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

다중혈관 관상동맥 환자에서 y-문합을 이용하여 양쪽 내흉동맥만을 사용한 우회술의 조기 성적

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

Sustainable economic and industrial growth requires safe, sustainable resources of energy. For the future re-arrangement of a sustainable economy to biological raw materials, completely new approaches in research and development, production, and economy are necessary. The ‘first-generation’ biofuels appear unsustainable because of the potential stress that their production places on food commodities. For organic chemicals and materials these needs to follow a biorefinery model under environmentally sustainable conditions. Where these operate at present, their product range is largely limited to simple materials (i.e. cellulose, ethanol, and biofuels). Second generation biorefineries need to build on the need for sustainable chemical products through modern and proven green chemical technologies such as bioprocessing including pyrolysis, Fisher Tropsch, and other catalytic processes in order to make more complex molecules and materials on which a future sustainable society will be based. This review focus on cost effective technologies and the processes to convert biomass into useful liquid biofuels and bioproducts, with particular focus on some biorefinery concepts based on different feedstocks aiming at the integral utilization of these feedstocks for the production of value added chemicals.

http://staff.cimap.res.in/PublicationFiles/Renew_Sustain_Energ_Rev_14_578.pdf

Production of first and second generation biofuels: A comprehensive review

Department of Pharmaceutics, National Institute of Pharmaceutical Education and Research (NIPER), Sector 67, S. A. S. Nagar,Mohali, Punjab-160 062, India, Institute of Biochemistry, Faculty of Medicine, Polytechnic University, Via Ranieri 67, IT-60100 Ancona, Italy,Green Biotechnology Research Group, The Special Division for Human Life Technology, National Institute of Advanced Industrial Science andTechnology, 1-8-31 Midorigaoka, Ikeda, Osaka-563-8577, Japan, and Department of Medicinal Chemistry & Natural Products,The Hebrew University of Jerusalem, School of Pharmacy-Faculty of Medicine, Jerusalem 91120, IsraelReceived March 2, 2004

Chitosan chemistry and pharmaceutical perspectives.

Rearrangement of α,δ-dichloroaldimines to 2-formylpyrrolidines: α,α-Azacyclobisalkylation of aldehydes

The bio‐based economy: step by step from demand push to market pull

The site time yield (STY) and stability of the primary amine sites in low molecular weight chitosan have been quantified for the aldol reaction of acetone with 4-nitrobenzaldehyde in a mixture of water and acetone as a solvent. Crude chitosan with varying degrees of deacetylation (DDA), as well as chitosan in hydrogel and aerogel forms, was used. Apart from the main reaction, accumulation of an imine formed from 4-nitrobenzaldehyde occurred in the early stages of the reaction. This imine acted as an inhibitor of the primary amine sites and was formed until an equilibrium was reached, after which the catalytic activity remained constant. Chitosan with a DDA amounting to 70.4% exhibited a STY of 2.18 ± 0.05 × 10−5 molproduct molamine−1 s−1. This STY increased with decreasing DDA, as a direct result of an increase in amine pKa. No differences in activity were observed between the crude, hydrogel, and aerogel forms of chitosan with the same DDA. Recycling in a second batch experiment allowed reproducing the same performance as that in the first experiment. Under continuous-flow conditions, the activity of chitosan was found to stabilize as a function of the time on stream, after the imine formation has equilibrated. Even though the catalytic activity of these chitosan catalysts was found to be lower than those of the current state-of-the-art catalysts for the aldol reaction, their stability in an aqueous environment opens new perspectives for future catalyst development.

/pdf/kinetic-evaluation-of-chitosan-derived-catalysts-for-the-53d291kexx.pdf

Kinetic evaluation of chitosan-derived catalysts for the aldol reaction in water

Au–Pd based catalytic systems are a unique couple due to the carbophilic Lewis acidity of Au and the redox properties of Pd. To gain more insight into this bimetallic couple, a synthetic and mechanistic investigation was conducted. As key substrates, ynamides (N-alkynyl allyloxycarbamates and N-alkynyl ethyloxycarbamates) were used. Essential for the mechanistic part was the isolation of the organogold(I) intermediate to validate the proposed mechanism. In total, 18 polysubstituted oxazolones and 12 organogold(I) complexes were synthesized.

Gold and Palladium Mediated Bimetallic Catalysis:Mechanistic Investigation through the Isolation of the Organogold(I)Intermediates

The objective of this chapter is to provide an overview of the conversion of various lipid sources (edible and non-edible) into biodiesel using traditional and new technologies emphasizing the quality standards mainly dependent on the used feedstock and technology, processing and purification

Christian V. Stevens

Papers

Rearrangement of α,δ-dichloroaldimines to 2-formylpyrrolidines: α,α-Azacyclobisalkylation of aldehydes

The bio‐based economy: step by step from demand push to market pull

Kinetic evaluation of chitosan-derived catalysts for the aldol reaction in water

Gold and Palladium Mediated Bimetallic Catalysis:Mechanistic Investigation through the Isolation of the Organogold(I)Intermediates

Production of biodiesel via chemical catalytic conversion