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

J. Appl. Cryst.の発刊に際して

The hydrogen bond is the most important of all directional intermolecular interactions. It is operative in determining molecular conformation, molecular aggregation, and the function of a vast number of chemical systems ranging from inorganic to biological. Research into hydrogen bonds experienced a stagnant period in the 1980s, but re-opened around 1990, and has been in rapid development since then. In terms of modern concepts, the hydrogen bond is understood as a very broad phenomenon, and it is accepted that there are open borders to other effects. There are dozens of different types of X-H.A hydrogen bonds that occur commonly in the condensed phases, and in addition there are innumerable less common ones. Dissociation energies span more than two orders of magnitude (about 0.2-40 kcal mol(-1)). Within this range, the nature of the interaction is not constant, but its electrostatic, covalent, and dispersion contributions vary in their relative weights. The hydrogen bond has broad transition regions that merge continuously with the covalent bond, the van der Waals interaction, the ionic interaction, and also the cation-pi interaction. All hydrogen bonds can be considered as incipient proton transfer reactions, and for strong hydrogen bonds, this reaction can be in a very advanced state. In this review, a coherent survey is given on all these matters.

The hydrogen bond in the solid state.

https://pubs.rsc.org/en/content/articlepdf/2019/NP/C8NP00092A

Marine natural products.

[CrIIIF(NCMe)5](BF4)2·MeCN (1) was synthesized from a prolonged dissolution of [CrIII(NCMe)6](BF4)3 in MeCN via fluoride abstraction from BF4−. Complex 1 exhibits a crystal field splitting, Δo, of 17 470 cm−1 and is a nonaqueous source of CrIIIF2+. The reaction of 1 with (NEt4)3[CrIII(CN)6] formed a new Prussian-blue-like magnetic material of (NEt4)0.04[CrIIIF]1.54[CrIII(CN)6](BF4)0.12·0.10(MeCN) (2) composition. Complex 2 magnetically orders at a critical temperature, Tc, of 85 K and at 2 K exhibits magnetic hysteresis with a coercive field, Hcr, of 60 Oe and a remanent magnetization, Mrem, of 1880 emuOe/mol.

Structure and Properties of [CrIIIF(NCMe)5](BF4)2·MeCN: A Nonaqueous Source of CrIIIF2+ and a Building Block for New Prussian-Blue-Like Magnetic Materials

Reactions between the carbene complex (I) and various nitroso compounds R-NO (R: Ph, tBu, 2,4,6-tri-tert.-butylphenyl) and (II) are studied in order to evidence the formation of (OC)5W=NR species on these metathesis-like reactions.

Metathesis-like reactions between the carbene complex (CO)5W:C(OMe)Ph and organic nitroso reagents

Binuclear Vanadium Complexes Containing Sulfur and Selenium Ligands: The Reactions of the Half-Sandwich Compounds CpV(CO)4 and Cp*V(CO)4 with Dichalcogenides E2R2 (E: S, Se; R: Me, Ph). The X-Ray Crystallographic Structures of Cp*2V2(

The synthesis of two biscarboranyl (bc) magnesium reagents is described. Treatment of 1,1'-bis(o-carborane) (H2-bc) or 8,8',9,9',10,10',12,12'-octamethyl-1,1'-bis(o-carborane) (H2-Mebc) with Mg(n-Bu)2 in 1,2-dimethoxyethane (DME) affords (bc)Mg(DME)2 (1a-b) as crystalline solids. The magnesium compounds, which have been characterized by NMR spectroscopy and single crystal X-ray crystallography in the case of 1a, serve as competent Grignard-type reagents to generate bc-containing species of tin from Me2SnCl2 (2a-b). The type of substitution of the bis(o-carboranyl) ligand framework is found to strongly effect the electronic character of the tin center, as judged by 119Sn NMR spectroscopy. The disclosed compounds, which are stable solids under an atmosphere of dry nitrogen gas at room temperature, provide a new class of bc-transfer reagents.

/pdf/magnesium-reagents-featuring-a-1-1-bis-o-carborane-ligand-5gr21uenmv.pdf

Arnold L. Rheingold

Papers

Structure and Properties of [CrIIIF(NCMe)5](BF4)2·MeCN: A Nonaqueous Source of CrIIIF2+ and a Building Block for New Prussian-Blue-Like Magnetic Materials

Metathesis-like reactions between the carbene complex (CO)5W:C(OMe)Ph and organic nitroso reagents

Binuclear Vanadium Complexes Containing Sulfur and Selenium Ligands: The Reactions of the Half-Sandwich Compounds CpV(CO)4 and CpV(CO)4 with Dichalcogenides E2R2 (E: S, Se; R: Me, Ph). The X-Ray Crystallographic Structures of Cp2V2(

Magnesium Reagents Featuring a 1,1′‐Bis(o‐carborane) Ligand Platform

Ein stabiler eta 5-germacyclopentadienyl-komplex : (eta 5-c5me5)rueta 5-c4me4gesi(sime3)3