Publications by authors named "Junbao Ma"

Background: The dynamic interplay between esterase activity and physicochemical microenvironments-such as polarity and viscosity-is critical for decoding early cellular dysfunction in processes like apoptosis, ferroptosis, and drug-induced toxicity. However, conventional probes typically report only a single parameter, obscuring interdependent changes in enzyme activity and membrane properties. This technological gap limits our ability to capture real-time, spatially resolved fluctuations within subcellular compartments.

View Article and Find Full Text PDF

Metal-organic frameworks (MOFs) have been widely used for separation, but amplifying subtle differences between similar molecules to achieve effective separation remains a great challenge. In this study, we utilize the fluorescent molecule uranine (Ura) to modulate the pores of zeolitic-imidazolate framework 8 (ZIF8), creating an unusual throttle effect. By monitoring fluorescence intensity changes in Ura, the transport diffusion process could be quantified to reveal the diffusion constant of solvents.

View Article and Find Full Text PDF
Article Synopsis
  • Fluorescence lifetime imaging is advancing biomedical research by improving multiplexing imaging through the use of probes that have unique excited state lifetimes while sharing spectral channels.
  • The study focuses on boron dipyrromethene (BODIPY) to develop methods for regulating its fluorescence lifetime using structural substitutions, with specific attention to the electronegativity at certain positions.
  • Findings suggest that by manipulating electronegativity of substituents, researchers can create diverse BODIPY probes for complex imaging applications, paving the way for broader controls over fluorescence lifetimes in different fluorescent molecules.
View Article and Find Full Text PDF

The microenvironment is indispensable for functionality of various biomacromolecules, subcellular compartments, living cells, and organisms. In particular, physical properties within the biological microenvironment could exert profound effects on both the cellular physiology and pathology, with parameters including the polarity, viscosity, pH, and other relevant factors. There is a significant demand to directly visualize and quantitatively measure the fluctuation in the cellular microenvironment with spatiotemporal resolution.

View Article and Find Full Text PDF

Direct asymmetric functionalization of the pyridyl C-H bond represents a longstanding challenge in organic chemistry. We herein describe the first enantioselective -C-H activation of pyridines through the use of a Ni-Al bimetallic catalyst system and N-heterocyclic carbene (NHC) ligand for intermolecular hydroarylation of styrenes. The reaction procceds in high to excellent enantioselectivities (up to 98.

View Article and Find Full Text PDF

Annulated pyridines are ubiquitous scaffolds in many bioactive molecules. A highly regio- and enantioselective Ni(0)-catalyzed endo-selective C-H cyclization of pyridines with alkenes has been developed. An unprecedented enantioselective C-H activation at pyridyl 3- or 4-positions was enabled by bulky chiral N-heterocyclic carbene ligands.

View Article and Find Full Text PDF

A novel pH-dependent two-photon fluorescent molecular probe ABMP has been prepared based on the fluorophore of 2, 4, 6-trisubstituted pyridine. The probe has an absorption wavelength at 354 nm and corresponding emission wavelength at 475 nm with the working pH range from 2.20 to 7.

View Article and Find Full Text PDF