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Plasmonic catalysis holds the promise of opening new reaction pathways that are inaccessible thermally or via direct UV–vis electronic transitions. Here, energetic carriers produced via the decay of surface plasmons excited by visible light at 532 nm (2.33 eV, green) on a Ag-grating-bearing pyrolytic carbon residue drive its transformation into light-emitting graphitized carbon dots. The pyrolytic carbon residue is detectable via high-magnification surface-enhanced Raman scattering but cannot be directly observed using optical, electron, atomic force, or helium ion microscopy. When a Ag-grating-bearing pyrolyzed residue is introduced into a high-purity O2-depleted gas environment (Ar, N2, and CO2) and excited with 532 nm light, bright yellow luminescence emerges and is readily observed. Light emission is not observed without the pyrolytic carbon, without the excitation of plasmons, or in air or an Ar/O2 gas mixture. This process, driven by visible light and a nanostructured Ag surface bearing pyrolytic carbon, will be of interest to researchers involved in plasmonic catalysis, catalytic processes involving carbon, and luminescent plasmonic surfaces. [ABSTRACT FROM AUTHOR]

In-depth statistics of individual defects observed during transmission electron microscopy (TEM) experiments are essential for the thorough characterization of materials. In this study, we aim to quantitatively characterize the population of dislocation loops in ion-irradiated CrFeMnNi alloys. To this end, we propose an efficient guideline to prepare TEM micrographs dataset for deep learning analysis, adapted for accurate characterization of microstructures produced by thousands of overlapping defects, a very common situation in TEM images, unfeasible by previous existing methods. To reduce human effort, we annotate only a few images and complement the database through a two-step process: initially, singular value decomposition to normalize image background, followed by a controlled data augmentation. The performed analysis provides precise quantitative information about the number of loops of different types, as well as their spatial distribution, their size, and the inter-object distances. These characteristics provide insights into the nucleation, mobility, and growth of dislocation loops, as well as the elastic anisotropy of the material. Our results emphasize how accurate analysis of complex microstructures can provide insights into the physical properties of materials and open up many perspectives for attaining quantitative information on materials properties based solely on their image analysis. [ABSTRACT FROM AUTHOR]

Herein, integrating GaN quantum dots (QDs) within a resonant cavity is focused on. Utilizing metal‐organic vapor phase epitaxy, controlled growth of GaN QDs on AlN is achieved. A deep‐UV distributed Bragg reflector (DBR) with high reflectivity in the 250–300 nm range, using AlN and Al0.7Ga0.3N layers to maximize refractive index contrast, is developed. A 50‐period DBR achieves 98% reflectivity at a wavelength of 272 nm. Scanning transmission electron microscopy and electron energy loss spectroscopy analyses reveal a trisection of DBR periods, attributed to a Ga composition pulling effect during growth. The real structure's reflectivity is simulated and matched well with measured data, though actual reflectivity is lower than the ideal. Cathodoluminescence studies at T = 17 K show emission peaks from both the DBR and the GaN QDs. Further, single‐photon emission is demonstrated with a g(2)(t = 0) value of 0.41 at 272.7 nm, confirming the potential for deep‐UV single‐photon sources. Additionally, the creation of a planar resonant cavity with enhanced emission intensity and vertical nanopillar structures with an aspect ratio of 11 and a diameter of 400 nm confirm the successful integration of GaN QDs in advanced UV photonic structures. [ABSTRACT FROM AUTHOR]

Single impurities in insulators are now often used for quantum sensors and single photon sources, while nanoscale semiconductor doping features are being constructed for electrical contacts in quantum technology devices, implying that new methods for sensitive, non‐destructive imaging of single‐ or few‐atom structures are needed. X‐ray fluorescence (XRF) can provide nanoscale imaging with chemical specificity, and features comprising as few as 100 000 atoms have been detected without any need for specialized or destructive sample preparation. Presently, the ultimate limits of sensitivity of XRF are unknown – here, gallium dopants in silicon are investigated using a high brilliance, synchrotron source collimated to a small spot. It is demonstrated that with a single‐pixel integration time of 1 s, the sensitivity is sufficient to identify a single isolated feature of only 3000 Ga impurities (a mass of just 350 zg). With increased integration (25 s), 650 impurities can be detected. The results are quantified using a calibration sample consisting of precisely controlled numbers of implanted atoms in nanometer‐sized structures. The results show that such features can now be mapped quantitatively when calibration samples are used, and suggest that, in the near future, planned upgrades to XRF facilities might achieve single‐atom sensitivity. [ABSTRACT FROM AUTHOR]

This paper presents an analysis of the field ion emission mechanism of tungsten–epoxy nanocomposite emitters and compares their performance with that of tungsten nano-field emitters. The emission mechanism is described using the theory of induced conductive channels. Tungsten emitters with a radius of 70 nm were fabricated using electrochemical polishing and coated with a 20 nm epoxy resin layer. Characterization of the emitters, both before and after coating, was performed using electron microscopy and energy-dispersive X-ray spectroscopy (EDS). The Tungsten nanocomposite emitter was tested using a field ion microscope (FIM) in the voltage range of 0–15 kV. The FIM analyses revealed differences in the emission ion density distributions between the uncoated and coated emitters. The uncoated tungsten tips exhibited the expected crystalline surface atomic distribution in the FIM images, whereas the coated emitters displayed randomly distributed emission spots, indicating the formation of induced conductive channels within the resin layer. The atom probe results are consistent with the FIM findings, suggesting that the formation of conductive channels is more likely to occur in areas where the resin surface is irregular and exhibits protrusions. These findings highlight the distinct emission mechanisms of both emitter types. [ABSTRACT FROM AUTHOR]

Physiologically relevant concentrations in biological tissue, in the in vivo, state are of the order of μmol L−1 and mmol L−1. Up to the present, mapping the major elements in the matrix and its thickness has been neglected, despite their importance for quantification of lesser and trace element concentrations. Ryan and Jamieson's dynamic analysis, statistical spectral decomposition approach, is developed to quantitatively measure ex vivo tissue sections cut using a cryomicrotome. This mitigates the problem that physical analysis methods require a vacuum environment. This approach is used to quantitatively image the major matrix elements H, C, N, and O as well as trace maps of Ca, Fe, and Zn in a tissue section of porcine intestine. This sample is selected as it exhibits a complex morphology with multiple tissue compartments (such as muscle and mucosa, as well as void areas from blood vessels, lymph ducts, sinuses crypts, and villi. In the results, it is demonstrated that different tissue types can have a different matrix composition and thickness. Using this information, quantitative maps and elemental molarities for the lesser and trace elements Ca, Fe, and Zn are obtained. [ABSTRACT FROM AUTHOR]

The local charge density and distribution of extracellular membranes play a crucial role in the various cellular processes, such as regulation and localization of membrane proteins, electrophysiological signal transduction, transcriptional control, cell growth, and cell death. In this study, a novel scanning ion conductance microscopy‐based method is employed to extracellular membrane mapping. This method allows to not only visualize the dynamic topography and surface charge distribution around individual cells, but also distinguish the charge difference. To validate the accuracy and effectiveness of this method, the charge density on model sample surfaces are initially manipulated and the charge sensing mechanism using finite element modeling (FEM) is explored subsequently. By applying this method, both the extracellular charge distributions and topography structures of normal and senescent human dental pulp stem cells (hDPSCs) are able to monitor. Interestingly, it is observed that the surface charge became significantly more negative after cellular senescence. This innovative approach enables us to gain valuable insights into surface charge changes during cellular senescence, which can contribute to a better understanding of the underlying mechanisms and potential therapeutic strategies for age‐related diseases. [ABSTRACT FROM AUTHOR]

Microwave-based reactions have gained traction in recent years due to their ability to enhance reaction rates and yield while reducing energy consumption. Also, according to the conception of 'waste to materials', various waste feeds are intensively sought to be tested. The experimental setup of this study involved varying pH levels, oxidation agents, and precipitation agents to optimize the synthesis process of iron red based on waste iron sulfate. The selection of oxidation and precipitation agents was found to significantly influence the pigment synthesis process. Various oxidizing agents, including hydrogen peroxide and atmospheric air, were evaluated for their effectiveness in promoting the oxidation of ferrous ions to ferric ions, essential for pigment formation. Additionally, different precipitation agents such as sodium hydroxide and ammonia solution were assessed for their ability to precipitate iron hydroxides and facilitate pigment particle formation. The characterization of synthesized pigments revealed promising results in terms of quality and color properties. Helium Ion Microscopy (HIM) analysis confirmed the formation of well-defined pigment particles with controlled morphology. X-ray diffraction (XRD) studies provided insights into the crystalline structure of the pigments, indicating the presence of characteristic iron oxide phases. By improving this technology, waste iron sulfate can be efficiently transformed into valuable iron pigments, offering a sustainable solution for waste management while meeting the growing demand for high-quality pigments. [ABSTRACT FROM AUTHOR]

Modern science is dependent on imaging on the nanoscale, often achieved through processes that detect secondary electrons created by a highly focused incident charged particle beam. Multiple types of measurement noise limit the ultimate trade-off between the image quality and the incident particle dose, which can preclude useful imaging of dose-sensitive samples. Existing methods to improve image quality do not fundamentally mitigate the noise sources. Furthermore, barriers to assigning a physically meaningful scale make the images qualitative. Here, we introduce ion count-aided microscopy (ICAM), which is a quantitative imaging technique that uses statistically principled estimation of the secondary electron yield. With a readily implemented change in data collection, ICAM substantially reduces source shot noise. In helium ion microscopy, we demonstrate 3x dose reduction and a good match between these empirical results and theoretical performance predictions. ICAM facilitates imaging of fragile samples and may make imaging with heavier particles more attractive. [ABSTRACT FROM AUTHOR]

[Display omitted] Colorectal cancer (CRC), a widespread malignancy, is closely associated with tumor microenvironmental hydrogen peroxide (H 2 O 2) levels. Some clinical trials targeting H 2 O 2 for cancer treatment have revealed its paradoxical role as a promoter of cancer progression. Investigating the dynamics of cancer cell H 2 O 2 eustress at the single–cell level is crucial. In this study, non–contact hopping probe mode scanning ion conductance microscopy (HPICM) with high-sensitive Pt–functionalized nanoelectrodes was employed to measure dynamic extracellular to intracellular H 2 O 2 gradients in individual colorectal cancer Caco–2 cells. We explored the relationship between cellular mechanical properties and H 2 O 2 gradients. Exposure to 0.1 or 1 mmol/L H 2 O 2 eustress increased the extracellular to intracellular H 2 O 2 gradient from 0.3 to 1.91 or 3.04, respectively. Notably, cellular F–actin–dependent stiffness increased at 0.1 mmol/L but decreased at 1 mmol/L H 2 O 2 eustress. This H 2 O 2 –induced stiffness modulated AKT activation positively and glutathione peroxidase 2 (GPX2) expression negatively. Our findings unveil the failure of some H 2 O 2 -targeted therapies due to their ineffectiveness in generating H 2 O 2 , which instead acts eustress to promote cancer cell survival. This research also reveals the complex interplay between physical properties and biochemical signaling in cancer cells' antioxidant defense, illuminating the exploitation of H 2 O 2 eustress for survival at the single–cell level. Inhibiting GPX and/or catalase (CAT) enhances the cytotoxic activity of H 2 O 2 eustress against CRC cells, which holds significant promise for developing innovative therapies targeting cancer and other H 2 O 2 - related inflammatory diseases. [ABSTRACT FROM AUTHOR]

Scanning ion conductance microscopy (SICM) enables the non-invasive three-dimensional imaging of live cells and other structures in physiological environments. However, when imaging complex samples, SICM faces challenges such as having a low temporal resolution during slow scanning and a reduced signal-to-noise ratio during fast scanning, making it difficult to simultaneously improve both temporal and spatial resolution. To address these issues, this paper proposes an algorithm for enhancing image resolution under high-speed scanning. Firstly, scanning images are preprocessed using a median filtering algorithm to remove the salt-and-pepper noise generated during high-speed scanning. Next, the Canny edge detection algorithm is employed to extract the edges of the image targets. To avoid blurring the edges, the new edge-directed interpolation (NEDI) algorithm is then used to fill the edges, while non-edge areas are filled using bilinear interpolation, thereby enhancing the image resolution. Finally, the peak signal-to-noise ratio (PSNR) and structural similarity index (SSIM) are used to analyze the imaging of articular chondrocytes. The results show that under a scanning speed of 480 nm/ms, the proposed algorithm improves the temporal resolution of imaging by 60% compared to traditional 2× resolution imaging, increases the peak signal-to-noise ratio of the scanning images by 7 dB, and achieves a structural similarity of 0.97. Therefore, the proposed algorithm effectively removes noise during high-speed scanning and improves the SICM scanning imaging resolution, thereby avoiding the reduction in temporal resolution when scanning larger resolution samples and effectively enhancing the performance of SICM scanning imaging. [ABSTRACT FROM AUTHOR]

Non-destructive analysis of the composition and structure of various ancient Chinese currencies, including two Ming-style knife money from the Zhou Dynasty and nineteen square-holed coins from the Tang and Northern Song Dynasties are presented. The knife money are estimated to have been minted around 360 to 255 B.C., while the nineteen square-holed coins are estimated to have been minted between 621 and 1117 A.D. All currency, except for the bent knife money, was analyzed non-destructively using synchrotron radiation X-ray diffraction and scanning electron microscopy with focused ion beam and energy dispersive spectroscopy to determine their structure (phases present), microstructure, and elemental distribution. The currency was generally found to be composed of primarily a CuSn alloy with small amounts of Pb and Fe and trace amounts of other elements and oxides. The main phase present in all coins examined using synchrotron radiation X-ray diffraction is an FCC CuSn alloy along with FCC reflections from the traces of Pb. The immiscible Pb within these Cu-based alloys was found to be distributed as small globules or islands ranging between 10 and 80 μm and scattered throughout the Cu-based matrix. Scanning electron microscopy with energy dispersive spectroscopy provided some microstructural and elemental distribution information, but analysis was made difficult due to corrosion/oxidation at the surface which cannot be removed non-destructively. Synchrotron radiation X-ray diffraction was much more helpful in providing crystallographic orientation and phases as it could be used to measure the bulk material of the samples past the relatively thinly oxidized surface. While authenticity of the currency is difficult to determine, the presence of Pb is a good indicator as it is not commonly used in modern CuSn alloys. [ABSTRACT FROM AUTHOR]

Solid-state nanopores have become a prominent tool in the field of single-molecule detection. Conventional solid-state nanopores are thick, which affects the spatial resolution of the detection results. Graphene is the thinnest 2D material and has the highest spatial detection resolution. In this study, a graphene membrane chip was fabricated by combining a MEMS process with a 2D material wet transfer process. Raman spectroscopy was used to assess the quality of graphene after the transfer. The mechanism behind the influence of the processing dose and residence time of the helium ion beam on the processed pore size was investigated. Subsequently, graphene nanopores with diameters less than 10 nm were fabricated via helium ion microscopy. DNA was detected using a 5.8 nm graphene nanopore chip, and the appearance of double-peak signals on the surface of 20 mer DNA was successfully detected. These results serve as a valuable reference for nanopore fabrication using 2D material for DNA analysis. [ABSTRACT FROM AUTHOR]

Deeper understanding of processes involved in operation of lithium‐ion batteries (LIBs) is necessary to further optimize them for future applications. Extensive research was conducted on the formation of a solid electrolyte interphase (SEI) on negative battery electrodes, still leaving several questions unanswered. Scanning probe microscopies (SPMs) enable in situ and operando investigations and have the potential to explain some phenomena. Scanning electrochemical microscopy (SECM) and scanning ion conductance microscopy (SICM) could be employed in LIB studies. A novel SICM method based on the redox couple ferrocene/ferrocenium is introduced for applications in carbonate solvents widely used in LIBs. Proof of concept measurements were conducted with a micro milled copper circuit board as model substrate. Furthermore, the proposed SICM approach was hyphenated with feedback mode SECM resulting in the simultaneous mapping of morphology and electrochemical activity. A flexible dual‐probe arrangement was developed enabling usage of both SPM techniques at the same time, and furthermore, an easy replacement of both individual probes if needed. The setup was applied in the characterisation of commercial graphite electrodes for LIBs before and after conducting a pre‐charging protocol. Changes in electrochemical activity and topography of the graphite electrode were resolved in simultaneously generated SECM/SICM recordings. [ABSTRACT FROM AUTHOR]

The microstructure is a critical factor governing the functionality of ceramic materials. Meanwhile, microstructural analysis of electron microscopy images of polycrystalline ceramics, which are geometrically complex and composed of countless crystal grains with porosity and secondary phases, has generally been performed manually by human experts. Objective pixel-based analysis (semantic segmentation) with high accuracy is a simple but critical step for quantifying microstructures. In this study, we apply neural network-based semantic segmentation to secondary electron images of polycrystalline ceramics obtained by three-dimensional (3D) imaging. The deep-learning-based models (e.g., fully convolutional network and U-Net) by employing a dataset based on a 3D scanning electron microscopy with a focused ion beam is found to be able to recognize defect structures characteristic of polycrystalline materials in some cases due to artifacts in electron microscopy imaging. Owing to the training images with improved depth accuracy, the accuracy evaluation function, intersection over union (IoU) values, reaches 94.6% for U-Net. These IoU values are among the highest for complex ceramics, where the 3D spatial distribution of phases is difficult to locate from a 2D image. Moreover, we employ the learned model to successfully reconstruct a 3D microstructure consisting of giga-scale voxel data in a few minutes. The resolution of a single voxel is 20 nm, which is higher than that obtained using a typical X-ray computed tomography. These results suggest that deep learning with datasets that learn depth information is essential in 3D microstructural quantifying polycrystalline ceramic materials. Additionally, developing improved segmentation models and datasets will pave the way for data assimilation into operando analysis and numerical simulations of in situ microstructures obtained experimentally and for application to process informatics. [ABSTRACT FROM AUTHOR]

Cytomegalovirus (CMV), a type of herpes virus, is the predominant cause of congenital anomalies due to intrauterine infections in humans. Adverse outcomes related to intrauterine infections with human cytomegalovirus (HCMV) vary widely, depending on factors such as fetal infection timing, infection route, and viral virulence. The precise mechanism underlying HCMV susceptibility remains unclear. In this study, we compared the susceptibility of neonatal human dermal fibroblast cells (NHDFCs) and human induced pluripotent stem cells (hiPSCs) derived from NHDFCs, which are genetically identical to HCMV, using immunostaining, microarray, in situ hybridization, quantitative PCR, and scanning electron microscopy. These cells were previously used to compare CMV susceptibility, but the underlying mechanisms were not fully elucidated. HCMV susceptibility of hiPSCs was significantly lower in the earliest phase. No shared gene ontologies were observed immediately post-infection between the two cell types using microarray analysis. Early-stage expression of HCMV antigens and the HCMV genome was minimal in immunostaining and in in situ hybridization in hiPSCs. This strongly suggests that HCMV does not readily bind to hiPSC surfaces. Scanning electron microscopy performed using the NanoSuit method confirmed the scarcity of HCMV particles on hiPSC surfaces. The zeta potential and charge mapping of the charged surface in NHDFCs and hiPSCs exhibited minimal differences when assessed using zeta potential analyzer and scanning ion conductance microscopy; however, the expression of heparan sulfate (HS) was significantly lower in hiPSCs compared with that in NHDFCs. Thus, HS expression could be a primary determinant of HCMV resistance in hiPSCs at the attachment level. [ABSTRACT FROM AUTHOR]

In situ analysis of surfaces during high-flux plasma exposure represents a long-standing challenge in the study of plasma–material interactions. While post-mortem microscopy can provide a detailed picture of structural and compositional changes, in situ techniques can capture the dynamic evolution of the surface. In this study, we demonstrate how spectroscopic ellipsometry can be applied to the real-time characterization of W nanostructure (also known as "fuzz") growth during exposure to low temperature, high-flux He plasmas. Strikingly, over a wide range of sample temperatures and helium fluences, the measured ellipsometric parameters (Ψ , Δ) collapse onto a single curve that can be directly correlated with surface morphologies characterized by ex situ helium ion microscopy. The initial variation in the (Ψ , Δ) parameters appears to be governed by small changes in surface roughness (<50 nm) produced by helium bubble nucleation and growth, followed by the emergence of 50 nm diameter W tendrils. This basic behavior appears to be reproducible over a wide parameter space, indicating that the spectroscopic ellipsometry may be of general practical use as a diagnostic to study surface morphologies produced by high-flux He implantation in refractory metals. An advantage of the methods outlined here is that they are applicable at low incident ion energies, even below the sputtering threshold. As an example of this application, we apply in situ ellipsometry to examine how W fuzz growth is affected both by varying ion energy and the temperature of the surface. [ABSTRACT FROM AUTHOR]

Mechanical properties of living cells play a crucial role in a wide range of biological functions and pathologies, including atherosclerosis. We used low-stress Scanning Ion-Conductance Microscopy (SICM) correlated with confocal imaging and demonstrated the topographical changes and mechanical properties alterations in EA.hy926 and THP-1 exposed to LDL extracted from CVD patients' blood samples. We show that the cells stiffened in the presence of LDL, which also triggered caveolae formation. Endothelial cells accumulated less cholesterol in the form of lipid droplets in comparison to THP-1 cells based on fluorescence intensity data and biochemical analysis; however, the effect on Young's modulus is higher. The cell stiffness is closely connected to the distribution of lipid droplets along the z-axis. In conclusion, we show that the sensitivity of endothelial cells to LDL is higher compared to that of THP-1, triggering changes in the cytoskeleton and membrane stiffness which may result in the increased permeability of the intima layer due to loss of intercellular connections and adhesion. [ABSTRACT FROM AUTHOR]

Systems with a focused ion beam, using gas field ion sources, are described. The principles of operation and ways of formation of these sources, in which the effective ionization region is determined by sizes of a single atom, are considered in the historical context. The described systems have a wide range of applications, both in the field of scanning ion microscopy in combination with various analytical methods and in the field of high-resolution modification of electrical, optical, magnetic, and other properties of materials. This modification, based on ion-induced changes in the structure of material, is most pronounced in crystalline semiconductors, superconductors, and magnets. [ABSTRACT FROM AUTHOR]

The article discusses the advanced characterization of materials in electronic devices using atom probe tomography (APT). APT, providing sub-nanometer 3D maps with high analytical sensitivity, is highlighted for its role in understanding failure modes influenced by material choice, processing methods, and service conditions. Topics include the evolution of APT, experimental overview, scope of material characterization, and examples of its applications in electronic devices.

High‐voltage cathode active materials, such as LiNi0.5Mn1.5O4 (LNMO), are of major interest for the development of high‐energy lithium‐ion batteries. However, it has been reported that composite cathodes based on high‐voltage active materials suffer from high impedances and low rate capabilities. The origin of the high impedances has not yet been clarified. Here, we use a combination of electrochemical impedance spectroscopy (EIS), focused ion beam/scanning electron microscopy/energy‐dispersive X‐ray spectroscopy (FIB/SEM/EDX) and time‐of‐flight secondary ion mass spectrometry (ToF‐SIMS) for showing that in the case of LNMO‐based cathodes, a major part of the cathode impedance is related to the formation of a passivating interphase on the Al current collector. Remarkably, the impedance of this interphase can be mitigated by the targeted formation of a distinct passivating interphase, namely on the surface of the LNMO particles. The interplay between these interphases is discussed. [ABSTRACT FROM AUTHOR]

Visualizing micro- and nano-scale biological entities requires high-resolution imaging and is conventionally achieved via optical microscopic techniques. Optical diffraction limits their resolution to ∼200 nm. This limit can be overcome by using ions with ∼1 MeV energy. Such ions penetrate through several micrometers in tissues, and their much shorter de Broglie wavelengths indicate that these ion beams can be focused to much shorter scales and hence can potentially facilitate higher resolution as compared to the optical techniques. Proton microscopy with ∼1 MeV protons has been shown to have reasonable inherent contrast between sub-cellular organelles. However, being a transmission-based modality, it is unsuitable for in vivo studies and cannot facilitate three-dimensional imaging from a single raster scan. Here, we propose proton-induced acoustic microscopy (PrAM), a technique based on pulsed proton irradiation and proton-induced acoustic signal collection. This technique is capable of label-free, super-resolution, 3D imaging with a single raster scan. Converting radiation energy into ultrasound enables PrAM with reflection mode detection, making it suitable for in vivo imaging and probing deeper than proton scanning transmission ion microscopy (STIM). Using a proton STIM image of HeLa cells, a coupled Monte Carlo+k-wave simulations-based feasibility study has been performed to demonstrate the capabilities of PrAM. We demonstrate that sub-50 nm lateral (depending upon the beam size and energy) and sub-micron axial resolution (based on acoustic detection bandwidth and proton beam pulse width) can be obtained using the proposed modality. By enabling visualization of biological phenomena at cellular and subcellular levels, this high-resolution microscopic technique enhances understanding of intricate cellular processes. [ABSTRACT FROM AUTHOR]

Growth cones of oligodendrocyte progenitor cells (OPCs) are challenging to investigate with conventional light microscopy due to their small size. Especially substructures such as filopodia, lamellipodia and their underlying cytoskeleton are difficult to resolve with diffraction limited microscopy. Light microscopy techniques, which surpass the diffraction limit such as stimulated emission depletion microscopy, often require expensive setups and specially trained personnel rendering them inaccessible to smaller research groups. Lately, the invention of expansion microscopy (ExM) has enabled super-resolution imaging with any light microscope without the need for additional equipment. Apart from the necessary resolution, investigating OPC growth cones comes with another challenge: Imaging the topography of membranes, especially label- and contact-free, is only possible with very few microscopy techniques one of them being scanning ion conductance microscopy (SICM). We here present a new imaging workflow combining SICM and ExM, which enables the visualization of OPC growth cone nanostructures. We correlated SICM recordings and ExM images of OPC growth cones captured with a conventional widefield microscope. This enabled the visualization of the growth cones' membrane topography as well as their underlying actin and tubulin cytoskeleton. [ABSTRACT FROM AUTHOR]

About 9 wt.% Cr steels are widely used in the design and fabrication of thick section components in combined cycle or coal-fired applications for working temperatures of 600 ~ 650°C. This family of materials possesses a martensitic microstructure stabilised by precipitates. The presence of nitrides, inclusions or evolution of second-phase particles may increase the metallurgical risk to creep. The chemical composition and microstructural evolution of 9 wt.% Cr steels contribute to thermal stability and long-term performance. In some specialist alloys, Ta is added to the composition which causes the formation of fine MX precipitates which are only present at the nanometre scale in tempered martensite, which hinders the recovery of dislocations and the migration of laths to extend creep life. However, the presence of large Ta-containing particles or inclusions in the 9 wt.% Cr steels may have a detrimental effect on its creep performance, as they may act as preferred sites for cavity nucleation. To fully appreciate the development of damage in these steels, it is necessary to link the pre- and post-test conditions, evaluate damage in the parent metal, develop procedures that provide consistency of results, and obtain statistically relevant data. The evolution of the Ta-containing phase has been tracked and quantified using a variety of correlative characterisation approaches. Utilising focused ion beam microscopy and two-dimensional electron-based microscopic characterisation, three-dimensional tomography has identified a strong relationship between creep cavities and Ta-containing phases from the early stages of creep. [ABSTRACT FROM AUTHOR]

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3D-Li ion batteries are identified as one of the most promising technologies for improving portable and safe energy storage devices. One of the main remaining challenges to be tackled in that regard is the manufacture of efficient nanostructured electrode materials. In this paper, we report on the first realization of an electrochemically active cathodic LixCoyOz material grown via a thermal atomic layer deposition process based on the combination of Co(thd)2 and Li(thd) organometallic ligands and O3 as an oxidizing agent. Comprehensive characterizations comprising XPS, Raman, HIM (helium ion microscopy)-SIMS, and the first ever SEM images of a thermal-atomic layer deposition (ALD) deposited LixCoyOz material are shown and discussed as well and the very first electrochemical results to attest the electrochemical activity of the deposited material. Those results act as the first demonstration that lithiated materials and more precisely, LixCoyOz, can be grown via an advanced thermal ALD. [ABSTRACT FROM AUTHOR]

Viruses come in various shapes and sizes, and understanding their morphology is central to understanding their activity and function. The need for fast recognition and real-time fingerprinting methods for pathogenic viruses is a critical bottleneck in implementing many diagnostic and therapeutic techniques. In this work, nanopore tomography (NT) is implemented for fast measurements of the characteristic dimensions of viruses and the optimal operating conditions are explored. Using a small filamentous bacteriophage as a model, it is demonstrated that NT can detect geometrical features in a few-nanometer regime, with high throughput and accuracy, in aqueous conditions. The instrumental parameters are optimized to obtain virus diameter measurements that are robust to the uncertainties of the external parameters. Furthermore, NT is critically compared to various single-particle imaging techniques, with a particular emphasis on emerging helium ion microscopy (HIM). It is shown that, with proper operating procedures, HIM can reach a nanometer-scale resolution in viral metrology, while retaining a high throughput second only to NT. The high throughput of both techniques can foster sufficient statistics for a precise exploration of viral heterogeneity. [ABSTRACT FROM AUTHOR]

Polymeric membranes are useful tools for water filtration processes, with their performance strongly dependent on the presence of hydrophilic dopants. In this study, polyaniline (PANI)-capped aluminosilicate (halloysite) nanotubes (HNTs) are dispersed into polyether sulfone (PES), with concentrations ranging from 0.5 to 1.5 wt%, to modify the properties of the PES membrane. Both undoped and HNT-doped PES membranes are investigated in terms of wettability (static and time-dependent contact angle), permeance, mechanical resistance, and morphology (using scanning electron microscopy (SEM)). The higher water permeance observed for the PES membranes incorporating PANI-capped HNTs is, finally, assessed and discussed vis-à-vis the real distribution of HNTs. Indeed, the imaging and characterization in terms of composition, spatial arrangement, and counting of HNTs embedded within the polymeric matrix are demonstrated using non-destructive Micro Particle Induced X-ray Emission (µ-PIXE) and Scanning Transmission Ion Microscopy (STIM) techniques. This approach not only exhibits the unique ability to detect/highlight the distribution of HNTs incorporated throughout the whole thickness of polymer membranes and provide volumetric morphological information consistent with SEM imaging, but also overcomes the limits of the most common analytical techniques exploiting electron probes. These aspects are comprehensively discussed in terms of practical analysis advantages. [ABSTRACT FROM AUTHOR]

Atomic layer engineering is investigated to tailor the morphotropic phase boundary (MPB) between antiferroelectric, ferroelectric, and paraelectric phases. By increasing the HfO2 seeding layer with only 2 monolayers, the overlying ZrO2 layer experiences the dramatic phase transition across the MPB. Conspicuous ferroelectric properties including record‐high remanent polarization (2Pr ≈ 60 µC cm−2), wake‐up‐free operation, and high compatibility with advanced semiconductor technology nodes, are achieved in the sub‐6 nm thin film. The prominent antiferroelectric to ferroelectric phase transformation is ascribed to the in‐plane tensile stress introduced into ZrO2 by the HfO2 seeding layer. Based on the high‐resolution and high‐contrast images of surface grains extracted precisely by helium ion microscopy, the evolution of the MPB between tetragonal, orthorhombic, and monoclinic phases with grain size is demonstrated for the first time. The result indicates that a decrease in the average grain size drives the crystallization from the tetragonal to polar orthorhombic phases. [ABSTRACT FROM AUTHOR]

We present a novel framework, Opto-SICM, for studies of cellular interactions in live cells with high spatiotemporal resolution. The approach combines scanning ion conductance microscopy, SICM, and cell-type-specific optogenetic interrogation. Light-excitable cardiac fibroblasts (FB) and myofibroblasts (myoFB) were plated together with non-modified cardiomyocytes (CM) and then paced with periodic illumination. Opto-SICM reveals the extent of FB/myoFB-CM cell-cell contacts and the dynamic changes over time not visible by optical microscopy. FB-CM pairs have lower gap junctional expression of connexin-43 and higher contact dynamism compared to myoFB-CM pairs. The responsiveness of CM to pacing via FB/myoFB depends on the dynamics of the contact but not on the area. The non-responding pairs have higher net cell-cell movement at the contact. These findings are relevant to cardiac disease states, where adverse remodeling leads to abnormal electrical excitation of CM. The Opto-SICM framework can be deployed to offer new insights on cellular and subcellular interactions in various cell types, in real-time. Opto-SCIM combines scanning ion conductance microscopy with optogenetic interrogation to study the hetero-cellular interactions between cardiac fibroblasts or myofibroblasts and cardiomyocytes. [ABSTRACT FROM AUTHOR]

[Display omitted] • ECAM enables advanced nano/microstructure fabrication. • Issues of ECAM, instability, structure–property links, and applications elucidated. • Enhancing 3D nano-resolutions via controlled printing parameters. • Recent applications of ECAM in strength enhancement summarized via literature. • Perspectives on challenges and new approaches in ECAM discussed briefly. Electrochemical additive manufacturing (ECAM) has emerged as a promising cluster of technologies with the potential to fabricate complex 3D micro/nanostructures within a diverse range of materials, serving a broad spectrum of applications. However, significant obstacles must be overcome in order to realize its full potential and produce durable materials capable of competing with present cutting-edge offers. For this, the current review provides an extensive overview of the state-of-the-art ECAM technologies including localized electrochemical deposition (LED), meniscus-confined electrodeposition (MCED), electrohydrodynamic redox printing (EHD-RP), fluid FM electrodeposition, and scanning ion conductance microscopy (SICM) and emphasizes esoteric developments in these technologies. Here, we deeply explore recent advances in printability of diverse material, structure–property correlations, dimensionality control, theoretical investigations, and modeling initiatives followed by the outline of difficulties and trends influencing the emerging research. This review, directs its focus toward the emerging scenarios of ECAM technologies, shedding light on their unique operational mechanisms and their potential utilization across numerous engineering domains, including micro-electronics (chips and circuits), energy storage (batteries and supercapacitors) sensing (electrochemical and SERS sensor), decorative art (warli art, spiritual, and abstract designs), electromagnetic shielding, catalysis and separation, to bridge the existing gaps between material properties and applications precisely. Inconclusive remarks, we discussed our perspective with unique ideas that can be used to collectively focus on this field to achieve freeform production of various materials for commercialization. [ABSTRACT FROM AUTHOR]

In an interview with FocalPlane, Lucy Collinson, Head of the Electron Microscopy Science Technology Platform at The Francis Crick Institute, discusses her career and the advancements in volume EM technology. She emphasizes the importance of collaboration and effective communication in scientific research, as well as the need to preserve ultrastructure in sample preparation for improved accuracy in techniques like super-resolution light microscopy and high-resolution X-ray imaging. Collinson also highlights her involvement in citizen science and outreach projects, including her work with the Zooniverse platform and education programs with primary and secondary schools. She mentions that her team works on numerous projects with Crick scientists each year and praises FocalPlane as a valuable communication tool for the microscopy community. [Extracted from the article]

The small conductance Ca2+-activated K+ current (I SK) is a potential therapeutic target for treating atrial fibrillation. To clarify, in rabbit and human atrial cardiomyocytes, the intracellular [Ca2+]-sensitivity of I SK , and its contribution to action potential (AP) repolarisation, under physiological conditions. Whole-cell-patch clamp, fluorescence microscopy: to record ion currents, APs and [Ca2+] i ; 35–37°C. In rabbit atrial myocytes, 0.5 mM Ba2+ (positive control) significantly decreased whole-cell current, from −12.8 to −4.9 pA/pF (P < 0.05, n = 17 cells, 8 rabbits). By contrast, the I SK blocker apamin (100 nM) had no effect on whole-cell current, at any set [Ca2+] i (∼100–450 nM). The I SK blocker ICAGEN (1 μM: ≥2 x IC 50) also had no effect on current over this [Ca2+] i range. In human atrial myocytes, neither 1 μM ICAGEN (at [Ca2+] i ∼ 100–450 nM), nor 100 nM apamin ([Ca2+] i ∼ 250 nM) affected whole-cell current (5–10 cells, 3–5 patients/group). APs were significantly prolonged (at APD 30 and APD 70) by 2 mM 4-aminopyridine (positive control) in rabbit atrial myocytes, but 1 μM ICAGEN had no effect on APDs, versus either pre-ICAGEN or time-matched controls. High concentration (10 μM) ICAGEN (potentially I SK -non-selective) moderately increased APD 70 and APD 90 , by 5 and 26 ms, respectively. In human atrial myocytes, 1 μM ICAGEN had no effect on APD 30–90 , whether stimulated at 1, 2 or 3 Hz (6–9 cells, 2–4 patients/rate). I SK does not flow in human or rabbit atrial cardiomyocytes with [Ca2+] i set within the global average diastolic-systolic range, nor during APs stimulated at physiological or supra-physiological (≤3 Hz) rates. [Display omitted] • Inhibiting the cardiac atrial cell ion current "I SK " can prevent atrial fibrillation. • Whether I SK flows in healthy cells with normal internal Ca2+ levels is under debate. • The I SK blockers apamin and ICAGEN did not affect I SK in rabbit or human atrial cells. • I SK inhibition also did not affect action potentials, even at high stimulation rates. • We add weight to the argument that I SK does not flow in healthy cardiac atrial cells. [ABSTRACT FROM AUTHOR]

This study evaluated the effect of a 0.5% chloramine T solution on a chemical-cured universal adhesive by comparing the light-cured, one-step, self-etch adhesive for the bonding performance, mechanical properties, and resin–dentin interfacial characteristics. Caries-free human molars were randomly assigned into eight groups based on the bonding systems employed (Bond Force II, BF and Bondmer Lightless, BL), the immersion solutions used before bonding (0.5% chloramine T solution and distilled water), and the immersion durations (5 and 60 min). Microtensile bond strength (μTBS), nanoleakage evaluation, and nanoindentation tests were performed, and the surface morphology of the resin–dentin interface was examined using a focus ion beam/scanning ion microscopy system. Immersion in chloramine-T for 5 min significantly decreased the μTBS of Bondmer Lightless (from 22.62 to 12.87 MPa) compared with that in distilled water. Moreover, there was also a decreasing trend after immersing in chloramine-T for 60 min (from 19.11 to 13.93 MPa). Chloramine T was found to have no effect on the hardness, elastic modulus, or morphological characteristics of the ion-beam milled resin–dentin interfacial surfaces in the tested adhesives, suggesting that chloramine T might reduce the bond strength by interfering with the interaction and the sealing between the adhesive resin and dentin in the chemical-cured universal adhesive, albeit without affecting the mechanical properties. [ABSTRACT FROM AUTHOR]

A cell's mechanical properties have been linked to cancer development, motility and metastasis and are therefore an attractive target as a universal, reliable cancer marker. For example, it has been widely published that cancer cells show a lower Young's modulus than their non-cancerous counterparts. Furthermore, the effect of anti-cancer drugs on cellular mechanics may offer a new insight into secondary mechanisms of action and drug efficiency. Scanning ion conductance microscopy (SICM) offers a nanoscale resolution, non-contact method of nanomechanical data acquisition. In this study, we used SICM to measure the nanomechanical properties of melanoma cell lines from different stages with increasing metastatic ability. Young's modulus changes following treatment with the anti-cancer drugs paclitaxel, cisplatin and dacarbazine were also measured, offering a novel perspective through the use of continuous scan mode SICM. We found that Young's modulus was inversely correlated to metastatic ability in melanoma cell lines from radial growth, vertical growth and metastatic phases. However, Young's modulus was found to be highly variable between cells and cell lines. For example, the highly metastatic cell line A375M was found to have a significantly higher Young's modulus, and this was attributed to a higher level of F-actin. Furthermore, our data following nanomechanical changes after 24 hour anti-cancer drug treatment showed that paclitaxel and cisplatin treatment significantly increased Young's modulus, attributed to an increase in microtubules. Treatment with dacarbazine saw a decrease in Young's modulus with a significantly lower F-actin corrected total cell fluorescence. Our data offer a new perspective on nanomechanical changes following drug treatment, which may be an overlooked effect. This work also highlights variations in cell nanomechanical properties between previous studies, cancer cell lines and cancer types and questions the usefulness of using nanomechanics as a diagnostic or prognostic tool. [ABSTRACT FROM AUTHOR]

Scanning ion-conductance microscopy allowed us to document an external Ca2+ dependent ATP driven volume increase (ATPVI) in capacitated human sperm heads. We examined the involvement of purinergic receptors (PRs) P2X2R and P2X4R in ATPVI using their co-agonists progesterone and Ivermectin (Iver), and Cu2+, which co-activates P2X2Rs and inhibits P2X4Rs. Iver enhanced ATPVI and Cu2+ and 5BDBD inhibited it, indicating P2X4Rs contributed to this response. Moreover, Cu2+ and 5BDBD inhibited the ATP-induced acrosome reaction (AR) which was enhanced by Iver. ATP increased the concentration of intracellular Ca2+ ([Ca2+] i) in >45% of individual sperm, most of which underwent AR monitored using FM4-64. Our findings suggest that human sperm P2X4R activation by ATP increases [Ca2+] i mainly due to Ca2+ influx which leads to a sperm head volume increase, likely involving acrosomal swelling, and resulting in AR. • External ATP induces a volume increase (ATPVI) in capacitated human sperm heads. • Ivermectin enhances ATPVI and Cu2+, and 5BDBD inhibits it, indicating P2X4Rs contributes to this response. • The ATP-induced acrosome reaction showed the same pharmacological profile as ATPVI. • ATP increased intracellular Ca2+ in 45% of sperm, most of which underwent AR. • P2X4R activation causes ATPVI, putative acrosomal swelling, and results in AR. [ABSTRACT FROM AUTHOR]

The emerging use of two-dimensional (2D) nanomaterials as boundary lubricants in water offers numerous benefits over oil-based lubricants; whereas the friction reduction varies significantly with nanomaterial type, size, loading, morphology, etc. Graphene oxide (GO) and Ti3C2Tx MXene, a relatively new 2D material, are investigated as boundary lubricants in water in this study. The contact pair mainly includes Si3N4 balls and Si wafer. The results found (1) monodispersed GO offers better lubricity than monodispersed MXene under identical concentration and testing conditions; and (2) the mixed dispersion of GO and MXene (0.1 mg/ml: 0.1 mg/ml) produced the lowest friction coefficient of ∼ 0.021, a value 4× and 10× lower than that produced by comparable mono-dispersions of GO or MXene, respectively. Wear track analysis, focused ion beam microscopy, in-situ contact observation, and atomic force microscopy (AFM) characterization suggest (1) GO nanoflakes have higher adhesion than MXene and are more easily adsorbed on the tribopairs' surfaces, and (2) GO/MXene tribofilm has a layered nanostructure constituting GO, MXene, amorphous carbon, and TiO2. We further hypothesized that the high lubricity of GO/MXene results from the synergy of GO's high adhesiveness, MXene's load support ability, and the low shear strength of both constituents. The present study highlights the key role of tribofilm stability in water-based boundary lubrication using state-of-the-art 2D nanomaterials. [ABSTRACT FROM AUTHOR]

Recent advances have rapidly facilitated development of new and improved high-resolution, high-throughput volume electron microscopy techniques. Investigating cell structures and interactions at higher resolution and in three dimensions is becoming increasingly important in parasitology. Understanding the different capabilities of light, X-ray, electron, and ion microscopy technologies is essential for choosing the right technique to solve current and challenging parasitology research questions. Volume electron microscopy techniques are underutilised in most fields of parasitology despite recent improvements in accessibility, user-friendliness, and cost. To best understand parasite, host, and vector morphologies, host–parasite interactions, and to develop new drug and vaccine targets, structural data should, ideally, be obtained and visualised in three dimensions (3D). Recently, there has been a significant uptake of available 3D volume microscopy techniques that allow collection of data across centimetre (cm) to Angstrom (Å) scales by utilising light, X-ray, electron, and ion sources. Here, we present and discuss microscopy tools available for the collection of 3D structural data, focussing on electron microscopy-based techniques. We highlight their strengths and limitations, such that parasitologists can identify techniques best suited to answer their research questions. Additionally, we review the importance of volume microscopy to the advancement of the field of parasitology. [ABSTRACT FROM AUTHOR]

High density nanotwinned copper films were pulse electroplated using an optimized electrolyte. In order to find out the influencing factors on the formation of nanotwins, series contents of MPS were added to the electrolyte during the pulse electroplating process. It was found that the copper films electroplated without MPS had large grains but a few nanotwins. And the grain size was about 0.9 mm on average, and the texture components of (110) and (111) crystal orientations were calculated as 49% and 27.8%, respectively. Differently, when 10 ppm MPS was added, the microstructure was changed to columnar grain with high density of horizontal nanotwins and the crystal orientation was also changed to highly (111) orientated one. However, when the MPS content was continuously increased from 10 ppm to 40 ppm, the microstructure and crystal orientation were almost unchanged as detected by the secondary ion microscopy of focus ion beam and X ray diffraction. Specifically, when 40 ppm MPS was used, the average grain size was 0.6 mm, and the texture components of (110) and (111) crystal orientations were 3.45% and 95.1%, respectively. It demonstrated that the nanotwinned copper can be electroplated at a large concentration range of MPS, which also meant that the filling ability of nanotwinned copper electrolyte could be adjusted by MPS content without influencing the microstructure. Finally, these electrolytes with different contents of MPS were used in the Damascene via filling. The results showed that when the content of MPS was 40 ppm, the Damascus via was completely filled without voids. The achievement of via filling with nanotwinned copper makes the application of nanotwinned copper possible in Integrated Circuit (IC) fabrication, which also greatly promotes the development of interconnected material for next generation. [ABSTRACT FROM AUTHOR]

Background: Investigations into the growth and self-organization of plant roots is subject to fundamental and applied research in various areas such as botany, agriculture, and soil science. The growth activity of the plant tissue can be investigated by isotope labeling experiments with heavy water and subsequent detection of the deuterium in non-exchangeable positions incorporated into the plant biomass. Commonly used analytical methods to detect deuterium in plants are based on mass-spectrometry or neutron-scattering and they either suffer from elaborated sample preparation, destruction of the sample during analysis, or low spatial resolution. Confocal Raman micro-spectroscopy (CRM) can be considered a promising method to overcome the aforementioned challenges. The substitution of hydrogen with deuterium results in the measurable shift of the CH-related Raman bands. By employing correlative approaches with a high-resolution technique, such as helium ion microscopy (HIM), additional structural information can be added to CRM isotope maps and spatial resolution can be further increased. For that, it is necessary to develop a comprehensive workflow from sample preparation to data processing. Results: A workflow to prepare and analyze roots of hydroponically grown and deuterium labeled Zea mays by correlative HIM-CRM micro-analysis was developed. The accuracy and linearity of deuterium detection by CRM were tested and confirmed with samples of deuterated glucose. A set of root samples taken from deuterated Zea mays in a time-series experiment was used to test the entire workflow. The deuterium content in the roots measured by CRM was close to the values obtained by isotope-ratio mass spectrometry. As expected, root tips being the most actively growing root zone had incorporated the highest amount of deuterium which increased with increasing time of labeling. Furthermore, correlative HIM-CRM analysis allowed for obtaining the spatial distribution pattern of deuterium and lignin in root cross-sections. Here, more active root zones with higher deuterium incorporation showed less lignification. Conclusions: We demonstrated that CRM in combination with deuterium labeling can be an alternative and reliable tool for the analysis of plant growth. This approach together with the developed workflow has the potential to be extended to complex systems such as plant roots grown in soil. [ABSTRACT FROM AUTHOR]

Spurred by a need to determine major (C, H, N and O) contents in biological tissue sections, a formalism for quantitative off-axis Scanning Transmission Ion Microscopy (OA-STIM) has been established. This can be used with, or without, simultaneous Elastic Backscattering Spectroscopy (EBS) to provide quantitative major element composition and thickness information. As part of the work, an empirical predictor with one free parameter for the proton–proton differential scattering cross section was implemented. The predictor values were in extremely close agreement with high accuracy literature data. For 2 MeV p– 12 C elastic scattering at forward angles ≤ 45°an interpolation procedure was used to determine the relative deviations from the Rutherford cross sections were determined to be ≤ 6. 4 %. The interpolation was based on a Coulomb field, angular momentum quantum number and nuclear structure dependent nuclear penetration factor. Finally, the quantitative combination of simultaneous OA-STIM and EBS data is discussed. [Display omitted] • A formalism to facilitate quantitative analysis of off-axis Scanning Transmission Ion Microscopy has been established. • An empirical predictor with one free parameter for the differential proton–proton scattering cross section d σ p − p / d Ω has been implemented. • The 12 C(p,p) 12 C cross section at ≤ 45 ° and 2 MeV deviates from the Rutherford value by a small amount. • The forward scattering cross sections at 2 MeV and ≤ 45 ° for 14 N(p,p) 14 and 16 O(p,p) 16 O likely deviate only slightly from the classical value. [ABSTRACT FROM AUTHOR]

In this study the oxide layer of technical 6xxx aluminium surfaces, pickled as well as passivated, were comparatively investigated by means of transmission electron microscopy (TEM), Auger electron and X-ray photoelectron spectroscopy (AES, XPS), the latter in two different operating modes, standard and angle resolved mode. In addition, confocal microscopy and focused ion beam cutting were used for structural studies of the surfaces and for specimen preparation. The results illustrate in detail the strengths and weaknesses of each measurement technique. TEM offers a direct way to reliably quantify the thickness of the oxide layer, which is in the range of 5 nm, however, on a laterally restricted area of the surface. In comparison, for AES, the destructiveness of the electron beam did not allow to achieve comparable results for the thickness determination. XPS was proven to be the most reliable method to reproducibly quantify the average oxide thickness. By evaluating the angle resolved XPS data, additional information on the average depth distribution of the individual elements on the surface could be obtained. The findings obtained in this study were then successfully used for the investigation of the increase in the aluminium oxide thickness on technical samples during an aging test of 12 months under standard storage conditions. [ABSTRACT FROM AUTHOR]

Atom probe (AP) is an elemental analysis technique that ionizes surface atoms by a strong field formed by a sharp needle-shaped sample and identifies ions in an atom-by-atom manner by the time of flight mass spectrometer. The detection efficiency of AP has been estimated to be extremely high by the correlation to field ion microscopy (FIM) observations, which show the surface morphology change in atomic scale during the field evaporation of the surface layer. The estimation of detection efficiency has been indirectly done by the comparison of AP data and FIM observation. We evaluated the detection efficiency of AP directly from ion data and counting spot change in FIM images by repeating two measurements sequentially in this work. The experimentally obtained ratio between the detected count over disappeared spots was 10/33 ≈ 0.30, which was ca. 1/2 of the optimal value expected from the opening area ratio of the microchannel plate (∼0.60). [ABSTRACT FROM AUTHOR]

We have developed a SERS stamp that can be pressed directly onto a solid surface for characterization of surface-adsorbed target molecules. The stamp was fabricated by transfer of a dense monolayer of SiO2 nanospheres from a glass surface onto a piece of adhesive tape and subsequent evaporation of silver. The performance of the resulting SERS stamps was evaluated by their exposure to methyl mercaptan vapor, and immersion in rhodamine 6G and ferbam solutions. It was found that beside the nanosphere diameter and metal deposition thickness, the extent of burial of the nanospheres into the adhesive tape, dictated by the pressure during the nanosphere transfer process, had a significant effect. We carried out FDTD calculations of the near field. Models are based on morphological information obtained from helium ion microscopy, which can provide high-resolution images of poor electrical conductors such as our SERS stamp. While one of our main eventual goals is detection of pesticides on agricultural produce, we have begun to take a careful step by testing our SERS stamp on better characterized surfaces such as a porous gel surface, having been immersed in fungicides such as ferbam. We also present our preliminary results with ferbam on oranges. It is expected that our well-characterized SERS stamp will play a role in shedding light on the poorly studied transfer process of target molecules onto a SERS surface as well as serving as a new SERS platform. [ABSTRACT FROM AUTHOR]

A technique to determine the molar concentration of elements in ex vivo tissue sections by Particle Induced X-ray Emission (PIXE) has been developed. The method is based on simultaneous off-axis scanning transmission ion microscopy (OA-STIM) and Elastic Backscattering Spectrometry (EBS) measurement of the sample thickness and major element (H, C, N, O) composition. The method was applied to determine the molarity of localised Ca concentration hot-spots in the outer epithelium tissue of nasal mucosa of a rhesus macaque subject infected with simian immunodeficiency virus (SIV). The results show Ca sequestration in concentration hot-spots and outer epithelial tissue that significantly exceeded the Ca concentration in the surrounding tissues. This may originate from mineralisation and/or Ca enhancement in goblet cells. [Display omitted] Sequestration of Ca in concentration hot-spots in the outer epithelium of nasal mucosa of a subject infect with simian immunodeficiency virus (SIV). • A MeV ion microprobe technique to measure the molarity of life elements in ex-vivo tissue sections has been developed. • The method is based on using the EBS andoff-axis STIM data to determien hte major element composition that is used to refine the PIXE composition. • Ca molarities in nansal mucosal tissue was determined. • Ca sequestration in concentration "hot-spots" was obseerved in a SIV infected subject. [ABSTRACT FROM AUTHOR]

Pioloform®, an often used support film for ion microprobe research is a terpolymer of polyvinyl butyral (PVB) and ≲ 18 mass % polyvinyl alcohol (PVA). Simultaneous off-axis Scanning Transmission Ion Microscopy (OA-STIM) and Elastic Backscattering Spectrometry (EBS) measurements have been used to measure the evolution of the C, H and O contents for an increasing proton fluence. The results showed that the composition at zero proton-fluence was in close agreement with the theoretical atomic composition. This strongly suggests OA-STIM measurements. With increasing proton fluences preferential loss of H and O was observed from the films. [Display omitted] • The thickness and composition of Pioloform® self supporting films was measured with EBS and off-axis STIM. • Proton irradiation induced composition changes of Pioloform were charactorised. • The fluence dependent composition allows Pioloform to be used as an internal reference material. [ABSTRACT FROM AUTHOR]

Focused ion beams have recently emerged as a powerful tool for ultrastructural imaging of biological samples. In this article, we show that helium ion microscopy (HIM), in combination with ion milling, can be used to visualize the inner structure of both major and minor ampullate silk fibers of the orb-web weaving spider Nephila madagascariensis. The internal nanofibrils were imaged in pristine silk fibers, with little or no damage to the sample structure observed. Furthermore, a method to cut/rupture the fibers using He+ ions combined with internal sample tension is presented. This showed that the stretching and rupturing of spider silk is a highly dynamic process with considerable material reorganization. [ABSTRACT FROM AUTHOR]

A secondary ion mass spectrometry (SIMS)‐based isotopic imaging technique of ion microscopy was used for observing calcium influx in single renal epithelial LLC‐PK1 cells. The CAMECA IMS‐3f SIMS instrument, used in the study, is capable of producing isotopic images of single cells at 500 nm spatial resolution. Due to the high‐vacuum requirements of the instrument the cells were prepared cryogenically with a freeze‐fracture method and frozen freeze‐dried cells were used for SIMS analysis. The influx of calcium was imaged directly by exposure of cells to 44Ca stable isotope in the extracellular buffer for 10 min. The 44Ca influx was measured at mass 44 and the distribution of endogenous calcium at mass 40 (40Ca) in the same cell. A direct comparison of interphase cells to cells undergoing division revealed that calcium influx is restricted in metaphase and post‐metaphase stages of cell division. This restriction is lifted in late cytokinesis. The net influx of 44Ca in 10 min was approximately half under calcium influx restriction in comparison to interphase cells. Under calcium influx restriction the 44Ca concentration was the same between the mitotic chromosome and the cytoplasm. These observations indicate that the endoplasmic reticulum (ER) calcium uptake is compromised under calcium influx restriction in cells undergoing division. LAY DESCRIPTION: A mass spectrometry‐based isotopic imaging technique of ion microscopy was used to study the influx of calcium in cells undergoing division. The cells growing in culture were exposed to extracellular nutrient medium made from 44Ca stable isotope for 10 min. The 44Ca influx in interphase and dividing cells was imaged directly with ion microscopy. A comparison of interphase to dividing cells revealed that cells in metaphase and post‐metaphase stages restrict 44Ca influx. This restriction continued through cytokinesis and is lifted in late cytokinesis stage when the daughter cells are barely attached. Physiological implications of such restriction are still to be studied and may include protection of dividing cells from harmful calcium waves. [ABSTRACT FROM AUTHOR]

Field emission microscopy and field ion microscopy (FEM and FIM) of two-dimensional layered material, MoS2, were carried out. MoS2 field emitters were prepared by mechanical peeling of a single crystal and by deposition of MoS2 suspension. FEM exhibited an array of elongated broad spots, and the corresponding FIM images presented patterns consisting of streaked spots and split spots (double spots), depending on electric voltages applied to the emitter. Since the probability of field ionization of imaging gas atoms (Ne gas was used in the present study) is governed by both field strength near surface atomic sites and accessible vacant electronic states, these patterns reflect the atomic site and/or spatial distribution of unoccupied electronic orbitals at the edges of MoS2 layers. [ABSTRACT FROM AUTHOR]