Search Results (2,659)

This study examines the effects and mechanisms of different Enzyme-Induced Carbonate Precipitation (EICP) treatments on loess structure improvement. The study focuses on ordinary EICP and three modified methods using MgCl₂, NH₄Cl, and CaCl₂. A series of unconfined compressive strength (UCS) tests, scanning electron microscopy (SEM), energy-dispersive spectroscopy (EDS), and elemental mapping were used to assess both macroscopic performance and microscopic characteristics. The results indicate that ordinary EICP significantly enhances loess particle bonding by promoting calcite precipitation. MgCl₂-modified EICP achieves the highest UCS (820 kPa) due to delayed urea hydrolysis and the formation of aragonite alongside calcite, which results in stronger and more continuous cementation. In contrast, NH₄Cl reduces urease activity and reverses the reaction, which limits carbonate precipitation and weakens structural cohesion. Excessive CaCl₂ leads to a “hijacking mechanism” where hydroxide ions form Ca(OH)₂, restricting carbonate formation and diminishing the overall enhancement. This study highlights the mechanisms behind enhancement, degradation, and diversion in the EICP process. It also provides theoretical support for optimizing loess subgrade reinforcement. However, challenges such as uneven permeability, environmental variability, and long-term durability must be addressed before field-scale applications can be realized, necessitating further research. Full article

In view of the need to increase the durability of working tools exposed to intense friction, this study analysed hybrid coatings (TiAlCN, AlTiCN, AlCrTiN, TiN, CrN) with a DLC (Diamond-Like Carbon) layer, deposited using PVD (Physical Vapour Deposition) methods (arc evaporation and magnetron sputtering). The structural characteristics of the coatings were determined using SEM (Scanning Electron Microscope) and AFM (Atomic Force Microscope) microscopy, as well as Raman spectroscopy, which confirmed the compact structure and amorphous nature of the DLC layer. Tribological tests were performed using a ball-on-disc test, revealing that DLC hybrid coatings significantly reduce the coefficient of friction (stabilisation in the range of 0.10 to 0.14 due to DLC graphitisation), limiting tool wear even under increased load. The SEM-EDS (Scanning Electron Microscope-Energy Dispersive Spectroscopy) microscopic examination revealed that the dominant wear mechanisms are abrasive and adhesive damage, and the AlCrTiN/DLC system is characterised by low wear and high adhesion (L_c = 10⁵ N), making it the optimal configuration for the given loads. Microhardness tests showed that high hardness does not always automatically translate into increased wear resistance (e.g., the AlTiCN coating with 4220 HV showed the highest wear), while coating systems with moderate hardness (TiAlCN/DLC, CrN/DLC) achieved very low wear values (~0.17 × 10⁻⁵ mm³/Nm), which highlights the importance of synergy between the hardness of the sublayer and the low friction of DLC in the design of protective coatings. Full article

Herbs offer people not just sustenance and housing but also serve as a key supplier of pharmaceuticals. This research is designed to assess the antioxidant and antidiabetic properties of green-produced zirconium dioxide and magnesium oxide nanoparticles (ZrO₂ and MgO NPs) utilizing extracts from unripe Solanum trilobatum fruit. ZrO₂ and MgO NPs have garnered considerable interest owing to their superior bioavailability, lower toxicity, and many uses across the healthcare and commercial industries. Scientific approaches, such as diverse spectroscopic and microscopic approaches, validated the creation of agglomerated spherical ZrO₂ and MgO NPs, measuring between 15 and 30 and 60 and 80 nm, with a mixed-phase composition consisting of monoclinic and tetragonal phases for ZrO₂ and a face-centered cubic structure for MgO NPs. UV–vis studies revealed a distinct peak at 378 and 290 nm for ZrO₂ and MgO NPs, suggesting efficient settling through the phytonutrients in S. trilobatum. The antioxidant capacity of ZrO₂ and MgO NPs was evaluated utilizing DPPH and FRAP reducing power assays. The diabetic effectiveness of ZrO₂ and MgO NPs was examined by alpha-amylase and alpha-glucosidase assays. The optimum doses of 500 and 1000 μg/mL were shown to be efficient in reducing radical species. Green-produced ZrO₂ and MgO NPs exhibited a dose-dependent reaction, with greater amounts of ZrO₂ and MgO NPs exerting a more pronounced inhibitory effect on the catalytic sites of enzymes. This work suggests that ZrO₂ and MgO NPs may attach to charge-carrying entities and function as rival inhibitors, therefore decelerating the enzyme–substrate reaction and inhibiting enzymatic degradation. Molecular docking analysis of ZrO₂ and MgO NPs with three proteins (2F6D, 2QV4, and 3MNG) implicated in antidiabetic and antioxidant studies demonstrated the interaction of ZrO₂ and MgO NPs with the target proteins. The results indicated the in vitro effectiveness of phytosynthesized ZrO₂ and MgO NPs as antidiabetic antioxidant agents, which may be used in the formulation of alternative treatment strategies against diabetes and oxidative stress. In summary, the green production of ZrO₂ and MgO NPs with Solanum trilobatum unripe fruit extract is an efficient, environmentally sustainable process that yields nanomaterials with significant antioxidant and antidiabetic characteristics, underscoring their prospective uses in biomedical research. Full article

The American cockroach (Periplaneta americana) serves as an exemplary model for regeneration research due to its exceptional regenerative capabilities, particularly in appendage regeneration. In this study, regenerated coxa tissue underwent histological analysis through H & E straining. Microscopic examination revealed the progression of regeneration. To elucidate the underlying mechanisms, a comparative transcriptomic analysis was conducted between regenerating legs and non-amputated control legs. This analysis identified 2343 differentially expressed genes (DEGs) between 0 days post-amputation (0 dpa) and 7 dpa, 2963 DEGs between 14 dpa and 0 dpa, and 3135 DEGs between 14 dpa and 7 dpa. Significantly, several DEGs are associated with growth- or regeneration-related processes, including extracellular matrix (different collagen, Pro-resilin isoforms, integrin beta (itgb) and matrix metalloproteinase (mmp)), immune-related genes (Toll-like receptor 13 (tlr13), defensin (def), drosomycin-like defensin (dld), Polyphenoloxidases2 (ppo2), cytochrome P450 (p450), peptidoglycan recognition protein (pgrp) and secreted C-type lectin (sClec)), insulin-like growth factor (IGF) and Epidermal Growth Factor Receptor (EGFR). Functional validation through RNA interference (RNAi) further suggested that EGFR and a specific C-type lectin (Regenectin) regulate leg regeneration in Periplaneta americana. These findings enhance our understanding of the molecular mechanisms governing regeneration in this species. Full article

Background/Objectives: Dermatophytosis is a widespread superficial fungal infection affecting skin, hair, and nails. Its diagnosis is often based on conventional methods such as microscopy and fungal culture. Laboratory confirmation is essential for guiding appropriate treatment and preventing the misuse of antifungal agents, which can contribute to the emergence of antifungal resistance. We retrospectively assessed the burden and species distribution of dermatophytosis in individuals attending a public dermatology institute in Italy over a 3-year period (2019–2021). Methods: We analyzed 3208 samples from 3037 individuals with clinical suspicion of superficial mycosis. All samples underwent direct microscopic examination and fungal culture. Data were stratified by demographics, body site, and fungal species. Agreement between diagnostic methods was assessed using raw concordance and Cohen’s Kappa statistic. Results: Dermatophytes were confirmed in 667 samples (20.8%). Buttocks and genitals showed the highest positivity rates (37.5% and 36.4%, respectively). T. rubrum (56.8%) and T. mentagrophytes (30.7%) were the predominant species among the dermatophyte-positive specimens. Agreement between microscopy and culture was good (raw concordance: 91.6%, Cohen’s Kappa: 0.77, 95% CI: 0.74–0.79). Younger age and male gender were significantly associated with dermatophyte positivity. Conclusions: Our data provide updated epidemiological insights into dermatophytosis in Italy and support appropriate antifungal stewardship. Laboratory confirmation remains essential for an accurate diagnosis and species identification, thus avoiding other non-dermatophytic or non-infectious conditions being treated as dermatophytosis. Full article

As mining operations extend deeper underground, support structures are increasingly subjected to severe impact loads. The dynamic mechanical performance of column-type support systems has, therefore, become a pressing concern. In the present research, a Split Hopkinson Pressure Bar (SHPB) apparatus, combined with Scanning Electron Microscopy (SEM), is used to systematically examine how the water-to-cement ratio, number of carbon-fiber reinforced polymer (CFRP) layers, and strain rate influence the dynamic compressive behavior and microstructural evolution of CFRP-confined high-water material. The results indicate that unconfined specimens are strongly strain rate-dependent, with peak strength following a rise–fall trend. A lower water–cement ratio results in a denser internal structure and improved strength. Additionally, CFRP confinement markedly enhances peak strength and impact resistance, refines failure modes, and promotes the formation of denser hydration products by limiting lateral deformation. This confinement effect effectively mitigates microstructural damage under high strain rates. These findings clarify the reinforcement mechanism of CFRP from both macroscopic and microscopic perspectives, offering theoretical insights and engineering references for the design of impact-resistant support systems in deep mining applications. Full article

As a core structure in coal mine underground reservoirs, the coal pillar dams’ stability is susceptible to the orientation of coal bedding planes. This study examines the deformation characteristics, acoustic emission (AE) evolution, and infrared radiation temperature (IRT) response of coal specimens with varying bedding angles (0°, 30°, 60°, 90°), investigating microscopic failure mechanisms and AE-IRT correlations. The results show that compressive strength and elastic modulus follow a V-shaped trend with increasing bedding angle, initially decreasing before rising. The proportion of low-amplitude events (40–60 dB) increases, while the higher-amplitude (>60 dB) AE signals decrease with the bedding angle. The AE b-values increase with the bedding angles. Mean IRT temperatures exhibit an overall increasing trend with significant fluctuations, and fluctuation amplitudes display an N-shaped pattern. Microscopically, all specimens undergo tensile–shear composite failure, but shear failure contribution varies markedly: 30° specimens show the highest shear proportion, while 60° specimens show the lowest. There is a positive correlation between AE and IRT. The correlation coefficient (γ) is relatively low at 0°, but it is higher at 30°, 60°, and 90°. This research provides a theoretical underpinning for optimizing the design and stability evaluation of coal mine underground reservoirs. Full article

With the ongoing electrification of vehicles and the resulting demand for higher power densities, drivetrain requirements are becoming increasingly stringent. Shaft-hub connections are particularly affected in terms of both quantity and design, making innovative solutions necessary. A key factor in meeting these requirements is knowledge of the stress state within the contact area. One promising approach is the application of a thin-film-based sensor system directly onto the shaft surface. This enables, for the first time, the direct measurement of contact pressure in the interface, allowing for more precise connection design. To fully exploit the potential of this sensor technology, its influence on the joining process of shaft-hub connections must be investigated. In this study, cylindrical interference-fits were coated with two thin-film systems relevant to the application, followed by joining tests. The resulting damage was analyzed to derive general recommendations for the joining of coated shaft-hub connections. The results show that shrink-fitting enables damage-free joining, provided specific parameters are met, as confirmed by experimental testing and microscopic examination. This not only preserves the integrity of the sensor system but also establishes the prerequisite for potential in situ measurements, thereby laying the foundation for the feasibility of direct load monitoring during operation. Full article

This paper presents experimental research on the relationship between the magnetic properties and the viscosity of ferrofluid based on ultra-pure magnetite nanoparticles, with the aim of studying behaviour through a microchannel. The magnetite nanoparticles have been obtained by chemical coprecipitation. Some examination methods, such as X-ray diffraction, transmission electron microscopy, and vibrating sample magnetometer, have been used to characterize the magnetite nanoparticles. The variation on the viscosity in the magnetic field of ferrofluids based on superparamagnetic magnetite has parabolic allure and in the absence of the magnetic field has a linear allure. The colloidal stability of the ferrofluids was evaluated using zeta potential measurements. Also, the behaviour of ferrofluids in a microchannel made inside the transparent polydimethylsiloxane (PDMS) matrix was observed under a digital microscope. Full article

This paper presents the results of wear tests of two types of commercial low-carbon, low-alloy martensitic abrasion-resistant steels, Hardox 450 and XAR 450, which belong to the hardness class 450 HBW. These steels, due to their increased resistance to the abrasive wear mechanism, are used for machine parts for applications in intensive abrasion environments such as construction, mining, and agriculture. The scope of work included microstructure analysis on an optical microscope, chemical composition analysis, Vickers hardness measurements at different loads (HV0.2, HV1 and HV2), and wear testing. Wear tests were carried out by the standard method “dry sand—rubber wheel”, and tests on the Taber abrader device. Microstructure analysis revealed that both steels have a similar non-oriented, homogenous, fine-grained martensitic microstructure. The results of HV2 hardness measurements showed a similar trend for both steels in all examined sections of the plates. For both tested steels, the hardness values of HV0.2 and HV1 are slightly higher than HV2, but the scattering of the results is also greater. Abrasion resistance testing using the standard “dry sand—rubber wheel” method showed that Hardox 450 steel has a lower volume loss of about 8%, but a greater scattering of the results compared to XAR 450 steel. The results of the abrasion resistance test on the Taber abrader device confirmed approximately the same behavior. For both steels, a prediction model was established for a reliable assessment of the wear intensity concerning the grain size. Although examined steels belong to the same hardness class, Hardox steel seems to be a more appropriate choice for the manufacture of machine components exposed to abrasive wear. Full article

In this mini-review, we compiled various types of Polyvinyl-alcohol-based hydrogel construction recipes and methodologies, categorizing them based on their added materials or production methods for wastewater applications. This classification is vital for identifying recipes that require improvement in future research and for analyzing their practical parameters, such as durability, surface area, and cleaning efficiency. To evaluate their potential for long-term use, we examined the durability of these groups. D- and E-type media demonstrated notable durability, exhibiting lower degradation rates compared to A- and B-types. Additionally, we gathered information on the measuring technologies available for assessing the specific surface area of these media, a crucial parameter for both biological and adsorbent applications. Based on the available data, we recommend enhancing the quality and quantity of measurements by integrating and improving microscopic analysis and adsorption techniques. Furthermore, these hydrogels showed superior cleaning capacities compared to traditional carriers, with D- and E-types excelling in adsorption capabilities, while the C-type exhibited exceptional potential for biological treatment. Full article

Background: Uterine leiomyomas are the most common pelvic tumors in women of reproductive age. There is no clear conclusion in the literature regarding the pathophysiology of these conditions. STAT proteins stimulate the transcription of target genes. STAT-3 leads to an increase in VEGF levels and plays a role in tumorigenesis. IL-26 and other cytokines are vital immune response mediators. Cytokine dysregulation affects the immune response of various organs and tissues, making them prone to various diseases, such as inflammation, infection, and tumors. Methods: In the present study, we aimed to determine whether STAT-3 and IL-26 play a role in the development of uterine leiomyoma. This case–control study included 38 patients who underwent hysterectomy due to uterine leiomyoma and 30 patients who underwent hysterectomy due to non-organic benign gynecological causes other than myoma. Sections from the myometrium of the control group and the leiomyoma tissue of the case group were subjected to immunohistochemical staining for STAT-3 and IL-26. Results: When the uterine tissue sections of the control group incubated with STAT-3 were examined under a light microscope, the smooth muscle and fibroblast cells in the myometrium were STAT-3-negative, while the number of smooth muscle and fibroblast cells showing strong STAT-3-staining in the leiomyoma sections was high. When the uterine tissue sections incubated with IL-26 were examined under a light microscope, the normal smooth muscle and fibroblast cells in the control group were IL-26-negative, while there was an increase in the number of cells showing strong IL-26-staining in the leiomyoma smooth muscle and fibroblast cells. Conclusions: Our findings show that STAT-3 and IL-26 levels are significantly increased in uterine leiomyomas, and this increase may play a role in the growth and progression of uterine fibroids. The current results may enable the development of innovative treatment options, as they demonstrate the role of novel pathways in the formation of uterine fibroids. Full article

Understanding the multi-crack coupling fracture behavior in brittle materials is particularly critical for aging dam infrastructure, where 78% of structural failures originate from crack network coalescence. In this study, we introduce the concepts of crack distance ratio (DR) and size ratio (SR) to describe the relationship between crack position and length and employ the discrete element method (DEM) for extensive numerical simulations. Specifically, a crack density function is introduced to assess microscale damage evolution, and the study systematically examines the macroscopic mechanical properties, failure modes, and microscale damage evolution of rock-like materials under varying DR and SR conditions. The results show that increasing the crack distance ratio and crack angle can inhibit the crack formation at the same tip of the prefabricated crack. The increase in the size ratio will promote the formation of prefabricated cracks on the same side. The increase in the distance ratio and size ratio significantly accelerate the rapid increase in crack density in the second stage. The crack angle provides the opposite effect. In the middle stage of loading, the growth rate of crack density decreases with the increase in crack angle. Overall, the size ratio has a greater influence on the evolution of microscopic damage. This research provides new insights into understanding and predicting the behavior of materials under complex stress conditions, thus contributing to the optimization of structural design and the improvement of engineering safety. Full article

This paper experimentally investigates the fretting fatigue behavior of metal additive-manufactured Ti-6Al-4V alloy specimens fabricated using the selective laser melting (SLM) method, focusing on damage characterization and fatigue life assessment. Based on the ASTM E466 standard, the test components were manufactured using metal 3D printing technology. Fretting fatigue tests were conducted under varying axial stress levels and contact loads, followed by microscopic examinations using scanning electron microscopy (SEM) to analyze damage mechanisms. A fretting map was developed based on SEM observations, providing insights into damage evolution under different loading conditions. These findings contribute to a better understanding of the relationship between fretting fatigue parameters and failure mechanisms. The developed fretting map and experimental observations provide a foundation for further studies aimed at enhancing the fretting fatigue life assessment of standard specimens for different test parameters. Finally, this paper includes design-oriented evaluation frameworks that can guide engineers in integrating AM components into safety-critical systems under fretting fatigue conditions. Full article

Manual tissue documentation is a critical step in the field of pathology that sets the stage for microscopic analysis and significantly influences diagnostic outcomes. In routine practice, technicians verbally dictate descriptions of specimens during gross examination; these are later transcribed into macroscopic reports. Fragment sizes are measured manually with rulers; however, these measurements are often inconsistent for small, irregular biopsies. No photographic record is captured for traceability. To address these limitations, we propose a proof-of-concept framework that automates the image capture and documentation of biopsy and resection cassettes. It integrates a custom imaging platform and a segmentation pipeline leveraging the YOLOv8 and YOLOv9 architectures to improve accuracy and efficiency. The framework was tested in a real clinical context and was evaluated on two datasets of 100 annotated images each, achieving a mask mean Average Precision (mAP) of 0.9517 ± 0107 and a tissue fragment spatial accuracy of 96.20 ± 1.37%. These results demonstrate the potential of our framework to enhance the standardization, reliability, and speed of macroscopic documentation, contributing to improved traceability and diagnostic precision. Full article