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

Shape selectivity in olefin hydrogenation using rhodium-containing zeolites

CdSe nanorod electrode arrays with the nanorods aligned normal to the substrate were fabricated using porous aluminum oxide (PAO) templates. Photovoltaic characteristics were determined electrochemically in an aqueous solution using polysulfide (Sn2−) as the redox mediator. Isolating the back electrode from the electrolyte with a 100-nm-thick TiO2 barrier layer increased the open circuit voltage from −0.23 to −0.34 V and the fill factor from 0.42 to 0.57. Depending on the electrolyte concentration, IPCE values between 2.5 and 8% were observed at an incident wavelength of 500 nm. Internal quantum efficiencies were estimated to approach 50%. This architecture could be beneficial for the fabrication of bulk-heterojunction photovoltaic devices in conjunction with solution-deposited semiconducting inorganic nanoparticles or organic semiconductors.

Fabrication and Electrochemical Photovoltaic Response of CdSe Nanorod Arrays

A dimeric naphthyl hydride derivative of zirconocene. Synthesis, structure, and chemical properties

As small-volume cationic charge centers and as a source of unoccupied valence orbitals, the early main group metals have a well-documented but remarkable organometallic chemistry. Unusual structural configurations are observed for organolithium, beryllium, and aluminum compounds including semibridging {sigma}-{pi} coordination in organometallic acetylenes such as (C{sub 6}H{sub 5}){sub 2} AlC{triple bond}CC{sub 6}H{sub 5}{sup 2} {pi} back-donation which leads to planar three coordinate metal atom configurations as in (BeN(CH{sub 3}){sub 2}){sub 3}, alkyl C-H coordination as in LiB(CH{sub 3}){sub 4} or (LiC{sub 6}H{sub 11}){sub 2}, and frontier orbital directed coordination away from charge potential energy minima in {pi} carbanions. The authors present here the results of recent structural studies of Li{sub 2}CD{sub 2} as obtained from neutron and x-ray scattering experiments. The nontrivial synthesis of a pure phase of Li{sub 2}CD{sub 2} used in this study was carried out by the Kawa-Lagow modified Ziegler technique.

Galen D. Stucky

Papers

Shape selectivity in olefin hydrogenation using rhodium-containing zeolites

Fabrication and Electrochemical Photovoltaic Response of CdSe Nanorod Arrays

A dimeric naphthyl hydride derivative of zirconocene. Synthesis, structure, and chemical properties

Some observations concerning the structure of dilithiomethane

Oxidized Thin Films of C60: A New Humidity‐Sensing Material