Synthesis and Applications of Monolithic HPLC Columns

Silica and carbon monolithic columns were synthesized and modified for liquid chromatography applications. Column configurations and cladding techniques were investigated in detail. Three novel approaches have been developed for the synthesis of bimodal porous rods. Out of these three methods, gel-casting was adopted for the synthesis of silica monoliths with ordered mesopores and uniform macropores; the use of colloidal templates and dual phase separation has been successfully implemented for the synthesis of carbon monoliths with well-controlled meso- and macro- porosities. The formation of mesopores in carbon materials has been further studied in the microphase separation of block copolymers. Electrochemical modification of carbon monoliths was discovered to be an efficient method for converting covalently bonded functionalities to carbon monoliths. N,N’-diethylaminobenzene has been attached to carbon surface for the separation of proteins and protein digests. The performances of carbon-based monolithic columns were studied intensely through frontal analysis and Van Deemter plot. Temperature and pressure effects were also investigated in carbon-based columns. The density of bonding on the modified carbon monoliths was characterized by thermogravimetric analysis

Site-selective DNA hydrolysis induced by a metal-free peptide nucleic acid-cyclen conjugate

A metal-free artificial restriction DNA cutter which is composed of cyclen and classical peptide nucleic acid (PNA) was synthesized. Analysis of DNA cleavage products indicates the site-selective hydrolysis.National Science Foundation of China[20725206, 20732004, 20972104]; Program for Changjiang Scholars and Innovative Research Team in University; Ministry of Education in China; Scientific Fund of Sichuan Province for Outstanding Young Scientist; DAA

DNA‐Incorporated Biomimetic Olfactory Neuroepithelium That Facilitates Artificial Intelligence

Designing biomimetic olfactory neuroepithelium (BONe) with subnanosized active domains as artificial olfactory receptors (ORs) is highly desirable to sense various colorless and odorless hazardous odorants which find no appropriate ORs in the human olfactory neuroepithelium (ONe), yet challenging because of the unsuitability of biomolecules for a design that requires effective electronic features and stability. Herein, a DNA‐incorporated 3D BONe is introduced, where DNA facilitates optimal tuning of d‐band center, and in situ anchoring of PdO2 subnanoscale clusters (PdO2‐sNCs) on the exfoliated single‐layer reduced graphene oxide (SL rGO), to mimic wrinkled morphology of natural ONe. Unprecedentedly, BONe demonstrates benchmarked H2‐sensing performance (small recovery time of ≈30 s with a limit of detection of 50 ppb) at room temperature with yearlong durability, satisfying prerequisites of safe adoption of H2 clean energy. The great recovery is innovatively illustrated by the downshift of d‐band center of PdO2‐sNCs and strong electron transport of SL‐rGO network. An adsorption/desorption model is proposed to clarify the sensing mechanism. BONe design may eventually be integrated with artificial intelligent electronics for ppb‐level sensing of harmful gases to ensure accident prevention in modern public and military environments

Astragalosidic Acid: A New Water-Soluble Derivative of Astragaloside IV Prepared Using Remarkably Simple TEMPO-Mediated Oxidation

There is an urgent need for a water-soluble derivative of astragaloside IV for drug R&D. In the present study, a remarkably simple method for the preparation of such a water-soluble derivative of astragaloside IV has been developed. This protocol involves oxidative 2,2,6,6-tetramethylpiperidine-1-oxyl free radical (TEMPO)-mediated transformation of astragaloside IV to its carboxylic acid derivative, which is a new compound named astragalosidic acid. The structure of astragalosidic acid was elucidated by means of spectroscopic analysis. Its cardioprotective activity was investigated using an in vitro model of cardiomyocyte damage induced by hypoxia/reoxygenation in H9c2 cells. The oxidative TEMPO-mediated transformation proposed in the present study could be applied to other natural saponins, offering an effective and convenient way to develop a new compound with greatly improved structure-based druggability