Abstract-As battery-powered mobile devices become more popular and energy hungry, wireless power transfer technology receives intensive interests, as it allows the power to be transferred from a charger to ambient devices wirelessly. The existing studies mainly focus on the power transfer efficiency but overlook the health impairments caused by RF exposure. In this paper, we study the Safe Charging Problem (SCP) of scheduling power chargers so that more energy can be received while no location in the field has electromagnetic radiation (EMR) exceeding a given threshold Rt. We prove that SCP is NP-hard and propose a solution which provably outperforms the optimal solution to SCP with a relaxed EMR threshold (1 − )Rt. Testbed results based on 8 Powercast TX91501 chargers validate our results. Extensive simulation results show that the gap between our solution and the optimal one is only 6.7% when = 0.1, while a naive greedy algorithm is 34.6% below our solution.

Regenerable nanozymes with high catalytic stability and sustainability are promising substitutes for naturally-occurring enzymes but are limited by insufficient and non-selective catalytic activities. Herein, we developed single-atom nanozymes of RhN4, VN4, and Fe-Cu-N6 with catalytic activities surpassing natural enzymes. Notably, Rh/VN4 preferably forms an Rh/V-O-N4 active center to decrease reaction energy barriers and mediates a “two-sided oxygen-linked” reaction path, showing 4 and 5-fold higher affinities in peroxidase-like activity than the FeN4 and natural horseradish peroxidase. Furthermore, RhN4 presents a 20-fold improved affinity in the catalase-like activity compared to the natural catalase; Fe-Cu-N6 displays selectivity towards the superoxide dismutase-like activity; VN4 favors a 7-fold higher glutathione peroxidase-like activity than the natural glutathione peroxidase. Bioactive sutures with Rh/VN4 show recyclable catalytic features without apparent decay in 1 month and accelerate the scalp healing from brain trauma by promoting the vascular endothelial growth factor, regulating the immune cells like macrophages, and diminishing inflammation.

Natural enzymes are efficient and versatile biocatalysts but suffer in their environmental tolerance and catalytic stability. As artificial enzymes, nanozymes can improve the catalytic stability, but it is still a challenge to achieve high catalytic activity. Here, we employed atomic engineering to build the artificial enzyme named Au24Ag1 clusterzyme that hosts an ultrahigh catalytic activity as well as strong physiological stability via atom manipulation. The designed Au24Ag1 clusterzyme activates the Ag–S active site via lattice expansion in the oligomer atom layer, showing an antioxidant property 72 times higher than that of natural antioxidant Trolox. Enzyme-mimicked studies find that Au24Ag1 clusterzyme exhibits high catalase-like (CAT-like) and glutathione peroxidase-like (GPx-like) activity with a maximum reaction rate of 68.9 and 17.8 μM/min, respectively. Meanwhile, the unique catalytic landscape exhibits distinctive reactions against inflammation by inhibiting the cytokines at an early stage in the brain. Atomic engineering of clusterzymes provides a powerful and attractive platform with satisfactory atomic dispersion for tailoring biocatalysts freely at the atomic level.

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NIR-II imaging is developed rapidly for noninvasive deep tissue inspection with high spatio-temporal resolution, taking advantage of diminished autofluorescence and light attenuation. Activatable NIR‐II fluorescence probes are widely developed to report pathological changes with accurate targeting, among which organic fluorescent probes achieve significant progress. Furthermore, the activatable NIR‐II fluorescent probes exhibited appealing characteristics like tunable physicochemical and optical properties, easy processability, and excellent biocompatibility. In the present review, we highlight the advances of activatable NIR-II fluorescence probes in design, synthesis and applications for imaging pathological changes like reactive oxygen species (ROS), reactive nitrogen species (RNS), reactive sulfur species (RSS), pH, hypoxia, viscosity as well as abnormally expressed enzymes. This non-invasive optical imaging modality shows a promising prospect in targeting the pathological site and is envisioned for potential clinical translation.

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However, current NIR-II probes cannot meet long-term monitoring in vivo due to their limitations. [3] Singlewalled carbon nanotubes are one of the most promising due to their high photostability and high-resolution intravital fluorescence imaging, but they meet the challenge of low quantum yield (QY). [1b,4] Rare earth-doped nanoparticles (RE NPs) hold strong stability, tunable multispectral emissions, and significantly improved NIR-II fluorescence emission, unfortunately, RE NPs raise critical biosafety concerns due to their long-term retention and accumulation in the body postimaging. [5] Although quantum dots (QDs) show excellent optical properties such as narrow band gaps and strong brightness, biological security and complex synthesis methods limit further application. [6] In addition, micromolecule fluorophores display excellent biosafety, providing a better alternative, but their easy photobleaching and weak stability also limit imaging applications. Moreover, clinically approved ICG decays more than 80% after a few minutes of laser irradiation, which prevent a potential application for long-term imaging. [7] Moreover, few NIR-II fluorescence probes have been reported to exhibit excellent biocatalytic activity. [8] Thus, it is desirable to design NIR-II probes with high brightness, strong stability, high catalytic activity, and elevated efficiency in renal clearance for wide biological and clinical applications. [9] Many diseases involve organ functional injury, which requires monitoring of pathological progress and deep tissue imaging. [10] NIR-II shows great potential in the diagnosis of acute kidney injury (AKI) and other functional organ injury. [11] AKI is a common clinical kidney disease with high morbidity and mortality, characterized by decreased kidney function and decreased glomerular filtration rate (GFR) over a short period of time. [12] Clinical and epidemiological studies have shown that AKI can cause damage to distant organs, especially irreversible brain damage, through inflammatory reactions and oxidative stress, among other mechanisms. [13] Unlike other diseases (such as myocardial infarction), AKI at the incipient stage does not immediately present with obvious symptoms. However, early diagnosis and intervention of AKI can effectively avoid the development of serious complications. [14] In the clinic, serum creatinine (sCr) and blood urea nitrogen (BUN) are typically Near-infrared-II (NIR-II) imaging has shown great potential for monitoring the pathological progression and deep tissue imaging but is limited to present unmet NIR-II agent. Present fluorophores show a promising prospect for NIR-II imaging, but brightness and photostability are still highly challenging during real-time monitoring. In this work, atom-engineered NIR-II Au 24 Cd 1 clusters with ultrahigh brightness, stability, and photostability are developed via single atomic Cd doping. Single atom Cd substitutions contribute to Cd 4d state in HOMO and redistribution of energy level near the gap, exhibiting 56-fold flu...