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

THE DESIGN AND ANALYSIS OF EXPERIMENTS. By Oscar Kempthorne. New York, John Wiley and Sons, Inc., 1952. 631 pp. $8.50. This book by a teacher of statistics (as well as a consultant for \"experimenters\") is a comprehensive study of the philosophical background for the statistical design of experiment. It is necessary to have some facility with algebraic notation and manipulation to be able to use the volume intelligently. The problems are presented from the theoretical point of view, without such practical examples as would be helpful for those not acquainted with mathematics. The mathematical justification for the techniques is given. As a somewhat advanced treatment of the design and analysis of experiments, this volume will be interesting and helpful for many who approach statistics theoretically as well as practically. With emphasis on the \"why,\" and with description given broadly, the author relates the subject matter to the general theory of statistics and to the general problem of experimental inference. MARGARET J. ROBERTSON

The Design and Analysis of Experiments

Although homogeneous gold catalysis was known previously, an exponential growth was only induced 12 years ago. The key findings which induce that rise of the field are discussed. This includes early reactions of allenes and furanynes and intermediates of these conversions as well as hydroarylation reactions. Other substrate types addressed are alkynyl epoxides and N-propargyl carboxamides. Important vinylgold intermediates, the transmetalation from gold to other transition metals, the development of new ligands for gold catalysis, and significant contributions from computational chemistry are other crucial points for the field highlighted here.

Gold-Catalyzed Organic Reactions

Polymeric graphitic carbon nitride materials (for simplicity: g-C(3)N(4)) have attracted much attention in recent years because of their similarity to graphene. They are composed of C, N, and some minor H content only. In contrast to graphenes, g-C(3)N(4) is a medium-bandgap semiconductor and in that role an effective photocatalyst and chemical catalyst for a broad variety of reactions. In this Review, we describe the "polymer chemistry" of this structure, how band positions and bandgap can be varied by doping and copolymerization, and how the organic solid can be textured to make it an effective heterogenous catalyst. g-C(3)N(4) and its modifications have a high thermal and chemical stability and can catalyze a number of "dream reactions", such as photochemical splitting of water, mild and selective oxidation reactions, and--as a coactive catalytic support--superactive hydrogenation reactions. As carbon nitride is metal-free as such, it also tolerates functional groups and is therefore suited for multipurpose applications in biomass conversion and sustainable chemistry.

Polymeric Graphitic Carbon Nitride as a Heterogeneous Organocatalyst: From Photochemistry to Multipurpose Catalysis to Sustainable Chemistry

Metal species with different size (single atoms, nanoclusters, and nanoparticles) show different catalytic behavior for various heterogeneous catalytic reactions. It has been shown in the literature that many factors including the particle size, shape, chemical composition, metal–support interaction, and metal–reactant/solvent interaction can have significant influences on the catalytic properties of metal catalysts. The recent developments of well-controlled synthesis methodologies and advanced characterization tools allow one to correlate the relationships at the molecular level. In this Review, the electronic and geometric structures of single atoms, nanoclusters, and nanoparticles will be discussed. Furthermore, we will summarize the catalytic applications of single atoms, nanoclusters, and nanoparticles for different types of reactions, including CO oxidation, selective oxidation, selective hydrogenation, organic reactions, electrocatalytic, and photocatalytic reactions. We will compare the results o...

Metal Catalysts for Heterogeneous Catalysis: From Single Atoms to Nanoclusters and Nanoparticles.

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Formulation of Ceramic Foams: a New Class of Amphiphiles

Propane Dehydrogenation over Chromia Catalysts: Microcatalysis, Deactivation, Macrokinetics, and Reactor Modeling

Deactivation, due primarily to the deposition of carbonaceous species onto the surface is well known in the catalytic dehydrogenation of light alkanes. Catalyst regeneration is by burning off the “coke”. This paper describes the experimental measurement and modelling of the kinetics of deactivation of a propane dehydrogenation catalyst. Stable isotope tracer experiments [ 8 ] showed that it is possible to neglect the adsorption terms. Thus a simplified kinetic model is derived based on a set of pseudo-reactions, and the changes to the kinetic parameters with deactivation studied. A simple, intrinsic deactivation model is derived and fitted based on the accumulated carbonaceous species on the catalyst surface. Finally, using a dynamic reactor simulation it is shown that the model can be successfully used to predict the catalyst activity change and performance of a given isothermal reactor.

Kinetic Based Deactivation Modelling of an Isothermal Propane Dehydrogenation Reactor

A kinetic based deactivation model is used to compare the performance of a deactivating propane dehydrogenation catalytic reactor. Different temperature profiles are imposed tos simulate the profiles obtained in current commerical and other potential reactor designs. Based on the simulation results it is concluded that the best design for abatement of deactivation is near isothermal, preferably with a gentle, increase in temperature through the reactor. It is also noted, that for this particular reaction, the most important factor in temperature profile selection for design is to achieve the best start of cycle results. Activity advantages obtained over fresh catalyst are largely retained through the deactivation.

E. Hugh Stitt

Papers

Formulation of Ceramic Foams: a New Class of Amphiphiles

Propane Dehydrogenation over Chromia Catalysts: Microcatalysis, Deactivation, Macrokinetics, and Reactor Modeling

Kinetic Based Deactivation Modelling of an Isothermal Propane Dehydrogenation Reactor

Modelling for design of a deactivating non-isothermal propane dehydrogenation reactor

Switching from Batch to Continuous Processing for Fine and Intermediate-Scale Chemicals Manufacture