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Ultrasmall Au25(MPA)18clusters show great potential in biocatalysts and bioimaging due to their well-defined, tunable structure and properties. Hence, in vivopharmacokinetics and toxicity of Au nanoclusters (Au NCs) are very important for clinical translation, especially at high dosages. Herein, the in vivohematological, tissue, and neurological effects following exposure to Au NCs (300 and 500 mg kg–1) were investigated, in which the concentration is 10 times higher than in therapeutic use. The biochemical and hematological parameters of the injected Au NCs were within normal limits, even at the ultrahigh level of 500 mg kg–1. Meanwhile, no histopathological changes were observed in the Au NC group, and immunofluorescence staining showed no obvious lesions in the major organs. Furthermore, real-time near-infrared-II (NIR-II) imaging showed that most of the Au25(MPA)18and Au24Zn1(MPA)18can be metabolized via the kidney. The results demonstrated that Au NCs exhibit good biosafety by evaluating the manifestation of toxic effects on major organs at ultrahigh doses, providing reliable data for their application in biomedicine.

Hydroformylation of olefins, as a study of olefinic downstream derivative production, is of great relevance in chemical production. Heterogeneous hydroformylation is beneficial for catalyst separation and recycling compared to homogeneous systems. Cobalt is a cheap metal with excellent catalytic activity in hydroformylation as well as the precious metal rhodium. Therefore, the research on cobalt-based catalysts for heterogeneous hydroformylation has great value and significance. The nano or atomic structures of cobalt-based catalysts have significant impact on the catalytic behaviors of the hydroformylation process. There is rarely the design principles report on how to achieve significant improvement in hydroformylation performance by regulating the structure of the cobalt-based catalyst. Herein, we review the recent research progress on heterogeneous hydroformylation by cobalt-based catalysts with different metal sizes (from nanostructures to single atoms). On the basis of the difference in the catalytic mechanism between homogeneous and heterogeneous hydroformylation, we summarize and propose the regulation principles to enhance the activity and stability of cobalt-based catalysts in hydroformylation, where single-atom engineering is expected to achieve unity of high activity and stability of cobalt-based catalysts for hydroformylation applications. At the end of this review, we present an outlook on the opportunities and challenges in developing cobalt-based catalysts for heterogeneous hydroformylation.

In autonomous driving, reinforcement learning’s interactive learning capabilities have garnered interest. Among these, risk-averse distributional reinforcement learning has demonstrated promise in situations where safety is crucial. On the other hand, risk-averse policies degrade training performance by discouraging exploration. To provide an adaptive exploration policy, this work offers a novel framework for risk-averse distributional reinforcement learning. The proposed method is evaluated in a highly uncertain safety-critical scenario, motion planning for pedestrian avoidance in the face of uncertain interactions. The simulation results demonstrate improved safety, achieving training flexibility between exploration and exploitation.

Magnetic catheter robots have great potential for application in minimally invasive surgical interventions that require submillimeter soft catheters to be inserted into the body. Compared to other medical continuum robots, the kinematic characteristics of the magnetic continuum robot are required to be improved, including operating dexterity. The opposite magnetic continuum robot (OMCR), which has oppositely-magnetized magnets on the robot, is capable of deforming in large and high-order curvatures and shows improved dexterity. However, unstable kinematic behaviors emerge owing to solution multiplicity and affect the actual operation. For example, snapping, which indicates the sudden jump from one state to another, induces danger for medical operations. In addition, the motion sequence of the external mobile magnet affects the final state of OMCR. Therefore, in this study, we first analyze the reason for these emerging behaviors by understanding the solution multiplicity of an OMCR. We then modified the OMCR kinematic model with instability analysis and additional constraints, to predict the critical point for snapping and avoid other unexpected behavior for path planning. Herein, our study aims to analyze the stability of the OMCR with relatively unstable configurations in their actuation space to ensure stable and dexterous motions for medical applications. Note to Practitioners—The motivation of this work is to analyze, predict, and avoid the unexpected behaviors of the medical magnetic catheter robots, and ensure stable and dexterous operation. Submillimeter magnetic catheter robots have received considerable attention in the past ten years owing to their small size and dexterous motion. They have great potential for minimally invasive surgical interventions that require the navigation of “tighter corners” inside the human body. However, there may exist multiple local solutions under an external field, especially when the robot deforms in high-order curvature for dexterous operation. This situation induces unexpected behaviors and danger for medical use, such as a sudden jump from one state to another. Herein, we analyze the solution evolution as the external field varies and predict the unexpected behaviors using a modified kinematic model with instability analysis. Preliminary experiments demonstrated the effectiveness of the modified model, which can predict unexpected behaviors, and evaluate and enhance the stability during path planning. This method can be implemented for the dexterous and stable operation of magnetic catheter robots, which is significant for medical applications.

DC microgrid (DCMG) is characterized by a high degree of power electronics, low system inertia, and CPL (CPL) with a negative damping feature. Its system-level transient stability is of great concern. The stability of a DCMG system is affected by many factors, such as component parameters, load types, converter control methods, etc. To analyze the system-level stability of the DCMG, the constraints of large signal stability of the DCMG based on droop control are derived by using the Lyapunov direct method. Based on this conclusion, the influence of system parameters on large signal stability and voltage deviation of the DCMG is revealed, and the optional range of filter element parameters and droop coefficient under the stability and voltage constraints is proposed. The parameter selection work involves two evaluation indicators, system stability, and voltage deviation. This article uses the variable weight coefficient method to normalize these two indicators into a comprehensive evaluation index, and the appropriate droop coefficient is selected based on the optimal comprehensive evaluation index. The work of this article has reference values for the parameter design of the DCMG system components and the selection of the droop coefficient.