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

A New Phase of Oriented Mesoporous Silicate Thin Films.

Publisher Summary Syntheses of nanoclusters can be carried out in a variety of ways to give unexpectedly different materials. These have varied structural, optical, and transport properties. Quantum confinement is responsible for many of these properties. This occurs when the individual clusters of a semiconductor are the same size or smaller than the radius of an exciton, which is a weakly bound electron-hole pair. The motion of the exciton, thus, becomes quantized, leading to unusual optical and electronic properties. Considerable effort has gone into the synthesis of quantum confined semiconductors as a result of their useful and interesting properties. This can be done from colloidal solution and by molecular beam or atomic layer epitaxy. The structures formed include quantum wells, dots, or wires. In the approach, quantum confined structures are synthesized by taking advantage of the vast internal 3-dimensional surface of molecular sieves and porous glasses. This allows controls not generally available in solution chemistry or epitaxy. The chapter reviews current methods employed to synthesize nanoclusters. It outlines the chemistry involved in preparing host/guest compounds of semiconductors in zeolites and porous silica glasses and describes their unique physical properties. The chapter also discusses the use of solid state nuclear magnetic resonance (NMR) to follow the reaction chemistry involved, which adds a dimension not previously available in this area.

Assembly of Supra Nanoclusters within Crystalline and Amorphous 3-D surfaces

Despite the recent progress in the synthesis of new germanates, no zinc germanate has been synthesized by using a molecular templating route. A unique type of zincogermanate framework has now been prepared by using ethylenediamine as the structure-directing agent. The three-dimensional framework can be simply described as the face-centered packing of an elongated neutral cluster unit, Ge9O18.

First Open-Framework Zinc Germanates by a Molecular Templating Route.

: Nonstoichiometric silver, sodium bromosodalites of the compositions M8-2nN2nX2-pOHp-SOD and M8-p-2nN2nX2-pp-SOD have been synthesized, where M, N = Ag+, Na+; X = Cl-; Br, I-; 2n = 0-8; p = 0-2; refers to anion-free cages and SOD = (SiAI04)66-. These materials allow one to control the filling of both Ag+ and X-ions in a sodalite host lattice in a systematic manner, to fabricate Na4-nAgnX semiconductor-component clusters. Combined results from powder XRD, Rietveld refinement, 23Na MAS and DOR NMR, far-IR and mid-IR indicate that these sodalites form a solid solution of Na3-mAgm clusters in anion-free Beta-cages interspersed with Na4nAgnX. The clusters are statistically distributed throughout the lattice. However, silver ions are associated preferentially with cavities containing halide anions. The data also demonstrate that these materials offer the opportunity to manipulate the extent of collective electronic and vibrational interactions between monodispersed Na4,AgnBr clusters in a perfectly crystalline host. 'Me anion strongly mediates the vibrational coupling. The electronic coupling between clusters increases with Ag+ and X-loading level. Support for this idea comes from extended Huckel molecular orbital calculations. At low Ag+/X-loadings, intrasodalite AgX resembles the gas phase molecule (bond length, optical spectra). Optical absorption bands broaden and the absorption edge moves towards that of the bulk semiconductor at higher Ag+/X-loadings.

Class B Sodalites: Nonstoichiometric Silver, Sodium Halosodalites.

The chapter on “Mesostructured Thin Film Oxides” addressed three main topics. The first is a brief introduction to mesostructured materials, focusing on mesostructure assembly and general synthesis and processing considerations as well as properties and characteristics of periodically ordered mesostructured materials with an emphasis on thin film oxides is given. In the second part, periodically organized transition metal oxide thin films with nanocrystalline mesostructure frameworks are discussed, including the assembly/nanocrystallization chemistry behind such inherently functional porous thin films, using mesostructured semiconducting anatase titania as a general example. A particular challenge is how to combine a three-dimensional ordered porous structure with a high degree of framework crystallinity. The third part focuses on recent promising applications of periodically organized multi-compositional mesostructured transition metal oxide-based thin films and is divided into the areas of (1) optical, electrical, and electrochemical applications, (2) photocatalytic and electrochromic applications and (3) photovoltaic/solar cell applications. The chapter ends with some conclusions and a brief outlook on the potential and promise of mesostructured thin film oxides as future low-cost solar energy conversion materials and photocatalysts.

Galen D. Stucky

Papers

A New Phase of Oriented Mesoporous Silicate Thin Films.

Assembly of Supra Nanoclusters within Crystalline and Amorphous 3-D surfaces

First Open-Framework Zinc Germanates by a Molecular Templating Route.

Class B Sodalites: Nonstoichiometric Silver, Sodium Halosodalites.

Mesostructured Thin Film Oxides