Microscopy Research and Technique最新文献

Investigation of different collagen cross-linking (CCL) agents, grape seed extract (GSE), Hesperidin (Hes), and rose bengal photosensitizer (RBP) on shear bond strength (SBS) and marginal leakage (ML) of composite bonded to carious affected dentin (CAD). Sixty-eight human molars in which carious lesions up to the middle third of the dentin were included. CAD was made flat followed by acid etching. Teeth were allocated randomly into four groups based on the application of CCL agents. Group 1: no CCL agent, Groups 2-4 samples treated with CCL agents. Bonding of adhesive and composite was performed followed by artificial aging. ML assessment was performed using a dye penetration test. SBS was evaluated using a universal testing machine followed by failure mode analysis. Analysis of the resin CAD interface with SEM was performed to identify the resin tag. For group comparisons, one-way ANOVA and post hoc Tukey test were used. The length and number of resin tags in GSE and Hes groups were greater than in the control and RBP. Furthermore, samples treated with GSE presented the highest scores of SBS and lowest ML. The control group presented the lowest bond integrity and highest ML. GSE and Hes positively influenced both SBS and ML.

The toxic impact of environmentally relevant nominal sub-lethal concentration of lead nitrate (23 mg/L) on the gills of Cyprinus carpio after 30 days of exposure was assessed. Structural alterations were analyzed through histopathology, and the DNA damage rate in peripheral erythrocytes was evaluated by alkaline comet assay. A significant deviation in the gill histoarchitecture was observed compared to the control group. Significant changes, including the curling of secondary lamellae, loss of filaments, necrosis, hyperplasia, hypertrophy of cells of primary filament, and vacuolization, were found in the fish exposed to nominal sub-lethal concentration of lead nitrate. Moreover, the comet assay showed lead nitrate-induced DNA damage, evidenced by the length of the DNA "tail" in the exposed fish. The findings of this study strongly indicated that lead nitrate, even at sub-lethal levels, could significantly alter the overall physiology of the fish. This situation could lead to severe ecological consequences.

Skin problems are a serious condition that affects people all over the world. Prolonged exposure to ultraviolet rays' damages melanocyte cells, leading to the uncontrolled proliferation of melanoma, a form of skin cancer. However, the dearth of qualified expertise increases the processing time and cost of diagnosis. Early detection of melanoma in dermoscopy images significantly enhances its chance of survival. Pathologists benefit substantially from the precise and efficient melanoma cancer diagnosis using automated methods. Nevertheless, the diagnosis of melanoma has consistently been a challenging procedure due to the imbalance images and limited data. Our objective was to employ a novel deep method to diagnose melanoma from dermoscopic images automatically. The research has proposed a novel framework for detecting skin malignancies. The proposed plan, which includes CNN, DenseNet, a batch normalization layer, maxpooling, and a ReLU layer activation function, solves the overfitting problem well. Furthermore, we used a large number of samples for testing and effectively employed data augmentation to prevent any issues related to class imbalance. The Adam optimizer is the most efficient deep learning optimizer for addressing challenges associated with large datasets, such as lengthy processing times. This is due to its specifically designed algorithm. Experiments ensure that the proposed framework achieved 95.70% micro average accuracy on the ISIC-2019 dataset and 93.24% accuracy on the HAM-10000 dataset. Comprehensive evaluation and analysis were used to evaluate our framework's performance. The results show that the proposed approach performs better with cross-validation by 94.8% accuracy than the most sophisticated deep learning-based technique. During studies, medical professionals will employ the proposed model to identify skin cancer in its early stages.

It is known that the interaction between electron beam and material surface enables a variety of physical phenomena, which hold significant inspiration for functional application. Herein, the process of in situ surface exsolution was observed and documented for the basalt phase in the Chang'e-5 lunar samples via scanning electron microscopy. Energy dispersive x-ray spectroscopy analysis confirmed the main existence of metal oxides such as plagioclase and pyroxene. Under electron beam irradiation, these components have undergone in situ dynamic mass loss and radiation decomposition, leading to an interesting in situ surface exsolution, as the energy of the electron beam exceeds the dissociation energy of metal-oxide bonds. It is clarified that the thermal effect of the electron beam is negligible under the experimental conditions. Alternatively, the "trinity" of electron beam-induced electric field-radiolysis-electron beam deposition is the key factor driving the surface exsolution. Our result not only deepens our understanding of the physical and chemical properties of lunar soil but also lays the groundwork for future applications of lunar soil for functional application.

Insects antennae serve as their primary sensory organs, playing a crucial role both in intra- and interspecific communication, a trait shared across the entire class Insecta. Representatives of Coccinellidae (ladybird) are known for being important natural enemies of economically relevant pests, and occasionally for being pests themselves. In this study, we investigated the ultrastructural organization of maxillary palps in several ladybird species exhibiting different feeding preferences, including entomophagous species (Harmonia axyridis, Scymnus interruptus, Delphastus catalinae, Cryptolaemus montrouzieri, Ceratomegilla undecimnotata, Propylea quatuordecimpunctata) and phytophagous species (Subcoccinella vigintiquatuorpunctata). We analyzed the ultrastructure of the maxillary palps using scanning and transmission electron microscopy. In all species, the maxillary palps were segmented, with the main sensory area located at the apical part of the enlarged distal segment. Our investigation revealed the presence of five distinct sensilla types on the maxillary palps, including uniporous, multiporous, campaniform, trichoidea, and digitiform sensilla. Interestingly, the sensilla shared a similar morphology across the investigated species. Uniporous and multiporous sensilla were the most abundant and were exclusively located in the apical sensory area. Campaniform sensilla were located on the apical sensory area, but positioned along the marginal zone, surrounding the area occupied by uniporous and multiporous sensilla. Digitiform sensilla were positioned in a restricted area of the dorsal side of the last palpomere. Our study hypothesizes that in Coccinellidae, maxillary palps play the role of primary sensory organ, along with the antennae. The comprehensive data presented here lay a robust foundation for further investigations into the role of maxillary palps in the chemical ecology of ladybirds.

Pollen content analysis of honey provides insight into the diversity of pollen grains and the development of a seasonal calendar to identify the diversity and availability of melliferous flora around the year. Melissopalynology is the most primitive and widely used technique for the qualitative and quantitative pollen profiling of honey. The honey of Azad Kashmir Pakistan has never been analyzed for pollen content despite the production at an industrial scale. A total of 60 samples were analyzed for the types and frequency of melliferous flora by the use of light microscopy and scanning electron microscopy. A wide diversity in morphological features differentiated 92 plant species belonging to 48 families. The most frequent plant families observed were Fabaceae, Poaceae, Asteraceae, Myrtaceae, Rosaceae, Betulaceae, and Buxaceae. Asteraceae showed the maximum species contribution. The obtained percentages of representative pollens were classified in frequency classes as follows: D: Predominant pollen (45%), S: Secondary Pollen (15%-45%), I: Important minor pollen (3%-15%), and M: Minor pollen (1%-3%). Most of the samples were multifloral containing not one dominant pollen, while one was bifloral containing two dominant pollen types and one was unifloral containing only one dominant pollen. The results reflect the melliferous potential of the native flora in the region. Indigenous floral resources from tropical vegetation to alpine meadows sustain bee colonies even during dearth periods. This work will benefit consumers, beekeepers, and regulatory bodies to maintain the authenticity of honey by the provenance of geographical and botanical origin.

Selenium nanoparticles (SeNPs) have garnered significant interest as anticancer and antimicrobial agents. The aqueous extract of medicinal plant Drimia indica leaves (DI-LAE) was used to synthesize SeNPs (DI-SeNPs) that were extensively characterized by UV-visible absorbance, TEM, EDX, XRD, zeta potential measurements, and FTIR. DI-SeNPs exhibited dose-dependent toxicity against the human lung adenocarcinoma cell line (A549; IC₅₀ of 43.21 μg/mL). DI-SeNPs increased reactive oxygen species (ROS) generation in A549 cells. DI-SeNPs caused cell cycle arrest in the G2/M phase and increased DNA damage in A549 cells, ultimately driving these cells toward apoptosis. DI-SeNPs significantly increased p53 levels, decreasing Akt levels and elevating cleaved caspase 3 levels in A549 cells. Additionally, DI-SeNPs exhibited antimicrobial activity against various bacteria and fungi. These findings suggest that DI-SeNPs possess significant anticancer and antimicrobial properties, mediated through mechanisms involving ROS generation, cell cycle arrest, and apoptosis induction.

The architecture of the avian oropharynx corresponds to the feeding pattern. The present study aims to provide data on morphology, morphometry, and spatial distribution of taste buds in the oropharyngeal floor of the northern bobwhite (Colinus virginianus) using gross anatomy, morphometric, and scanning electron microscopy. The lower beak tip and tomia revealed the presence of variably-sized dermal papillae. The prefrenular part of the oral floor had an interrupted median groove. Numerous taste buds and rostral submandibular salivary gland openings were detected alongside this groove. The tongue partially filled the oral floor. Its rostral end formed a median pointed process, the lingual nail. The dorsolateral aspects of the lingual apex and body showed hair-like and rosette-shaped filiform papillae of variable densities and sizes. However, these parts were devoid of taste buds. On the other hand, the surface mucosa of the lingual root presented numerous scale-like cellular elevations and a large number of taste buds. Examination of cross sections in the lingual root suggested the presence of two groups of caudal lingual salivary glands, central and lateral. The laryngeal mound contained taste buds that protruded from the surface epithelium into the lumen. The mucosa of the pharyngeal floor contained many taste buds that appeared similar to those detected on the laryngeal mound, except for the large taste pores, excessive cellular porosity, and denser microvilli. The total proportions of the taste buds in the oral and pharyngeal floors were 34.1% and 65.81%, respectively. The proportions of taste buds were 34.1%, 57.26%, 4.27%, and 4.27% in the sublingual floor, lingual root, laryngeal mound, and pharyngeal wall, respectively. In conclusion, this study provides comprehensive data on the oropharynx of northern bobwhite and will help to understand mechanisms governing food gustation in the studied bird and other related birds.

Segmentation and tracking are essential preliminary steps in the analysis of almost all live cell imaging applications. Although the number of open-source software systems that facilitate automated segmentation and tracking continue to evolve, many researchers continue to opt for manual alternatives for samples that are not easily auto-segmented, tracing cell boundaries by hand and reidentifying cells on consecutive frames by eye. Such methods are subject to inter-user variability, introducing idiosyncrasies into the results of downstream analysis that are a result of subjectivity and individual expertise. The methods are also susceptible to intra-user variability, meaning findings are challenging to reproduce. In this pilot study, we demonstrate and quantify the degree of intra- and inter-user variability in manual cell segmentation and tracking by comparing the phenotypic metrics extracted from cells segmented and tracked by different members of our research team. Furthermore, we compare the segmentation results for a ptychographic cell image obtained using different automated software and demonstrate the high dependence of performance on the imaging modality they were developed to handle. Our results show that choice of segmentation and tracking methods should be considered carefully in order to enhance the quality and reproducibility of results.

Analysis of indentation data of heterogeneous material, in particular, layer on an elastic substrate requires information about the contact area that is essential for calculating mechanical properties. The actual shape of the AFM-tip is not described by simple body of revolution. In this work, the indentation of a stiff layer on a hyperelastic substrate by a truncated conical tip is studied using finite element methods. The size of the tip, elastic modulus, and thickness of the layer are varied. The obtained model dependences of loading and contact area versus the depth of indentation are used in analysis of the experimental data of AFM indentation of stiff inhomogeneous nanolayers of polyurethane surface. Thickness and elastic modulus of the layers, fracture properties of the surface are studied. The obtained results can find application in the study of mechanical properties and fracture toughness of thin flexible films on an elastic substrate.