Peripheral arterial blood pressure monitoring adequately tracks central arterial blood pressure in critically ill patients: an observational study

INTRODUCTION: Invasive arterial blood pressure monitoring is a common practice in intensive care units (ICUs). Accuracy of invasive blood pressure monitoring is crucial in evaluating the cardiocirculatory system and adjusting drug therapy for hemodynamic support. However, the best site for catheter insertion is controversial. Lack of definitive information in critically ill patients makes it difficult to establish guidelines for daily practice in intensive care. We hypothesize that peripheral and central mean arterial blood pressures are interchangeable in critically ill patients. METHODS: This is a prospective, observational study carried out in a surgical-medical ICU in a teaching hospital. Fifty-five critically ill patients with clinical indication of invasive arterial pressure monitoring were included in the study. No interventions were made. Simultaneous measurements were registered in central (femoral) and peripheral (radial) arteries. Bias and precision between both measurements were calculated with Bland-Altman analysis for the whole group. Bias and precision were compared between patients receiving high doses of vasoactive drugs (norepinephrine or epinephrine >0.1 μg/kg/minute or dopamine >10 μg/kg/minute) and those receiving low doses (norepinephrine or epinephrine <0.1 μg/kg/minute or dopamine <10 μg/kg/minute). RESULTS: Central mean arterial pressure was 3 ± 4 mmHg higher than peripheral mean arterial pressure for the whole population and there were no differences between groups (3 ± 4 mmHg for both groups). CONCLUSION: Measurement of mean arterial blood pressure in radial or femoral arteries is clinically interchangeable. It is not mandatory to cannulate the femoral artery, even in critically ill patients receiving high doses of vasoactive drugs

Clinical review: The implications of experimental and clinical studies of recruitment maneuvers in acute lung injury

Mechanical ventilation can cause and perpetuate lung injury if alveolar overdistension, cyclic collapse, and reopening of alveolar units occur. The use of low tidal volume and limited airway pressure has improved survival in patients with acute lung injury or acute respiratory distress syndrome. The use of recruitment maneuvers has been proposed as an adjunct to mechanical ventilation to re-expand collapsed lung tissue. Many investigators have studied the benefits of recruitment maneuvers in healthy anesthetized patients and in patients ventilated with low positive end-expiratory pressure. However, it is unclear whether recruitment maneuvers are useful when patients with acute lung injury or acute respiratory distress syndrome are ventilated with high positive end-expiratory pressure, and in the presence of lung fibrosis or a stiff chest wall. Moreover, it is unclear whether the use of high airway pressures during recruitment maneuvers can cause bacterial translocation. This article reviews the intrinsic mechanisms of mechanical stress, the controversy regarding clinical use of recruitment maneuvers, and the interactions between lung infection and application of high intrathoracic pressures

CVD Graphene Contacts for Lateral Heterostructure MoS2{_2} Field Effect Transistors

Intensive research is carried out on two-dimensional materials, in particular molybdenum disulfide, towards high-performance transistors for integrated circuits. Fabricating transistors with ohmic contacts is challenging due to the high Schottky barrier that severely limits the transistors' performance. Graphene-based heterostructures can be used in addition or as a substitute for unsuitable metals. We present lateral heterostructure transistors made of scalable chemical vapor-deposited molybdenum disulfide and chemical vapor-deposited graphene with low contact resistances of about 9 k{\Omega}{\mu}m and high on/off current ratios of 10${^8}. We also present a theoretical model calibrated on our experiments showing further potential for scaling transistors and contact areas into the few nanometers range and the possibility of a strong performance enhancement by means of layer optimizations that would make transistors promising for use in future logic circuits.Comment: 23 page

Exploring Cosmic Origins with CORE: Cosmological Parameters

We forecast the main cosmological parameter constraints achievable with theCORE space mission which is dedicated to mapping the polarisation of the CosmicMicrowave Background (CMB). CORE was recently submitted in response to ESA'sfifth call for medium-sized mission proposals (M5). Here we report the resultsfrom our pre-submission study of the impact of various instrumental options, inparticular the telescope size and sensitivity level, and review the great,transformative potential of the mission as proposed. Specifically, we assessthe impact on a broad range of fundamental parameters of our Universe as afunction of the expected CMB characteristics, with other papers in the seriesfocusing on controlling astrophysical and instrumental residual systematics. Inthis paper, we assume that only a few central CORE frequency channels areusable for our purpose, all others being devoted to the cleaning ofastrophysical contaminants. On the theoretical side, we assume LCDM as ourgeneral framework and quantify the improvement provided by CORE over thecurrent constraints from the Planck 2015 release. We also study the jointsensitivity of CORE and of future Baryon Acoustic Oscillation and Large ScaleStructure experiments like DESI and Euclid. Specific constraints on the physicsof inflation are presented in another paper of the series. In addition to thesix parameters of the base LCDM, which describe the matter content of aspatially flat universe with adiabatic and scalar primordial fluctuations frominflation, we derive the precision achievable on parameters like thosedescribing curvature, neutrino physics, extra light relics, primordial heliumabundance, dark matter annihilation, recombination physics, variation offundamental constants, dark energy, modified gravity, reionization and cosmicbirefringence. (ABRIDGED

L. Evidence of spatial variation of the polarized thermal dust spectral energy distribution and implications for CMB B-mode analysis

Planck Collaboration.The characterization of the Galactic foregrounds has been shown to be the main obstacle in thechallenging quest to detect primordial B-modes in the polarized microwave sky. We make use of the Planck-HFI 2015 data release at high frequencies to place new constraints on the properties of the polarized thermal dust emission at high Galactic latitudes. Here, we specifically study the spatial variability of the dust polarized spectral energy distribution (SED), and its potential impact on the determination of the tensor-to-scalar ratio, r. We use the correlation ratio of the angular power spectra between the 217 and 353 GHz channels as a tracer of these potential variations, computed on different high Galactic latitude regions, ranging from 80% to 20% of the sky. The new insight from Planck data is a departure of the correlation ratio from unity that cannot be attributed to a spurious decorrelation due to the cosmic microwave background, instrumental noise, or instrumental systematics. The effect is marginally detected on each region, but the statistical combination of all the regions gives more than 99% confidence for this variation in polarized dust properties. In addition, we show that the decorrelation increases when there is a decrease in the mean column density of the region of the sky being considered, and we propose a simple power-law empirical model for this dependence, which matches what is seen in the Planck data. We explore the effect that this measured decorrelation has on simulations of the BICEP2-Keck Array/Planck analysis and show that the 2015 constraints from these data still allow a decorrelation between the dust at 150 and 353 GHz that is compatible with our measured value. Finally, using simplified models, we show that either spatial variation of the dust SED or of the dust polarization angle are able to produce decorrelations between 217 and 353 GHz data similar to the values we observe in the data.The Planck Collaboration acknowledges the support of: ESA; CNES, and CNRS/INSU-IN2P3-INP (France); ASI, CNR, and INAF (Italy); NASA and DoE (USA); STFC and UKSA (UK); CSIC, MINECO, J.A., and RES (Spain); Tekes, AoF, and CSC (Finland); DLR and MPG (Germany); CSA (Canada); DTU Space (Denmark); SER/SSO (Switzerland); RCN (Norway); SFI (Ireland); FCT/MCTES (Portugal); ERC and PRACE (EU). The research leading to these results has received funding from the European Research Council under the European Union’s Seventh Framework Programme (FP7/2007-2013) / ERC grant agreement No. 267934.Peer Reviewe

Photography-based taxonomy is inadequate, unnecessary, and potentially harmful for biological sciences

The question whether taxonomic descriptions naming new animal species without type specimen(s) deposited in collections should be accepted for publication by scientific journals and allowed by the Code has already been discussed in Zootaxa (Dubois & Nemésio 2007; Donegan 2008, 2009; Nemésio 2009a–b; Dubois 2009; Gentile & Snell 2009; Minelli 2009; Cianferoni & Bartolozzi 2016; Amorim et al. 2016). This question was again raised in a letter supported by 35 signatories published in the journal Nature (Pape et al. 2016) on 15 September 2016. On 25 September 2016, the following rebuttal (strictly limited to 300 words as per the editorial rules of Nature) was submitted to Nature, which on 18 October 2016 refused to publish it. As we think this problem is a very important one for zoological taxonomy, this text is published here exactly as submitted to Nature, followed by the list of the 493 taxonomists and collection-based researchers who signed it in the short time span from 20 September to 6 October 2016

Hyperoxemia and excess oxygen use in early acute respiratory distress syndrome : Insights from the LUNG SAFE study

Publisher Copyright: © 2020 The Author(s). Copyright: Copyright 2020 Elsevier B.V., All rights reserved.Background: Concerns exist regarding the prevalence and impact of unnecessary oxygen use in patients with acute respiratory distress syndrome (ARDS). We examined this issue in patients with ARDS enrolled in the Large observational study to UNderstand the Global impact of Severe Acute respiratory FailurE (LUNG SAFE) study. Methods: In this secondary analysis of the LUNG SAFE study, we wished to determine the prevalence and the outcomes associated with hyperoxemia on day 1, sustained hyperoxemia, and excessive oxygen use in patients with early ARDS. Patients who fulfilled criteria of ARDS on day 1 and day 2 of acute hypoxemic respiratory failure were categorized based on the presence of hyperoxemia (PaO2 > 100 mmHg) on day 1, sustained (i.e., present on day 1 and day 2) hyperoxemia, or excessive oxygen use (FIO2 ≥ 0.60 during hyperoxemia). Results: Of 2005 patients that met the inclusion criteria, 131 (6.5%) were hypoxemic (PaO2 < 55 mmHg), 607 (30%) had hyperoxemia on day 1, and 250 (12%) had sustained hyperoxemia. Excess FIO2 use occurred in 400 (66%) out of 607 patients with hyperoxemia. Excess FIO2 use decreased from day 1 to day 2 of ARDS, with most hyperoxemic patients on day 2 receiving relatively low FIO2. Multivariate analyses found no independent relationship between day 1 hyperoxemia, sustained hyperoxemia, or excess FIO2 use and adverse clinical outcomes. Mortality was 42% in patients with excess FIO2 use, compared to 39% in a propensity-matched sample of normoxemic (PaO2 55-100 mmHg) patients (P = 0.47). Conclusions: Hyperoxemia and excess oxygen use are both prevalent in early ARDS but are most often non-sustained. No relationship was found between hyperoxemia or excessive oxygen use and patient outcome in this cohort. Trial registration: LUNG-SAFE is registered with ClinicalTrials.gov, NCT02010073publishersversionPeer reviewe

Condicionantes del efecto de la presión positiva al final de la espiración (peep): los mecanismos de la lesión pulmonar y la adecuada determinación de las propiedades mecánicas del sistema respiratorio

Para los pacientes con fracaso ventilatorio, el uso de la ventilación mecánica es un procedimiento imprescindible para mantenerlos con vida. Sin embargo, desde que la ventilación mecánica comenzó a utilizarse la posibilidad de que la misma pudiera lesionar los pulmones ha sido motivo de preocupación. La lesión pulmonar inducida por el ventilador (VILI) es la culminación de un proceso donde interactúan procesos físicos y bioquímicos. Estos fenómenos dependen no sólo de la sobre-distensión asociada a elevadas presiones inspiratorias sino también de fenómenos de colapso y reapertura alveolar secundarios a bajas presiones al final de la espiración. En estas condiciones de ventilación, el agregado de presión positiva al fin de espiración (PEEP) puede prevenir o disminuir el desarrollo de VILI. La aparición de nuevas agresiones sobre el tejido pulmonar puede modificar el citado efecto de PEEP. Frente a la evidencia de que la ventilación mecánica puede generar, perpetuar o empeorar el daño pulmonar, se desarrollaron estrategias ventilatorias protectivas que han demostrado los beneficios de la disminución del volumen corriente, pero el nivel óptimo de PEEP no está claramente establecido. De hecho, tanto niveles menores como mayores de PEEP pueden ser deletéreos. Más aún, como las propiedades mecánicas de los pulmones de los pacientes sometidos a ventilación mecánica varían en función de la evolución del daño pulmonar, el nivel adecuado de PEEP variará a lo largo del tiempo de ventilación mecánica. La utilización de la curva presión-volumen para el ajuste de PEEP es una herramienta prometedora, pero los métodos estándares para trazarlas son dificultosos y potencialmente peligrosos para los pacientes. El desarrollo de un método eficaz, repetible y seguro permitiría valorar el mejor nivel de PEEP en un momento determinado. En la presente Tesis se exponen los resultados de dos estudios llevados a cabo para valorar los efectos protectivos de PEEP, cómo pueden estar condicionados por el tipo y cantidad de agresiones pulmonares, y cómo puede determinarse el nivel óptimo de PEEP utilizando la curva P-V. Los estudios que conforman esta tesis han sido publicados en revistas de alto “impact factor” de la especialidad de Cuidados Intensivos. Los principales hallazgos de esta Tesis son: 1) En un modelo de lesión pulmonar inducida por la ventilación, el uso de PEEP elevada protege los pulmones del daño mecánico; 2) Cuando se agrega una agresión química (modelo de doble agresión), el efecto protector de PEEP se pierde en gran parte, por lo que habría que considerar el tipo y la cantidad de agresiones responsables de la lesión pulmonar a la hora de ajustar PEEP; 3) Es posible realizar una curva P-V de forma fiable y precisa utilizando un método sencillo y reproducible, lo que permite 4) Determinar con facilidad los puntos de inflexión de la curva P-V y poder ajustar el nivel de PEEP de un paciente determinado, en un momento dado de su evolución.For patients with respiratory failure, the use of mechanical ventilation is a life-treating procedure. However, since mechanical ventilation first used, the possibility that it could injury the lungs has been a concern. Ventilator-induced lung injury (VILI) is the culmination of a process where physical and biochemical processes interact. These phenomena depend not only over-distention associated with high inspiratory pressures but also phenomena of collapse and reopening alveolar low pressure side at the end of exhalation. In these conditions of ventilation, the addition of positive end-expiratory pressure (PEEP) may prevent or slow the development of VILI. The emergence of new injuries on the lung tissue can modify the effect of PEEP. Faced with evidence that mechanical ventilation can create, perpetuate or worsen lung injury, protective ventilatory strategies were developed. Benefits of reduced tidal volume were showed, but the optimal level of PEEP is not clearly established. In fact, both minor and major levels of PEEP may be deleterious. Moreover, as the mechanical properties of the lungs of patients receiving mechanical ventilation vary depending on the development of lung injury, the appropriate level of PEEP will vary over time. The use of pressure-volume curve for adjusting the PEEP is a promising tool, but the standard methods are difficult to trace them and potentially dangerous to patients. The development of an effective, repeatable and safety method would assess the best level of PEEP at any given time. In this thesis presents the results of two studies conducted to evaluate the protective effects of PEEP, how they can be influenced by the type and amount of pulmonary aggression, and how to determine the optimal level of PEEP using the PV curve. The studies in this thesis have been published in journals with high impact factor of the specialty of intensive care. The main findings of this thesis are: 1) In a model of VILI, the use of high PEEP level protects the lungs from mechanical damage, 2) With the addition of a chemical injury (double hit model), the protective effect of PEEP was largely lost, so we should consider the type and amount of aggression responsible for lung injury to the adjustment of PEEP, 3) It is possible make a PV curve reliably and accurately using a simple and reproducible method, allowing 4) easily determine the inflexions points of the PV curve and to adjust the level of PEEP for a given patient, at one point in its evolution

A new automated method versus continuous positive airway pressure method for measuring pressure-volume curves in patients with acute lung injury

Objective: To compare pressure–volume (P–V) curves obtained with the Galileo ventilator with those obtained with the CPAP method in patients with ALI or ARDS receiving mechanical ventilation. P–V curves were fitted to a sigmoidal equation with a mean R2 of 0.994 ± 0.003. Lower (LIP) and upper inflection (UIP), and deflation maximum curvature (PMC) points calculated from the fitted variables showed a good correlation between methods with high intraclass correlation coefficients. Bias and limits of agreement for LIP, UIP and PMC obtained with the two methods in the same patient were clinically acceptable.Comparar les curves pressió-volum (PV) realitzades amb el ventilador Galileo amb aquelles realitzades amb el mètode CPAP, en malalts amb LPA/SDRA tractats amb ventilació mecànica. Les curves PV vàren ésser ajustades a una equació sigmoidal, amb una R2 de 0.994 ± 0.003. Els punts d’inflexió inferior (PII), superior (PSI) i el punt de màxima curvatura de la curva espiratòria (PMC) calculats vàren mostrar una bona correlació entres els mètodes, amb coeficients de correlació intra-classe molt alts. El biaix i els límits d’acord per PII, PSI i PMC aconseguits amb els mètodes en el mateix malalt vàren ésser clínicament acceptables

Wireless sensor network development for measuring ultraviolet radiation on human health application.

The measurement of ultraviolet radiation (UV) at different levels is of particular interest when people are exposed to the sun's apparent movement in order to reconstruct the solar incidence throughout the body. In addition, there are situations, conditions or activities where UV values are particularly high, and then it is necessary to take measurements in a systematic way. This paper reports a joint work performed by the Solar Energy Group of the Institute of Physics Rosario (CONICET – UNR) and the Intelligent Wireless Sensor Networks Group (Facultad de Ciencias Exactas, Ingeniería y Agrimensura – UNR) for the implementation of a Wireless Sensor Network to perform multiple measurements of ultraviolet index (UVI). This work included the physical c nstruction of a prototype sensor node and development of software for network configuration that also allows to collect and store the measured variables