Heterodyne background-oriented schlieren for the measurement of thermoacoustic oscillations in flames.

In aircraft engines, thermoacoustic oscillations in the combustion chamber contribute significantly to noise emissions, which, like all other emissions, must be drastically reduced. Thermoacoustic oscillations are not only a concern, they can also be beneficial in hydrogen combustion. This work demonstrates that thermoacoustic density oscillations with amplitudes at least an order of magnitude smaller than those resulting from density gradients in a turbulent flame can be detected using laser interferometric vibrometry.

Effectiveness of the First and Second Severe Acute Respiratory Syndrome Coronavirus 2 Vaccine Dose: A Nationwide Cohort Study From Austria on Hybrid Versus Natural Immunity.

Background: We aimed to evaluate the effectiveness of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) vaccinations in previously SARS-CoV-2-infected adults in the general population of Austria during the Delta wave and with extended follow-up.

Methods: In a nationwide retrospective cohort study, we calculated age-, sex-, and nursing home residency-adjusted Cox proportional hazard ratios (HRs) of coronavirus disease 2019 (COVID-19) deaths, SARS-CoV-2 infections, and non-COVID-19 deaths from 1 October to 31 December 2021, and secondarily with extended follow-up to 30 June 2022. Relative vaccine effectiveness (rVE) is rVE = (1 - HR) × 100.

Development of a high-fidelity digital twin using the discrete element method for a continuous direct compression process. Part 2. Validation of calibration workflow.

This paper is the second in a series of two that describes the application of discrete element method (DEM) and reduced order modeling to predict the effect of disturbances in the concentration of drug substance at the inlet of a continuous powder mixer on the concentration of the drug substance at the outlet of the mixer. In the companion publication, small-scale material characterization tests, a careful DEM parameter calibration and DEM simulations of the manufacturing process were used to develop a reliable RTD models. In the current work, the same calibration workflow was employed to evaluate the predictive ability of the resulting reduced-order model for an extended design space.

Development of a high-fidelity digital twin using the discrete element method for a continuous direct compression process. Part 1. Calibration workflow.

In this work, a high-fidelity digital twin was developed to support the design and testing of control strategies for drug product manufacturing via direct compression. The high-fidelity digital twin platform was based on typical pharmaceutical equipment, materials, and direct compression continuous processes. The paper describes in detail the material characterization, the Discrete Element Method (DEM) model and the DEM model parameter calibration approach and provides a comparison of the system's response to the experimental results for stepwise changes in the API concentration at the mixer inlet.

Harnessing nature's catalysts: Advances in enzymatic alkene cleavage.

Double bonds are prevalent in various substrates and renewable feedstocks, and their cleavage typically necessitates harsh reaction conditions involving high temperatures, organic solvents, and hazardous catalysts such as heavy metals or ozone. This review explores the sustainable enzymatic alternatives developed by nature for alkene cleavage. It provides a comprehensive overview of alkene-cleaving enzymes, detailing their mechanisms, substrate specificities, and applications.

An alternative filament fabrication method as the basis for 3D-printing personalized implants from elastic ethylene vinyl acetate copolymer.

In this work, a novel tool for small-scale filament production is presented. Unlike traditional methods such as hot melt extrusion (HME), the device (i) allows filament manufacturing from small material amounts as low as three grams, (ii) ensures high diameter stability almost independent of the viscoelastic behavior of the polymer melt, and (iii) enables processing of materials with rheological profiles specifically tailored toward fused filament fabrication (FFF). Hence, novel materials, previously difficult to process due to HME limitations, become easily accessible for FFF for the first time.

The phyllosphere of Nigerian medicinal plants, Euphorbia lateriflora and Ficus thonningii is inhabited by a specific microbiota.

The microbiota of medicinal plants is known to be highly specific and can contribute to medicinal activity. However, the majority of plant species have not yet been studied. Here, we investigated the phyllosphere composition of two common Nigerian medicinal plants, Euphorbia lateriflora and Ficus thonningii, by a polyphasic approach combining analyses of metagenomic DNA and isolates.

Demonstrating scalability between two blender types using DEM.

Powder blending is a critical step in pharmaceutical manufacturing that can impact product quality such as tablet tensile strength. This study utilized the Discrete Element Method (DEM) to investigate blending in a 5-liter mini-batch and a 2-liter Turbula blender. DEM parameters were calibrated using small-scale powder characterization tests, so that the particle behavior in the DEM simulations matches the measured behavior.

The Influence of Thermomechanical Conditions on the Hot Ductility of Continuously Cast Microalloyed Steels.

Continuous casting is the most common method for producing steel into semi-finished shapes like billets or slabs. Throughout this process, steel experiences mechanical and thermal stresses, which influence its mechanical properties. During continuous casting, decreased formability in steel components leads to crack formation and failure.

Handwritten character classification from EEG through continuous kinematic decoding.

The classification of handwritten letters from invasive neural signals has lately been subject of research to restore communication abilities in people with limited movement capacities. This study explores the classification of ten letters (a,d,e,f,j,n,o,s,t,v) from non-invasive neural signals of 20 participants, offering new insights into the neural correlates of handwriting. Letters were classified with two methods: the direct classification from low-frequency and broadband electroencephalogram (EEG) and a two-step approach comprising the continuous decoding of hand kinematics and the application of those in subsequent classification.

Implicit Is Not Enough: Explicitly Enforcing Anatomical Priors inside Landmark Localization Models.

The task of localizing distinct anatomical structures in medical image data is an essential prerequisite for several medical applications, such as treatment planning in orthodontics, bone-age estimation, or initialization of segmentation methods in automated image analysis tools. Currently, Anatomical Landmark Localization (ALL) is mainly solved by deep-learning methods, which cannot guarantee robust ALL predictions; there may always be outlier predictions that are far from their ground truth locations due to out-of-distribution inputs. However, these localization outliers are detrimental to the performance of subsequent medical applications that rely on ALL results.

A computational method to reveal psychological constructs from text data.

When starting to formalize psychological constructs, researchers traditionally rely on two distinct approaches: the quantitative approach, which defines constructs as part of a testable theory based on prior research and domain knowledge often deploying self-report questionnaires, or the qualitative approach, which gathers data mostly in the form of text and bases construct definitions on exploratory analyses. Quantitative research might lead to an incomplete understanding of the construct, while qualitative research is limited due to challenges in the systematic data processing, especially at large scale. We present a new computational method that combines the comprehensiveness of qualitative research and the scalability of quantitative analyses to define psychological constructs from semistructured text data.

A viscoelastic constitutive framework for aging muscular and elastic arteries.

The evolution of arterial biomechanics and microstructure with age and disease plays a critical role in understanding the health and function of the cardiovascular system. Accurately capturing these adaptative processes and their effects on the mechanical environment is critical for predicting arterial responses. This challenge is exacerbated by the significant differences between elastic and muscular arteries, which have different structural organizations and functional demands.

Electrochemically Induced Nanoscale Stirring Boosts Functional Immobilization of Flavocytochrome P450 BM3 on Nanoporous Gold Electrodes.

Enzyme-modified electrodes are core components of electrochemical biosensors for diagnostic and environmental analytics and have promising applications in bioelectrocatalysis. Despite huge research efforts spanning decades, design of enzyme electrodes for superior performance remains challenging. Nanoporous gold (npAu) represents advanced electrode material due to high surface-to-volume ratio, tunable porosity, and intrinsic redox activity, yet its coupling with enzyme catalysis is complex.

Spin Dynamics across Metallic Layers on the Few-Femtosecond Timescale.

We measure the light-driven response of a magnetic multilayer structure made of thin alternating layers of cobalt and platinum at the few-femtosecond timescale. Using attosecond magnetic circular dichroism, we observe how light rearranges the magnetic moment during and after excitation. The results reveal a sub-5 fs spike of magnetization in the platinum layer, which follows the shape of the driving pulse.

Testing for heterogeneous rates of discrete character evolution on phylogenies.

Many hypotheses in the field of phylogenetic comparative biology involve specific changes in the rate or process of trait evolution. This is particularly true of approaches designed to connect macroevolutionary pattern to microevolutionary process. We present a method to test whether the rate of evolution of a discrete character has changed in one or more clades, lineages, or time periods.

Microscale manipulation of bond exchange reactions in photocurable vitrimers with a covalently attachable photoacid generator.

Vitrimers are polymer networks with covalent bonds that undergo reversible exchange reactions and rearrange their topology in response to an external stimulus. The temperature-dependent change in viscoelastic properties is conveniently adjusted by selected catalysts. In these thermo-activated systems, the lack in spatial control can be overcome by using photolatent catalysts.

Microbiota regulates neonatal disease tolerance to virus-evoked necrotizing enterocolitis by shaping the STAT1-NLRC5 axis in the intestinal epithelium.

Microbiota and feeding modes influence the susceptibility of premature newborns to necrotizing enterocolitis (NEC) through mechanisms that remain unknown. Here, we show that microbiota colonization facilitated by breastmilk feeding promotes NOD-like receptor family CARD domain containing 5 (Nlrc5) gene expression in mouse intestinal epithelial cells (IECs). Notably, inducible knockout of the Nlrc5 gene in IECs predisposes neonatal mice to NEC-like injury in the small intestine upon viral inflammation in an NK1.

Is the Apple Vision Pro the Ultimate Display? A First Perspective and Survey on Entering the Wonderland of Precision Medicine.

At the Worldwide Developers Conference in June 2023, Apple introduced the Vision Pro. The Apple Vision Pro (AVP) is a mixed reality headset; more specifically, it is a virtual reality device with an additional video see-through capability. The video see-through capability turns the AVP into an augmented reality (AR) device.

Optimal and typical discrepancy of 2-dimensional lattices.

We undertake a detailed study of the discrepancy of 2-dimensional Korobov lattices and their irrational analogues, either with or without symmetrization. We give a full characterization of such lattices with optimal discrepancy in terms of the continued fraction partial quotients, and compute the precise asymptotics whenever the continued fraction expansion is explicitly known, such as for quadratic irrationals or Euler's number . In the metric theory, we find the asymptotics of the discrepancy for almost every irrational, and the limit distribution for randomly chosen rational and irrational lattices.

Unlocking biomedical data sharing: A structured approach with digital twins and artificial intelligence (AI) for open health sciences.

Objective: Data sharing promotes the scientific progress. However, not all data can be shared freely due to privacy issues. This work is intended to foster FAIR sharing of sensitive data exemplary in the biomedical domain, via an integrated computational approach for utilizing and enriching individual datasets by scientists without coding experience.

Bridging the gap between GRACE and GRACE Follow-On by combining high-low satellite-to-satellite tracking data and satellite laser ranging.

The satellite missions GRACE and GRACE Follow-On have undoubtedly been the most important sources to observe mass transport on global scales. Within the Combination Service for Time-Variable Gravity Fields (COST-G), gravity field solutions from various processing centers are being combined to improve the signal-to-noise ratio and further increase the spatial resolution. The time series of monthly gravity field solutions suffer from a data gap of about one year between the two missions GRACE and GRACE Follow-On among several smaller data gaps.

Antithrombogenic polysaccharide coatings to improve hemocompatibility, protein-repellence, and endothelial cell response.

Polyester biomaterials play a crucial in vascular surgery, but suffer from unspecific protein adsorption, thrombogenicity, and inadequate endothelial cell response, which limit their success. To address these issues, we investigated the functionalization of polyester biomaterials with antithrombogenic polysaccharide coatings. A two-step and water-based method was used to coat cationized polycaprolactone with different sulfated polysaccharides (SPS), which resulted in long-term stability, tunable morphology, roughness, film thickness, chemical compositions, zeta potential, and water content.

Characterization of Camphene- and Fenchol-Based Hydrophobic Eutectic Solvents and Their Application in Aldehyde Extraction.

Binary terpenoid-based eutectic systems consisting of the natural substances camphene (CA), fenchol (FE), thymol (TH), menthol (ME), dodecanoic acid (DA), and 1-dodecanol (DO) are synthesized and screened for their Solid-Liquid Equilibrium (SLE) and eutectic compositions. Out of nine eutectic systems, 13 solvent compositions at eutectic points and next to them, in addition to the reference solvent, TH:ME, are synthesized and applied for the solvent extraction of the aromatic aldehydes vanillin (VAN), syringaldehyde (SYR), and -hydroxybenzaldehyde (HYD) from an acidic aqueous model solution. The extraction efficiency is determined from aldehyde concentrations measured by High-Performance Liquid Chromatography (HPLC), taking into consideration mutual solubility measured by Karl Fischer titration (KF) and a Total Organic Carbon-analysis (TOC).