Display of Potassium Channel–Blocking Tertiapin‐Q Peptides on Gold Nanoparticles Enhances Depolarization of Cellular Membrane Potential

The use of nanoparticle (NP) systems to control cellular physiology, including membrane potential, can facilitate furthered understanding of many disparate cellular processes ranging from cellular proliferation to tissue regeneration. A gold NP (AuNP) bioconjugate system based on the honeybee venom peptide, tertiapin‐Q (AuNP‐TPN‐Q), that depolarizes membrane potential by targeting inward rectifier potassium channels (Kir), is developed. The conjugate elicits, in a peptide concentration–dependent manner, a greater and more rapid depolarization response compared to the free peptide alone. The specificity of the interaction of the AuNP‐TPN‐Q conjugate with the Kir channel using immunocytochemistry and competition binding assays is confirmed. It is further shown that membrane depolarization is photothermally reversible via the laser‐induced plasmonic heating of the AuNP, providing a level of control over Kir channels not afforded by currently available drugs. The functional nanobioconjugate described herein provides a new research tool for understanding the intricacies of ion channel activity and the modulation of cellular membrane potential.     

Skin‐worn Soft Microfluidic Potentiometric Detection System

A flexible skin‐mounted microfluidic potentiometric device for simultaneous electrochemical monitoring of sodium and potassium in sweat is presented. The wearable device allows efficient natural sweat pumping to the potentiometric detection chamber, containing solid‐contact ion‐selective Na⁺ and K⁺ electrodes, during exercise activity. The fabricated microchip electrolyte‐sensing device displays good analytical performance and addresses sweat mixing and carry‐over issues of early epidermal potentiometric sensors. Such soft skin‐worn microchip platform integrates potentiometric measurement, microfluidic technologies with flexible electronics for real‐time wireless data transmission to mobile devices. The new fully integrated microfluidic electrolyte‐detection device paves the way for practical fitness and health monitoring applications.     

某些分析化学实验教材中均相沉淀概念的误区

目前，均相沉淀法在大学分析化学实验中已很少采用。高锰酸钾间接滴定法测定钙含量是大学分析化学实验中的经典实验之一，历史上存在均相沉淀法和传统沉淀法2种不同的沉淀操作。虽然我国现有大学分析化学实验中已不采用均相沉淀法进行该实验，但在某些分析化学实验教材中，却存在概念混乱的现象，即把传统沉淀法称作均相沉淀法。对这种现象进行了探讨和总结。     

Synthesis of heterobiaryls via Suzuki‐Miyaura coupling reaction of potassium aryltrifluoroborates with heteroaryl halides in aqueous systems

A variety of heterobiaryl compounds have been synthesized by the Suzuki‐Miyaura coupling reactions of heteroaryl halides with potassium aryltrifluoroborates. Pd (OAc)₂ was found to be highly efficient for the Suzuki‐Miyaura coupling reactions of various heteroaryl halides with potassium aryltrifluoroborates in aqueous systems, delivering the corresponding heterobiaryl compounds in good to excellent yields.     

Crystal structure and pale‐yellow emitting properties of K3Gd1–xDyxB6O12 solid solutions

A new potassium dysprosium polyborate, K₃DyB₆O₁₂, has been prepared via the high‐temperature molten salt method and structurally characterized by single‐crystal X‐ray diffraction analysis. The structure can be described as a three‐dimensional framework composed of isolated bicyclic [B₅O₁₀]^5? groups and Dy³⁺ and K⁺ ions. The Fourier transform IR (FT–IR) and ultraviolet–visible (UV–Vis) spectra were investigated. A series of K₃Gd_1–xDy_xB₆O₁₂ phosphors was prepared and their photoluminescence properties were studied. The K₃Gd_1–xDy_xB₆O₁₂ phosphors exhibit a strong yellow emission band at 577 nm (the ⁴F_9/2→⁶H_13/2 transition of Dy³⁺) under UV excitation of 275 nm (the ⁸S_7/2→⁶I_J transition of Gd³⁺), suggesting the occurrence of the energy transfer Gd³⁺→Dy³⁺. The optimized doping concentration of the Dy³⁺ ion was 8 mol%. We may expect that K₃Gd_1–xDy_xB₆O₁₂ is a promising pale‐yellow emission phosphor for visual displays or solid‐state lighting.     

Astrocyte and ions metabolism during epileptogenesis:A review for modeling studies

As a large group of cells in a central nervous system, astrocytes have a great influence on ion and energy metabolism in a nervous system. Disorders of neuronal ion and energy metabolism caused by impaired astrocytes play a key role in the pathogenesis of epilepsy. This paper reviews the existing computational models of epileptogenesis resulting from impaired astrocytes and presents several open perspectives with regard to ion and energy metabolism-induced epileptogenesis in a neuron-astrocyte-capillary coupled model.     

Synthesis of highly functionalized selenophenes via a three-component condensation

Abstract

Reaction between arylidenemalononitriles and dimethyl acetylenedicarboxylate in the presence of KSeCN at room temperature provided a simple and efficient one-pot route for the synthesis of highly functionalized selenophenes. The reaction is characterized by mild conditions, short reaction time, and tolerance to various functional groups.     

g-C3N4催化石墨化碳质材料的制备及光催化性能研究

通常采用以氢氧化物作为造孔剂,过渡金属硝酸盐或氯化物作为石墨化催化剂的传统两步法策略制备多孔石墨化碳材料。然而制备过程中多涉及有毒和腐蚀性试剂,且多步骤的过程耗时较长。本文以双氰胺为原料通过热缩聚反应得到g-C₃N₄,采用高铁酸钾为催化剂一步法实现g-C₃N₄的同步碳化-石墨化,并研究其光催化性能。与传统的两步法相比,该方法耗时少、效率高、无污染。与初始的g-C₃N₄材料相比,石墨化g-C₃N₄衍生碳质材料不仅显著改善了可见光的吸收,而且大大增强了光催化活性。研究了不同石墨化温度对g-C₃N₄衍生碳质材料在可见光下降解甲基橙溶液的影响。700 ℃下制备的衍生碳质材料的降解率为12.4 mg/g。光电化学测试结果表明,多孔g-C₃N₄衍生碳质材料的光生载流子密度、电荷分离和光电流(提高了5.4倍)均得到显著提高。因此,该简便、灵活方法为提高g-C₃N₄衍生碳质材料的吸附和光催化性能提供了一种有前景的、高效的途径。     

新药炎琥宁的碳氢NMR信号全归属

炎琥宁为中药提取物穿心莲内酯经结构改造后获得的一个抗菌、抗病毒新药,本文应用1D NMR和脉冲梯度场2D NMR实验技术（gCOSY,gHSQC,gHSQC-TOCOSY,gHMBC）对其结构进行了研究,并首次对其¹H NMR、¹³C NMR谱信号进行了全归属.     

A Highly K+‐Selective Two‐Photon Fluorescent Probe

A highly K⁺‐selective two‐photon fluorescent probe for the in vitro monitoring of physiological K⁺ levels in the range of 1–100 mM is reported. The two‐photon excited fluorescence (TPEF) probe shows a fluorescence enhancement (FE) by a factor of about three in the presence of 160 mM K⁺, independently of one‐photon (OP, 430 nm) or two‐photon (TP, 860 nm) excitation and comparable K⁺‐induced FEs in the presence of competitive Na⁺ ions. The estimated dissociation constant (K_d) values in Na⁺‐free solutions (K_d^OP=(28±5) mM and K_d^TP=(36±6) mM ) and in combined K⁺/Na⁺ solutions (K_d^OP=(38±8) mM and K_d^TP=(46±25) mM ) reflecting the high K⁺/Na⁺ selectivity of the fluorescent probe. The TP absorption cross‐section (σ_2PA) of the TPEF probe+160 mM K⁺ is 26 GM at 860 nm. Therefore, the TPEF probe is a suitable tool for the in vitro determination of K⁺.