Protease-responsive mass barcoded nanotranslators for simultaneously quantifying the intracellular activity of cascaded caspases in apoptosis pathways

Quantitatively delineating the activation network of multiple proteases that participate in cellular processes is highly essential for understanding the physiological and pathological states of cells. In this study, protease-responsive mass barcoded nanotranslators (PRMNTs) were engineered for revealing the activity of cascaded caspases in apoptosis in a multiplex and quantitative manner. In the PRMNTs, a series of mass tag-decorated gold nanoparticles (AuNPs) were tethered onto magnetic Fe₃O₄ nanospheres via a linker containing the substrate peptide of the target protease to form a “one-to-many” core–satellite structure. This nanostructure was internalized into the cells, underwent an enzymatic reaction within the cells, and allowed post-reaction mass spectrometry (MS) interrogation after magnetic separation from the cells. In the presence of intracellular caspases, enzymatic cleavage of the linker could be translated to the decreased ion signals of the mass tags on the remaining AuNPs in the PRMNTs by MS decoding. Benefiting from the multiplexing capability of MS, the intracellular activity of caspase-3, -8 and -9 that orchestrate the apoptotic process was simultaneously quantified at any given time. Kinetic analysis of caspase activity under stimulation of diverse anticancer drugs revealed that programmed cell death followed individual apoptosis pathways, differing in the activation degree and sequence of the caspase cascade. This work represents a modality that interfaces nanotechnology with MS for quantitatively probing the intracellular activity of multiple proteases, which opens up new avenues for revealing the apoptosis mechanism and developing innovative drugs.

Protease-responsive mass barcoded nanotranslators (PRMNTs) were engineered for revealing the apoptosis pathways by MS-based multiplex quantification of the intracellular activity of cascaded caspases.     

有旋湍流场中湍流模型应用的研究

本文通过对三种双时间尺度湍流模型的理论分析，选择出最合理的模型，并在其基础上引入非线性Reynolds应力─应变关系式及梯度Richardson数修正，对有旋湍流场进行计算，其结果表明，双时间尺度模型能较好地预测出复杂湍流场中平均物理量的分布，尤其对回流区大小和强度的预测较常规k-ε模型结果有很大改进。因此，本文将双时间尺度模型应用于旋流燃烧器中气体颗粒两相流动的计算。     

焦测序技术及其在遗传分析中的应用

焦测序技术是一种新的实时DNA测序技术。它在DNA聚合酶、三磷酸腺苷硫酸化酶、荧光素酶和三磷酸腺苷双磷酸酶4种酶的协同作用下,使引物延伸聚合脱氧核糖核酸(dNTP)释放焦磷酸盐(PP i)、PP i转换三磷酸腺苷(ATP)、ATP产生荧光信号与dNTP和ATP的降解等化学反应偶联起来,检测结果准确可靠。本文综述了焦测序技术的基本原理、操作步骤和它在单核苷酸多态性(SNP)研究、微生物的分型鉴定和基因甲基化检测等遗传分析中的应用,并对焦测序技术的发展作了展望。     

Preparation and a time-resolved fluoroimmunoassay application of new europium fluorescent nanoparticles.

New silica-based europium fluorescent nanoparticles having surface amino groups were prepared by a covalent binding-copolymerization technique. In the nanoparticles, the fluorescent Eu3+ chelate molecules were covalently bound to silicon atoms to protect the nanoparticles from dye leaking in bio-applications. The amino groups on the surface of nanoparticles made the surface modification and bioconjugation of nanoparticles easier. The nanoparticles were characterized and developed as a new type of fluorescence probe for a highly sensitive time-resolved fluoroimmunoassay (TR-FIA) of human hepatitis B surface antigen (HBsAg).     

Recyclable alkylated Ru(bpy)32+ complex as a visible-light photoredox catalyst for perfluoroalkylation

A recyclable Ruthenium tris [4,4′-bis (dinonylmethyl)-2,2′-bipyridine] (Ru[(DNM)₂bpy]₃²⁺) photocatalyst (PC) was synthesized. Hexane-phase-selective solubility allowed its simple and efficient separation from reaction products via solvent extraction. The excellent catalytic activity and recoverability were demonstrated in batch and flow perfluoroalkylation reactions of coumarin under visible-light irradiation. High reaction rates and easy reusability of the catalyst make this approach attractive for large-scale applications.     

Managing pharmaceuticals delivery service using a hybrid particle swarm intelligence approach

Medicines or drugs have unique characteristics of short life cycle, small size, light weight, restrictive distribution time and the need of temperature and humidity control (selected items only). Thus, logistics companies often use different types of vehicles with different carrying capacities, and considering fixed and variable costs in service delivery, which make the vehicle assignment and route optimization more complicated. In this study, we formulate the problem to a multi-type vehicle assignment and mixed integer programming route optimization model with fixed fleet size under the constraints of distribution time and carrying capacity. Given non-deterministic polynomial hard and optimal algorithm can only be used to solve small-size problem, a hybrid particle swarm intelligence (PSI) heuristic approach, which adopts the crossover and mutation operators from genetic algorithm and 2-opt local search strategy, is proposed to solve the problem. We also adapt a principle based on cost network and Dijkstra’s algorithm for vehicle scheduling to balance the distribution time limit and the high loading rate. We verify the relative performance of the proposed method against several known optimal or heuristic solutions using a standard data set for heterogeneous fleet vehicle routing problem. Additionally, we compare the relative performance of our proposed Hybrid PSI algorithm with two intelligent-based algorithms, Hybrid Population Heuristic algorithm and Improved Genetic Algorithm, using a real-world data set to illustrate the practical and validity of the model and algorithm.

     

Synthesis, structure and luminescent properties of rare earth coordination polymers constructed from paddle-wheel building blocks

A series of three-dimensional (3D) novel coordination polymers M(bpdc)1.5(H2O) x 0.5DMF (M = Tb (1), Ho (2), Er (3), or Y (4)) have been synthesized by reaction of the rare earth ions (M3+) with 4,4'-biphenyldicarboxylic acid (H2bpdc) in a mixed solution of DMF and C2H5OH. They possess the same 3D architectures and crystallize in monoclinic space group C2/c. Two seven-coordinated metal centers and four dimonodentate bpdc groups construct a paddle-wheel building block. These building blocks connect with two carboxyl groups to lead to a one-dimensional inorganic chain, ---M-O-C-O-M---, along the [001] direction. The inorganic chains are linked with two biphenyl groups to form 25.15 A x 17.09 A rhombic channels along the c axis without interpenetration. These complexes exhibit strong fluorescence in the visible region, and complex 3 shows Er3+ characteristic emission in the range of 1450-1650 nm at room temperature. These complexes could be anticipated as potential fluorescent probes and an IR-emitter, respectively.     

硝酸镧处理对微弧氧化二氧化钛膜光催化性能的影响

以磷酸钠为电解液,采用交流微弧氧化技术在钛网上直接制备TiO2膜,利用硝酸镧浸渍方法对该膜进行表面处理,以酸性大红染料模拟废水来评价TiO2膜光催化水中有机污染物的能力。利用X射线衍射仪、SEM和EDX对微弧氧化膜晶型、表面形貌和成分进行分析。结果表明:微弧氧化TiO2膜主要由锐钛矿TiO2组成,由于膜表面钠离子的沉积,微弧氧化TiO2膜的光催化性能较差;硝酸镧浸渍处理可以减少微弧氧化TiO2膜表面钠离子含量,改善膜的光催化性能,120min酸性大红染料废水的光催化脱色率由15%提高到34.8%以上。     

Studies on the Catalytic Properties of Magnesia Supported on γ-Alumina

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