Superparamagnetic Composite Nanobeads Anchored with Molecular Glues for Ultrasensitive Label-free Proteomics

Mass spectrometry has emerged as a mainstream technique for label-free proteomics. However, proteomic coverage for trace samples is constrained by adsorption loss during repeated elution at sample pretreatment. Here, we demonstrated superparamagnetic composite nanoparticles functionalized with molecular glues (MGs) to enrich proteins in trace human biofluid. We showed high protein binding (>95 %) and recovery (≈90 %) rates by anchor-nanoparticles. We further proposed a Streamlined Workflow based on Anchor-nanoparticles for Proteomics (SWAP) method that enabled unbiased protein capture, protein digestion and pure peptides elution in one single tube. We demonstrated SWAP to quantify over 2500 protein groups with 100 HEK 293T cells. We adopted SWAP to profile proteomics with trace aqueous humor samples from cataract (n=15) and wet age-related macular degeneration (n=8) patients, and quantified ≈1400 proteins from 5 μL aqueous humor. SWAP simplifies sample preparation steps, minimizes adsorption loss and improves protein coverage for label-free proteomics with previous trace samples.     

以史为鉴——化学科普中的人文素养教育

中国古代历史中蕴含着丰富的化学史资源,对这些资源的挖掘、解读,形成化学科普题材,既是化学教育的需要,也是加强思想政治教育背景下课程思政的现实要求。以寒食散为例,探讨中国古代化学史资源所蕴含的人文素养教育价值,认为化学科普中汲取历史资源,不仅增加了科普的趣味性,有利于向公众普及化学知识,还有助于公众树立正确的世界观和价值观。     

一种考虑聚醚醚酮（PEEK）不同力学状态的本构模型

聚醚醚酮（简称PEEK）以其优良的性能而广泛应用于高端机械、 核工程和航空等科技领域.为了描述其在应变、应变率和温度3种因素作用下的力学行为,依据PEEK在不同温度下呈现的3种力学状态,在著名的JC(Johnson Cook)本构模型的基础上,提出了针对高分子不同力学状态的分段JC本构模型.与传统JC模型及文献中改进JC模型相比,提出的分段JC模型能够更精确地表征PEEK在中高温下的力学行为,为PEEK在复合材料中的应用和分析奠定了理论基础.     

In-tip nanoreactors for cancer cells proteome profiling

Mass spectrometry (MS)-based proteome profiling is essential for molecular diagnostics in modern biomedical study. To date, sample preparation including protein extraction and proteolysis is still very challenging and lack of efficiency. Recently tips-based sample preparation protocols exhibit strong potentials to achieve the goal of “a proteome in an hour”. However, in-tip proteolysis is still rarely reported and far from ideal for dealing with complex bio-samples. In this work, nanoreactors encapsulated micropipette tips were demonstrated as high performance devices for fast (∼minutes) and multiplexing proteolysis to assist the profiling of cancer cells proteome. Nanoporous silica materials with controlled pore size and surface chemistry were prepared as nanoreactors and encapsulated in micropipette tips for efficient in situ proteolysis. The as-constructed device showed desirable sensitivity (LOD of 0.204 ± 0.008 ng/μL and LOQ of 0.937 ± 0.055 ng/μL), selectivity, stability (two months under −20 °C), reusability (at least 10 times), and little memory effect in MS based bottom-up proteomic analysis. It was used for comprehensive protein mapping from cancer cell lines. The number of identified proteins was increased by 18%, 22%, 52%, and 52% dealing with HepG2, F56, MCF7, and HCCLM3 cancer cells, compared to traditional in-solution proteolysis based bottom-up proteomic strategy. With the enhanced performance, our work built a novel, efficient and miniaturized platform for facile proteomic sample preparation, which is promising for advanced biomarkers discovery in biomedical study.     

SYNTHESIS AND CHARACTERIZATION OF SURFACE-HYPERBRANCHED MAGNETITE NANOPARTICLE FOR BOVINE SERUM ALBUMIN IMMOBILIZATION

A hyperbranched polyamidoamine polymer was synthesized on the surface of magnetite nanoparticles to enhance bovine serum albumin (BSA) immobilization efficiency. The amount of immobilized bovine serum albumin (BSA) on the surface-hyperbranched magnetite nanoparticle was up to 2.5 times as much as that of magnetite nanoparticle modified with only amino silane.     

Simultaneous measurements of velocity and temperature fluctuations in thermal boundary layer in a drag-reducing surfactant solution flow

The mechanism of turbulent heat transfer in the thermal boundary layer developing in the channel flow of a drag-reducing surfactant solution was studied experimentally. A two-component laser Doppler velocimetry and a fine-wire thermocouple probe were used to measure the velocity and temperature fluctuations simultaneously. Two layers of thermal field were found: a high heat resistance layer with a high temperature gradient, and a layer with a small or even zero temperature gradient. The peak value of was larger for the flow with the drag-reducing additives than for the Newtonian flow, and the peak location was away from the wall. The profile of was depressed in a similar manner to the depression of the profile of in the flow of the surfactant solution, i.e., decorrelation between v and compared with decorrelation between u and v. The depression of the Reynolds shear stress resulted in drag reduction; similarly, it was conjectured that the heat transfer reduction is due to the decrease in the turbulent heat flux in the wall-normal direction for a flow with drag-reducing surfactant additives.List of symbols ensemble averaged value - (·)⁺ normalized by the inner wall variables - (·) root-mean-square value - C concentration of cetyltrimethyl ammonium chloride (CTAC) solution - c _p heat capacity - D hydraulic diameter - f friction factor - H channel height - h heat transfer coefficient - j _H Colburn factor - l length - Nu Nusselt number, h - Pr Prandtl number, c _p/ - q _w wall heated flux - Re Reynolds number, U _b/ - T temperature - T _b bulk temperature - T _i inlet temperature - T _w wall temperature - T friction temperature, q _w /c _p u - U local time-mean streamwise velocity - U ₁ velocity signals from BSA1 - U ₂ velocity signals from BSA2 - U _b bulk velocity - u streamwise velocity fluctuation - u1 velocity in abscissa direction in transformed coordinates - u friction velocity, - v wall-normal velocity fluctuation - v1 velocity in ordinate direction in transformed coordinates - var(·) variance - x streamwise direction - y wall-normal direction - z spanwise direction - _j junction diameter of fine-wire TC - _w wire diameter of fine-wire TC - angle of principal axis of joint probability function p(u,v) - _f heat conduction of fluid - _w heat conduction of wire of fine-wire TC - kinematic viscosity - local time-mean temperature difference, T _w –T - temperature fluctuation - standard deviation - density - _w wall shear stress     

基于连续小波变换的风速时程特性识别与分析

由于风速时程属于频域宽和频率变化剧烈的时变信号，需用具有良好时频局部化特性和弹性时．频窗口的小波变换进行分析。本文的目的是在风速时程的描述上较全面地了解风速的时频特性。利用小波分析方法在时域和频域的良好局部化性质，聚焦到风速时程的任意细节并加以分析，快速、准确地提取样本的局部谱密度特征，特别是对在整个时程记录中，具有相同功率谱但时频内容有差别的风速时程。用小波变换分析试验得到的风速时程，并研究和识别试验得到的曲线和实测风速曲线的时频特性、能量关系和局部谱密度特征。     

含多源损伤的胶接修补结构有限元分析方法

采用有限元法研究含多源损伤结构的胶接修补问题,利用二维三层有限元模型对损伤区进行了数值模拟,并选取典型多源损伤情况中含共线双裂纹铝板结构为算例,详细分析了含多裂纹胶接修补结构中两裂纹相对位置、补片尺寸、铺层和厚度对应力强度因子的影响.结果表明,复合材料胶接修补可明显降低含共线双裂纹母板的应力强度因子;对于确定的裂纹和应力场,应对复合材料补片长度和厚度等参数进行优化设计,以获得最佳的修补效果.