With a continuous study on the catalytic mechanism of semiconductors, it has been found that semiconductor materials can undergo catalytic reactions to produce reactive oxygen species under light/ultrasound stimulation. Therefore, it has been widely studied and applied to tumor treatment in recent years. Based on different excitation sources, semiconductor catalytic therapy can be mainly divided into photocatalytic therapy and sonocatalytic therapy. Heterojunctions exhibit better efficacy in tumor catalytic therapy due to their unique electron transfer methods compared to pure semiconductor materials. By analyzing the catalytic mechanism of heterojunction materials, this review classifies variously synthesized inorganic metal heterojunctions in recent years into four categories. Meanwhile, the research and development of different heterojunction materials in the field of photocatalytic and sonocatalytic therapy are discussed in detail. It is hoped to provide a new idea to design inorganic metal heterojunction materials for efficient tumor therapy based on the mechanism of catalytic enhancement of heterojunctions.
Osteoarthritis (osteoarthritis, OA) is a degenerative disease that can lead to disability, often affecting subchondral bone. Damaged articular cartilage and subchondral bone remain challenging to heal independently, and scaffolds for tissue regeneration are a promising therapeutic method. Recently, Magnesium alloys have been considered as promising candidates for biodegradable porous scaffolds due to their good mechanical and biological properties. However, there is still no consensus on the structural design and optimization of magnesium-based scaffolds suitable for subchondral bone regeneration. Therefore, this review summarizes the research progress of magnesium alloys used for osteochondral scaffolds, including fabrication methods of porous scaffolds, optimization strategies involving alloying elements and surface modifications, parametric and non-parametric structural design, degradation, mechanical and biological properties of magnesium-based scaffolds and their influencing factors. Also, this paper discussed the potential directions of future research, intending to provide references for the development and clinical applications of porous magnesium-based scaffolds.
The hot compression test of copper/graphite composites was conducted using a thermal simulation testing machine, Gleeble-3500, to study the thermal deformation behavior of the composites at a deformation temperature of 700-850 °C and a strain rate of 0.001-1.000 s−1. According to the experimental data, the constitutive equation and thermal processing map of the composites were constructed, and the microstructure evolution of the composites was studied by optical microscope. The rheological stress of the composites was studied according to Zener-Hollomon parameter model. The flow stress of the composites decreases with the increase of strain temperature and increases with the increase of strain rate. The calculated thermal deformation activation energy of the composites is 463.02 kJ/mol, which shows that the composites has good formability. The consistency of the maximum stress was verified through the constructed constitutive equation, and it was found that the error between the calculated and experimental values was within 9.5%, indicating that the equation has a guiding role in the rheological behavior of composites materials. The thermal processing map shows that the suitable working temperature is 780-820 °C and the deformation rate is around 0.050-0.100 s−1, when the deformation temperature is 830-850 °C, the deformation rate is about 0.001s−1.
Cobalt ion doped MnO2 was prepared on flexible carbon cloth by constant-current electrodeposition with a loading of 13.8 mg/cm2. The effect of cobalt ion doping on the electrochemical properties of MnO2 was investigated by characterizing the structure and properties of the material using an X-ray diffractometer (XRD), scanning electron microscope (SEM), X-ray photoelectron spectrometer (XPS) and electrochemical workstation. The results showed that when the electrode was assembled with activated carbon to form liquid zinc ion hybrid capacitors (Zn-HCs), the area-specific capacitance of Zn-HCs was as high as 5 883.0 mF/cm2 and the area energy density was 3 154.9 μWh/cm2 at a current density of 2 mA/cm2, comparable to the energy level of zinc ion batteries. When the electrodes were assembled with activated carbon to form quasi-solid flexible Zn-HCs, the Zn-HCs exhibited good energy density (1 351.1 μWh/cm2 at a power density of 1 mW/cm2) and excellent mechanical flexibility, which makes it promising for the next generation of flexible wearable devices.
External fixators, as the most common fixation devices, are widely used in open bone fracture surgeries. However, screws used in conjunction with external fixators are susceptible to infection. Utilizing radio frequency magnetron sputtering technology to prepare Ag-ZnO/Ti nano-composite coatings adhered to the surface of Ti6Al4V screws, it is possible to effectively reduce bacterial adhesion. By adjusting the ratio of target material bonding, the effect of the microstructure of different Ag content in composite coatings on the antibacterial performance of Ti6Al4V screws were investigated. The results indicate that when the volume ratio of Ag, ZnO, Ti target materials are 2:2:96, the mass fraction of Ag in the Ag-ZnO/Ti nanocomposite coating reaches 1.85%, with a roughness of 4.24 nm. The coating surface is smooth and hydrophobic, which is conducive to reducing bacterial adhesion. The cytotoxicity of the coating meets the biosafety standard, with the antibacterial rate as high as 99.62%.
