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

Comprehensive Organic Functional Group Transformations. Herausgegeben vonA. R. Katritzky, O. Meth-Cohn undC. W. Rees. Pergamon, Elsevier Science Ltd, Oxford, 1995. Vol. 1–7, 7800 S., geb. 4437.25 £.—ISBN 0-08-040604.

We report an efficient method for a formal anti ‐Markovnikov addition of water to styrenes through photocatalytic generation of redox equivalents, using a gold‐doped titanium dioxide (Au/TiO 2 ) semiconductor as photocatalyst. Under irradiation with UV‐A light the photocatalytic activity of Au/TiO 2 generates in situ under aerobic conditions hydrogen peroxide (H 2 O 2 ) and under anaerobic conditions dihydrogen (H 2 ). In the presence of oxygen and a Ru‐catalyst, the epoxidation of different styrene derivatives is achieved. Subsequently, regioselective reductive Pd‐catalyzed epoxide opening in the absence of oxygen gives the corresponding 2‐phenylethanol derivatives.

https://chemistry-europe.onlinelibrary.wiley.com/doi/pdf/10.1002/cptc.202000205

Synthesis of anti-Markovnikov Alcohols via Epoxidation and Hydrogenation of Styrenes using Photocatalytically Generated Redox Equivalents

Heterogeneous catalyzed reduction of polymer-bound nitroarenes

Benzenesulfonamides represent a hydrogen donor-acceptor moiety that is changed to a bisacceptor by deprotonation. The dimerization constant of N-tosyl-n-butylamine (7) and N-tosyl-L-alanine (9-H) in CDCl3 and the binding constant of the tetrabutylammonium salt 7·NBu4 to urea in DMSO were determined by 1H-NMR titration methods. The X-ray structure analysis of 9-H is reported.

Hydrogen Bonding of Benzenesulfonamides in Molecular Recognition Processes

Das Neue und nachhaltigere Organisch-chemische Praktikum NOP nutzt die zusatzlichen Moglichkeiten, die eine Website im Vergleich zu einem konventionellen Laborpraktikum in Buchform hat, um angehenden Synthesechemikern ein breiteres Verstandnis der durchgefuhrten Versuche zu vermitteln. Hierzu gehoren Informationen zu analytischen Methoden, Hintergrundinformationen zu den eingesetzten und entstehenden Stoffen sowie Kennzahlen zur Bewertung von Stoff- und Energieeffizienz der Versuche. Nicht zuletzt wird dabei Hintergrundwissen zum Konzept der nachhaltigen Entwicklung fur den Themenbereich Synthesechemie aufbereitet.



The sustainable organic chemistry lab course for the new milennium (NOP) makes use of the possibilities that an interactive website provides compared to a conventional lab course published as a textbook or manual. The prospective synthetic chemist can thus gain a more in-depth understanding of his/her experiments. Detailed information about analytical methods, background information about the sub- stances being used and being formed during the experiment and “management ratios” like substance efficiency and energy efficiency are provided. Last but not least, knowledge about the concept “sustainable development” is being adapted to the domain of synthetic chemistry.

Burkhard König

Papers

Comprehensive Organic Functional Group Transformations. Herausgegeben vonA. R. Katritzky, O. Meth-Cohn undC. W. Rees. Pergamon, Elsevier Science Ltd, Oxford, 1995. Vol. 1–7, 7800 S., geb. 4437.25 £.—ISBN 0-08-040604.

Synthesis of anti-Markovnikov Alcohols via Epoxidation and Hydrogenation of Styrenes using Photocatalytically Generated Redox Equivalents

Heterogeneous catalyzed reduction of polymer-bound nitroarenes

Hydrogen Bonding of Benzenesulfonamides in Molecular Recognition Processes

NOP – Ein neues organischchemisches Grundpraktikum: Nachhaltigkeit per Internet