Preparation for Endurance Competitions at Altitude: Physiological, Psychological, Dietary and Coaching Aspects. A Narrative Review

It was the Summer Olympic Games 1968 held in Mexico City (2,300 m) that required scientists and coaches to cope with the expected decline of performance in endurance athletes and to establish optimal preparation programs for competing at altitude. From that period until now many different recommendations for altitude acclimatization in advance of an altitude competition were proposed, ranging from several hours to several weeks. Those recommendations are mostly based on the separate consideration of the physiology of acclimatization, psychological issues, performance changes, logistical or individual aspects, but there is no review considering all these aspects in their entirety. Therefore, the present work primarily focusses on the period of altitude sojourn prior to the competition at altitude based on physiological and psychological aspects complemented by nutritional and sports practical considerations

Controllable Si oxidation mediated by annealing temperature and atmosphere

The morphology evolution by thermal annealing induced dewetting of gold (Au) thin films on silicon (Si) substrates with a native oxide layer and its dependences on annealing temperature and atmosphere are investigated. Both dewetting degree of thin film and Au/Si interdiffusion extent are enhanced with the annealing temperature. Au/Si interdiffusion can be observed beyond 800 °C and Au-Si droplets form in both argon and oxygen (Ar + O2) and argon and hydrogen (Ar + H2) environments. In Ar + O2 case, the passive oxidation (Si + O2 → SiO2) of diffused Si happens and thick silicon oxide (SiOx) covering layers are formed. A high temperature of 1050 °C can even activate the outward growth of free-standing SiOx nanowires from droplets. Similarly, annealing at 800 °C under Ar + H2 situation also enables the slight Si passive oxidation, resulting in the formation of stripe-like SiOx areas. However, higher temperatures of 950-1050 °C in Ar + H2 environment initiate both the SiOx decomposition and the Si active oxidation (2Si + O2 → 2SiO(g)), and the formation of solid SiOx is absent, leading to the only formation of isolated Au-Si droplets at elevated temperatures and droplets evolve to particles presenting two contrasts due to the Au/Si phase separation upon cooling

Synthesis, Molecular Structure, and Water Electrolysis Performance of TiO2-Supported Raney-IrOx Nanoparticles for the Acidic Oxygen Evolution Reaction

Developing low-cost, highly active, and stable catalysts for the acidic oxygen evolution reaction (OER) at the proton exchange membrane (PEM) water electrolyzer anodes remains a scientific priority. Reducing the iridium loading while increasing the intrinsic activity of the catalysts is essential for cost-effective hydrogen production. Here, we address a family of TiO2-supported Raney-IrOx catalysts with low iridium loading and high activity in single-cell PEM water electrolyzer anode environments. A controlled Raney-type Ni leaching process of pristine, supported IrNi alloy phases forms crystalline IrOx nanoparticles (NPs) featuring metallic Ir-rich cores surrounded by more amorphous IrOx surfaces. This structure is shown to be conducive to catalytic activity and the suppression of membrane poisoning due to Ni degradation. The trace amounts of Ni remaining after leaching in the IrOx NPs result in heterogeneous crystal structure and induce local lattice strain. Further, we synthetically strike a balance between conductivity and activity and succeed to narrow down the notorious large performance gap between liquid electrolyte rotating disk electrodes (RDEs) and single-cell membrane electrode assembly (MEA) electrolyzer measurements. OER stability numbers (S-numbers) of the identified Raney-IrOx anode catalysts surpass commercial IrO2 catalysts, confirming the stability of these catalysts. The PEM electrolyzer tests reveal that Raney-IrOx anodes achieve 3 A cm–2 at 1.8 V with a low geometric Ir loading of ca. 0.3 mgIr cm–2, meeting the technically important power specific Ir utilization target of 0.05 gIr/kW

Water vapor quantification in raw product gas by THz quantum cascade laser

Online quantification of water vapor in hot and complex gases, like raw product gas from biomass gasification, is essential for process understanding and control. The complex nature of these gases presents many challenges, e.g., band overlap or dust and tar deposits on equipment. Offline measurement by condensing water is labor-intensive and does not provide continuous real-time data. This study introduces a spectroscopic setup consisting of a quantum cascade laser emitting in the far-infrared range, a gas cell heated to around 250 °C, and a pyroelectric detector to quantify water vapor content in real-time. A 1st-order distributed feedback grating ensures single-mode operation of the laser at the desired water absorption line (2.294 THz). This setup was successfully tested for online analysis of raw product gas from steam gasification of waste wood. The average result from the new spectroscopic setup was 45.8 vol-% water vapor content, compared to the condensation measurement, which showed 46.7 vol-% water vapor content. Uncertainty was determined as −0.7 to +1.1 vol-% H2O. New data from the QCL-based measurement were available every 1 to 5 s, allowing for a better understanding of the process while operating the gasifier. The permanent gas species detected in the raw gas included CO, H2, CO2, CH4, NH3, and H2S. Additionally, 4.16 g/Nm3dry of tar was detected gravimetrically and 31.21 g/Nm3dry by gas chromatography-mass spectrometry. Measurement continued without issue in this raw, hot product gas from biomass steam gasification for two hours. This work showcases quantum cascade lasers’ strong potential for spectroscopy applications in hot and complex gases

Micro-mirror aided mid-infrared plasmonic beam combiner monolithically integrated with quantum cascade lasers and detectors

The development of novel mid-infrared (MIR) devices and systems is crucial for addressing applications in biomedical analysis, chemical reaction-monitoring, or high-bitrate free-space telecommunication. Combining multiple functional elements on one chip into complex miniaturized photonic integrated circuits (PICs), is the next step in these developments, yet limited by existing material and technology constraints. In this work, we introduce a new concept for realizing fully monolithic MIR-PICs based on low-loss on-chip plasmonic guiding and beam combining. The core of our study demonstrates a monolithic beam combiner by integration of active quantum cascade (QC) devices at ∼8μm (laser and detector) with tailored passive waveguides based on weakly-coupled Ge/Au plasmonics and on-chip micro-mirror optics. The on-chip gold-coated micro-mirrors enhance the directional control and beam combining capabilities of the plasmon waveguides while minimizing energy dissipation typically associated with tight plasmon confinement. We discuss the MIR-PIC beam combiner design, micro-fabrication, and characterization and compare it to the routing concept of simple plasmonic Ge/Au y-couplers exploiting strong-confinement

The Changing Landscape for Stroke\ua0Prevention in AF: Findings From the GLORIA-AF Registry Phase 2

Background GLORIA-AF (Global Registry on Long-Term Oral Antithrombotic Treatment in Patients with Atrial Fibrillation) is a prospective, global registry program describing antithrombotic treatment patterns in patients with newly diagnosed nonvalvular atrial fibrillation at risk of stroke. Phase 2 began when dabigatran, the first non\u2013vitamin K antagonist oral anticoagulant (NOAC), became available. Objectives This study sought to describe phase 2 baseline data and compare these with the pre-NOAC era collected during phase 1. Methods During phase 2, 15,641 consenting patients were enrolled (November 2011 to December 2014); 15,092 were eligible. This pre-specified cross-sectional analysis describes eligible patients\u2019 baseline characteristics. Atrial fibrillation disease characteristics, medical outcomes, and concomitant diseases and medications were collected. Data were analyzed using descriptive statistics. Results Of the total patients, 45.5% were female; median age was 71 (interquartile range: 64, 78) years. Patients were from Europe (47.1%), North America (22.5%), Asia (20.3%), Latin America (6.0%), and the Middle East/Africa (4.0%). Most had high stroke risk (CHA2DS2-VASc [Congestive heart failure, Hypertension, Age  6575 years, Diabetes mellitus, previous Stroke, Vascular disease, Age 65 to 74 years, Sex category] score  652; 86.1%); 13.9% had moderate risk (CHA2DS2-VASc = 1). Overall, 79.9% received oral anticoagulants, of whom 47.6% received NOAC and 32.3% vitamin K antagonists (VKA); 12.1% received antiplatelet agents; 7.8% received no antithrombotic treatment. For comparison, the proportion of phase 1 patients (of N = 1,063 all eligible) prescribed VKA was 32.8%, acetylsalicylic acid 41.7%, and no therapy 20.2%. In Europe in phase 2, treatment with NOAC was more common than VKA (52.3% and 37.8%, respectively); 6.0% of patients received antiplatelet treatment; and 3.8% received no antithrombotic treatment. In North America, 52.1%, 26.2%, and 14.0% of patients received NOAC, VKA, and antiplatelet drugs, respectively; 7.5% received no antithrombotic treatment. NOAC use was less common in Asia (27.7%), where 27.5% of patients received VKA, 25.0% antiplatelet drugs, and 19.8% no antithrombotic treatment. Conclusions The baseline data from GLORIA-AF phase 2 demonstrate that in newly diagnosed nonvalvular atrial fibrillation patients, NOAC have been highly adopted into practice, becoming more frequently prescribed than VKA in Europe and North America. Worldwide, however, a large proportion of patients remain undertreated, particularly in Asia and North America. (Global Registry on Long-Term Oral Antithrombotic Treatment in Patients With Atrial Fibrillation [GLORIA-AF]; NCT01468701

Robust estimation of bacterial cell count from optical density

Optical density (OD) is widely used to estimate the density of cells in liquid culture, but cannot be compared between instruments without a standardized calibration protocol and is challenging to relate to actual cell count. We address this with an interlaboratory study comparing three simple, low-cost, and highly accessible OD calibration protocols across 244 laboratories, applied to eight strains of constitutive GFP-expressing E. coli. Based on our results, we recommend calibrating OD to estimated cell count using serial dilution of silica microspheres, which produces highly precise calibration (95.5% of residuals <1.2-fold), is easily assessed for quality control, also assesses instrument effective linear range, and can be combined with fluorescence calibration to obtain units of Molecules of Equivalent Fluorescein (MEFL) per cell, allowing direct comparison and data fusion with flow cytometry measurements: in our study, fluorescence per cell measurements showed only a 1.07-fold mean difference between plate reader and flow cytometry data

Measurement data and efficiency analysis of battery-powered truck prototypes

Reducing the environmental impact of transport and reducing reliance on fossil fuels are key issues currently driving a turnaround in the automotive industry. A promising topic that has developed from these demands is the electric mobility. This is characterized by purely electrically powered vehicles and hybrid systems instead of internal combustion engines. With the help of this technology, a modern transport system is designed, which can meet the future requirements for an environmentally friendly freight traffic. The present work deals with the automated preparation and evaluation of measurement data of all-electric truck prototypes. For the vehicles under test, few details of the energy consumption of the assemblies and the use of the vehicles are currently known. The aim is to use an automated routine to prepare the measurement data from the real driving operation, to make it plausible and then to evaluate it. The variables and measurement signals relevant for the evaluation of the energy input are first defined and then validated. The validation of the measurement data is performed by specifying realistic limits for the signals to avoid introducing implausible readings into the modeling process. In order to counteract the different sampling rates of the measurement signals, they are brought to a common time base. It identifies the main consumers on the vehicle and uses simulation models to determine their contribution to the energy conversion. The model validation is carried out with measurement data from reference runs in which essential parameters were monitored on board. Various influences such as the ambient temperature, the vehicle operation, the influence of the route and the speed profile are considered and their influence on the consumption is determined. In addition, a simulation model for the calculation of the required drive energy, with known route and speed profile is created. Individual parameters are optimized in this model.Die Verringerung der Umweltbelastung durch den Verkehr sowie die Reduktion der Abhängigkeit von fossilen Brennstoffen sind zentrale Themen die derzeit für einen Umschwung in der Kfz-Branche sorgen. Ein vielversprechendes Themengebiet welches sich aus diesen Ansprüchen entwickelt hat ist die Elektromobilität. Diese zeichnet sich durch rein elektrisch betriebene Fahrzeuge und Hybridsysteme anstelle von Verbrennungsmotoren aus. Mit Hilfe dieser Technologie soll ein modernes Verkehrssystem gestaltet werden, welches die zukünftigen Anforderungen an einen umweltfreundlichen Güterverkehr erfüllen kann. Die vorliegende Arbeit beschäftigt sich mit der automatisierten Aufbereitung und Auswertung von Messdaten, rein elektrisch betriebener LKW-Prototypen. Für die in der Erprobungsphase befindlichen Fahrzeuge sind derzeit wenige Details zum Energieverbrauch der Baugruppen und zum Einsatz der Fahrzeuge bekannt. Ziel ist es, mithilfe einer automatisierten Routine die Messdaten aus dem realen Fahrbetrieb aufzubereiten, diese zu plausibilisieren und anschließend auszuwerten. Die zur Bewertung des Energieeinsatzes relevanten Größen und Messsignale werden zuerst definiert und anschließend validiert. Die Validierung der Messdaten wird mithilfe der Vorgabe von praxisgetreuen Grenzwerten für die Signale durchgeführt, um auszuschließen, dass unglaubwürdige Messwerte in die Modellbildung eingebracht werden. Um den unterschiedlichen Abtastraten der Messsignale entsprechend zu begegnen, werden diese auf eine gemeinsame Zeitbasis gebracht. Es werden die wesentlichen Verbraucher am Fahrzeug identifiziert und anhand von Simulationsmodellen deren Beitrag an der Energieumwandlung bestimmt. Die Modellvalidierung erfolgt mit Messdaten aus Referenzfahrten bei denen wesentliche Parameter an Bord überwacht wurden. Es werden verschiedene Einflüsse wie die Umgebungstemperatur, die Fahrzeugbedienung, der Einfluss der Fahrstrecke und das Geschwindigkeitsprofil betrachtet und deren Einfluss auf den Verbrauch ermittelt. Ausserdem wird ein Simulationsmodell zur Berechnung der benötigten Antriebsenergie, bei bekanntem Strecken- und Geschwindigkeitsprofil erstellt. Einzelne Parameter werden in diesem Modell optimiert