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In recent years, the morphology control of nanoparticles (NPs) has been an effective way to improve the catalytic performance of PtPd alloys. Polyvinylpyrrolidone (PVP) can be used as a multifunctional orientation and stabilizer for monodisperse nanostructure synthesis. In ethylene glycol (EG), PVP stabilizes the crystal plane by the interaction of the carbonyl group of the repeating unit with the metal surface. In this article, a series of Pt, Pd, and PtPd alloy NPs with different morphologies within 10 nm were synthesized by changing the content of PVP to explore the effects of different crystal plane exposure ratios on the morphology. The DFT results showed that different PVP contents would expose different crystal planes of NPs. The NPs exposed to different crystal planes have different effects on the hydrolysis performance of ammonia borane (AB). An appropriate {100}/{111} ratio was conducive to the adsorption of H2O and the desorption of H2 so as to promote the hydrolysis of AB. The morphology adjustment has endowed PtPd alloy NPs with superior AB hydrolysis performance. This work provides more insights for improving catalytic performance through the control of the morphology and crystal plane. [ABSTRACT FROM AUTHOR]

Metallic ultrathin nanosheets have drawn increasing attention due to their distinct properties and wide applications. Nonetheless, the successful preparation of metallic ultrathin nanosheets is still a huge challenge because metallic bonds have no direction and tend to form three-dimensional close-packed structures. Here, ultrathin curved PtPdMo nanosheets (UC-PtPdMo NSs) were obtained by controlling the anisotropic growth kinetics through the CO released from Mo-(CO)6. Meanwhile, different doses of PVP and CTAB could induce the formation of ultrathin porous PtPdMo NSs (UP-PtPdMo NSs) and ultrathin PtPdMo NSs (U-PtPdMo NSs). Among them, UC-PtPdMo NSs had the optimal catalytic activity for oxygen reduction reaction (ORR), and its specific and mass activities were 4.1 and 3.6 times as large as those of Pt/C. Moreover, it showed better stability than the other catalysts after 10k cycles. The strengthened catalytic properties might have resulted from the ultrathin structures and the electronic adjustment of Pt by Pd and Mo elements. [ABSTRACT FROM AUTHOR]

The development of a scalable, low-cost,and versatile biosensorplatform for the sensitive and rapid detection of human metabolitesis of great interest for healthcare, pharmaceuticals, and medicalscience. On the basis of hierarchically nanostructured conductingpolymer hydrogels, we designed a flexible biosensor platform thatcan detect various human metabolites, such as uric acid, cholesterol,and triglycerides. Owing to the unique features of conducting polymerhydrogels, such as high permeability to biosubstrates and rapid electrontransfer, our biosensors demonstrate excellent sensing performancewith a wide linear range (uric acid, 0.07–1 mM; cholesterol,0.3–9 mM, and triglycerides, 0.2–5 mM), high sensitivity,low sensing limit, and rapid response time (∼3 s). Given thefacile and scalable processability of hydrogels, the proposed conductivehydrogels-based biosensor platform shows great promise as a low-costsensor kit for healthcare monitoring, clinical diagnostics, and biomedicaldevices. [ABSTRACT FROM AUTHOR]

Polymer-derived ceramic (PDC)-based high-temperature thin-film sensors (HTTFSs) exhibit promising applications in the condition monitoring of critical components in aerospace. However, fabricating PDC-based HTTFS integrated with high-efficiency, high-temperature anti-oxidation, and customized patterns remains challenging. In this work, we introduce a rapid and flexible selecting laser pyrolysis combined with a direct ink writing process to print double-layer high-temperature antioxidant PDC composite thin-film thermistors under ambient conditions. The sensitive layer (SL) was directly written on an insulating substrate with excellent conductivity by laser-induced graphitization. Then, the antioxidant layer (AOL) was written on the surface of the SL to realize the integrated manufacturing of double-functional layers. Through characterization analysis, it was shown that B 2 O 3 and SiO 2 glass phases generated by the PDC composite AOL could effectively prevent oxygen intrusion. Therefore, the fabricated PDC composite thermistors exhibited a negative temperature coefficient in the temperature range from 100 to 1100 °C and high repeatability below 800 °C. Meanwhile, it has excellent high-temperature stability at 800 °C with a resistance change of only 2.4% in 2 h. Furthermore, the high-temperature electrical behavior of the thermistor was analyzed. The temperature dependence of the conductivity for this thermistor has shown an agreement with the Mott's variable range hopping mechanism. Additionally, the thermistor was fabricated on the surface of an aero-engine blade to verify its feasibility below 800 °C, showing the great potential of this work for state sensing on the surface of high-temperature components, especially for customized requirements.

The proinflammatory cytokine tumor necrosis factor-α (TNF-α)-induced degradation of extracellular matrix (ECM), such as type II collagen in chondrocytes, plays an important role in the development of osteoarthritis (OA). Telmisartan, an angiotensin II (Ang-II) receptor blocker, is a licensed drug used for the treatment of hypertension. However, the effects of Telmisartan in tumor necrosis factor-α (TNF-α)-induced damage to chondrocytes and the progression of OA are unknown. In this study, we found that treatment with Telmisartan attenuated TNF-α-induced oxidative stress by reducing the levels of mitochondrial reactive oxygen species (ROS) and the production of protein carbonyl in human C28/I2 chondrocytes. Interestingly, Telmisartan inhibited TNF-α-induced expression and secretions of proinflammatory mediators such as interleukin-1β (IL-1β), interleukin-6 (IL-6), and monocyte chemotactic protein 1 (MCP-1). Notably, stimulation with TNF-α reduced the levels of type II collagen at both the mRNA and the protein levels, which was rescued by the treatment with Telmisartan. Mechanistically, we found that Telmisartan restored TNF-α-induced reduction of SOX-9. Silencing of SOX-9 blocked the inhibitory effects of Telmisartan against TNF-α-induced degradation of type II collagen. These findings suggest that Telmisartan might be a potential and promising agent for the treatment of OA., Competing Interests: The authors declare no competing financial interest., (© 2021 The Authors. Published by American Chemical Society.)

Electrocatalytic water splitting is a promising technology for large-scale hydrogen production. However, it requires efficient catalysts to overcome the large overpotentials in the oxygen evolution reaction (OER) and hydrogen evolution reaction (HER). Herein, we report a novel heterostructure catalyst Co 9 S 8 /Cu 2 S on copper foam (Co 9 S 8 /Cu 2 S/CF) with multistep impregnation and electrodeposition. Due to the strong interfacial interaction, the interfacial electrons transfer from Co sites to S sites, which promote the adsorption of oxygen-containing intermediates, water molecules, as well as the dissociation of water molecules. Therefore, the heterostructure catalyst exhibits low overpotentials of 195 mV for OER and 165 mV for HER at 10 mA cm -2 , respectively. Moreover, it only needs 1.6 V to realize water splitting at 10 mA cm -2 in a two-electrode cell. This work provides an efficient method to tailor the surface electronic structure through specific morphological design and construct a heterostructure interface to achieve alkaline water splitting.

Endohedral clusterfullerenes (ECFs) are fullerene cages with various metallic clusters trapped inside. So far, the actinide-based ECFs are rather scarce with their possible structures and chemistry remaining largely unexplored. Herein, density functional theory calculations characterized that the recently synthesized U 2 O@C 76 could be U 2 O@ C s (17 490)-C 76 or U 2 O@ C 2 v (19 138)-C 76 , whose cages have two or one pentagon adjacencies (PAs) and thus both violate the isolated pentagon rule (IPR). It is noteworthy that they are the first actinide-based ECFs bearing non-IPR outer cages. They are also the first C s (17 490)- and C 2 v (19 138)-C 76 -based oxide ECFs. Moreover, U 2 O@ C 2 v (19 138)-C 76 is the first example of a hexavalent metal cluster within the C 2 v (19 138)-C 76 cage. Interestingly, although trapped by the two same-sized cages, the U 2 O unit exhibits a bent and a perfect linear configuration, respectively, indicative of the crucial role of cage shape in steering the internal cluster configuration. Their electronic structures can be formally described as (U 2 O) 6+ @C 76 6- with primary electrostatic attractions and secondary covalent interactions between cluster and cage. Significantly, bonding analyses reveal that the encaged U 2 O moiety may only features two three-center, two-electron (3c-2e) U-O-U bonds with completely absent common two-center bonds.

Putting different metal clusters into the fullerene cages form the so-called "endohedral clusterfullerenes" (ECFs), among which all the carbonitride ECFs feature a common NC unit coordinating with either one or three metal atoms. Unfortunately, their internal N and C atoms are difficult to be distinguished experimentally, resulting in the fact that the exact structure and bonding nature of the encased metal cluster still remain unclear thus far. In this work, density functional theory calculations were performed for several representative carbonitride ECFs: MNC@C 2 n (M = Y, Tb; 2 n = 76, 82) and Sc 3 CN@C 2 n (2 n = 78, 80). For the first time, we focused on the C ↔ N interchange inside the cages and its effect on the chemical bonding of the trapped clusters. Computational results reveal that the two types of ECFs energetically favor the N and C atoms at the cluster center, respectively. The preference can be interpreted by the difference in several aspects, such as the energy of isolated clusters, charge states of (CN) -/3- , and cluster-cage interactions, as well as hyperconjugation of the internal clusters. The detailed wave function analyses indicate that MNC@C 2 n and Sc 3 CN@C 2 n bear a C≡N triple bond and a C═N double bond, respectively, regardless of the NC orientation. Compared with its slightly influence on the bonding patterns of the encaged MNC clusters, the C ↔ N interchange dramatically affects that of the Sc 3 CN units involving two-center two-electron (2c-2e) bonds, undiscovered three-center two-electron (3c-2e), and four-center two-electron (4c-2e) bonds.

The stability of endohedral clusterfullerenes is generally understood in terms of the metal cluster shape, cage structure, and metal-cage interactions, with the electronic state of the internal cluster mostly neglected. Herein, theoretical calculations reveal that the (Ti 3 C 3 ) 6+ unit of recently synthesized Ti 3 C 3 @ I h (7)-C 80 exhibits a superatomic state with a perfect closed-shell 1S 2 1P 6 1D 10 electronic configuration in accordance with the famous jellium model. This "trapped superatom" features considerable aromaticity and hyperconjugation interactions never reported for other clusterfullerenes. Besides the localized two-center two-electron (2c-2e) Ti-C/C-C bonds, it also has two 3c-2e Ti-C-Ti bonds. Furthermore, the ring strain of the cyclopropane-like C 3 core is effectively released upon the metal coordination. All these factors greatly stabilize the (Ti 3 C 3 ) 6+ cluster, showing the critical role of metal-to-cage charge transfer and cage encapsulation in enhancing the stability of this exotic metal cluster.

Stimulated by the recent successful synthesis and crystallographic characterization of the first diuranium carbide endohedral metallofullerene (EMF) U 2 C@ I h (7)-C 80 ( Zhang et al. Nat. Commun. ; 2018 ), density functional theory calculations were performed for a series of U 2 C@C 2 n (2 n = 60, 68, 72, 78, 80, 88, 96, and 104) analogues. The internal UCU bond angle increases from 96.9° in I h -C 60 to 180.0° in D 3 d -C 104 , exhibiting cage-size-dependent cluster configuration. However, further evidence suggests that the U 2 C shape may be also affected by the amount of charge transferred from the cluster to the outer cage with 6e and 4e favoring bent and linear, respectively. The change of the bond angle closely correlates with the charge and hybrid state of the internal atom. Significantly, besides the covalent two-center two-electron (2c-2e) U-C bonds, the U 2 C unit always features two 3c-2e bonds regardless of its size, shape, and charge state. Furthermore, for the cluster-cage interactions, besides the dominated electrostatic attractions, all these EMFs show an obvious covalent character with the substantial participation of U 5f valence orbitals.

The increasing use of pesticides in agriculture and gardening has caused severe deterioration to both the ecosystem and the health of users (human beings), so there is an urgent need for eco- and user-friendly pesticides. Among a variety of herbicides, paraquat (PQ), frequently used as an effective herbicidal agent worldwide, is well-known for its serious toxicity that has killed, and harmed, thousands of people and countless wildlife such as fish. Herein, we present a facile supramolecular formulation of PQ@cucurbit[7]uril (PQ@CB[7]), prepared by simply mixing PQ with equivalent (molar) CB[7] in water. With addition of CB[7], PQ's cellular uptake was dramatically inhibited. The reactive oxygen species (ROS) generation and the associated apoptosis otherwise induced by PQ in cellular models were both reduced, resulting in increased cellular viability. In a wildtype zebrafish model that is a typical fragile wildlife species in the ecosystem, the supramolecular formulation exhibited significantly reduced hepatotoxicity and increased survival rate, in comparison with those of the fish exposed to free PQ. In a mouse model that is clinically relevant to human being, the administration of PQ@CB[7] significantly alleviated major organ injuries and unusual hematological parameters that were otherwise induced by free PQ, resulting in a significantly increased survival rate. Meanwhile, this formulation maintained effective herbicidal activity that was equivalent to that of free PQ. Taken together, this facile supramolecular PQ formulation is providing not only an extremely rare example of an eco- and user-friendly herbicide that has been desired for decades but also a practical solution for green agriculture.

Atherosclerosis is a leading cause of vascular diseases worldwide. Whereas antioxidative therapy has been considered promising for the treatment of atherosclerosis in view of a critical role of reactive oxygen species (ROS) in the pathogenesis of atherosclerosis, currently available antioxidants showed considerably limited clinical outcomes. Herein, we hypothesize that a broad-spectrum ROS-scavenging nanoparticle can serve as an effective therapy for atherosclerosis, taking advantage of its antioxidative stress activity and targeting effects. As a proof of concept, a broad-spectrum ROS-eliminating material was synthesized by covalently conjugating a superoxide dismutase mimetic agent Tempol and a hydrogen-peroxide-eliminating compound of phenylboronic acid pinacol ester onto a cyclic polysaccharide β-cyclodextrin (abbreviated as TPCD). TPCD could be easily processed into a nanoparticle (TPCD NP). The obtained nanotherapy TPCD NP could be efficiently and rapidly internalized by macrophages and vascular smooth muscle cells (VSMCs). TPCD NPs significantly attenuated ROS-induced inflammation and cell apoptosis in macrophages, by eliminating overproduced intracellular ROS. Also, TPCD NPs effectively inhibited foam cell formation in macrophages and VSMCs by decreasing internalization of oxidized low-density lipoprotein. After intravenous (i.v.) administration, TPCD NPs accumulated in atherosclerotic lesions of apolipoprotein E-deficient (ApoE -/- ) mice by passive targeting through the dysfunctional endothelium and translocation via inflammatory cells. TPCD NPs significantly inhibited the development of atherosclerosis in ApoE -/- mice after i.v. delivery. More importantly, therapy with TPCD NPs afforded stabilized plaques with less cholesterol crystals, a smaller necrotic core, thicker fibrous cap, and lower macrophages and matrix metalloproteinase-9, compared with those treated with control drugs previously developed for antiatherosclerosis. The therapeutic benefits of TPCD NPs mainly resulted from reduced systemic and local oxidative stress and inflammation as well as decreased inflammatory cell infiltration in atherosclerotic plaques. Preliminary in vivo tests implied that TPCD NPs were safe after long-term treatment via i.v. injection. Consequently, TPCD NPs can be developed as a potential antiatherosclerotic nanotherapy.

Multiplexing, one of the main trends in biosensors, aims to detect several analytes simultaneously by integrating miniature sensors on a chip. However, precisely depositing electrode materials and selective enzymes on distinct microelectrode arrays remains an obstacle to massively produced multiplexed sensors. Here, we report on a "drop-on-demand" inkjet printing process to fabricate multiplexed biosensors based on nanostructured conductive hydrogels in which the electrode material and several kinds of enzymes were printed on the electrode arrays one by one by employing a multinozzle inkjet system. The whole inkjet printing process can be finished within three rounds of printing and only one round of alignment. For a page of sensor arrays containing 96 working electrodes, the printing process took merely ∼5 min. The multiplexed assays can detect glucose, lactate, and triglycerides in real time with good selectivity and high sensitivity, and the results in phosphate buffer solutions and calibration serum samples are comparable. The inkjet printing process exhibited advantages of high efficiency and accuracy, which opens substantial possibilities for massive fabrication of integrated multiplexed biosensors for human health monitoring.

Resveratrol and its derivatives have been shown to display beneficial effects to neurodegenerative diseases. However, the molecular mechanism of resveratrol and its derivatives on prion conformational conversion is poorly understood. In this work, the interaction mechanism between prion and resveratrol as well as its derivatives was investigated using steady-state fluorescence quenching, Thioflavin T binding assay, Western blotting, and molecular dynamics simulation. Protein fluorescence quenching method and Thioflavin T assay revealed that resveratrol and its derivatives could interact with prion and interrupt prion fibril formation. Molecular dynamics simulation results indicated that resveratrol can stabilize the PrP 127-147 peptide mainly through π-π stacking interactions between resveratrol and Tyr128. The hydrogen bonds interactions between resveratrol and the PrP 127-147 peptide could further reduce the flexibility and the propensity to aggregate. The results of this study not only can provide useful information about the interaction mechanism between resveratrol and prion, but also can provide useful clues for further design of new inhibitors inhibiting prion aggregation.

The development of highly efficient sorbent materials for CO 2 capture under ambient conditions is of great importance for reducing the impact of CO 2 on the environment and climate change. In this account, strong CO 2 adsorption on a boron antisite (B N ) in boron-rich porous boron nitrides (p-BN) was developed and studied. The results indicated that the material achieved larger adsorption energies of 2.09 eV (201.66 kJ/mol, PBE-D). The electronic structure calculations suggested that the introduction of B N in p-BN induced defect electronic states in the energy gap region, which strongly impacted the adsorption properties of the material. The bonding between the B N defect and the CO 2 molecule was clarified, and it was found that the electron donation first occurred from CO 2 to the B N double-acceptor state then, followed by electron back-donation from B N to CO 2 accompanied by the formation of a B N -C bond. The thermodynamic properties indicated that the adsorption of CO 2 on the B N defect to form anionic CO 2 δ- species was spontaneous at temperatures below 350 K. Both the large adsorption energies and the thermodynamic properties ensured that p-BN with a B N defect could effectively capture CO 2 under ambient conditions. Finally, to evaluate the energetic stability, the defect formation energies were estimated. The formation energy of the B N defects was found to strongly depend on the chemical environment, and the selection of different reactants (B or N sources) would achieve the goal of reducing the formation energy. These findings provided a useful guidance for the design and fabrication of a porous BN sorbent for CO 2 capture.

N-Halamine-based antibacterial materials play a significant role in controlling microbial contamination, but their practical applications are limited because of their complicated synthetic process and indistinct antibacterial actions. In this study, novel antibacterial N-halamine-containing polymer fibers were synthesized via an one-step electrospinning of N-halamine-containing polymers without any additives. By adjusting the concentration of precursor and the molecular weight of polymers, the morphology and size of the as-spun N-halamine-containing fibers can be regulated. The as-spun fibers showed antibacterial activity against both Gram-positive and Gram-negative bacteria. After an antibacterial assessment using different biochemical techniques, a combined mechanism of contact/release co-determined killing action was evidenced for the as-spun N-halamine-containing fibers. With the aid of contact action and/or release action, this combined mechanism can allow N-halamines to attack bacteria, making the as-spun fibers wide in the application of antibacterial fields, whatever it is in dry or wet environment. Also, a recycle antibacterial test demonstrated that the as-spun fibers can still offer antibacterial property after five recycle experiments.

A series of potent indol-3-yl-tetramethylcyclopropyl ketones have been prepared as CB 2 cannabinoid receptor ligands. Two unsubstituted indoles ( 5, 32) were the starting points for an investigation of the effect of indole ring substitutions on CB 2 and CB 1 binding affinities and activity in a CB 2 in vitro functional assay. Indole ring substitutions had varying effects on CB 2 and CB 1 binding, but were generally detrimental to agonist activity. Substitution on the indole ring did lead to improved CB 2/CB 1 binding selectivity in some cases (i.e., 7- 9, 15- 20). All indoles with the morpholino-ethyl side chain ( 32- 43) exhibited weaker binding affinity and less agonist activity relative to that of their tetrahydropyranyl-methyl analogs ( 5- 31). Several agonists were active in the complete Freund's adjuvant model of chronic inflammatory thermal hyperalgesia ( 32, 15).