Applied Microscopy最新文献

The development of bispecific antibodies (BsAbs) represents a significant advancement in therapeutic antibody design, enabling the simultaneous targeting of two different antigens. This dual-targeting capability enhances therapeutic efficacy, particularly in complex diseases like cancer, where tumor heterogeneity presents a significant challenge for traditional treatments. By bridging two distinct pathways, BsAbs can improve specificity and minimize off-target effects, making them invaluable in therapeutic contexts. Integrating advanced imaging techniques, particularly Correlative Light and Electron Microscopy (CLEM), offers a unique opportunity to visualize the dynamic interactions of BsAbs within cellular environments. CLEM combines the strengths of optical and electron microscopy, allowing researchers to observe real-time antibody-antigen interactions at nanoscale resolution. This synergy not only deepens our understanding of BsAbs’ mechanisms of action but also provides critical insights into their spatial distribution, binding kinetics, and functional dynamics in live cells. In this review, the integration of BsAbs and CLEM paves the way for targeted therapeutic strategies, fostering the development of more effective treatments that can adapt to the complexities of disease pathology.

The olfactory organ of Synechogobius hasta was investigated with a focus on its environmental adaptation, using stereo microscopy and light microscopy. This research revealed the following anatomical and histological characteristics: (i) tubular anterior nostril, (ii) one longitudinal lamella, (iii) two accessory nasal sacs, (iv) lymphatic cells in the lower part of the sensory epithelium, (v) four to five villi of olfactory receptor neurons, (vi) abundant blood capillaries beneath the sensory epithelium, and (vii) rod-shaped erythrocytes. These findings hint that the olfactory organ of S. hasta has anatomical and histological adaptations to intertidal pools that undergo periodic hypoxia and increased temperature under stagnant water conditions due to the tidal cycle.

This study investigates the impact of excessive bleaching on the external morphology and internal microstructure of hair, compared to untreated hair. Using scanning electron microscopy (SEM) and transmission electron microscopy (TEM), we observed significant changes in both the surface and internal structures of bleached hair. SEM analysis of normal hair revealed a relatively clean surface with intact cuticle scales, while bleached hair showed brittle, torn scales with a rough appearance. In areas where the cuticle was broken, remnants of endocuticle debris were still attached, contributing to the rough surface. Complete separation of the cuticle layer resulted in numerous longitudinal fissures along the exposed cortical surface of bleached hair. TEM analysis further confirmed distinct differences; in normal hair, the cuticle layer and cortex were well-separated, and a small hole was observed within the endocuticle of the cuticle cells. Conversely, in bleached hair, the cuticle layer was separated from the cortex, with numerous pores formed by the dissolution of melanin granules scattered within the cortex, specifically between the macrofibrils. No melanin granules were detected in the cortex of bleached hair, although the macrofibril structure remained intact. The findings clearly indicate that excessive bleaching leads to the loss of the cuticle layer, exposing the cortex and significantly altering the hair’s structural integrity.

The cosmetic-tattoo industry is evolving every year and the microstructures of the equipment have the great potential for semi-permanent makeup applications. Present paper explores the materials and microparticles of semi-permanent makeup tattoo needles. The surface of the five-round-shader tattoo needle used in semi-permanent makeup process was examined by scanning electron microscopy, and its elemental composition was analyzed by energy-dispersive X-ray spectroscopy. The comparison of five-round-shader needles have undergone thorough observation: original five-round-shader needle and distorted five-round-shader needle. The diameter of the sharp and rounded needle tip was measured at approximately 6.80 μm, while the deformed needle tip was approximately 16 μm thick, about 2.5 times thicker than the rounded needle tip. Many rosette-shaped lead (Pb) particles and irregular clusters adhere to the welded areas and closely adjacent needle shaft surfaces. The lead particles have a diameter ranging from 4 μm to 5 μm and exhibit a grid-like structure with a consistent thickness of plate-like shape. The distorted structure of Pb in rosette-shaped formations is shown to have originated from the grinding and polishing processes during needle manufacturing. To produce sterilized tattoo needles, high-quality tattoo needle inspection processes are necessary to remove any unhygienic substances adhering to the needle surface.

Glass vials are the most widely used primary containers for the packaging of parenteral products due to their optical clarity, general inertness, and hermetic properties, but under certain circumstances, they can pose safety concerns. Most of these issues are related to the potential formation of glass particulates through delamination or precipitation, resulting from the chemical interaction between the drug product and the inner surface of the glass vial. Hence, it is imperative for pharmaceutical companies to conduct product-vial compatibility studies to determine the appropriate packaging/container closure system. To support this development activity, scientists need to develop analytical methods to detect subvisible glass particulates in parenteral products, along with the appropriate positive controls, to facilitate detection and identification. This paper outlines the utilization of coaxial/episcopic and oblique illumination microscopy, combined with spectroscopic techniques, to detect thin glass particulates generated from a modified procedure. It also showcases the importance of angle-dependent lighting in visualizing positive control samples containing thin glass particulates. The analytical microscopy techniques discussed in this paper can assist scientists in selecting suitable container closure systems for developing parenteral products.

Oxide-supported metal catalysts are essential components in industrial processes for catalytic conversion. However, the performance of these catalysts is often compromised in high temperature reaction environments due to sintering effects. Currently, a number of studies are underway with the objective of improving the metal support interaction (MSI) effect in order to enhance sintering resistance by surface modification of the oxide support, including the formation of inhomogeneous defects on the oxide support, the addition of a rare earth element, the use of different facets, encapsulation, and other techniques. The recent developments in in situ gas phase transmission electron microscopy (TEM) have enabled direct observation of the sintering process of NPs in real time. This capability further allows to verify the efficacy of the methods used to tailor the support surface and contributes effectively to improving sintering resistance. Here, we review a few selected studies on how in situ gas phase TEM has been used to prevent the sintering of catalyst NPs on oxide supports.

The sliding filament theory and the cross-bridge model have been fundamental in understanding muscle contraction. While the cross-bridge model explains the interaction between a single myosin head and actin filament, the native myosin molecule consists of two heads. This review explores the possibility and mechanism of two-headed binding in myosin II to the actin. Recent studies using electron tomography and resonance energy transfer have provided evidence in support of the occurrence of two-headed binding. The flexibility of the regulatory light chain (RLC) appears to play a significant role in enabling this binding mode. However, high-resolution structures of the RLCs in the two-headed bound state have not yet been reported. Resolving these structures, possibly through sub-tomogram averaging or single-particle analysis, would provide definitive proof of the conformational flexibility of RLCs and their role in facilitating two-headed binding. Further investigations are also required to address questions such as the predominance of two-headed versus single-headed binding and the influence of the state of each of the heads on the other. An understanding of the mechanism of two-headed binding is crucial for developing a comprehensive model of the cross-bridge cycle of the native myosin molecule.

Plant cells are uniquely characterized by exhibiting cell walls, pigments, and phenolic compounds, which can impede microscopic observations by absorbing and scattering light. The concept of clearing was first proposed in the late nineteenth century to address this issue, aiming to render plant specimens transparent using chloral hydrate. Clearing techniques involve chemical procedures that render biological specimens transparent, enabling deep imaging without physical sectioning. Drawing inspiration from clearing techniques for animal specimens, various protocols have been adapted for plant research. These procedures include (i) hydrophobic methods (e.g., Visikol™), (ii) hydrophilic methods (ScaleP and ClearSee), and (iii) hydrogel-based methods (PEA-CLARITY). Initially, clearing techniques for plants were mainly utilized for deep imaging of seeds and leaves of herbaceous plants such as Arabidopsis thaliana and rice. Utilizing cell wall-specific fluorescent dyes for plants and fungi, researchers have documented the post-penetration behavior of plant pathogenic fungi within hosts. State-of-the-art plant clearing techniques, coupled with microbe-specific labeling and high-throughput imaging methods, offer the potential to advance the in planta characterization of plant microbiomes.

In this study, we investigate the effectiveness of noise reduction in electron holography, based on the wavelet hidden Markov model (WHMM), which allows the reasonable separation of weak signals from noise. Electron holography observations from a Nd₂Fe₁₄B thin foil showed that the noise reduction method suppressed artificial phase discontinuities generated by phase retrieval. From the peak signal-to-noise ratio, it was seen that the impact of denoising was significant for observations with a narrow spacing of interference fringes, which is a key parameter for the spatial resolution of electron holography. These results provide essential information for improving the precision of electron holography studies.