Design, synthesis, and antifungal activity of carboxamide derivatives possessing 1,2,3-triazole as potential succinate dehydrogenase inhibitors.

Succinate dehydrogenase (SDH) is demonstrably one of the most important molecular targets in development of new fungicide. In our continuous efforts to discover novel SDH inhibitors, forty-two carboxamide derivatives containing 1,2,3-triazole ring were designed and synthesized, which were precisely characterized by 1H NMR, ESI-MS, elemental analysis and X-ray single-crystal diffraction. The compounds were screened for antifungal activities against phytopathogenic fungi by mycelia growth inhibition assay in vitro. Compound A3-3 exhibited significant antifungal activity against Sclerotinia sclerotiorum, Botrytis cinerea, Rhizoctonia cerealis and Gaeumannomyces graminsis with EC50 values of 1.08, 8.75, 1.67 and 5.30 µg/mL, respectively, comparable to those of commercial SDHI boscalid. In vivo testing demonstrated that A3-3 was effective for suppressing rape sclerotinia rot, cucumber grey mould and wheat powdery mildew caused by S. sclerotiorum， B. cinerea and Blumeria graminis at a dosage of 200 µg/mL. Inhibition activities against SDH test proved the designed analogues were effective in the enzyme level. The molecular docking simulation revealed that A3-3 interacted with ARG43，TYR58 and TRP173 of the SDH through hydrogen bond and pi-pi interaction, which could explain the probable mechanism of action between the inhibitor and target protein.

The Simplified Analytical Algorithm to the Time Effect of the Simple-Supported Steel and Concrete Composite Beam.

Based on Rusch's creep constitutive relation, differential equations for the redistribution of shrinkage internal force and creep of the composite beam are derived and solved. The closed solution is cumbersome and is inconvenient to be applied practically. It is hard to solve the accurate solution for coupled differential equations. Therefore, a simplified approach is given. However, it ignores the influence of the redistribution of bending moment of the concrete slab on the axial strain and removes the coupling relationship of differential equations so that it makes the solution become convenient. The comparison of the results calculated by the two approaches shows that their calculated errors are small, within 3%, when the stiffness ratio of the concrete slab and the steel beam are less than 0.185. It also shows that the greater the stiffness of the steel beam, the greater the constraint on the creep of the concrete slab, so is the redistribution of internal force.