Stenalpheops anacanthus Miya, 1997 is a commensal alpheid shrimp that inhabits burrows shared with other crustaceans and possesses a distinctive caudal appendix. In this study, scanning electron microscopy was used to examine the morphology of this structure and its associated surface structures. The caudal appendix is narrow and lamellar, gradually tapering from base to tip and exhibiting incomplete longitudinal curling. Apparent segmentation results from periodic constrictions along the lateral margins. The surface features numerous circular pores and two types of projections-simple and conical-showing certain external morphological similarities to sensilla on the second antenna. These observations provide a morphological basis for future investigations of the functional significance of this unique appendage and contribute to understanding the evolution of similar appendage structures across different crustacean lineages.
Scanning electron microscopy (SEM) methods were used for the first time to elucidate the external morphology of Patchiella reaumuri reaumuri (Kaltenbach, 1843) (Hemiptera: Aphididae: Pemphiginae). We examined and compared the external morphology of stem mothers and alate viviparous females from the parthenogenetic generation. Analysis identified diverse sensilla types, including coleoconic, campaniform, placoid, and trichoid sensilla, occurring on the antennae, mouthparts, and legs. Beyond the sensilla previously documented in the literature, we identified for the first time in aphids chaetic-type sensilla on the legs of alate viviparous females. In addition, species identity was confirmed by DNA barcoding based on the mitochondrial cytochrome c oxidase subunit I (COI) gene, and the obtained sequence was deposited in GenBank under accession number PP535559.
Accurate 3D topographical metrology of nanoscale semiconductor line patterns is essential for advanced process control. However, inferring 3D depth from single top-down Scanning Electron Microscopy (SEM) images is an inherently ill-posed inverse problem due to the fundamental loss of spatial information. In this paper, we propose a proof-of-concept, physics-driven multi-channel 1D deep learning framework designed to infer 3D line roughness and surface morphologies using models trained exclusively on Monte Carlo electron yield simulations. By integrating a localized multi-line spatial context window into an efficient 1D U-Net architecture, the proposed computational approach successfully mitigates depth ambiguity while bridging the gap between 1D computational efficiency and 2D spatial awareness. Quantitative evaluations on synthetic SEM datasets demonstrate the model's extrapolation robustness across out-of-distribution roughness parameters. Furthermore, frequency-domain analysis via Power Spectral Density (PSD) confirms that our framework effectively mitigates over-smoothing artifacts, faithfully preserving the essential high-frequency stochastic roughness signatures. Finally, we demonstrate the qualitative feasibility of the framework by applying it to experimental SEM images. While generating physically plausible 3D surface profiles, we identify and discuss the synthetic-to-experimental domain shift caused by unmodeled physical phenomena, establishing a clear pathway for future calibration strategies. Ultimately, this research establishes a scalable, non-destructive, and high-throughput computational foundation for 3D morphological profiling, paving the way toward fully quantitative in-line 3D line roughness metrology in next-generation semiconductor manufacturing.
Despite their weak out-of-plane interactions, two-dimensional materials such as WS2 can retain appreciable contamination on their surfaces, complicating characterization in the electron microscope. Polymers and other heavy molecular weight compounds have been historically challenging to remove despite many conventional cleaning procedures attempted. We investigate the influence of sample exfoliation, sample transfer, and sample cleaning methods on contamination levels. While no one method was effective, a combination of solvent, vacuum-oven annealing at high temperatures, and indirect air-plasma cleaning removes pervasive WS2 sheet contaminants. At sufficiently clean levels, electron microscopy characterization such as contamination-sensitive ptychography is performed on these materials.
Interfacial structure and its evolution play an important role in determining the functional properties of advanced materials and devices. However, real oxide heterointerfaces are typically far more complex than idealized abrupt boundaries; thus clarifying how interfacial structures evolve and how such evolution affects physical properties is essential. In this work, NiO/Cr2O3 heterostructures were epitaxially grown on single-crystalline SrTiO3 substrates by pulsed laser deposition under different deposition temperatures and subsequent post-annealing treatment, both of which strongly influence the thermally driven interfacial evolution. Interfacial structures were comprehensively characterized by high-resolution X-ray diffraction and transmission electron microscopy equipped with energy-dispersive X-ray spectroscopy. The evolution is revealed as a transition from an ultrathin interfacial transition zone in the as-deposited NiO/Cr2O3 heterostructure to the formation of a NiCr2O4 reaction interlayer, and finally to a NiO/NiCr2O4 bilayer after high-temperature annealing. Magnetic hysteresis loops measured by a superconducting quantum interference device reveal that all heterostructures exhibit weak ferrimagnetism, accompanied by a non-monotonic change in saturation magnetization with interfacial structural changes. These findings demonstrate that thermally controlled interfacial reactions and structural evolution can generate distinct magnetic characteristics, thereby providing a practical strategy for material interfaces design and performance engineering in functional oxides.
The effect of Ti addition on solidification and intermetallic phase formation in the FeMn40Co10Cr10C0.5 HEA was investigated by combining advanced microscopy with CALPHAD thermodynamic calculations. The Ti-free FeMn40Co10Cr10C0.5 alloy solidified predominantly as an FCC dendritic structure with limited elemental partitioning. In contrast, the addition of 2 at% Ti produced a multiphase microstructure comprising 78.4 vol% FCC matrix, 20.3 vol% Ti-enriched intermetallic phase, and 1.3 vol% TiC, with a mean TiC particle size of ∼0.89 μm. Elemental mapping and line-scan analyses showed relatively uniform distributions of Fe, Mn, Co, and Cr within the FCC matrix, localized Ti enrichment within the interdendritic constituent, and pronounced Ti and C enrichment in discrete carbide particles. The Ti-enriched phase formed an interconnected network along the interdendritic channels. Thermodynamic calculations indicated that this phase becomes stable near the terminal stage of solidification. The results demonstrate that the Ti-enriched intermetallic phase nucleates from the compositionally enriched residual liquid through the combined influence of solidification-induced microsegregation, negative mixing enthalpies between Ti and the transition-metal constituents, and Ti-induced atomic-size mismatch, while TiC precipitates from the remaining liquid.
We present a computational framework for converting a 2D image obtained via electron scanning microscopy to a 3D object with reconstructed invisible interconnections. The approach consists of depth estimation using a perspective- and depth-of-field-corrected grayscale level, followed by the skeletonization of images corresponding to a set of equal depths. The obtained skeletons are further adjusted against their visible counterparts using the Gaussian convolution transform, and the resulting set of images is assembled into a stack of slices that satisfies the requirements of DICOM (Digital Imaging and Communications in Medicine), allowing efficient exploration of spatial structures via software developed for computed tomography. The approach is implemented as computer code and applied to porous structures comprising the polymer component of a recently created organogel exhibiting efficient chemomechanical behavior.
Comprehensive analysis of polycrystalline microstructures, at times, demands information on the size and face-class of individual grains along with its neighbours. In experimental studies, this level of grain- and neighbourhood-resolved information is less routinely available when compared to average grain-size statistics owing to the intricate features of polycrystalline microstructures, which are characterised by closed grains, shared interfaces, and definite neighbour relations. In this work, a junction based algorithm is developed that estimates these critical geometrical and topological features of grains and their neighbours by converting the grain boundary network into a navigable graph. Within this framework, the polycrystalline microstructure is reconstructed as closed loops around individual grains, permitting quantitative estimation of grain size and face-class together with a direct realisation of these geometrical and topological properties of the neighbours. The performance of the algorithm is assessed against manual estimations of grain area obtained from careful boundary tracing, and a convincing agreement is observed, with deviations remaining small for the majority of grains. The topological output is additionally validated by comparing the algorithm-predicted number of sides with manually counted face class, and the full workflow is further demonstrated on an experimentally observed alumina microstructure. A central outcome is the complete digitisation of the available grain boundary network from experimental micrographs, in a form that closely parallels the detailed descriptions usually associated with computational investigations. This enables grain- and neighbourhood-resolved analysis of experimental polycrystalline microstructures, supporting a more comprehensive characterisation than largely size-based statistics.
Differential phase contrast (DPC) imaging in scanning transmission electron microscopy (STEM) is an advanced technique to visualize and measure electric fields in a specimen. With state-of-the-art lens aberration correction, electric fields can be investigated with sub-atomic resolution, opening up the possibility to connect atomic fields to optoelectronic material properties. However, quantitative DPC imaging is only possible for sufficiently thin specimens for which the weak-phase object approximation (WPOA) is generally assumed to be valid. An unambiguous interpretation of DPC measurements remains challenging even for specimen thicknesses of only a few atoms as unexpected electric field and charge density distributions are observed. Here, we present multislice image simulations performed to study the influence of the number of atoms, their atomic number, and the interatomic spacing on quantitative DPC imaging. It is found that the central results of DPC imaging, such as beam deflection and charge density, do not increase linearly nor monotonically with increasing atomic number, making it difficult to quantitatively analyse materials with different atomic species. Furthermore, the presence of two atoms above each other leads to an unexpected increase in the derived maximum positive charge density, which increases for increasing atomic number and results in an overestimation of about 9%. We show that the interpretation of quantitative DPC images is challenging even in the case of only two atoms on top of each other.
Scanning ion conductance microscopy (SICM) has emerged as an important technique in the biomedical field due to its non-contact, nanoscale imaging capabilities, but the slow imaging speed limits its ability to capture dynamic biological processes. Undersampling combined with computational reconstruction presents a promising paradigm to accelerate imaging. However, existing compressed sensing (CS) and deep learning methods either yield suboptimal reconstruction quality or require abundant training data that are difficult to acquire for SICM. To address these challenges, we propose a zero-shot super-resolution (SR) framework that uses artificial neural networks to reconstruct high-fidelity images from undersampled SICM measurements. By exploiting internal image statistics, the method extracts training samples solely from the input itself to train an image-specific SR network, eliminating the reliance on external datasets. Comparative experiments demonstrate that the proposed method achieves superior reconstruction accuracy compared to bicubic interpolation, CS, and the baseline zero-shot SR (ZSSR) algorithms, while exhibiting robust performance across random initialization. Furthermore, it attains comparable reconstruction quality with significantly fewer sampling points than CS methods, thereby enabling faster SICM imaging. Reconstruction experiments under noisy conditions further demonstrate the effectiveness of the proposed method in practical SICM applications. This work offers a practical strategy for high-speed SICM imaging and suggests a promising pathway for enhancing imaging speed in other data-scarce scanning probe microscopy techniques.
The structure of individual biological molecules can be investigated using scanning tunneling microscopy (STM). The stability and imaging precision of the STM are critically important for visualizing biological molecules, particularly in challenging solution conditions. In this paper, we present a newly constructed liquid-phase STM that features dual imaging modes and high stability, capable of simultaneously achieving high-precision atomic-level imaging via a small piezoelectric tube and large-area morphological imaging via a larger piezoelectric tube. High-quality atomic images of graphite obtained with smaller piezoelectric tube, along with the low drift rates measured under solution conditions, clearly demonstrate the STM's excellent stability and high precision. Furthermore, high-resolution morphologies of plasmid and DNA, as well as the dynamic folding process of nucleosomes, were resolved using the larger piezoelectric tube, highlighting the instrument's capability for investigating active biological molecules. Our results significantly advance the high-resolution STM study of biological samples under liquid conditions.
In this publication, we study the influence of strain and alloying on the mean inner potential (MIP) using density functional theory (DFT) within an augmented plane waves plus local orbitals (APW+LO) basis set. Two major effects have been identified allowing to model the influence of strain and alloying on the mean inner potential with a reasonable accuracy. First, alloying for constant volume results in a linear relationship between the MIP and the concentration. Second, the MIP scales with changes in volume as we already pointed out in an earlier publication [Appl. Phys. Lett. 85, 4938-4940 (2004)]. Specifically, a linear relationship between MIP and concentration x was found for AlxGa1-xAs (nearly no change in lattice parameter), whereas InxGa1-xP and GexSi1-x (volume changes with concentration x) exhibits a clear bowing. The bowing can be modelled by taking the rescaling of the MIP with the varying volume additionally into account. The rescaling could be also used to model the dependence of the MIP on strained binary cells and the density dependence of e.g. amorphous materials.
Moniligastrids are regarded as the most primitive group of earthworms; unlike Crassiclitellata, they lack a multilayered clitellum and produce yolky (mesolecithal) eggs, with some peculiarities in their reproductive systems not seen in other earthworms or Clitellata. While Moniligastridae have undergone classical morphological studies on reproductive organ localization and gross morphology, no reports detail ovary histology and ultrastructure. Here, using light and electron microscopy, histochemistry, and DNA barcoding, we analyzed Drawida pellucida from India to describe the ovary micromorphology and follow oogenesis. In the species studied, paired ovaries are feathery with multiple elongated lobes surrounding the intestine in segment XI. No ovarian chamber is present. Proximal lobe parts connect to the septum, housing oogonia and early meiotic cells (till diplotene), united into small germline cysts (≤10 cells). The cysts feature crassiclitellate-like architecture: a few cells interconnected by ring canals to a thin reticular cytophore. Distal regions contain growing oocytes appearing individual, lacking ring canals or cytophore. Notably, no nurse cells were observed, which is surprising as they occur in all studied clitellates to date. We propose to term these ovaries "Drawida" type due to substantial morphological and organizational differences from other earthworms. As oogenesis progresses, oocytes detach from ovarian lobes and gather in large, sac-shaped and irregularly thickened ovisacs, where they finalize yolk uptake. Oocytes are small (∼100 µm diameter), mesolecithal, rich in proteinaceous yolk and lipids. We also provide molecular markers for the studied species and compare the ovary/oogenesis with Crassiclitellata, aiding the debate on moniligastrid phylogeny.
Accurate detection of nanoparticles in transmission electron microscopy (TEM) images is essential for high-throughput characterization in chemistry and materials science. TEM micrographs of advanced photocatalysts often contain densely packed and overlapping nanoparticles, creating electron-dense regions where individual particle boundaries cannot be resolved. This challenges accurate particle counting, sizing, and morphological analysis, and motivates the development of reliable automated analysis workflows. Here, we present a deep learning workflow for robust nanoparticle detection that combines YOLO for fast and reliable localization with the Segment Anything Model (SAM) for pixel-level refinement of particle contours. The TEM dataset consists of newly developed photocatalysts, including undoped and noble metal (Ag, Pd, Ni), doped ZnO, TiO₂, Ni/g-C₃N₄, CdS, heterojunction copper(I/II) oxides, ZnO mixed metal oxides, and metal-organic frameworks. These novel materials produce distinctive TEM images with both well-separated and heavily overlapping nanoparticles. Multiple YOLO variants, including YOLOv8s, YOLOv8x, YOLOv11s, YOLOv12s, and YOLO26s, were benchmarked for nanoparticle detection. The YOLO-generated bounding boxes were subsequently refined using SAM to obtain accurate pixel-level segmentations of resolvable nanoparticles. Performance is evaluated on both the challenging TEM dataset and external literature images using standard metrics and confusion matrices. The proposed workflow was further benchmarked against widely used manual and semi-automated TEM analysis methods, demonstrating superior robustness, accuracy, and consistency, particularly in regions with severe particle overlap. Overall, this workflow provides an efficient and scientifically rigorous framework for high-throughput characterization of resolvable nanoparticles in complex TEM micrographs while avoiding unsupported measurements in regions where individual particle boundaries cannot be objectively determined.
A comprehensive micromorphological analysis of leaf surfaces was conducted on three model species of the genus Crataegus L. - Crataegus monogyna Jacq., Crataegus sanguinea Pall., and Crataegus submollis Sargent. - representing three subgenera: Crataegus, section Crataegus; Sanguineae, section Sanguineae Zabel ex C. K. Schneid.; and Americanae, section Coccineae Loudon (subtribe Malinae, Rosaceae). The study encompassed developmental stages from bud to mature leaf. Previously undescribed colleters were found on leaf blades and stipules of all species, which differed in petiolar colleter presence and traits. Intensive secretion occurred during intra-bud and early extra-bud stages. Secretory products accumulated in intercellular and periplasmic spaces and were released upon rupture of cell walls and cuticle; the secretion contained a red fluorochrome (715 nm). All species exhibited anomocytic/stephanocytic stomata on the abaxial leaf surface. Stomata were largest in C. monogyna and smallest in C. sanguinea. However, rare stomata were observed on the adaxial surface of leaf blades in C. monogyna, as well as on the adaxial side of marginal teeth in C. submollis and C. sanguinea. All three species showed stomatal dimorphism, radial cuticular (lateral) folds, and an annular folding (marginal stomatal ring). However, in C. monogyna, pronounced radial folds were observed only in larger primary stomata. Prominent cuticular folding was present on the adaxial epidermis of this species, accompanied by well-developed epicuticular wax on the abaxial side. By contrast, C. submollis and C. sanguinea showed weak adaxial folding and no abaxial wax deposits. These micromorphological traits may thus serve as valuable taxonomic markers within Malinae and Maleae (Rosaceae).
Collagen type-IV (Col-IV) is the principal basement membrane structural component of the blood-gas barrier (BGB) to which the strength, i.e., the structural integrity, of the profoundly thin tissue barrier of the lung has been attributed. In this study, Col-IV was immunolocalized and the spatial organization, and relative volume density in the exchange tissues (ETs) of the lung of an adult common quail (Coturnix coturnix) was determined. Formalin-fixed paraffin-embedded lung sections were immunolabeled with anti-collagen IV monoclonal primary antibody and detected using Alexa Fluor 488-conjugated secondary antibody, prior to confocal laser scanning microscopy. Three-dimensional reconstructions were prepared from the acquired image datasets to allow visualization of the spatial arrangement of Col-IV in the ETs. The volume densities of Col-IV in the BGB, the epithelial-epithelial cell connections, and the blood capillary-blood capillary connections were determined by the stereological method of point-counting. Three-dimensional reconstructions showed heterogeneous, vast distribution of Col-IV within the BGB. In the parabronchial ETs, Col-IV continues centripetally, i.e., inwards, to connect to the atrial smooth muscles. The structural feature shows existence of a functional continuum that may strengthen the parabronchus, contributing to the rigidity of the air- and the blood capillaries. The high-volume density of Col-IV in the ETs (∼20%) of the lungs of the investigated adult common quail indicates its significance as a structural component. The abundance and the organization of Col-IV in the ETs underpins its importance in stabilizing the lung histo-architecture, particularly the exceptionally thin BGB. The findings provide insights that may inform on optimal biomimetic designs of artificial gas-exchange membranes.
Xylem-feeding insects experience extreme mechanical and nutritional constraints, requiring highly specialised mouthparts and feeding apparatus to extract sap under negative pressure. While adults have been extensively studied, the ultrastructural and functional organization of nymphal feeding systems remains poorly understood. Here, we investigated the mouthparts and feeding apparatus of Philaenus spumarius nymphs using scanning electron microscopy and synchrotron radiation-based X-ray phase contrast micro-computed tomography, complementing the study with three-dimensional reconstructions. Our results show that nymphal feeding apparatus shares the same general organization as that of adults, including a three-segmented labium, elongated stylets, a complex salivary system, and a powerful cibarial pump. The labial sensory apparatus is largely conserved across developmental stages, suggesting that nymphs rely on similar sensory cues as adults during feeding site selection. Detailed reconstruction of the maxillary and mandibular stylets revealed a complex system composed of functional and presumptive (formative) stylets connected with several muscles. Moreover, we revealed the precibarial valve complex and its complete sealing mechanism of the food canal in the resting state. Overall, our results show that P. spumarius nymphs have a highly specialised and efficient xylem-feeding apparatus, closely linked in function to that of adults, while also exhibiting important adaptations unique to this developmental stage. This study provides new insights into the biomechanics of xylem feeding insects and contributes to a more comprehensive understanding of feeding adaptations during insects development.
This paper reports the presence of telocytes in the choroid, a pigmented vascular tissue layer of the eye, as examined by scanning and transmission electron microscopy. These cells are reported to occur in the stroma of heart, reproductive tissues, digestive tract, skin, lungs and excretory organs. In the choroid of the teleost Clarius gariepinus, telocytes are widespread over the entire area of the choroidal stroma. Their processes, called telopodes, are rather thin (<0.2 µm in diameter) and exceptionally longer (>50 µm), which branch into 3-5 short processes. These processes are intimately associated with the stromal collagen, melanocytes, and blood vessel walls. They formed homotypic contacts with adjacent telocytes, and heterocellular contacts with fibroblasts, mast cells, lymphocytes, macrophages and iridophores. Most cellular features were common in the choroidal telocytes that were described elsewhere in other organs of mammals. This study recognizes that telocytes are a regular cellular component of the choroid, and their intimate relationship with the stromal cells raises the possibility that they might play some hitherto unknown functions for those cells.
Crystals, such as quartz, table salt various gems and snowflakes, were noticed and documented by humankind for as long as we have records, but it took the development of microscope lenses to observe crystallization in detail. Robert Hooke used his 30X power compound microscope to describe crystals in his 1665 master work Micrographia. Leeuwenhoek was a Delft haberdasher, town hall chamberlain and metrologist, and creator of the world's most powerful microscopes until the last quarter of the 19th-century. He was the first person to observe and document dynamic crystallization and sublimation processes. Antoni Leeuwenhoek observed and documented the processes of crystallization and sublimation in dynamic detail, documenting the changes in letters to The Royal Society and to others. Unlike Hooke, who attended Oxford University, Leeuwenhoek was from the Dutch mercantile class and had little formal education. He is thought to have acquired a copy of Micrographia and, possibly inspired by Hooke's observations, would send improved descriptions to The Royal Society of materials Hooke had described (for instance, various fungi and insect parts). Hooke could not have been his only influence, as Leeuwenhoek's observations seem to concentrate on crystals forming from herbaceous materials used by physicians and found in an apothecary. The highly detailed nature of his observations also hints at influences, probably provided second-hand by some of his physician friends, at other influences. He documented these processes with his usual poetic flair, and his usual tendency to observe anything he thought might be interesting, including crystals found in plants and those found in gout sufferers. He sketched out what he saw, although he knew his drawing skills were poor, a fact he related in his correspondence. Examples of his observations, including illustrations and relevant comments from the various editors of his collected letters, are presented.
