Resolved Analysis Research Articles

The first annually resolved analysis of slash-and-burn practices in the boreal Eurasia suggests their strong climatic and socio-economic controls

Slash-and-burn (SAB) was a widespread agricultural practice across large parts of the boreal region until the early 20th century. Despite its paramount importance in the procurement of food and particularly in supporting frontier populations of settlers during the colonization of the Eurasian boreal zone, analyses of spatial and temporal patterns in the use of SAB at annual and sub-annual scales are currently missing. We present the first such analysis of climatic and social controls of SAB practices in a remote region in the northern Ural mountains from 1880 to 1894. We observed a significant positive correlation between the total number of burns and the village population (p = 0.005, R2 = 0.26), indicating that the frequency of burns directly reflected the local demand for food. The amount of agricultural land, regarded as a cumulative measure of burning activity over multiple decades, showed a strong positive correlation with the village population (p < 0.001, R2 = 0.60). This result supported our interpretation of burns as an important food procurement tool, probably also positively affected by higher labour availability in larger villages. Villages where the number of burns were higher than predicted by the “the population vs. burns” regression tended (p = 0.15) to have larger areas of arable land than predicted by the “population vs. arable land” regression. This pattern implied that variability in the local environmental and/or socio-economic settings of the villages made some of them more (or otherwise less) favourable for agricultural activities based on SAB. Most reported burns occurred in June and July. The three years with the maximum number of reported burns had a tendency to be wetter during these months when compared to the same period during an “average” year (p = 0.19). The pattern suggested that farmers preferred conducting burns during years with a below-average climatological fire hazard. An earlier start of the fire season favoured burning activity (p = 0.10 R2 = 0.33), while its later ending had no significant effect on the number of burns (p = 0.53). Our study documented strong climatic controls of SAB practices at the annual scale and their social controls at above-annual scales. These patterns emerged despite the common use of slash-and-burn to mitigate generally limited food availability in the northern Ural mountain region and likely conservative estimates of these practices in available records.

Selective Analysis of Redox Processes at the Electrode Interface with Time-Resolved Raman Spectroscopy.

Electrochemistry and electrochemical reactions are increasingly important in the transition to a sustainable chemical industry. The electron transfer that drives such reactions takes place within nanometers of the electrode surface, and follow-up chemical reactions take place within the diffusion layer. Hence, understanding electrochemical reactions requires time-, potential-, and spatially resolved analysis. The confocal nature of Raman spectroscopy provides high spatial resolution, in addition to detailed information on molecular structure. The intrinsic weakness of nonresonant Raman scattering, however, is not sensitive enough for relatively minor changes to the solution resulting from reactions at the electrode interface. Indeed, the limit of detection is typically well above the concentrations used in electrochemical studies. Here, we show that surface-enhanced Raman scattering (SERS) and resonance Raman (rR) spectroscopy allow for spatially and time-resolved analysis of solution composition at (<1-2 nm) and near (within 5 μm) the electrode surface, respectively, in a selective manner for species present at low (<1 mM) concentrations. We show changes in concentration of species at the electrode surface, without the need for labels, specific adsorption, or resonance enhancement, using a SERS-active gold electrode prepared readily by electrochemical surface roughening. A combination of smooth and roughened gold electrodes is used to distinguish between surface and resonance enhancement using the well-known redox couples ferrocene and 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS). We discuss the impact of specific adsorption on the spectral analysis with the ruthenium(II) polypyridyl complex, [Ru(bpy)3]2+. The dual function of the electrode (surface enhancement and electron transfer) in the analysis of solution processes is demonstrated with the reversible oxidation of TMA (4,N,N-trimethylaniline), where transient soluble species are identified in real time, with rapid spectral acquisition, making use of localized enhancement. We anticipate that this approach will find use in elucidating electro(catalytic) reactions at electrode interfaces.

Spatially resolved analysis of CO2 hydrogenation to higher hydrocarbons over alkali-metal promoted well-defined FexOyCz

A series of catalysts for CO2 hydrogenation to higher (C2+) hydrocarbons were prepared through controlled decomposition of iron (II) oxalate dihydrate impregnated with Li, Na, K, Rb or Cs carbonate. They consist of Fe3O4, Fe5C2, Fe3C and Fe. Their steady-state spatial phase distribution is, however, affected by the presence and the kind of the promoter. These structural characteristics determine catalyst activity and product selectivity. Fe3C seems to favor CH4 formation, while C2+-hydrocarbons are formed over Fe5C2. A positive relationship between the rate of C2+-hydrocarbons formation and the rate constant of dissociation of adsorbed CO2 was established, while an opposite dependence is valid for the rate of CO2 methanation. The rate constant of this reaction increases in the presence of alkali metal and with an increase in its atomic number. Therefore, CH4 is mainly formed over Rb- or Cs-doped catalysts through CO hydrogenation, while CO2 methanation prevails over the remaining catalysts.

Experimentelle und numerische Untersuchung von Fluid-Partikel-Interaktionen in Wasser

ZusammenfassungFür die Entwicklung verbesserter Modelle zur Beschreibung des Sedimenttransports in Fließgewässern ist das grundlegende Verständnis der Interaktion zwischen den festen Partikeln und dem bewegten Fluid (Wasser) bedeutend. In diesem Beitrag werden aktuelle Entwicklungen im Bereich der Fluid-Partikel-Interaktion anhand von zwei konkreten Forschungsarbeiten von Gold et al. (2023) und Worf et al. (2022) vorgestellt. Die experimentelle Forschungsarbeit von Gold et al. (2023) untersucht mithilfe von Messmethoden auf dem neuesten Stand der Technik die Strömung rund um Kugeln verschiedener Dichte, die in anfangs ruhendem Wasser oszillieren. Über den gesamten Dichtebereich (m^{*}=rho _{S}/rho _{F}= 1,14; 14,95; Dichteverhältnis von Solid und Fluid) konnte für das Kugelpendel eine vergleichbare Charakteristik der Wirbelablösung festgestellt werden. Ebenso wird eine neue Methode der Objektverfolgung (DOT) vorgestellt, welche eine zeitlich und räumlich aufgelöste Analyse der Strömungsstrukturen im Fluidfeld ermöglicht. Gold et al. (2023) zeigen, dass es während der ersten Periode zur Wirbelablösung kommt. Dieser Wirbel pflanzt sich in Richtung Beckenboden fort und dissipiert letztendlich. Weiters wurde ein Dämpfungsoptimum des Kugelpendels im Bereich von m^{*}=2{,}50 beobachtet. Außerdem wurde ein Experiment von einem Zylinderpendel mit m^{*}=4{,}98 mittels Immersed-Boundary-Methode numerisch untersucht. Dabei wurde der Vorgang der Bildung und Ablösung bis hin zum Zerfall eines Wirbelrings beschrieben. Zusätzlich wurde bei dieser Untersuchung von Worf et al. (2022) die Bildung von Randwirbeln beobachtet, beschrieben und mit der anfänglichen Entwicklung der dreidimensionalen Strömung und „zusätzlichen Masse“ in Verbindung gebracht.

The Interplay of Processing-Related Influences on the Formation of Volume Holographic Gratings in a Free-Surface Epoxy-Based Recording Material

Understanding the formation processes of holographic gratings in polymers as a function of material composition and processing is important for the development of new materials for holography and its associated applications. Among the processing-related factors that affect grating formation in volume holographic recording material, pre-exposure, prebaking and dark storage, as well as the associated variations in layer thickness and composition, are usually underestimated. This study highlights the influence and interaction of these factors and shows that they should not be neglected. This is of particular importance for samples with a free surface. Here, one such epoxy-based free-surface material is investigated. To determine the influence of prebaking on the holographic grating formation, as well as on the achieved refractive index contrast, angular resolved analysis of volume holographic phase gratings is applied through point-by-point scanning of the local material response. Grating characteristics are determined by comparison with simulations based on rigorous coupled wave theory. Thus, the optimal dose for prebaking can be determined, as well as the optimal exposure time, depending on the dose. The influence of dark storage on the material response is investigated over a period of 12 weeks and shows a strong dependence on the deposited energy density.

Band topology and non-trivial surface states in type-II Dirac semi-metal X(Ni, Pd)Te2

The semi-metals having electrons near the Fermi level follow the relativistic equation of motion, and show Dirac or Weyl-type behavior. Their orbital resolved electronic bands analysis indicates the non-trivial topological states. Through the first principle methods, the electronic band structure of bulk and thin layers of transition metal dichalcogenides NiTe2 and PdTe2 are calculated and analyzed. Implementation of Hubbard corrections to the band structure indicates zero magnetization, though atoms of Ni are magnetic. Z2 invariant index is calculated for topological classification for both materials and is found to possess strong topology indicating robust topological surface states. Further, Fermi surfaces and topological surface states are computed into kz plane showing the presence of Dirac-fermions by forming of Dirac cone for PdTe2 but for NiTe2 we do not get clear evidence.

Automated slip system identification and strain analysis framework using high-resolution digital image correlation data: Application to a bimodal Ti-6Al-4V alloy

Statistical analysis of slip system identification and quantitative study on local plasticity is crucial to understand the collective deformation by the sub-grain-scale slip activities in polycrystalline metallic materials. In this study, an automated framework for identifying slip system and assessing strain localization of slip bands termed ASSISL (automated Slip System Identification and Strain Localization analysis of slip bands) is introduced, using the results from high resolution digital image correlation (HR-DIC), and is demonstrated on 1591 primary α grains of a bimodal Ti-6Al-4V alloy under tensile loading. The framework includes: (1) alignment of electron backscattered diffraction (EBSD) maps with strain field maps from HR-DIC through treatment of EBSD distortion, (2) slip band orientations identification from strain field map of each grain through a Radon-transform-based algorithm, (3) slip system assignment with combined Schmid factor and critical resolved shear stress analysis, (4) quantification of plasticity by slip activities which provides information on the numbers, positions and mean strain of slip bands in each grain. The confidence of ASSISL is validated through comparing current statistical results with existing literature, as well as examining reasons for grains assigned with wrong slip systems, which accounts for 9.6 percent (153 out of 1591) of the primary α grains. A comparison between ASSISL and other HR-DIC-based slip identification methods is also conducted. This framework provides a method for analyzing slip activities in a large number of grains of polycrystalline metals in a time-saving and automated fashion.

Quantification and characterization of PFASs in suspended particulate matter (SPM) of German rivers using EOF, dTOPA, (non-)target HRMS

In this study, we compare analytical methods for PFAS determination–target analysis, non-target screening (NTS), direct total oxidizable precursor assay (dTOPA) and extractable organically bound fluorine (EOF). Therefore, suspended particulate matter (SPM) samples from German rivers at different locations in time series from 2005 to 2020 were analyzed to investigate temporal and spatially resolved trends. In this study 3 PFAS mass balances approaches were utilized: (i) PFAA target vs. PFAS dTOPA, (ii) PFAS target vs. EOF and (iii) PFAS target vs. PFAS dTOPA vs. organofluorines NTS vs. EOF. Mass balance approach (i) revealed high proportions of precursor substances in SPM samples. For the time resolved analysis an increase from 94% (2005) to 97% in 2019 was observable. Also for the spatial resolved analysis precursor proportions were high with >84% at all sampling sites. Mass balance approach (ii) showed that the unidentified EOF (uEOF) fraction increased over time from 82% (2005) to 99% (2019). Furthermore, along the river courses the uEOF increased. In the combined mass balance approach (iii) using 4 different analytical approaches EOF fractions were further unraveled. The EOF pattern was fully explainable at the sampling sites at Saar and Elbe rivers. For the time resolved analysis, an increased proportion of the EOF was now explainable. However, still 27% of the EOF for the time resolved analysis and 25% of the EOF for the spatial resolved analysis remained unknown. Therefore, in a complementary approach, both the EOF and dTOPA reveal unknown gaps in the PFAS mass balance and are valuable contributions to PFAS risk assessment. Further research is needed to identify organofluorines summarized in the EOF parameter.

Abstract LB079: An end-to-end Visium spatial transcriptomics computational pipeline for generating low-code interactive reports of spatial insights

Abstract In recent years, methods for analyzing and interpreting expression data have evolved rapidly. Newer and more complex datasets are being developed faster than ever, and the resources needed to perform rigorous data analysis have increased dramatically. In spatial transcriptomics analysis, researchers face many technical challenges: data management, compute power, and programming knowledge. In addition to these technical barriers, a constantly evolving field can make it difficult for scientists to understand if they are performing adequate quality control, proper data integration, choosing situationally correct methods, and showing accurate biological insights. Transcriptomics data comes with many meaningful caveats that make having the proper technical resources just a single piece of the puzzle. These obstacles keep scientists with valuable biological questions from maximizing the power of Spatial Transcriptomics. To address these challenges, we developed an end-to-end Visium spatial transcriptomics computational pipeline for generating interactive figures and reports for low-code exploration. This pipeline automated data quality control, batch-effects correction, and multiple peer-reviewed analysis techniques to perform a spatially resolved analysis of tissue heterogeneity. To demonstrate the effectiveness of this pipeline, we performed an analysis on a cohort consisting of 3 patients with adenocarcinoma and 1 patient with signet ring cell carcinoma, each with 1 sample of primary colon tumor and its matched adjacent normal tissue. All samples were formalin-fixed paraffin-embedded (FFPE) provided by BioChain Institute. The tissue sections were stained with Hematoxylin and Eosin, and the transcriptome was mapped using 10x Genomics Visium Spatial Gene Expression for FFPE. The raw base call files were then processed into feature-barcode matrices, followed by quality control measures that included data filtering, sample integration, batch-effect removal, and normalization. The pipeline then combined multiple analysis methods for feature extraction from genes and spatial spots, including clustering, neighborhood detection, and gene module detection. Further, we leveraged clinical metadata to perform differential expression and abundance analyses of the extracted features across different tissue and disease types. The pipeline finally generated an interactive report detailing analysis of spatially-resolved tissue biology, pathology, and microenvironment, allowing a scientist to analyze and explore the data further. This pipeline to identified differences in the spatial arrangement between tumor and normal tissue, in addition to demonstrating the spatial arrangements that differentiate adenocarcinoma and signet ring cell carcinoma relating to the invasive front and body of the tumors. Citation Format: Steven Hamel, Elim Cheung, Ying Qu, Malachi Loviska, Aaron Mayer, Lutong Zhang, Tong Lu, Vidyodhaya Sundaram, Baowen Zhang, Alex Trevino. An end-to-end Visium spatial transcriptomics computational pipeline for generating low-code interactive reports of spatial insights [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 2 (Clinical Trials and Late-Breaking Research); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(8_Suppl):Abstract nr LB079.

AGN feedback in an infant galaxy cluster: LOFAR-Chandra view of the giant FRII radio galaxy J103025+052430 at z = 1.7

In the nearby universe, jets from active galactic nuclei (AGN) are observed to have a dramatic impact on their surrounding extragalactic environment. The effect of jets at high redshift (z &gt; 1.5) is instead much more poorly constrained. However, studying the jet impact at cosmic noon, the epoch in which both star formation and AGN activity peak, is crucial for fully understanding galaxy evolution. Here we present a study of the giant (∼750 kpc) radio galaxy 103025+052430 located at the centre of a protocluster at redshift z = 1.7, with a focus on its interaction with the external medium. We present new LOFAR observations at 144 MHz, which we combine with VLA 1.4 GHz data and 0.5–7 keV Chandra archival data. The new radio map at 144 MHz confirms that the source has a complex morphology, which can possibly fit the hybrid morphology radio galaxy classification. The large size of the source enabled us to perform a resolved radio spectral index analysis, a very unique opportunity for a source at this high redshift. This revealed a tentative unexpected flattening of the radio spectral index at the edge of the backflow in the western lobe, which might be indicating plasma compression. The spatial coincidence between this region and the thermal X-ray bubble C suggests a causal connection between the two. In contrast to previous estimates for the bright X-ray component A, we find that inverse Compton scattering between the radio-emitting plasma of the eastern lobe and cosmic microwave background photons can account for a large fraction (∼45%–80%) of its total 0.5–7 keV measured flux. Finally, the X-ray bubble C, which is consistent with a thermal origin, is found to be significantly overpressurised with respect to the ambient medium. This suggests that it will tend to expand and release its energy into the surroundings, contributing to the overall intracluster medium heating. Overall, 103025+052430 enables us to investigate the interaction between AGN jets and the surrounding medium in a system that is likely the predecessor of the rich galaxy clusters we all know well at z = 0.

Resolving trabecular metaphyseal bone profiles downstream of the growth plate adds value to bone histomorphometry in mouse models.

Histomorphometry of rodent metaphyseal trabecular bone, by histology or microCT, is generally restricted to the mature secondary spongiosa, excluding the primary spongiosa nearest the growth plate by imposing an 'offset'. This analyses the bulk static properties of a defined segment of secondary spongiosa, usually regardless of proximity to the growth plate. Here we assess the value of trabecular morphometry that is spatially resolved according to the distance 'downstream' of-and thus time since formation at-the growth plate. Pursuant to this, we also investigate the validity of including mixed primary-secondary spongiosal trabecular bone, extending the analysed volume 'upstream' by reducing the offset. Both the addition of spatiotemporal resolution and the extension of the analysed volume have potential to enhance the sensitivity of detection of trabecular changes and to resolve changes occurring at different times and locations. Two experimental mouse studies of trabecular bone are used as examples of different factors influencing metaphyseal trabecular bone: (1) ovariectomy (OVX) and pharmacological prevention of osteopenia and (2) limb disuse induced by sciatic neurectomy (SN). In a third study into offset rescaling, we also examine the relationship between age, tibia length, and primary spongiosal thickness. Bone changes induced by either OVX or SN that were early or weak and marginal were more pronounced in the mixed primary-secondary upstream spongiosal region than in the downstream secondary spongiosa. A spatially resolved evaluation of the entire trabecular region found that significant differences between experimental and control bones remained undiminished either right up to or to within 100 μm from the growth plate. Intriguingly, our data revealed a remarkably linear downstream profile for fractal dimension in trabecular bone, arguing for an underlying homogeneity of the (re)modelling process throughout the entire metaphysis and against strict anatomical categorization into primary and secondary spongiosal regions. Finally, we find that a correlation between tibia length and primary spongiosal depth is well conserved except in very early and late life. These data indicate that the spatially resolved analysis of metaphyseal trabecular bone at different distances from the growth plate and/or times since formation adds a valuable dimension to histomorphometric analysis. They also question any rationale for rejecting primary spongiosal bone, in principle, from metaphyseal trabecular morphometry.

Tap Reactor for Temporally and Spatially Resolved Analysis of the CO2 Methanation Reaction

AbstractChemical energy carriers produced according to power‐to‐X concepts will play a crucial role in the future energy system. Here, CO2 methanation is described as one promising route. However, transient operating conditions and the resulting effects on catalyst stability are to be considered. In this contribution, a tap reactor for spatially and temporally resolved analysis of the methanation reaction is presented. The Ni catalyst investigated was implemented as coating. Reaction data as a function of time and reactor coordinate under various operating conditions are presented and discussed. A comparison with simulation data validates the presented tap reactor concept.

Multimodal study of CHI3L1 inhibition and its effect on angiogenesis, migration, immune response and refractive index of cellular structures in glioblastoma

Glioblastoma is one of the most aggressive tumours with a poor response to treatment and a poor prognosis for patients. One of the proteins expressed in glioblastoma tissue is CHI3L1 (YKL-40), which is upregulated and known for its angiogenesis-supporting and pro-tumour immunomodulatory effects in a variety of cancers. In this paper we present the anti-angiogenic, anti-migratory and immunomodulatory effects of the compound G721–0282, an inhibitor of CHI3L1. The inhibitor-induced changes were investigated using conventional techniques as well as the novel label-free digital holographic tomography (DHT), a quantitative phase imaging technique that allows the reconstruction of the refractive index (RI), which is used as an image contrast for 3D visualisation of living cells. DHT allowed digital staining of individual cells and intercellular structures based only on their specific RI. Quantitative spatially resolved analysis of the RI data shows that the concentration of G721–0282 leads to significant changes in the density of cells and their intracellular structures (in particular the cytoplasm and nucleus), in the volume of lipid droplets and in protein concentrations. Studies in the U-87 MG glioblastoma cell line, THP-1 monocytes differentiated into macrophages, human microvascular endothelial cells (HMEC-1) and in the spheroid model of glioblastoma composed of U-87 MG, HMEC-1 and macrophages suggest that inhibition of CHI3L1 may have potential in the antitumour treatment of glioblastoma. In this paper, we also propose a spheroid model for in vitro studies that mimics this type of tumour.

Influence of Tribolayer on Rolling Bearing Fatigue Performed on an FE8 Test Rig—A Follow-up

The tribological contact between raceways and rolling elements is essential for rolling bearing performance and lifetime. The geometrical description of these contacts is well known and can be used in several mechanical simulation tools. The material description, especially of the near-surface volume after interaction with lubricants, is not as simple. In particular, the Schaeffler FE8-25 test with cylindrical roller thrust bearings exhibits different failure modes depending on the lubricant chemistry. The main failure mechanisms of this test are sub-surface fatigue damage due to WECs (White Etching Cracks) and/or surface-induced fatigue damage (SIF). The harsh test conditions with mixed friction at high speeds and multiple slip conditions over the raceway width additionally provides different tribological conditions on a small area. This leads finally to the formation of certain tribological layers on the raceway because of the interaction of the surface with the lubricant chemistry under local frictional energies, which are worth investigating. The characterization of the layers was performed by the two less time-consuming, spatially resolved analysis methods of µXRF and ATR FTIR microscopy adapted by Schaeffler. This paper shows the results of this research and offers new approaches to optimizing rolling bearing testing and predicting the risk of early failures.

Solvation free energy arithmetic for small organic molecules.

Solvent-mediated interactions contribute to ligand binding affinities in computational drug design and provide a challenge for theoretical predictions. In this study, we analyze the solvation free energy of benzene derivatives in water to guide the development of predictive models for solvation free energies and solvent-mediated interactions. We use a spatially resolved analysis of local solvation free energy contributions and define solvation free energy arithmetic, which enable us to construct additive models to describe the solvation of complex compounds. The substituents analyzed in this study are carboxyl and nitro-groups due to their similar sterical requirements but distinct interactions with water. We find that nonadditive solvation free energy contributions are primarily attributed to electrostatics, which are qualitatively reproduced with computationally efficient continuum models. This suggests a promising route for the development of efficient and accurate models for the solvation of complex molecules with varying substitution patterns using solvation arithmetic.

JWST Insight into a Lensed HST-dark Galaxy and Its Quiescent Companion at z = 2.58

Using the novel James Webb Space Telescope (JWST)/NIRCam observations in the A2744 field, we present a first spatially resolved overview of a Hubble Space Telescope (HST)-dark galaxy, spectroscopically confirmed at z = 2.58 with magnification μ ≈ 1.9. While being largely invisible at ∼1 μm with NIRCam, except for sparse clumpy substructures, the object is well detected and resolved in the long-wavelength bands with a spiral shape clearly visible in F277W. By combining ancillary Atacama Large Millimeter/submillimeter Array (ALMA) and Herschel data, we infer that this object is an edge-on dusty spiral with an intrinsic stellar mass log (M */M ⊙) ∼ 11.3 and a dust-obscured star formation rate ∼300 M ⊙ yr−1. A massive quiescent galaxy (log (M */M ⊙) ∼ 10.8) with tidal features lies 2.″0 away (r ∼ 9 kpc), at a consistent redshift as inferred by JWST photometry, indicating a potential major merger. The dusty spiral lies on the main sequence of star formation, and shows high dust attenuation in the optical (3 < A V < 4.5). In the far-infrared, its integrated dust spectral energy distribution is optically thick up to λ 0 ∼ 500 μm, further supporting the extremely dusty nature. Spatially resolved analysis of the HST-dark galaxy reveals a largely uniform A V ∼ 4 area spanning ∼57 kpc2, which spatially matches to the ALMA 1 mm continuum emission. Accounting for the surface brightness dimming and the depths of current JWST surveys, unlensed analogs of the HST-dark galaxy at z > 4 would be only detectable in F356W and F444W in an UNCOVER-like survey, and become totally JWST-dark at z ∼ 6. This suggests that detecting highly attenuated galaxies in the Epoch of Reionization might be a challenging task for JWST.

Combination of Digital Image Correlation (DIC) and in situ 3D-μ-CT in the analysis of the relationship between strains and porosity under creep loading

Abstract In situ 3D μ-XCT allows the time and space resolved measurement and analysis of material damage in the component volume, whereas the Digital Image Correlation (DIC) is a 2D method for the analysis of deformation measured on the surfaces of components. In situ 3D μ-XCT measurements were performed on cylindrical specimen made of SiC particle reinforced titanium MMC (MMC: Metal Matrix Composite) (15 % SiC particles) during creep load. The formation and evolution of voids were subsequently analyzed. Due to the rotationally symmetric sample geometry, the analysis of the deformation in the interior of the material by DIC using 2D slices is possible and evident. The dot pattern required to calculate the strain using DIC (speckle pattern) is provided by the intrinsic particle reinforcement of the MMCs. Temporally and locally changing and time-variant strain fields in both the tensile as well as the compressive range could be detected correlating with void formation and development area.

Proteomic Insights into Cardiac Fibrosis: From Pathophysiological Mechanisms to Therapeutic Opportunities.

Cardiac fibrosis is a common pathophysiologic process in nearly all forms of heart disease which refers to excessive deposition of extracellular matrix proteins by cardiac fibroblasts. Activated fibroblasts are the central cellular effectors in cardiac fibrosis, and fibrotic remodelling can cause several cardiac dysfunctions either by reducing the ejection fraction due to a stiffened myocardial matrix, or by impairing electric conductance. Recently, there is a rising focus on the proteomic studies of cardiac fibrosis for pathogenesis elucidation and potential biomarker mining. This paper summarizes the current knowledge of molecular mechanisms underlying cardiac fibrosis, discusses the potential of imaging and circulating biomarkers available to recognize different phenotypes of this lesion, reviews the currently available and potential future therapies that allow individualized management in reversing progressive fibrosis, as well as the recent progress on proteomic studies of cardiac fibrosis. Proteomic approaches using clinical specimens and animal models can provide the ability to track pathological changes and new insights into the mechanisms underlining cardiac fibrosis. Furthermore, spatial and cell-type resolved quantitative proteomic analysis may also serve as a minimally invasive method for diagnosing cardiac fibrosis and allowing for the initiation of prophylactic treatment.

Stochastic analysis of micro-cone penetration tests in snow

Abstract. Cone penetration tests have long been used to characterize snowpack stratigraphy. With the development of sophisticated digital penetrometers such as the SnowMicroPen, vertical profiles of snow hardness can now be measured at a spatial resolution of a few micrometers. By using small penetrometer tips at this high vertical resolution, further details of the penetration process are resolved, leading to many more stochastic signals. An accurate interpretation of these signals regarding snow characteristics requires advanced data analysis. Here, the failure of ice connections and the pushing aside of separated snow grains during cone penetration lead to a combination of (a) diffusive noise, as in Brownian motion, and (b) jumpy noise, as proposed by previous dedicated inversion methods. The determination of the Kramers–Moyal coefficients enables differentiating between diffusive and jumpy behaviors and determining the functional resistance dependencies of these stochastic contributions. We show how different snow types can be characterized by this combination of highly resolved measurements and data analysis methods. In particular, we show that denser snow structures exhibited a more collective diffusive behavior supposedly related to the pushing aside of separated snow grains. On less dense structures with larger pore space, the measured hardness profile appeared to be characterized by stronger jump noise, which we interpret as related to breaking of a single cohesive bond. The proposed methodology provides new insights into the characterization of the snowpack stratigraphy with micro-cone penetration tests.

Microstructure and corrosion investigation of FeCoCrNiMo0,5(MnAl)0,3 high entropy alloy produced by 316 L stainless steel scrap

FeCrCoNiMo 0,5 (MnAl) 0.3 high-entropy alloy (HEA) was manufactured via arc melting process by adding the related metal powders into scrap of 316L stainless steel for corrosion resistance tests under salt and acid conditions. Cyclic potentiodynamic polarization experiments performed under acidic conditions revealed pre-passivation due to abundance of network modifying metals in HEA composition which was further analyzed by electrochemical impedance spectroscopy. Elemental resolved analysis of leftover solutions was used to compare metal ions released during corrosion. X-ray diffraction analysis indicated the phase change in heat treated HEA samples. Non-heat treated HEA samples can be compared with stainless steel under moderate corrosion conditions and had better hardness results.