Microscopy and Microanalysis最新文献

The current work provides a comprehensive structural insight into the foregut of the Arabian jerboa (Jaculus loftusi), using anatomical examination with histological and histochemical methods. The research included five adult male jerboas, collected from Aljouf desert in Saudi Arabia. The foregut consisted of an esophagus and a unilocular stomach, which matched the anatomy of most rodents. The esophageal mucosa has longitudinal folds, lined by keratinized epithelium, presenting a star-shaped lumen. The lamina propria lacked both lymphatic nodules and esophageal glands. The gastric lining consisted of simple columnar epithelium, which formed deep rugae while displaying multiple gastric pits. The fundic glands contained mucous neck cells, parietal cells, and chief cells, whereas the corpus glands were longer and denser, and the pyloric glands were coiled, lacking aforementioned cells. The histochemical analysis revealed that the gastric mucosa, along with the pit surface lining cells, exhibited strong Periodic Acid Schiff positivity and mild Alcian Blue staining. The stomach epithelium exhibits dominance of neutral mucins over acidic mucins as indicated by the histochemical analysis. The obtained results provide a comprehensive insight into the modifications of the Arabian jerboa's foregut, highlighting its architectural specializations for the desert habitat.

Experimental full-field stress and strain data are a valuable resource to quantify microscale material response and crystal plasticity. Such data are highly effective for calibration and validation of crystal plasticity models. Methods for acquiring such data exist in digital image correlation (DIC) and high-resolution electron backscatter diffraction (HREBSD) to calculate strain and stress, respectively, but are difficult to combine over a concurrent domain due to EBSD being incompatible with typical DIC surface preparation. In this work, microstamping is used to apply EBSD-compatible selective-electron-transparent DIC speckling to an additively manufactured polycrystalline Ni superalloy. Both data modalities are collected during in situ loading over the same region without the need to remove or reapply speckling.

Microscopy-based analysis of plant protein gels offers essential insights into their structural organization and functional performance. However, quantitative image segmentation is often constrained by the need for extensive manual annotations. In this study, we developed a semisupervised learning (SSL) framework to segment confocal and scanning electron microscopy (SEM) images of plant-based protein gels using only 10% labeled data combined with pseudo-labeling. The SSL model achieved segmentation accuracy [assessed using Intersection over Union (IoU) and Dice coefficients] comparable to fully supervised learning (SL) models trained on complete annotations, particularly for SEM images (SSL: IoU = 0.83, Dice = 0.91; SL: IoU = 0.84, Dice = 0.91). For confocal images, SSL reached an IoU of 0.73 and Dice of 0.85, versus 0.82 and 0.90 from SL. Structural metrics such as fractal dimension and protein aggregation area were extracted from both ground truth and predicted masks, showing strong correlations and demonstrating the robustness of the SSL model. These descriptors are inherently scale-invariant, enabling reliable comparisons across imaging conditions without magnification calibration. This work presents a high-throughput, annotation-efficient solution for food microstructure analysis. The SSL framework, coupled with scale-invariant structural descriptors, holds promise for broader applications in material characterization and offers a foundation for incorporating size-dependent features in future work.

Chronic relapsing colonic inflammation, specifically ulcerative colitis (UC), causes persistent mucosal injury and disrupts the gut-brain axis. This disruption leads to basal ganglia neuroinflammation and ultimately extrapyramidal motor dysfunction. Dysregulation of the Dectin 1/leucine-rich repeat kinase 2 (LRRK2)/α-synuclein (αSyn) signaling exacerbates inflammation. This study investigated whether modulation of this pathway affects UC progression and is associated with motor deficits using trimetazidine (TMZ) treatment in a Bagg albino c (BALB/c) mice model. Furthermore, we examined the role of this pathway through molecular docking followed by molecular dynamics simulations to evaluate the plausibility of TMZ interactions with Dectin-1, LRRK2, and α-syn proteins. Our results indicate that TMZ improved behavioral changes and also significantly reduced serum interferone-γ (IFN-γ) and NF-kB levels, along with decreased Dectin-1, LRRK2, and αSyn expression. TMZ also mitigated colonic inflammation, as shown by reducing fecal calprotectin and fecal occult blood, supported by histological examinations. Furthermore, TMZ restored autophagic flux by reducing P62 accumulation and enhancing LAMP2 expression. Molecular docking and dynamics confirmed TMZ binding to Dectin-1, LRRK2, and αSyn, through hydrophobic and hydrophilic interactions. These findings suggest a potential molecular basis for the observed associations between the Dectin-1/LRRK2/α-synuclein axis and UC-related motor dysfunction, warranting further experimental validation, establishing TMZ's therapeutic potential for managing colonic inflammation and associated neurological manifestations.

Understanding fish muscle development is vital for improving aquaculture food production. This study examined branchial muscle development in carp, identifying skeletal myoblasts by their distinct sarcolemma, which separates neighboring sarcoplasm while maintaining cytoplasmic connections containing electron-dense cytoskeletal components. Three myoblast stages were observed: pregranular (lacking granules but containing mitochondria, ribosomes, fibrils, and early myofilament assembly), granular (featuring granules, ribosomes, smooth endoplasmic reticulum, and minimal rough endoplasmic reticulum), and striated (characterized by sarcoplasmic reticulum, myofilaments, granular materials, and striated myofibrils). Sarcoplasmic vacuolation was observed near developing myofibrils, with cytoplasmic regions showing Z-disc formation and myofibril growth. The findings reveal unique skeletal myogenesis events in silver carp, highlighting the importance of molecular regulation in muscle development. These insights can enhance aquaculture efficiency by optimizing muscle growth and meat yield. Research on skeletal myogenesis in aquatic species provides a foundation for improving fish farming practices, ultimately supporting sustainable and increased fish meat production. This study contributes to a deeper understanding of muscle formation in carp and offers potential applications for selective breeding and aquaculture advancements.

Insect silk glands exhibit diverse origins, including epidermal, labial, and Malpighian tubule-derived structures. Polymitarcyidae mayfly nymphs (Ephemeroptera) are known to secrete silk for constructing and lining their tunnels. However, the organ responsible for silk production in this ancient insect lineage is poorly understood. This study provides the first histological, histochemical, and ultrastructural analysis of the Malpighian tubules in Polymitarcyidae (Campsurus truncatus, Campsurus sp., and Tortopsis canum), identified as the likely source of their silk. We found specialized cells with characteristics of intense protein synthesis and secretion in the distal regions of the tubules in all examined species. These findings represent the first detailed evidence confirming the Malpighian tubules as the site of silk production in Ephemeroptera, establishing a foundation for further studies on silk gland evolution in insects.

This paper presents and validates a center localization method based on the radial symmetric center (RSC) algorithm, specifically for atomic-column center localization in scanning transmission electron microscopy (STEM) images. The method leverages the radial symmetry of the particle intensity distribution and achieves subpixel localization accuracy through analytical computation, while avoiding the time-consuming iterative fitting process associated with traditional two-dimensional (2D) Gaussian fitting method. We performed a systematic comparison of the RSC method against the conventional center-of-mass (COM) and 2D-Gaussian fitting methods, focusing on the localization accuracy and computational speed. The results show that the RSC method maintains a high-localization accuracy comparable to Gaussian fitting, while providing a computational speed that is intermediate between that of 2D-Gaussian fitting and the COM method. It demonstrates advantages in both time efficiency and accuracy. Furthermore, we validate the accuracy and reliability of this method through three case studies: atomic-column localization and stress analysis of Au nanoparticles, statistical analysis of atomic spacing in Si/Ge superlattices, and ferroelectric polarization mapping of PbZrxTi1-xO3.

The purpose of our study was to investigate the neuroprotective effects of Nigella sativa (NSt) ethanolic extract (200 mg/kg) and/or Telmisartan(Tel) (10 mg/kg) against fipronil (Fip) (9.7 mg/kg)-induced neurobehavioral toxicity in rats, besides exploring the underlying mechanistic signaling pathways. Our results showed that the phytochemical analysis of NSt ethanolic extract by ultra-performance liquid chromatography-electrospray ionization-tandem mass spectrometry (UPLC-ESI-MS) revealed 43 compounds, mainly alkaloids, phenolics, terpenoids, fatty acids and flavonoids. While in our in vivo model of neurotoxicity, the combination of NSt and Tel effectively restored neurobehavioral alterations in rotarod, open field and T-maze tests. Additionally, the cotreatments of NSt and Tel significantly decreased acetylcholine, tumor necrosis factors-α, interleukin (IL)-6, IL-1β, MDA, BAX, P62, LC3B and IBA-1. Conversely, they significantly upregulated GABA, brain-derived neurotrophic factor, superoxide dismutase, catalase, glutathione peroxidase and antiapoptotic BCl2, P70S6K and miRNA137-5P without significant change in mTOR expression in hippocampus. Also, they ameliorated pathological alterations as detected by H&E staining, reduced glial fibrillary acidic protein and caspase-3 immunoreactivity. Electron microscopic examination of the combination group revealed the restoration of nuclear and mitochondrial structures with less glial activation and multivesicular bodies. In conclusion, the combination of NSt and Tel are notable agents in mitigating hippocampal neuronal necrosis and astrogliosis and reduced Fip-induced neurotoxicity.

This study is the first to describe the presence, localization, and temporal distribution of epithelial (E)-, neural (N)-, and placental (P)-cadherins within the chicken uropygial gland (UG) during the post-hatching growth period, using immunohistochemistry and Western blot techniques. In the luminal epithelium and secretory tubules of the UGs of 1-day-old chicks, the germinative layer sebocytes (GLS) exhibited cytoplasmic immunostaining for P-cadherin, while they were negative for E-cadherin. However, the secretory layer sebocytes (SLS) showed a membranous staining for both cadherins. N-cadherin was only localized in the lateral membrane of the end-bulb cells. From the 7th to the 150th day of post-hatching, all cadherins were detected in the membrane of SLS of the luminal epithelium and peripheral and central zones. E- and N-cadherin immunostainings were weak in the cytoplasm of GLS, but P-cadherin was strong. In addition, N-cadherin was strongly localized in the membrane of some GLS of peripheral tubules adjacent to the capsule. These results indicate that the localization patterns of cadherins differ based on the type of cadherin, age, and zones and cell layers of the UG. This suggests that cadherins play unique roles in maintaining tissue architecture and regulating holocrine secretion during the post-hatching growth of chicken UG.

Diffraction images in a scanning transmission electron microscope (STEM) provide a real-space projection of the sample at sufficient probe defocus. Such shadow images may be acquired patch by patch in a 4D-STEM setup using a pixelated detector and assembled into a shadow montage. Consequently, an upscaled bright-field image is rendered efficiently in time compared to other STEM techniques. We show that this procedure achieves the result of a tilt-corrected bright-field image. Furthermore, the solution is equivalent to cone-beam reconstruction in a particular scenario of a scanning point illumination source in a plane. Contrast transfer is similar to that of conventional TEM, but like STEM, the focus is insensitive to energy loss and objective lens chromatic aberration. By adjusting the overlap between shadow patch images, the shadow montage is derived from or synchronized to specific layers in the sample, similarly to multi-slice ptychography, rendering a 3D shadow volume from a single dataset. The method is amenable to conventional tilt tomography by summing shadow volumes of all tilt views to generate a full back-projection reconstruction. This approach effectively circumvents the basic presumption of parallel-projection tomography that the depth of field must be greater than the specimen thickness.