Evoking Photothermy by Capturing Intramolecular Bond Stretching Vibration-Induced Dark-State Energy.

Development of highly effective approaches to desirable photothermal conversion agents is particularly valuable. Herein, we report a concept, namely, bond stretching vibration-induced photothermy, that serves as a mechanism to construct advanced photothermal conversion agents. As a proof-of-concept, two compounds (DCP-TPA and DCP-PTPA) with donor-acceptor (D-A) structures were synthesized. The bond stretching vibration of the pyrazine-containing unit in these molecules is vigorous and insensitive to the external environmental restraint, which efficiently transforms the absorbed photons to dark-state heat energy. The nanoparticles (NPs) of DCP-TPA and DCP-PTPA show rather high photothermal conversion efficiency (52% and 59%) and stronger photoacoustic (PA) signal than commercial methylene blue and reported high-performance semiconducting polymer nanoparticles. The DCP-PTPA NPs perform better than DCP-TPA NPs in terms of photothermal conversion, PA signal production, and in vivo PA tumor imaging because of the increased bond stretching vibration in the former molecule.

Exploration of biocompatible AIEgens from natural resources.

Luminogens with aggregation-induced emission (AIEgens) characteristics have been well developed and applied in various areas such as bio-imaging, theranostics, organic photoelectronics and chemo/bio sensors. However, most of the reported AIEgens suffer from the disadvantages of complex organic synthesis and high cost, as well as being environmentally unfriendly and hard to degrade, which have largely limited their real applications. In this work, we discovered berberine chloride, a natural isoquinoline alkaloid isolated from Chinese herbal plants, as an unconventional rotor-free AIEgen with bright solid-state emission and water-soluble characteristics. Single crystal structure analysis and optical property, viscosity, and host-guest interaction studies suggested that intramolecular vibration and twisted intramolecular charge transfer were responsible for the AIE phenomenon of berberine chloride. Moreover, berberine chloride was biocompatible and could specifically target lipid droplets in a fluorescence turn-on and wash-free manner, demonstrating the great potential of natural products as promising AIE probes.

[Bletilla striata pseudobulb rot pathogen identification and its biological characteristic].

OBJECTIVE: To identify the pathogen of Bletilla striata pseudobulb rot and provide foundation for formulation effective control measures. METHODS: Surveyed the pathogenesis regularity and disease symptom of Bletilla striata pseudobulb rot,and conducted the pathogen separation, identification,vaccination and research on its biological characteristics. RESULTS: The conditions for mycelium growth were as follows: the temperature ranged from 5 to 35 degrees C, and the optimum temperature ranged from 25 to 30 degrees C. The pH ranged from 3 to 10,and the optimum pH ranged from 6 to 7. The germination rate of conidia was high when the relative humidity was 100%. The lethal temperature was 55 degrees C for 10 min. Illumination had little influence on the germ growth and development. CONCLUSION: The results showed that the pathogen was Fusarium oxysporum.