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Abstract Osteoarthritis (OA) is the most prevalent degenerative musculoskeletal disease, severely impacting the function of patients and potentially leading to disability, especially among the elderly population. Natural products (NPs), obtained from components or metabolites of plants, animals, microorganisms etc., have gained significant attention as important conservative treatments for various diseases. Recently, NPs have been well studied in preclinical and clinical researches, showing promising potential in the treatment of OA. In this review, we summed up the main signaling pathways affected by NPs in OA treatment, including NF-κB, MAPKs, PI3K/AKT, SIRT1, and other pathways, which are related to inflammation, anabolism and catabolism, and cell death. In addition, we described the therapeutic effects of NPs in different OA animal models and the current clinical studies in OA patients. At last, we discussed the potential research directions including in-depth analysis of the mechanisms and new application strategies of NPs for the OA treatment, so as to promote the basic research and clinical transformation in the future. We hope that this review may allow us to get a better understanding about the potential bioeffects and mechanisms of NPs in OA therapy, and ultimately improve the effectiveness of NPs-based clinical conservative treatment for OA patients.

Electrocatalytic alcohol oxidation (EAO) is an attractive alternative to the sluggish oxygen evolution reaction in electrochemical hydrogen evolution cells. However, the development of high-performance bifunctional electrocatalysts is a major challenge. Herein, we developed a nitrogen-doped bimetallic oxide electrocatalyst (WO-N/NF) by a one-step hydrothermal method for the selective electrooxidation of benzyl alcohol to benzoic acid in alkaline electrolytes. The WO-N/NF electrode features block-shaped particles on a rough, inhomogeneous surface with cracks and lumpy nodules, increasing active sites and enhancing electrolyte diffusion. The electrode demonstrates exceptional activity, stability, and selectivity, achieving efficient benzoic acid production while reducing the electrolysis voltage. A low onset potential of 1.38 V (vs. RHE) is achieved to reach a current density of 100 mA cm−2 in 1.0 M KOH electrolyte with only 0.2 mmol of metal precursors, which is 396 mV lower than that of water oxidation. The analysis reveals a yield, conversion, and selectivity of 98.41%, 99.66%, and 99.74%, respectively, with a Faradaic efficiency of 98.77%. This work provides insight into the rational design of a highly active and selective catalyst for electrocatalytic alcohol oxidation.

Since the rapid spread of the COVID-19 worldwide, the pandemic has led to a huge impact on global sporting events. As a major international event, the 2022 Beijing Winter Olympics has commonalities with the 2008 Beijing Olympics, the 2014 Sochi Winter Olympics, and the 2020 Tokyo Olympics in terms of international public opinion context and epidemiological background. In this study, over 1 million pieces of UGC(User Generated Contents) in Chinese and English languages were obtained from social media platforms such as Twitter, YouTube, as well as traditional mass media in various countries to compare the differences between the two languages in international public opinion. Using sentiment analysis, this study explores the evolution of international public opinion topics and sentiment differences among the above four Olympic Games. The analysis results show that:1) regardless of traditional mass media or online social media, there is a more obvious tendency of general politicization in the topics of the 2008 Beijing Olympics and 2022 Beijing Winter Olympics, and extreme emotional remarks of the 2022 Beijing Winter Olympics are more frequent; 2) in the topic of political opinion involving China, international Chinese public opinion presents more negative sentiment than those in English; 3) Among the topics involving COVID-19, the negative level of public opinion in Chinese and English is opposite for the 2020 Tokyo Olympics and the 2022 Beijing Winter Olympics;4) International public opinion on the topic of sports events is significantly more positive in Chinese than in English;5) YouTube’s Chinese opinion environment is better than English.

Despite many advantages of vat photopolymerization in microfluidic device fabrication, well-controlled μm-sized (< 100 μm) channels in the layer building direction remains a challenge. Here, authors present a general high resolution and low-cost 3D printing process that can produce devices within the 10 μm scale.

Poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) has emerged as a promising conductive polymer for constructing efficient hole-transport layers (HTLs) in perovskite solar cells (PSCs). However, conventional fabrication methods, such as spin coating, spray coating, and slot-die coating, have resulted in PEDOT:PSS nanofilms with limited performance, characterized by a low density and non-uniform nanostructures. We introduce a novel 3D-printing approach called electrically assisted direct ink deposition with ultrasonic vibrations (EF-DID-UV) to overcome these challenges. This innovative printing method combines programmable acoustic field modulation with electrohydrodynamic spraying, providing a powerful tool for controlling the PEDOT:PSS nanofilm’s morphology precisely. The experimental findings indicate that when PEDOT:PSS nanofilms are crafted using horizontal ultrasonic vibrations, they demonstrate a uniform dispersion of PEDOT:PSS nanoparticles, setting them apart from instances involving vertical ultrasonic vibrations, both prior to and after the printing process. In particular, when horizontal ultrasonic vibrations are applied at a low amplitude (0.15 A) during printing, these nanofilms showcase exceptional wettability performance, with a contact angle of 16.24°, and impressive electrical conductivity of 2092 Ω/square. Given its ability to yield high-performance PEDOT:PSS nanofilms with precisely controlled nanostructures, this approach holds great promise for a wide range of nanotechnological applications, including the production of solar cells, wearable sensors, and actuators.

The importance of conductive polymers has significantly increased over the decade due to their various applications, such as in electronic devices, sensors, and photovoltaics. Poly(3,4-ethylene dioxythiophene) polystyrene sulfonate (PEDOT:PSS) is one of the most successfully and widely used polymers in practical applications. Spin coating is extensively used to fabricate these conductive films; however, it has disadvantages. It is inherently a batch process with relatively low output and high solution wastage. To address these issues, we developed a novel printing process called electrical-field-assisted direct ink deposition (EF-DID), which yields a continuous, homogenous film with high electrical conductivity. In this process, we studied the formation of nanodroplets under an electrical field and their effects on film characteristics. Furthermore, dimethyl sulfoxide (DMSO) was considered as an additive solvent to increase the conductivity and wettability of the films. We then compared EF-DID-printed PEDOT:PSS films with spin-coated films to better understand the film properties. Finally, inverted perovskite solar cell devices were fabricated and compared, where the PEDOT:PSS layers were prepared by EF-DID printing and spin coating. Based on the experimental results, a solution of 20% PEDOT:PSS in DMSO (vol/vol) printed by EF-DID for 15 s provided optimal morphology.

Flame-retardant and thermal management structures have attracted great attention due to the requirement of high-temperature exposure in industrial, aerospace, and thermal power fields, but the development of protective fire-retardant structures with complex shapes to fit arbitrary surfaces is still challenging. Herein, we reported a rotation-blade casting-assisted 3D printing process to fabricate nacre-inspired structures with exceptional mechanical and flame-retardant properties, and the related fundamental mechanisms are studied. 3-(Trimethoxysilyl)propyl methacrylate (TMSPMA) modified boron nitride nanoplatelets (BNs) were aligned by rotation-blade casting during the 3D printing process to build the “brick and mortar” architecture. The 3D printed structures are more lightweight, while having higher fracture toughness than the natural nacre, which is attributed to the crack deflection, aligned BN (a-BNs) bridging, and pull-outs reinforced structures by the covalent bonding between TMSPMA grafted a-BNs and polymer matrix. Thermal conductivity is enhanced by 25.5 times compared with pure polymer and 5.8 times of anisotropy due to the interconnection of a-BNs. 3D printed heat-exchange structures with vertically aligned BNs in complex shapes were demonstrated for efficient thermal control of high-power light-emitting diodes. 3D printed helmet and armor with a-BNs show exceptional mechanical and fire-retardant properties, demonstrating integrated mechanical and thermal protection.

For the bottom-up based stereolithography (SL) process, a separation process is required to detach the newly cured layer from the constrained surface in the fabrication process. Excessive separation force will cause damage to the built layers and the constrained surface. Different surface coatings, platform motions including tilting and sliding, and the utilization of oxygen-permeable films have been developed to address the separation-related problems. Among these approaches, the vibration-assisted (VA) separation method to reduce the separation force has limited study. The underlying mechanism of the VA separation-based method remains unexplored, and the best way to use VA separation in the bottom-up based SL process is still unclear. In this paper, a new VA separation design for the SL process is presented. A prototype system was built to study the VA separation mechanism. Experiments on the separation performance under different parameters, including vibration frequency, pre-stress level, and exposure area, were conducted. Based on the collected separation force data, an analytical model based on the mechanics of fatigue fracture was built. The separation behaviors related to different shape size and topology were also studied and compared. The results showed that the separation force in SL was significantly reduced using the VA separation-based method. Furthermore, the relationship between the separation force and the separation time conforms to the stress-based fatigue model. This study also provides insights on how to choose process parameters by considering the trade-offs between separation force and building efficiency. [ABSTRACT FROM AUTHOR]

Noble Metal-free catalysts attracted much attention as promising candidates for Pt-based catalyst replacement to advance applications related to oxygen reduction reaction (ORR), which is critical for large-scale renewable energy storage and conversion. Herein, this work focused on a synthesis of noble metal-free ORR electrocatalysts consisting of porous N-rich carbon/MXene, which was obtained using very conductive and reactive Ti3C2 MXene and polypyrrole (PPy) as a C and N source. The electrocatalyst exhibited excellent electrocatalytic activity and stability with an onset and a half-wave potentials equal to 0.85 and 0.71 V, respectively. Results obtained in this work demonstrate how to design efficient noble metal-free ORR electrocatalysts applicable to other chemical systems. [ABSTRACT FROM AUTHOR]