
PubMed: 37398971
DOI: 10.5114/biolsport.2023.122480 -
Sensors (Basel, Switzerland) Nov 2023Most of the existing metasurfaces are effective for the incident wave with the specific circularly polarized (CP) or linearly polarized (LP) state, that is the...
Most of the existing metasurfaces are effective for the incident wave with the specific circularly polarized (CP) or linearly polarized (LP) state, that is the polarization-sensitive metasurface. This drawback dramatically hinders the practical use of the metasurface. Herein, this paper presents a strategy of polarization-insensitive transmissive microwave metasurfaces to manipulate the incident wave with arbitrary CP and LP states. The metasurface consists of polarization-insensitive unit cells. For the left circularly polarized (LCP) and right circularly polarized (RCP) incident waves, the same abrupt phase covering 0° to 360° can be realized by combining the Pancharatnam-Berry (PB) and resonant phases. As the arbitrary LP wave can decompose into the LCP and RCP waves, metasurfaces consisting of designed unit cells are valid for any polarization states. The polarization-insensitive transmissive microwave metalens and orbital angular momentum multiplexing metasurface working at 23 GHz are devised for verification. Simulation and measurement results verify the availability of the approach. The proposed method is suitable for designing microwave-transmissive metasurfaces capable of polarization insensitivity.
PubMed: 38067786
DOI: 10.3390/s23239413 -
Scientific Reports Nov 2023Our goal was to investigate the effects of head-thorax elevation (HUP) during chest compressions (CC) on lung ventilation. A prospective study was performed on seven...
Our goal was to investigate the effects of head-thorax elevation (HUP) during chest compressions (CC) on lung ventilation. A prospective study was performed on seven human cadavers. Chest was automatically compressed-decompressed in flat position and during progressive HUP from 18 to 35°. Lung ventilation was measured with electrical impedance tomography. In each cadaver, 5 sequences were randomly performed: one without CC at positive end-expiratory pressure (PEEP) 0cmHO, 3 s with CC at PEEP0, 5 or 10cmHO and 1 with CC and an impedance threshold device at PEEP0cmHO. The minimal-to-maximal change in impedance (VT in arbitrary unit a.u.) and the minimal impedance in every breathing cycle (EELI) the) were compared between flat, 18°, and 35° in each sequence by a mixed-effects model. Values are expressed as median (1st-3rd quartiles). With CC, between flat, 18° and 35° VT decreased at each level of PEEP. It was 12416a.u. (10,689; 14,442), 11,239 (7667; 13,292), and 6457 (4631; 9516), respectively, at PEEP0. The same was true with the impedance threshold device. EELI/VT significantly decreased from - 0.30 (- 0.40; - 0.15) before to - 1.13 (- 1.70; - 0.61) after the CC (P = 0.009). With HUP lung ventilation decreased with CC as compared to flat position. CC are associated with decreased in EELI.
Topics: Humans; Prospective Studies; Respiration, Artificial; Positive-Pressure Respiration; Thorax; Electric Impedance; Cadaver; Lung
PubMed: 37989865
DOI: 10.1038/s41598-023-47727-z