There is, I think, something ethereal about i —the square root of minus one. I remember first hearing about it at school. It seemed an odd beast at that time—an intruder hovering on the edge of reality.

Usually familiarity dulls this sense of the bizarre, but in the case of i it was the reverse: over the years the sense of its surreal nature intensified. It seemed that it was impossible to write mathematics that described the real world in …

I and i

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

A fundamental aim in the field of catalysis is the development of new modes of small molecule activation. One approach toward the catalytic activation of organic molecules that has received much attention recently is visible light photoredox catalysis. In a general sense, this approach relies on the ability of metal complexes and organic dyes to engage in single-electron-transfer (SET) processes with organic substrates upon photoexcitation with visible light.

Many of the most commonly employed visible light photocatalysts are polypyridyl complexes of ruthenium and iridium, and are typified by the complex tris(2,2′-bipyridine) ruthenium(II), or Ru(bpy)32+ (Figure 1). These complexes absorb light in the visible region of the electromagnetic spectrum to give stable, long-lived photoexcited states.1,2 The lifetime of the excited species is sufficiently long (1100 ns for Ru(bpy)32+) that it may engage in bimolecular electron-transfer reactions in competition with deactivation pathways.3 Although these species are poor single-electron oxidants and reductants in the ground state, excitation of an electron affords excited states that are very potent single-electron-transfer reagents. Importantly, the conversion of these bench stable, benign catalysts to redox-active species upon irradiation with simple household lightbulbs represents a remarkably chemoselective trigger to induce unique and valuable catalytic processes.






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Figure 1


Ruthenium polypyridyl complexes: versatile visible light photocatalysts.

/pdf/visible-light-photoredox-catalysis-with-transition-metal-5d1oxrsczo.pdf

Visible Light Photoredox Catalysis with Transition Metal Complexes: Applications in Organic Synthesis

A novel reactor for solvent-free, visible-light-driven photocatalytic transformations was developed. By rotation of the reaction vessel, the reaction mixture forms a thin film, which allows efficient excitation of the photocatalyst. The reactor was used for the coupling of aryl halides with pyrrole derivatives and phosphites, applying rhodamine 6G as the photocatalyst and DIPEA as the sacrificial electron donor. The necessary amounts of photocatalyst, trapping reagent, and sacrificial electron donor were reduced significantly compared to those for literature known reactions in solution, while isolating the products in moderate to good yields. In general terms, this solvent-free methodology is an interesting alternative to solution photocatalysis due to the presence of high mole fractions of trapping reagent, the exclusion of by-products formed with the solvent, and the reduction of toxic solvent waste.

Solvent-free coupling of aryl halides with pyrroles applying visible-light photocatalysis

Synthesis and Metal‐Ion Extraction Properties of para‐tert‐Butylcalixareneglycine Ester Acetamides

Supramolecular chemistry is chemistry beyond the molecule, the designed chemistry of the intermolecular non-covalent bond, just as molecular chemistry is that of the covalent bond. This highly interdisciplinary field covers the chemical, physical and biological features of chemical species held together by non-covalent binding interactions. The selective binding of a substrate by a molecular receptor involves molecular recognition. It requires the design of receptors possessing steric and electronic features complementary to those of the substrate to be bound, together with a rigidity-flexibility balance suitable for the function to be performed. How well things fit together often depends on their predisposition, frequently referred to as preorganization. While the term implies entropic effects, it is hard to separate these from enthalpic factors of binding. Artificial host-guest systems as imitations of biological receptors demonstrate the principle of molecular recognition in its simplest form, while the self-assembly of small molecules to extended supramolecular structures requires a repetitive recognition process.

Molecular Recognition. The principle and recent chemical examples

[2.2]Paracyclophane-1-yne: preparation and structural analysis of the bis(triphenylphosphane) platinum complex

Linear and cyclic oligomers of Me2Ge-bridged π-systems have been obtained by the reaction of carbo- and heterocyclic anions and dianions with Me2GeCl2. The spectroscopic properties of the new compounds are compared with analogous carbon- and Me2Si-bridged π-systems.

Burkhard König

Papers

Solvent-free coupling of aryl halides with pyrroles applying visible-light photocatalysis

Synthesis and Metal‐Ion Extraction Properties of para‐tert‐Butylcalixareneglycine Ester Acetamides

Molecular Recognition. The principle and recent chemical examples

[2.2]Paracyclophane-1-yne: preparation and structural analysis of the bis(triphenylphosphane) platinum complex

Synthesis and properties of me2ge-bridged arenes