Microscopy Research and Technique最新文献

Molecular forces drive phenomena such as self-assembly, aggregation, and protein folding, where hydrophobic interactions are paramount. However, the origin of the hydrophobic mechanism remains unknown. Advances in techniques like atomic force microscopy (AFM) have improved our ability to study this topic. Hydrophobic interactions are stronger and longer ranged than van der Waals (vdW) forces, potentially arising from water structuring, polarization, and entropic effects. In this primer, fluorocarbon surfaces were prepared via chemical vapor deposition (CVD) on gold to explore the impact of water:DMSO solvent binary mixtures on hydrophobic interactions. Force-distance curves measured with AFM were fitted to an extended vdW model, disclosing the influence of the medium polarity on the interactions.

Due to the high-contrast imaging capability for label-free cells, diverse quantitative phase imaging (QPI) systems have been developed. However, most existing solutions exhibit limitations, including incompatibility with commercial microscopes, bulky/complex architectures, and restricted frame rates caused by computationally intensive phase reconstruction processes, thereby hindering their applicability in dynamic QPI scenarios. To overcome these challenges, we developed a camera-like curvature wavefront sensor (CWS) that integrates simultaneous dual-view transport-of-intensity phase imaging with parallel computing. The cost-effective system comprises a prism and dual-CMOS sensor within a compact size of 55.7 × 58.0 × 49.4 mm³ compatible with commercial microscopes. Operating at 20 frames per second (fps) with 1024 × 1024-pixel resolution, it enables real-time image acquisition, phase retrieval, data storage, and result visualization. Experimental validation confirmed its robust performance in field-of-view (FoV) correction, phase recovery accuracy, and computational efficiency. Practical utility was demonstrated through QPI-based flow cytometry and live-cell dynamic imaging applications. This plug-and-play, imaging system compatible, and cost-effective CWS platform offers a versatile solution for practical QPI requirements.

Prostate cancer is a prevalent and serious health concern, ranking among the most frequently diagnosed cancers and a leading cause of cancer-related deaths in men worldwide. Early detection and accurate diagnosis are crucial for improving patient outcomes by limiting disease progression. Histopathological image analysis remains the gold standard for prostate cancer detection; however, manual interpretation is time-consuming and requires specialized expertise. To address these challenges, this study proposes a hybrid deep learning framework that combines an ensemble of transfer-learned CNNs (VGG-16, DenseNet-121, and AlexNet) with a fine-tuned Vision Transformer (ViT). The CNN ensemble extracts rich local features, while the ViT captures global contextual dependencies through a self-attention mechanism and a multilayer perceptron (MLP). Additionally, a cross-attention fusion (CAF) module integrates local and global features, and knowledge distillation (KD) enables a lightweight student network suitable for efficient clinical deployment. The study utilizes the publicly available PANDA dataset for training and testing. Preprocessing steps, including patch generation, gamma correction, and stain deconvolution, enhance image quality and feature representation. A comprehensive evaluation was conducted using standard performance metrics such as accuracy, true positive rate (TPR), true negative rate (TNR), precision, F1-score, false negative rate (FNR), and false positive rate (FPR). An ablation study confirmed the contribution of each module, highlighting the critical role of ensemble CNNs, CAF, and ViT in improving performance. Experimental results demonstrate that the proposed model outperforms conventional transfer learning models and existing state-of-the-art techniques, achieving 97.91% accuracy, along with significant improvements in TPR, TNR, and reduced FNR/FPR. The computational complexity, evaluated in terms of parameters, FLOPs, GPU memory, and inference time, indicates that the proposed model is more demanding than traditional CNNs. Nevertheless, the architecture strikes a practical balance between predictive accuracy and efficiency, making it suitable for real-world clinical applications. These findings underscore the potential of AI-powered hybrid models in expediting prostate cancer diagnosis and enabling timely intervention for improved patient outcomes.

3D-reconstruction analysis by array tomography using FE-SEM was applied to fibroblasts/stromal cells localized close to the epithelial base in the lamina propria of the ureter of normal adult mice. The cell processes of 0.3 μm and smaller in size, which extended away from their somata and appeared as extremely thin threads under phase-contrast light microscopy, were revealed in ultrastructural 3D to largely consist of filmy sheet-like structures. However, their tip portions measuring 0.1 μm and smaller in size were actually thread-formed and directly contacted with the epithelial basal lamina. In the present study, such thin processes taking filmy sheet forms were tentatively termed "secondary processes," distinct from processes protruding from their somata, which were termed "primary processes." The actual end portions were termed "tertiary processes". The functional significance of these sheet-like cell processes is discussed. Possible reasons why such sheet-formed features of processes of fibroblastic/subepithelial stromal cells have been previously overlooked are also described.

A microscope is essential in scientific and medical research, enabling the magnification of specimens too small for the naked eye. The conventional method of acquisition of images requires pathologists or technicians to manually focus the microscope and examine one slide at a time, making the process tedious, especially in health emergencies. However, manual focusing in traditional microscopes often leads to human errors, image drift, and fatigue. Therefore, the work aims to design and develop an automated high-throughput optical digital microscope-based device for scanning and capturing blood smear images of 10 peripheral blood smear slides sequentially in a batch, focusing on a particular field of view at an objective lens magnification of 40. Maintaining focus is especially challenging in high-magnification microscopes due to their sensitivity to vibrations, which can blur images. This study proposes an automated focusing system combining an optical assembly setup with a deep learning algorithm for real-time image acquisition. Leveraging transfer learning with pre-trained VGG-16 and Mobile Vision Transformer (ViT) models, the system overcomes the computational challenges of training CNNs from scratch. By fine-tuning the model's upper layers on a smaller dataset, it efficiently learns task-specific features while minimizing computation, time, and overfitting. The Mobile ViT model outperforms the VGG-16 model, achieving an accuracy of 99.28%, which establishes MobileViT as a more reliable and efficient model for the acquisition of well-focused images. The approach improves image sharpness, reliability, and stability, enhancing the efficiency of microscopic imaging. This advanced system offers practical solutions for biomedical imaging diagnostics and advancements in microscopy analysis.

The Al-Li alloy has the advantages of low density, high specific strength, good weldability, good fracture toughness, strong fatigue crack propagation resistance, and excellent corrosion resistance. However, the plasticity of Al-Li alloy is poor at room temperature, so it formability is not ideal. In order to solve the problem, the electric pulse-assisted forming test is carried out on the 2A97-T3 Al-Li alloy to explore the forming properties. The mechanism of the forming perfoemance is revealed by the stress-strain curve macroscopically and the microstructure morphology microscopically. The results show that the Joule heating effect and the electron wind effect are generated in electric pulse-assisted forming. As a result, the yield strength and the tensile strength of the 2A97-T3 Al-Li alloy are significantly reduced. The Joule heating effect is enhanced due to the large pulse current intensity at the necking part, which can easily cause overburning. The grain size increases due to overburning. The elongation at break decreases significantly. After conducting a certain number of electric pulse-assisted forming tests, the appropriate processing parameters are obtained as follows: the pulse current intensity is 450 A, the duty cycle is 60.0%, the frequency is 50 Hz, and the forming rate is 0.001 s^-1. The yield strength of Al-Li alloy is 89 MPa, and the elongation to fracture is 13.2% under that condition. The formability is obviously improved. Besides, the dynamic recovery and the dynamic recrystallization of the alloy occur.

Heavy metal contamination from industrial activities threatens global food security by causing phytotoxic effects in crops like wheat. This study examines the impact of heavy metals (As, Cd, Cr, Ni, and Pb) on the physiological, anatomical, and agronomic traits of two wheat cultivars, Pak-13 and SKD-1, through hydroponic and field experiments. In the hydroponic experiment, plants were grown for 21 days in metal-contaminated solutions. Anatomical studies revealed significant changes under heavy metal stress, such as increased thickness of the root endodermis, xylem, cortex, and stellar cells. Cd exposure caused enlarged parenchyma in Pak-13, while Ni and Pb led to cortical dissolutions in SKD-1. Both cultivars showed thickening of leaf tissues under metal exposure, with SKD-1 displaying better structural adaptations. In the field experiment, agronomic results indicated significant reductions in grain yield (GY) under heavy metal stress. Pak-13 experienced GY reductions of 60.94% (Cd), 91.96% (Ni), 62.68% (Cr), 27.45% (As), and 92.62% (Pb), while SKD-1 showed declines of 2.40% (Cd), 77.48% (Ni), 66.83% (Cr), and 86.76% (Pb). The field data also highlighted a decrease in traits such as tillers per plant (T/P) and spike length per spike (SL/S) for Pak-13, whereas SKD-1 exhibited increased grain yield under As stress and enhanced biomass yield under Cd, Ni, and Pb stress, reflecting better tolerance. This study highlights the importance of anatomical adaptations in understanding metal stress tolerance, with SKD-1 proving more resilient. These findings are essential for breeding wheat cultivars with enhanced tolerance to metal toxicity, contributing to sustainable agriculture in contaminated areas.

To elucidate the characteristics of pollen abortion in male sterile lines, scanning electron microscopy combined with energy dispersive x-ray spectrometry technology analysis (SEM-EDS) was employed to compare and analyze the morphological structure and mineral element content of pollen of 219A cytoplasmic male sterile line and double haploid DH01A male sterile line, as well as those induced by chemical hybridization agent SQ-1 male sterility in Brassica napus. The results showed that the pollen grains of the three types of male sterile lines all exhibited distinct irregular abortions. Among these, the physiological male sterile pollen induced by SQ-1 was the smallest average size of 320.14 ± 59.63 μm², with severe pollen deformities and the highest pollen abortion rate. The pollen grains of the DH01A male sterile line were smaller with a size of 451.38 ± 9.70 μm² and exhibited a deformed elliptical shape. The pollen grains of the 219A male sterile line had an average size of 633.94 ± 16.82 μm², which showed a relatively small difference in size compared to the fertile line, but the pollen was deformed and twisted into a long spherical shape. Moreover, the pollen exine sculpturing of all three types of sterile lines showed different degrees of damage to the reticular structure, perforation disruption, deformity and reduction in the number of colpi, and accumulation of granules in the perforation. These phenomena may be the causes of male sterility and abortion in rapeseed. Meanwhile, the EDS analysis of mineral elements in three types of male sterile lines indicated that the content of calcium (Ca) was significantly higher than that in the normal fertile line, while potassium (K) levels were lower in all three types of male sterile lines than in the fertile line. Additionally, magnesium (Mg) enrichment was detected in the pollen of the SQ-1 induced male sterile line, whereas Mg was not detected on the outer wall of the pollen from the genetic male sterile lines 219A and DH01A. Notably, sulfur (S) was only present in the genetic male sterile lines 219A and DH01A. These results suggested that there were significant differences in the morphological characteristics, elemental composition and content of pollen grains among different types of male sterility. These findings provide a foundation for elucidating the mechanisms underlying pollen abortion in male sterile lines.

The effects of treatments of pool frog embryos of Pelophylax lessonae with engineered zerovalent nanoparticles of Fe Co, and Ni at increasing concentrations (½ LC₅₀, LC₅₀, and 2 × LC₅₀) were studied at macroscopical and microscopical levels, focusing on the epidermis that is often subject to physiological changes in response to environmental factors. Total body length and eye diameter were statistically higher in the control groups. A significantly higher percentage of embryos in the controls reached later Gosner developmental stages (19-23) than the treatments. Malformations such as ventral blister, microcephalia, bent body axis, and microphthalmia were significantly more frequent in the Co and Ni treatments than in the controls. In treated epidermis, ciliated, goblet, and small secretory cells resulted in a significantly larger volume than the same cell types in control embryos. At the ultrastructural level, ciliated cells showed stuck cilia and mitochondrial swelling, as well as cytoplasmic inclusions. Small secretory cells exhibited a significantly higher number of secreting vacuoles, suggesting an increased secretion. In conclusion, nanoparticles affect the development of frog embryos in multiple ways, even if the mechanisms are still mostly unknown.

Skeletal muscle is a complex organ that undergoes aging through a multifactorial process leading to muscle atrophy and strength reduction. Mitochondrial dysfunctions prove to be a critical contributor to skeletal muscle aging, affecting the regenerative functions and differentiation of muscle satellite cells (MuSCs). Physical exercise is a nonpharmacological approach that positively affects mitochondrial functions, promoting increased mitochondrial biogenesis, enzyme activities, and respiration in the aging skeletal muscle. By means of morphological and morphometrical analyses at transmission electron microscopy, this in vitro study identified the fine structural modifications induced in mitochondria of MuSC-derived myoblasts by a long-term adapted physical exercise applied to old mice, and verified the persistence of the exercise-driven changes in the myoblast-derived myotubes. In myoblasts, physical exercise decreased mitochondrial volume while increasing mitochondrial elongation and cristae extension in comparison to the sedentary condition, a mitochondrial remodeling suggestive of higher functionality. In myotubes, physical exercise increased mitochondrial volume and decreased cristae extension, partially reverting the age-associated alterations. These findings demonstrate that physical exercise administered in elderly exerts positive effects on mitochondria of the progeny of resident MuSCs.