A 2-D liquid separations/mass mapping method for interlysate comparison of ovarian cancers

A two-dimensional liquid phase separation of proteins from whole cell lysates coupled on-line to an electrospray-ionization time-of-flight (ESI-TOF) mass spectrometer (MS) is used to map the protein content of ovarian surface epithelial cells (OSE) and an ovarian carcinoma-derived cell line (ES2). The two dimensions involve the use of liquid isoelectric focusing as the first phase and nonporous silica reversed-phase HPLC as the second phase of separation. Accurate molecular weight (MW) values are then obtained upon the basis of ESI-TOFMS so that an image of isolectric point (pI) versus MW analogous to 2-D gel electrophoresis is produced. The accurate MW together with the pI fraction and corresponding hydrophobicity (%B) are used to tag each protein so that protein expression can be compared in interlysate studies. Each protein is also identified on the basis of matrix-assisted laser desorption-ionization (MALDI) TOFMS peptide mapping and intact MW so that a standard map is produced against which other cell lines can be compared. Quantitative changes in protein expression are measured in these interlysate comparisons using internal standards in the on-line ESI-TOFMS process. In the ovarian epithelial cell lines under study, it is shown that in the three pI fractions chosen for detailed analysis, over 50 unique proteins can be detected per fraction, of which 40% can be identified from web-based databases. It is also shown that when using an accurate MW to compare proteins in the OSE versus ovarian cancer sample, there are proteins highly expressed in cancer cells but not in normal cells. In addition, many of the proteins in the cancer sample appear to be down-regulated, as compared to the normal cells. This two-dimensional (2-D) liquid/mass mapping method may provide a means of studying proteins in interlysate comparisons not readily available by other methods.     

Photo-induced proton gradients and ATP biosynthesis produced by vesicles encapsulated in a silica matrix

Sol-gel immobilization of soluble proteins has proven to be a viable method for stabilizing a wide variety of proteins in transparent inorganic matrices. The encapsulation of membrane-bound proteins has received much less attention, although work in this area suggests potential opportunities in microarray technology and high-throughput drug screening. The present paper describes a liposome/sol-gel architecture in which the liposome provides membrane structure and protein orientation to two transmembrane proteins, bacteriorhodopsin (bR) and F(0)F(1)-ATP synthase; the sol-gel encapsulation converts the liposomal solution into a robust material without compromising the intrinsic activity of the incorporated proteins. Here we report on two different proteoliposome-doped gels (proteogels) whose properties are determined by the transmembrane proteins. Proteogels containing bR proteoliposomes exhibit a stable proton gradient when irradiated with visible light, whereas proteogels containing proteoliposomes with both bR and F(0)F(1)-ATP synthase couple the photo-induced proton gradient to the production of ATP. These results demonstrate that materials based on the liposome/sol-gel architecture are able to harness the properties of transmembrane proteins and enable a variety of applications, from power generation and energy storage to the powering of molecular motors, and represent a new technology for performing complex chemical synthesis in a solid-state matrix.     

Nano-encapsulation of protein using an enteric polymer as carrier

In this preliminary work, an enteric polymer has been used for encapsulating bovine serum albumine (BSA) as a model protein drug. Poly (lactide-co- glycolide) has been commonly used for oral administration purposes as a polymer matrix, but in this case an enteric polymer was used effectively to protect the protein in a gastric environment. A modified water/oil/water technique was used to decrease the particle diameter, and transmission electron microscopy experiments showed that the average diameter of the nanoparticles obtained was below 100 nm. The spherical nature of the particles and their diameters strongly depend on the control of the process parameters. The encapsulation efficiency was 77% for sample B4, and protein release profiles for both samples B3 and B4 indicate that these systems possess controlled-release characteristics. Finally, as a result of electrophoresis (SDS-PAGE), the BSA was not chemically affected under encapsulation conditions.     

Improving the Stability of Metal Halide Perovskite Quantum Dots by Encapsulation

Metal halide perovskite quantum dots (PQDs), with excellent optical properties and spectacular characteristics of direct and tunable bandgaps, strong light‐absorption coefficients, high defect tolerance, and low nonradiative recombination rates, are highly attractive for modern optoelectronic devices. However, the stability issue of PQDs remains a critical challenge of this newly emerged material despite the recent rapid progress. Here, the encapsulation strategies to improve the stability of PQDs are comprehensively reviewed. A special emphasis is put on the effects of encapsulation, ranging from the improvement of chemical stability, to the inhibition of light‐induced decomposition, to the enhancement of thermal stability. Particular attention is devoted to summarizing the encapsulation approaches, including the sol–gel method, the template method, physical blending, and microencapsulation. The selection principles of encapsulation materials, including the rigid lattice or porous structure of inorganic compounds, the low penetration rate of oxygen or water, as well as the swelling–deswelling process of polymers, are addressed systematically. Special interest is put on the applications of the encapsulated PQDs with improved stability in white light‐emitting diodes, lasers, and biological applications. Finally, the main challenges in encapsulating PQDs and further investigation directions are discussed for future research to promote the development of stable metal halide perovskite materials.     

Zwitterionic hydrophilic interaction liquid chromatography (ZIC-HILIC and ZIC-cHILIC) provide high resolution separation and increase sensitivity in proteome analysis

The complexity of peptide mixtures that are analyzed in proteomics necessitates fractionation by multidimensional separation approaches prior to mass spectrometric analysis. In this work, we introduce and evaluate hydrophilic interaction liquid chromatography (HILIC) based strategies for the separation of complex peptide mixtures. The two zwitterionic HILIC materials (ZIC-HILIC and ZIC-cHILIC) chosen for this work differ in the spatial orientation of the positive and negative charged groups. Online experiments revealed a pH-independent resolving power for the ZIC-cHILIC resin while ZIC-HILIC showed a decrease in resolving power at an acidic pH. Subsequently, we extensively evaluated the performances of ZIC-HILIC and ZIC-cHILIC as first dimension in an off-line two-dimensional liquid chromatography (2D-LC) strategy in combination with reversed phase (RP), with respect to peptide separation efficiency and how the retention time correlates with a number of peptide physicochemical properties. Both resins allowed the identification of more than 20,000 unique peptides corresponding to over 3500 proteins in each experimental condition from a remarkably low (1.5 μg) amount of starting material of HeLa lysate digestion. The resulting data allows the drawing of a comprehensive picture regarding ZIC- and ZIC-cHILIC peptide separation characteristics. Furthermore, the extent of protein identifications observed from such a level of material demonstrates that HILIC can rival or surpass traditional multidimensional strategies employed in proteomics.     

Generation of High‐Order All‐Aqueous Emulsion Drops by Osmosis‐Driven Phase Separation

Droplets containing ternary mixtures can spontaneously phase‐separate into high‐order structures upon a change in composition, which provides an alternative strategy to form multiphase droplets. However, existing strategies always involve nonaqueous solvents that limit the potential applications of the resulting multiple droplets, such as encapsulation of biomolecules. Here, a robust approach to achieve high‐order emulsion drops with an all‐aqueous nature from two aqueous phases by osmosis‐induced phase separation on a microfluidic platform is presented. This technique is enabled by the existence of an interface of the two aqueous phases and phase separation caused by an osmolality difference between the two phases. The complexity of emulsion drops induced by phase separation could be controlled by varying the initial concentration of solutes and is systematically illustrated in a state diagram. In particular, this technique is utilized to successfully achieve high‐order all‐aqueous droplets in a different aqueous two‐phase system. The proposed method is simple since it only requires two initial aqueous solutions for generating multilayered, organic‐solvent‐free all‐aqueous emulsion drops, and thus these multiphase emulsion drops can be further tailored to serve as highly biocompatible material templates.     

相变材料微胶囊研究进展

相变材料微胶囊有许多优点,如增加了热传导的面积,降低了相变材料与外界环境的反应活性并在相变发生时可以控制蓄能材料体积的变化.介绍了可作为芯材的相变材料及其主要性质,重点总结了2002年以来相变材料微胶囊的制备方法、表征与材料特点,同时讨论了国内外相变材料微胶囊在建筑节能、纺织及其他领域中的应用现状、存在的问题以及发展前景.     

纳米钛白的制备及应用进展

纳米钛白的制备方法大致可分为两类,即气相法和液相法,而液相法是研究的重点和热点。目前已经发现纳米钛白在催化及环境保护方面有广泛的应用前景,已经形成了相关的产业,并有可能成为本世纪利用太阳能净化环境的又一次技术革命。纳米钛白的分散性问题依然是未来相当一段时间内急待解决的技术核心,这也是纳米钛白研究的关键技术之一。另外纳米钛白在环保、塑料、涂料等相关领域中的应用技术的开发同样具有重大意义。     

One‐Pot Synthesis of Multiple Protein‐Encapsulated DNA Flowers and Their Application in Intracellular Protein Delivery

Inspired by biological systems, many biomimetic methods suggest fabrication of functional materials with unique physicochemical properties. Such methods frequently generate organic–inorganic composites that feature highly ordered hierarchical structures with intriguing properties, distinct from their individual components. A striking example is that of DNA–inorganic hybrid micro/nanostructures, fabricated by the rolling circle technique. Here, a novel concept for the encapsulation of bioactive proteins in DNA flowers (DNF) while maintaining the activity of protein payloads is reported. A wide range of proteins, including enzymes, can be simultaneously associated with the growing DNA strands and Mg₂PPi crystals during the rolling circle process, ultimately leading to the direct immobilization of proteins into DNF. The unique porous structure of this construct, along with the abundance of Mg ions and DNA molecules present, provides many interaction sites for proteins, enabling high loading efficiency and enhanced stability. Further, as a proof of concept, it is demonstrated that the DNF can deliver payloads of cytotoxic protein (i.e., RNase A) to the cells without a loss in its biological function and structural integrity, resulting in highly increased cell death compared to the free protein.     

Hydrogen under extreme conditions

Some recent advances in our understanding of the properties of hydrogen and deuterium at megabar pressures are reviewed. The emphasis is on recent spectroscopic experiments to elucidate the nature of the H-A phase (Phase III), the high-pressure phase diagram, and on the reported generation of liquid metallic hydrogen under shock compression conditions. Density Functional and Quantum-Monte Carlo calculations have proved a useful guide to interpreting the experimental results: these will also be reviewed.     

Gel-eluted liquid fraction entrapment electrophoresis: an electrophoretic method for broad molecular weight range proteome separation

Although well-established as a technique for protein purification, the application of continuous elution tube gel electrophoresis to proteome fractionation remains problematic. Difficulties associated with sample collection, particularly at the high mass range or at low sample loadings, continue to plague the technique. Furthermore, an upper mass limit is imposed as slow-moving higher molecular weight proteins are progressively diluted during the collection phase. In short, with current technology, effective separation over a broad mass range has not been achieved. In this work, we present improved techniques for continuous elution tube gel electrophoresis to accommodate broad mass range separation of proteins. Our device enables rapid partitioning of a proteome into discrete mass range fractions in the solution phase. High recovery is achieved at submicrogram to milligram sample loadings. We demonstrate comprehensive, reproducible separations of protein mixtures, as well as separation of a proteome in as fast as 1 h, over mass ranges from below 10 to 250 kDa. Finally, we identified proteins from a prefractionated standard protein mixture using liquid chromatography tandem mass spectrometric (LC-MS/MS) analysis.     

相反转界面细乳液聚合法制备石蜡纳胶囊与表征

采用相反转乳化的界面细乳液聚合法制备了以交联聚甲基丙烯酯甲酯为壁材,以石蜡为芯材的纳胶囊。利用光学显微镜、激光粒度分析仪、透射电镜、红外光谱仪、差示扫描量热分析仪等研究了含氟助乳化剂FC-4430、丙烯酸十八酯(SA)及芯材投料量对聚合过程、产品表面形貌、粒径、化学结构、储热性能和包覆率的影响。结果表明,FC-4430对相反转有促进作用,可降低胶囊粒子尺寸且利于包封;SA能提高纳胶囊的包覆率和热稳定性;当FC-4430用量为0.4%,SA用量为2%,m(core)∶m(shell)为2∶1时,纳胶囊的相变潜热为91.7 J/g,包覆率为63.3%,包覆效率为95.0%,胶囊粒子为球形,表面光滑,粒径为0.6~1μm,呈明显的核壳结构,芯材直径为300~500 nm。     

Growth and characterization of InGaAsP lattice-matched to InP

The development of InGaAsP lattice-matched to InP as a suitable material for a range of electronic devices is reviewed. Currently accepted values of fundamental material parameters such as lattice constant, energy band-gap and effective mass as a function of composition are presented. The various growth techniques are discussed with particular emphasis given to the liquid phase epitaxy (LPE) method which has emerged as the most popular. Details of the determination of the liquidus and solidus phase diagrams both theoretically and experimentally are given and a comparison of the two is carried out. The problems of doping control and lattice matching are discussed. The other less widely-used growth methods, vapour phase epitaxy (VPE) and molecular beam epitaxy (MBE), are also outlined. The development of optical sources (lasers and LED's) and photodetectors for optical-fibre communication systems is presented with particular attention being paid to the device technology. The latest performance figures in this rapidly moving area are reviewed. Prospects for the use of this material in non-optical applications are discussed in terms of its transport properties and device technology for applications in microwaves and high-speed logic.     

晶体的熔化和过热

熔化是自然界中的一种普遍现象，也是材料的重要相变过程之一。本文综述近年来晶体熔化过程研究取得的主要结果和最新进展，着重论述晶体界面对熔化过程的影响和过热晶体的获得，并分析晶体过热的极限。     

相变材料的研究进展及其在建筑领域的应用综述

相变材料是相变物质与传统建筑材料复合而成的一种新型储能建筑材料,本文对相变材料的概念、相变材料的分类、相变材料的筛选和改进、相变材料的制备方法以及封装方法进行了阐述,同时论述了相变材料在建筑领域的应用,并提出了相变材料应用于建筑领域的发展方向。     

Differential screening and mass mapping of proteins from premalignant and cancer cell lines using nonporous reversed-phase HPLC coupled with mass spectrometric analysis

Nonporous (NPS) RP-HPLC has been used to rapidly separate proteins from whole cell lysates of human breast cell lines. The nonporous separation involves the use of hard-sphere silica beads of 1.5-microm diameter coated with C18, which can be used to separate proteins ranging from 5 to 90 kDa. Using only 30-40 microg of total protein, the protein molecular weights are detectable on-line using an ESI-oaTOF MS. Of hundreds of proteins detected in this mass range, approxinately 75-80 are more highly expressed. The molecular weight profiles can be displayed as a mass map analogous to a virtual "1-D gel" and differentially expressed proteins can be compared by image analysis. The separated proteins can also be detected by UV absorption and differentially expressed proteins quantified. The eluting proteins can be collected in the liquid phase and the molecular weight and peptide maps determined by MALDI-TOF MS for identification. It is demonstrated that the expressed protein profiles change during neoplastic progression and that many oncoproteins are readily detected. It is also shown that the response of premalignant cancer cells to estradiol can be rapidly screened by this method, demonstrating significant changes in response to an external agent. Ultimately, the proteins can be studied by peptide mapping to search for posttranslational modifications of the oncoproteins accompanying progression.     

石英套管封装光纤光栅温度传感器

针对光纤光栅温度传感器管式封装时,高温下环境聚合物粘接材料性能不稳定的问题,提出一种无胶封装方法,选用石英套管作为封装材料,利用高频CO2激光脉冲加热,使传输光纤与石英套管实现可靠焊接,并对封装后的传感器的温度特性进行测试,实验结果表明:石英套管封装的光纤光栅温度传感器在室温至300℃具有很好的线性,可实现对环境温度的测量。     

液液两相流法制备海藻酸钠包覆的液态金属微滴

本文以室温液态金属(GaInSn)为分散相、海藻酸钠(NaAlg)溶液(1wt%)为连续相,采用液液两相流方法,在竖直共轴微通道中,制备得到NaAlg凝胶包覆的多个GaInSn微滴,具有单分散、尺寸一致的特点。GaInSn/NaAlg两相流存在四种流型:分散相滴流、分散相柱塞流、连续相滴流和连续相射流。GaInSn微滴的包覆模式三种:Squeezing、Dripping和Compound Jetting,其中Dripping和Compound Jetting是主要的包覆模式。在较低的GaInSn流量下,NaAlg流量增加到一定程度后,包覆模式由Dripping转变Compound Jetting。固定两相流量比,随着两相流量的同比例增加,GaInSn微滴的特征频率呈线性增加、包覆个数增加、特征长度变化不显著。     

A virus-based biocatalyst

Virus particles are probably the most precisely defined nanometre-sized objects that can be formed by protein self-assembly. Although their natural function is the storage and transport of genetic material, they have more recently been applied as scaffolds for mineralization and as containers for the encapsulation of inorganic compounds. The reproductive power of viruses has been used to develop versatile analytical methods, such as phage display, for the selection and identification of (bio)active compounds. To date, the combined use of self-assembly and reproduction has not been used for the construction of catalytic systems. Here we describe a self-assembled system based on a plant virus that has its coat protein genetically modified to provide it with a lipase enzyme. Using single-object and bulk catalytic studies, we prove that the virus-anchored lipase molecules are catalytically active. This anchored biocatalyst, unlike man-made supported catalysts, has the capability to reproduce itself in vivo, generating many independent catalytically active copies.