In this paper the loading role of industrial structure in optimization of configuration of Lanzhou was pointed out based on the analysis of the exterior space shape evolution and internal spatial structure reorganization in this city,and the relation between the adjustment of urban industrial structure and the urban spatial restructure was tried to identify.
Chinese salt-lake brine is mainly of the magnesium sulfate subtype with a high Mg/Li ratio. To extract high purity lithium chloride from Chinese brine has been a decade-long challenge. This review summarizes the state-of-the-art of lithium extraction from Chinese salt-lake brine.
Microbial ferulic acid decarboxylase (FADase) catalyzes the transformation of ferulic acid to 4-hydroxy-3-methoxystyrene (4-vinylguaiacol) via non-oxidative decarboxylation. Here we report the crystal structures of the Enterobacter sp. Px6-4 FADase and the enzyme in complex with substrate analogues. Our analyses revealed that FADase possessed a half-opened bottom β-barrel with the catalytic pocket located between the middle of the core β-barrel and the helical bottom. Its structure shared a high degree of similarity with members of the phenolic acid decarboxylase (PAD) superfamily. Structural analysis revealed that FADase catalyzed reactions by an "open-closed" mechanism involving a pocket of 8×8×15 Å dimension on the surface of the enzyme. The active pocket could directly contact the solvent and allow the substrate to enter when induced by substrate analogues. Site-directed mutagenesis showed that the E134A mutation decreased the enzyme activity by more than 60%, and Y21A and Y27A mutations abolished the enzyme activity completely. The combined structural and mutagenesis results suggest that during decarboxylation of ferulic acid by FADase, Trp25 and Tyr27 are required for the entering and proper orientation of the substrate while Glu134 and Asn23 participate in proton transfer.
An electron bridge in place of a ferry Respiratory complexes are massive, membrane-embedded scaffolds that position redox cofactors so as to permit electron transfer coupled to the movement of protons across a membrane. Gong et al. used cryo–electron microscopy to determine a structure of a stable assembly of mycobacterial complex III–IV, in which a complex III dimer is sandwiched between two complex IV monomers. A potential direct electron transfer path stretches from the quinone oxidizing centers in complex III to the oxygen reduction centers in complex IV. A loosely associated superoxide dismutase may play a role in detoxifying superoxide produced from uncoupled oxygen reduction. Science , this issue p. eaat8923
The use of low-cost agricultural and forestry waste for the preparation of modified phenolic foam (MPF) has attracted widespread attention and has shown promising prospects. This study proposes a novel method for producing MPF using pine sawdust. The full components of pine wood powder and its liquefied products were used as raw materials, and the resin was modified with a silane coupling agent (KH560), triethylene glycol (TEG), and nylon 66 (PA66). Subsequently, three novel MPFs were successfully fabricated using a transplanted core foaming technique, and their material properties were subsequently investigated. The results showed that all three MPFs exhibited excellent compressive strength and flame retardancy, with compressive strength ranging from 5.93 MPa to 12.22 MPa and oxygen index values between 36.2% and 41.5%. In terms of water resistance, the MPFs significantly outperformed traditional phenolic foam (PF); in particular, the addition of 4% KH560 and PA66 reduced the water absorption rate to as low as 2.5%. Furthermore, the powdering rate and thermal conductivity of all MPFs were significantly reduced, with chalking rates decreasing by 28.57% to 50%. This research presents a novel method for preparing MPF using agroforestry waste as a partial replacement for phenol. This approach achieves high-value utilization of pine sawdust while maintaining the performance of the MPF, thus broadening the avenues for MPF production.
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