Using a convergent synthetic strategy, the synthesis of the previously elusive CVsymmetrical calix-[4]naphthalene from 1-naphthol is described. Using other independent convergent routes, syntheses of the other three isomeric calix[4]naphthalenes originally formed from the direct base-catalyzed condensation of formaldehyde with 1-naphthol are also described. All of these methods involved either a TiCl4or TFA-assisted coupling reaction to achieve the cyclization steps. A mechanism is proposed to account for the formation of the original three isomeric calix[4]naphthalenes from the base-catalyzed condensation of formaldehyde with 1-naphthol.

BackgroundThe proteome reflects the available cellular machinery to deal with nutrients and environmental challenges. The most common E. coli strain BL21 growing in different, commonly employed media was evaluated using a detailed quantitative proteome analysis.ResultsThe presence of preformed biomass precursor molecules in rich media such as Luria Bertani supported rapid growth concomitant to acetate formation and apparently unbalanced abundances of central metabolic pathway enzymes, e.g. high levels of lower glycolytic pathway enzymes as well as pyruvate dehydrogenase, and low levels of TCA cycle and high levels of the acetate forming enzymes Pta and AckA. The proteome of cells growing exponentially in glucose-supplemented mineral salt medium was dominated by enzymes of amino acid synthesis pathways, contained more balanced abundances of central metabolic pathway enzymes, and a lower portion of ribosomal and other translational proteins. Entry into stationary phase led to a reconstruction of the bacterial proteome by increasing e.g. the portion of proteins required for scavenging rare nutrients and general cell protection. This proteomic reconstruction during entry into stationary phase was more noticeable in cells growing in rich medium as they have a greater reservoir of recyclable proteins from the translational machinery.ConclusionsThe proteomic comparison of cells growing exponentially in different media reflected the antagonistic and competitive regulation of central metabolic pathways through the global transcriptional regulators Cra, Crp, and ArcA. For example, the proteome of cells growing exponentially in rich medium was consistent with a dominating role of phosphorylated ArcA most likely a result from limitations in reoxidizing reduced quinones in the respiratory chain under these growth conditions. The proteomic alterations of exponentially growing cells into stationary phase cells were consistent with stringent-like and stationary phase responses and a dominating control through DksA-ppGpp and RpoS.

The lower energy density and safety issues of liquid sodium-ion batteries have been unable to satisfy the ever-increasing demands for large-scale energy storage system. As a low-cost alternative, solid-state sodium metal batteries (SSMBs) have shown great competitive advantages and extensive application prospects due to their high energy density and desirable safety. However, the solid-state electrolytes (SSEs) often possess low ionic conductivity, and the poor interface compatibility and inferior stability between SSEs and electrodes can result in the continuous deterioration of the electrochemical performance. This review summarizes the recent progresses of sodium-based SSEs, including the sodium ion transport mechanisms of different types of SSEs, some emerging materials in different dimensions, and interface engineering. Furthermore, the critical challenges and new perspectives are emphasized in detail. This review provides deeper insights to construct more comprehensive and effective SSEs for next-generation high-performance SSMBs.

Protein production under the control of lac operon regulatory elements using autoinduction is based on diauxic growth of Escherichia coli on lactose after consumption of more preferred carbon substrates. A novel simple and cost-effective defined autoinduction medium using a mixture of glucose, glycerol, and lactose as carbon substrate and NH(4)(+) as sole nitrogen source without any supplementation of amino acids and vitamins was developed for T7-based E. coli expression systems. This medium was successfully employed in 96-well microtiter plates, test tubes, shake flasks, and 15-L bioreactor cultivations for production of different types of proteins achieving an average yield of 500 mg L(-1) product. Cell-specific protein concentrations and solubility were similar as during conventional isopropyl β-D-1-thiogalactopyranoside induction using Luria-Bertani broth. However, the final yield of target proteins was about four times higher, as a higher final biomass was achieved using this novel defined autoinduction broth.