抗原变异可使得多种致病微生物易于逃避宿主免疫应答。表达在感染红细胞表面的恶性疟原虫红细胞表面蛋白1（PfPMP1）与感染红细胞、内皮细胞、树突状细胞以及胎盘的单个或多个受体作用，在黏附及免疫逃避中起关键的作用。每个单倍体基因组var基因家族编码约60种成员，通过启动转录不同的var基因变异体为抗原变异提供了分子基础。

疟原虫var基因转换速率变化导致抗原变异[英]／Paul H, Robert P, Christodoulou Z, et al//Proc Natl Acad Sci U S A

Although gold is the subject of one of the most ancient themes of investigation in science, its renaissance now leads to an exponentially increasing number of publications, especially in the context of emerging nanoscience and nanotechnology with nanoparticles and self-assembled monolayers (SAMs). We will limit the present review to gold nanoparticles (AuNPs), also called gold colloids. AuNPs are the most stable metal nanoparticles, and they present fascinating aspects such as their assembly of multiple types involving materials science, the behavior of the individual particles, size-related electronic, magnetic and optical properties (quantum size effect), and their applications to catalysis and biology. Their promises are in these fields as well as in the bottom-up approach of nanotechnology, and they will be key materials and building block in the 21st century. Whereas the extraction of gold started in the 5th millennium B.C. near Varna (Bulgaria) and reached 10 tons per year in Egypt around 1200-1300 B.C. when the marvelous statue of Touthankamon was constructed, it is probable that “soluble” gold appeared around the 5th or 4th century B.C. in Egypt and China. In antiquity, materials were used in an ecological sense for both aesthetic and curative purposes. Colloidal gold was used to make ruby glass 293 Chem. Rev. 2004, 104, 293−346

Gold nanoparticles: assembly, supramolecular chemistry, quantum-size-related properties, and applications toward biology, catalysis, and nanotechnology.

Use of amphiphilic triblock copolymers to direct the organization of polymerizing silica species has resulted in the preparation of well-ordered hexagonal mesoporous silica structures (SBA-15) with uniform pore sizes up to approximately 300 angstroms. The SBA-15 materials are synthesized in acidic media to produce highly ordered, two-dimensional hexagonal (space group p6mm) silica-block copolymer mesophases. Calcination at 500°C gives porous structures with unusually large interlattice d spacings of 74.5 to 320 angstroms between the (100) planes, pore sizes from 46 to 300 angstroms, pore volume fractions up to 0.85, and silica wall thicknesses of 31 to 64 angstroms. SBA-15 can be readily prepared over a wide range of uniform pore sizes and pore wall thicknesses at low temperature (35° to 80°C), using a variety of poly(alkylene oxide) triblock copolymers and by the addition of cosolvent organic molecules. The block copolymer species can be recovered for reuse by solvent extraction with ethanol or removed by heating at 140°C for 3 hours, in both cases, yielding a product that is thermally stable in boiling water.

Triblock copolymer syntheses of mesoporous silica with periodic 50 to 300 angstrom pores

Problems associated with large-scale pattern growth of graphene constitute one of the main obstacles to using this material in device applications. Recently, macroscopic-scale graphene films were prepared by two-dimensional assembly of graphene sheets chemically derived from graphite crystals and graphene oxides. However, the sheet resistance of these films was found to be much larger than theoretically expected values. Here we report the direct synthesis of large-scale graphene films using chemical vapour deposition on thin nickel layers, and present two different methods of patterning the films and transferring them to arbitrary substrates. The transferred graphene films show very low sheet resistance of approximately 280 Omega per square, with approximately 80 per cent optical transparency. At low temperatures, the monolayers transferred to silicon dioxide substrates show electron mobility greater than 3,700 cm(2) V(-1) s(-1) and exhibit the half-integer quantum Hall effect, implying that the quality of graphene grown by chemical vapour deposition is as high as mechanically cleaved graphene. Employing the outstanding mechanical properties of graphene, we also demonstrate the macroscopic use of these highly conducting and transparent electrodes in flexible, stretchable, foldable electronics.

Large-scale pattern growth of graphene films for stretchable transparent electrodes

The carrier collection efficiency (ηc) and energy conversion efficiency (ηe) of polymer photovoltaic cells were improved by blending of the semiconducting polymer with C60 or its functionalized derivatives. Composite films of poly(2-methoxy-5-(2′-ethyl-hexyloxy)-1,4-phenylene vinylene) (MEH-PPV) and fullerenes exhibit ηc of about 29 percent of electrons per photon and ηe of about 2.9 percent, efficiencies that are better by more than two orders of magnitude than those that have been achieved with devices made with pure MEH-PPV. The efficient charge separation results from photoinduced electron transfer from the MEH-PPV (as donor) to C60 (as acceptor); the high collection efficiency results from a bicontinuous network of internal donor-acceptor heterojunctions.

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Polymer photovoltaic cells : enhanced efficiencies via a network of internal donor-acceptor heterojunctions

The high-temperature/high-pressure hydrothermal synthesis and X-ray single crystal structure of Be3(AsO4)2 · 2H2O are described. The title compound contains a three-dimensional network of BeO4 and AsO4 tetrahedra, whose structural motif includes infinite layers of "bridged" tetrahedral 3- and 4-rings. 9Be MAS NMR data are consistent with the Be-atom environments in the crystal structure. Crystal data for Be3(AsO4)2 · 2H2O: Mr = 340.91, monoclinic, space group C2/c (No. 15), a = 16.318(2) A, b = 4.6664(3) A, c = 9.8755(7) A, β = 93.777(3)°, V = 750.37 A3, Z = 4. Final disagreement values of R = 3.59% and Rw = 3.79% were obtained for 1289 observed reflections with I > 3σ(I).

Be3(AsO4)2 2H2O: A new berylloarsenate phase containing bridged tetrahedral 3-rings

Publisher Summary The 3-D organized molecular assembly of components into an integrated system is an, particularly, intriguing challenge that are both functionally and compositionally distinct. In addition to the requirement of the multicompositional, hierarchical assembly of spatially distinct domains, there must be information exchange between the domains that can be selectively coupled with the external environment. Living systems provide a sophisticated model for this that is currently well beyond the best bench-top efforts. In biogenesis, the components of the organized and integrated system are created via nonlinear parallel, multivalent syntheses, and processing. The bioassembly is typically directed by entropy change and interface interactions in confined spaces. The space/time assembly definition of structure and function makes possible the closely coupled organization and processing of integrated organic and inorganic domains. It is also utilized to create, among other things, gradient interface structures that enable the coupling of the components of the organism internally or with the external environment. This presentation describes selected biogenic model systems and the related use of kinetic control, competing processes, nonequilibria phenomena, multiphase media, entropy, and organic/inorganic interfaces to synthesize the composite materials that have patterned 3-D structural and coupled functional properties.

Integrating interfaces and function with molecular assembly

On the association of the Grignard reagent

The overall project objective is the development and application of combinatorial methods to discover an efficient, practical, and economically sensible material for photoelectrochemical production of hydrogen from water and sunlight. We are exploring a shift in the research paradigm from conventional serial chemical research to a combinatorial approach featuring a systematic and deliberate high-speed exploration of the composition-structure-property relationships of new metal-oxide based solid-state materials. By intelligent and rapid design, synthesis, and analysis of large diverse collections of potential photoelectrochemical materials in libraries we are attempting to discover new and useful energy producing materials as well as better understand fundamental mechanism and composition-structure function relationships of these materials. Since funding began in September 2001 we have remained on or ahead of schedule for milestone completion as outlined in the monthly reports. We have designed and built several prototype systems for automated electrosynthetic deposition of metal oxides including both parallel and serial systems. We now have developed direct cathodic routes to oxides of several metals including W, Ni, Nb, Ti, Fe, Cu, Co, Mo, Zn by stabilization with several ligand types and made preliminary studies with libraries which have shown general trends. Specific improvements in W doped with Ni, Pt, and Ru have been observed. Preliminary work on electrosynthesis of mesoporous WO3 and TiO2 films from a peroxo-stabilized electrolyte using ionic surfactants has not yet shown highly ordered materials, however, increases in photocurrent have been observed which we are attempting to explain. Finally, an important derivative of our work has been from libraries of pulsed electrodeposited Pt doped WO3 whereby a new means of creating nanoparticles has been developed which show high activity for methanol oxidation without the poisoning problems of pure Pt electrodes.

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Galen D. Stucky

Papers

Be3(AsO4)2 2H2O: A new berylloarsenate phase containing bridged tetrahedral 3-rings

Integrating interfaces and function with molecular assembly

On the association of the Grignard reagent

Photoelectrochemical Hydrogen Production Using New Combinatorial Chemistry Derived Materials

High throughput screening and measurements of proton conductivity of newly developed PEM materials based on proton transport visualization