Ceramic aerogels are attractive for thermal insulation but plagued by poor mechanical stability and degradation under thermal shock. In this study, we designed and synthesized hyperbolic architectured ceramic aerogels with nanolayered double-pane walls with a negative Poisson’s ratio (−0.25) and a negative linear thermal expansion coefficient (−1.8 × 10−6 per °C). Our aerogels display robust mechanical and thermal stability and feature ultralow densities down to ~0.1 milligram per cubic centimeter, superelasticity up to 95%, and near-zero strength loss after sharp thermal shocks (275°C per second) or intense thermal stress at 1400°C, as well as ultralow thermal conductivity in vacuum [~2.4 milliwatts per meter-kelvin (mW/m·K)] and in air (~20 mW/m·K). This robust material system is ideal for thermal superinsulation under extreme conditions, such as those encountered by spacecraft.
The emergence and ongoing spread of multidrug-resistant bacteria puts humans and other species at risk for potentially lethal infections. Thus, novel antibiotics or alternative approaches are needed to target drug-resistant bacteria, and metabolic modulation has been documented to improve antibiotic efficacy, but the relevant metabolic mechanisms require more studies. Here, we show that glutamate potentiates aminoglycoside antibiotics, resulting in improved elimination of antibiotic-resistant pathogens. When exploring the metabolic flux of glutamate, it was found that the enzymes that link the phosphoenolpyruvate (PEP)-pyruvate-AcCoA pathway to the TCA cycle were key players in this increased efficacy. Together, the PEP-pyruvate-AcCoA pathway and TCA cycle can be considered the pyruvate cycle (P cycle). Our results show that inhibition or gene depletion of the enzymes in the P cycle shut down the TCA cycle even in the presence of excess carbon sources, and that the P cycle operates routinely as a general mechanism for energy production and regulation in and These findings address metabolic mechanisms of metabolite-induced potentiation and fundamental questions about bacterial biochemistry and energy metabolism.
In this work, it is demonstrated that random copolymerization is a simple but effective strategy to obtain new conductive copolymers as high‐performance thermoelectric materials. By using a polymerizing acceptor unit diketopyrropyrrole with donor units thienothiophene and oligo ethylene glycol substituted bithiophene (g32T), it is found that strong interchain donor–acceptor interactions ensure good film crystallinity for charge transport, while donor–donor type building blocks contribute to effective charge transfers. Hall effect measurements show that the high electrical conductivity results from increased free carriers with simultaneously improved mobility reaching over 1 cm2 V−1 s−1. The synergistic effect of improved molecular doping and carrier mobility, as well as a high Seebeck coefficient ascribed to the structural disorder along polymer chains via random copolymerization, results in an impressive power factor up to 110 µW K−2 m−1 which is 10 times higher than that of solution‐processed polythiophenes.
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