Search

Diabetes mellitus (DM) has been suggested as a potential risk factor for tinnitus, but evidence remains inconclusive. This meta-analysis aimed to evaluate the association between DM and tinnitus by systematically reviewing and synthesizing data from observational studies. A comprehensive literature search was conducted in PubMed, Embase, and Web of Science up to August 16, 2024. Observational studies with a sample size of at least 100 participants that assessed the relationship between DM and tinnitus were included. Studies involving populations with specific diseases were excluded. Odds ratios (ORs) and 95% confidence intervals (CIs) were pooled using a random-effects model. Study quality was assessed using the Newcastle-Ottawa Scale (NOS), and sensitivity and subgroup analyses were performed. Publication bias was evaluated using funnel plots and Egger’s regression test. Twelve studies comprising 2,277,719 participants were included. The pooled analysis revealed a significant association between DM and tinnitus (OR: 1.18, 95% CI: 1.06–1.31, P = 0.002), with moderate heterogeneity (I² = 51%). Sensitivity analyses confirmed the robustness of these findings. Subgroup analyses showed no significant differences by geographical region, mean age, sex distribution, tinnitus diagnosis method, or model used for association estimation. Publication bias was not detected (Egger’s test P = 0.29). These findings suggest that DM is significantly associated with an increased risk of tinnitus. Further research is warranted to explore underlying mechanisms and causal relationships. Nonetheless, the results underscore the importance of monitoring tinnitus in patients with diabetes.

Abstract Malignancy is a major public health problem and among the leading lethal diseases worldwide. Although the current tumor treatment methods have therapeutic effect to a certain extent, they still have some shortcomings such as poor water solubility, short half-life, local and systemic toxicity. Therefore, how to deliver therapeutic agent so as to realize safe and effective anti-tumor therapy become a problem urgently to be solved in this field. As a medium of information exchange and material transport between cells, exosomes are considered to be a promising drug delivery carrier due to their nano-size, good biocompatibility, natural targeting, and easy modification. In this review, we summarize recent advances in the isolation, identification, drug loading, and modification of exosomes as drug carriers for tumor therapy alongside their application in tumor therapy. Basic knowledge of exosomes, such as their biogenesis, sources, and characterization methods, is also introduced herein. In addition, challenges related to the use of exosomes as drug delivery vehicles are discussed, along with future trends. This review provides a scientific basis for the application of exosome delivery systems in oncological therapy. Graphical Abstract

Background The pathogenesis of primary spontaneous pneumothorax (PSP) is unclear. Fine particles aggregated in the lung can be phagocytosed by alveolar macrophages (AMs) to induce an inflammatory reaction and damage local pulmonary tissue, which could be a mechanism of PSP. This project aimed to explore the pathological association between fine particulate matter and PSP. Methods Thirty pulmonary bullae tissues were obtained from surgery of PSP patients (B group). The adjacent normal tissues of the lungs were defined as the control S group. Another 30 normal lung tissues with nonpneumothorax disease (NPD) were applied as the control N group. Hematoxylin and eosin (H & E), Wright-Giemsa (W-G), Victoria blue, and immunohistochemical (IHC) staining experiments were performed to measure the levels of fine particulate matter, alveolar macrophages (AMs), pulmonary elastic fibers, monocyte chemoattractant protein-1 (MCP-1), and matrix metalloproteinase-9 (MMP-9) in the lung tissues. The serum levels of MCP-1 and MMP-9 were prospectively analyzed as well. Results Histopathological examinations revealed obvious deposition of fine particulate matter and inflammatory reactions (proliferation of AMs) in the B group, compared with those in the S group and the N group. These alterations were significantly associated with PSP. The numbers of AMs and pulmonary elastic fibers, the positive area of the H-score, as well as the concentrations of MCP-1 and MMP-9 in the lungs of the experimental group were obviously raised compared with the controls (P < 0.05). Conclusions Fine particulate matter aggregation, inflammation (macrophage hyperplasia), and overexpression of MCP-1 and MMP-9 may contribute to the pathogenesis of PSP. The overaccumulation of fine particulate matter may play a crucial part in the occurrence of adolescent and young adult PSP. Trial registration This project was enrolled on the Chinese Clinical Trial Registry: ChiCTR2100051460.

To meet the emerging demands for thermal protection materials for hypersonic aircraft, developing porous ultrahigh-temperature ceramics with both robust mechanical properties and superior thermal insulation performance is a critical challenge. Herein, we report novel porous (Ta0.2Nb0.2Ti0.2Zr0.2Hf0.2)C high-entropy carbide (PHEC) ceramics fabricated by a self-foaming method using commercially available metal chloride and furfuryl alcohol (FA) as precursors. The PHEC ceramics are constructed of microspheres with a size of 2 µm, leading to a high porosity of 91.3% and an interconnected frame. These microspheres consist of high-entropy carbide grains (20 nm), resulting in abundant interfaces and nanosized pores in the PHEC ceramics. Due to its unique hierarchical structure, the prepared PHEC ceramics have outstanding compressive strength (28.1±2 MPa) and exceptionally low thermal conductivity (κT, 0.046 W·m−1·K−1) at room temperature. This makes it a promising thermal insulation materials for ultrahigh temperature applications. This work provides a cost-effective and facile strategy for producing porous ultrahigh-temperature ceramics.

Carbon nanomaterials are promising microwave catalytic materials due to their abundant inhomogeneous interfaces capable of producing ideal interfacial polarization and multiple relaxation, which are favorable for microwave attenuation and dissipation. However, the microwave absorption performance of carbon materials is not ideal in practical applications due to poor impedance matching and single dielectric loss. To solve this problem, a ternary system of “carbon-magnetic” Ni@SiC/CNFs (C/Ni, C/SiC) composites was synthesized by electrostatic spinning, and they efficiently degraded methylene blue under microwave radiation. The results imply that the catalyst Ni@SiC/CNFs with a double-shell structure gave a 99.99% removal rate in 90 s for the degradation of methylene blue under microwave irradiation, outperforming the C/Ni and C/SiC and most other reported catalysts in similar studies. On the one hand, the possible mechanism of the methylene blue degradation should be ascribed to the fact that the double-shell structure increases the polarization source of the material, resulting in excellent microwave absorption properties; and on the other, the in situ generation of ·OH and O2− active species under microwave radiation and the synergistic coupling effect of metal plasma greatly improved the degradation efficiency of methylene blue. The findings of this study could provide a valuable reference for the green degradation of industrial dye wastewater and its sustainable development process.

A novel hydrothermal co-deposition method was proposed to fabricate C/C-CuNi composites as high-speed railway pantograph strip. The bulk density of composites reached 1.83 g/cm3 with 5 cycles of co-deposition. The effect of Ni addition on the microstructure and properties of the composites was investigated. The Ni addition not only improves the graphitic degree of the carbon matrix but also enhances the fiber/matrix interface bonding. The composites presented outstanding properties when the Ni/Cu molar ratio was 0.6. It possesses high flexural strength (92.4 MPa) and low electrical resistivity (10.78 μΩ m). The friction coefficient was stabilized at 0.223 and wear rate was just 0.45 g h−1 under 10 N applied load. The outstanding tribological performance resulted from the micro-spall fatigue wear and the formation of self-lubricating film owing to the Ni addition. The C/C-CuNi composite provides an attractive high-speed railway pantograph strip material, and the hydrothermal co-deposition method is a feasible strategy to improve the interfacial bonding of Cu-based carbon fiber reinforced composites.

Abstract A dense ZrB2 particles reinforced glass (ZrB2/SiO2) coating was prepared on the SiC coated carbon/carbon composites by a facile sol-dipping approach. The prepared ZrB2/SiO2 coating could protect the composites from being oxidized for 160 h at 1773 K with a weight loss of 6.9 mg/cm2. The flexural strength retention ratio of the ZrB2/SiO2 coated composites is 87% after oxidation for 160 h at 1773 K. The continuous SiO2 glass layer embedded with the submicron ZrSiO4 particles was formed during oxidation. This was helpful to lower the diffusion rate of oxygen and improve the stability of SiO2 glass film, thus improving the oxidation resistance of the coated samples. After thermal cycles between 1773 K and room temperature for 15 times, penetrated cracks formed in the coating. The weight loss of the ZrB2/SiO2 coated sample presented linear relationship, and the final weight loss per unit area was 6.35 mg/cm2. The generation of the penetrative cracks and the debonded coating interface resulted in the failure of the ZrB2/SiO2 coating.

C/C-Zr-Si-O composites were prepared by carbothermal reduction of hydrothermal co-deposited ZrO2, SiO2, and C. The bulk density of composites reached 1.71 g/cm3 with 8 cycles of co-deposition. The matrix of the composites includes ZrC, SiC, ZrO2, and SiO2 with fine grain size (300–500 nm) and homogeneous distribution. The mass and linear ablation rate of C/C-Zr-Si-O composites were 0.112 mg/cm2·s and 0.46 μm/s, respectively, under a plasma flame for 120 s. The attractive ablation resistance of the composites resulted from its unique structure, which tends to form a continuous ZrO2-SiO2 glass layer in the ablation center, a layer of SiO2-ZrO2 bubbles in the transition region, and fluffy SiO2 nanowires layer in the heat-affected region. These ablation layers were barriers to restrain the diffusion of oxidative gas and heat. The C/C-Zr-Si-O composites provide an alternative ceramics system with attractive ablation resistance, while carbothermal reduction of hydrothermal co-deposited oxides is a feasible method for the structural design of carbon fiber reinforced ultra-high temperature ceramic. Keywords: Ultra-high temperature ceramic composites, Hydrothermal synthesis, Carbothermal reduction, Microstructure, Ablation resistance