This collection of chapters, each one written by internationally recognized experts in the corresponding field, covers in a comprehensive fashion all the major aspects related to the synthesis, ...characterization and properties of macromolecular materials prepared using renewable resources as such, or after appropriate modifications. Thus, monomers such as terpenes and furans, oligomers like rosin and tannins, and polymers ranging from cellulose to proteins and including macromolecules synthesized by microbes, are discussed with the purpose of showing the extraordinary variety of materials that can be prepared from their intelligent exploitation. Particular emphasis has been placed on recent advances and imminent perspectives, given the incessantly growing interest that this area is experiencing in both the scientific and technological realms. The book discusses bio-refining with explicit application to materials, replete with examples of applications of the concept of sustainable development, and presents an impressive variety of novel macromolecular materials. This book is suitable for university chemistry, materials science and physics departments, research institutions, industrial laboratories, and industrial libraries.
New drugs introduced to the market every year represent privileged structures for particular biological targets. These new chemical entities (NCEs) provide insight into molecular recognition while ...serving as leads for designing future new drugs. This annual review describes the most likely process-scale synthetic approaches to 29 new chemical entities (NCEs) that were approved for the first time in 2015.
Although known for over a quarter of a century, the oxidative radical cyclisation route to spiroketals has found limited use in natural product synthesis in comparison to classical approaches. Its ...successful application in this field of research forms the subject of this perspective.
Even though there are dozens of biologically active 2‐substituted and 2,6‐disubstituted piperidines, only a limited number of approaches exist for their synthesis. Herein is described two ...Mannich‐type additions to nitrones, one using β‐ketoacids under catalyst‐free conditions and another using methyl ketones in the presence of chiral thioureas, which can generate a broad array of such 2‐substituted materials, as well as other ring variants, in the form of β‐N‐hydroxy‐aminoketones. Both processes have broad scope, with the latter providing products with high enantioselectivity (up to 98 %). The combination of these methods, along with other critical steps, has enabled 8‐step total syntheses of the 2,6‐disubstituted piperidine alkaloids (−)‐lobeline and (−)‐sedinone.
Just Mannich enough: Despite their prevalence, 2‐ and 2,6‐disubstituted piperidines are challenging to prepare enantioselectively, particularly when they possess β‐functionalization. Two new approaches based on the use of cyclic nitrones provide the means to readily fashion an array of such materials, one of which proceeds with high enantioselectivity (up to 98 % ee) using a chiral thiourea promoter. Their sequential use has enabled 8‐step total syntheses of both (−)‐lobeline and (−)‐sedinone from a common intermediate.
Click chemistry is an approach that uses efficient and reliable reactions, such as Cu(I)-catalyzed azide–alkyne cycloaddition (CuAAC), to bind two molecular building blocks. CuAAC has broad ...applications in medicinal chemistry and other fields of chemistry. This review describes the general features and applications of CuAAC in solid-phase synthesis (CuAAC-SP), highlighting the suitability of this kind of reaction for peptides, nucleotides, small molecules, supramolecular structures, and polymers, among others. This versatile reaction is expected to become pivotal for meeting future challenges in solid-phase chemistry.
Deployable structures have the ability to change their shape and volume, being used to design mobile structures with various applications in architecture. Planar or spatial mechanisms with ...articulated bars, folding plates or membranes could be used to realize such structures. In this paper, dimensional synthesis and simulation of two deployable structures based on a modified scissor mechanism will be presented.
In order to develop better wound dressings, a novel chitosan hydrogel (Cn-Nm gel) was designed and fabricated by using aldehyde-4-arm polyethylene glycol (4r-PEG-CHO) to crosslink the chitosan ...dissolved in alkaline solution, amino-4-arm polyethylene glycol (4r-PEG-NH2) was chosen as the additive simultaneously. The special dissolution technique and macromolecular crosslinking structure endows the Cn-Nm gels with better performance than that of gels prepared by acid dissolving method with micromolecule crosslinker. First, Cn-Nm gels own strong toughness with 500 kPa tensile strength and 1000% elongation, about 400% swelling ratio and fast water absorption rate. Second, about 300 kPa adhesive strength and strippability between the gels and skin is achieved. More importantly, Cn-Nm gels show nearly 100% antibacterial rate towards Escherichia coli and Staphylococcus aureus. Excellent biocompatibility is also proved by the mouse fibroblasts tests. All of the performance makes this developed chitosan-based gel be the potential candidate as a wound dressing.
The current and future state of animal coloration research Endler, John A.; Mappes, Johanna
Philosophical transactions of the Royal Society of London. Series B. Biological sciences,
07/2017, Letnik:
372, Številka:
1724
Journal Article
Recenzirano
Animal colour patterns are a model system for understanding evolution because they are unusually accessible for study and experimental manipulation. This is possible because their functions are ...readily identifiable. In this final paper of the symposium we provide a diagram of the processes affecting colour patterns and use this to summarize their functions and put the other papers in a broad context. This aUows us to identify significant 'holes' in the field that only become obvious when we see the processes affecting colour patterns, and their interactions, as a whole. We make suggestions about new directions of research that will enhance our understanding of both the evolution of colour patterns and visual signalling but also illuminate how the evolution of multiple interacting traits works. This article is part of the themed issue 'Animal coloration: production, perception, function and application'.
In 2008, we reported a new class of pillar-shaped macrocyclic hosts, known as “pillarnarenes”. Today, pillarnarenes are recognized as key players in supramolecular chemistry because of their ...facile synthesis, unique pillar shape, versatile functionality, interesting host–guest properties, and original supramolecular assembly characteristics, which have resulted in numerous electrochemical and biomedical material applications. In this Review, we have provided historical background to macrocyclic chemistry, followed by a detailed discussion of the fundamental properties of pillarnarenes, including their synthesis, structure, and host–guest properties. Furthermore, we have discussed the applications of pillarnarenes to materials science, as well as their applications in supramolecular chemistry, in terms of their fundamental properties. Finally, we have described the future perspectives of pillarnarene chemistry. We hope that this Review will provide a useful reference for researchers working in the field and inspire discoveries concerning pillarnarene chemistry.
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