Mutually Pumped Phase Conjugation of Three Incoherent Beams with a Novel Photorefractive Crystal

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电位滴定法测定模拟高放废液中的游离酸

本文研究了用电位滴定法测定模拟高放废液中游离酸的方法。用草酸钾做络合剂以消除Ｆｅ＾３＋、Ａｌ＾３＋、Ｎｄ＾３＋等多种水解离子的影响，用标准碱直接进行电位滴定，即可快速准确地测定模拟高放废液中游离酸的含量。方法的相对标准偏差为１．８％，标准加入回收率为１００－１０１％，能为放射性废物固化试验提供可靠的分析数据。     

温度及pH敏感的树枝状高分子衍生物合成及药物控制释放研究

对合成的系列聚酰胺-胺型(PAMAM)树枝状高分子进行端基的羟基化和氯乙酰化两步修饰,使PAMAM最外层接上烷基氯.以修饰产物为引发剂,通过原子转移自由基引发甲基丙烯酸N,N-二甲氨基乙酯(DMAEMA)聚合得到树枝状PAMAM高分子衍生物,并对其结构用FTIR、1H-NMR和粒径分析进行了表征.紫外可见分光光度仪测定证实此高分子具有温度及pH敏感性.通过对小分子药物控制释放研究表明,此树枝状高分子衍生物通过环境pH值可有效地控制小分子药物的释放.     

Mechanisms of ATPases--a multi-disciplinary approach

ATPases are important molecular machines that convert the chemical energies stored in ATP to mechanical actions within the cell. ATPases are among the most abundant proteins with diverse functions involved in almost every cellular pathway. The well characterised ATPases include the various motor proteins responsible for cargo transfers, cell motilities, and muscle contractions; the protein degradation machinery - the proteasome; the ATP synthase, F-ATPase; and the chaperone systems. Other ATPases include DNA helicases and DNA replication complex; proteins responsible for protein/complex disassembly; and certain gene regulators. It is beyond the scope of this review to cover the complete range of ATPases. Instead, we will focus on a few representative ATPases, chosen based on their diverse mechanisms and properties. Furthermore, this review is by no means trying to cover comprehensively the literature for each ATPase nor the historical aspects in each field. We will focus on describing the various techniques being employed to derive the mechanisms and properties of the chosen ATPases. Among them, high and low resolution structural studies combined with biochemical assays seem to be the dominant technical advances adapted to reveal mechanisms for most of the ATPases except the bacterial sigma54 activators, whose mechanism of action is mostly derived from large amount of biochemical studies. A number of them, especially the F-ATPase and motor proteins, have been studied successfully by various single molecule and imaging techniques. We will therefore discuss them in greater details in order to describe the wide range techniques being utilised.     

Speciation analysis of aluminium(III) in natural waters and biological fluids by complexing with various catechols followed by differential pulse voltammetry detection

The biological effects of aluminium have received much attention in recent years. Speciation of Al is of basic relevance as it concerns its reactivity and bioavailability. A differential pulse voltammetry (DPV) procedure is proposed for speciation analysis of Al(III) in natural waters and biological fluids using six catechols (L-dopa, dopamine, epinephrine, norepinephrine, caffeic acid and o-benzenediol) as electroactive ligands. The decrease of the DPV anodic peak current for each catechol ligand is linear with the increase of Al concentration. This speciation analysis idea is based on the measurement of the complexation capacity, namely, different affinities of Al(III) for catechols and organic ligands under two pH conditions. The labile monomeric Al fraction (mainly inorganic aluminium) is determined at pH 4.6, while the total monomeric Al fraction is determined at pH 8.5. The principle for Al(III) speciation analysis by an electrochemical method is discussed. This sensitive and simple fractionation method is successfully applied to the speciation analysis of Al in natural waters and the results agree well with those of Driscoll's method. The speciation analysis of Al in biological fluids is also explored and the results are compared with those obtained by ultrafiltration and dialysis. Compared with other speciation protocols the electrochemical method possesses some remarkable advantages: rapidity, high sensitivity, cheap instrumentation and a simple operation procedure.     

Elastic scattering cross sections for 160<Superscript>°</Superscript> and 170<Superscript>°</Superscript>backscattering of 1.40-2.64 MeV protons from natural vanadium

Summary The elastic scattering cross sections of natural vanadium for protons have been measured for beam energies below 2.64 MeV in steps of 10 keV and in the angular 160° and 170°. The overall standard error (Δσ_Exp/σ_Exp) in the measured cross sections is estimated to be better than ±3% at all the beam energies and angles. The results are presented in graphical and tabular forms that should be useful for those who wish to use the cross sections for material analysis.     

二维卷积在动力学分析中的应用

本文用计算机模拟和二维卷积研究了稀土与间乙酰基偶氮氯膦的显色反应，选择不同的模型参数可描述这类反应的细节，二维卷积则增强对叠合二维谱的分辨。     

A general microcantilever surface modification method using a multilayer for biospecific recognition

The key to microcantilever surface modification technology is to selectively modify one side of a microcantilever surface with molecular recognition layers. In this paper, we report a general microcantilever modification method using a multilayer film.     

套索冠醚毛细管色谱柱的研制

用套索冠醚N,N′-双(2-甲基吡啶)-二氮杂-18-冠-6作为固定相,涂渍在弹性石英毛细管内,测其柱效、惰性、热稳定性、平均极性及选择性等性质.其结构由元素分析、红外光谱、核磁共振及质谱分析的试验数据所证实.试验表明,它具有良好的色谱性能、中等极性,适用于对醇、卤代烃、芳香烃等各类异构体的分离,并用分子结构观点探讨了保留机理.     

A novel small-molecule near-infrared II fluorescence probe for orthotopic osteosarcoma imaging

Osteosarcoma is the most common primary malignant tumor of bone, particularly among children and adolescents. Advances in imaging, surgical techniques, and implants have dramatically reduced the need for amputation in the past three decades.Recently, in vivo fluorescence imaging in the second near-infrared window(NIR-II, 1,000–1,700 nm) shows impressive advantages of deeper tissue penetration and higher spatial resolution, which makes it a promising tool for the early diagnosis and post-operative observation of Osteosarcoma. To the best of our knowledge, this paper is the first time to develop a novel NIR-II fluorescence probe conjugated with an osteosarcoma targeted oligopeptide for molecular tumor imaging in a xenograft orthotopic osteosarcoma mouse model.