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

Deposits of clastic carbonate-dominated (calciclastic) sedimentary slope systems in the rock record have been identified mostly as linearly-consistent carbonate apron deposits, even though most ancient clastic carbonate slope deposits fit the submarine fan systems better. Calciclastic submarine fans are consequently rarely described and are poorly understood. Subsequently, very little is known especially in mud-dominated calciclastic submarine fan systems. Presented in this study are a sedimentological core and petrographic characterisation of samples from eleven boreholes from the Lower Carboniferous of Bowland Basin (Northwest England) that reveals a >250 m thick calciturbidite complex deposited in a calciclastic submarine fan setting. Seven facies are recognised from core and thin section characterisation and are grouped into three carbonate turbidite sequences. They include: 1) Calciturbidites, comprising mostly of highto low-density, wavy-laminated bioclast-rich facies; 2) low-density densite mudstones which are characterised by planar laminated and unlaminated muddominated facies; and 3) Calcidebrites which are muddy or hyper-concentrated debrisflow deposits occurring as poorly-sorted, chaotic, mud-supported floatstones. These

Phd by thesis

Dye-sensitized solar cells (DSCs) offer the possibilities to design solar cells with a large flexibility in shape, color, and transparency. DSC research groups have been established around the worl ...

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Dye-Sensitized Solar Cells

J. Appl. Cryst.の発刊に際して

Atom transfer radical polymerization.

The title compound, [–Si(C12H9)2OSi(CH3)2O–]2, was obtained unintentionally as the product of an attempted crystallization of caesium bis­(biphenyl-2,2′-di­yl)fluoro­silicate from dimethyl­formamide. In the crystal, the mol­ecule is located on an inversion center and the siloxane ring adopts a twist-chair conformation with the two dimethyl-substituted Si atoms lying 0.7081 (5) A out of the plane defined by the two bis­(biphenyl-2-yl)-substituted Si atoms and the four O atoms. In each Si(C12H9)2 unit, the orientation of one terminal phenyl ring relative to the phenyl­ene ring of the other biphenyl moiety suggests a parallel displaced π–π stacking inter­action [centroid distance = 4.2377 (11) A and dihedral angle = 15.40 (9)°].

https://journals.iucr.org/e/issues/2009/09/00/vm2002/vm2002.pdf

2,2,6,6-Tetrakis(biphenyl-2-yl)-4,4,8,8-tetramethylcyclotetrasiloxane

Both enantiomers of the novel benzimidazole-derived bidentate P,N-ligand (I) are synthesized (not shown) and applied to Ir-catalyzed hydrogenation reactions.

Development of a Benzimidazole-Derived Bidentate P,N-Ligand for Enantioselective Iridium-Catalyzed Hydrogenations.

Meerwein recommended nitrilium salts (2) as catalysts for the Beckmann rearrangement of oximes (1) under neutral and water-free conditions. For the first time, primary adducts (Z)–(3) of oximes to nitrilium salts have been isolated. Reported are activation energies for Beckmann rearrangements of these adducts, and an X-ray structural analysis of (Z)–3a. Rearrangement of 3 produces mixtures of up to four different N-acylamidinium salts 5–8, which arise from fast reactions of primary-formed secondary amides (4) with nitrilium salts (2). Because of their ambident electrophilic character the N-acylamidinium salts react with excess of oxime not only to amides (4) but to mixtures of products. It is shown that nitrilium salts cannot be used as catalysts for the Beckmann rearrangement.

Meerwein′s Catalytic Beckmann Rearrangement.

A novel modular synthetic approach toward constrained peptidomimetics is reported. The approach involves a highly efficient three-step sequence including two multicomponent reactions, thus allowing unprecedented diversification of both the peptide moieties and the turn-inducing scaffold. The turn-inducing properties of the dihydropyridone scaffold were evaluated by molecular modeling, X-ray crystallography, and NMR studies of a resulting peptidomimetic. Although modeling studies point toward a type IV β-turn-like structure, the X-ray crystal structure and NMR studies indicate an open turn structure.

Synthesis of Conformationally Constrained Peptidomimetics Using Multicomponent Reactions.

The preparation of a series of new macrocyclic carbodiazasilane molecules functionalized with the monoanionic (2,6-(CH2NMe2)2C6H3) ˇ N,C,N-pincer ligand has been accom- plished. Palladation of these systems was possible through oxidative addition with (Pd(dba)2) affording exclusive formation of the meso diastereoisomer. The X-ray crystal structures of these novel ligands and of the palladium(ii) complex 10 were determined and confirmed the stereo- chemistry of the organopalladium cage. Attachment of the para-OH functional- ized carbodiazasilane macrocycle 16 to a central core led to the formation of the dendritic structure 18 which was palla- dated to afford the novel multimetallic dendritic system with encapsulated cat- alytic sites 1. This cyclopalladated car- bosilane dendrimer (1) as well as the mononuclear organopalladium cage 10 can be conveniently converted into ac- tive Lewis acid catalysts for the aldol condensation reaction. The catalytic da- ta showed higher reaction rates for the dendritic structure than for the corre- sponding mononuclear systems.

Martin Lutz

Papers

2,2,6,6-Tetrakis(biphenyl-2-yl)-4,4,8,8-tetramethylcyclotetrasiloxane

Development of a Benzimidazole-Derived Bidentate P,N-Ligand for Enantioselective Iridium-Catalyzed Hydrogenations.

Meerwein′s Catalytic Beckmann Rearrangement.

Synthesis of Conformationally Constrained Peptidomimetics Using Multicomponent Reactions.

New Mono‐ and Tricyclopalladated Dendritic Systems with Encapsulated Catalytic Sites.