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Gradually aggravated disease caused by phytopathogenic bacteria severely restricts food security and crop yield, and few pesticides can relieve this severe situation. Thus, development and excavation of new agrochemicals with high bioactivity and novel action mechanism may be a feasible strategy to control intractable bacterial diseases. As a privileged molecular framework, steroid molecules exhibit diversiform bioactivities. Herein, a series of novel androst-4-ene derivatives were designed, synthesised and investigated for their antibacterial behaviour to excavate novel agrochemicals on the base of steroid molecules.Bioassay results indicated that target compounds displayed high bioactivities toward three destructive phytopathogenic bacteria, including Xanthomonas oryzae pv. oryzae (Xoo), Xanthomonas axonopodis pv. citri (Xac) and Pseudomonas syringae pv. actinidiae (Psa). Compound IIIGiven these profiles of target compounds, we highlight a new strategy for controlling intractable plant bacterial diseases by inducing plant resistance and targeting the bacterial cell membrane. © 2022 Society of Chemical Industry.

Plant bacterial diseases are an intractable problem due to the fact that phytopathogens have acquired strong resistances for traditional pesticides, resulting in restricting the quality and yield of agricultural products around the world. To develop new agrochemical alternatives, we prepared a novel series of sulfanilamide derivatives containing piperidine fragments and assessed their antibacterial potency. The bioassay results revealed that most molecules displayed excellent in vitro antibacterial potency towards Xanthomonas oryzae pv. oryzae (Xoo) and Xanthomonas axonopodis pv. citri (Xac). In particular, molecule C4 exhibited outstanding inhibitory activity toward Xoo with EC50 value of 2.02 µg mL−1, which was significantly better than those of the commercial agents bismerthiazol (EC50 = 42.38 µg mL−1) and thiodiazole copper (EC50 = 64.50 µg mL−1). A series of biochemical assays confirmed that compound C4 interacted with dihydropteroate synthase, and irreversibly damaged the cell membrane. In vivo assays showed that the molecule C4 presented acceptable curative and protection activities of 34.78% and 39.83%, respectively, at 200 µg mL−1, which were greater than those of thiodiazole and bismerthiazol. This study highlights the valuable insights for the excavation and development of new bactericides that can concurrently target dihydropteroate synthase and bacterial cell membranes.

Developing multipurpose agricultural chemicals is appealing in crop protection, thus eventually realizing the reduction and efficient usage of pesticides. Herein, an array of versatile pyrazole hydrazide derivatives bearing a 1,3,4-oxadiazole core were initially synthesized and biologically evaluated the antifungal, antioomycetes, and antibacterial activities. In addition, the pyrazole ring was replaced by the correlative pyrrole, thiazole, and indole scaffolds to extend the molecular diversity. The results showed that most of these hybrid compounds were empowered with multifunctional bioactivities, which are exemplified by compounds a1-a6, b1-b3, b7, b10, b13, and b18. For the antifungal activity, the minimal EC50 values could afford 0.47 (a2), 1.05 (a2), 0.65 (a1), and 1.32 μg/mL (b3) against the corresponding fungi Gibberella zeae (G. z.), Fusarium oxysporum, Botryosphaeria dothidea, and Rhizoctonia solani. In vivo pot experiments against corn scab (caused by G. z.) revealed that the compound a2 was effective with protective and curative activities of 90.2 and 86.3% at 200 μg/mL, which was comparable to those of fungicides boscalid and fluopyram. Further molecular docking study and enzymatic activity analysis (IC50 = 3.21 μM, a2) indicated that target compounds were promising succinate dehydrogenase inhibitors. Additionally, compounds b2 and a4 yielded superior anti-oomycete and antibacterial activities toward Phytophora infestins and Xanthomonas oryzae pv. oryzae with EC50 values of 2.92 and 8.43 μg/mL, respectively. In vivo trials against rice bacterial blight provided the control efficiency within 51.2-55.3% (a4) at 200 μg/mL, which were better than that of bismerthiazol. Given their multipurpose characteristics, these structures should be positively explored as agricultural chemicals.

Characteristics of ZrO2 polycrystalline ceramic foam catalyst including crystal structure, phase composition, and microstructure were analyzed by Py-IR, XRD, SEM, and BET. Effects of preparation conditions such as calcination temperature, calcination time, ZrO2 (catalyst matrix), Al2O3 (flux), TiO2 (stabilizer), NaHCO3 (low-temperature pore-forming agents), and NaCl (high-temperature pore-forming agents) on catalytic activity were investigated. The optimum composition of ZrO2 polycrystalline ceramic foam catalyst were optimized using response surface methodology (RSM) to be 88.47% ZrO2, 9.62% Al2O3, 3.31% TiO2, 10% NaHCO3, and 25% NaCl (compared with the standard number 100). After calcination at 1550°C for 120 min, fatty acid methyl ester conversion rates were substantially maintained at around 97.31%, The FAME content in the product oil exceeded 97% after five successive reuses of the catalyst. In addition, catalytic activity did not significantly fluctuate. The proposed catalyst presents a new type of ...

Study on the thermoelectric effect of electric on vehicle performance problems. Local fuzzy logic control strategy based on, the application of ADVISOR simulation software, The established vehicle model of the hybrid system simulation, the simulation results show that, better improve the vehicle fuel economy and emissions, make the motor work in high load area, high efficiency with low emissions. At the same time system engine, motor, transmission system and battery efficiency can be better maintained.

This paper takes the project oriented small and medium-sized enterprises as the research object and analyses the importance and necessity, summarizes the connotation of project oriented small and medium-sized enterprises, the stability of dynamic alliances, the performance of small and medium-sized enterprises and the risk management of small and medium-sized enterprises from the theoretical level. This is a basis for further study of construction problem of small and medium-sized enterprises dynamic.