Two asymmetrical molecules with substituted acetylene as central rigid elongated conjugation are reported as potential chromophores for two-photon microscopic imaging. These molecules consist of a typical D-pi-A structure, have different donors (D), the same pi-conjugated center (pi) and the same acceptor (A). Structural characterization and spectroscopic properties, including single-photon (linear) absorption, quantum yields, single-photon fluorescence, and two-photon absorption spectra, were studied in solvents with different polarity. These acetylene-substituted molecules were found to have high two-photon absorption cross-sections (for example, 690 GM for molecule 1 in toluene), which were determined by a two-photon induced fluorescence method using a femtosecond Ti: sapphire laser as excitation source. Single- and two-photon cellular imaging experiments demonstrate that the substituted acetylene derivatives could be one kind of promising two-photon fluorescence probes for cellular imaging.
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http://dx.doi.org/10.1007/s10895-007-0219-8 | DOI Listing |
Curr Biol
January 2025
Peking University Institute of Advanced Agricultural Sciences, Shandong Laboratory of Advanced Agricultural Sciences in Weifang, Weifang 261000, Shandong, China. Electronic address:
As one of the most influential environmental factors, light fundamentally shapes plant physiology and growth traits. The hypocotyl is critical for the morphological establishment of the seedling, and its length displays remarkable plasticity upon perception of changes in the light conditions. Although remodeling of the primary cell walls is well-documented to play an important role in hypocotyl growth, how the hypocotyl elongation rate is swiftly repressed at the dark-to-light transition remains elusive.
View Article and Find Full Text PDFInt J Biol Macromol
January 2025
Department of Chemistry, Mississippi State University, Mississippi State, MS 39762, USA.
The inherent heterogeneity, poor compatibility with polymers, and dark color of lignin limit its application in composites. In this study, original lignin (OL) was fractionated sequentially using four green organic solvents to obtain lignin fractions with different chemical structures. These well-defined lignin fractions were then blended with polybutylene succinate (PBS) to fabricate biocomposites.
View Article and Find Full Text PDFMacromol Rapid Commun
January 2025
Department of Materials Science and Engineering, National University of Singapore (NUS), 9 Engineering Drive 1, Singapore, 117575, Singapore.
The modification of thermoplastic polymers is frequently impeded by the inherent contradiction between their toughness and strength. In this study, an effective strategy to significantly improve the mechanical properties of ductile polymers by simply adding a complimentary rigid polymer is introduced. This work uses a semi-crystalline polymer aliphatic polyketone (POK) as the matrix material and a small quantity of polymethyl methacrylate (PMMA) as the rigid polymer, through establishing molecular chain entanglements at the interface to produce POK/PMMA blends with exceptional mechanical property.
View Article and Find Full Text PDFFood Chem X
January 2025
Key Laboratory of Ministry of Agriculture for Germplasm Resources Conservation and Utilization of Cassava, Tropical Crops Genetic Resources Institute, Chinese Academy of Tropical Agricultural Sciences, Haikou, China.
This study aimed to prepare a composite film by blending cross-linked tapioca starch (CLTS) with sodium alginate (SA), silver nanoparticles (AgNPs), and ZnO nanoparticles (ZnOs). The effects of SA, AgNPs, and ZnOs at different concentrations (1-3 wt%) on the mechanical properties, optical properties, thermal stability, and antibacterial activity of cross-linked starch films were also investigated. The structures of the films were examined by Fourier transform infrared spectroscopy and X-ray diffraction.
View Article and Find Full Text PDFBiophys J
January 2025
Department of Physics, Northeastern University, Boston, MA, 02115, USA. Electronic address:
Binuclear ruthenium complexes have been investigated for potential DNA-targeted therapeutic and diagnostic applications. Studies of DNA threading intercalation, in which DNA base pairs must be broken for intercalation, have revealed means of optimizing a model binuclear ruthenium complex to obtain reversible DNA-ligand assemblies with the desired properties of high affinity and slow kinetics. Here, we used single-molecule force spectroscopy to study a binuclear ruthenium complex with a longer semi-rigid linker relative to the model complex.
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