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Thermal expansion regulation by chemical decoration at a molecular level is of great technological value for materials science. Herein, we show that the spin crossover active compound Fe(pyz)Pt(CN)4 (pyz = pyrazine) shows a rare 2D negative thermal expansion (NTE) in the ab-plane. By introducing axial coordination iodine ions or reducing the framework dimension from 3D to 2D, the NTE behavior can be effectively switched to positive thermal expansion (PTE) or even zero thermal expansion (ZTE). Moreover, it is found that different spin states of Fe2+ also influence the magnitude of NTE. Compared with the low-spin (LS) sate, the high-spin (HS) state tends to enhance the magnitude of NTE. Combined in situ structural and Raman spectral analyses revealed that the NTE mainly originates from the transverse vibration of a bridging cyano group and the tailorable thermal expansion is closely related to the state of the Fe–C≡N–Pt linkage. The present study shows how the rational regulation of the building unit and framework dimensions can effectively control thermal expansion behaviors. This insight can serve as guidance for designing and synthesizing novel NTE materials. [ABSTRACT FROM AUTHOR]

In light of the potential for enhancing SrTiO3 (STO)'s photocatalytic efficiency, particularly in the visible light region, a study is conducted on Al, N codoping in STO herein using first‐principles calculations. The effect of oxygen vacancy (VO) is also considered. It is found that AlSr, NO can significantly reduce the bandgap; however, their formation energies are rather high, and the defect levels they brought in may induce recombination centers. Under O‐deficient conditions, VO can facilitate Al, N doping in STO. When Al, N codope in STO, AlTi, NO, and VO would tend to combine, and formation of complex defect AlTi + NO + VO can further enhance N dopability in STO. Moreover, AlTi + NO + VO can simultaneously reduce the bandgap and eliminate the defect levels induced by NO. However, AlTi + NO + VO may not fully realize the potential for the photocatalytic activity due to the low optical absorption and unsuitable band alignment. The work provides a theoretical guidance for the photocatalytic performance of STO in the visible light region. [ABSTRACT FROM AUTHOR]

Metallic phase (1T) MoS2 has been regarded as an ideal catalytic material for the hydrogen evolution reaction (HER) due to its high active site density and favorable electrical conductivity. However, the preparation of 1T-phase MoS2 samples requires tough reaction conditions and 1T-MoS2 has poor stability under alkaline conditions. In this work, 1T-MoS2/NiS heterostructure catalysts grown in situ on carbon cloth were prepared by a simple one-step hydrothermal method. The obtained MoS2/NiS/CC combines the advantages of high active site density and a self-supporting structure, achieving stable 77% metal phase (1T) MoS2. The combination of NiS and 1T-MoS2 enhances the intrinsic activity of MoS2 while the electrical conductivity is improved. These advantages enable the 1T-MoS2/NiS/CC electrocatalyst to have a low overpotential of 89 mV (@10 mA cm−2) and a small Tafel slope of 75 mV dec−1 under alkaline conditions and provide a synthetic strategy of stable 1T-MoS2-based electrocatalysts for the HER by a heterogeneous structure. [ABSTRACT FROM AUTHOR]

Cu clusters supported on CeO2 have been reported as a promising and active catalyst for CO oxidation. However, the identification of interfacial interactions and active sites is still a great challenge. In this work, we demonstrated that interfacial chemistry can be understood and predicted by using a simple descriptor of adsorbate‐surface interactions that uncovers structure‐activity relationships. The catalytic activity of CeO2 supported Cu clusters for CO oxidation was studied by density functional theory. The Cu−Ce dual site mechanism enables the Cu/CeO2 catalyst to have a much lower reaction energy barrier than the Mars‐van Krevelen (M‐vK) mechanism and the Cu‐only mechanism. The reaction energy barriers of Cu/CeO2‐x with an oxygen vacancy on the CeO2 surface were 0.10, 0.37 and 0.77 eV, respectively. The excellent performance of Cu/CeO2 catalysts is related to the interfacial interaction between Cu and CeO2 and their synergistic redox behaviors, and oxygen vacancies facilitate the generation and stabilization of active Cu+ species through the interaction with Cu clusters. And we have identified the binding energy of O2* can describe the CO oxidation activity of Cu/CeO2. Our study provides insight into the nature of active sites for Cu/CeO2 catalysts and guidance for high‐performance. [ABSTRACT FROM AUTHOR]

Lipids affect cartilage growth, injury, and regeneration in diverse ways. Diet and metabolism have become increasingly important as the prevalence of obesity has risen. Proper lipid supplementation in the diet contributes to the preservation of cartilage function, whereas excessive lipid buildup is detrimental to cartilage. Lipid metabolic pathways can generate proinflammatory substances that are crucial to the development and management of osteoarthritis (OA). Lipid metabolism is a complicated metabolic process involving several regulatory systems, and lipid metabolites influence different features of cartilage. In this review, we examine the current knowledge about cartilage growth, degeneration, and regeneration processes, as well as the most recent research on the significance of lipids and their metabolism in cartilage, including the extracellular matrix and chondrocytes. An in-depth examination of the involvement of lipid metabolism in cartilage metabolism will provide insight into cartilage metabolism and lead to the development of new treatment techniques for metabolic cartilage damage. [ABSTRACT FROM AUTHOR]

As the global energy shortage and environmental pollution worsen, the development of clean and renewable energy becomes more urgent. Electrochemical technology can achieve high-efficiency, low-cost clean energy conversion, mainly relying on highly efficient electrocatalysts, including noble metals such as Au, Pt, Pd. MXenes, an emerging class of two-dimensional materials, have been widely used in electrocatalysis due to their high conductivity, large specific surface area, and good hydrophilicity. In particular, MXenes and their derivatives have been widely used to support various noble metal nanomaterials. They have shown outstanding catalytic performances and good stability in the hydrogen evolution reaction, oxygen evolution reaction, oxygen reduction reaction, nitrogen reduction reaction, and methanol oxidation reaction. Herein, we review the strategies for the synthesis of noble metal MXene-based catalysts, emphasize the application of noble metal MXene-based catalysts in the field of electrocatalysis, and focus on the strategy of enhancing the electrocatalytic performance of noble metal MXene-based catalysts. Based on this, the limitations and future development of noble metal MXene-based catalysts in electrocatalysis are discussed. [ABSTRACT FROM AUTHOR]

TLR7 and TLR8 are key members of the Toll-like receptor family, playing crucial roles in the signaling pathways of innate immunity, and thus become attractive therapeutic targets of many diseases including infections and cancer. Although TLR7 and TLR8 show a high degree of sequence homology, their biological response to small molecule binding is very different. Aiming to understand the mechanism of selective profiles of small molecule modulators against TLR7 and TLR8, we carried out molecular dynamic simulations on three imidazoquinoline derivatives bound to the receptors separately. They are Resiquimod (R), Hybrid-2 (H), and Gardiquimod (G), selective agonists of TLR7 and TLR8. Our MD trajectories indicated that in the complex of TLR7-R and TLR7-G, the two chains forming the TLR7 dimer tended to remain "open" conformation, while the rest systems maintained in the closed format. The agonists R, H, and G developed conformational deviation mainly on the aliphatic tail. Furthermore, we attempted to quantify the selectivity between TLR7 and TLR8 by binding free energies via MM-GBSA method. It showed that the three selected modulators were more favorable for TLR7 than TLR8, and the ranking from the strongest to the weakest was H, R and G, aligning well with experimental data. In the TLR7, the flexible and hydrophobic aliphatic side chain of H has stronger van der Waals interactions with V381 and F351 but only pick up interaction with one amino acid residue i.e. Y353 of TLR8. Unsurprisingly, the positively charged side chain of G has less favorable interaction with I585 of TLR7 and V573 of TLR8 explaining G is weak agonist of both TLR7 and TLR8. All three imidazoquinoline derivatives can form stable hydrogen bonds with D555 of TLR7 and the corresponding D543 of TLR8. In brief, the set of total 400ns MD studies sheds light on the potential selectivity mechanisms of agonists towards TLR7 and TLR8, indicating the van der Waals interaction as the driving force for the agonists binding, thus provides us insights for designing more potent and selective modulators to cooperate with the hydrophobic nature of the binding pocket. [ABSTRACT FROM AUTHOR]