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The advantages of ammonia as a hydrogen carrier have led to proposals for on-site hydrogen production through its decomposition. Rapid cold start of ammonia decomposition is crucial for applications such as ammonia-powered vehicles, but conventional heating methods are challenged by the high decomposition temperature of ammonia. In this study, we successfully achieved the rapid cold start of ammonia decomposition using Co nanoparticle catalysts driven by magnetic induction heating, demonstrating excellent catalytic performance and stability. The magnetic induction heating-driven ammonia decomposition system was integrated with a hydrogen fuel cell, proving its ability to achieve the cold start of ammonia decomposition within 10 s, as demonstrated by comparative experiments using 75% H 2 -25% N 2 from a gas cylinder as the control. This study provides a deeper understanding of hysteresis heating catalysis, promoting the practical use of ammonia as a hydrogen carrier for rapid hydrogen production in the energy industry.

In this study, we present an innovative "click-to-release" strategy for the design of highly specific H 2 S n bioorthogonal probes that undergo a specific click reaction with H 2 S n and release fluorophores by a following rearrangement. A library of cyclooctyne derivatives was established and successfully demonstrated the availability of the release strategy. Then, a model probe CM-CT was synthesized, which can achieve effective fluorophore release (>80%) in the presence of a H 2 S n donor. To further validate the application of this class of probes, a new probe QN-RHO-CT based on Rhodamine 110 was developed. This probe showed good water solubility (>160 μM) and fast release kinetics and can achieve selective H 2 S n detection in living cells. We used this probe to study the process of H 2 S-mediated protein S-persulfidation and demonstrated that excess H 2 S would directly react with protein persulfides to generate H 2 S 2 and reduce the persulfides to thiols. Additionally, we elucidated the click-to-release mechanism in our design through a detailed mechanistic study, confirming the generation of the key intermediate α, β-unsaturated cyclooctanethione. This bioorthogonal click-to-release reaction provides a useful tool for investigating the function of H 2 S n and paves the way for biological studies on H 2 S n .

The exploration of non-noble metal catalysts for alkane dehydrogenation and their catalytic mechanisms is the priority in catalysis research. Here, we report a high-density coordinatively unsaturated Zn cation (Zn cus ) catalyst for the direct dehydrogenation (DDH) of ethylbenzene (EB) to styrene (ST). The catalyst demonstrated good catalytic performance (∼40% initial EB conversion rate and >98% ST selectivity) and excellent regeneration ability in the reaction, which is attributed to the high-density (HD) distribution and high-stability structure of Zn cus active sites on the surface of zinc silicate (HD-Zn cus @ZS). Density functional theory (DFT) calculations further illustrated the reaction pathway and intermediates, supporting that the Zn cus sites can efficiently activate the C-H bond of ethyl on ethylbenzene. Developing the high-density Zn cus catalyst and exploring the catalytic mechanism laid a good foundation for designing practical non-noble metal catalysts.

Polymeric nanoreactors in water fabricated by the self-assembly of amphiphilic copolymers have attracted much attention due to their good catalytic performance without using organic solvents. However, the disassembly and instability of relevant nanostructures often compromise their potential applicability. Herein, the preparation of 2,2,6,6-tetramethylpiperidine-1-oxyl (TEMPO)-containing nanoreactors by the self-assembly of amphiphilic bottlebrush copolymers has been demonstrated. First, a macromonomer having a norbornenyl polymerizable group was prepared by RAFT polymerization of hydrophobic and hydrophilic monomers. The macromonomer was further subjected to ring-opening metathesis polymerization to produce an amphiphilic bottlebrush copolymer. Further, TEMPO, as a catalyst, was introduced into the hydrophobic block through the activated ester strategy. Finally, TEMPO-functionalized polymeric nanoreactors were successfully obtained by self-assembly in water. The nanoreactors exhibited excellent catalytic activities in selective oxidation of alcohols in water. More importantly, the reaction kinetics showed that the turnover frequency is greatly increased compared to that of the similar nanoreactor prepared from liner copolymers under the same conditions. The outstanding catalytic activities of the nanoreactors from bottlebrush copolymers could be attributed to the more stable micellar structure using the substrate concentration effect. This work presents a new strategy to fabricate stable nanoreactors, paving the way for highly efficient organic reactions in aqueous solutions.

Drug addiction is a chronic relapsing brain disease. Alterations of glucose uptake and metabolism are found in the brain of drug addicts. Insulin mediates brain glucose metabolism and its abnormality could induce brain injury and cognitive impairment. Here, we established a rat model of phenobarbital addiction by 90 days of dose escalation and evaluated addiction-related symptoms. We also performed 18 F-fluorodeoxyglucose (FDG) positron emission tomography/computed tomography (PET/CT) to detect glucose uptake in the brain and proteomic analysis of the function of the differentially expressed (DE) proteins via bioinformatics in brain tissues by liquid chromatography coupled with tandem mass spectrometry (LC-MS/MS) on days 60 and 90 of phenobarbital or 0.5% carboxymethyl cellulose sodium (CMC-Na) (vehicle) administration. The results showed that phenobarbital-addictive rats developed severe withdrawal symptoms after abstinence and glucose uptake was significantly increased in the brain. Proteomics analysis showed that numerous DE proteins were enriched after phenobarbital administration, among which CALM1, ARAF, and Cbl proteins (related to the insulin signaling pathway) were significantly downregulated on day 60 but not day 90. However, SLC27A3 and NF-κB1 proteins (related to insulin resistance) were significantly upregulated on day 90 (data are available via ProteomeXchange with identifier PXD021101). Our data indicate that the insulin signaling pathway and insulin resistance may play a role in the development of phenobarbital addiction and brain injury, so the findings may have important clinical implications.

Nanoparticles (NPs) have shown great promise as intracellular imaging probes or nanocarriers and are increasingly being used in biomedical applications. A detailed understanding of how NPs get "in and out" of cells is important for developing new nanomaterials with improved selectivity and less cytotoxicity. Both physical and chemical characteristics have been proven to regulate the cellular uptake of NPs. However, the exocytosis process and its regulation are less explored. Herein, we investigated the size-regulated endocytosis and exocytosis of carboxylated polystyrene (PS) NPs. PS NPs with a smaller size were endocytosed mainly through the clathrin-dependent pathway, whereas PS NPs with a larger size preferred caveolae-mediated endocytosis. Furthermore, our results revealed exocytosis of larger PS NPs and tracked the dynamic process at the single-particle level. These results indicate that particle size is a key factor for the regulation of intracellular trafficking of NPs and provide new insight into the development of more effective cellular nanocarriers.