Rational design of a novel turn-on fluorescent probe for the detection and bioimaging of hydrazine with barbituric acid as a recognition group.

A novel turn-on fluorescent probe with barbituric acid as a unique recognition group has been rationally designed and synthesized using a facile method for detecting hydrazine. The 5-((7-(dimethylamino)-4,5-dihydronaphtho [1,2-b] thiophen-2-yl)methylene)pyrimidine-2,4,6 (1H,3H,5H)-trione (DPT) probe displays a large emission signal ratio variation (more than a 40-fold enhancement) in the presence of hydrazine under neutral conditions. Interestingly, a novel recognition mechanism based on a hydrazine-triggered addition-cyclisation-retro aldol was proposed and confirmed. Additionally, the DPT probe exhibits a low detection limit (5 × 10-8 M), applicable to the physiological pH range (3-12), a broad linear response range for hydrazine concentrations between 0 and 34 µM and a large Stokes shift (147 nm) for hydrazine detection in aqueous solution. Moreover, the DPT probe was successfully implemented for hydrazine imaging in vivo.

Challenges Faced with Small Molecular Modulators of Potassium Current Channel Isoform Kv1.5.

The voltage-gated potassium channel Kv1.5, which mediates the cardiac ultra-rapid delayed-rectifier (IKur) current in human cells, has a crucial role in atrial fibrillation. Therefore, the design of selective Kv1.5 modulators is essential for the treatment of pathophysiological conditions involving Kv1.5 activity. This review summarizes the progress of molecular structures and the functionality of different types of Kv1.5 modulators, with a focus on clinical cardiovascular drugs and a number of active natural products, through a summarization of 96 compounds currently widely used. Furthermore, we also discuss the contributions of Kv1.5 and the regulation of the structure-activity relationship (SAR) of synthetic Kv1.5 inhibitors in human pathophysiology. SAR analysis is regarded as a useful strategy in structural elucidation, as it relates to the characteristics that improve compounds targeting Kv1.5. Herein, we present previous studies regarding the structural, pharmacological, and SAR information of the Kv1.5 modulator, through which we can assist in identifying and designing potent and specific Kv1.5 inhibitors in the treatment of diseases involving Kv1.5 activity.

A Layered Approach for Robust Spatial Virtual Human Pose Reconstruction Using a Still Image.

Pedestrian detection and human pose estimation are instructive for reconstructing a three-dimensional scenario and for robot navigation, particularly when large amounts of vision data are captured using various data-recording techniques. Using an unrestricted capture scheme, which produces occlusions or breezing, the information describing each part of a human body and the relationship between each part or even different pedestrians must be present in a still image. Using this framework, a multi-layered, spatial, virtual, human pose reconstruction framework is presented in this study to recover any deficient information in planar images. In this framework, a hierarchical parts-based deep model is used to detect body parts by using the available restricted information in a still image and is then combined with spatial Markov random fields to re-estimate the accurate joint positions in the deep network. Then, the planar estimation results are mapped onto a virtual three-dimensional space using multiple constraints to recover any deficient spatial information. The proposed approach can be viewed as a general pre-processing method to guide the generation of continuous, three-dimensional motion data. The experiment results of this study are used to describe the effectiveness and usability of the proposed approach.