Hong Kong Baptist University

About: Hong Kong Baptist University is a education organization based out in Hong Kong, China. It is known for research contribution in the topics: China & Population. The organization has 7811 authors who have published 18919 publications receiving 555274 citations. The organization is also known as: Hong Kong Baptist College & HKBU.

Solving Constrained Total-variation Image Restoration and Reconstruction Problems via Alternating Direction Methods

Abstract: In this paper, we study alternating direction methods for solving constrained total-variation image restoration and reconstruction problems. Alternating direction methods can be implementable variants of the classical augmented Lagrangian method for optimization problems with separable structures and linear constraints. The proposed framework allows us to solve problems of image restoration, impulse noise removal, inpainting, and image cartoon+texture decomposition. As the constrained model is employed, we need only to input the noise level, and the estimation of the regularization parameter is not required in these imaging problems. Experimental results for such imaging problems are presented to illustrate the effectiveness of the proposed method. We show that the alternating direction method is very efficient for solving image restoration and reconstruction problems.

Design of bis-spiropyran ligands as dipolar molecule receptors and application to in vivo glutathione fluorescent probes

Abstract: Despite considerable efforts toward the development of various sophisticated spiropyrans for metal ion sensing, less attention has been paid to organic molecule sensing One of the major difficulties for detection of organic molecules using a spiropyran is the weak and nonspecific interaction between the spiropyran and the target Here, we report the synthesis and molecular recognition characterization of two bis-spiropyrans for dipolar molecules and their application to in vivo glutathione (GSH) fluorescent probes Unlike the mono-spiropyrans, the newly designed bis-spiropyran molecules feature a rigidly maintained molecular cleft and two spiropyran units as binding modules The molecular recognition is based on multipoint electrostatic interactions and structure complementarity between the opened merocyanine form of the spiropyran and the analyte It was observed that the spiropyran 1a binds GSH in aqueous solution with high affinity (K = (752 +/- 183) x 10(4) M(-1)) and shows strong fluorescence emission upon binding Remarkably, fluorescence output of 1a is not significantly affected by other amino acids and peptides, especially, structurally similar compounds, such as cysteine and homocysteine Furthermore, fluorescence anisotropy and confocal fluorescent microscopy confirmed that spiropyran 1a is a comparatively good candidate for intracellular delivery and can be accumulated intensively into cells Thus, 1a can be utilized in vivo as a GSH probe or as a marker to show the level of intracellular GSH