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

J. Appl. Cryst.の発刊に際して

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

Marine natural products.

Dioxygen activation at mononuclear nonheme iron active sites: enzymes, models, and intermediates.

Recent developments in the chemistry of selenoethers and telluroethers

Stereochemical and conformational control of metal redox processes: the co-ordination chemistry of the mixed N- and S-donor macrocyclic crowns [18]aneN2S4 and Me2[18]aneN2S4

Coordination chemistry of the main group elements with phosphine, arsine and stibine ligands

The major oxygenation product of catechol by dioxygen in the presence of FeCl2 or FeCl3, 1,4,7-triazacyclononane (TACN), and pyridine in methanol is the extradiol cleavage product 2-hydroxymuconic semi-aldehyde methyl ester (Lin, G.; Reid, G.; Bugg, T. D. I-I. J. Chem. Sec. Chem. Commun. 2000, 1119-1120). Under these conditions, extradiol cleavage of a range of 3- and 4-substituted catechols with electron-donating substituents is observed. The reaction shows a preference in selectivity and rate for iron(II) rather than iron(III) for the extradiol cleavage, which parallels the selectivity of the extradiol dioxygenase family. The reaction also shows a high selectivity for the macrocyclic ligand, TACN, over a range of other nitrogen-and oxygen-containing macrocycles. Reaction of anaerobically prepared iron-TACN complexes with dioxygen gave the same product as monitored by UV/vis spectroscopy. KO2 is able to oxidize catechols with both electron-donating and electron-withdrawing substituents, implying a different mechanism for extradiol. cleavage. Saturation kinetics were observed for catechols, which fit the Michaelis-Menten equation to give k(cat)(app) = 4.8 x 10(-3) s(-1) for 3-(2' ,3'-dihydroxyphenyl)propionic acid. The reaction was also found to proceed using monosodium catecholate in the absence of pyridine, but with different product ratios, giving insight into the acid/base chemistry of extradiol cleavage. In particular, extradiol cleavage in the presence of iron(II) shows a requirement for a proton donor, implying a role for an acidic group in the extradiol dioxygenase active site.

Extradiol oxidative cleavage of catechols by ferrous and ferric complexes of 1,4,7-triazacyclononane: insight into the mechanism of the extradiol catechol dioxygenases.

Gillian Reid

Papers

Recent developments in the chemistry of selenoethers and telluroethers

Stereochemical and conformational control of metal redox processes: the co-ordination chemistry of the mixed N- and S-donor macrocyclic crowns [18]aneN2S4 and Me2[18]aneN2S4

Coordination chemistry of the main group elements with phosphine, arsine and stibine ligands

Extradiol oxidative cleavage of catechols by ferrous and ferric complexes of 1,4,7-triazacyclononane: insight into the mechanism of the extradiol catechol dioxygenases.

Developments in the coordination chemistry of stibine ligands