Microscopy Research and Technique最新文献

This study provides a detailed histological and immunohistochemical analysis of the kidney and adrenal gland in Varanus niloticus (Nile monitor lizard), highlighting their structural features and adaptive mechanisms. Ten adult female Nile monitors were collected from Qena Province, Egypt, and their kidneys and adrenal glands were examined. Kidney tissues were processed for histological analysis, and immunohistochemistry was performed to evaluate the expression of key markers, including vimentin, E-cadherin, CK7, and NSE. In contrast to other reptiles, the kidney was divided into the cortex and medulla and contained a loop of Henle. The cortex contains renal corpuscles and nephron tubules, while the medulla primarily comprises collecting ducts. The proximal tubules were lined with acidophilic cuboidal cells, whereas the distal tubules exhibited pale cuboidal cells with fewer microvilli. Immunohistochemistry revealed vimentin expression in podocytes and a few renal tubule epithelial cells, while E-cadherin was expressed in the distal tubules, loop of Henle, and collecting ducts. NSE was strongly expressed in the renal corpuscles and macula densa of the juxtaglomerular apparatus, as well as in the peripolar cells, but was absent in the proximal tubules. CK7 was predominantly expressed in the distal tubules and collecting ducts. The adrenal glands comprise steroidogenic and chromaffin cells associated with the posterior cardinal veins of the kidney. NSE was strongly expressed in chromaffin cells, while vimentin was detected in steroidogenic cells. E-cadherin and CK7 are not expressed in the adrenal tissues. These findings provide insights into the structural and functional adaptations of the kidney and adrenal glands in Nile monitors, offering a foundation for future research into the comparative anatomy and functional ecology of reptilian excretory and endocrine systems.

Colloidal forces are essential for maintaining the stability and functionality of colloidal systems, affecting various industrial, biological, and environmental processes. They play an important role in determining the behavior of particles in suspensions, including stability, aggregation, and surface interactions. In this primer, we present basic concepts and protocols for studying colloidal interactions at different salt concentrations using atomic force microscopy (AFM). Following this methodology, hydrophilic substrates (i.e., silica) were easily functionalized with a hydrophobic fluorocarbon (1H,1H,2H,2H-Perfluorooctyltrimethoxysilane, FOTS) via chemical vapor deposition (CVD) and characterized by the sessile drop method, electrophoretic light scattering, AFM imaging, and scanning electron microscopy (SEM) to determine parameters such as contact angle, zeta potential, and surface roughness, respectively. Thus, after the preparation and characterization of a well-defined colloidal system, force-distance experiments using AFM allowed for the measurement of hydrophobic and hydrophilic interactions in salt solutions. Furthermore, we describe in detail the processing and fitting of the experimental data with an extended DLVO model.

The present lab-based research aimed to assess the impact of different nanofillers: silver (Ag) chitosan (CH), and arginine nanoparticles (ArgNPs) infused in the eighth-generation universal adhesive (UA) on the antimicrobial potency, micro-tensile bond strength (μTBS), and degree of conversion (DC) bonded to carious-affected dentin (CAD) surface. Forty extracted human molars with Class 1 carious lesions were included. CAD was exposed and samples were allocated into four groups based on the type of adhesive (n = 10): Group 1 (UA), Group 2 (1 wt% AgNPs-UA), Group 3 (1 wt% CHNPs-UA), and Group 4 (1 wt% ArgNPs-UA). Survival rate assessment of inoculated Streptococcus mutans was performed after exposing them to different NPs. Characterization of tested nanoparticles (NPs) was also performed using scanning electron microscopy and energy-dispersive X-ray spectroscopy (EDX). The DC of modified and unmodified eighth-generation adhesive cured and uncured was assessed using Fourier transform infrared spectroscopy (FTIR). Composite was bonded on the CAD and samples underwent artificial aging. Beams were prepared for scanning electron microscopy (SEM) and μTBS analysis followed by failure mode assessment using a stereomicroscope. Statistical analysis was conducted using one-way analysis of variance (ANOVA) and Tukey's post hoc test to compare the means and standard deviations (SDs) between the different experimental groups (p < 0.05). Group 2 (1 wt% AgNPs-UA) samples exhibited the lowest S. mutans survival (0.10 ± 0.02 CFU/mL). Whereas Group 1 (UA) displayed the highest survival of tested bacteria (0.41 ± 0.08 CFU/mL). The maximum score of bond strength of composite to the CAD was detected in Group 2 (1 wt% AgNPs-UA) (21.11 ± 0.59 MPa) samples. However, the μTBS was minimal in Group 1 (UA) (16.18 ± 0.91 MPa). DC between the modified adhesive with 1 wt% AgNPs and the unmodified adhesive was comparable (p > 0.05). The incorporation of 1 wt% AgNPs in eighth-generation adhesives represents a favorable and reasonable alternative to unmodified adhesives when used on caries-affected dentin.

Acidic beverages can cause significant demineralization and erosive ultrastructural changes in human teeth, while milk and yogurt can prevent dental erosion. This in vitro study aimed to quantify and compare the protective efficacy of yogurt and milk against acidic beverages using stereomicroscopy, weight reduction experiments, and scanning electron microscopy (SEM). Overall, 24 freshly extracted single-rooted human teeth (preserved in neutral buffered formalin) were randomly divided into four treatment subgroups: yogurt, milk, topical fluoridated tooth cream (TFTC), and unprotected teeth. They were immersed periodically in the six commonly consumed acidic beverages. Four control teeth were neither protected nor immersed in any beverage. The protective efficacy of these agents was calculated from the quantification of surface changes using stereomicroscopy and the extent of percentage weight reduction. SEM was also conducted on selected samples to validate the stereomicroscopic observations. One-way analysis of variance and Tukey's honestly significant difference analysis of the quantified stereomicroscopic features showed that TFTC significantly outperformed other agents in terms of preventing erosive surface changes in human teeth (p < 0.05). Similar findings were observed in the weight reduction experiment, which further supported the stereomicroscopic findings. It revealed that TFTC, yogurt, and milk provided significant protection in comparison to the unprotected group of teeth (p < 0.05) against weight reduction caused by acidic beverages. SEM analysis supported the hypothesis that protected teeth showed lesser ultrastructural damage when compared to unprotected teeth.

Glaucoma, a leading cause of irreversible blindness worldwide, can be effectively managed if detected early. Glaucoma is directly associated with aging as it commonly occurs in people over the age of 40 and in elderly people. Glaucoma detection in retinal fundus images typically involves utilizing image processing and machine learning techniques. By leveraging advancements in computer vision, a robust and automated system is developed to assist ophthalmologists in screening and diagnosing glaucoma from retinal fundus images. Furthermore, fundus images can vary significantly in quality due to factors like illumination variations, focus, and artifacts. Ensuring consistent image quality across different datasets and acquisition devices is essential for reliable detection. Addressing these challenges requires interdisciplinary collaboration between ophthalmologists to develop robust and reliable solutions for the detection of glaucoma. Hence a novel mask autoencoder-based crossover binary sand cat (MA-CBSC) algorithm is proposed to detect glaucoma. In this algorithm, the mask autoencoder recognizes the features indicating the presence of glaucoma in the input images and the crossover binary sand cat algorithm is used to fine tune the overall performance of the algorithm by selecting the most appropriate features escaped due to overfitting issues. Preprocessing steps such as image enhancement, filtering, and data cleaning are applied to the extracted ROI for the purpose of increasing the image quality and enhancing the visibility of features relevant to glaucoma detection. ROI extraction attributes namely optic disc, cup-to-disc ratio, bean-pot cupping, and vertical enlargement are derived from the ROI along with some other relevant features. In this work, the crossover-based binary sand cat optimization algorithm is utilized for hyperparameter tuning to enhance the efficiency of the MA-CBSC method. Extensive experimental assessments are conducted, comparing the effectiveness of MA-CBSC algorithms with the Retinal Disease Classification dataset, Fundus Glaucoma Detection Data Dataset, and Glaucoma Dataset. The results obtained by the proposed method are compared with the results obtained by the existing techniques such as DLCNN-MGWO-VW, FRCNN-FKM, ML-DCNN, and DNN-MSO to show its superiority. Seven evaluation parameters are used in assessing the efficiency of the developed model including positive predictive value (PPV), accuracy, precision, F1 score, sensitivity, recall, and specificity. These evaluation measures show that the model has a more promising performance than the existing methods with 98.3% accuracy.

The study aims to assess the effectiveness of four different root canal disinfection techniques: passive ultrasonic irrigation (PUI), photon induced photoacoustic streaming (PIPS), and shock wave enhanced emission photoacoustic streaming (SWEEPS) on the smear layer (SL) removal, pushout bond strength (PBS) and sealer adaptation to the radicular dentin. Root canal treatment of 64 human mandibular premolars was initiated. Disinfection was performed. Group 1 (2.5% NaOCl (SI) + EDTA), Group 2 (2.5% NaOCl (PUI) + EDTA), Group 3 (2.5% NaOCl (PIPS) + EDTA), and Group 4 (2.5%NaOCl (SWEEP) + EDTA). This was followed by obturation and sectioning at three different thirds of the canal. Universal testing machine (UTM) and stereomicroscope assessed the PBS and failure mode. Residual SL and sealer dentin interface were assessed via SEM. To compare the mean scores among tested groups, one-way ANOVA and post hoc Tukey test were applied (p < 0.05) The lowest residual SL (1.22 ± 0.11) and highest PBS (11.27 ± 0.09 MPa) were observed in the cervical third of Group 3 (2.5% NaOCl + PIPS). However, the highest remaining SL (2.51 ± 0.08) and lowest bond strength (8.11 ± 0.12 MPa) were observed in the apical third of Group 1 (2.5% NaOCl + SI) Laser-activated irrigation (PIPS, SWEEPS) presents a promising approach for improving the efficacy of SL removal and enhancing the adhesion and bond strength of root canal sealers to root dentin.

Silver nanoparticles (AgNPs) synthesized through green methods have garnered significant attention in nanomedicine due to their unique inorganic properties and potential for a wide range of biomedical applications, including drug delivery, wound healing, and antimicrobial therapies. This study presents a novel, eco-friendly method for synthesizing AgNPs using Mirabilis jalapa leaf extract, which functions as both a reducing and stabilizing agent. The leaf extract, rich in bioactive compounds such as triterpenes, alkaloids, flavonoids, steroids, and phenolic compounds, plays a critical role in the reduction of silver ions (Ag⁺) to form elemental AgNPs. The synthesized AgNPs were rigorously characterized using powder X-ray diffraction (XRD), UV-visible spectroscopy, scanning electron microscopy (SEM), and energy-dispersive X-ray (EDX) analysis. UV-visible spectra exhibited an absorption peak in the range of 431-446 nm, indicative of the formation of polydispersed AgNPs with surface plasmon resonance, while XRD analysis confirmed their crystalline face-centered cubic (FCC) structure. SEM imaging revealed spherical and quasi-spherical morphologies, while EDX spectra confirmed the presence of silver with minimal contamination. Antibacterial activity, assessed using the agar well diffusion method, demonstrated significant inhibitory effects against Gram-positive and Gram-negative bacteria, although the nanoparticles showed reduced efficacy against Pseudomonas aeruginosa and Bacillus subtilis. These promising antimicrobial properties, coupled with the long-established use of silver in wound healing and infection management, highlight the potential of these AgNPs in biomedical applications. The novelty of this research lies in the use of M. jalapa leaf extract for the synthesis of AgNPs, offering a green and sustainable alternative to conventional chemical methods. Future studies should delve into optimizing the synthesis process for large-scale production, evaluating the in vivo efficacy of the nanoparticles, and exploring their interactions with a broader range of pathogens. This work paves the way for the development of green-synthesized AgNPs as effective, eco-friendly agents for infection control and wound care in nanomedicine, with the potential to significantly advance the field by offering safer, more sustainable solutions for clinical applications.

Nickel ions were reduced on the surface of cotton fibers under the effect of gamma radiation. The NiO nanoparticles grew as semispherical aggregates along the cotton fibers with average crystallite size of 32 nm as calculated from the x-ray diffraction results. The FTIR data showed the presence of a new IR peak at 613 cm^-1 (assigned to the NiO stretching vibration) confirming the successful loading of NiO nanoparticles into cotton matrix. The NiO nanoparticles were adhered to the surface of cotton fibers through the complexation with hydroxyl and carbonyl groups. The NiO@cotton nanocomposite showed high performance in the catalytic degradation of both 4-nitrophenol and bromophenol blue. The rate constant of the catalytic degradation of 4-nitrophenol was 8.24 × 10^-3 s^-1 at pH = 10. The resultant heterogeneous catalyst is green, cheap, separable/recyclable, and has considerable catalytic activity.

In this study, the preconcentration of Cr(III) ion in Pichia kudriavzevii JD2 immobilized perlite adsorbent by solid phase extraction was investigated. The determination of Cr(III) was performed using flame atomic absorption spectrometry (AAS). The effects of pH, adsorbent amount, recovery solution volume and type, and sample solution flow rate and volume on the recovery efficiency of Cr(III) ions were investigated. Optimized preconcentration conditions for Cr(III) were established using a column technique. The optimal parameters were determined as pH 4, a recovery solution of 2 mol/L HNO₃ with a volume of 10 mL, and a sample flow rate of 1-3 mL/min, preconcentration factor 25. Under these conditions, the recovery efficiency of Cr(III) ion on perlite immobilized with Pichia kudriavzevii JD2 was found to be 100.1% ± 0.3% with a 95% confidence level. Analytical variables with a limit of detection (LOD) of 4.8 μg/L and a limit of quantification (LOQ) of 15.8 μg/L were determined for the Cr(III) ion. The accuracy of the method was determined using standard reference materials (SPS-WW1). The relative error of the recovery efficiency was determined to be less than 10%. The method was applied to the determination of Cr(III) in various water samples, such as tap water and mineral waters.

Dicliptera bupleuroides has been used traditionally for treating various ailments in many countries. Its detailed phytochemical profiling and pharmacological evaluation in treating cancer based on reactive oxygen species (ROS) and mitochondrial membrane potential (MMP) analysis along with caspase activation studies has not been done previously. This study was conducted for detailed phytochemical profiling of D. bupleuroides by using ultra-high performance liquid chromatography-quadrupole time-of-flight mass spectrometry (UHPLC-QTOF-MS) and to evaluate its antioxidant and anticancer potential against hepatocellular carcinoma (HepG2) cells. The extract was subjected to UHPLC-QTOF-MS analysis for metabolite profiling, and GNPS Molnet enhancer determined its major phytochemical classes. Phytochemical tests and multimode antioxidant assays were also executed. The extract was pharmacologically evaluated for its anticancer potential against HepG2 cells using CCK-8 assay. Intracellular ROS generation and loss in MMP were studied by fluorescence microscopy. Network pharmacology and molecular docking of selected compounds were executed. The extract contains total phenolic content as 58.37 ± 0.32 μg GAE/mg extract, and remarkable antioxidant potential was revealed in total antioxidant contents (TAC) and total reducing power (TRP) assays, i.e., 70.4 ± 0.4, 83.2 ± 1.9 μg ascorbic acid equilant (AAE) Borges/mg extract. The UHPLC-QTOF-MS analysis showed that the extract contains flavonoid glycosides, phenolic acids, flavans, O-methylated flavonoids, linoleic acids, terpene glycosides, triterpenoid saponins, and certain other phytoconstituents. Maximum inhibition of 77.13% ± 1.60% against HepG2 cells was observed at 24 h. Loss in MMP by JC-1 (5,5',6,6'-tetrachloro-1,1',3,3'-tetraethylbenzimi- dazolylcarbocyanine iodide) staining and increased ROS generation, and caspase-3, caspase-8 activation by extract significantly illustrated the cancer cell death by apoptosis. D. bupleuroides could be a potential source of safe and therapeutically active compounds that can be purified to develop safer, selective, and efficacious anticancer agents with fewer side effects.