Braunmcguire6801
The recent advancements in interfacial evaporation of salty water using renewable solar energy provide one of the promising pathways to solve worldwide water scarcity. Pursuing a stable evaporation rate of water has been the central focus of this field, as it is directly related to the throughput, while salt deposition on the evaporator becomes a critical issue. Although Janus-structured evaporators with an upper hydrophobic layer and a bottom hydrophilic layer have been demonstrated as an effective way to suppress the salt precipitation, the hydrophobic upper layer, achieved usually by some special organic groups, suffers from a photochemical oxidation when exposed to oxidative chemicals in water and high-energy light, resulting in a deteriorated surface hydrophobicity. Here, we report our design of an efficient salt-rejecting Janus evaporator by taking advantage of the self-recovering surface hydrophobicity of poly(dimethylsiloxane) (PDMS) against photochemical damages, which ensures a long-term surface hydrophobicity. With its upper layer partially covered with PDMS, the Janus evaporator demonstrates an excellent salt rejection capability and exhibits a stable evaporation rate of 1.38 kg·m-2·h-1 under 1 sun illumination for 400 min of continuous operation, or 90 d of intermittent work. By combining the advantages of high structural integration, long-term salt-rejection, and efficient evaporation, our Janus evaporator holds great promise for the stable production of clean water from seawater.We demonstrate here that the α subunit C-terminal domain of Escherichia coli RNA polymerase (αCTD) recognizes the upstream promoter (UP) DNA element via its characteristic minor groove shape and electrostatic potential. In two compositionally distinct crystallized assemblies, a pair of αCTD subunits bind in tandem to the UP element consensus A-tract that is 6 bp in length (A6-tract), each with their arginine 265 guanidinium group inserted into the minor groove. The A6-tract minor groove is significantly narrowed in these crystal structures, as well as in computationally predicted structures of free and bound DNA duplexes derived by Monte Carlo and molecular dynamics simulations, respectively. The negative electrostatic potential of free A6-tract DNA is substantially enhanced compared to that of generic DNA. Shortening the A-tract by 1 bp is shown to "knock out" binding of the second αCTD through widening of the minor groove. Furthermore, in computationally derived structures with arginine 265 mutated to alanine in either αCTD, either with or without the "knockout" DNA mutation, contact with the DNA is perturbed, highlighting the importance of arginine 265 in achieving αCTD-DNA binding. These results demonstrate that the importance of the DNA shape in sequence-dependent recognition of DNA by RNA polymerase is comparable to that of certain transcription factors.Microbial electrochemical catalysis based on respiratory reactions coupled with extracellular electron transport (EET), which is critical for bioenergy applications, strongly depends on the biocompatibility of the electrode material. However, the comparison of materials for such physiological responses has been difficult because of the lack of a quantitative assay for characterizing cellular metabolism at the electrode surface. Here, we developed a single-cell analysis method specific for the cells attached to the electrode to quantify active metabolic pathway heterogeneity as an index of physiological cell/electrode interaction, which generally increases with metabolic robustness in the microbial population. Nanoscale secondary ion mass spectrometry followed by microbial current production with model EET-capable bacteria, Shewanella oneidensis MR-1 and its mutant strains lacking carbon assimilation pathways, showed that different active metabolic pathways resulted in nearly identical 13C/15N assimilation ratios for individual cells in the presence of isotopically labeled nutrients, demonstrating a correlation between the 13C/15N ratio and the active metabolic pathway. Compared to the nonelectrode conditions, the heterogeneity of the assimilated 13C/15N ratio was highly enhanced on the electrode surface, suggesting that the metabolic robustness of the microbial population increased through the electrochemical interaction with the electrode. Fetuin compound library chemical The present methodology enables us to quantitatively compare and screen electrode materials that increase the robustness of microbial electrocatalysis.Photocatalytic water splitting to produce hydrogen is a potential means of achieving scalable and economically feasible solar hydrogen production. Two-dimensional (2D) triphosphides are 2D materials with potential applications in photovoltaics and optoelectronics. Here, we theoretically investigated 56 systems in total, including seven monolayer XP3 (X = Al, Ga, Ge, As, In, Sn, and Sb) and their combined vertical and lateral heterostructures. We found that the lateral heterostructure AlP3-GaP3 should be a promising photocatalyst for water splitting, through a quadruple screening process combining free energy calculations. It is fascinating that AlP3-GaP3 ingeniously combines all the desired features for photocatalytic water-splitting reactions, including a nearly direct band gap (1.43 eV), perfect band edge position, high STH efficiency (16.89%), broad light absorption region of sunlight, ultrahigh carrier mobility (20,000 cm2 V-1 s-1), low exciton binding energy (0.33 eV), and excellent stability in a water environment. Moreover, through Gibbs free energy calculations, the active sites and possible reaction pathways of the overall water-splitting reaction by AlP3-GaP3 were also confirmed. Our work offers a strategy for the design and fabrication of novel lateral heterostructures for a high-performance photocatalyst in water-splitting reactions.Glass nanopipettes are widely used for various applications in nanosciences. In most of the applications, it is important to characterize their geometrical parameters, such as the aperture size and the inner cone angle at the tip region. For nanopipettes with sub-10 nm aperture and thin wall thickness, transmission electron microscopy (TEM) must be most instrumental in their precise geometrical measurement. However, this measurement has remained a challenge because heat generated by electron beam irradiation would largely deform sub-10 nm nanopipettes. Here, we provide methods for preparing TEM specimens that do not cause deformation of such tiny nanopipettes.