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Houmann Kearney posted an update 1 day, 5 hours ago
While numerous oxygen electrocatalysts have been reported to enhance zinc-air battery (ZAB) performance, highly efficient electrocatalysts for the oxygen electrocatalysis need to be developed for broader commercialization of ZABs. Furthermore, areal (instead of volumetric) power density has been used to benchmark the performance of ZABs, often causing ambiguities or confusions. Here, we propose a methodology for evaluating the performance of a ZAB using the volumetric (rather than the areal) power density by taking into consideration the air electrode thickness. A nitrogen and sulfur co-doped metal-free oxygen reduction electrocatalyst (N-S-PC) is used as a model catalyst for this new metric. The electrocatalyst exhibited a half-wave potential of 0.88 V, which is similar to that of the Pt/C electrocatalyst (0.89 V) due to the effects of co-doping and a highly mesoporous structure. In addition, the use of volumetric activity allows fair comparison among different types of air electrodes. The N-S-PC-loaded air electrode demonstrated a higher peak power density (5 W cm-3) than the carbon felt or paper electrode in the ZAB test under the same testing conditions.Where the basic units of molecular chemistry are the bonds within molecules, supramolecular chemistry is based on the interactions that occur between molecules. Understanding the “how” and “why” of the processes that govern molecular self-assembly remains an open challenge to the supramolecular community. While many interactions are readily examined in silico through electronic structure calculations, such insights may not be directly applicable to experimentalists. The practical limitations of computationally accounting for solvation is perhaps the largest bottleneck in this regard, with implicit solvation models failing to comprehensively account for the specific nature of solvent effects and explicit models incurring a prohibitively high computational cost. Since molecular recognition processes usually occur in solution, insight into the nature and effect of solvation is imperative not only for understanding these phenomena but also for the rational design of systems that exploit them.Molecular balances ances for association. Moreover, the use of simple model systems facilitates the interrogation and further dissection of the physicochemical origins of molecular recognition. This tandem experimental/computational approach has married less common computational techniques, like symmetry adapted perturbation theory (SAPT) and natural bonding orbital (NBO) analysis, with experimental observations to elucidate the influence of effects that are difficult to resolve experimentally (e.g., London dispersion and electron delocalization).The interactions between auxochromic groups in π-conjugated functional molecules dictate their electronic properties. From the standpoint of potential applications, understanding and control of such interactions is a vital requirement for the material design. In this communication, we describe the design, synthesis, and functional properties of a novel class of helically chiral diimide molecules, namely, [n]HDI-OMe (n = 5, 6, and 7), in which two imide units are connected via an [n]helicene skeleton. The experimental results supported by quantum chemical calculations reveal that the helical backbone in these molecules offers not only through-bond but also through-space conjugation between imide groups, which leads to distinct optical and electrochemical properties when compared to the related [n]helicenes and rylene diimides.Destructive effects of surface lithium residues introduced in synthesis and degradation of the microstructure and electrode/electrolyte interface during cycling of Ni-rich cathode materials are the major problems hindering their wide application. Herein, we demonstrate an exquisite surface modification strategy that can utilize lithium residues on the surface of LiNi0.8Co0.15Al0.05O2 to form a uniform coating layer of lithium boron oxide on the surface of the material. The resulting lithium boron oxide layer can not only efficiently serve as a protective layer to alleviate the side reactions at the electrode/electrolyte interface but also tightly interlink the primary grains of the LiNi0.8Co0.15Al0.05O2 material to prevent the material from degradation of the microstructure. As a result, the optimized lithium boron oxide-coated LiNi0.8Co0.15Al0.05O2 material exhibits a high initial discharge capacity of 202.1 mAh g-1 at 0.1 C with a great capacity retention of 93.59% after 100 cycles at 2 C. Thus, the uniform lithium boron oxide coating endows the NCA material with excellent structural stability and long-term cycling capability.This work presents the concept of establishing interfacial charge-transfer transitions (ICTT) on ferroelectric perovskites for efficient photoelectrochemical (PEC) bioanalysis. The model system was exemplified by using representative lead titanate (PbTiO3) and an enzyme tandem consisting of the isocitrate dehydrogenase (ICDH) and p-hydroxybenzoate hydroxylase (PHBH). The enzymatic generation of protocatechuic acid (PCA) can coordinate onto the surface of the PbTiO3 and hence form the ICTT that enables direct ligand-to-metal charge transfer from the highest occupied molecular orbital (HOMO) of PCA to the conduction band (CB) of PbTiO3 under light irradiation. Due to the ferroelectric polarization induced electric field of PbTiO3 and the surface polarity of PCA modification, enhanced charge separation of the ICTT contributes to the generation of anodic photocurrent and thus underlies a unique route for detecting the enzymatic activity or its substrate. For dehydrogenase detection, this strategy has better performance than some classical methodologies in terms of high sensitivity and improved selectivity. This work not only features ICTT establishment on ferroelectric perovskites for unique bioanalysis but also provides new insights into the utilization of ferroelectric perovskites for advanced PEC bioanalysis.Current therapeutic interventions for both heart disease and heart failure are largely insufficient and associated with undesired side effects. Biomedical research has emphasized the role of sarcomeric protein function for the normal performance and energy efficiency of the heart, suggesting that directly targeting the contractile myofilaments themselves using small molecule effectors has therapeutic potential and will likely result in greater drug efficacy and selectivity. In this study, we developed a robust and highly reproducible fluorescence polarization-based high throughput screening (HTS) assay that directly targets the calcium-dependent interaction between cardiac troponin C (cTnC) and the switch region of cardiac troponin I (cTnISP), with the aim of identifying small molecule effectors of the cardiac thin filament activation pathway. We screened a commercially available small molecule library and identified several hit compounds with both inhibitory and activating effects. Selleck iCRT14 We used a range of biophysical and biochemical methods to characterize hit compounds and identified fingolimod, a sphingosin-1-phosphate receptor modulator, as a new troponin-based small molecule effector.