Microscopy (Oxford, England)最新文献

The Li K-L emission spectra of lithium metal and its binary compounds (Li3N, Li2O, and LiF) were measured by using a soft X-ray emission spectrometer (SXES), which was equipped with a newly developed high-efficiency diffraction grating (JS35BC) and attached to an electron probe microanalyzer (EPMA). The new grating enables the observation of the entire intensity profile of both Li K-L and Mg L2,3-M emission spectra. The systematic energy shift of the Li K-L spectra to the lower energy side with an increasing electronegativity (or the ionization tendency) of elements of N, O, and F bonded with the Li atom was clearly detected. This shift was reproduced by theoretical calculations and was assigned mainly due to the change of the binding energy of the valence band of those materials. The main peak and its distinct shoulder structure observed in Li K-L spectrum of LiF were assigned as 2p dominated and 2 s + 2p mixed states, respectively, from the comparison with theoretical calculations.

Osteoporosis frequently presents with lower back pain, often accompanied by hypersensitivity, even in the absence of vertebral fractures, suggesting the involvement of central neuroinflammatory mechanisms. The activation of spinal glia has been implicated as a key driver of pain. Clinical and preclinical studies have also shown that teriparatide (TPTD), a bone anabolic drug, alleviates osteoporotic pain and raises the possibility of anti-neuroinflammatory effects. We previously reported that TPTD suppresses neuroinflammatory microglial proliferation in the spinal dorsal horn of an ovariectomized (OVX) rat model of postmenopausal osteoporosis. To further substantiate these previous findings, this study morphometrically investigated neuroinflammatory alterations in the same patho-pharmacological setting by establishing an AI-driven morphometric pipeline applied to DAB-stained bright-field images. OVX increased the number of microglia, induced process shortening and higher circularity, and expanded GFAP-positive astrocytic areas. TPTD partially attenuated OVX-induced glial changes. These findings indicate that OVX induces spinal neuroinflammation involving both microglia and astrocytes and that TPTD mitigates these neuroinflammatory responses. Moreover, the combination of 2D bright-field imaging and AI-driven morphometry represents a practical, accessible approach that requires minimal specialized equipment, yet sensitively captures OVX- and TPTD-induced microglial alterations, and enables phenotype-based classification.

We discuss the computational treatment of both singlepass systems like those used in microscopy and spectroscopy where careful consideration and control of aberrations is important, as well as multipass system where other priorities arise. This is largely due to the fact that many of the aberrations cancel out when traversing a system repeatedly, which is greatly helped by the adjustment of the linear transfer matrix to be non-resonant. However, some other effects have a tendency to build up over time either linearly or exponentially, and a specific form of analysis is necessary to understand and control this behavior. This is achieved using normal form methods which allow a clear separation of multipass effects that are transient and those that are persistent, as well as the use of symplectic integration. The Differential Algebraic (DA) methods employed in COSY INFINITY allow for the computation of aberrations of arbitrary order and also the relevant normal forms. The tools allow the automatic computation of fully Maxwellian 3D fields if only midplane or on-axis field information is available, which for example allows recovering all nonlinear effects arising from increasing or decreasing fields in the fringes of particle optical elements. They also allow the computation of such fields from surface or volume field measurements, leading to a fully Maxwellian representation even in the presence of noise in the data. Utilizing metrics on symplectic spaces, it is possible to construct minimally invasive symplectification schemes for study of multipass systems based on transfer maps.

The Muon g-2 Experiment (E989) at Fermilab measured the muon anomalous magnetic moment aμ with unprecedented precision of 127 ppb using a storage ring. The experiment pushed the limits in terms of accuracy and systematic errors. Achieving the 78-ppb total systematic uncertainty required precise beam dynamics modeling and corrections for effects on the measured muon precession frequency. We derived the first analytic aberration formulas up to the second order for the muon g-2 storage ring's combined-function electrostatic quadrupoles (superimposed magnetic dipole and electric quadrupole fields) using an order-by-order perturbation method. From these, we obtained the exact chromaticity formulas for three ring models of different granularity and validated them against numerical calculations using COSY INFINITY, achieving analytic-numerical agreement to O(10-10). This work resolved discrepancies between previous approximate derivations and provided essential beam dynamics results for Runs 4-6 analyses. We also calculated nonlinear chromaticities up to ninth order. The experiment completed its final Run 6 in July 2023, collecting 21 times more data than the previous muon g-2 experiment at Brookhaven National Laboratory, with the final result announced in June 2025.

High-resolution structural analysis of adhesive interfaces between resins (soft materials) and inorganic materials (hard materials) is indispensable for understanding the underlying adhesion mechanisms. Scanning transmission electron microscopy-based electron energy-loss spectroscopy (STEM-EELS) is a key technique for obtaining information regarding the local chemical environment at the interfaces between amorphous resins and inorganic materials, such as metals. For realizing high-resolution STEM-EELS analysis, the design of the soft/hard interface model must be optimized. Furthermore, damage to resins caused by ion-beam irradiation during the sample milling must be avoided. Herein, we report an optimized protocol for fabricating specimens of soft/hard interfaces with ultrathin cross-sections for STEM-EELS analysis.

Microscope images are acquired under a wide range of optical conditions-regardless of whether optical alignment is complete-when using projection-type electron microscopes such as transmission, low-energy, photoemission, and mirror electron microscopes. Although paraxial rays and aberration coefficients are often calculated to describe electron optical conditions, image simulations are rarely conducted. Therefore, interpreting images under non-optimal experimental setups, such as misaligned apertures or off-center electron beams, can be challenging for users and electron-optics designers. To address this issue, we developed a fast and simple image-simulation method that is based on paraxial rays and aberration coefficients. As a demonstration, we simulated three types of image effects: field-of-view loss due to displacement of an angular limitation aperture along the optical axis, shadow-contrast formation caused by the angular limitation aperture, and change in images due to lens wobbling. The simulated images well reproduce those commonly observed in daily experiments. The proposed method provides a more intuitive and quantitative understanding of image formation under non-optimal conditions and can serve as a useful tool for both experimentalists and designers in the field of electron optics.

This review focus on the recent advances of practical application of low-vacuum scanning electron microscopy to informative three-dimensional imaging of cell/tissue architectures and biomedical target localization on microscope slides for biomedical sciences and clinical diagnoses. Scanning electron microscopy under low-vacuum conditions allows high-resolution imaging of complex cell/tissue architectures in nonconductive specimens because the negative charge that accumulates on the nonconductive materials can be neutralized by the positive ions in the residual gas molecules. However, the conventional methods for metal staining of biological specimens require harmful uranium compounds, which hampers the applications of electron microscopy. The development of uranium-free KMnO4/Pb metal staining allows multiscale imaging of extensive cell/tissue architectures to intensive subcellular ultrastructure. The obtained image contrast was equivalent to that of Ur/Pb staining and sufficient for ultrastructural observation. Observation of the 20 µm-thick section facilitates distinctive perception of the face-side images of the epithelium, which are seldom seen within 5 µm-thin sections. Visualization of the exact location of targeting molecules by in situ strategy provides unique insight into nanogold development via nanogold nucleation and secondary growth under hot-humid air conditions. These user-friendly techniques are highly anticipated to fill the gap between light and electron microscopy to correlate cell/tissue structure and function. Importantly, paraffin and cryostat blocks of cell or tissue samples are semipermanent, making them valuable for retrospective studies through the re-evaluation of archived specimens.

A detector was developed for scanning electron microscopy (SEM) in which microchannel plates (MCPs) were mounted on the facets of a regular dodecahedron. This detector enables the detection of electrons emitted in multiple directions. By placing a bias grid in front of each MCP, both backscattered electrons (BSE) and secondary electrons (SE) can be discriminated and detected. Using this detector, images were obtained by detecting electrons emitted in the direction normal to the sample surface (Top0), in two different oblique upward directions (Up1 and Up2), and in an oblique downward direction (Down6), to evaluate the emission-angle dependence including components emitted toward the lower hemisphere. Three specimens were examined: (1) a Cu plate with fine curtain-like surface waviness, (2) a Cu-Al eutectic microstructure, and (3) a three-dimensional stainless-steel sphere. For the Cu plate, surface corrugations were emphasized in the Up1/Up2 BSE images, whereas Top0 showed nearly uniform contrast. For the Cu-Al specimen, Top0 primarily provided compositional contrast, while the Up1/Up2 highlighted interfacial regions due to illumination-effect-like directional acceptance. For the stainless-steel sphere, obliquely downward BSE were clearly detected with Down6, indicating the usefulness of the downward channel for three-dimensional geometries. Since this regular dodecahedral detector operates without electric or magnetic fields that could distort electron trajectories, it enables analysis of the energy and emission-angle dependence of emitted electrons. This design uses identical MCP detectors at multiple viewing directions, which simplifies signal handling and facilitates multi-view analysis of direction- and energy-resolved signals.

The effective mass (m*) and Fermi velocity (vF) are two fundamental gauges of the electronic properties of materials and conventionally measured by magnetotransport characterizations. In this Review, we introduce momentum(q)-resolved electron energy loss spectroscopy (q-EELS) as an alternative method for probing m* and vF, and demonstrate its applications in semiconductor Si and semimetal FeGe. The q-EELS methodology is based on the q-dependent plasmon dispersion in the context of the random-phase approximation (RPA) for a free-electron gas (FEG), featuring a quantitative dependence on m* and vF and thus providing the route for retrieving these parameters. We outline the experimental principles for characterizing plasmon dispersions from the optical light line (the order of 10-3 Å-1) to Brillouin-zone boundaries (the order of Å-1), and elucidate the theoretical framework for pertinent elaborations on m* and vF. This work provides both the conceptual and practical guidelines for employing the q-EELS to extract m* and vF of fundamental significances to electronic characteristics of matters.