Non-Calcifying/Langerhans Cell-Rich Calcifying Epithelial Odontogenic Tumour: A Critical Review of the Rare and Distinctive Entity.

BACKGROUND: The study aims to analyse the non-calcifying/Langerhans cell rich (NCLC) subtype of calcifying epithelial odontogenic tumour (CEOT).  METHOD: The features of cases of the NCLC subtype of CEOT noted in the English literature by PubMed as well as 3 new cases were reviewed. RESULTS: Overall, twenty-one cases were noted. Many were women in the fourth to sixth decades (male-to-female ratio =1 to 2). Radiologically, the lesion is often unilocular with resorption of the affected teeth. Nineteen of the 21 cases occurred in the maxilla, especially the anterior portion. On pathological examination, epithelial cells are noted in non-calcifying amyloid-rich fibrous stroma. The main differential diagnosis is the amyloid subtype of central odontogenic fibroma. Immunohistochemical studies revealed the tumour epithelial cells were positive for cytokeratins and p63 and contained CD1a, S-100, and langerin-positive Langerhans cells. On a median follow-up of 2 years, one patient had a recurrence one year after curettage. CONCLUSION: The NCLC subtype of CEOT is unique as it contains significant numbers of Langerhans cells and has clinicopathological features distinctive from classic CEOT.

Development of an Antiswelling Hydrogel System Incorporating M2-Exosomes and Photothermal Effect for Diabetic Wound Healing.

Diabetic wounds represent a persistent global health challenge with a substantial impact on patients' health and overall well-being. Herein, a hydrogel system that integrates functionalized gold nanorods (AuNRs) and M2 macrophage-derived exosomes (M2-Exos) was developed to achieve an efficient and synergistic therapy for diabetic wounds. We introduced an ion-cross-linked dissipative network into a prefabricated covalent cross-linked network (long-chain polymer network), which was prepared using AuNRs as a specific cross-linker. The ion network was then cross-linked with the long-chain polymer in situ to form a specific network structure, imparting antiswelling and photothermal effects to the hydrogel. This integrated hydrogel system effectively scavenged reactive oxygen species levels, inhibited inflammation, promoted angiogenesis, and stimulated photothermal antibacterial activity through near-infrared (NIR) irradiation. To demonstrate the potential of the hydrogel, we established experimental animal models of oral mucosa ulceration and full-thickness skin defects. In vivo results confirmed that M2-Exos released from the hydrogels played a crucial role in wound closure. Furthermore, the synergistic effect of AuNRs and NIR photothermal effects eradicated bacterial infections in the wound area. Overall, our integrated hydrogel system is a promising tool for accelerating chronic diabetic wound healing and tissue regeneration. This study highlights the potential benefits of combining bioactive M2-Exos and the photothermal effect of AuNRs into an antiswelling hydrogel platform to achieve satisfactory wound healing in patients with diabetes.

Machine learning-based rail corrugation recognition: a metro vehicle response and noise perspective.

Rail corrugation is a common problem in metro lines, and its efficient recognition is always an issue worth studying. To recognize the wavelength and amplitude of rail corrugation, a particle probabilistic neural network (PPNN) algorithm is developed. The PPNN is incorporated with the particle swarm optimization algorithm and the probabilistic neural network. On the basis of the above, the in-vehicle noise characteristics measured in the field are used to recognize normal rail wavelengths of 30 and 50 mm. A stepwise moving window search algorithm suitable for selecting features with a fixed order was developed to select in-vehicle noise features. Sound pressure levels at 400, 500, 630 and 800 Hz of in-vehicle noise are fed into the PPNN, and the average accuracy can reach 96.43%. The bogie acceleration characteristics calculated by the multi-body dynamics simulation model are used to recognize normal rail amplitudes of 0.1 and 0.2 mm. The bogie acceleration is decomposed by the complete ensemble empirical mode decomposition with adaptive noise, and a reconstructional signal is obtained. The energy entropy of the reconstructional signal is fed into the PPNN, and the average accuracy can reach 95.40%. This article is part of the theme issue 'Artificial intelligence in failure analysis of transportation infrastructure and materials'.

Microstructure and Properties of NiCoCrAlTi High Entropy Alloy Prepared Using MA-SPS Technique.

In this study, Ni35Co35Cr12.6Al7.5Ti5Mo1.68W1.39Nb0.95Ta0.47 high entropy alloy (HEA) was prepared using mechanical alloying (MA) and spark plasma sintering (SPS) based on the unique design concept of HEAs and third-generation powder superalloys. The HEA phase formation rules of the alloy system were predicted but need to be verified empirically. The microstructure and phase structure of the HEA powder were investigated at different milling times and speeds, with different process control agents, and with an HEA block sintered at different temperatures. The milling time and speed do not affect the alloying process of the powder and increasing the milling speed reduces the powder particle size. After 50 h of milling with ethanol as PCA, the powder has a dual-phase FCC+BCC structure, and stearic acid as PCA inhibits the powder alloying. When the SPS temperature reaches 950 °C, the HEA transitions from a dual-phase to a single FCC phase structure and, with increasing temperature, the mechanical properties of the alloy gradually improve. When the temperature reaches 1150 °C, the HEA has a density of 7.92 g cm-3, a relative density of 98.7%, and a hardness of 1050 HV. The fracture mechanism is one with a typical cleavage, a brittle fracture with a maximum compressive strength of 2363 MPa and no yield point.

TOMM34 promotes cell proliferation, migration, and invasion of OSCC and modulates mitochondrial function.

BACKGROUND: 34-kDa translocase of the outer mitochondrial membrane (TOMM34) has been reported highly expressed in many cancers and is positively correlated to poorer prognosis. Our prior study showed TOMM34 is highly expressed in oral squamous cell carcinoma (OSCC) and is closely related to TNM classification and tumor size. TOMM34 is also associated with lymph node metastasis and poorer overall survival and disease-free survival in HPV-negative OSCC. METHODS: We knocked down TOMM34 in OSCC cells (SCC15, HPV positive; Cal27, HPV negative) with siRNA and over-expressed with plasmids. The effects of TOMM34 on cell proliferation, migration and invasion abilities were detected by EdU assay, CCK-8 assay, wound-healing assay, and Transwell assay. We also detected the mitochondrial morphology and the intracellular Reactive Oxygen Species (ROS) level by fluorescence staining and flow cytometry. Finally, we monitored the protein levels of ERK pathway-related molecules. RESULTS: TOMM34 knockdown decreased the proliferation in SCC15 and Cal27, and weakened the migration and invasion abilities as well. Mitochondria became shorter, in the shape of dots or short rods, suggesting that mitochondrial damage occurred. Intracellular ROS levels increased significantly after knockdown TOMM34 and decreased after over-expressing TOMM34. The phosphorylation levels of ERK1/2 and MEK1/2 in SCC15 were significantly higher than in Cal27. Besides, the phosphorylation levels of ERK1/2 and MEK1/2 were inhibited in SCC15 after knockdown of TOMM34, but not in Cal27. CONCLUSION: TOMM34 promotes the cell proliferation, migration, and invasion of OSCC. In addition, TOMM34 participates in maintaining the mitochondrial shape and reducing the intracellular ROS level to protect cancer cells. Furthermore, TOMM34 increases the activity of ERK1/2 and MEK1/2 in HPV-positive OSCC cells but not in HPV-negative.

A Study of Hot Deformation Behavior of T15MN High-Speed Steel during Thermal Compression.

The hot deformation behavior of T15MN high-speed steel during thermal compression was studied by experiment and simulation. Specifically, the hot compression test was carried out on a Gleeble-1500 thermal-mechanical simulator at temperatures from 1273 to1423 K and strain rates from 0.01 to 10 s-1 with the deformation degree of 60%. It was found that all the flow stress curves were characterized by a single peak, indicating the occurrence of dynamic recrystallization (DRX), and flow stress will increase with increasing strain rate and decreasing deformation temperature. Based on the experimental data, the constitutive equations and thermal activation energy were obtained (Qact = 498,520 J/mol). Meanwhile, a cellular automaton model was established via the MATLAB platform to simulate the dynamic recrystallization phenomenon during hot deformation. The simulation results indicate that a good visualization effect of the microstructural evolution is achieved. Both increasing deformation temperature and decreasing strain rate can promote the increase in the average size and volume fraction of recrystallized grains (R-grains). Additionally, the calculated flow stress values fit in well with the experimental ones in general, which indicates that the established CA model has a certain ability to predict the deformation behavior of metal materials at elevated temperatures.

Evaluation of cytotoxicity and biodistribution of mesoporous carbon nanotubes (pristine/-OH/-COOH) to HepG2 cells in vitro and healthy mice in vivo.

Mesoporous carbon nanotubes (mCNTs) hold great promise interests, owing to their superior nano-platform properties for biomedicine. To fully utilize this potential, the toxicity and biodistribution of pristine and surface-modified mCNTs (-OH/-COOH) should preferentially be addressed. The results of cell viability suggested that pristine mCNTs induced cell death in a concentration-dependent manner. As evidence of reactive oxygen species (ROS), malondialdehyde (MDA) and superoxide dismutase (SOD), pristine mCNTs induced noticeable redox imbalance. 99mTc tracing data suggested that the cellular uptake of pristine mCNTs posed a concentrate-dependent and energy-dependent manner via macropinocytotic and clathrin-dependent pathways, and the main accumulated organs were lung, liver and spleen. With OH modification, the ROS generation, MDA deposition and SOD consumption were evidently reduced compared with the pristine mCNTs at 24/48 h high-dose exposure. With COOH modification, the modified mCNTs only showed a significant difference in SOD consumption at 24/48 h exposure, but there was no significant difference in the measurement of ROS and MDA. The internalization mechanism and organ distribution of modified mCNTs were basically invariant. Together, our study provides evidence that mCNTs and the modified mCNTs all could induce oxidative damage and thereby impair cells. 99mTc-mCNTs can effectively trace the distribution of nanotubes in vivo.

Corrosion Behavior of Reinforcing Steel Undergoing Stray Current and Anodic Polarization.

Different concrete structures (viaducts, bridges, or tunnels) in the neighborhoods of railways may be subject to the stray current leaking from the rails. In these cases, the reinforcing rebars embedded in concrete act as conductors, "pick up" the stray current, and can corrode. For simulating the stray current-induced corrosion of metals, most researchers just supplied anodic polarization on samples. However, stray current induces both cathodic polarization and anodic polarization. This work experimentally justifies the different effects of stray current and anodic polarization on reinforcing steel embedded in mortar. A comparison between stray current and anodic polarization effects on the corrosion behavior of embedded steel is performed for both fresh (24 hour-cured) and hardened matrix (28 day-cured) in chloride-free (Cl-free) and chloride-containing (Cl-containing) environments. It is found that in all studied conditions, anodic polarization leads to a significantly different electrochemical performance of the steel rebar compared to the stray current. Hence, anodic polarization cannot reflect all the effects of stray current, and therefore, it has limited significance for simulating stray current. It is also clarified that the curing regimes and starting time of the stray current play significant roles in the formation of a corrosion product layer on the steel surface.

Nanotubular topography enhances the bioactivity of titanium implants.

Surface modification on titanium implants plays an important role in promoting mesenchymal stem cell (MSC) response to enhance osseointegration persistently. In this study, nano-scale TiO2 nanotube topography (TNT), micro-scale sand blasted-acid etched topography (SLA), and hybrid sand blasted-acid etched/nanotube topography (SLA/TNT) were fabricated on the surfaces of titanium implants. Although the initial cell adherence at 60 min among TNT, SLA and TNT/SLA was not different, SLA and SLA/TNT presented to be rougher and suppressed the proliferation of MSC. TNT showed hydrophilic surface and balanced promotion of cellular functions. After being implanted in rabbit femur models, TNT displayed the best osteogenesis inducing ability as well as strong bonding strength to the substrate. These results indicate that nano-scale TNT provides favorable surface topography for improving the clinical performance of endosseous implants compared with micro and hybrid micro/nano surfaces, suggesting a promising and reliable surface modification strategy of titanium implants for clinical application.