NHS-mediated QDs-peptide/protein conjugation and its application for cell labeling

3-Mercaptopropyl acid-stabilized CdTe nanoparticles synthesized in aqueous solution are found to be able to conjugate with peptides or proteins mediated by N-hydroxysulfo-succinimide (NHS) but 1-ethyl-3(3-dimethylaminopropyl) carbodiimides hydrochloride (EDC). The reaction time and pH have been optimized. Gel-permeation HPLC was applied following the conjugation, which could quickly and simultaneously detect and purify the quantum dots (QDs) conjugates. The biological activities of QDs conjugates are maintained and give superior results in cell labeling. These results are encouraging regarding the application of QDs molecules for use in living cells, diagnostics and drug delivery.     

直接Z型MIL-100(Fe)/BiOBr异质结的构建及光芬顿降解磺胺甲恶唑的性能

通过原位共沉淀法可控制备了系列直接Z型MIL-100(Fe)/BiOBr异质结。使用粉末X射线衍射(PXRD)、傅里叶红外变换(FTIR)光谱、紫外可见漫反射光谱(UV-Vis DRS)、扫描电镜(SEM)、高倍透射电镜(HRTEM)以及 X 射线光电子能谱(XPS)对MIL-100(Fe)/BiOBr 异质结晶体结构、微观形貌、光学性能、化学组成进行表征。以低功率发光二级管可见光为光源，探究了MIL-100(Fe)/BiOBr异质结光芬顿降解磺胺甲恶唑(SMX)性能。最佳反应体系MB-7/Vis/H₂O₂(MB-7是MIL-100(Fe)质量为BiOBr质量的10%时制备的样品)在光源照射70 min后可降解99.8% SMX(5 mg·L^-1)。同时，还考察了H₂O₂浓度、催化剂投加量、pH值以及无机阴离子对 MB-7/Vis/H₂O₂降解 SMX 影响。MB-7/Vis/H₂O₂能够在经过 5轮循环降解实验后保持 95% 以上的 SMX 降解效率，表明其具有较好的循环稳定性。通过光致发光(PL)光谱、光电化学测试、活性物质捕获实验以及电子自旋共振(ESR)技术对光芬顿降解SMX机理进行了揭示。增强的光芬顿活性的机制主要来自于异质结的构建加速了光生载流子的分离，进而促进了活性物质产生以及Fe³⁺/Fe²⁺的循环。     

土-地铁车站及其上盖结构体系地震反应分析

为研究地震作用下地铁车站及其上盖结构体系的地震反应特征，本文以一典型的地铁车站及上盖结构体系为背景，采用ABAQUS软件建立土-地铁车站及其上盖结构体系的三维有限元模型，利用等效线性化方法考虑土的非线性，以不同类型的单向地震波和双向地震波（含水平向和竖向）作为输入，对土-地铁车站及其上盖结构体系进行了地震反应分析，比较了不同类型地震波作用下地铁车站及其上盖结构体系地震反应的差异，探讨了竖向地震动效应和转换梁刚度的影响．本文的算例结果表明：与普通基岩波和El-centro反演波输入相比较，在长周期基岩地震波作用下地铁车站及其上盖结构体系的内力响应和位移响应均最大．这一地铁车站及其上盖结构体系的薄弱部位位于地铁车站底层第2列、第3列柱的柱端和侧墙与底板连接处．竖向地震动对地铁车站及其上盖结构体系中柱的轴力响应值有较大影响．对于本文的动力计算工况，适当弱化转换梁刚度可降低上盖结构层间位移角的动力响应值．     

Mathematical model of the effect of electrodiffusion on biomineralization

Biofilm-induced mineral precipitation is a fundamentally important phenomenon with many potential applications including carbon sequestration and bioremediation. Based on a mixture model consisting of three phases (calcite, biofilm, and solvent) and also accounting for chemistry, mechanics, thermodynamics, fluid, and electrodiffusive transport effects, we describe the self-induced generation of an electric field due to different diffusivities of different ion species and study the effects of this field on ionic transport and calcite precipitation. Numerical simulations suggest that one of these effects is enhanced precipitation.     

Synthesis of Ultrathin and Grid-Structural Carbon Nanosheets Coupled with Mo2C for Electrocatalytic Hydrogen Production

Molybdenum carbide possessing a Pt-like d-band electronic structure is considered as one of potential candidates of electrocatalysts and it shows intrinsic catalytic property. However, a high carbonizing temperature easily leads to the coalescence of nanoparticles (NPs). Here, we propose a simple sol-gel route to achieve high dispersity of carbide NPs by designing a Mo-involved xerogel. The results show that molybdenum carbide NPs are dispersed and anchored on the nitrogen-doped carbon nanosheets (Mo₂C@NC). Ultrathin carbon layers resemble graphene and the network structures act as a support of carbide NPs, which can hinder NPs’ coalescence effectively. Nanpoparticles cross-coupled on network-structure nanosheets display the grid shapes. Electrochemical studies indicate that Mo₂C@NC material exhibits outstanding hydrogen evolution performance in alkaline electrolyte.     

Porphyrin nanofiber patterning by air/water interfacial assembly: effect of molecular structure, surface pressure, and ionic liquid doped subphase

Porphyrin nanofiber patterning was generated by air/water interfacial assembly. The air/water interfacial aggregation behavior of two prophyrins, both of which contain two hydrophobic alkyl chains and two carboxylic acid substituent groups at different positions, was investigated using UV spectra, FT-IR spectra, and AFM measurements on the corresponding transferred films. The porphyrin nanofiber patterning can only be produced on ionic liquid (IL) doped water subphases by the assembly of the building blocks with two carboxylic acids located at the para-position (TPPA2b-A). The results suggest that the bulky cations of ionic liquids (ILs) can interact with the carboxylate of porphyrin electrostatically. The appropriate molecular geometries, ionic liquid (IL) doped water subphases, and relatively high surface pressures help the TPPA2b-A to form nanofiber patterns.     

Hydrophilic,Upconverting, Multicolor,Lanthanide‐Doped NaGdF4 Nanocrystals as Potential Multifunctional Bioprobes

Monodisperse water‐soluble hexagonal phase Ln³⁺‐doped NaGdF₄ upconverting nanocrystals (UCNCs) have been successfully fabricated by means of a fast, facile, and environmentally friendly microwave‐assisted route with polyethylenimine as the surfactant. Fine‐tuning of the UC emission from visible to near‐IR and finally to white light has been achieved. Furthermore, studies of the magnetic resonance imaging as well as the magnetization (magnetization–magnetic field curves) and the targeted recognition properties of FA‐coupled amine‐functionalized NaGdF₄@SiO₂ UCNCs indicate that the obtained NaGdF₄ UCNCs can be potential candidates for dual‐mode optical/magnetic bioapplications.