惯性微流体的应用与发展

根据流式细胞仪对样品“均一化”的需求,研制了一套基于微流控细胞分选技术的流式细胞仪样品预处理系统,装置可以实现对粒径小于100 μm细胞或微粒的驱动和分选. 系统主要包含微流控分选芯片和样品驱动模块两部分,通过聚焦不同位置,实现了对不同粒径细胞/颗粒的有效分离. 系统无需对细胞进行标记处理,经分选的细胞便于后续流式细胞仪检测. 经验证,系统能够有效去除牡蛎血淋巴细胞样品中的大粒子杂质,提高细胞样品的稳定性和均一性,增加流式细胞仪检测结果的准确性.

     

Multiresolution quantum chemistry: basic theory and initial applications

We describe a multiresolution solver for the all-electron local density approximation Kohn-Sham equations for general polyatomic molecules. The resulting solutions are obtained to a user-specified precision and the computational cost of applying all operators scales linearly with the number of parameters. The construction and use of separated forms for operators (here, the Green's functions for the Poisson and bound-state Helmholtz equations) enable practical computation in three and higher dimensions. Initial applications include the alkali-earth atoms down to strontium and the water and benzene molecules.     

Recent developments, characteristics, and potential applications of electrochemical biosensors.

The objective of this study is to analyze the technical importance, performance, techniques, advantages, and disadvantages of the biosensors in general and of the electrochemical biosensors in particular. A product of reaction diffuses to the transducer in the first generation biosensors (based on Clark biosensors). The mediated biosensors or second generation biosensors use specific mediators between the reaction and the transducer to improve sensitivity. The second generation biosensors involve two steps: first, there is a redox reaction between enzyme and substrate that is reoxidized by the mediator, and eventually the mediator is oxidized by the electrode. No normal product or mediator diffusion is directly involved in the third generation biosensors, direct biosensors. Based on the type of transducer, current biosensors are divided into optical, mass, thermal, and electrochemical sensors. They are used in medical diagnostics, food quality controls, environmental monitoring, and other applications. These biosensors are also grouped under two broad categories of sensors: direct and indirect detection systems. Moreover, these systems could be further grouped into continuous or batch operation. Therefore, amperometric biosensors and their current applications are focused on more in detail since they are the most commonly used biosensors in monitoring and diagnosing tests in clinical analysis. Problems related to the commercialization of medical, environmental, and industrial biosensors as well as their performance characteristics, their competitiveness in comparison to the conventional analytical tools, and their costs determine the future development of these biosensors.     

Porphyrin derivatives: Synthesis and potential applications

Porphyrin‐porphyrin and porphyrin‐chlorin dimers have been synthesized and evaluated for their photo‐physical and in vivo photodynamic therapy properties. Two of them can become potential new photosensitizers. Study of the reactivity of meso‐tetraaryl porphyrins, as dienophiles, in Diels‐Alder transformations and as dipolarophiles in 1,3‐dipolar cycloadditions, has been undertaken. New synthetic methodologies for certain chlorin, bacteriochlorin and isobacteriochlorin type macrocycles, with potential biological significance, have been established.     

Nanofibrillated cellulose: surface modification and potential applications

Interest in nanofibrillated cellulose has been increasing exponentially because of its relatively ease of preparation in high yield, high specific surface area, high strength and stiffness, low weight and biodegradability etc. This bio-based nanomaterial has been used mainly in nanocomposites due to its outstanding reinforcing potential. Solvent casting, melt mixing, in situ polymerization and electrospinning are important techniques for the fabrication of nanofibrillated cellulose-based nanocomposites. Due to hydrophilic character along with inherent tendency to form strong network held through hydrogen-bonding, nanofibrillated cellulose cannot uniformly be dispersed in most non-polar polymer matrices. Therefore, surface modification based on polymer grafting, coupling agents, acetylation and cationic modification was used in order to improve compatibility and homogeneous dispersion within polymer matrices. Nanofibrillated cellulose opens the way towards intense and promising research with expanding area of potential applications, including nanocomposite materials, paper and paperboard additive, biomedical applications and as adsorbent.     

Fullerene-containing porphyrins: Synthesis and potential practical applications

The review focuses current research in the rapidly developing field of the chemistry of porphyrin–fullerene complexes. Recent advances in the synthesis, properties, and potential applications of these compounds are considered. An overview of the most popular methods to prepare porphyrin complexes with C₆₀ fullerene is given. The discussion of porphyrin?fullerene complexes includes the structures of noncovalently linked porphyrin?fullerenes along with covalently linked complexes. Much attention is paid to potential applications of porphyrin?fullerene conjugates.     

Metal-enhanced fluorescence: potential applications in HTS

Metallic surfaces and particles can have dramatic effects on fluorescence, including localized excitation, increased quantum yields, increased photostability and increased distances for resonance energy transfer (RET), and directional emission. While all these effects have not yet been realized in a single system, metal-enhanced fluorescence promises to provide the next generation of high sensitivity fluorescence assays for low copy number detection of biochemical species.     

Structural investigations on 'smectic D' and related mesophases

We have performed time resolved diffraction experiments in order to obtain a better insight upon the metastable phases surrounding some thermotropic mesophases of cubic Ia 3 d and Im 3 m symmetries. These metastable phases are columnar hexagonal, smectic or tetragonal, depending on the nature of the mesogenic molecule. Moreover, it appears that the structure of the cubic phase of the 4-alkyloxybiphenyl-4-carboxylic acids previously labelled smectic D varies with the lateral group substituted on the biphenyl core.     

Electrochemistry of plants: basic theoretical research and applications in plant science

Journal of Solid State Electrochemistry - Electrochemistry of plants can be viewed as a multifaceted research fields including electrophysiological studies around signaling in plants and those...     

Graphene electrochemistry: an overview of potential applications

Graphene, a 2D nanomaterial that possesses spectacular physical, chemical and thermal properties, has caused immense excitement amongst scientists since its freestanding form was isolated in 2004. With research into graphene rife, it promises enhancements and vast applicability within many industrial aspects. Furthermore, graphene possesses a vast array of unique and highly desirable electrochemical properties, and it is this application that offers the most enthralling and spectacular journey. We present a review of the current literature concerning the electrochemical applications and advancements of graphene, starting with its use as a sensor substrate through to applications in energy production and storage, depicting the truly remarkable journey of a material that has just come of age.     

化学修饰的寡核苷酸: 合成、性质和应用

本文综述了近年来化学修饰的寡核苷酸研究的进展,介绍了化学修饰的寡核苷酸的种类, 化学合成方法, 生物作用原理及应用方面已达到的成継34This review deals with the progress in the research of chemically modified oligonucleotides: the synthesis, the chemical and biological properties and the potential applications as a new research tool and new therapeutic approach.     

DNA and RNA aptamers: from tools for basic research towards therapeutic applications

The systematic evolution of ligands by exponential enrichment (SELEX) is a combinatorial oligonucleotide library-based in vitro selection approach in which DNA or RNA molecules are selected by their ability to bind their targets with high affinity and specificity, comparable to those of antibodies. Nucleic acids with high affinity for their targets have been selected against a wide variety of compounds, from small molecules, such as ATP, to membrane proteins and even whole organisms. Recently, the use of the SELEX technique was extended to isolate oligonucleotide ligands, also known as aptamers, for a wide range of proteins of importance for therapy and diagnostics, such as growth factors and cell surface antigens. The number of aptamers generated as inhibitors of various target proteins has increased following automatization of the SELEX process. Their diagnostic and therapeutic efficacy can be enhanced by introducing chemical modifications into the oligonucleotides to provide resistance against enzymatic degradation in body fluids. Several aptamers are currently being tested in preclinical and clinical trials, and aptamers are in the process of becoming a new class of therapeutic agents. Recently, the anti-VEGF aptamer pegaptanib received FDA approval for treatment of human ocular vascular disease.     

Molecular reactors and machines: applications, potential, and limitations

Molecular reactors are miniature vessels for the assembly of reactants at the molecular level, in order to change the nature of chemical transformations. It seems probable that those that will find most immediate applications are those that change product ratios or give products which would not readily form in the absence of the reactors, and thereby afford easy access to materials that are otherwise difficult to obtain. Molecular machines consist of interrelated parts with separate functions and perform some kind of work, at the molecular level. Practical examples are likely to be relatively uncomplicated and not based on individual functions of single-molecule devices. Instead they will probably rely on extensive redundancy of the molecular components and their interactions and reactions, as well as of the machines themselves.     

One-dimensional nanostructures of metals: large-scale synthesis and some potential applications

We review recent developments in our group regarding the solution-phase synthesis of one-dimensional nanostructures of metals. The synthetic approaches include solution-liquid-solid growth for nanowires of low-melting-point metals such as Pb; seed-directed growth for Ag nanowires, nanobeams, and nanobelts; kinetically controlled growth for Pt nanorods, nanowires, and multipods; and galvanic replacement for nanotubes of Au, Pt, and Pd. Both characterization and mechanistic studies are presented for each nanostructure. Finally, we highlight the electrical and plasmonic properties of these metal nanostructures and discuss their potential applications in nanoscale devices.     

Hollow polymer shells from biological templates: fabrication and potential applications

Three-dimensional ultrathin polymer shells have been produced by a combination of step-by-step adsorption of polyelectrolytes on glutaraldehyde-treated human erythrocytes and subsequent solubilization of the cytoplasmatic constituents by means of a deproteinizing agent. The obtained hollow films preserve both the size and shape of the templating cells. This opens a pathway for the fabrication of polymeric capsules within a wide range of size and shape by using various biological templates. They may have exciting potential applications, such as templates for nanocomposites, as containers for a large class of materials, or as cages for chemical reactions. The thickness of the films can be adjusted over a large range: from a few nm up to several tens of nm. The polymer shells are permeable to small molecules and ions but not to macromolecules. An increase in the ionic strength of the solution up to 100 mmol make the capsules permeable for proteins. Permeability and conductivity studies have provided evidence that the adsorption of lipids on polyelectrolyte layers is a means of producing capsules with controlled permeability properties. 6-Carboxyfluorescein and Rhodamin 6G were precipitated within the capsules.     

Electrically conductive pili: Biological function and potential applications in electronics

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超卤素的结构、特性及应用研究进展

卤族(halogen)元素,包括氟(F)、氯(Cl)、溴(Br)、碘(I)和砹(At),具有高的电子亲和能(EA)与强反应活性及氧化性.它们在材料合成与改性方面的广泛应用极大地激励人们研究超卤素(superhalogen),即EA比卤素原子的EA(3.0～3.6eV)更高的一类基团或分子.与卤素原子相比,超卤素表现出电负性更大、结构更丰富、性质更新颖等更加丰富的特征.本文总结了最近30年来人们在设计与合成新型超卤素和飙卤素(hyperhalogen)方面所取得的实验和理论研究进展,讨论了超卤素和飙卤素的电子结构和物性,展望了超卤素在开发新型磁性材料、环境净化材料、高能密度材料以及非线性光学材料等方面的应用前景.     

双原子催化剂:制备、表征和应用

发展可持续和清洁的电化学能源转化技术是应对能源短缺和环境污染挑战的关键一步,燃料电池、电解电池和金属空气电池作为清洁能源储存和转换装置目前得到广泛应用推广,这些装置依靠电催化反应以及电极材料上发生的电荷转移过程来转换电能和化学能.而电催化剂是该类装置电极材料的核心部件,电催化反应的热力学和动力学过程与电催化剂的物理性质和化学状态密切相关.因此探索和开发性能优良、成本低廉的新型电催化剂,将进一步促进这些能源转化技术的商业化应用.单原子催化剂(SACs)以其暴露的活性位点、高选择性和最大限度地原子利用率而受到人们的广泛关注.然而,随着单原子表面自由能的增加,粒子在制备和催化过程中的聚集,催化活性位点的降低和催化剂负荷的相对较低,严重制约了SACs的发展和应用.考虑到SACs的缺点,为了进一步增加单原子活性位点的数量和负载,双原子催化剂(DACs)作为SACs家族成员的扩展近年来逐渐兴起,且两种金属原子(同核/异核)在DACs中的协同作用显著提高了催化剂的催化活性.本文基于当前最新的研究工作对比了同核/异核DACs的不同优势,列举了一系列包括原子层沉积法、湿化学吸附法以及高温热处理法等方法用于制备性能优异的DACs,其中高温热处理法因应用广泛被重点强调.同时,本文也对DACs的表征和识别手段进行了重点概括,包含XANES, EXAFS, IR, DFT等;详细概括和对比了当前DACs在电化学方面的主要应用,如氧还原反应(ORR)和二氧化碳还原反应.目前, DACs作为一个新兴的研究领域,由于其金属原子负载量高、活性位点比SACs更为灵活,已经在电催化领域取得了快速的发展.相对于同核DACs,原则上不同的两个金属原子会组成更多的异核DACs,因此,对于性能优异的异核DACs还有更多的可能性值得深入探索.可以预见, DACs的发展将弥补SACs的不足,在电化学能源的转换和储存方面发挥全面的优势;借助于异核DACs中不同的两个金属原子的多样性,探索以过渡金属为主的DACs,将会为节约贵金属资源及环境保护带来巨大贡献,进一步设计和优化DACs,有利于燃料电池和金属-空气电池创造出更大的经济效益和社会效益.因此,我们相信DACs的发展将成为材料研究的一个新前沿,并为合成更多的高效应用催化剂开辟一条新的途径.     

Langmuir-Blodgett films of octadecanethiol--properties and potential applications

Octadecanethiol (ODT) is known to form self-assembled monolayer on noble metal surfaces which has potential technological applications. Langmuir-Blodgett (LB) technique is another useful method of obtaining highly ordered assembly of molecules. It is of interest to find whether ODT molecules can also form a stable Langmuir monolayer which facilitates the preparation of LB films. In literature, it has been reported that ODT molecules form an unstable Langmuir monolayer. We have studied the stability of the monolayer of the ODT molecules at air-water interface using surface manometry and microscopy techniques. We find the monolayer to be stable on ultrapure water of resistivity greater than 18MOmega cm. However, the behavior changes in the presence of even small amount of additives like NaOH or CdCl2 in the subphase. Our AFM studies on the LB films of ODT deposited from ion-free ultrapure water showed streak-like bilayer domains. The LB films of ODT deposited from CdCl2 containing aqueous subphase yield dendritic domains of the complexed unit grown over ODT monolayer. These nanostructures on surfaces may have potential applications in molecular electronics.