Current trends in leather science

Abstract In preparing the second edition of ‘Tanning Chemistry. The Science of Leather.’, the literature was updated and the content was revised and reviewed. Here, the new findings are presented and discussed. Notable developments include the necessary rethinking of the mechanism of sulfide unhairing because of new understanding of the aqueous chemistry of sulfide species. Revision upwards of the value of the second pKa for sulfide species ionisation means that S2− cannot exist in an aqueous medium, so the unhairing species in hair burn reactions is HS−. Although the technology remains the same, this means the mechanisms of associated reactions such as immunisation must be revised. Rawstock preservation has benefitted from studies of the potential role of materials from plants which accumulate salt, but which also contribute terpene compounds. There is also further discussion on the continuing issue of chromium (VI) in the leather industry. The application to processing of new solvents, ionic liquids and deep eutectics, is the coming technology, which offers transforming options for new chemistries and products. Renewed interest in vegetable tanning and methods of wet white processing are current trends. Also, within the topic of reagent delivery is processing in a solid medium of plastic beads. Graphical abstrac

Formation of Virus-Like Particles of the Dengue Virus Serotype 2 Expressed in Silkworm Larvae

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Plastid-Based Expression Strategies

Since the development of methodologies for achieving genetic modification of chloroplast genomes, termed transplastomic technologies, a straightforward use in the field of plant-based vaccines was initiated. Chloroplast transformation is mediated by homologous recombination that allows for site-specific insertion of foreign DNA into the plastome. This focus offers substantial advantages that include high yields, improved biosafety given by maternal inheritance in most plant species, and multigene expression through polycistrons allowing in theory for the straightforward production of multicomponent vaccines. One limitation of the system consists of the lack of glycosylation pathways, which are of relevance in some cases. State of the art in this area reflects a number of well-characterized vaccination models, although no one has passed clinical evaluations, which contrasts with other nuclear transient expression systems. Transplastomic technologies are envisioned as a relevant tool for developing new convenient vaccines