Search Results (88)

In this study, we demonstrated that lrp6a, a co-receptor in the Wnt signaling pathway, is essential for proper median fin formation and somitogenesis in goldfish. We analyzed the gene’s sequence features and expression patterns in both wen-type and egg-type goldfish, uncovering distinct tissue-specific expression differences between the two varieties. To explore the functional role of lrp6a, we performed CRISPR/Cas9-mediated gene knockout using eight designed single-guide RNAs (sgRNAs), of which four showed effective targeting. Three high-efficiency sgRNAs were selected and co-injected into embryos to achieve complete gene disruption. Morphological assessments and X-ray microtomography (μCT) imaging of the resulting mutants revealed various abnormalities, including defects in the dorsal, caudal, and anal fins, as well as skeletal deformities near the caudal peduncle. These results confirm that lrp6a plays a key role in median fin development and axial patterning, offering new insights into the genetic regulation of fin formation in teleost fish. Full article

MgO–C refractory materials were developed by incorporating different ratios of alumina/titania nano-additives which were synthesized chemically. Their physical and mechanical properties, oxidation resistance, slag wettability, bulk density, apparent porosity, cold crushing strength, oxidation index, and closed porosity were tested, evaluated, and compared using conventional techniques as well as X-ray micro-computed tomography (µCT). This investigation indicated a slight degradation of physical properties and mechanical strengthening which was stronger for samples with increased alumina content. Oxidation and corrosion extent were tested both with X-ray tomography and conventional methods. The first method allowed for the calculation of the oxidation index, the detection of closed porosity, and an improved analysis of the internal corrosion, avoiding the sectioning of the materials. This result confirms the supremacy of the first technique. On the contrary, although conventional methods such as the Archimedes procedure cannot detect close porosity, they provide more accurate measurements of the physical properties of refractories. This study shows that conventional methods exhibit superiority in investigations of the pore structures of refractories for pore sizes in the range 1–2 μm, while the use of the μCT system is limited for pore sizes equal to or larger than 20 μm. Full article

Apatite pastes derived from eggshell waste (BAp) were implanted onto the calvarial bone of rats, and bone formation was evaluated using X-ray μ-computed tomography (CT) and histological evaluation. BAp was mixed with distilled water to prepare a paste. Monoclinic hydroxyapatite of mineral resources (HAp) was used as a control. A 5 mm diameter PTFE (polytetrafluoroethylene) tube was filled with apatite pastes and implanted in the calvarial bone of 9-week-old Sprague Dawley rats for 8 weeks. A larger radiopaque area, similar to that of native bone, was observed in the BAp paste-implanted specimens than that of HAp paste. The bone mineral density (BMD) value of the BAp paste was significantly higher than that of the HAp paste (p < 0.05). In the histological evaluation, new bone formation was noticed from the calvarial side for both apatite specimens, and HAp remained in the PTFE unlike BAp. The bone mass (BM) value of the BAp paste was significantly higher than that of the HAp paste (p < 0.05). SEM and XRD analyses revealed that BAp was microcrystalline and poorly crystalline. The promotion of new bone formation may contribute to the crystallinity and Mg content of BAp. BAp was found to be useful as a bone regeneration material. Full article

Ultra-high-performance fiber-reinforced concrete (UHPFRC) exhibits exceptional tensile properties, but its tensile strength is highly dependent on fiber distribution, orientation, and count, making accurate strength estimation challenging. This study introduces a novel approach in which tensile strength estimation is achieved by analyzing fiber characteristics at predicted cracking locations using deep learning. Using X-ray computed tomography (CT) and image analysis techniques, the fiber orientation factor (μ₀) and average efficiency factor ((μ₁)⁻) were determined at predicted cracking locations. A deep learning model (YOLOv11) was trained to identify regions with a defective distribution, achieving a mean Average Precision (mAP@0.5) of 0.87, demonstrating its high reliability in predicting cracking locations. The overall cracking location prediction success rate was 73% for strain-hardening specimens. The estimated tensile strength was then compared with uniaxial tensile test (UTT) results, revealing an average experiment-estimation error of 5.72% and an average theory-estimation error of 3.34% for strain-hardening specimens, whereas strain-softening specimens exhibited significantly higher errors, with an average experiment-estimation error of 43.09% and an average theory-estimation error of 15.73%. These findings highlight the strong correlation between fiber count, cracking behavior, and tensile strength in UHPFRC, offering a trustworthy, non-destructive framework for estimating tensile performance in UHPFRC elements. Full article

We report the synthesis and characterization of five novel metal complexes. Three of them are vanadium complexes with the general formula [VO(Lⁿ)₂], where Lⁿ are Schiff bases derived from the condensation of 2-carbaldehyde-8-hydroxyquinoline with either 4-(2-aminoethyl)morpholine (L¹), 3-morpholinopropylamine (L²) or 1-(2-aminoethyl)piperidine (L³). The two other metal complexes are [Ni(L¹)₂] and [Fe(L¹)₂]Cl. They were characterized by analytical, spectroscopic (Fourier transform infrared, UV-visible absorption), and mass spectrometric techniques as well as by single-crystal X-ray diffraction (for all [VO(Lⁿ)₂] complexes and [Ni(L¹)₂]). While, in the crystal structure, the V(IV)O complexes show distorted square–pyramidal geometry with the ligands bound as bidentate through quinolate NO donors, the Ni(II) complex shows octahedral geometry with two ligand molecules coordinated through NNO donors. Stability studies in aqueous media revealed that the vanadium complexes are not stable, undergoing oxidation to VO₂(L), which was corroborated by ⁵¹V NMR and MS. This behavior is also observed in organic media, though at a significantly slower rate. The Ni complex exhibited small spectral changes over time in aqueous media. Nonetheless, all compounds show enhanced stability in the presence of bovine serum albumin (BSA). Fluorescence studies carried out for the Ni(II) and Fe(III) complexes indicate reversible binding to albumin. The cytotoxicity of the L¹ metal complexes was assessed on melanoma (B16F10 and A375) and colon cancer (CT-26 and HCT-116) cell lines, with 5-fluorouracil (5-FU) as a reference drug. The V- and Ni complexes showed the lowest IC₅₀ values (<10 μM) in either A375 or HCT-116 cells after 48 h of incubation, while the Fe(III) complex presented minimal antiproliferative effects. The complexes were generally more cytotoxic to human than murine cancer cells. Synergistic in vitro studies with 5-FU revealed antagonism in most cases, except in A375 cells, where an additive effect was observed for the combination with the V-complex. Overall, these compounds show promising potential for cancer treatment, mostly for melanoma. Full article

This study presents a multi-analytical investigation of the wooden components from Khufu’s Second Solar Boat, one of the valuable archaeological discoveries in ancient Egypt. The research integrates advanced imaging and analytical techniques to identify wood species, assess deterioration patterns, and characterize the fungal and bacterial biodeteriogens. The initial visual examination documented the state of preservation at the time of discovery. Subsequently, the identification of the wood species was carried out. The deterioration status was assessed using a variety of tools, including scanning electron microscopy (SEM) and high-resolution synchrotron radiation computed microtomography (SR-μCT) for morphological alterations, X-ray diffraction (XRD) for crystallinity changes and Fourier-transform infrared spectroscopy (FTIR) to assess chemical degradation indexes of wood. Moreover, molecular techniques were used to identify and characterize the presence of biodeterioration agents. Results indicate that ancient craftsmen used cedar wood for the boat construction. The analysed samples exhibited advanced biotic and abiotic degradation, as evidenced by microbiological assessments, XRD measurements of cellulose crystallinity, FTIR indices, SEM micrographs and SR-μCT data. These results provide crucial insights into the long-term degradation processes of archaeological wood in arid environments, enhancing our understanding of ancient Egyptian woodworking practices and informing future conservation strategies for similar artifacts. Full article

Egyptian Blue was the first synthetic pigment by humankind. It contains of cuprorivaite, which is a calcium-copper-silicate (CaCuSi₄O₁₀). This study reports the results of a mineralogical and computer tomographic study of Egyptian Blue finds from Aguntum in East Tyrol along with Retznei and Wagna (formerly Flavia Solva) from southern Styria in Austria. The present work aims to extend our understanding of the processes involved in the production of the artificial pigment Egyptian Blue. The samples were investigated with respect to their elemental composition and spatial distribution of the calcium-copper-silicate cuprorivaite CaCuSi₄O₁₀ and then compared with data from previous studies. Thin sections of an Egyptian Blue sphere from Aguntum were examined using optical microscopy (OP), micro-X-ray fluorescence analysis (μ-XRF) and scanning electron microscopy coupled with energy dispersive X-ray spectroscopy (SEM-EDX). The pigment’s initial mixture as well as the manufacturing process seem to be the decisive factor for the quality of the final product. A relationship between the presence of trace iron (Fe) and titanium (Ti) with the quartz and copper source of the initial mixture is discussed. SEM-EDX analysis revealed that cuprite (Cu₂O) was used as a copper source. In addition, micro-computed tomography (µCT) of the Egyptian Blue finds (Aguntum, Retznei, Wagna-Flavia Solva) was performed. Hence, revealing several concise differences between the samples. Texture and volumetric results show a distinctive difference in cuprorivaite content and particle size. To better analyse the spatial distribution, µCT-3D images of the individual mineral phases identified within each sample were obtained. The clear differences in the results may not only enable a differentiation of the production process but also show another potential of non-destructive µCT for assessment of archaeological findings. Full article

This paper investigates the effects of particle morphology (PM) and particle size distribution (PSD) on the micro-macro mechanical behaviours of granular soils through a novel X-ray micro-computed tomography (μCT)-based discrete element method (DEM) technique. This technique contains the grain-scale property extraction by the X-ray μCT, DEM parameter calibration by the one-to-one mapping technique, and the massive derivative DEM simulations. In total, 25 DEM samples were generated with a consideration of six PSDs and four PMs. The effects of PSD and PM on the micro-macro mechanical behaviours were carefully investigated, and the coupled effects were highlighted. It is found that (a) PM plays a significant role in the micro-macro mechanical responses of granular soils under triaxial shear; (b) the PSD uniformity can enhance the particle morphology effect in dictating the peak deviatoric stress, maximum volumetric strain, contact-based coordination number, fabric evolution, and shear band formation, while showing limited influences in the maximum dilation angle and particle-based coordination number; (c) with the same PSD uniformity and PM degree, the mean particle volume shows minimal effects on the macro-micro mechanical behaviours of granular soils as well as the particle morphology effects. Full article

The idea supporting the investigation of the current manuscript was to develop customized filters for air conditioners with different pore percentages and geometry with the additional advantage of presenting antibacterial performance. This property was expected due to the reinforcement of Cu nanoparticles in the polymeric matrix of poly(lactic acid) (PLA) and polyurethane (TPU). The filaments were characterized by their chemical composition, thermal and mechanical properties, and antibacterial behavior before and after processing by fused filament fabrication. An X-ray photoelectron spectroscopy showed that the nanocomposite filaments presented Cu particles at their surface in different valence states, including Cu⁰, Cu⁺, and Cu²⁺. After processing, the metallic particles are almost absent from the surface, a result confirmed by micro-computer tomography (μ-CT) characterization. Antibacterial tests were made using solid-state diffusion tests to mimic the dry environment in air conditioner filters. The tests with the nanocomposite filaments showed that bacteria proliferation was hindered. However, no antibacterial performance could be observed after processing due to the absence of the metallic element on the surface. Nevertheless, antimicrobial performance was observed when evaluated in liquid tests. Therefore, the obtained results provide valuable indications for developing new nanocomposites that must maintain their antimicrobial activity after being processed and tested in the dry conditions of solid-state diffusion. Full article

Given the functional and aesthetic quality expected from concrete surfaces, this study investigated the influence of different formwork materials on their surface density, porosity, voids, and elementary chemical composition by relying on X-ray Microtomography (μCT), Scanning Electronic Microscopy (SEM), and Energy Dispersive X-ray Spectroscopy (EDS). The formwork materials assessed were galvanized steel, regular plywood (pink), marine plywood, polyvinyl chloride (PVC), and silicone. μCT showed that distinct formwork affected the surface density of the concrete. In this case, specimens cast within silicone and marine plywood had similar pore volumes although different pore sizes, whereas PVC led to the highest pore volume with small pore sizes. Galvanized steel and regular plywood resulted in similar porosity. SEM showed that the concrete surfaces produced with marine plywood formwork had the highest void content. EDS identified surface products resulting from the contact of concrete with the different formwork materials, suggesting the potential migration of chemical elements. This research significantly contributes to optimizing formwork material selection and enhancing concrete quality and durability. Moreover, it establishes a foundation for further investigations into how formwork materials affect concrete surfaces and the pathological manifestations potentially arising from the molding process. Full article

Organometallic complexes of fac-tricarbonylrhenium have been shown to exhibit anticancer properties. Anthrapyrazole anticancer agents act as DNA intercalators and topoisomerase IIα inhibitors, leading to double-strand breaks (DBS) and cell cycle arrest. This work involves the synthesis and biological evaluation of novel fac-tricarbonyl-rhenium complexes with anthrapyrazole derivatives. The anthrapyrazole moiety was synthesized from 1,8-dihydroxyanthraquinone, and three ligands L1, L2 and L3 were prepared. Ligand L1 coordinates via the phenolic O and pyrazole N as bidentate chelator forming the fac-[Re(CO)₃(κ²-N,O)(MeOH)]-type complex, ReL1. Ligand L2 contains a pendant picolylamine N,N′-chelating system, forming the bidentate fac-[Re(CO)₃(κ²-N,N′)Br]-type complex, ReL2. Ligand L3 contains a pendant picolylaminomonoacetic acid chelating system, forming a tridentate fac-[Re(CO)₃(κ³-N,N′,O)]-type complex, ReL3. Complex ReL4 contains a picolylamine chelator, forming a complex with structure fac-[Re(CO)₃(κ²-N,N′)Br], which was synthesized as a model for ReL2, and its coordination mode was resolved by X-ray crystallography. The complexes were characterized spectroscopically, and their biological properties were evaluated in vitro, in terms of DNA binding as well as for the cytotoxicity against CT-26 tumor cell line. Tumor cell cytotoxicity was high for ligand L2 and complex ReL2, exhibiting IC₅₀ values of 0.36 and 0.64 μΜ, respectively. The most promising complex ReL2 was evaluated further by the preparation of its congener γ-emitting technetium-99m radio-complex, ^99mTcL2. The in vitro uptake in CT26 tumor cells and the in vivo uptake in CT26 tumor-bearing mice of ^99mTcL2 was determined, and its pharmacokinetic profile was established. These data indicate that the ^99mTc complex has suitable properties to enter tumor cells in vitro and in vivo, and therefore ReL2 is promising for further evaluation. Full article

Permeability measurement of engineering textiles is a key step in preparing composite manufacturing processes. A radial flow experimental setup was used in this work to measure the unsaturated and saturated in-plane permeabilities of five different types of E-glass textiles and their ratios. In parallel, delayed tow saturation during the oil injection stage was visually observed to identify fabrics that exhibited a significant dual-scale effect. A numerical approach to determine the saturated permeability of a given fabric geometry at the mesoscale was tested and validated against analytical models found in the literature. It was then applied to a realistic geometry acquired from an E-glass plain weave textile using an X-ray microtomography scanner (μCT). Two numerical methods were adopted: the single-scale method, where the tows are considered impermeable, and the dual-scale method, where the permeability of the tows is taken into account. The numerical results from both methods were then compared with the experimental values and showed good agreement, especially with the second method. Full article

Several novel copper (II) complexes of reduced Schiff bases containing fluoride substituents were prepared and structurally characterized by single-crystal X-ray diffraction. The complexes exhibited diverse structures, with the central atom in distorted tetrahedral geometry. The biological effects of the products were evaluated, specifically their cytotoxicity, antimicrobial, and antiurease activities, as well as affinity for albumin (BSA) and DNA (ct-DNA). The complexes showed marked cytotoxic activities in the HepG2 hepatocellular carcinoma cell line, considerably higher than the standard cisplatin. The cytotoxicity depended significantly on the substitution pattern. The best activity was observed in the complex with a trifluoromethyl group in position 4 of the benzene ring—the dichloro[(±)-trans-N,N′-bis-(4-trifluoromethylbenzyl)-cyclohexane-1,2-diamine]copper (II) complex, whose activity (IC₅₀ 28.7 μM) was higher than that of the free ligand and markedly better than the activity of the standard cisplatin (IC₅₀ 336.8 μM). The same complex also showed the highest antimicrobial effect in vitro. The affinity of the complexes towards bovine serum albumin (BSA) and calf thymus DNA (ct-DNA) was established as well, indicating only marginal differences between the complexes. In addition, all complexes were shown to be excellent inhibitors of the enzyme urease, with the IC₅₀ values in the lower micromolar region. Full article

Advanced laboratory methods play a crucial role in bone research, allowing researchers and scientists to study the complex biology and nature of the skeleton. Dual-energy X-ray absorptiometry (DXA) is a non-invasive method of measuring bone mass, which is an important parameter for the diagnosis and treatment of several bone diseases. Micro-computed tomography (μCT) is a very high-resolution technique that can be used to investigate the 3D microstructure of trabecular bone. Dynamic bone histomorphometry is used to assess histological indices of bone formation and resorption using fluorochromes embedded into newly formed bone. Mechanical testing is used to measure bone strength and stiffness, providing important information about bone quality and fracture risk. All these methods are widely used in preclinical in vivo studies using rodents and in most clinical studies. Therefore, it is important for both researchers and scientists within the field of bone biology, and those in neighboring fields, to be familiar with their use, strengths, limitations, and important technical aspects. Several guidelines and protocols about the topic have been published, but are very exhaustive. The present review aimed to provide instructions for early-career researchers and outline important concepts and technical aspects of DXA, μCT, dynamic bone histomorphometry, and mechanical testing in bone research. Full article

Detection and characterization of hidden defects, impurities, and damages in homogeneous materials like aluminum die casting materials, as well as composite materials like Fiber–Metal Laminates (FML), is still a challenge. This work discusses methods and challenges in data-driven modeling of automated damage and defect detectors using measured X-ray single- and multi-projection images. Three main issues are identified: Data and feature variance, data feature labeling (for supervised machine learning), and the missing ground truth. It will be shown that simulation of synthetic measuring data can deliver a ground truth dataset and accurate labeling for data-driven modeling, but it cannot be used directly to predict defects in manufacturing processes. Noise has a significant impact on the feature detection and will be discussed. Data-driven feature detectors are implemented with semantic pixel Convolutional Neural Networks. Experimental data are measured with different devices: A low-quality and low-cost (Low-Q) X-ray radiography, a typical industrial mid-quality X-ray radiography and Computed Tomography (CT) system, and a state-of-the-art high-quality μ-CT device. The goals of this work are the training of robust and generalized data-driven ML feature detectors with synthetic data only and the transition from CT to single-projection radiography imaging and analysis. Although, as the title implies, the primary task is pore characterization in aluminum high-pressure die-cast materials, but the methods and results are not limited to this use case. Full article