Lean design of a strong and ductile dual-phase titanium–oxygen alloy
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Evolution of temporomandibular joint reconstruction: from autologous tissue transplantation to alloplastic joint replacement
The reconstruction of the temporomandibular joint presents a multifaceted clinical challenge in the realm of head and neck surgery, underscored by its relatively infrequent occurrence and the lack of comprehensive clinical guidelines. This review aims to elucidate the available approaches for TMJ reconstruction, with a particular emphasis on recent groundbreaking advancements. The current spectrum of TMJ reconstruction integrates diverse surgical techniques, such as costochondral grafting, coronoid process grafting, revascularized fibula transfer, transport distraction osteogenesis, and alloplastic TMJ replacement. Despite the available options, a singular, universally accepted ‘gold standard’ for reconstructive techniques or materials remains elusive in this field. Our review comprehensively summarizes the current available methods of TMJ reconstruction, focusing on both autologous and alloplastic prostheses. It delves into the differences of each surgical technique and outlines the implications of recent technological advances, such as 3D printing, which hold the promise of enhancing surgical precision and patient outcomes. This evolutionary progress aims not only to improve the immediate results of reconstruction but also to ensure the long-term health and functionality of the TMJ, thereby improving the quality of life for patients with end-stage TMJ disorders.
Dietary protein restriction elevates FGF21 levels and energy requirements to maintain body weight in lean men
Dietary protein restriction increases energy expenditure and enhances insulin sensitivity in mice. However, the effects of a eucaloric protein-restricted diet in healthy humans remain unexplored. Here, we show in lean, healthy men that a protein-restricted diet meeting the minimum protein requirements for 5 weeks necessitates an increase in energy intake to uphold body weight, regardless of whether proteins are replaced with fats or carbohydrates. Upon reverting to the customary higher protein intake in the following 5 weeks, energy requirements return to baseline levels, thus preventing weight gain. We also show that fasting plasma FGF21 levels increase during protein restriction. Proteomic analysis of human white adipose tissue and in FGF21-knockout mice reveal alterations in key components of the electron transport chain within white adipose tissue mitochondria. Notably, in male mice, these changes appear to be dependent on FGF21. In conclusion, we demonstrate that maintaining body weight during dietary protein restriction in healthy, lean men requires a higher energy intake, partially driven by FGF21-mediated mitochondrial adaptations in adipose tissue.
Global self-organization of solute induced by ion irradiation in polycrystalline alloys
Most materials are brought into nonequilibrium states during processing and during their service life. Materials for nuclear and space applications, for instance, are continuously exposed to energetic particle irradiation, which is often detrimental to materials’ performance. Here we demonstrate, however, that sustained irradiation can induce self-organization of the microstructure of polycrystalline alloys into steady-state patterns and, in turn, improve their radiation resistance. Using an Al −1.5 at.% Sb alloy as a model system, we show using transmission electron microscopy and atom probe tomography that, for nanocrystalline thin films irradiated at 75 °C with 2 MeV Ti ions to large doses, the microstructure consists of finite-size, self-organized AlSb nanoprecipitates inside the grains and along the grain boundaries. Furthermore, this steady state is independent of the initial microstructure, thus self-healing. Phase field modeling is employed to construct a steady-state phase diagram and extend the experimental results to other alloy systems and microstructures.
Vision-based tactile sensor design using physically based rendering
High-resolution tactile sensors are very helpful to robots for fine-grained perception and manipulation tasks, but designing those sensors is challenging. This is because the designs are based on the compact integration of multiple optical elements, and it is difficult to understand the correlation between the element arrangements and the sensor accuracy by trial and error. In this work, we introduce the digital design of vision-based tactile sensors using a physically accurate light simulator. The framework modularizes the design process, parameterizes the sensor components, and contains an evaluation metric to quantify a sensor’s performance. We quantify the effects of sensor shape, illumination setting, and sensing surface material on tactile sensor performance using our evaluation metric. The proposed optical simulation framework can replicate the tactile image of the real vision-based tactile sensor prototype without any prior sensor-specific data. Using our approach we can substantially improve the design of a fingertip GelSight sensor. This improved design performs approximately 5 times better than previous state-of-the-art human-expert design at real-world robotic tactile embossed text detection. Our simulation approach can be used with any vision-based tactile sensor to produce a physically accurate tactile image. Overall, our approach enables the automatic design of sensorized soft robots and opens the door for closed-loop co-optimization of controllers and sensors for dexterous manipulation.
Strong-weak dual interface engineered electrocatalyst for large current density hydrogen evolution reaction
Supported nanocatalysts are crucial for hydrogen production, yet their activity and stability are challenging to manage due to complex metal-support interfaces. Herein, we design Pt@ anatase&rutile-TiO2 with a strong-weak dual interface by modifying TiO2 using high-energy ball milling and in-situ reduction to vary surface energies. Experiments and density functional theory calculations reveal that the strong Pt-anatase TiO2 interface enhances hydrogen adsorption. In contrast, the weak Pt-rutile TiO2 interface facilitates hydrogen desorption, simultaneously preventing Pt agglomeration and increasing reaction rate. As a result, the tailored catalyst has a 529.3 mV overpotential at 1000 mA cm−2 in 0.5 M H2SO4, 0.69 times less than commercial Pt/C. It also possesses 8.8 times the mass activity of commercial Pt/C and maintains a low overpotential after 2000 cyclic voltammetry cycles, suggesting high activity and stability. This strong-weak dual interface engineering strategy shows potential for overall water splitting and proton exchange membrane water electrolyzer, advancing the design of efficient supported nanocatalysts.
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