The neural representation of metacognition in preferential decision-making

Humans regularly assess the quality of their judgements, which helps them adjust their behaviours. Metacognition is the ability to accurately evaluate one's own judgements, and it is assessed by comparing objective task performance with subjective confidence report in perceptual decisions. However, for preferential decisions, assessing metacognition in preference-based decisions is difficult because it depends on subjective goals rather than the objective criterion. Here, we develop a new index that integrates choice, reaction time, and confidence report to quantify trial-by-trial metacognitive sensitivity in preference judgements. We found that the dorsomedial prefrontal cortex (dmPFC) and the right anterior insular were more activated when participants made bad metacognitive evaluations. Our study suggests a crucial role of the dmPFC-insula network in representing online metacognitive sensitivity in preferential decisions.

Process Optimization of SiC-Reinforced Aluminum Matrix Composites Prepared Using Laser Powder Bed Fusion and the Effect of Particle Morphology on Performance

Process parameters and powder spreading quality are important factors for aluminum matrix composites (AMCs) prepared using laser powder bed fusion (LPBF). In this study, a Box-Behnken Design (BBD) was used to optimize the process parameters, and near-spherical β-SiC was selected to improve the quality of powder spreading. The rationality of parameter optimization was verified by testing the density of samples prepared using different laser power levels. Al4C3 diffraction peaks were found in XRD patterns, which indicated that interface reactions occurred to form good interface bonding between the Al matrix and the SiC particles. The tensile strength and plasticity of LPBF α-SiC/AlSi10Mg were lower than that of LPBF AlSi10Mg, which was mainly due to the poor fluidity of the powder mixtures and powder spreading quality. For LPBF β-SiC/AlSi10Mg, the tensile strength increased and elongation decreased slightly compared to LPBF α-SiC/AlSi10Mg. The data in this study were compared with the data in other studies. In this study, LPBF AlSi10Mg and LPBF β-SiC/AlSi10Mg not only showed the inherent high strength of their LPBF parts, but also had relatively high plasticity. Matching between strength and plasticity was mainly dependent on the scanning strategy. Most studies use uni-directional or bi-directional scanning strategies with a certain rotation angle between layers. A chessboard scanning strategy was used in this study to form a coarse remelted connected skeleton inside the material and significantly improve plasticity. This study lays a theoretical and experimental foundation for the controllable preparation of SiC-reinforced AMCs using LPBF.

Strain Effects on Flexible Perovskite Solar Cells

Flexible perovskite solar cells (f-PSCs) as a promising power source have grabbed surging attention from academia and industry specialists by integrating with different wearable and portable electronics. With the development of low-temperature solution preparation technology and the application of different engineering strategies, the power conversion efficiency of f-PSCs has approached 24%. Due to the inherent properties and application scenarios of f-PSCs, the study of strain in these devices is recognized as one of the key factors in obtaining ideal devices and promoting commercialization. The strains mainly from the change of bond and lattice volume can promote phase transformation, induce decomposition of perovskite film, decrease mechanical stability, etc. However, the effect of strain on the performance of f-PSCs has not been systematically summarized yet. Herein, the sources of strain, evaluation methods, impacts on f-PSCs, and the engineering strategies to modulate strain are summarized. Furthermore, the problems and future challenges in this regard are raised, and solutions and outlooks are offered. This review is dedicated to summarizing and enhancing the research into the strain of f-PSCs to provide some new insights that can further improve the optoelectronic performance and stability of flexible devices.

A Lotus Seedpods-Inspired Interfacial Solar Steam Generator with Outstanding Salt Tolerance and Mechanical Properties for Efficient and Stable Seawater Desalination

Interfacial solar steam generators (ISSGs) can capture solar energy and concentrate the heat at the gas-liquid interface, resulting in efficient water evaporation. However, traditional ISSGs have limitations in long-term seawater desalination processes, such as limited light absorption area, slow water transport speed, severe surface salt accumulation, and weak mechanical performance. Inspired by lotus seedpods, a novel ISSG (rGO-SA-PSF) is developed by treating a 3D warp-knitted spacer fabric with plasma (PSF) and combining it with sodium alginate (SA) and reduces graphene oxide (rGO). The rGO-SA-PSF utilizes a core-suction effect to achieve rapid water pumping and employs aerogel to encapsulate the plasma-treated spacer yarns to create the lotus seedpod-inspired hydrophilic stems, innovatively constructing multiple directional water transport channels. Simultaneously, the large holes of rGO-SA-PSF on the upper layer form lotus seedpod-inspired head concave holes, enabling efficient light capture. Under 1 kW m-2 illumination, rGO-SA-PSF exhibits a rapid evaporation rate of 1.85 kg m-2  h-1 , with an efficiency of 96.4%. Additionally, it shows superior salt tolerance (with no salt accumulation during continuous evaporation for 10 h in 10% brine) and self-desalination performance during long-term seawater desalination processes. This biomimetic ISSG offers a promising solution for efficient and stable seawater desalination and wastewater purification.

Cancer Cell-Specific Fluorescent Prodrug Delivery Platforms

Targeting cancer cells with high specificity is one of the most essential yet challenging goals of tumor therapy. Because different surface receptors, transporters, and integrins are overexpressed specifically on tumor cells, using these tumor cell-specific properties to improve drug targeting efficacy holds particular promise. Targeted fluorescent prodrugs not only improve intracellular accumulation and bioavailability but also report their own localization and activation through real-time changes in fluorescence. In this review, efforts are highlighted to develop innovative targeted fluorescent prodrugs that efficiently accumulate in tumor cells in different organs, including lung cancer, liver cancer, cervical cancer, breast cancer, glioma, and colorectal cancer. The latest progress and advances in chemical design and synthetic considerations in fluorescence prodrug conjugates and how their therapeutic efficacy and fluorescence can be activated by tumor-specific stimuli are reviewed. Additionally, novel perspectives are provided on strategies behind engineered nanoparticle platforms self-assembled from targeted fluorescence prodrugs, and how fluorescence readouts can be used to monitor the position and action of the nanoparticle-mediated delivery of therapeutic agents in preclinical models. Finally, future opportunities for fluorescent prodrug-based strategies and solutions to the challenges of accelerating clinical translation for the treatment of organ-specific tumors are proposed.