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We report the detailed study of mechanically induced free radical (mechanoradical) formation of glucosebased polysaccharides such as cellulose and amylose based on electron spin resonance (ESR) on its comparison with plasma-induced radicals of polysaccharides. The observed ESR spectra of mechanically fractured samples by ball milling at room temperature have shown the multicomponent spectra, which differ in pattern from those of plasma-irradiated cellulose but are similar to those of plasma-irradiated amylose. The systematic computer simulations disclosed that the observed spectra of cellulose consist of three kinds of spectral components, an isotropic doublet (I) assigned to a hydroxylalkyl-type radical at C 1 , an anisotropic doublet of doublets (II) assigned to an acylalkyl-type radical at C 2 and/or C 3 as discrete components, and a singlet spectrum (III) assigned to dangling-bond sites (DBS), while those of amylose consist of two kinds of spectral components, I and III. One of the most intriguing facts is that the component radicals are all glucose-derived mid-chain alkyl-type radicals as in the case of plasma irradiation, although it is known that mechanoradicals are produced by the polymer main-chain scission. It can be reasonably assumed, therefore, that the mechanoradicals primarily formed by 1,4-glucosidic bond cleavage of polysaccharides at room temperature underwent a hydrogen abstraction from the glucose units to give rise to the glucose-derived mid-chain alkyl-type radicals. Furthermore, spectrum III was a major component in the simulated spectra of both cellulose and amylose, unlike those in the case of plasma irradiation, suggesting that cross-linking reactions simultaneously occur accompanied by a decrease in the molecular weight in the course of vibratory milling.

Shape formation (or pattern formation) is a basic distributed problem for systems of computational mobile entities. Intensively studied for systems of autonomous mobile robots, it has recently been investigated in the realm of programmable matter, where entities are assumed to be small and with severely limited capabilities. Namely, it has been studied in the geometric Amoebot model, where the anonymous entities, called particles, operate on a hexagonal tessellation of the plane and have limited computational power (they have constant memory), strictly local interaction and communication capabilities (only with particles in neighboring nodes of the grid), and limited motorial capabilities (from a grid node to an empty neighboring node); their activation is controlled by an adversarial scheduler. Recent investigations have shown how, starting from a well-structured configuration in which the particles form a (not necessarily complete) triangle, the particles can form a large class of shapes. This result has been established under several assumptions: agreement on the clockwise direction (i.e., chirality), a sequential activation schedule, and randomization (i.e., particles can flip coins to elect a leader).In this paper we obtain several results that, among other things, provide a characterization of which shapes can be formed deterministically starting from any simply connected initial configuration of n particles. The characterization is constructive: we provide a universal shape formation algorithm that, for each feasible pair of shapes (S 0 , S F ), allows the particles to form the final shape S F (given in input) starting from the initial shape S 0 , unknown to the particles. The final configuration will be an appropriate scaled-up copy of S F depending on n.If randomization is allowed, then any input shape can be formed from any initial (simply connected) shape by our algorithm, provided that there are enough particles.Our algorithm works without chirality, proving that chirality is computationally irrelevant for shape formation. Furthermore, it works under a strong adversarial scheduler, not necessarily sequential.We also consider the complexity of shape formation both in terms of the number of rounds and the total number of moves performed by the particles executing a universal shape formation algorithm. We prove that our solution has a complexity of O(n 2 ) rounds and moves: this number of moves is also asymptotically optimal.