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

The Huisgen 1,3-dipolar cycloaddition reaction of organic azides and alkynes has gained considerable attention in recent years due to the introduction in 2001 of Cu(1) catalysis by Tornoe and Meldal, leading to a major improvement in both rate and regioselectivity of the reaction, as realized independently by the Meldal and the Sharpless laboratories. The great success of the Cu(1) catalyzed reaction is rooted in the fact that it is a virtually quantitative, very robust, insensitive, general, and orthogonal ligation reaction, suitable for even biomolecular ligation and in vivo tagging or as a polymerization reaction for synthesis of long linear polymers. The triazole formed is essentially chemically inert to reactive conditions, e.g. oxidation, reduction, and hydrolysis, and has an intermediate polarity with a dipolar moment of ∼5 D. The basis for the unique properties and rate enhancement for triazole formation under Cu(1) catalysis should be found in the high ∆G of the reaction in combination with the low character of polarity of the dipole of the noncatalyzed thermal reaction, which leads to a considerable activation barrier. In order to understand the reaction in detail, it therefore seems important to spend a moment to consider the structural and mechanistic aspects of the catalysis. The reaction is quite insensitive to reaction conditions as long as Cu(1) is present and may be performed in an aqueous or organic environment both in solution and on solid support.

Cu-catalyzed azide-alkyne cycloaddition.

Controlled/living radical polymerization: Features, developments, and perspectives

Block copolymer (BCP) self-assembly has attracted considerable attention for many decades because it can yield ordered structures in a wide range of morphologies, including spheres, cylinders, bicontinuous structures, lamellae, vesicles, and many other complex or hierarchical assemblies. These aggregates provide potential or practical applications in many fields. The present tutorial review introduces the primary principles of BCP self-assembly in bulk and in solution, by describing experiments, theories, accessible morphologies and morphological transitions, factors affecting the morphology, thermodynamics and kinetics, among others. As one specific example at a more advanced level, BCP vesicles (polymersomes) and their potential applications are discussed in some detail.

/pdf/self-assembly-of-block-copolymers-381hzqnmce.pdf

Self-assembly of block copolymers

Supramolecular self assembly techniques have provided a versatile means by which to selectively assemble polymer molecules into well-defined three dimensional core-shell nanostructures. The covalent stabilisation and tailoring of these dynamic nanostructures can be achieved using a range of chemistries within the assembly to afford robust functional nanoparticles. Many examples of the stabilisation, functionalisation and decoration of these nanoparticles have been reported in the literature and this tutorial review will focus on these recent developments and highlight their potential applications.

https://www.chem.tamu.edu/rgroup/wooley/chem689/Articles/CHEM%20689-Supp/CHEM%20689-Supp/Stabilization%20and%20Functionalization.pdf

Cross-linked block copolymer micelles: functional nanostructures of great potential and versatility

End group removal and modification of RAFT polymers

Polymer vesicles prepared by self-assembly techniques have attracted increasing scientific interest in recent years. This is as a result of their numerous potential applications such as tunable delivery vehicles, for the templating of biomineralization, as nanoreactors and as scaffolds for biological conjugation. Presented in this review are the recent advances in the preparation and application of ‘smart’ and functional block copolymer vesicles such as those which respond to external stimuli to afford a change in structure, morphology or controlled release event. In this Highlight, we first give an overview of the structure of polymer vesicles, followed by a summary of the methods used for their preparation. We then focus on recently developed intelligent polymer vesicles which can respond to the application of external stimuli such as a change in temperature, pH or redox to afford novel nanomaterials. The potential applications of these materials are explored with specific focus on the functionalization of various domains of the polymer vesicles. Finally, the current limitations in the preparation and application of polymer vesicles are explored as are the challenges facing the development of these nanostructures towards real-world applications.

Advances and challenges in smart and functional polymer vesicles

Anisotropic particles, such as patchy, multicompartment and Janus particles, have attracted significant attention in recent years due to their novel morphologies and diverse potential applications. The non-centrosymmetric features of these particles make them a unique class of nano- or micro-colloidal materials. Patchy particles usually have different compositional patches in the corona, whereas multicompartment particles have a multi-phasic anisotropic architecture in the core domain. In contrast, Janus particles, named after the double-faced Roman god, have a strictly biphasic geometry of distinct compositions and properties in the core and/or corona. The term Janus particles, multicompartment particles and patchy particles frequently appears in the literature, however, they are sometimes misused due to their structural similarity. Therefore, in this critical review we classify the key features of these different anisotropic colloidal particles and compare structural properties as well as discuss their preparation and application. This review brings together and highlights the significant advances in the last 2 to 3 years in the fabrication and application of these novel patchy, multicompartment and Janus particles (98 references).

Anisotropic particles with patchy, multicompartment and Janus architectures: preparation and application.

Dramatic developments in the burgeoning field of polymer science are enabling new materials designs, synthetic methods, functional architectures, and applications. Today’s polymers are finding utility in broad areas, ranging from everyday commodity plastics to emerging, specialized, and high-tech materials. Moreover, it is apparent that the continued development of polymeric systems will be facilitated by ever-increasing understanding of advanced polymer synthesis and characterization techniques. This enhanced toolbox and knowledge-base will foster the facile design of next-generation precision materials with predictable and changeable properties. The present themed issue focuses on recent developments in the design of polymers that change properties in response to a single stimulus or multiple stimuli. These so-called ‘smart’ or stimuliresponsive polymers represent a growing cadre of materials that support various applications (e.g., controlled release agents, responsive coatings, and adaptive shape memory materials). Stimuli-responsive materials have benefited from significant advances in polymer science in recent years, and this themed issue highlights several of the fascinating developments that could have a major impact on the implementation of new smart materials. To fully address the field of stimuli responsive polymers, first we must understand the breadth of available stimuli that can induce a desired response, then we must design the polymer functionalities and systems that enable such a response; finally, we must develop methods to characterize the macromolecular changes as a result of that response. As demonstrated in this issue, many of the interesting properties of responsive materials arise from a transition in solubility or conformation of a macromolecule in the presence of a solvent. In this manner, transitions at the molecular level can be amplified to result in a change in nanoscale structure and/or materials properties. Gibson and O’Reilly (DOI: 10.1039/C3CS60035A) overview these transitions in the specific area of thermoresponsive polymers with particular attention to the effect of nanoscale geometry on the resulting change in chain conformation following a temperature change. Sumerlin and co-workers (DOI: 10.1039/ C3CS35499G) also highlight temperatureresponsive polymers with particular emphasis on design parameters that facilitate tuning of the specific transition temperatures. Light-responsive materials have received significant attention, as discussed by Gohy and Zhao (DOI: 10.1039/ C3CS35469E) in a review focused on reversible and irreversible transitions of photoresponsive copolymer micelles. Further, many systems can be designed a Institute for Technical and Macromolecular Chemistry, University of Hamburg, Bundesstrasse 45, D-20146 Hamburg, Germany. E-mail: theato@chemie.uni-hamburg.de b George & Josephine Butler Polymer Research Laboratory, Department of Chemistry, University of Florida, Gainesville, FL 32611, USA. E-mail: sumerlin@chem.ufl.edu c Department of Chemistry, University of Warwick, Coventry CV4 7AL, UK. E-mail: Rachel.OReilly@warwick.ac.uk d Department of Chemical & Biomolecular Engineering, University of Delaware, 150 Academy Street, Newark, DE 19716, USA. E-mail: thepps@udel.edu

Rachel K. O'Reilly

Papers

Cross-linked block copolymer micelles: functional nanostructures of great potential and versatility

End group removal and modification of RAFT polymers

Advances and challenges in smart and functional polymer vesicles

Anisotropic particles with patchy, multicompartment and Janus architectures: preparation and application.

Stimuli responsive materials