Search Results (173)

The geological structural complexity and microscale heterogeneity of shale reservoirs, characterized by the brittleness index and natural fracture density, exert a decisive effect on hydraulic fracturing’s effectiveness. However, the mechanisms underlying the true microscale heterogeneity of shale structures, which is neglected in conventional models and influences fracture evolution, remain unclear. Here, high-resolution scanning electron microscopy (SEM) was employed to obtain realistic distributions of mineral components and natural fractures, and hydraulic–mechanical coupled simulation models were developed within the Realistic Failure Process Analysis (RFPA) simulator using digital rock techniques. The analysis examined how the brittleness index and natural fracture density affect the fracture morphology’s complexity, mineral failure behavior, and flow conductivity. Numerical simulations show that the main fractures preferentially propagate toward areas with high local brittleness and dense natural fractures. Both the fracture’s fractal dimension and the stimulated reservoir volume increased with the brittleness index. A moderate natural fracture density promotes the fracture network’s complexity, whereas excessive densities may suppress the main fracture’s propagation. Microscopically, organic matter and silicate minerals are more prone to damage, predominantly tensile failures under external loading. These findings highlight the dominant role of microscale heterogeneity in shale fracturing and provide theoretical support for fracture control and stimulation optimization in complex reservoirs. Full article

To describe a technique for managing acute corneal hydrops in eyes with keratoconus using dome stromal drainage with intracameral air injection under real-time three-dimensional (3D) microscope-integrated optical coherence tomography (OCT) guidance. We describe a retrospective case series of six eyes from six patients with keratoconus who developed acute corneal hydrops. All eyes underwent intracameral air injection with controlled dome puncture for stromal fluid drainage, without the use of sutures. The procedure was performed using a 3D visualization system that enables integrated and simultaneous viewing of the surgical field and intraoperative OCT scan (a 3D digitally assisted visualization system that displayed a split-screen view of the surgical field and OCT cross-sections simultaneously). Postoperative resolution of edema and improvement in clarity were documented. The resolution of corneal edema allowed for subsequent mushroom-shaped penetrating keratoplasty performed with a femtosecond laser in four eyes of four patients. All six eyes showed significant resolution of corneal edema within 2 to 4 weeks. Stromal clefts collapsed rapidly after drainage. In each case, the thick edema was reduced to a confined leucoma. No intraoperative or postoperative complications were observed. All four eyes that underwent a femtosecond laser-assisted mushroom-shaped penetrating keratoplasty showed optimal anatomical and functional success. Air-assisted dome drainage, combined with simultaneous 3D and OCT visualization, is a safe and effective technique for treating acute corneal hydrops. This technology enables real-time decision-making and enhances surgical precision, opening the door to advanced procedures that are otherwise limited by corneal opacity. Full article

The peening process plays a pivotal role in enhancing the properties of aluminium alloys across various industries, including aerospace, automotive, and construction. Among the critical factors influencing this process, the shot peening time is of paramount importance for studying material characteristics. In the present study, we undertook a comprehensive investigation into the mechanical properties, surface roughness, and damage evolution behaviour of 7075 aluminium alloy subjected to different shot peening durations. This investigation was conducted using a microhardness tester, laser confocal microscope, scanning electron microscope, and other advanced equipment, in conjunction with digital image correlation methods and temperature evolution analysis. Our findings demonstrate that the shot peening time has a profound impact on the mechanical properties of the 7075 alloy. Specifically, the microhardness, tensile strength, and surface roughness of the alloy increased with increasing shot peening time, whereas the elongation rate exhibited a non-monotonic trend, initially decreasing and then increasing. Utilising DIC and temperature evolution analysis, we analysed the influence of shot peening time on the damage evolution behaviour of the alloy and developed tensile damage evolution equations tailored to different shot peening durations. The damage evolution of the 7075 alloy under various shot peening times was observed to proceed through two distinct stages: smooth development and rapid damage. Notably, the damage evolution laws derived from both techniques exhibited good consistency and agreement. The present study serves as a theoretical foundation for exploring the surface peening and damage evolution of 7075 aluminium alloy, which holds significant implications for optimising peening parameters and predicting material life in engineering applications. Full article

Microbially induced concrete deterioration (MID) poses a significant and urgent challenge to urban sewerage systems globally, particularly in tropical coastal regions. Despite the acknowledged importance of biofilms in MICC, limited research on sewer pipe biofilms has hindered a comprehensive understanding of their deterioration mechanisms. To overcome this limitation, our research employed multiple staining techniques and digital volume correlation (DVC) technology, creating a new method to analyze the microstructure of biofilms, precisely identify the components of EPSs, and quantitatively examine MID mechanisms from a microscopic viewpoint. Our results revealed that the biofilm on concrete surfaces regulates the types of amino acids, thereby creating an environment conducive to microbial aggregate survival. Additionally, salinity significantly influences biofilm component distribution, while proteins play a pivotal role in biofilm mechanical stability. Notably, a high salinity fosters microbial migration within the biofilm, exacerbating deterioration. Through this multidimensional inquiry, our study established an advanced echelon of comprehension concerning the intricate mechanisms underpinning MICC. Meanwhile, by peering into the biofilms and elucidating their interplay with concrete, our findings offer profound insights, which can aid in devising strategies to counter urban sewer system deterioration. Full article

This study takes limestone crushed stone concrete as the research object and systematically investigates its mechanical property changes and microstructural damage characteristics under different confining pressures using triaxial compression tests, scanning electron microscope (SEM) tests, and digital image processing techniques. The results show that, in terms of macro-mechanical properties, as the confining pressure increases, the peak strength increases by 192.66%, the axial peak strain increases by 143.66%, the elastic modulus increases by 133.98%, and the ductility coefficient increases by 54.61%. In terms of microstructure, the porosity decreases by 64.35%, the maximum pore diameter decreases by 75.69%, the fractal dimension decreases by 19.56%, and the interfacial transition zone cracks gradually extend into the aggregate interior. The optimization of the microstructure makes the concrete more compact, reduces stress concentration, and thereby enhances the macro-mechanical properties. Additionally, the failure characteristics of the specimens shift from diagonal shear failure to compressive flow failure. According to the Mohr–Coulomb strength criterion, the calculated cohesion is 6.96 MPa, the internal friction angle is 38.89°, and the breakage angle is 25.53°. A regression analysis established a quantitative relationship between microstructural characteristics and macro-mechanical properties, revealing the significant impact of microstructural characteristics on macro-mechanical properties. Under low confining pressure, early volumetric expansion and rapid volumetric strain occur, with microcracks mainly concentrated at the aggregate interface that are relatively wide. Under high confining pressure, volumetric expansion is delayed, volumetric strain increases slowly, and microcracks extend into the interior of the aggregate, becoming finer and more dispersed. Full article

Background/purpose: Fiber-reinforced materials are commonly used as biobases beneath indirect restorations, potentially affecting the seating and marginal accuracy of the restorations. This study intended to assess the impact of various biobase techniques on the marginal adaptation of lithium disilicate overlay restorations. Methods: Fifty sound maxillary first premolar teeth of comparable dimensions were prepared using a full-bevel overlay design (3 mm occlusal reduction) and allocated randomly to five groups as follows (n = 10): Group A, delayed dentin sealing; Group B, immediate dentin sealing using Optibond FL; Group C, immediate dentin sealing with a 1 mm flowable composite layer (Clearfil AP-X Flow); Group D, immediate dentin sealing followed by a 1 mm short-fiber-reinforced composite layer (everX Flow); and Group E, immediate dentin sealing coated with a 1 mm flowable composite layer reinforced with polyethylene Ribbond fibers. Digital impressions were obtained using a Medit i700 intraoral scanner, and the overlays were digitally designed via the Sirona inLab CAD software and milled via a four-axis milling machine. The overlays were luted with a preheated composite (Clearfil AP-X). Marginal gap assessments were conducted pre- and post-cementation via a digital microscope at 230× magnification. The data were statistically analyzed using a one-way analysis of variance and paired t-tests. Results: The one-way ANOVA disclosed no significant differences among the groups before or after cementation (p > 0.05). Conclusions: The presence or absence of fiber-reinforced biobases did not impact the marginal adaptation of the restorations; these biobases can be incorporated to optimize the mechanical behavior of indirect restorations without adversely affecting their seating accuracy. These findings suggest that fiber-reinforced and non-reinforced biobase techniques can be safely integrated into clinical adhesive protocols to enhance the mechanical performance of restorations without comprising their marginal adaptation. Full article

This research focuses on the development, design, implementation, and testing (with complete hardware and software integration) of a 6D Electromagnetic Actuation (EMA) system for the precise control and navigation of micro/nanorobots (MNRs) in high-viscosity fluids, addressing critical challenges in targeted drug delivery within complex biological environments, such as blood vessels. The primary objective is to overcome limitations in the actuation efficiency, trajectory stability, and accurate path-tracking of MNRs. The EMA system utilizes three controllable orthogonal pairs of Helmholtz coils to generate uniform magnetic fields, which magnetize and steer MNRs in 3D for orientation. Another three controllable orthogonal pairs of Helmholtz coils generate uniform magnetic fields for the precise 3D orientation and steering of MNRs. Additionally, three orthogonal pairs of Maxwell coils generate uniform magnetic field gradients, enabling efficient propulsion in dynamic 3D fluidic environments in real time. This hardware configuration is complemented by three high-resolution digital microscopes that provide real-time visual feedback, enable the dynamic tracking of MNRs, and facilitate an effective closed-loop control mechanism. The implemented closed-loop control technique aimed to enhance trajectory accuracy, minimize deviations, and ensure the stable movement of MNRs along predefined paths. The system’s functionality, operation, and performance were tested and verified through various experiments, focusing on hardware, software integration, and the control algorithm. The experimental results show the developed system’s ability to activate MNRs of different sizes (1 mm and 0.5 mm) along selected desired trajectories. Additionally, the EMA system can stably position the MNR at any point within the 3D fluidic environment, effectively counteracting gravitational forces while adhering to established safety standards for electromagnetic exposure to ensure biocompatibility and regulatory compliance. Full article

Background: Schistosomiasis (SCH) and soil transmitted helminthiasis (STH) have been targeted for elimination as a public health problem (EPHP) within the World Health Organization (WHO)’s Roadmap for Neglected Tropical Diseases (NTDs) 2021–2030. One of the global strategies for the control and elimination of these diseases is the mass administration of praziquantel and albendazole/mebendazole without prior individual diagnosis. To measure the progress towards the 2030 target, we conducted an assessment to determine the impact of the 3–5 rounds of annual mass drug administration among school age children in Ekiti State. Such scientific insights into the impact of these treatments will facilitate improved planning and targeting of resources towards reaching the last mile. Methodology: This assessment was conducted in 16 local government areas (LGAs) of Ekiti State between October and November 2023. Samples were collected from pupils in 166 primary and junior secondary schools across 166 wards of the State. Urine and stool samples were collected from 7670 pupils of ages 5 to 14 years, following standard laboratory procedures. Urine membrane filtration techniques were used for urine preparation while the Kato–Katz technique was used for stool preparation. A novel AiDx digital microscope was used to examine the presence of any ova in the prepared specimen. Parasite ova in urine were reported as the number of ova/10 mL of urine, and were categorized as light infection (˂50 ova/10 mL of urine) or heavy infection (>50 ova/10 mL of urine) while ova of parasites in stool samples were reported as eggs per gram of stool (EPG) and categorized into light, moderate and heavy infection. Results: Overall, 0.76% (0.56–0.95) at 95% CI of the 7670 respondents were infected with Schistosomia haematobium. No Schistosoma mansoni infection was recorded in the study. Similarly, 3.9% (3.43–4.29) at 95% CI were infected with STHs. The overall prevalence of schistosomiasis had significantly reduced from 8.2% in 2008 to 0.8%, while the overall prevalence of STHs significantly reduced from 30.9% to 3.9% with Ascaris lumbricoides being the dominant species of STH. In the 16 LGAs assessed, Ekiti West had the highest S. haematobium prevalence of 4.26%. Ise/Orun and Oye ranked second and third with a prevalence of 3.48% and 2.40% respectively, while all other LGAs had <1% prevalence. The prevalence of STHs was highest in Ekiti-West with a prevalence of 10.45% while Emure and Ikole Local Governments had the lowest prevalence of 0.31% and 0.38%, respectively. There was no significant difference in the prevalence of schistosomiasis between male (0.76%) and female (0.75%) as p ≥ 0.05. Similarly, the difference in prevalence for STH among males (3.95%) was not significantly different from their female counterparts (3.77%), p ≥ 0.05. Conclusions: Based on the WHO guidelines, this study demonstrated that only three LGAs require continued MDA every 2/3 years, seven require only surveillance while six are now non-endemic for schistosomiasis. Similarly, two of the LGAs require one round of MDA yearly, eight LGAs need one round of MDA every two to three years and six LGAs are now below the treatment threshold and no longer require treatment for STH. Full article

Although heavy oil remains a crucial energy source, its high viscosity makes its utilization challenging. We have performed an interpretable analysis of the relationship between the molecular structure of digital oil and its viscosity using molecular dynamics simulations combined with machine learning. In this study, we developed three “digital oils” to represent light, medium, and heavy oils in consideration of their composition and molecular structure. Using molecular dynamics (MD) simulations, we calculated the density, self-diffusion coefficient, and viscosity of these digital oils at various temperatures (323–453 K). The accuracy of the simulation results was demonstrated by their good fit to the experimental data. We further explored the correlation between interaction energy and viscosity. As interaction energy increased, molecular attraction strengthened, resulting in greater friction between molecules and a higher viscosity of the digital oil. Cluster analysis revealed that, compared with the other two oils, the heavy oil contained rod-shaped molecular aggregates in greater quantity and larger clusters. Additionally, we computed the radial distribution functions of the SARA (saturates, aromatics, resins, and asphaltenes) components; among molecular pairs, aromatics and resins showed the largest interaction energy and were the most tightly bound, contributing to increased viscosity. To more effectively predict the viscosity of digital oils, we integrated four machine learning (ML) techniques: linear regression, random forest, extra trees, and gradient boosting. Post-hoc analysis coupled with SHapley Additive exPlanations (SHAP) was applied to interpret how macroscopic and microscopic features influence the viscosity and to identify the contributions of individual molecules. This work presents a novel and efficient method for estimating the viscosity of digital oils by combining MD simulations with ML approaches, offering a valuable tool for quick and cost-effective analysis. Full article

Background: The standard diagnostic approach for prostate cancer (PCa) diagnosis consists of serum prostate-specific antigen (PSA) testing, digital rectal examination (DRE) and image-guided targeted biopsies. Given the invasive nature, potential adverse events and costs associated with these techniques, alternative approaches have been investigated, specifically with serum and urine assays. The work presented here is intended to further validate a novel noninvasive optical technique for PCa detection, targeting the VPAC genomic receptors that are overexpressed on prostate cancer’s malignant cells (MC), in non-DRE voided urine. Methods: Patients (N = 62) who had image-guided biopsy and histologically confirmed localized PCa, and who were scheduled for radical prostatectomy, provided a non-DRE voided urine sample prior to surgery. Urine was cytocentrifuged and cells fixed on a glass slide, incubated with 0.5 μg TP4303 (a receptor-specific fluorophore developed in our laboratory with high affinity for VPAC), excess washed and treated with 4,6-diamidodino-2-phenylindole (DAPI) for nuclear staining. The field of cells on each slide was analyzed using a Zeiss AX10 Observer microscope (20×). The total number of cells and MC were then counted, and the florescent intensity around each MC was measured using Zeiss software. Additionally, non-DRE voided urine samples collected from clinically determined BPH patients (N = 97), were also analyzed similarly. Results: Urine samples from 62 patients were processed and analyzed. Mean PSA levels by Gleason grade (GG) group were 6.5 ± 4.1 ng/mL for GG1 (N = 10), 7.2 ± 3.8 for GG2 (N = 31), 13.2 ± 14.6 for GG3 (N = 13), 6.2 ± 2.2 for GG4 (N = 2) and 50.2 ± 104.9 for GG5 (N = 6). Like the PSA, % MC shed (66.7 ± 27.7) in voided urine and the fluorescent intensity (35.8 ± 5.7) were highest in patients with GG5 prostate cancer. All PCa patients in GG1 to GG5 shed MC in voided urine with increasing % of MC and increasing fluorescence intensity which correlated with the increasing GG for PCa. For BPH, the specificity for the assay was 89.6% (95% CI:81.9–94.9%), PPV was 0.0% and NPV was 100% (95.9% CI, 95.9–100%). Conclusions: These data indicate the following: (i) PCa MC shed in non-DRE voided urine can be detected by targeting VPAC receptors, (ii) MC are shed in non-DRE voided urine with increasing quantity, corresponding to the severity of the disease, and (iii) this non-DRE voided urine optical assay provides a simple, noninvasive, and reliable method for the preliminary detection of PCa with potentially a lower cost than the currently available pre-biopsy detection technologies. Full article

The gold standard diagnosis for malaria is the microscopic visualization of blood smears to identify Plasmodium parasites, although it is an expert-dependent technique and could trigger diagnostic errors. Artificial intelligence (AI) tools based on digital image analysis were postulated as a suitable supportive alternative for automated malaria diagnosis. A diagnostic evaluation of the iMAGING AI-based system was conducted in the reference laboratory of the International Health Unit Drassanes-Vall d’Hebron in Barcelona, Spain. iMAGING is an automated device for the diagnosis of malaria by using artificial intelligence image analysis tools and a robotized microscope. A total of 54 Giemsa-stained thick blood smear samples from travelers and migrants coming from endemic areas were employed and analyzed to determine the presence/absence of Plasmodium parasites. AI diagnostic results were compared with expert light microscopy gold standard method results. The AI system shows 81.25% sensitivity and 92.11% specificity when compared with the conventional light microscopy gold standard method. Overall, 48/54 (88.89%) samples were correctly identified [13/16 (81.25%) as positives and 35/38 (92.11%) as negatives]. The mean time of the AI system to determine a positive malaria diagnosis was 3 min and 48 s, with an average of 7.38 FoV analyzed per sample. Statistical analyses showed the Kappa Index = 0.721, demonstrating a satisfactory correlation between the gold standard diagnostic method and iMAGING results. The AI system demonstrated reliable results for malaria diagnosis in a reference laboratory in Barcelona. Validation in malaria-endemic regions will be the next step to evaluate its potential in resource-poor settings. Full article

Spontaneous abortion, commonly known as miscarriage, is a significant concern during early pregnancy. Histopathological examination of tissue samples is a widely used method to diagnose and classify tissue phenotypes found in products of conception (POC) after spontaneous abortion. Background: Histopathological examination is subjective and dependent on the skill and experience of the examiner. In recent years, artificial intelligence (AI)-based techniques have emerged as a promising tool in medical imaging, offering the potential to revolutionize tissue phenotyping and improve the accuracy and reliability of the histopathological examination process. The goal of this study was to investigate the use of AI techniques for the detection of various tissue phenotypes in POC after spontaneous abortion and evaluate the accuracy and reliability of these techniques compared to traditional manual methods. Methods: We present a novel publicly available dataset named HistoPoC, which is believed to be the first of its kind, focusing on spontaneous abortion (miscarriage) in early pregnancy. A diverse dataset of 5666 annotated images was prepared from previously diagnosed cases of POC from Atia General Hospital, Karachi, Pakistan, for this purpose. The digital images were prepared at 10× through a camera-connected microscope by a consultant histopathologist. Results: The dataset’s effectiveness was validated using several deep learning-based models, demonstrating its applicability and supporting its use in intelligent diagnostic systems. Conclusions: The insights gained from this study could illuminate the causes of spontaneous abortion and guide the development of novel treatments. Additionally, this study could contribute to advancements in the field of tissue phenotyping and the wider application of deep learning techniques in medical diagnostics and treatment. Full article

This paper describes the methodology of the preparation and analyses of the structure and anticorrosion properties of silane coatings modified with poly(3,4-ethylenedioxythiophene) (PEDOT) with phosphododecamolybdic acid (PMo₁₂). Protective coatings, consisting of vinyltrimethoxysilane (VTMS), PEDOT powder with PMo₁₂ admixture (at different concentrations), and ethanol, were deposited on X20Cr13 and 41Cr4 steels by immersion. The physicochemical properties of these silane coatings (e.g., surface morphology, thickness, roughness, and adhesion to the substrate) were elucidated using a digital microscope, a Fourier transform infrared spectrophotometer with attenuated total reflectance, and various electrochemical diagnostic techniques. Protective properties were assessed in acidified sulfate solutions with and without chloride ions (pH 2). Experimental results have shown that this coating displayed the effective protection of steel against general and pitting corrosion, stabilized the corrosion potential in the passive state, and provided barrier protection. Full article

Characterizing the fractal nature of shale pores is critical for understanding their heterogeneity, which significantly impacts hydrocarbon mobility. A critical technique in this analysis involves the digital evaluation of scanning electron microscopy (SEM) images. While the cumulative size distribution model is a viable method in SEM fractal analysis, its accurate application necessitates exhaustive microimaging of entire sample cross-sections, rendering it impractical. To address this challenge, we propose an innovative approach that develops a universal equation for this model, along with numerical solving methods. This approach expands the model’s applicability, enabling accurate fractal analysis of entire samples using only randomly selected microscopic fields. It enhances the existing framework for fractal modeling and potentially serves as a valuable tool for studying fractal structures. Using this method, we investigated the fractal characteristics of various macropore types across different lithological units in the Chang-7 shale of the Ordos Basin. Our findings indicate that macropore heterogeneity is influenced by variations in pore type composition, their response under compaction, and organic acid dissolution, all of which are driven by differences in lithology. These findings provide new insights into the mechanisms driving macropore heterogeneity from the perspective of lithological and pore-type variations, potentially yielding valuable implications for the exploration and development of Chang-7 shale oil. Full article

Background: Ex vivo fluorescence laser scanning microscopes (FCMs) allow digital tissue imaging directly from fresh, unfixed specimens without the need for conventional histological slide preparation. To date, no data have been reported on the use of FCMs in the endoscopy suite for immediate evaluation of endoscopic ultrasound (EUS)/endobronchial ultrasound (EBUS) fine needle aspiration/biopsy (FNA-B) specimens of lung lesions and/or mediastinal lymph nodes. Objectives: The aim of this study was to evaluate the performance of the FCM Vivascope 2500 (Vivascope, Munich, Germany) in providing real-time adequacy assessment and diagnostic information on the digital images of fresh unprocessed EUS/EBUS FNA-B specimens and to compare it with the corresponding final histological sections of formalin-fixed and paraffin-embedded cell blocks. Methods and Results: Thirty-two patients (50% male; 71 ± 8 years old) were enrolled between May 2023 and June 2024. In 28/32 (87.5%) patients, samples were defined as adequate at Vivascope evaluation, and in 20/28 (71.4%) patients, samples were classified as malignant. At final cytohistological evaluation, 87.5% of specimens were defined as adequate and 20/28 (71.4%) were diagnosed as malignant. There was perfect agreement between the Vivascope assessment of adequacy and the final cytohistological assessment on the same specimen (k Cohen 1). From a diagnostic point of view, perfect agreement was found between the two techniques in the identification of malignant neoplasms (k Cohen 1). Conclusions: The use of FCM could provide rapid information on both the adequacy and malignancy of the sample obtained during EBUS tissue acquisition (EBUS-TA), with minimal or no preparation and without destroying or losing the tissue. This technique allows for obtaining representative material in EBUS/EUS for lung cancer staging and is expected to change the turnaround time from biopsy sampling to diagnostic characterization of the tumor, ultimately improving patient management both at diagnosis and at restaging in follow up. Full article