Microscopy Research and Technique最新文献

The synergistic effects of a CuFe₂O₄ and cobalt/nickel metal organic framework (Co/Ni-MOF) based composite (MOF/CuFe₂O₄) were explored for photodegradation of Bisphenol A (BPA), various MOF/CuFe₂O₄ composites were synthesized via a hydrothermal method, By adjusting CuFe₂O₄ to Co/Ni-MOF mass ratios of 2:1, 1:1, and 1:2 and were denoted as MOF/CuFe₂O₄ (2:1), MOF/CuFe₂O₄ (1:1), and MOF/CuFe₂O₄ (1:2), respectively. The composite MOF/CuFe₂O₄ (1:1) with a band gap energy (Eg) of 2.28 eV exhibited excellent photocatalytic activity achieving 98% degradation of a 10 ppm BPA solution under visible light (50 W) irradiation within 75 min, at pH 3, 25°C. This process achieved a quantum yield (QY) of 9.10 × 10^-6 molecules photon^-1 and a space-time yield (SY) of 9.10 × 10^-7, highlighting the composite's efficiency and potential for practical applications. Visible-light absorption efficiency improved as photon energy increased (25 to 50 W) and facilitated the generation of $\dot{}{O}_2^{-}$ radicals. Kinetic studies indicated a first-order reaction rate (R² = 0.964) for BPA photodegradation by MOF/CuFe₂O₄ (1:1) composite. Additionally, the MOF/CuFe₂O₄ composite demonstrated superior antimicrobial activity against Staphylococcus aureus (S. aureus) and Escherichia coli (E. coli) under light compared with dark environment. Remarkably, the composite maintained its photocatalytic efficiency over at least six cycles. The results of the current study highlight the effectiveness and reusability of the MOF/CuFe₂O₄ (1:1) composite as a nanomaterial for the photodegradation of BPA and its potential applications in water treatment.

Skin cancer is recognized as one of the most harmful cancers worldwide. Early detection of this cancer is an effective measure for treating the disease efficiently. Traditional skin cancer detection methods face scalability challenges and overfitting issues. To address these complexities, this study proposes a random cat swarm optimization (CSO)with an ensemble convolutional neural network (RCS-ECNN) method to categorize the different stages of skin cancer. In this study, two deep learning classifiers, deep neural network (DNN) and Keras DNN (KDNN), are utilized to identify the stages of skin cancer. In this method, an effective preprocessing phase is presented to simplify the classification process. The optimal features are selected using the feature extraction phase. Then, the GrabCut algorithm is employed to carry out the segmentation process. Also, the CSO is employed to enhance the effectiveness of the method. The HAM10000 and ISIC datasets are utilized to evaluate the RCS-ECNN method. The RCS-ECNN method achieved an accuracy of 99.56%, a recall of 99.66%, a specificity value of 99.254%, a precision value of 99.18%, and an F1-score value of 98.545%, respectively. The experimental results demonstrated that the RCS-ECNN method outperforms the existing techniques.

The green methods for the synthesis of silver nanoparticles (AgNPs) has developed popularity recently due to the low preparation costs, environmental friendliness, and non-toxicity of the precursors. In this study, AgNPs were synthesized using leaf extract from Merremia quinquefolia. Spectroscopic techniques were used for analyzing the functional groups, morphology, crystalline phase, and elemental composition of nanomaterials. The ultraviolet (UV) visible spectrometry absorption spectra of the AgNPs had a surface plasmon resonance band at 459 nm and Fourier transformed infrared spectrum (FTIR) analysis showed the presence of elements groups. X-ray diffraction (XRD) analysis indicates the crystalline structure and the energy-dispersive x-ray spectroscopy (EDAX) analysis shows strong signals for the silver element. Morphological analysis using transmission electron microscope (TEM) and scanning electron microscopy (SEM) analyses revealed that the AgNPs exhibited spherical shapes with an average size of 14 nm. Furthermore, it was indicated by the Raman spectra vibrational peak at 240 and 470 cm^-1. The disk diffusion method showed that AgNPs were highly effective in inhibition of Gram-positive bacteria Staphylococcus aureus with a high inhibitory zone (14 ± 0.23 mm). Antioxidant activity, the IC₅₀ values for assays DPPH (145.7 μg/mL) and ABTS (112.09 μg/mL), and albumin denaturation in human red blood cells showed higher anti-inflammatory activity. AgNPs had an IC₅₀ value of 4.62 μg/mL against breast cancer (MCF-7) cells. Methylene blue (MB) degrading studies were used to assess the photocatalytic activity of AgNPs. They are at 240 min observed sunlight, the MB degradation efficiency was 94.89%. Overall, although M. quinquefolia synthesizes AgNPs for environmentally friendly applications, the study is indicated to fully understand the potential involved in treating breast cancer cells.

Effect of different root canal irrigation regimes microbubble emulsion (MBE) via riboflavin photosensitizer (RFP), cerium oxide (CeO₂) nanoparticles (NPs), and Nd: YAP laser on antibacterial efficiency, microhardness (MH), smear layer (SL) removal efficacy, and push-out bond strength (PBS) of AH plus sealer to canal dentin. Sixty single-rooted teeth were selected, disinfected, and categorized into four groups based on the type of disinfection. Following disinfection, a pair of samples were randomly selected and visualized under scanning electron microscope (SEM) for SL evaluation. Three samples from each disinfection group were mounted on a Vickers MH tester for hardness testing. A brain-heart infusion (BHI) agar plate was inoculated with a single colony of Enterococcus faecalis (E. faecalis), and their survival rate was measured following different disinfecting regimes. The remaining samples were filled with gutta-percha (GP) and sectioned to evaluate PBS via universal testing machine (UTM), followed by failure analysis. Data were analyzed using analysis of variance (ANOVA) and Tukey's post hoc test. The survival rate of E. faecalis was lowest for Group 3 (0.11 CFU/mL) with the highest MH values (49.72 ± 1.02 N/mm²). The PBS was highest for Group 3 cervical (11.54 ± 0.49 MPa) and middle third (11.12 ± 0.50 MPa). SL removal efficacy was comparable in groups 3 and 4 at the coronal and middle third. The application of CeO₂NPs as a canal irrigant in conjunction with EDTA resulted in enhanced bond values, demonstrating superior SL removal capabilities. This type of disinfection notably enhances the MH of canal dentin while demonstrating significant sterilization efficacy against E. faecalis.

One area of technological advancement has been the shift from stainless steel hand tools to nickel-titanium (Ni-Ti) rotary tools. This paper aims to perform an in vitro comparative study to evaluate the efficacy of five endodontic manual and rotary instruments such as Kerr files, Orodeka Plex V, ProTaper Flydent NiTi super files, and ProTaper Flydent NiTi super files in combination with an ultrasonic endodontic E3D Diamantata EMS scaler used for root canal shaping. The following aspects were highlighted: effective removal of smear layer (SL) from the dentinal tubules in the coronal 1/3, middle 1/3, and apical 1/3 of the root canal, appearance of cracks in the dentinal walls by SEM analysis, and highlighting of dentin mineral content and remnant debris by EDX analysis. In the study, 48 monoradicular, uninjured teeth were taken and divided into four groups, each with 12 teeth to be canal modeled, then longitudinally sectioned; the active surface was metallized for SEM-EDX analysis. From the SEM micrograph analysis, the morphology of the crystallites, the distribution of SL components, and the highlighting of instrumentation path traces/amplitudes were observed. By analyzing the SEM photomicrographs at 750 and 800× magnification, it was possible to highlight the cracks in the root dentinal walls. Thus, in comparison with Lots I and II which did not present cracks, in Lot III multiple cracks of the root dentinal walls were identified, especially in the coronal 1/3, and in Lot IV cracks were present with preponderance in the coronal and apical 1/3 of the root canals. The EDX images with atom mapping show very well the rather homogeneous elemental distribution for Ca, N, and P, respectively inhomogeneous for Na, Ca, Si, C, N, O, and P elements, as a result of the presence of remnant products from the processing of the root dentinal walls. Root canal instrumentation performed with both manual Kerr needle instrumentation by a convection technique and the rotary, Orodeka system, by crown-down technique, resulted in minimal SL formation in all three root canal areas, unlike the ProTaper FlyDent system. Most cracks were recorded in the case of the ProTaper Flydent rotary instruments and the one in which it was paired with a diamond ultrasonic scaler. The occurrence of dentinal cracks causes a decrease in dentinal microhardness, favoring the occurrence of root fractures.

Endometrial cancer, termed uterine cancer, seriously affects female reproductive organs, and the analysis of histopathological images formed a golden standard for diagnosing this cancer. Sometimes, early detection of this disease is difficult because of the limited capability of modeling complicated relationships among histopathological images and their interpretations. Moreover, many previous methods do not effectively handle the cell appearance variations. Hence, this study develops a novel classification technique called transfer learning convolution neural network with artificial bald eagle optimization (TL-CNN with ABEO) for the classification of uterine tissue. Here, preprocessing is done by the median filter, followed by image enhancement by the multiple identities representation network (MIRNet). Moreover, pelican crow search optimization (PCSO) is used for adapting weights in MIRNet, where PCSO is generated by combining the crow search algorithm (CSA) and pelican optimization algorithm (POA). Then, segmentation quality assessment (SQA) helps in tissue segmentation, and deep convolutional neural network (DCNN) helps in parameter selection that is trained by fractional PCSO (FPCSO). Furthermore, feature extraction is done and, finally, cell classification is done by TL with CNN, which is trained by the proposed ABEO algorithm. Here, ABEO is newly developed by the integration of the bald eagle search (BES) algorithm and artificial hummingbird algorithm (AHA). Furthermore, ABEO + TL-CNN achieved a high accuracy of 89.59%, a sensitivity of 90.25%, and a specificity of 89.89% by utilizing the cancer image archive dataset.

By applying various image analysis methods, the distribution of titania pigments in water-based paint films is assessed in this work. Cross-sections of paint films containing titania are prepared using triple ion beam milling, and the milled cross-sections are imaged using scanning electron microscopy. The obtained morphology of the paint films with known difference in pigment distribution is then determined and quantified by means of image analysis. It is found that the inter-particle distance which is calculated by determining the distance between each individual particle can serve as good differentiator for assessing the quality of pigment distribution. Furthermore, a comparison is made between 2D (triple ion beam milling) and 3D (focused ion beam with slice and view) imaging methods on the same sample. The 2D method, with its ease of use, short experimental time and artefact free imaging, gives better results in the system studied in this work.

Arrhythmia is a common and serious global health problem, contributing to cardiovascular morbidity and mortality. The cardiac muscle is susceptible to ischemia-reperfusion (I/R) injury, which can lead to fatal arrhythmias during open-heart surgery. We investigated the potential prophylactic effect of angiotensin 1-7 (Ang 1-7) using an in vivo rat model of I/R injury and examined the underlying mechanisms. Rats were treated with Ang 1-7 (1 mg/kg, IP) 30 min before the surgical procedures. Twenty-four rats were equally divided into four groups: sham control, sham-treated with Ang 1-7, I/R injury group, and I/R injury group treated with Ang 1-7. In vivo I/R injury was induced by clamping the left coronary artery for 30 min, followed by 1 hour of reperfusion. The I/R group showed abnormal electrophysiological changes and arrhythmic episodes during electrocardiography (ECG) recording, increased oxidative stress, downregulation of peroxisome proliferator-activated receptor gamma (PPAR-γ), and upregulation of C-X-C motif chemokine ligand 16 (CXCL16) expression in cardiac tissue, which increased cardiac NF-kB expression and IL-17 levels. Moreover, I/R injury caused significant histological disruption and increased cyclooxygenase 2 (COX-2) and heat shock protein 90 (HSP90) immunoreactions, correlating with the extent of cardiac damage. However, preoperative Ang 1-7 administration significantly improved the electrophysiological, biochemical, and histopathological changes induced by I/R injury. This study demonstrated that Ang 1-7 exerted protective anti-arrhythmic, anti-inflammatory, and pro-healing effects by upregulating PPAR-γ and downregulating CXCL16, IL-17, and NF-kB pathways, suggesting it is a promising cardioprotective agent for preventing arrhythmias induced by I/R injury.

MINFLUX nanoscopy relies on the localization of single fluorophores with expected ~ 2 nm precision in 3D mapping, roughly one order of magnitude better than standard stimulated emission depletion microscopy or stochastic optical reconstruction microscopy. This "brilliant" technique takes advantage of specialized localization principles and algorithms that require only dim fluorescence signals with a minimum flux of photons; hence the name follows. With this level of performance, MINFLUX imaging and tracking should allow for the routine study of biological processes down to the molecular scale, revealing previously unresolved details in cell structures, such as the organization of calcium channels in muscle cells or the clustering of receptors in synapses. Whereas the high localization precision is definitely a strength of the MINFLUX technique, limitations and challenges also exist, especially in the labeling procedures aiming at appropriate density and on/off switching kinetics. This primer presents some significant results achieved with MINFLUX so far and highlights specific operational procedures crucial for this technique.