14 research outputs found
Visualizing Graphene Based Sheets by Fluorescence Quenching Microscopy
Graphene based sheets have stimulated great interest due to their superior
mechanical, electrical and thermal properties. A general visualization method
that allows quick observation of these single atomic layers would be highly
desirable as it can greatly facilitate sample evaluation and manipulation, and
provide immediate feedback to improve synthesis and processing strategies. Here
we report that graphene based sheets can be made highly visible under a
fluorescence microscope by quenching the emission from a dye coating, which can
be conveniently removed afterwards by rinsing without disrupting the sheets.
Current imaging techniques for graphene based sheets rely on the use of special
substrates. In contrast, the fluorescence quenching mechanism is no longer
limited by the types of substrates. Graphene, reduced graphene oxide, or even
graphene oxide sheets deposited on arbitrary substrates can now be readily
visualized by eye with good contrast for layer counting. Direct observation of
suspended sheets in solution was also demonstrated. The fluorescence quenching
microscopy offers unprecedented imaging flexibility and could become a general
tool for characterizing graphene based materials.Comment: J. Am. Chem. Soc., Article ASA
Effects of fermented rapeseed meal on antioxidant functions, serum biochemical parameters and intestinal morphology in broilers
Impact of prosthesis–patient mismatch on short-term outcomes after aortic valve replacement: a retrospective analysis in East China
Proteomic analysis of β-1,3-glucanase in grape berry tissues
Grape berries are considered recalcitrant
materials in proteomic analysis, because berry tissues
contain large amounts of secondary metabolites, especially
phenolic compounds, which severely interfere with protein
extraction and electrophoresis separation. We report hereby
a PVPP/TCA-based protein extraction protocol for grape
berries. Phenolic compounds in berry extracts were
removed with repeated PVPP cleanups, and proteins were
recovered with TCA precipitation. Protein resolution in
2-D gels was gradually improved with the increase of
PVPP cleanup steps. By the protocol, about 760 protein
spots of berry tissues were clearly resolved in 2-D gels with
CBB staining. This protocol was also used to analyze
b-1,3-glucanase (EC 3.2.1.39) in berry tissues. An antisynthetic
peptide antibody was prepared against 15 amino
acid sequence residing on the surface of b-1,3-glucanase
molecule. It detected two major spots in 2-D blots of berry
extracts. The spots were identified by MALDI-TOF analysis
as b-1,3-glucanase. The present study validates that
b-1,3-glucanase is present in higher abundance in berry
skins than in pulps, and in red berries than in white berries.
Therefore, b-1,3-glucanase displays a tissue-specific
expression. The preferential accumulation of b-1,3-glucanase
in skins may be relevant to berry ripening